JPH09317908A - Pressure regulating valve - Google Patents

Abstract

(57) [Abstract] (Correction) [Problem] To absorb the tilting and tilting of the valve shaft due to welding distortion of the bellows to secure a uniform contact surface and seal allowance, and to smooth the flow rate characteristics at a minute opening. To do. A pressure balance chamber in which a balance bellows 24 is attached to a valve shaft 13 supporting a valve body 10 capable of opening and closing a valve opening 7.
19 is formed by dividing the primary pressure chamber 4 from the pressure balance chamber 1.
9 is connected to the secondary pressure chamber 5, and the bottom plate is attached to the upper end of the valve shaft 13.
The control bellows 26 that abuts 30 is fixed to the valve box 1 to form the adjustment chamber 20 by partitioning it from the secondary pressure chamber 5, and the tension of the adjustment spring 31 that allows the tension to be adjusted from the outside and added to the valve body The valve port is opened and closed by the balance with the applied pressure, and the valve body 10 and the valve seat 9 on and off the valve body are
It is formed by a part of a spherical surface centered on the fixed center of the valve body and the valve shaft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure adjusting valve for adjusting the pressure on the primary side or secondary side of a fluid flowing in a pipe line.

[0002]

2. Description of the Related Art Conventionally, the tension of a pressure adjusting spring is applied to one surface of a valve body, and the pressure to be adjusted is applied to the other surface of the valve body to balance the tension of the spring with the pressure of the fluid to be adjusted. A pressure regulating valve adapted to regulate the pressure on the primary side or the secondary side is known, and is used for regulating the pressure of various fluids.

Conventionally known pressure adjusting valves are designed to adjust the pressure by the elastic force of a pressure adjusting spring that normally applies tension to the valve body. Therefore, when adjusting a large pressure, the pressure is adjusted to that pressure. A spring having a correspondingly large resilience must be used, and the size of the spring inevitably becomes large, and the size of the entire valve also becomes large. Therefore, the present applicant first applies an adjusting pressure to both sides of the valve body and the balance bellows to balance the pressure applied to the valve body, thereby obtaining a large operating force with a spring having a small force, A pressure regulating valve capable of performing precise pressure regulation is disclosed in Japanese Patent Application No. 7-353.
Proposed in No. 584.

However, the pressure regulating valve proposed by the present applicant has a structure in which the valve body and the valve seat abut on a flat surface to close the valve, and the valve body is fixed to the valve shaft by screw connection,
Since the bellows assembly is welded to the valve shaft, it is difficult to fix the individual parts at right angles, and there is little play, and both the valve body and valve seat are flat. Therefore, the so-called quick-open characteristic, in which the flow rate greatly changes with a small opening, makes it extremely difficult to adjust the flow rate when the valve is throttled.

Further, since both the valve body and the valve seat have a flat structure, after the fluid collides with the flat surface of the valve body when the valve is squeezed, the fluid changes its direction at a right angle and flows out. However, dust and foreign matter in the fluid are apt to adhere to the valve body, resulting in problems such as insufficient closing of the valve and scratches. Further, by welding the bellows assembly to the valve shaft, it is difficult to secure the perpendicularity between the valve shaft and the bellows due to heat distortion during welding, etc., so that the contact between the valve body and the valve seat becomes uneven and the closing ability is There was a risk of decrease.

[0006]

SUMMARY OF THE INVENTION According to the present invention, the seat surfaces of the valve body and the valve seat, which are in contact with each other, are formed into a spherical shape, so that the tilt and tilt of the valve shaft due to the welding strain of the bellows is absorbed to achieve a uniform contact. The surface and the seal allowance are secured, and the flow rate characteristics at the minute opening can be smoothed to easily adjust the flow rate and pressure, etc., and the fluid flow can be smoothed to prevent the accumulation of foreign matter. It is what

[0007]

Means for Solving the Problems In order to solve the above problems, the means adopted by the present invention pivotally supports a valve body (10) capable of opening and closing a valve opening (7) in a valve box (1). Attach the balance bellows (24) to the valve shaft (13) to turn the pressure balance chamber (19) into the primary pressure chamber.
The pressure balance chamber (19) communicates with the secondary pressure chamber (5) and is formed at the upper end of the valve shaft (13) by the bottom plate (3).
The control bellows (26) that abuts (0) is fixed to the valve box (1) to form the adjustment chamber (20) from the secondary pressure chamber (5).
An adjusting spring (31) that allows the tension to be adjusted from the outside is placed in the adjusting chamber (20) and is stretched on the bottom plate (30) of the control bellows to add the tension of the adjusting spring (31) and the valve body. The valve seat is designed to open and close the valve opening depending on the balance with the pressure to be applied, and the valve body (10) and the valve seat where the valve body contacts and separates.
(9) is formed by a part of a spherical surface centered on the fixed center of the valve body and the valve shaft.

Further, the valve shaft (13) is divided into upper and lower two valve shafts (13a) and (13b) at the valve disc mounting position, and the valve disc (10) is divided into two valve shafts.
(13a) and (13b) are sandwiched and connected.

Further, a shaft hole (17) is bored in the valve shaft (13), a lower end of the shaft hole (17) is opened to a lower part of the valve body (10), and an upper part thereof is an upper part of the pressure balance chamber (19). It is characterized by opening in.

Furthermore, a sealing material (14) having elasticity is inserted in the lower portion of the valve body (10) to allow a slight swing of the valve body (10).

Further, the valve shaft (13) is pivotally supported at two points above and below the valve shaft (13) to prevent the valve shaft from swinging.

Further, a cup-shaped mounting cylinder (21) is fixed to the upper part inside the valve box (1), the bottom of the mounting cylinder (21) is closed by a bearing plate (23), and the bearing plate (23) is closed. ), The upper part of the valve shaft (13) is pivotally supported through the upper valve shaft guide (16), the balance bellows (24) is fixed to the lower surface of the mounting cylinder (21), and the bottom of the balance bellows (24) is fixed. The valve shaft (13) is fixed to the plate (25).

Further, the mounting cylinder body (21), bearing plate (23), upper bearing guide (16), balance bellows (24) and upper valve shaft (1)
It is characterized in that it is integrated with 3a) into one unit.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described in detail with reference to the drawings. Although the illustrated embodiment shows a pressure reducing valve to which the present invention is applied, the present invention is not limited to the pressure reducing valve according to the present invention, and may be applied to a primary pressure adjusting valve, a secondary pressure adjusting valve, or another pressure adjusting valve. It is applicable as well.

In the figure, (1) is a valve box having a primary pressure inlet (2) and a secondary pressure outlet (3), and a primary pressure chamber (4) and a secondary pressure chamber (4) in the valve box (1). It is partitioned from the pressure chamber (5) by a partition wall (6). Partition
A valve opening (7) is pierced at the center of (6), and a cylindrical valve seat body (8) is inserted into the valve opening (7). The valve seat body (8) is firmly fitted and fixed to the valve opening (7), and the valve seat (9) is formed on the lower end surface. (10) is a valve element, which is brought into contact with or separated from the valve seat (9),
The valve port (7) is opened and closed to connect the primary pressure chamber (4) and the secondary pressure chamber (5). (11) is a closing member that closes the lower opening of the valve box (1), and is fixed to the valve box (1) with bolts (12).

The valve body (10) is attached to the valve shaft (13) and moves up and down together with the valve shaft under the tension of a pressure adjusting spring applied to the upper portion of the valve shaft (13) as described later. . The valve shaft (13) is divided into an upper valve shaft (13a) and a lower valve shaft (13b) at the position of the valve body (10), and the inner screw of the upper valve shaft (13a) is attached to the lower valve shaft (13b). It is connected to one valve shaft (13) by screwing an outer screw. When connecting the upper and lower valve shafts, the upper and lower valve shafts (13a) (13
The valve body (10) and the sealing material (14) having elasticity are sandwiched between b) and connected. This makes it easy to assemble the valve body (10), the valve shaft (13) and the seal material (14), and
Due to the elasticity of (14), a slight swing of the valve body (10) is allowed, and as a result, the adhesion of the valve body (10) to the valve seat (9) is improved.

As shown in FIG. 3, the valve body (10) and the valve seat (9) have a radius (R) centered on the fixed center point (A) of the valve shaft (13) and the valve body (10). The contact surface formed by part of the spherical surface (Q) makes contact and seals. Valve seat (9) and valve body (10)
By contacting and sealing with a spherical surface, even if the axial center of the valve seat and the valve body are relatively misaligned and not on the same axial center, the contact between the valve seat and the valve body is secured, There is no risk of fluid leakage. As a result, even if the valve shaft tilts due to thermal strain during welding of the bellows assembly, the valve element and the valve seat can accurately contact each other. Further, since the gap between the valve body and the valve seat when opening / closing increases / decreases in proportion to the opening degree, the flow rate characteristic at a small opening degree becomes smooth and the flow rate and pressure can be easily adjusted. Further, since the fluid smoothly flows out from the inflow direction along the spherical surface of the sealing surface when the valve is throttled, the fluid does not collide with the valve body and foreign matter in the fluid does not accumulate.

In the illustrated embodiment, the valve body and valve seat utilize the upper half of a spherical surface. If the thickness of the valve body is increased, the valve opening stroke becomes longer and the length of the entire valve becomes longer, which is not preferable.

The lower part of the valve shaft (13) is pivotally supported by the lower valve shaft guide (15) attached to the center of the closing member (11), and the upper part thereof is pivotally supported by the upper valve shaft guide (16). It is supported so that it can move up and down. The upper and lower valve shaft guides (15) and (16) are made of carbon-containing polytetrafluoroethylene, for example. By vertically supporting the valve shaft (13) with the valve shaft guides (15) and (16), the valve shaft is stably supported, and a stable opening / closing operation of the valve body (10) is ensured. A shaft hole (1 that extends along the center of the valve shaft (13)
7) is formed, the lower part of the shaft hole (17) opens below the valve body (10) into the secondary pressure chamber (5) through the side hole (18), and the lower end is at the lower end of the valve shaft. Open and the upper part is the upper valve shaft guide (16)
An opening is made in the adjustment chamber (20) described later at the upper part of the.

At the upper part of the primary pressure chamber (4), a cylindrical mounting cylinder is installed.
(21) is inserted from above. As shown in FIGS. 1 and 2, the mounting cylinder body (21) has a flange (22) on the upper portion and the bearing plate on the lower portion.
(23) is a cup-shaped member closed, the upper valve shaft guide (16) is fixed to the center of the bearing plate (23)
It supports (13a). The bearing plate (23) is perforated,
The upper and lower sides of the bearing plate (23) are communicated with each other to maintain the same pressure. At the bottom of the mounting cylinder (21), the upper end of the balance bellows (24) is hermetically sealed and fixed, and the pressure balance chamber (19) is inside the primary pressure chamber.
It is formed by partitioning from (4). A substantially central portion of the upper valve shaft (13a) is fixed to a bottom plate (25) of the balance bellows (24). The upper valve shaft guide (16) has a plurality of slits cut from the lower end to the middle.When the upper valve shaft guide (16) is inserted into the center hole of the bearing plate (25) from above, the diameter is reduced, and after insertion, the diameter is expanded and then comes out. Is blocked.

The mounting cylinder (21), the bearing plate (23), the upper valve shaft guide (16), the balance bellows (24) and the upper valve shaft (13a) are configured as one unit, and the parts can be made compact. It is intended to facilitate the assembly. Then, in this unit, the flange (22) at the upper end of the mounting cylinder (21) is placed on the upper end of the valve box (1), and the top plate (27) of the control bellows (26) is sandwiched together for sealing, It is fixed by a screw cylinder (28) fixed to the upper end of the valve box (1) with a bolt (29).

The bottom plate (30) of the control bellows (26), which is formed by partitioning the adjusting chamber (20) from the secondary pressure chamber (5) of the valve box (1), is provided at the upper end of the upper valve shaft (13a). The bottom plate (30) is in contact with the center of the valve shaft and bulges upward in the shape of a cone to prevent the valve shaft from shifting. On the top of the bottom plate (30), adjust spring
The lower end of the (31) is placed, and the upper end of the adjusting spring (31) is stretched on the adjusting plate (32). The adjusting plate (32) is the adjusting screw rod (33).
It is screwed up and down freely, and the adjusting screw rod (33) is
(28) Penetrating the upper wall and extending to the outside, adjusting knob (34)
It is stuck to. (36) is provided between the primary pressure inlet (4) and the primary pressure inlet (4) to prevent the pressure fluid flowing from the primary pressure inlet (2) from directly hitting the balance bellows (24) and swinging the bellows. The cover is fixed to the screen (35) made of punching metal.

FIG. 1 shows the valve closed state. Since the pressure on the secondary side is higher than the tension of the adjusting spring (31), the valve body (10) is
Is in close contact with the valve seat (9) and the valve mouth (7) is closed. The pressure entering the primary pressure chamber (4) from the primary pressure inlet (2) is added to the bottom plate (25) of the balance bellows (24), and the valve shaft (1
3) is pushed up and at the same time it is added to the upper part of the valve disc (10) and pushes down the valve shaft (13), but the primary pressure receiving area of the valve disc (10) and the primary pressure of the bottom plate (25) are Since the pressure receiving area is the same, the pressure applied to the valve body (10) is in a balanced state.

When the secondary pressure decreases, the valve body (10) is pushed down by the tension of the adjusting spring (31) as shown in FIG. 2, and the valve port (7) is opened. Due to the opening of the valve opening (7), the primary pressure enters the secondary side through the valve opening (7) and the secondary pressure becomes high. The secondary pressure passes through the hole in the bearing plate (23) that divides the upper part of the pressure balance chamber (19), and reaches the bottom plate (30) of the control bellows.
When the pressure is applied and the pressure becomes larger than the tension of the adjusting spring (31), the valve body comes into close contact with the valve seat (9) to close the valve. In this way, the valve element is brought into and out of contact with the valve seat without interruption, and the secondary pressure is reduced and maintained at the predetermined pressure set by the adjusting spring (31).

The control bellows (26) for airtightly isolating the adjusting chamber (20) containing the adjusting spring for adjusting the pressure from the secondary pressure chamber (5) and the pressure balance chamber (19) for the primary pressure chamber
Since the pressure is adjusted using two bellows, the balance bellows (24), which is airtightly isolated from (4), there is an advantage that a large adjusting operation force can be obtained with the adjusting spring (31) having a small force. . Further, since the valve shaft (13) is supported by the valve shaft guides (15) and (16) at two points on the upper and lower sides, stable vertical movement is brought about, and it is possible to prevent the valve shaft from swinging and Since the opening (18) on the secondary side of the hole (17) is located in the lower part of the valve body, it is possible to take in pressure from a stable pressure range where there is almost no pressure fluctuation, and more precise pressure adjustment is possible. Become. Moreover, since the valve shaft (13) is divided into the upper and lower valve shafts at the position of the valve body (10), it becomes easy to drill the shaft hole (17) passing through the center of the valve shaft, resulting in the highest pressure. It is possible to take out the secondary pressure from the lower region of the valve body with less fluctuation. Further, since the valve body (10) is attached to the valve shaft (13) via the seal material (14) and the valve body is allowed to slightly swing, the valve body (9) to the valve seat (9) ( The adhesion of 10) is improved.

[0026]

According to the present invention, since the shape of the closing portion of the valve element is spherical, the flow rate characteristic at a small opening becomes smooth, the flow rate and pressure can be easily adjusted, and the operation is stabilized. In addition, even if the perpendicularity between the valve shaft and the bellows assembly is slightly lost or the valve shaft slightly tilts due to fluid pressure, the valve body and valve seat are in contact with each other in a spherical shape, Uniformity of the contact surface is secured and valve closing ability is improved. Further, the fluid smoothly flows out from the inflow direction along the spherical surface of the sealing surface, it is possible to avoid the accumulation of foreign matter due to the collision with the valve body, and the secondary surface can be maintained without damaging the surface of the valve body or the valve seat. Since it flows out to the side, the sealing performance is improved and the reliability of the valve closing ability is increased.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a valve closed state

FIG. 2 is a vertical cross-sectional view of a valve open state

FIG. 3 is an enlarged sectional view of a main part.

FIG. 4 is an exploded perspective view of the same.

[Explanation of symbols]

 (1) Valve box (2) Primary pressure inlet (3) Secondary pressure outlet (4) Primary pressure chamber (5) Secondary pressure chamber (6) Partition wall (7) Valve port (8) Valve seat (9) Valve Seat (10) Valve body (11) Closing member (12) Bolt (13) Valve shaft (13a) Upper valve shaft (13b) Lower valve shaft (14) Seal material (15) Lower valve shaft guide (16) Upper valve shaft Guide (17) Shaft hole (18) Side hole (19) Pressure balance chamber (20) Adjustment chamber (21) Mounting cylinder (22) Flange (23) Bearing plate (24) Balance bellows (25) Bottom plate (26) Control bellows (27) Top plate (28) Screw cylinder (29) Bolt (30) Bottom plate (31) Adjustment spring (32) Adjustment plate (33) Adjustment screw rod (34) Adjustment knob (35) Screen cover (36) )cover

Claims (7)

[Claims] 1. A valve body (1) capable of opening and closing a valve opening (7) in a valve box (1).
The pressure bellows (24) is attached to the valve shaft (13) that rotatably supports (0) to form the pressure balance chamber (19) separated from the primary pressure chamber (4). Communicating with the pressure chamber (5),
A control bellows (26) in which the bottom plate (30) is in contact with the upper end of the valve shaft (13) is fixed to the valve box (1) to form the adjustment chamber (20) from the secondary pressure chamber (5). Then, an adjusting spring (31) which can adjust the tension from the outside is arranged in the adjusting chamber (20) and is stretched on the bottom plate (30) of the control bellows, and the tension of the adjusting spring (31) and the valve disc The valve opening is opened and closed by the balance with the pressure applied to
Pressure adjustment characterized in that the valve body (10) and the valve seat (9) with which the valve body contacts and separates are formed by a part of a spherical surface centered on the fixed center of the valve body and the valve shaft. valve. 2. A valve shaft (13) is divided into two upper and lower valve shafts (13a) (13b) at a valve disc mounting position, and the valve disc (10) is divided into two valve shafts (13).
The pressure regulating valve according to claim 1, characterized in that the pressure regulating valve is sandwiched between (a) and (13b). 3. A shaft hole (17) is bored in the valve shaft (13), and the shaft hole (17)
The pressure regulating valve according to claim 2, wherein a lower end of the valve body is opened to a lower portion of the valve body (10) and an upper portion thereof is opened to an upper portion of the pressure balance chamber (19). 4. A sealing material (1) having elasticity at the bottom of the valve body (10).
The pressure regulating valve according to claim 1 or 2, characterized in that the valve body (10) is allowed to slightly swing by inserting 4). 5. A valve shaft (13) is axially supported at two points above and below the valve shaft (13),
The pressure regulating valve according to claim 1, 2 or 3, characterized in that the valve shaft is prevented from swinging. 6. A cup-shaped mounting cylinder (21) in the upper part of the valve box (1).
And the bottom of the mounting cylinder (21) is closed by the bearing plate (23), and the valve shaft (1) is attached to the bearing plate (23) through the upper valve shaft guide (16).
The balance bellows (24) is fixed to the lower surface of the mounting cylinder (21), and the valve shaft (13) is fixed to the bottom plate (25) of the balance bellows (24). The pressure regulating valve according to claim 1, which is characterized in that. 7. The mounting cylinder (21), the bearing plate (23), the upper bearing guide (16), the balance bellows (24) and the upper valve shaft (13a) are integrated into one unit. The pressure regulating valve according to claim 6.