JPH0942489A - Ball valve having check valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce manufacturing process steps and item number by integrating a valve seat formed on a leading end of a valve box of a check valve with a seat holding part on which a circular ball seat being in sealing contact with the surface of a ball is installed. SOLUTION: A circular valve seat 11b fitted to a valve body 12 is integrated with a leading end of a valve box on an inflow side. A seat holding part 8 is constantly formed on an inflow side end face of a valve seat 11b for installing a ball seat 7. The ball seat 7 is installed on the seat holding part 8 formed on a leading end of the valve box 11 of a check valve 10, and is in sealing contact with the surface of a ball 3. One ball seat 6 is held by a stepped portion 2c formed inside a body 2 and in sealing contact with the surface of the ball 3. It is thus possible to reduce manufacturing process steps and item number, and also reduce a manufacturing cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball valve with a non-return valve for opening and closing a flow path and for preventing backflow of a fluid in the flow path, such as water, oil or gas.

[0002]

2. Description of the Related Art One form of a conventional ball valve with a check valve will be described with reference to FIGS. 4 and 5. Reference numeral 101 is a ball valve with a check valve (hereinafter referred to as valve 101), which is a pair of ball seats. A ball 103 having a through-hole 103a is rotatably provided in the valve body via a ball seat 106. It is attached to the tip of the insert 108 and is in contact with the ball 103. The insert 108 is fixed by a cap 109 that is screwed into the open end of the valve 101.

Further, a check valve 110 is built in the outlet side flow passage of the body 102. This check valve 110
Installs the valve box 111 of the check valve 110 in the cap 109, and further attaches the cap 109 to the body 102.
It is incorporated in the body 102 by being screwed into the outlet side opening. In addition, a valve seat portion 111a that contacts the valve body 112 of the check valve 110 is formed inside the end portion of the valve box 111, and when the fluid starts to flow backward, the valve body 112 contacts the valve seat portion 111a. The flow path is closed to prevent backflow of fluid.
Further, O-rings 113a and 113b are attached to the outer peripheral portions of the valve box 111 and the insert 108, respectively, and
A sheet member 114 is attached to the and the contact surface is sealed. The insert 108 is usually formed by processing a brass rod.

In the valve 101, the valve shaft 104 joined to the ball 103 is rotated by a manual handle, an electric actuator or the like (not shown) to open and close the flow path, and the check valve 110 prevents the reverse flow of fluid.

[0005]

Since the ball valve with a check valve has both a closing function and a check function with a single valve, the check valve and the check valve can be installed in pipes requiring backflow prevention. Since there is no need to install in parallel with each other, the facility cost and the construction cost are low, and there is an advantage that a piping space is not required.

However, since the ball valve has a large number of parts, a large number of manufacturing steps, and a high cost, it has been desired to reduce the cost by simplifying the ball valve. In particular, since the insert is formed by using a brass rod, the cost of parts has increased.

In order to solve the above-mentioned problems, the present invention provides a ball valve with a check valve which simplifies the structure of the check valve ball valve, reduces the number of manufacturing steps, the number of parts, etc., and is cost effective. With the goal.

[0008]

In order to achieve the above object, the present invention provides a ball having a through hole inside a body rotatably via a valve shaft, and In a ball valve with a check valve having a built-in check valve, a valve seat portion provided at the tip of the valve box of the check valve, and a seat holding portion for mounting an annular ball seat in seal contact with the surface of the ball. The step of incorporating the check valve in the body and the step of bringing the ball seat into contact with the ball can be performed simultaneously.

Further, since the valve box is made of synthetic resin and the seat holding portion is integrally formed at the tip of the valve box, the check valve and the ball seat can be easily assembled.

Further, the non-return check valve is a lift type non-return valve with a spring, in which an annular valve seat portion is integrally formed at a tip portion and a seat holding portion is integrally formed at a tip end surface of the valve seat portion. Further, a short cylindrical holder is fixed in a substantially cylindrical valve box having the inflow hole formed at the center of the seat holding portion, and a spring is interposed between the holder and the valve body of the check valve. Since the stem of the valve body is slidably held in the guide hole of the cylindrical guide portion provided at the center of the holder, and further, the stopper is provided on the outer peripheral surface of the valve body.
It is possible to reliably prevent the reverse flow of fluid, and the stopper comes into contact with the end face of the valve seat to stop excessive movement of the valve body, so the valve body does not come off while it is still fitted in the valve seat portion and opens the valve. Prevent from becoming impossible.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a schematic sectional view showing an embodiment of the ball valve with a check valve according to the present invention, and FIG. 2 is an enlarged sectional view of the check valve used in the embodiment.

In the figure, 1 is a ball valve with a check valve in the present embodiment (hereinafter referred to as valve 1), 2 is a valve body, and this body 2 has an opening on both sides and has a primary side flow passage 2a. Further, a secondary side flow path 2b is formed, and a ball 3 having a through hole 3a therein is rotatably provided. Then, the valve shaft 4 connected to the upper part of the ball 3
Is rotated to make the through hole 3a of the ball 3 parallel to the flow path, so that the primary side flow path 2a and the secondary side flow path 2b
And the valve 1 is opened and closed.

The valve shaft 4 is regulated so as to be rotatable within a range of 90 degrees, and the slit 4 is provided at the upper end of the valve shaft 4.
a is formed. Then, an annular convex portion 5b is provided on the inner peripheral surface of the engagement hole 5a of the handle 5 attached to the valve shaft 4, and the convex portion 5b is locked in the slit 4a of the valve shaft 4, whereby the handle 5 The valve shaft 4 can be attached and detached with one touch.

Further, two ball seats 6 and 7 are in seal contact with the surface of the ball 3, and one ball seat 6 is held by a step portion 2c provided inside the body 2 and is in seal contact with the surface of the ball 3. However, the other ball seat 7 is attached to a seat holding portion 8 provided at the tip of a valve box 11 of a check valve 10 which will be described later, and is in sealing contact with the surface of the ball 3. The ball seats 7 and 8 have PTFE
A polymer material such as (tetrafluoroethylene resin) may be used.

Further, a check valve 10 is built in the secondary side flow passage 2b of the body 2 through a cap 9, and the cap 9 is screwed into the check valve 10, so that the secondary side flow passage 2b of the body 2 is inserted.
Has a diameter larger than that of the primary side flow passage 2a, and has a thread 2d formed on the inner peripheral surface thereof. A thread 2e is formed on the outer peripheral surface of the end of the body 2 on the primary side flow path 2a side so that it can be connected to other equipment.

Further, threads 9a and 9b are formed on the outer peripheral surfaces of both ends of the cap 9, a check valve 10 is attached to the inside of the cap 9, and the check valve 10 is screwed into the secondary passage 2b of the body 2. As a result, the check valve 10 is built in the body 2. The cap 9 is provided with a flow passage 9c and a check valve mounting portion 9d having a one-step two-step portion formed to be larger in diameter than the flow passage diameter.

Then, the cap 9 is screwed into the secondary passage 2b of the body 2 so that the ball seat 7 held by the seat holding portion 8 integrally formed with the valve box 11 is moved to the surface of the ball 3. It is possible to make a seal contact with, and the check valve 10 can be attached and detached by removing the cap 9, so that the assembly and maintenance are easy. In addition, screw threads 9a, 9 are formed on the outer peripheral surfaces of both ends of the cap 9.
Since b is formed, piping with other equipment is possible.

Next, the check valve 10 attached to the valve 1 of this embodiment will be described. The check valve 10 is a lift type check valve with a spring, which is arranged along the direction of fluid flow.
The valve body 12 is provided in the valve box 11 so as to be capable of reciprocating, and the valve body 12 is formed in the valve box 11 when the fluid flows backward.
The backflow of the fluid is prevented by closing the.

The valve box 11 is made of synthetic resin and is formed into a substantially cylindrical shape. The valve body 1 is attached to the inflow-side end of the valve box 11.
2 is integrally formed with an annular valve seat portion 11b that fits with the seat 2, and a seat holding portion 8 for mounting the ball seat 7 is integrally formed on the inflow side end surface of the valve seat portion 11b. An annular groove 11d is formed in the annular groove 11d, and an O-ring 13 is attached to the annular groove 11d. As described above, since the valve box 11 and the seat holding portion 8 are integrally formed of synthetic resin, the number of parts can be reduced, the material cost can be reduced, and the price can be reduced, and the conventional valve box 11 can be used.
Since only one O-ring is required for each of the and the sheet holding portion 8, the number of parts can be further reduced.

Further, an annular convex portion 11e is provided on the inner peripheral surface of the outflow side end of the valve box 11, and an inflow hole for allowing a fluid to flow into the valve box 11 in the central portion of the seat holding section 8. 11a is formed, and the fluid that has passed through the through hole 3a of the ball 3 flows into the valve box 11 through the inflow hole 11a.

A circular recess 12c is formed at the tip of the valve body 12.
And an annular seal member 14 made of an elastic material is attached to the outer peripheral surface. The stem 12a protruding from the valve body 12 is slidably inserted into the guide hole 17 of the guide portion 16 provided in the holder 15, and the spring 18 is interposed between the valve body 12 and the holder 15. Further, by fixing the holder 15 in the valve box 11, the valve body 12 can be housed in the valve box 11 so as to be capable of reciprocating between the valve seat portion 11b and the holder 15.

A stopper 12b is provided on the end of the valve body 12 on the stem 12a side so as to project in the radial direction. When the valve body 12 is fitted inside the valve seat portion 11b when the fluid flows backward, the stopper 12b is provided. Since it contacts the side surface of the valve seat portion 11b,
The valve body 12 is prevented from being excessively fitted inside the valve seat portion 11b.

As shown in FIG. 3, the holder 15 is formed in a short tubular shape, and further has a tubular guide portion 16 in the center through a thin connecting plate 15a. The connecting plate 15a extends along the radial direction with the guide portion 16 as the center so as to overlap the stopper 12b provided on the valve body 12, and the side surface having a large area with respect to the fluid direction so as to reduce the fluid resistance. It is parallel and is interposed between the holder 15 and the guide portion 16.

Further, on the inner peripheral surface of the guide hole 17 formed at the center of the guide portion 16, a plurality of ridges 17a, 17a, ... Having a substantially semispherical cross section are provided along the axial direction. It is prevented that dust and the like enter the hole 17 and the stem 12a cannot slide.

Then, on the outer peripheral surface of the holder 15,
An annular groove 15b is provided along the outer peripheral surface.
The holder 15 can be fixed in the valve box 11 by engaging 5b with the annular projection 11e provided on the inner peripheral surface of the valve box 11. The check valve 10 used in the present embodiment is not limited to this, and various check valves can be used.

The operation of the above embodiment will be described below. The handle 5 attached to the upper end portion of the valve shaft 4 connected to the upper end of the ball 3 is rotated to rotate the ball 3, and the primary side flow passage 2a and the secondary side flow passage 2b are connected by the through hole 3a. When the valve 1 is opened by communicating the fluid, the fluid flows from the primary side flow passage 2a toward the secondary side flow passage 2b. Then, the fluid flows into the valve box 11 through the inflow hole 11a formed in the central portion of the seat holding portion 8.

The fluid flowing into the valve box 11 moves the valve body 12 in the valve opening direction against the elastic force of the spring 18.
The check valve 10 is opened. At this time, the base portion of the stem 12a protruding from the valve body 12 contacts the tip 16a of the guide portion 16 to stop the valve body 12. Then, the fluid flowing into the valve box 11 passes through between the connection plates 15 a provided in the holder 15 and flows out from the opening of the cap 9. Since the recess 12c is formed in the tip of the valve body 12, the fluid pressure applied to the valve body 12 increases, and the valve body 12 opens against the elastic force of the spring 18 even if the flow rate is small. It can move in the valve direction.

When the fluid flows backward, the fluid pressure applied to the valve body 12 and the elastic force of the spring 18 cause the valve body 1 to move.
2 moves in the valve closing direction, the valve body 12 is fitted inside the valve seat portion 11b provided at the tip of the valve box 11, and the seal member 14 attached to the outer peripheral surface of the valve body 12 serves as the valve seat portion 11b. The check valve 10 is closed by being pressed against the inner peripheral surface and sealing the valve body 12 and the valve seat portion 11b. At this time, the tip of the valve body 12 comes into contact with the outer periphery of the inflow hole 11a formed in the central portion of the seat holding portion 8 to stop the valve body 12, and thus the valve body 12 is stopped.
However, it is prevented from excessively entering the inside of the valve seat portion 11b. Thereby, when the fluid pressure increases again and the valve body 12 moves in the valve opening direction, the valve body 12 easily moves in the valve opening direction,
The valve seat portion 11a is prevented from entering and making it impossible to open the valve.

When the inflow hole 11a formed in the central portion of the seat holding portion 8 is formed larger than the diameter of the valve body 12, a stopper 12b protruding from the valve body 12 is provided on the end surface of the valve seat portion 11b. Since the contact is made, the valve body 12 is reliably stopped, and the valve body 12 is prevented from entering the valve seat portion 11b and becoming unable to open the valve.

[0030]

As described in detail above, according to the present invention, since the seat holding portion for mounting the ball seat is integrally formed on the check box of the check valve, the number of parts and the number of manufacturing steps are reduced. Therefore, the cost can be significantly reduced. In addition, by integrally molding the valve box, valve seat, and seat holding part with synthetic resin, the material cost can be reduced and the O-ring that was required in the past can be omitted. A ball valve can be provided.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a ball valve with a check valve according to the present invention.

FIG. 2 is an enlarged cross-sectional view of the check valve in the above embodiment.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a schematic sectional view showing a conventional ball valve with a check valve.

5 is an enlarged cross-sectional view of the check valve of FIG.

[Explanation of symbols]

 1 Ball Valve with Check Valve 2 Body 2a Primary Side Flow Path 2b Secondary Side Flow Path 2d Screw Thread 3 Ball 3a Through Hole 6 Ball Seat 7 Ball Seat 8 Seat Holding Section 9 Cap 10 Check Valve 11 Valve Box 11a Inlet Hole 11b Valve seat part 12 Valve body 12a Stem 12b Stopper 15 Holder 16 Guide part 17 Guide hole 17a Protrusion 18 Spring

Claims (3)

[Claims] 1. A ball valve with a check valve, wherein a ball having a through hole is rotatably provided inside a body through a valve shaft, and a check valve is built in a secondary side flow passage of the body. A ball with a check valve, characterized in that a valve seat portion provided at a tip end portion of a valve box of the check valve and a seat holding portion for mounting an annular ball seat in seal contact with a surface of the ball are integrally provided. valve. 2. The ball valve with a check valve according to claim 1, wherein the valve box is made of synthetic resin, and the valve seat portion and the seat holding portion at the tip of the valve box are integrally formed. 3. The check valve is a lift type check valve with a spring, wherein an annular valve seat portion is integrally formed at a tip portion and a seat holding portion is integrally formed at a tip end surface of the valve seat portion. Further, a short cylindrical holder is fixed in a substantially cylindrical valve box having the inflow hole formed at the center of the seat holding portion, and a spring is interposed between the holder and the valve body of the check valve. 3. The non-return valve according to claim 1, wherein the stem of the valve body is slidably held in the guide hole of the cylindrical guide portion provided in the center of the holder, and the stopper is provided on the outer peripheral surface of the valve body. Ball valve with valve.