JPS6145115B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to improvements in conventional pressure reducing valves that reduce and supply high pressure fluid to a suitably low pressure.

(Prior art) A pressure reducing valve is an automatic valve that extracts fluid from a high-pressure fluid source at a lower required pressure. ) side static pressure is maintained, and the amount of primary fluid supplied is dynamically controlled in response to increases and decreases in the flow rate used on the secondary side.

The pressure reducing valve is operated by adjusting the opening degree of the valve, but this is done by maintaining a balance between a pressure-operated element such as a diaphragm that operates in response to secondary pressure, and an elastic element such as a spring that opposes it. This is done by relating the valve body to the desired force balance mechanism.

That is, when the secondary pressure increases, the opening of the valve is reduced, and when the secondary pressure decreases, the opening is adjusted.

Conventional pressure reducing valves have a structure in which a blind disc-shaped valve body opens and closes fluid in conjunction with an opening valve seat, so the valve body applies thrust in the direction of the primary fluid due to the differential pressure generated before and after it. receive. Moreover, this thrust fluctuates greatly with changes in the pressure of the primary fluid, the opening degree of the valve, the flow rate of the secondary fluid, etc.

The force balance mechanism, which is directly connected to the valve body and is supposed to control its operation, is affected by this fluctuating thrust force and cannot perform its normal function, making it impossible to stably supply the secondary fluid.

In conventional pressure reducing valves, the important point is how to reduce the thrust of the primary fluid exerted on the valve body, which seriously impedes the adjustment function as described above, and the following measures are adopted.

A: For extremely small-diameter gases, the pressure-receiving area of the force-balancing mechanism that is directly connected to the valve body in a single-seat valve is particularly large, and its output is made large enough to be unaffected by the thrust of the fluid.

B Two valve bodies (including valve seat) directly connected to the force balance mechanism
A double-seat valve type in which the thrust forces applied to these are applied in opposite directions to cancel each other out.

C. One of the two valve bodies directly connected to the force balance mechanism,
A piston-shaped balance valve that slides into the cylinder and balances the thrust of both.

D. A pilot balance valve that uses the differential pressure before and after the valve body as its power source, and the controlled pressure is sent to the piston chamber via a pilot valve that functions as a small-diameter pressure reducing valve, opening and closing the main valve. Format, etc.

(Problems to be Solved by the Invention) However, the above-mentioned conventional devices are (a) complicated in structure and large in size, resulting in increased costs, and the smaller the device, the more expensive it is.

(b) If the structure focuses on operating functions, problems such as valve leaks and troubles and leaks from moving parts will occur, reducing sealing ability. Improving one function will impair other functions, which has its advantages and disadvantages. I couldn't help it.

C. Maintenance is not easy because the structure is complex.

D. Difficult to adapt to incompressible fluids such as water.

There were other problems.

An object of the present invention is to provide a pressure reducing valve that has a simple structure and stable functions, taking the above points into consideration.

(Means for solving the problems) In order to solve the above problems, the present invention has the following features:
In a conventional pressure reducing valve, as shown in FIGS. 1 to 3, it is tubular and has a sealing shaft part 15 on one side so that fluid can flow through the inside, and the opening end surface of the valve is provided with a sealing rim 14.
a primary valve chamber 4 into which the sealing shaft portion 15 of the main cylinder 12 reciprocally enters through the shaft sealing element 11; 12, a pressure operating element 17 that operates the main cylinder 12 in the seating direction by secondary fluid pressure, and an elastic element 28 that presses the main cylinder 12 in the valve opening direction. It is composed of

(Example) Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view of the present invention, in which a valve body 1 is integrated by joining a primary body 1a with an inlet 2, an intermediate body 1b, and a secondary body 1c with an outlet 3. It is composed of

A vacant primary valve chamber 4 communicating with the inlet 2 is formed inside the primary body 1a, and the bottom of the primary valve chamber 4 is connected to the inlet 2.
Connected to a via gasket 5 (threaded as shown)
It is divided by a partition wall 6 on the upper part of the intermediate body 1b. Inside the primary valve chamber 4, a blind plate-shaped valve seat 7 is provided which is supported by a plurality of arms and has a downward sealing surface. In order to improve the sealing effect, it is desirable to load a disk 8 made of soft elastic rubber or synthetic resin suitable for the fluid used on the sealing surface.

As shown in Fig. 2 (A-A sectional view in Fig. 1), sufficient gaps are ensured on both upper and lower sides of the valve seat 7 and on the outer periphery to introduce the fluid from the inlet 2 to the lower surface of the valve seat 7. has been done.

The lower part of the intermediate body 1b has an enlarged diameter part 9 which is made thicker by one step.
The inside of the lower side of the partition wall 6 is a vacant room that almost follows the external shape.

A through hole 10 is bored in the center of the partition wall 6, and a shaft sealing element (O-ring shown) 11 is inserted inside.

Reference numeral 12 denotes a tubular main cylinder with a through hole 13 bored along its axis so that fluid can flow through the inside, and the outer surface near its upper end is machined into a parallel and smooth sealing shaft part 15. .

The main cylinder 12 is inserted into the primary valve chamber 4 by having the sealing shaft portion 15 vertically movably inserted into the through-hole 10 of the partition wall 6 and sealingly by sliding engagement with the shaft sealing element 11. However, its end face faces the valve seat 7.

FIG. 4 is an enlarged vertical cross-sectional view of the upper end of the main cylinder 12, and the sealing edge 1 that comes into contact with the opposing valve seat 7 is shown on the end surface.
It has 4. As shown in the figure, the sealing edge 14 is formed in the shape of a ring with a narrow width, rounded corners, and as close to the outer edge as possible.

Reference numeral 16 denotes a collar provided on the body of the main cylinder 12. The opening edge of a diaphragm 17, which is one of the inserted pressure operating elements, is placed on the upper side of the collar, and is screwed into the main cylinder 12 from above. The plate 18 is sealed in a sealed manner.

The periphery of the diaphragm 17 is formed by the intermediate body 1b.
The annular surface 19 cut into the expanded diameter portion 9 of the intermediate portion 1b and the annular surface 20 provided on the upper side of the secondary portion 1c screwed to the intermediate portion 1b are tightly tightened. ing.

21 is a cylindrical guide section below the main cylinder 12;
is a step-shaped stopper provided at the upper end of this guide portion 21.

The upper side of the secondary body 1c is dug into a concave shape leaving an annular surface 20 on the periphery, and an outflow port 3 is opened at the bottom.
The guide portion 21 of the main cylinder 12 is loosely engaged with the guide portion 21 of the main cylinder 12 .

A pressurizing chamber 23 is formed between the diaphragm 17 and the recess of the secondary body 1c, and communicates with the flow path through a communication hole 24 formed in the main cylinder 12.

The main cylinder 12 moves up and down with its upper part supported by the through hole 10 and its lower part supported by the outflow port 3. At the upper limit, the sealing edge 14 contacts the valve seat 7, and at the lower limit, the sealing edge 14 is supported by the valve seat 7, and at the lower limit, the main cylinder 12 is supported by the through hole 10 and the lower part by the outlet 3. Stepped stopper 22 is opened at the point where the opening degree is obtained.
is received at the bottom of the pressurizing chamber 23.

In this way, the main cylinder 12 controls opening and closing of the fluid by moving up and down, and performs the same function as a conventional valve body.

As shown in FIG. 3 (B-B sectional view in FIG. 1), a plurality of guide structures 25 (three in the figure) extending through the intermediate body 1b in the axial direction are provided on the side wall of the trunk of the intermediate body 1b. It is being

Reference numeral 26 denotes a spring seat that is fitted into the main cylinder 12 with a sufficient gap in the body of the intermediate body 1b, and a guide pin 27 (not shown in the figure) is provided on the outer periphery of the spring seat at a position that matches each of the plurality of guide grooves 25. 3) are implanted, and their outer ends protrude outside the guide groove 25.

The spring seat 26 can move up and down without rotating because the implanted guide pin 27 slides within the guide groove 25.

A coil spring 28 (hereinafter simply referred to as a spring), which is an elastic element, is inserted between the spring seat 26 and the plate 18, and presses the main cylinder 12 downward, that is, in the valve opening direction.

Reference numeral 29 denotes an adjustment ring screwed onto a male thread 30 carved on the outside of the body of the intermediate body 1b, and when the ring is screwed downward, the guide pin 2 whose lower surface protrudes
7 is pressed down, so that the spring seat 26 compresses the spring 28. In this manner, the elasticity of the spring 28 that presses the main cylinder 12 downward can be adjusted by vertically screwing the adjustment ring 29.

The present invention has the above configuration, and its operation will be described next.

In FIG. 1, the figure shows a state in which fluid has not yet been introduced into the valve body 1 , the spring 28 is slightly compressed, the main cylinder 12 is pushed down, and the valve is open, and the inlet port 2 is opened. The outlet 3 is connected to the primary side and the outlet 3 is connected to the secondary side. A pressure gauge for detecting the internal pressure of this flow path is attached to a position close to the valve body 1 of the secondary flow path piped to the outlet 3.

Next, the adjustment ring 29 is screwed up and the spring 28
After reducing the load on the pressure gauge and closing off the area downstream from the pressure gauge with a stop valve, fluid is introduced into the valve body 1 from the inlet 2. The primary fluid flows from the through hole 13 of the main cylinder 12 opened in the primary valve chamber 4 to the secondary fluid via the outlet 3 while reducing its pressure.

However, since the secondary flow path is closed as described above, the fluid that enters the secondary flow path and once its pressure drops tries to quickly rise to the primary pressure again, and the fluid inside the pressurizing chamber 23 communicating with the flow path. Press down on the bottom side of the diaphragm.

When the diaphragm 17 receives the pressure, the elasticity of the spring 28 is reduced as described above, and the main cylinder 12 is tubular and the pressure-receiving area of the cross section is extremely small compared to the conventional blind disc-shaped valve body, so that the primary fluid When it receives only a slight downward thrust from the main cylinder 12, it operates quickly even under a slight pressure, seating the main cylinder 12 and shutting off the fluid.

Since the outer edge of the end face of the main cylinder 12 seated as described above is in contact with the valve seat 7 as shown in FIG. 4, no pressure is applied to the front side, and even a small thrust of the diaphragm 17 as described above will prevent valve leakage. There isn't.

Next, to set the desired secondary pressure, the adjustment ring 29 is screwed downward and the spring 28 is compressed to increase the load, which causes the main cylinder 12 to be seated under the secondary pressure as described above. This lever pushes down the main cylinder 12 to overcome the upward thrust of the diaphragm 17 causing the primary fluid to flow in.

Fluid entered. The pressure on the secondary side increases, and the output of the diaphragm 17 increases accordingly, overcoming the elasticity of the spring 28 strengthened as described above and attempting to seat the main cylinder 12 again.

Following this, as the load on the spring 28 is further increased using the adjustment ring 29, the spring 28
The secondary pressure necessary for the diaphragm 17 to seat the main cylinder 12 against the force increases,
The change is detected by a pressure gauge.

Then, when the pressure gauge shows the value to be set and the adjustment of the spring 28 is stopped, the diaphragm 1
17 is activated immediately to seat the main cylinder 12, shut off the primary fluid, and set the secondary pressure.

The process of setting the secondary pressure described above is no different from that of a conventional pressure reducing valve.

After setting the secondary pressure, when the flow path is opened and the supply of secondary fluid begins, the pressure on the secondary side of the valve body 1 drops again, the thrust of the diaphragm 17 decreases, and the main cylinder 12 opens to supply the primary fluid. Supply begins.

The larger the amount of secondary fluid supplied, the greater the pressure drop.
2 increases, the amount of primary fluid supplied to the secondary side also increases, and the stopper 22 provided in the main cylinder 12 comes into contact with the bottom of the pressurizing chamber 23, becoming fully open.

Furthermore, when the flow rate of the secondary fluid decreases, its pressure increases accordingly, and the diaphragm 17 raises the main cylinder 12 until it balances the elasticity of the opposing spring 28, and throttles the opening so that the primary fluid does not exceed the set pressure. Suppress fluid inflow. In this action, the main cylinder 1
2 receives only a slight thrust from the primary fluid, and can smoothly adjust the opening with almost no effect on the delicate balance between the diaphragm 17 and the spring 28.

As mentioned above, the thrust of the primary fluid is small but acts in the direction of opening the main cylinder 12, so hunting (vibration) occurs when the opening is extremely restricted, even in the case of gas or incompressible fluids such as water. does not occur (it tends to occur when acting in the valve closing direction as in the conventional type).

Finally, when the flow path is closed and the supply of secondary fluid is stopped, the diaphragm 17 is activated, the primary fluid is cut off, and the static pressure on the secondary side shows the set pressure.

FIG. 5 is a longitudinal cross-sectional view showing this blocked state, and the seated main cylinder 12 is not subjected to any force pushing it down as described above. Therefore, to completely shut off the fluid, only the pressing force required for close contact with the valve seat 7 (disc 8) is required. Further, even if there is a large fluctuation in the primary pressure, such as severe water hammer, the fluctuation only affects the side surface of the main cylinder 12 protruding into the primary valve chamber 4, and the sealing is not affected and no valve leakage occurs.

In the above implementation, the diaphragm 17 is used as the pressure-operated element, but in FIG.
FIG. 2 is a vertical cross-sectional view showing another embodiment employing No. 1.

In addition, a bellofram or a power cylinder in which a cylinder is formed inside the valve body and a piston that interlocks with the main cylinder 12 is slidably fitted thereto can also be used as the pressure-operated element. In either case, there is no difference in function from the diaphragm 17.

Note that Fig. 6 shows a specification in which the set secondary pressure is not changed, and the pre-calculated spring 28
It is also a diagram illustrating another embodiment in which the holder is bent as necessary and the adjusting means is omitted.

FIG. 7 is a longitudinal sectional view showing another embodiment incorporating a seating spring 32 that acts in a direction opposite to the spring 28 that pushes down the main cylinder 12.

This seating spring 32 has a weak repulsive force that easily deflects when the main cylinder 12 is pushed down by the elasticity of the spring 28, but when the load on the spring 28 is released or reduced to the minimum, it pushes the main cylinder 12 upward. Have them sit down.

In the embodiments described above, the diaphragm 17 operates after receiving the secondary pressure and the main cylinder 12 is seated, so it was impossible to substantially reduce the secondary pressure to zero. In this embodiment, the secondary pressure setting can be started from zero.

(Effects of the Invention) Since the present invention has the above configuration and operation, it exhibits the following effects.

A: It has a simple structure, small size, and light weight.

Unlike conventional products, there is no need for a complicated structure to reduce the resistance of the primary fluid that the valve body receives, and the output (pressure-receiving area) of the pressure-operated element can be small, and the main cylinder 12 allows the fluid to flow through it. Therefore, there are fewer bends in the fluid path, making it smaller and lighter.

B: Even if there are large fluctuations in the primary fluid, the set secondary pressure will not change.

The main cylinder 12 is not affected by the fluid in any state, whether the valve is open or closed or the opening is adjusted, and there are few moving parts, so there is no functional failure or change in the set pressure over time, and maintenance is easy. It doesn't cost anything.

C. Respond quickly to changes in the flow rate of the secondary fluid.

The ability to quickly adjust the opening of the primary fluid supply, which is necessary to cover increases and decreases in the flow rate of the secondary fluid, is particularly effective when performing delicate processes such as fine flow adjustment or constant flow in the secondary flow path. Demonstrate your sexuality.

D Hunting does not occur.

It is adaptable to the harsh conditions of non-compressible fluids such as water, where hunting is likely to occur, the obstacles are large, and it is difficult to prevent hunting, and hunting does not occur.

E There is no leakage.

Since it is a single-seat valve type and only requires a small seating thrust, the sealing members (valve seat 7, sealing edge 14 of the main cylinder 12)
There is very little wear and tear on the valves and there is no valve leakage, and since there are few moving parts, there is no leakage other than valve leakage as with conventional products.

F You can freely select the mounting orientation.

Even if the valve body 1 is installed vertically, horizontally, or upside down, the operation and effect will not change.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view of the present invention, Figure 2 is Figure 1A.
-A cross-sectional view, Figure 3 is also a B-B cross-sectional view, Figure 4
The figure is an enlarged longitudinal sectional view of the upper end portion of the main cylinder 12, and the fifth
6 is a longitudinal sectional view showing the state of valve closing action, FIG. 6 is a longitudinal sectional view showing another embodiment using a pressure actuating element different from that in FIG. FIG. 7 is a longitudinal sectional view of another embodiment in which a seating spring 32 is installed. 1 is the valve body, 1a is the primary body, 1b is the intermediate body, 1c is the secondary body, 2 is the inlet, 3 is the outlet,
4 is a primary valve chamber, 7 is a valve seat, 11 is a shaft sealing element, 12
13 is the main cylinder, 13 is the through hole, 15 is the sealing shaft portion, 17
is the diaphragm, 26 is the spring seat, 28 is the spring, 2
9 is an adjustment ring.

Claims (1)

[Claims] 1 A main cylinder having a tubular shape and having a sealing shaft portion on one side so that fluid can flow therethrough, and the opening end face of the side being formed as a sealing edge, and the sealing shaft portion of the main cylinder having a sealing shaft portion. A primary valve chamber that reciprocally protrudes through the element, a blind disc-shaped valve seat that correlates with the sealing edge of the main cylinder within the primary valve chamber, and a secondary fluid pressure that causes the main cylinder to close. A pressure reducing valve comprising: a pressure operating element that operates the main cylinder in the seating direction; and an elastic element that presses the main cylinder in the valve opening direction.