High speed circuit is often used in hydraulic machine tools to ().
A. increase the speed of working feed and improve the working efficiency of the system
B. increase the speed of the working mechanism when there is no load, and improve the working efficiency of the system
C. increase the machining speed of working mechanism and improve the working efficiency of the system
D. increase the oil pressure of the system to speed up the speed of working mechanism, and improve the working efficiency of the system
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In the inlet throttling speed regulating circuit, when the load is constant and the opening of throttle valve decreases, the pressure difference of the throttle valve would ().
A. Increase
B. decrease
C. unchange
A milling machine should work in the situation of large range of cutting force. When selecting the speed control circuit of the milling machine, what type of speed control circuit should be chosen? ()
A. inlet throttle speed control circuit with throttle valve
B. outlet throttle speed control circuit with throttle valve
C. inlet throttle speed control circuit with speed regulating valve
D. outlet throttle speed control circuit with speed regulating valve
In a hydraulic circuit, the operating sequence needs to be changed frequently, what type of circuit should be adopted? ()
A. Sequential action circuit controlled by stroke switch
B. Sequential action circuit controlled by stroke valve
C. Sequential action circuit controlled by pressure relay
D. Sequential action circuit controlled by sequence valve
In order to make the working mechanism can stay at any position reliably, for instance payload of a hydraulic crane, and the working mechanism will not slip under the condition of force, what circuitis usually used? ()
A. unloading loop
B. pressure regulation circuit;
C. pressure counter-balance circuit;
D. back pressure circuit.
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