JPH0681667B2 - Inert gas supply device for welding work - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mainly used in building air conditioning work, in welding and joining copper pipes that form a circulation passage of a refrigerant between an outdoor unit and an indoor unit. The present invention relates to an inert gas supply device that sends an active gas to prevent the inner surface of a weld from being oxidized.

[0002]

[Prior art and its problems] In building air-conditioning work, an outdoor unit is installed on the rooftop floor and an indoor unit is installed on each floor.
The outdoor unit and the indoor unit are connected by a refrigerant circulation line. As shown in FIG. 6, the pipe line is formed by inserting the copper pipes (92) and (92) into both ends of the tubular joint (93) and welding the ends of the joint and the outer periphery of the copper pipe. When the above-mentioned copper pipe is welded in the atmosphere, there is a problem that black oxide is generated in the welded portion, which is mixed with the refrigerant and circulates to block the orifice of the air conditioner to cause a failure.

In order to solve the above-mentioned problem, an inert gas such as nitrogen may be fed into the pipe during welding to perform welding in an inert gas atmosphere to prevent oxidation of the inner surface of the welded portion. However, to do this, bring a gas cylinder to the rooftop floor of the building, connect the cylinder to a copper pipe via a hose, open and close the valve on the cylinder at each weld, or turn on the gas all day long. You have to keep releasing it.

In the former case, an operator who opens and closes the valve is required, and the operator who opens and closes the valve and the welding operator cannot hear each other or cannot see each other because of a shield. Many are not practical because it is difficult to confirm the signal of opening and closing the valve. Also, in the latter case, gas is discharged and wastefully consumed other than during welding, so even a large cylinder can be emptied in a day, and heavy labor is required to carry a heavy cylinder to the rooftop floor every day.

Although it is conceivable to control the valve of the cylinder by remote control by radio, it is not practical at all because radio waves are blocked in the building.

From the above, the hand-cutting work in which welding is carried out without feeding the inert gas into the copper pipe is uninterrupted, and the failure of the air conditioner due to the hand-cutting work is It may occur after a considerable period of time after operating the equipment, and there was a problem in investigating the cause of failure and responsibility. The present invention focuses on the fact that the cold pipe of the air-cooling equipment is covered with a heat insulating material over the entire length and is electrically insulated from the steel structure of the building, so that this can be effectively used as a communication medium for communication. did. INDUSTRIAL APPLICABILITY The present invention reveals an inert gas supply device for welding operation in which a welding operator himself can remotely control the supply and stop of the inert gas by utilizing a pipe to be welded as a communication medium. It is a thing.

[0007]

The inert gas supply apparatus of the present invention comprises an inert gas supply apparatus master unit (1) and a slave unit (5) transmitting to the master unit (1) through a metal pipe to be welded. The main unit (1) has an inert gas hose connection port (21),
Gas outlet (22), gas hose connection (21) and gas outlet (2
2) The solenoid valve (24) is connected to the conduit (20) that connects with the electronic circuit (39) that sends an open signal to the solenoid valve (24) by receiving an open signal from the slave unit (5) and welding. A receiving terminal (42) that can be detachably attached to an appropriate metal pipe is provided, and a blow start switch (53), a blow stop switch (54) and a master unit (1) are operated on the slave unit (5) by operating each switch. On the other hand, an electronic circuit (8) for issuing an open or close signal to the electromagnetic on-off valve (24) and a transmission terminal (62) capable of contacting a metal pipe to be welded are provided.

[0008]

[Operation and effect] A pressure-resistant hose (9) is attached to the connection port (21) of the master unit (1).
The cylinder (95) is connected via 4), and the outlet (22) is connected via a gas blow hose (96) to one end of the metal pipe to be welded. Keep the valve on the cylinder (95) open. Base unit (1)
Lock the terminal (42) of the
Complete the preparation of (1) side.

The welding operator puts the terminal (62) of the slave unit (5) on the surface of the metal pipe in the vicinity of the welding position and turns on the blow start switch (53). Solenoid electronic circuit (8) for solenoid valve
An open signal is issued to (24), and this signal is transmitted to the electronic circuit (7) of the parent device (1) using the metal pipe as a carrier medium. This opens the solenoid on-off valve (24) and opens the cylinder in the metal pipe.
Inert gas is supplied from (95).

When welding the metal pipe and the tubular joint (93) in which the end portion of the pipe is fitted, the inside of the metal pipe is in an inert gas atmosphere, oxidation due to welding heat is prevented, and air conditioning equipment It does not produce oxides that cause the failure of the. Oxide is generated on the outer surface of the welded portion, but the oxide does not enter the inside of the pipe, which cannot be a cause of failure of the air conditioning equipment.

When the welding at one location is completed, the slave unit (5) is again activated.
The terminal (62) of is contacted with the metal pipe, and the blow stop switch (54) is turned on. Solenoid electronic circuit (8) for solenoid valve
A close signal is issued to (24), and this signal is transmitted to the electronic circuit (7) of the parent device (1) through the metal pipe in the same manner as described above. As a result, the electromagnetic opening / closing valve (24) is closed, and the supply of the inert gas into the metal pipe is stopped. The welding operator moves to the next welding location and performs the welding operation in the same procedure as above.

As described above, the inert gas can be fed into the metal pipe only when necessary, eliminating the waste of releasing the gas all day long as in the conventional case, and manually operating the valve of the cylinder for each welding. Freed from the hassle of opening and closing.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a main unit (1) and a gas cylinder (95) of an inert gas supply device of the present invention in a building air conditioning work.
2 shows the arrangement state and the piping system of the refrigerant circulation copper pipe (92) to be welded. The copper pipe (92) forms a long pipeline by temporary fixing (the joint and the pipe are not yet welded) through the tubular joint (93) shown in FIG. 6, and the pipe has a joint. (93) The insulating heat insulating material is covered except for the vicinity. An outdoor unit (9) for an air conditioner and a master unit (1) for an inert gas supply device for welding are arranged on the rooftop floor of the building, and an indoor unit (91) is provided for each floor.
A gas cylinder (95) filled with an inert gas such as nitrogen is placed on the ground.

In FIG. 1, the master unit (1) is shown to be about the same size as the outdoor unit (9), but in reality, as shown in FIG.
Box about 30 cm long, about 20 cm wide, about 10 cm thick (1
It is stored in 1), much smaller than the outdoor unit (9), and can be carried by an operator.

A control circuit (3) including an electromagnetic switching valve (24) for the air pipe (2) and an electronic circuit (7) is provided in the box (11). The air pipe (2) shown in FIG. 4 has an inert gas hose connection port (21) at one end and a gas flow outlet (22) at the other end. Solenoid on-off valve on the downstream side
(24) is provided, and a pressure gauge (28) is provided between the flow rate adjusting valve (23) and the electromagnetic opening / closing valve (24). A branch pipe (25) is connected between the connection port (21) and the flow rate adjusting valve (23), and the branch pipe (25) is provided with a manual opening / closing valve (27). The tip of the branch pipe (25) is a connection port (26) to another master unit, and the connection port (26),
The connection port (21) and the outflow port (22) are attached with metal fittings that can be attached / detached to / from other connection pipes with one touch, and are exposed to the side surface of the box (11).

As shown in FIG. 2, the flow control valve (23), the operating handle of the manual on-off valve (27) and the pressure gauge (28) are provided in the box (11).
Is exposed on the upper surface of. Further, in the box (11), a power ON / OFF switch (31), a power lamp (32) that lights up when the switch is ON, and a prober (33) that sounds when the solenoid on-off valve (24) is open. , A buzzer lamp (35) that lights only while the buzzer (33) is ringing, a blow indicator lamp (34) that lights when the solenoid on-off valve (24) is open, and a solenoid on-off valve (24) from the master unit (1) side. ) Forcibly open the manual forced blow switch (36),
A buzzer switch (37) is provided to stop the buzzer from sounding and turn off the buzzer lamp (35). On the side of the box (11) is a jack (3
8) is projected. A cord (4) having a clip terminal (42) at the tip and a pin (41) protruding at the base end is attached by detachably fitting the pin (41) into the jack (38).

The master unit control circuit (3) shown in FIG. 3 includes a power outlet (30), the ON-OFF switch (31), a power lamp (32), and an electromagnetic on-off valve that receives signals from a slave unit described later. (2
4) Open and close, blow indicator lamp (34), buzzer (33)
And the buzzer lamp (35) is turned on or off,
Furthermore, an electronic circuit (3 that issues a talkback signal to the handset (5)
9), the set time (the time required for welding one place, for example, 2 to 3) since the electromagnetic on-off valve (24) connected to the electronic circuit (39) is opened.
(It is desirable that the setting time is about 5 minutes as a minute.)
The dial (39a) for setting the open time of 4), the manual forced blow switch (36) that can open the solenoid on-off valve (24) regardless of the signal of the slave unit, and the buzzer (33) and buzzer lamp. It has a buzzer manual switch (37) for manually turning on and off the energization of (35). The electronic circuit (39) will be described later.

The slave unit (5) has a length of about 13 as shown in FIG.
A small box (51 cm) with a width of about 9 cm and a thickness of about 3.5 cm contains a battery (not shown) and an electronic circuit (8), and an ON-OFF switch (50) for the power supply (50)
By turning on the power lamp (57), the blow start switch (53), and the switch (53) which are turned on in the ON state, a signal is sent to the master unit (1) as described below, and the solenoid opening / closing valve based on the signal is sent. Blow start confirmation lamp (56) that lights up in response to the talkback signal indicating the open state of (24), blow stop switch (5
4) By turning on the switch (54), the blow stop confirmation lamp (57) and the blow stop confirmation lamp (57) which are turned on in response to the talkback signal indicating the closed state of the electromagnetic on-off valve (24) from the master unit (1) in the same manner as above. Blow stop confirmation buzzer (59) that sounds in response to a signal, buzzer stop switch (52) for turning off the blow stop confirmation lamp (57) and stopping the sounding of the buzzer (59), transmission / reception terminal (6
The jack (58) for connecting 2) is projected. In the embodiment, the tip (62) is exposed and the terminal (62) is formed, and the cord (6) having the pin (81) projecting from the base end connects the pin (81) to the jack (5).
8) is detachably fitted and attached, but not limited to this, by fitting a hollow thin rod-shaped protrusion into the jack (58) and inserting a wire-shaped terminal into the protrusion. The form of the terminal does not matter, for example, it may be projected from the tip of the protrusion.

Next, the slave unit electronic circuit (8) and the master unit electronic circuit (7)
Will be described. As shown in FIG. 5, by pressing the blow start switch (53) or the blow stop switch (54) on the slave unit (5), a preset open cord or closed cord is supplied with a pulse train of different lengths. The encoder section (81) which is converted into and sends out, the pulse train sent from the encoder section (81) is modulated into a carrier wave of a predetermined kHz in cooperation with the oscillator (82), and the copper pipe (92) to be welded is transmitted. A modulation sending unit (83) for sending out as a medium, an amplification detecting unit (84) for converting a talkback signal from a master unit (1) described later into a pulse train, a converted pulse train is converted into a preset code, and blown. It has a decoder section (85) for sending an energization signal to the start confirmation lamp (56) or the blow stop confirmation lamp (57).

The electronic circuit (39) of the master unit (1) has an amplification detecting section (7) for converting the signal sent from the slave unit (5) into the original pulse train.
1), a decoder unit (72) that converts the converted pulse train into a preset open or closed code and sends a signal, a decoder unit
The electromagnetic on-off valve (24), blow indicator lamp (34), buzzer (33) and buzzer indicator lamp (35) are closed by a signal from (72), and a talkback signal is sent after about 0.5 seconds. A timing control section (73), an encoder section (74) which receives a talkback signal, converts an open code or a closed code of the signal into a pulse train having a different length, and sends the pulse train, and the encoder (7
4) The pulse train sent from 4) cooperates with the oscillator (75), and the predetermined k
It has a modulation transmitter (76) which modulates to a carrier wave of Hz and sends out a copper pipe (92) to be welded as a transmission medium.

However, as shown in FIG. 1, the connection port (2
A cylinder (95) is connected to 1) via a pressure-resistant hose (94), and is connected to an outlet (22) via a gas blow hose (96) to one end of a copper pipe to be welded. Keep the valve on the cylinder (95) open.

As shown in FIG. 2, the transmission / reception clip-shaped terminal (42) of the master unit (1) is sandwiched between copper pipes and locked, and turned on and off.
Turn on the switch (31) to complete the preparation. The welding operator puts the terminal (62) of the slave unit (5) on the exposed surface of the copper pipe in the vicinity of the welding location and turns on the blow start switch (53). The preset open code is converted into a pulse train having a different length and sent from the encoder section (81) to the modulation transmission section (83). The pulse train is modulated by the cooperation of the oscillator (82).
The signal is modulated by a carrier wave of a predetermined kHz, 455 kHz in the embodiment by (83), and transmitted to the electronic circuit (7) of the parent device (1) using the copper pipe (92) as a transmission medium. This opens the solenoid on-off valve (24), the inert gas is supplied from the cylinder (95) into the copper pipe, the buzzer (33) sounds, and the buzzer indicator lamp (35) and blow indicator lamp (34) ) Lights up.

The signal entering the master unit electronic circuit (7) is sent to the timing control unit (73), and after about 0.5 seconds, the talkback start signal is sent to the encoder (74) and the talkback signal is sent to the copper pipe. It is sent to the child device (5) through (92).

The talkback signal is converted into a pulse train by the amplification detection unit (84) of the slave unit (5), and the converted pulse train is converted into a preset code by the decoder unit (85) to confirm the blow start confirmation lamp. (56) lights up. After confirming the lighting of the blow start confirmation lamp (56), the welding operator goes around the joint end portion and welds the copper pipe (92). Since the inert gas is supplied into the copper pipe (92), the inner surface of the welded portion is not oxidized.

When welding at one location is completed, the terminal (6
2) is brought into contact with the exposed surface of the copper pipe (92) again, and the blow stop switch (54) is turned on. In the same manner as above, the signal is transmitted to the master unit (1), the electromagnetic on-off valve (24) is closed, the talkback signal enters the slave unit (5), the blow stop confirmation lamp (57) is turned on, and the blow stop buser ( 50) is sounded to inform the operator that the electromagnetic on-off valve (24) is closed and the supply of the inert gas is stopped. The welder moves to the next weld point,
Welding work is performed by the same procedure as above.

As described above, the inert gas can be fed into the copper pipe only when necessary, eliminating the waste of discharging the gas all day long as in the conventional case, and the valve of the cylinder is manually operated every time welding is performed. Freed from the hassle of opening and closing. In implementing the present invention, it is omitted to issue a talkback signal from the master unit (1) to the slave unit (5), and the electromagnetic opening / closing valve ( The opening / closing control of 24) can also be performed. In addition, as shown in FIG. 1, the connection port (26) of the master unit (1) and the hose connection port (21) of the other master unit (1a) are connected by a hose (97) to connect the master unit (1). By opening the on-off valve (27), it is possible to send the inert gas into the pipelines of the two systems by the two parent machines (1) (1a), and further, in the same way to the downstream parent machine (1a). It is possible to send inert gas to multiple pipelines by connecting different master units one after another. The present invention is not limited to the welding of the copper pipe (92) for the refrigerant circulation of the above-mentioned air conditioning equipment,
It is needless to say that the present invention can be applied to a device for supplying an inert gas into a pipe in welding various metal pipes, and various modifications can be made within the scope of the claims.

[Brief description of drawings]

FIG. 1 is a piping system diagram for blowing an inert gas.

FIG. 2 is a perspective view of a master unit and a slave unit.

FIG. 3 is a control circuit diagram of a master unit.

FIG. 4 is an air piping diagram of a parent device.

FIG. 5 is a transmission / reception block diagram between a master unit and a slave unit.

FIG. 6 is a sectional view of a connecting portion of a pipe.

[Explanation of symbols]

 (1) Master unit (2) Air piping (21) Connection port (22) Outlet port (3) Master unit control circuit (42) terminal (5) Slave unit (62) terminal (7) Master unit electronic circuit (8) Handset electronic circuit

Claims (1)

[Claims] 1. A master unit (1) comprising an inert gas supply device master unit (1) and a slave unit (5) transmitting data to the master unit (1) through a metal pipe to be welded. Inert gas hose connection port (21), gas outlet (22), solenoid valve (24) in the conduit (20) connecting the gas hose connection port (21) and the gas outlet (22),
An electronic circuit (39) for sending an open signal to the electromagnetic on-off valve (24) in response to an open signal from the slave unit (5) and a receiving terminal (42) detachably attachable to the metal pipe to be welded are provided, Child machine (5)
Blow start switch (53), blow stop switch (54)
And an electronic circuit (8) for issuing an open or close signal to the electromagnetic on-off valve (24) to the master unit (1) by operating each switch, and a transmission terminal (62) capable of contacting a metal pipe to be welded. Inert gas supply device for welding work.