JPS6125052B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a safety valve used in a water pipe in a hot water supply device such as a first stop instantaneous water heater. Regarding the safety valve provided.

Conventionally, as shown in FIG. 1, this type of safety valve has a structure in which a valve body 2 is provided inside a main body 1 and is normally biased in the valve closing direction by a spring 4, and has a threaded portion 1A. It is installed in a water pipe of a water heater or the like (not shown).

In such a safety valve, when the internal pressure of the water pipe increases, a force that presses the valve body 2 acts on the upstream side A of the valve body 2, and if the force becomes greater than the preset spring 4 force, the spring 4 When contracted, the valve body 2 separates from the valve seat 3 to open the valve, and water passes through the interior of the main body 1 and flows out to the outside in order to release the pressure inside the water pipe.

Generally, the safety valve operates when an abnormal condition occurs and the water heating combustion device is activated, causing an abnormal increase in internal pressure, even though the faucet on the discharge side of the water pipe is closed. be. However, during normal use, for example, when the faucet is closed after hot water is drawn, a so-called lag phenomenon occurs, where the flow of water stops instantaneously but the combustion is delayed for several seconds before extinguishing the fire. Water heaters installed indoors have the drawback of causing inconvenient situations such as the need to dispose of the spilled water, which requires piping equipment.

Therefore, in view of the above-mentioned conventional circumstances, the present invention is designed to absorb the volumetric expansion of water in the water pipe due to, for example, rear-drilling, inside the safety valve, so that the safety valve does not operate when the volumetric expansion of water occurs during general use. To provide a safety valve for a water heater that prevents water from flowing out.

Hereinafter, the present invention will be explained based on FIGS. 2 to 5.

In FIG. 2, 11 is a safety valve body, 11A and 11B are water inlets and outlets provided at both ends of the main body 11, respectively, and 11C is a threaded portion formed on the inlet 11A side of the main body 11. It is for connecting to water pipes. Reference numeral 12 denotes a valve body disposed in a space 17 on the side of the inlet 11A in the main body 11, which can slide along the inner circumferential wall of the main body 17 in the space 11 via an O-ring 13 attached to the outer periphery. ing. Reference numeral 14 denotes a spring that always urges the valve body 12 to press against the inner end wall of the space 11, and is interposed between the valve body 12 and a spacer 15 supported within the main body 11 on the side of the outlet 11B. .

Next, the inner space 18 of the main body 11 excluding the space 17 is formed to have an inner diameter D ₂ larger than the inner diameter D ₁ of the space 17, and while the valve body 12 slides from the A position to the B position in the diagram of the space 17, The space 17 is closed by the O-ring 13.
is sealed and the O-ring 13 passes the B position in the figure, the O-ring 13 is no longer in contact with the inner peripheral wall of the space 17, and the outer peripheral surface of the valve body 12 and the space 1 are no longer in contact with each other.
A gap is formed between the inner circumferential surface of the main body 11 in the 8th part and allows water flowing in from the inlet 11A to reach the outlet 11B.

The spring 14 is operated by the operating pressure required to slide the valve body 12 from the A position to the B position when absorbing the volumetric expansion of the water in the water pipe at the rear, etc., and when the valve body 12 operates as a safety valve. The operating pressure for moving from position B onward is set.

In such a safety valve, if, for example, after closing the discharge side faucet of the water pipe of a water heater, a pressure rise occurs due to the volumetric expansion of the water in the water pipe, the valve body 12 is first moved to the closed position A, 17 body 11
It slides along the inner circumferential surface, and at this time the space 17 expands to absorb the volumetric expansion of the water. That is, the space 17 becomes an expansion chamber with a maximum predetermined volume that expands before the valve opening operation of the valve body 12 and absorbs the volumetric expansion of water generated in the water pipe.

On the other hand, during normal operation as a safety valve, the valve body 12
moves the O-ring 13 past the B position,
The O-ring 13 cannot maintain a seal between the valve body 12 and the inner peripheral surface of the main body 11, and water in the water pipe flows through the main body 11 and flows out from the outlet 11B.

In the above configuration, if an adjustment screw 19 as shown in FIG. 3 is used instead of the spacer 15, the above-mentioned setting pressure by the spring 14 can be easily adjusted.

Next, another embodiment of the present invention is shown in FIGS. 4 and 5.

The valve shown in FIG. 4 has a valve body 121 that functions as a safety valve and absorbs the volumetric expansion of water, whereas the valve shown in FIG. It separately includes a valve body 12B that operates as a safety valve and a sliding body 12A that absorbs the volumetric expansion of water. That is, the sliding body 12A
is configured to slide inside the main body 11 via an O-ring 13 on the outer periphery, and is always supported by a spring 14.
A is biased toward the inlet port 11A.
On the other hand, the valve body 12B is biased by a spring 14B so as to come into pressure contact with the downstream end surface of the sliding body 12A.

The operating pressure of the sliding body 12A and the valve body 12B is set by springs 14A and 14B, respectively, and 27 expansion chambers each having a maximum predetermined volume expand when the sliding body 12A slides. After absorbing the expansion, the valve body 12B moves away from the sliding body 12A and opens, opening the inlet 11A and the outlet 11B.
The water in the water pipe is allowed to flow out to the outside by communicating with the water pipe.

Also, what is shown in FIG. 5 is the valve body 2 of the valve body 11.
An expansion chamber 37 having a maximum predetermined volume is constructed by forming a part of the upstream space with an elastic member.
0, the diaphragm 20 deforms and the expansion chamber 37 expands to absorb the volumetric expansion of water.

As explained above, according to the present invention, before operating as a safety valve, a maximum predetermined volume expansion chamber is provided in the main body, which expands to absorb the volumetric expansion of water that occurs during general use such as after-drilling. By doing this, it is possible to prevent the situation in which the safety valve is activated and the water in the water pipe flows out to the outside during general use, and there is no need to take the trouble to install water outflow pipes etc. in water heaters etc. installed indoors. There is an advantage that there is no need to provide special measures for the volumetric expansion of water.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view showing the structure of a conventional safety valve.
FIG. 2 is a longitudinal sectional view showing the structure of the safety valve according to the present invention, FIG. 3 is a longitudinal sectional view showing another embodiment of a part of the same safety valve, and FIGS. FIG. 7 is a vertical cross-sectional view showing another embodiment of such a safety valve. 11... Safety valve body, 2, 12, 12B... Valve body,
12A...Sliding body, 14, 14A, 14B...Spring, 20...Diaphragm, 17, 27, 37...
expansion chamber.

Claims (1)

[Scope of Claims] 1. A safety valve that is installed in a part of a water pipe of a water heater and opens a valve body to release water from the water pipe to the outside when the internal pressure of the water pipe reaches a predetermined value. A safety valve for a water heater, characterized in that an expansion chamber having a maximum predetermined volume is provided in a space within the valve body on the upstream side of the main body to absorb volumetric expansion of water generated in a water pipe. 2. The expansion chamber according to claim 1, wherein the expansion chamber is configured to expand the space upstream of the valve body within the valve body by a sliding body that slides within the valve body against an elastic biasing force. Safety valve for water heater. 3. The safety valve for a water heater according to claim 2, wherein the sliding body is integrally formed with the valve body. 4. The safety valve for a hot water supply apparatus according to claim 1, wherein the expansion chamber is formed by forming a part of the wall of the space upstream of the valve body of the valve body from an elastic member.