JP2003294002A - Control valve and liquid pressure control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve cost reduction of a hydraulic device and circuit through making them simple structure by downsizing them, whereas providing them with functions as a check valve and a relief valve. <P>SOLUTION: A control valve 100 is structured as a valve having a poppet structure. A valve seat of a head of a poppet 23 and a poppet 22 form a drawn portion S<SB>3</SB>between ports 11 and 12. A spring 32 is provided in the poppet 23 so that a spring force Fs is applied to the poppet 23 in such a direction that the valve seat of the head of the poppet 23 closes an opening of the drawn portion S<SB>3</SB>. Among portions in the head of the poppet 23, a portion on which oil pressure p12 of the port 12 acts is formed so that a spring force Fa depending on difference (SA-SB) in an area subjected to pressure may be applied in the opposite direction to a spring force Fs. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION

2. Description of the Related Art Some valves for controlling the flow rate of fluids such as oil, water and glycol have a poppet structure. The case of controlling the hydraulic pressure will be described below as an example.

A poppet valve is a check valve (check valve).
Widely used as. Using a poppet valve as a check valve allows pressure oil to flow in only one direction and not in the other direction unless an external force is applied, and effectively prevents pressure oil from leaking from the other direction. You can For example, a control valve 100 'having a poppet structure shown in FIG.
Allows the flow of pressure oil to the hydraulic actuator (hydraulic cylinder) 84 and allows the hydraulic actuator 84 to move to the tank 99.
Shut off the flow of pressure oil to.

However, if a large load W acts on the hydraulic actuator 84 and the pressure of the hydraulic oil in the hydraulic actuator 84 exceeds the set pressure and stresses exceeding the allowable stress act on the hose, valve block, etc., these Machinery such as hoses and valve blocks may be damaged.

Therefore, conventionally, the hydraulic actuator 84 has been used.
When the load applied to the tank is overloaded, the high pressure oil of the hydraulic actuator 84 is released to the tank 99 by using a relief valve (safety valve).

Conventionally, the following two methods have been adopted for this solution.

1) A method of bypassing the pressure oil of the hydraulic actuator 84 directly to the tank 99 2) The pressure oil of the hydraulic actuator 84 is replaced by the poppet valve 10
Method of bypassing through the oil chamber 42 inside 0 ′ The method of the above 1) is a relief valve (check valve) between the hydraulic actuator 84 and the tank 99 as shown in FIG.
This is achieved by providing 85. That is, when the load applied to the hydraulic actuator 84 becomes overloaded, the relief valve 85 opens according to the high pressure oil of the hydraulic actuator 84, and the high pressure oil can escape to the tank 99.

In the method 2), as shown in FIG. 8 for convenience of explanation, a bypass passage 87 for communicating the oil chamber 42 inside the poppet valve 100 'with the tank 99 is provided in the block 60'. Formed, on this bypass passage 87,
This is achieved by providing the relief valve 86. The relief valve 86 opens and guides the pressure oil to the tank 99 when the pressure in the oil chamber 42 communicating with the hydraulic actuator 84 becomes equal to or higher than the set relief pressure. By opening the relief valve 86, the pressure in the oil chamber 42 is reduced, and accordingly, the variable throttle S2, which is the main passage of the poppet valve 100 ', opens. Therefore, the high pressure oil of the hydraulic actuator 84 passes through the variable throttle S2 of the poppet valve 100 'and the tank 99
Is discharged to.

[0008]

However, according to the above method 1), since the high pressure oil of the hydraulic actuator 84 is guided to the full amount tank 99, the relief valve 85 having a relatively large opening area is required. become. Relief valve 85
It is necessary to increase the poppet and the spring used for increasing the opening area of the relief valve 85, which increases the area of the relief valve 85. That is, the product area of the hydraulic circuit increases by the amount indicated by the broken line 185.

According to the above method 2), the poppet valve 1
The opening area of the relief valve 86 can be made relatively small because the flow rate to the extent that the pressure in the inner oil chamber 42 of 00 'is reduced to the tank 99. Therefore, the product area of the relief valve 86 can be reduced. However, since it is necessary to provide the relief valve 86 in the block 60 ', the area of the block 60' is increased by the amount indicated by the broken line 186.

As described above, even if any of the conventional methods is adopted, there is a problem that the hydraulic equipment and the hydraulic circuit become large in size. Further, since the relief valve needs to be provided separately from the poppet valve 100 ′ having a function as a check valve, the structure is complicated due to an increase in the number of parts and the cost is increased. The present invention has been made in view of these circumstances, and while having the function as a check valve and the function as a relief valve described above, the hydraulic equipment and hydraulic circuit can be made compact, and the cost can be reduced with a simple structure. This is a problem to be solved.

[0011]

[Means for Solving the Problems and Effects] The first invention is
When the pressure of the second port (12) becomes equal to or higher than the set pressure while permitting the flow of the pressure liquid from the first port (11) to the second port (12), the second port (12) In the control valve for guiding the pressurized liquid of No. 1 to the first port (11), the control valve is a valve having a poppet structure, and the first poppet (2
The second poppet (23) is provided inside the second poppet (23), the chamber (42) is formed inside the first poppet (22), and the chamber (42) inside the second port (12) and the first poppet (22) is formed. ) Is formed in the first poppet (22), and the valve seat of the head of the first poppet (22) and the block (60) allow the first port (11) and the second port (11) to communicate with each other. Forming a first aperture (S2) between the port (12) and a second aperture
By the valve seat of the head of the poppet (23) and the first poppet (22), the first port (11) and the second port (1)
2) to form a second throttle (S3), so that the spring force is applied so that the valve seat of the head of the second poppet (23) closes the opening of the second throttle (S3). (32) is applied to the second poppet (23), and the portion of the head of the second poppet (23) on which the hydraulic pressure of the second port (12) acts is the pressure receiving area difference (SA-SB). It is characterized in that it is formed so that a force corresponding to is applied in a direction opposite to the spring force.

A second aspect of the present invention is the same as the first aspect of the present invention, in which the second poppet (23) is opposed to the spring force.
An external force applying means for applying an external force to open the second diaphragm (S3) is further provided.

According to the first and second aspects of the invention, as shown in FIG. 7, the control valve 100 is constructed as a valve having a poppet structure. The second poppet 23 is provided inside the first poppet 22, and the chamber 42 is formed inside the first poppet 22. Chamber 42 inside the second port 12 and the first poppet 22
The first poppet 22 is formed with a passage 22a that communicates with the. The valve seat on the head of the first poppet 22 and the block 60 form a first throttle S2 between the first port 11 and the second port 12. Due to the valve seat on the head of the second poppet 23 and the first poppet 22, the first port 1
A second diaphragm S3 is formed between 1 and the second port 12.

The second poppet 23 has the poppet 23.
The spring 32 is provided so that the spring force Fs is applied in the direction in which the valve seat of the head of the head closes the opening of the second diaphragm S3. In the portion of the head of the second poppet 23 where the hydraulic pressure p12 (pressure in the chamber 42) of the pressurized liquid in the second port 12 acts, the force Fa corresponding to the pressure receiving area difference (SA-SB) is the spring force. It is formed so as to be applied in the direction opposite to Fs.

Therefore, the hydraulic pressure p12 of the second port 12 is the first
When the pressure is higher than the hydraulic pressure p11 of the port 11 and lower than the relief pressure determined by the spring force Fs, that is, the force Fa corresponding to the pressure receiving area difference (SA-SB) is the spring force Fs of the spring 32. If smaller, the second poppet 23 is pressed against the first poppet 22 by the spring 32, and the second diaphragm S3 is closed. Further, since the hydraulic pressure p12 of the second port 12 (pressure inside the chamber 42) is higher than the hydraulic pressure p11 of the first port 11, the first poppet 22 is blocked by the force corresponding to the pressure inside the chamber 42. It is pressed against 60 and the first diaphragm S2 is closed. This blocks the flow of fluid from the second port 12 to the first port 11.

The hydraulic pressure p11 of the first port 11 is the second port 1
When the hydraulic pressure is greater than the hydraulic pressure p12 of 2, the first poppet 22 is blocked by the block 6 by the force corresponding to the hydraulic pressure p11 of the first port 11.
The first aperture stop S2 is opened apart from 0. This allows the fluid to flow from the first port 11 to the second port 12.

As described above, the control valve 100 of the present invention is
Functions as a check valve that allows only the flow of fluid from the first port 11 to the second port 12.

When the hydraulic pressure p12 of the second port 12 exceeds the relief pressure determined by the spring force Fs, that is, when the force Fa corresponding to the pressure receiving area difference (SA-SB) exceeds the spring force Fs of the spring 32, The second poppet 23 is separated from the first poppet 22 and the second diaphragm S3 is opened. As the second diaphragm S3 opens, the chamber 42 communicates with the first port 11, so that the chamber 42
The inside is decompressed. As the chamber 42 is decompressed, the first poppet 22 pressed against the block 60 according to the pressure inside the chamber 42 is separated from the block 60 and the first aperture S2 is opened. This allows the high-pressure fluid in the second port 12 to escape to the first port 11 and functions as a relief valve.

When an external force is applied to the second poppet 23 by the external force applying means, the second poppet 23 is separated from the first poppet 22 and the second diaphragm S3 is opened. As the second diaphragm S3 opens, the chamber 42 communicates with the first port 11, so that the pressure inside the chamber 42 is reduced. As the chamber 42 is depressurized, the first poppet 22 pressed against the block 60 in accordance with the pressure inside the chamber 42 moves to the block 60.
And the first diaphragm S2 is opened. Thereby, the fluid in the second port 12 can be guided to the first port 11.

According to the present invention, the second poppet 23 is accommodated inside the first poppet 22 and the head portion of the second poppet 23 is formed so as to have a pressure receiving area difference, thereby functioning as a check valve and a relief valve. Has realized the function as.
Therefore, the relief valves 85 and 86 are separately provided as in the prior art.
It is not necessary to provide (FIG. 8), the field product can be made extremely small, and the number of parts can be reduced. As described above, according to the present invention, the hydraulic device and the hydraulic circuit can be made compact while having the function as a check valve and the function as a relief valve, and the cost can be reduced with a simple structure.

A third aspect of the invention is to allow the flow of the pressurized liquid from the first port (11) to the second port (12) and when the pressure of the second port (12) becomes equal to or higher than a set pressure. The pressure liquid in the second port (12) to the first port (11)
In the control valve to be led to, the control valve is a valve having a poppet structure, a second poppet (22) is provided inside the first poppet (21), and a chamber (4) is provided inside the first poppet (21).
1) is formed, a third poppet (23) is further provided inside the second poppet (22), a chamber (42) is formed inside the second poppet (22), and a second port (12) and a second port (12) are formed. A passage (21a) communicating with the chamber (41) inside the first poppet (21) is formed in the first poppet (21), and the chamber (41) inside the first poppet (21) and the second poppet (22).
A passage (22a) communicating with the inner chamber (42) of the first poppet (21) is formed in the second poppet (22) by the valve seat of the head of the first poppet (21) and the block (60). 11) and the second aperture (12) between the first aperture (S
1) forming the valve seat on the head of the second poppet (22) and the first
The poppet (21) forms a second throttle (S2) between the first port (11) and the second port (12), and the second seat (23) and the valve seat of the head of the third poppet (23). The poppet (22) forms a third aperture (S3) between the first port (11) and the second port (12),
The first spring (31) is applied to the second poppet (22) so that the spring force is applied in the direction in which the valve seat of the head of the poppet (22) closes the opening of the second throttle (S2), and the third The second spring (3) is so arranged that the valve seat of the head of the poppet (23) applies a spring force in the direction of closing the opening of the third throttle (S3).
2) is applied to the third poppet (23), and the portion of the head portion of the third poppet (23) on which the hydraulic pressure of the second port (12) acts acts as the pressure receiving area difference (SA-SB). A corresponding force is formed so as to be applied in a direction opposite to the spring force of the second spring (32), and further, the second poppet (22) is opposed to the spring force of the first spring (31). In the direction, external force applying means (90, 92, 98, 83) for applying an external force to open the second diaphragm (S2) is provided.

According to the third invention, as shown in FIG. 1, the control valve 100 is constructed as a valve having a poppet structure. The second poppet 22 is provided inside the first poppet 21,
A chamber 41 is formed inside the poppet 21, a third poppet 23 is further provided inside the second poppet 22, and a chamber 42 is formed inside the second poppet 22. 2nd port 12
A passage 21 a is formed in the first poppet 21 so that the passage 21 a communicates with the inner chamber 41 of the first poppet 21. A chamber 41 inside the first poppet 21 and a chamber 42 inside the second poppet 22
A passage 22a is formed in the second poppet 22 for communicating with the.

Due to the valve seat on the head of the first poppet 21 and the block 60, the first port 11 and the second port 12 are
A first aperture S1 between the two is formed. Second poppet 22
A second seat S2 between the first port 11 and the second port 12 is formed by the valve seat of the head of the head and the first poppet 21. Further, the valve seat on the head of the third poppet 23 and the second
The poppet 22 forms a third diaphragm S3 between the first port 11 and the second port 12.

The third poppet 23 has the poppet 23.
The second spring 32 is provided such that the spring force Fs is applied in the direction in which the valve seat of the head of the head closes the opening of the third diaphragm S3. Of the head of the third poppet 23, the second port 1
In the portion where the hydraulic pressure p12 (pressure inside the chamber 42) of the second hydraulic fluid acts, the force Fa corresponding to the pressure receiving area difference (SA-SB) is the spring force Fs.
Is formed so as to be applied in a direction opposite to.

Therefore, the hydraulic pressure p12 of the second port 12 is the first
When the pressure is higher than the hydraulic pressure p11 of the port 11 and lower than the relief pressure determined by the spring force Fs, that is, the force Fa corresponding to the pressure receiving area difference (SA-SB) is the spring force Fs of the spring 32. If smaller, the third poppet 23 is pressed against the second poppet 22 by the second spring 32, and the third diaphragm S3 is closed.

A first spring 31 is attached to the second poppet 22, the second poppet 22 is pressed against the first poppet 21 by the first spring 31, and the second diaphragm S2 is closed.

Further, since the hydraulic pressure p12 of the second port 12 (the pressure inside the chamber 41) is higher than the hydraulic pressure p11 of the first port 11, a force corresponding to the pressure inside the chamber 41 is applied to the first poppet. Two
1 is pressed against the block 60, and the first diaphragm S1 is closed. This blocks the flow of fluid from the second port 12 to the first port 11.

The hydraulic pressure p11 of the first port 11 is the second port 1
When the hydraulic pressure is greater than the hydraulic pressure p12 of 2, the first poppet 21 is blocked by the block 6 by the force corresponding to the hydraulic pressure p11 of the first port 11.
The first diaphragm S1 is opened apart from 0. This allows the fluid to flow from the first port 11 to the second port 12.

As described above, the control valve 100 of the present invention is
Functions as a check valve that allows only the flow of fluid from the first port 11 to the second port 12.

When the hydraulic pressure p12 (pressure in the chamber 42) of the second port 12 becomes equal to or higher than the relief pressure determined by the spring force Fs, that is, the force Fa corresponding to the pressure receiving area difference (SA-SB) is applied to the second spring 32. When the spring force of Fs exceeds Fs, the third poppet 2
3 is separated from the second poppet 22 and the third diaphragm S3 is opened. As the third diaphragm S3 opens, the chamber 41 moves to the passage 2
The interior of the chamber 41 is depressurized because it communicates with the first port 11 via the chamber 2a, the chamber 42 and the third throttle S3. As the chamber 41 is depressurized, the first poppet 21 pressed against the block 60 in accordance with the pressure inside the chamber 41 becomes
And the first diaphragm S1 is opened. This allows the high-pressure fluid in the second port 12 to escape to the first port 11 and functions as a relief valve.

An external force is applied to the second poppet 22 by the external force applying means (the handle 90, the spools 92 and 98, the actuator 83, etc. shown in FIGS. 1, 3, 4 and 5) and the spring of the first spring 31 is applied. When it becomes larger than the force, the second
The poppet 22 is separated from the first poppet 21 and the second diaphragm S
2 opens. As the second diaphragm S2 opens, the chamber 41
Communicate with the first port 11, so that the pressure inside the chamber 41 is reduced. By decompressing the chamber 41, the first poppet 21 pressed against the block 60 according to the pressure inside the chamber 41 is separated from the block 60 and the first diaphragm S1 is opened. This allows the fluid in the second port 12 to flow through the first port 11
Can be led to.

According to the present invention, the second poppet 22 is accommodated inside the first poppet 21, the third poppet 23 is accommodated inside the second poppet 22, and the head pressure receiving area of the third poppet 23 varies. Thus, the function as a check valve and the function as a relief valve are realized. For this reason, the relief valve 85,
Since it is not necessary to provide 86 (FIG. 8), the field product can be made extremely small and the number of parts can be reduced. As described above, according to the present invention, the hydraulic device and the hydraulic circuit can be made compact while having the function as a check valve and the function as a relief valve, and the cost can be reduced with a simple structure.

Further, according to the present invention, the force for moving the second poppet 22 by the external force applying means is the first spring 31.
It is determined only by the spring force of, and is constant without being affected by the magnitude of hydraulic pressure. Therefore, the controllability is good because the disturbance force in the left and right directions of the poppet due to the difference in pressure receiving area is not generated due to the fluctuation of the hydraulic pressure. Further, unlike the second spring 32, the first spring 31 does not determine the relief pressure, but may be any one that generates a small spring force that presses the second poppet 22 against the first poppet 21. Therefore, as the external force applying means such as an actuator, a small one that can generate a small force that overcomes the spring force of the small first spring 31 can be used. As a result, the external force applying means can be downsized and the cost can be reduced.

In a fourth aspect based on the third aspect, the external force imparting means (90, 92, 98, 83) is substantially coaxial with the second poppet (22) along the longitudinal direction of the second poppet (22). It is characterized by being arranged above.

According to the fourth aspect of the invention, external force applying means (for example, spool 97 and actuator 83 shown in FIG. 4).
Are arranged coaxially with the poppet 22 along the longitudinal direction of the poppet 22, so that the block 60 can be made smaller in the width direction.

The fifth aspect of the invention is to connect the first port (A1) to
A hydraulic fluid is allowed to flow to the second port (12) communicating with the hydraulic actuator (84), and when the pressure of the hydraulic actuator (84) becomes equal to or higher than a set pressure, the hydraulic actuator (84). In the fluid pressure control device for guiding the pressurized fluid of No. 2 to the first port (A1) via the second port (12), the second poppet (22) is provided inside the first poppet (21), and the first poppet (22) is provided. A chamber (41) is formed inside the (21), and a second poppet (22) is further formed.
A control valve (100) having a poppet structure in which a third poppet (23) is provided inside and a chamber (42) is formed inside the second poppet (22), and the second port (12) and the first poppet ( 21) is formed in the first poppet (21) with a passage (21a) communicating with the inner chamber (41) of the first poppet (21) and the second poppet (22) inside the first poppet (21).
A passage (22a) communicating with the inner chamber (42) of the first poppet (21) is formed in the second poppet (22) by the valve seat of the head of the first poppet (21) and the block (60). The first aperture (S) between A1) and the second port (12)
1) forming the valve seat on the head of the second poppet (22) and the first
The poppet (21) forms a second throttle (S2) between the first port (A1) and the second port (12), and the valve seat of the head of the third poppet (23) and the second The poppet (22) forms a third aperture (S3) between the first port (A1) and the second port (12), and
The first spring (31) is applied to the second poppet (22) so that the spring force is applied in the direction in which the valve seat of the head of the poppet (22) closes the opening of the second throttle (S2), and the third The second spring (3) is so arranged that the valve seat of the head of the poppet (23) applies a spring force in the direction of closing the opening of the third throttle (S3).
2) is applied to the third poppet (23), and the portion of the head portion of the third poppet (23) on which the hydraulic pressure of the second port (12) acts acts as the pressure receiving area difference (SA-SB). It is formed so that a corresponding force is applied in a direction opposite to the spring force of the second spring (32), and further, it opposes the spring force of the first spring (31) with respect to the second poppet (22). In the direction, external force applying means (90, 92, 98, 83) for applying an external force to open the second diaphragm (S2) is provided.

According to the fifth aspect of the invention, as shown in FIG. 3 (a), the hydraulic fluid is allowed to flow from the first port A1 to the second port 12 communicating with the hydraulic actuator 84, and the hydraulic pressure is reduced. A hydraulic pressure control device that guides the hydraulic fluid of the hydraulic actuator 84 to the first port A1 via the second port 12 when the pressure of the actuator 84 becomes equal to or higher than the set pressure is configured. The fifth invention has the same effects as the above-mentioned third invention.

A sixth aspect of the invention is the directional control valve (80) according to the fifth aspect of the invention, which selectively communicates with the discharge port of the hydraulic pump (98) or the tank (99) with respect to the first port (A1). Is further provided.

According to the sixth aspect of the invention, as shown in FIG. 3A, when the directional control valve 80 operates and the first port A1 communicates with the discharge port of the hydraulic pump 98, the hydraulic pressure is reduced. Pump 9
The hydraulic fluid of No. 8 can be supplied to the hydraulic actuator 84 via the first port A1 and the first throttle S1 of the control valve 100. Also, the directional control valve 80 is activated to operate the first port A1.
Is communicated with the tank 99, the pressure oil of the hydraulic actuator 84 can be discharged to the tank 99 via the first throttle S1 of the control valve 100 and the first port A1.

[0040]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

First Embodiment As shown in FIG. 1, the control valve 100 of the first embodiment is roughly divided into a block 60, a poppet 21 housed in the block 60, and an inside of the poppet 21. It includes a poppet 22, a poppet 23 accommodated inside the poppet 22, a shaft 52 inserted into the poppet 23, and a handle 90 for applying a force to the shaft 52 from the outside.

In block 60, port 11 and port 12
Are formed. The port 12 communicates with a hydraulic actuator (hydraulic cylinder) 84 as in FIG.

The control valve 100 includes ports 11 to 1
The function as a check valve that allows the flow of pressure oil to the hydraulic actuator 84 via 2 and the pressure oil of the hydraulic actuator 84 via the port 12 when the hydraulic pressure in the hydraulic actuator 84 becomes equal to or higher than the set relief pressure. It has a function as a relief valve that leads to the port 11.

The poppet 21 is slidably accommodated in the block 60. The poppet 21 is formed with an opening 21b penetrating the inside and the outside thereof along the longitudinal direction.

Inside the poppet 21, a poppet 22 is provided so that it can be seated in the opening 21b. Therefore, an oil chamber 41 defined by the poppet 22 is formed inside the poppet 21.

The poppet 22 has an opening 22b penetrating the inside and the outside thereof along the longitudinal direction.

Inside the poppet 22, a poppet 23 is provided so that it can be seated in the opening 22b. Therefore, an oil chamber 42 defined by the poppet 23 is formed inside the poppet 22.

The poppet 21 is formed with a passage 21a for communicating the port 12 with the oil chamber 41 inside the poppet 21. Further, the poppet 22 is formed with a passage 22a for communicating the oil chamber 41 inside the poppet 21 and the oil chamber 42 inside the poppet 22. Therefore, the oil chamber 4
The hydraulic pressure inside the ports 1 and 42 is the same as the hydraulic pressure at the port 12.

The valve seat on the head of the poppet 21 and the block 60
The valve seat abutment surface of (1) forms a variable throttle S1 between the port 11 and the port 12. The opening area (diaphragm diameter) of the variable diaphragm S1 changes according to the moving position of the poppet 21. When the valve seat of the head of the poppet 21 contacts the valve seat contact surface of the block 60, the opening of the variable throttle S1 is closed and the communication between the port 11 and the port 12 is cut off. When the valve seat of the head of the poppet 21 separates from the valve seat contact surface of the block 60, the variable throttle S1 opens and the port 1
1 communicates with the port 12.

The valve seat on the head of the poppet 22 and the valve seat abutting surface of the poppet 21 form a variable throttle S2 between the port 11 and the oil chamber 41. Variable aperture S2
The opening area (diaphragm diameter) varies depending on the relative movement position of the poppet 22 with respect to the poppet 21. When the valve seat of the head of the poppet 22 contacts the valve seat contact surface of the poppet 21,
The opening of the variable diaphragm S2 is closed, and the port 11 and the oil chamber 41 are closed.
Communication with and is cut off. The oil chamber 41 communicates with the port 12 via the passage 21a. Therefore, the communication between the port 11 and the port 12 is cut off. When the valve seat of the head of the poppet 22 separates from the valve seat contact surface of the poppet 21, the variable throttle S2 opens and the port 11 communicates with the port 12 through the oil chamber 41 and the passage 21a.

The valve seat on the head of the poppet 23 and the valve seat abutment surface of the poppet 22 form a variable throttle S3 between the port 11 and the oil chamber 42. Variable aperture S3
The opening area (diaphragm diameter) varies depending on the relative movement position of the poppet 23 with respect to the poppet 22. When the valve seat of the head of the poppet 23 contacts the valve seat contact surface of the poppet 22,
The opening of the variable diaphragm S3 is closed, and the port 11 and the oil chamber 42 are
Communication with and is cut off. The oil chamber 42 communicates with the port 12 via the passage 22a, the oil chamber 41, and the passage 21a. Therefore, the communication between the port 11 and the port 12 is cut off. When the valve seat of the head of the poppet 23 separates from the valve seat contact surface of the poppet 22, the variable throttle S3 opens and the port 11 opens the oil chamber 42, the passage 22a, the oil chamber 4
1. Communicates with the port 12 via the passage 21a.

A passage 23a is formed inside the poppet 23 so as to penetrate therethrough in the longitudinal direction. A shaft 52 is inserted through the inside passage 23a of the poppet 23, the opening 22b of the poppet 22, and the opening 21b of the poppet 23.

The shaft 52 is screwed onto the shaft 51. The shaft 51 is screwed to the poppet 22. That is, the shafts 51 and 52 are formed integrally with the poppet 22, and the poppet 22 moves integrally with the shafts 51 and 52 according to the force applied to the shafts 51 and 52. One end of a spring 31 is in contact with the shaft 51 so that a spring force is applied to the valve seat of the head of the poppet 22 in the direction of closing the opening of the variable throttle S2. The other end of the spring 31 is in contact with the plug 71. The plug 71 is screwed into the block 60. Shaft 51 is plug 71
It is provided slidably with respect to. A plug 72 is further screwed onto the plug 71. Therefore, the shaft 5
An oil chamber 44 defined by a plug 71 and a plug 72 is formed at the rear end 52d of the second member.

One end of the spring 32 is in contact with the poppet 23 so that the valve seat on the head of the poppet 23 applies a spring force in the direction of closing the opening of the variable throttle S3. The other end of the spring 32 is in contact with the shaft 51. The poppet 23 is slidably provided on the shaft 51. Therefore, an oil chamber 43 defined by the shaft 51 and the shaft 52 is formed at the rear end 23d of the poppet 23.

A passage 52 is provided along the longitudinal direction of the shaft 52.
a is formed. This passage 52a is connected to the port 11.
The shaft rear end 52d communicates with the oil chamber 44.

The shaft passage 52a communicates with the oil chamber 43 via the passage 52b.

As described above, since the oil chambers 43 and 44 communicate with the port 11 via the shaft internal passages 52a and 52b, the pressure in the oil chambers 43 and 44 becomes the same as the port 11.

The block 60 includes a shaft portion 9 of the handle 90.
0a is screwed so that it can move linearly. The shaft portion 90a is arranged along the longitudinal direction of the poppet 22 and coaxially with the central axis thereof. That is, the shaft portion 90a is arranged coaxially with the shaft 52. The shaft portion 90a is arranged at a position where its tip 90b can abut the tip 52c of the shaft 52.

When the handle 90 is manually rotated, the shaft portion 90a is directly moved and the shaft portion tip 90b is moved to the shaft tip 5.
Push 2c.

Shaft tip 52c by shaft tip 90b
When the force pushing the spring becomes larger than the spring force of the spring 31, the shaft 52 becomes integral with the poppet 22 and the spring 3 moves.
Move in the direction opposite to 1.

Next, the shape of the head of the poppet 23 will be described with reference to FIG.

FIG. 2A shows the poppets 21 and 2 of FIG.
A configuration centered on the reference numerals 2 and 23 is extracted and shown. Further, FIG. 2B is an enlarged view of a part of the poppet 23 in FIG. As shown in FIG. 2 (a), of the pressure receiving surfaces of the left and right ends of the poppet 23 in the drawing, the pressure receiving area of the right end face of the port 11 which receives the hydraulic pressure in the left direction in the drawing is Sa,
The pressure receiving area of the left end face of the oil chamber 43 that receives the hydraulic pressure in the right direction in the drawing is Sb. Here, the head of the poppet 23 is formed so that a pressure receiving area difference of Sb-Sa> 0 occurs.

FIG. 2B shows the poppet 2 as seen in the oil chamber 42.
3 shows the pressure receiving areas at the left and right ends of the head of FIG. This Figure 2
As shown in (b), of the pressure receiving surfaces at the left and right ends of the head of the poppet 23, the pressure receiving area at the right end of the head that receives the hydraulic pressure in the oil chamber 42 in the left direction in the figure is SA, and in the right direction in the figure, Oil chamber 42
If the pressure receiving area at the left end of the head that receives the internal hydraulic pressure is SB,
The pressure receiving area difference SA-SB between the left and right ends of the head is equal to the pressure receiving area difference Sb-Sa (> 0) between the left and right ends of the poppet described above. That is, a force corresponding to the pressure receiving area difference SA-SB is applied to the head of the poppet 23 in the direction opposite to the spring force of the spring 32.

Next, the operation of FIG. 1 will be described.

Operation as Check Valve 1) When the oil pressure p12 of the port 12 is higher than the oil pressure p11 of the port 11 and the oil pressure p12 of the port 12 is smaller than the set relief pressure, the oil pressure in the oil chamber 43 is as described above. It has the same pressure as the hydraulic pressure of the port 11. Therefore, forces corresponding to the pressure receiving areas Sb and Sa are applied to the left and right ends of the poppet 23 in the figure, respectively. In other words, the pressure receiving area difference Sb is at both ends of the poppet 23.
A force Fb obtained by multiplying -Sa by the hydraulic pressure of the port 11 is applied in the right direction in the figure, that is, in the direction to close the variable throttle S3.

The oil pressure in the oil chamber 42 is the same as the oil pressure in the port 12. Therefore, a force Fa obtained by multiplying the pressure receiving area difference SA-SB (or Sb-Sa) by the hydraulic pressure p12 of the port 12 is applied to the head of the poppet 23 in the left direction in the figure, that is, in the direction of opening the variable throttle S3. Has been.

The spring force Fs of the spring 32 is applied to the poppet 23 in the right direction in the figure, that is, in the direction to close the variable aperture S3.

Therefore, the force Fp shown in the following equation acts on the poppet 23 in total.

Fp = Fs + Fb−Fa (1) Fa = (SA−SB) · p12 (2) As shown in the above equation, when the hydraulic pressure p12 of the port 12 is small, the force Fa becomes small and Fp> 0. Has been established. Therefore, this force Fp causes the valve seat of the poppet 23 to move to the poppet 22.
Is pressed against the valve seat contact surface (seat surface). Therefore, the aperture of the variable diaphragm S3 is closed.

Next, the force acting on the poppet 22 will be described.

The poppet 22 includes the above-mentioned poppet 23.
Unlike the above, no pressure receiving area difference Sb-Sa or SA-SB is provided at the left and right ends of the poppet and the left and right ends of the poppet head.
Therefore, in total, only the spring force of the spring 31 acts on the poppet 22, and the valve seat of the poppet 22 is pressed against the valve seat contact surface (seat surface) of the poppet 21 by this spring force. The aperture of the variable diaphragm S2 is closed.

Next, the force acting on the poppet 21 will be described with reference to FIG.

The hydraulic pressure p11 of the port 11 acts on most of the pressure receiving area Sd at the right end of the poppet 21 in the figure, and the hydraulic pressure p12 of the port 12 acts on the remaining pressure receiving area (Sc-Sd).
Works. Also, the pressure receiving area S at the left end of the poppet 21 in the figure
The hydraulic pressure p12 of the port 12 (oil chamber 41) acts on c. Now the hydraulic pressure p12 of port 12 is the hydraulic pressure p11 of port 11.
Is higher than. Therefore, the hydraulic pressure p12 of the port 12
The valve seat of the poppet 21 is pressed against the valve seat abutment surface (seat surface) of the block 60 by a force proportional to, and the opening of the variable throttle S1 is closed. As a result, the flow of the pressure oil from the port 12 to the port 11 is blocked, and the leakage of the pressure oil from the hydraulic actuator 84 is prevented.

2) When the oil pressure p11 of the port 11 becomes higher than the oil pressure p12 of the port 12, when the oil pressure p11 of the port 11 rises and the oil pressure of the port 11 is received by the pressure receiving area Sd at the right end of the poppet 21 in the figure, The poppet 21 (and the poppet 22) pushed rightward in the figure can be pushed leftward in the figure by the oil pressure p12 of the oil chamber 41 and the port 12. Therefore, the valve seat of the poppet 21 is blocked by the force proportional to the hydraulic pressure p11 of the port 11 in the block 6
0 from the valve seat abutment surface (seat surface), the variable throttle S1
Opens. For this reason, the pressure oil in the port 11 is variable throttle S1.
To flow into the port 12, and the pressure oil is supplied to the hydraulic actuator 84.

As described above in 1) and 2), the control valve 100 of the embodiment functions as a check valve that allows the flow of pressure oil only from the port 11 to the port 12.

Operation as Relief Valve 3) When the oil pressure p12 of the port 12 is higher than the oil pressure p11 of the port 11 and the oil pressure p12 of the port 12 is higher than the set relief pressure. The force Fp expressed by the following equation is acting.

Fp = Fs + Fb−Fa (1) Fa = (SA−SB) · p12 (2) If the hydraulic pressure p11 of the port 11 is sufficiently smaller than the hydraulic pressure p12 of the port 12, the above (1) is used. Force Fb in the formula
Can be ignored. Therefore, the relief pressure can be set according to the spring force Fs of the spring 32.

Therefore, when the hydraulic pressure p12 of the port 12 becomes large due to an excessive load applied to the hydraulic actuator 84 and exceeds the set relief pressure, that is, the force Fa is the spring force Fb.
When it becomes larger than that, Fp <0, the valve seat of the poppet 23 is separated from the valve seat contact surface (seat surface) of the poppet 22, and the variable throttle S3 is opened. Therefore, the pressure oil in the port 12 flows into the port 11 through the passage 21a, the oil chamber 41, the passage 22a, the oil chamber 42, and the variable throttle S3. At this time, the hydraulic pressure in the oil chamber 41 is the passage 21a that functions as a "throttle".
Is reduced from the hydraulic pressure p12 of the port 12. The oil pressure in the oil chamber 41 is an intermediate oil pressure between the oil pressure p12 of the port 12 and the oil pressure p11 of the port 11.

By reducing the hydraulic pressure in the oil chamber 41, the force acting on the poppet 21 in the right direction in the figure in accordance with the hydraulic pressure is reduced. Therefore, the valve seat of the poppet 21 separates from the valve seat contact surface (seat surface) of the block 60, and the variable throttle S1 opens. Therefore, the pressure oil in the port 12 passes through the variable throttle S1 and flows into the port 11. In this way, the high pressure oil in the port 12 can be released to the port 11 by using the variable throttle S1 as a main bypass passage. Thereby, the hydraulic pressure of the port 12 can be lowered.

As the poppet 23 moves, the oil chamber 43
The pressure oil inside passes through the internal passages 52b and 52a of the shaft 52 and is guided to the port 11, or passes through the internal passage 23a of the poppet 23 and is guided to the port 11.

As shown in the above 3), the control valve 1 of the embodiment
00 functions as a relief valve that releases the high-pressure oil to the port 11 when the oil pressure in the port 12 becomes high.

4) When the pressure oil flows from the port 12 to the port 11 by the handle 90 By manually rotating the handle 90, the shaft portion 90a
Moves linearly, and the shaft end 90b pushes the shaft end 52c.

Shaft tip 52c by shaft tip 90b
When the force pushing the spring becomes larger than the spring force of the spring 31, the shaft 52 becomes integral with the poppet 22 and the spring 3 moves.
Move in the direction opposite to 1.

Therefore, the valve seat of the poppet 22 is the poppet 2
1 is separated from the valve seat contact surface (seat surface), and the variable throttle S2
Opens. For this reason, the pressure oil in the port 12 passes through the passage 21a,
The oil passes through the oil chamber 41 and the variable throttle S2 and flows into the port 11. At this time, the oil pressure in the oil chamber 41 is reduced from the oil pressure p12 of the port 12 by passing through the passage 21a functioning as a "throttle". The oil pressure in the oil chamber 41 is an intermediate oil pressure between the oil pressure p12 of the port 12 and the oil pressure p11 of the port 11.

By reducing the hydraulic pressure in the oil chamber 41, the force acting on the poppet 21 in the right direction in the figure in accordance with the hydraulic pressure in the oil chamber 41 is reduced. Therefore, the valve seat of the poppet 21 separates from the valve seat contact surface (seat surface) of the block 60, and the variable throttle S1 opens. Therefore port 1
The second pressure oil passes through the variable throttle S1 and flows into the port 11. In this manner, the pressure oil in the port 12 can be freely guided to the port 11 by using the variable throttle S1 as a main bypass passage. Operation amount of the handle 90, that is, the shaft portion 9
The movement amount of the shaft 52, that is, the movement amount of the poppet 22 can be controlled according to the displacement amount of 0a, and the flow rate of the pressure oil from the port 12 to the port 11 can be changed according to the movement amount.

According to the embodiment described above, the force for moving the poppet 22 by the handle 90 is the spring 31.
It is determined only by the spring force of, and is constant without being affected by the magnitude of hydraulic pressure. Therefore, the controllability is good because the disturbance force in the left and right directions of the poppet due to the difference in pressure receiving area is not generated due to the fluctuation of the hydraulic pressure. Further, unlike the spring 32, the spring 31 does not determine the relief pressure (the above formulas (1) and (2)), but may generate a small spring force such that the poppet 22 is pressed against the poppet 21. Can be used. Therefore, handle 9
The force to operate 0 is small and the operability is improved. An actuator may be used instead of the handle 90. In this case, a small actuator that can generate a small force that overcomes the spring force of the small spring 31 can be used. Can be realized and the cost can be reduced. Specifically, the actuator 83, which will be described later with reference to FIGS. 5 and 6, can be downsized and the cost thereof can be reduced.

According to the present embodiment, the poppet 22 is provided inside the poppet 21 and the poppet 23 is provided inside the poppet 22 so that the head of the poppet 23 is formed so as to have a pressure receiving area difference. The function as a check valve and the function as a relief valve are realized. For this reason, the space is extremely small and the number of parts can be reduced. Specifically, the product area of the block 60 can be reduced by the amount shown by the broken line 186 of the conventional technique shown in FIG. 8, and the oil passage 87 and the like in the block can be omitted. As described above, according to this embodiment, the hydraulic device and the hydraulic circuit can be made compact while having the function as a check valve and the function as a relief valve, and the cost can be reduced with a simple structure.

The following various modifications can be made to the first embodiment described above. Hereinafter, each modified example of the first embodiment will be described while the same components as those of the first embodiment are denoted by the same reference numerals and the description thereof is appropriately omitted.

Second Embodiment In the first embodiment described above, the shaft 5 of the control valve 100 is used.
2 is operated by the handle 90, the shaft 52 of the control valve 100 may be driven by an actuator.

FIG. 3A shows a hydraulic circuit of the second embodiment.

As shown in FIG. 3 (a), the apparatus of the present embodiment is roughly the same as the control valve 100 shown in FIGS.
And a spool 92 as a flow control valve and a directional control valve 8
It is composed of 0 and 0. In this embodiment, port 12
Communicate with the hydraulic actuator 84. An oil chamber A1 corresponding to the port 11 in FIG. 1 is formed in the block 60. A tank port T is formed in the block 60, and the tank port T communicates with the tank 99. A pump port P is formed in the block 60, and the pump port P communicates with the discharge port of the pump 98. A port 13 is formed in the block 60, and the port 13 communicates with the pump port P. A port 14 is formed in the block 60, and the port 14 communicates with the tank port T.

A spool 92 is slidably accommodated in the block 60. The spool 92 constitutes an external force applying means for applying an external force to the poppet 22 via the shaft 52 in a direction opposite to the spring force of the spring 31 to open the variable diaphragm S2. This spool 9
2 is the poppet 22 along the longitudinal direction of the poppet 22.
It is arranged coaxially with.

A pilot spool (shaft) 91 is accommodated inside the spool 92 so as to be movable relative to the spool 92 via springs 96 and 97.

A stop shaft 93 is fixed to the block 60. A pilot spool 91 is fixed to the stop shaft 93.

Inside the spool 92, the pilot spool 91 defines pressure receiving chambers α1 and α2 on the left and right in the figure. A port P1 and a port P2 are formed in the block 60, and a pilot pressure is input from the outside via the port P1 and the port P2. Port P1, Port P2
When the pilot pressure is input from the outside via the, the pilot pressure is supplied to the pressure receiving chambers α1 and α2 via the oil passage in the block 60 and the oil passage formed in the spool 92, respectively.

When the pilot pressure in the pressure receiving chamber α1 on the left side in the figure acts on the spool 92, the spool 92 is pushed leftward in the figure in opposition to the spring force of the spring 96. Similarly, when the pilot pressure in the pressure receiving chamber α2 on the right side of the drawing acts on the spool 92, the spool 92 opposes the spring force of the spring 97,
Is pushed to the right in the figure.

The pilot spool 91 is formed with an in-spool passage 92a whose both ends communicate with each other. Both ends of the spool inner passage 92a communicate with the oil chambers A1 and A2 at both ends of the spool 92, respectively. Therefore, the oil chambers A1 and A2 on the left and right sides of the spool 92 are held at the same pressure.

The chamber A1 communicates with the tank port T via a variable throttle 94. The chamber A2 communicates with the pump port P via the variable throttle 95.

The directional control valve 80 has the above-mentioned ports P1 and P.
2, connected to ports 13 and 14.

The directional control valve 80 is an electromagnetic solenoid 80a.
The valve position changes in response to the electric signal applied to the port, and the pressure oil supply direction is switched to the port P1 or port P2.
The pilot pressure is input to and the pilot pressure is supplied to either one of the pressure receiving chambers α1 and α2.

Next, the operation of FIG. 3A will be described.

When the directional control valve 80 is located at the neutral position When the directional control valve 80 is located at the neutral position, the ports P1 and P2 are shut off, and the insides of the pressure receiving chambers α1 and α2 are It becomes the same pressure. At this time, the left and right springs 96 and 97 do not expand and contract, and the spool 92 is held at the neutral position.

When the directional control valve 80 moves from the neutral position (when the directional control valve 80 is located at the left valve position in the figure), when the directional control valve 80 is located at the left valve position in the figure,
The discharge pressure of the hydraulic pump 98 is the pump port P, port 13
Is input to the directional control valve 80 via. Then, the pilot pressure is supplied from the direction control valve 80 to the port P1. The tank 99 communicates with the port P2 via the tank port T, the port 14, and the direction control valve 80.

Therefore, when the pilot pressure in the pressure receiving chamber α2 becomes larger than the pilot pressure in the pressure receiving chamber α1, that is, when there is a difference in pilot pressure, the right spring 97 expands and the left spring 96 contracts. Spool 92
Moves to the right relative to the pilot spool 91.

Here, the shape of the spool 92 is designed so that the variable diaphragm 94 is closed first, and then the variable diaphragm 95 is opened when the spool 92 is further moved to the right after the variable diaphragm 94 is completely closed.

Therefore, the pressure oil supplied from the pump port P flows into the A2 chamber, further flows into the A1 chamber through the in-spool passage 92a, and rises to the same pressure at both ends of the spool 92.

The operation after the pressure in the A1 chamber rises is the same as the operation in 2) of the first embodiment described above. That is, when the oil pressure in the A1 chamber rises, the poppet 21 is pushed leftward in the figure, the variable throttle S1 opens, and the pressure oil in A1 flows into the port 12. Thereby, the pressure oil discharged from the pump 98 can be supplied to the hydraulic actuator 84. (When the directional control valve 80 is located at the valve position on the right side in the figure) When the directional control valve 80 is located at the valve position on the right side in the figure,
The discharge pressure of the hydraulic pump 98 is the pump port P, port 13
Is input to the directional control valve 80 via. Then, the pilot pressure is supplied from the direction control valve 80 to the port P2. The tank 99 communicates with the port P1 via the tank port T, the port 14, and the direction control valve 80.

Therefore, the pilot pressure in the pressure receiving chamber α1 becomes larger than the pilot pressure in the pressure receiving chamber α2, the left side spring 96 expands and the right side spring 97 retracts.
The spool 92 moves to the left relative to the pilot spool 91.

Here, the shape of the spool 92 is designed so that the variable diaphragm 95 is first closed and the variable diaphragm 94 is opened when the spool 92 is moved to the left.

Therefore, the pressure oil supplied from the pump port P does not flow into the A1 and A2 chambers, but the pressure oil inside the A2 and A1 chambers is discharged to the tank port T, and the pressure inside the A2 and A1 chambers becomes low. Become.

The operation after the spool 92 has moved to the left and the pressure in the A1 chamber has become low is the same as the operation in 4) of the first embodiment described above.

That is, when the force for pushing the shaft tip 52c by the spool 92 becomes larger than the spring force of the spring 31, the poppet 22 is pushed to the left in the figure, and the variable aperture S2 is opened, and accordingly the poppet 22 is opened. 21 moves to the left side in the figure, and the variable diaphragm S1 opens. Therefore, port 12
Pressure oil flows into the A1 chamber. As a result, the pressure oil of the hydraulic actuator 84 can be discharged to the tank 99.

According to the second embodiment, the spool 92
Are arranged coaxially with the poppet 22 along the longitudinal direction of the poppet 22, so that the block 60 can be made smaller in the width direction.

Third Embodiment Instead of the directional control valve 80 shown in FIG. 3 (a), FIG. 3 (b) is used.
The pressure control valves 81 and 82 shown in FIG.

As shown in FIG. 3B, pressure control valves 81 and 82 are provided for each pressure receiving chamber α1 and α2 of the spool 92. The pressure control valves 81 and 82 change their valve positions according to the electric signals applied to the electromagnetic solenoids 81a and 82a, respectively, to turn on / off the communication with the pump port P.

When the pressure control valve 81 is in a position where it communicates with the pump port P and the pressure control valve 82 is in a position where it blocks communication with the pump port P, pressure oil is supplied to the pressure receiving chamber α1 through the port P2. It When the pressure control valve 82 reaches a position communicating with the pump port P and the pressure control valve 81 reaches a position blocking communication with the pump port P, pressure oil is supplied to the pressure receiving chamber α2 via the port P1.

Fourth Embodiment In the second and third embodiments, the spool 92 is moved according to the pilot pressure, but as shown in FIG. 4, the spool 92 is moved according to the force applied from the actuator 83. 97 may be moved.

FIG. 4 shows the configuration of the fourth embodiment.

In the fourth embodiment, a spool 97 is provided instead of the spool 92 of FIG. 3 (a). Like the spool 92, the spool 97 opens and closes the variable diaphragms 94 and 95 according to the moving position. Inside the spool 97, an in-spool passage 97a communicating with the A1 and A2 chambers at both ends of the spool 97 is formed. Spool 97 is rod 84
It is connected to the mover 83b of the actuator 83 via.

The actuator 83 is an electromagnetic proportional solenoid. When an electric command is input, the coil is energized and the mover 83b moves. Therefore, the spool 97 connected to the rod 84 moves to a position according to the electric command.

The spool 97 and the actuator 83 are arranged coaxially with the poppet 22 along the longitudinal direction of the poppet 22.

When the spool 97 moves to the right side in the figure, the variable diaphragm 94 is closed and the variable diaphragm 95 is opened.

Therefore, the pressure oil supplied from the pump port P flows into the A2 chamber, further flows into the A1 chamber through the in-spool passage 97a, and rises to the same pressure at both ends of the spool 97.

The operation after the pressure in the A1 chamber rises is the same as the operation in 2) of the first embodiment described above. That is, when the oil pressure in the A1 chamber rises, the poppet 21 is pushed leftward in the figure, the variable throttle S1 opens, and the pressure oil in A1 flows into the port 12. Thereby, the pressure oil discharged from the pump 98 can be supplied to the hydraulic actuator 84.

When the spool 97 moves to the left side in the figure, the variable diaphragm 95 is closed and the variable diaphragm 94 is opened.

Therefore, the pressure oil supplied from the pump port P does not flow into the A1 and A2 chambers, but the pressure oil in the A2 and A1 chambers is discharged to the tank port T, and the A2 and A1 chambers have a low pressure. Become.

The operation after the spool 97 moves to the left and the pressure in the A1 chamber becomes low is similar to the operation of 4) of the first embodiment described above.

That is, when the force for pushing the shaft tip 52c by the spool 97 becomes larger than the spring force of the spring 31, the poppet 22 is pushed to the left in the drawing and the variable aperture S2 is opened, and accordingly the poppet 22 is opened. 21 moves to the left side in the figure, and the variable diaphragm S1 opens. Therefore, port 12
Pressure oil flows into the A1 chamber. As a result, the pressure oil of the hydraulic actuator 84 can be discharged to the tank 99.

According to the fourth embodiment, since the spool 97 and the actuator 83 are arranged coaxially with the poppet 22 along the longitudinal direction of the poppet 22, the block 60 has a small area in the width direction. can do.

Although the actuator 83 uses an electrically driven actuator, an actuator driven according to hydraulic pressure may be used.

Fifth Embodiment In the first embodiment shown in FIG. 1, the shaft 52 is moved by the operation of the handle 90. However, as shown in FIG. 5, even if the shaft 52 is moved by the actuator 83, Good.

FIG. 5 shows a fifth embodiment. In this embodiment, the actuator 83 similar to that shown in FIG.
Are using. The mover 83b of the actuator 83 is connected to the rod 83c. The actuator 83 is
The rod 83c is arranged at a position where it can come into contact with the tip 52c of the shaft 52 as the mover 83b moves.
That is, the rod 83c (moving element 83b) is arranged on the right side of the control valve 100 in the figure so that its longitudinal direction is coaxial with the shaft 52. In this embodiment, the rod 83
c and the shaft 52 are separated, but the rod 83c
And the shaft 52 may be connected.

When an electric command is input to the actuator 83, the rod 83c moves to a position corresponding to the electric command. The operation after the rod 83c moves is the same as the operation after the shaft portion 90a of the handle 90 moves in FIG. 1, and thus the description thereof will be omitted.

According to the fifth embodiment, the actuator 83 is moved along the longitudinal direction of the poppet 22.
Since it is arranged on the same axis as 2, the field product of the block 60 in the width direction can be reduced.

Although the actuator 83 uses an electrically driven actuator, an actuator driven according to hydraulic pressure may be used.

Sixth Embodiment In FIG. 5, the actuator 83 is arranged on the right side of the control valve 100 in the figure, but as shown in FIG.
3 may be arranged on the left side of the control valve 100 in the drawing.

In this case, the moving element 83 of the actuator 83
The rod 83c connected to b is connected to the shaft 52 at the rear end 52d.

When an electric command is input to the actuator 83, the rod 83c moves to a position corresponding to the electric command. As the rod 83c moves, the shaft 52 is pulled to the left side in the figure. The variable diaphragm S2 opens by pulling the shaft 52 to the left side in the figure.

According to the sixth embodiment, the actuator 83 is arranged along the longitudinal direction of the poppet 22.
Since it is arranged on the same axis as 2, the field product of the block 60 in the width direction can be reduced.

Although the actuator 83 uses an electrically driven actuator, an actuator driven according to hydraulic pressure may be used.

Seventh Embodiment In the first embodiment shown in FIG. 1, the poppets 21, 22,
Although the control valve 100 is configured by the triple structure of 23,
As shown in FIG. 7, the control valve 100 may be configured by a double structure of the poppets 22 and 23.

The control valve 100 of this embodiment is roughly
The block 60 includes a poppet 22 housed in the block 60, a poppet 23 housed inside the poppet 22, and a shaft 52 integrally formed with the poppet 23. As the handle 90, the actuator 83, the spools 92, 98, and the like that apply a force to the shaft 52 from the outside, the same ones as in the above-described first to sixth embodiments can be used.

In block 60, port 11 and port 12
Are formed. The port 12 communicates with a hydraulic actuator (hydraulic cylinder) 84 (not shown) as in FIG.

The control valve 100 has ports 11 to 1
The function as a check valve that allows the flow of pressure oil to the hydraulic actuator 84 via 2 and the pressure oil of the hydraulic actuator 84 via the port 12 when the hydraulic pressure in the hydraulic actuator 84 becomes equal to or higher than the set relief pressure. It has a function as a relief valve that leads to the port 11.

The poppet 22 is slidably accommodated in the block 60. The poppet 22 has an opening 22b penetrating the inside and the outside thereof along the longitudinal direction.

Inside the poppet 22, a poppet 23 is provided so that it can be seated in the opening 22b. Therefore, an oil chamber 42 defined by the poppet 23 is formed inside the poppet 22.

The poppet 22 is formed with an opening 22b penetrating the inside and the outside thereof along the longitudinal direction.

The poppet 22 is formed with a passage 22a for communicating the port 12 with the oil chamber 42 inside the poppet 22. Therefore, the hydraulic pressure in the oil chamber 42 becomes the same as the hydraulic pressure in the port 12.

The valve seat and the block 60 on the head of the poppet 22
The valve seat abutment surface forms a variable throttle S2 between the port 11 and the port 12. The opening area (diaphragm diameter) of the variable diaphragm S2 changes according to the moving position of the poppet 22. When the valve seat of the head of the poppet 22 contacts the valve seat contact surface of the block 60, the opening of the variable throttle S2 is closed and the communication between the port 11 and the port 12 is cut off. When the valve seat of the head of the poppet 22 separates from the valve seat contact surface of the block 60, the variable throttle S2 opens and the port 1
1 communicates with the port 12.

The valve seat on the head of the poppet 23 and the valve seat abutting surface of the poppet 22 form a variable throttle S3 between the port 11 and the oil chamber 42. Variable aperture S3
The opening area (diaphragm diameter) varies depending on the relative movement position of the poppet 23 with respect to the poppet 22. When the valve seat of the head of the poppet 23 contacts the valve seat contact surface of the poppet 22,
The opening of the variable diaphragm S3 is closed, and the port 11 and the oil chamber 42 are
Communication with and is cut off. The oil chamber 42 communicates with the port 12 via the passage 22a. Therefore, the communication between the port 11 and the port 12 is cut off. When the valve seat on the head of the poppet 23 separates from the valve seat contact surface of the poppet 22, the variable throttle S3 opens and the port 11 communicates with the port 12 via the oil chamber 42 and the passage 22a.

A shaft 52 integral with the poppet 23 is inserted through the opening 22b of the poppet 22. The poppet 23 moves integrally with the shaft 52 according to the force applied to the shaft 52. One end of a spring 32 is in contact with the poppet 23 so that the valve seat of the head of the poppet 23 applies a spring force in the direction of closing the opening of the variable throttle S3. The other end of the spring 32 is in contact with the inner wall surface of the block 60. The poppet 23 is slidably provided on the block 60. Therefore, at the rear end 23d of the poppet 23, an oil chamber 43 defined by the poppet 23 and the inner wall of the block 60 is formed.

An internal passage 23a is formed along the longitudinal direction of the poppet 23. This passage 23a is port 11
And the oil chamber 43 at the rear end 23d of the poppet.

As described above, since the oil chamber 43 communicates with the port 11 via the passage 23a, the pressure of the oil chamber 43 becomes the same as that of the port 11.

The head of the poppet 23 is formed in the same manner as described with reference to FIG.

That is, of the pressure receiving surfaces of the left and right ends of the poppet 23 in the drawing, the pressure receiving area of the right end face of the port 11 which receives the hydraulic pressure in the left direction in the drawing is Sa, and the hydraulic pressure in the oil chamber 43 in the right direction in the drawing is received. The pressure receiving area of the left end face is Sb. Where S
b-Sa> 0 so that there is a pressure receiving area difference, poppet 23
Forming the head of.

When this is seen in the oil chamber 42, the poppet 23
Of the pressure receiving surfaces at the left and right ends of the head of the
If the pressure receiving area at the right end of the head that receives the hydraulic pressure in 2 is SA, and the pressure receiving area at the left end of the head that receives the hydraulic pressure in the oil chamber 42 in the right direction in the drawing is SB, the pressure receiving areas at the left and right ends of these heads are shown. The difference SA-SB is the pressure receiving area difference S at the left and right ends of the poppet described above.
It becomes equal to b-Sa (> 0). That is, a force corresponding to the pressure receiving area difference SA-SB is applied to the head of the poppet 23 in the direction opposite to the spring force of the spring 32.

Next, the operation of FIG. 7 will be described.

Operation as Check Valve 1) When the oil pressure p12 of the port 12 is higher than the oil pressure p11 of the port 11 and the oil pressure p12 of the port 12 is lower than the set relief pressure, the oil pressure in the oil chamber 43 is as described above. It has the same pressure as the hydraulic pressure of the port 11. Therefore, forces corresponding to the pressure receiving areas Sb and Sa are applied to the left and right ends of the poppet 23 in the figure, respectively. In other words, the pressure receiving area difference Sb is at both ends of the poppet 23.
A force Fb obtained by multiplying -Sa by the hydraulic pressure of the port 11 is applied in the right direction in the figure, that is, in the direction to close the variable throttle S3.

The oil pressure in the oil chamber 42 is the same as the oil pressure in the port 12. Therefore, a force Fa obtained by multiplying the pressure receiving area difference SA-SB (or Sb-Sa) by the hydraulic pressure p12 of the port 12 is applied to the head of the poppet 23 in the left direction in the figure, that is, in the direction of opening the variable throttle S3. Has been.

The spring force Fs of the spring 32 is applied to the poppet 23 in the right direction in the figure, that is, in the direction to close the variable diaphragm S3.

Therefore, the force Fp represented by the following equation acts on the poppet 23 in total.

Fp = Fs + Fb−Fa (1) Fa = (SA−SB) · p12 (2) As shown in the above equation, when the hydraulic pressure p12 of the port 12 is small, the force Fa becomes small and Fp> 0. Has been established. Therefore, this force Fp causes the valve seat of the poppet 23 to move to the poppet 22.
Is pressed against the valve seat contact surface (seat surface). Therefore, the aperture of the variable diaphragm S3 is closed.

Next, the force acting on the poppet 22 will be described.

The hydraulic pressure p11 of the port 11 acts on most of the pressure receiving area Sd at the right end of the poppet 22 in the figure, and the hydraulic pressure p12 of the port 12 acts on the remaining pressure receiving area (Sc-Sd).
Works. Also, the pressure receiving area S at the left end of the poppet 22 in the figure
The hydraulic pressure p12 of the port 12 (oil chamber 42) acts on c. Now the hydraulic pressure p12 of port 12 is the hydraulic pressure p11 of port 11.
Is higher than. Therefore, the hydraulic pressure p12 of the port 12
The valve seat of the poppet 22 is pressed against the valve seat abutment surface (seat surface) of the block 60 by a force proportional to, and the opening of the variable throttle S2 is closed. As a result, the flow of the pressure oil from the port 12 to the port 11 is blocked, and the leakage of the pressure oil from the hydraulic actuator 84 is prevented.

2) When the oil pressure p11 of the port 11 becomes higher than the oil pressure p12 of the port 12, when the oil pressure p11 of the port 11 rises and the oil pressure of the port 11 is received by the pressure receiving area Sd of the poppet 22 at the right end in the figure, The poppet 22 (and the poppet 23) pushed rightward in the figure can be pushed leftward in the figure by the oil pressure p12 of the oil chamber 42 and the port 12. Therefore, the valve seat of the poppet 22 is blocked by the block 6 with a force proportional to the hydraulic pressure p11 of the port 11.
0 from the valve seat abutment surface (seat surface), the variable throttle S2
Opens. For this reason, the pressure oil in the port 11 changes the variable throttle S2.
To flow into the port 12, and the pressure oil is supplied to the hydraulic actuator 84.

As described in 1) and 2) above, the control valve 100 of the embodiment functions as a check valve that allows the flow of pressure oil only from the port 11 to the port 12.

Operation as Relief Valve 3) When the oil pressure p12 of the port 12 is higher than the oil pressure p11 of the port 11 and the oil pressure p12 of the port 12 is larger than the set relief pressure As described above, the poppet 23 has a total of The force Fp expressed by the following equation is acting.

Fp = Fs + Fb−Fa (1) Fa = (SA−SB) · p12 (2) When the hydraulic pressure p11 of the port 11 is sufficiently smaller than the hydraulic pressure p12 of the port 12, the above (1) is used. Force Fb in the formula
Can be ignored. Therefore, the relief pressure can be set according to the spring force Fs of the spring 32.

Therefore, when the hydraulic pressure p12 of the port 12 becomes large due to an excessive load applied to the hydraulic actuator 84 and exceeds the set relief pressure, that is, the force Fa is the spring force Fb.
When it becomes larger than that, Fp <0, the valve seat of the poppet 23 is separated from the valve seat contact surface (seat surface) of the poppet 22, and the variable throttle S3 is opened. Therefore, the pressure oil in the port 12 flows into the port 11 through the passage 22a, the oil chamber 42 and the variable throttle S3. At this time, the oil pressure in the oil chamber 42 passes through the passage 22a that functions as a "throttle",
The pressure is reduced from the hydraulic pressure p12 of the port 12. The hydraulic pressure in the oil chamber 42 is an intermediate hydraulic pressure between the hydraulic pressure p12 of the port 12 and the hydraulic pressure p11 of the port 11.

By reducing the hydraulic pressure in the oil chamber 42, the force acting on the poppet 22 in the right direction in the figure in accordance with the hydraulic pressure is reduced. Therefore, the valve seat of the poppet 22 separates from the valve seat contact surface (seat surface) of the block 60, and the variable throttle S2 opens. Therefore, the pressure oil in the port 12 passes through the variable throttle S2 and flows into the port 11. In this way, the high pressure oil in the port 12 can be released to the port 11 by using the variable throttle S2 as a main bypass passage. Thereby, the hydraulic pressure of the port 12 can be lowered.

With the movement of the poppet 23, the oil chamber 43
The pressure oil inside passes through the internal passage 23a and is guided to the port 11.

As shown in the above 3), the control valve 1 of the embodiment
00 functions as a relief valve that releases the high-pressure oil to the port 11 when the oil pressure in the port 12 becomes high.

4) When the pressure oil is made to flow from the port 12 to the port 11 by the force applied from the outside, the shaft tip 52c is pushed by the force applied from the outside.

When the force for pushing the shaft tip 52c becomes larger than the force Fp defined by the above equation (1), that is, the force substantially equal to the spring force of the spring 32, the shaft 52 becomes integral with the poppet 23 and the spring 32 is integrated. Move in the direction opposite to.

Therefore, the valve seat of the poppet 23 is the poppet 2
The variable throttle S3 is separated from the valve seat contact surface (seat surface) of No.2.
Opens. For this reason, the pressure oil in the port 12 passes through the passage 22a,
It passes through the oil chamber 42 and the variable throttle S3 and flows into the port 11. At this time, the oil pressure in the oil chamber 42 is reduced from the oil pressure p12 of the port 12 by passing through the passage 22a which functions as a "throttle". The hydraulic pressure in the oil chamber 42 is an intermediate hydraulic pressure between the hydraulic pressure p12 of the port 12 and the hydraulic pressure p11 of the port 11.

By reducing the hydraulic pressure in the oil chamber 42, the force acting on the poppet 22 in the right direction in the drawing in accordance with the hydraulic pressure in the oil chamber 42 decreases. Therefore, the valve seat of the poppet 22 separates from the valve seat contact surface (seat surface) of the block 60, and the variable throttle S2 opens. Therefore port 1
The second pressure oil passes through the variable throttle S2 and flows into the port 11. In this way, the variable throttle S2 can be used as the main bypass passage to freely guide the pressure oil of the port 12 to the port 11. The flow rate of the pressure oil from the port 12 to the port 11 can be changed according to the movement amount of the shaft 52, that is, the movement amount of the poppet 23.

According to the seventh embodiment described above, the structure of providing the poppet 23 inside the poppet 22 is formed so that the head of the poppet 23 is formed so as to have a pressure receiving area difference. Since the function as a relief valve is realized, the space is extremely small and the number of parts can be reduced. Specifically, the product area of the block 60 can be reduced by the amount shown by the broken line 186 of the conventional technique shown in FIG. 8, and the oil passage 87 and the like in the block can be omitted. As described above, according to this embodiment, the hydraulic device and the hydraulic circuit can be made compact while having the function as a check valve and the function as a relief valve, and the cost can be reduced with a simple structure.

In the embodiment described above, it is assumed that the ports 11 and 12 of the control valve 100 are connected to the hydraulic actuator 84 such as a hydraulic cylinder, the tank 99, and the pump 98. However, the hydraulic equipment connected to the ports 11 and 12 is arbitrary.

In the embodiment, oil is assumed as the working fluid, and it is assumed that it is driven by hydraulic pressure. However, in addition to oil, various liquids such as water and glycol are used as the working fluid in the present invention. A structure driven by pressure may be adopted.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment.

2 (a) and 2 (b) are views showing a part of FIG.

FIG. 3 (a) is a diagram showing a configuration of a second embodiment, and FIG. 3 (b) is a diagram showing a configuration of a part of the third embodiment.

FIG. 4 is a diagram showing a configuration of a fourth exemplary embodiment.

FIG. 5 is a diagram showing a configuration of a fifth exemplary embodiment.

FIG. 6 is a diagram showing a configuration of a sixth exemplary embodiment.

FIG. 7 is a diagram showing a configuration of a seventh embodiment.

FIG. 8 is a diagram showing a conventional technique.

[Explanation of symbols]

11 (A1), 12 ports 21, 22, 23 poppets 31, 32 spring 41, 42 Oil chamber 52 shaft 60 blocks 80 directional control valve 83 Actuator 84 Hydraulic actuator (hydraulic cylinder) 90 handle 92, 97 spool

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3H002 BB01 BB06 BC01 BD01 BE01                 3H059 AA06 BB07 BB22 CA04 CA05                       CA12 CC02 CD05 DD05 EE01                       FF03 FF14                 3H089 AA58 BB27 DB03 DB34 DB78                       GG01

Claims (6)

[Claims] 1. When the flow of pressure fluid from the first port (11) to the second port (12) is allowed and the pressure of the second port (12) becomes equal to or higher than a set pressure, the second
In the control valve for guiding the pressure liquid from the port (12) of the first port (12) to the first port (11), the control valve is a valve having a poppet structure, and the second poppet (23) is provided inside the first poppet (22). , A chamber (42) is formed inside the first poppet (22), and a passage (22a) that connects the second port (12) and the chamber (42) inside the first poppet (22) is provided with the first poppet. (22) formed by the valve seat and the block (60) of the head of the first poppet (22), the first port (11) and the second port (1).
2) forms a first throttle (S2) between the second poppet (23) head seat and the first poppet (2)
2) forms a second throttle (S3) between the first port (11) and the second port (12), and the valve seat of the head of the second poppet (23) is the second throttle (S3). The spring (32) is applied to the second poppet (23) so that the spring force is applied in the direction of closing the opening of S3), and the pressure of the second port (12) of the head of the second poppet (23) is applied. The pressure receiving area difference (SA-SB)
The control valve is formed so that a force corresponding to is applied in a direction opposite to the spring force. 2. The second aperture (S) is applied to the second poppet (23) by applying an external force in a direction opposite to the spring force.
3. The control valve according to claim 1, further comprising external force applying means for opening 3). 3. The flow of the pressure liquid from the first port (11) to the second port (12) is allowed, and the second pressure is set when the pressure of the second port (12) exceeds a set pressure.
In the control valve for guiding the pressure liquid of the port (12) of the first poppet (21) to the first port (11), the control valve is a valve having a poppet structure, and the second poppet (22) is provided inside the first poppet (21). , A chamber (41) is formed inside the first poppet (21), a third poppet (23) is further provided inside the second poppet (22), and a chamber (4) is formed inside the second poppet (22).
2) forming the second port (12) and the first poppet (2)
Passage (21a) for communicating with the chamber (41) inside 1)
Is formed on the first poppet (21), and the first poppet (2
1) A passageway (22a) that connects the inner chamber (41) and the inner chamber (42) of the second poppet (22) is formed in the second poppet (22), and the passage of the first poppet (21) head is formed. The valve seat and the block (60) enable the first port (11) and the second port (1).
2) forms a first throttle (S1) between the second poppet (22) head seat and the first poppet (2)
1) forms a second throttle (S2) between the first port (11) and the second port (12), and the valve seat of the head of the third poppet (23) and the second poppet ( Two
2) forms a third throttle (S3) between the first port (11) and the second port (12), and the valve seat of the head of the second poppet (22) is the second throttle (S3). First, so that the spring force is applied in the direction of closing the opening of S2).
The spring (31) is applied to the second poppet (22) so that the spring force is applied in the direction in which the valve seat of the head of the third poppet (23) closes the opening of the third throttle (S3).
The spring (32) is applied to the third poppet (23), and the portion of the head of the third poppet (23) on which the hydraulic pressure of the second port (12) acts is the pressure receiving area difference (SA-SB). )
A force corresponding to the spring force of the second spring (32) is applied in a direction opposite to the spring force of the second spring (32), and the spring force of the first spring (31) is opposed to the second poppet (22). To the second diaphragm (S
External force applying means (90, 92, 98, 8) for opening 2)
A control valve characterized in that 3) is provided. 4. The external force applying means (90, 92, 9)
The control valve according to claim 3, wherein the second and third poppets (8, 83) are arranged substantially coaxially with the second poppet (22) along a longitudinal direction of the second poppet (22). 5. A second port (12) communicating with the hydraulic actuator (84) from the first port (A1).
When the pressure of the hydraulic actuator (84) becomes equal to or higher than a set pressure, the pressure liquid of the hydraulic actuator (84) is allowed to flow to the second port (12) via the second port (12). In the hydraulic control device for leading to the first port (A1), the second poppet (22) is provided inside the first poppet (21), and the chamber (41) is formed inside the first poppet (21). A third poppet (23) is provided inside the second poppet (22), and a chamber (4) is provided inside the second poppet (22).
2) is formed in the control valve (100) having a poppet structure, and the passage (21a) for communicating the second port (12) with the chamber (41) inside the first poppet (21) is provided with the first poppet (21). ), The chamber (4) inside the first poppet (21)
The second poppet (22) is formed with a passage (22a) for communicating the chamber (42) inside the first poppet (22) with the valve seat and the block (60) of the head of the first poppet (21). ), The first port (A1) and the second port (1
2) forms a first throttle (S1) between the second poppet (22) head seat and the first poppet (2)
1) forms a second throttle (S2) between the first port (A1) and the second port (12), and the valve seat of the head of the third poppet (23) and the second poppet ( Two
2) forms a third throttle (S3) between the first port (A1) and the second port (12), and the valve seat of the head of the second poppet (22) is the second throttle (S3). First, so that the spring force is applied in the direction of closing the opening of S2).
The spring (31) is applied to the second poppet (22) so that the spring force is applied in the direction in which the valve seat of the head of the third poppet (23) closes the opening of the third throttle (S3).
The spring (32) is applied to the third poppet (23), and the portion of the head of the third poppet (23) on which the hydraulic pressure of the second port (12) acts is the pressure receiving area difference (SA-SB). )
A force corresponding to the spring force of the second spring (32) is applied in a direction opposite to the spring force of the second spring (32), and the spring force of the first spring (31) is opposed to the second poppet (22). To the second diaphragm (S
External force applying means (90, 92, 98, 8) for opening 2)
3) A hydraulic control device characterized by being provided. 6. A discharge port or a tank (9) of a hydraulic pump (98) selectively to the first port (A1).
The fluid pressure control device according to claim 5, further comprising a directional control valve (80) for communicating the (9).