JPH056269U - Overflow prevention valve - Google Patents

Abstract

(57) [Summary] [Purpose] To delay the operating time of the safety valve 12 at the time of overflow. [Structure] An eccentric portion 12e is a portion of a shaft portion 12a of a safety valve 12 which is located upstream of a seal portion 12b. The axis of the eccentric portion 12e is S on one plane.
It meanders as if the letters were continuous. This eccentric part 12e
The inner ring 14 in the upstream side support ring 14.
It is inserted into the insertion hole 14e of a. When the gas overflows, the resilient force of the spring 15 is overcome and the safety valve 12 moves to the downstream side. When the eccentric portion 12e passes through the insertion hole 14e during the movement, the safety valve 12 advances while swinging its hip up and down, with the portion supported by the inner ring 13a of the downstream side support ring 13 as a fulcrum. By moving while swinging the buttocks, the moving distance of the safety valve 12 becomes long, and the outer peripheral surface of the eccentric portion 12e slides on the wall surface of the minimum diameter portion 14f of the insertion hole 14e, so that frictional resistance is generated between them. It works, and the moving speed of the safety valve 12 becomes slow.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to an overflow prevention valve that shuts off gas flow in an emergency.

[0002]

[Prior Art]

 Some gas cocks have a built-in overflow prevention valve. The basic type of this type of gas cock is that a spherical safety valve is housed inside the gas passage of the gas cock so that it can move up and down.In normal use, the safety valve moves away from the valve seat due to its own weight to prevent gas flow. The flow is secured, and when the gas overflows, the safety valve rises and sits on the valve seat, blocking the flow of gas.

By the way, in recent years, a gas appliance equipped with a pressure regulator has emerged for the purpose of energy saving. If the gas cock is connected to this type of gas appliance, the gas will momentarily overflow and the safety valve will sit on the valve seat for a short time until the gas pressure stabilizes immediately after operating the gas appliance. After that, there was a situation in which gas could not be supplied to the gas appliances after that.

A gas cock with a built-in overflow prevention valve that solves this problem is disclosed in Japanese Patent Publication No. 58-7868. In this gas cock, in order to secure the operation time of the safety valve for a predetermined time, an obstacle protrusion is provided in the movement passage of the safety valve. That is, the obstacle protrusions meander the movement path of the safety valve to extend the movement distance, and when the safety valve moves closer to the valve seat due to excessive gas outflow, the safety valve collides with the obstacle protrusions to dissipate energy. , Reduce the moving speed of the safety valve. As a result, the time required to complete the operation of the safety valve can be lengthened by a predetermined amount.

[0005]

[Problems to be solved by the device]

 By the way, the above-mentioned overflow prevention valve, in which the safety valve is separated from the valve seat by its own weight, has a drawback in that its mounting posture is restricted due to its structure. Therefore, as a solution to this problem, as disclosed in Japanese Utility Model Laid-Open No. 62-196968, an overflow prevention valve has been developed that uses the elastic force of the spring to separate the safety valve from the valve seat. Has been done. However, in the case of a gas cock incorporating the above-mentioned overflow prevention valve, it was not possible to adopt the same structure as described above in order to solve the above-mentioned problem when connected to a gas appliance with a pressure regulator. This is because the safety valve urged by the spring was designed to move linearly.

The present invention has been made in view of the above-mentioned problems of the conventional technique, and an object thereof is to prevent the gas passage from being blocked by an instantaneous outflow of gas in a normal use state. There is an attempt to provide an overflow prevention valve that reliably blocks the flow of gas only when the overflow state of gas continues for a predetermined time.

[0007]

[Means for Solving the Problems]

 This invention was made in order to achieve the above-mentioned object, and its gist consists of a casing having a gas passage inside and a safety valve movably accommodated in the gas passage of this casing. The above-mentioned safety valve separates from the valve seat provided in the above-mentioned gas passage to allow the flow of gas, and when the gas flows in an overflow state, the above-mentioned safety valve sits on the valve seat and shuts off the flow of gas. In the above, the safety valve is composed of a shaft portion and a seal portion that is seated on the valve seat of the casing.In the gas passage of the casing, the shaft portion of the safety valve is inserted into the insertion hole to pass the safety valve to the gas passage. A support ring is provided to support the shaft so that it can move in the axial direction.The shaft of the safety valve has an eccentric part that extends while eccentrically extending the shaft center at the position where the insertion hole of the support ring is inserted. Thus, when the safety valve moves, the eccentric portion of the shaft portion is guided by the insertion hole of the supporting ring so that the shaft portion can be swung in the radial direction. It is in the prevention valve.

[0008]

[Operation] When the gas overflows, the safety valve moves forward toward the valve seat. During the movement, the eccentric part provided on the shaft part of the safety valve passes through the insertion hole of the support ring. As a result, the safety valve advances while swinging the hip or neck in the radial direction. Since the safety valve meanders in this way, the travel distance is longer than before. Further, since the outer peripheral surface of the eccentric portion comes into contact with the inner surface of the insertion hole and moves while sliding, frictional resistance acts between them and the moving speed of the safety valve approaching the valve seat becomes slow. As a result, if the force acting on the safety valve at the time of overflow of gas is the same, the overflow prevention valve of the present invention requires more time than the conventional overflow prevention valve from the start of operation of the safety valve to the completion of operation. Becomes longer.

Therefore, in the momentary overflow state in the normal gas flow state, even if the safety valve starts operating, it takes a long time to complete its operation. Then, the operation of the overflow prevention valve is avoided. On the other hand, if an unexpected situation occurs in the gas line incorporating this overflow prevention valve and the gas overflow state continues for a while, the safety valve will sit on the valve seat after the elapse of a predetermined time, ensuring reliable gas flow. Shut off.

[0010]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. 1 to 8. The overflow prevention valve in this embodiment is built in the gas cock. As shown in FIG. 1, in a gas cock 1 according to this embodiment, a valve body 3 for connecting and disconnecting the above passages 2A and 2B is rotatably provided in a gas cock body 2 having an inflow passage 2A and an outflow passage 2B. The inflow passage 2A of the gas cock body 2 is provided with an overflow prevention valve 10 which is the gist of the present invention.

The valve body 3 is formed in a tapered shape having a small diameter on the lower side, and is inserted into the valve body housing space of the gas cock body 2 from above. The tapered surface on the outer periphery is in close contact with the tapered sliding surface 2C of the gas cock body 2. The valve body 3 is provided with a communication hole 3A that connects the inflow passage 2A and the outflow passage 2B of the gas cock body 1. Then, by operating the knob 4 to rotate the valve body 3, the inflow passage 2A and the outflow passage 2B can be connected or disconnected. The open end of the inflow passage 2A of the gas cock body 2 is a threaded portion 2a, which can be connected to the gas pipe. Further, in the inflow passage 2A, an accommodating portion 2b for accommodating the overflow prevention valve 10 is formed on the downstream side that is continuous with the screw portion 2a.

As shown in the sectional view of the entire assembly of FIG. 2, the overflow prevention valve 10 is a casing 11 screwed and fixed to the accommodation portion 2 b of the gas cock body 2, and is movably accommodated in the casing 11. The safety valve 12 includes a downstream support ring 13 and an upstream support ring 14, which are attached to the downstream side and the upstream side of the casing 11 and movably support the safety valve 12.

The casing 11 has a substantially cylindrical shape having a cavity inside, and by screwing a male screw portion 11d provided in a part of the outer peripheral portion into a female screw portion 2c formed in the housing portion 2b of the gas cock body 2, It is fixed to the gas cock body 2. An O-ring 16 seals between the casing 11 and the gas cock body 2. The casing 11 has an opening end arranged on the downstream side (left side in FIG. 2) in the gas cock body 2 as a mounting hole 11a for the downstream side support ring 13, and is arranged on the upstream side (right side in FIG. 2). The opening end is a mounting hole 11b for the upstream support ring 14, and both mounting holes 11a, 11b are connected by a gas passage 11c whose axis coincides with the axis of the inflow passage 2A of the gas cock body 2.

On the other hand, as shown in FIGS. 4 and 5, the safety valve 12 is composed of an elongated shaft portion 12a having a circular cross section and a seal portion 12b formed in the middle of the shaft portion 12a. The outer surface 12c of the seal portion 12b is formed of a part of a spherical surface, and can be seated on a valve seat 11e formed of a tapered surface provided in the middle of the gas passage 11c of the casing 11. Then, as shown by an imaginary line in FIG. 2, when the seal portion 12b of the safety valve 12 is seated on the valve seat 11e of the casing 11, the gas passage 11c of the casing 11 is closed, and at that time, the tip of the shaft portion 12a is closed by the gas cock. It is dimensioned so that it projects from the inflow passage 2A of the body 2 and projects into the gas passage 3A of the valve body 3.

The shaft portion 12a has a circular cross section, and its outer diameter is the same throughout its entire length. In the shaft portion 12a, a portion located downstream of the seal portion 12b (left side in FIG. 4) is a straight portion 12d, and a portion located upstream of the seal portion 12b (right side in FIG. 4) is eccentric. It is a part 12e. The axis of the straight portion 12d extends in a straight line, but the axis of the eccentric portion 12e meanders in a continuous S-shape on one plane.

As shown in FIGS. 6 (A) and 6 (B), the downstream side support ring 13 has an inner ring 13a through which the straight portion 12d of the shaft portion 12a of the safety valve 12 is inserted, and the inner ring 13a which is concentric with the inner ring 13a. It is composed of an outer ring 13b arranged and fitted in the mounting hole 11a of the casing 11, and an arm 13c connecting the inner ring 13a and the outer ring 13b. Gas can flow between the inner ring 13a and the outer ring 13b. It is like this. The inner diameter of the insertion hole 13e of the inner ring 13a is slightly larger than the outer diameter of the straight portion 12d. A wedge 13d is formed on the outer peripheral surface of the outer ring 13b to prevent the wedge from falling off.

The upstream side support ring 14 basically has the same structure as the downstream side support ring 13. As shown in FIGS. 7 (A) and 7 (B), the inner ring 14 a and this inner ring 14 a 14a and an outer ring 14b arranged concentrically with each other and fitted into a mounting hole 11b of the casing 11, and an arm 14c connecting the inner ring 14a and the outer ring 14b, and between the inner ring 14a and the outer ring 14b. The gas can be distributed.

The inner peripheral surface of the inner ring 14a is formed into a tapered surface having a minimum diameter at the center and a maximum diameter at both ends. The inside of this tapered surface is an insertion hole 14e through which the eccentric portion 12e of the safety valve 12 is inserted. The inner diameter of the minimum diameter portion 14f in the insertion hole 14e is slightly larger than the outer diameter of the eccentric portion 12e. A wedge 14d is also provided on the outer peripheral surface of the outer ring 14b of the upstream support ring 14. The safety valve 12 is urged to the upstream side by a spring 15 interposed between the seal portion 12b and the inner ring 13a of the downstream side support ring 13.

In the gas cock 1 having the above-described configuration, when the valve body 3 is closed and when gas is not flowing, the safety valve 12 is caught by the arm 14c of the upstream side support ring 14 and stops, and the inoperative position. Is located in. At this time, the axis of the straight portion 12d of the safety valve 12 is substantially aligned with the axis of the insertion hole 13e of the downstream support ring 13 and the axis of the insertion hole 14e of the upstream support ring 14. Further, when the valve body 3 is open and in a normal gas circulation state, the force for pushing the safety valve 12 to the downstream side by the gas pressure is smaller than the elastic force of the spring 15, and the safety valve 12 is Remains in the inoperative position.

On the other hand, when the flow of gas becomes an outflow state and the force for pushing the safety valve 12 to the downstream side by the gas pressure overcomes the elastic force of the spring 15, the safety valve 12 moves to the downstream side. During the movement, the eccentric portion 12e of the safety valve 12 passes through the insertion hole 14e of the upstream side support ring 14. As a result, as shown in FIG. 8, the safety valve 12 moves forward while swinging its butt up and down in FIG. 8 with the portion supported by the inner ring 13a of the downstream side support ring 13 as a fulcrum. In the figure, the alternate long and short dash line represents the axis of the insertion holes 13e, 14e of the support rings 13, 14 (that is, the axis of the gas passage 11c).

Since the safety valve 12 meanders by the action of the eccentric portion 12e in this manner, the moving distance thereof becomes longer than in the conventional case. Further, when the safety valve 12 moves in the gas overflow state, the outer peripheral surface of the eccentric portion 12e comes into contact with the wall surface of the minimum diameter portion 14f of the insertion hole 14e and moves while sliding. During this period, frictional resistance acts, and the moving speed of the safety valve 12 approaching the valve seat 11e becomes slow. Then, by the synergistic effect of (i) the movement distance of the safety valve 12 becomes longer than before, and (ii) the friction that slows the movement speed of the safety valve 12 works, the safety valve 12 is pushed to the downstream side by the gas pressure. If the moving force is the same as that of the conventional one, the overflow prevention valve 10 of the present invention is better than the conventional overflow prevention valve in that the safety valve 12 starts moving and is seated on the valve seat 11e. It takes a long time.

Therefore, when a gas appliance with a pressure regulator is connected to the gas cock 1, even if the safety valve 12 begins to operate due to a momentary overflow condition at the beginning of use of the gas appliance, the safety valve 12 operates as a valve. Since it takes a long time to sit on the seat 11e, the safety valve 12 returns from the above-mentioned overflow state to the normal gas flow state before the operation is completed, and the operation of the overflow prevention valve 10 is avoided. On the other hand, when the gas hose is disconnected from the gas appliance, the overflow state of the gas continues, so that the safety valve 12 is seated on the valve seat 11e after a predetermined time, and the flow of the gas is surely cut off.

The overflow valve 10 is reset by closing the valve body 3. That is, a cam surface (not shown) is provided on the outer peripheral surface of the valve body 3 of the gas cock 1, and when the valve body 3 is rotated in the closing direction when the overflow prevention valve 10 is operated, the cam surface described above is provided. However, the tip of the shaft portion 12a of the safety valve 12 protruding into the communication hole 3A of the valve body 3 is pushed upstream to separate the safety valve 12 from the valve seat 11e. As a result, the safety valve 12 is biased by the spring 15 and returned to the upstream side. Also at this time, the safety valve 12 retreats while meandering and returns to the inoperative position.

The present invention is not limited to the above-mentioned embodiment and various modes can be adopted. For example, the inner peripheral surface of the insertion hole 13e of the downstream side support ring 13 is a tapered surface corresponding to the insertion hole 14e of the upstream side support ring 14 in the above embodiment, and the insertion hole 14e of the upstream side support ring 14 is a straight hole. The straight portion 12d of the safety valve 12 is provided behind the seal portion 12b, the eccentric portion 12e is provided ahead of the seal portion 12b, and the spring 15 is attached so as not to interfere with the eccentric portion 12e. You may move forward while shaking your head.

Further, in the above-described embodiment, the eccentric portion 12e of the safety valve 12 is eccentric so as to meander on one plane, but the eccentric portion 12e is spirally extended to be three-dimensionally eccentric. You may do it. By doing so, the safety valve 12 can meander and move in a spiral shape, and the moving distance can be further lengthened.

Further, in the above-described overflow prevention valve 10, the safety valve 12 is separated from the valve seat 11e by the elastic force of the spring 15, but the safety valve 12 is changed depending on the mounting posture of the overflow prevention valve 10. When the valve is moved upward to approach the valve seat 11e, the spring 15 may not be provided and the safety valve 12 may be separated from the valve seat 11e by gravity.

If dimensionally permitted, the overflow prevention valve 10 can be housed in the communication hole 3 A of the valve body 3 of the gas cock 1. Further, it can be incorporated in a ball valve type gas cock in which the valve element is spherical. Further, although the overflow prevention valve in this embodiment is built in the gas cock, it may be built in the pipe joint or the like.

[0028]

[Effect of the device]

 As described above, according to the present invention, when the gas overflows, the safety valve moves in a zigzag manner and the moving distance becomes longer than before, and the eccentric portion of the safety valve and the wall surface of the support ring are Since friction acts between the safety valves, the moving speed of the safety valve is slowed, and as a result, the time required from the start of operation of the safety valve to the completion of operation can be lengthened.

Therefore, when the gas momentarily overflows in the normal gas flow state, even if the safety valve starts to operate, it returns from the overflow state to the normal gas flow state before the operation is completed, and It has an excellent effect that the operation of the outflow prevention valve can be avoided. Then, only when the gas outflow state continues for a long time and an emergency shutoff is required, the safety valve is seated on the valve seat after a predetermined time elapses, and the gas flow is shut off.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a gas cock having a built-in overflow prevention valve according to the present invention.

FIG. 2 is a vertical cross-sectional view of an overflow prevention valve.

FIG. 3 is a view on arrow I of FIG.

FIG. 4 is a front view of a safety valve.

FIG. 5 is a view on arrow II in FIG.

6A and 6B show a downstream side support ring, FIG. 6A is a plan view thereof, and FIG. 6B is a sectional view taken along the line III-III of FIG.

7A and 7B show an upstream side support ring, FIG. 7A is a plan view thereof, and FIG. 7B is a sectional view taken along the line IV-IV of FIG.

FIG. 8 is a schematic front view showing the operation of the safety valve.

[Explanation of symbols]

 10 Overflow Prevention Valve 11 Casing 11c Gas Passage 11e Valve Seat 12 Safety Valve 12a Shaft 12b Seal Part 12e Eccentric Part 14 Support Ring 14e Insertion Hole

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yasushi Kosugi 4-20-14 Toyohashi, Shinagawa-ku, Tokyo Gwangyang Industrial Co., Ltd. (72) Inventor Hitoshi Denda 4-20-14 Toyohachi, Shinagawa-ku, Tokyo Gwangyang Industrial stock company

Claims (1)

[Claims for utility model registration] [Claim 1] A casing having a gas passage therein, and a safety valve movably accommodated in the gas passage of the casing. Usually, the safety valve is provided in the gas passage. In the overflow prevention valve that separates from the valve seat and allows the gas to flow, and when the gas flows in the overflow state, the safety valve sits on the valve seat and blocks the flow of the gas. And a seal portion that is seated on the valve seat of the casing.In the gas passage of the casing, the shaft portion of the safety valve is inserted through the insertion hole to support the safety valve so as to be movable in the axial direction of the gas passage. There is a support ring for the safety valve shaft.
An eccentric part that extends while decentering the shaft center is provided at a portion of the support ring that is inserted through the insertion hole, so that when the safety valve moves, the eccentric part of the shaft part is guided by the insertion hole of the support ring and the shaft part. Is designed to be swung in the radial direction of the valve.