JPH07180778A - Check valve - Google Patents

Abstract

PURPOSE:To dissolve seat pass in a check valve and unstable flow at the time of minute flow amount. CONSTITUTION:A check valve has a valve box 1 on which an inlet 17 and an outlet 16 for fluid are formed, a valve body 4 which is arranged rotatably in the valve box 1 for applying closing action to one way flow of the fluid, a piston 6 which is connected to the valve body 4 through an arm 5, a cylinder 2 in which the piston 6 is housed, and pressure fluid supplying devices 23, 24, 25, 26 for closing or opening the valve body 4 by the piston 6 by leading pressure fluid through three-way valves 25, 26 which are connected in series to the upper part and lower part of the piston 6.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a check valve.

[0002]

2. Description of the Related Art A conventionally used check valve will be described below with reference to FIGS. In FIG. 5 (a), a check valve 20 is formed, and a valve body 4 abutting against a valve seat 19 is disposed via an arm 5 in a valve box 1 in which a fluid inlet 17 and an outlet 16 are formed. ing. A valve lid 18 is fixed to the upper portion of the valve box 1 by bolts or the like not shown, and the valve body 4 in the valve box 1 is fixed.
A valve body support portion 15 is formed at a position where the valve body support portion 15 abuts during the opening operation.

The drive of the valve body 4 of the check valve 20 is shown in FIG.
The valve drive mechanism 9 shown in FIG. The valve drive mechanism 9 is supported on its side portion by the valve box 1 via the support portion 15. The compulsory opening and closing operations of the valve body 4 are performed by upward and downward movements of the piston 6 housed in the air cylinder 2 that constitutes the valve drive mechanism 9.

The forced opening operation of the valve body 4 causes the solenoid valve 3 arranged in the air supply pipe 14 connected to the lower portion of the air cylinder 2 to open, and the compressed air is guided below the piston 6. , Raise the piston 6. The piston rod 13 connected to the piston 6 as the piston 6 rises
Rises and the arm 5 is rotated by the rotation of the crank 12. The rotation of the arm 5 causes the valve body 4 connected to the lower end of the arm 5 to open.

The closing operation of the valve element 4 is performed by the weight of the valve element 4 and the arm 5, and further, the compression force of the spring 7 arranged above the piston 6 causes the piston 6 to move downward. Is made.

Further, as another conventional example, as shown in FIG. 6 which shows only a main part, an air supply pipe 14a is connected to an upper part of the piston 6 of the air cylinder 2 so that compressed air is introduced into the air cylinder 2 when the valve is closed. Therefore, a structure for moving the piston 6 downward has been proposed.

[0007]

In the conventional example as described above, as shown in FIG. 5, the valve closing force of the valve body 4 and the arm 5 are small in an operating condition in which there is almost no differential pressure before and after the valve. Since the weight depends on the weight, the seat path 8 may occur and the check valve 20 may not fully function.

In the system having the structure shown in FIG. 7, when the downstream pressure P1 is increased extremely slowly,
In the case of a system in which the upstream pressure P2 similarly rises due to the seat path 8 and the differential pressure is detected at the set pressure and the process proceeds to the next step, the differential pressure detector 21 does not raise the differential pressure either. An event occurs that impairs the function of.

On the other hand, since the opening degree of the check valve is determined by the lift force on the valve body caused by the flow rate, the lift force is small in the case of a minute flow rate, and the force of opening the valve body 4 and the force of closing it by its own weight are balanced and repeated opening and closing There was a risk that the flow would become unstable.

Further, as described above, the valve is forcibly operated in either the opening direction or the closing direction, and it is difficult to realize the forcible operation in both directions with these structures. An object of the present invention is to obtain a check valve capable of eliminating an unstable flow at a seat path and a small flow rate in order to solve the above-mentioned problems.

[0011]

In order to achieve the above object, in the present invention according to claim 1, a valve box having a fluid inlet and an outlet is formed, and a valve box is rotatably arranged in the valve box. A valve body that is provided to close and block a flow of fluid in one direction, a piston connected to the valve body via an arm, a cylinder that houses the piston, and an upper portion and a lower portion of the piston in series. Via the connected three-way valve,
A check valve is provided, which has a pressure fluid supply device that guides pressure fluid and causes the piston to close or open a valve body. Further, in the invention according to claim 2, there is provided a check valve in the cylinder. A check valve comprising a spring for applying a force in the closing direction,
In the invention described above, the check valve is characterized in that the pressure fluid supply device comprises a pressure adjusting valve for controlling the fluid supply pressure according to the closing force of the valve body and the opening operation time. provide.

[0012]

According to the present invention having the above-mentioned structure, the pressure fluid is switched between the upper and lower portions when the valve is opened and closed by the pressure fluid supply device, so that the closing force and the opening actuating force when the valve is closed. Can be increased. Further, in the check valve according to the third aspect, the closing force and the opening actuation force can be controlled by the pressure adjusting valve, and the opening / closing operation can be performed more smoothly.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In FIG. 1, the same parts as those in FIG. 5 are designated by the same reference numerals, and the description of the structure of those parts is omitted.

1 (a) and 1 (b), air supply pipes 23, 23 are provided on the upper and lower portions of a cylinder 2 which constitutes a valve drive mechanism 22 disposed on the side of the valve housing 1 of the check valve 20. 24 are provided. The supply pipes 23, 24 are connected to a compressed air supply system (not shown) via three-way valves 25, 26 connected in series.

To forcibly open the valve body 4, compressed air is introduced from the air supply pipe 24 to the lower surface of the piston 6 via the three-way valves 25 and 26 so that the piston 6 is resistant to the pressure of the spring 7. And raise. Further, for the forcible closing operation of the valve body 4 and the closing at the minute flow rate, the compressed air is guided from the air supply pipe 23 to the upper surface of the piston 6 via the three-way valves 25 and 26, and the piston 6 is lowered.

Therefore, by adding this structure,
In the valve closed state, the closing force due to the pressure of air is added to the closing force due to the weight of the valve body 4 and the arm 5, so that the closing force of the valve increases and the seat path can be prevented.

Further, when the differential pressure P is detected as shown in FIG. 7 shown in the conventional example and the process proceeds to the next step, first, as step 1, as shown in FIG. The forced closing force is maintained up to the differential pressure P _L. After that, FIG. 2 (b)
As shown in step 2, the three-way valves 25 and 26 are controlled as step 2,
The pressure supply can be stopped so that the function of the system works smoothly and the check valve can be opened by the differential pressure.

Further, in the forced opening operation, as shown in FIG. 2 (c), in step 3, the three-way valves 25, 26 are switched to supply the air in the opening direction of the check valve into the cylinder 2.
Next, a second embodiment of the present invention will be described with reference to FIG. In FIG. 3, the same parts as those in FIG. 1 are designated by the same reference numerals, and the description of the structure of those parts will be omitted. In FIG. 3, the air cylinder 2 that constitutes the valve drive mechanism 30 is shown in FIG.
The spring 7 shown in is not provided. In this case, since the pressing force of the spring 7 is eliminated, the introduction direction of compressed air is switched by the three-way valves 25 and 26. Therefore, the check valve can be opened / closed by controlling only the compressed air, and the check valve can be forcedly opened / closed.

Next, a third embodiment of the present invention will be described with reference to FIG. Note that, in FIG. 4, the same parts as those in FIG.
In FIG. 4, a pressure adjusting valve 11 is provided upstream of the three-way valve 26 to adjust the supply pressure for driving and adjust the closing force of the valve.

With this structure, the valve body 4 can be closed and held up to the magnitude of the lift force due to an arbitrary flow rate, and the differential pressure for the opening operation can be arbitrarily selected by the adjusting valve 11. In addition, in the above-described embodiment, the example in which the compressed air is the pressure fluid is shown, but the same action and effect can be obtained by utilizing the water pressure.

[0021]

According to the first and second aspects of the present invention, the pressure fluid is guided to the upper or lower portion of the piston of the air cylinder of the valve drive mechanism constituting the check valve when the valve body is opened or closed, and the valve body is forcibly forced. Since the opening / closing operation can be performed, the closing force of the valve body can be increased even when the valve is closed, and the seat path of the fluid flowing in the check valve can be prevented.

Further, in the invention according to claim 3,
Further, since the pressure adjusting valve for controlling the compression pressure is arranged in the pressure fluid supply system, the check valve can be smoothly opened and closed.

[Brief description of drawings]

1A is a longitudinal sectional view of a check valve according to an embodiment of the present invention, and FIG. 1B is a front view showing the right half of the check valve shown in FIG.

FIG. 2 is an explanatory view showing the operation of the three-way valve shown in FIG.

FIG. 3 is a schematic system diagram showing a main part of a check valve according to a second embodiment of the present invention.

FIG. 4 is a schematic system diagram showing a main part of a check valve according to a third embodiment of the present invention.

FIG. 5 (a) is a vertical sectional view showing a conventional example of a check valve,
(B) is a front view showing the right half of the check valve shown in (a).

FIG. 6 is a schematic system diagram showing a main part of another conventional check valve.

FIG. 7 is an explanatory view showing a problem of a conventional check valve.

[Explanation of symbols]

 1 ... Valve box 2 ... Air cylinder 4 ... Valve body 5 ... Arm 6 ... Piston 7 ... Spring 11 ... Pressure adjusting valve 12 ... Crank 13 ... Piston rod 16 ... Exit 17 ... Inlet 18 ... Valve lid 19 ... Valve seat 20 ... Reverse Stop valve 22,30 ... Valve drive mechanism 23,24 ... Air supply piping 25,26 ... Three-way valve

Claims (3)

[Claims] 1. A valve box having a fluid inlet and an outlet, a valve body rotatably disposed in the valve box to close and block a one-way flow of the fluid, and the valve body. To the piston through an arm, a cylinder that accommodates the piston, and a three-way valve that is connected in series to the upper and lower parts of the piston to guide pressure fluid, and the piston closes or opens the valve body. A non-return valve having a pressure fluid supply device for causing the check valve. 2. The check valve according to claim 1, further comprising a spring for applying a force in a closing movement direction of the piston in the cylinder. 3. The pressure fluid supply device comprises a pressure regulating valve for controlling the fluid supply pressure in accordance with the closing force of the valve body and the opening time of the valve body. Check valve described.