JP2010060000A - Constant-flow valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constant-flow valve which is compact and equipped with a simple structure and moreover suppresses overshoot in low-pressure range and cavitation in high-pressure range. <P>SOLUTION: The constant-flow valve, which comprises: an outer-side valve member changing a cross-sectional area of a first channel formed, in a space with an inner-circumferential section of constant flow valve body; an inner-side valve member which is arranged slidably in the inside of the outer-side valve member, and changes a cross-sectional area of a second channel formed between a periphery and an inner-circumferential section of the outer-side valve member; an outer-side coil spring which slides the outer-side valve member when a hydraulic pressure is applied to the outer-side valve member, and contracts so that the cross-sectional area of the first channel is reduced; and an inner-side coil spring which slides the inner-side valve member when the hydraulic pressure is applied to the inner-side valve member, and contracts so that the cross-sectional area of the second channel may be reduced, wherein a spring constant of the inner-side coil spring is larger than the spring constant of the outer-side coil spring, and the outer-side coil spring becomes larger in the spring constant, as the outer-side valve member moves. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a constant flow valve, and more particularly to a constant flow valve that adjusts the flow rate of water to flow out regardless of fluctuations in the pressure of supplied water.

2. Description of the Related Art Conventionally, a constant flow valve that adjusts the flow rate of cleaning water to a predetermined amount regardless of fluctuations in the supply water pressure from a water supply source has been used in a cleaning water supply path or the like in a direct water pressure toilet.
As such a conventional constant flow valve, for example, as described in Patent Document 1, a plurality of movable valve bodies are connected in series to a fixed valve body fixed in a constant flow valve body extending in a cylindrical shape. As for the opening and closing of each movable valve body, a spring constant attached to each movable valve body is adjusted by the elastic force of a different coil spring.

  However, in the conventional constant flow valve described in Patent Document 1, since a plurality of movable valve bodies are arranged in series along the longitudinal direction in the constant flow valve main body, an operation space is required and narrow. It is difficult to use in a limited space, which is a factor that hinders the downsizing of the constant flow valve. Therefore, downsizing of the constant flow valve has been conventionally demanded.

  Also, as described in Patent Document 2, a constant flow valve using a conical coil spring and utilizing the non-linear spring characteristic of this spring is also known, but the conical coil spring used in this constant flow valve is known. Since manufacturing requires high dimensional accuracy and shape accuracy, the yield is poor and the manufacturing cost is increased. Therefore, a constant flow valve having a simple structure with a low cost has been conventionally demanded.

In order to meet the above request, the present applicant has proposed a constant flow valve having a small and simple structure (Patent Document 3).
The constant flow valve shown in Patent Document 3 is a constant flow valve that adjusts the flow rate of water to flow out to a predetermined amount regardless of fluctuations in the pressure of supplied water, and is a constant flow valve in which an inlet and an outlet are formed. The flow valve main body is disposed inside the flow valve main body so as to be slidable with respect to the constant flow valve main body, and is formed between the outer peripheral portion and the inner peripheral portion of the constant flow valve main body by the sliding. An outer valve member that changes a cross-sectional area of the first flow path, and an inner side of the outer valve member that is slidable with respect to the outer valve member. An inner valve member that changes the cross-sectional area of the second flow path formed between the inner peripheral portion, the constant flow valve main body, and the outer valve member are disposed between the inner valve member and the outer valve member in the axial direction. When urging is performed and water pressure acts on the outer valve member, the outer valve member is slid, and the cross-sectional area of the first flow path is reduced. An outer coil spring that shrinks to a minimum, and an inner valve member that is disposed between the outer valve member and the inner valve member, urges the inner valve member in an axial direction, and water pressure acts on the inner valve member. It is comprised by the inner coil spring which slides a member and shrinks so that the cross-sectional area of the said 2nd flow path may be reduced.
In the constant flow valve in Patent Document 3, the outer valve member and the inner valve member that are slidably disposed on the flow valve main body do not operate when the pressure of supplied water is extremely small. As the pressure increases, a differential pressure is generated between the inlet and the outlet, and the outer valve member urged by the outer coil spring having a small spring constant slides first due to the differential pressure. However, since the cross-sectional area of the first flow path is larger than the water pressure at the initial stage of sliding, a sufficient differential pressure cannot be obtained, and the spring force of the outer coil spring is larger than the differential pressure. The sliding of the outer valve member is extremely small. Until the water pressure rises and the spring force and the differential pressure of the outer coil spring become equal, the sliding of the outer valve member is extremely small, so that the cross-sectional area of the first flow path is extremely reduced, so that the first flow The flow rate through the cross-sectional area of the road increases with the water pressure. When the water pressure is increased stepwise until a differential pressure is generated in the cross-sectional area of the first flow path, the differential pressure and the spring force of the outer coil spring antagonize at a certain water pressure. When the water pressure is further increased, the generated differential pressure becomes larger than the spring force of the outer coil spring, the outer valve member slides under the differential pressure, and the cross-sectional area of the first flow path is also reduced. Since the cross-sectional area of the first flow path is reduced, the differential pressure is further increased, and the outer valve member is further slid by receiving the differential pressure, so that the outer cross-sectional area is reduced, so the flow rate through the cross-sectional area is The outer coil spring contracts rapidly and decreases rapidly. As a result, the outer valve member closes rapidly, and overshoot and undershoot occur.
Further, in the constant flow valve, when the water pressure is increased in a state where the outer valve member is completely closed, the differential pressure becomes larger than the spring force of the inner coil spring urging the inner valve member, The inner valve member slides. In the inner valve member, cavitation is induced by a jet generated from the second flow path at a certain water pressure, and the inner valve member may vibrate or generate abnormal noise.

Japanese Utility Model Publication No. 61-40569 JP-A-6-331051 WO 2006/100383 gazette

  Therefore, the present invention is a constant flow valve having a small and simple structure, and can suppress overshoot and undershoot in a low pressure region, and can suppress the occurrence of cavitation in a high pressure region. The object is to provide a constant flow valve.

  In order to solve the above problems, the present invention is a constant flow valve that adjusts the flow rate of water to flow out to a predetermined amount regardless of fluctuations in the pressure of supplied water, and has an inlet and an outlet. The constant flow valve main body is disposed inside the flow valve main body so as to be slidable with respect to the constant flow valve main body. By this sliding, between the outer peripheral portion and the inner peripheral portion of the constant flow valve main body. An outer valve member that changes a cross-sectional area of the formed first flow path, and an outer valve member that is slidably disposed with respect to the outer valve member inside the outer valve member. An inner valve member that changes a cross-sectional area of the second flow path formed between the inner peripheral portion of the member, the constant flow valve main body, and the outer valve member; When the water pressure acts on the outer valve member, the outer valve member is slid to interrupt the first flow path. An outer coil spring that contracts to reduce the product, and is disposed between the outer valve member and the inner valve member, urges the inner valve member in the axial direction, and water pressure acts on the inner valve member. In the constant flow valve constituted by the inner coil spring that slides the inner valve member and contracts so as to reduce the cross-sectional area of the second flow path, the spring constant of the inner coil spring is greater than the spring constant of the outer coil spring. The outer coil spring is constituted by a single spring whose spring constant increases with the movement of the outer valve member.

  In the constant flow valve of the present invention configured as described above, the outer valve member and the inner valve member that are slidably disposed on the flow valve body operate in a state where the pressure of supplied water is extremely small. However, as the water pressure increases, a differential pressure is generated between the inlet and the outlet, and the outer valve member biased by the outer coil spring having a small spring constant is received by the differential pressure. Slide in one. Since the outer coil spring is a spring whose spring constant increases with the movement of the outer valve member, the outer valve member slides to reduce the cross-sectional area of the first flow path and greatly increase the differential pressure. Even if a force acts in the direction in which the member is further slid, the outer coil spring contracts following the sliding of the outer valve member, and the spring constant changes so that the outer constant is increased. The resistance against sliding in the direction in which the valve member suddenly closes can be prevented, and the sudden closing of the outer valve member can be prevented, thereby preventing the occurrence of overshoot and undershoot.

The outer coil spring is a coil spring wound at an unequal pitch in the moving direction of the outer valve member.
Since the spring constant is changed by making the winding pitch unequal, the manufacture of the spring is relatively simple and the diameter of the spring is constant, so the diameter of the storage space of the outer coil spring is constant. However, the constant flow valve structure can be simplified and miniaturized.

  Further, in the present invention, a constant flow valve for adjusting the flow rate of water to flow out to a predetermined amount regardless of fluctuations in the pressure of the supplied water, the constant flow valve main body having an inlet and an outlet formed therein, The first flow formed between the outer peripheral portion and the inner peripheral portion of the constant flow valve main body is arranged inside the flow valve main body so as to be slidable with respect to the constant flow valve main body. An outer valve member that changes a cross-sectional area of the passage; and an outer valve member disposed inside the outer valve member so as to be slidable with respect to the outer valve member. An inner valve member that changes a cross-sectional area of the second flow path formed between the constant flow valve body and the outer valve member, and biases the outer valve member in the axial direction, When water pressure acts on the outer valve member, the outer valve member is slid to reduce the cross-sectional area of the first flow path. An outer coil spring that is contracted in such a manner that the inner valve member is disposed between the outer valve member and the inner valve member, biases the inner valve member in the axial direction, and water pressure acts on the inner valve member. In the constant flow valve constituted by an inner coil spring that slides and contracts so as to reduce the cross-sectional area of the second flow path, the outer valve member has an arch portion that extends across the outer valve member; A support projection formed in a tubular shape so as to support the inner valve member so as to be slidable in the axial direction, and the inner valve member has an inner periphery in the tubular shape of the support projection. And the annular recessed part is formed in both surfaces of outer periphery so that an opposing wall surface may be comprised, It is characterized by the above-mentioned.

  As a result, when the support protrusion slides in the recess of the inner valve member, the water contained in the cylindrical shape of the support protrusion is caused by the entry of the inner valve member into the support protrusion. And the outer peripheral wall surface of the inner valve member, the outer peripheral wall surface of the support protrusion, and the outer annular wall surface of the inner valve member. At that time, due to the viscous resistance of each wall surface and water, a large resistance is given in the direction opposite to the sliding direction of the inner valve member, which can serve as a damper, and the inner valve due to the jet generated from the second flow path. Induction of cavitation of the member can be suppressed, and the inner valve member can be prevented from vibrating or generating abnormal noise.

  According to the present invention, there is provided a small and simple structure that adjusts the flow rate of water to be discharged to a predetermined amount regardless of fluctuations in the pressure of supplied water, and suppresses overshoot and undershoot in a low pressure region. In addition, it is possible to provide a constant flow valve that can suppress the occurrence of cavitation in a high pressure region.

Hereinafter, embodiments of the constant flow valve of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is an exploded perspective view showing a constant flow valve according to the first embodiment of the present invention, and FIG. 2 is a perspective view showing the constant flow valve according to the first embodiment of the present invention.
As shown in FIGS. 1 and 2, the constant flow valve 1 of the present embodiment includes a casing 2 that forms a substantially cylindrical constant flow valve main body, and an outer compression not as an outer coil spring accommodated in the casing 2. An equal pitch coil spring 4, an outer valve member 6, an inner compression coil spring 8 as an inner coil spring, an inner valve member 10, and a lid 12 attached to the upstream end of the casing 2.
The lid 12 attached to the upstream end of the casing 2 is formed with an inlet 12 a of the constant flow valve 1, and the outlet 2 a of the constant flow valve 1 is formed at the downstream end of the casing 2. Yes.

3 is a cross-sectional view taken along the line II of the constant flow valve according to the first embodiment of the present invention shown in FIG. 2, and FIG. 4 is a cross-sectional view of the constant flow valve according to the first embodiment of the present invention shown in FIG. It is II sectional drawing. Here, in FIG. 3, the flow of water in the constant flow valve 1 is indicated by arrows.
As shown in FIGS. 1 to 4, the outer valve member 6 is slidably disposed in the casing 2 in the axial direction, and the inner valve member 10 slides in the axial direction inside the outer valve member 6. Arranged to be possible.
The outer valve member 6 receives the pressure of water flowing into the casing 2 from the inlet 12 a by the pressure receiving portion 6 a at the upstream end of the outer valve member 6 and the pressure receiving portion 10 c at the upstream end of the inner valve member 10. The slider slides in the axially downstream side in accordance with the water pressure received by the pressure receiving portion 6a.
Moreover, as shown in FIG. 1, the valve body part 6b which is the principal part of the outer side valve member 6 is formed in the shape restrict | squeezed relatively toward the downstream from the upstream.
Further, as shown in FIG. 4, an outer variable flow path 14 is formed as a first flow path between the outer peripheral portion of the valve body 6 b and the outlet 2 a of the casing 2, and the outer valve member 6 is By sliding in the axial direction, the valve body portion 6b variably adjusts the opening degree or flow path cross-sectional area of the outer variable flow path 14. In FIGS. 3 and 4, water flows into the casing 2 from the inlet 12a of the constant flow valve 1 at the time of initial low water pressure, but the outer valve member 6 does not slide in the axial direction and is variable outside. The state where the flow path 14 is opened to the maximum is shown.

Further, an outer compression unequal pitch coil spring 4 is disposed substantially coaxially with the outer valve member 6 between the inner peripheral portion 2 c of the casing 2 and the outer peripheral portion 6 c of the outer valve member 6.
As shown in FIG. 1, the outer compression unequal pitch coil spring 4 is configured such that the winding pitch gradually becomes narrower. Therefore, the outer valve member 6 moves and the unequal pitch coil spring is moved. When 4 is contracted, the spring constant becomes large. The spring load and the contraction of the spring have nonlinear spring characteristics. When the outer valve member 6 is not operated, the inner peripheral portion 2c of the casing 2 and the outer valve member 6 Between the outer peripheral part 6c, it accommodates so that the outer side valve member 6 may be urged | biased to an axial direction. When water flows into the casing 2 from the inlet 12a of the constant flow valve 1, the pressure of this water causes the pressure receiving portion 6a at the upstream end of the outer valve member 6 and the pressure receiving portion 10c at the upstream end of the inner valve member 10. Are pressed in the downstream axial direction. Further, the pressing of the outer valve member 6 and the pressing of the inner valve member 10 press the outer valve member 6 via the inner compression coil spring 8, whereby the upstream end 4 a of the outer compression unequal pitch coil spring 4. It is pressed in the downstream axial direction.
Further, the downstream end portion of the valve body portion 6 b of the outer valve member 6 includes an arch portion 18 that extends so as to cross the outer valve member 6. As the water pressure received by the pressure receiving portion 6a of the outer valve member 6 and the pressure receiving portion 10c at the upstream end of the inner valve member 10 rises, the outer valve member 6 moves downstream and moves outward from the outer valve member 6. As the spring load applied to the upstream end 4a of the compression non-uniform pitch coil spring 4 increases, the step 6d formed on the outer peripheral portion of the valve body 6b of the outer valve member 6 approaches the outlet 2a of the casing 2, Ultimately, the outer variable flow path 14 comes into contact with each other and is completely closed.
Further, the arch portion 18 has leg portions formed at intervals of 90 degrees in the circumferential direction, and the leg portions abut on the inner circumference of the outlet 2 of the casing 2, thereby moving the outer valve member 6. And also serves to rectify the water ejected from the outer variable flow path 14.

The valve body 10a, which is the main part of the inner valve member 10, is formed in a shape that is relatively narrowed from the upstream side toward the downstream side.
Further, an inner variable flow path 16 is formed as a second flow path between the inner peripheral portion 6e of the outer valve member 6 and the valve body portion 10a of the inner valve member 10, and the inner valve member 10 serves as the outer valve. By sliding in the axial direction with respect to the member 6, the valve body portion 10 a variably adjusts the opening degree or flow path cross-sectional area of the inner variable flow path 16. 3 and 4, water flows into the casing 2 from the inlet 12 a of the constant flow valve 1, but the inner valve member 10 does not slide in the axial direction with respect to the outer valve member 6. The state where the variable flow path 16 is opened to the maximum is shown.

An inner compression coil spring 8 is disposed substantially coaxially with the inner valve member 10 between the inner peripheral portion 6 e of the outer valve member 6 and the outer peripheral portion 10 b of the inner valve member 10.
The inner compression coil spring 8 has an average diameter smaller than the coil average diameter of the outer compression unequal pitch coil spring 4, and is arranged coaxially and nested with respect to the outer compression unequal pitch coil spring 4. Further, the inner compression coil spring 8 has a linear spring characteristic, the outer compression unequal pitch coil spring 4 has a non-linear spring characteristic, and is larger than the spring constant of the outer compression unequal pitch coil spring 4. Has a constant. That is, the constant flow valve 1 of the present embodiment is configured to be used in combination by arranging two compression coil springs 4 and 8 having different coil average diameters, spring constants, and spring characteristics in a coaxial and nested manner. ing.

Further, the inner compression coil spring 8 moves the inner valve member 10 in the axial direction between the inner peripheral portion 6e of the outer valve member 6 and the outer peripheral portion 10b of the inner valve member 10 in a state where the inner valve member 10 does not operate. Contained to be energized. When water flows into the casing 2 from the inlet 12a of the constant flow valve 1, the pressure receiving portion 10c at the upstream end of the inner valve member 10 is pressed in the downstream axial direction by the pressure of the water, and this inner valve member. The downstream end 8b of the inner compression coil spring 8 is pressed against the outer valve member 6 in the downstream axial direction by the pressure of 10.
Furthermore, after the outer valve member 6 completely closes the outer variable flow path 14, the inner valve member 10 moves to the downstream side in response to an increase in water pressure received by the pressure receiving portion 10 c of the inner valve member 10, and the inner valve member As the spring load applied to the inner compression coil spring 8 increases from 10, the stepped portion 10 d formed on the outer peripheral portion 10 b of the inner valve member 10 contacts the inner peripheral portion 6 e of the outer valve member 6, and the inner variable flow path 16 is formed. It is closed to a predetermined opening or a channel cross-sectional area.

In the constant flow valve 1 of the above-described embodiment, as an example, when the water pressure difference (differential pressure) P between the inlet 12a and the outlet 2a is approximately 0.15 MPa, the outer valve member 6 is first the most downstream. When the differential pressure P is approximately 1.0 MPa, the outer valve member 6 completely closes the outer variable flow channel 14 in the state where the outer variable flow channel 14 is completely closed. 10 slides on the most downstream side is opened to a minimum inner variable flow path 16, target constant from the lower target flow rate value Q ₀ flow rate Q at the outlet 2a in each case to the upper limit target flow rate value Q ₁ The dimensions and shape of the outer valve member 6 and the inner valve member 10 and the specifications of the outer compression unequal pitch coil spring 4 and the inner compression coil spring 8 are determined so that the flow rate range is 20 L / min to 25 L / min. It has been.

Further, as shown in FIGS. 1 to 3, a support protrusion 22 that supports the inner valve member 10 so as to be slidable in the axial direction is formed at the center of the arch portion 18 of the outer valve member 6.
The support protrusion 22 is formed in a cylindrical shape, and a recess 22a is formed inside.
On the other hand, the inner valve member 10 is formed with a protrusion 20 that slidably receives the support protrusion 22 of the outer valve member 6, and a protrusion protrusion 20b is formed inside the protrusion 20a inside the protrusion 20 as a result. The recess 20a is formed in an annular shape. In a state where the protrusion 20 of the inner valve member 10 is received by the support protrusion 22 of the outer valve member 6, the support protrusion 22 is received in the recess 20 a, and the protrusion protrusion 20 b is received in the recess 22 a of the support protrusion 22. When the inner valve member 10 moves and moves so that the support protrusion 22 is accommodated in the recess 20a, the water present in the recess 22a inside the support protrusion 22 is circular with the inner peripheral wall surface 22c of the support protrusion 22. The outer wall surface 20c of the annular recess 20a, the outer peripheral wall surface 22d of the support protrusion 22 and the outer wall surface 20d of the annular recess 20a go out of the inner valve member. At that time, due to the viscous resistance of each wall surface 20c, 20d, 22c, 22d and water, a large resistance is given in the direction opposite to the sliding direction of the inner valve member 10 and it can serve as a damper, and the water pressure is high. Suppressing induction of cavitation of the inner valve member 10 by a jet generated when the first flow path is closed and water flows only through the second flow path, and the inner valve member vibrates or generates noise. Can be prevented.
Further, the arch portion 18 of the outer valve member 6 includes wing portions 24 that are radially formed in the radial direction, and the wing portions 24 rectify the downstream side of the outer valve member 6, thereby causing disturbance of water flow. The lateral vibration of the outer valve member 6 is prevented.

Next, the operation (action) of the constant flow valve 1 according to the first embodiment of the present invention described above will be described.
FIG. 5 is a characteristic diagram qualitatively showing the relationship between the water pressure and the flow rate and the relationship between the water pressure and the total flow path cross-sectional area in the constant flow valve 1 of the present embodiment. Here, in FIG. 5, the horizontal axis represents the water pressure difference (differential pressure) P between the inlet 12 a and the outlet 2 a, the left vertical axis represents the flow rate Q, and the right vertical axis represents the entire flow path at the outlet 2 a of the constant flow valve 1. The sectional area S is shown, the flow chart is shown by a solid line, and the characteristic chart of the entire flow path sectional area is shown by a broken line.
Moreover, in the diagram of FIG. 5, each operation state of the constant flow valve in operation is represented by O, A, B, C, and D in ascending order of the pressure of water flowing into the constant flow valve.
6 to 9 are cross-sectional views showing the constant flow valves in the operating states A to D of FIG. FIG. 10 is a cross-sectional view showing an operating state D according to the III-III cross section of FIG. 2 in the constant flow valve 1 according to the first embodiment of the present invention.

First, as shown in FIGS. 3 to 5, in the constant flow valve 1 in the operation state O which is an initial state, water flows into the casing 2 from the inlet 12 a of the constant flow valve 1, but the differential pressure P Is in a state where almost no has occurred. In this state, the outer valve member 6 and the inner valve member 10 are located on the most upstream side, and the outer variable flow channel 14 and the inner variable flow channel 16 are opened to the maximum.
Here, in the operating state O in which the outer variable flow channel 14 and the inner variable flow channel 16 are opened to the maximum, the flow rate Q is almost zero because the differential pressure P hardly occurs.
Furthermore, the outer valve member 6 and the inner valve member 10 of the constant flow valve 1 are changed from the operating state O to the operating state A (see FIGS. 5 and 6) and the operating state B as the differential pressure P of the inflowing water increases. (Refer FIG.5 and FIG.7), it act | operates in order of the operation state C (refer FIG.5 and FIG.8) and the operation state D (refer FIG.5 and FIG.9-10).

As shown in FIGS. 5 and 6, in the constant flow valve 1 in the operating state A, the water pressure applied to each of the pressure receiving part 6 a of the outer valve member 6 and the pressure receiving part 10 c of the inner valve member 10 is higher than that in the operating state O. It becomes a state. In this state, the outer compression unequal pitch coil spring 4 is pressed in the downstream axial direction by the pressure receiving portion 6 a of the outer valve member 6 and the pressure receiving portion 10 c of the upstream end of the inner valve member 10, and the inner compression coil spring 8. Is pressed in the downstream axial direction by the pressure receiving portion 10 c of the inner valve member 10. At this time, the outer compression unequal pitch coil spring 4 having a small spring constant contracts more in the axial direction than the inner compression coil spring 8, and the outer compression unequal pitch coil spring 4 is wound at an unequal pitch. Since the spring constant is particularly small in the initial stage of contraction, the outer valve member 6 slides in the downstream axial direction larger than the inner valve member 10 in the casing 2. Moreover, the outer variable flow passage 14 and the inner variable flow passage 16 is open both, the flow rate Q is increased toward the flow rate value Q ₀ of the lower limit target with increasing water pressure, total flow cross-sectional area S is decreasing.

As shown in FIGS. 5 and 7, the constant flow valve 1 in the operating state B has a higher water pressure applied to each of the pressure receiving portion 6 a of the outer valve member 6 and the pressure receiving portion 10 c of the inner valve member 10 than in the operating state A. Further rises. In this state, the outer compression unequal pitch coil spring 4 is further pressed in the downstream axial direction by the pressure receiving portion 6a of the outer valve member 6 and the pressure receiving portion 10c of the upstream end of the inner valve member 10, and the inner compression coil spring. 8 is further pressed in the downstream axial direction by the pressure receiving portion 10 c of the inner valve member 10. At this time, the step portion 6d of the arch portion 18 of the outer valve member 6 contacts the outlet 2a of the casing 2 and the outer variable flow channel 14 is completely closed, but the inner variable flow channel 16 is opened in the operating state A. Slightly closed than the state.
Further, in the intermediate state from the operating state A to B, the flow rate Q is maximized once exceeded the flow rate value Q ₀ of the lower limit target increases with increasing pressure, the subsequent operating state B, the flow rate Q is reduced to fit the target constant flow area close to the flow rate value Q ₀ of goals. On the other hand, the total cross-sectional area S of the channel decreases from the operating state A to B as the water pressure increases. In the middle from the operating state A to B, the spring constant of the outer compression unequal pitch coil spring 4 becomes larger than that during the movement from the operating state O to A, so that the outer valve member 6 is suddenly closed. When the outer valve member 6 is prevented from abruptly closing and overshooting can be suppressed, and the outer coil spring is an equal pitch coil spring and the spring constant is increased. The outer variable flow path 14 is hardly completely closed, and undershoot may occur. However, by using an unequal pitch coil spring, the spring constant increases as the outer valve member closes, so that the undershoot is reduced. Occurrence can be suppressed.

Further, as shown in FIGS. 5 and 8, in the constant flow valve 1 in the operating state C, the water pressure applied to each of the pressure receiving part 6 a of the outer valve member 6 and the pressure receiving part 10 c of the inner valve member 10 is higher than that in the operating state B. Further rises. In this state, the outer compression unequal pitch coil spring 4 does not contract any further, the step 6d of the arch portion 18 of the outer valve member 6 contacts the outlet 2a of the casing 2, and the outer variable flow path 14 is completely closed. The inner compression coil spring 8 is further pressed in the downstream axial direction by the pressure receiving portion 10c of the inner valve member 10 in the state where it is left. At this time, the inner variable flow path 16 is further closed than in the open state of the operating state B.
Further, in the state on the way from the operating state B to C, the flow rate Q slightly increases from the flow rate in the operating state B as the water pressure increases, and once reaches the maximum, but in the operating state C, the flow rate reaches the minimum target. the downward trend toward the flow rate value Q _0. On the other hand, the total cross-sectional area S of the flow path further decreases from the operating state B to C as the water pressure increases.

Next, as shown in FIGS. 5 and 9 to 10, in the constant flow valve 1 in the operation state D, the water pressure applied to each of the pressure receiving portion 6 a of the outer valve member 6 and the pressure receiving portion 10 c of the inner valve member 10 is operated. It becomes a state further elevated than state C. In this state, both the outer compression unequal pitch coil spring 4 and the inner compression coil spring 8 are not further compressed, and the step portion 6d of the arch portion 18 of the outer valve member 6 is in contact with the outlet 2a of the casing 2 to be outside. The variable flow path 14 remains closed.
Further, the inner valve member 10 does not slide further in the downstream axial direction, and the inner variable flow passage 16 is slightly closed from the open state of the operating state C to the minimum opening or flow passage cross-sectional area. It becomes a closed state. That is, the outer valve member 6 and the inner valve member 10 are located on the most downstream side with respect to the casing 2, the outer variable flow channel 14 remains closed, and only the inner variable flow channel 16 is opened to the minimum. And the water flow state is maintained.
Further, in the state on the way from the operating state C to D, the flow rate Q decreases as the water pressure increases, and approaches the lower limit target flow rate value Q ₀ in the operating state D. On the other hand, the total channel cross-sectional area S further decreases as the water pressure increases from the operating state C to D, and the total channel area is minimum in D. Thereafter, even if the water pressure increases from the operating state D, the cross-sectional area S does not change and becomes substantially constant, and further, the water pressure increases and the flow rate increases.

According to the constant flow valve 1 according to the first embodiment of the present invention described above, the outer valve member 6, the inner valve member 10, the outer compression unequal pitch coil spring 4 according to the differential pressure of the water flowing in from the inlet 12 a, a series of operation of the inner compression coil spring 8, the upper limit target flow rate value Q ₁ the flow rate of the water to flow out from the outlet 2a regardless of the variations in the pressure of the water supplied to the constant flow valve 1 from the lower limit target flow rate value Q ₀ It can adjust so that it may become in the target constant flow area which is the range.

  In addition, according to the constant flow valve 1 of the present embodiment, the outer valve member 6 is slidably disposed in the axial direction in the casing 2 forming the constant flow valve body, and the inner valve is disposed inside the outer valve member 6. The member 10 is disposed so as to be slidable in the axial direction. Further, the outer compression unequal pitch coil spring 4 is disposed substantially coaxially with the outer valve member 6 between the inner peripheral portion 2c of the casing 2 and the outer peripheral portion 6c of the outer valve member 6, and the inner compression coil spring 8 is disposed outside. Between the inner peripheral portion 6e of the valve member 6 and the outer peripheral portion 10b of the inner valve member 10, the inner valve member 10 is disposed substantially coaxially. Accordingly, since the plurality of members 4, 6, 8, and 10 are compactly concentrated in a limited space in the casing 2 by using the mutual space, the entire constant flow valve 1 is reduced in size. be able to.

  Furthermore, according to the constant flow valve 1 of the present embodiment, the two linear coil springs 4 and 8 having different coil average diameters and spring constants are arranged almost coaxially and nested, and are used in combination. A constant flow valve with a simple structure can be realized.

  Further, according to the constant flow valve 1 of the present embodiment, the outer valve member 6 includes the arch portion 18 that supports the inner valve member 10 so as to be slidable in the axial direction. Since the inner valve member 10 is inserted into the recess 20, the inner valve member 10 can slide accurately in the axial direction with respect to the outer valve member 6. Further, when the inner valve member 10 slides in the axial direction, vibration in the lateral direction can be prevented, and rapid movement of the inner valve member 10 due to the flow of water can be prevented.

  In the above-described embodiment, the outer coil spring has been described as being wound at an unequal pitch as a configuration in which the spring constant increases with the movement of the outer valve member. It is possible to change the pitch, for example, by using a conical spring wound by changing the diameter at an equal pitch.

It is a disassembled perspective view which shows the constant flow valve by 1st Embodiment of this invention. It is a perspective view which shows the constant flow valve by 1st Embodiment of this invention. It is II sectional drawing of the constant flow valve by 1st Embodiment of this invention shown in FIG. It is II-II sectional drawing of the constant flow valve by 1st Embodiment of this invention shown in FIG. It is the characteristic line figure which showed the relationship between the water pressure and flow volume in the constant flow valve of 1st Embodiment of this invention, and the relationship between a water pressure and all the flow-path cross sections qualitatively, respectively. It is sectional drawing which shows the operating state A of the constant flow valve by 1st Embodiment of this invention. It is sectional drawing which shows the operating state B of the constant flow valve by 1st Embodiment of this invention. It is sectional drawing which shows the operating state C of the constant flow valve by 1st Embodiment of this invention. It is sectional drawing which shows the operating state D of the constant flow valve by 1st Embodiment of this invention. FIG. 3 is a cross-sectional view showing an operating state D along the III-III cross section of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Constant flow valve 2 Casing 4 Outer compression non-uniform pitch coil spring 6 Outer valve member 8 Inner compression coil spring 10 Inner valve member 12 Lid 14 Outer variable flow path 16 Inner variable flow path 18 Arch part 20 Concave 22 Support protrusion 24 Wing part

Claims (3)

A constant flow valve that adjusts the flow rate of water to flow out to a predetermined amount regardless of fluctuations in the pressure of the supplied water, and a constant flow valve body having an inlet and an outlet, and an inner side of the flow valve body Is slidably arranged with respect to the constant flow valve main body, and this sliding changes the cross-sectional area of the first flow path formed between the outer peripheral portion and the inner peripheral portion of the constant flow valve main body. An outer valve member;
The second valve is formed inside the outer valve member so as to be slidable with respect to the outer valve member, and the sliding of the second flow path formed between the outer peripheral portion and the inner peripheral portion of the outer valve member is caused by this sliding. An inner valve member that changes the area;
It is arranged between the constant flow valve main body and the outer valve member, urges the outer valve member in the axial direction, and slides the outer valve member when water pressure acts on the outer valve member, An outer coil spring that shrinks to reduce the cross-sectional area of the flow path;
The second valve is disposed between the outer valve member and the inner valve member, urges the inner valve member in the axial direction, and slides the inner valve member when water pressure acts on the inner valve member. In a constant flow valve constituted by an inner coil spring that shrinks so as to reduce the cross-sectional area of the path, the spring constant of the inner coil spring is larger than the spring constant of the outer coil spring, and the outer coil spring is the outer valve member. A constant flow valve comprising a single spring having a spring constant that increases with movement of the valve.   The constant flow valve according to claim 1, wherein the outer coil spring is a coil spring wound at an unequal pitch in the moving direction of the outer valve member. A constant flow valve that adjusts the flow rate of water to flow out to a predetermined amount regardless of fluctuations in the pressure of the supplied water, and a constant flow valve body having an inlet and an outlet, and an inner side of the flow valve body Is slidably arranged with respect to the constant flow valve main body, and this sliding changes the cross-sectional area of the first flow path formed between the outer peripheral portion and the inner peripheral portion of the constant flow valve main body. An outer valve member;
The second valve is formed inside the outer valve member so as to be slidable with respect to the outer valve member, and the sliding of the second flow path formed between the outer peripheral portion and the inner peripheral portion of the outer valve member is caused by this sliding. An inner valve member that changes the area;
It is arranged between the constant flow valve main body and the outer valve member, urges the outer valve member in the axial direction, and slides the outer valve member when water pressure acts on the outer valve member, An outer coil spring that shrinks to reduce the cross-sectional area of the flow path;
The second valve is disposed between the outer valve member and the inner valve member, urges the inner valve member in the axial direction, and slides the inner valve member when water pressure acts on the inner valve member. In a constant flow valve composed of an inner coil spring that shrinks to reduce the cross-sectional area of the path,
The outer valve member includes an arch extending so as to cross the outer valve member, and a support protrusion formed in the arch so as to support the inner valve member so as to be slidable in the axial direction. A constant flow valve in which the inner valve member is formed with an annular recess so as to constitute opposing wall surfaces on both the inner periphery and the outer periphery of the cylindrical shape of the support protrusion.