JPH087156Y2 - Position control valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a position control valve suitable for use in a vibration isolation table on which a precision measuring machine or a precision processing machine is mounted.

[Conventional technology]

Conventionally, as a position control valve, when a vibration isolation table is largely deviated from a reference position, a return operation is performed rapidly, and when the vibration isolation table is near the reference position, the return operation is gentle.
The one disclosed in Japanese Patent No. 000 has been proposed. This position control valve is an I / O that communicates with a position control actuator such as a cylinder or air spring that supports the body of the vibration isolation table.
An O chamber, an import chamber communicating with a compressed air source, and an exhaust chamber for releasing the air in the position control actuator to the atmosphere are provided in the valve body and opened in the import chamber.
A taper on-off valve, which is biased toward the I / O chamber by the air valve hole of the I / O chamber and gradually narrows in the I / O chamber, is arranged to be openable and closable, and the taper on-off valve has a small diameter. Insert the sliding cylinder that protrudes to the side from the I / O chamber to the exhaust chamber so that the outer peripheral surface is in an airtight state, and make a communication passage that connects the I / O chamber and the exhaust chamber to the sliding cylinder. A piston is installed in the exhaust chamber, which slides according to the movement of the vibration isolation table body, and the insertion end of which is constantly urged in the direction away from the sliding cylinder. The conical opening / closing valve is arranged in an exhaust valve hole on the exhaust chamber side of the communication passage so as to be openable / closable.

[Problems to be solved by the device]

However, since the conical opening / closing valve is integrally formed at the insertion end of the piston in the conventional position control valve, the vibration isolation table main body is held at the reference position and the conical opening / closing valve is connected to the exhaust passage. With the chamber side exhaust valve hole closed, if the sliding cylinder part and the center axis of the on-off valve cross at an angle due to manufacturing or assembly error of the sliding cylinder part, piston and conical on-off valve, Of the open-close valve and the exhaust chamber-side exhaust valve hole of the communication passage, a gap is created in the sealing surface, and the sealing performance deteriorates. Therefore, from the position control actuator I /
There is a problem in that the amount of air leaking through the O chamber to the exhaust chamber varies, resulting in unstable position control operation.

In addition, although a cylinder is used in a precision measurement room that does not have a compressed air source, if the air leaks as described above, the gas in the cylinder is immediately consumed, and there is a problem that noise is generated due to the air leak. is there.

Conventionally, in order to improve the position control accuracy of the anti-vibration table body, the elastic seal method is changed to a metal seal method without dead zone. Air leaks occur. Therefore, it is necessary to increase the dimensional accuracy of the piston or the conical on-off valve in order to prevent the sealability from being deteriorated, and as a result, there is a problem that manufacturing and assembly are difficult and cost reduction cannot be achieved. .

The purpose of this invention is to ensure the sealability regardless of the inclination of the piston and the on-off valve, improve the position control accuracy, and reduce the dimensional accuracy of the piston and the on-off valve to reduce the cost. An object is to provide a position control valve that can be achieved.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention has an I / O chamber communicating with a position control actuator such as a cylinder or an air spring that supports a vibration isolation table main body with respect to a valve main body, and a compression unit. An import chamber communicating with the air source and an exhaust chamber for releasing the air in the position control actuator to the atmosphere are provided.
The I / O chamber and the import chamber communicate with each other through the air supply valve hole, and the taper on-off valve that opens and closes the air supply valve hole is housed in the import chamber, and the I / O chamber has a taper on-off valve. The outer peripheral surface of the sliding cylinder portion provided in the I / O chamber (8) and the exhaust chamber are reciprocally slidably inserted with airtightness, and the sliding cylinder portion is connected to the I / O chamber. A communication passage that communicates with the exhaust chamber is formed, and a piston that slides in accordance with the operation of the vibration isolation table main body and is biased in a direction that is always separated from the on-off valve is disposed in the exhaust chamber, Further, a means is provided for loosely accommodating a spherical on-off valve or a conical on-off valve for opening and closing the exhaust valve hole between the exhaust chamber side exhaust valve hole of the communication passage and the piston. .

[Action]

In this invention, when a load such as a device is placed on the vibration isolation table body, the vibration isolation table body is lowered according to the load. Then, the piston of the position control valve is pushed down together with the vibration isolation table body, and the insertion end of the piston pushes down the tapered on-off valve.
Connect the import room and the I / O room. For this reason, compressed air is supplied to the actuator from the import chamber through the I / O chamber, and the vibration isolation table body is pushed up. When the main body of the anti-vibration table is pushed up to the vicinity of the reference position, the piston also rises accordingly and the tapered on-off valve gradually closes the valve hole from the import chamber to the I / O chamber, and
Suppress the flow of compressed air into the / O chamber. As a result, the anti-vibration table main body is gradually pushed up toward the reference position, and is soft-landed to the reference position.

Conversely, when the load is removed, the vibration isolation table rises, but at this time the piston rises and
Since the spherical on-off valve or the conical on-off valve is opened by the air flowing from the I / O chamber through the communication passage into the exhaust chamber,
The air inside the actuator is released to the atmosphere, and the vibration isolation table body descends.

When it comes close to the reference position, the spherical on-off valve or conical on-off valve is lowered by the piston, the communication state between the I / O chamber and the exhaust chamber is gradually blocked, and air leakage is restricted. Soft land at the reference position.

In this invention, the spherical on-off valve or the conical on-off valve is accommodated between the sliding cylinder portion and the piston so that the on-off valve can move freely with respect to the exhaust side exhaust valve hole of the communication passage. The optimum sealing position is pressed and held, and the sealing property is secured.

〔Example〕

A first embodiment embodying the present invention will be described below in detail with reference to FIGS. 1 to 5.

As shown in FIG. 5, the vibration isolation table main body 1 is supported by a position control actuator such as a cylinder or an air spring 2. In the case of the air spring 2, this actuator is composed of a pressure vessel 3 and a rubber spring portion 4. In this embodiment, the air spring 2 is described as an actuator, but the actuator is not limited to this.

A position control valve 6 of the present invention is erected on a side wall of the pressure vessel 3 via a support arm 5. The position control valve 6 will be described mainly with reference to FIG. 2. An I / O chamber 8 is formed in the valve body 7, and the chamber 8 is connected to the pressure container via an I / O port 9 and a pipe line P2. It is connected to 3. In addition, an import chamber 10 is formed in the valve body 7,
The chamber 10 is provided with a compressed air source 12 via an import 11 and a line P1.
It is connected to the. Further, an exhaust chamber 13 is formed in the upper portion of the valve body 7, and the chamber 13 is communicated with the atmosphere by an exhaust 14.

The I / O chamber 8 and the import chamber 10 are communicated with each other through a tapered air supply valve hole 15, and the import chamber 10 is provided with a tapered on-off valve 16 for opening and closing the air supply valve hole 15. It is accommodated and is always urged by a pressing spring 17 in a direction to close the air supply valve hole 15. Further, the I / O chamber 8 is provided with a sliding cylinder portion 16a integrally formed on the small diameter portion side of the on-off valve 16.
An outer peripheral surface of the / O chamber 8 to the exhaust chamber 13 is slidably inserted so as to be airtight.

A communication passage 18 capable of communicating the I / O chamber 8 and the exhaust chamber 13 is formed in the sliding cylinder portion 16a. A piston 19 is vertically reciprocally slidable in the exhaust chamber 13 by a compression spring 20 and is always biased in a direction away from the sliding cylinder portion 16a. The exhaust valve hole 18a can be opened / closed between the accommodating recess 19a provided in the inner end surface of the piston 19 and the exhaust side exhaust valve hole 18a formed at the upper end of the sliding cylinder portion 16a. A spherical on-off valve 21 is movably accommodated.

A bracket 22 is erected on the upper end surface of the valve body 7, and a lever 24 is rotatably supported on the bracket 22 via a support shaft 23. The lever 24 contacts the upper end surface of the piston 19. The operating pin 25 which contacts is fixed by screwing. A contact rod 26 is supported at the tip of the lever 24 as shown in FIG. 5, and the upper end of the contact rod 26 is in contact with the lower surface of the vibration isolation table body 1. Then, when the vibration isolation table body 1 is moved up and down, the piston 19 is reciprocated up and down via the contact rod 26, the lever 24, and the operation pin 25.

Next, the operation of the position control valve configured as described above will be described.

In FIG. 2, the tapered on-off valve 16 closes the air supply valve hole 15,
The spherical on-off valve 21 is connected to the exhaust passage valve hole 18 of the communication passage 18.
By closing a, the pressure in the pressure vessel 3 is kept constant,
The state where the vibration isolation table body 1 is held at the reference position S is shown.

In this state, when the load (not shown) placed on the upper surface of the vibration isolation table main body 1 is removed, the lever 24 is pivoted upward about the shaft 23 as shown in FIG. The piston 19 is moved upward by the compression spring 20. Then, the spherical on-off valve 21 moves from the pressure vessel 3 to the pipe line P2, the I / O port 9, the I / O.
Air is released by the air flowing from the chamber 8 and the communication passage 18 to the exhaust chamber 13, and the air is released from the exhaust chamber 13 to the atmosphere via the exhaust 14, so that the pressure in the air spring 2 is reduced. Therefore, the vibration isolation table main body 1 is lowered, the piston 24 is pushed down against the biasing force of the compression spring 20 by the lever 24 and the operating pin 25, and the spherical on-off valve 21 moves toward the exhaust valve hole 18a of the communication passage 18. Be moved. As the spherical on-off valve 21 approaches the exhaust valve hole 18a, the exhaust chamber 13 moves from the communication passage 18 to the exhaust chamber 13.
Since the amount of air flowing in the vibration isolation unit gradually decreases, the vibration isolation table body is gradually returned to the reference position S. Then, as shown in FIG. 2, the vibration isolation table body 1 is stopped and held at the reference position S in a closed state where the spherical on-off valve 21 is in contact with the exhaust valve hole 18a.

At this time, the spherical on-off valve 21 has a recess 19a for accommodating the piston 19.
Since it is accommodated movably in the inside, the spherical on-off valve 21 has the exhaust valve hole 18a depending on the dimensional accuracy of the on-off valve 16 and the piston 19 even when the piston 19 is inclined as shown in FIG. It is possible to loosen and make contact with the appropriate position, and ensure the sealing. As a result, air can be prevented from leaking from the communication passage 18 to the exhaust chamber 13, and the position control operation can be stably performed.

On the other hand, when a load is applied to the vibration isolation table main body 1, the lever 24 is rotated downward about the shaft 23 as shown in FIG. 4, and the piston 19 is attached to the compression spring 20 by the operating pin 25. Since it is pushed downward against the force, the sliding cylinder portion 16a and the on-off valve 16 are moved downward against the urging force of the pressing spring 17 via the spherical on-off valve 21. Air is supplied from the source 12 into the I / O chamber 8 through the conduit P1, the import 11, the import chamber 10, and the air supply valve hole 15 as shown by the arrow in FIG. Compressed air is supplied into the pressure container 3 from the I / O port 9 and the conduit P2. Therefore, the vibration isolation table body 1 is moved upward, and the biasing force of the compression spring 20 and the pressing spring 17 causes the lever 24 to rotate upward. Then, when the on-off valve 16 rises to close the air supply valve hole 15, the supply of air into the pressure vessel 3 is stopped and the vibration isolation table body 1 is stopped and held at the reference position S as shown in FIG. To be done.

Next, a second embodiment of the present invention will be described with reference to FIG.

In the second embodiment, a guide cylinder portion 7a for guiding the piston 19 is formed in the exhaust chamber 13 of the valve body 7, and a central portion of a diaphragm 31 made of, for example, rubber is provided at the upper end portion of the piston 19. It is fixed to the upper surface of the piston 19 with a tightening bolt 32, and the outer peripheral portion of the diaphragm 31 is fixed to the upper end surface of the valve body 7 with a sandwiching ring 33 and a tightening bolt 34. Further, an exhaust chamber 13 is formed inside the guide tube portion 7a, and a closed chamber 35 is formed outside.

Since the closed chamber 35 is formed in this second embodiment, the elasticity of the compression spring 20 can be weakened, and the pressure of the exhaust chamber 13 presses the piston 19 upward and the pressure of the closed chamber 35. Since the piston 19 is lifted by the force that pushes the piston 19 upward by the above, when the spherical on-off valve 21 is opened, the rising speed of the piston 19 becomes faster, so that the upper surface of the piston 19 and the operating pin 25 The contact state is stably maintained, and the operation reliability can be improved.

 Another embodiment of the present invention will be described with reference to FIG.

Another example of this is a conical on-off valve 27 for the lower end of the piston 19.
The conical on-off valve 27 is movably connected at its base end so that the tapered surfaces of both of them can be kept in close contact with each other in a closed state where they are in contact with the exhaust valve hole 18a of the communication passage 18. .

[Effect of device]

As described above in detail, the present invention stabilizes the sealing performance by bringing the spherical on-off valve or the conical on-off valve into contact with a predetermined sealing position even if the dimensional accuracy or the assembly accuracy of the sliding cylinder or piston changes. And can then hold this,
Since the position control operation is performed stably and strict dimensional accuracy is not required, there is an effect that manufacturing and assembling can be easily performed and the cost of the product can be reduced.

[Brief description of drawings]

FIG. 1 is an enlarged partial sectional view showing an essential part of the present invention, FIGS. 2 to 4 are sectional views showing a position control operation of a vibration isolation table main body, and FIG. 5 is an overall vibration isolation device. A front view, FIG. 6 is a sectional view showing a second embodiment of the present invention, and FIG. 7 is a partial sectional view showing another example of the present invention. 1 ... Vibration isolation table body, 2 ... Air spring, 3 ... Pressure vessel, 4 ... Spring part, 6 ... Position control valve, 7 ... Valve body, 8 ... I /
O chamber, 10 ... Import chamber, 12 ... Compressed air source, 13 ... Exhaust chamber, 15 ... Air supply valve hole, 16 ... Open / close valve, 16a ... Sliding cylinder part, 17 ... Press spring, 18 ... Communication passage, 18a … Exhaust side exhaust valve hole, 19… Piston, 19a… Housing recess, 20… Compression spring, 21… Spherical on-off valve, 24… Lever, 27… Conical on-off valve.

Claims (1)

[Scope of utility model registration request] 1. A vibration isolation table body (1) for a valve body (7)
The I / O chamber (8) that communicates with the position control actuator such as the cylinder or the air spring (2) that supports the air, the import chamber (10) that communicates with the compressed air source (12), and the position control actuator An exhaust chamber (13) for opening the air to the atmosphere is provided, and the I / O chamber (8) and the import chamber (10) are connected by an air supply valve hole (15) and the air supply valve hole (15 The taper-shaped on-off valve (16) for opening and closing 15) is housed in the import chamber (10), and the I / O chamber (8) is provided with the sliding cylinder part (16a) provided on the taper-shaped on-off valve (16). The outer peripheral surface of the I / O chamber (8) and the exhaust chamber (13) are inserted so as to be capable of reciprocating sliding with airtightness, and the sliding cylinder portion (16a) has the I / O chamber (8). And the exhaust chamber (1
A direction in which a communication passage (18) that communicates 3) is formed, slides in the exhaust chamber (13) according to the operation of the vibration isolation table main body (1), and is constantly separated from the opening / closing valve (16). The piston (19) biased to the
9) A spherical on-off valve (21) or a conical opening / closing for opening / closing the exhaust valve hole (18a) between the exhaust chamber (13) side exhaust valve hole (18a) and the piston (19). A valve for position control, characterized in that the valve (27) is housed so as to be movable.