JPS58221089A - Solenoid-control-pilot operated type remote control valve - Google Patents

Abstract

PURPOSE:To aim at the miniaturization of a pilot hydraulic source, by making an opening area of a variable throttle smaller when no electric command is given to a solenoid valve part but large when the command is given the other way. CONSTITUTION:When an electric command is given to a solenoid coil 24, a space between an output port 22 and a tank T is blocked up by a poppet valve 25 and thereby a pressure difference between in front and in the rear of a fixed throttle 23b of a control valve 23 decreases so that a control valve 23c is shifted by dint of a spring 23a and the opening area of a variable throttle 26 is increased. When pressing force by hydraulic pressure inside the output port 22 exceeds the pressing force of the solenoid coil 24 acting on a pilot valve 25, pressure oil in a pilot hydraulic source 5 flows out into the tank T, decreasing the opening area of the variable throttle 26. Therefore, the pilot hydraulic source is enough even being small in capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic pilot type remote control valve that operates a directional control valve by controlling pressure oil from a pilot oil pressure source with an electromagnetic pilot valve.

Conventionally, this type of technology is shown in Figure 1 (Japanese Unexamined Patent Publication No. 52-7
In Fig. 1, the directional control valve 1 has a spool 2 slidably fitted therein, although not shown in detail, and when the spool 2 is moved, hydraulic pressure is applied to the actuator. This is used to switch the supply and discharge of pressure oil from the source. 8a and 8b are the ends 2a of the spool 2.

2b is a pilot chamber into which the pilot chambers 8a and 8b are connected to the pilot hydraulic pressure source 5 via throttles 94a and 4b, and the end portion 2 of the spool 2
a, 2b suppressing spring 1. ．． 2. These springs 12a and 12b are installed in the pilot chamber 8.
When hydraulic pressure does not act on a and 8b, the spool 2 is held in a neutral position, and when hydraulic pressure acts on the pilot chambers 8a and 8b, and when the spool 2 is pressed in either direction, it is compressed and a reaction force against the hydraulic pressure It acts as. Further, the aperture 4a.

4b has an opening area large enough to maintain the oil pressure of the pilot oil pressure source 5 at a constant value even if one or both of the pilot chambers 8a, 8b are connected to the tank T.

6a and 6b are electromagnetic valve parts, and the pilot chamber 3a
, 8b. These solenoid valve parts 6a and 6b are
Electromagnetic coils 7a, 7b and electromagnetic coils 7a, 7b
Iron cores 9g and 9b are slidably fitted into the iron cores 9g and 9b, and poppet valves 8a and 8b are provided at the tips of these iron cores 9a and 9b. Then, these iron cores 9a, 9b and the electromagnetic coil 7a
, 7b means the piping chamber 8a, 8blC valve seat 10a,
A valve chamber l is connected to the tank T via 10b.
It is provided in la#11b. In addition, the poppet valve 8a,
8b is the valve seat 10 to open and close the valve seats 10a and lOb.
a, 10b so that it can come into contact with the electromagnetic coil 'I
When an electric command is given to a and 'Tb, the poppet valves 8a and 8b are pressed against the valve seats 10a and 10b in accordance with the electric command.

In such an electromagnetic pilot type remote control valve, the electromagnetic coils 7a, 7 of the electromagnetic valve parts 6a, 6b
When the blC electric command is not given, pressure oil from the pilot oil pressure source 5 is supplied to the pilot chambers 8a, 8b via the throttles 4a, 4b, but this pressure oil is not supplied to the valve seat 10a.
, 10b, and flows into the tank T via the valve chambers 11a and llb. Therefore, no hydraulic pressure acts on the pilot chambers 8a, 8b, and the spool 2 is held at the neutral position shown in FIG. 1 by the pressing force of the springs 12a, 12b.

In this state, when an electric command is applied to the electromagnetic coil 7aK of the electromagnetic valve section 6a, a pressing force to the right acts on the iron core 9a, and the poppet valve 8a is pressed against the valve seat 10a, causing the pilot chamber 8. A and the valve chamber 11a are closed, and the oil pressure in the pilot chamber 3a increases. This oil pressure in the pilot chamber 8a acts on the end 2a of the spool 2, and moves the spool 2 to the right. As the spool 2 moves to the right, the spring 12b is compressed, so the pilot chamber 3a
The hydraulic pressure inside rises in accordance with the amount by which the spring 12b is compressed, and when the pressing force due to this hydraulic pressure exceeds the pressing force acting on the iron core 9a, the poppet valve 8a is separated from the valve seat 10a. , the hydraulic pressure in the pilot chamber 8a is maintained at a value corresponding to the electric current of the electric command supplied to the electromagnetic coil 7a, and the spool 2 is
It is operated to a position where the pressing force due to the hydraulic pressure of the pilot chamber 3a and the pressing force of the spring 12b are balanced.

Note that when an electric command is given to the electromagnetic coil 7b of the electromagnetic valve section 6b, the spool 2 is operated to the left.

In this electromagnetic pilot type remote control valve, when an electric command is not given to either of the electromagnetic valve parts 6a and 6b, the pressure oil of the pilot hydraulic pressure source 5 is , 10b1 valve chamber 11
Since the pilot oil pressure source 5 is configured to flow out to the tank T via the a and
It must be set to a value necessary to maintain a predetermined oil pressure on the upstream sides of a and 4b. In addition, when installing multiple such electromagnetic pilot type remote control valves,
Since the pressure oil of the pilot hydraulic power source 6 flows out into the tank through the pilot chamber of each directional control valve, there is a drawback that a larger biloft hydraulic power source is required.

The technical problem of the present invention is to miniaturize the pilot hydraulic power source by using a variable diaphragm that reduces the opening area when no electrical command is given to the solenoid valve section and increases the opening area when an electrical command is given. It is something to do.

The basic configuration for solving this technical problem consists of a first valve part equipped with a main valve that connects pilot chambers provided at both ends of the directional control valve to either a pilot hydraulic pressure source or a tank, and A poppet valve driven by an electromagnetic coil is provided between the discharge port connected to the valve 1 and the tank, and a variable throttle is arranged between the output port and the pilot oil pressure source. A solenoid valve part is connected to the pilot chamber button and includes a second valve part having a control valve whose area increases according to a decrease in the pressure difference between the pilot hydraulic pressure source and the output port.

In the present invention having such a basic configuration, unless an electric command is given to the electromagnetic coil, no pressing force is applied to the poppet valve, so that the output port is connected to the tank. Since the output port is connected to the tank, the main valve of the first valve part connects the pilot chamber to the tank, and the control valve of the second valve part minimizes the opening area of the variable restrictor, and connects the pilot hydraulic pressure source to the tank. Reduce the flow rate to a small value. Next, when an electric command is given to the electromagnetic coil, the poppet valve closes between the output port and the tank due to the pressing force of the electromagnetic coil, so the pressure difference between the pilot hydraulic pressure source and the output port decreases, and the variable throttle opens. The area is increased by the control valve, the pressure at the output port increases, and the main valve of the first valve portion connects the pilot pressure oil source and the pilot chamber, thereby operating the spool of the directional control valve.

The present invention has the following unique effects due to the above basic configuration.

The technical problem of the present invention is, for example, Japanese Patent Publication No. 47-1075
This problem can be solved by the technical means disclosed in No. 1.

This technical means provides a spool-type switching valve between the pilot chamber provided at the end of the directional switching valve and the pilot hydraulic pressure source, which switches the pilot chamber between the pilot hydraulic pressure source and the tank. One end is connected to an electromagnetic coil, and the other end forms a pressure chamber to which the hydraulic pressure in the pilot chamber acts.

In this technical measure, when no electrical command is supplied to the electromagnetic coil, the spool-type switching valve closes the gap between the pilot hydraulic pressure source and the tank, so that the spool-type switching valve closes the gap between the pilot hydraulic pressure source and the tank. Valve leakage can only be a small value. However, spool-type switching valves require a sliding part between the spool and the inner hole of the switching valve body to reduce oil leakage when closed, so the spool must be moved when switching. It is something.

For this reason, the electromagnetic coil for moving the spool,
It has the disadvantage of requiring a special type of electromagnetic coil whose pressing force remains constant regardless of the amount of movement of the spool.

However, in the present invention, the second valve part is configured to drive a poppet valve with an electromagnetic coil, the first valve part is connected to the output port of the second valve part, and the pilot chamber is controlled by the pilot hydraulic pressure. Since it is configured to be connected to either the source or the tank, a large amount of pilot pressure oil can be supplied and discharged to the pilot chamber, so it can be used for large switching valves, and the poppet valve is driven by an electromagnetic coil. Therefore, an embodiment according to the present invention will be described below, which has the effect of not requiring a special electromagnetic coil by setting the amount of movement of the poppet valve to an extremely small value.

6c is a first valve part 15 which is connected to the pilot chambers 8c and 8c', and to which the pilot hydraulic power source 5 and the tank T are connected, and a second valve part which is connected to the first valve part 15. The configuration of the solenoid valve section 6c6cl will be explained below, but since the solenoid valve sections 6c and 6c' have the same configuration, only the configuration of the solenoid valve section 6c will be explained. The valve part 6c' has the same sign as the solenoid valve part 6c.
Display with a dashi translation and quote as necessary.

In FIG. 8 showing an enlarged view of the electromagnetic valve section 6c, the first valve section 15 is connected to the pilot chamber 3c and the output port 22 of the second valve section 16.
The main valve 18 is provided with an inner hole 17 connected to the inner hole 17 and a main valve 18 slidably fitted into the inner hole 17. A passage 19a connected to the pilot hydraulic power source 5 and a passage 19b connected to the tank T are opened in the inner hole 17, respectively. The main valve 18 is
The pilot chamber 8c is constantly pressed to the left by the spring 20.
A passage 18a connected to the passage 18a and a hole 1 connected to the passage 18a.
8b, and a pressure chamber 1 connected to the output port 22 at its left end.
Form 8c. When the pressure chamber 18C is connected to the tank T, the main valve 18 is moved to the left by the pressing force of the spring 20, and the pilot chamber 8C is connected to the tank T.
Hydraulic pressure acts on the pressure chamber 18c, and when the pressure chamber 18c moves to the right, the pilot chamber 8c is connected to the pilot hydraulic pressure source 5.

The second valve part 6 is provided with a pressure chamber 21a connected to the passage 19a of the first valve part 15, a discharge chamber 21b connected to the passage 19b, and an output port 22. A flow rate limiting valve 2.3 is provided between the output port 22 and the discharge chamber 21b, and a poppet valve 25 pressed by an electromagnetic coil 24 is provided between the output port 22 and the discharge chamber 21b. The flow rate restriction valve 28 is
The control valve 28c is always pressed downward by a spring 28a and has a fixed diaphragm 928b, and a variable diaphragm 26 whose opening area is controlled by the control valve 28c and opens to the output port 22 is provided.

In this embodiment having the above configuration, the electromagnetic coil 2
If the electromagnetic command is not given to the poppet valve 25, no pressing force will be applied to the poppet valve 25, so the pressure oil from the pilot oil pressure source 5 will flow through the electromagnetic valve parts 6c, 6c' and the passage 19a.
, 19 a', chambers 21 a, 21 a', fixed number 23 b, 23 b', variable diaphragm #) 26, 26
', Output port 22, 22', Poppet valve 25, 25'
The water flows out from the passages 19 b and 19 b' into the tank T via the passages 19 b and 19 b'. At this time, the flow rate limiting valves 28 , 28 ′ are controlled by the pressure oil while the control valves 28 c , 28 c ′ are controlled by the fixed throttle 28 .
b, fixed aperture 2 created by passing through 28b'
8b, 28b' due to the pressure difference before and after the spring 28a
, 28 a' is pressed against the variable aperture 26 , 2
The aperture ITII product of the control valves 28 c and 6' is increased in accordance with the decrease in the upstream side of the variable throttles 26 and 26' (downstream side of the control valves 2 J3 Ct 28 c').
The pressure difference before and after 28 c' decreases. The pressing force due to the pressure difference before and after the control valve 28c and the spring 28
a and 28 a' are reduced until they are balanced. Therefore, the amount of oil flowing out from the pilot oil pressure source 5 to the tank T is limited.

Next, the poppet valve 25 is pressed in accordance with the current of the electric command given to the electromagnetic coil 24, so that the space between the output port 22 and the tank T is closed. The pressure oil flows through the flow restriction valve 23. It acts on the pressure chamber 18c via the output port 22. By closing the space between this output port 22 and the tank T with the poppet valve 25,
The oil pressure at the output port 22 increases, and the fixed throttle 23 of the control valve 23
Since the pressure difference across b decreases, the control valve 28c is moved by the spring 23a, increasing the opening area of the variable throttle 26. This reservoir, the hydraulic pressure of the output port 22 (pressure chamber 1
8c) begins to rise rapidly almost at the same time as an electric command is given to the electromagnetic coil 24. The hydraulic pressure of the output port 22 acts on the pressure chamber 18C, and the main valve 18 of the first valve part 15 is moved to the right against the pressing force of the spring 20, and the passage 18b is connected to the passage 19a. When the pressure oil from the pilot oil pressure source 5 flows into the pilot chamber 8c via the passage 19a and the passages 18b and 18a of the main valve 18, the oil pressure is applied to the pilot chamber 3c. This oil pressure acts on the end 2c of the spool 2 and begins to move the spool 2 to the right against the pressing force of the spring 12c' holding the spool 2 in the neutral position. When the spool 2 is moved in this way, the spring 12c' is compressed, and the reaction force increases as the spool 2 moves to the right. The oil pressure of will rise. Since this oil pressure also acts on the right side of the main valve 18, the oil pressure in the output port 22 also rises.The oil pressure in the output port 22 is opposed to the pressing force of the electromagnetic coil 24 of the pilot valve 25. Therefore, the pressing force due to the hydraulic pressure inside the output port 22 is constant.

When the pressing force of the electromagnetic coil 24 acting on the poppet valve 25 is exceeded, the pilot valve 25 opens and connects the output port 22 to the tank T. At the same time, the main valve 18 of the first valve part 15 is also moved to the right, and the passage 18b is changed to the passage 19a (!: When reaching the intermediate position of 19b, the supply of hydraulic pressure from the pilot hydraulic pressure source 5 to the pilot chamber 8C is stopped, and the space between the pilot chamber 3c and the tank is also closed, so that the pilot chamber 8
The oil pressure at C has a value that corresponds to the electric command given to the electromagnetic coil 24, and the spool 2 is moved to a position in the pilot chamber 8C that corresponds to the oil pressure.

Then, when the electric command to the electromagnetic coil 24 is stopped, there is no pressing force on the poppet valve 25, so the output 1''22
Pressure oil flows out from the passage 19b to the tank T via the poppet valve 25, so the main valve 18 returns to the position shown in FIG.
It flows out into tank T via 9b. Therefore, the spool 2 receives the pressing force of the spring l 2 c' and returns to the neutral position.

The case where an electric command is given to the solenoid valve part 6c has been described above, but when an electric command is given to the solenoid valve part 6c', the solenoid valve part 6c' operates in the same way as the solenoid valve part 6C. ,
The spool 2 moves to the left in response to an electric command given to the solenoid valve section 6c'IC.

[Brief explanation of the drawing]

FIG. 1 is a functional explanatory diagram of a conventional electromagnetic pilot type remote control valve, FIG. 2 is a sectional view of an embodiment of the present invention, and FIG. 8 is a partially enlarged sectional view of the electromagnetic valve section. l... Directional switching valve 2... Spool Ba, 8b
,Be,3c'-Pilot room-15・
...First valve part 16...Second valve part 18...Main valve 2
2... Output port 23... Flow rate limiting valve 24... Electromagnetic coil 25... Poppet valve 26... Variable throttle Applicant: Japan Air Brake Co., Ltd.

Claims (1)

[Claims] (1) A pilot chamber with the ends of the spool protruded into both ends of the directional control valve is retracted, this pilot chamber is connected to a pilot hydraulic pressure source, and a solenoid valve section is provided between this pilot chamber and the tank. In the electromagnetic pilot type remote control valve, the electromagnetic valve part is arranged between a pilot hydraulic pressure source, a tank, and a pilot chamber, and has a main valve that switches the pilot chamber to either the pilot hydraulic pressure source or the tank. A poppet valve driven by an electromagnetic coil is provided between the first valve part, the output port connected to the first valve part, and the tank, and a restrictor is provided between the output port and the pilot pressure oil source. An electromagnetic pilot type remote control valve comprising a second valve part equipped with a control valve that reduces the opening area of the throttle according to an increase in the pressure difference between the pilot hydraulic pressure source and the output port.