JPH08276274A - Detector for nozzle clogging in welding torch - Google Patents

Abstract

PURPOSE: To provide such a detector for nozzle clogging in a welding torch that detects as nozzle clogging when the deposit of spatter is small yet inside the torch to prevent welding defects from occurring. CONSTITUTION: A gas feeding passage 17 is formed between the tip 12 for guiding a welding wire 11 and the torch nozzle 13 for surrounding the outside of the tip 12. A circuit 14 for detecting nozzle clogging is provided between the tip 12 and the torch nozzle 13. The circuit 14 is provided with an AC power source 15 as a high voltage power source. The circuit 14 is also provided with a detector 16 for detecting the energizing by discharge through the spatter 18 that is deposited between the tip 12 and the torch nozzle 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle clogging detection device for a welding torch for detecting clogging due to spatter adhesion in a torch nozzle of an automatic welding machine.

[0002]

2. Description of the Related Art Usually, during arc welding, high-temperature molten metal particles, so-called spatter, are scattered and adhere to the inner surface of the torch nozzle at the tip of the welding torch and the outer surface of the tip that guides the welding wire. To do.

When the amount of the spatter adhered increases, the shield gas is not smoothly ejected through the gas supply passage formed between the tip and the torch nozzle,
The jetted shield gas is turbulent, and the shield function of the welded part cannot be exhibited well, and the shield effect of the shield gas is reduced, which may cause welding defects such as blowholes.

Therefore, it is necessary to regularly clean the spatter which adheres to the inside of the torch nozzle of the welding torch. As a means for detecting the cleaning time, there is conventionally a detection device as shown in FIG. That is, the energization detection circuit 4 is provided between the tip 2 that guides the welding wire 1 and the torch nozzle 3 that surrounds the tip 2 with a space therebetween, and the energization detection circuit 4 is low. The voltage source 5 and the relay 6 are provided, and one end side of the energization detection circuit 4 is connected to the chip 2 and the other end side of the energization detection circuit 4 is connected to the torch nozzle 3.

A gas supply passage 7 is formed between the outer peripheral surface of the tip 2 and the inner peripheral surface of the torch nozzle 3 so that the shield gas is jetted and supplied.

In this detection apparatus, as shown in FIG. 3, the spatter 8 during welding gradually adheres and accumulates on the outer peripheral surface of the tip 2 and the inner peripheral surface of the torch nozzle 3, so that the tip 2 and the torch nozzle 3 adhere to each other. When electrically short-circuited by the spatter 8, a current flows through the energization detection circuit 4 and the relay 6 operates to detect the nozzle as a clog.

Examples of this type of detecting device include, for example, Japanese Utility Model Laid-Open No. 58-111178 and Japanese Patent Laid-Open No. 59-15657.
Some are disclosed in Japanese Patent Publication No. 8 and the like.

[0008]

However, according to the above-mentioned conventional detecting device, when the chip 2 and the torch nozzle 3 are short-circuited due to the deposition of the spatter 8, the electrical conduction state is first obtained and the conduction is not achieved. Since it is a method of detecting as a nozzle clogging, there is a possibility that a considerable amount of spatter 8 is accumulated in the torch nozzle 3 at the time of detection, and there is also a risk of causing welding defects such as blow holes.

Further, as shown in FIG. 4, even if a large amount of spatter 8 is deposited on the outer peripheral surface of the chip 2 and the inner peripheral surface of the torch nozzle 3, if there is no short circuit due to the sputter 8, it is not detected as a nozzle clogging, and this In this case, there is a great risk of causing welding defects such as blowholes.

In view of the above problems, the present invention provides a nozzle clogging detection device for a welding torch that detects a nozzle clogging while the amount of spatter adhered in the torch nozzle is small, and prevents welding defects from occurring. The purpose is to

[0011]

The technical means for achieving the above object is to provide a gas supply path between a tip for guiding a welding wire and a torch nozzle surrounding the tip of the welding wire. In a nozzle, that is, a detection device in a welding torch provided with a detection circuit for detecting energization through spatter attached to each other with the torch nozzle,
The power supply of the detection circuit is a high voltage power supply, and the high voltage applied to the detection circuit detects the electrical conduction between the tip and the torch nozzle by the discharge generated through the attached spatter.

[0012]

According to the present invention, since the power supply of the detection circuit is a high voltage power supply, even if the tip and the torch nozzle are not short-circuited by the spatter when spatter adheres to the torch nozzle and is gradually deposited. When the distance between the outer peripheral surface of the tip and the inner peripheral surface of the torch nozzle reaches a specified distance due to the adhered and deposited spatter, a discharge occurs, and the energization between the tip and the torch nozzle is detected. It can be detected as a nozzle block within a few
It is possible to prevent occurrence of welding defects such as blowholes due to nozzle clogging.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. In FIG.
1 is provided with a tip 12 and a torch nozzle 13 surrounding the tip 12 at a predetermined interval, and a nozzle as a detection circuit for detecting energization between the tip 12 and the torch nozzle 13. That is, the detection circuit 14 is provided.

The nozzle, that is, the detection circuit 14 is, for example, an AC power supply 15 of 400 V as a high voltage power supply and an energization detector 16.
The nozzle, that is, the detection circuit 14 has one end connected to the chip 12, and the nozzle, that is, the detection circuit 14 has the other end connected to the torch nozzle 13.

Further, the outer peripheral surface of the tip 12 and the torch nozzle 1
A gas supply passage 17 for jetting and supplying the shield gas to the welded portion is formed between the inner peripheral surface 3 and the inner peripheral surface.

The first embodiment of the present invention is configured as described above, and in the course of performing the welding work, scattered spatter 18 is gradually attached to the outer peripheral surface of the tip 12 and the inner peripheral surface of the torch nozzle 13. Deposited, as shown in FIG.
Spatter 18 and torch nozzle 1 attached to the tip 12 side
When the mutual distance from the spatter 18 attached to the third side reaches a predetermined dischargeable distance, electric discharge occurs between them, and the energization detector 16 detects energization between the tip 12 and the torch nozzle 13. Then, by detecting the energization by the energization detector 16, it is determined that the nozzle 18 is a nozzle in which the spatter 18 has accumulated in the torch nozzle 13, and the welding operation is controlled to be stopped.

As described above, since the nozzle clogging is detected by utilizing the discharge, the nozzle clogging can be detected in advance even if the tip 12 and the torch nozzle 13 are not short-circuited by the sputter 18, and the torch nozzle is here. The nozzle clogging can be detected while the amount of the spatter 18 adhered to the inside of the nozzle 13 is small, and the occurrence of welding defects such as blow holes due to the nozzle clogging can be prevented.

FIG. 2 shows a second embodiment. In this welding robot as an automatic welding machine, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 2, 20 is a welding machine that supplies power to the welding wire 11, 21 is a so-called touch sensor circuit that uses the welding wire 11 as a sensor, and the switching means 22 allows the welding machine 20 side and the touch sensor circuit 21.
It is configured so that it can be selectively switched to the side.

The touch sensor circuit 21 includes an AC power source 23 of, for example, 400 V as a high voltage power source, and a detector 24 for detecting energization through a work (not shown). One end of the touch sensor circuit 21 is a switching means. 22 is connected to the welding wire 11 side through the touch sensor circuit 21.
The other end is grounded to the same level as the work.

The welding wire 11 protruding from the tip of the tip 12 is electrically contacted with the work to detect the energization of the work by the detector 24 so that the teaching can be performed.

The torch nozzle 13 is grounded to the same level as the touch sensor circuit 21 via a resistor 25 as appropriate. Further, the earth circuit 26 and the touch sensor circuit 21 constitute a nozzle, that is, a detection circuit 27 as a detection circuit for detecting the energization between the tip 12 and the torch nozzle 13.

At this time, when the value detected by the detector 24 of the energization caused by the electrical contact between the welding wire 11 and the workpiece by the touch sensor circuit 21 is set to 100, the spatter 18 adhering to the outer peripheral surface of the tip 12 and the inner periphery of the torch nozzle 13 are attached. The detected value by the detector 24 of the current flow due to the discharge due to the close distance to the spatter 18 attached to the surface is lower than 20
The number is about 30, and it is configured to judge whether or not the nozzle is clogged based on the difference in the detected value by the detector 24.

In the second embodiment as well, the first
As in the embodiment, since the method for detecting the nozzle clogging using discharge is used, the nozzle clogging can be detected in advance even if the chip 12 and the torch nozzle 13 are not short-circuited by the sputter 18, and the inside of the torch nozzle 13 can be detected. The nozzle clogging can be detected even when the amount of the spatter 18 adhered is small, and the occurrence of welding defects such as blow holes due to the nozzle clogging can be prevented.

Further, in this case, the touch sensor circuit 21 can be effectively used, and it is not necessary to separately provide the nozzle, that is, the detection circuit 27 as an external circuit, and the manufacturing cost can be reduced.

In each of the above embodiments, the AC power sources 15 and 23 are used as the high voltage power source, but a DC power source may be used.

[0027]

As described above, according to the nozzle, that is, the detection device in the welding torch of the present invention, the power source of the detection circuit is the high voltage power source, and the high voltage applied to the detection circuit causes the spatter to deposit. It detects electrical conduction between the tip and the torch nozzle by electric discharge, and can detect it as a nozzle clogging even when the amount of spatter adhered inside the torch nozzle is small, and it is possible to prevent the occurrence of welding defects such as blow holes due to the nozzle clogging. There are advantages.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a second embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a conventional example.

FIG. 4 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

 10 Welding torch 11 Welding wire 12 Tip 13 Torch nozzle 14 Nozzle or detection circuit 15 AC power supply 16 Energization detector 17 Gas supply path 18 Sputter 21 Touch sensor circuit 23 AC power supply 24 Detector 26 Earth circuit 27 Nozzle or detection circuit

Claims (1)

[Claims] 1. A detection for detecting energization through a spatter attached between a tip and a torch nozzle by forming a gas supply path between the tip for guiding a welding wire and a torch nozzle surrounding the tip. In a nozzle in a welding torch including a circuit, that is, a detection device, the power source of the detection circuit is a high-voltage power source, and a high voltage applied to the detection circuit causes electricity to flow between the tip and the torch nozzle due to discharge generated through the attached spatter. Nozzle or detection device in a welding torch, which is characterized by detecting