JPH0247826Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a flow rate regulating valve that controls the flow rate of fluid using pneumatic pressure.

[Conventional technology]

Flow control valves operated by air pressure are often used, for example, in automatic painting equipment that automatically controls the amount of paint discharged during spray painting. A conventional flow rate regulating valve used for such applications will be explained. FIG. 4 is a sectional view of a conventional diaphragm type flow regulating valve. A diaphragm 3 is held between the valve body 1 and the operating air chamber case 2. A valve stem 4 is directly connected to the diaphragm 3, a valve 5 is fixed to the valve stem 4,
Together with the valve seat 6, it constitutes a globe valve. A diaphragm 3 separates an upper operating air chamber 7 from a lower valve outlet chamber 9. Compressed air is introduced into the operating air chamber 7 from an operating air inlet 8, and the operating air pressure pushes down the diaphragm 3 and opens the valve 5. The pressurized paint, which is a fluid, enters the fluid inlet 1.
0 and is blocked by valve 5. When the operating air chamber 7 is pressurized, the diaphragm 3 is pushed down, the valve 5 is opened, and the paint passes through the valve outlet chamber 9 and the fluid outlet 11 and is blown out from a spray nozzle (not shown).

The operating air pressure in the operating air chamber 7 and the paint discharge pressure in the valve outlet chamber 9 are balanced through the diaphragm 3, and if the operating air pressure in the operating air chamber 7 is higher than the paint pressure in the valve outlet chamber 9, the diaphragm 3 moves downward. When pressed, the valve stem 4 moves down and opens the valve 5. Since the paint at the fluid inlet 10 is pressurized to a sufficiently high pressure,
The paint pressure in the valve outlet chamber 9 is approximately equal to the operating air pressure in the operating air chamber 7. Therefore, by controlling the operating air pressure, the paint discharge pressure of the fluid outlet 11 can be controlled, and the amount of paint discharged from the spray nozzle (not shown) can be controlled.

In the conventional flow rate regulating valve, the operating air pressure and the paint discharge pressure are balanced through the diaphragm 3, so the relationship between the operating air pressure and the paint discharge pressure is as follows.
The ratio is always 1:1. In other words, only the conversion accuracy or conversion sensitivity of the paint discharge pressure to the operating air pressure can be obtained.

[Purpose of the invention] This invention was developed in response to these problems.The relationship between the operating air pressure and the fluid discharge pressure is not 1:1, but can be set to any constant value, and the relationship between the operating air pressure and the fluid discharge pressure can be set to any constant value, and the relationship between the operating air pressure and the fluid discharge pressure can be set to any constant value, and the relationship between the operating air pressure and the fluid discharge pressure can be set to any constant value. Alternatively, the present invention aims to provide a flow rate regulating valve with sensitivity.

[Means for solving problems]

For this reason, this invention is a diaphragm valve that controls the flow rate of fluid using operating air pressure, and is equipped with two diaphragms directly connected to the valve stem, one of the diaphragms serving as a pressure-receiving surface that receives operating air pressure to open the valve. The other diaphragm forms a pressure receiving surface that receives the pressure of the fluid in the valve outlet passage, and the other diaphragm receives pressure in the direction of closing the valve, and the pressure receiving areas of the two diaphragms are different from each other. is provided.

[Effect]

According to the configuration of this invention, the diaphragm that receives air pressure pushes the valve stem in the valve opening direction with a force corresponding to the product of the air pressure and the pressure receiving area of the diaphragm.
The diaphragm that receives the fluid pressure pushes the valve stem in the valve closing direction with a force corresponding to the product of the fluid pressure and the pressure receiving area of the diaphragm. Therefore, the fluid pressure at the valve outlet is such that the forces transmitted from the two diaphragms to the valve stem are balanced. By arbitrarily setting the pressure receiving area ratio of the above two diaphragms,
The conversion accuracy or sensitivity of fluid pressure to air pressure can be set to an arbitrary value.

〔Example〕

An embodiment of this invention will be explained based on the drawings. FIG. 1 is a sectional view of a flow rate regulating valve to which the present invention is applied. At the top of the valve body 1, there are a small diameter ring 12 having a small inner diameter, an intermediate ring 13, a large diameter ring 14 having a large inner diameter, and an operating air chamber case 2.
are centered by their respective pilot rows, stacked one on top of the other, and fastened with bolts (not shown). A small diameter diaphragm 15 is held between the small diameter ring 12 and the intermediate ring 13, and a large diameter diaphragm 16 is held between the intermediate ring 13 and the large diameter ring 14, respectively. Above two diaphragms 1
5 and 16 are fixed to a core 17 having a truncated cone shape at the center. The valve stem 4 is directly connected to the core 17 and assembled, and the valve 5 at the tip of the valve stem 4 and the valve seat 6 of the valve body 1 constitute a globe valve. The two diaphragms 15 and 16 provide an operating air chamber 7 in the upper part of the diaphragm 16, an intermediate ring chamber 18 surrounded by the two diaphragms, and a valve outlet chamber 9 in the lower part of the diaphragm 15. The intermediate ring chamber 18 is communicated with the outside through a communication hole 19, and the pressure of the intermediate ring chamber 18 is maintained at atmospheric pressure.

A pressurized paint fluid is introduced through a fluid inlet 10 and blocked by a valve 5. When pressurized air is applied from the operating air inlet 8, the diaphragm 16 is pressed, the valve stem 4 moves downward and opens the valve 5, and the paint passes through the valve outlet chamber 9 and the fluid outlet 11 to a spray nozzle (not shown). The lead is spray painted. At this time, a large-diameter diaphragm 1 receives the air pressure in the operating air chamber 7.
6 pushes the valve stem 4 in the valve opening direction with a force represented by the product of the operating air pressure and the area of the large diameter diaphragm 16, while the small diameter diaphragm 15 that receives the paint discharge pressure in the valve outlet chamber 9 receives the paint discharge pressure. and the area of the small diameter diaphragm 15.
Push in the valve closing direction. Therefore, the paint discharge pressure in the valve outlet chamber 9 is such that the forces transmitted from the two diaphragms 15 and 16 to the valve stem 4 are balanced. In this embodiment, the ratio of the pressure receiving areas of the large diameter diaphragm 16 and the small diameter diaphragm 15 is set to 3:1, so the ratio between the operating air pressure and the paint discharge pressure is 1:3, and as shown in FIG. The characteristics are as shown in . FIG. 3B shows the characteristics of the previously described conventional flow rate regulating valve consisting of a single diaphragm. In Figure 3, the horizontal axis is the operating air pressure pair, and the vertical axis is the fluid outlet 1.
1 shows the paint discharge pressure Pout. The characteristics shown in FIG. 3A are those of a highly sensitive flow rate regulating valve that has a wide operating range and can provide high paint discharge pressure even at low operating air pressure. In this embodiment, by recombining the components of the flow regulating valve, the high sensitivity flow regulating valve shown in FIG. 3A has the characteristics shown in FIG. 3C. It can be converted into a low-sensitivity, high-conversion-accuracy flow rate regulating valve that can precisely adjust paint discharge pressure and is less affected by connected equipment. This will be explained with reference to FIG.

FIG. 2 is a sectional view of a high-conversion-accuracy flow regulating valve obtained by recombining the high-sensitivity flow regulating valve shown in FIG. 13, large diameter ring 14, 2
A unit consisting of two diaphragms 15, 16 and a core 17 is turned upside down and assembled. That is, on the valve body 1, a large diameter ring 14 having a large inner diameter, a large diameter diaphragm 16,
The intermediate ring 13, the small diameter diaphragm 15, the small ring 12 having a small inner diameter, and the operating air chamber case 2 are stacked one on top of the other, and are fastened with bolts (not shown). The valve stem 4 is fixed to the core 17 to which the two diaphragms 15 and 16 are fixed. Since each ring 12, 13, 14 is centered with a spigot, it can be assembled accurately without shifting the center even if it is reassembled upside down.

In this example, the diaphragm facing the operating air chamber 7 is a small-diameter diaphragm 15, and the diaphragm facing the valve outlet chamber 9 is a large-diameter diaphragm 16. Therefore, since the ratio of the area of the diaphragm that receives the operating air pressure to the area of the diaphragm that receives the paint discharge pressure is 1:3, the ratio of the operating air pressure to the paint discharge pressure is 3:1, and as shown in FIG. The low sensitivity and high conversion accuracy characteristics shown in C are shown.

In the embodiments described above, the diaphragm has a pressure-receiving area ratio of 1:3, but by changing the area ratio, it is possible to manufacture a diaphragm having arbitrary conversion accuracy characteristics or operation sensitivity characteristics.
Furthermore, in this embodiment, by recombining the parts of the regulating valve, it is possible to convert the regulating valve into one with high precision characteristics or one with high sensitivity characteristics. Therefore, if you prepare a diaphragm with an appropriate ratio of diaphragms, such as 1:3, 1:2, or 2:3, you can easily find the most suitable characteristics for the area to be painted on site. It has the advantage that it can be used by being recombined with a flow rate regulating valve.

[Effect of idea]

As explained above, in this invention, the relationship between the fluid discharge pressure and the operating air pressure is not 1:1, but can be set to any constant value, and the conversion accuracy or conversion sensitivity characteristics of the fluid discharge pressure to the operating air pressure can be set to any value. There is an effect that can be achieved.

Therefore, when this invention is used as a paint flow rate regulating valve in an automatic painting device, the flow rate regulating valve can have characteristics most suitable for the painting area.
This has the advantage of improving coating quality and reducing the amount of paint used.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an embodiment of this invention, Fig. 2 is a sectional view of a flow rate regulating valve with different characteristics that is a combination of the one in Fig. 1, Fig. 3 is a characteristic diagram, and Fig. 4 is a conventional one. FIG. 3 is a sectional view of the flow rate regulating valve. 1...Valve body, 2...Operation air chamber case, 3...
...Diaphragm, 4...Valve stem, 5...Valve, 6...
Valve seat, 7... Operating air chamber, 9... Valve outlet chamber, 12
...Small diameter ring, 13...Middle ring, 14...
Large diameter ring, 15, 16...Diaphragm, 17
... Core, 18 ... Middle ring chamber, 19 ... Communication hole.

Claims (1)

[Scope of utility model registration request] The flow rate regulating valve is a diaphragm valve that controls the flow rate of fluid using operating air pressure, and is equipped with two diaphragms directly connected to the valve stem, one diaphragm serving as a pressure-receiving surface that receives operating air pressure. The other diaphragm forms a pressure receiving surface that receives the pressure of the fluid in the regulating valve outlet passage, receives pressure in a direction to close the valve, and the two diaphragms have different pressure receiving areas.