JP3077425B2 - Constant pressure hot and cold water mixing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Object of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot and cold water mixing apparatus having an automatic temperature control function.

[0002]

2. Description of the Related Art A general automatic temperature-adjusting hot water mixing apparatus is provided with a thermosensitive element in which a heat-expandable wax is sealed. When a user sets a desired hot water supply temperature by turning a temperature setting handle. The wax temperature sensing element responds to the temperature of the hot and cold water mixture to position the mixing valve body to automatically adjust the hot and cold water mixing ratio and mechanically feedback control the hot and cold water temperature toward the set value. ing.
When the conditions such as water pressure, hot water supply pressure, hot water temperature from hot water heater, tap water temperature and flow rate fluctuate transiently, and as a result, the temperature of the hot water mixture changes, the wax thermosensitive element expands and contracts according to the temperature change. Then, the mixing valve body is displaced to correct the mixing ratio of the hot and cold water, and the temperature of the hot and cold water mixture gradually converges to almost the target value while repeating overshoot and undershoot. Although this type of automatic temperature control mixing device is widely used,
Since the thermal capacity of the wax thermosensitive element is large and the thermal conductivity is not good, there is a drawback that the response to a transient temperature change is slow and a considerable overshoot or undershoot occurs.

[0003] In order to improve such disadvantages of the wax thermosensitive element, a hot water mixer tap using a thermosensitive element made of a shape memory alloy has been proposed in the prior art (Japanese Utility Model Publication No. 61-4).
No. 4062). The hot-water mixer tap has a valve body that slides in a housing, and the valve body is positioned by a balance between a coil spring made of a shape memory alloy and a bias spring made of a usual spring material. When the coil spring made of a shape memory alloy expands and contracts according to the temperature of the hot and cold water mixture, the valve body is displaced between the fully open position of the hot water and the fully open position of the water, and the temperature of the hot and cold water mixture is automatically adjusted.

In this hot / water mixer tap, a coil spring as a temperature sensing element is formed of a shape memory alloy, and since such an alloy has a smaller heat capacity and better heat conductivity than a wax temperature sensing element, This hot / water mixer tap has an advantage that it has superior responsiveness as compared with a hot / water mixer using a wax temperature sensing element.

However, since the valve element slides along the cylindrical bore of the housing, there is a drawback that hot and cold water leaks through a gap between the outer circumference of the valve element and the inner circumference of the bore. . That is, in the embodiment illustrated in FIGS. 1 and 2 of the publication, a spool valve is used as a valve body, and in the embodiments of FIGS. 3 and 4, a lift valve is used. . In any valve configuration, in order to allow the valve body to slide smoothly in the housing, a sufficient gap must be provided between the outer circumference of the valve body and the inner circumference of the bore of the housing. No. Since there is such a gap, when a pressure difference occurs between the upstream side and the downstream side of the valve body, hot water or water leaks to the downstream side through the gap. Such leakage of hot and cold water is caused by the fact that when the valve element is in the fully open position (and thus the fully closed position) to supply hot water, lukewarm water diluted with water is discharged, and conversely, cold water is supplied. When the valve element is in the water fully open position (therefore, the hot water fully closed position), the result is that warm water diluted with hot water is discharged. Therefore, the temperature control function is not sufficient. In addition, hot water may unnecessarily ignite due to leakage of hot water when supplying cold water.

In the embodiment using a lift valve (FIGS. 3 and 4), the valve body is held by a balance between a coil spring made of a shape memory alloy and a bias spring. If the hot water supply pressure transiently fluctuates and the hot water differential pressure fluctuates transiently, the valve body may be unintentionally displaced and the temperature of the hot water mixture may deviate from the target temperature.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a hot and cold water mixing apparatus which is excellent in responsiveness and excellent in temperature control function.

It is another object of the present invention to provide a hot and cold water mixing apparatus which prevents leakage of hot water and water and has an excellent shut-off performance.

Another object of the present invention is to provide a hot and cold water mixing apparatus which is not affected by transient fluctuations in hot and cold water pressure.

[0010]

Configuration of the Invention

SUMMARY OF THE INVENTION The present invention achieves the above object based on a new principle different from the prior art hot water mixing apparatus. That is, generally, the flow rate of the fluid flowing through the pipeline can be expressed by the following equation.

Q = k · Cv · P ^1/2 (1) (where k is a constant, Cv is the flow coefficient of the pipe, P is the pressure of the fluid in the pipe) In this case, the condition of the pipeline downstream of the hot and cold water mixing chamber is constant, and it can be considered that the flow coefficient Cv takes a unique value. Therefore, if the pressure P of the hot water mixture in the hot water mixing chamber is kept constant, the flow rate Q of the hot water mixture discharged from the hot water mixing apparatus can be made constant. However, the hot and cold water mixing of the flow rate Q is of the hot water flowing into the hot and cold water mixing chamber the flow rate Q _H and since the sum of the flow rate Q _C of water (Q = Q _H +
Q _C), thus when the mixture pressure P was mixture flow rate Q constant by the constant flow rate Q _C of the water is reduced accordingly be increased hot water flow rate Q _H is in the opposite The relationship is such that the flow rate Q _{C of} water increases as the flow rate Q _{H of} hot water decreases. Thus, by controlling only one of the flow rate either the hot water flowing into the hot and cold water mixing chamber (Q _H or Q _C), resulting in also control the other flow (Q _C or Q _H), hot and cold water mixing ratio of Can be changed.

Based on the above principle, the present invention provides (1) a method of making the flow rate Q of the hot water mixture constant by making the pressure P of the hot water mixture in the hot water mixing chamber constant by the pressure control means;
(2) by controlling the hot water of Izure or the other of the flow rate (Q _H or Q _C) depending on the hot water temperature of the mixture by flow control means, is that attempts to control the hot and cold water mixing ratio.

More specifically, the hot and cold water mixing apparatus of the present invention comprises a housing, a hot and cold water mixing chamber, a hot water flow path for supplying hot water under pressure to the hot and cold water mixing chamber,
A water flow path for supplying water under pressure to the hot and cold water mixing chamber and a hot and cold water mixture outlet for discharging the hot and cold water mixture from the hot and cold water mixing chamber are formed. The pressure of the hot water mixture in the hot water mixing chamber is controlled to be constant by pressure control means such as a pressure control valve. Therefore, the flow rate Q of the hot water mixture discharged from the hot water mixing chamber is constant. Yuryuro (or water flow path) flow rate Q _H (or Q _C) of the hot water through the supplied to the hot and cold water mixing chamber (or water) is controlled by a flow control valve. The flow control valve includes a temperature-responsive coil spring, which is formed of a metal such as a shape memory alloy, whose spring constant changes according to the temperature, and responds to the temperature of the hot and cold water mixture. It is arranged in the hot and cold water mixing chamber. The flow control valve preferably has a poppet-type valve element which is positioned by a balance between a temperature-responsive coil spring and a bias spring. Target temperature of the hot and cold water mixture is set by the temperature setting means, the flow control valve is a temperature of the hot and cold water mixture to control the flow rate Q _H (or Q _C) of the hot water so that the target temperature (or water).

Since the poppet valve does not require a gap between the outer periphery of the valve body and the valve housing as in the above-described prior art mixing valve, in the fully closed position, the flow of fluid is effectively shut off, and leakage of hot and cold water is prevented. Can be prevented.

In a preferred embodiment, the temperature setting means sets the target temperature by adjusting the preload of the bias spring. The bias spring preload can be adjusted by manual means, such as a manual handle, or by electrical means, such as an electric motor controlled by a control circuit.

The above-mentioned features and effects, as well as other features and advantages of the present invention will become more apparent according to the description of the following embodiments.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a hot water mixing apparatus 10 includes a pressure control valve 12 and a flow control valve 14. In the embodiment shown, the pressure control valve 12 and the flow control valve 14 are integrated in a common housing 16, but they may be separated separately. Housing 16 has inlets 18 and 20
And a hot and cold water mixing chamber 22 are formed. In the embodiment shown, the inlet 18 acts as a water inlet, the inlet 20 acts as a hot water inlet, the pressure control valve 12 keeps the pressure of the water supplied from the water inlet 18 to the mixing chamber 22 constant, and the flow control valve 14
Is adapted to control the flow rate of hot water supplied from the hot water inlet 20 to the mixing chamber 22.

The pressure control valve 12 is conventional and includes a primary pressure chamber 24, a secondary pressure chamber 26, a valve seat 28 disposed therebetween, a poppet valve 30, and a diaphragm 32. In order to improve the closing performance, the poppet valve 30
Is fitted with a rubber packing 34. Diaphragm 3
2 has an effective pressure receiving area equal to the effective pressure receiving area of the poppet valve 30, its outer periphery is liquid-tightly fastened to the housing by a retainer 36 fixed to the housing 16, and its inner periphery is screwed to the poppet valve. A nut 38 is fastened to the poppet valve flange 40 in a fluid-tight manner. Nut 3
Reference numeral 8 serves as a guide member for the poppet valve 30 and also serves as a spring receiver for the compression coil spring 42, and is fitted in the retainer 36 so as to be slidable in the axial direction. The upper end of the coil spring 42 is supported by an adjusting screw 44 screwed to the retainer 36, and the preload of the coil spring 42 can be adjusted by rotating the adjusting screw 44. The stroke of the poppet valve 30 is
Regulated by

Since the effective pressure receiving area of the poppet valve 30 is equal to the effective pressure receiving area of the diaphragm 32, the primary pressure chamber 2
The force acting downward on the poppet valve 30 due to the primary pressure in 4 and the force acting upward on the diaphragm 32 cancel each other. Therefore, the poppet valve 30 is connected to the secondary pressure chamber 2.
The pressure control valve 12 controls the secondary pressure to a pressure value corresponding to the preload of the coil spring 42 by being positioned by the balance between the upward force due to the back pressure in 6 and the downward force due to the coil spring 42. Water having the secondary pressure controlled in this way is applied to the hot and cold water mixing chamber 22 through the water inlet 18,
Since the hot water mixture in the hot water mixing chamber 22 is maintained at a constant pressure P, the flow rate Q of the hot water mixture discharged from the mixture outlet 48 of the hot water mixing apparatus 10 (the flow rate Q _{H of} hot water and the sum of the flow rate Q _C of the water .Q = Q _H + Q _C) is constant. As will be described later, by adjusting the preload of the coil spring 42 by turning the adjusting screw 44 and changing the pressure P, the flow rate Q can be variably adjusted.

The flow control valve 14 uses many components having the same structure as the above-mentioned components of the pressure control valve 12 in order to share parts with the pressure control valve 12. The functions of the elements are not necessarily the same. That is, the flow control valve 14 is provided with a valve seat 50 formed in the housing 16.
A poppet valve 54 with a rubber packing 52 for controlling the flow rate of hot water from the hot water inlet 20 in cooperation with the valve seat 50; a diaphragm 56 having an effective pressure receiving area equal to the effective pressure receiving area of the poppet valve 54; A temperature-responsive compression coil spring 58 for urging the valve 54 in the valve closing direction and a compression bias spring 60 for urging the poppet valve 54 in the valve opening direction are provided. As in the case of the pressure control valve 12, the outer periphery of the diaphragm 56 is liquid-tightly fastened to the housing 16 by a retainer 62, and the inner periphery thereof is connected to the flange 66 of the poppet valve 54 by a nut 64 screwed to the poppet valve. Tightly tightened. The nut 64 acts as a guide member for the poppet valve 54 and also acts as a spring receiver for the bias spring 60, as in the case of the pressure control valve 12. Therefore, the nut 64 is slidable in the retainer 62 in the axial direction. Is fitted.

The temperature-responsive coil spring 58 is made of a metal whose spring constant changes according to the temperature.
A different spring force is generated according to the temperature of the hot and cold water mixture in 2 and acts on the poppet valve 54. As such a metal material whose spring constant changes according to temperature, an alloy made of a nickel-titanium alloy or the like and belonging to the category of a shape memory alloy is known. This kind of alloy changes its elastic coefficient according to temperature, and as a result, the spring constant of the coil spring 58 made of a shape memory alloy changes according to temperature.

On the other hand, the bias spring 60 is formed of a normal spring material, and its spring constant is constant with respect to temperature. Therefore, the biasing force generated by the bias spring 60 is proportional to the preload applied thereto. The upper end of the bias spring 60 is provided with a retainer 62 as in the case of the pressure control valve 12.
The preload of the bias spring 60 can be adjusted by rotating the adjusting screw 68.

Next, referring to FIGS. 2 and 3, an example of use of the hot water mixing apparatus 10 and the operation of the flow control valve 14 will be described. As shown in FIG. A water pipe is connected to the pressure chamber 24, and hot water can be supplied to the hot water inlet 20 from a water heater 70 such as an instantaneous water heater connected to the water pipe. The hot water pressure applied to the hot water inlet 20 due to the pressure loss of the water heater 70 will be slightly lower than the tap water pressure. However, the pressure control by the pressure control valve 12 is performed by keeping the secondary pressure constant at a value lower than the primary pressure, and a secondary pressure considerably lower than the tap water pressure is output to the mixing chamber 22. The pressure at 14 hot water inlet 20 will be higher than the pressure at water inlet 18. Therefore, the hot water flows into the mixing chamber 22 according to the opening degree of the flow control valve 14, and is mixed with the water flowing through the pressure control valve 12. The hot and cold water mixture formed in the hot and cold water mixing chamber 22 can be connected to a caran 74 or a shower via a water stopcock 72.

When the water stopcock 72 is opened, hot water and water are mixed by the hot water mixing device 10 and supplied from the curran 74. At this time, the pressure control valve 12 maintains the pressure of the hot and cold water mixture in the hot and cold water mixing chamber 22 at a constant value P as described above. Thus, the pressure P is constant and the outlet 48 of the mixing device 10
Since the flow coefficient Cv of the downstream flow path is constant, the flow rate Q of the hot water mixture flowing out from the outlet 48 is constant, as can be seen from the above equation (1).

Next, the operation of the flow control valve 14 will be described with reference to the effective pressure receiving area of the poppet valve 54 and the diaphragm 56.
Are equal to each other, the force acting downward on the poppet valve 54 by the pressure of the hot water entering the hot water inlet 20 and the force acting upward on the diaphragm 56 by the pressure of the hot water cancel each other. That is, the poppet valve 54
The force resulting from the pressure in the hot water inlet 20 does not act. The pressure in the mixing chamber 22 acts as a force F for pushing the poppet valve 54 upward. On the other hand, the poppet valve 54, the upward force F _S due to a temperature-responsive coil spring 58, and the downward force F _B by the bias spring 60 is acting. Therefore, the poppet valve 54 has an upward force (F
+ F _S) and is the downward force F _B is stabilized at a position commensurate as shown in the following _{formula: F B = F + F S} ··· (2) More specifically, the temperature responsive coil spring made of a shape memory alloy 58 is sensitive to the temperature of the hot and cold water mixture in the mixing chamber 22,
Since the spring constant changes according to the mixture temperature, the coil spring 58 generates a spring force according to the mixture temperature as shown in FIG. On the other hand, the bias spring 60 generates a spring force according to the preload, and the preload changes according to the position of the poppet valve 54. A spring force is generated as shown in FIG. Poppet valve 54, the occurrence spring force F _B of bias spring 60, generating the spring force F _S of the force F and the temperature-responsive coil spring 58 by the pressure in the mixing chamber 22
Is positioned at a position that balances the sum of This position corresponds to the intersection of the curve of the spring force F _B of the curve and the bias spring 60 of the F + F _S 3, the flow control valve 14 in this position of the hot water to hot water mixture temperature T ° C. is formed to control the flow rate Q _H. Flow rate Q of the hot and cold water mixture as described above is constant, and, because the sum of the flow rate Q _C of the hot water flow rate Q _H and water, the hot water by the flow control valve 14 the flow rate Q _H
By controlling only the water flow rate Q _C is complementarily controlled.

If the temperature of the hot and cold water mixture rises transiently for some reason, the temperature-responsive coil spring 58
Generated spring force F _S rises, displacing the poppet valve 54 upward. Thus, at the same time when the flow rate of the hot water decreases the flow rate of water is increased, the bias spring 60 increases the spring force F _B is compressed. And generating a spring force F _S of the temperature responsive coil spring 58 which is determined by the temperature of the hot water mixture, by a new spring force F _B of bias spring 60, (2) When the equation is satisfied, the poppet valve 54 to the balanced position Will be retained.
Conversely, if the temperature of the hot water mixture drops transiently,
Conversely, the flow rate of hot water increases and the flow rate of water decreases. In this way, the mixture temperature is maintained at T ° C.

If the user wants to change the temperature of the hot and cold water mixture, the adjustment spring 68 is turned to adjust the bias spring 60.
Movement of the increasing and decreasing the preload, generating the spring force F _B of bias spring 60 is moved parallel to the vertical in FIG. 3, the intersection of the curve of the curve and F _B of corresponding F + F _S to the left and right in FIG. 3 So that the mixture temperature is modified. Thus, the adjusting screw 68 acts as a means for setting the target temperature of the hot and cold water mixture.

As a variation of the first embodiment, a small-diameter back pressure introducing hole may be passed through the poppet valve 54 in the axial direction to apply the pressure in the hot / water mixing chamber 22 to the diaphragm 56 as a back pressure. In this case, the force F that pushes the poppet valve 54 upward by the pressure in the mixing chamber 22
Is canceled by the force for pushing down the diaphragm 56 due to the back pressure, the equation (2) can be rewritten as F _B = F _S. However, also in this case, in FIG. 3, the generated spring force F _S of the temperature-responsive coil spring 58 and the bias spring 60
Sadamari of balance load as the intersection of the spring force F _B, the mixture temperature is changed.

Next, when the user wants to change the flow rate of the hot and cold water mixture, the preload of the coil spring 42 is increased or decreased by turning the adjusting screw 44 of the pressure control valve 12, and the secondary pressure of the pressure control valve 12 is increased. P changes, and the flow rate Q of the hot and cold water mixture is variably adjusted according to the equation (1). Therefore, the adjusting screw 44 functions as a means for variably controlling the flow rate Q of the hot and cold water mixing device 10.

In the embodiment described above, the pressure control valve 1
2 controls the pressure of water, and the flow control valve 14 controls the flow rate of hot water. In the second embodiment of the present invention, the pressure of the hot water may be controlled by the pressure control valve 12 and the flow rate of the water may be controlled by the flow control valve 14, as shown in FIG. In this case, as shown in FIG. 4, a sliding skirt 78 provided with a plurality of hot water flow openings 76 is provided integrally with the poppet valve 54, and the temperature-responsive compression coil spring 58 made of a shape memory alloy is provided with a poppet. The skirt 78 is acted on to bias the valve 54 in the valve opening direction, and a tension spring is used as the bias spring 60. Alternatively, as a variation, the bias spring 60 may be formed of a compression spring and disposed in the mixing chamber 22 to bias the poppet valve 54 in the valve closing direction. In the embodiment of FIG. 4, the flow control valve 14 changes the water inlet 2 according to the temperature rise of the hot water mixture.
It operates to increase the flow of water from zero and decrease the flow of water as the mixture temperature decreases.

In the embodiment described above, the target temperature is set by manually adjusting the preload of the bias spring 60 using the adjusting screw 68, and the temperature of the hot and cold water mixture is mechanically controlled by the temperature-responsive coil spring 58. Feedback control. In the third embodiment of the present invention, as shown in FIG. 5, the temperature of the hot and cold water mixture can be electronically feedback-controlled. That is, as shown in FIG.
Are spline-fitted so that they can be displaced in the axial direction, but cannot rotate. The upper end of the bias spring 60 is
0 is supported. A screw hole is formed through the movable spring receiver 80, and a worm 84 formed on the output shaft of the motor 82 is engaged with the screw hole. Therefore, the motor 8
By rotating 2 in either direction, the movable spring receiver 80 can be displaced, and the preload of the bias spring 60 can be adjusted. The motor 82 is controlled by a control circuit 86 composed of a microcomputer. The control circuit 86 receives a signal from a temperature detector such as a thermistor 88 installed facing the mixing chamber 22 and a target temperature. From the switch 90 is input. The control circuit 86 controls the motor 8 based on the mixture temperature detected by the thermistor 88 and the target temperature inputted by the switch 90 so that the mixture temperature becomes the target temperature.
2 is feedback-controlled.

In the third embodiment, the temperature fluctuation due to the transient condition fluctuation is promptly dealt with by the mechanical feedback control of the temperature-responsive spring 58 made of a shape memory alloy. The main role of the feedback control by the control circuit 86 is to correct the hysteresis of the temperature-responsive spring 58 made of a shape memory alloy, to remove an offset based on the variation of the spring constant of the temperature-responsive spring 58 and the bias spring 60, Removing stationary offsets caused by deterioration of components over time, removing other offsets, and the like.

[0033]

According to the hot water mixing apparatus of the present invention, the temperature of the mixture can be controlled by controlling the flow rate of either hot water or water.
It is sufficient that the flow rate of one of the fluids 4 can be controlled, and there is no need to form a valve portion for controlling hot water and a valve portion for controlling water as an integrated unit as in a mixing valve of the prior art. Therefore, in the hot water mixing apparatus of the present invention, there is no portion where the hot water leaks due to its structure. Therefore, the hot and cold water mixing device of the present invention can supply sufficiently hot or cold water according to the user's request, and is excellent in the temperature control function.

The poppet valve 5 is used as the flow control valve 14.
In the case of using No. 4, more excellent fluid shutoff performance can be ensured.

Next, in the hot and cold water mixing apparatus of the present invention,
Since the pressure in the mixing chamber 22 is kept constant by the pressure control valve 12, the flow control valve 14 is not affected by the pressure fluctuation of the hot and cold water. Therefore, even if there is a transient fluctuation in the water pressure or hot water supply pressure, the mixture temperature can be controlled to a stable value.

Further, the temperature-responsive spring 58 is made of metal, and therefore has a significantly smaller heat capacity and better heat conductivity than the prior art wax temperature-sensitive element, so that the temperature change of the mixture is instantaneous. Responsive. Therefore, the mixing device of the present invention can perform high-precision temperature control with respect to transient condition fluctuation.

According to a preferred embodiment of the present invention, the means for adjusting the preload of the bias spring 60 is electric,
In the case of performing feedback control according to 6,
It is also possible to correct the influence of the hysteresis of the temperature-responsive spring 58, the steady offset caused by the variation of the spring constant due to the manufacturing tolerance, and the offset caused by other causes.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a first embodiment of a hot and cold water mixing apparatus of the present invention.

FIG. 2 is a schematic diagram showing an example of use of the mixing device shown in FIG.

FIG. 3 is a graph showing a temperature change of a load generated by a temperature-responsive spring and a bias spring of the mixing device shown in FIG. 1;

FIG. 4 is a schematic sectional view of a second embodiment of the hot and cold water mixing apparatus of the present invention.

FIG. 5 is a schematic view of a third embodiment of the hot and cold water mixing apparatus of the present invention, in which a flow control valve is notched.

[Explanation of symbols]

 10: Hot water mixing apparatus 12: Pressure control means 14: Flow control means 16: Housing of mixing apparatus 20: Hot water or water flow path 22: Hot water mixing chamber 24: Water or hot water flow 44: Flow rate variable adjusting means 54: Poppet valve 58: Temperature-responsive coil spring 60: Bias spring 68: Temperature setting means 80/82: Electric preload adjusting means 86: Control means 88: Temperature detecting means

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16K 11/00-11/24 F16K 31/64-31/70 F24D 17/00

Claims (5)

(57) [Claims] A hot water mixing chamber, a hot water flow path for supplying hot water under pressure to the hot water mixing chamber, a water flow path for supplying low pressure water to the hot water mixing chamber, and discharging a hot water mixture from the hot water mixing chamber. A housing having a hot and cold water mixture outlet, a pressure control means for making the pressure of the hot and cold water mixture in the hot and cold water mixing chamber constant, a temperature setting means for setting a target temperature of the hot and cold water mixture formed in the hot and cold water mixing chamber, A flow control valve for controlling a flow rate of only one of the hot water and the water supplied to the hot and cold water mixing chamber through the flow path, the metal being a metal having a spring constant that changes in accordance with the temperature. A temperature-responsive flow control valve for controlling the flow rate of one of the fluids so that the temperature of the hot and cold water mixture reaches the target temperature. What Hot water mixing equipment. 2. The flow control valve according to claim 1, wherein the flow control valve is arranged to receive a pressure of the hot and cold water mixture in the hot and cold water mixing chamber. A poppet-type valve element for controlling the flow of air, the temperature-responsive coil spring for urging the valve element in the valve closing direction, and a non-temperature-responsive bias spring for urging the valve element in the valve opening direction. 2. A hot and cold water mixing apparatus according to claim 1, wherein said temperature setting means sets a target temperature by adjusting a preload of said bias spring. 3. The flow control valve according to claim 1, wherein the flow control valve is arranged to receive a pressure of a hot and cold water mixture in the hot and cold water mixing chamber. A poppet-type valve element for controlling the flow of air, the temperature-responsive coil spring for urging the valve element in the valve opening direction, and a non-temperature-responsive bias spring for urging the valve element in the valve closing direction. 2. A hot and cold water mixing apparatus according to claim 1, wherein said temperature setting means sets a target temperature by adjusting a preload of said bias spring. 4. The hot water mixing apparatus further comprises: an electric means for adjusting a preload of the bias spring; and a target temperature input means for inputting a target temperature of the hot water mixture. A temperature detecting means for detecting the temperature of the mixture, and control means for controlling the electric means based on the mixture temperature detected by the detecting means and a target temperature inputted by the input means. A hot water mixing apparatus based on 2 or 3. 5. The pressure control means further comprises means for variably adjusting the pressure of the hot water mixture in the hot water mixing chamber, wherein the flow rate of the hot water mixture is adjusted by variably adjusting the pressure of the hot water mixture. A hot and cold water mixing apparatus based on any one of claims 1 to 4.