A, too short b, too long c, neither too long nor too short d, and the grinding rod head is too small.
34, shearing machine is a special equipment for cutting (C).
A, bar b, block c, plate d and soft material
35. When assembling the belt transmission mechanism, the central plane of the two pulleys should be (C), and the inclination angle and axial offset should not be too large.
A, inclined B, coincident C, parallel D, perpendicular to each other
36, pulley tension adjustment method is to change the two pulleys (A) or tension with a tensioner.
A, center distance b, position c, speed d, parallelism
37, belt drive depends on (C) between the drive belt and pulley to drive power.
A, force b, tension c, friction d, elasticity
38, the main movement of grinding is (A).
A, grinding wheel circular motion b, workpiece rotation motion c, table movement d, grinding wheel rack movement
39, machinery and equipment reasonable use of lubricating materials can reduce the relative movement of machine parts (C), improve the service life of equipment.
A, speed b, time c, friction d, ability
40, the following material brand, belongs to the gray cast iron is (A).
A、HT250 B、KTH350- 10 C、QT800-2 D、RUT420
4 1, fuse has (c) protection.
A, overcurrent b, overheating c, short circuit d, undervoltage
42. You can know the name of the assembly from (a).
A, parts list b, part drawing c, title bar d, technical documents
43, standard twist drill is mainly used in (b).
A, reaming B, drilling C, reaming D and counterboring
44. Reaming D <: 40 mm, IT8 precision, surface roughness Ra 1.6 hole, its technological process is (a).
A, drilling-reaming-reaming B, drilling-reaming-rough hinge-fine hinge
C, drilling-rough hinge-fine hinge D, drilling-reaming-fine hinge
45, two basic geometry, in the form of plane contact with each other is called (D).
A, intersection b, tangency c, joint d, combination
46, two bearings installed on the same shaft, there must be a new outer ring (or inner ring) can produce (A) when thermal expansion, so as not to be bitten by the bearing.
A, radial movement b, axial movement c, axial rotation d, radial jump
47. The sawing angle is about (A).
A、 10° B、 15° C、20° D、25°
48, manufacturing twist drill should choose (B) material.
A、T 10 B、W 18Cr4V C、5CrMnMo D、4Cr9Si2
49, * * * steel quenching heating temperature should be chosen in (b).
A, Ac 1 below b, AC1+(30 ~ 50)℃ c, AC3+(30 ~ 50)℃ d, accm+(30 ~ 50)℃.
50, shaper is suitable for processing (c) parts.
A, box type B, lathe bed guide rail C, small plane, groove D and machine base type
5 1, turning the excircle is completed by the (d) of the workpiece and the longitudinal movement of the turning tool.
A, longitudinal movement b, lateral movement c, vertical movement d, rotary movement
52, sprocket axis must be parallel, otherwise it will aggravate the chain and sprocket wear, reduce the transmission (A), and increase the noise.
A, stationarity b, accuracy c, reliability d, robustness