JPS63123949A - Small size water heater - Google Patents

Abstract

PURPOSE:To prevent high-temperature hot water from being supplied by constituting the water heater so that it is provided with a self-holding type solenoid for actuating a capacity changeover valve for turning down the thermal power of a burner by a predetermined quantity and a capacity changeover switch manually operating the solenoid, and that the thermal power of the burner is turned down by the solenoid when the supply hot water temperature reaches an extraordinarily high temperature. CONSTITUTION:When a temperature sensor 34 detects the supply hot water of an extraordinarily high temperature by lowering of a water supply temperature, a self-holding type solenoid 25 is actuated through a control circuit 35 by a capacity changeover switch 8, a capacity changeover valve 24 is closed, the thermal power of a gas burner 16 is turned down, and high temperature hot water is prevented from being supplied. By these procedures, the prevention of a scald due to the too hot water supply and that of wasteful consumption of a fuel due to unnecessary combustion can be attempted.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application The present invention relates to a small-sized water heater that is mainly installed and used in a kitchen or the like.

(b) Conventional technology In relatively large water heaters, the temperature of hot water, water supply temperature, etc. are detected by sensors, and the burner combustion amount, water supply amount, etc. are controlled by a control circuit, so that the user can Although it is configured to provide hot water at a set temperature, it requires a large number of parts for control, making it difficult to use in the above-mentioned small water heaters due to cost. As shown in Publication No. 62751, since the combustion capacity of the burner is semi-fixedly adjusted by manual operation using a temperature control knob, the water supply pressure may drop due to any reason during heavy twist firing, causing hot water to be discharged. Even if the temperature rises, there are openings that cannot be prevented.

(c) Problems to be Solved by the Invention The present invention aims to prevent hot water from flowing out at a high temperature due to a sudden drop in water supply pressure.

(d) Means for solving the problem The present invention provides a capacity switching valve that reduces the thermal power of the burner by a predetermined amount in the fuel flow path of the burner that heats the heat exchanger, and also drives this capacity switching valve. It is equipped with a self-holding solenoid and a switch to manually operate the solenoid, and a temperature sensor that detects the hot water temperature of the heat exchanger.When the output of this temperature sensor reaches an abnormally high temperature, the self-holding solenoid is activated. A control means for reducing the firepower of the burner is provided.

(e) When the temperature sensor detects hot water at an abnormally high temperature due to a drop in the working water supply pressure, etc., the control means operates a self-holding solenoid to throttle the firepower of the burner to prevent hot water from flowing out at a high temperature.

(1) is a relatively small water heater body installed in a kitchen etc., and the front case (2) is
) is equipped with an exhaust hole (3) at the top, an operation panel (4) is installed at the front of the bottom, and a hot water tap (5) is installed at the bottom.
) is attached so that it can be rotated left and right.

The operation panel (4) is equipped with a start/stop switch (6) on the right side, and a plurality of water volume setting buttons (7) (7)... and a capacity selection switch (
8).

On the other hand, inside the main body (1), as shown in FIG.
Water flow control valve (11), heat exchanger (12), faucet (13)
are arranged in sequence. The water volume adjustment valve (11) is operated by the drive mechanism (14) to control the water volume setting buttons (7) (7)...
Set to a predetermined amount according to the selected button.

(15) is a fuel flow path to the gas burner (16) that heats the heat exchanger (12), and from upstream, the former solenoid valve (17),
A gas governor (18), a diaphragm (19) interlocked with the water governor (10), and a seat valve (21) interlocked via a spindle (20) are sequentially arranged, and the gas burner is connected to the gas burner from downstream of the seat valve. (16), a first flow path (22) that extends to approximately half of the flow path, and a second flow path (22) that extends to approximately half of the flow path (16);
It branches into a flow path (23), and this second flow path is provided with a capacity switching valve (24).

Also, the opening/closing of the faucet (13) and the capacity switching valve (24) are performed using a self-holding solenoid (2) as shown in Fig. 3.
5), and as is well known, this solenoid is constructed by attaching an electromagnetic coil (28) and a permanent magnet (29) around a cylinder (27) that slidably houses a plunger (26). The plunger (26) is moved by momentarily energizing the electromagnetic filter (28) in the direction of canceling and increasing the magnetic force of the permanent magnet (29), and after the movement, the permanent magnet (29)
9) Hold it in that position using the magnetic field.

The valve body (17') of the original solenoid valve (17) is driven to the valve open position via the drive shaft (31) by the swing jack 30), and at the same time, DC power is supplied from a source (not shown) for a predetermined period of time. The valve is driven to open when the gas burner (16) is ignited.

Also, after the gas burner (16) is ignited, its combustion flame (32)
An electromotive force for keeping the valve open is supplied to the original TM valve (17) from a thermocouple (33) heated by the thermocouple (33).

(34) is a temperature sensor such as a thermistor installed downstream of the heat exchanger (12) of the water passageway (9).
In addition to detecting the hot water temperature, the output is connected to the control circuit (35-inch).

The control circuit (35) is also connected to the operation panel (4), and when the start/stop switch (6) is turned on, the self-holding solenoid (25') is energized and the faucet (13) is turned on.
At the same time, the main solenoid valve (17) is energized for a predetermined period of time, the plunger (30) is energized to open the valve body (17'), and the ignition plug (36) is used to discharge electricity. This allows water to flow through the water passageway (9) and the seat valve (21)
opens, gas is supplied to the gas burner (16), and ignition combustion occurs. At this time, the water volume control valve (11) is pressed by pressing the water volume setting button <7) (
7)..., and hot water at a temperature corresponding to the temperature is discharged from the hot water outlet pipe (5).

On the other hand, the capacity selector valve (24) is a self-holding solenoid (25'') that opens and closes in response to the on/off operation of the capacity selector switch (8), and also prevents water supply from decreasing due to an abnormal drop in water supply pressure, etc. , as shown in Figure 4, the temperature sensor (3
When the output of step 4) reaches, for example, 95° C. shown in step S1, the control circuit (35) closes the firing, and even after a predetermined period of time (for example, several seconds) has elapsed in step S3, the outlet temperature remains as shown in step S4. For example, if the temperature does not drop below 75°C, the electromotive force supply from the thermocouple (33) to the original solenoid valve (17) is stopped and the original solenoid valve (17) is closed (step S5). When one second has elapsed in step S8 after opening the solenoid valve, the faucet (13) is closed in step S7.

In addition, if the temperature is below 95°C in step S1 and step S4
If the temperature is 75° C. or lower, the process proceeds to step Ss and normal tapping process is performed, but if the process proceeds from step S4 to step SO, the gas burner (16) performs hot water tapping process with weak combustion.

(g) Effects of the invention Using a capacity switching valve that is normally switched manually,
It is possible to prevent hot water from spewing out due to a drop in water supply pressure, etc., to prevent burns caused by hot water, and to prevent waste of fuel due to unnecessary combustion.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the present invention, FIG. 2 is a structural explanatory diagram,
Figure 3 is a vertical cross-sectional view of the self-holding solenoid, and Figure 4
The figure is also a flowchart of the main part. (8) Capacity selector switch, <12) Heat exchanger, (15) Fuel flow path, (16) Gas burner, (24) Capacity selector valve, (25 )...Self-holding solenoid, (34)...Temperature sensor, 35)
...Control circuit. Figure 1

Claims (1)

[Claims] (1) A capacity switching valve is installed in the fuel flow path of the burner that heats the heat exchanger to reduce the thermal power of the burner by a predetermined amount, and a self-holding solenoid that drives this capacity switching valve and this self-holding solenoid can be operated manually. There is also a temperature sensor that detects the hot water temperature of the heat exchanger, and when the output of this temperature sensor reaches a preset abnormally high temperature, the self-holding solenoid is activated to reduce the burner power. A small water heater comprising a control means.