JP2879315B2 - Safety device for gas welding and fusing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art As a conventional safety device for gas welding and fusing, when a backflow of a combustion gas accompanied by a flashback occurs, the backflow is blocked by a filter and a flow passage is checked. To prevent back flow from the torch side to the combustion gas supply side, and to shut off the flow path with the shut-off valve to open the torch from the combustion gas supply side.
A device that prevents normal flow to the front side is known.

[0003]

In the above conventional safety device, the shut-off valve body is restrained by the restraining means at the valve opening position, and the restraint is released by the backflow pressure. When a backflow accompanied by fire is generated in a wavy manner, the shut-off valve is opened each time by the backflow pressure, and the combustion gas is sent from the supply side to the torch side, and a hose generated at an abnormally high pressure. There is a risk that it will not be possible to prevent fire from blowing through the cracks or cut parts of the gasket, and the check valve will open with the opening of the shut-off valve, and the mixed gas of the combustion gas will There is a danger of exploding by flowing backward.

The present invention solves the above-mentioned conventional problems,
It is possible to more reliably prevent the risk of fire blowing from the nicks and cut surfaces of the hose and the explosion of the supply tank. This provides high safety in welding and fusing work, and the overall structure of the safety device It is to provide something that is simple and can be handled very easily.

[0005]

In order to achieve the above object, a safety device according to the present invention comprises a filter for preventing a backfire from passing through and a backflow from a torch side to a combustion gas supply side. A check valve body, and a shut-off valve body for preventing normal flow from the combustion gas supply side to the torch side. The shut-off valve body mainly includes an annular connecting groove and a connecting ball engaged with the connecting groove. The restraining means, which is formed by a restraining ring that holds this engagement, is automatically restrained at the shut-off position simultaneously with the occurrence of flashback, and the restraint valve body is also restrained to the closed position by this restraint. The restraint release of the shutoff valve body and the check valve body is performed by one-hand manual operation on the restraint ring.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A safety device for gas welding and fusing according to the present invention includes a straight cylindrical main body (1) and a cylindrical branch body (2) extending from the main body in a direction intersecting the main body. I have.
The tubular main body (1) is composed of a main body part (3) and a joint part (5) connected to the main body part by a screw (4), and the joint part (5) has an outer male screw (6). Is connected to a hose joint (not shown) on the torch (not shown) side. The tubular branch (2) is integrally connected to the main body (3), and is connected to an instrument (not shown) on the combustion gas supply side by a cap nut (7) at one end of the tubular branch.

The cylindrical main body (1) has a first linear flow path (8) for combustion gas formed in the main body part (3) and the joint part (5). Communicates with the torch side. The tubular branch (2) is connected to a second channel (8) communicating with the first channel (8).
It has a flow path (9), and this flow path (9) communicates with the combustion gas supply side.

In the first flow path (8), a rod-shaped shutoff valve (10) has a rear end face (14) at an end (50) on the torch side.
Built toward reciprocates between the shutoff valve body (10) is positioned to open the first flow path (8) (retracted position) (Fig. 1) for blocking the position (advanced position) (Fig. 2) . The shut-off valve element (10) further has a first compression coil spring (1
1) is wound, and both ends of the spring (11) are shut off the valve body (1).
0) and the shoulder of the flow path (8), and are constantly urged by the force of the spring (11) toward the open position of the flow path (8) (in the direction of arrow A).

In a normal flow state (in the direction of arrow A), the shutoff valve element (10) is held at the open position of the flow path (8) by a spring (11) (FIG. 1). Unusually high backflow with flashback (arrow B
Direction), the shut-off valve element (10)
Is moved against the spring (11) in the direction (arrow B direction) where the flow path (8) is interrupted by receiving the backflow pressure, and is automatically restrained by the restraining means described later at the interrupted position ( (Fig. 2). When the restraining of the restraining means is released by manual operation, the shut-off valve body (10) returns to the open position of the flow path (8) by the spring (11) (FIG. 1).

In the channel (9) of the tubular branch (2), means for preventing backflow is incorporated. As this means, an annular valve seat (15) made of rubber is inserted into the flow path (9), fixed with a holding screw (16), and comes into contact with the valve seat (15) in an airtight manner. 17) is reciprocally inserted into the flow path (9). The check valve element (17) is composed of a weak third compression coil spring (19) provided between the valve element and the shoulder of the flow path (9).
(15) is always energized, and when the normal flow pressure and the backflow pressure approach a nearly equilibrium state, the flow path (9) is positively shut off,
Prevent backflow accidents.

In a state where the combustion gas is not supplied,
The check valve element (17) is pressed against the valve seat (15) by a spring (19) to close the flow path (9). When gas is supplied, check valve (17)
Is pushed in to open the flow path (9), and the gas flows through the check valve (17)
Through the vent hole (20) from outside to inside, and flows out of the flow path (9) to the flow path (8). When a backflow occurs, the check valve (17) is placed in the valve seat (15) regardless of the level of the backflow pressure.
To close the flow path (9).

The restraining means for the shut-off valve element (10) includes an annular connecting groove (21) formed in the shut-off valve element (10) and an annular connecting groove (21) in the main body portion (3) of the cylindrical main body (1). A plurality of holding holes (22) drilled at predetermined intervals, and a connection ball (23) filled in these holding holes and a part of which is engaged with the connection groove (21).
And a restraining ring (24) fitted reciprocally on the outer periphery of the main body portion (3) to engage or disengage the connecting ball (23) with the connecting groove (21); Connect the ring (24) to the connecting ball (2
3) and a second compression coil spring (25) for urging in a direction for maintaining the engagement between the connection groove (21) and the connecting groove (21).

In a normal flow state of the combustion gas (in the direction of arrow A), the shut-off valve element (10) has its connection groove (21) disengaged from the position of engagement with the connection ball (23), and the flow path (8). Has been moved by the spring (11) to the retracted position to release (FIG. 1). In this state, the tip (26) of the shut-off valve (10) is drawn into the end face (27) of the main body (3), indicating that the gas flow is in a normal flow state. The shoulder (29) of the annular projection (28) on the inner peripheral surface of the restraining ring (24) engages with the connecting ball (23) and is restrained at the restraining release position retracted against the spring (25). (FIG. 1).

Depending on the strength of the spring (11), when a relatively low-pressure backflow without backfire occurs, the shut-off valve (10) can receive the backflow pressure on the rear end face (14). It cannot advance in the reverse flow direction (arrow B direction) against the spring (11), and is stationary at the position (FIG. 1) where the flow path (8) is opened, and only the check valve element (17) Moves in the direction of the valve seat (15) to close the flow path (9). When abnormally high pressure backflow with flashback occurs,
The check valve element (17) is pressed against the valve seat (15) to close the flow path (9) and prevent backflow, and the shut-off valve element (10) also has a spring (11).
Forward in the reverse flow direction (arrow B direction) against the shutoff valve body (1
The first annular packing (30) made of rubber fixed to (0) is in airtight contact with the wall surface (31) of the flow path (8) to close the flow path (8) and prevent backflow and normal flow. This allows the check valve element (1
The gas in the flow passages (8) and (9) surrounded by 7) and the shutoff valve (10) is sealed, and the sealing pressure presses the check valve (17) against the valve seat (15). Tied to the state.

When the shut-off valve element (10) advances to the position for closing the flow path (8) (in the direction of arrow B), the connecting groove (21) of the valve element reaches the position of the connecting ball (23) (FIG. 2). . At this time, the restraining ring (2
4) While pushing the connecting ball (23) into the connecting groove (21),
Move forward in 5) (direction of arrow B), and the annular projection (28) on its inner peripheral surface
Press the connecting sphere (23) with the raised plane (32) of the connecting sphere (23)
And the engagement state of the connecting groove (21) is maintained (FIG. 2). Shut-off valve
(10) indicates that the tip (26) protrudes from the end face (27) of the main body part (3), and an abnormally high backflow pressure is generated.

When the shut-off valve body (10) is restrained at the shut-off position of the flow path (8) by the restraining means (FIG. 2), the rear end face of the shut-off valve body (10).
Even if the backflow pressure acting on (14) is released, the pressure of the gas sealed between the check valve (17) and the shut-off valve (10) is maintained, and the check valve (17) is Does not open like body (10).

After the backflow pressure is eliminated, the restraining ring (24)
Is pressed by hand (in the direction of arrow A) against the spring (25),
The raised plane (32) of the annular projection (28) is disengaged from the connecting ball (23), and the pressing force on the connecting ball (23) is released. as a result,
The shut-off valve (10) is retracted by the spring (11) in the opening direction (arrow A) of the flow path (8), and the sealing pressure on the check valve (17) is also released.

A red backflow mark (3) indicating the occurrence of backflow
3) is provided at the protruding tip (26) of the shut-off valve body (10), or a red backflow mark (34) is provided on the outer periphery of the main body (3) to restrain this mark (34). If the ring (24) is shielded by retreating (arrow A direction) and exposed forward (arrow B direction), it becomes easier to recognize the backflow.

The cylindrical filter (35) permits the passage of the combustion gas but prevents the backfire, and is provided in the cylindrical portion (36) of the joint portion (5) by the seat (37). Built-in this seat
A guide cylinder portion (38) of (37) supports a rear end portion (39) of the shutoff valve body (10) in a reciprocating manner.

The receiving seat (37) has, in addition to the guide cylinder (38), a flange (40) connected to one end thereof and a split shaft (41) connected to the flange. . The corner of the guide cylinder (38) that intersects the flange (40) is formed in a large-diameter portion (42).
The filter (35) is fitted into 2), and an annular flow path (44) is formed between the filter (35) and the small diameter section (43) connected to the large diameter section (42). The filter (35) has one end face abutting on the flange (40) through a rubber annular packing (45), and the other end face also has a flow path of the main body part (3) through a similar packing (46). (8) It abuts against the inner shoulder (47) and is fixed. The filter (35) and the tube part (3
An annular flow path (48) is also formed between 6). Catch (37)
The shaft part (41) is fitted and supported on the small-diameter flow path wall surface (49) of the joint part (5).

The normal flow (in the direction of arrow A) is a filter (35).
From the inside to the outside, the flange (40) and the shutoff valve (10)
It flows out from the end (50) of the joint part (5) via the rear end face (14). The reverse flow (in the direction of arrow B) flows in the reverse path.

The shut-off valve element (10) includes a rubber second annular packing (51) in addition to the rubber first annular packing (30).
Is mounted between the first packing (30) and the connecting groove (21) of the valve body (10) and in the vicinity of the connecting groove, and a third annular packing (52) made of rubber is provided with the first packing (30). Valve (10)
Between the rear end (14) and near the rear end. The second packing (51) is provided between the holding portion (22) and the portion (53) of the first channel (8) communicating with the second channel (9). 8) The gas is always in airtight contact with the wall surface (54), and the gas flows into the cylindrical body (1) and the tip of the shut-off valve (10).
(26) to prevent leakage from the fitting surface. The third packing (52) also constantly comes into contact with the inner wall surface (55) of the guide cylinder (38) in an airtight manner, so that gas flows in the guide cylinder (38) and the rear end portion (3) of the shutoff valve body (10).
The flange (40) of the seat (37) and the shut-off valve (10) prevent leakage from the mating surface with the filter (9) and allow both normal flow and reverse flow gas to pass through the filter (35). It is guided smoothly by the rear end face (14).

[0023]

As described above, the safety device of the present invention has a cylindrical main body (1) having a first flow path (8) for combustion gas and connected to the torch side for gas welding or fusing. ) And a second flow path (9) for the combustion gas extending from the cylindrical main body in a direction intersecting with the cylindrical main body and communicating with the first flow path (8), and connected to the combustion gas supply side. And a first spring (1) reciprocally incorporated in the first flow path (8).
With the force of 1), the combustion gas moves in the normal flow direction to open the first flow path (8), and receives the pressure in the reverse flow direction of the combustion gas to oppose the force of the first spring (11) in that direction. Move to the first
A rod-shaped shut-off valve element (10) for shutting off the flow path (8), and a restraining means for restraining the shut-off valve element at a shut-off position of the first flow path (8) against the force of the first spring (11). Check valve means comprising a valve seat (15) incorporated in the second flow path (9) for preventing backflow and a check valve element (17); and the first flow path (8) A filter (35) incorporated therein to allow the passage of combustion gas but prevent the passage of flashback, wherein the restraining means is a shut-off valve body (10).
An annular connecting groove (21) provided in the cylindrical body (1) and a holding hole (22) annularly arranged in the cylindrical main body (1) are filled with the connecting groove (21).
A connecting ball (23) engaged with the connecting groove (21) is reciprocally fitted on the outer periphery of the cylindrical main body (1), is moved in the forward direction by the force of the second spring (25), and is connected to the connecting groove (21). Holding the engagement of the ball (23), the ball is manually moved in the retreating direction against the force of the second spring (25) to release the engagement between the connection groove (21) and the connection ball (23). It is composed of a restraining ring (24) that is restrained against the force of the second spring (25) by the connecting ball (23) at the release position, so that the backflow with secondary and tertiary and backfire is wavy. In this case, the shut-off valve (10) and the check valve (17) are not opened at all, so that the combustion gas is not sent from the supply side to the torch side and the hose is broken. And the cut surface can completely prevent the fire from blowing, there is no danger of explosion even if the combustion gas flows back to the supply tank side, and the overall structure of the safety device is simple, and the restraining ring (24) Return the shut-off valve (10) to the open position by one push operation. To be able,
Its handling is very easy. In the safety device of the present invention, the rod-shaped shutoff valve body (10) is moved in the normal flow direction of the combustion gas by the force of the first spring (11) to open the first flow path (8). In the state where the
6) is drawn into the end face (27) of the cylindrical main body (1) to indicate that the combustion gas is in a normal flow state, and receives the pressure in the reverse flow direction of the combustion gas to move the first spring (11) in that direction. In a state where it moves against the force and is in a position where it blocks the first flow path (8), the distal end portion (26) has an end surface (2) of the cylindrical main body (1).
7) Since it is configured to protrude outside to indicate that the combustion gas is in the reverse flow state, it is possible to easily recognize the normal flow state and the reverse flow state, and it is possible to perform the operation with confidence. In the safety device according to the present invention, furthermore, the back-flow marks (33, 34) for notifying the occurrence of back-flow protrude from the end face (27) of the tubular body (1) in the back-flow state.
Is provided at one or both of the tip portion (26) of the cylindrical body (1) and the outer peripheral portion of the cylindrical body (1) that is shielded by the restraining ring (24) in the normal flow state and exposed in the reverse flow state. This is convenient because it is possible to more easily and reliably recognize the normal flow state and the backflow state.

[Brief description of the drawings]

FIG. 1 is a partially longitudinal front view of a welding and fusing safety device showing a normal flow state according to the present invention.

FIG. 2 is a partially longitudinal front view showing a backflow prevention state in the safety device of FIG. 1;

FIG. 3 is a perspective view of a seat used in the safety device of FIG. 1;

FIG. 4 is a partially longitudinal enlarged front view of a restraining ring used in the safety device of FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cylindrical main body 2 Cylindrical branch 3 Body part
5 Joint part 8 First flow path 9 Second flow path 10 Shut-off valve body 11
1st compression coil spring 15 Valve seat 17 Check valve 19 3rd compression coil spring
21 Connection groove 22 Holding hole 23 Connection ball 24 Restriction ring 25
Second compression coil spring 28 Annular protrusion 30 First annular packing 33 Backflow mark 34 Backflow mark 35 Filter 37 Receiver 38 Guide cylinder 40 Flange 41 Shaft 44 Annular flow path 48 Annular flow path 51 Annular flow path 51 Second annular Packing 52 Third circular packing

Claims (4)

(57) [Claims] 1. A tubular body (1) having a first flow path (8) for combustion gas and connected to a torch side for gas welding or welding, and extending from the tubular body in a direction intersecting therewith. its inside the first flow passage (8) to the second channel (9) has a combustion gas supply side connected to the cylindrical branch of the combustion gases which communicates with (2), the rear end face Te (14 ) To the cylindrical body (1)
And is reciprocally incorporated into the first flow path (8) toward the end (50) on the side of the combustion chamber, and moves in the normal flow direction of the combustion gas by the force of the first spring (11). The flow path (8) is opened and the pressure in the reverse flow direction of the combustion gas is reduced by the rear end face (14).
And a rod-shaped shut-off valve element (10) that moves in the direction against the force of the first spring (11) to shut off the first flow path (8).
Restraining means for restraining the shut-off valve body at a shut-off position of the first flow path (8) against the force of the first spring (11); and a reverse flow incorporated in the second flow path (9). Valve seat (15)
A check valve means comprising a check valve element (17) and a filter (35) incorporated in the first flow path (8) to permit the passage of combustion gas but prevent the passage of flashback. Wherein the restraining means is filled in an annular connecting groove (21) provided in the shut-off valve body (10) and a holding hole (22) annularly arranged in the tubular main body (1), so that the connecting means is filled. A connecting ball (23) engaged with the groove (21) is fitted reciprocally on the outer periphery of the cylindrical main body (1) and is moved in the forward direction by the force of the second spring (25) to be connected to the connecting groove (23). 21) and the connecting ball (23) are held in an engaged state, and are manually moved in the retreating direction against the force of the second spring (25) to engage the connecting groove (21) with the connecting ball (23). Gas welding comprising a restraining ring (24) which is released and restrained at its release position by a connecting ball (23) against the force of a second spring (25) Safety device for fusing. 2. The rod-shaped shut-off valve body (10) moves in the normal flow direction of the combustion gas by the force of a first spring (11) so as to move to a first position.
In a state where the flow path (8) is open, the tip portion (26) is drawn into the end face (27) of the cylindrical body (1), indicating that the combustion gas is in a normal flow state,
The first spring (1) receives the backflow pressure of the combustion gas and moves in the backflow direction.
In a state where it moves against the force of 1) and is located at a position where the first flow path (8) is shut off, the tip portion (26) protrudes out of the end surface (27) of the tubular main body (1). safety device for gas welding and fusing of claim 1, wherein indicating that the combustion gas is flowing back state. 3. A backflow mark (3) indicating occurrence of backflow.
3, 34) protrudes from the end surface (27) of the cylindrical body (1) in the reverse flow state, or the constraining ring (2) in the normal flow state.
The safety device for gas welding and fusing according to claim 3, wherein the safety device is provided on one or both of the outer peripheral portions of the cylindrical main body (1) which is shielded in (4) and exposed in the reverse flow state. 4. The filter (35) has a tubular shape and is supported by a seat (37) having a guide cylinder (38), and the guide cylinder (38) is accommodated in the filter (35).
Are fitted, and the shut-off valve element (1) is inserted into the guide cylinder (38).
0) The rear end portion (39) is inserted so as to be able to reciprocate. A second annular packing (51), and a third annular packing (52) near the rear end thereof. The first annular packing (30) has a shut-off valve element (10) indicating a normal flow state. When in the position, the first flow path (8)
When a ventilation gap is formed between the first flow path (8) and the wall (31), the first flow path (8) is opened, and when the shut-off valve element (10) is at the backflow state instruction position, the first flow path (8) is closed. The first channel (8) is shut off by airtightly contacting the wall surface (31), and the second annular packing (51) is a portion of the first channel (8) communicating with the second channel (9). (53) and the wall (54) of the first flow path (8) of the cylindrical main body (1) between the holding hole (22) for the connecting ball (23) is always in airtight contact with the combustion gas. From the fitting surface between the cylindrical body (1) and the distal end portion (26) of the shutoff valve body (10), and the third annular packing (5) is prevented.
2) is also the inner wall surface (5) of the guide cylinder (38) of the seat (37).
Combustion gas comes into contact with the guide cylinder (38) in an airtight manner to 5).
The seat (3) prevents leakage of the normal flow gas and reverse flow combustion gas through the filter (35) while preventing leakage from the fitting surface of the rear end portion (39) of the valve and the shutoff valve body (10).
7. The gas welding device according to claim 1, wherein the guide is provided at a rear end face of the shut-off valve body.
Safety device for fusing.