JPH0247324Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a gate valve for opening and closing a vacuum piping route, and more specifically to a gate valve that also has a conductance adjustment function.

(Prior art) Conventionally, as this type of gate valve, for example, the fourth
As shown in the figure, the valve body 9a is raised and lowered in a non-contact state away from the valve seat surface 4a, and when the valve body 9a is at the lowest position, the back side of the valve body 9a is placed into an air cylinder, etc. There is a device that completely closes the valve by pressing the valve body 9a, and this method can prevent wear of the sealing gasket 15 etc. when the valve body 9a is raised and lowered, smooth the valve operation, etc. This provides the following advantages.

(Problem that the invention aims to solve) However, in the piping route of the vacuum pumping system that uses this type of gate valve, it is often necessary to adjust the conductance to adjust the degree of vacuum, pumping speed, etc. There is.

However, in the conventional method, both the valve body 9a and the valve seat surface 4a are always separated from each other when the valve is in a state other than the fully closed state. Even if it is attempted to change the opening area of the gate 2 of the valve in various ways by making appropriate changes, a large gap 16 is generated around the entire periphery between the valve body 9a and the valve seat surface 4a.
Due to the existence of the conductance, it was practically impossible to accurately control the conductance adjustment.

Therefore, in the past, this type of gate valve was only used to fully open or fully close a piping route.
A separate special valve is used for conductance adjustment, which not only increases the size of the device and creates difficulties when installing the device, but also increases the cost of the device due to the increased number of valves. It had the following problems.

In addition, as a means to solve the above-mentioned difficulties,
It is conceivable to set the distance 16 between the valve body 9a and the valve seat surface 4a to be extremely small, for example, on the order of several tenths of a millimeter. Not only is it difficult to raise and lower the valve 9a with such high precision, but the mounting state of the gasket provided on either the valve body 9 or the valve seat surface 4a may be affected by wear during use of the gasket. Immediately, larger dimensional errors than those described above arose, making the implementation completely impossible.

This invention was devised in view of the conventional problems as described above, and its purpose is to provide a gate valve with a conductance adjustment function.
The point is that there is no need for a valve for adjusting conductance.

(Means for solving the problem) The present invention prevents problems such as deterioration of valve operability and wear of the sealing surface such as the valve seat surface, and prevents the valve from opening when the gate is partially opened. This valve was constructed in an attempt to solve the above-mentioned conventional problems by developing a means for preventing the occurrence of a gap between the main body and the valve seat surface.

That is, the gist of the configuration of the present invention is that a cylindrical auxiliary seal body 5 is slidably fitted into the gate 2, and that the auxiliary seal body 5 closes the gap between the valve body 9 and the valve seat surface 4. The auxiliary seal body 5 is pressed to make a shut-off seal or a small valve body 9.
The point is that a pressing means 8 is separately provided for contacting or approaching the front surface of the holder.

(Function) Therefore, in the gate valve characterized by the above configuration, when the gate 2 is partially opened in the valve body 9, the auxiliary seal body 5 is pressed by the pressing means 8, and the valve body 9 is pressed. Since the gap between the valve body 9 and the valve seat surface 4 can be sealed or minimized, when calculating the effective opening area of the gate 2, the gap size between the valve body 9 and the valve seat surface 4 can be There is no need to consider the above, and very accurate conductance adjustment can be performed only by setting the position of the valve body 9. Furthermore, since the auxiliary seal body 5 is slidably fitted into the gate 2, the auxiliary seal body 5 prevents the valve body 9 from closing when the gate 2 is closed or when the valve body 9 is reciprocating. It does not move back freely due to pressure or the like, thereby interfering with the valve closing operation, etc.

(Example) Hereinafter, embodiments of the present invention will be described according to an example shown in the drawings.

In FIG. 1, reference numeral 1 indicates a valve casing formed with a gate 2 for fluid circulation, and a valve seat surface 4 with a packing 3 attached thereto is provided on the inner surface of the periphery of the gate of the casing 1. There is. Reference numeral 5 denotes a substantially ring-shaped auxiliary seal body having a flange-like step 6 at the rear end, and the auxiliary seal body 5 is designed so that its tip can protrude into the casing 1 beyond the position of the valve seat surface 4. The gate 2 is fitted into the gate 2 in a slidable manner, and the inner peripheral wall of the gate 2 has an engagement step 7 that can be engaged with the rear step 6 of the auxiliary seal body 5.
is formed. Reference numeral 8 denotes a spring for urging the auxiliary seal body 5 inwardly of the casing 1.

9 indicates a valve body supported by a valve shaft 10 etc. that can be raised and lowered and provided inside the valve casing 1;
The valve body 9 is fitted into a guide groove 14 provided in the vertical direction along the inner wall of the casing 1, and is mounted on the front surface of a leaf spring 12 having freely rolling guide rollers 11, 11 at both upper and lower ends. It is attached appropriately with bolts 13, etc. In addition, the valve body 9
An air cylinder (not shown) is separately provided on the back side of the valve body 9 to press the valve body 9 toward the front side facing the valve seat surface 4. Reference numerals 17 and 17 respectively indicate rollers for guiding the valve body 9 in the width direction.

The present embodiment has the above configuration, and its usage and operation will be explained next.

First, when completely blocking gate 2,
With the valve body 9 positioned at the lowest end as shown in Fig. 1, press the back side of the valve body 9 toward the valve seat surface 4 (in the direction of arrow A) with an air cylinder or the like via the leaf spring 12 as shown in Fig. 2. urge Therefore, the leaf spring 12 bends forward due to its pressing force as shown in the figure, and the valve body 9 tightly contacts the valve seat surface 4, thereby completely sealing the gate 2 under vacuum. This allows it to fully perform its function as a stop valve. At this time, the auxiliary seal body 5 is pushed by the valve body 9 and is in a retracted state.

Next, when opening the gate 2 and adjusting its conductance, the pressure on the valve body 9 is first stopped and released, and the valve body 9 is returned to its original state as shown in FIG. 1 by the elastic restoring force of the leaf spring 12. After returning to the state shown in FIG. 3, the dimensions of the valve body 9 are appropriately increased as shown in FIG. 3, and the opening area of the gate 2 is variously set.

However, in the state shown in the figure, the auxiliary seal body 5 is urged forward by the elastic force of the spring 8 and comes into contact with the front surface of the valve body 9.
The gap 16 between the valve body 9 and the valve seat surface 4 is maintained in a sealed state by the auxiliary seal body 5. Therefore, the air passing through the gate 2 does not pass between the valve body 9 and the valve seat surface 4, and the effective opening area of the gate 2 can be adjusted by raising and lowering the valve body 9. This allows for accurate adjustment, which allows highly accurate conductance adjustment. Further, even during the vertical movement of the valve body 9, the auxiliary seal body 5 comes into contact with the valve body 9 due to the pressing force of the spring 8. Since the contact force only needs to be very weak, it not only does not have any adverse effect on the valve operation surface, but also does not cause undue wear on the valve body 9.
Further, if the auxiliary seal body 5 is made of soft resin or the like, wear of the valve body 9 can be further prevented, and even if the auxiliary seal body 5 is worn, the valve body 9 and the valve seat surface 4 This does not cause any deterioration in the sealing function.

In the above embodiment, the tip of the auxiliary seal body 5 is brought into contact with the front surface of the valve body 9, but the present invention is not limited to this. For example, the tip of the auxiliary seal body 5 It is also possible to simply make the gap between the valve body 9 and the valve seat surface 4 very small without bringing the valve into contact with the front surface of the valve body 9.
Even in this case, the purpose of the present invention can be achieved.

Further, in the above embodiment, the auxiliary seal body 5
Since a step 6 that can engage with the engagement step 7 on the inner circumferential surface of the gate 2 is provided at the rear of the gate 2, the protrusion size of the auxiliary seal body 5 can be adjusted by setting the formation position and dimensions of the step 6. Of course, when the valve body 9 rises to an upper position where it does not face the valve seat surface 4 at all (when the gate is fully open), the auxiliary seal body 5 is pressed by the spring 8 and the gate 2 However, in the present invention, such a means is not an essential requirement, and the specific shape of the auxiliary seal body 5 can be arbitrarily determined depending on the shape of the gate 2, etc. It can be changed freely, and the specific material is not a problem. The point is that when the valve body 9 comes into contact with or approaches the valve body 9, the valve body 9
It suffices if it has a cylindrical shape that can be sealed or miniaturized to block the gap between the valve seat surface 4 and the valve seat surface 4, and is slidably fitted into the gate 2.

Furthermore, in the above embodiment, the auxiliary seal body 5
By pressing the auxiliary seal body 5 with the spring 8, when the valve is fully closed, the auxiliary seal body 5 is automatically pressed against the valve body 9 and retreated, and when adjusting the conductance of the gate 2, the auxiliary seal body 5 is appropriately pressed against the valve body 9. This has the advantage that there is no need to touch the auxiliary seal body 5 after the valve is assembled, but the present invention is by no means limited to this. There is no problem even if the auxiliary seal body 5 is brought into contact with and separated from the valve body 9 as necessary when the lever is operated. In short, the pressing means 8 may be any means that can press the auxiliary seal body 5 and come into contact with or approach the front surface of the valve body 9. However, in practice, it is preferable to use a spring as in the above embodiment.

Furthermore, the present invention is not limited to the configuration of the valve body 9 as in the above embodiments, and its specific shape and reciprocating means, as well as the configuration of the valve body 9 from the back side for pressure contacting the valve seat surface when the valve is fully closed. There is no particular limitation on the pressing means, and any known means may be used as appropriate.

In addition, the gate valve to which the present invention is applied is one in which the valve body 9 is provided so as to be able to reciprocate in the direction along the valve seat surface 4 while being separated from the valve seat surface 4, and the various parts of the valve are The specific configuration can be freely changed in design as necessary.

(Effects of the invention) As described above, the present invention presses the auxiliary seal body fitted into the gate and brings it into contact with or approaches the front surface of the valve body, thereby creating a connection between the valve body and the valve seat surface. Since the gap between the two can be sealed or minimized, there is no need to create a gap between the valve body and the valve seat surface as in the past when changing the gate opening area by adjusting the position of the valve body. As a result, the opening area of the gate can be adjusted accurately and the conductance can be suitably adjusted, which is a desirable effect.

Therefore, by using the gate valve according to the present invention, there is no need to use a separate conductance adjustment valve in addition to the gate valve as in the past, and the device can be made smaller, lighter, and less expensive. We have achieved great benefits by being able to save space when installing the equipment.

Moreover, since the auxiliary seal body of the present invention is made to be able to slide freely on the gate, the auxiliary seal body is moved back when the valve is closed, etc., so that the operability and airtight performance of the valve are not affected in any way. Without compromising the advantages of this type of valve, its practical value is enormous.

[Brief explanation of drawings]

FIG. 1 is a partially omitted sectional view showing an embodiment of the valve according to the present invention. Figures 2 and 3 show the state of use; Figure 2 is a sectional view of the main part when the valve is fully closed;
The figure is a cross-sectional view of the main parts during conductance adjustment. FIG. 4 is an explanatory diagram showing a conventional example. 2... Gate, 4... Valve seat surface, 5... Auxiliary seal body, 8... Spring (pressing means), 9... Valve body.

Claims (1)

[Claims for Utility Model Registration] 1. A gate valve in which a valve body 9 is provided so as to be able to reciprocate in a direction along the valve seat surface 4 while being separated from the valve seat surface 4 provided on the periphery of the gate 2. A cylindrical auxiliary seal body 5 is slidably fitted into the gate 2, and the auxiliary seal body 5 seals or seals the gap between the valve body 9 and the valve seat surface 4. A gate valve with a conductance adjustment function, characterized in that a pressing means 8 is separately provided for pressing the auxiliary seal body 5 so as to make it contact or approach the front surface of the valve body 9 in order to make the auxiliary seal body 5 very small. 2. The gate valve with a conductance adjustment function according to claim 1, wherein the pressing means 8 is a spring provided behind the auxiliary seal body 5.