JPH0222402B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water control device used in instantaneous water heaters, hot water boilers, etc., in which the control valve is not provided in the main water passage, but is operated indirectly. This controls the amount of water.

Conventionally, to adjust the water flow, a method was used to change the opening degree of a control valve installed in the main passage, but due to water flow resistance, the valve required a certain size or more. There was a limit to how much the operating stroke and operating force could be reduced. In addition, if you want to completely open and close the water volume, you can use a control valve installed in the main passage to completely close the valve. For example, when the diaphragm is stopped, supply water pressure is applied to one side of the diaphragm, and the other side becomes almost open, which increases durability. There is a problem in terms of In this case,
It is difficult to detect the presence or absence of water flow based on the amount of movement of the diaphragm.

The present invention operates a control valve in an indirectly provided water passage to open/close and change the amount of water, and aims to reduce the force and stroke of valve operation. Further, the opening and closing operations can be performed by operating the control valve, and in this case, it is another object of the present invention to obtain a means that not only does not impair the durability of the diaphragm, but also allows water flow to be detected by moving the diaphragm. It is a purpose.

Next, an embodiment of the present invention will be described in detail based on drawings in which it is applied to a gas instantaneous water heater.

FIG. 1 is a block diagram showing an example of application to a gas instantaneous water heater, and only the water flow control device is shown in cross section.
Here, 1 is a water flow control device, and a diaphragm 2 forms a primary pressure chamber 3 on the lower side and a secondary pressure chamber 4 on the upper side. Water flows from the inlet 5 through the chamber 6, through the control hole 7, through the shutoff valve seat 8, and through the inflow passage 9 leading to the primary pressure chamber 3. It then flows away through an outflow passage 12 having a low pressure section formed by a valve port 10 and a ventilate tube 11. A control valve 13 is located corresponding to the control hole 7 and is fixed to the diaphragm 2 together with a shutoff valve 14 . The control valve 13 and the shutoff valve 14 have opposite opening directions. The control valve 13 has a horizontal hole 15
A vertical hole 16 is bored therein, and together with a communication hole 18 of a nut 17 for fixing the control valve 13 to the diaphragm 2, it forms a first communication path. During operation, the inflow passage 9 located between the control hole 7 and the shutoff valve 8 and the secondary pressure chamber 4 are communicated with each other. The secondary pressure chamber 4 includes a spring 1 that constantly presses the diaphragm 2 downward.
9 and when the pressure difference between the primary pressure chamber 3 and the secondary pressure chamber 4 is small, the shutoff valve 14 is pressed against the shutoff valve seat 8 to stop the water flow. There is a second communication passage 20 that connects the secondary pressure chamber 4 and the constricted part of the ventilate tube 11, and a control valve 21 is disposed in the middle of this passage, which controls the variable and total water flow resistance of the second communication passage 20. Can be closed. 22 is an operation knob for operating the control valve 21. An automatic valve 23 is provided corresponding to the valve port 10, and this automatic valve 23 has a through hole 24 in the center and is always pressed in the direction of the valve port 10 by a spring 25.

The movement of the diaphragm 2 of the water amount control device 1 is taken out to the outside by a sealed pin 26, so that the state of water flow can be known.

In the middle of the outflow passage 12, there is a heat exchanger 27 having a large number of fins, which heats and supplies hot water. On the other hand, in the middle of the gas supply circuit 28, there is a gas supply circuit 29.
Then, from the pilot circuit 30 to the pilot burner 31, from the main circuit 32 to the water-responsive valve 33.
It also goes to the main burner 34 through.

The gas circuit is the same as a normal one, and in conjunction with the operation of the cooker 29, devices (not shown) such as an ignition device and a flame detection device are operated to ignite the pilot burner 31. When the water-responsive valve 33 is opened, main combustion is performed in the main burner 34 to heat the heat exchanger 27.

Now, the operation of the water amount control device 1 will be explained using the operation explanatory diagram of FIG. 2. FIG. 2A shows a state in which the pressure difference between the primary pressure chamber 3 and the secondary pressure chamber 4 changes depending on the amount of water. Here, the differences in A, B, and C are caused by differences in the opening degree of the control valve 21, with A being fully open and opening degrees becoming narrower in the order of B and C. Further, d is the portion generated by the automatic valve 23 in the differential pressure. The automatic valve 23 only passes through the through hole 24 in a low water flow state, but the pressure difference due to the through hole 24 generates a force that moves the automatic valve 23 itself in the opening direction, so the position is located where this force and the spring 25 are balanced. The valve opening degree is determined by In other words, as the amount of water increases, the automatic valve 23
moves downward in the figure, and the water flow pressure loss of the automatic valve 23 remains approximately constant despite the increase in water flow. In the figure, the automatic valve 23 separates from the valve port 10 from the water level Ws. The pressure drop due to this automatic valve 23 and the ventilate pipe 11
The sum of the pressure drops caused by this will act on the diaphragm 2. By the way, the pressure in the primary pressure chamber 3 also acts on the secondary pressure chamber 4 through the first communication path formed by the holes 15, 16, and 18.
The pressure in the primary pressure chamber 3 and the pressure in the ventilate tube 1 are
1 is divided by the resistance in the first communication path and the resistance in the second communication path 20. That is,
When the control valve 21 is fully open, the pressure in the secondary pressure chamber 4 exhibits a value close to the pressure in the ventilary tube 11, and as the control valve 21 is throttled, the pressure rises to approach the pressure in the primary pressure chamber 3. B and C in Figure 2 A are control valves 2
1 is slightly narrowed down. Furthermore, I, B,
The difference between curve C and curve D is the pressure difference generated solely in the ventilate tube 11, and in the low water flow region where the water flow is less than Ws, most of the pressure difference is caused by the automatic valve 23.
The effect of the ventilate tube 11 is not very apparent. As described above, the control valve 21 has the function of changing the pressure acting on the diaphragm 2 even if the amount of water flowing is the same. Next, in FIG. 2B, the diaphragm 2 generates a force in response to a pressure difference, and the position where this is balanced with the strength of the spring 19 and becomes stable is shown by the valve opening degrees of the control valve 13 and the shutoff valve 14. . Until the force of the diaphragm 2 exceeds the set load of the spring 19, the shutoff valve 14 is fully closed, while the control valve 1
3 is full throttle. Then, as the force of the diaphragm 2 increases, the control valve 13 gradually moves in the closing direction, and the stop valve 14 moves away from the stop valve seat 8. When the inlet water pressure is a certain value and the setting of the control valve 21 is A, the water volume is W ₁ and a differential pressure △p ₁ is generated,
The force is _F1 , and as a result of force comparison with the spring 19, the opening gap of the control valve 13 is _Δg1 . Next, FIG. 2C shows how the pressure drop from the inlet 5 of the inflow passage 9 to the primary pressure chamber 3 changes as the valve opening changes, and the water amount is used as a parameter. When the diaphragm 2 is pressed against the closing valve seat 8 by the spring 19, no water flows and the pressure drop is the supply water pressure itself. When the diaphragm 2 rises in FIG. 1, the valve opening moves to the left in FIG. 2C, and the pressure drop rapidly decreases. Eventually, when the control valve 13 approaches the control hole 7, the pressure drop exhibits a sudden exponential change in response to a slight change in the valve opening gap, even if the amount of water is the same.
Therefore, when the supply water pressure increases from the state of W ₁ water volume mentioned above, the water volume tends to increase, but since the valve opening gap △g ₁ further decreases, the sudden increase as shown in Figure 2 C occurs. As a result of the pressure drop across the valve, the increase in water volume is much smaller than the increase in water pressure. In reality, by selecting an appropriate valve shape and spring constant, it is possible to obtain a characteristic in which the amount of water remains almost constant despite changes in water pressure. It has the effect of a so-called governor. Since the pressure drop curve at the control valve section 13 differs slightly depending on the amount of water, the higher the amount of water, the wider the valve opening gap will operate. Changing the pressure difference acting on the diaphragm 2 with the control valve 21 changes the set water volume of the governor effect, which acts to maintain the set water volume even when water pressure changes. For example, if you change from state A to state B,
Since the differential pressure is small when the amount of water is W ₁ , the opening degree of the control valve 13 moves in the opening direction (to the right in FIG. 2B) by the force of the spring 19, and a new stable point is obtained as the amount of water increases. The water volume moves from W ₁ to W ₂ , the differential pressure moves from △p ₁ to △p ₂ , the diaphragm force moves from F ₁ to F ₂ , and the opening gap of the control valve 13 moves from △g ₁ to △g ₂ . . This means that when the setting of the control valve 21 is changed from B to C or from C to A, the movement automatically seeks a new stable point.

Now, consider the case when the control valve 21 is fully closed. Second
Since the communication passage 20 is closed, the secondary pressure chamber is the horizontal hole 1.
5, it communicates only with the primary pressure chamber 3 through the first communication path formed by the vertical hole 16 and the communication hole 18, and no pressure difference acts on the diaphragm 2. As a result,
The diaphragm 2 moves downward by the force of the spring 19,
The shutoff valve 14 is pressed against the shutoff valve seat 8 to stop the water flow. When the water flow stops, a closing force acts on the entire effective area of the diaphragm 2 in the secondary pressure chamber 4 above the diaphragm 2, whereas a force in the opening direction is applied below only by the area of the shutoff valve seat 8. Doesn't work. As a result, the supply water pressure acts in the direction of closure as a whole, so water can be completely stopped.
Next, when the control valve 21 is opened, the pressure in the secondary pressure chamber 4 escapes to the outflow passage 12 through the second communication passage 20, so that only the inlet water pressure applied to the area of the shutoff valve seat 8 acts on the diaphragm 2. . When the upward force of the diaphragm 2 due to the force of this water pressure overcomes the spring 19 and the closing valve seat 14 opens, the water pressure acts on the entire primary pressure chamber 3, causing the diaphragm 2 to rise all at once. If the control valve 21 is opened only slightly, the pressure in the secondary pressure chamber 4 may not be completely released, and a water pressure that is somewhat lower than the supply water pressure may remain through the first communication passage. At this time, only a small amount of water flows through both communication passages. The necessary opening degree of the control valve 21 is determined by the effective area of the diaphragm 2, the area of the closing valve seat, the strength of the spring 19, the size of the hole forming the first communicating path, and the like. As mentioned above, the diaphragm 2 is suddenly displaced from the closed state to the open state, so if this displacement is taken out to the outside by the pin 26 and the water-responsive valve 33 is opened,
Water flow and gas combustion can be connected. In other words, it also has the function of water flow detection.

Note that the first communication passage is not limited to a structure that penetrates through the center of the control valve 13; for example, the control valve 13 is energized with another spring so as to interlock with the diaphragm 2, and the first communication passage is formed so as to penetrate through the center of the diaphragm. A hole may also be provided. Alternatively, the second communicating path 20 may be provided through the body forming the main body. The only requirement is that the water pressure between the control hole 7 and the closing valve seat be introduced into the secondary pressure chamber 4.

As described above, in the present invention, by changing the diaphragm differential pressure by operating the control valve provided in the communication passage, it is possible to open and close the passageway and adjust the water volume. It has become possible to significantly reduce the operating force. Additionally, since it closes using water pressure, water leaks are less likely to occur, and complete closure is possible even under high water pressure. Furthermore, it has a governor function that prevents water flow fluctuations from occurring due to water pressure fluctuations, and a water flow detection function, and even when the diaphragm is stopped, the difference between the supply pressure and the release pressure is not applied to the entire diaphragm, which improves durability. It is also advantageous in terms of

In addition, when the control valve is closed, pressure upstream from the shutoff valve seat is introduced into the secondary pressure chamber and water flow can be stopped.
It is economical as there is no need to provide a faucet or solenoid valve for this purpose.

Furthermore, since the pressure downstream of the control hole is used when the control valve is open, a stable flow rate can be maintained even when the supply water pressure fluctuates.

In addition, since no external force is used as in the case of a pump, the device can be made smaller and simpler, and the number of failure factors can be reduced, increasing reliability.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a gas water heater using a water flow control device according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram of the same operation. 1...Water flow control device, 2...Diaphragm, 3
...Primary pressure chamber, 4...Secondary pressure chamber, 7...Control hole,
8... Closing valve seat, 9... Inflow passage, 13... Control valve, 14... Closing valve, 15... Horizontal hole, 16... Vertical hole, 17... Communication hole, 10... Valve port, 23 ... automatic valve, 11 ... bench lily, 21 ... control valve,
20...Second communication path.

Claims (1)

[Scope of Claims] 1. A diaphragm, a primary pressure chamber and a secondary pressure chamber partitioned by the diaphragm, and a control hole and a shutoff valve seat provided in the order of passage in an inflow passage leading to the primary pressure chamber;
A low pressure part provided in the outflow passage exiting from the next pressure chamber, a control valve that changes the opening degree of the control hole, a shutoff valve corresponding to the shutoff valve seat, and an inflow passage downstream of the control hole and upstream of the shutoff valve seat. a first communication passage connecting the secondary pressure chamber;
The second chamber connects the next pressure chamber and the low pressure section and has a control valve in the middle.
The control valve and the shutoff valve are arranged in a positional relationship such that the control valve and the shutoff valve are interlocked with a diaphragm and their respective opening degrees change inversely according to the displacement of the diaphragm. 2. The water flow control device according to claim 1, wherein the first communicating passage is provided through the center of the control valve fixed to the diaphragm. 3. The water flow control device according to claim 1, wherein the low pressure section is formed by an automatic valve whose opening degree automatically changes depending on the flow rate of water, and a fixed constriction section such as a bench lily or an orifice. .