JPH0247326Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a small diaphragm valve that operates a diaphragm by injecting pressurized air into a cylinder and driving a piston. More specifically, the present invention relates to a diaphragm valve suitable for fluid control used in the microbial industry and the like.

[Prior Art] In the microbial industry, a large number of pipes are installed around a small reactor, etc., and a diaphragm valve is provided in each pipe in close proximity to the reactor. For this reason, diaphragm valves used in the microbial industry and the like are required to be small and to respond quickly to valve opening/closing commands. Further, a normally closed valve for temporarily injecting fluid into a reactor or the like and a normally open valve for temporarily stopping the fluid are used in combination.

A small diaphragm valve that can be used both as a normally closed valve and as a normally open valve is disclosed in Fig. 3 of Japanese Utility Model Publication No. 101058/1983. The valve divides the inside of the cylinder into first and second chambers using a flat disk-shaped piston, and when pressurized air is introduced into one chamber, it becomes a normally closed valve, and when pressurized air is introduced into the other chamber, it becomes a normally open valve.

[Problems to be solved by the invention] Since the above diaphragm valve does not have a return spring, its normally closing force or normally opening force is weak. To solve this problem, if you insert a strong return spring that is longer than half the length of the cylinder, when changing from a normally closed valve to a normally open valve, or vice versa, there is a chamber where the pressurized air and the return spring enter. In addition to changing the position of the piston relative to the spindle, it is also necessary to change the position where the piston is fixed relative to the spindle, but a problem arises in that it is not easy to change the position where the piston is fixed relative to the spindle.

The present invention was made to solve the above problems, and its purpose is to create a small diaphragm valve that uses a strong return spring that is longer than half the length of the cylinder, and that is relatively simple. To provide a valve that can be used both as a normally closed valve and a normally open valve simply by rearranging the same parts.

[Means for Solving the Problems] In order to achieve the above object, the means adopted by the present invention is to form an annular recess in which the return spring is fitted in the piston, turn the piston upside down at the same position on the spindle, and then attach and detach it. It is possible to fix it. The configuration will be explained based on FIG. 1 and FIG. 2 corresponding to the embodiment. The present invention is based on the opening 10 of the valve body 10.
a, and a drive unit 26 that drives the diaphragm 11 to open and close the flow path 10b of the valve body 10. a piston 20 that moves within the cylinder to drive the diaphragm 11, and a return spring 15 that returns the piston 20 when pressurized air does not flow in.
It is a diaphragm valve consisting of a and 15b.

This diaphragm valve is fixed to the center of the piston 20 through a spindle 14, one end of the spindle 14 is connected to the diaphragm 11 via a compressor 16 and a screw 17, and the other end is connected to the bottom 18a of the cylinder 18. The cylinder 18 is partitioned by a piston 20.
A first port 23 and a second port 2, which serve as selective inflow ports for pressurized air, are provided in the first chamber 21 on the diaphragm side and the second chamber 22 on the opposite side of the diaphragm 11.
4 are respectively provided, and when the first port 23 is used as an inlet for pressurized air, the return springs 15a and 15b are arranged so that the diaphragm 11 closes the flow path 10b, and the second port 24 is used as an inlet for pressurized air. The return springs 15a and 15b are arranged so that the diaphragm 11 opens the flow path 10b.

[Function] By fixing the piston 20 to the spindle 14 and connecting one end of the spindle 14 to the diaphragm 11, the cylinder 18 can be made smaller and the responsiveness of the diaphragm operation when pressurized air flows in is improved. When the first port 23 is used as an air inflow port, the annular recess in which the return spring of the piston 20 is fitted faces upward, and the distance between its inner bottom surface and the bottom 18a of the cylinder is longer than half the inner length of the cylinder, and a strong Since the return spring 15b is attached, the valve becomes a normally closed diaphragm valve with a strong normally closing force that opens only when pressurized air flows in. Second port 24
When using the pressurized air inlet, the piston 20
is turned upside down and fixed to the spindle 14, with its annular recess facing downward. Next, the bottom surface of the annular recess and the surface 12b that supports the return spring of the bonnet 12.
The interval is longer than half the inner length of the cylinder, and a strong return spring is fitted there, resulting in a diaphragm normally open valve 15b with a strong normally open force that closes when pressurized air flows in.

[Example] Next, one embodiment of the present invention will be described in detail.

As shown in FIGS. 1 to 3, a diaphragm 11 made of tetrafluoroethylene resin is placed around the opening 10a of a valve body 10 made of stainless steel, a bonnet 12 is placed on top of the diaphragm 11, and the whole is tightened with bolts 13. wear. A spindle 14 is slidably passed through the center of the bonnet 12. A compressor 16 is hooked to the lower end of this spindle 14, and the compressor 1
The diaphragm 11 is connected to the diaphragm 6 via a screw 17.

The cylinder 18 is fastened to the outer periphery of the bonnet 12 with bolts 19. 12a is an O-ring that maintains airtightness between the bonnet 12 and the cylinder 18. A piston 20 having a substantially W-shaped cross section is slidably provided in the cylinder 18. A piston stopper 18b is provided on the inner wall of the cylinder 18. The spindle 14 is passed through the center of the piston 20 and fixed thereto. The other end of this spindle 14 is the cylinder 1
8 and protrudes through the bottom 18a. Reference numerals 15a and 15b are return springs that return the piston 20 displaced by pressurized air, which will be described later. cylinder 1
8. The piston 20 and the return springs 15a and 15b constitute a diaphragm driving section 26.

A first chamber 21 on the diaphragm side and a second chamber 22 on the opposite side of the diaphragm of the cylinder 18 partitioned by the piston 20 are provided with a first port 23 and a second port 24, respectively, which serve as selective inflow ports for pressurized air. 20a is an O-ring, and the first chamber 21
and the second chamber 22 are kept airtight.

With such a configuration, the piston 20 is fixed to the spindle 14 in a W-shaped direction as shown in FIG.
and the return springs 15a and 15b between the piston 20 and the piston 20.
If pressurized air is introduced from the first port 23 through the
moving the spindle 14 against the acting force of b;
The diaphragm 11 is separated from the valve seat 10c to open the valve. Upon releasing the pressure in the cylinder 18, the return springs 15a and 15b move the diaphragm 11 towards the closed position and drive the piston 20 along the cylinder 18 towards the diaphragm 11.

Next, as shown in FIG. 2, the piston 20 is fixed to the spindle 14 in an inverted W-shaped direction, and return springs 15a and 15b are interposed between the surface 12b of the bonnet 12 of the first chamber 21 and the piston 20. , if pressurized air is introduced from the second port 24, the piston 2
0 moves the spindle 14 against the acting force of the return springs 15a and 15b, and, contrary to FIG. 1, seats the diaphragm 11 on the valve seat 10c and closes the valve. When the pressure in the cylinder 18 is released, the return springs 15a and 15b move the diaphragm 11 towards the open position and move the piston 20 into the cylinder 1.
8 toward the bottom 18a.

The piston 20 shown in FIGS. 1 and 2 acts directly on the diaphragm 11 via the compressor 16 hooked on the spindle 14 and the screw 17 connected to the compressor 16, so the response speed of the diaphragm 11 is extremely fast. . Further, the open and closed states of the diaphragm 11 can be easily visually recognized by the change in the length of the other end of the spindle 14 protruding from the bottom 18a of the cylinder 18 (indicated by a broken line in FIGS. 1 and 2).

[Effects of the invention] As described above, according to the invention, by fixing the piston to the spindle and connecting one end of the spindle to the diaphragm, the cylinder can be made smaller, and pressurized air can flow into the cylinder. The responsiveness of the diaphragm operation is improved when

The piston and return spring are reversed and reassembled using a port for introducing pressurized air, but since the piston is fixed at the same position on the spindle with the vertical relationship reversed, reassembly work is relatively easy; Since a strong spring with a length longer than half the inner length of the cylinder is used, the normally closing force or normally opening force of the valve is strong.
Also, if the first port is used as the inlet for pressurized air, it becomes a diaphragm valve that opens only when pressurized air flows into the first port, and if the second port is used as the inlet for pressurized air, A diaphragm valve that is "closed" only when pressurized air flows into the second port is obtained. As a result, the same parts can be reassembled into either normally-closed or normally-open valves by simply changing the assembly method, making it possible to mass-produce at low cost for the microbial industry, etc., where normally-closed and normally-open valves coexist. can.

[Brief explanation of the drawing]

FIG. 1 is a half-sectional front view of a diaphragm valve according to an embodiment of the present invention. FIG. 2 is a front view corresponding to FIG. 1 in which the piston is installed in the opposite direction and the pressurized air inlet is changed. Figure 3 is a cross-sectional view taken along line AA in Figure 1. 10: valve body, 10a: opening, 11: diaphragm, 14: spindle, 15a, 15b: return spring, 18: cylinder, 20: piston, 21:
First chamber, 22: Second chamber, 23: First port, 2
4: Second port, 26: Diaphragm drive unit.

Claims (1)

[Scope of utility model registration request] It is equipped with a diaphragm 11 provided in the opening 10a of the valve body 10, and a drive unit 26 that drives the diaphragm to open and close the flow path of the valve body. A piston 20 that moves inside the cylinder with air to drive the diaphragm, and return springs 15a and 15b that return the piston when pressurized air does not flow in.
and a spindle 14 connected at one end to the diaphragm and slidably journalled in the bonnet 12.
and a diaphragm consisting of a first port 23 and a second port 24 that serve as selective inflow ports for pressurized air into a first chamber 21 on the diaphragm side of the cylinder partitioned by a piston and a second chamber 22 on the opposite side from the diaphragm. In the valve, the piston is fixed at the same position on the spindle in a vertically inverted and removable manner,
A diaphragm valve characterized in that the piston is formed with an annular recess into which the return spring fits, and the length of the return spring is longer than half the inner length of the cylinder.