JPH0350126B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a remote control valve that can be applied to pressure control valves, pressure reducing valves, control valves, and the like.

(Prior Art) FIG. 2 shows a longitudinal sectional view of a conventional remote control valve.
The remote control valve is a type of pressure reducing valve, and has a supply port P, secondary pressure ports A and B, and an oil drain port T, and the supply port P receives main pressure from a hydraulic pressure source such as a hydraulic pump. .
The secondary pressure ports A and B are connected to the controlled object, and the oil flowing from the secondary pressure port A through the supply port 11 is adjusted to a pressure corresponding to the load pressure of the controlled object. Further, the oil drain port T is a flow path through which the oil is returned from the secondary pressure ports A and B to the tank when the load pressure is no longer required.

Here, the adjustment of the secondary pressure port A or B is performed as follows. First, when the operation knob 1 is tilted in the X direction, the rotational deviation is applied to the lever 2, head cover 4,
The spring 10 is compressed via the push rod 7, and the spool 8 is displaced downward while pushing the spring 9. The spool 8 is displaced and the supply port 11
When the oil passes through the overlapping part of Supply port 11 is closed. That is, it is possible to generate a secondary pressure (equal to the load pressure when there is no flow) corresponding to the rotational deviation of the operating knob 1. When the operating knob 1 is returned to the middle direction, the force of the spring 9 becomes weaker and the secondary pressure displaces the spool 8 upward, so that the secondary pressure passes through the oil drain port 12 and at the same time flows to the oil drain port T. flows, and the secondary pressure decreases.

Next, an application example of the remote control valve will be explained with reference to FIG. In the figure, when operating lever b of remote control valve a is operated, secondary pressure is generated in either secondary pressure port c or b. For example, when pressure is built up in c, control valve e moves in the direction of the arrow. Pressure oil from pump f flows into load line g of control valve e, and actuator i also moves in the direction of the arrow. At this time, the oil on the low pressure side of the actuator i returns to the load line h and flows to the tank via the control valve e. Similarly, the oil on the opposite side of the control valve e passes through the secondary pressure port d, flows through the spool on the non-operated side, and returns to the tank.

(Problems to be Solved by the Invention) Since the remote control valve operates as described above, in order to reduce the operating force of the operating knob 1, it is necessary to reduce the pressure receiving area of the spool 8. Further, in order to speed up the flow rate, that is, the operation of the load, it is necessary to increase the flow rate, and when the pressure is increased, the operating force becomes large unless the pressure receiving area of the spool 8 is made small. On the other hand, in order to reduce the operating force, the lever 2 may be made longer, but this increases the operating range, is inconvenient, and requires a large amount of force for operation.

Therefore, if the pressure-receiving area of the spool 8 is made smaller in order to reduce the operating force, the flow rate becomes smaller and the pressure loss of the valve becomes larger. Furthermore, if the diameter of the spool 8 is increased in order to increase the flow rate, not only will the operating force increase as described above, but the stress of the spring 9 will also exceed its limit. In addition, increasing the pressure (increasing the secondary pressure) also had the disadvantage of causing the same problems as described above.

(Means for Solving the Problem) To this end, the present invention has a control spool that controls communication between a hydraulic pressure supply port and a secondary pressure port, and generates secondary pressure corresponding to the rotational deviation of the operating lever. At least the remote control valve for operating the control spool is fitted to the control spool so as to be relatively slidable therein;
A piston that generates a downward force commensurate with the upward force due to the secondary pressure generated on the control spool by applying the secondary pressure to the upper surface is attached to the operating force low range rod, which is fixed to the lower end of the operating lever. The push rod is held in a hanging state at the lower end of the push rod that is pressed by the operation of the push rod.This is a means for solving the problem.

(Function) When the operating lever is tilted in the direction, this movement is transmitted to the push rod, the operating force reduction rod is displaced downward, and the control spool is also displaced downward. Eventually, when the spool's supply port passes the overlapping part,
Pressure oil from the supply port flows into the supply port, and the flow passes from the secondary pressure port to the secondary pressure port via the oil passage. When pressure builds up in the load (controlled object) connected to the secondary pressure port, pressure is applied to the secondary pressure port accordingly. When the secondary pressure builds up, the spool tries to move upward, but when the force of the pressure adjustment spring is met, the openings between the supply port and the supply opening are cut off and balance is achieved. At this time, the piston of the low operating force rod is also receiving the same pressure, so the same force that moves the spool upward is generated as a force that moves the piston downward, resulting in a larger flow rate than before. , low pressure loss prevention, high pressure, low operating force, etc. can be achieved.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings. Fig. 3 shows an embodiment of the present invention, in which 1 is an operating knob, 2 is a lever, and 3 is a universal joint. In the figure, the operating knob 1 is rotatable in the X-Y direction and in the front-rear direction perpendicular to the plane of the paper. Also, 4 is a cover,
5 is the remote control valve body, 6 is the lid, 7 is the push rod, 8 is the spool, 9 is the pressure adjustment spring, 10 is the return spring for the operating knob 1 and lever 2, 11 is the spool 8
The supply port 12 is also an oil drain port.

P is a supply port connected to a hydraulic pressure source, A and B are secondary pressure ports connected to, for example, an operating pressure port of a hydraulic cylinder, and T is a drain port connected to a tank. 21 is an operating force reducing rod, 22 is a piston integrated with the lower part of the operating force reducing rod 21, 23 is an oil passage formed by the inner diameter part of the spool 8 and the outer diameter part of the operating force reducing rod 21, and 24 is 2 Shows secondary pressure port.

Next, the action will be explained. When the operating lever consisting of the operating knob 1 and lever 2 is tilted in the X direction, the head cover 4 is rotated about the universal joint 3,
This movement is transmitted to the push rod 7 and the operating force reduction rod 21 is displaced downward, and the spool 8 is also displaced downward while compressing the return spring 10 and pushing the pressure adjustment spring 9. Eventually, when the supply port 11 of the spool 8 passes the overlapping part, the pressure oil from the supply port P flows into the supply port 11, and the flow passes through the oil path 23 and flows from the secondary pressure port 24 to the secondary pressure port A.
Leads to.

When pressure builds up in the load (controlled object) connected to the secondary pressure port A, pressure is applied to the secondary pressure port 24 accordingly. When secondary pressure builds up, spool 8
tries to move upward, but when the force of the pressure adjustment spring 9 is met, the openings between the supply port 11 and the supply port P are cut off and the supply port P is balanced. At this time, since the piston 22 of the operating force reduction rod 21 is also receiving the same pressure, the same force as the force that moves the spool 8 upward is generated as the force that moves the piston 22 downward. As a result, the only force acting on the push rod 7 is the repulsive force of the return spring 10.

When the operating knob 1 is now deflected, the push rod 7 is displaced by x. If the spring constant of the spring 9 is κ9 and the mounting load is ignored, the force F1 that lowers the spool 8 is (κ9×x). Moreover, if the pressure receiving area of the secondary pressure is set as as, ignoring the amount of polymerization of the spool 8, then the secondary pressure PA=F1/as=κ9×x/as.

Furthermore, since the spring force of the return spring 10 also acts on the push rod 7, if the spring constant is κ10, the displacement x is the same, so the reaction force F2 is (κ10×x). That is, to generate the secondary pressure PA, the reaction force F1 + F2 = (κ9 + κ10) x = PA・as+κ10・x When the operating force reduction rod 21 acts on this,
Since the PA・as component acts in the opposite direction (downward in the figure), the above equation becomes only F2=κ10・x, which shows that it is not affected by pressure.

On the other hand, if secondary pressure occurs due to some phenomenon in the spool on the side that is not operated in the state shown in the figure, the pressure PA
As a result, the operating force reduction rod is displaced xR downward by xR = κ10/as・PA. However, the control piston is also displaced xP upward by xP=κP/as·PA due to the secondary pressure PA. If we now set κ9 and κ10 equal, the piston will be displaced by the amount compensated by the secondary pressure PA, so it can be seen that no actual damage will occur.

(Effects of the Invention) As described above in detail, the present invention provides a piston that generates a downward force commensurate with an upward force due to the secondary pressure generated on the control spool by applying the secondary pressure to the upper surface of the piston. Since the operating force low range rod fixed to the control spool is held in a hanging state at the lower end of the push rod that is pressed by operating the control lever, a downward force equal to the upward force acting on the control spool is generated, and the push rod is The influence of the secondary pressure acting on the push rod, that is, the operating force of the operating lever, will not increase significantly even if the secondary pressure becomes high.

[Brief explanation of drawings]

FIG. 1 is a piping diagram showing an application state of a conventional remote control valve, FIG. 2 is a vertical cross-sectional view of the conventional remote control valve, and FIG. 3 is a vertical cross-sectional view of a remote control valve showing an embodiment of the present invention. Explanation of the main parts of the diagram, 1... Operation knob, 2...
Lever, 5... Remote control valve body, 7... Push rod, 8... Spool, 9... Pressure adjustment spring, 10
...Return spring, 21...Operating force reduction rod, 21...
piston.

Claims (1)

[Claims] 1. In a remote control valve that has a control spool that controls communication between a hydraulic pressure supply port and a secondary pressure port, and that operates the control spool by generating secondary pressure corresponding to rotational deviation of an operating lever, the control spool A piston is fixed to the lower end of the control spool to generate a downward force commensurate with the upward force due to the secondary pressure generated on the control spool by applying the secondary pressure to the upper surface. A remote control valve characterized in that a low operating force rod is held in a hanging state at the lower end of a push rod that is pressed by operating the operating lever.