JPH0751614Y2 - Pressure reducing valve with residual pressure discharge function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a pressure reducing valve having a residual pressure discharge function, and more particularly, to a fluid having an inflow port and an outflow port and connected to the outflow port. A pressure reducing valve having a residual pressure discharging function for supplying fluid to a device having a predetermined pressure selected, the first valve element for opening and closing a communication state between the inflow port and the outflow port. The present invention relates to a pressure reducing valve having a residual pressure discharging function, which is provided with a second valve body for releasing the secondary side pressure fluid when the fluid supply from the primary side inflow port is cut off.

BACKGROUND OF THE INVENTION Generally, in a fluid pressure device such as a pneumatic device, a pressure reducing valve is used to regulate the outlet pressure to a set pressure lower than that regardless of the inlet pressure and supply air. There is.

Conventionally, this type of pressure reducing valve is configured as follows. That is, it includes a body and a bonnet and a diaphragm stretched at a joint portion between the body and the bonnet, and an inflow port and an outflow port are formed in the body.
In this case, a passage that connects the inflow port and the outflow port is defined in the body, and a valve body for opening and closing the passage is provided therein. The valve element abuts on a substantially central portion of the diaphragm via a slam.

On the other hand, a coil spring is arranged inside the bonnet, and one end of the coil spring is in pressure contact with the diaphragm and the other end is engaged with the spring receiving plate. The spring receiving plate is engaged with one end side of a screw screwed to the bonnet, so that the coil spring is configured to adjust its elastic force by the screwing operation of the screw.

By the way, in the pressure reducing valve configured as described above, in order to supply a large flow rate of fluid to the fluid device connected to the outflow port side, the inflow port and the outflow port and the passages connecting these are enlarged. Therefore, the valve body for opening and closing the passage also has a relatively large outer diameter corresponding to the passage. However,
As described above, when the outer diameter of the valve body is increased, the area of the valve body that receives the pressure of the fluid on the inflow port side, that is, the pressure receiving area increases. Therefore, when the passage that connects the inflow port and the outflow port is opened and the fluid is supplied from the inflow port to the outflow port side, the valve body closes the passage due to the pressure fluctuation on the inflow port side. May be displaced in the direction. Therefore, when such a situation is reached, there is a drawback that it becomes impossible to supply a desired flow rate of fluid to the fluid device connected to the outflow port.

[Object of the Invention] The present invention has been made in order to overcome the above-mentioned inconvenience, and in a pressure reducing valve for reducing the pressure of a fluid of a desired flow rate and supplying it to a fluid pressure device, an image is formed on the body of the pressure reducing valve. Defining a preload chamber in which the valve body is fitted at one end side of the valve body that opens and closes a passage that connects the inflow port and the outflow port that are formed,
The preload chamber is connected to the outflow side port, and the preload chamber and the inflow port are connected to each other, whereby a fluid having a relatively large flow rate is supplied to the fluid pressure device connected to the outflow port side. While enabling suitable supply, when the pressure on the inflow port side is reduced, the pressure on the outflow port side is discharged to the inflow port side via the preload chamber, and the pressure on the outflow port side is reduced. An object of the present invention is to provide a pressure reducing valve having a residual pressure discharging function that enables reduction.

[Means for Achieving the Object] In order to achieve the above object, the present invention provides a pressure reducing valve for reducing the pressure of a fluid having a desired flow rate and supplying the fluid to a fluid device. A body that is defined, a bonnet that is attached to the body, a diaphragm that is stretched at the joint between the body and the bonnet, and a passage that connects the inflow port and the outflow port that are defined by the body. A first valve body that opens and closes the valve, a preload chamber that is defined on the bottom side of the first valve body, and that communicates with the inflow port and the outflow port, and substantially engages with the outer peripheral portion of the first valve body. The packing member has a substantially V-shaped cross section, and when the pressure on the inflow port side increases, the diameter increases to close the inflow port and the preload chamber, while the preload chamber decreases when the pressure on the inflow port side decreases. Contracted by side pressure A second valve body that communicates the inflow port and the preload chamber with a diameter, and connects the preload chamber and the outflow port through a hole defined in the axial center of the first valve body. The flow passage area between the inflow port and the preload chamber controlled by the second valve body to have a large fluid flow area, and the fluid pressure in the inflow port is lower than the pressure in the outflow port, By reducing the diameter of the second valve body, the fluid remaining in the preload chamber is discharged to the inflow port side, and a pressure difference is generated from the difference in the fluid flow area between the preload chamber and the outflow port.
It is characterized in that the fluid remaining on the outflow port side is discharged to the inflow port side by displacing the first valve body.

[Embodiment] Next, a pressure reducing valve having a residual pressure discharge function according to the present invention will be described in detail below with reference to preferred embodiments.

In FIG. 1, reference numeral 10 indicates a pressure reducing valve according to the present invention, and the pressure reducing valve 10 having a residual pressure discharging function basically includes a body 12 and a bonnet 14 attached to the body 12, The bonnet 14 bulges and extends largely upward from the body 12, and a side wall of the bonnet 14 has a hole 14a communicating with the atmosphere.

An inflow port 16 is defined on one side wall of the body 12, and an outflow port 18 is formed on the other side.
The inflow port 16 communicates with the outflow port 18 via a passage 20, a decompression chamber 22, a passage 24 and a passage 26. The lower part of the decompression chamber 22 is substantially closed by a fitting member 28 which is screwed from below the body 12. An O-ring 30 is interposed between the body 12 and the fitting member 28.

A recess 32 communicating with the decompression chamber 22 is defined in the fitting member 28, and a cylindrical portion 34 that enters the recess 32 is formed at an end surface portion that defines the recess 32. A first valve body 36 having a flange portion is fitted inside the cylindrical portion 34.
Therefore, the preload chamber 37 is defined between the first valve body 36 having the flange portion and the cylindrical portion 34, and one end side of the coil spring 38 is engaged with the outer peripheral portion of the cylindrical portion 34. The other end of the coil spring 38 extends upward in the drawing and is in pressure contact with the flange portion of the first valve body 36. Therefore, the end surface of the first valve body 36 on the flange side is pressed against the tip of the valve seat portion 39 which is erected between the passages 20 and 24 under the pressing action of the coil spring 38, and the passage is concerned. It can be easily appreciated that the communication between 20 and 24 is blocked. The pressure receiving area of the first valve body 36 on the side of the preload chamber 37 is selected to be substantially equal to the pressure receiving area on the side of the outflow port 18 so that the first valve body 36 changes the pressure on the side of the inflow port 16. The displacement is prevented as much as possible.

A peripheral groove 40 is defined on the outer peripheral surface of the first valve body 36 on one end side, and the second valve body 42 engages with the peripheral groove 40. In this case, the second valve body 42 has a substantially V-shaped cross section with an open upper side in the drawing, and the outer peripheral portion of the second valve body 42 contacts the inner peripheral wall surface of the cylindrical portion 34. The decompression chamber 22 and the precompression chamber 37 are cut off from each other by the communication, and the diameter of the second valve body 42 is reduced to reduce the decompression chamber 22 and the precompression chamber 37.
It is configured so that it can communicate with 37 (see FIGS. 2 and 3).

A hole extending in the axial direction is formed in the substantially central portion of the first valve body 36.
44 is provided, and a plurality of slits 46 communicating with the hole 44 are formed in the substantially central portion of the upper surface of the first valve body 36. Actually, the small diameter portion 48a of the stem 48 is loosely fitted in the hole portion 44, the end portion of which is projected into the preload chamber 37, and the ring member 50 is fitted externally so as to be integrated with the first valve body 36. Is being pursued. On the other hand, the large-diameter portion 48b integrally formed with the small-diameter portion 48a of the stem 48 extends upward from the side surface of the flange portion of the first valve body 36, penetrates the passage 24, and passes through the body 12
It faces the room 52 defined on the upper part of the. In this case, the chamber 52 is provided with a static pressure pipe 54 which is oriented downward.
In addition to being in communication with the above, the upper portion thereof is closed by a diaphragm 56 stretched at a joint portion between the body 12 and the bonnet 14.

A diaphragm retainer 58 is fitted to the diaphragm 56 at a substantially central portion thereof. One end side of the diaphragm retainer 58 is in the chamber 52 and has a large diameter, and a recessed step 58a is formed at a substantially central portion thereof. On the other hand, a screw groove 58b is formed in the bonnet 14 on the other end side of the diaphragm retainer 58. Further, the diaphragm retainer 5
A hole 58c for communicating the chamber 52 with the inside of the bonnet 14 is formed in a substantially central portion of the hole 8. In this case, the hole 5c
The communication state between 8c and the chamber 52 can be shut off by the tip portion of the stem 48.

A first coil spring receiving plate 60 that fits into the diaphragm retainer 58 and contacts the diaphragm 56 is disposed inside the bonnet 14, and the coil spring receiving plate 60 is provided.
Is fixed by a nut member 62 screwed into the screw groove 58b of the diaphragm retainer 58. A protrusion 60a is formed on the upper surface of the first coil spring receiving plate 60 so as to project upward and circulate, and one end of the coil spring 64 engages with the recess defined by the protrusion 60a.

On the other hand, a hole having a plurality of steps is formed in the upper portion of the bonnet 14, and the insert metal 66 is formed in this hole.
Engage. In this case, a screw hole 66a is formed substantially in the center of the insert metal 66, and a pressure adjusting screw 68 is screwed into the screw hole 66a. One end side of the pressure adjusting screw 68 projects upward, and a handle 70 is engaged with the end portion thereof. Also, the pressure adjusting screw 68
The other end of the bonnet is inserted into the inside of the bonnet 14, the end of which has a spherical shape, and the end of the pressure adjusting screw 68 is engaged with the second coil spring receiving plate 72. That is, the second coil spring receiving plate 72 is in the shape of a disc having an engaging recess 72a in its substantially central portion, and this engaging recess 72a engages with the spherical end of the pressure adjusting screw 68. is doing. The second coil spring support plate 72 has the coil spring 64.
The other end side of the contact. Therefore, the coil spring 64
It will be easily understood that the elastic force can be adjusted by the screwing operation of the pressure adjusting screw 68.

In the figure, reference numeral 74 indicates a nut member, and this nut member 74 is for preventing the screwing operation of the pressure adjusting screw 68.

The pressure reducing valve having the residual pressure discharging function according to the present invention is basically constructed as described above. Next, its operation and effect will be described.

First, in order to reduce the pressure of the fluid discharged from the inflow port 16 to the desired pressure and to discharge it from the outflow port 18, the handle 70 is used.
To rotate. The rotation of the handle 70 causes the pressure adjusting screw 68 to rotate equally, and as a result, the second coil spring receiving plate 72 engaging with the end of the pressure adjusting screw 68 descends. For this reason, the coil spring 64 interposed between the first coil spring receiving plate 60 and the second coil spring receiving plate 72 is pressed, and the elastic force thereof is increased to bend the diaphragm 56. As a result, the stem 48 is displaced downward via the diaphragm retainer 58 arranged substantially in the center of the diaphragm 56, and the first valve body is engaged with the stem 48.
36 is displaced downward. The passage 24 and the decompression chamber 22 are communicated with each other by the displacement operation of the first valve body 36, and as a result, the inflow port 16 and the outflow port 18 are in communication with each other.

Therefore, the fluid from the inflow port 16 to the outflow port 18 is regulated by the pressure between the first valve body 36 and the valve seat portion 39, and as a result, a predetermined decompression action is applied to the fluid. To the outflow port 18 side. Ie the handle
Since the distance between the first valve body 36 and the valve seat portion 39 is adjusted by screwing 70, the pressure reducing action is preferably achieved. In this case, the fluid discharged to the outflow port 18 side flows into the preload chamber 37 through the slit 46 and the hole 44 formed in the first valve body 36, and the chamber 52 through the static pressure pipe 54.
Flows in. Therefore, in the preload chamber 37 and the chamber 52, substantially the same pressure as the pressure on the outflow port 18 side can be obtained.
As described above, since the pressure receiving area on the outflow port 18 side of the first valve body 36 and the pressure receiving area on the preload chamber 37 side are substantially equal, the first valve body 36 has substantially the same load due to the respective pressures. Is added from the outflow port 18 side and the preload chamber 37 side. For this reason,
The first valve body 36 can accurately perform the depressurizing action without being displaced in the vertical direction due to the change in the pressure on the outflow port 16 side.

On the other hand, the pressure on the side of the inflow port 16 causes a load to displace the first valve body 36 upward. In this case, if the pressure on the inflow port 16 side is unstable, the load that attempts to displace the first valve body 36 upward is also unstable.
Therefore, the first valve body 36 moves up and down in accordance with the change in the pressure on the side of the inflow port 16, and eventually the first valve body 36 and the valve seat portion 39.
The opening between and is not constant. However, in this embodiment, a preload chamber 37 is provided below the first valve body 36, and a constant pressure (pressure on the outflow port 18 side) is constantly applied to the preload chamber 37, whereby the first valve The body 36 is constantly pressed upward with a constant load. Therefore, the first
The valve body 36 is hardly affected by the pressure change on the inflow port 16 side. At this time, the V-shaped second valve body 42 that engages with the first valve body 36 is in a state in which its V-shaped recess is expanded by receiving the pressure on the side of the inflow port 16 side. The pressure in the preload chamber 37 is never discharged to the inflow port 16 side (see FIG. 2).

Next, in the above-described state, when the pressure on the outflow port 18 side increases, for example, the passage 26 is formed in the outflow port 18.
And the pressure of the chamber 52, which is communicated via the static pressure pipe 54, also increases,
This increases the load that displaces the diaphragm 56 that closes the upper portion of the chamber 52 upward. This increased load resists the elastic force of the coil spring 64 arranged inside the bonnet 14 and eventually causes the diaphragm 56 to be displaced upward. As a result, the hole 58 of the diaphragm retainer 58 fitted to the substantially central portion of the diaphragm 56.
The fluid in the chamber 52 is discharged into the bonnet 14 via c, and is discharged from the bonnet 14 to the atmosphere via the hole 14a communicating with the atmosphere. Along with this, the first valve element 36
Further, the stem 48 engaging with the first valve body 36 is displaced upward under the pressing action of the coil spring 38 to close the inflow port 16 and the outflow port 18 and prevent the flow of the fluid to the outflow port 18. . Therefore, the pressure on the side of the outflow port 18 decreases. That is, when the pressure is lowered to a desired pressure, the stem 48 and the first valve body 36 are pressed downward by the elastic force of the coil spring 64 via the diaphragm 56 and the diaphragm retainer 58 fitted to the substantially central portion of the diaphragm 56. To be done. As a result, the inflow port 16 and the outflow port 18 are brought into communication with each other again, and the fluid having a desired flow rate is decompressed and discharged to the outflow port 18 side.

As described above, the fluid with a constant pressure always flows out the port.
It is supplied to a fluid device (not shown) via 18.

Next, the supply of the fluid to the outflow port 18 side may be interrupted by adjustment work of a fluid device (not shown) connected to the outflow port 18. In this case, first, the supply source (not shown) connected to the inflow port 16 is deenergized to cut off the fluid supply and reduce the pressure on the inflow port 16 side. As a result, the V-shaped second valve body 42 that engages with the first valve body 36 is formed.
Due to the pressure in the preload chamber 37, the preload chamber 37 and the inflow port 16 communicate with each other (see FIG. 3). Therefore,
The fluid in the preload chamber 37 is discharged to the inflow port 16 side, and the fluid in the outflow port 18 and the fluid device connected to the outflow port 18 is formed in the passages 26 and 24 and the first valve body 36. It will be discharged to the inflow port 16 side through the slit 46, the hole portion 44, and the preload chamber 37. In this case, since the gap between the slit 46 and the hole 44 is extremely small, the fluid in the outflow port 18 and the passages 26, 24 flows into the preload chamber 37 little by little. On the other hand, since the passage that connects the preload chamber 37 and the inflow port 16 is formed to be relatively large, the fluid in the preload chamber 37 is smoothly discharged to the inflow port 16 side. As a result, a difference occurs between the pressure in the preload chamber 37 and the pressure in the passage 24, and this difference in pressure causes a load that displaces the first valve body 36 downward. The load displaces the valve body 36 downward against the elastic force of the coil spring 38 disposed below the first valve body 36, so that the passage 24 passes through the decompression chamber 22 and the passage 20. Inflow port 16
Communicate with. Therefore, the fluid remaining on the outflow port 18 side is discharged all at once to the inflow port 16 side.

Thus, by reducing the pressure on the inflow port 16 side, the fluid on the outflow port 18 side is discharged to the inflow port 16 side, and the pressure on the outflow port 18 side can be reduced. Therefore, when performing the adjustment work of the fluid device connected to the outflow port 18, there is no residual pressure in the fluid device, and the adjustment work of the fluid device can be safely performed after all.

[Advantages of the Invention] As described above, according to the present invention, in a pressure reducing valve for reducing the pressure of a fluid of a desired amount and supplying the fluid to a fluid pressure device, the pressure reducing valve having the residual pressure discharging function is configured. An inflow port, an outflow port, and a first valve body that opens and closes a passage that connects the inflow port and the outflow port to the body;
A preload chamber into which one end side of the valve body is fitted is provided. Further, a second valve body capable of opening and closing the preload chamber and the inflow port is engaged with the first valve body. Thus, when decompressing a predetermined flow rate of fluid from the inflow port and discharging it to the outflow port, a fluid having a relatively large flow rate can be suitably applied to the outflow port side without being influenced by a pressure change on the inflow port side. Can be derived to.
When the pressure on the inflow port side is reduced, the second valve body engaging with the first valve body contracts due to the pressure in the preload chamber, and the fluid on the outflow port side passes through the preload chamber. It can be discharged to the inflow port side. Further, after the fluid on the outflow port side starts discharging to the inflow port side via the preload chamber, the first valve body opens, and the fluid on the outflow port side is discharged to the inflow port side at once. It is possible to reduce the pressure in the fluid device connected to the outflow port. Therefore, not only can a fluid having a relatively large flow rate be depressurized to a desired pressure to be suitably supplied to the fluid device, but also the pressure in the fluid device can be reduced when adjusting the fluid device. Accordingly, there is an advantage that the adjustment work of the fluid device can be performed safely.

Although the present invention has been described with reference to the preferred embodiment, the present invention is not limited to this embodiment.
For example, the second valve body may be arranged in the cylindrical portion that defines the preload chamber, and it is a matter of course that various improvements and design changes can be made without departing from the scope of the present invention.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional explanatory view of a pressure reducing valve having a residual pressure discharging function according to the present invention, and FIGS. 2 and 3 show an operating state of essential parts of a pressure reducing valve having a residual pressure discharging function according to the present invention. It is a partially omitted sectional view. 10 ... Pressure reducing valve having residual pressure discharging function, 12 ... Body 14 ... Bonnet, 16 ... Inflow port 18, Outflow port, 36, 42 ... Valve body 44 ... Hole, 46 ... Slit 56 ... Diaphragm, 64 ... Coil spring 68 … Pressure screw

Claims (2)

[Scope of utility model registration request] 1. A pressure reducing valve for reducing the pressure of a fluid having a desired flow rate and supplying the fluid to a fluid device; a body defining an inflow port and an outflow port; and a bonnet attached to the body. A diaphragm that is stretched at the joint between the body and the bonnet, a first valve body that opens and closes a passage that connects the inflow port and the outflow port defined by the body, and the bottom portion of the first valve body. A pressure chamber on the side of the inflow port, the preload chamber being defined on the side of the inflow port and the outflow port and communicating with the inflow port and the outflow port; When the pressure on the inflow port side decreases, the diameter is reduced by the pressure on the preload chamber side so that the inflow port and the preload chamber communicate with each other. A second valve body that An inflow port and a preload chamber that are controlled to communicate by the second valve body with respect to a passage that connects the preload chamber and the outflow port through a hole defined in the axial center of the first valve body. When the fluid flow area of the passage between them is made large and the pressure of the fluid in the inflow port is lower than the pressure in the outflow port, the fluid remaining in the preload chamber is removed by the diameter reduction of the second valve body. While discharging to the side, the pressure difference is generated from the difference in the fluid flow area between the preload chamber and the outflow port,
A pressure reducing valve having a residual pressure discharging function, wherein the fluid remaining on the outflow port side is discharged to the inflow port side by displacing the first valve body. 2. The pressure reducing valve according to claim 1 of the utility model registration, wherein the second valve body is disposed on an inner wall portion defining the preload chamber, and the inner peripheral surface of the second valve body is the first. A pressure reducing valve having a residual pressure discharge function, characterized in that the inlet port and the preload chamber are controlled to communicate with each other by coming into and out of contact with an outer peripheral portion of a valve body.