JPS626433Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an antifreeze valve used in an instantaneous water heater. Conventionally, anti-freeze valves (low-temperature operating valves) have been commonly used, which detect a drop in outside temperature and open the valve body on its own to allow water to flow out to prevent freezing of the water passages inside the vessel. is usually installed on the hot water outlet pipe side to prevent the entire water passageway from freezing. That is, in FIG. 1, the antifreeze valve 1 is connected to the outlet pipe 2 in a branched manner. An example of the structure of this antifreeze valve is as shown in FIG. It is opened and closed by a valve body 6 attached to the upper end of the temperature sensing element 5 enclosed in the temperature sensing part A. It is slidably inserted into the temperature sensing element 5 and supports the lower end of the shaft 7 which is pushed out by the expansion of wax. It is supported at the lower end of the cylinder 8, and when the temperature sensing element 5 moves relative to the shaft 7, the valve hole 4
The valve hole 4 is opened and closed by moving toward and away from the drain channel 3. Conventionally, when the valve hole 4 is opened, the drain channel 3
The following drawbacks occurred because the water from the temperature sensor was flowing in contact with the surface of the temperature sensing element 5. That is, in this conventional example, even at low temperatures when the antifreeze valve 1 is operating, if the hot water outlet pipe 2 downstream of the valve 1 is not blocked by freezing, the ignition operation is performed and the hot water supply valve 9 is turned on.
By opening the door, hot water can be supplied. With the start of hot water supply, hot water also flows to the antifreeze valve 1, and the temperature sensing element 5 of the valve 1 is heated and the operation stops. However, if the hot water supply is stopped at this point, the water flow will stop. Eventually, the temperature sensor 5 detects the outside temperature and the valve body 6
When the valve hole 4 is opened, the hot water remaining in the heat exchanger 10 and the hot water outlet pipe 2 comes out and comes into contact with the temperature sensing element 5, especially the temperature sensing part A, and heats it. The body 6 closes immediately without fully opening, and after dissipating the residual heat of the temperature sensing body 5, it opens again, repeating an intermittent operation. In this case, the valve opening time is extremely short, and since the valve opening is small, the amount of water flowing out is small, so freezing occurs and progresses, especially from the water inlet pipe 11 to the heat exchanger 10, and eventually the hot water is completely discharged. Even when the antifreeze valve was fully opened and the flow increased due to the cold water, there was a high risk that the ice that had formed inside would block the water passage, stopping the water flow and causing complete freezing.

The present invention aims to eliminate the inconveniences caused by the conventional antifreeze valve structure, and will be explained below with reference to the embodiment shown in FIG. However, its structure includes a cap 1 made of a material with low thermal conductivity, such as a skirt-shaped resin, at least in the temperature sensing part A of the temperature sensing element 5 excluding the valve body 6, except for the lower surface thereof.
2 is covered by a method such as press fitting. In addition, 1
Reference numeral 3 denotes a number of water outlet holes provided in the peripheral wall of the support cylinder 8 which holds the lower end of the shaft 7 of the temperature sensor 5 and surrounds the temperature sensor 5; 14 indicates the direction in which the temperature sensor 5 is always opened ( This is a spring for opening the valve body 6 that presses downward (downward).

The present invention has such a configuration, and as described above,
When the antifreeze valve 1 senses the outside temperature through the water outlet 13 and operates again from the start of hot water supply to the stop of hot water supply while the antifreeze valve 1 is operating, the hot water remaining in the hot water outlet pipe 2 flows out from the valve hole 4. However, since the temperature sensing element 5 is covered with a cap 12 having low thermal conductivity at least over the temperature sensing part A, the sensing of hot water in the temperature sensing part A is delayed, and during this time the opening of the valve hole 4 is longer than in the conventional example. The process continues, and most of the remaining hot water is drained out.
Even if the thermosensor 5 is indirectly warmed by the residual hot water flowing out and the valve hole 4 is closed, the water in the water passage inside the vessel is still flowing a lot while it is flowing, so it is especially difficult to freeze. Freezing does not occur even in the heat exchanger 10, which is likely to occur.

In this way, after the residual hot water has drained out, water can continue to flow out to completely prevent freezing. Then, by indirectly receiving the temperature of the water that comes out, the temperature sensor 5 moves, and the valve hole 4 moves according to the temperature of the water that comes out.
Since the amount of water flowing out can be increased or decreased by adjusting the degree of opening, water wastage can be reduced.

In addition, in the normal operation of the antifreeze valve 1,
Since the outside temperature gradually decreases, there is no change in the valve opening temperature. If the lower part of the cap 12 is opened so that the lower surface of the temperature-sensing section A is directly exposed to the outside air, the cap 12 can sufficiently cope with sudden changes in the outside temperature.

As described above, in this invention, the tip of the shaft that is slidably inserted into the temperature sensor is fixed with a support tube that surrounds the temperature sensor, and the temperature sensor moves as the outside temperature changes. In anti-freezing valves in which a valve body installed in the section opens and closes the drainage channel, at least the temperature-sensing section of the temperature-sensing element is covered with a cap made of a material with low thermal conductivity such as resin, so that In addition to the anti-freeze function, when the anti-freeze valve is activated after hot water is used at low temperatures, the hot water inside the vessel is discharged without any delay, which prevents freezing caused by delays in water flow. , has excellent effects.

[Brief explanation of the drawing]

Figure 1 is an overall view of a water heater equipped with an anti-freeze valve, Figure 2 is a vertical cross-sectional view showing a conventional anti-freeze valve structure, and Figure 3 is a vertical cross-section showing an embodiment of the anti-freeze valve of the present invention. It is a diagram. DESCRIPTION OF SYMBOLS 1...Anti-freezing valve, 3...Drain channel, 5...Temperature sensing element, 6...Valve body, 7...Shaft, 8...Support tube, 12
... Cap, A ... Temperature sensing part.

Claims (1)

[Scope of utility model registration request] The tip of the shaft that is slidably inserted into the thermosensor is fixed with a support tube that surrounds the thermosensor, and as the thermosensor moves as the outside temperature changes, the valve body provided at the end of the shaft releases water. 1. An antifreeze valve for opening and closing a passage, characterized in that at least a temperature sensing portion of a temperature sensing element is covered with a cap made of a material with low thermal conductivity such as resin.