JPH043163Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a butterfly valve mainly used for controlling the flow in a gas distribution path.

[Prior art] Butterfly valves are capable of freely changing the opening of the flow path from fully open to fully closed by rotating the valve plate approximately 90 degrees around its fulcrum.
It is used in various parts of fluid passages that circulate various gases, air, etc. In this type of butterfly valve, as shown in Fig. 5, an example is shown in Fig. 5.
Disc-shaped valve plate 7 installed in pipe D
By rotating the plate around its installation center o in conjunction with the rotational movement of the operating shaft 1 inserted from the outside, its outer peripheral end 7a is brought into close contact with the seat surface s from a fully open state in a horizontal plate position within the flow path. The mechanism allows you to freely change the opening degree up to a fully closed state with a vertical plate position.

[Problems to be solved by the invention] By the way, when a butterfly valve is used in a vacuum device or the like, in order to ensure a vacuum seal when the butterfly valve is fully closed, it is necessary to place an O between the outer peripheral end 7a of the valve plate 7 and the seat surface s. It is common to use a sealing material such as a ring (not shown), but in conventional valve mechanisms, this sealing material cannot be used effectively. That is, the valve plate 7 and the seat surface s
The sealing effect of the sealing material interposed between the two is most effective when it is compressed between the two, but in the conventional butterfly valve, its opening/closing mechanism does not touch the valve plate 7. Since it is rotated around the installation center o, the outer peripheral end 7a of the valve plate 7 slides parallel to the seat surface s, and if the rotational driving force is weak, the sealing material An accurate closed state may not be obtained due to friction, or the sealing material may be incompletely deformed, resulting in insufficient sealing action. In addition to this operational uncertainty, the sealing material is also rubbed against each other during each opening/closing operation, resulting in other inconveniences such as severe abrasion of the sealing material.

On the other hand, as shown in Japanese Patent Publication No. 38-24930, for example, the rotational force of the operating shaft is transmitted through a transmission mechanism consisting of a pinion fixed to the operating shaft and a rack protruding from the valve plate. A valve plate has also been developed in which a force is applied to the valve plate to move it forward and backward, thereby bringing the valve plate into close contact with the seat surface.

However, with such a configuration, once the valve plate is tightened by rotationally driving the operating shaft by the driving means, and when the driving force is released, the rack and pinion easily operate in reverse due to the tightening reaction force. , the valve plate may separate from the seat surface. Therefore, in order to maintain an effective tightening force, the driving means must have a self-locking mechanism, which is a disadvantage. Moreover, various transmission mechanisms such as a rack and pinion mechanism are interposed between the drive means and the valve plate, and there is backlash between them, so even if the actuation shaft can be locked through the drive means, the valve plate There is a possibility that the bolt will loosen at least by the amount of backlash, and it cannot be used to reliably prevent the tightening force from decreasing.

The present invention was developed with an eye to these problems, and its purpose is to enable the valve plate to be brought into contact with and be removed from the seat surface without sliding, and to provide high sealing performance when the valve is fully closed. It is an object of the present invention to provide a butterfly valve with a mechanism that guarantees this and at the same time ensures the life of the sealing material.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes an operating shaft provided with a bevel gear, and an operating shaft that is connected to the operating shaft so as to be rotatable in synchrony with the operating shaft, and that only when the rotation is restrained, the operating shaft is rotated. a plate support that is rotatable relative to the plate support; a screw that is provided with a bevel gear rotatably perpendicular to the operating shaft and that meshes with a bevel gear of the operating shaft; To provide a butterfly valve constituted by a valve plate integrally provided with a fitting nut and movably attached to the plate support, and a rotation stopper for stopping rotation of the valve plate in an attitude parallel to a seat surface.

[Operation] The butterfly valve having the above configuration operates as follows. First, the valve closing operation is performed by rotating the operating shaft in a predetermined valve closing direction, and at this time, the plate support rotates in synchronization with the operating shaft, and the valve plate rotates together with this. When the valve plate rotates to a position parallel to its seat surface, a rotation stopper acts to prevent further rotation of the valve plate, and at the same time, the rotation of the plate support is restrained, so that the operating shaft is further rotated. When rotated, the operating shaft rotates independently. However, when the operating shaft rotates relative to the plate support, the bevel gear that meshes with the bevel gear of the operating shaft rotates as a result, and the screw that extends through the plate support also rotates. It is possible to cause the nut to perform a relative screwing-back motion. As a result, the valve plate attached to the plate support can be advanced from the plate support and pressed against the seat surface while remaining parallel to the seat surface.

The valve opening operation is then performed by rotating the operating shaft in the opposite direction. In other words, when the operating shaft is reversed from the fully closed state of the valve, the valve plate and plate support cannot rotate because the valve plate is prevented from rotating by the seat surface, and only the operating shaft rotates, causing the screw to rotate in the opposite direction. . Then, due to the relative spiral movement of the screw relative to the nut, the valve plate is once retreated and separated from the seat surface. Thereafter, the plate support rotates in synchronization with the operating shaft, and the valve plate rotates together with the plate support, increasing the valve opening degree and reaching the fully open position.

In this way, when the valve is opened or closed, the valve plate moves forward and backward parallel to the seat surface and comes into contact with and separates from the seat surface, which prevents the inconvenience of the outer peripheral edge sliding against the seat surface. This can definitely be avoided. Furthermore, even if the rotational driving force to the operating shaft is released after the valve is closed, the nut and screw will not easily move in the opposite direction due to the tightening reaction force.
A holding force acts directly on the valve plate. Therefore, the valve plate remains in close contact with the seat surface effectively.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

Figures 1 and 2 show the structure of a butterfly valve in a fully closed state. In the figure, 1 is the operating shaft inserted into the duct D, and the tip is positioned eccentrically without penetrating the flow path. There is. In addition, this operating shaft 1
is the same as the conventional example shown in FIG.
is eccentric from the center of the flow path. A bevel gear 2 is integrally connected to the tip of the operating shaft 1.

The operating shaft 1 with this bevel gear 2 installed in the duct D
A plate support 3 is disposed so as to be rotatable in synchronization with the operating shaft 1 in a straight line. This plate support 3 includes a block-like main body 3a and a block-like main body 3a.
A support shaft portion 3 protrudes integrally and concentrically from the upper and lower surfaces of a.
b, 3c, and the supporting shaft portions 3b,
3c is aligned with the operating shaft 1, and the upper short support shaft portion 3b is closely fitted into a shaft hole 2a recessed in the distal end surface of the bevel gear 2 at the tip of the operating shaft. , the lower elongated support shaft portion 3c is inserted into the insertion hole of the duct D, and is stably supported within the duct D by being rotatable around its axis. This plate support 3 is normally operated by appropriately adjusting the fit between the short support shaft 3b at the top and the shaft hole 2a on the operating shaft 1 side where the support shaft 3b is fitted and connected. The plate support 3 is caused to rotate synchronously with the bevel gear 2, that is, the operating shaft 1, due to the friction generated at the fitting surfaces. However, since such a frictional rotation transmission mechanism is adopted, when the rotation of the plate support 3 is restricted, relative rotation is possible in which the plate support 3 does not rotate and only the operating shaft 1 side rotates independently. Ru.

A screw 4 and a guide rod 5, each of which extends in a direction perpendicular to the operating axis 1, extend through the plate support 3 in parallel. The screw 4 is positioned and penetrates the plate support 3 so that it can rotate freely around its axis but cannot move forward or backward (slide).On the other hand, the guide rod 5 has its base end connected to the valve as described later. It is fixedly attached to the plate and can move forward and backward with respect to the plate support 3, but is not rotatable. The screw 4 is provided on the penetrating back side of the plate support 3, which is opposite to the valve plate.
A bevel gear 6 that meshes with the bevel gear 2 provided at the tip of the operating shaft 1 is fixedly installed, and when the operating shaft 1 rotates relative to the plate support 3, driven rotation occurs via these meshing bevel gears 2 and 6. do. The screw 4 is positioned with respect to the plate support 3 by the bevel gear 6 on the rear side and the collar 4b provided on the entire surface side, and is held so that it cannot be slid.

In this way, the screw 4 and the guide rod 5 are attached to the front of the plate support 3 through which the screw 4 and the guide rod 5 are inserted so that they can move forward and backward, and the outer peripheral end 7a is shaped to correspond to the seat surface s on the inner surface of the duct D. A disk-shaped valve plate 7 is provided. This valve plate 7 has the proximal end of the guide rod 5 fixedly attached to the deflected portion on the back surface, and has a female thread carved on the inner periphery at a portion centrally symmetrical to the fixed portion of the guide rod 5. The provided cylindrical nut 8 is integrally provided and protrudes. The rear end 4a of the screw 4, which has a male thread, is screwed into the nut 8 so as to be able to move forward and backward.

The valve plate 7, which is attached to the plate support 3 through the screw 4 and the guide rod 5 in this manner, uses the screw nuts 4, 8 and the guide rod 5, which are screwed together against the rotation of the plate support 3, as a pivot arm. The rotation of the screw 4, which rotates integrally at equal angles and cannot move forward or backward from the plate support 3, is supported by the relative screw movement of the nut 8 while maintaining the posture of the slideable guide rod 5. It moves forward or backward from the plate support 3 while remaining parallel to the plate support 3.

In addition to these components, the valve plate 7 is provided with a rotation stopper 9 that stops further rotation when the valve plate 7 rotates to a position parallel to the seat surface s as shown in FIGS. 2 and 3. There is. This rotation stopper 9 is in this case the plate support 3
A protrusion 9a integrally provided on a portion of the lower long support shaft portion 3c extending from the insertion hole of the duct D.
and a branch tube 9b with a notch, which is provided integrally with the duct D around the insertion hole and allows the protrusion 9a of the support shaft portion 3c to rotate within a range of 90 degrees. In other words, the plate support 3 has a range of postures from horizontal to the flow path to perpendicular to the flow path, with the protrusion 9a of the lower long support shaft 3c in contact with both notched surfaces of the notched branch tube 9b. At the same time, the valve plate 7 is stopped from rotating in a position exactly parallel to the seat surface s.

Note that a sealing material 10 such as an O-ring is interposed between the outer peripheral end 7a of the valve plate 7 and the seat surface s.
can be attached to either side.

Next, the operation of this butterfly valve will be explained with reference to FIGS. 2 to 4.

First, a case will be described in which the valve is brought from a fully open state to a fully closed state as shown in FIG. 4. At that time, the actuating shaft 1 is rotated in a predetermined direction by a suitable driving means. Then, the plate support 3 connected to the operating shaft 1 rotates in synchronization with the friction between its upper support shaft 3b and the shaft hole 2a of the bevel gear 2, and the valve plate 7 rotates together with this. Then, when the valve plate 7 rotates to a position parallel to its seat surface s (the state shown in FIG. 3), the protrusion 9a provided on the lower long support shaft 3c of the plate support 3 moves into the notched branch tube 9b. The rotation stopper 9 works by coming into contact with the plate support 3.
Its own rotation is restrained, and at the same time the valve plate 7
Further rotation of is prevented. Therefore, when the actuating shaft 1 is further rotated in the closing direction, the actuating shaft 1 rotates independently. However, when the operating shaft 1 rotates relative to the plate support 3, the bevel gear 6 meshing with the bevel gear 2 of the operating shaft 1 rotates accordingly, and the screw 4 extending through the plate support 3 also rotates. . Since the screw 4 itself cannot slide and is screwed into a nut 8 provided on the valve plate 7, it cannot be screwed back relative to the nut 8 under rotational restraint by the guide rod 5. It can be done. As a result, the valve plate 7 attached to the plate support 3 is
While maintaining the posture with the guide rod 5, it can be advanced from the plate support 3 and pressed against the seat surface s while maintaining the posture parallel to the seat surface.

On the other hand, the valve opening operation is performed by reversing the operating shaft 1. That is, when the operating shaft 1 is rotated in the predetermined opening direction from the fully closed state of the valve shown in FIG. 2, the valve plate 7 is prevented from rotating by the seat surface s.
is rotationally restrained, first only the operating shaft 1 rotates, and with this, the valve plate 7 is temporarily retreated from the plate support 3 due to the relative spiral movement of the screw nuts 4 and 8 opposite to the above, and the seat surface s (restored to approximately the state shown in FIG. 3). When the valve plate 7 separates from the seat surface s, the rotational resistance decreases and the valve plate 7 and the plate support 3 are free to rotate in the opening direction. The valve plate 7 rotates in synchronization with the operating shaft 1, and the valve opening degree increases until it reaches a fully open position (the state shown in FIG. 4).

As is clear from the above operation, according to the butterfly valve according to the present invention, when the butterfly valve is closed or opened, the valve plate 7 moves forward and backward in a posture parallel to the seat surface s, and does not come into contact with or separate from the seat surface s. It is something that can be done. Therefore, when the valve is closed, the sealing material 10 can be squeezed between the outer circumferential end 7a of the valve plate 7 and the seat surface s, and the vacuum sealing performance is exhibited in the most effective state. In addition, since the inconvenience of the outer peripheral end 7a of the valve plate 7 sliding on the seat surface s during both opening and closing can be reliably avoided, uncertainties in operation due to friction can be eliminated, and at the same time, wear and tear on the sealing material 10 can be reduced. This will improve its lifespan. Furthermore, according to the butterfly valve according to the present invention, even if the driving force applied to the actuating shaft 1 is released after the valve plate 7 is once tightened, the nut 8 and the screw 4 can be easily moved depending on the tightening reaction force. There is no reverse action, and the holding force acts directly on the valve plate 7. Therefore, even if a simple drive means without a self-locking mechanism is adopted, the tightening force during drive will continue to be exerted even after the drive force is released, and the tightening force on the seat surface s of the valve plate 7 will continue to be exerted. This results in a special effect of dramatically improving the adhesion state.

Note that the rotation stopper 9 necessary for the butterfly valve of the present invention can be of a mechanism that directly stops the rotation of the valve plate 7, but it is possible to adopt a rotation stopper 9 that directly stops the rotation of the valve plate 7. A simple structure and reliable stopper function can be guaranteed. Further, the guide rod 5 for allowing the valve plate 7 to move smoothly forward and backward with respect to the plate support 3 may be arranged on the right and left sides of the screw 4 as in the embodiment, or may be arranged above and below the screw 4. good. When using this guide rod 5, it is also possible to arrange a plurality of guide rods as necessary.

[Effect of idea]

According to the butterfly valve of the present invention having the configuration and operation described in detail above, the valve plate approaches and separates by moving forward and backward in a posture parallel to the seat surface, so contact failure due to friction does not occur. The sealing state is reliably achieved without any problems, and the wear of the sealing material interposed on the sheet surface is also reduced. Moreover, even if the driving force applied from the outside is released after the valve plate is brought into close contact with the seat surface, the valve plate will be effectively held in that position by the holding force generated between the nut and the screw. . Therefore, even if a simple drive means without a self-locking mechanism is used, the effect of dramatically improving the sealing performance of the valve plate can be obtained.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, with FIG. 1 being a cutaway perspective view of the main parts, and FIG. 2 being a side sectional view. 3 and 4 are side sectional views for explaining the operation of the embodiment. FIG. 5 is a sectional view showing a conventional example. 1... Operating shaft, 2... Bevel gear, 2a... Shaft hole,
3...Plate support, 3a...Main body, 3b...
Upper short support shaft portion, 3c...Lower long support shaft portion, 4...
... Screw, 4a... Rear end, 5... Guide rod,
6...Bevel gear, 7...Valve plate, 8...Nut, 9...Rotation stopper, 9a...Protrusion, 9b
...Branch tube with notch, 10...Sealing material, s...Seat surface, D...Duct.

Claims (1)

[Scope of utility model registration request] an operating shaft provided with a bevel gear; a plate support that is connected to the operating shaft so as to be rotatable in synch with the operating shaft and can rotate relative to the operating shaft only when the rotation is restricted; and a plate support that rotates orthogonally to the operating shaft. a screw provided with a bevel gear freely extending therethrough and meshing with the bevel gear of the operating shaft; a valve plate integrally provided with a nut into which the screw is screwed and attached to the plate support so that it can move forward and backward; This butterfly valve is characterized by comprising a rotation stopper that stops the rotation of the valve plate in a position parallel to the seat surface.