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Fundamentals of Mechanical Engineering (I) 1: What are the common types of hammers used by riveters? Answer: There are hand hammers, sledge hammers, and claw hammers. 2: What are the common types of chisels used by riveters? Answer: There are two main categories: flat chisels and narrow chisels. 3: What is steel? Answer: An iron-carbon alloy with a carbon content of less than 2.11% is called steel. 4: What is high-carbon steel? Answer: Steel with a carbon content of more than 0.6% is called high-carbon steel. 5: Into how many categories can steel be divided based on its use? Answer: It can be divided into structural steel, tool steel, and special-purpose steel. 6: Into how many categories can steel be divided based on the shape of its end face? Answer: It can be divided into sheets, pipes, profiles, and wires. 7: What are the two basic methods for correcting steel deformation? Answer: There is cold working correction and heating correction. 8: What is a mounting fixture? Answer: It refers to the process equipment used during assembly to apply external forces to parts in order to achieve a reliable positioning of them. 9: How many categories are there for the basic methods of cold working correction? Answer: There are manual correction and mechanical correction. 10: What are the categories of heat correction? Answer: It is divided into full heating correction and local heating correction. 11: How many ways are there to shape the heating area using local heating for correction? Answer: There are three types: dot-shaped, line-shaped, and triangular. 12: What are the types of deformation in angle steel? Answer: There are three types: distortion, bending, and corner deformation. 13: What are the types of deformation in channel steel? Answer: There is warping, bending, and local deformation of the wing plates. 14: What is cold working correction? Answer: Correction carried out at room temperature is called cold working correction. 15: What processes are included in separation? Answer: It includes three processes: blanking, punching, and cutting. 16: What is stamping? Answer: The process of obtaining a finished part by separating or shaping sheet metal. 17: What are the advantages of stamping? Answer: Good product quality, high productivity, material savings, cost reduction, and easy automation. 18: What is bending forming? Answer: A processing method for bending the blank into the desired shape. 19: What are the three basic forms of riveting? Answer: Butt joint, lap joint, corner joint. 20: What is riveting? Answer: Rivets are used to connect two or more components into a single unit. 21: How many types of rivets are commonly used? Answer: There are half-round head, countersunk head, semi-countersunk head, flat head, flat tapered head, oval, and flat. 22: What are the types of riveting? Answer: There are strong riveting, secure riveting, and tight riveting. 23: What is assembly? Answer: The process of combining various parts into components according to certain technical requirements. 24: What are the three elements of assembly? Answer: Positioning, support, clamping. 25: What are the various methods of connecting metal structures? Answer: There are welding, riveting, bolt connection, and hybrid riveted-welded connections. 26: What are the common tools used for sample prevention? Answer: Powder line, stone pencil, drawing needle, ruler, template punch, hammer. 27: What are the main methods for finding the intersection line? Answer: There are the straight line method, the auxiliary plane method, and the spherical surface method. 28: What are the methods for finding the actual length of a straight line segment? Answer: Rotation method, right triangle method, face transformation method, branch line method. 29: What are the methods for creating development diagrams? Answer: There are graphical methods and computational methods. 30: What are the common expansion methods? Answer: There are the parallel lines method, the radial lines method, and the triangle method. 31: Into which parts can the cross-section of a cut material be divided? Answer: Chipping, bright band, shear zone, burrs. 32: What are the types of corrections? Answer: There are manual correction, mechanical correction, and flame correction. 33: What is a benchmark? Answer: The points, lines, and surfaces on a part diagram used to determine the positions of other points, lines, and surfaces. 34: What is plasticity? Answer: The ability of metal materials to undergo permanent deformation without breaking under external forces. 35 ； What is resilience? Answer: The ability of metal materials to resist destruction under impact loads. 36: What measures can be taken to prevent welding deformation? Answer: Anti-deformation method, rigid fixation method, proper welding sequence. 37: What are the properties of spatial linear projection? Answer: Authenticity, accumulability, contractility. 38: What is an intersection line? Answer: The intersection lines resulting from a plane intersecting a solid. 39: What is an intersection line? Answer: The line of intersection of surfaces formed by the intersection of two planes. 40: How many types of views are there? Answer: They include basic views, partial views, diagonal views, and rotated views. 41: What is a basic view? Answer: The view obtained by projecting the machine part onto the basic projection plane. 42: What are the basic views? Answer: Front view, top view, left view, right view, upward view, rear view. 43: What are the different types of sectional views? Answer: There are full sectioning, half-sectioning, and partial sectioning. 44: What is the impact of cutting parameters on drilling? Answer: Choosing appropriate cutting parameters can prevent the drill bit from wearing out prematurely or being damaged. Prevents machine tool overload and improves the cutting accuracy and surface roughness of workpieces. 45: What is tapping? Answer: A tap is used to cut internal threads on the wall of the hole. 46: What is the impact of the bottom hole diameter on the drill bit? Answer: If the diameter of the bottom hole is the same as that of the internal thread, the tap will get stuck as the material expands, and in such cases the tap is prone to breaking ； If it is too large, the height of the thread profile formed will be insufficient, resulting in defective products. 47: What is threading? Answer: Use a die to cut threads on the outer diameter of a round rod tube. 48: What principles should be considered when selecting a groove? Answer: (1) Minimize the amount of weld metal filler, (2) Ensure full penetration and avoid cracks, (3) Consider minimizing welding deformation, (4) Facilitate machining. 49: What is the purpose of leaving a root bevel when cutting grooves? Answer: To prevent the joint from burning through. 50: What are the methods for cutting grooves? Answer: Machining with an air chisel, mechanical processing, gas cutting for grooving, and carbon arc gouging for grooving. 51: What is carbon arc gas gouging? Answer: The high temperature of the carbon electrode arc is used to melt a local area of the metal, and then a stream of compressed air is used to blow away this melted metal, thereby achieving the purpose of planing or cutting the metal. 52: What is the purpose of grinding? Answer: It can remove burrs at the edges of weld scars on the plate surface, grind welds, and perform grinding before re-inspecting the welds of pressure vessels. 53: What is bending forming? Answer: Bend flat sheet blanks, profiles, or tubes at a certain angle and with a specific curvature to form parts of a particular shape. 54: Answer: What is the rebound phenomenon? Answer: When bent, the material undergoes elastic deformation; once the external force is removed, part of this elastic deformation is reversed, causing changes in the shape and angle of the bent component. 55: What are the common bending methods used by riveters? Answer: There are bending under pressure, rolling bending, rolling, and hydrothermal bending of plates. 56 ； What are the factors that affect bending forming? Answer: Bending force, springback phenomenon, minimum bending radius, cross-sectional shape. 57: How to determine the magnitude of the bending force? Answer: Based on the mechanical properties of the material to be bent, the bending method and type, as well as the shape of the bent part. 58: What are the factors that affect the elastic recovery of bending? Answer: The mechanical properties of the material being bent, the relative bending radius of the material, the bending angle, and some other factors. 59: What are the factors that affect the minimum bending radius? Answer: The mechanical properties of the material being bent, the bending angle, the direction in which the material is bent, the surface quality of the material and the quality of the cut surface, as well as other factors. 60: What are the factors that affect the change in cross-sectional shape during bending? Answer: The main factors are the relative bending radius, the geometric characteristics of the cross-section, and the bending method. What is the impact of heating 61 steel on its bending processing? Answer: When steel is heated, the bending force required decreases, the springback phenomenon disappears, and the minimum bending radius is reduced, which facilitates controlling deformation according to processing requirements. 62: Under what circumstances is heating bending usually used? Answer: Use it at room temperature again. 63: Why must the heating temperature of steel be limited to a certain level? Answer: Excessively high temperatures can cause the steel to overheat, while too low temperatures make shaping difficult and lead to cold work hardening. 64: What measures are commonly used to address the springback issue when contact bending is employed? Answer: Modify the mold shape, use pressure correction methods, add a blank holder, and reduce the mold clearance. 65: What is bending under pressure? Answer: A processing method that uses bending dies on a press for bending formation. 66: What are the various forms of bending deformation of materials? Answer: There are free bending, contact bending, and corrective bending. 67: Why are the dies used by rivet workers usually of welded construction? Answer: Because this not only makes manufacturing easier and reduces the mold-making cycle, but also improves material utilization and lowers costs. 68: What is roll bending? Answer: A processing method for bending and shaping on a rolling bed. 69: What measures are commonly used with symmetric three-roller plate rolling machines to eliminate the straight edges of the workpiece? Answer: Bend at both ends and leave machining allowance. 70: Into which two categories can calendering be divided? Which one do riveters usually use? Answer: There are thinning rolling without change and thinning rolling with change. Riveters commonly use non-thinning rolling. 71: What measures should be taken when rolling conical surfaces? Answer: Adjust the position of the upper roller so that it is tilted at a certain angle relative to the lower roller ； Make the feed speed for small openings greater than that for large openings. 72: How to roll larger workpieces? Answer: To avoid additional deformation caused by its own weight, the sheet metal should be divided into three sections; roll the two sides first, then the middle, with lathe assistance if necessary. 73: Any rolling for non-cylindrical workpieces? Answer: Areas on the sheet metal should be divided according to their different radii of curvature, and the spacing between the rollers should be adjusted for rolling. 74: What preparations are needed before rolling the workpiece? Answer: The surface of the roller and the sheet metal should be cleaned thoroughly, and burrs should be removed to avoid damaging the workpiece or the roller. 75: What is calendering? Answer: It is a pressing process in which a flat blank of a certain shape is deformed under the pressure of a punch to form an open hollow part through a die. 76: What is a water-fire bent plate? Answer: It is formed by locally heating the steel plate with an oxy-acetylene flame to cause it to contract. 77: What are the uses of water and fire bent plates? Answer: Water and fire bending is only suitable for shaping parts with low curvature; it is more often used in combination with rolling to process parts with complex shapes that have double bends. 78: What are the methods for bending plates in water and fire? Answer: There is strip heating and spot heating. 79: What are the processes for bending plates in water and fire? Answer: There are options for the heating element, heating temperature and speed, as well as the cooling method. 80: How many cooling methods are there for water and fire bending plates? Answer: There are two types, air-cooled and water-cooled; among water-cooled types, there is also a distinction between front and back water cooling. 82: What is air cooling? Answer: After local heating by the flame, the workpiece cools naturally in the air. 83: What is water cooling? Answer: Water is used to force-cool the heated part of the metal, causing it to cool down rapidly. This reduces the transfer of heat to the back side, increases the temperature difference between the front and back sides, and thereby improves the molding effect. 84: What are the characteristics of explosive forming? Answer: It can simplify the mold structure ； Hollow parts with complex shapes that are difficult to manufacture using rigid molds ； Low rebound, high precision, excellent quality ； Fast processing and shaping speed ； No stamping equipment is required. 85: What is corner jointing? Answer: When two plates are connected at an angle to each other, angle steel is used as a connecting element at the joint to rivet the workpieces together. 86: What are the main parameters for rivet arrangement? Answer: There are rivet spacing, row spacing, and margin spacing. 87: What is rivet pitch? Answer: The distance between the centers of two adjacent rivets in a row of rivets. 88: What is pitch? Answer: It refers to the distance between the centers of adjacent rows of rivet holes. 89: What is a margin? Answer: It refers to the distance from the center of the outward-facing rivet to the edge of the workpiece plate. 90: What is the relationship between the thickness of the component plate and the diameter of the rivet? Answer: For single-row and double-row lap joints, the rivet diameter is taken as twice the thickness ； When connecting single-row and double-row double covers, the rivet diameter should be 1.5 to 1.75 times the plate thickness. 91: What are the principles for determining plate thickness? Answer: When overlapping, it is determined based on the thickness of the thicker plate material ； When riveting materials with a large difference in thickness, the thinner sheet shall determine the parameters ； When riveting steel plates and profiles together, use the average thickness of the two ； The total thickness of the joined parts should not exceed 5 times the diameter of the rivet. 92: What is the relationship between rivet length and riveting quality? Answer: If the rivet is too long, its head becomes too large, making the shank prone to bending ； If the rivet is too short, the amount of bulging will be insufficient, and the head of the rivet will not be properly formed, which affects the strength and tightness of the riveting. 93: How is the rivet hole diameter determined during cold riveting? Answer: During cold riveting, it is difficult for the rivet shank to become thicker; to ensure connection strength, the diameter of the rivet hole should be close to that of the rivet shank. 94: Is the rivet hole diameter determined during hot riveting? Answer: During hot riveting, the material expands and thickens due to heat; to facilitate piercing, the diameter of the rivet hole should be slightly larger than the diameter of the rivet shank. 95: What are the components of a rivet? Answer: It consists of a handle, gun body, switch, and pipe connector. 96: What are the features of a rivet gun? Answer: It has a small volume, is easy to operate, and can be used for riveting in various positions. 97: Into which two types can riveting be divided? Answer: It can be divided into cold riveting and hot riveting. 98: What is cold riveting? Answer: It refers to riveting at room temperature. 99: What is the final riveting temperature? Answer: Between 450 and 600 degrees Celsius. 100: What is the impact of the final riveting temperature on riveting? Answer: Too high, and it will reduce the initial stress of the nail shank ； Too low, and the rivets will suffer from blue brittle failure. (II) 1 500 Questions on Mechanical Basics: What is referred to as a line parallel to that projection plane? What properties does the projection of this line have? Answer: When a line is parallel to a projection plane, it is called a line parallel to that projection plane. The projection of this line is genuine. 2: Any metal sheet has a thickness, and how does this sheet thickness affect the shape and size of the diagrams produced? Answer: It does affect the shape and size of the developed diagram. 3: For components such as spheres, rings, and helical surfaces, how are their surfaces developed into surfaces? Answer: Their surfaces are all non-developable surfaces. 4: For the development of prisms and cylinders, what development method is generally used? Answer: Generally, the parallel line expansion method is used. 5: When a conical tube and a cylindrical tube intersect orthogonally, what method is commonly used to determine their intersection line? Answer: It is commonly obtained using the auxiliary plane method. 6: Which method is commonly used to find the actual length of a curve? Answer: Use the expansion method more often. 7: When a friction press is overloaded, what does it cause to slide against what, without damaging the components? Answer: It will only cause sliding between the flywheel and the friction disc, without damaging any components. 8: The stroke of the slider in an open-crank press can be adjusted by changing what and what? Answer: This can be achieved by changing the eccentric sleeve on the upper part of the connecting rod ； It is adjusted by the center distance of the spindles. 9: In drawing and extrusion processes, due to the die clearance, what strict requirements are there for the material? Answer: The tolerance requirements for the material thickness are quite strict. 10: Into which three stages can the separation process of sheet metal during blanking be roughly divided? Answer: 1: Elastic deformation, 2: Plastic deformation, 3: Cracking and separation. 11: How does the drawing coefficient affect the degree of deformation of the material during drawing? Answer: The smaller the drawing coefficient, the greater the degree of deformation of the material during drawing. 12: What is cold stamping? Answer: Stamping operations carried out at room temperature are called cold stamping. 13: What is a composite process? Answer: Combining two or more basic processes into one and completing them within a single stroke of the press is called a compound process. 14: What is a simple blanking die? Answer: In one stroke of the press, only a die for one blanking operation can be used. 15: What is a compound punching die? Answer: A die that can simultaneously perform multiple stamping operations in one stroke of the press. 16: How to explain the blanking force correction coefficient Kp? Answer: When calculating the blanking force, factors such as the wear of the die edges, die clearance, and the mechanical properties of the material are taken into account. The safety factor selected is generally set to Kp equal to 13.17. What is oblique-edge blanking? Answer: Oblique die cutting is a method to reduce the blanking force. It involves making the die edge inclined at a certain angle relative to the blank, so that during punching the contact between the die edge and the blank is gradual, resulting in a uniform and steady load. 18: What is stepped punch blanking? Answer: Stepped punch blanking is a method to reduce the blanking force. During porous simultaneous blanking, the punch is designed in a stepped shape that varies in height relative to the blank, which helps to effectively distribute the blanking force. 19: What is the difference between open-crank presses and closed-crank presses? Answer: Structurally, the bed of an open-crank press has a C-shaped design, and connecting rods are used to convert the rotational motion of the eccentric shaft into up-and-down reciprocating motion of the slider. The bed of a closed-type press has a frame-shaped structure, with a crank replacing the eccentric shaft. 2: What are the characteristics of open-type crank press machines and closed-type crankshaft press machines? Answer: The C-shaped bed of an open-type crank press has three open sides, making it particularly suitable for stamping the edges of large sheets of material. However, this type of bed structure has poor rigidity, and as a result, it can withstand only a small load. The frame structure of closed-type crank press is constrained by the columns, resulting in a limited worktable area and small operating space; therefore, there are certain restrictions on the dimensional dimensions of the stamped parts. Frame-type structural beds have good stiffness, and can withstand large and uniform loads. 21: What are the factors that affect material stamping? Answer: There are (1) elasticity, (2) plasticity, (3) hardness, (4) the quality of the material’s surface condition, and (5) the thickness tolerance of the material. 22: What is the impact of die clearance on blanking quality? Answer: When the gap between the punch and die is too small, the cracks in the material near the punch edge shift outward by a certain distance. As a result, the material in the area between the upper and lower cracks is affected by a second shear action during the stamping process, which impacts the quality of the cut surface. When the gap is too large, the cracks in the material near the punch edge shift inward by a certain distance; the material is subjected to significant tension. Moreover, burrs, chipped edges, and large slopes at the material’s edges also affect the quality of the cut parts’ cross-sections. Furthermore, either too small or too large a gap has a certain impact on the dimensional tolerance of the cut parts. 23: What are the factors that affect the minimum bending radius of materials? Answer: 1: The mechanical properties of the material and its heat treatment condition; 2: The bending angle of the workpiece; 3: The geometric shape and dimensions of the material; 4: The direction of bending; 5: Other factors such as the thickness of the material, and the quality of the surface and sides. 24: How is the neutral layer of the material defined when it is bent? Answer: During bending, the outer layer of the material is under tension while the inner layer is under compression. In its cross-section, there must be a transition layer that is neither under tension nor under compression, with stress almost equal to zero; this transition layer is known as the neutral layer of the material. 25: When correcting components made up of multiple beams and columns, what interconnections need to be fully considered? Answer: The interrelationship between beams and columns must be fully considered. 26: What must be ensured to meet the requirements when correcting the deformation of thin plates in steel structures? Answer: It is necessary to ensure that all types of frames meet the requirements before considering straightening the thin plates. 27: What is the heating point of spot heating related to in the sheet material? What should be the distance between the heating points? Answer: The heating point of spot heating is related to the thickness of the sheet. The distance between the heating points should be uniform. 28: What is called longitudinal contraction? Answer: A form of contraction of the weld and the metal surrounding it; the contraction along the length of the weld is known as longitudinal contraction. 29: What is called lateral contraction? Answer: A form of contraction of the weld and the metal surrounding it, referring to the contraction perpendicular to the length of the weld, is called transverse contraction. 30: How are internal stresses generated in steel structural members? Answer: For riveted and welded structures, the welding process is a process of uneven heating and cooling, which is the main cause of internal stresses in such structural components. Furthermore, in steel structural components, the various parts may have residual stresses either in their raw state or after being processed into components; once these parts are welded together to form a whole, these residual stresses can combine to create new internal stresses within the component. 31: Why is stress relief treatment required for some steel structural components after welding? Answer: After welding some steel structural components, they exhibit little welding deformation due to their high stiffness, but the welding stresses are quite significant. After the structures have been in use for a while, these stresses may be released for some reason, resulting in deformation and ultimately leading to failure. Therefore, for steel structures used in certain critical applications, such as high-pressure vessels, containers for hazardous materials, and boilers, various stress-relief methods are employed after welding, with the aim of preventing the internal stresses in the steel components from causing damage to them. 32: What are the factors that affect welding deformation in steel structural members? Answer: The factors affecting the welding deformation of steel structural members include design and process aspects. In terms of design, this refers to the rationality of the structural design, the location of welds, and the shape of welding grooves, etc. In terms of process, this refers to reasonable welding procedure specifications, the sequence of assembly and welding, the use of various methods to prevent and counter deformation, as well as the stress-relief measures taken. 33: How to understand the internal relationships of steel structural components? Answer: So-called steel structural components are formed by joining various parts together using methods such as welding, riveting, or bolting. These parts are interconnected and interdependent, forming an organic whole. 34: What are the key points for correcting the deformation of steel structural members? Answer: 1: Analyze the causes of deformation in the component to determine whether it is caused by external forces or internal stresses. 2: Examine the internal relationships within the component to understand the constraints between its various parts. 3: Select the appropriate location for correction, addressing the main issues first before dealing with the secondary ones. 4: It is necessary to understand and be familiar with the properties of the steel used in the component, in order to prevent breakage, cracks, or springback during the correction process. 5: Determine the correction method based on the actual situation, as well as the sequence in which multiple methods are used. 35: What is the only method that can be used to correct deformation in thin plates in steel structures? Answer: To correct deformation in thin plates within steel structures, only local heating (and specifically point heating) can be employed. 36: What aspects should be considered when using spot heating to correct thin plate deformation? Answer: It should be noted that: 1. The heating temperature must be appropriate – it should be high enough to cause plastic deformation in the steel, but not too high; generally, it ranges from 650 to 800 degrees. 2: The size of the heating points and the distance between them should be appropriate. Under normal circumstances, depending on the thickness of the sheet material, the arrangement should be even, often in a plum blossom pattern. 3: The purpose of rapid watering and hammering with a wooden mallet is to accelerate the contraction of the fiber structure in the steel plate. 4: When heating, do not move the gas welding torch back and forth; the small flame beam should be perpendicular to the steel plate, and avoid using too many heating points to prevent unnecessary internal stress. 37: What are the characteristics of deformation in framed structural members? Answer: Frame-type components have many parts, and there are strong inter-restrictive relationships within their structure; the deformation of one part significantly affects those of others. 38: When using a bending machine to bend round blanks, it is usually done after heating, right? Answer: No. 39: To heat and bend, to what temperature should the material be heated? How should heating be done at the same time? How do I operate it? What is the minimum ending temperature? Answer: The material should be heated to 950-1100. The heating should be even at the same time, with the final temperature not falling below 700. 40: What are the possible defects that can occur when rolling curved cylinders? Answer: Defects that may occur when rolling curved cylinders include warping, uneven curvature, excessive curvature, and bulging in the middle. (III) 1: What is the function of the shank of a drill bit? Answer: It clamps and transmits the torque and axial force required for drilling. 2: What is the function of the flat tail in a tapered shank drill bit? Answer: It is used to increase the torque transmitted, preventing the drill bit from breaking out in the spindle hole or drill sleeve. 3: What is the function of the guiding portion in the drill bit? Answer: It maintains the drill bit’s straight cutting direction during the cutting process. It serves both to smooth the wall of the hole and as a backup for the cutting portion. 4: What adverse phenomena occur when the hole is about to be drilled through? Answer: When the drill bit just penetrates the workpiece, the axial resistance suddenly decreases. Due to the sudden restoration of the clearance and elastic deformation in the drilling machine’s feed mechanism, the drill bit will automatically advance at a high speed, which can lead to the breakage of the drill bit or a decrease in the quality of the drilled hole. 5: What is the role of cutting fluid during drilling? Answer: It reduces friction, lowers the drill bit resistance and cutting temperature, and improves the cutting capacity of the drill bit as well as the surface quality of the hole walls. 6: What is cutting parameter? Answer: It refers to the combined term for cutting speed, feed rate, and depth of cut. 7: What is grinding? Answer: It is a method of machining the surface of a workpiece using an abrasive wheel. 8: What does \"expand\" mean? Answer: The process of unfolding the surface or a part of a metal structure onto a flat surface according to its actual shape and size is called unfolding. 9: How many ways are there to unfold a drawing? Answer: There are the parallel line method, the triangle method, and the radial method. 10: What are the expansion conditions for the parallel line method? Answer: Yes, it means that the generatrices on the surface of the component are parallel to each other, and their actual lengths are reflected in the projection plane. 11: What does thickness treatment include? Answer: Determine the neutral layer of the bent part and eliminate thickness interference. 2: What factors are related to the change in the position of the neutral layer in plate thickness? Answer: It is related to the bending radius of the sheet and the thickness of the material. 3: What are the general principles for dealing with plate thickness in interpenetrating parts? Answer: The unfolded length is based on the dimension of the member’s neutral axis, while the height of the curves in the unfolded view is determined by the height at the point where the members meet. 14: What is the main content of lofting? Answer: Plate thickness processing, lofting drawing, and preparing cutting templates based on the lofted drawings of the components already made. 15 What are the common shearing tools used by riveters? Answer: There are gantry shears, bevel shear machines, disc shear machines, and combined punching-and-shearing machines. 16: How can roll formers be classified based on the number of shaft rollers and their arrangement? Answer: There are three types: symmetric three-roller, asymmetric three-roller, and four-roller. 17: How can punching dies be classified according to their structure? Answer: They are divided into simple molds, molds with guide pillars, and composite molds. 18: What are the structural features of a compound punching die? A male and female die that serves both as a blanking punch and as a punching die. 19: What is blanking force? Answer: It refers to the maximum resistance of the material to the die during blanking. 20: Into which stages can the deformation process of sheet separation during blanking be divided? Answer: It is divided into the elastic deformation stage, the plastic deformation stage, and the shear fracture stage. 21: What is the minimum bending radius? Answer: The minimum radius of curvature that can be achieved without the material failing. 22: What are the common methods to reduce the springback of bent parts? Answer: There are the mold correction method and the pressure correction method. 23: What is the purpose of using a blank holder during stretching? Answer: It is mainly to prevent wrinkling at the edges of the stretched parts. 24: What is the function of the crank-slider mechanism in a crank press? Answer: It can not only convert rotational motion into back-and-forth linear motion, but also amplify force. 25: What does manual shaping in sheet metalworking include? Answer: It includes bending, arching, flanging, curling, interlocking, and straightening. 26: What are the functions of deformation templates? Answer: It can be used for marking materials, manufacturing separation molds, and producing milling templates. 27: What does \"putting the edge\" mean? What are the formation methods? Answer: The process of stretching and thinning the edge material in the deformed area during shaping is called flanging. The formation methods include thinning and drawing. 28: What is pulling the edge? Answer: By using flanging and trimming methods, the edges of the sheet metal are processed into curved workpieces. 29: What is curling? Answer: Curling the edge of a workpiece is called bending in order to increase the stiffness and strength of that edge. 30: What is gapping? Answer: When the edges of two sheets of material, or the two sides of one sheet, are folded and brought together to press against each other, this is called interlocking. 31: What is thickness treatment? Answer: A method adopted to eliminate the effect of plate thickness on the shape and size of the developed drawing. 32: What are the general steps for calculating the unfolded length of bent parts? Answer: Divide the curved part into straight segments and arc segments ； Calculate the length of each segment separately ； Add up the calculated lengths. 33: Under what circumstances should cut-to-length processing be used for structural steel? Answer: Angle steel, channel steel, and I-beam are bent into corners. 34: How many stages are there in the entire blanking process? Answer: There are three stages. Elastic deformation stage ； Plastic deformation stage ； Shearing stage. 35: What is blanking? Answer: A stamping process in which a die is used to separate one part of a sheet metal from another along a specific closed contour. 36: How many types of bolt connections are there? Answer: There are two types: connections that withstand axial tensile loads ； Connection subjected to lateral forces. 37: What are the anti-loosening measures for bolted connections? Answer: Increase friction ； Mechanical lockout. 38: What are the methods of mechanical anti-loosening? Answer: Split pin ； Retaining washer ； stop washer ； Series-wound steel wire. 39: What is a welding arc? Answer: A strong and sustained discharge phenomenon occurs in the gas medium between the two electrodes. 40: What are the components of a welding arc? Answer: From the cathode area ； It consists of an anode region and an arc column. 41: What are the three directions of movement for the welding rod? Answer: Move in the direction of the molten pool ； Move in the welding direction ； Make a lateral swing. 42: How many types can welds be classified into based on their spatial position? Answer: It is divided into flat welding, vertical welding, horizontal welding, and overhead welding. 43: What are the characteristics of intersection lines? Answer: It is both a common line on the surfaces of the two shapes and a boundary line ； In space, it is always closed. 44: What is an intersection line? Answer: A component formed by the intersection of two or more geometric solids. 45: What are the factors that affect stamping quality? Answer: Mold clearance ； The center lines of the punch and die do not coincide ； The working edge of the mold is worn and blunted. 46: What are the general principles of mold design? Answer: On the premise of ensuring stamping quality, efforts are made to design molds that are easy to manufacture, have simple processes and low costs, and are convenient to use. 47: What is the purpose of calculating rolling force? Answer: It is to properly select the rolling equipment. 48: What is free bending? Answer: When bending is complete and the punch, the blank, and the die fit together, no impact force is generated any longer. 49: What is correction bending? Answer: It refers to the punch, the blank, and the die; once these three are aligned, there is another impact that serves to correct the bent part. 50: What defects are likely to occur when pressing seal heads? Answer: Wrinkling and bulging ； Straight-edge scratch indentation ； Microcracks on the outer surface ； Longitudinal tear ； skew ； ellipse ； The diameters vary. 51: What is expansion jointing? Answer: A connection method that achieves sealing and fastening through the deformation of pipes and tube sheets. 52: What is the purpose of calculating blanking force? Answer: To reasonably select the equipment capacity and design the mold. 53: What methods can be used to reduce blanking force? Answer: Bevel die ； Step die ； Heat the die. 54: What is the purpose of calculating bending force? Answer: To select the bending press and design the mold. 55: What does the degree of deformation include? Answer: Includes: degree of mold adhesion ； The degree of deformation allowed for material drawing. 56: How to determine the number of drawing passes for a workpiece? Answer: Based on the maximum deformation of the drawn workpiece and the material’s elongation rate. 57: How is the drawing coefficient determined? Answer: It depends on the properties of the material, the drawing angle, the friction coefficient, and whether drawing is preformed. 58: Which materials are not suitable for cold working? Answer: Brittle materials such as high-carbon steel, high-alloy steel, and cast iron. 59: What is the correction sequence when angle steel undergoes complex deformation? Answer: First correct the distortion, then the bending, and finally the angular deformation. 60 What are the causes of deformation in steel structures? Answer: One is caused by external forces, and the other is caused by internal stresses. 61: What are the methods for eliminating residual welding stresses? Answer: Overall high-temperature tempering ； Local high-temperature tempering ； temperature difference stretching method ； Mechanical stretching method ； Vibration method. 62: What is welding overall deformation? Answer: It refers to the changes in shape and size that occur across the entire structure. 63: What is the hammer spreading method? Answer: The fiber structure of the metal sheet is stretched by hammering. 64: How is the rivet rod length determined? Answer: It is determined based on factors such as the total thickness of the components being joined, the gap between the rivet hole and the diameter of the rivet shank, and the riveting process. 65: What are the reasons for the rivet head being too small after riveting? Answer: Because the nail rod is too short or the hole diameter is too large. 156: Depending on the state of the metal during welding, how many types can it be divided into? Answer: There are three types: fusion welding, pressure welding, and brazing. 67: What is fusion welding? Answer: A method of using local heating to bring the welded joint to a molten state. 68: What is clamping? Answer: It involves using external forces to fix the positioned part, so that it remains in its position during the processing. 69: What is the six-point positioning rule? Answer: Six positioning points are used to restrict the freedom of the part in space, in order to fully determine its spatial position. 60: What is relative parallelism? Answer: It refers to the parallelism of the line or surface being measured on a part, with respect to the measurement reference line or surface. 61: What is relative perpendicularity? Answer: It refers to the degree of perpendicularity of the line or surface being measured on a part, with respect to the measurement reference line or surface. 162: What types of tools and fixtures are used in assembly? Answer: Assembly tool ； Assembly fixture ； Assemble the *tools. 163: What are the common types of assemblies*? Answer: There are steel cables, chains, hand chain hoists, and specialized tools. 64: How many types of guidance are there for blanking dies? Answer: There are two types: guide posts, guide sleeves, and guide plates. 65: How many parts does a punching die consist of? Answer: It consists of a working section, a material positioning section, a unloading section, and a mold base. 66: What is the function of the drawing die clearance? Answer: Reduce the friction between the material and the die, and control the flow of the material within the die cavity. 67: How many types can cracks be classified into based on their structure? Answer: It can be divided into vertical single-joint type ； Vertical double interlock ； Horizontal flat joint seams and various angled joint seams. 68: What is the reason why a bent piece rebounds when the external force is removed? Answer: It is because when bending manually, the outer surface of the sheet is under tension while the inner surface is under compression, which results in springback. 169: How to obtain cold buckling and thermal buckling? Answer: Cold buckling is achieved by expanding the edges of the sheet while contracting its center, whereas hot buckling results from heating the sheet, which causes it to contract. 70: How many methods are there for stripping the edge? Answer: There are two methods; one is to use a general-purpose tool to remove the flange, and the other is to use a die to do so. 71: What is edge finishing? Answer: Edge finishing involves first causing the sheet metal to wrinkle, and then pressing the wrinkled areas flat while preventing them from stretching back; as a result, the length of the sheet metal is reduced, leading to an increase in its thickness. 72 ； What is the basic principle of hemming? Answer: The principle is that, for the forming of convex curved-edge workpieces, it is mainly the material on the outer edge of the bent planar edges that contracts, becoming thicker and shorter, thereby forcing the vertical edges to take on a curved shape. 73: What is the purpose of correction? Answer: It is achieved by applying external force or local heating to shorten the longer fibers and lengthen the shorter fibers, thereby bringing the fibers in each layer to a similar length and achieving correction. 74: What is the principle of flame correction? Answer: It involves using the deformation that occurs when a metal is locally heated to counteract the original deformation, thereby achieving correction. 75: What are the factors that affect the effectiveness of flame correction? Answer: The rigidity of the workpiece ； Heating position ； Flame heat ； Heating area and cooling method. 76: What are the heating methods for flame correction? Answer: There is spot, linear, and triangular heating. 77: What are the factors that determine process tolerance? Answer: There is the influence of lofting errors ； The impact of errors during part processing ； Impact of assembly errors ； Impact of welding deformation ； The impact of flame correction. 78: Into which categories can templates be divided according to their purpose? Answer: They can be divided into material sample templates, molding sample templates, positioning sample templates, and sample rods. 79: What are the methods for drawing patterns? Answer: There are two methods, the direct sketching method and the transitional sketching method. 80: How are lofting baseline lines generally selected? Answer: With two lines or planes that are perpendicular to each other ； Using the two center lines as reference lines ； Using a plane and a center line as a reference. 81: What is the lofting tolerance? Answer: During the lofting process, due to factors such as the accuracy of the lofting tools and equipment as well as the skill level of the operator, certain dimensional deviations may occur in the resulting model. Keeping such deviations within a specified range is what is referred to as the allowable lofting error. 82: What does structural lofting include? Answer: Determine the fitting positions and connection methods of various components ； Make the necessary adjustments based on the actual production capabilities ； Calculate or measure the length of the parts and the actual shape of planar parts ； Design the mold or jig. 83: What are the methods for finding the actual length of a straight line segment? Answer: Rotation method ； Right triangle method ； Face-changing method ； Branch method. 84: What is the geometric rule for determining the actual length of a line segment using the right triangle method? Answer: It uses the projection of the line segment on any projection plane as one leg of the right triangle, and the projection length of the corresponding projection onto the axis perpendicular to that plane as the other leg; the hypotenuse is then the actual length of the line segment. 85: What is the rotation method for finding the actual length? Answer: It involves rotating a point in general space around a fixed axis until it becomes parallel to a certain line; the projection of this line on the plane parallel to it then reflects its true length. 86: What are the methods for finding the actual length of a curve? Answer: There is a face-swapping method ； Expansion method. 87: What is the face-swapping method? Answer: It involves creating a new projection plane parallel to the curve, so that the projection of the curve on this plane reflects its true length. 88: What is the expansion method? Answer: It is the developed line obtained by straightening a length in the curve view while keeping the height in the other view unchanged; this is what is sought. 89: What are the basic characteristics of intersection lines? Answer: The intersection line must be a planar figure enclosed by closed straight lines or curves ； The intersection line is the common line between the cutting plane and the surface of the solid; it is formed by the set of points that are simultaneously on the cutting plane and on the surface of the solid. 90: What are the methods for finding the intersection of solids? Answer: Face normal ； Edge line method. 91: What are the methods for finding the intersection lines of a surface with a solid? Answer: The warp method and the weft method. 92: What are the characteristics of intersection lines? Answer: First, it is the line common to the surfaces of the two intersecting shapes, and it also serves as the boundary between them ； Second, the intersection lines are all closed. 93: What is the essence of finding the intersection line? Answer: It involves finding a certain number of common points on the surfaces of the two shapes, and then connecting these common points in sequence to obtain the desired result. 94: What are the selection principles for methods to find intersection lines? Answer: To determine the intersection line using the straight-line method, at least one projection of the intersection line must be known ； When using the auxiliary plane method to find the intersection line of intersecting solids, the intersection itself should be the simplest geometric shape ； The spherical method is only applicable to intersecting bodies that are rotatable and have intersecting axes. 95: Under what other conditions is the intersection curve a planar curve? Is the front projection of the curve two intersecting lines? Answer: When two arbitrary solids that are tangent to the same sphere intersect, their line of intersection is a planar curve. In this case, if the axes of both solids are parallel to their corresponding fundamental projection planes, then the projection of the line of intersection on those planes is formed by two intersecting lines. 96: What is a ruled surface? Answer: It is a surface formed with a straight line as its generatrix. 97: What are the characteristics of a cylinder? Answer: Yes, all the filaments are parallel to each other ； When a cylindrical surface is cut by mutually parallel planes, the cross-sectional shapes are identical. 98: What are the characteristics of a conical surface? Answer: Yes, all the prime wires intersect at one point ； When a conical surface is cut by mutually parallel planes, their cross-sectional shapes are similar ； The intersection line passing through the apex of the cone is a triangle. 99: During drawing, into which stages is the plastic deformation process of the material divided? Answer: Material bending ； The material is deformed by stretching ； Pull again. 100: What is drawing? Answer: It is a forming method in which the sheet metal is subjected to tension, causing it to undergo plastic deformation according to an ideal surface while overcoming springback. (IV) 1: What are the main forms of metal structures? Answer: There are frame structures, container structures, box structures, and general component structures. 2: How many parts can the riveting operation be divided into based on the nature of the process? Answer: It is divided into material preparation, lofting, machining and shaping, and assembly and connection. 3: What are the various methods of connecting metal structures? Answer: There are riveting, welding, hybrid riveting and welding connections, and bolted connections. 4: In the machinery manufacturing industry, riveters belong to the (heat processing) category. 5: What is hot working? Answer: Metal materials are shaped through partial or full heating and processing. 6: What is the main component used to construct a broach structure? Answer: It is based on profiles as the main component. 7: What is the main material used to construct the container structure? Answer: It is based on sheet material. 8: The box structure and the general structure are both of a structure manufactured by combining (sheet metal) and (profiled materials). 9: Material preparation refers to the preparation of (raw materials) and (part blanks). 10: Steel plates and profiles can become deformed during (transport, *placement, storage). 11: The deformation of steel materials can affect the proper progress of processes such as (*transport, cutting, gas cutting) of parts. 12: If the deformation that occurs to parts during processing is not corrected, it will affect the (proper assembly) of the structure. 13: Deformation resulting from welding reduces the (precision) of assembly, creates additional stresses within the steel structure, and affects the (strength) of the components. 1: The deformations of flat steel include (bending, twisting, and combined bending-twisting deformation). 15: How can multi-roller straightening machines be classified based on the arrangement of the shaft rollers and the position of the adjustment rollers? Answer: It can be divided into parallel correction machines with upper and lower roller rows, and inclined correction machines with upper and lower rollers. 16: What are the heating methods for flame correction? Answer: There is dot-shaped, linear, and triangular heating. 17: What factors determine the effectiveness of flame correction? Answer: It is determined by the heating location and heating temperature. 18: What are the methods of correction? Answer: Mechanical correction, manual correction, flame correction, high-frequency heat bending. 19: What is the first step in manufacturing metal structures? Answer: Lofting and material cutting are the first steps in manufacturing metal structures. 20: What are the impacts of lofting and marking on products? Answer: It will have a direct impact on product quality, as well as on the production cycle and costs. 21: What are the commonly used measurements in lofting? Answer: There are wooden folding rulers, straight rulers, steel tape measures, and steel ruler strips, etc. 22: What are the common tools used for lofting? Answer: There are a straightedge, a square, a pattern punch, a marking needle, and a small hammer. 23: What is the procedure for true-size lofting? Answer: The procedures are linear lofting, structural lofting, and development lofting. 24: What is included in the displayed samples? Answer: There is plate thickness processing, drafting, and production of pattern templates. 25: How are templates classified according to their purpose? Answer: There are pattern templates for numbering, pattern verification, and positioning. 26: What materials are generally used to make prototypes? Answer: Thin iron sheet with a thickness of 0.5–2 millimeters is used. 27: What are the main methods for drawing templates and sample rods? Answer: There are the straight-line pattern drawing method and the transition pattern drawing method. 28: How to use materials reasonably? Answer: Concentrate scheduling and make use of leftover materials. 29: What are the different types of curves? Answer: They are divided into planar curves and spatial curves. 30: What are the methods for finding the actual length of a straight line segment? Answer: There are the rotation method, the right triangle method, the branch line method, and the plane transformation method. 31: What are the steps to display a sample? Answer: It is done by using geometric drawing to first draw the intersection lines, the actual length lines, and the actual shapes of the cross-sections, and then creating the development diagram. 32: What are the basic methods for finding the intersection lines of a plane and a solid? Answer: Edge line method and edge face method. 33: What are the basic methods for finding the intersection curves of a surface with a solid? Answer: It is the meridian method and the latitude method. 34: What are the main methods for finding the intersection line? Answer: They are the auxiliary plane method, the generatrix method, and the spherical method. 35: What are the characteristics of intersection lines? Answer: (1) The intersection line is the common line and boundary line of two intersecting shapes. (2) Since the shapes have a certain extent, the intersection line is always closed. 36: What is an intersection line? Answer: The intersection line of the cutting plane and the surface of the solid. 37: What is a plain thread? Answer: Any position of the busbar on the surface of a component is called a generatrix. 38: What are the common expansion methods? Answer: There are the parallel line method, the radial method, and the triangle method. 39: What are the common ways to divide a sphere? Answer: There are the zoning method, the partitioning method, and the segmentation method. 40: What are the main aspects of plate thickness treatment? Answer: Determine the neutral layer of the bent part and eliminate thickness interference. 41: How is the material length for bent angle steel parts calculated? Answer: Calculated based on the centroid layer. 42: What are the types of shearing machines for cutting straight lines? Answer: There are gantry slant notching shears, crossbeam slant notching shears, and combined punching and shearing machines. 43: What types of machine tools have shear curves? Answer: There are disc shear machines and vibrating shear machines. 44: What are the characteristics of a vibrating shear machine? Answer: Vibration shear machines can cut various curves and internal holes. 46: What components does a combined shearing and punching machine consist of? Answer: It consists of a miter shear, a section steel shear, and a small punch. 47: Analyze the transmission sequence of the shear machine. Answer: The order is prime mover – transmission component – workpiece. 48: What is the function of the front and rear guards on a guillotine shear? Answer: It mainly serves a positioning function. 49: What are the various forms of positioning cutting on a guillotine or slant shear? Answer: There is sheet cutting with positioning, rear panel cutting with positioning, and panel cutting with positioning. 50: How can the shear force exerted by a miter saw on a material be decomposed? Answer: It can be divided into shear force, horizontal tensile force, and opening force. 51: What materials are not suitable for shearing with shear machinery? Answer: It is not suitable for cutting alloy materials and quenched materials. 52: How to select the cutting oxygen pressure? Answer: It needs to be selected based on the workpiece thickness, the nozzle diameter of the cutting torch, and the purity of oxygen. 53: What is the ignition point of ordinary carbon steel in oxygen? Answer: Approximately 1100–1150°C. 54: What are the metal materials that meet the conditions for gas cutting? Answer: There is pure iron, low-carbon steel, medium-carbon steel, and ordinary low-alloy steel. 55: What is the process of gas cutting? Answer: It is the preheating of the metal, the combustion of the metal, and the removal of the oxides. 57: What are the common drill bits? 66: What is the function of a round plate die? What are its components? Answer: It is a tool used for machining external threads, consisting of a cutting portion, a positioning portion, and chip evacuation holes. 67: What does the shape of the groove opening depend on? Answer: It depends on the type of material, thickness, welding method, and mechanical properties of the product. 68: What is matte? Answer: Processing the surface of a workpiece with a grinding wheel is called grinding. 69: What are the main types of grinding tools? Answer: There are pneumatic grinders and electric grinders. 70: What kind of deformation occurs in steel during bending processing? Answer: Elastic deformation and plastic deformation will occur. 71: What are the common bending methods used by riveters? Answer: There are cold bending, hot bending, manual bending, and mechanical bending. 72: What are the various forms of bending deformation of materials during press bending? Answer ； There are free bending, contact bending, and correction bending. 73: What determines the change in the shape of the material’s cross-section during bending? Answer: It is related to the relative bending radius, cross-sectional geometry, and bending method. 74: What are the methods to prevent the blank from shifting during bending? Answer: It has a material holding device and positioning holes. 75: What types of roll bending machines are there? Answer: Including rolling mills and steel bar bending machines. 76: What are the main processes in manual pipe bending? Answer: There are lining, sand filling, and heating bending. 77: What are the methods for connecting metal structures? Answer: There are three types: rivet connection, threaded connection, and welding. 78: What factors should be considered when choosing a connection method? Answer: Factors such as the strength of the components, operating environment, materials, and construction conditions need to be considered. 79: What are the types of riveted joints? Answer: There are butt joints, corner joints, and lap joints. 80: What are the types of solid rivet heads? Answer: There are half-round head, countersunk head, and semi-countersunk head. 81: What are the main types of AC arc welders? Answer: There are the BX1--330 model and the BX--500 model. 82: What is the basic procedure for hot riveting? Answer: Fastening of riveted parts, hole repair, rivet heating, rivet joining and threading, rivet pushing, and riveting. 83: What are the types of riveting? Answer: There are strong riveting, secure riveting, and tight riveting. 84: What tools are used for drilling holes? Answer: There is a reamer. 85: What are the common anti-loosening measures for threaded connections? Answer: It increases friction and provides mechanical anti-loosening. 86: What components does a welding arc consist of? Answer: It consists of an anode region, a cathode region, and an arc column. 87: What are the main types of welding machines? Answer: There are DC welders and AC welders. 88: What is local deformation? What is included? Answer: It refers to the deformation that occurs in a certain part of a component, including angular deformation, wavy deformation, and local unevenness. 89: What are the different types of welding based on spatial position? Answer: There are flat welding, vertical welding, horizontal welding, and overhead welding. 90: During welding, in which three directions does the welding rod move? Answer: Moving in the direction of the molten pool, moving along the welding direction, and swinging laterally. 91: What are the three elements of assembly? Answer: It is positioning, supporting, and clamping. 92: What are the manual clamps? Answer: There are screw clamps, wedge clamps, lever clamps, and eccentric clamps. 93: What are the non-manual clamps? Answer: There are pneumatic clamps, hydraulic clamps, and magnetic clamps. 94: What is the function of a screw clip? Answer: It has functions such as clamping, pressing, pushing up, and supporting. 95: What are the common measurement items used in assembly? Answer: There are linear dimensions, parallelism, perpendicularity, coaxiality, and angles. 96: What is the support method for the workpiece during assembly? Answer: There is support from an assembly platform and support from an assembly jig. 97: How can jigs be classified according to their functions? Answer: They can be divided into general jigs and special jigs. 98: What are the common positioning methods used in assembly? Answer: There are marking-based positioning, template-based positioning, and positioning element-based positioning. 99: What are the basic methods for finding the intersection line of planes? Answer: There are the edge-face method and the edge-line method. 100: Hot riveting usually involves four people. What are their roles? Answer: One person heats and transfers, one person inserts and drives the nails, one person holds the nails in place, and one person rivets them. 111: What are the common presses used by riveters? Answer: There are hydraulic presses and pneumatic presses.