The interview provides a two-way communication opportunity for the company and the applicant, so that the company and the applicant can get to know each other and make a more accurate decision on whether to hire or not. The following are the frequently asked questions of mechanical interview that I collected and sorted out. Welcome everyone to refer to it, I hope I can help you.
Frequently asked questions in mechanical interview:
1: What kinds of hammers are commonly used by riveters?
A: There are hand hammers, sledgehammers and hammers.
2. What kinds of chisels are commonly used by riveters?
Answer: There are two categories: flat chisel and narrow chisel.
3: What is steel?
Answer: Iron-carbon alloy with carbon content below 2. 1 1% is called steel.
4. What is high carbon steel?
A: Steel with carbon content greater than 0.6% is called high carbon steel.
5. According to the purpose, how many kinds of steel can be divided into?
Answer: It can be divided into structural steel, tool steel and special purpose steel.
6. According to the end face shape of steel, how many kinds of steel can it be divided into?
Answer: It can be divided into plates, pipes, profiles and wires.
7. What are the two basic methods of steel bar deformation correction?
A: There are cold correction and heat correction.
8: What is an assembly fixture?
Answer: it refers to the process equipment used to apply external force to the parts in the assembly process to make them obtain reliable positioning.
9. What are the basic methods of cold working correction?
A: There are manual correction and mechanical correction.
10: What are the types of heating correction?
Answer: It can be divided into comprehensive heating correction and local heating correction.
1 1: How many shapes can be corrected by local heating?
A: There are three kinds: point, line and triangle.
12: What kinds of angle steel deformation are there?
A: There are three kinds of distortion, bending and angular deformation.
13: What are the deformations of channel steel?
Answer: The wing plate is twisted, bent and partially deformed.
14: What is a cold correction?
A: Normal temperature correction is called cold correction.
15: What steps does the separation include?
Answer: Including blanking, punching and cutting.
16: What is a seal?
Answer: The process of separating or forming metal plates to obtain parts.
17: What are the advantages of stamping?
Answer: The product has good quality, high productivity, material saving, cost reduction and easy automation.
18: What is bending?
Answer: the processing method of bending the blank into the required shape.
19: What are the basic forms of riveting?
Answer: Butt joint, lap joint and corner joint.
20: What is riveting?
Answer: Use rivets to connect two or more parts into a whole.
2 1: How many rivets are commonly used?
Answer: There are semi-circular head, countersunk head, semi-countersunk head, flat head, flat cone head, flat round head and flat round head.
22: What are the types of riveting?
A: There are strong riveting, tight riveting and tight riveting.
23: What is assembly?
Answer: All the parts are combined into one part and weighed according to certain technical conditions.
24: What are the three elements of assembly?
Answer: Positioning, supporting and clamping.
25: What are the connection methods of metal structures?
Answer: There are welding, riveting, bolt connection and riveting.
26: What are the common tools for sample prevention?
Answer: chalk line, pencil, drawing needle, ruler, sample punch, hammer.
27: What are the main methods to find the intersection line?
A: Mass method, auxiliary plane method and spherical method.
28: What are the methods to find the true length of a straight line segment?
Answer: Rotation method, right triangle method, surface changing method and branch line method.
29: What are the methods to make an expanded diagram?
A: There are drawing methods and calculation methods.
30: What are the common ways to expand?
Answer: There are parallel lines, rays and triangles.
3 1: What parts can the shear section of materials be divided into?
Answer: Corner collapse, bright band, shear band and burr.
32: What kinds of amendments are there?
Answer: There are manual correction, mechanical correction and flame correction.
33: What is a benchmark?
Answer: Points, lines and surfaces used to determine the positions of other points, lines and cotton on the part drawing.
34: What is plasticity?
Answer: The ability of metal materials to be permanently deformed without being destroyed by external force.
35; What is resilience?
Answer: The ability of metal materials not to be destroyed under impact load.
36: What measures are there to prevent welding deformation?
Answer: Anti-deformation method, rigid fixation method and reasonable welding sequence.
37: What are the characteristics of spatial linear projection?
Answer: authenticity, accumulation and contraction.
38: What is the intersection line?
A: The intersection line generated by cutting the shape on a plane.
39: What is the intersection line?
Answer: The intersection line of two surfaces.
40: How many views?
Answer: There are basic view, partial view, oblique view and rotation view.
4 1: What is the basic idea?
Answer: The view obtained by projecting the machine parts onto the basic projection plane.
42: What is the basic idea?
A: Front view, top view, left view, right view, look up and look back.
43: What are the sectional views?
A: It is divided into full, half and partial segments.
44: What are the effects of cutting parameters on drilling?
A: Reasonable selection of cutting parameters can prevent premature wear or damage of the drill bit. Prevent the machine tool from being overloaded and improve the cutting accuracy and surface roughness of the workpiece.
45: What is tapping?
Answer: Cut the internal thread on the hole wall with a tap.
46: What effect does the diameter of bottom hole have on the power cord?
Answer: If the diameter of the bottom hole is the same as that of the internal thread, the tap will get stuck when the material expands, and the tap will break easily; If it is too large, the height of the thread profile will be insufficient.
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47: What is a set of silk?
Answer: Cut the thread on the outer diameter of the round rod tube with the die.
48: What principles should be paid attention to when choosing grooves?
Answer: (1) Minimize the weld metal filling, (2) ensure the penetration and avoid cracks, and (3) consider the minimum welding deformation.
(4) easy to process.
49: What is the function of leaving a blunt edge when slotting?
Answer: Prevent the connector from burning through.
50: What are the slotting methods?
Answer: Machining with air shovel, machining, gas cutting groove and carbon arc gas gouging groove.
5 1: What is carbon arc gouging?
Answer: The high temperature of carbon electrode arc is used to partially melt the metal, and at the same time, the molten metal is blown off by the airflow of compressed air to achieve the purpose of planing or cutting the metal.
52: What's the use of grinding?
Answer: It can eliminate the burr on the edge of welding scar on the plate, repair and polish the weld, and polish the weld of pressure vessel before re-inspection and inspection.
53: What is bending forming?
Answer: Bend a flat blank, profile or pipe into a certain angle and curvature, thus forming a part with a certain shape. 54: A: What is the rebound phenomenon?
A: When bending, the material is elastically deformed. When the external force is removed, part of the elastic deformation returns to its original state, which changes the shape and angle of the bending part.
55: What are the common bending forming methods used by riveters?
A: There are bending, rolling bending, calendering and water-fire bending.
56; What are the factors that affect bending forming?
Answer: bending force, rebound phenomenon, minimum bending radius, cross-section shape.
57: How to determine the magnitude of bending force?
Answer: According to the mechanical properties of the material to be bent, the bending mode and nature, and the shape of the bent part.
58: What are the factors that affect bending springback?
Answer: The mechanical properties of the material to be bent, the relative bending radius of the material, the bending angle and other factors.
59: What are the factors that affect the minimum bending radius?
A: The mechanical properties of the material, bending angle, bending direction, surface quality of the material and cutting surface quality and other factors.
60: What are the factors that affect the change of section shape when bending?
Answer: There are mainly relative bending radius, geometric characteristics of cross section and bending mode.
6 1 what effect does steel heating have on steel bending?
Answer: After heating, the required bending force decreases, the rebound phenomenon disappears, and the minimum bending radius decreases, which is conducive to controlling deformation according to machining requirements.
62: Under what circumstances do you usually bend by heating?
A: Then use it at room temperature.
Why should the heating temperature of steel be limited to a certain temperature?
A: Too high a temperature can easily lead to overheating of steel, while too low a temperature will make it difficult to form, resulting in cold work hardening.
64: When contact bending is adopted, what measures are often taken to solve the elastic recovery problem?
Answer: Modify the mold shape, adopt the pressure correction method, increase the blank holder ring, and reduce the mold gap.
65: What is bending?
Answer: the processing method of bending with bending die on the press.
66: How many forms of material bending deformation are there?
Answer: There are free bending, contact bending and correction bending.
67: Why do the dies used by riveters usually adopt welding structure?
Answer: Because it is not only convenient to manufacture, but also can shorten the molding cycle, improve the material utilization rate and reduce the cost. 68: What is roll bending?
Answer: The processing method of bending and forming on the roller.
69: What measures does the symmetrical three-roll bending machine often take to eliminate the straight edge of the workpiece?
Answer: Both ends are bent, leaving machining allowance.
70: What are the two kinds of calendering? What kind of riveters do you usually use?
Answer: There are continuous thinning calendering and thinning calendering. Riveting workers often use continuous thinning calendering.
7 1: What measures should be taken when rolling a conical surface?
Answer: Adjust the position of the upper roller to make it incline at a certain angle with the lower roller; Therefore, the eating speed of small mouth is faster than that of big mouth. 72: Larger workpieces made in How Do I Roll?
Answer: In order to avoid additional deformation caused by its own weight, the sheet should be divided into three areas, first rolling the two sides, then rolling the middle, and if necessary, the lathe should cooperate.
73: Rolling of any non-cylindrical workpiece?
Answer: The plate should be divided into areas according to its different curvature radius, and the distance between the shaft and the roller should be adjusted for rolling.
74: What preparations are made before rolling the workpiece?
Answer: the shaft roller and the plane of the plate should be cleaned and deburred to avoid damaging the workpiece and the shaft roller.
75: What is calendering?
Answer: A flat blank with a certain shape is punched with a punch and an open hollow part is formed through a concave die.
76: What is a water-fire bending plate?
Answer: The steel plate is locally heated and shrunk by oxyacetylene flame.
77: What are the uses of water-fire bending plate?
Answer: Hydro-thermal bending plate is only suitable for forming parts with small curvature, and is mostly used for double bending combined with rolling to process parts with complex shapes.
78: What are the methods of water-fire bending?
A: There are strip heating and point heating.
79: What are the processes of water-fire bending?
Answer: There are the selection of baking nozzle, heating temperature and heating speed, and cooling mode.
80: How many cooling methods are there for water-fire bending plate?
Answer: There are two kinds of air cooling and water cooling, and water cooling can be divided into front water cooling and rear water cooling.
82: What is air cooling?
Answer: After the flame is locally heated, the workpiece naturally cools in the air.
83: What is water cooling?
Answer: The heated metal is forced to cool with water, so that it can be cooled quickly, reduce heat transfer to the back, expand the temperature difference before and after, and improve the molding effect.
84: What are the characteristics of explosive molding?
Answer: it can simplify the mold structure; Hollow parts with complex shapes can be processed, but rigid molds are difficult to process; Small rebound, high precision and good quality; The processing and forming speed is fast; No need to stamp.
Equipment.
85: What is a corner joint?
Answer: When two plates are connected at a small angle perpendicular to each other, angle steel is used as the connector at the joint to rivet the workpieces together. 86: What are the main parameters of rivet arrangement?
Answer: There are rivet spacing, row spacing and margin.
87: What is the rivet spacing?
Answer: The distance between the centers of two adjacent rivets in a row.
88: What is line spacing?
Answer: refers to the distance between the centers of two adjacent rows of rivet holes.
89: What is a deposit?
Answer: It refers to the distance from the center of the outer row rivets to the edge of the workpiece plate.
90: What is the relationship between the component thickness and the rivet diameter?
Answer: When single-row and double-row lap joints are connected, the rivet diameter should be twice as thick; When a single row is connected with a double row of double cover plates, the rivet diameter is 1.5~ 1.75.
9 1: What are the principles for determining the thickness of plates?
Answer: when overlapping, it should be determined according to the thickness of thicker plates; When riveting materials with great difference in thickness, they should be determined by thinner plates; When the steel plate and the profile are riveted, the average thickness of the two is taken; pass by
The total thickness of the connection should not exceed 5 times the diameter of the rivet.
92: What is the relationship between rivet length and riveting quality?
Answer: the rivet is too long, the rivet pier head is too large, and the nail rod is easy to bend; The rivet is too short, the pier thickness is insufficient, and the nail head is not fully formed, which affects the riveting strength and tightness.
93: How to determine the rivet aperture when cold riveting?
Answer: the nail rod is not easy to be thick when cold riveting. In order to ensure the connection strength, the diameter of nail hole should be close to the diameter of nail rod.
94: When hot riveting, is the rivet aperture determined?
Answer: When hot riveting, the diameter of the nail hole should be slightly larger than the diameter of the nail shaft for punching.
95: What are the parts of the rivet?
Answer: It consists of handle, gun body, switch and pipe joint.
96: What are the characteristics of rivet gun?
Answer: Concrete is small in size and easy to operate, so it can be riveted in various positions.
97: What are the two ways of riveting?
Answer: It can be divided into cold riveting and hot riveting.
98: What is cold riveting?
A: It's very attractive at room temperature.
99: What is the final riveting temperature?
A: Between 450 and 600 degrees Celsius.
100: What is the effect of final riveting temperature on riveting?
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