JPH0418177B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is applicable to fluid transport piping, etc., which requires constant supply and discharge of water, industrial water, agricultural water, petroleum plants, petrochemical plants, and other plants. It relates to constant flow valves used in pipes for chemical liquids, gas pipes, slurry fluid transport pipes, etc.

[Conventional technology]

Conventionally, there are various types of constant flow valves, but among them, a constant flow valve with particularly good accuracy is described in Japanese Patent Publication No. 13652/1986 as a "fixed flow rate control valve".
Further, as a constant flow valve having a particularly simple and compact structure, a "constant flow valve" is disclosed in Japanese Patent Publication No. 52-22450. The former includes a throttle valve and a differential pressure regulating valve, and maintains a constant flow rate according to the opening degree of the throttle valve by detecting the pressure difference between upstream and downstream sides of the throttle valve and operating the differential pressure regulating valve. In the latter case, an orifice body made of rubber is deformed by a fluid pressure difference, and the cross-sectional area and flow velocity between the orifice body and the valve body are compensated to maintain a constant flow rate.

[Problem to be solved by the invention]

However, the constant flow valve described above has the following problems.

In other words, the former constant flow valve has a very complicated piping structure that connects the two valve bodies to the fluid, and the differential pressure regulating valve in particular requires a large-area diaphragm to amplify the pressure difference between the upstream and downstream sides of the throttle valve. Therefore, there is a problem that the valve device becomes large and very expensive.

In addition, in the latter type of constant flow valve, the orifice body that maintains a constant flow rate is made of rubber, so rubber fatigues in liquid, and the rate of fatigue increases especially when the temperature is above room temperature, resulting in changes in physical properties. is most evident in the decrease in elongation and elastic modulus.
Therefore, it is difficult to expect long-term durability from this constant flow valve, which relies on the deformation of rubber due to a fluid pressure difference to provide a constant flow rate. Furthermore, since rubber has hysteresis, there is a problem in that the accuracy of flow rate adjustment is poor.

The present invention was developed in view of the problems of the prior art as described above, and has an extremely simple structure, is suitable for mass production, allows external flow rate adjustment, and prevents large fluctuations in fluid pressure on the upstream and downstream sides. The purpose of the present invention is to provide a constant flow valve that is capable of accurately maintaining a set flow rate even when the flow rate is changed, has a valve closing function and can completely stop the flow of fluid, is durable, and is inexpensive.

[Means to solve the problem]

After various studies, the inventors focused on a valve in which the direction of fluid flow changes at a right angle or at an arbitrary angle.The inventors installed an orifice inside the inlet flow path, attached a valve body and a spring to the spindle, and conducted flow rate experiments. I went to As a result, we discovered a phenomenon in which the set flow rate can be maintained constant even if the differential pressure between the upstream and downstream sides fluctuates significantly.
In addition, the sensors, mini-computers, and positioners that are indispensable to other conventionally known flow rate regulating valve devices are no longer required, and the functions of each device can be integrated into the constant flow valve, making it extremely economical, inexpensive, and simple in shape. It was discovered that a constant flow valve can be obtained. Based on the above discovery, we have completed the present invention.

The structure of the present invention for solving the above problems will be explained below with reference to FIG.

The constant flow valve of the present invention includes an inlet channel 2 having an orifice 5 inside, a hollow chamber 4 provided in a direction parallel to this inlet channel 2 and communicating with this inlet channel 2, and this hollow chamber. 4 and an outlet passage 3 which is open perpendicularly or obliquely to the axis of the inlet passage 2, and whose axis coincides with the axis of the orifice 5. A spindle 8 supported by the lid 9 of the valve body 1 so as to be movable forward and backward within the hollow chamber 4, and an upstream end surface 1 thereof whose axis coincides with the axis of the spindle 8.
A valve body is slidably fitted to the lower end of the spindle 8 so that 0a is always located on the upstream side of the orifice 5, and has a gently convex curved shape whose outer diameter is reduced toward the downstream side. 10, a spring 12 attached to the spindle 8 and urging the valve body 10 toward the lower end of the spindle 8, and a spring 12 integrally attached to the spindle 8 so as to include the spindle 8 and the spring 12. It is characterized by comprising a closing cylindrical body 14 provided.

There are various embodiments of the present invention as follows.

As shown in FIG. 2, a cylindrical body 15 containing a spindle 8 and a spring 12 and slidably fitted to the spindle 8 is provided integrally with the valve body 10 to absorb sudden changes in fluid pressure. .

Further, as shown in FIG. 3, the cylindrical body 15 is provided with a through hole 10b that communicates with the inside from the upstream side of the valve body 10, parallel to its axis, and a through hole 15a is also provided on the side surface of the cylindrical body 15. This prevents solid matter in the slurry from accumulating inside the cylindrical body 15.

Furthermore, as shown in FIG.
The metal spring 16 is completely coated with polychlorotrifluoroethylene resin (hereinafter abbreviated as PCTFE resin) 17 to provide a high degree of corrosion resistance.

The material of the constant flow valve of the present invention may be plastic or metal, and is not particularly limited.

[Effect]

In the constant flow valve of the present invention having the above configuration, when the pressure difference between the fluid on the upstream side and the downstream side of the valve body 10 becomes large, the valve body 10 receiving the fluid pressure at the upstream end face 10a thereby moves downstream on the spindle 8 while biasing the spring 12. Through this movement, the valve body 10 is gradually inserted into the orifice 5, and the opening area of the orifice 5 is gradually reduced. When the pressure difference and the elastic force of the spring 12 are balanced, the movement of the valve body 10 is stopped and the setting is completed. Maintain flow rate. Conversely, when the pressure difference becomes smaller, the valve body 10 moves upstream until the elastic force of the spring 12 and the pressure difference are balanced, and the opening area of the orifice 5 is increased, so that the flow rate remains unchanged and reaches the set flow rate. will be maintained.

In this way, the fluid flow rate is automatically controlled to the set value even if the upstream and downstream fluid pressures fluctuate significantly.

Further, when the valve body 10 is moved upstream by rotation of the spindle 8, the opening area of the orifice 5 becomes larger and the fluid flow rate also increases, so that the flow rate set value becomes larger. Even if the fluid pressure fluctuates in this state, the newly set flow rate is maintained by the actions of the respective components similar to those described above.

Conversely, when the valve body 10 is moved downstream by rotation of the spindle 8, the opening area of the orifice 5 becomes smaller and the fluid flow rate also decreases, so that the flow rate set value becomes smaller. Even if the fluid pressure fluctuates in this state, the newly set flow rate is maintained by the actions of the respective components similar to those described above.

In this way, by rotating the spindle 8, the set flow rate can be changed over a wide range.

Furthermore, as the valve body 10 is moved upstream by rotation of the spindle 8, the closing cylindrical body 14 provided integrally with the spindle 8 descends, and finally its lower end 14a becomes the inlet. The upper end surface 2c of the flow path 2, that is, the flange portion 6 provided on the valve seat equivalent portion 7 is brought into close contact with the upper end surface 2c of the flow path 2, thereby blocking the flow of fluid. On the other hand, when the spindle 8 is rotated in the opposite direction to the above, the valve is opened and fluid begins to flow. That is, opening and closing operations of the valve can also be performed.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a constant flow valve according to a first embodiment of the present invention.

In the figure, 1 is a valve body, which includes an inlet channel 2, an outlet channel 3 that opens perpendicularly to the axis of the inlet channel 2, and a hollow space provided in a direction parallel to the inlet channel 2. It has a chamber 4 inside.

Reference numeral 5 denotes an orifice that communicates the inlet channel 2 with the hollow chamber 4;
a, that is, is formed in the valve seat equivalent portion 7, and is opened with its axis aligned with the axis of the inlet flow path 2.

6 is a flange forming the orifice 5;
Although the position may be anywhere inside the inlet flow path 2, it is preferably provided at the upper end 2a of the inlet flow path 2, that is, the valve seat 7, as shown in the figure. Reference numeral 8 denotes a spindle, which has its axis aligned with the axis of the orifice 5 and can move forward and backward within the hollow chamber 4.
A lid body 9 is screwed onto the upper end of the valve body 1.
is supported by screwing. The lower part of the spindle 8 has a stepped portion 8b, and a reduced diameter portion 8a is provided below the stepped portion 8b to facilitate insertion of a valve body 10 and a spring 12, which will be described later.

10 is a bell-shaped valve body, and the spindle 8
Its axis line coincides with the axis line of the upstream end surface 1
0a is always located upstream of the orifice 5, it is slidably fitted into the reduced diameter portion 8a of the spindle 8, and its outer diameter is contracted toward the downstream side to form a gently convex curved surface. diameter.

If the outer shape of the valve body is designed to have a conical or truncated conical shape with a linearly reduced diameter toward the downstream side, there is a problem in that control accuracy is poor, but the valve body shape of the present invention has better control accuracy. is obtained.

This valve body 10 is prevented from detaching from the spindle 8 by a nut 11 screwed onto the end 8c of the spindle 8.

Reference numeral 12 denotes a spring whose axis coincides with the axis of the spindle 8, is inserted into the reduced diameter portion 8a of the spindle 8, and its lower end is connected to the valve body 10.
The upper end contacts the stepped portion 8b of the spindle 8, and the valve body 10 is brought into contact with the lower end 8c of the spindle 8.
It is biased towards the side.

13 is a handle fixed to the upper end of the spindle 8.

The constant flow valve of this embodiment has an extremely simple structure, and when the spindle 8 is lowered by rotating the handle 13 and the valve body 10 is moved upstream (downward in the drawings, the same applies hereinafter), Since the opening area of the orifice 5 becomes larger and the fluid flow rate also increases, the flow rate setting value can be increased. Conversely, if the valve body 10 is moved downstream (upward in the drawings, the same applies hereinafter) by raising the spindle 8, the opening area of the orifice 5 will become smaller and the fluid flow rate will also decrease, so the flow rate setting value will be reduced. It is possible to adjust the flow rate.

Further, the valve body 10 receiving fluid pressure at the upstream end face 10a biases the spring 12 on the spindle 8 when the difference in fluid pressure between the upstream side and the downstream side of the valve body 10 becomes large. Due to this movement, the valve body 10 is gradually inserted into the orifice 5, the opening area of the orifice 5 is gradually reduced, and the pressure difference and the spring 12 are gradually reduced.
When the elastic forces of the valve body 10 are balanced, the movement of the valve body 10 is stopped, and the set flow rate is maintained. Conversely, when the pressure difference becomes smaller, the valve body 10 moves upstream until the elastic force of the spring 12 and the pressure difference are balanced, increasing the opening area of the orifice 5, so that the flow rate does not decrease. It becomes possible to maintain the set flow rate.

Reference numeral 14 denotes a closing cylindrical body integrally formed on the upper part of the stepped portion 8b of the spindle 8. Due to the rotation of the spindle 8, this closing cylindrical body 14
is lowered and its lower end surface 14a is brought into close contact with the upper end surface 2c of the inlet flow path 2, that is, the flange portion 6 provided on the valve seat equivalent portion 7, thereby making it possible to block the fluid flow.

Further, a socket 18 is provided at the lower part 2b of the inlet flow path 2.
The outer periphery of this socket 18 has a packing groove 20 in which a ring 19 for sealing the joint is attached, and a support 21 for holding the connection.
An annular groove 22 is provided in which the holder is mounted. The connection between this socket 18 and the valve body 1 is first made using the O-ring 1.
9 and the support 21 are attached to the valve body 1.
The valve body 1 and the support 23 are connected with bolts (not shown) in order to insert the support 21 into the inlet flow path 2 of the valve body 1 and the support 23, and then attach the support 23 to the valve body 1 and the support 23. Join. Therefore, the valve body 1 is rotatably connected to the socket 18. Here, the socket 18 is not inserted into the lower part 2b of the inlet flow path 2,
It may be a straight tube as it is, or it may be flange-shaped.

Further, the valve body 1 may be bulged in the middle.

FIG. 2 is a vertical cross-sectional view of a main part of a constant flow valve according to a second embodiment, in which a damper effect function is further added to the constant flow valve shown in FIG.

In the figure, reference numeral 15 denotes a cylindrical body integrally formed with the valve body 10, which is the reduced diameter portion 8 of the spindle 8.
a and a spring 12. The upper end of this cylindrical body 15 is slidably fitted to the spindle 8. This constant flow valve has a damper effect, so even if the fluid pressure changes suddenly due to water hammer or the like, the impact is absorbed and the set flow rate is maintained.

FIG. 3 is a vertical sectional view of a main part of a self-cleaning constant flow valve according to a third embodiment, in which the valve body 10 and the cylindrical body 15 of the constant flow valve shown in FIG. 2 are modified to be particularly suitable for slurry fluid.

In the figure, 10b is the upstream end surface 10 of the valve body 10.
This is a through hole provided parallel to the axis of the cylindrical body 15 from a and penetrating inside the cylindrical body 15. Further, 15a is a through hole provided in the side surface of the cylindrical body 15.
In this constant flow valve, a flow is generated in the cylindrical body 15 due to the pressure received by the through hole 10b of the valve body 10 and the reduced pressure received by the through hole 15a of the cylindrical body 15, and the solids in the slurry are moved downstream. This causes the spring 12 to operate normally and maintain a constant flow rate.

In addition, as another embodiment of the present invention, the first
It is also conceivable to combine what is shown in FIG. 2 and FIG.

FIG. 4 is a longitudinal cross-sectional view of the PCTFE resin coated spring.

By completely covering the metal spring 16 with PCTFE resin 17, a high degree of corrosion resistance is obtained. Therefore, when used in the constant flow valve of the present invention made of corrosion resistant plastic, this constant flow valve can be used for corrosive fluids. It can be used stably for long periods of time during transportation.

Figure 5 shows a constant flow valve with a diameter of 25A having the structure of the constant flow valve shown in Figure 1, which is used to pump water at 25°C by 0.5.
m ³ /hr, a differential pressure gauge was installed between the upstream and downstream of this constant flow valve, and the differential pressure ΔP was varied from 0 to approximately 2.0 Kg/cm ² to measure the fluid flow rate Qv. The results are graphed. This is what is shown.

As can be seen from the figure, this constant flow valve was excellent in that it could maintain a constant flow rate with an accuracy of approximately ±5% from around the operating differential pressure ΔP≒0.3 Kg/cm ² .

Figure 6 similarly shows how water at 25°C is pumped through a constant flow valve with a diameter of 50A having the structure of the constant flow valve shown in Figure 1.
m ³ /hr and 15m ³ /hr, and a differential pressure gauge is installed between the upstream and downstream of this constant flow valve, and the differential pressure ΔP is 0 to approximately
The graph shows the results of measuring the fluid flow rate Qv while varying it up to 6.0Kg/cm ² .

As can be seen from the figure, this constant flow valve was excellent in that it was able to maintain a constant flow rate with an accuracy of about ±5% in both cases from around the operating differential pressure ΔP≈0.6 Kg/cm ² .

It goes without saying that the metering valve of the present invention is not limited to the above embodiments.

〔Effect of the invention〕

As explained above, the constant flow valve of the present invention includes a valve body and a valve body having an inlet passage and an outlet passage opening perpendicularly or obliquely to the axis of the inlet passage. By providing a resilient spring and an orifice, a compact and inexpensive constant flow valve can be obtained, and a constant flow valve that can always maintain a set constant flow rate and easily adjust the flow rate by operating a spindle can be obtained.

In addition, since a closing cylindrical body is provided integrally with the spindle, it is possible to completely stop the fluid flow and open the valve with certainty, and it also has the function of a so-called stop valve, so a separate stop valve is provided. There's no need.

In addition, when a cylindrical body is provided integrally with the valve body,
The fluid inside the cylindrical body acts as a kind of damper, so even if the fluid pressure fluctuates rapidly, the valve body does not immediately follow it, and the valve body does not vibrate, resulting in always stable flow control. be able to do the following.

Further, when a through hole communicating with the inside of a cylindrical body provided integrally with the valve body is provided from the upstream end of the valve body parallel to its axis, and the through hole is provided on the side surface of the cylindrical body, In particular, when a slurry fluid is flowed, the solid matter in the slurry flows out from the through hole, so that a self-cleaning constant flow valve that always operates normally without the solid matter accumulating inside the cylindrical body can be obtained.

In addition, when using a metal spring completely coated with PCTFE resin, the PCTFE resin itself has excellent corrosion resistance, has a low degree of crystallinity, and has a low modulus of elasticity, so it does not interfere with the spring characteristics of the metal.
Furthermore, since it has very good gas barrier properties, when used in the constant flow valve of the present invention made of a corrosion-resistant material, it can be used stably for a long period of time even for transporting corrosive fluids.

In addition, since the structure is simple, assembly and repair are easy, especially when using plastic materials.
Since it can be mass-produced by injection molding or the like, it can be manufactured at a much lower cost than conventional constant flow valves.

[Brief explanation of drawings]

Fig. 1 is an overall longitudinal sectional view of a constant flow valve according to a first embodiment of the present invention, Fig. 2 is a longitudinal sectional view of essential parts of a constant flow valve according to a second embodiment of the same, and Fig. 3 is a longitudinal sectional view of a main part of a constant flow valve according to a second embodiment of the same. FIG. 4 is a vertical cross-sectional view of a main part of a constant flow valve, FIG. 4 is a vertical cross-sectional view of a PCTFE resin-coated spring, and FIGS. 5 and 6 are graphs showing the results of flow rate experiments. DESCRIPTION OF SYMBOLS 1... Valve body, 2... Inlet channel, 2a... Internal upper end, 2b... Lower part, 2c... Upper end side view, 3
... Outlet channel, 4 ... Hollow chamber, 5 ... Orifice, 6 ... Flange, 7 ... Valve seat, 8 ... Spindle, 8a ... Reduced diameter part, 8b ... Step part, 8c ... …
End, 9... Lid body, 10... Valve body, 10a... Upstream end surface, 10b... Through hole, 11... Nut,
12...Spring, 13...Handle, 14...
...Closing cylindrical body, 14a... Lower end surface, 15... Cylindrical body, 15a... Through hole, 16... Metal spring, 17... PCTFE resin.

Claims (1)

[Scope of Claims] 1. An inlet channel having an orifice therein, a hollow chamber provided in a direction parallel to the inlet channel and communicating with the inlet channel, and an inlet communicating with the hollow chamber. A valve body having an outlet flow path opening perpendicularly or obliquely to the axis of the flow path,
A spindle supported by the lid of the valve body so as to be movable back and forth within the hollow chamber so that its axis coincides with the axis of the orifice, and a spindle whose axis line coincides with the axis of the spindle so that its upstream end face is always aligned with the axis of the orifice. a valve body that is slidably fitted to the lower end of the spindle so as to be located on the upstream side and has a gently convex curved shape with an outer diameter decreasing toward the downstream side; a valve body that is attached to the spindle; The spindle is characterized by comprising a spring biasing the spindle toward the lower end side of the spindle, and a closing cylindrical body integrally provided with the spindle so as to enclose the spring and the spindle. Constant flow valve. 2. The constant flow valve according to claim 1, characterized in that a cylindrical body containing the spindle and the spring and slidably fitted to the spindle is provided integrally with the valve body. 3. A through hole communicating with the inside of the cylindrical body integrally provided with the valve body is provided from the upstream end of the valve body parallel to its axis, and a through hole is also provided on the side surface of the cylindrical body. A constant flow valve according to claim 2, characterized in that: 4. According to any one of claims 1, 2, and 3, the spring is a spring made of a metal completely coated with polychlorotrifluoroethylene resin. Constant flow valve as described.