JP2010001964A - Ball valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a durable and compact ball valve. <P>SOLUTION: This ball valve 1 structured to open and close a valve by rotating a ball valve element 7 with an actuator has a ring-like ball seat 4 and an O-ring 5 between a body 3 and the ball valve element 7. The ball seat 4 has a cantilever 41 to be brought in contact with the ball valve element 7, and the O-ring 5 is elastically deformed to push the cantilever 41 to the ball valve element 7. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention is a ball valve that changes the opening / closing or flow direction of a valve by rotating the ball valve body with an actuator, and a ring-shaped ball seat and an O-ring are used between the body and the ball valve body. It relates to the ball valve.

Conventionally, as this type of technology, there is a ball valve structure described below.
The structure of the conventional ball valve 110 is shown in FIG.
The ball valve 110 includes a valve body 111 having a flow path and a cylinder 112 that controls the ball valve body 103. A ball valve body 103 is disposed in the valve body 111, and the ball valve body 103 is rotated 90 degrees by an actuator (not shown) in the cylinder 112, thereby opening and closing the flow path.
FIG. 8 shows an enlarged view of the ball valve body 103, the triangular groove of the body 104, the ball seat 101, and the O-ring 102 of the ball valve 110 of FIG.
As shown in FIG. 8, there is a ball seat 101 and an O-ring 102 between the triangular groove of the body 104 and the ball valve body 103. The O-ring 102 is sandwiched between the triangular groove and the ball sheet 101 and is installed in a shape pushed in the angular direction of the triangular groove.
The ball seat 101 is pressed against the ball valve body 103 by the pressing force 102 b generated from the O-ring 102. Since the ball seat 101 is pressed against the ball valve body 103, no internal leakage of fluid occurs between the ball valve body 103 and the body 104 at the initial stage.

However, the conventional ball valve has the following problems.
Since there is no O-ring 102 at a position perpendicular to the surface where the ball seat 101 and the ball valve body 103 are in contact with each other, the pressing force 102a of the O-ring 102 is efficiently transmitted to the pressing force 102b where the ball sheet 101 presses the ball valve body 103. I couldn't. This is because the pressing force generated from the O-ring is the strongest in the vertical direction, whereas the conventional ball valve does not have the O-ring 102 in the vertical direction of the surface where the ball seat 101 and the ball valve body 103 are in contact with each other. .
Since the pressing force 102a of the O-ring 102 cannot be efficiently transmitted to the pressing force 102b, the O-ring 102 requires a pressing force stronger than the pressing force required for the pressing force 102b. As the pressing force based on the reaction force of the O-ring 102 is greatly deformed, its deterioration with time is faster, and the O-ring 102 cannot generate the necessary pressing force 102b that does not cause leakage. There has been a problem that the ring 102 needs to be replaced early.
Further, since the ball sheet 101 has a large contact surface with the ball sheet, there is a problem that the ball valve body 103 is worn out by the operation of the ball valve body 103 and is likely to leak.

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a compact ball valve having high durability.

In order to achieve the above object, a ball valve according to the present invention has the following configuration.
(1) The valve is opened and closed by rotating the ball valve body with an actuator, and a ball valve having a ring-shaped ball seat and an O-ring between the body and the ball valve body, The ball seat has a cantilever portion that contacts the ball valve body, and the cantilever portion is pressed against the ball valve body by elastic deformation of the O-ring.
(2) In the ball valve of (1), a convex portion is provided at a tip portion of the cantilever portion of the ball seat, or a convex portion is provided in the body corresponding to the tip portion of the cantilever portion. It is characterized by this.
(3) The ball valve body is opened and closed by rotating the ball valve body by an actuator, and a ball valve having a ring-shaped ball seat and an O-ring between the body and the ball valve body, The ball seat has a first cantilever portion and a second cantilever portion, an elastically deformed first O-ring that presses the first cantilever portion against the ball valve body, and a second cantilever portion as a ball valve. And having an elastically deformed second O-ring that presses against the body.

(1) In the present invention, by providing a cantilever portion and pressing a part of the ball seat, the position of the O-ring is shifted to the seal point side where the ball seat and the ball valve body come into contact with each other. The pressing force of the ring can be transmitted directly to the seal point. Therefore, the pressing force of the O-ring can be efficiently transmitted to the seal point, and the pressing force of the O-ring is about half better than the conventional pressure. Can be used about twice as long.
Further, since the cantilever portion itself is also elastically deformed, its own elastic deformation force acts in the same direction as the pressing force.
Therefore, since the pressing force of the O-ring can be efficiently transmitted to the ball seat, the O-ring can be used for a long time.

(2) When the present inventors repeated the experiment by providing a cantilever portion, it was found that there is a problem that the elastically deformed O-ring jumps out of the ball seat. As in the prior art, when the O-ring is pressed against the ball valve body as a whole, the reaction force acting on the O-ring is balanced, so the O-ring does not jump out of the ball seat. It was. However, in the cantilever portion, it is considered that the mouth of the ball valve body jumps out of the ball seat by squeezing the O-ring through the ball seat. In this invention, since the convex part is provided in the said body corresponding to the front-end | tip part of the said cantilever part, it can prevent that an O-ring jumps outside by a convex part.
(3) Since there are two places to be sealed, the sealing performance can be improved, so that the ball seat can be reliably pressed against the ball valve body.
Moreover, since the pressing force of the O-ring can be efficiently transmitted to the ball seat, the O-ring can be used for a long time.

The first embodiment will be described.
A ball valve according to a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view for explaining the valve body 3 in the front view of the ball valve 1. FIG. 2 is a cross-sectional view taken along the line AA in FIG. FIG. 3 is an exploded perspective view of the valve body 3.
As shown in FIG. 1, the ball valve 1 includes a cylinder 2 and a valve body 3.
As shown in FIG. 3, the outer shape of the valve body 3 is constituted by a valve body main body 8 and a valve cap 6. Between the valve body main body 8 and the valve cap 6, ring-shaped ball seats 4A and 4B and O-rings 5A and 5B are formed on the left and right with the ball valve body 7 for opening and closing the ball valve 1 as the center. Yes. The ball seats 4A and 4B are attached to prevent the fluid from leaking between the ball valve body 7 and the valve body main body 8. The O-rings 5A and 5B are attached to press the ball seats 4A and 4B against the ball valve body 7 so that the fluid does not leak. A packing 17 is attached to a joint portion between the valve body main body 8 and the valve cap 6. A flow path 8 b is formed in the valve body body 8. A channel 6 a is formed in the valve cap 6.
The ball valve body 7 is formed with a flow path 7b through which a fluid flows. The spherical wall surface of the ball valve body 7 is referred to as a wall surface 7c.
A shaft hole 8 a and a screw hole 8 c are formed in the joint surface of the valve body main body 8 with the cylinder 2. A shaft 9 capable of rotating by 90 degrees is inserted into the shaft hole 8a. There is an O-ring 10 for preventing fluid leakage in the gap with the shaft hole 8a when the shaft 9 is inserted. A ball joint portion 9 a is provided at the lower end portion of the shaft 9 and is fitted to the shaft joint portion 7 a of the ball valve body 7. There is a pinion joint 9 c at the upper end of the shaft 9, which is fitted with a pinion 16 in the cylinder 2.

FIG. 4 shows a characteristic part of the present invention. FIG. 4 is a view in which the ball seat 4A, the O-ring 5A, the valve body main body 8, and the ball valve body 7 of FIG. 1 are characteristically extracted.
The valve body main body 8 has two contact surfaces 81 and 82.
The shape of the ball seat 4 </ b> A has a substantially pentagonal shape formed by a surface 422, a surface 411, a surface 43, and a surface obtained by extending the surfaces 413 and 421. The angle M formed by the surface obtained by extending the surface 413 and the surface 411 is about 50 degrees in this embodiment. The ball seat 4A has a substantially pentagonal shape with a substantially trapezoidal shape cut out. The notched substantially trapezoidal shape has a bottom surface that is the length of the surface 423 and a top surface that is a length L. Since the length of the surface 423 is longer than the length L, the notch width becomes wider toward the surface 423. The length L is about 1 mm in this embodiment. The angle N formed by extending the surface 412 and connecting to the contact surface 81 is about 30 degrees in this embodiment.

The surfaces 421 and 422 are in contact with the contact surfaces 81 and 82. A portion surrounded by the surfaces 421 and 422 and the surface 423 is a support column 42A. Since the support 42A is in contact with the contact surfaces 81 and 82, it is in a fixed state. The surface 423 is in contact with the O-ring 5A.
A portion surrounded by the surfaces 411, 412, and 413 is a cantilever portion 41A. The surface 411 of the cantilever 41A is in contact with the ball valve body 7. An O-ring 5A is attached in a vertical direction from a contact surface where the surface 411 and the ball valve body 7 are in contact. The surface 412 is in contact with the O-ring 5A. Since the cantilever 41A is in a state of being pressed against the ball valve body 7, it is formed in a state of being pressed inward. Therefore, the cantilever portion 41 </ b> A itself has an elastic deformation force and has a pressing force to push the ball valve body 7.
The O-ring 5A is surrounded on three sides by the contact surface 81 of the valve body main body 8, the surface 412 of the cantilever 41A, and the surface 423 of the support column 42A.

  As shown in FIG. 2, the cylinder 2 has an outer shape formed by a cylinder body 12 and a cylinder cap 11. Inside the cylinder 2, a pinion 16 is rotatably attached to the center, and racks 14 </ b> A and 14 </ b> B are attached to both sides thereof so as to be linearly movable so as to be fitted to the pinion 16. An O-ring 13 is attached to the racks 14A and 14B to prevent fluid leakage. The racks 14A and 14B are joined to actuators (not shown).

Next, the operation of the present invention according to the first embodiment will be described.
The ball valve 1 is divided into a state in which the flow path is opened and a state in which it is closed by the rotation of the ball valve body 7. First, the closed state of the flow path will be described with reference to FIG.
In the state shown in FIG. 1, for example, when the fluid is flowing from the flow path 8b side, the flow of the fluid flows to the flow path 6a side because the flow path is blocked by the wall surface 7c of the ball valve body 7. I can't.
The fluid blocked by the wall surface 7c of the ball valve body 7 tends to flow toward the flow path 6a through the space between the wall surface 7c of the ball valve body 7 and the valve body main body 8. However, fluid cannot flow between the wall surface 7c of the ball valve body 7 and the valve body body 8 due to the ball seat 4A and the O-ring 5A. That is, the fluid that is about to flow along the wall surface 7 c of the ball valve body 7 is such that the O-ring 5 A presses the cantilever portion 41 A, and the surface 411 of the cantilever portion 41 A contacts the wall surface 7 c of the ball valve body 7. Because it is, it can not flow. Further, the fluid cannot flow from the O-ring 5A side because the O-ring 5A is sealed.

The sealing characteristics of the ball seat and O-ring, which are the features of the present invention, will be described by comparing FIG. 8 showing the prior art with FIG. 5 showing the present invention.
The characteristic by forming the cantilever 41A will be described.
First, the prior art will be described with reference to FIG. In FIG. 8, the pressing force generated from the O-ring 102 obtained as a result of the experiment is represented by arrows 102a, 102b, 102c, and 102d.
The pressing force 102a directly generated from the O-ring 102 presses the ball seat 101, and the pressing force 102b is generated to press the ball valve body 103.
The prior art shown in FIG. 8 does not form a first cantilever portion 41A of the present invention which will be described later.
In the prior art shown in FIG. 8, there is no O-ring 102 at a position perpendicular to the surface where the ball seat 101 and the ball valve body 103 are in contact. Therefore, the pressing force 102a of the O-ring 102 cannot be transmitted efficiently. This is because the pressing force generated from the O-ring is best transmitted in the vertical direction.
For example, with respect to the pressing force 102b that presses the ball sheet 101 against the ball valve body 103, the pressing force 102a that the O-ring 102 presses the ball sheet 101 must be pressed with a force stronger than the pressing force 102b.
As the pressing force based on the reaction force of the O-ring 102 is greatly deformed, its deterioration with time is faster, and the O-ring 102 cannot generate the necessary pressing force 102b that does not cause leakage. It was necessary to replace the ring 102 at an early stage.

Next, an embodiment of the present invention will be described with reference to FIG. In FIG. 5, the figure which represented the pressing force which arises from O-ring 5A obtained by the experimental result with the arrows 51, 52, 53, 54 is shown.
The pressing force 51 by which the O-ring 5A presses the cantilever portion 41A presses the cantilever portion 41A, and the cantilever portion 41A receives the pressing force 51 and presses the wall surface 7c of the ball valve body 7. A pressing force pressed against the wall surface 7 c is indicated by a pressing force 52.
In the present invention shown in FIG. 5, an O-ring 5 </ b> A is disposed at a location perpendicular to the surface of the ball seat 4 </ b> A that contacts the ball valve body 7. In the present embodiment, by providing the cantilever portion 41A, the position of the O-ring 5A is shifted to the seal point side where the ball seat 4A and the ball valve body 7 come into contact with each other. The ball valve body 7 could be positioned in the vertical direction of the surface in contact with it.

The pressing force 51 generated from the O-ring 5A is best transmitted in the vertical direction. Therefore, in this embodiment, since the O-ring 5A is positioned in a direction perpendicular to the surface where the ball seat 4A and the ball valve body 7 are in contact, the pressing force 51 for the O-ring 5A to press the ball seat 4A is 52 can be efficiently transmitted. Therefore, if the O-ring generates the same pressing force, conventionally, only about half of the pressing force of the O-ring 102 can be transmitted to the contact surface between the ball seat 101 and the ball valve body 103. In this embodiment, substantially the same pressing force can be transmitted to the contact surface between the ball seat 4A and the ball valve body 7.
Therefore, in this embodiment, when an O-ring having the same pressing force as in the prior art is used, the ball valve body 7 and the ball seat 4 come into contact with each other even if the pressing force 51 is reduced due to deterioration over time of the O-ring 5A. Therefore, the O-ring 5A can be continuously used because the pressing force required for the operation is small. Therefore, it is not necessary to replace the O-ring 5A at an early stage, and the sealing performance can be maintained for a long time.

Since the cantilever 41A is in a state of being pressed against the ball valve body 7, it is in contact with the ball valve body 7 while being pressed inward. Since the cantilever 41A is pushed inward, the cantilever 41A itself has an elastic deformation force, and the ball valve body 7 is pressed by the elastic deformation force. Therefore, compared with the prior art, the ball valve body 7 can be strongly pressed in that the cantilever 41A itself also has a pressing force.
Further, the fluid flowing in from the flow path 8b flows into the notch formed by the surface 412 and the surface 423 of the cantilever 41A. When the fluid flows into the notch, the cantilever 41A is lifted, and the cantilever 41A is further pressed against the ball valve body 7 to further improve the sealing performance.
When the fluid flows into the ball valve 1 shown in FIG. 1, the ball valve body 7 is pushed into the flow channel 6a. When the ball valve body 7 is pushed into the flow path 6a, the cantilever 41B of the ball seat 4B is pushed further inward. When the cantilever 41B is pushed inward, the sealing performance is further enhanced.

Second, the state where the flow path is opened will be described.
The racks 14A and 14B are moved outward by an actuator not shown in FIG. By moving the racks 14 </ b> A and 14 </ b> B outward, the pinion 16 is given a leftward rotational motion. When the pinion 16 rotates to the left, the shaft 9 fitted to the pinion 16 and the ball valve body 7 fitted to the shaft 9 rotate 90 degrees to the left.
Since the ball valve body 7 is rotated 90 degrees, the flow path 7b of the ball valve body 7 is aligned with the flow paths 6a and 8b, so that the fluid flowing from the flow path 8b passes through the flow path 7b. It flows to 6a. Even when the fluid passes through the flow path 7b of the ball valve body 7, the fluid may flow along the wall surface 7c of the ball valve body 7. However, the O-ring 5A presses the cantilever 41A and cantilevered. Since the outer portion 411 of the beam portion 41A is in contact with the wall surface 7c of the ball valve body 7, fluid leakage can be prevented.

Since the pressing force of the O-ring 5A can be efficiently transmitted to the ball valve body 7, the sealing performance and durability are improved. Further, since there is no increase in the number of components for improving the sealing performance and durability, there is an economic effect that the cost can be reduced.
Further, since the load torque of the ball valve body 7 is stable, a small actuator can be used, which can contribute to miniaturization of the valve or low pilot pressure.
In addition, since the configuration is simple, it is easy to assemble and maintain.

As shown in FIG. 6, by providing the convex portion 8d on the body corresponding to the tip of the cantilever portion 41A of the ball seat 4A, it is possible to prevent the O-ring 5A from jumping out.
That is, as shown in FIG. 8, when the O-ring 102 presses the entire ball seat 101 against the ball valve body 103, reaction forces acting on the O-ring 102 are balanced. Did not jump out of the ball sheet 101.
However, in the cantilever 41A as shown in FIG. 4, it is considered that the O-ring 5A jumps out of the ball seat 4A when the mouth of the ball valve body 7 squeezes the O-ring 5A via the ball seat 4A. . In the present invention, since the convex portion 8c is provided on the body corresponding to the tip portion of the cantilever portion 41A, the convex portion 8c can prevent the O-ring 5A from jumping to the outside.
In order to prevent the O-ring 5A from popping out, the same effect can be obtained by providing a convex portion on the cantilever portion 41A.

The second embodiment will be described.
A second embodiment of the ball valve according to the present invention will be described with reference to FIG.
Since the shape of the ball seat portion is the same as that of the first embodiment, description of forms other than the portion shown in FIG. 7 is omitted.
The ball seat 50 has a T shape, and includes a first cantilever part 50a, a second cantilever part 50b, and a support part 50c.
The cantilever portion 50a is sandwiched between the ball valve body 54 and the first O-ring 51A. Further, the cantilever portion 50b is sandwiched between the ball valve body 54 and the second O-ring 51B. The support column 50 c is fixedly provided at a corner 53 A of the valve body 53.

Next, the operation of the second embodiment will be described.
Also in the second embodiment, it is necessary to prevent the fluid from flowing out through the gap between the ball valve body 54 and the valve body 53 as in the first embodiment.
In the second embodiment, the fluid cannot flow due to the ball seat 50, the first O-ring 51A, and the second O-ring 51B between the ball valve body 54 and the valve body 53. That is, the fluid that is about to flow along the wall surface 54c of the ball valve body 54 is such that the first O-ring 51A presses the cantilever portion 50a, and the cantilever portion 50a comes into contact with the wall surface 54c of the ball valve body 54. Therefore, it cannot flow. Furthermore, in the second embodiment, the second O-ring 51B presses the cantilever portion 50b, and the cantilever portion 50b comes into contact with the wall surface 54c of the ball valve body 54, so that it cannot flow.
In the second embodiment, there are two places to be sealed, so that the sealing performance can be improved.
Moreover, since the pressing force of the O-rings 51A and 51B can be efficiently transmitted to the ball seat 50, the O-rings 51A and 51B can be used for a long time.

Note that the present invention is not limited to the above-described embodiment, and various applications are possible.
For example, by changing the hardness and material of the O-ring, the pressing force can be changed and various fluids can be handled.
Further, the surface pressure distribution can be freely adjusted by changing the O-ring to a specially shaped product or by changing the structure of the ball seat.
Further, by changing the material of the ball sheet to PTFE or the like, the wear resistance can be improved and the durability can be further improved.
Further, the ball valve structure may be a one-way rotating ball valve as well as 90-degree forward / reverse rotation.
Further, the actuator may be not only an air operated type but also an electric drive.
Further, the elastic body that presses a part of the ball seat may be a disc spring or the like as well as the O-ring.

The figure made into sectional drawing for demonstrating the valve body 3 among the front views of the ball valve 1 is shown. AA sectional drawing of FIG. 1 is shown. An exploded perspective view of valve body 3 is shown. The figure which extracted the ball seat 4A of FIG. 1, O-ring 5A, the valve body main body 8, and the ball valve body 7 is shown. The pressing force generated from the O-ring 5A obtained as a result of the experiment is added to the drawing in which the ball seat 4A, the O-ring 5A, the valve body main body 8, and the ball valve body 7 are extracted. The figure which provided the convex part 8c in the body corresponding to the front-end | tip part of 41 A of cantilever parts of the ball seat 4A is shown. The figure which showed 2nd Embodiment is shown. The ball valve body 103, the triangular groove of the body 104, the ball seat 101, and the O-ring 102 are extracted from the ball valve 110 of FIG. The figure made into sectional drawing for demonstrating the valve body 3 among the front views of the ball valve 110 which is prior art is shown.

Explanation of symbols

1 Ball valve 2 Cylinder 3 Valve body 4A, 4B Valve seat 5A, 5B O-ring 6 Valve cap 7 Ball valve body 8 Valve body body

Claims (3)

By opening and closing the valve by rotating the ball valve body with an actuator, the ball valve having a ring-shaped ball seat and an O-ring between the body and the ball valve body,
The ball seat has a cantilever portion in contact with the ball valve body;
Pressing the cantilever part against the ball valve body by elastically deforming the O-ring;
Ball valve characterized by The ball valve of claim 1,
Providing a convex portion at the tip of the cantilever portion of the ball seat, or providing a convex portion on the body corresponding to the tip portion of the cantilever portion;
Ball valve characterized by By opening and closing the valve by rotating the ball valve body with an actuator, the ball valve having a ring-shaped ball seat and an O-ring between the body and the ball valve body,
The ball sheet has a first cantilever portion and a second cantilever portion;
An elastically deformed first O-ring that presses the first cantilever portion against the ball valve body, and an elastically deformed second O-ring that presses the second cantilever portion against the ball valve body,
Ball valve characterized by

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