JPH0356781A - Flow control valve - Google Patents

Abstract

PURPOSE:To prevent the occurrence of cavitation bubbles in a flow control valve for a hot water supply unit by closing a valve when source water pressure is high, and controlling a water flow via a throttle passage formed in a gap between a valve body and a valve bearing through a nozzle hole provided in the valve. CONSTITUTION:A flow control valve has a spindle 5 moving when the angle of rotation of a gear becomes large. The area of a gap between a valve 12 and a valve body 6 is thereby made variable, and when water pressure is high, a maximum flowrate is obtained at the small angle of rotation of a gear. The tip of the spindle 5 is always kept off the valve 12 until an intermediate gear comes to have a certain angle of rotation. Also, the valve 12 and the valve bearing 7 are made in contact with each another at a large angle of rotation and only the valve body 6 is made movable back and forth. When water pressure is high, therefore, water passes through a nozzle 11 at the valve 12 and the pressure thereof is reduced. Then, water passes through a gap 9 between the valve body 6 and the valve spring 7, and a flowrate is thereby controlled. According to the aforesaid construction, the occurrence of cavitation bubbles can be prevented and a noise can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a low-noise valve structure that reduces noise generation in a water flow control valve that adjusts and controls the flow rate of hot water etc. discharged from a water heater.

BACKGROUND OF THE INVENTION Generally, in a water heater, as shown in Fig. 6, a water flow control valve B that suppresses excessive flow is connected to a hot water outlet path C in order to maintain a constant temperature of hot water discharged from a heat exchanger 8. It is set up in D is a water flow sensor, and E is a thermistor for detecting water temperature. A water flow control device using such a water flow control valve B is 7
Figure 8 is a sectional view of the water flow control valve.
In this device, when a motor 1 rotates, a gear 3 rotates in conjunction with a gear 2, and a shaft 5 moves back and forth by rotation with a bearing 4 having a screw inside.

Accordingly, the valve body 6 attached to the tip of the shaft 5 moves and adjusts the flow rate by changing the area of the gap 9 between it and the valve seat 7. When the source water pressure is high, the flow rate is adjusted by reducing the gap 9 between the valve body 6 and the valve seat 7, so the water passing through the gap 9 will have a high velocity, especially when a large flow rate is flowing. Problems to be Solved by the Invention In the conventional example shown in FIG. 8, in which the flow rate is adjusted simply by changing the area of the gap 9 between the valve body 6 and the valve seat 7, the flow rate is increased as described in the conventional technology. When flowing a large flow rate with water pressure, the gap 9 should be
The overflowing water reaches a high velocity, and due to the collision of the jets, the seventh
As shown in the figure, cavitation bubbles 8 are generated and there is a problem in that large water flow noise is generated.

The present invention solves the above-mentioned problems, and reduces the high differential pressure between the valve body and the valve seat to reduce the collision of jets, thereby reducing the generation of cavity silane bubbles and reducing noise. Purpose. Means for Solving the Problems In order to achieve the above object, the water flow control valve of the present invention, as a first means, opens and closes a valve having a nozzle hole provided in front of the valve body at an intermediate position of the full stroke. to change the path resistance. Further, the second means of the present invention is to increase the distance between the facing surfaces of the valve body and the valve receiver to narrow the gap area to a large surface, and to provide a plurality of It is designed to provide resistance by providing a depression. Furthermore, the third means of the present invention is to increase the distance between the facing surfaces of the valve body and the valve seat to narrow the gap area to a large surface, and to form a plurality of vertical depressions on the inner circumferential surface of the valve seat. It is used to provide resistance.

Furthermore, the fourth means of the present invention is a fluid regulating hole 14 having a large number of small diameter regulating holes 13 at a constant distance downstream of the valve body.
Establish. Effect In the first means described above, when the water pressure is high, by bringing the valve having the nozzle hole into contact with the valve receiver, water passes through the nozzle hole,
The pressure is greatly reduced, the local high differential pressure in the gap is reduced, and the flow rate of water passing through the gap is reduced. In addition, when water pressure is low, the valve is opened by increasing the angle of one rotation of the gear, reducing water flow resistance and ensuring a large flow rate. In the second method, the pressure is gradually reduced by the resistance created by a plurality of depressions perpendicular to the direction of movement of the valve body provided on the inner circumferential surface of the valve seat facing the valve body, and the local high differential pressure in the gap is reduced. As the gap becomes smaller, the flow rate of water passing through the gap becomes smaller. In the third method, the surface is perpendicular to the facing surface provided on the inner circumferential surface of the valve seat that faces the valve body. 3 [The pressure is greatly reduced due to the resistance caused by the several depressions, the local high differential pressure in the gap becomes smaller, and the flow rate of water passing through the gap becomes smaller. In the fourth method, the water passing through the gap is composed of many small particles,
The collision of the jets is alleviated by passing through a rectifier that has a rectifier hole that is a certain distance away. EXAMPLES Below, each example of the present invention will be explained according to FIGS. 1 to 5. This is used in place of the water flow control valve of the water flow control device shown in Figure 7. Figure l (a), (b)
2 shows the first embodiment, FIG. 2(a) shows the conventional example, and FIG. 2(b) shows the gear rotation angle of the first embodiment. A characteristic diagram of JLit is shown.

As shown in Figure 2 (a), water heaters generally have a maximum flow rate limit for hot water supply capacity and equipment protection. As the gear rotation angle increases, the shaft 5 moves and the valve 12 and valve body 6 move to vary the area of the gap 9 and control the flow rate.

Therefore, in the case of high water pressure (6 kg/c+J), the maximum flow rate is reached with one small gear rotation angle, and in the case of low water pressure (1 kg/cd), the maximum flow rate is reached with one large gear rotation angle. Utilizing this characteristic, the tip of the shaft 5 and the valve l2 are prevented from contacting each other up to a certain rotation angle of the intermediate gear, and once the rotation angle of the intermediate gear is exceeded, the valve 12 and the valve receiver 7 are brought into contact, and the valve body 6
Make sure the chisel moves back and forth.

As shown in Figure 1 (a), water entering under high pressure is removed from valve 1.
After the pressure is greatly reduced by passing through the nozzle hole 1) provided in the valve body 2, the velocity of the flow passing through the gap 9 between the valve body 6 and the valve seat 7 becomes smaller, the collision of the jet flow is alleviated, and the cavitation bubbles 8 are reduced. The occurrence can be suppressed. In addition, in a state of low water pressure, by increasing the rotation angle of the gear, the shaft 5 is moved and brought into contact with the valve l2, and by further movement, the valve l2 is moved to the valve receiver 7 as shown in FIG. 1(b). away from the nozzle hole l1, valve 12 and valve receiver 7.
By also flowing from between 15 and 15, the pressure loss is reduced,
Ensure a large flow rate. As shown in Fig. 2(b), in the first embodiment, when the water pressure is high, the maximum flow rate is reached at an angle smaller than one rotation angle of the intermediate gear, and when the water pressure is low, the maximum flow rate is reached temporarily when the flow rate becomes larger than one rotation angle of the intermediate gear. The flow rate increases at , and then gradually increases as the angle increases. FIG. 3 shows a second embodiment of the present invention, in which both the outer circumferential surface 61a of the valve body 6l and the inner circumferential surface 71a of the valve receiver 71 are made to have diameters gradually decreasing in a straight line from upstream to downstream.
In addition, a plurality of depressions 10 are provided in the middle of the inner circumferential surface 71a of the valve receiver 7l, which is perpendicular to the direction of movement of the valve body. Therefore, the water entering under high water pressure passes through the gap 9 which has a plurality of depressions 10 perpendicular to the direction of movement of the valve body provided on the inner circumferential surface 71a of the valve receiver 7l facing the valve body 6l as shown by the arrow. At that time, the valve receiver 7l
The pressure is gradually reduced due to the resistance of the depression 10 on the inner circumferential surface 71a, and the velocity of the flow passing through the gap 9 is reduced, the collision of jets is alleviated, and the generation of cavity silane bubbles 8 can be suppressed. In addition, in a state of low water pressure, the shaft 5 is moved and the valve body 61 is
By enlarging the gap 9 between the valve holder 71 and the valve seat 71, pressure loss is reduced and a large flow rate is ensured. FIG. 4 shows a third embodiment, which differs from the above-described second embodiment in that it covers the entire circumference of the inner peripheral surface 7lb of the valve receiver 71;
The structure is otherwise the same except that a plurality of depressions 10 are provided perpendicular to the inner circumferential surface 7lb. Therefore, when water entering under high pressure passes through the gaps 9 between the plurality of depressions 10 in the valve seat 7l facing the valve body 61, the water directly collides with the depressions 10, resulting in a large energy loss. As a result, the pressure is greatly reduced and the flow velocity passing through the gap 9 is increased, the collision of the jet flow after passing through the valve body 61 is alleviated, and the generation of cavitation bubbles 8 can be suppressed. Also, in a state of low water pressure, a large flow rate can be ensured as in the second embodiment. FIG. 5 shows a fourth embodiment, in which a rectifier l4 having a large number of rectifier holes l3 of small diameter and fixed distance apart is provided downstream of the valve body 6 and valve receiver 7. Therefore, the water that enters under high pressure becomes a jet after passing through the gap 9 between the valve body 6 and the valve seat 7, but by passing through the rectifier l4 having a large number of rectifier holes l3 provided in the wake, The jet stream is rectified, collisions are alleviated, and the generation of cavitation bubbles 8 can be suppressed.
Furthermore, in a state of low water pressure, the total area of the many rectifying holes l3 is larger than the area of the gap 9, so pressure loss is reduced and a large flow rate can be ensured. Effects of the Invention As explained above, according to the present invention, the following effects can be expected. According to claim 1, when the source water pressure is high, the valve is closed, and after the water passes through the nozzle hole l1 provided in this valve, the flow rate is controlled by the throttle passage formed in the gap between the valve body and the valve seat. It can greatly reduce pressure, prevent the generation of cavitation bubbles, and has a great effect on reducing noise. In addition, in a state of low water pressure, when the rotation angle of the intermediate gear becomes greater than one rotation angle, the valve 12 is opened to allow water to pass through, thereby reducing pressure loss and ensuring a large flow rate.

In addition, in claims 2 and 3, since energy is lost in the throttle passage formed by the opposing surfaces of the valve body and the valve seat having a plurality of depressions, the pressure is gradually reduced, suppressing the generation of cavitation bubbles, and reducing noise. It is effective in reducing Moreover, especially in the third embodiment, the pressure reduction effect is large, and the noise reduction effect is large.

Furthermore, according to claim 4, since the jet flow after the water amount has been controlled is rectified, the collision of the jet flow is alleviated, the generation of cavitation bubbles is suppressed, and noise is reduced. Furthermore, since the area of the numerous rectifying holes is larger than the area of the gap between the valve body and the valve seat, pressure loss does not become large even at low water pressure, so a large flow rate can be ensured.

[Brief explanation of drawings]

FIG. 1(a) is a cross-sectional view of a closed state of the water flow control valve according to the first embodiment of the present invention, and FIG. 1(b) is a valve showing the first embodiment of the water flow control valve of the present invention. 2(a) is a characteristic diagram of gear rotation angle and flow rate of the conventional example. FIG. 2(b) is a characteristic diagram of gear rotation angle - 2 itl of the first embodiment. 3 is a cross-sectional view showing a second embodiment of the water flow control valve of the present invention, FIG. 4 is a cross-sectional view showing a third embodiment of the water flow control valve of the present invention, and FIG. 5 is a cross-sectional view of the water flow control valve of the present invention. A sectional view showing the fourth embodiment, FIG. 6 is a structural diagram of a water heater having a water flow control valve, FIG. 7 is a detailed sectional view of a water control device employing a water flow control valve, and FIG. It is a detailed cross-sectional view of a conventional water flow control valve.

Claims (4)

[Claims] (1) Two-stage valve configuration that opens and closes sequentially as the valve body moves, and from fully closed to open, the valve body located on the downstream side controls the valve opening, and then opens at the position halfway moved. A water flow control valve that controls the opening of a valve with multiple nozzle holes in different directions. (2) In a valve body that changes the opening area by moving back and forth, the valve body is provided with an inclined surface having a certain distance, and the valve receiver facing the valve body is formed with a constant distance at approximately the same angle. A water flow control valve having a tilted surface and a plurality of depressions perpendicular to the direction of movement of the valve body. (3) In a valve body that changes the opening area by moving back and forth, the valve body is provided with an inclined surface having a certain distance, and the inclined surface having a certain distance and approximately the same angle on the valve receiver facing the valve body. A water flow control valve having multiple depressions perpendicular to its inclined surface. (4) A water flow control valve in which a valve body whose opening area changes by moving back and forth is provided with a flow regulator having a large number of small-diameter and fixed-distance regulating holes downstream of the valve body and valve receiver. .