JP5007370B1 - Constant flow valve - Google Patents

Abstract

It is possible to suppress a significant decrease in flow rate under high pressure and to reduce a pressure loss of a fluid in a constant flow valve.
A first chamber 213 formed by a housing lid 218 and a movable valve body 22, a second chamber 214 formed by a housing body 217 and the movable valve body 22, a first chamber 213 and a second chamber. 214 corresponds to the first hole 223 that causes a pressure difference between the first chamber 213 and the second chamber 214 by the passage of fluid and the valve portion 222 provided in the movable valve body 22. In the constant flow valve 2 provided with the valve seat 212a provided and the elastic member 23 that urges the movable valve body 22 in the direction in which the valve portion 222 and the valve seat 212a open, the valve corresponding to the valve seat 212a A portion 222 is provided on the movable valve body 22, and the fluid flows directly from the second chamber 214 or the first chamber 213 to the outlet 212 without passing through the gap 212 b between the valve portion 222 and the valve seat 212 a. Second hole 224 that can be formed It is.
[Selection] Figure 3

Description

  The present invention relates to a constant flow valve that adjusts the flow rate of a fluid flowing through a pipeline, and more particularly to a constant flow valve that can suppress a significant decrease in flow rate under high pressure.

  Conventionally, the flow rate per unit time of the fluid flowing through the pipe line may need to be adjusted appropriately depending on the application of the fluid, and a constant flow valve may be used to adjust the flow rate.

  In general, the flow rate of the fluid flowing through the pipe line often needs to be appropriately adjusted according to the application. For example, when the fluid flowing through the pipeline is water, when water is supplied to the faucet, the nozzle of the washing toilet seat, the hot water supply device, the mist generator, etc. through the pipeline such as a water pipe, As a result, not only will the user experience be reduced, but an excessive load will be placed on the water supply equipment such as the water tap and the toilet seat.

  As a method of adjusting the flow rate of water flowing through the pipeline, there is a method of adjusting the pressure of water before flowing water through the pipeline, or a method of adjusting by reducing the pressure of water after flowing water through the pipeline. . Here, according to the method of adjusting the pressure before flowing water through the pipeline, the flow rate is uniformly reduced for all the water supply devices that receive the supply of water through this pipeline. At this time, the flow rate is uniformly reduced even for water supply devices that require a relatively large flow rate, such as a water heater, and there is a possibility that the necessary flow rate cannot be supplied to these water supply devices. For this reason, a method has been adopted in which the pressure is lowered after flowing water through the pipe and an appropriate flow rate is supplied to each of the different water supply devices. In addition, the field | area which needs to adjust the flow volume of the fluid which flows through a pipe line is not restricted to water supply, It is required in various fields.

  A constant flow valve disclosed in Patent Document 1 has been proposed as an instrument for adjusting the flow rate by lowering the pressure after flowing a fluid through a pipeline. The constant flow valve is controlled by an area control type in which an elastic member such as an O-ring is crushed when a high pressure is applied to reduce the passage area of the fluid, and a differential pressure between the upstream side and the downstream side of the valve body. There is a differential pressure control type in which the body is moved to reduce the passage area of the fluid, and the constant flow valve disclosed in Patent Document 1 is classified as a differential pressure control type. The area control type has a simpler configuration and lower pressure loss than the differential pressure control type, but if the area control unit becomes clogged with dust, the flow rate will decrease and the O-ring will tend to deteriorate. There is a disadvantage that it is inferior in continuous use and long-term durability. The differential pressure control type, on the other hand, can adjust the valve opening by itself to avoid a decrease in flow rate even if the differential pressure control unit is clogged with dust. However, there are drawbacks in that the structure is complicated and the size is increased, and the pressure loss tends to increase.

A constant flow valve 2a disclosed in Patent Document 1 is shown as a cross-sectional view (a) and a plan view (b) in FIG. 2 as an embodiment for comparison with the present invention. As shown in FIG. 2A and a cross-sectional view for explaining the control flow rate in the constant flow valve 2a, the fluid pressure in the first chamber 813 is P ₁ , and the fluid pressure in the second chamber 814 is P ₂ , the fluid pressure in the downstream fluid passage 12 is P ₃ , the effective pressure receiving area of the movable valve body 822 is A _d , the spring load of the coil spring is F _S , the fluid passage cross-sectional area of the first hole 823 is A _o , When a fluid passage area a _s of the outlet 812 (valve seat 812a), a fluid passage effective area of the gap 812b of the valve portion 822 and the valve seat 812a and a _v, the following relation by a factor α (1) ~ (4) It is generally known that

となる。 With increasing P ₁ due to the increase of the fluid pressure in the upstream fluid passage 11, so that the A _v decreases movable valve body 822 is pushed in the direction of the downstream side fluid passage 12. On the other hand, when the position of the movable valve body 822 is a fluid pressure that does not move from the initial position, _Av is maximized, and in this time the pressure region of P ₁ (hereinafter referred to as “pressure loss characteristic region”). The flow rate Q ₂₁ in the downstream fluid passage 12 is

It becomes.

となり、Ｐ₃＝０とすると、

となる。 The position of the movable valve member 822 with increasing P ₁ is pushed in the direction of the downstream side fluid passage 12 from the initial position, the P ₁ a maximum and which was A _v in pressure loss characteristics zone gradually decreases In the pressure region (hereinafter referred to as “flow rate control region”), the relational expression for the constant flow valve 2a shown in FIG.

If P ₃ = 0, then

It becomes.

となる。 Furthermore, the flow rate Q ₂₂ in the downstream fluid passage 12 in the flow rate control region is:

It becomes.

Here, if A _s is sufficiently smaller than A _d −A _o −A _s , the reduction term can be ignored. Furthermore, when Fs is a minute displacement, it can be said that Fs / (A _d −A _o −A _s ) = const.
Therefore, ΔP = P ₁ −P ₂ = const.
Accordingly, the flow rate Q ₂₂ = αA _o (ΔP) 1/2 = const α: proportionality constant is obtained, and it can be seen that the flow rate Q ₂₂ in the downstream fluid passage 12 becomes a constant flow rate (const).

However, in the design of the constant flow valve, the very reducing the A _s to negligibly small reduction terms in equation (2) ~ (4), A v , which is proportional to A _s is very with A _s As a result, it becomes smaller and Q ₂₁ is lowered, resulting in a problem that the working pressure is narrowed or the control flow rate accuracy is lowered at a low pressure. On the other hand, decreasing section by increasing A _s in order to suppress a decrease in Q ₂₁ is increased, a problem that the flow rate decreases at high pressure is considerably occurs. Further, if a significant decrease in Q ₂₁ is suppressed by increasing A _o , Q ₂₂ fluctuates and cannot be controlled to a predetermined flow rate, and there is a tradeoff between suppression of pressure loss and suppression of decrease in flow rate at high pressure. There is a relationship. Means for reducing the reduction section by increasing the A _d is also considered, but the cost increase and layout constraints will be constant flow valve 2a is totally large, there is a big problem in terms like breakdown voltage design. That is, the constant flow valve 2a disclosed in Patent Document 1 has a dilemma that it is impossible to achieve both suppression of pressure loss, suppression of a decrease in flow rate at high pressure, and avoiding an increase in the size of the constant flow valve 2a.

Japanese Patent No. 4586099

  The present invention has been made in order to solve the above-described problems, and the object of the present invention is to make it possible to suppress a significant decrease in flow rate particularly when a fluid flows through a pipe line at a high pressure. It is to provide a constant flow valve.

  The constant flow valve according to claim 1 of the present application is formed by a first housing having an inflow port through which fluid flows from an upstream fluid passage, a diaphragm, and a movable valve body integrally attached to the diaphragm. A second chamber formed by the first chamber, a second housing having an outlet communicating with the downstream fluid passage, the diaphragm, and the movable valve body; the first chamber and the second chamber; And a first hole that creates a pressure difference between the first chamber and the second chamber by passing a fluid, and a passage that communicates the second chamber and the outlet. And a valve seat provided corresponding to a valve portion provided in the movable valve body, and the movable valve body is urged by a predetermined elastic force in a direction in which the valve portion and the valve seat open. And a flow rate of the fluid flowing through the downstream fluid passage having the biasing means. In the constant flow valve, the valve portion has a shape capable of coming into contact with the valve seat, and has a second hole through which fluid flows from the second chamber to the outlet. .

  The constant flow valve according to claim 2 of the present application is the constant flow valve according to claim 1, wherein the second hole is formed substantially on the same straight line with respect to the flow direction of the fluid. It is characterized by that.

  The constant flow valve according to claim 3 of the present application is the constant flow valve according to claim 1, wherein the second hole is formed eccentrically with respect to the flow direction of the first hole and the fluid. It is characterized by.

  The constant flow valve according to claim 4 of the present application is the constant flow valve according to any one of claims 1 to 3, wherein the movable valve body is between the first hole and the second hole. And it has the barrier provided in the substantially same straight line with respect to the flow direction of a fluid, It is characterized by the above-mentioned.

  The constant flow valve of the present invention is a constant flow valve classified into a so-called differential pressure control type, and a valve portion corresponding to the valve seat is provided in the movable valve body, and the valve portion includes a valve portion, a valve seat, By forming the second hole through which the fluid can flow directly from the second chamber or the first chamber to the outlet without passing through the gap, it is possible to suppress a significant decrease in flow rate under high pressure, The constant flow valve itself can be made compact, and the pressure loss of the fluid in the constant flow valve can be reduced.

1 is an overall view showing a water supply system provided with a constant flow valve to which the present invention is applied. (A) is sectional drawing of the flow direction of the pipe line in the constant flow valve which modeled the indication technique of patent document 1. FIG. (B) is a top view from the upstream fluid passage of the pipe line in this constant flow valve. (C) is sectional drawing for demonstrating the control flow volume in this constant flow valve. (A) is sectional drawing of the flow direction of the pipe line in the constant flow valve to which this invention is applied. (B) is a top view from the upstream fluid passage of the pipe line in this constant flow valve. (C) is sectional drawing for demonstrating the control flow volume in this constant flow valve. (A) is sectional drawing of the flow direction of the pipe line in the constant flow valve to which this invention is applied. (B) is a top view from the upstream fluid passage of the pipe line in this constant flow valve. (C) is sectional drawing for demonstrating the control flow volume in this constant flow valve. FIG. 5 is a pressure flow diagram showing the relationship between pressure and flow rate in the constant flow valve shown in FIG. 2 and the constant flow valve shown in FIGS. 3 and 4. (A) is sectional drawing of the flow direction of the pipe line in the constant flow valve to which this invention is applied. (B) is sectional drawing for demonstrating the control flow volume in this constant flow valve. FIG. 7 is a pressure flow diagram showing the relationship between pressure and flow rate in the constant flow valve shown in FIG. 2 and the constant flow valve shown in FIG. 6.

  Hereinafter, a constant flow valve to which the present invention is applied will be described in detail with reference to the drawings.

  FIG. 1 is an overall view showing a water supply system 3 provided with a constant flow valve 2 to which the present invention is applied. As shown in FIG. 1, water is supplied at a predetermined pressure from the upstream side of the pipe 1 and is supplied into the water supply device 4 or supplied through a constant flow valve 2 provided in the middle of the pipe 1. Water is discharged from the instrument 4.

  Fig.3 (a) is sectional drawing of the flow direction S of the pipe line 1 in the constant flow valve 2 to which this invention is applied. FIG. 3B is a plan view from the upstream fluid passage 11 of the constant flow valve 2 to which the present invention is applied in FIG. As shown in FIG. 3A, the constant flow valve 2 to which the present invention is applied includes a housing 21, a movable valve body 22, an elastic member 23, and a diaphragm 24.

  The housing 21 includes a housing body 217 and a housing lid 218, and an inflow port 211 through which water flows from the upstream fluid passage 11 is formed in the housing lid 218, and a valve seat is formed on the downstream fluid passage 12 side of the housing body 217. 212a is provided to form an outlet 212 through which water flows out. The housing 21 has a valve chamber 215 separated by a movable valve body 22 and a diaphragm 24 into a first chamber 213 and a second chamber 214. In FIG. 3A, the housing 21 has a housing groove 21 a formed by a housing body 217 and a housing lid 218. The housing 21 is not limited to the one having the housing main body 217 and the housing lid 218, and may be integrally formed by one member. The housing body 217 may be provided with an auxiliary hole (not shown) that allows the second chamber 214 and the downstream fluid passage 12 to communicate with each other so that the fluid flows directly from the second chamber 214 to the downstream fluid passage 12. It is.

  In FIG. 3B, the inflow port 211 is provided by opening a part of the housing lid 218. Further, in FIG. 3A, the inflow port 211 and the outflow port 212 are provided so as to be arranged on substantially the same straight line with respect to the flow direction S of the pipe line 1, but not limited thereto, You may provide so that it may mutually eccentrically arrange with respect to the flow direction S of the pipe line 1. FIG.

  The movable valve body 22 includes a valve body main body 221 having a valve body upper surface 221a on the first chamber 213 side and a valve body lower surface 221b on the second chamber 214 side, a valve portion 222 loosely fitted on the valve seat 212a, And a valve body hollow portion 226 opened in the second chamber 214. The movable valve body 22 is movably supported in the valve chamber 215 by the elastic member 23 and the diaphragm 24. The valve portion 222 is not limited to be loosely fitted to the valve seat 212a, and may have a shape that can contact the valve seat 212a as shown in FIG. Further, the movable valve body 22 may have any shape, and may be a needle type, a spherical type, a flat plate type, a rod type, a trumpet type poppet valve or the like.

  The valve body body 221 has a first hole 223 that communicates with the first chamber 213 and the second chamber 214. The valve body main body 221 is formed in the valve body main body groove 221d on the valve body side 221c of the valve body main body 221 that continues from the valve body upper surface 221a on the first chamber 213 side to the valve body lower surface 221b on the second chamber 214 side. Have The valve portion 222 has a second hole 224 that communicates from the second chamber 214 toward the outflow port 212. In FIG. 3A, the first hole 223 and the second hole 224 are formed so as to be arranged on substantially the same straight line with respect to the flow direction S of the pipe line 1. The gap 212b is formed by the valve portion 222 and the valve seat 212a. In the valve body hollow part 226, as shown in FIG. 3A, a barrier 225 may be provided between the first hole 223 and the second hole 224. Although the valve body main part 221, the valve part 222, and the valve body hollow part 226 are integrally formed by one member, it is not limited to this, and may be a combination of a plurality of members.

  A coil spring or the like is used for the elastic member 23. The elastic member 23 is provided between the housing body 217 and the movable valve body 22, and one end of the elastic member 23 is in contact with the valve body lower surface 221 b of the valve body body 221, and the movable valve body 22 faces the upstream fluid passage 11. Is energized. The diaphragm 24 is disposed between the housing groove 21a and the valve body main body groove 221d.

  FIG. 4A is a cross-sectional view of the flow direction S of the pipe line 1 in one embodiment of the constant flow valve 2 to which the present invention is applied. FIG. 4B is a plan view from the upstream fluid passage 11 in the constant flow valve 2. In FIG. 4A, the first hole 223 and the second hole 224 are formed so as to be eccentric with respect to the flow direction S of the pipe line 1. The barrier 225 can be provided regardless of the arrangement of the first hole 223 and the second hole 224.

  The flow rate of the fluid flowing through the pipe line 1 is adjusted by passing through the constant flow valve 2. Specifically, in FIG. 3A, the fluid first flows into the first chamber 213 from the upstream fluid passage 11 via the inflow port 211, and then the first hole 223 of the valve body main body 221. It flows into the second chamber 214 via the valve body hollow portion 226. Furthermore, the fluid that has flowed into the second chamber 214 flows out to the downstream fluid passage 12 through the second hole 224 or the gap 212b.

When the fluid flowing in the pipe line 1 flows into the first chamber 213 through the inflow port 211, a pressure loss a due to the contracted flow is generated in the inflow port 211. The valve body upper surface 221a of the valve body main body 221 is pressed by the pressure P ₁ which is reduced by the pressure loss a due to the contracted flow.

When the fluid flowing into the pipe line 1 flows into the second chamber 214 via the first hole 223 and the valve body hollow portion 226, the first hole 223 from the first chamber 213 and the valve body from the first hole 223. A pressure loss b due to the contraction flow is generated from the hollow portion 226 and the valve body hollow portion 226 to the second chamber 214. Further, as shown in FIG. 3A, a barrier 225 is provided in the valve body hollow portion 226, and as shown in FIG. 4A, the first hole 223 and the second hole 224 are deviated from each other. Since the flow direction of the fluid is complicated by being arranged as a core, the fluid also generates a pressure loss c due to the contraction flow. Further, when the elastic member 23 such as a coil spring is disposed in the second chamber 214, the fluid similarly generates a pressure loss d due to contraction. The valve body lower surface 221b of the valve body main body 221 is pressed by the pressure P ₂ that is reduced by the pressure loss b to d due to these contraction flows, and is urged by the urging force Fs of the elastic member 23 such as a coil spring. . In the present embodiment, the fluid passage area in the first hole 223 is constant regardless of the fluid pressure, but the present invention is not limited to this.

The movable valve body 22 is supported so as to be movable in the flow direction S by a diaphragm 24 made of resin, rubber or the like. The movable valve body 22, by the pressing of the valve body top surface 221a by the pressure P _1, is pushed into the second chamber 214 side. By this pushing, the movable valve body 22 moves to the second chamber 214 side, and the urging force Fs such as a coil spring increases as the amount of movement increases. Thereby, the movable valve body 22 moves to the second chamber 214 side to a position where the pressure P ₂ and the urging force Fs and the pressure P ₁ are balanced. The movement in the second chamber 214 side of the movable valve body 22, close the valve portion 222 on the valve seat 212a, since the gap 212b is narrowed, the greater the pressure P _1, the gap 212b becomes narrower.

  In the constant flow valve 2 to which the present invention is applied, the second hole 224 is formed in the valve portion 222, and the second hole 224 is always communicated from the second chamber 214 toward the outlet 212. Even when 212b is significantly narrowed, a predetermined flow rate can be secured in the downstream fluid passage 12 close to the constant flow valve 2 through the second hole 224.

The movable valve body 22 can directly receive the pressure P ₂ of the fluid in the second chamber 214 at the valve body lower surface 221 b of the valve body main body 221. Since the flow rate of the fluid in the second chamber 214 is slower than the flow rate of the fluid in the first hole 223 or the second hole 224, it is possible to avoid the pressure P _{2 from} being excessively reduced due to the influence of the viscosity of the fluid. it can. Moreover, the barrier 225 is provided in the valve body hollow part 226, or the first hole 223 and the second hole 224 are arranged eccentric to each other, thereby complicating the direction of fluid flow. Also by this, the flow velocity of the fluid in the second chamber 214 is decreased, and it is possible to avoid the pressure P _{2 from} being excessively decreased due to the influence of the viscosity of the fluid. Accordingly, the constant flow valve 2 to which the present invention is applied can control the gap 212b with high accuracy.

As shown in FIGS. 3A and 3C, the fluid pressure in the first chamber 213 is P ₁ , the fluid pressure in the second chamber 214 is P ₂ , and the fluid pressure that has passed through the valve seat 212a is P ₃ . The effective pressure receiving diameter area of the valve body 22 is A _D , the spring load of the coil spring is F _S , the fluid passage sectional area of the first hole 223 is A _O , the fluid passage sectional area of the second hole 224 is A _B , and the outlet 212 a fluid passage area a _S of the (valve seat 212a), the fluid passage effective area of the gap 212b of the valve portion 222 and the valve seat 212a and a _v, the following relation by a factor α is (5) to (8) holds .

となる。 The flow rate Q ₃₁ in the downstream fluid passage 12 in the pressure loss characteristic region of the constant flow valve 2 shown in FIG. 3 and FIG.

It becomes.

となり、Ｐ₃＝０とすると、

となる。 Further, in the flow rate control region, the relational expression for the constant flow valve 2 shown in FIG.

If P ₃ = 0, then

It becomes.

となる。 The flow rate Q ₃₂ in the downstream fluid passage 12 in the flow control region of the constant flow valve 2 shown in FIG. 3 and FIG.

It becomes.

Compared with equation (4), equation (8) has an increasing term. Since both the increase term and the decrease term depend on P ₁ , a small increase term is generated for a small decrease term when the pressure P ₁ is small, and a large increase term is generated for a large decrease term when the pressure P ₁ is large. . Therefore, the increase term acts in a direction to suppress the flow rate decrease in accordance with the size of the decrease term, and the constant flow valve 2 to which the present invention shown in FIGS. 3 and 4 is applied has an excessive flow rate decrease in the flow rate control region. It can be seen that this can be suppressed.

Further, an expression for subtracting the square of Q ₂₁ from the square of Q ₃₁ is expressed as Expression (9) from Expression (1) and Expression (5).

The value obtained by subtracting the square of the Q ₂₁ from the square of the Q _31, since it becomes a positive value as shown in equation (9), the constant flow valve according to the present invention shown in FIGS. 3 and 4 2 shows that the pressure loss is smaller than that of the constant flow valve 2a shown in FIG. Therefore, the constant flow valve 2 to which the present invention shown in FIGS. 3 and 4 is applied can obtain a predetermined flow rate even if the housing body 217 is made small, and the constant flow valve 2 itself can be made compact. .

In order to avoid the narrowing of the gap 212b, a method of setting the repulsive force of the elastic member 23 such as a coil spring high is also conceivable. However, if the repulsive force of the elastic member 23 is set high, the movable valve body 22 cannot be pushed when the pressure P ₁ is low under low pressure, and the flow rate of the fluid cannot be reduced sufficiently. There is. Although also conceivable to set a large effective pressure receiving diameter area A _d, constant flow valve 2a According to this method generally will be large, and that the problem of limitations such as cost increase and layout is generated Become. Since the constant flow valve 2 of the present invention can ensure a predetermined flow rate under high pressure by the second hole 224, it is not necessary to set the repulsive force of the elastic member 23 high, and the enlargement of the constant flow valve 2a is avoided. Thus, the flow rate can be sufficiently adjusted even under a low pressure.

As shown in FIG. 3A, the constant flow valve 2 to which the present invention is applied has a flow rate in order to ensure a predetermined flow rate by combining the fluid through the second hole 224 and the fluid through the gap 212b. Even if the outlet 212 is enlarged, the flow rate from the gap 212b decreases as the pressure increases, and at the same time, the flow rate from the second hole 224 increases, that is, the flow rate can be accurately controlled. Thus eliminating the need of a large effective pressure-receiving diameter area A _d in order to reduce the impact of lower terms in equation (8). Therefore, it is possible to reduce the housing body 217 to form an effective pressure-receiving diameter area A _d, it can be made compact constant flow valve 2 itself. In addition, the constant flow valve 2 to which the present invention is applied always communicates with the second hole 224 from the second chamber 214 toward the outflow port 212, and therefore, compared with the constant flow valve 2 a through only the gap 212 b. The pressure loss can be reduced. Furthermore, the valve body main part 221, the valve part 222, and the valve body hollow part 226 are integrally formed by one member, so that the constant flow valve 2 can be formed as compared with the case where these are formed by a plurality of members. The number of parts can be reduced, and a compact constant flow valve 2 that is less likely to break can be manufactured at low cost.

  FIG. 5 shows that the fluid pressure flows out into the downstream fluid passage 12 on the horizontal axis in the constant flow valve 2a shown in FIG. 2 and the constant flow valve 2 to which the present invention shown in FIGS. 3 and 4 is applied. It is a pressure flow figure showing the relation between pressure and flow volume on the vertical axis of fluid flow. As shown in FIG. 5, the constant flow valve 2 a shown in FIG. 2 increases in pressure from 0 to U ′. However, if the pressure increases beyond U ′, the movable valve body 22 is pushed and the gap 212b is narrowed, so that the flow rate is reduced, and a predetermined flow rate cannot be secured under high pressure, resulting in a significant flow rate drop. It cannot be suppressed.

As shown in FIG. 5, in the constant flow valve 2 to which the present invention is applied, the pressure increases from 0, and the flow rate increases until the elastic member 23 starts moving from the initial position. Next, when the pressure increases beyond U, the movable valve body 22 is pushed to narrow the gap 212b, and the flow rate starts to decrease until R when the valve portion 222 contacts the valve seat 212a and the gap 212b disappears. Since the increase term shown in the equation (8) also acts between the U and R, the amount of decrease in Q ₃₂ at high pressure is suppressed and accuracy compared with the conventional constant flow valve 2a shown in FIG. The flow rate is well controlled. Furthermore, when the pressure increases beyond R, the fluid flows through the second hole 224, so the flow rate increases. Even in the case where the pressure is higher than R, the constant flow valve 2 to which the present invention is applied can always ensure a predetermined flow rate by forming the second hole 224 and suppress a significant flow rate decrease. be able to. Further, it can be seen that the constant flow valve 2 to which the present invention is applied is small in size and compact as compared with the conventional constant flow valve 2a having the same flow rate adjusting function.

  In the constant flow valve 2 to which the present invention is applied, the second hole 224 is integrally provided in the valve portion 222, so that for the first time, the pressure loss is suppressed, the flow rate decrease at a high pressure is suppressed, and the constant flow valve 2 is prevented from being enlarged. The problem was solved simultaneously in principle. Furthermore, the constant flow valve 2 to which the present invention is applied goes beyond the original purpose of avoiding an increase in the size of the constant flow valve 2 and realizing suppression of pressure loss and reduction of flow rate at high pressure. While achieving downsizing, the performance improvement that surpasses the conventional technology was achieved at the same time without increasing the number of parts.

  The present invention is not limited to the above-described embodiment. For example, another embodiment of the constant flow valve 2 to which the present invention is applied as shown in FIG. 6 may be applied.

  In the constant flow valve 2 shown in FIG. 6A, the point that the second hole 224 formed in the valve portion 222 communicates the first chamber 213 and the outlet 212 is shown in FIGS. This is different from the constant flow valve 2 to be operated. Further, the movable valve body 22 is not provided with a portion corresponding to the valve body hollow portion 226. Therefore, the part from which the said structure differs is demonstrated in detail, about the element similar to the constant flow valve 2 shown by FIG.3 and FIG.4, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  In the constant flow valve 2 shown in FIG. 6A, the second hole 224 and the outlet 212 formed in the valve portion 222 are provided on substantially the same straight line in the flow direction S of the pipe line 1. Therefore, in the constant flow valve 2 shown in FIG. 6, the fluid flowing into the first chamber 213 flows into the second chamber 214 through the first hole 223, and further flows into the downstream fluid passage 12 through the gap 212b. To the downstream fluid passage 12 through the second hole 224. The constant flow valve 2 shown in FIG. 6 may be a movable valve body 22 provided with a valve portion 222 that is loosely fitted to the outflow port 212.

As shown in FIG. 6A and a cross-sectional view for explaining the control flow rate in the constant flow valve 2, the fluid pressure in the first chamber 213 is P ₁ , and the fluid pressure in the second chamber 214 is P ₂ , the fluid pressure passing through the valve seat 212 a is P ₃ , the effective pressure receiving diameter area of the movable valve body 22 is A _D , the spring load of the coil spring is F _S , the fluid passage sectional area of the first hole 223 is A _O , fluid passage cross-sectional area of the a _B 2 hole 224, the fluid passage area a _S of the outlet 212 (valve seat 212a), the fluid passage effective area of the gap 212b of the valve portion 222 and the valve seat 212a and a _v, the coefficient The following relational expressions (10) to (13) are established by α.

となる。 The flow rate Q ₆₁ in the downstream fluid passage 12 in the pressure loss characteristic region of the constant flow valve 2 shown in FIG.

It becomes.

となり、Ｐ₃＝０とすると、

となる。 In the flow rate control region, the relational expression for the constant flow valve 2 shown in FIG.

If P ₃ = 0, then

It becomes.

となる。 The flow rate Q ₆₂ in the downstream fluid passage 12 in the flow control region of the constant flow valve 2 shown in FIG.

It becomes.

Compared to equation (4), equation (13) has an increasing term. Since both the increase term and the decrease term depend on P ₁ , a small increase term is generated for a small decrease term when the pressure P ₁ is small, and a large increase term is generated for a large decrease term when the pressure P ₁ is large. . Therefore, the increase term acts in the direction of suppressing the flow rate decrease according to the size of the decrease term, and the constant flow valve 2 to which the present invention shown in FIG. 6 is applied suppresses the excessive flow rate decrease in the flow rate control region. You can see that

Also, the equation for subtracting the square of Q ₂₁ from the square of Q ₆₁ is as shown in equation (14) from equations (1) and (10).

Since the value obtained by subtracting the square of Q ₂₁ from the square of Q ₆₁ is a positive value as shown in Expression (14), the constant flow valve 2 to which the present invention shown in FIG. It can be seen that the pressure loss is small compared to the constant flow valve 2a shown in FIG. Therefore, the constant flow valve 2 to which the present invention shown in FIG. 6 is applied can obtain a predetermined flow rate even if the housing body 217 is made small, and the constant flow valve 2 itself can be made compact.

As a result, even when the movable valve body 22 approaches the outlet 212 under high pressure and the gap 212b is significantly narrowed, the fluid can flow from the outlet 212 through the second hole 224. A predetermined flow rate can be secured in the downstream fluid passage 12 adjacent to the flow valve 2. In addition, since the fluid flows from the outlet 212 through the second hole 224, a sufficient flow rate can be ensured even under a low pressure. Even if the outlet 212 is enlarged, the gap increases as the pressure increases. At the same time as the flow rate from 212b decreases, the flow rate from the second hole 224 increases, that is, the flow rate can be accurately controlled. Thus eliminating the need of a large effective pressure-receiving diameter area A _d in order to reduce the effect of decreasing term in Equation (13). Therefore, it is possible to reduce the housing body 217 to form an effective pressure-receiving diameter area A _d, it can be made compact constant flow valve 2 itself.

  7 shows the constant flow valve 2a shown in FIG. 2 and the constant flow valve 2 to which the present invention is applied shown in FIG. It is a pressure flow chart showing the relation between pressure and flow rate with the flow rate as the vertical axis. As shown in FIG. 7, the constant flow valve 2a shown in FIG. 2 increases in pressure from 0 to U ′. However, if the pressure increases beyond U ′, the movable valve body 22 is pushed and the gap 212b is narrowed, so that the flow rate is reduced. Therefore, the predetermined flow rate cannot be secured, and a significant decrease in the flow rate is suppressed. I can't.

As shown in FIG. 7, in the constant flow valve 2 to which the present invention is applied, the pressure increases from 0, and the flow rate increases until the elastic member 23 starts moving from the initial position. Next, when the pressure increases beyond U, the movable valve body 22 is pushed, the gap 212b is narrowed, and the flow rate starts to decrease until R disappears. Since the increase term shown in Equation (13) also acts between U and R, the amount of decrease in Q ₆₂ at high pressure is suppressed and accuracy is higher than in the conventional constant flow valve 2a shown in FIG. The flow rate is well controlled. Furthermore, when the pressure increases beyond R, the fluid flows through the second hole 224, so the flow rate increases. Even in the case where the pressure is higher than R, the constant flow valve 2 to which the present invention is applied can always ensure a predetermined flow rate by forming the second hole 224 and suppress a significant flow rate decrease. be able to. Further, it can be seen that the constant flow valve 2 to which the present invention is applied is small in size and compact as compared with the conventional constant flow valve 2a having the same flow rate adjusting function.

1 Pipeline 11 Upstream fluid passage 12 Downstream fluid passage 13 Flow direction 2 (2a) Constant flow valve 21 Housing 21a Housing groove 211 Inlet 212 Outlet 212a Valve seat 212b Gap 213 First chamber 214 Second chamber 215 Valve chamber 217 Housing body 218 Housing cover 22 Movable valve body 221 Valve body body 221a Valve body upper surface 221b Valve body lower surface 221c Valve body side surface 221d Valve body body groove 222 Valve portion 223 First hole 224 Second hole 225 Barrier body 226 Valve body hollow Part 23 Elastic member 24 Diaphragm 3 Water supply system 4 Water supply apparatus

Claims (4)

A first chamber formed by a first housing having an inflow port through which fluid flows from an upstream fluid passage, a diaphragm, and a movable valve body attached integrally to the diaphragm;
A second housing formed by a second housing having an outlet communicating with a downstream fluid passage, the diaphragm, and the movable valve body;
A first hole that communicates the first chamber and the second chamber, and causes a pressure difference between the first chamber and the second chamber by passing a fluid;
A valve seat provided facing a passage communicating the second chamber and the outlet, and corresponding to a valve portion provided in the movable valve body;
A biasing means for biasing the movable valve body with a predetermined elastic force in a direction in which the valve portion and the valve seat open;
In a constant flow valve for controlling the flow rate of the fluid flowing through the downstream fluid passage with a predetermined flow rate,
The valve unit has a shape capable of coming into contact with the valve seat, and is formed with a second hole through which fluid flows from the second chamber to the outlet. 2. The constant flow valve according to claim 1, wherein the second hole is formed on substantially the same straight line with respect to the flow direction of the first hole and the fluid. 2. The constant flow valve according to claim 1, wherein the second hole is formed eccentrically with respect to the fluid flow direction of the first hole. The said movable valve body has a barrier provided on the substantially same straight line with respect to the flow direction of a fluid between the said 1st hole and the said 2nd hole, The any one of Claims 1-3 characterized by the above-mentioned. The constant flow valve according to item 1.

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