I. True or false questions (* *15 small questions, 2 points for each small question, 30 points for * * *)

1. The limiter and safety device of the crane shall be complete and effective. (√)

2. The center of gravity of an object is related to its placement. ㈩；

3. Proper hoisting methods must be adopted according to the shape and volume structure of the object, otherwise accidents will occur. (√)

4. In the actual work of the crane, the safety limit part and the safety interlock part form a closed loop and always participate in the crane work. (√)

5. The classification principle of working level of crane mechanism is the same as that of crane. (√)

6. The working level of the crane is based on different loads and different action times of the crane. (10)

7. The swing of heavy objects will produce centrifugal force, which will directly lead to the instability of the crane. ㈩；

8. Whether the foundation is firm directly affects the stability of the crane. (√)

9. The travel limiter is actually composed of push rod and limit switch. (√)

10. The adjustment of the hook superelevation limit must be carried out under no-load condition. (√),

1 1. When the lifting torque limiter is empty, the lifting number displayed by inspection should be zero, otherwise it should be adjusted. (√)

12. Ensuring the good and safe operation of mechanical equipment is the primary issue in production management and safety management. (√)

13. In addition to technical maintenance, cranes should also be regularly overhauled, which can be divided into minor repairs, medium repairs and major repairs. (10)

14. The core of safe production is to regulate people's behavior. (√)

15. Strengthening cooperation and mutual insurance in production is an important part of strengthening team management. (√)

Second, multiple-choice questions (***20 questions, 2 points for each question, 40 points for * * *)

1. The pollution of crane hydraulic system can be generally divided into (C) according to its pollution source.

A. 1

2. The total water content of hydraulic oil used by crane should not exceed B. ..

a . 0.05% b . 0. 1% c . 0. 15% d . 0.2%

3. Select hydraulic oil. If it is in the north, you can choose hydraulic oil with a kinematic viscosity of one D.

A. high B. high bar low D. low

4. When the crane is working, when the wind speed is high, it is easy to cause the crane to lose stability. When the wind speed is greater than Grade B, the crane stops working.

A.4 B .6 C.8 D. 10

5. The inclined crane will swing the heavy objects, which will lead to the instability of the crane directly.

A. centrifugal force B. inertial force C. gravity D. tensile force

6. Torque limiter, which will automatically give an alarm when the allowable lifting weight of the crane reaches a limit value of B..

A.80% B .90% c 100% d 1 10%

7. Torque limiter, when the allowable lifting weight of the crane reaches a limit value of C, it will automatically disconnect the power supply of the working loop.

a . 80% b . 90% c . 100% d . 1 10%

8. The function of hook superelevation limit is to prevent hook B. ..

A. Broken rope B. Jacking C. Pulling rope D. Overloading

9. The distance from the outer edge of the drum to the outermost wire rope should be not less than c times the diameter of the wire rope.

a . 1 b . 1.2 c . 1.5d . 2

10. If the crack length of the drum exceeds b mm, it shall be scrapped.

a . 5 b . 10 c . 15d . 20；

1 1. The abrasion of pulley groove wall shall not exceed the original thickness d.

15% 20% 25% d . 30%

12. The radial wear of pulley groove should not exceed C of the wire rope diameter.

15% 20% 25% d . 30%

13. The wear of the brake pin shaft reaches A and should be replaced with a new one.

a . 3% ~ 596 b . 5% ~ 7% c . 8% ~ 10% d . 10% ~ 12%

14. The pulley block that works normally can rotate flexibly by hand, and the lateral swing does not exceed DO/B..(Do is the nominal diameter of the pulley).

1000

15. The defective area in the shaft hole of pulley shall not exceed D cm2.

a 0. 1 b 0. 15 c 0.2:d 0.25

16. When the cross section of the main load-bearing components of the crane is corroded to B of the original thickness, those that cannot be repaired shall be scrapped.

A.5% B. 10%

17. The circular semicircular piece of the rope drum safety device shall not exceed the edge of the rope drum -a-cm.

A.0.5 B. 1 C. 1.5 D.2

18. The key component of crane safety device is B. ..

A. limiter B. brake C. buffer D. alarm

19. Regular inspection and maintenance system refers to the regular inspection and maintenance system for mechanical equipment.

A. Regular maintenance B. Regular repair C. Regular maintenance D. Fixed project repair

20. the three-step system of mechanical equipment is a person, a machine and b.

A. Post creation B. Post creation responsibility system C. Post creation measures D. Post creation implementation