JP2563355Y2 - Flow control valve - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a flow control valve, more specifically, a free flow state for one-way flow, and a constant pressure flow control for a reverse flow. And a pressure-compensating flow control valve for performing the above.

[0002]

2. Description of the Related Art An example of a conventional flow control valve is disclosed in Japanese Utility Model Laid-Open No. 44305/1987. FIG. 6 illustrates this,
The valve body 21 has a spool 22 slidably built in the center. The spool 22 includes a first oil chamber 23 and a second oil chamber 2.
4 and a throttle 25 formed between the oil chambers 23 and 24. The valve body 21 includes a first port 26 and a second port 27, the spool 22 and an inner wall of the valve body 21. The first port 26 is provided only when oil flows in from the first port. A control orifice, which includes an opening / closing portion 28 for communicating with the second port, a spool 22 and a first port 26, and controls the oil flow rate to be constant only when the oil flows through the throttle 25 from the second port. The unit 29 is provided.

[0003] The conventional flow control valve configured as described above is often used in a civil engineering machine such as a hydraulic shovel by being interposed in a hydraulic circuit. FIG. 7 shows a hydraulic system diagram of a control valve of a hydraulic shovel and a hydraulic actuator operated by the control valve.

In FIG. 1, when the lever 32 of the pilot valve 31 for control is first tilted rightward (in the direction of arrow C), the pressure oil of the pump 33 is introduced, and pilot pressure is generated in the pilot line 34b. Room 36 on the right side of 35
b, the spool 35 moves to the left in the drawing, and as a result, the pressure oil from the pump 38
7 to drive it, and the discharged oil is discharged to the tank 39. Next, when the lever 32 is returned to the neutral position from this state, the pilot pressure in the pilot line 34b disappears, so that the spool 35 also rapidly returns to the neutral position, and as a result, the actuator 37 stops suddenly with a shock.

In order to reduce the shock, the flow control valve shown in FIG. 6 is used by being provided in the middle of the pilot lines 34a and 34b. The connection procedure is shown in FIG.
As shown by the dashed line in the figure, the pilot line 34a
34b is a space 36a at each end of the control table 31 and the spool 35.
36b, without being directly connected to each other, and connected via the flow control valves Pa and Pb.
Chamber 36a (same for 36b) is provided with a flow control valve Pa
(The same is true for Pb). Each flow control valve P
a · Pb indicates that oil flows from the first port 26 to the second port 2
7, the oil is allowed to pass in a free flow state, and the pressure compensation flow control is performed only when flowing from the second port 27 to the first port 26. Therefore, the actuator 37 stops. The shock at the time can be reduced.

[0006]

In the hydraulic system illustrated in FIG. 7, a conventional flow control valve having the above-described structure is provided in the middle of the pilot line of the control valve for the purpose of reducing the shock. If you set up
There are the following problems.

(1) When the lever 32 of the control table 31 is suddenly returned to the original "neutral position" from the position where the lever 32 is tilted in the direction of arrow C, the actuator 37 stops after a certain time delay. This time delay is usually not a problem in many cases.However, depending on the purpose of use of the target hydraulic device, there is a case where it is desired to eliminate the time delay described above, or when a time delay is not allowed due to an emergency or the like. There is also. For such a case, it is desirable for the flow control valve to have a release means for the flow control function. However, such a release means is not provided in the conventional flow control valve.

(2) The lever 32 is brought from the position where the lever 32 is tilted in the direction of arrow C to the position where the lever 32 is suddenly passed to the left side in the opposite direction past the "neutral position", whereby the actuator 37 is suddenly reversely rotated. Or you may want to move it backwards. In this case, it is desirable that the actuator 37 responds at a high speed in response to the operation of the lever 32. However, in the case of a conventional device having a flow control valve, the operation of the actuator 37 is stopped after a certain time delay. However, the operation in the reverse direction starts after the stop, and the expected high-speed response cannot be realized. For example, in a hydraulic excavator, after performing excavation work with a bucket, the bucket is lifted, and the bucket is alternately shaken in a front-rear direction at a considerable speed to sweep off attached soil and sand from the surface of the bucket. Although repetitive work may be required, when such a work is performed by the conventional hydraulic device with a flow control valve, the repetitive work for brushing off the sediment of the bucket becomes an extremely slow operation, and comfortable operation is performed. Work progress is not desired, and work efficiency is extremely low.

According to the present invention, the flow control function provided by the flow control valve for a flow in a specific direction is arbitrarily released by a simple configuration and an easy operation, and the flow control valve is also released for the flow in the specific direction. So that it can flow in a free-flow state,
Alternatively, it is an object of the present invention to easily and easily restore the function from the state, thereby improving the function of the conventional flow control valve and expanding the use of the flow control valve.

Further, the means for releasing and restoring the flow control function can be performed by using the pressure oil of the hydraulic circuit to which the flow control valve belongs, so that the related devices can be rationalized and simplified. Is also aimed at.

[0011]

In order to achieve the above object, in the flow control valve of the present invention, a) a valve body 1;
B) a large-diameter spool 5 which is built therein so as to be slidable within a bore 2 provided therein, has a longitudinal groove 3 on the outer peripheral surface, and has a longitudinal hole 4 therein; A small-diameter spool 8 provided so as to be slidable in the hole 4 of the large-diameter spool, and a throttle 7 provided in the middle of an oil chamber 6 provided in the longitudinal direction at the center; and d) one end face of the valve body 1 And a first port 1 that opens to the first port and communicates with a first clearance 9 provided in the lumen 2.
0) a second port 12 which is open at the other end face of the valve body 1 and communicates with a second clearance 11 provided in the lumen 2;
F) an oil chamber 13 and a piston 18 which are opened on the other end face of the valve body 1 and move the large-diameter spool 5 in the direction of the first port 10 by introducing pressure oil; Only when the oil flows into the oil chamber 13 or when the oil is introduced into the oil chamber 13, the groove 3 on the outer peripheral surface of the large-diameter spool 5 is moved to the second position in accordance with the movement of the large-diameter spool 5 toward the first port 10.
Opening / closing section 14 for communicating the second port 12 with the first port 10 by communicating the clearance 11 with the first clearance 9;
A control orifice section 15 for controlling the oil flow rate to be constant only when the oil flows through the throttle 7 from the first port 10, and 3) moving the large diameter spool 5 in the direction in which the opening / closing section 14 is closed. And a spring 17 for urging the small-diameter spool 8 in a direction in which the control orifice portion 15 is opened.

When the flow control valve is used in the middle of a pressure oil line for controlling the driving of the actuator using the hydraulic control valve, the pressure oil for introducing into the oil chamber 13 of the flow control valve is used. It is effective to guide the hydraulic control valve from the hydraulic pilot pipe system for controlling the spool position.

[0013]

(A) When oil flows in from the first port 10 opening at the end of the valve body 1 of the flow control valve, the large-diameter spool 5
Is moved in the oil inflow direction by the spring 16 to open and close the
Is in a closed state, the inflowing oil advances to the oil chamber 6 via the throttle 7 and passes through the control orifice section 15 to the second chamber.
And flows from here to the second port 12. At this time, according to the pressure difference before and after the throttle 7, if the pressure difference is large, the small-diameter spool 8 moves in the direction to narrow the control orifice portion 15 against the spring 17 and restricts the passing flow rate to reduce the pressure. Make compensation. Conversely, if the differential pressure is small,
The small-diameter spool 8 moves in a direction to widen the control orifice portion 15, so that the flow rate control for the passing oil is performed in a stable state.

(B) Conversely, when oil flows in from the second port 12, the large-diameter spool 5 is pushed toward the first port 10 against the spring 16 and moves. Groove 3 of opening / closing portion 1 is provided on outer peripheral surface of large diameter spool 5 according to movement.
4 communicates with the first clearance 9 provided in the lumen 2 of the valve body 1 and the second clearance 11 and the first clearance 9 communicate with each other, so that the second port 12 and the first port 10 Communicate in a free flow state.

(C) Next, when pressurized oil is introduced into the oil chamber 13 opened to the other end face of the valve body 1, the large-diameter spool 5 is pushed by the piston 18 and is opposed to the spring 16 by the first spool. As a result, the first gap 9 and the second gap 11 are placed in communication with each other through the opening / closing section 14 by the groove 3 of the large diameter spool 5.

In this state, when oil flows from the first port 10, the oil flows into the first port 10, the first clearance 9, the opening / closing section 14, the groove 3, the second clearance 11, and the second port 1.
2 to realize a free-flow state flow of the oil flowing from the first port 10 to the second port 12.

(D) In this state, ie, in the oil chamber 13
When the oil flows in from the second port 12 in a state in which the pressure oil is introduced into the oil, since the large-diameter spool 5 is already at the position moved toward the first port 10, the oil flow path Is a route completely equivalent to the route described in the above (b), and is in a free flow state.

When the flow control valve of the present invention is used in connection with a hydraulic pilot pipe system for controlling the spool position of the hydraulic control valve, the hydraulic pilot line is used as a source of hydraulic oil introduced into the oil chamber 13. The use of pressure oil can simplify the device.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the flow control valve of the present invention will be described below with reference to the drawings.

1, 2 and 3, the valve body 1
Has a large-diameter spool 5 built therein so as to be slidable in a lumen 2 provided therein. The large-diameter spool 5 has a longitudinal groove 3 on its outer peripheral surface, and has a longitudinal hole 4 therein and a small-diameter spool 8 built therein so as to be slidable in the hole 4. The small-diameter spool 8 is provided with a throttle 7 in the middle of the oil chamber 6 provided in the center in the longitudinal direction.

The valve body 1 is open at one end face and has a lumen 2.
Port 10 which communicates with a first clearance 9 provided in
And a second opening provided on the other end face of the valve body 1 and provided in the lumen 2.
And a second port 12 communicating with the gap 11.

An oil chamber 13 is provided on the other end face of the valve body 1.
Is provided. The oil chamber 13 has a large-diameter spool 5
The piston 18 is provided at a position facing the end face of the piston 18 so as to be slidable between the oil chamber 13 and the bore 2. Therefore, when pressure oil is introduced into the oil chamber 13, the large-diameter spool 5 receives hydraulic pressure at its end face via the piston 18,
The movement is forced in the direction of the first port 10.

An opening / closing section 14 is provided between the first gap 9 and the groove 3. A spring 16 for urging the large-diameter spool 5 in a direction in which the opening / closing portion 14 is closed is provided in the lumen 2. The opening / closing section 14 is configured such that the large-diameter spool 5 moves in the direction of the first port 10 against the spring 16 when oil flows in from the second port 12 or when oil is introduced into the oil chamber 13. The second clearance 11 communicates with the first clearance 9 through the groove 3 on the outer peripheral surface of the large diameter spool 5. Due to the communication, the second port 12 and the first port 10 communicate with each other.

The control orifice portion 15 is provided with a large-diameter spool 5.
A small hole for communicating the hole 4 with the outer peripheral surface of the large-diameter spool 5;
And an end of a small-diameter spool 8 that slides in the hole 4. A spring 17 is provided between the small-diameter spool 8 and the large-diameter spool 5 to bias the small-diameter spool 8 in a direction in which the control orifice portion 15 is opened. The control orifice portion 15 is configured such that when oil flows in from the first port 10 through the throttle 7, the small-diameter spool 8 is moved against the spring 17 by a differential pressure across the throttle 7, and the end portion is formed in a passage. By controlling the opening area of the small holes as
The oil flow is controlled to be constant only when flowing in the above-mentioned direction.

The operation of the flow control valve thus configured will be described below. In FIG. 1, when oil flows in the direction of arrow A from the first port 10 of the valve body 1, the large-diameter spool 5 moves in the oil flowing direction by the spring 16 and the opening / closing section 14 is in a closed state. So the oil is squeezed 7
Through the control orifice portion 15, flows from the second clearance 11 toward the second port 12, and flows out in the direction of arrow A. Therefore, the flow rate control for the passing oil is performed in a stable state.

Next, as shown in FIG. 2, when oil flows from the second port 12 in the direction of arrow B, the large-diameter spool 5 moves toward the first port 10 against the spring 16. Pressed and moved, the groove 3 on the outer peripheral surface of the large-diameter spool 5 communicates with the first clearance 9 through the opening / closing portion 14 in accordance with the movement, and the second clearance 11 communicates with the first clearance 9. As a result, the second port 12 and the first port 10 communicate with each other, and the oil flows out in the direction of arrow B in a free flow state.

Next, as shown in FIG. 3, when pressure oil is introduced into the oil chamber 13 in the direction of arrow P, the large-diameter spool 5
Is moved by the piston 18 in the direction of the first port 10 against the spring 16, so that the first gap 9 and the second gap 11 are opened and closed by the groove 3 of the large-diameter spool 5. It is placed in communication through 14.

In this state, an arrow A1 from the first port 10
When the oil flows in the direction of?, The oil flows into the first port 10, the first clearance 9, the opening / closing part 14, the groove 3, the second clearance 1
1, the oil flowing from the second port 12 and flowing from the first port 10 toward the second port 12 is caused to flow in a free flow state.

When oil flows from the second port 12 in the above state, that is, in a state where pressure oil is introduced into the oil chamber 13, the large-diameter spool 5 has already Since it is located at a position moved in the direction of the first port 10, the oil flow path is exactly the same as the path described with reference to FIG. 2 and is in a free flow state.

FIG. 4 shows a flow control valve 20b according to the present invention.
To a pair of pilot lines 34a and 34b of the hydraulic system.
Of these, an example of a circuit interposed in the middle of 34b is shown. When the flow control valve of the present invention is applied to a hydraulic circuit as shown, an actuator 37 operated by the lever 32 is used.
It is the same as that already described in the description of the conventional apparatus of FIG.

The flow control valve 20b of the present invention differs from the conventional flow control valve in that the oil chamber 13 is provided on the end face of the valve body 1 as described with reference to FIGS. 1, 2 and 3. Therefore, by connecting the introduction pipe 21 for introducing the pressure oil to the oil chamber 13 and controlling the pressure oil introduced through the introduction pipe 21, the flow rate control function can be optionally performed as necessary. Can be canceled.

In this way, when the pressure oil is introduced from the introduction pipe 21 to release the flow control function, it is possible to arbitrarily eliminate the time delay which could not be realized with the conventional flow control valve. This makes it possible to shorten the time required for starting and stopping the actuator, including emergency measures.

As shown in FIG. 4, when the introduction pipe 21 is connected to the pilot line 34a, the lever 32 is once tilted in the direction of the arrow C, and then suddenly passes through the "neutral position" from that position in the opposite direction. When the operator wants to suddenly reverse or move the actuator 37 in the reverse direction or the reverse direction, the generation of hydraulic pressure shifts from the pilot line 34b to the pilot line 34a in accordance with the operation of the lever 32. At the same time, the hydraulic pressure of the pilot line 34a reaches the oil chamber 13 of the flow control valve 20b via the introduction pipe 21 to release the flow control function, so that the release operation is performed completely automatically with the operation of the lever 32, In particular, when the tilting operation of the lever 32 is repeatedly performed within a short period of time, this contributes to an improvement in work efficiency. At the same time, the apparatus can be simplified with respect to the pressure oil piping, which is convenient.

Generally, as shown in FIG. 5, when an introduction pipe 21 for introducing pressure oil into the oil chamber 13 of the flow control valve is provided and an opening / closing valve 22 is provided in the middle thereof, for example,
It is apparent that a further effect can be obtained by improving the maneuverability by selecting the location of the operation switch near the lever 32 by using the as an electromagnetic valve.

[0035]

[Effects of the Invention] Since the flow control valve of the present invention is configured as described above, the flow control function for the flow in a specific direction provided by the original flow control valve is retained as it is. With a simple configuration and easy operation, this can be arbitrarily released to allow the flow in the specific direction to flow in a free flow state, and the function can be easily restored from that state. As a result, the function of the conventional flow control valve can be improved and the use of the flow control valve can be expanded.

Further, since the operation of releasing and restoring the flow control function can be performed using the pressure oil of the hydraulic circuit to which the flow control valve belongs, the rationalization and simplification of the related devices can be further improved. You can proceed.

[Brief description of the drawings]

FIG. 1 is a sectional view of one embodiment of a flow control valve of the present invention.

FIG. 2 is a sectional view showing a different operation mode of the flow control valve of FIG. 1;

FIG. 3 is a sectional view showing still another operation mode of the flow control valve of FIG. 1;

FIG. 4 is a hydraulic system diagram of an embodiment of the hydraulic apparatus having the flow control valve of the present invention.

FIG. 5 is a hydraulic system diagram of another embodiment of the hydraulic device having the flow control valve of the present invention.

FIG. 6 is a sectional view of a conventional flow control valve.

FIG. 7 is a hydraulic system diagram including a conventional flow control valve.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 valve body 2 lumen 3 groove 4 hole 5 large diameter spool 6 oil chamber 7 throttle 8 small diameter spool 9 first clearance 10 first port 11 second clearance 12 second port 13 oil chamber 14 opening / closing section 15 control Orifice part 16/17 Spring 18 Piston

Claims (2)

(57) [Scope of request for utility model registration] 1. A valve body (1), and a valve body (1), which is provided so as to be slidable in a lumen (2) provided therein, and has a longitudinal groove (3) on an outer peripheral surface thereof, and a longitudinal inside. Large-diameter spool (5) with directional holes (4)
And is provided so as to be able to slide in the hole (4) of the large diameter spool,
A small-diameter spool (8) in which a throttle (7) is provided in the middle of an oil chamber (6) provided in the center in the longitudinal direction; and an opening in one end face of the valve body (1) and provided in a lumen (2) A first port (10) communicating with the first clearance (9)
A second port (12) opening at the other end face of the valve body (1) and communicating with a second clearance (11) provided in the lumen (2).
An oil chamber (13) and a piston (18), which are opened at the other end face of the valve body (1) and move the large-diameter spool (5) in the direction of the first port (10) by introducing pressure oil. )
Only when the oil flows from the second port (12) or when the oil is introduced into the oil chamber (13), the large-diameter spool (5) moves in the direction of the first port (10). The groove (3) in the outer peripheral surface of the large-diameter spool (5) has the second clearance (1).
By connecting 1) with the first clearance (9),
The first port (10) is constituted by an opening / closing part (14) for communicating the second port (12) with the first port (10), a large-diameter spool (5) and a small-diameter spool (8). A control orifice section (15) for controlling the flow rate of the oil to be constant only when the oil flows through the throttle (7), and a spring for biasing the large-diameter spool (5) in a direction in which the opening / closing section (14) is closed. (16) A flow control valve comprising: a spring (17) for urging the small diameter spool (8) in a direction in which the control orifice portion (15) is opened. 2. A pipe for introducing pressure oil into an oil chamber (13) of a flow control valve when the flow control valve is interposed in the middle of a pressure oil line for controlling driving of an actuator using a hydraulic control valve. 3. The flow control valve according to claim 1, wherein the valve is connected to a hydraulic pilot pipe system for controlling a spool position of the hydraulic control valve.