JP3093983B2 - Flow path opening / closing valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow passage opening / closing valve, and more particularly to a flow passage opening / closing valve used in a vacuum apparatus.

[0002]

2. Description of the Related Art As a flow passage opening / closing valve used in a conventional vacuum apparatus, an L-type valve, an S-type valve, a clapper valve, a gate valve and a butterfly valve as shown in FIGS. Are known. These valves are provided in the middle of a pipe connecting the vacuum chamber and the vacuum pump, and are opened when the gas in the vacuum chamber is exhausted by the vacuum pump, and closed when the vacuum chamber reaches a predetermined degree of vacuum. You.

On the other hand, the vacuum chamber is required to reach a high degree of vacuum in a short time when exhausting the gas (ie, when the valve is opened), and when maintaining the vacuum degree (ie, when the valve is closed). ) Requires that the fluid does not flow back into the chamber from the valve outlet side. In order to meet these requirements, it is important for the performance of the flow path opening / closing valve to be low in exhaust resistance (large conductance) when the valve is opened, and sealing performance against back pressure (valve outlet side pressure) when the valve is closed. Become.

[0004]

However, in the conventional L-type valve (FIG. 6 (a)) and S-type valve (FIG. 6 (b)), when the valve is closed, the valve is caused by a reverse pressure. Since the body 101 is pressed toward the valve seat 102, the sealing property is good. However, when the valve is opened, there is a problem that the exhaust resistance increases because the fluid flows through a curved path.

A clapper valve (FIG. 6 (c))
Also, in the gate valve (FIG. 6D), when the valve is closed, the valve body 101 is pressed in a direction away from the valve seat 102 due to the back pressure, so that there is a problem that the sealing property is poor.

Further, since the swinging fulcrum 103 of the valve body is provided near the inner wall of the valve housing 104 of the clapper valve, when the outside diameter of the valve body is increased, the valve body 101 is opened when the valve is opened.
Hits the inner wall of the valve housing and the valve cannot be opened sufficiently (the swingable angle of the valve body cannot be increased), and the exhaust resistance increases. On the other hand, the swingable angle of the valve body is increased to open the valve sufficiently. To do so, the inner diameter of the valve housing must be increased or the inner diameter of the flow path of the valve seat 102 must be reduced. In this case, too, there is a problem that the exhaust resistance is relatively increased.

Further, in the gate valve, when the valve is opened, the storage chamber 105 for storing the valve element 101 is provided at a right angle to the fluid flow path, so that the gas in the storage chamber is hardly exhausted, and the inner wall of the valve housing is also prevented. Since the surface area is large, the amount of degassing from the inner wall surface is also large, so that there is a problem that exhaustability is poor.

In the butterfly valve (FIG. 6 (e)), when the valve is opened, the valve body 101 can be made parallel to the flow of the fluid, so that there is no problem that the exhaust resistance increases.
When the valve is closed, the valve body is rotated at the center thereof and the outer peripheral portion is brought into contact with the conical valve seat 102 to seal the valve body, so that the valve body rotation center shaft 106 and the valve seat 102 are concentric. If the processing is not performed with a high degree of accuracy, a leak may occur when the valve is closed.

Further, even if the concentricity is accurately processed, the mutual sealing portion between the valve body and the valve seat receives different torsional forces over the entire circumference with the rotation of the valve body 101 when the valve is closed. However, there is a problem that the contact pressure at each seal portion is not uniform and the sealability is unreliable.

[0010] Further, in order to smoothly slide the mutual sealing surfaces of the valve seat 102 and the valve body 101, it is necessary to coat or apply a lubricant to the sealing surfaces. Had a disadvantage. In addition, when the valve body is held at the valve open position for a long time, there is a problem that a part of the seal is permanently deformed and leaks easily when the valve is closed.

The present invention has been made in view of the above-mentioned problems of the conventional flow passage opening / closing valve, and has as its object to provide a flow passage opening / closing valve having small exhaust resistance and excellent sealing properties.

[0012]

In the present invention, the above object is achieved by (a) having a pipe portion and a valve seat integrally provided at one end of the pipe portion substantially orthogonal to the axis of the pipe portion. A valve housing, (b) a valve body that closes a flow passage when seated on a valve seat, and (c) a part that extends substantially orthogonal to the pipe axis and extends into the pipe part, and is rotatable with respect to the valve housing. (D) a first link attached to the drive shaft so as to be able to rotate together with the drive shaft in the pipe portion, and (e) a second link for linking the first link and the valve body. (F) a third link for linking the valve body and the valve housing; and (g) a first link based on a connection point between the first link and the second link when the valve body is seated on the valve seat. The angle on one side consisting of the link and the second link is 180 degrees. (H) when the valve element is separated from the valve seat, the third link is located on the other side with respect to the one side angle with respect to the connection point. Stopper means for limiting the swing of the third link so that the connection point with the valve body is not separated from the valve seat more than a predetermined amount, wherein the valve body can be made substantially parallel to the pipe section axis when the valve is opened. This is achieved by a flow passage opening / closing valve.

According to the present invention, when the valve body is seated on the valve seat, that is, when the flow path is closed, the first link and the second link are determined with reference to the connection point between the first link and the second link. Since the angle on one side formed with the link is less than 180 degrees, the axial component of the first and second links with respect to the rotational force transmitted from the drive shaft to the connection point can be extremely increased. Therefore, the valve body can be strongly seated on the valve seat, and the seat state can be maintained even when a counter pressure is applied to the valve body, that is, a pressure for separating the valve body from the valve seat. That is, in the present invention, excellent sealing properties are exhibited.

When the valve is opened, that is, when the valve body is separated from the valve seat,
The drive shaft is rotated so that the angle of the one side formed by the first link and the second link is reduced. By the rotation
1, The valve body floats until the second, third and third links move together, and the third link stops its rotation by the stopper.

After the rotation of the third link is stopped by the stopper, the drive shaft is further rotated in the same direction, so that the valve element pivots around the connection point between the valve element and the third link, and the pipe is rotated. It can be made substantially parallel to the part axis. Therefore, in the present invention, the fluid resistance can be reduced (it has excellent conductance when used in a vacuum exhaust system).

To change from the above-described valve-open state to the valve-closed state, the drive shaft is rotated in the direction opposite to the direction during the valve-opening operation. The operation of each component at that time is in reverse order to the operation at the time of valve opening described above.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to FIGS. In FIG. 1, reference numeral 1 denotes a passage opening / closing valve, and reference numeral 2 denotes a valve housing thereof. The valve housing 2 has a pipe portion 3 and
It has pipe mounting flange parts 4 and 5 provided integrally at both ends of the pipe part 3. The flange portion 5 is provided with a valve seat 6.

The flange portion 4 is connected to a low-pressure side conduit (not shown).
The flange portions 5 are air-tightly connected to high-pressure-side pipes (not shown). When this embodiment is used as a vacuum valve, the flange 4 is connected to the vacuum chamber side pipe, and the flange 5 is connected to the suction port side of the vacuum pump.

Reference numeral 7 denotes a valve body. In FIG. 1, the valve body 7 has a disk portion 8 in contact with the valve seat 6 and a valve body projection 9 integrally provided on the disk portion 8. And
An airtight seal ring 8a is integrally attached to the lower circumference of the disk portion 8, and when the valve body 7 is seated on the valve seat 6 (that is, the seal ring 8a of the disk portion 8 is attached to the valve seat 6). , The fluid flow path 10 is closed.

Reference numeral 11 denotes a drive shaft rotatably supported by the valve housing 2 and intersecting at a right angle to the pipe axis. The drive shaft 11 is provided in the valve housing 2 as shown in FIG. It has a housing inner shaft portion 12 extending and a projecting shaft portion 13 projecting from the valve housing 2. A well-known drive mechanism including a combination of an air cylinder and a link (not shown) that converts the piston stroke of the air cylinder into a rotational motion to rotate the drive shaft 11 is provided at the tip of the protruding shaft portion 13. Instead of such a driving mechanism, a handle may be attached to the tip of the protruding shaft portion 13 to manually rotate the rotating shaft 11, and the rotation of the driving shaft 11 is controlled by directly connecting a motor. Is also good. Reference numeral 14 denotes a seal ring for airtightness generally known in vacuum technology, and reference numerals 15a and 15b denote retaining rings for restricting the axial movement of the drive shaft 11.

One end of a first link 16 is fixed to a central portion of the inner shaft portion 12 of the housing of the drive shaft 11 by known fixing means (not shown). Therefore, the first link 16
Is attached to the drive shaft 11 so as to rotate together with the drive shaft 11 in the pipe portion 3.

Reference numeral 17 denotes a first pin rotatably fitted to the other end of the first link 16.
On one side of the other end of one link 16 (FIG. 2), one end of each of a pair of second links 18 is rotatably attached.

Reference numeral 19 denotes a second pin rotatably fitted in the valve body projection 9. The second pin 19 has a pair of second pins on both sides (FIG. 2) of the valve body projection 9. The other ends of the links 18 are rotatably mounted.

The second link 18 is, as described above,
The first link 16 and the valve element 7 are connected to the first and second pins 17 and 19.
Are connected via the valve body 7.
In the state in which the valve seat 6 is seated on the valve seat 6, as shown in FIG. 1, the axes of the drive shaft 11 and the second pin 19 are substantially on the center axis 20 of the pipe portion, and the axis of the first pin 17 is It is configured to be located at a point A slightly deviated from the center axis 20 of the section. That is, the valve element 7 is
In the state where the first link 16 and the second link 18 are connected, the angle α1 on one side formed by the first link 16 and the second link 18 with respect to the connection point A between the first link 16 and the second link 18 is less than 180 degrees. It has been done.

Reference numeral 21 denotes a third pin rotatably fitted to the valve body projection 9, and reference numeral 22 denotes a fourth pin rotatably fitted to a housing projection 23 provided integrally with the valve housing 2. It is a pin. The third pin 21 has a valve body projection 9.
2 (FIG. 2), a pair of third links 24, 2
4 is rotatably attached to one end of the fourth pin 22.
The other end of each of the pair of third links 24 is rotatably mounted on both sides of the housing projection 23.

The third link 24 is, as described above,
The third and fourth pins 2 connect the valve body 7 and the valve housing 2 to each other.
1 and 22, the connecting relationship between the first link 16 and the second link 18 in the state where the valve body 7 is seated on the valve seat 6 as shown in FIG. With reference to the connection point A, the third link 24 forms the angle α on one side.
1 and the second pin 19 and the third pin 2
1 is located on a plane substantially parallel to the disk portion 8, and the fourth pin 2
2 is located slightly closer to the first pin 17 than the third pin 21.

When the fluid on-off valve 1 of this embodiment is fully opened and the valve body 7 is substantially parallel to the center axis 20 of the pipe, that is, the drive shaft 11 is rotated in the direction of arrow L as shown in FIG. Then, the disk portion 8 of the valve body 7 is moved to the center axis 2 of the pipe portion.
0, the angle α1 on the one side formed by the first link 16 and the second link 18 is substantially 90 degrees, and the center line connecting the third pin 21 and the fourth pin 22 is a disc portion. 8 and approximately 90 degrees.

Reference numeral 25 denotes a pin as stopper means which is press-fitted and fixed to the housing projection 23.
Protrudes from both sides of the housing projection 23, as shown in FIG. 3, the fluid opening / closing valve of the present embodiment is fully opened, and the center line connecting the third pin 21 and the fourth pin 22
When the angle reaches approximately 90 degrees with the third link 24
3rd link 24 so that the
Abuts the back surface 24a. That is, when the valve body 7 separates from the valve seat 6,
The swing of the third link 24 is restricted so that the connection point B between the third link 24 and the valve body 7 is not separated from the valve seat 6 by a predetermined amount or more.

In FIG. 2, reference numerals 26 and 26 denote a pair of tension springs as elastic means.
7, 21 via spring mooring rings 27a, 27b, 27c, 27d attached to both ends of each.
Between the third pins 17 and 21 (and thus the first and third links 1)
(Between 6, 24). Accordingly, the pair of springs 26 serving as the elastic means, as is apparent from FIG. The third of the seen valve element 7
It acts on the valve element 7 so that the end 7a in the direction of the link 24 (the direction of the fourth pin 22) is separated from the valve seat 6.

In FIG. 2, 28, 29, 3
Reference numerals 0 and 31 denote retaining rings, and pins 1 of the links 18 and 24 and the spring mooring rings 27a, 27b, 27c and 27d.
The movement in the directions of the axes 9 and 21 is regulated.

Next, the operation of the flow passage opening / closing valve 1 according to the embodiment of the present invention will be described. When the flow path opening / closing valve 1 is closed, that is, in a state where the valve body 7 is seated on the valve seat 6 and the flow path 10 is closed, as shown in FIG. Drive shaft 11
Are locked by rotation fixing means (not shown).

In this state, the first link 16 and the second link 16
The angle α1 on one side formed of the first link 16 and the second link 18 with respect to a connection point A with the link 18 is set to 180
As shown in FIG. 4, each component F2 in the axial direction of the first and second links 16, 18 with respect to the rotational force F1 transmitted from the drive shaft 11 to the connection point A, as shown in FIG.
Becomes very large, and each component force F3 acting in the pipe axis direction also becomes very large. It goes without saying that these component forces F2 and F3 can be increased as the angle α1 is closer to 180 degrees. Therefore, the valve body 7 can be moved to the valve seat 6 only by applying a small holding torque to the drive shaft 11.
The seat can be held strong even if a counter pressure is applied to the valve body 7, that is, a pressure for separating the valve body 7 from the valve seat 6. That is, the flow path opening / closing valve according to the present embodiment exhibits excellent sealing properties.

The tension spring 26 lifts the end 7a of the valve disc 8 in the direction of the third link 24 (the direction of the fourth pin 22) when the valve is opened and closed, as will be described later. Therefore, it is sufficient if there is such a tensile force. Therefore, the spring force is negligible compared to the component force F3, and the effect of the spring force on the sealing performance is negligible. Things.

When the valve is opened from the above-mentioned closed state, that is, when the valve body 7 is separated from the valve seat 6, the drive shaft 11 is rotated in the L direction shown in FIG. When this rotation is started, first, the fourth pin-side end 7a of the disk portion 8 floats away from the valve seat 6 by the tensile force of the spring 26. Further, as the drive shaft 11 is rotated, the link mechanism (the first, second, and third links and the valve element 7) is configured such that the one-side angle α1 formed by the first link 16 and the second link 18 gradually decreases. Operates, and the valve element 7 floats until the back surface 24a of the third link abuts the stopper pin 25 and the rotation of the third link 24 is stopped.

After the rotation of the third link 24 is stopped by the stopper pin 25, the drive shaft 11 is further rotated in the direction of the arrow L, so that the valve body 7 is in
It turns around the connection point B with the link, and as shown in FIG. 3, the valve disc 8 is located at a position substantially overlapping the pipe center axis 20, and the valve 1 is fully opened. When such a fully opened state is reached, the drive shaft 11 stops rotating and is locked by rotation fixing means (not shown).

As described above, in this embodiment, the valve element 7
Can be made substantially parallel to the center axis 20 of the pipe portion, so that the fluid resistance can be reduced (having excellent conductance when used in a vacuum exhaust system).

At the start of the valve opening, the tension spring 26 lifts the fourth pin end 7a of the valve disc 8 to the second link 18 side so as to separate it from the valve seat 6, and the valve 7 is moved to the second pin 1 position.
When the turning motion is performed around the turning center 9, the end portion 7 a of the disk portion 8 acts so as not to contact the valve seat 6, so that the valve opening operation can be performed smoothly. Also, the tension spring 26
In the valve closing operation, an end 7b of the valve disc 8 opposite to the fourth pin end 7a starts to abut on the valve seat 6, and the fourth pin end 7a is finally closed. Since it acts so as to come into contact with the seat 6, the valve closing action can be performed smoothly.

[0038]

As described above, according to the present invention,
A flow path opening / closing valve having a small exhaust resistance and excellent sealing properties can be obtained. The flow passage opening / closing valve according to the present invention is particularly suitable as a valve used in a vacuum system, and this point will be described. A typical vacuum system comprises a vacuum chamber 50, as shown in the circuit diagram of FIG.
Turbo molecular pump 51, oil rotary pump (roughing pump)
52, main valve 53, roughing valve 54, holding valve 5
5, a leak valve 56, 57, 58 and a vacuum gauge port 59 are provided. The flow passage opening / closing valve according to the present invention can be used as the main valve 53, the roughing valve 54, and the holding valve 55 in such a vacuum system.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a flow path opening / closing valve according to an embodiment of the present invention, showing a closed state.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a diagram illustrating a state when a flow path opening / closing valve in FIG. 1 is opened.

FIG. 4 is a connection point A between a first link and a second link;
FIG. 4 is an explanatory diagram of a force acting on the sword.

FIG. 5 is a circuit diagram of a general vacuum system.

6 (a), 6 (b), 6 (d), and 6 (e) are cross-sectional views schematically showing different types of flow passage opening / closing valves in the related art.

[Explanation of symbols]

 2 ‥‥ Valve housing 3 ‥‥ Pipe portion 6 ‥‥ Valve seat 7 ‥‥ Valve 10 ‥‥ Flow path 11 ‥‥ Drive shaft 16 ‥‥ First link 18 ‥‥ Second link 24 ‥‥ Third link 25 ‥ ‥ Stopper means α1 ‥‥ Angle on one side

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16K 1/16-1/24 F16K 31/44 F16K 51/02

Claims (1)

(57) [Claims] (A) a valve housing (2) having a pipe portion (3) and a valve seat (6) integrally provided at one end of the pipe portion substantially orthogonal to an axis of the pipe portion; (B) a valve element (7) that closes a flow path (10) when seated on a valve seat; and (c) a valve that is substantially orthogonal to the pipe section axis and a part (12) of which extends into the pipe section. A drive shaft (11) rotatably supported by the housing; (d) a first link (16) attached to the drive shaft so as to be able to rotate with the drive shaft in the pipe portion; and (e) a first link. (F) a third link (24) linking the valve body 7 to the valve housing; and (g) a state in which the valve body is seated on the valve seat. , The first link and the second link based on the connection point (A) between the first link and the second link In one side of the angle which constitutes the ([alpha] 1) 18
(H) when the valve body is separated from the valve seat, the third link is positioned on the other side with respect to the one side angle with respect to the connection point. Stopper means (25) for restricting the swing of the third link so that the connection point (B) between the third link and the valve body is not separated from the valve seat more than a predetermined distance.
And a flow passage opening / closing valve, wherein the valve body can be made substantially parallel to the pipe section axis when the valve is opened.