JPH0154563B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a switching control device for a reciprocating actuator.

[Conventional technology]

A conventional switching control device for a reciprocating actuator, for example, a diaphragm pump, as shown in FIG. )
In addition to supplying compressed air to
When air is discharged to the atmosphere through the switching valve body 6 and the exhaust port 7, the center rod 9 between the diaphragms 8 on both sides moves to the right, and the diaphragm 8 on the right side removes the check valve 11 from the pump chamber 10 on the right side. At the same time, the left diaphragm 8 sucks the liquid into the left pump chamber 13 from the suction port 15 via the check valve 14. At the end of this operation, the left bush 16 fitted on the rod 9 engages with the switching actuator 17 which is slidable on the rod 9 and moves.
7 switches the switching valve body 6 to the right side, reverses the intake and exhaust of the left and right chambers, and connects the rod 9 and the diaphragm 8.
This is to switch the drive to the left.

In this way, in the case of pneumatic drive, the rod 9
moves forward and backward normally, and the pump action continues.

[Problem that the invention seeks to solve]

The power of such a reciprocating actuator can be increased by replacing pneumatic drive with hydraulic drive.

However, when the diaphragm pump is hydraulically driven, the pressure in the pneumatic supply chamber 1 increases, and this pressure strongly presses the switching valve element 6 upward, making the sliding friction resistance of the valve element 6 extremely large. Therefore, the switching action will not be performed properly.

Therefore, in the case of hydraulic drive, it is better to switch the hydraulic pressure using a spool that can be operated with a small force because the pressure applied in the axial direction is balanced between the left and right sides.

For example, the main valve that controls the supply and discharge of hydraulic pressure to the left ventricle 4 and the right ventricle 3 has a spool structure, and this main valve is switched by the pilot pressure output from a pilot valve that is linked to the forward and backward movements of the center rod or diaphragm. There is something.

In this case, the problem is that pilot pressure for switching the main valve is output during the switching operation of the pilot valve.

In such a case, pilot pressure is generated in an unstable state before the pilot valve spool is completely switched, and the main valve is switched. Therefore, when operating at slow speed, malfunctions due to early switching of the main valve may occur. (hazard) may occur, and the pump may stop operating when switching forward or backward.

An object of the present invention is to provide a switching control device for controlling pilot pressure for operating a main valve.
By providing self-holding means for the spool and means for delaying the action of pilot pressure on the main valve, malfunctions due to premature switching of the main valve are prevented.

[Means for solving problems]

The present invention provides a device for switching and controlling the working pressure supplied to and discharged from working pressure chambers 26 and 27 on both sides of a reciprocating actuator by means of a spring return type pilot operated main valve 24. Spring 4 on the circumferential surface
3, and is engaged with the reciprocating member 32 and moved against the spring 43 at the final stage of movement of the reciprocating member 32 of the actuator in one direction and the other direction. The spool 44 and the pilot pressure control spool 45 are slidably fitted. The sleeve 42 has a small diameter inner circumferential surface portion 55 in which a portion of the pilot pressure control spool 45 fits into one end of a large diameter inner peripheral surface portion 55 into which the supply pressure control spool 44 and the pilot pressure control spool 45 fit. A peripheral surface portion 56 is provided,
A valve seat portion 57 is provided on the open end surface of this small diameter inner circumferential surface portion 56, and this valve seat portion 57 faces the exhaust pressure chamber 58 on one side of the sleeve 42, and the valve seat portion 57 is on the opposite side of the sleeve 42. A stopper 62 for locking the supply pressure control spool is provided at the open end 61 of the sleeve 42, and the open end 61 faces the exhaust pressure chamber 63 on the other side of the sleeve 42. The large diameter inner circumferential surface portion 55 in order from the side.
The self-hold pressure exhaust port 66, which communicates with the exhaust pressure chamber 63 on the other side by the movement of the supply pressure control spool 44, and the supply port 68, which is constantly supplied with pilot pressure, are connected to each other in the first outer circumferential groove of the sleeve. 69, and a third intermediate port 73 and a fourth intermediate port 74, which communicate with each other via the sleeve second outer circumferential groove 72, are provided. A pilot pressure output port 75 is provided on the peripheral surface portion 56. The first outer circumferential groove 69 of the sleeve communicates with the self-hold pressure discharge port 66 via a passage 76 for self-hold pressure discharge. The supply pressure control spool 44 has a closing portion 81 that opens and closes between the self-hold discharge port 66 and the exhaust pressure chamber 63.
and a spool outer circumferential groove 82 that communicates the supply port 68 and the first intermediate port 70.
Further, the pilot pressure control spool 45 has an end outer peripheral convex portion 8 that opens and closes the second intermediate port 71.
3, and a spool first outer circumferential groove 84 that communicates the second intermediate port 71 and the third intermediate port 73, and closely fits into the large diameter inner circumferential surface portion 55 and engages with the small diameter inner circumferential surface portion 56. The self-hold convex portion 85, the spool second outer circumferential groove 87 that communicates the fourth intermediate port 74 and the pilot pressure output port 75, and the valve body 89 that opens and closes the valve seat portion 57 are arranged in the axial direction. They will be set up sequentially. The pilot pressure output port 75 is connected to the main valve 2.
It communicates with the pilot pressure acting part 41 on one side of 4.
Furthermore, a pilot pressure delay means is provided to delay the generation of pilot pressure for switching the main valve in the pilot pressure acting portion 41 relative to the operation of the spool 45 operated by the reciprocating member 32, thereby delaying the switching of the main valve 24. This pilot pressure delaying means may, for example, be fitted and removed between the small-diameter inner circumferential surface and the large-diameter inner circumferential surface of the sleeve 42 via the spool second outer circumferential groove 87 and connected to the fourth intermediate port 74 and the pilot pressure. a first valve portion 86 that opens and closes between the pressure output port 75 and the valve seat portion 57;
A second valve part 88 is provided between the inner peripheral surface of the valve seat part 57 and the exhaust pressure chamber 58 to suppress the outflow of pilot pressure from the valve seat part 57 to the exhaust pressure chamber 58, or and main valve 2
4, a delay circuit consisting of an aperture resistor and a chamber is provided.

[Effect]

In the present invention, for example, in the final stage of movement of the reciprocating member 32 to the right, the reciprocating member 32 integrally moves the left spool 45 to the right. At this time, the spring 43 is compressed. The right protrusion 83 of the left spool 45 opens the port 71, and the port 71 and the ports 73 and 74 communicate with each other. Note that at that moment, the port 74 and port 75 are shut off by the first valve portion 86. Therefore, at this instant, although the internal pressure on the left side of the central convex portion 85 of the left spool 45 is sufficiently high, no pilot oil pressure is generated in the port 75. At the same time, the valve body 89 approaches the valve seat portion 57, and the first valve portion 88 closes first. Next, the left spool 45 is pressed to the right by a strong differential pressure based on the difference in pressure receiving area between the left side surface of the central convex portion 85 and the right side surface of the first valve portion 86, and the left side spool 45 is pressed to the right. body 89 is completely closed,
The left spool 45 is self-held at high pressure.
At the same time, first valve portion 86 opens a passage between port 74 and port 75 . As a result, pilot pressure is generated at port 75 after a delay time for self-holding of spool 45 from the pilot pressure supply to port 74. This pilot pressure from port 75 switches main valve 24. By switching the main valve 24 in this manner, supply and discharge of the working pressure to and from the working pressure chambers 26 and 27 on both sides of the actuator are reversed, so the actuator is driven to the left and the reciprocating member 32 is also moved to the left. Such a switching operation is repeated on the left and right sides.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail based on FIGS. 1 to 4.

FIG. 2 shows a diaphragm pump as a reciprocating actuator, for example, from the hydraulic supply port 22 of the body 21 to the supply oil passage 23,
(one-way pilot operated spring return type 4-way valve), further supplies pressure oil to the right working pressure chamber (hereinafter referred to as the right chamber 26) via the right oil supply and drainage passage 25, and also supplies pressure oil to the left working pressure chamber (hereinafter referred to as the right chamber 26). Pressure chamber (hereinafter referred to as left ventricle 2)
Hydraulic oil is discharged from the oil supply/drain passage 28 on the left side (referred to as 7) to a tank (not shown) via the main valve 24.

Then, while the center rod 32 as a reciprocating member provided between the diaphragms 31 on both sides moves to the right, the diaphragm 31 on the right side passes from the pump chamber 33 on the right side to the discharge port 3 through the check valve 34.
5, while pushing out the liquid to the left diaphragm 3.
1 sucks liquid into the left pump chamber 36 from the suction port 38 via the check valve 37.

At the end of this action, the switching control device mounted on the body 21 supplies pilot hydraulic pressure to the pilot pressure acting portion 41 of the return spring type main valve 24 shown in FIG.
The supply and discharge of pressure oil to the right chamber 26 and left chamber 27 of the pump are reversed, and the rod 32 and diaphragm 31 are switched to leftward drive.

As shown in FIG. 1, the outer peripheral surface of the reciprocating rod 32 of the diaphragm pump and the inner peripheral surface of the fixed sleeve 42 fitted to the body 21 are separated from each other via a spring 43. The supply pressure control spool 44 and the pilot pressure control spool 45 are slidably fitted. Further, the reciprocating rod 32 includes a stepped portion 47 of a bush 46 on one side that engages with the supply pressure control spool 44 at the final stage of movement of the rod 32 to move the spool 44 against the spring 43; A stepped portion 49 of the bushing 48 on the other side is provided which engages with the pilot pressure control spool 45 and moves the spool 45 against the spring 43.

The spools 44 and 45 engage with the stepped portions 47 and 49, respectively, and the spring 4
Convex portions 51 and 52, which are also receiving portions of No. 3, are provided protruding from the inner peripheral surface over the entire circumference.

Further, the sleeve 42 has a large-diameter inner circumferential surface portion 55 in which a portion of the pilot pressure control spool 45 fits into one end of a large diameter inner peripheral surface portion 55 into which the supply pressure control spool 44 and the pilot pressure control spool 45 fit. The diameter inner peripheral surface portion 56 is integrally screwed, and a valve seat portion 57 is attached to the open end surface of the small diameter inner peripheral surface portion 56.
is provided, and this valve seat portion 57 faces the exhaust pressure chamber 58 on one side of the sleeve 42 communicating with the tank. Further, a stopper 62 for locking the supply pressure control spool is provided at the open end 61 of the sleeve 42 opposite to the valve seat 57, and the open end 61 is connected to the sleeve 42 communicating with the tank. It faces the exhaust pressure chamber 63 on the other side. Further, a self-hold pressure discharge port 66 is sequentially provided from the side of the exhaust pressure chamber 63 on the other side to the large diameter inner circumferential surface portion 55 and communicates with the exhaust pressure chamber 63 on the other side by movement of the supply pressure control spool 44. and the supply oil hole 6 of the body 21.
Supply port 68 that constantly receives pressure oil supply from 7
and a first intermediate port 70 and a second intermediate port 71 that communicate with each other via a mutual sleeve first outer circumferential groove 69.
and a third intermediate port 73 and a fourth intermediate port 7 that communicate with each other via the sleeve second outer circumferential groove 72.
4, and a pilot pressure output port 75 is provided on the small diameter inner peripheral surface portion 56.

This pilot pressure output port 75 communicates with the pilot pressure acting portion 41 of the main valve 24.

The sleeve first outer circumferential groove 69 communicates with the self-hold pressure discharge port 66 via a self-hold pressure discharge passage 76 bored in the body 21 .

The supply pressure control spool 44 has a closing part 81 that opens and closes between the self-hold pressure discharge port 66 and the exhaust pressure chamber 63, and a closing part 81 that opens and closes between the self-hold pressure discharge port 66 and the exhaust pressure chamber 63, and a first
Spool outer circumferential groove 82 communicating with intermediate port 70
and are provided all around the circumference.

Further, the pilot pressure control spool 45 is
an end outer peripheral convex portion 83 that opens and closes the second intermediate port 71; a spool first outer peripheral groove 84 that communicates the second intermediate port 71 and the third intermediate port 73;
A self-holding convex portion 85 extending over the entire circumference that tightly fits into the large diameter inner circumferential surface portion 55 and engages with the small diameter inner circumferential surface portion 56, and a self-holding convex portion 85 that extends over the entire circumference and fits tightly into the large diameter inner circumferential surface portion 55, and the small diameter inner circumferential surface and the large diameter inner circumferential surface of the sleeve 42. a first valve portion 86 that extends over the entire circumference and serves as a pilot pressure delay means that is fitted and removed between the fourth intermediate port 74 and the pilot pressure output port 75;
4 and the pilot pressure output port 75, the spool is fitted and removed between the inner circumferential surface of the valve seat part 57 and the exhaust pressure chamber 58, and the valve seat part 57 is connected to the exhaust pressure chamber 58. A second valve part 88 covering the entire circumference as a pilot pressure delaying means for suppressing the outflow of pilot pressure to the valve seat part 58, and a ring valve 89 as a valve body for opening and closing the valve seat part 57 are sequentially provided in the axial direction.

Next, the operation of this embodiment will be explained. Note that the ports 66 and 70 communicate with each other via a passage 76, and the port 68 is constantly supplied with hydraulic pressure.

1 In the main valve state shown in FIG. 1, the oil pressure in the left ventricle 27 returns to the tank and the right
Hydraulic pressure is supplied to 6.

2. The diaphragm 31 bulges to the right.

3 Rod 32 also moves to the right.

4 At the final stage of movement of the rod 32, the left stepped portion 49 of the rod 32 touches the left spool 45.
move to the right. At this time, the spring 43
Compress.

5 The right protrusion 83 of the left spool 45 is connected to port 7
1 and connect this port 71 and ports 73 and 74
communicate with. Note that at that moment, the port 74 and port 75 are blocked by the first valve portion 86.

6. Therefore, at this moment, the internal pressure applied to the left side surface of the convex portion 85 of the left spool 45 is sufficiently high, but no pilot oil pressure is generated in the port 75.

7 At the same time, the ring valve 89 approaches the valve seat part 57, and the second ring valve 89 on the right side
Valve section 88 closes first.

8 Next, the left spool 45 is pressed to the right by a strong differential pressure based on the difference in pressure receiving area between the left side of the central convex portion 85 of the left spool 45 and the right side of the first valve portion 86. As shown in FIG. 3, the ring valve 89 is completely closed and the left spool 45 is self-held at high pressure.

9 At the same time, the first valve portion 86 connects port 74 and port 7.
Open a passage between 5.

10 As a result, pilot hydraulic pressure is generated at port 75 after a delay time for self-holding of spool 45 after hydraulic pressure is supplied to port 74.

11 Pilot oil pressure from port 75 switches main valve 24 as shown in FIG.

12 The hydraulic pressure that was in the right ventricle 26 returns to the tank.

13 At the same time, hydraulic pressure is supplied to the left chamber 27, and the diaphragm 31 moves to the left.

14 Rod 32 also moves to the left.

15 At the end of this movement, the right shoulder 47 of the rod 32 moves the right spool 44 to the left.

16 As shown in FIG. 4, the port 68 is closed and the port 66 is connected to the right exhaust chamber 6
Connects to 3.

17 The hydraulic pressure of ports 70, 71, 73, 74 passes through passage 76 and port 66 to exhaust pressure chamber 63 on the right side.
and is discharged into the tank.

18 Therefore, the central convex portion 85 of the left spool 45
Since the previously existing differential pressure disappears, the left spool 45 instantly and reliably moves to the left by the restoring force of the compressed spring 43.

19 At this time, since the second valve part 88 is initially closed, the pilot oil pressure acting on the main valve 24 does not disappear immediately, and the slight amount of pressure until the second valve part 88 comes off from the valve seat part 57 increases. After a delay time, ring valve 89 is opened as shown in FIG.

20 At the same time, port 71 is closed.

21 The pilot pressure of the main valve 24 flows from the port 75 through the opening of the ring valve 57 to the tank and becomes zero.

22 The spool of the main valve 24 is switched to the state shown in FIG. 4 by the return spring 91.

23 Return to step 1 and repeat the same action.

In the above embodiment, the first and second valve portions 86 and 88 were provided as pilot pressure delay means, but
As this pilot pressure delay means, port 75
and the pilot pressure line 92 between the main valve 24 and the main valve 24
An RC circuit (delay circuit) may be provided by making the main valve 24 thinner to provide a throttle resistance there, and by making the pilot pressure chamber in the main valve 24 function as a capacitor in the electric circuit. In the pilot pressure path 92,
An aperture resistor serving as an R element and a chamber serving as a C element may be specially provided. Note that the valve portion 8
If 6 and 88 are provided, this RC circuit is not necessary.

Furthermore, in the above embodiment, the spools 44, 4
Although the center rod 32 is selected as the reciprocating member for moving the diaphragm 31, the present invention is not necessarily limited to this. For example, the center disk 95 that holds the diaphragm 31 is selected as the reciprocating member, 3
Spools 44, 4 are attached to the body 21 independently from 2.
5 is assembled, and the pins protruding from the end faces of the spools 44, 45 are made to protrude into the left and right chambers 26, 27, and the pins of the spools 44, 45 are connected to the center disks 95 of the left and right diaphragms 31. At the final stage of movement, press and release spool 4.
4 and 45 may be moved.

Further, the reciprocating actuator to which the present invention is applied is not limited to the diaphragm pump of the embodiment. A double acting cylinder may also be used.

〔Effect of the invention〕

According to the present invention, the self-holding means includes a self-holding convex portion that tightly fits into the large-diameter inner circumferential surface portion of the sleeve and engages with the small-diameter inner circumferential surface portion, and a valve body that opens and closes the valve seat portion of the sleeve. is provided on the spool, and further a pilot pressure delay is provided to delay the generation of the main valve switching effective pressure at the pilot pressure acting part of the main valve from the initial operation of the spool operated by the reciprocating member of the actuator. Since the means is provided, it is possible to reliably create a predetermined time difference between the initial switching operation of the spool and the generation of the pilot effective pressure for switching the main valve, and to ensure that the spool self-holds due to the operating pressure during that time. It is possible to prevent malfunctions such as a reciprocating actuator stopping (hazard) due to early switching of the main valve.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the switching control device for a reciprocating actuator of the present invention, FIG. 2 is a sectional view of the actuator, and FIGS. 3 and 4 explain the operation of the control device. Cross-sectional view, FIG. 5 is a cross-sectional view showing a conventional example. 24... Main valve, 26, 27... Working pressure chambers on both sides of reciprocating actuator, 32... Center rod as a reciprocating member, 41... Pilot pressure acting part of main valve, 42... Fixed sleeve, 4
3...Spring, 44...Spool for supply pressure control,
45...Pilot pressure control spool, 55...Large diameter inner circumferential surface part, 56...Small diameter inner circumferential surface part, 57...Valve seat part, 58, 63...Exhaust pressure chamber, 61...Open end part,
62... Stopper, 66... Self-hold pressure discharge port, 68... Supply port, 69... Sleeve first outer circumferential groove, 70... First intermediate port, 71... Second intermediate port, 72... Sleeve second outer circumferential groove, 73... Third 3 intermediate port, 74... fourth intermediate port, 75... pilot pressure output port, 76... passage for self-hold pressure discharge, 81... closing part, 82... spool outer circumferential groove, 8
3... End outer circumference convex portion, 84... Spool first outer circumference groove,
85...Self-hold convex part, 87...Spool 2nd
Outer circumferential groove, 89...Ring valve as valve body, 8
6, 88...first valve part and second valve part as pilot pressure delay means.

Claims (1)

[Scope of Claims] 1. In a device for switching and controlling the working pressure supplied to and discharged from working pressure chambers on both sides of a reciprocating actuator by a spring return type pilot operated main valve, the inner circumferential surface of a fixed sleeve To,
a supply pressure control spool that is separated from each other via a spring and is engaged with the reciprocating member and moved against the spring in the final stage of movement of the reciprocating member of the actuator in one direction and the other direction; and a pilot pressure control spool are slidably fitted, and the sleeve has a pilot pressure control spool attached to one end of a large diameter inner circumferential surface portion into which the supply pressure control spool and the pilot pressure control spool are fitted. A small-diameter inner circumferential surface part into which a part of the spool fits is provided, a valve seat part is provided on the open end surface of this small-diameter inner circumferential surface part, and this valve seat part faces the exhaust pressure chamber on one side of the sleeve, and the above-mentioned valve A stopper for locking the supply pressure control spool is provided at the open end on the opposite side of the sleeve to the seat part, and the open end faces the exhaust pressure chamber on the other side of the sleeve. A self-hold pressure discharge port that communicates with the exhaust pressure chamber on the other side by movement of the supply pressure control spool and a supply port that constantly receives pilot pressure supply are sequentially arranged on the large diameter inner peripheral surface from the pressure chamber side. and a first intermediate port and a second intermediate port that communicate with each other via the sleeve first outer circumferential groove, and a third intermediate port and a fourth intermediate port that communicate with each other via the sleeve second outer circumferential groove, A pilot pressure output port is provided on the small diameter inner circumferential surface, the first outer circumferential groove of the sleeve communicates with the self-hold pressure discharge port via a passage for self-hold pressure discharge, and the supply pressure control spool is connected to the self-hold pressure discharge port. A closing part that opens and closes between the hold pressure discharge port and the exhaust pressure chamber, and a spool outer peripheral groove that communicates between the supply port and the first intermediate port are provided, and the pilot pressure control spool is connected to the second intermediate port. an end outer peripheral convex portion that opens and closes the second intermediate port and the third
a spool first outer circumferential groove that communicates with the intermediate port;
a self-holding protrusion that closely fits into the large-diameter inner circumferential surface portion and engages with the small-diameter inner circumferential surface portion; a spool second outer circumferential groove that communicates the fourth intermediate port with the pilot pressure output port; A valve body for opening and closing the valve seat portion is provided in sequence in the axial direction, and the pilot pressure output port is communicated with a pilot pressure acting portion on one side of the main valve, and the main valve switching pressure is controlled at this pilot pressure acting portion. A switching control device for a reciprocating actuator, characterized in that a pilot pressure delay means is provided for delaying the switching of the main valve by delaying generation of the pressure relative to the operation of the spool operated by the reciprocating member. 2. As a pilot pressure delay means, the spool is fitted and removed between the small-diameter inner circumferential surface and the large-diameter inner circumferential surface of the sleeve via the second outer circumferential groove of the spool, and between the fourth intermediate port and the pilot pressure output port. A first valve part that opens and closes, and a second valve part that is fitted and removed between the inner peripheral surface of the valve seat part and the exhaust pressure chamber and suppresses the outflow of pilot pressure from the valve seat part to the exhaust pressure chamber. 2. A switching control device for a reciprocating actuator according to claim 1, further comprising a reciprocating actuator. 3. The reciprocating actuator according to claim 1, characterized in that a delay circuit consisting of a throttle resistance and a chamber is provided between the pilot pressure output port and the main valve as the pilot pressure delay means. switching control device.