JPH05306780A - Safety device for welding - Google Patents

Abstract

PURPOSE:To provide the safety device for welding, in which the structure of a means for hindering the backflow and the normal flow of the combustion gas is simplified to facilitate the assembling thereof and which is made compact, at a low manufacturing cost. CONSTITUTION:In a safety device for welding, as a means for hindering the backflow and the normal flow of the combustion gas, a packing 16 common to the backflow preventing airtight surface 19 and the normal flow preventing airtight surface 20 is brought into airtight contact.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding safety device, and more particularly to a safety device used for gas welding.

[0002]

2. Description of the Related Art As a safety device on the combustion gas side such as acetylene gas conventionally used for gas welding, when an oxygen gas or a mixed gas of oxygen-acetylene flows back to the acetylene gas side in a combustion or non-combustion state, It is known that the backflow is blocked and the normal flow is blocked when returning to the normal flow.

[0003]

In the above welding safety device, the valve means is separately used as means for preventing the reverse flow and the normal flow, so that the structure is complicated and the assembly is not easy. , Large overall size and high manufacturing cost.

An object of the present invention is to provide a means for preventing the reverse flow and the normal flow, which has a simple structure and is easy to assemble, and is compact as a whole and has a low manufacturing cost.

[0005]

In order to achieve the above object, in the welding safety device of the present invention, as a means for blocking the reverse flow and the normal flow, the airtight surface for preventing the backflow and the airtight surface for preventing the normal flow are provided. The packing that is common to the two is configured to contact in an airtight manner.

[0006]

Embodiments of the present invention will be specifically described below with reference to the drawings.

A tubular body (2) having a flow path (1) for combustion gas is connected to a body portion (4) having an integral joint portion (3) at one end with a screw (5). It is composed of a joint part (6). The joint portion (3) is connected to the combustion gas supply side pipe or the like by its outer peripheral external thread (7), and the joint portion (6) is connected to the welding tool side pipe or the like by its outer peripheral external thread (8). It In the normal flow state, the combustion gas flows in from the joint portion (3) and flows out from the joint portion (6) as shown by arrow A.

Valve means for preventing back flow and normal flow of gas is incorporated in the flow path of the body portion (4). The valve body (9) of the valve means is reciprocally inserted in the guide tube (10), and the guide tube (10) is incorporated in the flow path of the main body portion (4). On the outer periphery of the guide tube (10), a filter (11) made of sintered metal or the like for preventing passage of flashback is provided as a seat (12). Both normal flow and reverse flow gas are guided by the seat (12) to pass through the filter (11).

While the valve means may be constructed in various ways,
The first embodiment is shown in FIGS. The valve body (9) is composed of a small diameter portion (13) and a large diameter portion (14). The small-diameter portion (13) is made of rubber in one annular groove (15) on the outer periphery thereof, and has a first packing (16) made of rubber and having an annular shape and commonly used for preventing normal flow and backflow, and the other of the other. Annular groove (1
Similarly to 7), it is made of rubber and has an annular shape, and second packings (18) for preventing backflow of an abnormally high pressure such as at the time of explosion are fitted and fixed to each other. An airtight surface (19) for preventing backflow, an airtight surface for preventing normal flow (20) and an airtight surface for preventing backflow of abnormally high pressure at the time of explosion (21), which are in airtight contact with these packings (16, 18) Are formed on an annular raised portion (22) raised in the inner peripheral surface of the joint portion (3). The small-diameter portion (13) further has a vent hole (23) that communicates the inside and outside thereof and guides a normal flow from the outside to the inside of the valve body (9).

In FIG. 1, the valve body (9) is in the state of being opened by being pushed rightward by the pressure of the normal flow. The normal flow flows from the joint portion (3), passes between the airtight surface (19) and the packing (16), and flows from the vent hole (23) of the valve body (9) into the valve body (9). .. The normal flow flowing out from the valve body (9) passes through the filter (11) from the inside to the outside, flows to the back surface of the seat (12), and flows out from the joint portion (6).

When a comparatively low-pressure backflow that does not reach the high pressure at the time of explosion occurs, the valve body (9) is pushed to the left as shown in FIG. 2 and the packing (16) becomes the airtight surface (19). Airtightly contact and prevent its backflow.

When a backflow accompanied by a backfire is generated by explosion, the filter (11) blocks the passage of the backfire, but the abnormally high backflow pressure generated at this time causes the valve body (9) to move as shown in FIG. Push it further to the left. The tip of the valve body (9) engages with the shoulder portion (24) of the joint portion (3) and stops. Meanwhile, the packing (16) moves from the airtight surface (19) through the airtight surface (21) to the airtight surface (20) side, and at the same time, the packing (18) is the airtight surface.
It moves to the position where it comes into airtight contact with (21). This packing (18) also prevents abnormal high pressure backflow.

When the normal flow acts on the valve body (9) due to the backflow pressure being released due to damage to the hose, the valve body is pushed to the right as shown in FIG. 4, and the packing (16) is removed. It contacts the airtight surface (20) and prevents outflow of normal flow.

In order to return the valve body (9) to the initial position where it is possible to prevent backflow, the valve body is pushed in with a rod-like object to move the packing (16) from the airtight surface (20) side to the airtight surface (19). Airtight side
Move through (21).

As a second embodiment of the valve means, FIGS.
It shows in FIG. This valve means differs from that of the first embodiment in that one third packing (25) blocks the flow of low backflow pressure to abnormally high backflow pressure and normal flow pressure. The packing (25) is also made of rubber and has an annular shape, and is fitted and fixed in the annular groove (15) of the small diameter portion (13) of the valve body (9). An annular ridge in which an airtight surface (27) for preventing low-pressure backflow and an airtight surface (28) for preventing normal flow that are in airtight contact with the packing (25) are bulged in the inner peripheral surface of the joint part (3). It is formed on both sides of the part (30). The airtight surface (31) for preventing an abnormally high-pressure backflow that occurs during an explosion is formed on the inner peripheral surface of the joint portion (3) connected to the airtight surface (28).

In FIG. 5, the valve body (9) is in a valve open state in which it is pushed out to the right by the pressure of a normal flow. Normal flow is first
As in the embodiment, it flows in from the joint portion (3) and flows out from the joint portion (6).

When a relatively low-pressure backflow without explosion occurs, the valve body (9) is pushed to the left as shown in FIG. 6, and the packing (25) comes into contact with the airtight surface (27) to cause the backflow. Prevent.

When a backflow accompanied by a backfire occurs due to an explosion, the backflow is blocked by the filter (11) as in the first embodiment, but an abnormally high backflow pressure is applied to the valve body (9). Further push out to the left as shown in FIG. The valve body (9) is stopped by the engagement of its tip with the shoulder portion (24) of the joint portion (3). During that time, the packing (25) moves from the airtight surface (27) to the airtight surface (31) side through the ridge surface (32) of the annular ridge (30),
Contact with 1) to prevent backflow of abnormally high pressure.

When the reverse flow pressure is released due to damage to the hose, etc., the valve body (9) is pushed out to the right with normal flow pressure as shown in FIG. 8, and the packing (25) contacts the airtight surface (28). To prevent the outflow of the normal flow.

In order to return the valve body (9) to the initial position, the valve body is pushed out to the right with a rod-shaped member as in the first embodiment.

As a third embodiment of the valve means, FIGS.
It shows in FIG. This valve means has a fourth packing (33)
In the point that the flow of abnormally high backflow pressure and abnormal flow pressure from low backflow pressure is blocked, it is in line with that of the second embodiment, but differs in the following points. The ring-shaped rubber packing (33) is fitted and fixed in the ring-shaped groove (34) on the inner peripheral surface of the joint portion (3). The low pressure backflow preventing airtight surface (35) and the normal flow preventing airtight surface (36) in contact with the packing (33) are provided on both sides of the annular ridge (37) which is raised on the outer peripheral surface of the valve body (9). Is formed on the surface. An airtight surface (38) for preventing an abnormal high-pressure backflow that occurs at the time of explosion is formed on the circumferential surface of the annular groove of the valve body (9) which is continuous with the airtight surface (36).

In FIG. 9, the valve body (9) is in the valve open state under the pressure of the normal flow as in the first and second embodiments.
A normal flow also flows in from the joint portion (3) and flows out from the joint portion (6).

When a low-pressure backflow occurs during non-explosion, the valve body (9) is pushed to the left and the airtight surface (35) at the tip of the valve body (9) is packed (33) as shown in FIG. ),
Stop the backflow.

When an abnormally high-pressure backflow accompanied by flashback at the time of explosion is generated, the flashback is blocked by the filter (11) as in the above embodiment, but the valve body (9) is It is further pushed to the left as shown at 11. The airtight surface (35) of the valve body (9) engages with the shoulder portion (39) of the joint portion (3) and stops at that position. Meanwhile, the ridge (37) moves past the packing (33) and moves between the shoulder (39) and the packing (33), and the airtight surface (38) contacts the packing (33) to cause abnormally high pressure backflow. Prevent.

When the reverse flow pressure is released, the valve body (9) is pushed out to the right as shown in FIG. 12 by the normal flow pressure, and the airtight surface (36) of the valve body (36) comes into contact with the packing (33) to allow the normal flow. Stop.

In order to return the valve body (9) to the initial position, the valve body is pushed by a rod-shaped member as in the above-mentioned embodiment, and the ridge (37) is moved past the packing (33). ..

In the first to third embodiments, the valve body (9)
When a compression coil spring (40) is installed between the guide tube (10) and
The valve body moves and closes the flow path as soon as any backflow pressure occurs.

[0028]

INDUSTRIAL APPLICABILITY As described above, the present invention provides an airtight surface (19, 27, 35) for preventing backflow as a means for preventing backflow and normal flow.
And the common packing (16, 25, 33) is brought into contact with the airtight surface (20, 28, 36) for preventing normal flow, the structure of the blocking means is simple and easy to assemble. Therefore, it can be compactly assembled as a whole and the manufacturing cost can be reduced. The present invention further includes, as a blocking means, an explosion or the like by the packing (25, 33) which is also used for blocking the above-mentioned reverse flow and the normal flow, or a packing (18) which is separate from the packing (25, 33) and moves integrally. Since it is configured so as to prevent an abnormally high backflow of backflow pressure that occurs at the time of welding, it is possible to maintain safety as a welding safety device while maintaining the effects of the above configuration, assembly, size, and manufacturing cost. The function becomes higher.

[Brief description of drawings]

FIG. 1 is a partially longitudinal front view of a welding safety device showing a normal flow state in a first embodiment of the present invention.

FIG. 2 is a partially longitudinal front view showing a backflow blocking state in the welding safety device of FIG.

FIG. 3 is a partially longitudinal front view showing a state in which a backflow of abnormally high pressure is blocked in the welding safety device of FIG.

FIG. 4 is a partially longitudinal front view showing a normal flow blocking state in the welding safety device shown in FIG.

FIG. 5 is a partially longitudinal front view of a welding safety device showing a normal flow state in a second embodiment of the present invention.

FIG. 6 is a partially longitudinal front view showing a backflow blocking state in the welding safety device of FIG. 5;

FIG. 7 is a partially longitudinal front view showing a state in which a backflow of abnormally high pressure is blocked in the welding safety device of FIG.

FIG. 8 is a partially longitudinal front view showing a normal flow blocking state in the welding safety device of FIG.

FIG. 9 is a partial vertical sectional front view of a welding safety device showing a normal flow state in a third embodiment of the present invention.

FIG. 10 is a partially longitudinal front view showing a backflow blocking state in the welding safety device of FIG. 9.

11 is a partially longitudinal front view showing a state in which a backflow of abnormally high pressure is blocked in the welding safety device of FIG. 9.

FIG. 12 is a partially longitudinal front view showing a normal flow blocking state in the welding safety device of FIG. 9.

[Explanation of symbols]

2 Main body 9 Valve body 10 Guide tube 11 Filter
12 Seat 16 First packing 18 Second packing 19 Low pressure backflow prevention airtight surface 20 Normal flow prevention airtight surface 21 High pressure backflow prevention airtight surface 23 Vent hole
25 Third packing 27 Airtight surface for low pressure backflow prevention
28 Airtight surface for normal flow prevention 31 Airtight surface for high pressure backflow prevention
33 4th packing 35 Airtight surface for low pressure backflow prevention 36 Airtight surface for normal flow prevention 38 Airtight surface for high pressure backflow prevention
40 compression coil spring

Claims (7)

[Claims] 1. A cylindrical main body (2) having a flow path for combustion gas, and a valve body (9) incorporated in the flow path of the main body. Airtight (19,27,3
5) and the airtight surface for normal flow prevention (20, 28, 36) and the packing (16, 25, 33) A welding safety device that is relatively provided. 2. The backflow prevention airtight surface (19, 27) and the normal flow prevention airtight surface (20, 28) of claim 1 are annular ridges (22, 30) on the inner peripheral surface of the flow path of the main body. ). The packings (16,25) formed on both side surfaces of the () contacting these airtight surfaces are fixed to the outer peripheral surface of the valve body (9), and the packings (16,25) have a relatively low backflow pressure. When it occurs, it comes in contact with the backflow prevention airtight surface (19, 27) to prevent the backflow, and when an abnormally high backflow occurs due to an explosion, etc., it normally passes through the inner peripheral surface of the annular ridge (22, 30). The welding for welding according to claim 1, wherein the air is sent to the airtight surface (20, 28) for blocking the flow and contacts the airtight surface (20, 28) for blocking the normal flow when the normal flow occurs to prevent the normal flow. Safety device. 3. The valve body (9) according to claim 2 is a packing (16).
Is moved from the backflow prevention airtight surface (19) to the normal flow prevention airtight surface (20) side through the annular ridge (22), it is stopped at that position by the shoulder (24) of the main body. , At the stop position, the airtight surface (21) of the inner peripheral surface between the airtight surfaces (19, 20) of the ridge (22)
Another packing (1
The welding safety device according to claim 2, wherein 8) is fixed to the outer peripheral surface of the valve body. 4. The valve body according to claim 2, wherein the packing (25) moves from the backflow preventing airtight surface (27) toward the normal flow preventing airtight surface (28) through the annular ridge (30). On the shoulder of the body
(3) It is stopped at that position at (31), and at that stop position, the packing (25) comes into contact with the airtight surface (31) of the inner peripheral surface of the flow path of the main body to prevent abnormally high backflow. Welding safety device. 5. The backflow prevention airtight surface (35) and the normal flow prevention airtight surface (36) of claim 1 are annular ridges (3) on the outer peripheral surface of the valve body.
The packings (33) formed on both side surfaces of (7) and contacting these airtight surfaces are fixed to the inner peripheral surface of the flow passage of the main body, and the backflow preventing airtight surface (35) of the valve body is relatively When a low backflow pressure is generated, it contacts the packing (33) to prevent the backflow, and with the occurrence of an abnormally high backflow due to an explosion, etc., the bulge (37) of the valve body.
Is an airtight surface to prevent normal flow through the packing (33)
The welding safety device according to claim 1, wherein the (36) is sent to a side in contact with the packing (33), and contacts the packing (33) to prevent the normal flow when the normal flow is generated. 6. The shoulder (39) of the main body of the valve body (9) according to claim 5, when the airtight surface (36) for preventing normal flow of the valve body moves to the side in contact with the packing (33). At that position,
The welding safety device according to claim 5, wherein the airtight surface (38) on the outer peripheral surface of the valve body comes into contact with the packing (33) at the stop position to prevent an abnormally high backflow. 7. The valve body (9) is rod-shaped and has packings (16, 25, 33) from an airtight surface (20, 28, 36) for preventing normal flow to an airtight surface (19, 27) for backflow prevention. The welding safety device according to any one of claims 1 to 6, which is sent so as to move relatively to the (35) side.