JP2713868B2 - Pressure reducing valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure reducing valve for reducing the pressure of a fluid supplied to an air cylinder or the like to a predetermined pressure.

[0002]

2. Description of the Related Art Conventionally, in a pressure reducing valve, it has been required to secure a wide range of pressure at which the pressure can be reduced and to reduce the size of the pressure reducing valve. The reason is that a small number of models can meet a wide range of required pressures and can be used even when the installation space is small.

As such a pressure reducing valve, there is a pressure reducing valve 51 shown in FIG. A housing 54 provided with an input port 52 and an output port 53 of the pressure reducing valve 51 has a valve body 5 for changing the size of the flow path between the ports 52 and 53.
5 are provided. A part of a piston 56 is in contact with the valve body 55, and the piston 56 is urged by a pressure adjusting spring 57. The pressure adjusting spring 57 is in contact with a lower end of an adjusting screw 59 screwed into a nut 58 fixed to the housing 54. An adjustment knob 6 is provided on the upper part of the housing 54.
0 is attached. The adjustment knob 60 is formed in a shape in which the upper ends of the outer and inner double cylinders 61 and 62 are closed by an upper plate 63. Engagement ridges 60a are formed all around the inner lower part of the outer cylinder 61 of the adjustment knob 60. The adjustment knob 60 is rotatably engaged with the housing 54 by engaging the engagement protrusion 60 a with a circumferential groove 54 a formed on the entire outer periphery of the housing 54. An engagement hole 64 is formed inside the inner cylindrical body 62, and a hexagonal head 65 of the adjusting screw 59 is engaged with the engagement hole 64 so as not to rotate and move vertically. Therefore, when the adjustment knob 60 is rotated, the adjustment screw 59 moves vertically in the engagement hole 64 without moving the adjustment knob 60 itself vertically. As a result, since the amount of expansion and contraction of the pressure adjusting spring 57 changes and the force applied to the piston 56 changes, the pressure of the fluid led out to the output port 53 side is reduced to a pressure corresponding to the turning position of the adjustment knob 60. You. Therefore, in this pressure reducing valve, the set pressure can be changed by moving the adjustment screw 59 without moving the adjustment knob 60 in the vertical direction. In addition, the movement amount of the adjustment screw 59 is maximized while minimizing the size of the adjustment screw 59 in the movement direction.

[0004]

However, in this pressure reducing valve 51, when the adjusting knob 60 is carelessly turned with the adjusting screw 59 most retracted from the pressure adjusting spring 57 side, the adjusting knob 60 It will come off from the peripheral groove 54a. Because the adjusting screw 59 is screwed into the nut 58 fixed to the housing 54, the adjusting screw 59
This is because if the adjusting screw 59 is turned too much in a state where the adjusting screw 59 is in contact with the lower surface of the upper plate 63, the thrust by screwing acts directly on the adjusting knob 60.

[0005] The housing 54 of such an adjustment knob 60
Various methods are conceivable for preventing falling off from the surface, but there is a problem that the production cost increases when the number of parts is increased or the number of processing steps is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to reduce the size of the adjusting screw in the moving direction and to adjust the pressure without changing the position of the adjusting knob. Another object of the present invention is to provide a pressure reducing valve that can prevent the adjustment knob from falling off from the pressure reducing valve main body without increasing the number of parts and the number of processing steps.

[0007]

In order to solve the above-mentioned problems, the invention according to the first aspect of the present invention is such that an adjustment knob is rotatably engaged with a valve body, and the rotation of the adjustment knob is based on the rotation of the adjustment knob. The amount of expansion and contraction of the pressure adjusting spring is changed by displacing the adjusting screw in the axial direction, and the pressure is reduced so that the valve element adjusts the pressure of the fluid flowing from the primary chamber to the secondary chamber based on the change in the amount of expansion and contraction. In the valve, a shaft portion is formed at a distal end portion of a male screw portion formed on the adjustment screw, the adjustment screw is supported on the adjustment knob so as not to rotate and can move in the axial direction, and a female screw member is provided on the valve body. Is supported so as to be non-rotatable and movable in the axial direction, and a male screw portion is screwed to the female screw member via the shaft portion.

According to a second aspect of the present invention, in the first aspect of the present invention, when the female screw member is displaced from the male screw portion to the shaft portion side, the female screw member is moved toward the male screw portion by the pressure adjusting spring. I was energized.

According to a third aspect of the present invention, in the first or the second aspect of the present invention, the amount of screwing with the female screw member when the adjusting screw moves toward the pressure adjusting spring is adjusted by a plurality of pitches. And

[0010]

According to the first aspect of the present invention, when the adjusting knob is rotated in the direction in which the adjusting screw is retracted from the pressure adjusting spring, the adjusting screw is retracted without moving the female screw member.
When the adjusting knob is further rotated in the same direction with the adjusting screw retracted to the maximum, the female screw member moves to the adjusting spring side, and finally comes off the male screw portion to the shaft portion. As a result, the thrust due to the engagement between the female screw member and the adjusting screw does not act on the adjusting knob. When the adjustment knob is rotated in the direction in which the adjustment screw moves toward the pressure adjustment spring, the adjustment screw moves toward the pressure adjustment spring without moving the female screw member. As a result, the amount of expansion and contraction of the pressure adjusting spring is changed.

According to the second aspect of the present invention, in addition to the function of the first aspect, the female screw member disengaged from the male screw portion to the shaft portion is attached to the male screw portion side by a pressure adjusting spring. Since the adjustment knob is rotated in the direction in which the adjustment screw moves toward the pressure adjustment spring, the female screw member is screwed into the male screw portion.

According to the third aspect of the present invention, in addition to the operation of the first or second aspect of the present invention, the female screw when the adjusting screw moves to the adjusting spring side without moving the female screw member. Since the screwing amount with the member is plural pitches, the spring force of the pressure adjusting spring is supported at plural pitches.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will now be described with reference to FIGS.
This will be described with reference to FIG. As shown in FIG. 1, a valve main body 1 a of a pressure reducing valve 1 of the present embodiment includes a body 2 and a cover 3. An adjustment knob 4 is provided on the upper part of the cover 3. An input port 5 and an output port 6 are formed in the body 2, and a primary chamber 8 in which the input port 5 and the output port 6 are isolated by a partition wall 7 is formed between the input port 5 and the output port 6. . The input port 5 and the primary chamber 8 are communicated via a flow path 9. Above the primary chamber 8, an accommodation hole 10 communicating with the primary chamber 8 is formed. An inner cylindrical portion 11 which is formed in a substantially cylindrical shape and is in contact with the upper end of the partition wall 7 is disposed below the inside of the accommodation hole 10. The accommodation hole 10 communicates with the outside via a flow path 12 formed in the cover 3.

At the center of the bottom surface of the inner cylinder portion 11, the primary chamber 8 is provided.
A hanging portion 13 that fits inside is formed. At the center of the hanging part 13, a flow path 14 for communicating the accommodation hole 10 with the primary chamber 8 is formed, and the lower end of the hanging part 13 is a valve port 15 which opens into the primary chamber 8. The output port 6 is isolated from the primary chamber 8 by the inner cylinder portion 11, and is connected to the primary chamber 8 via the flow path 16 and the flow path 14 formed at a position facing the output port 6 of the inner cylinder portion 11. Is communicated to. A valve element 17 is provided inside the primary chamber 8. The valve body 17 is a compression coil spring 1 disposed on the lower surface of the primary chamber 8.
At 8, it is urged toward the valve port 15.

A guide hole 19 is formed inside the inner cylindrical portion 11. A piston 20 is disposed in the guide hole 19 so as to be movable in a vertical direction (in FIG. 1). At the center of the lower surface of the piston 20, a hanging portion 21 extending through the inside of the flow path 14 is formed. A flow path 22 is formed in the hanging part 21 so as to penetrate the piston 20 in the vertical direction. When the piston 20 is disposed at the lower end of the inner cylindrical portion 11, the lower end of the hanging portion 21 is disposed below the valve port 15. In the lower part of the guide hole 19, a secondary chamber 23 isolated by the piston 20 is formed.
Therefore, the secondary chamber 23 is connected to the output port 6 via the flow path 16 and to the valve port 15 via the flow path 14. The upper surface of the piston 20 is recessed, and the lower end of a pressure regulating spring 24 made of a compression coil spring is in contact with this upper surface.

The upper portion of the cover 3 is provided with a through hole 25 in a vertical direction.
An adjusting screw 26 made of a hexagonal bolt is inserted into the through hole 25 so as to be slidable in the vertical direction. The head 26a of the adjusting screw 26 is formed in a hexagonal shape, and the tip end is a shaft portion 26c without the male screw portion 26b. An engagement hole 27 is formed in the upper inner surface of the cover 3.
A nut 28 serving as a female screw member screwed to the adjusting screw 26 is held in the engagement hole 27 so as not to rotate and move in the axial direction. The tip of the adjusting screw 26 is in contact with the upper end of the pressure adjusting spring 24 via the disk 29. The adjusting screw 26 and the nut 28 are urged upward by the spring force of the pressure adjusting spring 24. Note that an engagement hole 30 having a circular horizontal cross section is formed in the upper outer surface of the cover 3. A circumferential groove 31 is formed on the outer peripheral side of the cover 3.

The adjustment knob 4 is formed by closing the upper end of an outer and inner double cylinder with an upper plate 4a. A grip portion 32 is formed by an outer cylinder of the adjustment knob 4, and an engagement hole 33 is formed inside the inner cylinder to hold the head 26 a of the adjustment screw 26 so as not to rotate and move vertically. Have been. The lower end of the inner cylinder is rotatably fitted into the engagement hole 30. An engaging ridge 34 that engages with the peripheral groove 31 is formed on the entire inner lower end of the outer cylindrical body. As a result, the adjustment knob 4 is held rotatably with respect to the cover 3 and immovable in the vertical direction.

As shown in FIG. 2, when the external thread 26b of the adjusting screw 26 is out of the threaded state with the nut 28, the nut 28 is pressed toward the external thread 26b by the pressure adjusting spring 24. . Therefore, the head 26a of the adjusting screw 26 comes into contact with the lower surface of the upper plate 4a of the adjusting knob 4, and the male screw 2
When the nut 6b is disengaged from the nut 28, a gap is formed between the upper surface of the nut 28 and the upper end of the engagement hole 27 for a plurality of pitches of the male screw portion 26. At this time, the engagement ridge 34 of the adjustment knob 4 is prevented from coming off the engagement groove 31 of the cover 3 by the force applied from the pressure adjustment spring 24 to the adjustment screw 26. In this state, the lower end of the hanging portion 21 of the piston 20 is arranged closer to the primary chamber 8 than the valve port 15.

As shown in FIG. 1, the head 26a of the adjusting screw 26 contacts the lower surface of the upper plate 4a and the nut 2
When the upper surface of 8 is in contact with the upper end of the engagement hole 27, the disc 29 pressed upward by the pressure adjusting spring 24 is in contact with the lower end of the adjusting screw 26. At this time, the nut 28 and the male screw portion 26b of the adjusting screw 26 are screwed together for a plurality of pitches. In this state, the lower end of the hanging portion 21 of the piston 20 is disposed at the same height as the valve port 15,
5 is closed by the valve element 17. Therefore, this state is a state in which the set pressure on the secondary chamber 23 side is set to zero.

Further, as shown in FIG.
When the lower surface of the head 26a contacts the upper surface of the cover 3 and the upper surface of the nut 28 contacts the upper end of the engagement hole 27, the lower end of the hanging portion 21 of the piston 20
Than the primary room. Therefore, this state is a state in which the set pressure on the secondary chamber 23 side is set to the maximum.

Next, the operation of the pressure reducing valve configured as described above will be described. In the pressure reducing valve 1, as shown in FIG. 1, when the set pressure on the secondary chamber 23 side is set to 0, that is, the adjusting screw 26 is most retracted from the piston 20 side and the head 26a is The valve port 15 is closed by the valve element 17 in a state of contacting the lower surface of the upper plate 4a. Therefore, even if air is supplied to the input port 5 side, the output port 6
No air is supplied to the side. In this state, nut 2
8 is in contact with the upper end of the engagement hole 27.

From this state, the adjusting screw 26 is
When the adjustment knob 4 is turned in the direction of retreating from the side 4, that is, when the operator further turns the adjustment knob 4 even though the set pressure has become 0, the following occurs. . That is, the head 26a of the adjusting screw 26 is connected to the upper plate 4a of the adjusting knob 4.
The adjustment screw 26 is held immovable by contact with the lower surface of the nut 2.
8 moves toward the pressure adjusting spring 24 along the engagement hole 27. Therefore, even if the adjusting screw 4 is further rotated from the state where the set pressure is 0 so that the adjusting screw 26 retreats from the piston 20 side, the thrust by the screwing of the adjusting screw 26 and the nut 28 acts on the adjusting knob 4. There is no. And FIG.
When the male screw portion 26b comes off the nut 28, the upper surface of the disk 29 pressed by the pressure adjusting spring 24 comes into contact with the lower surface of the nut 28 as shown in FIG. As a result, the head 26a of the adjusting screw 26 is held in a state of being in contact with the lower surface of the upper plate 4a of the adjusting knob 4.

From this state, the adjusting screw 26 is
When the adjustment knob 4 is rotated in the direction of moving forward, the nut 2
8 is pressed by the adjusting screw 26 by the pressure adjusting spring 24 and a gap is formed between the nut 28 and the upper end of the engaging hole 27, so that the nut 28 and the male screw portion 26b are screwed together. In this state, since the nut 28 or the adjusting screw 26 is pressed toward the adjusting knob 4 by the pressure adjusting spring 24, the position of the adjusting screw 26 does not change. As shown in FIG.
8 and the adjustment screw 26 are screwed together, and the nut 28 is
7 (that is, the pressure set on the secondary chamber 23 side is set to 0), the nut 28 cannot move. Therefore, this time, the adjusting screw 26 moves to the piston 20 side as the screwing proceeds. At this time, since a plurality of pitches of the male screw portion 26b are screwed into the nut 28, the spring force of the adjusting spring 24 is supported at a plurality of pitches of the male screw portion 26b and the nut 28. Therefore, even if the spring force applied from the pressure adjusting spring 24 to the screwed portion is large, the adjusting screw 26 rotates smoothly.

As a result of the adjustment screw 26 being moved toward the pressure adjusting spring 24, the pressure applied to the piston 20 is gradually increased because the pressure adjusting spring 24 is pressed and contracted by the adjustment screw 26, and the piston 20 is moved toward the primary chamber. Then, since the valve element 17 moves from the position in contact with the valve port 15 to the primary chamber 8 side, the flow path of the valve port 15 communicates with the primary chamber 8. In this state, when air is supplied to the input port 5, air is introduced into the secondary chamber 23 via the primary chamber 8. When the pressure of the air introduced into the secondary chamber 23 is higher than the pressure set by the pressure adjusting spring 24, the piston 20 retreats from the primary chamber 8 side, and the flow path at the valve port 15 becomes small. Become. As a result, the amount of air introduced from the primary chamber 8 to the secondary chamber 23 decreases, and the air pressure in the secondary chamber 23 decreases. On the contrary, when the pressure of the air introduced into the secondary chamber 23 is lower than the pressure set by the pressure adjusting spring 24, the piston 20 advances to the primary chamber 8 side and the flow path of the valve port 15 is growing. As a result, the amount of air introduced from the primary chamber 8 to the secondary chamber 23 increases, so that the air pressure in the secondary chamber 23 increases. By this action, the air pressure in the secondary chamber 23 is reduced to the air pressure set by the pressure adjusting spring 24 and is led out to the output port 6.

When the adjustment knob 4 is further rotated in a direction in which the adjustment screw 26 moves toward the piston 20, the lower side of the head 26a of the adjustment screw 26 is covered with the cover 3 as shown in FIG.
The rotation of the adjustment knob 4 becomes impossible at a position where the adjustment knob 4 comes into contact with the upper surface of the upper part. That is, the set pressure on the secondary chamber 23 side becomes maximum.

As described in detail above, the pressure reducing valve 1 of this embodiment
According to this, when the adjustment knob 4 is further rotated from a state in which the adjustment screw 26 is fully retracted from the piston 20 side (that is, a state in which the set pressure on the secondary chamber 23 side is zero), the nut 2
8 is moved to the pressure adjusting spring 24 side along the engagement hole 33 so that the nut 28 is finally disengaged from the male screw portion 26b of the adjusting screw 26. Therefore, no thrust is exerted on the adjusting knob 4 by the screwing of the adjusting screw 26 and the nut 28, so that the adjusting knob 4 can be prevented from falling off from the valve body 1a. That is, as compared with the conventional pressure reducing valve, the size of the adjusting screw 26 in the moving direction is not increased, the position of the adjusting knob 4 is not changed, and only the shaft portion 26c is provided at the tip of the adjusting screw 26. The adjustment knob 4 can be prevented from falling off the cover 3.

Further, according to the present embodiment, the nut 28 is disengaged from the male screw portion 26b to the shaft portion 26c and the pressure adjusting spring 2
At 4, it is pressed toward the male screw portion 26b. Therefore, even if the nut 28 is disengaged from the male screw portion 26b by turning the adjustment knob 4 too much, the nut 28 can be screwed into the male screw portion 26b again.
The function of the pressure reducing valve can be secured.

Further, according to the present embodiment, the adjusting screw 26
When the nut moves to the pressure adjusting spring 24 side, the amount of screwing with the nut 28 is plural pitches. Therefore, the spring force of the pressure adjusting spring 24 is supported at plural pitches of the male screw portion 26b and the nut 28.
Therefore, even if there is a spring force of the pressure adjusting spring 24, the adjusting screw 2
6 can be smoothly rotated.

It should be noted that the present invention is not limited to the above embodiment, but may be configured as follows. (1) With the nut 28 disengaged from the male thread 26b of the adjusting screw 26 to the shaft 26c, the nut 28 is
4 so as not to be pressed against the male screw portion 26b.

(2) The amount of screw engagement with the nut 28 when the adjusting screw 26 moves toward the pressure adjusting spring 24 is not limited to a plurality of pitches, but may be, for example, one pitch. (3) The adjusting screw 26 is not limited to a hexagon bolt, and may be a square bolt, an octagon bolt, or the like.

(4) The present invention is not limited to the piston 20, and may be applied to a pressure reducing valve having a diaphragm. In this case, there is no need to provide the inner cylinder 11 for sliding the piston 20.

(5) The connection between the piston 20 and the valve body 17 is made by the hanging part 21 provided integrally with the piston 20. This is a member formed separately from the piston 20. It may be configured to perform this.

(6) The engaging hole 27 may be of any form that supports the nut 28 so that it cannot rotate and can move.
For example, a plurality of protrusions formed to extend in the axial direction may be provided, and each of the protrusions may support the nut 28. The same applies to the engagement hole 33.

(7) The fluid to be depressurized is not limited to air,
For example, a fluid such as LP gas may be used.

[0035]

As described above in detail, according to the first aspect of the present invention, the size of the adjusting screw in the moving direction can be reduced, and the pressure can be adjusted without changing the position of the adjusting knob by changing the pressure reduction value. Further, it is possible to prevent the adjustment knob from falling off from the pressure reducing valve main body without increasing the number of parts and the number of processing steps.

According to the second aspect of the present invention, in addition to the effect of the first aspect, the female screw member disengaged from the male screw portion of the adjusting screw to the shaft portion is screwed to the male screw portion. Thus, the function of the pressure reducing valve is ensured.

According to the third aspect of the present invention, in addition to the effects of the first or second aspect, the spring force of the pressure adjusting spring is controlled by a plurality of pitches of the adjusting screw and the female screw member. Since the support screw is supported, the adjusting screw can be smoothly rotated even when the spring force of the pressure adjusting spring is present.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a pressure reducing valve.

FIG. 2 is also a schematic sectional view.

FIG. 3 is a partially schematic sectional view similarly.

FIG. 4 is a schematic sectional view of a conventional pressure reducing valve.

[Explanation of symbols]

1a: Valve body, 4: Adjusting knob, 8: Primary chamber, 23: Secondary chamber, 24: Pressure adjusting spring, 26: Adjusting screw, 26b: Male screw part, 26c: Shaft part, 28: Nut as female screw member.

Claims (3)

(57) [Claims] An adjusting knob (4) for a valve body (1a).
Is pivotally engaged, and the adjusting screw (26) is displaced in the axial direction based on the rotation of the adjusting knob (4), so that the amount of expansion and contraction of the pressure adjusting spring (24) is changed. A pressure reducing valve in which the valve element (17) adjusts the pressure of the fluid flowing from the primary chamber (8) to the secondary chamber (23) based on the change of the external thread portion formed on the adjusting screw (26) (26b)
A shaft part (26c) is formed at the tip of the adjusting screw (2).
6) is supported on the adjustment knob (4) so as to be non-rotatable and movable in the axial direction, and the valve body (1a) is supported on the valve body (1a) so as to be non-rotatable and movable in the axial direction. A pressure reducing valve having a male screw portion (26b) screwed into the female screw member (28) via the shaft portion (26c). 2. A female screw member (28) having a male screw portion (26).
In a state in which the female screw member (28) is disengaged from the shaft part (26c) side from the shaft part (26c) by the pressure adjusting spring (24), the male screw part (26b) is formed.
The pressure reducing valve according to claim 1, wherein the pressure reducing valve is biased to the side. 3. The decompression according to claim 1, wherein the amount of engagement with the female screw member (28) when the adjusting screw (26) moves toward the pressure adjusting spring (24) is a plurality of pitches. valve.