JPH04367375A - Shield gas distribution device in welding robots - Google Patents

Abstract

PURPOSE:To offer the shielding gas distributing device which can supply prescribed shielding gas to a torch part of a welding robot in accordance with a welding method without changing a welding machine itself. CONSTITUTION:The device is constituted of plural pieces of gas supply pipes 21-23 in which one end part is connected to supply bombs 11-1.3 of shielding gas of different kinds, respectively, and the other end part is led to a torch part 2 of a robot side, a gas mixing device 18 which is allowed to branch from the half way of these prescribed gas supply pipes 22, 23 and mixes each prescribed shielding gas, a second mixed gas supply pipe 26 for supplying the shielding gas mixed by this gas mixing device 18 to the torch part 2 of the robot side, and solenoid opening/closing valves 31-34 provided on the way of each gas supply pipe, and also, the gas mixing device 18 is constituted of a gas cutting machine 17, and a mixing part 16 for leading and mixing gas cut by this gas cutting machine 17 and gas from other kind of gas supply pipe.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shielding gas distribution device for a welding robot.

0002

[Prior Art] Conventionally, when welding work is performed using a welding robot, for example, the welding method for the parts to be welded is fixed to one type in order to increase the operating efficiency.For example, in the case of MIG welding, the entire line is All were considered to be MIG welding.

0003

[Problem to be solved by the invention] By the way, recently,
As parts to be welded become more sophisticated, various materials such as steel plates, stainless steel plates, cast metals, etc., are being used in combination even for one part to be welded. For this reason, in car body welding lines that use hot-dip galvanized steel sheets for rust prevention parts, metal flux-cored wire is used, and a mixture of argon gas and carbon dioxide gas (20%) is used as the shielding gas. For those using stainless steel plate, use stainless steel wire and use argon gas and carbon dioxide gas (5 to 20%) as shielding gas.
It is necessary to use it properly, such as using MIG welding using a mixed gas.

However, as mentioned above, the wire and shielding gas must be replaced for each type of wire.
There was a problem in that the number of work steps increased and productivity decreased. Therefore, an object of the present invention is to provide a shielding gas distribution device that can supply an optimal shielding gas depending on the wire used.

[0005]

[Means for Solving the Problems] In order to solve the above problems, a shielding gas distribution device for a welding robot according to the present invention has one end connected to supply cylinders of different types of shielding gas, and the other end connected to supply cylinders of different types of shielding gas. A plurality of gas supply pipes led to the torch section on the robot side, a gas mixing device that is branched and connected from the middle of a predetermined gas supply pipe and mixes predetermined shielding gases, and It consists of a mixed gas supply pipe that supplies the shielding gas mixed in the gas mixing device to the torch section on the robot side, and an on-off valve provided in the middle of each of the gas supply pipes, and the mixing device is used to cut out the gas. The gas extractor is composed of a gas cutter and a mixing section that guides and mixes the gas cut out by the gas cutter and gas from other types of gas supply pipes.

[0006]

[Function] According to the above configuration, the prescribed shielding gas can be supplied to the torch section of the welding robot by simply opening and closing the on-off valve provided in each gas supply pipe according to the welding method. Therefore, a welding method suitable for the material of the parts to be welded can be adopted without replacing the welding machine itself.

[0007] Furthermore, since a mixed gas having an arbitrary mixing ratio can be obtained using the mixing device, the generation of spatter can be suppressed by blowing out this mixed gas from a nozzle provided around the torch body in the torch section. At the same time, the appearance of the weld bead can be improved.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 5. First, the overall schematic configuration of the welding robot used in this embodiment will be described based on FIGS. 2 and 4.

That is, this welding robot has a robot main body 4 provided with an arm portion 3 for holding a torch portion 2 provided with a cover nozzle 1 around a torch main body 2a.
and a predetermined welding machine main body (for example, C
A wire distributor 7 for dispensing the wire 6 supplied from the O2 welding machine, MAG welding machine, MIG welding machine, etc.) 5 to the torch section 2, and a predetermined shield according to each wire 6, that is, each welding method. Gas (e.g. argon gas, carbon dioxide gas,
A shield gas distribution device 8 that supplies a mixed gas of argon gas and carbon dioxide gas, etc.) to the robot main body 4 side, a welding power source 9 controlled by an inverter, and each of the above-mentioned welding machine main bodies 5,
It is comprised of a welding power source 9 and a control device (for example, a microcomputer) 10 that controls the torch section 2. Note that the above-mentioned shielding gas is supplied to the torch main body 2a of the torch section 2 and the nozzle 1.

Next, the shield gas distribution device 8 is shown in FIG.
The explanation will be based on. This shield gas distribution device 8 is a first mixed gas supply pipe (gas supply pipe) that supplies a fixed ratio of mixed gas of carbon dioxide gas and argon gas from a mixed gas supply cylinder 11 to the torch section 2 of the robot main body 4. 21, and a carbon dioxide gas supply pipe (gas supply pipe) 22, which supplies carbon dioxide from the carbon dioxide gas supply cylinder 12 to the torch section 2 of the robot body 4. A second electromagnetic on-off valve 32 and an argon gas supply pipe (gas supply pipe) 23 that supplies argon gas from the argon gas supply cylinder 13 to the torch section 2 of the robot body 4
A third electromagnetic on-off valve 33 provided midway, a carbon dioxide gas branch supply pipe (gas supply pipe) 24 branched from the middle of the carbon dioxide gas supply pipe 22, and an argon gas branch branched from the argon gas supply pipe 23. Supply pipe (gas supply pipe)
25 for mixing carbon dioxide gas and argon gas at an arbitrary ratio (specifically, a mixing chamber 16a
and a baffle plate 16b disposed in the mixing chamber 16a), a cutting machine 17 provided in the middle of the carbon dioxide branch supply pipe 24, and a mixed gas mixed in this mixing section 16. A second mixed gas supply pipe (gas supply pipe) 26 that supplies the gas to the torch section 2 of the robot body 4, a fourth electromagnetic on-off valve 34 provided in the middle of the second mixed gas supply pipe 26, and It consists of a gas flow meter (not shown) provided midway through the supply pipes 21-26. In addition,
The mixing section 16 and cutter 17 constitute a gas mixing device 18.

[0011]Furthermore, a flow rate signal from a gas flow meter provided midway through each of the gas supply pipes 21 to 26 is input to a control device 10, and each electromagnetic on-off valve 31 to 34 is also controlled by the control device 10. Ru.

As shown in FIG. 3, the cutting machine 17 has a gas inlet 41 and a gas outlet 4 on one end surface.
2 (in Fig. 3,
43 (shown with the middle cut off) is rotatably arranged inside the cylinder body 43, and the inlet 41 and the outlet 42 are communicated with each other within a predetermined angular range on one end surface thereof. It is comprised of a cylindrical body 45 in which an arcuate communication groove 44 is formed, and a motor (see FIG. 1) 47 that rotates the cylindrical body 45 in a predetermined direction via an engagement plate 46. The motor 47 and the engaging plate 46 are connected to each other by a connecting shaft portion 46a provided on the engaging plate 46 and protruding from the other end surface of the cylinder body 43. Further, this motor 47 is also controlled by the control device 10. Furthermore, the cylindrical body 45 and the engagement plate 46 are
They are engaged with each other by a hole 45a provided on the cylindrical body 45 side and a pin portion 46b provided on the engagement plate 46 side and engaged with the hole 45a.

Therefore, the carbon dioxide gas flows into the mixing section 1 only while the cylindrical body 45 is rotated by the rotation of the motor 47 and the inlet 41 and the outlet 42 are in communication with each other through the communication groove 44.
6, that is, a predetermined amount of carbon dioxide gas is extracted. Of course, this cutting amount can be arbitrarily controlled by the rotational speed of the motor 47 and the time period during which the inlet 41 and the outlet 42 are in communication with each other.

[0014]Flexible hoses are used for predetermined portions of each of the gas supply pipes 21 to 26, such as the connection portion from the gas distribution device 8 to the robot body 4. Next, the entire welding operation will be explained based on the flowchart of FIG. 5.

First, a welding method is input from the control device 10 according to the parts to be welded (step 1), and then a solenoid on-off valve (either 31, 32 or 33) in a predetermined gas supply pipe is opened. , the gas flow rate is confirmed by the flow meter (
Steps 2-4).

Then, if the gas flow rate is correct and the shielding gas is to be blown out from the nozzle 1, an instruction is given from the control device 10 (step 5). When an instruction to supply shielding gas is given, the amount of carbon dioxide mixed with argon gas is adjusted by the cutter 17 and supplied to the mixing section 16, where a mixed gas of a predetermined mixing ratio is obtained. After the four electromagnetic on-off valves 34 are opened and the flow rate of the mixed gas is confirmed, welding is started (steps 6 to 10).

[0017] In this way, depending on the welding method, the prescribed shielding gas can be supplied to the torch section simply by opening and closing the electromagnetic on-off valve provided on each gas supply pipe, and therefore the welding machine itself can be replaced. It is possible to adopt a welding method according to the material of the parts to be welded without having to do so.

Furthermore, since the shielding gas is also supplied to the nozzle 1 provided around the torch body 2a, in this case as well, the optimal mixing ratio of gas depending on the welding method is applied to the shield around the torch body. Since the gas can be supplied as a gas, the occurrence of spatter can be suppressed and the appearance of the weld bead can be improved.

In some cases, instead of supplying the mixed gas from the mixed gas supply cylinder 11, the mixed gas may be supplied from the gas mixing device 18 to the torch body 2a via the second mixed gas supply pipe 26. Of course, in this case, in order to supply the mixed gas in the second mixed gas supply pipe 26 to the torch main body 2a side, a bypass pipe having an electromagnetic on-off valve 35 in the middle, as shown by the imaginary line in FIG. 27 are provided.

[0020]

[Effects of the Invention] As described above, according to the configuration of the present invention, a predetermined shielding gas can be supplied to the torch portion by simply opening and closing the on-off valve provided in each gas supply pipe according to the welding method. Therefore, it is possible to adopt a welding method according to the material of the parts to be welded without replacing the welding machine itself, so that the work process can be shortened.

[0021] Furthermore, since a mixed gas having an arbitrary mixing ratio can be obtained using the gas mixing device, by supplying this mixed gas to the nozzle provided around the torch body in the torch section, it is possible to cut off the outside air. This is effectively carried out, and therefore the occurrence of spatter can be suppressed and the appearance of the weld bead can be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a schematic configuration of a shielding gas distribution device in an embodiment of the present invention.

FIG. 2 is a block diagram showing the overall general configuration of a welding robot in the same embodiment.

FIG. 3 is an exploded perspective view of a cutting machine in the gas mixing device in the same embodiment.

FIG. 4 is a sectional view of the torch portion of the welding robot in the same embodiment.

FIG. 5 is a flowchart showing welding work in the same embodiment.

[Explanation of symbols]

1 Cover nozzle 2
Torch part 4 Robot body 5 Welding machine body 6 Wire 7 Wire distributor 8 Shield gas distribution device 10
Control device 11 Mixed gas supply cylinder 12
Carbon dioxide gas supply cylinder 13
Argon gas supply cylinder 16
Mixing section 17 Cutting machine 18 Gas mixing device 21
First mixed gas supply pipe 22
Carbon dioxide gas supply pipe 23 Argon gas supply pipe 24 Carbon dioxide gas branch supply pipe 25 Argon gas branch supply pipe 26
Second mixed gas supply pipe 31
First electromagnetic on-off valve 32
Second electromagnetic on-off valve 33 Third electromagnetic on-off valve 34 Fourth electromagnetic on-off valve 41
Inlet port 42 Outlet port 43 Cylinder body 44
Communication groove 45 Cylindrical body 47 Motor

Claims (1)

[Claims] 1. A plurality of gas supply pipes each having one end connected to a supply cylinder of a different type of shielding gas and the other end led to a torch portion on the robot side; A gas mixing device that is branch-connected from the middle of a predetermined gas supply pipe and mixes predetermined shielding gases, and a mixed gas supply pipe that supplies the shielding gas mixed by the gas mixing device to the torch section on the robot side. , an on-off valve provided in the middle of each of the gas supply pipes, and the mixing device includes a gas cutting machine, and a gas cut out by the gas cutting machine and gas from other types of gas supply pipes. A shielding gas distribution device for a welding robot, comprising a mixing section that guides and mixes gas.