JPS6317899Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) This invention relates to a ball valve, and more particularly to a block type ball valve that prevents the balls from coming 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 abutted against this ball from both sides of the flow path, and this ball seat is used as a ball presser. There is a so-called flexible ball valve that is pressed toward a ball by a ball valve. In this ball valve, by connecting the connecting sleeve to the valve body, the ball holder 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 the ball seat can be adjusted. When the union nut wears out and leaks, the union nut can be tightened to prevent leakage.

(Problem to be solved by the invention) The biggest disadvantage 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 on the other side closes the flow path. The nut and the connecting sleeve cannot be removed. That is, when a pipe connected to a 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 retainer are This was dangerous as it flew out from the valve body.

To solve this problem, there is a system in which the ball holder is provided only on one side and the other is integrated with the valve body (for example, the one described in US 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 retightening the union nut on one side, repeated retightening can cause the ball and spindle to become misaligned, making it difficult to open and 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. .

Also, JP-A No. 57-37160, JP-A No. 57-37160,
Publication No. 110873, Publication of Utility Model Publication No. 57-105474, etc.,
By screwing the ball holder into the valve body,
It is disclosed that the ball holder can be prevented from popping out, and furthermore, in Japanese Patent Publication No. 53-6375, by pushing a ball holder with a dog around it into the valve body and turning it, the dog is attached to the inner peripheral surface of the valve body. It has been disclosed that a so-called bayonet, which engages with a provided groove, prevents the ball presser from popping out.

However, with simple screw fitting or bayonet fitting, the amount of axial sliding of the ball presser is small, and there is a limit to the range in which additional tightening can be performed.
In order to prevent the ball presser from popping out, a separate part from the ball presser is used, but the parts are small and assembly is troublesome.

(Means for Solving the Problems) The purpose of this invention is to eliminate the drawbacks of the above-mentioned block type ball valves, provide a block type ball valve that can be tightened over a wide range, and has excellent sealing properties. The gist is that an annular groove is formed in the circumferential direction on the inner periphery of the end of the valve body, and a split ring having an internal thread and narrower than the width of the groove is fitted into this groove. In this ball valve, a ball retainer having a male thread on the outer periphery is screwed into the female thread of the split ring, and an annular elastic body is provided between the rear side surface of the groove and the split ring.

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

In the figure, 1 is a valve body, a ball 2 is inserted into the body 1, and a spindle 3 passing through the wall of the body 1 is fitted into a groove 21 of the ball 2.

Ball seats 4 are applied to both sides of the ball 2, and a ball presser 5 is inserted and held therein. The ball seat 4 is fitted into and supported by a ball presser 5.

The ball presser 5 is inserted into and held at the end of the valve body 1 in the following manner. That is, an annular groove 11 is formed in the inner periphery of the end of the valve body 1 in the circumferential direction, and a split ring 6 having a female thread 61 and having a width narrower than the groove width of the groove 11 is fitted into this groove 11. A female thread 61 is formed on the inner periphery of the valve body 1, and a ball presser 5 having a male thread 51 on the outer periphery is screwed into this female thread 61.

The ball presser 5 is prevented from popping out by screwing the male screw 51 of the ball presser 5 into the female screw thread 61 of the split ring 6 fitted into the inner periphery of the valve body 1.

When no external force is applied to the split ring 6, the outer periphery is in contact with the bottom of the groove 11, and the thread tip of the female thread 61 has a diameter that is approximately the same as or slightly larger than the inner surface of the valve body 1. There is. Further, the width of this split ring 6 is made narrower than the groove width of the groove 11, so that the split ring 6 is movable in the groove width direction of the groove 11. The amount of movement of the split ring 6 in the groove width direction within the concave groove 11 should be at least the size required to retighten the ball holder 5 to the ball 2, and for a normal ball valve, it is around 1 mm. It is. The split ring 6 may be fitted into the groove 11 from one end, and the split ring 6 may be sequentially fitted into the groove 11 while being deformed.

In this invention, in order to fit the split ring 6 into the groove 11, an annular elastic body 6 made of synthetic rubber or the like is placed in advance in the gap between the rear side surface of the groove 11 and the split ring 6.
This is done after setting 2. Preferably, the elastic body 62 is provided in a compressed state. In this way, groove 1
An elastic body 62 is placed in the gap between the rear side surface of 1 and the split ring 6.
By providing this, the pressing force of the ball presser 5 in the direction of the ball 2 is alleviated by the compressive deformation of the elastic body 62, and the repulsive force of the elastic body 62 prevents the ball seat 4 from being worn out. Sealing performance between the ball presser 5 and the connection sleeve that presses the ball presser 5 can be maintained. This elastic body 62 can be further compressed and deformed by 1 mm or more by retightening the union nut 8, which will be described later.

Further, in this invention, a shallow groove portion is formed in a part of the circumferential direction of the concave groove 11, and a split ring 6 is formed in this shallow groove portion.
It is preferable that the split ring 6 is prevented from rotating in the circumferential direction within the concave groove 11 by abutting against each other.
This connects the ball presser 5 to the female thread 61 of the split ring 6.
This is to prevent the split ring 6 from interlocking with the ball presser 5 when screwing together, making screwing difficult. The shallow groove portion may be formed by making a part of the groove 11 shallow, or may be formed by interrupting the groove.

Then, a male thread 12 on the outer periphery of the end of the valve body 1
A union nut 8 is screwed into the holder, and the union nut 8 presses the connecting sleeve 7 toward the ball presser 5 to connect it to the pipe. When the connection sleeve 7 is pressed against the end surface of the ball retainer 5 by the union nut 8, a gap is provided between the end surface of the connection sleeve 7 and the end surface of the valve body 1, and leakage due to wear of the ball seat 4 is prevented. When this happens, the union nut 8 can be further tightened to eliminate leakage.

An O-ring 53 is fitted into a groove 52 on the outer periphery of the ball holder 5 to form a seal with the inner surface of the valve body 1, and an annular groove 54 is also formed on the end surface of the ball holder 5. An O-ring 55 is fitted into this groove 54 to provide a seal with the connection sleeve.

Further, the mechanism for preventing the ball holder 5 and the ball 2 from popping out by screwing the split ring 6 and the ball holder 5 described above may be provided on both sides of the ball 2 or only on one side.

(Effect of the invention) The ball valve of this invention has the configuration as described above, and a split ring is fitted into an annular groove formed on the inner periphery of the end of the valve body to form a female thread. As it is assembled by screwing together a ball holder with a male thread, even if the ball valve is closed and the union nut is removed to separate the connection sleeve in order to repair damage to the piping, there will be no damage to the ball. Fluid pressure is maintained by the screw engagement between the ball holder and the split ring, so that the ball and ball holder do not fly out.

In addition, the split ring is narrower than the groove width of the groove, and the split ring can move in the width direction within the groove, so by retightening the union nut, the pressing force toward the ball of the ball holder can be reduced. It can be adjusted, and if leakage occurs due to wear of the ball seat, etc., you can easily prevent leakage by tightening the union nut. Further, the amount of movement of the split ring within the groove can be increased by appropriately setting the width of the split ring and the width of the groove, and the range of retightening can be increased.

Furthermore, since the annular elastic body is provided between the inner side surface of the groove and the split ring, the pressing force of the ball holder in the direction of the ball is alleviated by compressive deformation of the annular elastic body. Even if the ball seat is worn out due to the repulsive force of the body, the sealing performance between the ball presser and the connection sleeve can be maintained.

[Brief explanation of drawings]

Figure 1 is a partially sectional front view of an example of a ball valve of this invention, Figure 2 is an enlarged sectional view of the main part of Figure 1, and Figure 3A is a front view of an example of a split ring. FIG. 3B is a sectional view of FIG. 3A. 1...Valve body, 11...Concave groove, 2...Ball, 4...Ball seat, 5...Ball holder, 5
1...Male thread, 6...Split ring, 61...Female thread, 62...Elastic body, 7...Connection sleeve, 8...
...Union Nat.

Claims (1)

[Claims for Utility Model Registration] 1. An annular groove is formed in the circumferential direction on the inner periphery of the end of the valve body, and a split ring having a female thread and having a width narrower than the width of the groove is fitted into this groove. A ball valve characterized in that a ball retainer having a male thread on the outer periphery is screwed into the female thread of the split ring, and an annular elastic body is provided between the rear side surface of the groove and the split ring. 2. The ball valve according to claim 1, wherein the concave groove has a shallow groove, and the end face of the split ring abuts against the shallow groove and is prevented from rotating.