JPH05133512A - Safety device for welding - Google Patents

Abstract

PURPOSE:To provide a safety device wherein a backflow mark informs occurrence of a backflow, while a normal flow mark informs a normal flow. CONSTITUTION:A movable valve seat 11 and a check valve body 12 are incorporated in a combustion gas flow passage 1 of a cylindrical body 2 and a cylindrical cover 10 is slipped onto the outside periphery of the body 2 so as to be movable in forward and rearward directions, while a backflow mark 27 and a normal flow mark 28 are provided. When either one of these marks is shielded with a cover 10 according to a backflow or normal flow, the other one is exposed.

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, There is known a backflow mark which prevents the backflow and indicates the occurrence of the backflow, and informs the operator of the occurrence of the backflow.

[0003]

In the above-described welding safety device, although the occurrence of backflow can be known by the backflow mark, it is inconvenient because the state of normal flow cannot be positively known.

The present invention is intended to provide a device capable of not only knowing the occurrence of a backflow by the backflow mark but also a normal flow state by the normal flow mark.

[0005]

In order to achieve the above object, in the welding safety device of the present invention, a check valve means is provided in a cylindrical main body having a flow path for combustion gas, and is provided outside the main body. A cylindrical cover is fitted in a reciprocating manner, and a reverse flow mark and a normal flow mark are provided on the outer periphery of the main body with a predetermined interval, and one of these marks is the cover. It is configured to be shielded according to the reverse flow or the normal flow and to be exposed on the other side.

[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 has a central body portion (3) and a joint portion (6) connected to both ends thereof with screws (4) and (5). , (7). The joint portion (6) is connected to a pipe or the like on the combustion gas supply side by an outer screw (8) on its outer circumference, and the joint portion (7) is connected to a pipe or the like on the welding tool side by an outer screw (9) on its outer circumference. It In the normal flow state, the combustion gas flows in from the joint portion (6) and flows out from the joint portion (7).

The cylindrical cover (10) is fitted in the main body portion (3) and is rotatable with respect to the main body portion and linearly reciprocable, and a part of the cover is a joint portion. (6)
It is also fitted to the outer periphery of.

The check valve means for preventing the reverse flow of gas is incorporated in the flow path of the main body portion (3) and has a movable valve seat (11) and a check valve body (12).

The movable valve seat (11) has a small diameter portion (13) and a medium diameter portion (1
It is formed by a cylindrical body of 4) and a large diameter portion (15), and the small diameter portion (13) faces the gas supply side. The small diameter portion (13) is a rubber O-ring (1) on the inner peripheral surface of the inner flange (16) of the main body portion (3).
When a backflow occurs in 7), it is fitted airtightly to prevent the backflow.
Furthermore, the small diameter part (13) has a rubber O-ring (18) on its outer circumference.
The O-ring also comes into airtight contact with the side surface of the inner flange (16) when a backflow occurs to prevent the backflow. Also the small diameter part
The tip of (13) is closed, and the valve seat (11) receives backflow pressure.
Is quickly moved in the reverse flow direction (counter arrow A). The medium diameter portion (14) has a plurality of air holes (19) at equal intervals, and gas flows from the supply side to the tool side through the air holes (19).
A check valve body (12) is incorporated in the inner peripheral surface of the large diameter portion (15), and the check valve body (12) mainly blocks the backflow.

The check valve body (12) also has a small diameter portion (20) and a medium diameter portion (2).
It consists of 1) and a large diameter part (22). The small-diameter portion (20) can be inserted into the medium-diameter portion (14) of the valve seat (11), and a rubber O-ring (23) is attached to the outer periphery, and the O-ring (23) is the large-diameter portion of the valve seat. The step (24) of the portion (15) is contacted in an airtight manner to prevent backflow. Also, the small diameter part (20) has its tip closed,
Upon receiving the backflow pressure, the check valve body (12) is promptly moved in the backflow direction (counter arrow A). The middle diameter portion (21) has a plurality of ventilation holes (25) at equal intervals, and gas flows from the supply side to the tool side through the ventilation holes. The large diameter portion (22) is the large diameter portion of the valve seat (1
5) Sliding on the inner peripheral surface, the compression spring on the inner surface of the large diameter part (22)
At (26), the check valve body (12) is operated to close even if the reverse flow pressure is small.

A backflow mark (27) for informing the occurrence of backflow is provided on the outer periphery of the joint portion (6) and is displayed in red, and a normal flow mark (28) showing a normal flow state is a main body portion ( It is provided in 3) and is displayed in blue. These marks (27),
(28) has a relationship that when one is covered by the cover (10), the other is exposed.

The cover (10) has an annular raised portion (29) between both ends of its inner circumference, one side surface (30) of the raised portion is formed obliquely, and the other side surface (31) is at a right angle. Formed and on the other side
A compression spring (32) is provided between the (31) and the end surface of the joint portion (6), and the spring applies a force in the normal flow direction (arrow A) to the cover (10).

The body portion (3) has a plurality of ball holding holes (33) at equal intervals, and the balls (34) are filled in the holes.

The valve seat (11) has an annular groove (35) on its outer circumference, and one side surface (36) of the groove has a steep slope and the other side surface (37).
Is formed gently and this valve seat also has a compression spring (38)
Is always urged in the normal flow direction (arrow A).

FIG. 1 shows a state in which gas flows in the normal direction (arrow A) in the safety device. The cover (10) is moved in the reverse flow direction (counter arrow A) against the force of the spring (32),
The valve seat (11) is moved in the normal flow direction (arrow A) by the force of the spring (38). The ball (34) is pushed outward by the outer peripheral surface of the valve seat (11), and a part of the ball (34) contacts the inner peripheral surface (39) of the cover (10) to prevent the ball from protruding. Blocks and ridges (29)
The cover (10) is restrained at the position moved in the reverse flow direction (counter arrow A) against the force of the spring (32) by contacting the slope (30) of the. The valve seat (11) and the check valve body (12) are located at the positions where the flow paths are opened. In this state, the cover (10) shields the reverse flow mark (27) and exposes the normal flow mark (28) to inform the normal flow state.

When a reverse flow occurs in the direction opposite to the arrow (A), the check valve body (12) moves in the direction opposite to the arrow A by the reverse flow pressure, and the O-ring (23) of the check valve body (12) moves to the stage of the valve seat (11). The part (24) is pressed in an airtight manner to prevent backflow. Further, the check valve body (12) moves the valve seat (11) in the same direction against the force of the spring (38), and the small diameter portion (13) of the valve seat (11) is moved to the main body portion (3) side. O-ring (1
7) Airtightly insert it into the valve seat (11) O-ring (1
8) is pressed against the flange (16) of the main body part (3) in an airtight manner to prevent a backflow leaking from the check valve body (12). valve seat
When the annular groove (35) reaches the position of the ball (34) by the movement of (11), the ball (34) can move into the groove (35).
At that time, the cover (10) is moved in the direction of the arrow (A) by the spring (32), and a part of the ball (34) is inserted into the groove (35) by the slope (30) of the ridge (29). Push it in and restrain it at that position by the inner peripheral surface of the raised portion (29). As a result, the valve seat (11) is restricted to the closed position of the flow path. The moved cover (10) exposes the reverse flow mark (27) and shields the normal flow mark (28) to inform the occurrence of the reverse flow (Fig. 2).

When a normal flow gas is flowed, the cover (10) is manually moved from the state shown in FIG. 2 to the state shown in FIG. When the restraint of the ball (34) is released, the valve seat (11) springs in the direction of opening the flow path (arrow A).
It moves by the force of (38), and the ball (34) restrains the cover (10) in the state of FIG. Now the cover (10) is backflowing again.
The mask (27) is shielded and the normal flow mark (28) is exposed.

The joint portion (6) is provided with a dust removing filter (40), and the joint portion (7) is provided with a sintered metal filter (41) for preventing the passage of flashback. It is provided in (42). Both the normal flow gas and the reverse flow gas are guided by the seat (42) so as to pass through the filter (41).

[0020]

INDUSTRIAL APPLICABILITY As described above, the present invention provides a backflow mark (27).
One of the normal flow mark (28) and the normal flow mark (28) is shielded by the cover (10) so that the other is exposed.Under normal gas flow conditions, the normal flow mark (28) is exposed. At the same time as the occurrence of the backflow, the backflow mark (27) is associated with the operation of the check valve means.
Since the exposure is exposed, the operator can know the normal flow and the reverse flow at a glance, and the work safety is improved.

[Brief description of drawings]

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

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

[Explanation of symbols]

2 Main body 10 Cover 11 Movable valve seat 12 Check valve body 26 Compression spring 27 Reverse flow mark 28 Normal flow mark 32 Compression spring
34 ball 35 annular groove 38 compression spring 40
Filter 41 Filter 42 Catch

Claims (1)

[Claims] 1. A tubular body having a flow path for combustion gas,
The main body comprises a check valve means provided in the flow path of the main body, and a tubular cover fitted to the outer periphery of the main body so as to reciprocate, and the main body has an outer periphery with a predetermined space therebetween. A normal flow marker that informs the normal flow state of combustion gas to a position that can be recognized from
And a backflow mark for notifying the occurrence of the backflow.The cover covers the backflow mark and exposes the backflow mark in a normal flow state, and the backflow mark occurs at the same time as the backflow occurs. A welding safety device having a position where the normal flow mark is shielded and the reverse flow mark is exposed in relation to the operation of the stop valve means.