JPH05823Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a water amount sensor for measuring the amount of water supplied to a water heater or the like.

[Conventional technology]

Instant water heaters for kitchens and hot water systems for showers are equipped with a water heater to supply hot water in the required amount and temperature.

In such water heaters, it is necessary to control the amount and temperature of water, so it is possible to determine the amount of water supplied, the temperature of the water supplied, and the temperature of hot water after heating, and perform optimal control from these to obtain the required amount of heating. Normal.

There are various devices for determining the amount of water supplied, one example of which is a water amount sensor as shown in FIG. This is done by attaching the main body 1 of the water sensor between the water supply pipe 2 that connects to the water supply source and the water supply pipe 3 that sends water to the heating part of the water heater, and measuring the flow rate of water passing through the internal flow path. Detection is performed by a detection system provided in the main body 1 of the sensor.

The main body 1 is a cylinder having an inlet 4 and an outlet 5 for connecting the water supply pipe 2 and the supply pipe 3 in an axial direction perpendicular to each other, and defining a chamber for flow rate detection in the part where the flow path is bent. Body 6 is arranged. Inside this cylindrical body 6, a rotary shaft 9 is rotatably supported by bushes 7 and 8 integrated at both the upper and lower ends.
A blade 1 that rotates this rotating shaft 9 by the flow of water.
0 is fixed to the rotating shaft 9. A rotor 11 equipped with a magnet is attached to the upper end of the rotating shaft 9, and the rotor 11 is positioned in a recess 13 formed in the lower surface of a bush 12 fixed to the upper end of the main body 1. Furthermore, a rotation speed detector 14 is attached to the top surface of the bush 12 to detect the approach and separation of the magnets provided on the rotor 11, and input the pulse signal to the control system to detect the flow rate of water to be supplied. are doing.

[Problem that the invention attempts to solve]

By the way, when detecting the flow rate by the rotation speed of the rotary shaft 9 having such blades 10, the rotation speed when the water is flowing in the forward direction from the water supply pipe 2 to the supply pipe 3 cannot accurately measure the passing flow rate. give to On the other hand, when a mistake flows backward from the supply pipe 3 toward the water supply pipe 2, the rotating shaft 9 is rotated by the blades 10, and this is calculated as a passing flow rate.

Therefore, for example, if hot water supply is stopped and a backflow occurs, there is a problem that the backflow will be detected and ignited even though ignition has actually been stopped. Also, backflow may occur during hot water supply and the rotor 11 may stop.
There is also the problem of misfires occurring during hot water supply.

Further, in cold weather, it is unavoidable that the inside of the flow path freezes, but in a device with a built-in rotating element such as a water flow sensor, the effects of such a freezing accident are extremely large. In other words, when using a water heater, water is supplied by heating the piping to make the water fluid, but if the rotating shaft 9 is frozen, it will not rotate even if it receives the flow of this supplied water, resulting in In some cases, it may become impossible to measure the flow rate.

The present invention was devised in view of such problems, and aims to enable accurate flow rate detection at all times even when water backflows or freezes.

[Means and actions for solving problems]

In order to achieve the above object, the present invention connects the main body to the middle of the water supply channel to the water heater, and uses a rotating shaft equipped with wings and a rotation speed detector that detects the rotation speed of the rotating shaft. In a water flow sensor that detects water flow, a valve body that can be opened by water pressure is provided upstream of the position where the rotating shaft is disposed, and a water drainage channel is formed in the valve body. The present invention is characterized in that an auxiliary valve body for a check valve that opens and closes is attached, and an elastic means is further provided for biasing the auxiliary valve body in the valve opening direction.

When the water supply is stopped, the valve body returns to the closed position, but the flow path provided in the valve body communicates the flow path between the water supply source side and the water heater side, and after the valve closes, the flow path on the water heater side is connected. Water in the road is drained through this waterway. Also,
In a situation where backflow occurs, the auxiliary valve body, which is open, closes the flow channel and functions as a check valve.

〔Example〕

Hereinafter, the present invention will be specifically described based on embodiments shown in the drawings.

FIG. 1 is a longitudinal cross-sectional view of the water flow sensor according to the present invention.
2 are cross-sectional views taken along the - line arrow in FIG. 1, and explanations of members common to those shown in the conventional example will be omitted.

In the figure, a valve body 20 for preventing backflow and freezing is arranged on the inlet 4 side of the main body 1, that is, at the bottom of the cylinder 6 used as a chamber for flow rate detection. This valve body 20 has a flange portion 2 at the upper end.
1, and has a cone shape with a cross section that decreases in diameter toward the bottom. The flange portion 21 is seated on the upper surface of an annular stepped portion 15 provided on the inner periphery of the inlet 4 as a valve seat, and functions as a check valve.

That is, the valve body 20 is loosely inserted into an annular opening surrounded by the stepped portion 15, and when water is supplied from the inlet 4, the valve body 20 is moved by the water pressure as shown by the dashed line in the figure. It rises like this and opens the valve. Furthermore, when the water supply is stopped, the valve body 20 falls due to its own weight, and the flange portion 21 seats on the step portion 15 to close the flow path and prevent backflow from the water heater side toward the water supply source side.

Further, the valve body 20 has a passageway 22 having a stepped cross-sectional shape extending through the valve body 20 in its axial direction, so that even when the valve body 20 closes the flow passage, the inlet 4 can be communicated with the flow passage on the downstream side. . An auxiliary valve body 23 for draining water and preventing backflow is disposed inside this water passage 22 and is biased upward by a compression coil spring 24 as an elastic means, and its upper limit position is restrained by a pin 25. are doing.

The auxiliary valve body 23 has a substantially T-shaped cross section, and the lower surface of the annular plate body 26 at the upper end touches and separates from the valve seat surface 27 of the water passage 22 of the valve body 20, so that the opening and closing of the flow passage in the water passage 22 is reversed. This can be done by the water pressure at the time and the biasing force of the compression coil spring 24.

FIG. 4 shows an example of a control system including a system for detecting the amount of water supplied to the water heater using the water amount sensor of the present invention. In the figure, a supply pipe 3 is connected to a heat exchanger B provided in a water heater A, and hot water heated by a burner C is discharged from a hot water supply pipe D. Reference numeral E denotes a control device which inputs a pulse signal from the rotational speed detector 14 of the water amount sensor and a signal from a temperature measuring device F such as a thermistor, calculates these, and determines the amount of water to be supplied and the temperature of the water to be supplied. Also, based on these data, a signal is input to the electromagnetic valve G that adjusts the flow rate of fuel such as gas to the burner C so that the hot water can be heated to the required temperature, and the amount of heat generated is set. Note that H is a hot water temperature setting device, which sets the required hot water temperature.

In the above configuration, during the water supply stop period, the first
As shown in the figure, the flange portion 21 of the valve body 20 is seated on the step 15 surface of the inner periphery of the main body 1, and the auxiliary valve body 23 is moved onto the valve seat surface 27 by the biasing force of the compression coil spring 24.
It is in a state of separation from. That is, since the auxiliary valve body 23 is open, the inflow port 4 side and the discharge port 5 side are connected to the valve body 2 by the water passage 22 in the valve body 20.
Even when the valve 0 is in the open position, it is in communication.

When water supply starts, the valve body 20 is raised by the water supply pressure, and the flange part 21 separates from the step part 15 to open the valve, and water from the inlet 4 is supplied to the water heater A.
Note that during this water supply period, the auxiliary valve body 23 is also open.

By opening the valve body 20 as described above, when water passes through the cylinder body 6, the rotary shaft 9 rotates using the blades 10 that receive the water flow, and the rotor 11 at the upper end and the rotation speed are detected. A signal is input to the control device E through the device 14. Then, based on this input signal, the supply flow rate is calculated, and at the same time, based on the measurement result of the supply water temperature, control is performed to set the fuel supply amount by the electromagnetic valve G so that the required calorific value is achieved.

Furthermore, when the water supply is stopped, the valve body 20 descends under its own weight as the water pressure attenuates, and the flange portion 21 seats on the upper surface of the stepped portion 15 to close the valve. However,
The auxiliary valve body 23 remains open due to the biasing force of the compression coil spring 24.
Therefore, even after the water supply is stopped, the inlet 4 side and the outlet 5 side are communicated with each other, so that the water accumulated in the flow path can be discharged from the flow path 22 to the water supply source side. In other words, the cylindrical body 6 has a built-in rotating shaft 9 for detecting the flow rate.
Water can be drained automatically to prevent freezing in cold weather.

Furthermore, if water tries to flow backwards due to fluctuations in the internal pressure of the channel during water supply or stoppage, the auxiliary valve body 23 receives the water pressure and moves downward, as shown in FIG. 3, and the annular plate body 26 Take a seat on the seat surface 27. As a result, the valve body 20 and the auxiliary valve body 23 are both closed, thereby preventing backflow toward the inlet 4 direction. Therefore, by preventing the occurrence of backflow, the flow of water in the flow path can be suppressed, the rotating shaft 9 is not rotated, and the measurement signal from the rotation speed detector 14 is sent to the control device E. is not entered.

In this way, backflow in the flow path is prevented, so the flow rate in the water supply direction can always be accurately detected without malfunctions caused by the control system, and heating can be performed efficiently in accordance with the set amount of heat generated. .

[Effect of idea]

As described above, in the water flow sensor of the present invention, the valve body that has a drainage passageway formed therein is further provided with an auxiliary valve body that closes the passageway against backflow of water. Therefore, when the water supply is stopped, water can be drained from the water supply channel, the rotating shaft for flow rate detection, etc. is prevented from freezing, and the water heater can operate without malfunction even when reused.

Furthermore, since backflow in the flow path can be prevented by the auxiliary valve body, malfunction of the rotating shaft for detecting the flow rate, etc. will not occur.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of the water flow sensor according to the present invention.
Figure 2 is a sectional view taken along the - line arrow in Figure 1;
Fig. 3 is a longitudinal cross-sectional view showing the opening of the auxiliary valve body due to backflow, Fig. 4 is a schematic diagram showing an example of a control system for detecting the amount of water to the water heater using a water flow sensor, and Fig. 5 is a longitudinal cross-section of a conventional example. It is a diagram. 1... Main body, 2... Water supply pipe, 3... Supply pipe, 4
...Inlet, 5...Outlet, 6...Cylinder, 7,8
...Butsuyu, 9...Rotation axis, 10...Wing, 11
... rotor, 12 ... bush, 13 ... recess,
14... Rotation speed detector, 15... Stepped portion, 20...
Valve body, 21... flange portion, 22... water passage, 2
3... Auxiliary valve body, 24... Compression coil spring (elastic means), 25... Pin, 26... Annular plate body,
27... Valve seat surface, A... Water heater, B... Heat exchanger, C... Burner, D... Hot water supply pipe, E... Control device, F... Temperature measuring device, G... Solenoid valve, H...Setting device.

Claims (1)

[Scope of utility model registration request] In a water flow sensor, the main body is connected to the middle of a water supply channel to a water heater, and the water flow rate is detected by a rotary shaft provided with wings and a rotation speed detector that detects the rotation speed of the rotary shaft, the arrangement of the rotary shaft. A valve body that can be opened by water pressure is provided upstream of the position, and a water drainage channel is formed in the valve body, and an auxiliary valve body for a check valve that opens and closes the water channel is attached. A water amount sensor further comprising elastic means for biasing the auxiliary valve body in the valve opening direction.