The tree of wisdom knows the answer to the course of Hydraulic and Pneumatic Transmission (Jiaxing College)

The tree of wisdom knows the answer to the course of Hydraulic and Pneumatic Transmission (Jiaxing College)

1, the oil with high viscosity index means the oil.

A. high viscosity

B. Due to the pressure change, the viscosity changes greatly.

C. Due to the temperature change, the viscosity changes little.

D. Due to the temperature change, the viscosity changes greatly.

Correct answer: viscosity does not change much due to temperature change.

2. Bernoulli equation is the expression of () in fluid mechanics.

A. Law of conservation of energy

B. momentum theorem

C. law of conservation of matter

D. Others

Correct answer: the law of conservation of energy

3. The flow rate of liquid flowing through the thin-walled hole is proportional to the pressure difference before and after the hole ()

A. Primary prescription

B. 1/2 power

C. secondary

D. cubic

Correct answer: 1/2 power

4, through the fixed parallel plate gap flow is proportional to the gap value ().

A. Primary prescription

B. 1/2 power

C. secondary

D. cubic

Correct answer: Cube.

1. As shown in the figure, the speed change circuit with the speed control valves in parallel adopts two speed control valves in parallel to realize the speed change, and the speed change is realized by turning on and off the electromagnet 3 when the hydraulic cylinder 7 moves.

A. correct

B. mistakes

Correct answer: b

2. The so-called pressure maintaining circuit is to keep the system pressure basically unchanged when the actuator stops working or only slightly displaces due to the deformation of the workpiece. The simplest pressure maintaining circuit is the pressure maintaining circuit with hydraulic control one-way valve with good sealing performance.

A. correct

B. mistakes

Correct answer: a

3. The function of synchronous action loop is to ensure that two or more hydraulic actuators in the system move at the same displacement or speed. Two hydraulic cylinders with the same working area can be synchronized by inputting the same amount of oil.

A. correct

B. mistakes

Correct answer: b

4. The unloading circuit of the reversing valve can be realized by the following three-position reversing valve with intermediate function ().

morning

B.O

C.P

D.H

Correct answer: M#H

5. The two-way hydraulic lock often realizes the intermediate function through the following () type three-position reversing valve.

morning

B.O

C.P

D.H

Correct answer: H.

6. When the double-pump oil supply circuit moves rapidly, the check valve 4 plays a role in the circuit.

A separate oil channels to prevent mutual interference between oil channels.

B prevent the hydraulic shock in the system from affecting the work of the hydraulic pump.

C. provide back pressure for the oil return cavity.

D. prevent excessive pressure.

Correct answer: divide oil circuits to prevent mutual interference between oil circuits.

1, when the check valve is used as a back pressure valve, its spring should be replaced by a soft spring.

A. correct

B. mistakes

Correct answer: b

2. The electromagnetic reversing valve is suitable for occasions where the flow is not too large.

A. correct

B. mistakes

Correct answer: a

3. When the hydraulic control check valve controls the pressure oil at the oil port, its function is the same as that of the check valve.

A. correct

B. mistakes

Correct answer: a

4. When the intermediate function of the reversing valve is O-type, the pump can be unloaded.

A. correct

B. mistakes

Correct answer: b

5. The spring stiffness of the main valve of the pilot safety valve is less than that of the pilot valve.

A. correct

B. mistakes

Correct answer: a

6. The slide valve is used in the differential cylinder function, and the formula () can be used in the function.

A.O

B.H

C.P

D.M

Correct answer: p

1, hydraulic transmission depends on the hydrostatic pressure in the sealed volume to transmit force, as shown in ().

A. 10,000 tons hydraulic press

B. Centrifugal water pump

C. hydraulic turbine

D. hydraulic torque converter

Correct answer: 10,000 tons hydraulic press

2, the hydraulic system of machine tools, commonly used () pump, its characteristics are: medium pressure, small flow and pressure pulsation, uniform delivery, stable and reliable work.