JPS628704Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is an overflow prevention valve, in particular, a type in which a ball valve made of synthetic resin is housed in a cylindrical body. The present invention relates to a so-called omnidirectional overflow prevention valve that is automatically closed by being moved toward the valve seat port side by the flow, and which has no restrictions on its mounting orientation.

As shown in FIG. 1, this type of overflow prevention valve has a cylindrical main body 1 housed in a gas flow path in an airtight manner around the outer periphery, an upper end opening of the main body serving as a valve seat opening 2, and a cylinder below the It is known that a chamber 3 is opened to the upstream side and a ball valve 4 made of synthetic resin and having an appropriate weight is housed in the cylinder chamber in a free state.

In this overflow prevention valve, in a steady state of use, gas flows from the outer circumferential gap and the opening 6 with the ball valve 4 stopped on the wire 5 installed at the lower end of the cylinder chamber 3. When an abnormal overflow condition occurs downstream of the overflow prevention valve, such as when a rubber tube comes off, the gas flow rate through the outer peripheral gap of the ball valve 4 increases, and the ball valve 4 is lifted by the gas flow, causing the valve seat opening to rise. 2 to automatically shut off the gas flow path.

In this conventional valve, the ball valve 4 is placed in a free state away from the valve seat port 2 only by gravity, and therefore cannot be inserted into the gas flow path with the valve seat port 2 facing downward. . In this mounting position,
This is because the ball valve 4 will fit into the valve seat opening 2 in a steady state.

To solve this problem, as shown in Fig. 2, a spring 7 is interposed between the ball valve 4 and the fixed part of the main body, so that even if the overflow prevention valve is mounted downward, it will not close to the valve seat port 2 in a steady state. A method has been proposed that prevents intrusion.

In this prior art, a biasing force directed toward the upstream side is always applied to the ball valve 4 by the spring 7, and this biasing force is set to a value larger than the own weight of the ball valve 4. If the overflow prevention valve shown in the figure is simply provided with a spring 7, the operating flow rate in the upward mounting position will be excessive.

In order to reduce the difference between the operating flow rate in the downward mounting position and that in the upward mounting position, the spring constant of the spring 7 should be
The spring constant is significantly smaller than that of the spring used in the springs disclosed in No. 65272, etc.).

In the case of a conventional overflow prevention valve, the ball valve 4 is
A synthetic resin ball with a diameter of about 10 mm is used,
For example, in order to use this ball valve 4 as an overflow prevention valve that can be used in a horizontal mounting position and an upward mounting position, the spring 7 must match the weight of the ball valve 4 in its maximum compression state. It must be set so that it has a biasing force to the extent that it does.

In this way, the spring constant of the spring 7 must be extremely small in order to provide an overflow prevention valve with a large margin in the mounting position.

Therefore, when a compression spring with such a spring constant is interposed between the ball valve 4 and the vicinity of the valve seat opening 2 as shown in FIG. 2, the spring 7 is likely to buckle. The operation of the ball valve 4 is unstable.

Once activated, the buckling may cause the strands of the spring 7 to become hooked to each other, making it impossible to return to normal, or the overflow prevention valve may become unusable due to the buckling that occurs during transportation.

In the present invention, between the ball valve 4 and the cylindrical main body 1 that accommodates the ball valve 4 in a free state,
A compression spring type spring 7 is inserted to constantly bias the ball valve 4 toward the upstream side, and the biasing force of the spring 7 is set to an extent that allows the ball valve 4 to move downstream in an overflow state. In order to solve the above-mentioned problems in the overflow prevention valve, the technical problem is to prevent the spring for biasing the ball valve 4 in the upstream direction from buckling.

The technical means of the present invention taken to solve the above technical problem is as follows: The spring 7 is fitted onto the main body 1, and the support rod 8 connected to the ball valve 4 can be moved vertically to the outside of the main body 1. The spring 7 is interposed between the support rod 8 and the downstream end of the main body 1.

The above technical means of the present invention operates as follows.

Since the biasing force of the spring 7 is set to a predetermined value, the ball valve 4 is fitted into the valve seat opening 2 against the biasing force of the spring 7 in the overflow state.

In addition, since a predetermined biasing force acts on the ball valve 4 at all times or during operation, even in the mounting position of the overflow prevention valve in which gravity in the upstream direction does not act on the ball valve 4, the ball is not in the initial state. A valve 4 is located away from the valve seat port 2.

Further, when the ball valve 4 is operated, the pressurizing force generated by the flow of gas acting on the ball valve 4 acts on the spring 7 via the support rod 8, and the spring 7 is compressed. Since the spring 7 is externally fitted onto the main body 1, a buckling phenomenon (a phenomenon in which the center line of the spring is bent) does not occur.

Since the present invention has the above configuration, it has the following unique effects.

Since the spring 7 does not buckle when the ball valve 4 is operated, the biasing force acting on the ball valve 4 is stable. Therefore, the operation of the overflow prevention valve is also stable.

In addition, the spring 7 may be damaged due to vibrations generated during transportation.
This prevents the spring 7 from buckling.
damage can be prevented.

Since the repulsive force of the spring acts during the movement of the ball valve, this has a braking performance, and compared to the conventional gravity-type overflow prevention valve (Fig. 1), the ball valve is able to fit into the valve seat opening from the start of its upward movement. The so-called operating time to reach this point is longer, and the malfunction that occurs when a gas appliance equipped with a quick-opening/closing valve such as a solenoid valve on the downstream side is connected, that is, a sudden flow of gas when the appliance starts operating. This can prevent the inconvenience of the overflow prevention valve being activated due to the overflow prevention valve.

Hereinafter, embodiments of the present invention will be explained based on the drawings. In the embodiments shown in FIGS. 3 and 4,
A ball valve 4 is connected to the tip of the central rod of an inverted T-shaped support rod 8, and a pair of slits 9 are provided in the body of the main body 1.
The tip of the support rod that extends through the support rod 9 and projects therefrom supports the spring 7 fitted onto the main body. The distance is set smaller than the distance from the head 10 of No. 1. In this embodiment, since the spring 7 is in a free length state, the repulsive force (lowering force) of the spring 7 does not act on the ball valve 4 in the upward mounting position, and only the gravity of the spring acts on the ball valve 4. Just do it. Therefore, it functions in the same manner as the conventional overflow prevention valve shown in FIG. 1, as described above.

In addition, as shown in Fig. 4, the valve seat opening 2 is set downward.
In the downward mounting position, in its steady state,
Due to the biasing force of the spring 7, the ball valve 4 is suspended from the support rod 8 and positioned in the middle of the valve chamber 3, and the ball valve 4 does not fit into the valve seat opening 2, and the valve is closed. When the amount of gas passing through the seat port 2 reaches the operating flow rate, the ball valve 4 is pushed down against the repulsive force of the spring 7 due to the gas flow resistance at that time, and is fitted into the valve seat port 2.

Even if the overflow prevention valve is placed in any mounting position other than the above, diagonally upward or diagonally downward, the ball valve 4 operates in the operating flow rate range in the same manner as described above.

In the illustrated embodiment, the spring 7 is fitted onto the main body 1, but as in the conventional example shown in FIG.
It is also possible to accommodate the In this case as well, it is necessary to provide an appropriate distance between the upper end of the spring 7 and its opposing fixed wall in the upward mounting position, or to accommodate the spring in a free state.

Furthermore, although it is not necessary to use a spherical body as the ball valve 4, it is desirable that the head that fits into the valve seat opening 2 be spherical. This is because the sealing between the valve seat opening 2 and the ball valve 4 is ensured even if the ball valve 4 is inserted in an inclined position.

Further, in the illustrated embodiment, a compression spring is used as the spring 7, but the above-mentioned effects can be obtained even if the spring 7 is a tension spring and is interposed between the ball valve and the lower end of the main body 1.

[Brief explanation of the drawing]

Figures 1 and 2 are explanatory diagrams of the conventional example, Figure 3 is a sectional view of the embodiment of the present invention in the upward mounting position, and Figure 4 is a sectional view of the downward mounting position. Valve, 7... spring, 8... support rod.

Claims (1)

[Scope of utility model registration request] A compression spring type spring 7 is interposed between the ball valve 4 and the cylindrical main body 1 that accommodates the ball valve 4 in a free state, so that the ball valve 4 is always urged upstream. 7
In the overflow prevention valve, the biasing force of which is set to such an extent as to allow movement of the ball valve 4 in the downstream direction in an overflow state, a spring 7 is fitted onto the main body 1, and a support rod is connected to the ball valve 4. 8 protrudes to the outside of the main body 1 in a vertically movable manner, and the spring 7 is connected to the support rod 8 and the main body 1.
omnidirectional gas overflow prevention valve interposed between the downstream end of the