JPH0331957B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is applicable to fluid transportation piping, etc., which require constant supply and discharge of water, industrial water, agricultural water, petroleum plants, petrochemical plants, and others. This invention relates to constant flow valves used in chemical liquid piping, gas piping, etc.

[Conventional technology]

Conventionally, there are various types of constant flow valves, but one of them includes a throttle valve and a differential pressure regulating valve, as disclosed in Japanese Patent Publication No. 13652/1983.
There are those that maintain a constant flow rate according to the degree of opening of the throttle valve using a differential pressure regulating valve that operates by detecting the pressure difference between the upstream and downstream sides of the throttle valve, and those disclosed in Japanese Patent Publication No. 54-39619. , a control valve body made of an elastic body whose outer periphery can be bent in the axial direction is supported by a valve shaft and placed against a valve seat with a tapered surface provided in the flow path of the valve body, and is controlled by fluid pressure. A constant flow rate is maintained by creating deflection of the valve body and expanding or contracting the gap between the outer circumference of the control valve and the tapered surface of the valve seat, and by displacing the control valve in the axial direction by external operation. There is also one in which the set flow rate can be adjusted by changing the time interval.

[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, the latter constant flow valve is susceptible to aging and fatigue of the control valve body made of an elastic body, and therefore lacks durability as a control valve.
Furthermore, it is extremely difficult to provide the control valve body with a wall thickness and hardness sufficient to withstand particularly high fluid pressures, and uneven thickness and hardness variations cause an imbalance in the deflection throughout the valve. , adversely affecting flow control. For this reason, high precision management is required to eliminate uneven thickness and changes in hardness of the control valve body, which, together with the aging problem, tends to increase manufacturing costs. In addition, in the low fluid pressure region, there are control performance problems such as difficulty in obtaining a constant flow rate due to constraints such as the wall thickness and hardness, and valve function problems such as the inability to completely block the fluid with this type. There's a problem.

In view of the problems of the above-mentioned prior art, the present invention has been made to:
It has a simple structure and is suitable for mass production, can accurately maintain the set flow rate even if the fluid pressure on the upstream and downstream sides fluctuates greatly, and can easily adjust the set flow rate over a wide range. It also has a valve closing function. Furthermore, the present invention aims to provide an inexpensive and durable constant flow valve that can be opened and closed reliably.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention includes a cylindrical body having a flow path therein, and a protrusion mounted on the inner periphery of the cylindrical body so as to be movable in the axial direction of the cylindrical body. a cylindrical body provided therein; a drive mechanism for moving and fixing the cylindrical body in the axial direction; a fixed shaft supported so that its axis coincides with the axis of the flow path; The shaft is slidably fitted onto the fixed shaft so that their axes coincide with each other, and its maximum outer diameter is larger than the diameter of the opening formed by the protrusion on the periphery of the cylindrical body. A valve body having a shape in which the outer diameter of the downstream side of the maximum outer diameter part is reduced in diameter from the upstream side to the downstream side so that an orifice part can be formed between the valve body and the valve body, and the valve body is connected to the valve body. a spring that is fitted into the fixed shaft and springs the valve body; and a stop mechanism that always positions the upstream end surface of the valve body upstream of the protrusion. , consisting of a hollow part formed inside the valve body and a flange provided on the fixed shaft so as to be located in the hollow part, and when the valve body moves, one end surface of the hollow part is connected to the flange. To provide a constant flow valve, characterized in that it is configured so that its movement is stopped when it comes into contact with a part.

[Effect]

In the constant flow valve of the present invention having the above configuration, when fluid flows through the flow path, the valve body receives the flow at its upstream end face, thereby creating a pressure difference between the upstream side and the downstream side. This causes it to move downstream on the fixed shaft while biasing the spring.
Due to this movement, the valve body is gradually inserted into the opening formed by the protrusion in the flow path, and the opening area of the orifice formed between the protrusion and the protrusion is gradually reduced, and the pressure difference and the elastic force of the spring are reduced. When the flow rate is balanced, the movement stops and the set flow rate is obtained.
Next, when the pressure difference decreases due to a decrease in the upstream pressure of the valve body or an increase in the downstream pressure, the valve body moves upstream until the elastic force of the spring and the pressure difference are balanced. The flow rate is maintained at the set flow rate without decreasing because the opening area of the orifice part is increased.

In this way, even if the fluid pressures on the upstream and downstream sides vary significantly, the fluid flowing through the flow path is automatically controlled to the set value.

When the cylindrical body is moved downstream in the flow path axis direction by the drive mechanism of the cylindrical body, its protrusion also moves downstream at the same time, so the opening area of the orifice part is reduced due to the shape of the valve body whose diameter is reduced toward the downstream side. becomes larger and the flow rate also increases. In this state, even if the fluid pressure fluctuates, the newly set flow rate can be maintained by the actions of the respective components similar to those described above.

If the cylindrical body is moved upstream in the opposite direction to the above, the opening area of the orifice becomes smaller, and the flow rate also decreases. Even if fluid pressure fluctuates from this state, the newly set flow rate can be maintained by the actions of the respective components similar to those described above. In this way, by moving the cylinder, the set flow rate can be changed over a wide range.

If fluid pressure exceeding the elastic limit of the spring is applied to the valve body, the upstream end surface of the hollow part of the valve body will hit the fixed shaft flange and stop the movement of the valve body, so that the valve body will close the opening. There is a possibility that the valve body may become blocked and stop the flow of fluid, or the upstream end face of the valve body may pass through the opening and move downstream, rapidly increasing the orifice area and causing problems in flow control. It acts like there is no such thing.

When the fluid flow stops, the valve body returns to the upstream side due to the elastic force of the spring, and the downstream end face of the hollow part hits the fixed shaft flange, stopping its movement. maintain the initial position.

Furthermore, in the event of a sudden large change in fluid pressure such as due to water hammer, the damper action between the fluid in the hollow part of the valve body and the fixed shaft flange will reduce the rapid movement of the valve body, causing sudden force on the spring. is prevented from being applied, and the valve body does not vibrate.

Furthermore, if it becomes necessary to completely stop the fluid flow, the cylindrical body is moved upstream and its protrusion comes into contact with the maximum outer diameter of the valve body, thereby controlling most of the fluid flow. is stopped, and the cylindrical body is further moved upstream to press the downstream end face of the hollow part of the valve body into contact with the flange of the fixed shaft, thereby completely sealing the fluid at this part. To change the state from this state to the open state, move the cylindrical body downstream in the opposite direction, and the flange will come into contact with the upstream end surface of the hollow part of the valve body.If you move the cylindrical body further downstream, the valve will close. The body is pulled out of the opening to ensure an open position.

〔Example〕

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

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention showing a state in which fluid is flowing. In the same figure, 1 is a cylindrical body 1 having a linear flow path 6 therein.
It is a cylindrical body consisting of a and 1b, and the cylindrical body 1a is provided with an inlet 19, and the cylindrical body 1b is provided with an outlet 20. Reference numeral 2 denotes a fixed shaft on which a spring 3 and a valve body 4 are fitted.
It is supported at two points by supports 12 and 13 screwed onto the inner peripheral surfaces of the cylindrical bodies 1a and 1b near the outlet 20. The supports 12 and 13 have a fourth
As shown in the figure, flow ports 12a and 13a are provided, and holes 12b and 13b are provided on the axis of the flow path 6, and the fixed shaft 2 is fixed by fitting its both ends into the holes 12b and 13b, respectively. There is.

The fixed shaft 2 is provided with a flange 2a that is always located within a hollow portion 4a of a valve body 4, which will be described later, at positions approximately equidistant from both ends thereof. This flange portion 2a forms a narrow gap 4b as shown in FIG. 2 between the flange portion 2a and the inner circumferential surface of the valve body hollow portion 4a so as not to hinder smooth sliding displacement of the valve body 4. Due to the damper effect produced by the cooperation with the fluid in the hollow portion 4a of the valve body, which will be described later, the rapid movement of the valve body 4 is alleviated and the spring 3 is prevented from vibrating. Further, the flange portion 2a and the hollow portion 4a are such that the upstream end surface of the valve body 4 is connected to the projection portion 5.
The movement range of the valve body 4 is restricted and assembled so that it does not displace downstream.

The valve body 4 is slidably fitted onto the outer periphery of the fixed shaft 2 so that its axis coincides with the axis of the fixed shaft 2, and its downstream end is fitted near an opening formed by a protrusion 5 to be described later. The valve body 4 is inserted into the opening under fluid pressure to change the opening area of the orifice portion 6a. The outer diameter of the valve body 4 is a shape in which the outer diameter is gradually reduced from the upstream side to the downstream side of the flow path 6, and may be a conical shape or a truncated conical shape, but in this embodiment, the upstream It is formed into a bell shape with a flange 4c having a maximum outer diameter larger than the opening diameter of the opening at the side end. A cylindrical hollow portion 4a is provided inside the valve body 4, and the length of this hollow portion 4a is determined so that the upstream end surface of the valve body 4 has a protrusion due to the positional relationship with the flange 2a of the fixed shaft 2. Although it is possible to move up to around 5,
It is set so that it cannot move further downstream than that.

The spring 3 is fitted around the outer periphery of the fixed shaft 2, and one end thereof is connected to the downstream end of the valve body 4, and the other end is in contact with the fixed shaft support 13 to prevent the valve body 4 from moving. It acts as a trigger. Note that the other end of the spring 3 may be fixed to the fixed shaft 2. The spring constant of the spring 3 is such that the opening area of the orifice portion 6a can maintain a predetermined flow rate, which changes sequentially depending on the degree of insertion of the valve body 4 into the opening in relation to the shape of the valve body 4. This setting is made with due consideration given to the relationship with the force exerted by the fluid on the valve body 4, etc. Furthermore, as a method of connecting the spring 3 and the valve body 4, in addition to the connection method shown in the drawings, it is conceivable to connect one end of the spring 3 to the upstream end of the valve body 4, or to the upstream and downstream flow ends. When connecting to the upstream end of the valve body 4, the other end of the spring 3 is fixed to the fixed shaft 2 or the upstream fixed shaft support 12, and when connecting to the upstream and downstream sides of the valve body 4 at the same time. The other end of each spring is fixed to the fixed shaft 2 or the fixed shaft supports 12 and 13 on the upstream and downstream sides.

Reference numeral 8 denotes a cylindrical body mounted on the inner periphery of the cylindrical bodies 1a and 1b so as to be movable in the axial direction, and there is an orifice portion 6a between the valve body 4 near the center of the inner periphery.
A protrusion 5 that forms a is integrally provided.
The position where the protrusion 5 is provided may be the inner circumference of the upstream end of the cylindrical body, and is not particularly limited. Further, although the shape of the protrusion 5 is formed to have a triangular cross section in this embodiment, it is not limited to this shape. The outer peripheral surface of the cylindrical body 8 is provided with a male threaded portion 8a that is screwed into a female threaded portion 11a provided on the inner peripheral surface of a worm wheel 11, which will be described later. Furthermore, four anti-rotation ribs 8b are provided on the outer peripheral surface of the downstream end of the cylindrical body 8 at 90° intervals in the diametrical direction, as shown in FIG. It is slidably fitted into a guide groove 7 provided in the axial direction of the flow path 6 . This anti-rotation rib 8b functions to prevent the cylindrical body 8 from rotating and to move it only in the axial direction of the flow path. Further, an annular groove is provided on the outer circumferential surface of the upstream end of the cylindrical body 8, into which an O-ring 8c is fitted.

9 is a cylindrical body 1 extending in a direction perpendicular to the axis of the flow path 6.
A rotating shaft rotatably attached to the outside of the
A worm 10 is provided integrally with the main body cover 2.
Warm cover 21 provided on the side of the central part of 1
It is held at a. As shown in FIG. 2, the rotary shaft 9 is sealed between the worm covers 21a by an O-ring 16. Warm 1
0 is engaged with a worm wheel 11 which is held between the cylindrical bodies 1a and 1b so as to be rotatable about their axes. Furthermore, this worm wheel 11
As shown in the figure, since its both sides are held between the cylindrical body 1, it cannot move in its axial direction.
It is rotatable only around the axis. By rotating the rotary shaft 9, the worm 10 and the worm wheel 11 rotate accordingly, and the cylindrical body 8 is moved in the axial direction of the flow path 6. The movement range of the cylindrical body 8 is equal to or larger than the movement range of the valve body 4, and as shown in FIG. The collar part 2a provided in 2
is set to such an extent that it presses into close contact with the downstream end face of the hollow portion 4a of the valve body.

In addition, when using a cam as a movement transmitting body of the cylindrical body 8, the cam is provided integrally with the rotating shaft,
A spring is installed between the cylindrical body 8 and the upstream fixed shaft support 12 to make the cylindrical body 8 resilient,
The cylindrical body 8 is moved in the axial direction of the flow path 6 while the downstream end surface of the cylindrical body 8 is always kept in contact with the cam in response to rotational displacement of the cam.

Male threads are provided on the outer periphery of both ends of the main body cover 21, and by screwing with the cap nuts 17 and 18, the cylindrical body 1 is inserted through the seats 14 and 15.
a and 1b are covered and fixed.

The constant flow valve of this embodiment configured as described above has flanges (not shown) at both ends of the cylindrical body 1.
It is installed in the piping line by attaching it and connecting it to the pipe end flange (not shown) of the pipeline.

The operation of this embodiment having the above configuration is as follows.

When fluid flows through the flow path 6 of the cylindrical body 1, the valve body 4
receives the flow at its upstream end face, creating a pressure difference between the upstream and downstream sides, which causes the valve body 4 to move downstream on the fixed shaft 2 while compressing and biasing the spring 3. . As the valve body 4 is gradually inserted into the opening formed by the protrusion 5 in the flow path 6 as described above, the orifice formed between the valve body and the protrusion 5 due to the bell-shaped shape of the valve body. Part 6
The opening area of a gradually decreases. Then, when the pressure difference and the elastic force of the spring are balanced, the valve body 4 stops moving, and the set flow rate is obtained. From this state, when the fluid pressure on the upstream side of the valve body 4 further increases, the valve body 4 is also further inserted into the opening, and the opening area of the orifice portion 6a becomes further smaller, so the flow rate does not increase. , controlled to the set flow rate.

Next, when the pressure difference decreases due to a decrease in the upstream pressure of the valve body 4 or an increase in the downstream pressure, the valve body 4 moves upstream until the elastic force of the spring 3 and the pressure difference are balanced. Since the opening area of the orifice portion 6a is increased by moving to the side, the flow rate is maintained at the set flow rate without decreasing.

In this way, the flow rate is automatically controlled to the set value without being affected by large fluctuations in upstream and downstream fluid pressures.

Next, when increasing the set flow rate, the rotary shaft 9 is rotated and the rotation is transmitted to the worm wheel 11 via the worm 10 formed integrally with the rotary shaft 9.
to communicate. As the worm wheel 11 rotates, the cylindrical body 8 screwed thereon moves toward the downstream side in the axial direction of the flow path 6. Along with this, the protrusion 5 also moves downstream, so that the opening area of the orifice 6a becomes larger in relation to the shape of the valve body 4, and the flow rate increases. In this state, even if the fluid pressure fluctuates, the newly set flow rate can be maintained by the actions of each of the above-mentioned components. On the other hand, when reducing the set flow rate, when the rotary shaft 9 is rotated in the opposite direction to the above, the rotation is similarly transmitted to the cylindrical body 8, and the cylindrical body 8 is moved upstream. Therefore, since the opening area of the orifice portion 6a becomes smaller, the flow rate also decreases. From this state, even if the fluid pressure fluctuates, the newly set flow rate can be maintained by the actions of each component in the same manner as described above. In this way, the set flow rate can be changed over a wide range by the simple operation of rotating the rotary shaft.

If a fluid pressure that exceeds the elastic limit of the spring 3 is applied to the valve body 4, the movement of the valve body 4 will cause the upstream end surface of the hollow portion 4a to move against the fixed shaft 2.
Since the movement is stopped there, the valve body 4 passes through the opening and moves to the downstream side thereof, rapidly increasing the opening area of the orifice 6a and controlling the flow rate. It acts in such a way that it does not cause any trouble.

Conversely, when the flow of fluid stops, the valve body 4 moves upstream due to the elastic force of the spring 3, but the downstream end surface of the hollow part 4a hits the flange part 2a, preventing movement. Since it stops there, the valve body can maintain the preset initial position.

Furthermore, if the fluid pressure changes suddenly and greatly, such as due to water hammer, the valve body 4 will immediately follow this change and try to move rapidly. However, as the valve body 4 moves, the fluid existing in the valve body hollow part 4a on the upstream and downstream sides of the collar part 2a passes through the narrow gap formed between the hollow part 4a and the collar part 2a. Due to the so-called damper effect in which the fluid resistance generated during this movement alleviates the rapid displacement of the valve body 4, no sudden force is applied to the spring 3.
Therefore, the valve body 4 does not vibrate.

Furthermore, if it is necessary to completely stop the flow of fluid, the rotary shaft 9 is rotated to move the cylindrical body 8 upstream, and when the cylindrical body 8 is displaced to a certain extent, the protrusion 5 touches the flange of the valve body 4. Since the portion 4c abuts and reduces the opening area of the orifice portion 6a to zero, it becomes possible to stop most of the fluid flow. However, the valve body 4 is fixed shaft 2
Since it is fitted into the fixed shaft 2, it is inevitable that fluid will leak from between the sliding parts with the fixed shaft 2. Therefore, when the cylindrical body 8 is further moved upstream, the downstream end face of the hollow part 4a of the valve body comes into contact with the flange part 2a provided on the fixed shaft 2, and this part completely prevents fluid leakage. Seal.

In order to open the flow path 6 from this state, the rotary shaft 9 is rotated in the opposite direction and the cylindrical body 8 is moved downstream, so that the flange 2a is moved to the upstream side of the hollow part 4a of the valve body. When the valve body 4 hits the end face and is moved further downstream, the orifice portion 6a is formed between the valve body 4 and the protrusion 5, and the valve body 4 reliably shifts to the open state.

[Effects of the Invention] Since the present invention has the above configuration and operation, the movement of the valve body can be automatically controlled even if the fluid pressure on the upstream and downstream sides of the constant flow valve fluctuates significantly. , the set flow rate is always obtained.

In addition, since the cylindrical body can be moved in the axial direction of the flow path, the set flow rate can be changed over a wide range, and the changed set flow rate is not affected by fluctuations in fluid pressure. It will be controlled at a constant level.

Even if a fluid pressure that exceeds the elastic limit of the spring is applied to the valve body, the movement of the valve body is restricted by the stop mechanism, so the valve body may block the orifice and stop the flow of fluid, or Prevents the upstream end face from moving downstream from the orifice portion and causing trouble in flow rate control.

In addition, the simple structure makes repairs easy, and the structure is especially suitable for mass production, such as injection molding using plastic materials, so it can be manufactured at a much lower cost than conventional constant flow valves. can do.

In addition, since the stop mechanism that restricts the movement of the valve body is composed of a flange provided on the fixed shaft and a hollow part provided inside the valve body, the interaction between the flange and the hollow part prevents fluid flow. Since it can reliably completely stop and open the flow, and has the function of a so-called control valve, there is no need to provide an on-off valve in addition to the constant flow valve, and it can also be used at the end of piping. .

Furthermore, in this case, the fluid in the hollow part of the valve body and the flange of the fixed shaft act as a kind of damper, so even if the fluid pressure changes suddenly and greatly, the valve body does not immediately follow it, and the valve The body does not vibrate, and stable flow control can be performed at all times.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line A-A' in FIG. 1, and FIG. 3 is a cross-sectional view taken along line B-B' in FIG. 4 is an inner side view of the fixed shaft support in FIG. 1, and FIG. 5 is a longitudinal sectional view of the main part of the embodiment shown in FIG. 1 in a closed state. 1... Cylindrical body, 2... Fixed shaft, 2a...
...Flame, 3...Spring, 4...Valve body, 4a...
... Valve body hollow part, 5 ... Protrusion, 6 ... Channel, 6a
... Orifice part, 7 ... Guide groove, 8 ... Cylindrical body, 9 ... Rotating shaft, 10 ... Worm, 1
1... Worm wheel, 19... Inlet, 20
... Outlet.

Claims (1)

[Scope of Claims] 1. A cylindrical body having a flow path therein, and a cylindrical body mounted on the inner periphery of the cylindrical body so as to be movable in the axial direction thereof and provided with a protrusion on the inner periphery. , a drive mechanism for moving and fixing the cylindrical body in the axial direction; a fixed shaft supported so that its axis coincides with the axis of the flow path; and a fixed shaft supported so that its axis coincides with the axis of the fixed shaft. is slidably fitted onto the fixed shaft, and has a maximum outer diameter larger than the diameter of the opening formed by the protrusion on the periphery of the cylindrical body, and has a diameter larger than the maximum outer diameter. a valve body having a shape in which the outer diameter of the downstream side is reduced from the upstream side to the downstream side so that an orifice portion can be formed between the valve body and the fixed shaft connected to the valve body; a spring that is inserted into the valve body and springs the valve body; and a stop mechanism that always positions the upstream end surface of the valve body upstream of the protrusion; and a flange provided on the fixed shaft so as to be located in the hollow, and one end surface of the hollow portion comes into contact with the flange when the valve body moves. A constant flow valve, characterized in that its movement is stopped. 2. The cylindrical drive mechanism includes a rotating shaft disposed in a direction perpendicular to the axis of the flow path, a drive transmission body interposed so as to come into contact with the rotating shaft and the cylindrical body, and the cylindrical body. 2. The constant flow valve according to claim 1, wherein the constant flow valve comprises a rotation preventing member, and is configured to transmit rotation of the rotating shaft to the cylindrical body via the drive transmission body. 3 The drive transmission body is a worm and a worm wheel, the former is fixed to a rotating shaft, and the latter meshes with the worm and has a threaded part on its inner periphery that is threaded with a threaded part on the outer periphery of the cylindrical body, and has a constant shape. 3. The constant flow valve of claim 2, wherein the constant flow valve rotates about the axis of the flow path in position. 4. The constant flow valve according to claim 1, wherein the fluid in the hollow portion and the collar portion have a damper function. 5. The constant flow valve according to claim 1, wherein the movement range of the cylindrical body is greater than or equal to the movement range of the valve body.