JPH0429911B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a ball valve, and more particularly to a block type ball valve in which the balls are prevented from slipping out of the valve body.

(Prior art) As a conventional ball valve, a ball that can open and close a flow path is arranged in a cylindrical valve body, and a ball seat is brought into contact with this ball from both sides of the flow path, and this ball seat is held by a ball presser. There is a so-called flexible ball valve that is pressed toward a ball. In this ball valve, by connecting the connecting sleeve to the valve body, the ball retainer is pressed by the connecting sleeve and is pressed toward the ball. For example, the ball retainer is pressed by a connection sleeve connected to the valve body by a union nut, and by adjusting the tightness of the union nut, the contact pressure between the ball and ball seat can be adjusted, causing wear and tear on the ball seat. The mechanism is such that when liquid leaks, the union nut can be tightened to prevent the leak.

(Problem to be Solved by the Invention) The biggest drawback of this type of ball valve is that the ball closes the flow path and maintains fluid pressure on one side of the ball, while the union nut on the other side and The connection sleeve cannot be removed. That is, when the pipe connected to the connecting sleeve needs to be repaired or replaced, the connecting sleeve must be removed by loosening the union nut, but when the connecting sleeve is removed, the ball and ball The presser foot flew out from the valve body, which was dangerous.

To solve this problem, there is a device that has a ball holder on only one side and integrates the other with the valve body (for example, the one described in U.S. Pat. No. 3,550,902), and the ball holder is placed on the pressure side. It will be piped towards. However, since the wear of the ball seat is adjusted by tightening the union nut on one side, repeated tightening may cause the ball and spindle to become misaligned, making it difficult to open or close the ball by turning the handle. The rotational torque becomes large, making it difficult to operate smoothly, and if the spindle is turned forcibly, the spindle is pressed down strongly from only one side, which has the disadvantage of causing leakage from the seal around the spindle. Ta.

Also, JP-A-57-37160, JP-A-57-
Publication No. 110873, Publication of Utility Model Publication No. 57-105474, etc.,
By screwing the ball holder into the valve body,
Although it is disclosed that the ball holder can be prevented from popping out, there is a drawback that it is not possible to retighten the ball seat from the outside when it wears out, and furthermore, Japanese Patent Publication No. 53-6375 discloses a ball holder with a dog around the periphery. It is disclosed that the dog is pushed into the valve body and rotated to cause the dog to engage with a groove provided on the inner circumferential surface of the valve body to prevent the ball holder from popping out, but is the ball holder engaged with the valve body? To check whether this is the case, you must remove the union nut and turn the ball holder.

Also, screw the ball holder into the valve body,
The disadvantage is that a special tool is required to push it in and turn it.

Further, a ball valve in which a ball integrally formed with a spindle is insert-molded together with a ball seat into a synthetic resin valve body during injection molding of the valve body is described, for example, in US Pat. No. 3,807,692. If the ball is formed as an insert in the valve body in this way, the ball will not pop out when the union nut is loosened and the connection sleeve is removed, but since the ball seat is also insert molded with the ball, The disadvantage is that the contact pressure of the ball seat against the ball cannot be adjusted, and once the ball seat wears out and leaks occur, the entire valve must be replaced, which is uneconomical.

(Means for Solving the Problems) The present invention has been made in order to eliminate the above-mentioned drawbacks of conventional ball valves, and provides a mechanism for tightening the ball seat in a universal ball valve to tighten the ball between the balls of the valve body. By press-fitting it into the housing, the ball and ball seat will not pop out even if the union nut is loosened and the connection sleeve is removed, and the ball seat will not come into contact with the ball by retightening the union nut. The present invention aims to provide a ball valve that can adjust pressure and prevent fluid leakage.

The gist of the present invention is that a ball is inserted into a ball storage part of a plastic valve body, and this ball is fitted into a concave groove of the ball with an inner end parallel part of a spindle that protrudes from the valve body, and the ball seats from both sides of the ball. A connecting sleeve with a flange is connected to the ball holder, and the ball holder is held down by a union nut screwed into a thread formed on the outer peripheral surface of the end of the valve body. In the ball valve that is pressed toward the ball, the inner surface of the ball storage portion is an annular concave spherical surface larger than the outer diameter of the ball,
The ball valve is characterized in that the inner diameter of both sides of the annular concave spherical surface in the flow path direction is at least 1% smaller than the outer diameter of the ball.

(Function) In the present invention, the inner surface of the ball storage portion is an annular concave spherical surface, and the inner diameter of both sides of the concave spherical surface in the flow path direction is made smaller by a dimension corresponding to at least 1% of the ball outer diameter. Therefore, even if the ball holder is removed, the ball will not fly out from the ball storage section. Further, since the concave spherical surface of the ball storage part is made larger than the outer diameter of the ball, the ball can move in the flow path direction within the ball storage part. Furthermore, leakage can be prevented by tightening the union nut.

(Example) Next, the ball valve of the present invention will be explained with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view showing an example of a ball valve of the present invention. In the figure, 1 is a valve body, 2
is a ball, and 3 and 4 are ball holders. ball 2
And the ball pressers 3 and 4 have through holes 21 of approximately the same diameter,
31 and 41 are provided, and these through holes serve as fluid flow paths.

In the center of the valve body 1, there is a ball storage part 11.
A ball 2 is housed therein, and ball holders 3 and 4 are fitted on both sides of the ball 2.

The inner surface of the ball storage portion 11 is an annular spherical surface larger than the outer diameter of the ball 2, and the inner diameter of both sides 12, 12 of this spherical surface in the flow path direction is at least 1% smaller than the outer diameter of the ball 2. being done. That is, in order to attach the ball 2 to the ball storage part 11, it is necessary to apply a force sufficient to deform both or one of the ball 2 and the side part 12 of the ball storage part 11. In addition, since the deformation is restored after one pair is press-fitted, the balls 2 cannot be taken out from the ball storage portion 11 unless the same pressure as that used when they were press-fitted is applied.

This is possible by making the ball body 1 or the ball body 1 and the ball 2 made of plastic, and by appropriately determining their dimensions in accordance with the characteristics of the resin.
For example, in the figure, the side part 12 of the ball storage part 11
The inner diameter of the ball 2 is smaller than the outer diameter of the ball 2 by a dimension corresponding to at least 1% of the outer diameter of the ball 2. This is a condition to prevent the ball 2 from flying out from the ball storage portion 11, and is a condition that takes a safety factor at a maximum working pressure of the valve of 10 kg/cm ² and a working temperature of 60°C. Also, if the difference between the inner diameter of the side part 12 and the outer diameter of the ball 2 becomes large, it becomes difficult to press-fit the ball 2 into the ball storage part 11, but an example in which the ball and the valve body are made of hard vinyl chloride resin In this case, even when the inner diameter of the side part 12 is smaller than the outer diameter of the ball 2 by a dimension corresponding to 7.6% of the outer diameter of the ball 2, it can be press-fitted at room temperature. Press-fitting becomes easy by heating and press-fitting. Further, if the shape of the side part 12 of the ball contracting part 11 is tapered so that it becomes wider on the insertion side of the ball 2, or if a lubricant is applied before insertion, press-fitting can be further facilitated. Further, the inner surface of the ball storage portion 11 has an annular spherical surface larger than the outer diameter of the ball 2. It is preferable that the radius of this spherical surface is approximately 1 mm larger than the radius of the ball, since this will reduce the amount of fine powder mixed in the fluid. Further, the inner surface of the ball storage portion 11 near both sides 12, 12 may be a spherical surface, and the center portion may be a recess having a larger diameter than the spherical surface. Reference numeral 5 denotes a spindle, which protrudes from the central bearing part 13 of the ball storage part 11 of the valve body 1, and has an inner end formed into a parallel part 51, and a concave groove 2 provided in the ball 2.
2 and ball 2 are fitted in a closed state, and a handle 6 is fitted to the outer end. This spindle 5
is inserted from inside the valve body 1, and when the ball 2 is press-fitted into the ball storage portion 11, it is attached by aligning the concave groove of the ball 2 with the parallel portion 51 of the spindle 5. A collar 52 is provided on the spindle 5, and this collar 52 fits into the stepped portion of the bearing portion so that the outer portion cannot come off.
53 is an O-ring.

Annular notches 32, 42 are formed on the sides of the ball holders 3, 4 that come into contact with the balls 2, and annular ball seats 33, 43 are fitted into these notches 32, 42. 4 toward the ball 2, the ball seats 33, 43 are pressed against the ball 2, and the sealing properties of the flow path are maintained.

In order to have a structure that allows the ball holders 3 and 4 to be pressed toward the balls 2, the flange side of the connecting sleeve 7 that connects the pipes is brought into contact with the outer end surface of the ball holders 3 and 4, and the connecting sleeve 7 is pressed against the ball 2. It has the same structure as the conventional flexible type, in which the union nut 71 is screwed into a screw formed on the outer peripheral surface of the end of the valve body 1. Even when the ball holders 3 and 4 are pressed toward the ball 2, a gap is still maintained between both end surfaces of the valve body 1 and the connection sleeve 7, and by retightening the union nut 71, the ball seat 3
The contact pressure of balls 3 and 43 against ball 2 is adjusted.

In the figure, 34 and 44 are O-rings provided between the ball retainers 3 and 4 and the valve body 1;
45 is an O-ring provided between the ball pressers 3, 4 and the connection sleeve 7.

In the embodiment described above, the connecting sleeves 7, 7
The valve body 1 is placed between the connecting sleeves 7, 7, and the union nuts 71, 71 are screwed into threaded portions at both ends of the valve body 1, thereby installing the valve body 1 in the middle of the piping. When the ball seat is damaged and needs to be replaced, or when the pipe is damaged and needs to be redone,
It is sufficient to close the ball 2, remove the union nut 71, disconnect the connected pipe, and replace the ball seat and pipe. Since the ball 2 is held in the ball storage part 11 in contact with the side part 12 of the ball storage part 11 which has an annular concave spherical surface, even if liquid pressure is applied to the ball 2 from the opposite side, the ball 2 will not pop out.

In the present invention, the ball 2 may be made of metal or synthetic resin, but is preferably made of synthetic resin from the viewpoint of chemical resistance. In addition, in order to have heat resistance, vinyl chloride resin, particularly chlorinated vinyl chloride resin, is preferable.

Further, the valve body 1 is molded from a moldable resin such as vinyl chloride resin.

In the present invention, the ball 2 is connected to the handle 6 and the valve body 1.
Due to the locking mechanism with the bearing portion 13, it is possible to rotate only within a range of 90 degrees (fully open state) in one direction from the closed state shown in FIG.

(Effects of the Invention) The ball valve of the present invention is configured as described above, and the inner surface of the ball storage portion is an annular concave spherical surface, and the inner diameter of both sides of the concave spherical surface in the flow path direction is equal to the outer diameter of the ball. Since the ball is made smaller by at least 1%, the ball will not fly out of the ball housing even if the ball holder is removed, and the concave spherical surface of the ball housing is larger than the outer diameter of the ball. The ball is movable in the direction of the flow path within the ball storage section, and when the ball is in the closed state, the pressure of the fluid acting on the ball presses the ball against the ball seat, improving sealing performance, a so-called float ball. It has the same effect as the type. Furthermore, leakage can be prevented by tightening the union nut.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an example of the ball valve of the present invention. 1: Valve body, 11: Ball storage section, 12:
Side part of ball storage section, 2: Ball, 22: Concave groove,
3, 4: Ball holder, 33, 43: Ball seat, 5: Spindle, 51: Inner end parallel part of spindle, 6: Handle, 7: Connection sleeve, 71:
Union nut.

Claims (1)

[Claims] 1 A ball is inserted into the ball storage part of the plastic valve body, this ball is fitted with the inner end parallel part of the spindle protruding from the valve body through the concave groove of the ball, and the ball is held from both sides by a ball presser with a ball seat. A connecting sleeve with a flange is connected to this ball holder, and a union nut of this connection sleeve is screwed into a thread formed on the outer peripheral surface of the end of the valve body, so that the ball holder is pressed toward the ball. In the ball valve, the inner surface of the ball storage portion is an annular concave spherical surface larger than the outer diameter of the ball, and the inner diameter of both sides of the annular concave spherical surface in the flow path direction is at least 1% smaller than the outer diameter of the ball. A ball valve characterized by: