JPH04113173U - MIG welding equipment with preheating head - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent poor penetration at the arc starting point by using the MIG welding equipment itself, without using a separate heat source such as a gas burner, in MIG welding of aluminum etc. Allows to preheat things. [Configuration] A preheating head 6 made of a resistance heating element such as a carbon material, which is removably attached to the tip of the current-carrying tip 2 of the welding torch and is in conductive contact with the current-carrying tip 2 and the workpiece 1, and this preheating head. A preheating current and shielding gas are supplied to the welding torch equipped with the welding torch 6 while the supply of the consumable electrode 3 is stopped, and the workpiece 1 can be preheated by the heat generated by the preheating head 6. The workpiece 1 to be welded is preheated using a welding power source 7 having a preheating circuit.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is suitable for consumable electrode type arc welding (MIG welding) of aluminum etc. This invention relates to a MIG welding device with a preheating head that can also be used to preheat objects to be welded.

0002

[Conventional technology]

Generally, in MIG welding of aluminum etc., the area near the arc start point is where the heat transfer of the material occurs. Due to its good conductivity, poor penetration is likely to occur. As a means to improve this, Preheat the area near the arc start point for a short time using another heat source such as a gas burner or TIG arc. things are being done.

0003

[Problem that the idea aims to solve]

In the above conventional technology, a gas burner or TIG welding device is used to preheat the workpiece. must be prepared separately from the MIG welding equipment, which is not economical.

0004 The purpose of this invention is to solve the above problem by equipping the MIG welding equipment itself with a preheating function. It is about solving problems.

[0005]

[Means to solve the problem]

The above purpose is removable from the tip of the current-carrying tip of the welding torch. A preheating head consisting of a resistive heating element, such as a carbon material, that is in conductive contact with the workpiece. and a welding torch equipped with this preheating head until the consumable electrode feed is stopped. Also, the preheating current and shielding gas are supplied, and the heat generated by the preheating head prevents the melt from being melted. A welding power source with constant voltage characteristics that has a preheating circuit configured to preheat the objects it comes in contact with. This is achieved by having the following.

[0006]

[Effect]

In the above configuration, when preheating is set, the preheating circuit of the welding power source is activated and the welding temperature is The welding power source is connected to the preheating head, which is in conductive contact with the energizing tip of the welding tool and the workpiece. The preheating current is roughly determined from the rated load voltage (V) and the resistance value (Ω) of the preheating head. Since the preheating head generates heat, the workpiece to be welded can be preheated by the heat generated. can.

[0007] Please note that supplying shield gas (argon gas) during preheating is When the tip of the preheating head wears out, it prevents the oxidation and wear of The base metal melts due to the generated arc, or the base metal melts due to the gouging effect. It also prevents melting of the current-carrying tip due to excessive heat generation in the preheating head. In addition to preheating by heat conduction directly under the preheating head, the arc starting point is heated by high-temperature gas. This is essential for preheating the surrounding area.

[0008]

【Example】

An embodiment of the present invention will be described below with reference to the drawings.

[0009] In Figure 1, 1 is the object to be welded, 2 is the current-carrying tip of the welding torch, and 3 is the consumable electrode. , 4 is the shield gas, 5 is the gas shield nozzle, 6 is the preheating head, 7 is the preheating and 8 is a welding power source with constant voltage characteristics that supplies power for welding and welding; , an electrode feeding motor control circuit that controls the feeding speed of electrode 3, forward feeding, and reverse feeding. It is usually built into the welding power source 7. 10 is a preheater provided in the remote controller 11; This is a welding selector switch.

0010 The preheating head 6 is made of a resistance heating element such as carbon material, and is located at the tip of the current-carrying tip 2. It is removable from the end and is in conductive contact with the current-carrying tip 2 and the workpiece 1. A tapered hole 6a into which the tip of the energizing tip 2 is pushed and a flat bottom surface 6b are formed. It is. The preheating head 6 also includes a consumable material protruding from the current-carrying tip 2. An insertion hole 6c for the electrode 3 is provided.

[0011] When preheating the workpiece 1, the preheating/welding selector switch 10 is set on the preheating side. to be determined. As a result, the preheating circuit of the welding power source 7 is selected, and the feeding of the consumable electrode 3 is performed. Only the preheating current and shielding gas can be supplied while the system is stopped. The preheating head 6 is pressed into contact with the tip of the current-carrying tip 2 of the welding torch and installed. With the bottom surface 6b of the thermal head 6 pressed against the workpiece 1, the welding tip (not shown) is pressed. When the trigger switch is pulled, the preheating circuit causes the welding power supply A preheating current is supplied to the preheating head 6 and the workpiece 1 through the tap 2, and at the same time the gas Shielding gas 4 is released from shielding nozzle 5 along the outer periphery of preheating head 6. .

0012 The resistive heating element that forms the preheating head generates heat due to the current flowing through the preheating head 6. The workpiece 1 directly under the preheating head is preheated by thermal conduction, and the preheating head The shielding gas that came into contact with 6 becomes a high-temperature gas, and the area around the arc starting point of the workpiece 1 is heated. Preheat at the same time. At this time, the current value flowing through the preheating head 6 is the rated value of the welding power source 7. It is approximately determined by the load voltage (V) and the resistance value (Ω) of the preheating head 6, but the welding voltage is set so as not to exceed the equivalent continuous output current (usage rate x rated output current) of source 7. There is.

[0013] Preheating heat input can be controlled by adjusting the preheating time (long or short) and the output voltage of the welding power source. It can be changed depending on the material, size, shape, etc. of the object 1. Material of preheating head 6 Carbon materials are suitable as materials due to their ease of availability and processing. The material is not limited to carbon material as long as it can provide the same effect. Also, preheating In operation, the preheating head 6 is placed on the workpiece 1, and the energizing switch of the welding torch is connected to it. It is also possible to force the cups into contact with each other.

[0014] After preheating is completed, set the preheat/welding selector switch 10 to the welding side, and turn the preheating head 6 on. When removed from the energizing tip 2, turn on the welding torch trigger switch (not shown). When you pull the button, welding current, shielding gas supply, and consumable electrode 3 are delivered. Then, normal MIG welding begins.

[0015]

[Effect of the idea]

As explained above, according to the present invention, during preheating, the tip of the current-carrying tip of the welding torch Simply attach the preheating head to the welding power source and select the preheating circuit of the welding power source to start the MIG welding equipment. Since the arc starting end of the workpiece can be preheated using the equipment itself, conventional It is economical as the gas burner and TIG welding equipment used as heat sources are no longer required. . Also, compared to the method of attaching a tab plate at the arc starting end of the workpiece, the tab plate It saves the trouble of bevelling, mounting, and removing, and can be used for welded objects where it is not possible to attach a tab plate. It is also valid even if

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a MIG welding apparatus showing an embodiment of the present invention.

[Explanation of symbols]

1... object to be welded, 2... energizing tip, 3... consumable electrode, 4...
Shield gas, 6... Preheating head, 7... Welding power source, 8... Electrode feeding motor control circuit, 9... Electrode feeding motor, 10... Preheating, welding changeover switch.

Claims (1)

[Scope of utility model registration request] [Claim 1] A welding torch that is removably attachable to the tip of the current-carrying tip and comes into conductive contact with the current-carrying tip and the object to be welded;
A preheating head made of a resistance heating element such as carbon material,
The welding torch equipped with this preheating head is supplied with a preheating current and shielding gas while the supply of the consumable electrode is stopped, and the workpiece is preheated by the heat generated by the preheating head. 1. A MIG welding device with a preheating head, characterized in that it is equipped with a welding power source with constant voltage characteristics and a circuit for use in the welding process.