JPS6339493Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a swing type check valve that prevents backflow of fluid.

[Conventional technology and its problems]

Conventionally, check valves are installed on the discharge side of pumps, but when pumps are operated in parallel, there is a problem that back pressure may be applied due to deterioration or performance differences in the pumps, and the check valves may not open. Ta.

In addition, due to problems with the foot valve installed on the suction side of the pump, attempts to prime the pump may take a long time in the case of large diameter pumps, or the pump may not be able to operate until the foot valve is repaired. Ta.

Further, an operation switching device disclosed in Japanese Utility Model Publication No. 40-29152 is known as a device capable of switching between manual opening/closing operation and automatic opening/closing operation using fluid pressure. This device uses a lever fixed to a portion of the valve stem that protrudes outward from the main body, and a lever loosely fitted to the lever to move the protrusion of a slider that reciprocates along a guide plate fixed to the main body. A pin is inserted into and removed from a hole drilled in each lever, and a threaded rod whose movement in the axial direction is restricted is screwed into the slider. be.
Therefore, with this device, by inserting and removing a single pin, it is possible to switch between an automatic opening/closing check valve and a manual opening/closing butterfly valve.
It is necessary to align the holes of both levers when inserting the pin, there is a risk of losing the pin if you do not decide where to place it when removing the pin, and the pin does not come out easily when there is a strong flow of fluid, or it may come out again. However, the structure was complicated, and there were problems with operability and safety, such as the lever attached loosely to the protruding part of the valve stem, which could be dangerous if swung.

The present invention was developed in view of these conventional circumstances, and its purpose is to provide a simple structure, ease of operation, and
It is an object of the present invention to provide a swing type check valve which has excellent safety and can be opened by manual operation.

[Means for solving problems]

In order to achieve the above object, the present invention is a swing type check valve, in which the valve stem of the swing type valve is extended outside the valve body, and a lever is fitted loosely into the extended part, and a lever is inserted between the lever and the valve stem. a connecting shaft that is slidably inserted into and supported by a supporting member of the lever and arranged in parallel and substantially parallel to the lever; and a handle that links and connects the rear end of the connecting shaft and the free end of the lever. A groove into which the distal end of the connecting shaft can fit is provided in the extending portion of the valve stem, and a biasing means for urging the connecting shaft in a direction to separate from the groove is provided. .

[Effect]

In such a configuration, a lever loosely fitted into the extending portion of the valve stem of the swing type valve and the connecting shaft are arranged in parallel, and the two are linked and connected by a handle, and the connecting shaft is connected to the extending portion of the valve stem. It is biased in the direction of leaving the groove.

Therefore, under normal conditions, the connecting shaft does not disengage from the groove in the extending part of the valve shaft and prevent the automatic opening/closing operation of the swing type valve by fluid pressure, and when the back pressure is large and it is difficult to open the valve, the handle cannot be When squeezed, the tip of the connecting shaft immediately fits into the groove of the extending portion of the valve shaft, allowing manual operation of the swing type valve to be performed easily and quickly. Therefore, the structure is simple, and operability and safety are improved.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings. Note that FIG. 1 is a longitudinal cross-sectional view showing the overall structure of a swing type check valve according to the present invention, and FIG. 2 is a partially cutaway plan view showing the main structure of FIG. 1.

In these figures, a swing type valve 3 is fixed to a valve shaft 8 within the valve body 1, and the valve shaft 8 extends outside the valve body 1. A lever 5 is loosely fitted into the extending portion of the valve shaft 8, and is fixed to a saucer 10 provided on the valve shaft 8.

Further, a groove 9 is provided in the valve stem 8 near the mounting portion of the saucer 10, and the connecting shaft 7 whose tip end enters and exits the groove 9 slides on a support member 11 provided at the intermediate portion of the lever 5. It is freely inserted and supported. The rear end of the connecting shaft 7 is attached to the free end of the lever 5 via a handle 6. That is, the handle 6, the connecting shaft 7, and the support 11 constitute a link mechanism.

Note that 12 is a spring for returning the handle 6 to its original position, and urges the connecting rod 7 in the direction of leaving the groove 9. Further, 13 is a sealing material such as an O-ring for sealing to prevent fluid from leaking out of the valve body 1.

Next, the operation of this embodiment will be explained.

In the above configuration, normally the swing type valve 3, through which fluid flows from the fluid inlet 2, opens, and when fluid attempts to flow in the opposite direction from the fluid outlet 4, the swing type valve 3 operates to close.

When the back pressure increases and the swing type valve 3 no longer opens, the connecting shaft 7 is moved in the direction of arrow A by grasping the handle 6, and the connecting shaft 7 slides within the support member 11 and enters the groove 9. Get into it. As a result, the lever 5 and the valve shaft 8 are connected, and the swing type valve 3 can be opened by moving the handle 6 counterclockwise (arrow B) in FIG.

In addition, when returning the swing type valve 3 to normal automatic opening/closing operation, by releasing the handle 6,
The handle 6 is returned to its original position by the action of the spring 12, and the connecting shaft 7 is removed from the groove 9.

[Effect of idea]

According to the present invention, in a swing type check valve, the connecting shaft does not normally disengage from the groove of the extending portion of the valve shaft and obstruct the automatic opening/closing operation of the swing type valve by fluid pressure, and When it is difficult to open the valve, such as when the back pressure is large, by grasping the handle, the tip of the connecting shaft is immediately inserted into the groove of the valve shaft extension, making manual operation of the swing type valve easy and quick. The structure improves operability and safety. Therefore, if the check valve does not open due to back pressure during startup due to differences in performance of the pumps during parallel operation of the pumps, the problem can be solved by manually opening the check valve. In addition, when priming is required due to a foot valve malfunction, the check valve must be manually opened to use water in the piping located downstream of the check valve for priming, which previously took a long time. Priming can be done in an instant. Furthermore, even if the foot valve leaks significantly and no amount of priming is effective, it can be used for priming and emergency response by manually opening the check valve.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing the overall structure of a check valve according to the present invention, and FIG. 2 is a partially cutaway plan view showing the main structure of FIG. 1. 1... Valve body, 3... Swing type valve, 5... Lever, 6... Handle, 7... Connection shaft, 8... Valve stem,
9... Groove, 10... Receiver, 11... Support member.

Claims (1)

[Scope of utility model registration request] In a swing type check valve, the valve stem of the swing type valve is extended outside the valve body, and a lever is loosely fitted into the extended part, and the lever is slidably inserted into the support member at the middle of the lever. a connecting shaft supported and arranged in parallel and substantially parallel to the lever; a handle linking the rear end of the connecting shaft and the free end of the lever;
characterized in that a groove into which the distal end of the connecting shaft can fit is provided in the extending portion of the valve stem, and urging means for urging the connecting shaft in a direction to separate from the groove. check valve.