JPS597667Y2 - Flow control valve with pressure control valve - Google Patents

Description

[Detailed explanation of the invention] In a general pneumatic circuit, when a normal speed control valve is used for meter-out control as shown in Fig. 8, both sides of the piston that slides in an air-watertight manner in the cylinder of the actuator are at atmospheric pressure. There are many cases where pressure is supplied to one side and the piston runs out of control due to the compressibility of the air, resulting in damage to jigs and equipment and even personal injury. .

Furthermore, in order to prevent this piston from running out of control, conventional speed control valves have been used under meter-in control as shown in FIG.

This method has the disadvantage that after the piston reaches the stroke end, pressure is gradually supplied due to meter-in control, resulting in a delay in pressure transmission time, and it takes time for the cylinder to obtain the necessary force.

Furthermore, in order to prevent wasted energy by reducing air consumption, a control circuit has been provided which includes a pressure regulating valve 1, a check valve 2, a speed control valve 3, etc., as shown in FIG.

In this method, when the piston 5 of the cylinder 4 moves to the left by switching the directional control valve 6, the chamber 8 on the load side of the cylinder 8
The pressure PR reduced by the pressure regulating valve 1 is supplied to the head side chamber 7, and the pressure in the head side chamber 7 is gradually reduced as it is exhausted from the direction switching valve 6 around the variable throttle 10 of the speed control valve 9. .

Therefore, in order for the piston to move to the left, negative pressure or piston 5
If we ignore the difference in pressure-receiving area of
Since the piston is throttled at 0, the pressure gradually drops, which has the disadvantage that it takes a long time from when the directional control valve 6 is switched until the piston starts moving, that is, it takes a long time to start.

Here, the purpose of this invention is, first, to prevent the piston from running out of control by meter-in control when the pressure inside the cylinder is atmospheric pressure, and second, to use a normal speed control valve in meter-in mode. The delay in pressure transmission time caused by the pressure control valve is compensated for by the rapid air supply action of the pressure control valve to prevent time loss. Thirdly, the delay in starting time due to the pressure difference before and after the piston is compensated for by the rapid air exhaust action of the pressure control valve. The present invention aims to provide a flow rate regulating valve with a pressure control valve that can prevent time loss.

Next, this idea will be explained with reference to the drawings.

First, in FIG. 1, a main body 1 is provided with ports 2 and 3 for inlet and outlet of compressed air, and a passage 4 that communicates these ports 2 and 3 includes a throttle valve 5 that narrows the passage 4. A check valve 6 is disposed in a parallel operational relationship to the throttle valve 5.

The throttle valve 5 includes a twenty-one dollar 8 inserted into a through hole 7 formed in the main body 1, a threaded rod 9 for advancing and retracting the twenty-one dollar 8 by rotation, and a screw rod 9 formed at one end of the threaded rod 9. When the handle 10 is rotated to adjust the opening degree of the twenty-one dollar 8, the lock nut 11, which is threadedly fitted onto the threaded rod 9, is attached to the main body 1. It is maintained by tightening it.

Note that reference numeral 12 is a port, which allows the narrow passage formed between the twenty-one dollar 8 and the through hole 7 to communicate with the passage 4.

The check valve 6 disposed in a parallel working relationship with the throttle valve 5 includes a main valve body 13 , a pressure regulating screw 14 screwed into the main body 1 , and the main valve body 13 and the pressure regulating screw 14 . a pressure regulating spring 15 for elastic force loading compressed between the valve seat 16 formed on the main body 1;
The auxiliary valve element 18 is seated on the auxiliary valve seat 17 formed within the main valve element 13 and the elastic force that causes the auxiliary valve element 18 to be seated on the auxiliary valve seat 17. It has a double-valve structure with a spring 19 that applies a load.

At this time, the pressure regulating spring 15 can be adjusted so as to apply a predetermined working pressure, but the spring 19 has a slight elasticity necessary to seat the sub-valve element 18 against the sub-valve seat 17. It merely applies force to the sub-valve body 18.

FIG. 11 shows a working stroke (G
This is an example in which meter-out control is used to prevent the piston from running out of control when performing the operation shown by the arrow.

In this figure, among the pipes 55 and 56 between the directional control valve 53 and the cylinder 54 of the actuator, the valve 2 is connected to the pipe 55 communicating with the chamber 57 on the head side of the piston 51.
Connect port 0 to the directional control valve 53 side and port 3 to the cylinder 54 side in FIG.
3 and the speed control valve 58 is connected to the meter-out.

Note that the speed control valve 60 may be disposed meter-out in the pipe line 56 communicating with the rod-side chamber 59 in the cylinder 54.

With the above structure, when the head side chamber 57 and the rod side chamber 59 of the cylinder 54 are first at atmospheric pressure, during the working stroke, the pressure source 61 passes through the directional control valve 53 by the switching operation of the directional control valve 53. The compressed air entering line 55 is introduced in free flow through speed control valve 58 to flow port 2 .

The compressed air introduced into port 2 passes through main valve body 13 and sub valve body 1.
8, the flow rate is adjusted by the throttle valve 5 and gradually enters the chamber 57, and the piston 51
Push the rod 52 through the .

During this working stroke, even if the pressure in the chamber 59 is atmospheric, the piston does not run out of control because meter-in control is performed by the throttle valve 5.

In addition, when performing a work stroke from a state where the chamber 59 is pressurized, the compressed air from the port 2 passes through the throttle valve 5 and gradually flows into the chamber 59, increasing the pressure. However, since the pressure in the port 3 increases, the main valve body 13 is pushed down against the force of the pressure regulating spring 15 and becomes fully open, and the valve 20 is free-flowing into the chamber 57.
flow inside.

Therefore, the pressure in the chamber 59 is controlled by the speed control valve 60, and is exhausted from the directional control valve 53, so that the pressure in the chamber 59 is metered out.

During the return stroke (indicated by arrow G') after the work is completed, the directional control valve 53 is operated to pass through the conduit 56, and the air is supplied into the chamber 59 in a free flow from the speed control valve 60.

At this time, the compressed air in the chamber 57 corresponding to the discharge side is
0, the sub-valve body 18 is pushed open against the weak force of the spring 19, resulting in a 7-leaf flow, and the flow rate is adjusted by the speed control valve 58, that is, it is discharged under meter-out control.

If the pressure in the chamber 57 is PH and the pressure in the chamber 59 is PR, if the pressure in each chamber 57, 59 during the working stroke is atmospheric pressure, if the inside of the chamber 59 is pressurized during the working stroke. and each chamber 5 during the return stroke
7. 12, 13 and 1 show the relationship between the pressure inside the piston 59, the stroke of the piston, and time, respectively.
4, in FIG. 12, a indicates the movement of the piston, and PH and PR indicate the movement of each chamber 57. 59 shows the change in pressure inside 59.

Here, the dotted lines PH' and PR' indicate the head side chamber 5 and rod side chamber 6 of the cylinder 3 when the normal speed control valves 1 and 2 are used in meter-out mode in FIG.
In each pressure curve, a' is the piston 4.
Compared to the device according to this invention, the pressure changes suddenly and presents an unstable condition, and the piston movement changes rapidly in a short period of time.

In other words, this indicates that the piston is running out of control at high speed.

On the other hand, when pressure is applied to each of the chambers 59 and 57, as in the case of FIGS. 13 and 14,
The conventional embodiment shown in FIG. 8 and the present invention exhibit stable control modes in the same way.

Next, FIG. 2 shows an example in which the pressure control valve-equipped flow rate regulating valve 20 of this invention is implemented in a meter-in control mode.

In this figure, among the pipes 23 and 24 between the directional control valve 21 and the cylinder 22 of the actuator, the valve 2 is connected to the pipe 23 communicating with the chamber 26 on the head side of the piston 25.
Connect 0 to meter in.

That is, in this case, port 2 in FIG. 1 is connected to the directional control valve 21 side, and port 3 to the cylinder 22 side.

Note that an ordinary speed control valve 28 may be provided meter-in in the pipe line 24 communicating with the rod-side chamber 27 in the cylinder 22.

In the above structure, the rod 29 connected to the piston 25
When performing a work stroke (indicated by arrow F), the pressure source 30 causes the directional control valve 21 to be moved by the switching operation of the directional control valve 21.
Compressed air enters the pipe line 23 through the port 2 and is checked by the main valve body 13 and the sub-valve body 18, so the flow rate is adjusted by the throttle valve 5, enters the chamber 26, and the piston Push the rod 29 through 25.

In this working stroke, even if the pressure in the chamber 27 is atmospheric, meter-in control is used, so the speed is controlled by the throttle valve 5 and runaway of the piston does not occur.

When the piston 25 reaches the stroke end, the pressure in the chamber 26 is gradually increased as the flow rate is adjusted by the throttle valve 5 and the pressure in the chamber 4 is also gradually increased. The main valve body 13 is pushed down against the force 15 to open the main valve body 13 and the valve seat 16, and the compressed air on the port 2 side is rapidly supplied into the chamber 26 through the chamber 4.

The return stroke (indicated by arrow F') after the work is completed is performed by compressed air supplied meter-in to the chamber 27 via the pipe line 24 by the switching operation of the directional control valve 21. The compressed air in the chamber 26 corresponding to the valve 2
0, the sub-valve body 18 is pushed open against the weak force of the spring 19, allowing for immediate exhaustion, and when the pressure on the port 2 side becomes even lower, the main valve body 13 is also opened. The flow from port 3 becomes free flow.

This makes rapid exhaust possible.

Assuming that the pressure in the chamber 26 is P1 and the pressure in the chamber 27 is P2, FIG. 3 shows the relationship between the pressure in each of the chambers 26 and 27, the stroke of the piston, and time during the working stroke and the return stroke. and Fig. 4, where a indicates the movement of the piston, and P1, P2
Each room 26. 27 shows the change in pressure within 27.

Here, the dotted line P1' is the pressure curve when the normal speed control valve in FIG. The pressure transmission time after reaching t1 in this invention requires t2 when using a normal speed control valve, that is, compared to using the valve 20 of this invention, t2 - t1 is required. Pressure transmission lag occurs.

On the other hand, in FIG. 4 showing the return stroke, the movement of the piston is indicated by a, and the pressure in the chamber 26 is P1, the pressure in the chamber 2 is
7 pressure is represented by P2.

In this case, P1 works like a normal speed control valve due to the two functions of the check valve and the rapid exhaust valve.
The valve 20 indicates free flow discharge.

Next, for the purpose of preventing wasted energy by reducing air consumption, the flow rate regulating valve 20 with a pressure control valve of this invention is used.
FIG. 5 shows an example of meter-out control.

In this figure, among the pipes 33 and 34 between the directional control valve 31 and the cylinder 32 of the actuator, the valve 2 is connected to the pipe 33 communicating with the chamber 36 on the head side of the piston 35.
Connect 0 to meter out.

That is, in this case, port 3 in FIG. 1 is connected to the directional control valve 31 side, and port 2 to the cylinder 32 side.

In addition, a pressure regulating valve 38, a check valve 41, and a speed control valve 42 are respectively arranged in the pipe line 34 communicating with the rod-side chamber 37 in the cylinder 32 as shown in the drawing.

In the above configuration, the rod 39 connected to the piston 35
When performing a working stroke (arrow f), the compressed air 40 enters the pipe line 33 via the directional control valve 31, is guided from the port 3 into the valve 20, and flows freely into the chamber 36. and pushes the rod 39 through the piston 35.

The flow rate adjustment in this case is performed by a speed control valve 42 in the conduit 34.

The return stroke (indicated by arrow f') after the work is completed is performed by the pressure reduced by the pressure reducing valve 38 in the chamber 37 via the pipe line 34 by the switching operation of the directional control valve 31. In this case, the pressure in the chamber 36 is reduced. The compressed air is supplied to the chamber 3 in the valve 20.
The main valve body 13 is pushed down against the force of the pressure regulating spring 15 to which the pressure inside the valve body 6 is set, and the main valve body 13 and the valve seat 16 are opened, thereby rapidly exhausting the air.

When the pressure in the chamber 36 decreases due to rapid exhaust, the main valve body 13 is pushed up against the force of the pressure regulating spring 15 and sits on the valve seat 16, and the flow rate is adjusted by the throttle valve 5. In other words, it is discharged under meter-out control.

Assuming that the pressure in the chamber 36 is P1 and the pressure in the chamber 37 is P2, FIGS. In FIG. 7, which shows the working stroke, b represents the movement of the piston, and P1 and P2 represent the transition of the pressure in each chamber 36, 37.

In FIG. 7 showing the return stroke, b represents the movement of the piston, and P1 and P2 represent the respective chambers 36 and 37.
In Fig. 10, the dotted line P1' corresponds to Pe when a normal speed control valve is used in the pipe line of chamber 7 on the one side. The pressure curve corresponding to the stroke of the piston is designated b'.

That is, when a normal speed control valve is used, there is a piston stop time of t5, which results in a time loss during operation.

[Brief explanation of the drawing]

In the figure, Fig. 1 is a sectional view of the valve of this invention, Fig. 2 is a circuit diagram of an embodiment in which the valve of this invention is used for meter-in control, and Figs. 3 and 4 are pressures during the working stroke and return stroke. Figure 5 is a circuit diagram of a mode in which the valve of this invention is used for meter-out control, and Figures 6 and 7 are pressure and stroke hour diagrams during the working stroke and return stroke. Fig. 8 is a circuit diagram of a conventional example in which a normal speed control valve is used for meter-out control, Fig. 9 is a circuit diagram of a conventional example in which a normal speed control valve is used for meter-in control, and Fig. 10. Figure 11 is a circuit diagram of a conventional example aimed at reducing air consumption, Figure 11 is a circuit diagram of an embodiment in which the valve of this invention is used for meter-out control with the purpose of preventing piston runaway, Figures 12 and 12 are Figure 13,
Figure 14 shows the pressure when the rod-side chamber is not pressurized during the working stroke, when the rod-side chamber is pressurized, and when the head-side chamber is pressurized during the return stroke. , is a stroke time diagram. In the figure, 1... main body, 2, 3...
... Port, 4 ... Passage, 5 ... Throttle valve, 6 ... Check valve, 7 ... Through hole,
8...21 dollars, 9...screw rod, 10
...Handle, 11...Lock nut, 12...Port, 13...Main valve body, 1
4...Pressure regulating screw, 15...Pressure regulating spring, 16...Valve seat, 17...
Sub-valve seat, 18... sub-valve body, 19... spring, 20... flow rate regulating valve with pressure regulating valve.

Claims (1)

[Scope of utility model registration request] A main body 1 having two ports 2 and 3 for fluid entry and exit, and a passage 4 that communicates these ports 2 and 3, a throttle valve 5 that narrows the passage 4 in the main body 1, and this throttle valve 5. The check valve 6 is provided with an elastic force so that a predetermined operating pressure is applied to the valve seat 16 formed in the main body 1. The main valve body 13 is seated under a load, and the sub valve seat 17 is formed in the main valve body 13.
A flow regulating valve with a pressure control valve, which has a double-valve configuration with a sub-valve body 18 loaded with a slight elastic force necessary for seating the flow rate regulating valve.