JP2591578B2 - Constant flow valve with water temperature compensation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mounted on a supply water side of a water heater or the like so that it can be supplied to the apparatus at a constant flow rate irrespective of fluctuations in the supply pressure, and is capable of controlling the temperature of the supply water. The present invention relates to a constant flow valve having a water temperature correction function for adjusting a water supply amount, and particularly to a constant flow valve using a coil spring made of a shape memory alloy as a heat-sensitive element for water temperature.

[0002]

^2. Description of the Related Art Generally, the supply pressure of tap water supplied to houses varies from 0.3 to 7.0 kg / cm ² . This may be due to regional differences between mountains and valleys, lack of capacity of water supply pipes, demand for supply, and the like. For example, the hot-water supply water heater is provided with a constant flow valve so that there is no problem even if the supply pressure of tap water varies.

[0003] Fig. 4 of Japanese Utility Model Publication No. 4-10450 discloses a general structure of the constant flow valve. In the constant flow valve, the liquid supplied from the liquid inlet 3 into the primary hydraulic chamber 12 between the intermediate portion of the cylindrical valve body 8 and the valve box 2 is indicated by the reference numeral in the drawings of the publication. Then, the liquid flows through the base end chamber 1 and the secondary hydraulic chamber 13 in the cylindrical valve body 8, sequentially flows through the orifice 6 to the liquid outlet 4.

As shown by the solid line in the pressure flow characteristic diagram of FIG. 9, such a constant flow valve is set so that the differential pressure before and after the valve does not reach 1.0 to 1.5 kg / cm ^2. It has been found from experimental results that the flow rate (20 l / min in the figure) is not satisfied. That is, in this case, in the area where the supply pressure of the tap water is 0.3 kg / cm ² , which is the lower limit of the variation, the water heater for hot water cannot be used soundly, and the user will be dissatisfied. .

Conventionally, as means for improving such pressure loss on the low pressure side, a valve diameter is increased, or two valves are provided as shown in JP-B-62-35574. Thus, the passage hole area of the valve section is enlarged to reduce the passage resistance value.

Conventionally, a shape memory alloy (SMA; hereinafter simply referred to as S
As a constant flow valve with water temperature correction using a coiled spring manufactured by MA Co., Ltd., there is one known from JP-A-63-303281. The configuration of the feature is as follows, with the reference numerals in the drawings of the publication. That is, this constant flow valve with water temperature correction is formed by biasing the movable valve body V2 with respect to the fixed valve body V1 in the direction away from the coiled spring 1 made of SMA, and is arranged in an overlapping manner. It has a configuration based on the structure.

[0007]

SUMMARY OF THE INVENTION
In the constant flow valve disclosed in FIG. 4 of Japanese Patent Publication No. -10450, the method of increasing the valve diameter increases the size of the valve housing itself and increases the cost. Also, as disclosed in the above-mentioned Japanese Patent Publication No. 62-35574, the method of providing two valves complicates the valve structure and increases the cost.
However, there were problems such as a small improvement effect.

In the conventional constant flow valve as shown in FIG. 4 of Japanese Utility Model Publication No. 4-10450 and Japanese Patent Publication No. 62-35574, the number of constituent parts is large in the first place, and the shape of the parts is large. Is complicated, and the number of processing steps and assembly steps for manufacturing parts increases, and the cost increases.
An inexpensive constant flow valve could not be supplied. For this reason, there were some places where the expansion of the market did not remain while many fields of use could be expected.

In the constant flow valve with water temperature correction using an SMA coil spring disclosed in Japanese Patent Application Laid-Open No. 63-303281, as described above, the structure is complicated, so that the flow resistance of the fluid is reduced. However, the pressure loss value was high and the cost was high.

Incidentally, the heat exchange capacity of a water heater or the like is finite, and the water supply capacity of a water heater or the like must be maintained. Therefore, stable supply of the fluid pressure on the water supply side and stable supply of the fluid temperature as the supply water are required. In the constant flow valve, the former stable supply of fluid pressure can be performed by a governor function, and the latter stable supply of fluid temperature is handled by a water temperature correction function.

Here, the temperature of the general tap water is as follows:
The temperature difference is about 5 ° C in winter and about 25 ° C in summer, and the temperature difference is 20 ° C. For this reason, when the temperature setting dial of the water heater is adjusted to, for example, winter, overheating occurs in summer, and when adjusted to summer, overheating becomes insufficient in winter, and the temperature fluctuates greatly. Therefore, many of the prior art in the constant flow valve with water temperature correction are:
The base point of the control is set in winter, and the ability to overheat in summer is dealt with by increasing the flow rate of supply water, so that the temperature of hot water is constant throughout the year, and a method of stabilizing supply capacity is considered. Has been taken.

The present invention is based on the same concept. The purpose of the present invention is to not only exert the original pressure regulation function and the water temperature correction function, but also to reduce the above-mentioned pressure loss value. Enables sound use of hot water heaters in low pressure areas where the supply pressure is 0.3 kg / cm ² or less.Also, by simplifying the structure, the number of parts is reduced and the shape of the parts is simplified. An object of the present invention is to provide an inexpensive constant flow valve with water temperature correction at a low cost by greatly improving the number of processing steps and the number of assembly steps.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is provided with a valve body which is installed in a fluid supply channel and which varies a passage hole area of the fluid in accordance with a fluctuation in pressure of the fluid. A constant flow valve with a water temperature correction function in which the passage hole area of the valve body is corrected by an SMA material which is a thermosensitive element corresponding to a change in supply water temperature so that a predetermined flow rate corresponding to the supply water temperature can be obtained. Wherein the valve body is formed by a coil spring that expands and contracts according to the pressure fluctuation of the fluid,
The gap between the windings of the coil spring corresponds to the passage hole area that is variable according to the pressure fluctuation of the fluid, and the passage hole area by the gap between the windings of the coil spring, The spring load characteristic of the coiled spring is set to be non-linear so that the product of the fluid and the square root of the differential pressure of the fluid at the boundary of the coiled spring is substantially constant, and the coiled spring is set at the supply water temperature. S corresponding to the change of
It is configured to be formed of MA material.

[0014]

The coil spring that forms the valve body expands and contracts in accordance with the fluctuation of the pressure of the fluid, and the area of the passage hole due to the gap between the windings is variable according to the fluctuation of the pressure of the fluid. Moreover, the spring load characteristic of the coil spring forming the valve element is a non-linear characteristic in which the product of the area of the passage hole due to the gap between the windings and the square root of the differential pressure of the fluid bordering this is substantially constant. For example, in a low-pressure area where the supply pressure of tap water is 0.3 kg / cm ² or less, the occurrence of fluid passage resistance is small and the pressure loss is very small.

When the water temperature changes, the spring load changes in proportion to the SMA coil spring as the valve body, and the passage hole area due to the gap between the windings also increases and decreases. Water supply also increases and decreases proportionally.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a constant flow valve with water temperature correction according to the present invention will be described below with reference to FIGS. FIG. 1 shows a first embodiment of a constant flow valve with water temperature correction according to the present invention, and is a longitudinal sectional side view showing a state before the start of use, and FIG. 2 is taken along the line AA of FIG. FIG. 3 is a cutaway plan view illustrating a pressure receiving area of a valve housing and the like in cross section, FIG. 3 is a vertical sectional side view showing a stable state of flow control, and FIG. 4 is an enlarged view of a portion B in FIG.

FIGS. 1 to 4 show a first embodiment of the present invention. FIG. 1 shows a state before the start of use of a constant flow valve 10 with water temperature compensation according to the first embodiment. 1
1 is a valve housing, 12 is a flow path, 13 is an inlet, 15 is an outlet, 2
1 is a valve support plate, 23 is a through hole, 25 is a bearing cylinder, 31 is a spring receiving plate, 33 is a guide shaft, 35 is a snap ring, and 41 is an SMA coil spring forming a valve body. The valve housing 11 has an inlet 13 at one end and an outlet 15 at the other end, with the cylindrical body serving as a flow path 12, and a tapered screw 14 provided on the outer circumference on the inlet 13 side and an outer circumference on the outlet 15 side. The taper screw 16 provided is connected to, for example, a water supply pipe of a hot water heater (not shown).

The outlet 15 in the intermediate portion 17 of the valve housing 11
On the side, the valve support plate 21 is divided so that the flow path 12 is divided at right angles.
Are formed. A plurality of through holes 23, 23,... Are formed in the circumferential direction of the valve support plate 21, and a bearing cylinder 25 extending toward the outlet 15 is formed at the center. The bearing hole 26 in the bearing cylinder 25 is
It has an opening on the upper surface. A guide shaft 33 having a disc-shaped spring receiving plate 31 at the upper end is slidably and rotatably assembled in the bearing hole 26, and the lower surface of the spring receiving plate 31 and the upper surface of the valve support plate 21. A conical SMA coil spring 41 forming a valve body is interposed between the valve housing intermediate portion 17 and the step portion 22.

That is, in the conical SMA coil spring 41 forming the valve element, the small-diameter portion side abuts against the lower surface of the spring receiving plate 31, and the large-diameter portion side contacts the step portion 22 on the upper surface of the valve support plate 21. It is in a slightly compressed state in contact with, and a retaining ring 35 is fitted in an annular groove 34 formed at an end of a guide shaft 33 protruding from the bearing cylinder 25 to the outlet 15 side. Thus, a conical SMA that forms a valve body with the spring receiving plate 31 so as to close the flow path 12 is provided in the valve housing 11.
A coil spring 41 is assembled. And the pressure of the tap water flowing from the inlet 13 into the flow path 12, ie,
The primary pressure P1 is determined by the cross section of the guide shaft 33 of the spring receiving plate 31 and the upper surfaces of the windings 43, 43,... Of the conical SMA coil spring 41 forming a valve body (the upper surface of the spring element wire development length). Equivalent).

The pressure receiving area A for controlling the opening and closing of the valve as the constant flow valve 10 has the maximum range of the granular pattern shown in FIG. 2, and the coil spring 41 made of SMA has the shape as shown in FIGS. In addition, since the winding 43 starts to contact from the large diameter side and sequentially shifts to the small diameter side as the displacement amount advances, as shown in FIG. It decreases in a form substantially proportional to the passage hole area S. The constant flow valve 10 responds by detecting a change in water pressure at the pressure receiving area A as described above. Here, the conical SMA coil spring 41 forming the valve body is shown in FIG.
As shown in FIG. 4, each winding 43, 43,... Is spirally formed toward the small diameter side so as to sequentially contact the inside of each large diameter side. It becomes a disk shape.

FIGS. 3 and 4 are longitudinal side views showing a stable state of the flow control. As shown in FIG.
Windings 43, 43, 43, on the small diameter side of the coil spring 41 made of
43 are not in contact with each other, and a gap 45,
45, 45, 45,... This gap 45, 4
The sum of the perimeters of 5, 45, 45,... Becomes the passage hole area S for controlling the fluid at the time of this stable state. In addition, each winding 43, 4
At the contact portions of 3,..., The leakage of the fluid from the contact surface is required to be of such an extent that the function as a constant flow valve can be ensured. Further, the valve support plate 21 has a backup function of the conical SMA coiled spring 41 forming a valve body during the above-described displacement. The fluid pressure changes from the primary pressure P1 to the secondary pressure P2 at the boundary of the conical SMA coil spring 41 forming the valve body.

Incidentally, the flow rate Q of the fluid is generally represented by the following equation.

Q = αSV = αS√ (2g (P1−P2) / r) = αS√ (2g △ P / r) (1) where α is a coefficient, S is a fluid passage area, g is the acceleration of gravity, P1 is the primary pressure, P2 is the secondary pressure, r is the specific gravity of the fluid, V is the fluid velocity, and ΔP = P1−P2.

Since α, g, and r are coefficients and constants, the equation (1) is rearranged to find a condition for controlling the constant flow rate: Q∝S√ △ P (2) As described above, the condition that the flow rate Q is constant is that the passage hole area S
And that the product of the square root (差 P) of the differential pressure at the boundary of the coil spring 41 forming the valve body becomes constant.

The balance between ΔP at one point of ΔP which changes continuously and the coil spring 41 forming the valve element is expressed by the following equation.

ΔPA = KL = F (3) ΔP = F / A Q∝S√ (F / A) (4) where K is the spring constant of the spring 41, and A is the pressure receiving pressure. The area, L represents the amount of displacement of the spring 41, and F represents the force generated by the displacement of the spring 41.

FIG. 7 is a characteristic diagram showing a change state of the passage hole area S with respect to the displacement amount L of the conical coil spring 41 forming the valve body. As shown in FIG. The characteristic has a non-linear characteristic falling to the right.
Therefore, in order to satisfy the expression (2), the displacement load characteristic of the coil spring 41 is set to “upward to the right”, so that the above-mentioned area S of the through hole is “downward to the right”.
It can be seen that the characteristics should be corrected.

FIG. 8 is a characteristic diagram showing the change of the spring load F with respect to the displacement L of the conical coil spring 41 constituting the valve body. It has a non-linear characteristic that rises to the right. That is, this "right-up" characteristic can be obtained by using a conical coiled spring 41 as in this embodiment.

However, in the actual plane, the pressure receiving area A is also "downward to the right" similarly to the passage hole area S. Therefore, in determining the displacement characteristics of the spring 41, the equations (3) and (4) are used. Is determined and confirmed by an experiment in consideration of the passage hole area S while ensuring the relationship of

The above spring characteristics (lower right characteristic of the passage hole area S and upper right characteristic of the spring load F) can be achieved by the conical coiled spring 41, as shown in FIG. Simple cylindrical SMA coil spring 5
1 is also possible. In the case of the cylindrical SMA coil spring 51 forming such a valve body, each winding 53,
The pitch of 53,... Is small at one end of the cylindrical shape,
The configuration is made such that the pitch is gradually increased and becomes the maximum at the other end side with an irregular pitch. The pressure receiving area A in this case is
It is determined by the coil center diameter of the cylindrical SMA coil spring 51 and is different from the conical one. In the figure,
Reference numeral 55 denotes a gap between the windings 53. In addition, the first
Conical SMA coil spring 4 constituting the valve element of the embodiment
Also in the case of No. 1, by changing the pitch for each winding 43, 43,... To freely adjust the degree of the non-linear curve of the spring characteristic, the effect of further characteristic correction can be obtained, and the above equation (2) can be obtained. It is possible to approach.

Next, the operation of the constant flow valve 10 provided with the conical SMA coil spring 41 constituting the valve body of the first embodiment will be described.

In FIGS. 1, 3 and 4, when the use of a hot water heater (not shown) is started and fluid flows into the inlet 13, a conical SM having a valve body with the spring receiving plate 31 is formed.
The supply pressure of the tap water acts on the pressure receiving area A formed by the upper surface of the A-shaped coil spring 41. As a result, the SMA coil spring 41 is pushed, and the state shown in FIG. 1 changes to the state shown in FIG.

That is, the SMA coil spring 41 starts contacting from the large diameter side of the conical shape, the contact proceeds to the small diameter side, and one end is almost fully closed. The spring 41 itself is pushed back to the valve opening side by receiving the reaction force of the generated force F due to the displacement of the spring 41 itself. Then, the operation of being pushed back to the valve closing side by the acting force of the pressure receiving area A is repeated, and the flow rate is stabilized at the set flow rate value. In practice, the repetition of this operation is completed instantaneously.

FIGS. 3 and 5 show the stable state. In addition, when it is stable, it corresponds to an intermediate position in the characteristic diagram of FIG. In such a stable state, the above-described equation (2) is satisfied, and the actual fluid is used while being controlled according to the above-mentioned equation (1).
Here, as already described, the supply pressure of the tap water, in fact, there is 0.3~7.0kg / cm ² and variations, constant in the low-pressure side (0.3kg / cm ²⁾ which is a problem Considering the state of the flow valve 10, the fact that the pressure acting on the pressure receiving area A is small means that the displacement of the conical SMA coil spring 41 forming the valve body is small. It is expected that this is close to the state of FIG.

As is apparent from FIG. 1, the winding gaps 45, 45, 45, 45, 4 of the coil spring 41 made of SMA are provided.
, Are sufficiently provided over the respective windings 43, 43, 43, 43, 43,..., So that the passage hole area S of the valve portion is equal to the respective winding gaps 45, 45, 45, 45, 45, 45,. .. And the circumference thereof, the number of which is incomparably larger than that of the constant flow valve disclosed in FIG. 4 of Japanese Utility Model Publication No. 4-10450. This situation corresponds to the left side of the characteristic shown in FIG. Such a state on the low pressure side corresponds to the left side of the characteristic shown by the dotted line in the characteristic diagram of FIG. Therefore,
The occurrence of fluid passage resistance is small and the pressure loss is very small.

Incidentally, the SMA material, which is a thermosensitive element, has a characteristic that the transverse elastic coefficient (G) of the material changes when the temperature is changed, and this characteristic is known to be linear in a constant temperature range. ing. Accordingly, the spring load proportional to the transverse elastic coefficient also has a linear characteristic in the temperature range (see Japanese Patent Application Laid-Open No. 63-303281).
(See FIG. 3 of the publication). The temperature range is easily determined by selecting a heat treatment temperature in the manufacturing process.

In the embodiment of the present invention, the SMA coil spring 41 is heat-treated on the extension side, and this shape is stored. Therefore, the SMA coil spring 41
Has a property of performing a compression deformation once on a low temperature side, and then recovering the stored original shape on the extension side when heated.

Here, it has already been mentioned that the base point of the control of the water temperature correction function is in winter, but the position of this base point is particularly important for the present invention in which the valve element is controlled by the coil spring 41. It is. Since the coil spring 41 is an SMA material, the product of the area S of the passage hole and the square root (√ △ P) of the differential pressure of the fluid at the boundary of the coil spring 41 is substantially constant. This is because it is important to determine the temperature at which the spring load characteristic of the coil spring 41 is set nonlinearly.

FIG. 8 shows the mounting relationship with the valve housing 11.
It shows the spring load characteristics of the coil spring 41 made of MA, and the curve shown by a solid line shows the characteristics at a predetermined constant temperature (T ° C.) when the base point is set in the above-mentioned winter season. It is. Therefore, the minimum hot water supply capacity of the water heater or the like can be guaranteed by the constant flow valve 10 having the spring load characteristic shown by the solid line. The curve shown by the one-dot chain line shows the characteristics at a water temperature (T1 ° C.) slightly higher than the above T ° C., and the curve shown by the two-dot chain line shows the characteristics at a higher water temperature (T2 ° C.). It is a thing.

Next, the temperature of the supply water of the water heater or the like changes from T1 to T2 during use, and the function of the coil spring 41 made of SMA serving as a valve element increases or decreases the amount of hot water. Is considered. Here, the above-mentioned equations (2), (3) and (4) are used. In each equation, Q is the control flow rate at the base point T ° C., S is the area of the fluid passage hole, ΔP = P1−P2 (differential pressure), A is the pressure receiving area, and K is the base point of the SMA coil spring 41. T is the spring constant of T ° C, L is the displacement of the SMA coil spring 41, F is SM
This is the spring load at the base point T ° C. of the coil spring 41 made of A.

According to the present invention, as described above, since the valve element is supported by the coil spring 41 made of SMA,
In Equations (3) and (4), when the temperature of the supply water changes, the F, S, K, and Q change, and so on. .

In FIG. 8, a diagram shown on the horizontal axis side of the spring load characteristic diagram shows a coil spring 41 made of SMA and a spring receiving plate which constitute a valve body provided on the valve support plate 21 of the valve housing 11. 31
And, for ease of understanding, the above L
Between the spring height H and the SMA coil spring 4
1 shows the relationship between the free length of 1 and the set length. here,
Assuming that the SMA coil spring 41 operates and balances at the spring height H, this H is constant and does not change, and when the water temperature is assumed to rise to T, T1, T2, as shown in FIG. The spring load also changes to F, F1, and F2. In the following, the control flow rate at T1 ° C. is represented by Q1, and the control flow rate at T2 ° C. is represented by Q2.

Therefore, at T1 ° C., the above equation (2) becomes Q1∝S√ △ P1, and from the above equation (4), △ P1
= F1 / A, Q1∝S√ (F1 / A) In this equation, S and A are the conditions that H does not change.
Since the equation does not change even at 1, Q1∝S√F1 (5) Also at T2 ° C., Q2∝S√ △ P2 △ P2 = F2 / A Q2 ∝S√ (F2 / A) Q2∝S√F2 (6) The spring load expansion rate of the SMA coil spring 41 is α = F
Since 2 / F1, F2 = αF1 (7) By substituting the equation (7) into the equation (6) and extracting the flow rate, Q2∝S√ (αF1) Compare with the equation (5). Then, Q2∝Q1√α (8).

Accordingly, it can be seen that the increase in the amount of hot water when the supply water temperature changes from T1 to T2 is Δα times that at T1. FIG. 9 shows the time course of these Q, Q1, and Q2. Conversely, when the water temperature drops from T2 to T1, the spring load reduction rate is α = F2 / F1, so that Q1 is reduced to √ (1 / α) of Q2.

Next, a second embodiment of the present invention shown in FIG. 6 will be described. The constant flow valve 60 with water temperature correction according to the second embodiment is of a type that is inserted into a water supply pipe 61 and directly assembled.

That is, the valve support plate 71 is incorporated so as to divide the inside of the water supply pipe 61 at a right angle. This valve support plate 71
The plurality of through holes 73, 73,
, A bearing cylinder 75 and a bearing hole 76, and a support cylinder 77 for stabilization in the water supply pipe 61 is integrally provided.
The support cylinder 77 comes into contact with the step 62 toward the upstream side in the water supply pipe 61, and a sealing member 79 such as an O-ring is assembled in an annular groove 78 on the outer peripheral surface, so that the inside of the water supply pipe 61 is airtight. Relationship.

As in the first embodiment, the guide shaft 83 having the spring receiving plate 81 is slidably and rotatably assembled in the bearing hole 76, and the spring receiving plate 8 is provided.
Step portion 72 between lower surface 1 and support tube 77 on upper surface of valve support plate 71
, A conical SMA coil spring 91 serving as a valve element is interposed. A retaining ring 85 is fitted in an annular groove 84 at the end of the guide shaft 83 projecting downstream from the bearing cylinder 75, 93 is a winding, and 95 is a gap therebetween. In this way, the valve support plate 71 provided with the conical SMA coil spring 91 having a conical shape forming a valve body with the spring receiving plate 81 is directly assembled in the water supply conduit 61 so as to close the flow path.

The same function as that of the first embodiment can be obtained by the constant flow valve 60 with water temperature correction according to the second embodiment. Since the body can be omitted, there is an advantage that the cost can be further reduced.

In the above embodiment, the temperature of the hot water is stabilized as the constant flow valve with the water temperature correction provided in the water supply line of the water heater for hot water supply. The use of the flow valve is not limited to this, and it is installed in a cooling water supply line such as a high-temperature heat treatment furnace and an air compressor to stabilize operation and save water. It can be used widely, for example, by installing it in a water supply pipe of a washing device (such as a ball tap) to save water.

Further, the constant flow valve with water temperature correction according to the present invention is installed on the supply side of equipment and devices to which the invention is applied.
If inexpensive supply as a product is possible, it can be installed and used at the outlet side of equipment and devices. For example, as an example, in a general household, in addition to a general hot water supply such as a kitchen, a bath, a shower, etc. by installing a large-sized hot water heater, a heating device for arranging a heat exchanger in each room to supply hot water. The use of is increasing.

As described above, when hot water is supplied to a large number of locations by using one hot water heater, the problem with the installation of each device and apparatus, that is, the distance from the hot water heater, Differences in fluid resistance due to differences in height, number of joints, etc. may cause differences in hot water supply flow rates to each.
Therefore, if the constant flow rate valve with water temperature correction according to the present invention is provided at the inlet of each hot water supply pipe to stabilize the flow rate, the above-described problem can be solved.

Further, the specific arrangement of the constant flow valve with water temperature correction according to the present invention, the type of fluid to be flow-controlled, and the like are arbitrary, and other specific detailed structures and the like can be appropriately changed. Of course, it is.

[0053]

As described above, according to the constant flow valve with water temperature correction according to the present invention, for example, the pressure loss on the low pressure side of the supply pressure of tap water can be reduced to 0.2 kg / cm ² or less. Even in a low pressure area where the supply pressure of tap water is 0.3 kg / cm ² , for example, in the case of a hot water supply water heater, a set flow rate (20 l / min in the embodiment) can be sufficiently supplied. Therefore, not only can the water heater for hot water supply be used soundly, but also sufficient hot water can be used, so that the user can be satisfied.

According to the present invention, the water supply amount can be corrected in accordance with the change in the water temperature of the supply water by a simple structure in which the coil spring forming the valve element is made of an SMA material which is a heat-sensitive element. Since it also has a governor (pressure regulation) function, the temperature of hot water from a water heater or the like can always be stabilized regardless of time.

Further, the constant flow rate valve with water temperature correction according to the present invention can simplify the structure of the valve by providing a constant flow rate control function to the coil spring as a valve element.
Since parts can be simplified, mass production is possible, and the number of steps can be significantly reduced. Therefore, it is possible to widely provide a constant flow valve with water temperature correction with good performance at low cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing a first embodiment of a constant flow valve with water temperature correction according to the present invention, showing a state before starting use.

FIG. 2 is a cutaway plan view illustrating a pressure receiving area of a cross section of a valve housing and the like along a line AA of FIG. 1;

FIG. 3 is a vertical sectional side view showing a stable state of a flow rate control.

FIG. 4 is an enlarged view of a portion B in FIG. 3;

FIG. 5 is a cutaway side view showing a modified example of an SMA coil spring forming a valve element.

FIG. 6 is a longitudinal sectional side view showing a second embodiment of the constant flow valve with water temperature correction according to the present invention, and showing a state before starting use.

FIG. 7 is a characteristic diagram of a passage hole area (pressure receiving area) of a valve body by the constant flow valve with water temperature correction according to the present invention.

FIG. 8 is a diagram illustrating a function for water temperature fluctuation by combining an SMA coil-shaped spring portion with a spring load characteristic diagram of a valve body by a constant flow valve with water temperature correction according to the present invention.

FIG. 9 is a pressure flow characteristic diagram comparing pressure loss between a constant flow valve with water temperature correction according to the present invention and a conventional constant flow valve.

[Explanation of symbols]

 10, 60 Constant flow valve with water temperature correction according to the present invention 11 Valve housing 12 Flow path 13 Inlet 15 Outlet 21, 71 Valve support plate 22, 72 Stepped portion 23, 73 Through hole 25, 75 Bearing cylinder 31, 81 Spring Receiving plates 33, 83 Guide shafts 35, 85 Retaining rings 41, 51, 91 SMA coiled springs 43, 53, 93 forming valve bodies Windings 45, 55, 95 Clearance 61 Water supply pipeline 62 Step 77 Support cylinder 79 Seal member

Claims (1)

(57) [Claims] A valve body that is provided in a fluid water supply passage and that varies a fluid passage hole area in response to a pressure change of the fluid;
Furthermore, the constant flow valve is configured such that the passage hole area of the valve body is corrected by a shape memory alloy material which is a thermosensitive element corresponding to a change in supply water temperature so that a predetermined flow rate corresponding to the supply water temperature can be obtained. The valve body is formed of a coil spring that expands and contracts in accordance with the pressure fluctuation of the fluid, and the clearance between the windings of the coil spring changes according to the pressure fluctuation of the fluid. While corresponding to the hole area, so that the product of the passage hole area due to the gap between the windings of the coil spring and the square root of the differential pressure of the fluid at the boundary of the coil spring is substantially constant, A constant flow rate with water temperature correction, wherein a spring load characteristic of the coil spring is set to be non-linear, and the coil spring is formed of the shape memory alloy material corresponding to a change in the supply water temperature. valve.