JPH04270068A - Method for welding ring gear - Google Patents

Abstract

PURPOSE:To obtain sound welded part without any cracking by subjecting mild steel wire to a carbon dioxide gas arc welding and successively, executing arc post-heating treatment with arc heat of a TIG welder. CONSTITUTION:After fitting a ring gear 2 and a plate 3, the mild steel wire 6 is successively supplied with a carbon dioxide gas arc welder 8, and after welding the ring gear 2 and the plate 3 as shown in the welded part (bead) 4, the arc post-heating treatment is executed with the arc heat of tungsten inert gas welder 10. By this method, in the case of welding different kinds of materials, by applying post-heating treatment with the TIG welding because of a need to make the cooling velocity after welding slow, the sound weld part having the prescribed value or lower of hardness Hv in the ordinary martensitic structure without any cracking can be obtd.

Description

[Detailed description of the invention]

The present invention relates to a method for welding two members made of different materials, and is used for welding a ring gear in a drive plate of an automatic transmission for an automobile.

0002

2. Description of the Related Art As a prior art related to the present invention, there is Japanese Patent Publication No. 2-51712.

[0003] When manufacturing a drive plate in which a ring gear and a plate are integrally constructed for an automatic transmission for an automobile, a medium carbon steel material is used for the ring gear, a rolled mild steel plate is used for the plate, This is a ring gear welding method in which welding is performed by carbon dioxide arc welding using stainless steel welding wire, and then post-arc heating is performed using arc heat from a tungsten inert gas welding machine (hereinafter referred to as T1G welding machine).

[0004] However, although the above welding method does not cause cracks in the welded portion, (a) many spatters are generated during welding, and it takes many man-hours to remove the spatters in the post-welding process.

(b) The rigidity of the wire is high, and the friction of the power supply chip is fast, and the frequency of chip replacement becomes quick.

(c) The cost of wire materials used for welding is high.

[0007] There is a problem.

[0008]

[Problems to be Solved by the Invention] The problems to be solved are that when welding a ring gear and a plate by carbon dioxide arc welding, there is no cracking in the welded part, there is not a small amount of spatter, and the electrode tip is Replacement is less frequent,
The technical issue is to develop a welding method that can reduce the overall cost of the welding process.

[0009]

[Means for Solving the Problems] The present invention uses a mild steel wire as a welding wire when welding a ring gear and a plate by carbon dioxide arc welding, and then uses arc heat from a T1G welding machine to perform post-arc heat. The ring gear welding method used does not cause cracks in the welded portion, and also causes less spatter and less wear on the electrodes.

0010

[Example] Examples will be explained below.

In FIG. 1, 1 is a drive plate used in an automatic transmission for automobiles, 2 is a ring gear, 3 is a plate, and 4 is a welded portion (bead).

5 is a carbon dioxide gas welding torch, 6 is a welding wire made of mild steel, 7 is a supply bobbin, 8 is a carbon dioxide arc welding machine, 10 is a T1G welding machine, and 9 is a torch for post-arc heating. It is.

After fitting the ring gear 2 and the plate 3 as shown in FIG. 1, a carbon dioxide arc welding machine 8 sequentially supplies mild steel wire 6, and after welding the ring gear 2 and the plate 3 as shown in 4, T1G Post-arc heat treatment is performed using the torch 9 of the welding machine 10.

In this case, the welding conditions are a welding current of 220A,
Welding voltage 22V, gas flow rate CO2 + Ar 15 liters/min, welding speed 500mm/min (0.7 rpm
), beat length 10 mm or more, T1G current 190 A, gas flow rate Ar 5 liters/min, time after carbon dioxide gas welding to post heat 7.0 sec, post heat length with arc treatment 1
It is 0 to 12 mm.

Table 1 shows a comparison of the main welding conditions between the present example and the conventional example when stainless steel wire is used.

[0016]

[Figure 1]

As shown in Table 1, the heating temperature, current, etc. of this example is about 10% higher than that of the conventional example, but due to the use of mild steel wire, a component that eliminates spatter is included in the mild steel wire. Therefore, the occurrence of spatter is extremely reduced, and since mild steel wire is less rigid and more flexible than stainless steel wire, it can be fed smoothly, and the wear of the electrodes is significantly less.

[0018]

[Effects of the Invention] The present invention has the following effects.

When welding dissimilar materials such as drive plates, it is necessary to slow down the cooling rate after welding, so by applying post-heating by T1G welding, we can create very healthy cracks with a conventional martensitic structure with a hardness of Hv400 or less. It is possible to obtain a welded part without any welds, and furthermore, compared to the case where the stainless steel wire is used, (a) the frequency of electrode tip replacement is reduced to 1/2, and (b) the number of man-hours for removing spatter is reduced to about 1/2. (c) The cost of mild steel wire is about 1/5 or less compared to stainless steel wire, resulting in a significant cost reduction.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a ring gear welding method according to the present embodiment.

[Explanation of symbols]

1 Drive plate 2 Ring gear 3 Plate 6 Mild steel wire 8 Carbon dioxide welding machine 10 T1G welding machine

Claims (1)

[Claims] Claim 1: In a drive plate formed by welding a ring gear and a plate of an automatic transmission for automobiles, the ring gear is made of medium carbon steel, the plate is made of a rolled steel plate, and a mild steel wire is used to form a carbonated drive plate. A ring gear welding method that performs gas arc welding and then performs post-arc heating using the arc heat of a tungsten inert gas welding machine.