JP2002113573A - Axle housing made of steel sheet, welding method therefor and welding torch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cost, and to increase strength by eliminating backing or the faucet working of a tube. SOLUTION: After butting the housing main body 21 of an axle housing made of a steel sheet and the tube 22, the butt part is joined by welding from the inside and the outside. When welding the butt part from the inside and the outside, inside welding is precedingly started and outside welding is performed in the same direction as that of the inside welding from the start end of the inside welding after the inside welding started. In the welding torch, the part 25b of the torch is shortened and is bent at a comparatively sharp angle. In the welding torch, the distance from the axial center of a part succeeding its tip part to the tipmost of the welding torch is shortened, thus a welding wire 26 and gas are correctly directed to the butt part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel plate axle housing, a method for welding the same, and a welding torch used for the welding.

[0002]

2. Description of the Related Art The steel plate axle housing is widely used except for special large vehicles. If this steel plate axle housing is explained by taking an example for a heavy truck, first, as shown in an exploded view of FIG. 8, a central portion is formed to form a space for housing a differential mechanism (not shown). The upper member 2 of the housing body 1 and the lower member 3 of the same shape are swelled outward, and the upper and lower members 3 and 4 are welded to each other with the triangular plate 4 therebetween. A housing body 1 is formed by welding a reinforcing ring 5 and a cover 6 to the other side, and an outer end of the main body 1 is provided on a tube 7 through which an axle (not shown) has a large diameter side having the same diameter as the outer end. Are integrated by applying butt welding.

In this case, as shown in FIGS. 8 to 11, a ring-shaped backing (backing metal) having an outer diameter matching the inner diameter of the abutting portion 8 of the tube 7 and the outer end of the axle housing body 1 is usually used. Then, as shown in FIG. 10 in an enlarged manner, the welding metal 10 is divided into two or three layers and welded into the groove 7a from the outside. By using the backing 9 in this manner, the butting portion 8
The amount of penetration necessary for the back side of the butting portion 8 (inside)
The welding metal 10 can be melted without melting.

However, the above-described welding method requires a backing 9 for preventing the weld metal 10 from being burnt into the butted portion 8 and has problems in parts cost and weight. Since the multi-layer welding is performed only from the outside of the butt portion 8, the second layer cannot be welded unless the first layer is hardened, resulting in high labor costs. Furthermore, in the welding method, the backing 9 and the housing body 1 or the backing 9 and the tube 7
However, a notch-shaped unwelded portion exists at the boundary contacting the weld metal 10, that is, at the root portion indicated by 11 in FIG. 11, and this may be the weakest portion in terms of the durability of the axle housing.

[0005] In order to eliminate the backing 9, the outer periphery of the large diameter side end is shaved and spliced to the outer end 1 of the axle housing main body as in a tube 7 ′ shown in FIG. 12 and the joined end is welded from the outside. Although it is also known, this also costs the same as described above for processing the tube 7 ′ and multi-layer welding, and the same as described above for the root portion 12 where the processed portion of the tube 7 ′ and the housing body 1 are in contact with the weld metal 10. There is a notch-shaped unwelded portion, which may also be the weakest portion of the axle housing in terms of durability.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to eliminate the above-mentioned backing or to eliminate the processing for connecting the tubes by spigot, thereby reducing parts and labor costs and increasing strength. To provide an axle housing, a welding method therefor, and a welding torch used therefor.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a steel plate axle housing, in which an outer end of an axle housing body and a tube are butted, and the butted portion is welded from inside and outside. And the invention relating to the steel plate axle housing in which the tube is joined, and the outer end of the axle housing main body of the steel plate axle housing and the tube are butt-jointed. An invention relating to a welding method of a steel plate axle housing that performs outer welding in the same direction as the inner welding from the start end of the inner welding delayed from the inner welding, and butt the outer end of the axle housing body of the steel plate axle housing to the tube. A torch for welding a butt portion from the inside. Consisting of invention relates to a welding torch bent manner steep angle.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION
This will be described in detail with reference to FIGS. As shown in FIG. 1, the steel plate axle housing 20 of the present invention abuts the outer end of the axle housing main body 21 to the large diameter side of the tube 22 having the same diameter as the outer end, and welds the butted portion 23 from inside and outside. The housing body 21 and the tube 22
As shown in FIG. 2, in this example, only one layer of the weld metal 10 is melted between the inside and outside of the groove 23a, 23b inside and outside of the butted portion 23 and welded.
As described above, in order to melt only one layer of the weld metal 10,
The groove 23b is made as large as possible within a range where the weld metal 10 can be piled up in one layer, and the size of the inner groove 23a that is difficult to weld is determined accordingly.

In this case, the outside of the butting portion 23 is welded by a normal carbon dioxide-arc welding torch 24 as shown in FIGS. 3 to 6, but the inside is entirely shown in FIG. 1 according to the present invention. , A bending torch 25 is used. That is, in the bending torch 25, the tip 25b of the torch following the portion 25a that enters the tube 22 is bent at a short and relatively steep angle. Accordingly, the distance from the axis of the portion 25a to the tip of the torch 25 can be reduced, and the welding wire 26 and carbon dioxide can be accurately directed to the groove 23a. The curvature of the tip (tip) 25b is determined by experiments or the like.
A replaceable small tip (not shown) is attached to the tip of the tip portion 25b, and a tapered hole (not shown) for smoothly feeding a welding wire (not shown) is provided in this small tip.
Has been devised.

The bending torch 25 and the welding torch 2
The method of welding the butting portion 23 from inside and outside using the first and fourth parts will be described. First, the axle housing body 21 and the tube 22 are placed on a turntable (not shown) so that the butting portion 23 can rotate accurately about the axis. And the outer end of the housing body 21 and the large-diameter end of the tube abut each other.

Next, after the bending torch 25 is leveled and inserted into the tube 22, the tip 25b of the torch 25 is positioned as shown in FIG. 1, that is, the welding wire 26 and carbon dioxide gas are accurately transferred to the groove 23a. , And as close to vertical as possible, and the portion 25a following the distal end portion 25b should be inclined with its base end upward as much as possible.
The outer welding torch 24 also has a welding wire 2 at the tip thereof.
6 and the carbon dioxide gas are set accurately toward the groove 23b. At this time, the outer welding torch 24
So that it is directly above 5.

When the preparation state is completed, the welding metal 10 is first melted into the groove 23a by the bending torch 25 while the housing body 21 and the tube 22 are rotated, for example, in the direction of the arrow, as shown in FIG. I do. At the end of the inner welding half-turn, the outer welding torch 24
Starts the welding in the groove 23b.

While the housing body 21 and the tube 22 continue to rotate in the direction of the arrow, the bending torch 25 and the outer welding torch 24 melt the weld metal 10 into the inner groove 23a and the outer groove 23b. (FIG. 4).

The welding by the bending torch 25 is stopped when the housing main body 21 and the tube 22 make one rotation from the start of welding by the torch 25, but the welding metal 10 is melted into the outer groove 23b by the outer welding torch 24. Welding continues (FIG. 5).

The welding by the outer welding torch 24 also stops when the housing main body 21 and the tube 22 make one rotation from the start of welding by the torch 24 (FIG. 6).

FIG. 7 shows an application example of the bending torch 25. As shown in FIG. 14, the cover 6 attached around the central circular portion 1a of the housing body 1 has a structure as shown in FIG. Is welded to the housing 1 from the outside. However, the root portion 27 may be generated to cause insufficient strength, and welding from the inside may be necessary to reinforce the strength. At this time, by using the bending torch 25 of the present invention, the tip can be easily inserted and welded from the central circular portion 1a of the housing main body 1 as shown in FIG.

Conventionally, the cover 6 is attached as described above,
When welding from the inside, since the welding torch T does not enter, it is necessary to cut out several places on the peripheral edge of the central circular portion 1a of the housing main body 1 as shown in FIGS. Therefore, the stress concentration p
And this was a weak point in strength.

[0018]

The present invention relates to an axle housing made of a steel plate, in which an outer end of an axle housing body and a tube are butted, and the butting portion is welded from inside and outside to join the housing body and the tube. When the outer end of the axle housing body of the steel plate axle housing and the tube are butted, and when the butted portion is welded from the inside and the outside, the inside welding is started in advance, and after the inside welding, the inside welding is started from the beginning of the inside welding. An invention relating to a method for welding a steel plate axle housing in which outer welding is performed in the same direction as inner welding, and a torch for welding the outer end of an axle housing body of a steel plate axle housing to a tube and welding the butted portion from the inside. And a welding torch in which the tip of the torch is bent short and at a relatively steep angle. For the axle housing made of steel plate, the outer end of the axle housing body and the tube are butted and the butted portion is welded from inside and outside, so that the conventional backing becomes unnecessary, and the cost and weight of parts are reduced. And welding can be performed in a shorter time than in the case of performing multi-layer welding only from the outside of the butt portion using the backing, thereby reducing labor costs. Further, unlike the conventional steel plate axle housing, a root portion does not occur, so that the durability of the axle housing is improved. Furthermore, even if the outer periphery of the large-diameter end of the tube is shaved and spliced to the outer end of the axle housing main body, and compared with the case where the joined end is welded from the outside, there is no processing of the tube or multilayer welding, so the cost is low. In addition to reducing the root portion, the durability of the steel plate axle housing is improved.

The method of welding the steel plate axle housing is as follows.
When the outer end of the axle housing body of the steel plate axle housing is butted with the tube, and when the butted portion is welded from inside and outside, the inside welding is started before the inside welding and the inside welding is started from the beginning of the inside welding after the inside welding. By performing the outer welding in the same direction as above, a single-layer outer welding can be performed using the inner welding of the butt portion to be welded in advance instead of the backing, thereby making the backing unnecessary as described above. In addition to reducing parts cost and weight,
Welding can be performed in a shorter time than that in which multi-layer welding is performed only from the outside of the butt using a backing, and labor costs are reduced. In addition, the root portion does not occur, and the durability of the steel plate axle housing is improved.

The welding torch of the present invention is a torch for abutting an outer end of an axle housing body of a steel plate axle housing with a tube and welding the abutting portion from the inside. By bending the steep angle, the distance from the axis of the portion following the tip to the tip of the welding torch can be shortened, and the welding wire and carbon dioxide gas can be accurately directed to the butted portion.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing an axle housing made of a steel plate according to the present invention and an inner welding state of a butt portion by the bending torch.

FIG. 2 is a detailed sectional view of a portion A in FIG.

FIG. 3 is an operation cross-sectional view showing a state in which the inner side welding of the butted portion of the axle housing made of a steel sheet according to the present invention has been performed for half the circumference and the outer side welding has been started.

FIG. 4 is an operation cross-sectional view showing a state in which the inner side welding of the butted portion of the axle housing made of the steel sheet according to the present invention is performed more than half a circumference and the outer side welding is continuously performed.

FIG. 5 is an operational cross-sectional view showing a state in which inner welding of the butted portion of the steel plate axle housing according to the present invention has been completed and outer welding has been performed up to half a circumference;

FIG. 6 is an operational cross-sectional view showing a state in which both the inner welding and the outer welding of the butted portion of the steel plate axle housing according to the present invention are completed.

FIG. 7 is a sectional view showing an application example of the bending torch according to the present invention.

FIG. 8 is an exploded perspective view of an axle housing made of a steel plate to which the present invention is applied.

FIG. 9 is a partial cross-sectional view of a conventional steel plate axle housing.

10 is a detailed sectional view of a portion B in FIG. 9;

11 is an enlarged sectional view of a portion B in FIG. 9;

FIG. 12 is a partial cross-sectional view of another example of the conventional steel axle housing.

13 is an enlarged sectional view of a portion C in FIG.

FIG. 14 is a partial perspective view showing the vicinity of a cover of a steel axle housing to which the present invention is applied.

15 is a partially enlarged cross-sectional view taken along the line DD in FIG. 14;

FIG. 16 is a partially enlarged cross-sectional view illustrating a case where inside welding is performed on the structure shown in FIG.

FIG. 17 is a view as seen in the direction of arrow E in FIG. 16;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1, 21 Housing main body 2 Upper member 3 Lower member 4 Triangular plate 5 Reinforcement ring 6 Cover 7, 7 ', 22 Tube 8, 23 Butt part 9 Backing 10 Weld metal 11, 27 Root part 20 Steel plate axle housing 24 Welding torch 25 Bending torch 26
Welding wire 28 Notch.

Claims (3)

[Claims] An axle housing made of a steel plate, wherein an outer end of an axle housing body and a tube are butted, and the butted portion is welded from inside and outside to join the housing body and the tube. 2. An outer end of an axle housing body of an axle housing made of a steel plate is abutted against a tube, and when the abutting portion is welded from the inside and the outside, the inside welding is started prior to the inside welding and the inside welding is delayed after the inside welding. A method of welding an axle housing made of a steel sheet, comprising performing outer welding in the same direction as inner welding from the start end of the axle housing. 3. A torch for abutting an outer end of an axle housing body of a steel plate axle housing with a tube and welding the butted portion from the inside, wherein the tip of the torch is bent at a short and relatively steep angle. A welding torch characterized in that: