JPS596294Y2 - Gas overflow prevention valve - Google Patents

Description

[Detailed description of the invention] The present invention relates to a so-called overflow prevention valve that is built into a gas cock, etc., and automatically shuts off the gas flow path when an overflow condition occurs in the gas flow path due to a gas rubber pipe coming off, etc. be.

This type of overflow prevention valve consists of a cylindrical body that is inserted in a gas circuit in an airtight manner around its outer periphery and has a valve seat opening at the downstream end, and a ball valve made of a synthetic resin housed within the cylindrical body, In an overflow condition, the ball valve is lifted by the gas flow resistance and fits into the valve seat opening, automatically shutting off the gas circuit.

In this case, the ball valve has a structure that is maintained in the lowered position by gravity, and there are restrictions on the installation position of conventional linear overflow prevention valves. It cannot be used as is.

On the other hand, in the overflow prevention valve, the time from when the ball valve starts rising to when it fits into the valve seat opening in an overflow state is extremely short, and a solenoid valve or the like is installed at the downstream end of the overflow prevention valve. When a quick-open/close valve is connected, despite the normal operation of the solenoid valve, its instantaneous opening causes a pseudo-overflow condition similar to the instantaneous overflow condition, and at this time, the ball valve closes to the valve seat. It gets stuck in your mouth.

In order to solve this problem, as shown in Fig. 1, the cylindrical body housing the ball valve is bent into an L-shape, and the valve seat opening is placed at the downstream end of the horizontal flow path, while the valve seat opening is placed in the vertical flow path. We have proposed an overflow prevention valve in which a pair of arcuate pieces located in opposite directions are positioned at appropriate intervals. This invention has the drawback that the pressure loss increases when the ball valve does not operate, that is, in a steady state, because The purpose is to sufficiently extend the time required from when the valve starts rising until it fits into the valve seat opening, and to reduce pressure loss.

The technical means of the present invention for achieving the above object is to provide a cylindrical main body with two or more bending points at approximately right angles, provide a tapered valve seat opening at the downstream end, and provide a tapered valve seat opening at the downstream end. The following flow path portion is provided horizontally, and the other flow path portions are arranged to rise toward the downstream side.

The above technical means of this invention works as follows.

When the ball valve moves from the most upstream end toward the valve seat opening, the direction of movement suddenly changes to approximately a right angle at each bending point, and at this point, the moving speed of the ball valve temporarily decreases.

Furthermore, since two or more bending points are provided on the main body, the movement path from the initial position of the ball valve to the valve seat opening becomes longer even if the height of the main body is the same as that of the conventional one.

Therefore, in an overflow condition, the ball valve travels a long distance to reach the valve seat port while temporarily slowing down at the inflection point.

When a ball valve that is fitted into the valve seat opening is pushed in from the downstream side of the valve seat opening, it will fall down in the vertical flow passage, and will move upstream in the horizontal flow passage according to its inclination. returns to its initial position at the most upstream end.

Therefore, this device has the following unique effects due to the above-mentioned precepts.

(1) This operation time becomes longer for two reasons: a temporary reduction in speed during movement of the ball valve and an increase in the distance traveled.

Therefore, malfunctions in pseudo-overflow conditions can be reliably prevented.

(2) Since there is no passage resistance member inside the main body, pressure loss in a steady state due to insertion of an overflow prevention valve is reduced.

Hereinafter, details of embodiments of this invention will be explained based on the drawings.

In the embodiment shown in FIGS. 2 and 3, the downstream end of the cylindrical main body 1 is horizontally oriented and has a tapered valve seat opening 2 that expands toward the upstream side, and the upstream side thereof is vertically disposed. The flow path 3 is continuous, and a lateral flow path 4 is further provided on the upstream side thereof, and each bending point is a sudden change in the flow path, and in this embodiment, the first
The bending point 5 is set at a right angle, and the lower second bending point 6 is set at an obtuse angle close to the right angle, and in the initial state, the ball valve 7 is accommodated in the lower transverse flow path 4 in a free state.

For this reason, a wire body 8 is installed at the open end of the horizontal flow path 4.

In this embodiment, the valve is inserted into the gas flow path in an airtight manner on the outer periphery as in FIG. Gas is supplied from the shaped body 1 to the downstream side of the valve seat port 2.

In this steady state, there are no protrusions or other passage resistance imparting members within the cylindrical main body 1, and pressure loss due to insertion of the overflow prevention valve is suppressed to a minimum.

Next, when an overflow condition occurs in this gas circuit, the ball valve 7 rises obliquely along the horizontal flow path 4, abruptly changes its direction of movement at the second bending point 6, and then moves further up the vertical flow path 3. 1st
After reaching the bending point 5 and changing the direction of movement again, the valve seat enters the valve seat opening 2 and the gas circuit is automatically shut off.

The movement path of the ball valve 7 described above is sufficiently long, and the first
, since the direction changes at the second bending point, the moving speed temporarily decreases during this direction change.

Therefore, the operating time of the ball valve 7 is not only significantly longer than that of a conventional straight-line overflow prevention valve, but also much longer than a so-called L-type overflow prevention valve that has one bending point. The operating time is extended.

In addition, the above-mentioned example and the linear overflow prevention valve of the conventional example described above that is not equipped with a delay activation member (subject example 1)
) and the conventional example shown in Fig. 1 described above (conventional example 2)
The following is a comparison of its structure, performance, etc.

Here, the height l indicates the dimension from the upstream end of the main body 1 to the center of the valve seat port 2, and the total length L indicates the total length of the center line of the main body 1.

Moreover, the pressure loss is a measured value under the condition of an operating flow rate of 12001/h.

Conventional example 1 Conventional example 2 Example height (A?) 20 20
20 Chief Sasa (L) Fight 20 20
20 operating hours milliseconds 20~30 3
0~50 60~70 Pressure loss 11+1H20
25 40 30 From the above table, according to the embodiment of the present invention, operation in a pseudo-overflow state (duration: 20 to 30 milliseconds) can be reliably prevented, and the pressure loss is 10 mnlH2o compared to conventional example 2. The degree has decreased.

The ones shown in FIGS. 4, 5, and 6 are those in which the vertical flow path 3 intersects with the valve seat opening 2 at an acute angle, and in this case, the amount of change in the moving direction of the ball valve 7 is Since it is larger than that in the above embodiment, the effect of extending the operating time is further improved.

In the case shown in FIG. 7, there is a second
Since a vertical flow path 9 is provided, the operating time is further extended than in the above two embodiments.

In any of the above cases, the operating flow rate will differ depending on the gas type, but the outer circumferential gap of the ball valve 7 is set to correspond to the gas type with the minimum flow rate, and for other gas types, it is set to correspond to the gas type with the minimum flow rate. An opening with an appropriate degree of opening may be provided at or above the middle of the main body 1, and the inside of the main body 1 may be communicated with the upstream side thereof through the opening.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional example, Fig. 2 is a perspective view of an embodiment of the present invention, Fig. 3 is a sectional view thereof, Fig. 4 is a front view of another embodiment, and Fig. 5 is a sectional view thereof. Fig. 6 is a plan view thereof, and Fig. 7 is a cross-sectional view of another embodiment, in which 1... main body, 2... valve seat opening, 7... ...Ball valve.

Claims (1)

[Scope of utility model registration request] A ball valve with a certain weight is built in a cylindrical main body in a free state, and a tapered valve seat opening is provided at the downstream end of the main body, and when the flow rate in the main body exceeds a certain level, the ball valve In a gas overflow prevention valve that is fitted into a valve seat opening, the main body is provided with two or more bending points that are substantially perpendicular to each other, and a flow passage section that continues upstream of the valve seat opening is provided horizontally, and other than that A gas overflow prevention valve in which the flow path section rises toward the downstream side.