JPH01307576A - Liquid pressure control valve - Google Patents

Abstract

PURPOSE:To obtain a new liquid pressure control valve by providing the spool of a counter-balance valve with the function as a check valve. CONSTITUTION:When fluid is carried into a primary pressure port 22 through a main pipe passage 46, part of said fluid passes through a communication passage 39 and goes into a primary pressure chamber 31 to act on the spool 30. At the same time, the other part of said fluid is carried via an orifice 41 into a pressure balance chamber 32 from a communication passage 40, however, the liquid pressure inside said balance chamber is released via a one-way passage 42. The spool 30 slides toward a balance chamber against the load of a spring 33 so that the primary pressure port 22 is communicated with a primary discharge port 26. The fluid is discharged from the discharge port 26 sequentially to operate an actuator. Return fluid is carried back into a tank via a secondary discharge port 27 and a secondary pressure port 23.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a hydraulic control valve that is mainly used as a counterbalance valve, and more specifically, to a hydraulic control valve that is installed in a circuit of a hydraulic device such as hydraulic pressure, and is used as an actuator. This relates to a hydraulic control valve that is used to generate a constant pressure on the return side of a liquid to prevent its own weight from falling and to make the flow in the opposite direction a free flow.

<Prior Art> A conventional counterbalance valve is generally constructed as shown in FIG. This technology will be explained below with reference to FIG. 6. ■ is a housing, and the housing 1 houses a normally closed main counterbalance in which a piston 4 is housed in a cylinder 3 so as to be slidable in the axial direction. A valve 2 and a check valve 5 are built in, and 6 is a sling that presses the piston 4 toward the closing side, 7 is a pressure port, 8 is a discharge port, 9 is an internal drain, and 10 is an external pressure introduction passage. .

A conventional counterbalance valve is constructed as described above and is generally used by being installed in a hydraulic circuit as shown in FIG. 7. In FIG. 7, reference numeral 11 indicates a directional control valve;
3 is a main pipe, 14 is a branch passage, and 15 is an actuator such as a motor.

Therefore, when the pump P is driven and the switching valve 11 is switched to the A side, pressure oil is supplied to the actuator 15 through the main pipe, operates the actuator 15, and passes through the main pipe 13 to the pressure port of the counterbalance valve. Enter 7.

On the other hand, the pressure oil in the main pipe 12 branches at the branch passage 14, and a part of it is introduced into the introduction passage 10 through the passage 14.
When this pressure reaches a set value, the piston 4 is pressed against the spring and the piston slides, so that the discharge port 8 is opened and communicated with the pressure port 7.

Therefore, the return oil returns to the tank T from the main pipe 13 through the pressure port 7 and the discharge port 8 as shown by the solid line arrow in FIG.

Next, when the switching valve 11 is switched to the B side, the pressure oil is transferred to the main pipe 13.
The oil flows freely through the check valve 5 and is supplied to and actuates the actuator 15, with return oil returning through the main line 12 to the tank.

According to the above, when the switching valve 11 is in the A side position, a constant pressure is generated on the return side of the actuator 15, thereby preventing the dead weight from falling, and when the switching valve 11 is in the B side position, the check valve is activated. It will flow freely through.

<Problems to be Solved by the Invention> As described above, the conventional technology has a main counterbalance valve and a check valve built into the housing, but it is difficult to arrange the check valve in a limited space. has the problem of requiring time and effort in manufacturing.

The present invention has been made in view of the above points, and one of the objects of the present invention is to provide a check valve without providing a check valve.
The object of the present invention is to provide a completely new type of hydraulic control valve that functions well as a counterbalance valve.

Another object of the present invention is to provide a hydraulic control valve that can be simplified in structure and therefore easy to manufacture.

<Means for Solving the Problems> The structure of the present invention for achieving the above object will be explained using FIGS. 1 to 4, which correspond to embodiments.
(A) A housing 21 in which a first pressure port 22 and a second pressure port 23 are formed, (B) A first cylinder 24 formed in the housing 21 connected to the first pressure port 22, (C) A first cylinder (d) a second cylinder 25 formed in the housing 21 and connected in series with the first cylinder 24;
1 and the first cylinder 24 is formed in the first cylinder 24.
A first discharge port 26 configured to communicate with the pressure port 22; 2nd discharge port 27
(f) A first pressure chamber 31 is housed in the first cylinder 24 so as to be slidable in the axial direction, and a first pressure chamber 31 is provided at the end of the first cylinder 24 on the second cylinder 25 side, and a first pressure chamber 31 is provided on the opposite end. is configured to form a pressure balance chamber 32, and is pressed toward the second cylinder 25 by a spring 33 provided in the pressure balance chamber 32, and the first pressure port 22 is Always above/first cylinder 2
a spool 30 configured to open into the first cylinder 24 and communicate with the first pressure port 22 only when sliding toward the pressure balance 32 side; (g) It is connected in series with the spool 30 and is housed in the second cylinder 25 so as to be slidable in the axial direction, and a stone end portion of the second cylinder 25 opposite to the first cylinder 24 has a second stone. A piston 34 configured to form a pressure chamber 35 and pressed toward the second pressure chamber by a spring 36, (h) communicating the second pressure port 23 with the second pressure chamber 35; Communication path 37
(S) A communication passage 39 that communicates the first pressure port 22 and the first pressure chamber 31; A communication path 40 that communicates with the balance chamber 32 (L)
One-way passage 4 configured to communicate the pressure balance chamber 32 and the first discharge port 26 and allow liquid to flow only from the pressure balance chamber 32 to the first discharge port 26 side.
2. The present invention is characterized by comprising the following.

(Operation of the Invention) The present invention configured as described above operates as follows. When liquid is introduced into the first pressure port 22, a part of this liquid passes through the communication path 39 and enters the first pressure chamber 31. , the spool 30 is pressed, and at the same time, a part of the liquid is also introduced from the communication path 40 into the pressure balance chamber 32 through the orifice 41, but the pressure in the balance chamber 32 remains constant. Since it escapes through the directional passage 42, the orifice 41
A differential pressure is generated, and the spool 30 slides against the spring 33 toward the balance chamber, and the first pressure port 22 and the first discharge port 26 are communicated as shown in the third figure, so that the liquid is are sequentially discharged from the discharge port 26,
Actuator 47 (see FIG. 5) is activated. The return liquid is then transferred to the second discharge port 27 and the second pressure port 2.
3 and return to tank T (see Figure 5).

As described above, when liquid is supplied from the first pressure port side, the spool 30 functions similarly to a check valve and allows the liquid to flow freely.

Next, when liquid is introduced from the second pressure port 23, this liquid is sequentially discharged through the second discharge port 27 which is connected to the second pressure port 23 and actuates the actuator 47, but at the same time, the liquid A portion is introduced into the second pressure chamber 35 through the communication path 37, so the piston 34 is pressed. When the pressure in the second pressure chamber 35 reaches a set value or higher and overcomes the spring force of the springs 36 and 33, the piston 34 slides toward the first cylinder, and the spool 30 also slides together. , the first exhaust port 26 and the first pressure port 22 are connected as shown in the fourth figure. The return liquid therefore returns to the tank T through the first discharge port 26 and the first pressure port 22.

As described above, when liquid is supplied from the second pressure port side, the piston 34 and the spool 30 work together to function as a counterbalance valve to generate a predetermined pressure on the return side.

<Example) Embodiments of the present invention will be described below with reference to the drawings.

1 to 5 show a hydraulic pressure control valve showing one embodiment of the present invention. In these figures, 21 is a housing, and the housing 21 has a first pressure port 22 and a second pressure port 23 formed therein. 24 is the first cylinder;
A cylinder 24 is formed within the housing 21 in communication with the first pressure port 22 . 25 is the second cylinder,
The second cylinder 25 is connected in series with the first cylinder 24 and formed within the housing.

26 is the first discharge port, and the port 26 is the first cylinder 2
4 and is formed in the housing 21 so as to communicate with the first pressure port 22 via the first cylinder 24. Reference numeral 27 denotes a second exhaust port formed in the housing 21 in connection with the second pressure port 23, and the second exhaust port 27 and the second pressure port 23 are configured to form a free passage. -28 is a lid member that closes the outer end of the first cylinder 24; 29 is a lid member that closes the outer end of the second cylinder 25;
9 is fixed to the housing 21 with bolts or the like.

A spool 30 is housed in the first cylinder 24 so as to be slidable in the axial direction, and the spool 30 has a first pressure chamber 31 (see FIGS.
) is configured to form a pressure balance chamber 32 at the opposite end (lid member 28 side), and a second cylinder is formed by an opening force spring 33 provided in the pressure balance chamber 32 25 side, the first pressure port 22 is always opened into the first cylinder 24, and the first discharge port 26 is opened only when the spool 30 is slid toward the pressure balance chamber 32 side. is configured to open into the first cylinder 24 and communicate with the first pressure port 22.

Also, depending on the sliding position of the spool 30, the first discharge port 2
6 into the cylinder 24 is configured to vary.

34 is a second cylinder 2 connected in series with the spool 30.
5, the piston 34 is a piston housed in the outer end of the second cylinder 25 (the first cylinder 2
The spring 36 is configured to form a second pressure chamber 35 (see FIG. 4) at the end opposite to the spring 33, and has an appropriate spring force (stronger than the spring 33 described above). It is arranged so as to be pressed toward the second pressure chamber 35 side.

Reference numeral 37 denotes a communication passage that communicates the second pressure port 23 and the second pressure chamber 35, and a part of the liquid (hydraulic pressure) supplied to the second pressure port 23 passes through the communication passage 37 and enters the second pressure chamber 35. The piston 34 is introduced toward the first cylinder 24 by the hydraulic pressure.

38 is a needle valve, and the valve 38 is connected to the communication path 3.
It is also for adjusting the opening degree of 7. Reference numeral 39 denotes a communication path formed to communicate the first pressure port 22 and the first pressure chamber 31. A part of the liquid (hydraulic pressure) supplied to the first pressure port 22 passes through the communication path 39 and is transferred to the first pressure chamber 31. The liquid is introduced into the pressure chamber 31, and the spool 30 is moved into the pressure balance chamber 3 by the hydraulic pressure.
It is configured to be pressed toward the second side. 40 is formed to be connected to the communication path 39 via an orifice 41,
A communication path is formed to communicate the first pressure chamber 31 and the pressure balance chamber 32, and a part of the liquid (pressure) in the first pressure port 22 is introduced into the pressure balance chamber from the communication path 40 through the orifice 41. , is configured to apply the hydraulic pressure to the spool 30. As a result, the first pressure chamber 31
The pressure inside the pressure balance chamber 32 is P2, and the pressure inside the pressure balance chamber 32 is P2.
If the pressure (spring force) of the spring 33 is P'+, then P
+ −P z = P s.

Reference numeral 42 denotes a one-way passage configured to communicate the pressure balance chamber 32 and the first discharge port 26 and allow liquid to flow only from the balance chamber 32 to the first discharge port 26 side. A one-way passage is shown with a check valve 43 interposed therebetween.

The present invention is constructed as described above, and the method of use and operation thereof will now be explained.

FIG. 5 shows an example of a circuit diagram of a hydraulic device using the present invention as a counterbalance valve.
4 is a directional control valve, 45 and 46 are main pipes, and 47 is an actuator such as a motor.

Therefore, when the pump P is driven and the switching valve 44 is switched from the neutral position to the A side, the fluid is introduced into the second pressure port 23 through the main pipe 45, so this fluid is transferred to the second discharge port. 27 and actuates the actuator 47, but at the same time, a part of the fluid in the second pressure port 23 is introduced into the second pressure chamber 35 through the communication passage 37, so that it acts on the piston 34. .

When the pressure in the second pressure chamber 35 reaches the set value and overcomes the spring force of both springs 36 and 33, the piston 3
4 slides toward the first cylinder, the spool 30 also slides together, and the first discharge port 26 and the first pressure port 22 are connected (see FIG. 4). Return fluid therefore returns to tank T through first exhaust port 26 and first pressure port 22.

In this manner, when switching to the A side, the piston 34 and the spool 30 work together to function as a counterbalance valve to generate a predetermined pressure on the return side. therefore,
It is possible to prevent the product from falling due to its own weight.

Next, when the switching valve 44 is switched to the B side, the fluid flows through the main pipe 46.
A portion of this fluid is introduced into the first pressure chamber 31 through the communication passage 39 and acts on the spool 30 . At the same time, a part of the fluid is also introduced into the pressure balance chamber 32 from the communication passage 40 through the orifice 41, but the liquid pressure in the balance chamber 32 escapes through the one-way passage 42, so that the spool 30 It slides toward the balance chamber against the spring 33, and the first
The pressure port 22 and the first discharge port 26 are in communication (see FIG. 3). Therefore, fluid is sequentially discharged from the discharge port 26 and actuates the actuator 47. and,
Return fluid is supplied to the second exhaust port 27 and the second pressure port 2
3 and return to Tank T.

Thus, when switching to the B side, the spool 30 functions like a check valve in the prior art, allowing fluid to flow freely.

(Effects of the Invention) According to the present invention, the following effects can be expected.

(1) A hydraulic control valve that functions well as a counterbalance valve can be obtained.

(2) A new type of hydraulic control valve that is completely different from the conventional technology can be obtained.

(3) Since the structure is simplified, a hydraulic control valve that can be manufactured easily can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of a hydraulic control valve according to the present invention, FIG. 2 is a sectional view taken along the line 1-1 in FIG. 1, FIGS.
5 is a diagram showing an example of a circuit diagram of a hydraulic device employing the hydraulic pressure control valve of the present invention. FIG. 6 is a vertical sectional view showing a conventional counterbalance valve. The figure is a diagram showing an example of a circuit diagram of a hydraulic device that employs a conventional counterbalance valve. 21----Housing 22--First pressure port 23--
...-Second pressure port 24--First cylinder 25--
...Second cylinder 26-----First exhaust port 27---Second exhaust port 3
0...--Spool 31--First pressure chamber 32--Pressure balance chamber 33.36-
・-----1---- Spring 35--------
1.Second pressure chamber 37.39.40--Series of passages 41--1--Orifice 42--One-way passage Patent applicant Sumiyoshi Seisakusho Co., Ltd. Figure 3 5 [! ] Figure 7

Claims (1)

[Claims] (1) (A) A housing in which a first pressure port and a second pressure port are formed, (B) A first cylinder connected to the first pressure port and formed in the housing, (C) In series with the first cylinder. (d) a second cylinder formed in the housing and connected to the first cylinder; (d) a second cylinder connected to the first cylinder and configured to communicate with the first pressure port through the first cylinder; 1
a discharge port; (e) a second discharge port formed in the housing in connection with the second pressure port and forming a free passage with the second pressure port; (f) a shaft within the first cylinder; The first
The cylinder is configured to form a first pressure chamber at an end on the second cylinder side and a pressure balance chamber at the opposite end, and a spring provided in the pressure balance chamber The first pressure port is always opened in the first cylinder, and the first discharge port is opened in the first cylinder only when sliding to the pressure balance side. a spool configured to open at the opening and communicate with the first pressure port;
The second cylinder is connected in series with the spool and is slidably housed in the second cylinder in the axial direction, and is configured to form a second pressure chamber at an end of the second cylinder opposite to the first cylinder. , and a piston disposed to be pressed toward the second pressure chamber by a spring, (h) a communication passage that communicates the second pressure port with the second pressure chamber, (l) the first
a communication path that communicates the pressure port and the first pressure chamber; (v) a communication path formed by connecting the communication path via an orifice and communicates the first pressure chamber and the pressure balance chamber; (l) the above-mentioned communication path; communicating the pressure balance chamber and the first discharge port;
A one-way passage configured to allow liquid to flow only from the pressure balance chamber to the first discharge port side.