JPS5925910B2 - Solenoid pilot type remote control valve - Google Patents

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
No. 6585).

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, it supplies and discharges pressure oil from the hydraulic source to the actuator. It is something that can be switched.

3 a and 3 b are the ends 2 a of the spool 2. 2b is the pilot room to enter, and this pilot room 3a
t 3 b is connected to the pilot hydraulic pressure source 5 via the throttles 4 a and 4 b, and the end portion 2 a of the spool 2,
Spring 12'a, 12b is provided to suppress 2b.

These springs 12a and 12b are connected to the pilot chamber 3a t3.
When no hydraulic pressure is applied to b, the spool 2 is held in a neutral position, and when hydraulic pressure is applied to the pilot chambers 3a and 3b and the spool 2 is pushed in either direction,
It is compressed and acts as a reaction force against hydraulic pressure.

Further, the aperture 4a. 4b is the pilot room 3a, 3
Even if either one or both of b are connected to tank T,
The opening area is large enough to keep the oil pressure of the pilot oil pressure source 5 at a constant value.

6a and 6b are electromagnetic valve parts, and the pilot chamber 3
It is connected to a and 3b.

This electromagnetic valve part 6 a t 6 b has an electromagnetic coil 7 a
, 7b, this electromagnetic coil 7a, 7b has an iron core 9a,
9b is slidably inserted into the iron core 9a t.
Poppet valves 8a and 8b are provided at the tip of 9b.

And the iron cores 9a, 9b and the electromagnetic coil 7a,
7b means the valve seats 10a in the pilot chambers 3a and 3b.
, 10b, and a valve chamber 11a connected to the tank T.

11b.

Also, a poppet valve 8a. 8b is the valve seat 10a, 10
It is arranged so that it can come into contact with the valve seat 10a>10b so as to open and close b, and the electromagnetic coil? When an electrical command is given to a, 7b, the poppet valves 8a, 8b are activated according to the electrical command.
It is configured to press the valve seats 10a and 10b against the valve seats 10a and 10b.

In such an electromagnetic pilot type remote control valve, the electromagnetic coils of the electromagnetic valve parts 6a and 6b? a,
When no electrical command is given to 7b, pressure oil from the pilot oil pressure source 5 is applied to the throttle 4a.

The pressure oil is supplied to the throat chambers 3a and 3b through the valve seats 10a and 10b and the valve chambers 11a and 11.
It flows out into tank T via b.

Therefore, no hydraulic pressure acts on the pilot chambers 3a, 3b, 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 given to the electromagnetic coil 7a of the electromagnetic valve section 6a, a pushing force in the right direction acts on the iron core 9a, the poppet valve 8a is pressed against the valve seat 10a, and the pilot chamber 3a and the valve chamber 11a are pressed. The space between pilot room 3 and
The oil pressure in a increases.

The oil pressure in this pilot chamber 3a is the same as that at the end 2a of the spool 2
and moves the spool 2 to the right.

As the spring 12b is compressed by the rightward movement of the spool 2, the hydraulic pressure in the pilot chamber 3a increases according to the amount by which the spring 12b is compressed, and the pressing force due to this hydraulic pressure is applied to the iron core 8a. When the pressing force is exceeded,
The poppet valve 8a is separated from the valve seat 10a, the oil pressure in the pilot chamber 3a 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 moved away from the pilot chamber 3a.
It is operated to a position where the pressing force of the hydraulic pressure 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 portion 6b, the spoo/L/2 is operated to the left.

In this electromagnetic pilot type remote control valve, when no electric command is given to any of the electromagnetic valve parts 6a, 6b, the pressure oil of the pilot hydraulic pressure source 5 is
4b, pilot chambers 3a, 3b, valve seats 10a, 10b,
Since the configuration is such that the oil flows out into the tank T via the valve chambers 11a and 11b, the pilot oil pressure source 5 maintains the amount of pressure oil necessary to maintain a predetermined oil pressure upstream of the throttles 4a and 4b. Must be a value.

In addition, when multiple such electromagnetic pilot type remote control valves are installed in series, the pressure oil from the hydraulic pressure source 5 flows out to the tank via the pilot chamber of each directional control valve, so a larger pilot hydraulic pressure is required. It has the disadvantage of requiring a source.

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 first valve part and the tank, and a variable throttle is arranged between the output port and the pilot hydraulic pressure source, and the opening area of this variable throttle is A solenoid valve part is connected to the pilot chamber, and includes a second valve part having a control valve that increases the pressure in response 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.

By connecting the output port to the tank, the main valve of the first valve section connects the pilot chamber to the tank, and the control valve of the second valve section minimizes the opening area of the variable throttle, thereby reducing the flow from 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 the gap between the output port and the tank due to the pressing force of the electromagnetic coil, reducing the pressure difference between the pilot oil pressure source and the output port, and opening the variable throttle. 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, by setting the amount of movement of the poppet valve to an extremely small value, there is an effect that no special electromagnetic coil is required.

Examples according to the present invention will be described below.

In FIG. 2 showing an embodiment of the present invention in which electromagnetic valve parts 5c and 5c' are provided at the end of the directional control valve 1, the electromagnetic valve part 6c is
It consists of a first valve part 15 which is connected to the pilot chambers 3c and 3c' and to which the pilot hydraulic pressure source 5 and the tank T are connected, and a second valve part 16 which is connected to the first valve part 15. be.

The configurations of the solenoid valve parts 6c and 60' will be explained below, but since the solenoid valve parts 6c and 6c' have the same configuration, only the configuration of the solenoid valve part 6c will be explained. It is indicated with the same symbol as the valve part 6c, with the ``datsunyu'' added, and quoted as necessary.

In FIG. 3 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.
An inner hole 17 is connected to the inner hole 17, and a main valve 18 is slidably fitted into the inner hole 17 of 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 constantly pressed leftward by a spring 20 and is connected to a passage 18a connected to the pilot chamber 3c and this passage 18.
A has a hole 18b connected to the hole 18b, and a pressure chamber 18c connected to the output port 22 is formed at the left end thereof.

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 3c is connected to the tank T, and hydraulic pressure is applied to the pressure chamber 18c. When it is moved to the right by the hydraulic pressure, the pilot chamber 3c is connected to the pilot hydraulic pressure source 5.

The second valve part 16 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 23 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 23 is constantly pressed downward by a spring 23a,
A control valve 23c having a fixed throttle 23b and this control valve 23
A variable diaphragm 26 whose opening area is controlled by c and opens at the output port 22 is provided.

In this embodiment having the above configuration, the electromagnetic coil 2
If no electromagnetic command is 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 to the electromagnetic valve parts 5c, 6c'.

Passages 19a, 19a', chambers 21a, 21a', fixed throttle 23 b t 23 b', variable throttle 26, 26',
It flows out into the tank T from the passages 19b, 19b' via the output ports 22, 22' and the poppet valves 25, 25'.

At this time, the flow rate limiting valves 23, 23' are caused by pressure oil flowing through the control valve 2.
3c.

230' is pressed against the springs 23a, 23a' by the pressure difference before and after the fixed throttles 23b, 23b' caused by passing through the fixed throttles 23b, 23b', and the opening area of the variable throttles 26, 26' is Variable aperture 26, 26'
The pressure difference on the upstream side (downstream side of the control valves 23c, 23c') increases in accordance with the decrease thereof, so the pressure difference before and after the control valves 23c, 23c' decreases.

Then, the pressing force due to the pressure difference before and after the control valve 23c and the pressing force of the springs 23a and 23a' 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, when an electric command is given to the electromagnetic coil 24, the poppet valve 25 is pressed according to the electric current of the electric command.
Although the space between the output port 22 and the tank T is closed, the pressure oil from the pilot hydraulic pressure source 5 acts on the pressure chamber 18c via the flow rate restriction valve 23 and the output port 22.

By closing the space between the output port 22 and the tank T with the poppet valve 25, the oil pressure at the output port 22 increases, and the pressure difference across the fixed throttle 23b of the control valve 23 decreases, so that the control valve 23c is moved by the spring 23a,
The aperture area of the variable diaphragm 26 is increased.

Therefore, the oil pressure of the output port 22 (the oil pressure of the pressure chamber 18c) starts to rise rapidly almost at the same time as the electric command is given to the electromagnetic coil 24.

The oil 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 of the pilot oil pressure source 5 reaches the passage 19a,
, flows into the pilot chamber 3c through the passages 18b and 18a of the main valve 18, and applies hydraulic pressure within 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 120' 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 spunil 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 hydraulic pressure of the output port 22 acts against the pressing force of the electromagnetic coil 24 of the pilot valve 25.

Therefore, when the pressing force due to the hydraulic pressure in the output port 22 exceeds the pressing force of the electromagnetic coil 24 acting on the pilot valve 25,
The pilot valve 25 opens and connects the output port 22 to the tank T, so that the pressure oil from the pilot oil pressure source 5 flows through the flow restriction valve 2.
3. The water flows out to the tank T via the poppet valve 25, and the control valve 23c reduces the opening area of the variable throttle 26.

At the same time, the main valve 18 of the first valve part 15 is also moved to the right, and its passage 18b is replaced by passages 19a, 4. When reaching the intermediate position of j9b, the supply of hydraulic pressure from the pilot hydraulic pressure source 5 to the pilot chamber 3c is stopped, and the space between the pilot chamber 3c and the tank is also closed, so that the hydraulic pressure in the pilot chamber 3c is transferred to the electromagnetic coil. 24, and the spool 2 is moved to a position corresponding to the oil pressure in the pilot chamber 3c.

Then, when the electric command to the electromagnetic coil 24 is stopped, the pressing force on the poppet valve 25 disappears, so the pressure oil at the output port 22 flows from the passage 19b to the tank T through the poppet valve 25.
The main valve 18 returns to the position shown in FIG. 3, and the oil in the pilot chamber 3c flows into the passages 18a, 18b and the passage 19
It flows out into tank T via b.

Therefore, the spool 2 receives the pressing force of the spring 120' 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, and the spool 2 moves to the left in response to an electric command given to the solenoid valve section 6c'.

[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. 3 is a partially enlarged sectional view of the electromagnetic valve section. 1... Directional switching valve, 2... Spool,
3a. 3b, 3c, 3c'...Pilot room, 5...
...Pilot hydraulic power source, 6a, 6b, 6c, 5c'
...Solenoid valve part, 15...First valve part, 1
6...Second valve part, 18...Main valve, 22
...Output port, 23...Flow rate limiting valve, 2
4... Electromagnetic coil, 25... Poppet valve, 26... Variable throttle.

Claims (1)

[Claims] 1. An electromagnetic pilot type in which a pilot chamber with the ends of a spool inserted into both ends of the directional control valve is provided, this pilot chamber is connected to a pilot hydraulic pressure source, and a solenoid valve is provided between this pilot chamber and a tank. In the remote control valve, the electromagnetic valve part is disposed between a pilot hydraulic pressure source, a tank and a pilot chamber, and has a first main valve that switches the first throat chamber to either the pilot hydraulic pressure source or the tank. A poppet valve driven by an electromagnetic coil is provided between the valve part, the output port connected to this first valve part, and the tank, and a throttle 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 whose opening area is reduced in accordance with an increase in pressure difference between a pilot hydraulic pressure source and an output port.