JPS61202781A - Assembly welding method of wheel - Google Patents

Abstract

PURPOSE:To improve the strength of a wheel by performing the correction treatment of the bead contact angle between a welding bead and unweld zone of the joining member beyond the specified angle. CONSTITUTION:A correction treatment is performed by TIG or plasma treatment or grinder treatment on the starting end part 3 and finishing end part 4 of a weld bead 1. First the prescribed range of the starting end part 3 is re-melted by plasma treatment, etc. and the end part of the bead 1 is corrected in smooth sectional shape by moving the fused part to the joining member 2 side. In this case, the correction is performed so as to make the contact angle theta between the weld bead 1 and unweld zone 5 >=130 deg.. The finishing end part 4 of the bead 1 is made similar as well and the correction of the contact angle theta between the bead 1 and unweld zone 5' is performed in the angle of >=130 deg.. Due to the stress concentration of the end part of the weld bead 1 being prevented with this method the strength and durability of the wheel are increased.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a welding method for assembling a wheel in which a rim and a disc are welded together. Assembling to improve the durability of wheels in cases where wheels are assembled involves welding methods.

[Prior art] There are two welding methods for assembling a wheel by welding the rim and disc together: one is to weld the entire circumference of the wheel, and the other is to weld intermittently along a certain length in the circumferential direction of the wheel. There are cases where welding is performed intermittently, and weld beads are formed intermittently. When weld beads are formed intermittently in this manner, structural discontinuities are caused by the weld beads, and fatigue strength may become a problem.

In general, methods for improving the fatigue strength of welded joints include TiG treatment, plasma treatment, grinder treatment, coated arc treatment, etc. along the weld line direction of the weld bead, as seen in methods for improving the fatigue strength of the weld bead of welded joints. A method of performing a welding process is known as a known technique. However, in the current wheel assembly, the welded parts are left as welded, and no measures have been taken to improve fatigue strength as seen in the above-mentioned welded joints.

Problems to be Solved by the Invention However, when assembling a wheel in which weld beads are formed intermittently, there is a risk that sufficient durability as a wheel may not be achieved if the welding is done as it is. . This is clarified, for example, by the following test. That is, as shown in FIG.
The durability of the wheel is evaluated by a lifespan evaluation using a drum durability test in which the wheel assembly equipped with the wheel assembly is rotated on the drum 7 while applying an appropriate radial load, and the number of revolutions until the disc wheel 8 cracks is determined. . In a wheel with insufficient durability, a problem arises in that cracks occur at the beginning and end of the weld bead formed at the weld between the wheel rim and the disc before a sufficient number of rotations can be achieved. . For example, as shown in FIGS. 12 and 13, when a pressure P is repeatedly applied to the wheel from a certain direction, the rim 9 and disc 10 of the wheel are intermittently formed by a certain length in the circumferential direction. Stress 11 is concentrated at the starting end 3 and ending end 4 of the welding bead 1 as shown in the figure, causing a crack 1 as shown in FIG.
2 may occur.

If such cracks occur under a predetermined load condition and below a predetermined rotation speed, the durability of the wheel will not be satisfied. That is, the following problems can be considered in the current wheels having intermittent weld beads.

(a) Current tires (bias tires) may not meet the durable rotational speed required by vehicle manufacturers, even if they are made of steel.

(b) For radial load applications with severe stress loading conditions,
The rotational speed at which cracks occur from the start and end of the weld bead is much lower than that of bias tires, and may not meet vehicle manufacturer specifications.

(c) Furthermore, even if high-tensile steel is used as the steel plate for wheels, the fatigue strength of high-tensile steel welded joints is generally low, so it is expected that the drum durability life will not be as long as expected.

In addition, the fatigue strength improvement method used for the welded joints mentioned above,
It is conceivable to apply it directly to the welded part of the wheel, but there are the following problems.

(B) TiG1 plasma, grinder, and shielded arc welding treatments are usually only for processing long weld beads in the weld line direction, and are applied locally focusing only on the start and end of the weld, which is the problem with this wheel. No consideration was given to ways to do so. Therefore, the effect of improving strength in the stress concentration area is small.

(b) In terms of welding productivity, it is difficult to assemble the wheels using processes that involve manual labor such as covered arc welding.

Therefore, in order to solve the above problems, the present invention has the following features:
When assembling the wheel by joining the rim and disc, the welding method locally improves the bead shape at the start and end of the weld bead that is formed intermittently, eliminating stress concentration areas and increasing the durability of the wheel. The purpose is to effectively improve sexual performance.

"Means for Solving the Problem" In order to achieve this objective, the wheel assembly of the present invention uses a welding method to prevent cracks from forming intermittently during a drum durability test to evaluate the durability of the wheel. The weld bead and the joining member are locally aligned along the bead shape line according to the respective bead shapes at the start and end ends of the weld bead. A modification process such as TiG, plasma, or grinder treatment is performed so that the pead tangent angle, which is the angle between the welded part and the non-welded part, becomes 130 degrees or more.

[Function] When assembling such a wheel, in the welding method, the bead shapes at the starting and terminal ends of the weld bead that are formed intermittently are locally and efficiently corrected, and the bead tangent angle is adjusted to 130 mm. The weld bead is smoothed and connected to the non-welded parts. Therefore, the problematic stress concentration at the start and end portions of the weld bead is significantly alleviated or eliminated, suppressing the occurrence of cracks, and improving the durability of the wheel.

Preferred embodiments of the wheel assembly and welding method of the present invention will be described below with reference to the drawings.

1 and 2 show a welded part of the assembly of the wheel before treatment according to the invention. Therefore, when assembling the wheel, the weld bead 1 of the welded portion is not modified in any way as in the conventional case, and remains welded to the rim 9 and disk 10 as the joining member 2. The cross-sectional shape of the starting end 3 of the welding bead 1 is often formed in a convex manner in the direction of the non-welded portion 5 of the joining member 2.

In addition, the cross-sectional shape of the terminal end 4 of the weld bead 1 becomes concave once, and the distal end that connects to the welded part 5' is the non-welded part 5.
It often rises so that the bead tangential angle between - and becomes large.

If the starting end 3 and ending end 4 of the weld bead 1 are not modified in any way as described above, stress concentration will occur as described above.

However, in the present invention, the starting and ending ends 3 of the weld bead 1
．． 4 is subjected to correction processing as follows.

First, FIG. 3 shows a case where the starting end 3 is subjected to a modification process by TiG or plasma treatment. The area within the dashed line range of the starting end 3 shown in FIG. The end shape of 1 is corrected to a smooth cross-sectional shape line. This modification is performed depending on the bead shape of the starting end 3, for example, its overhang, and as shown in FIG.
This is done locally along the bead shape line.

This local correction process at the starting end may be performed by a grinder process. For example, as shown in FIG. 4, the overhanging portion (within the dashed line in the figure) of the starting end 3 is ground down by a grinder to modify the end bead shape.

However, in this case, the excess bead part is scraped off,
Since it is not remelted, the amount of weld bead 1 to be processed (the amount of bead outside the broken line in Fig. 4) is:
As shown by the broken line shape in the figure, the number is slightly larger than in the case shown in FIG. 3.

Next, regarding the terminal part 4, Fig. 5 shows TiQ,
As shown in Fig. 6, the processing area 6' (
FIG. 7) is processed. At the II end 4, the leading edge of the weld bead 1 is the main target, and the bead shape in the range shown by the broken line in FIGS. 5 and 6 is modified so as to smoothly connect to the joining member 2.

As a result of this correction process, as shown in FIG. The bead tangent angle θ, which is the angle formed by the welding part 5.5', is 1
The bead shape is locally improved to 30 degrees or more. That is, the welding bead 1 is clearly connected to the joining member 2 without exhibiting a discontinuous bent cross-sectional shape line within the range along the bead shape line of the starting and ending portions 3.4.

Therefore, stress concentration at the start and end portions 3.4 of the weld bead 1 is prevented, and the strength of this portion is improved.

[Effects of the Invention] As is clear from the above explanation, when the present invention is applied,
The following various effects can be obtained.

First, instead of simply processing along the bead weld line direction, correction processing is performed locally at the start and end, and in the necessary range along the bead shape line depending on the bead shape, so that The shape of the bead end can be modified, the bead tangent angle can be set to 130 degrees or more, stress concentration can be efficiently prevented, and the strength of the wheel can be improved.

In order to clarify this strength improvement effect, the results of testing using the same method as shown in Figure 11 are shown in Figures 9 and 10.
As shown in the figure. FIG. 9 shows the relationship between the bead tangential angle at the beginning and end and the durable rotation speed of the wheel, and the bead tangential angle can be reduced to 13 Or by the treatment of the present invention! By doing the above,
Be sure to exceed the durable rotational speed (standard value).

In addition, as shown in Figure 10, which shows a comparison between the conventional welding process and the modification process according to the present invention, the present invention dramatically improves the durable rotation speed, that is, the life of the wheel. Be able to do that.

Moreover, the correction process according to the present invention only needs to be carried out locally on the weld bead ridge portion, so that the process can be completed in a short time, and a large strength improvement effect can be easily obtained with a simple process.

Furthermore, as the correction process, the conventionally commonly used Tr G, plasma, and grinder processes may be used, so the present invention can be easily carried out without using any special equipment and with good work efficiency. You can also get the effect of being able to.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of the weld bead showing the state before the welded part is corrected according to the present invention when the wheel is assembled, and FIG.
FIG. 3 is a partial vertical sectional view of the weld bead showing the state of correction processing at the starting end of the weld bead according to the present invention; FIG. 4 is a welding treatment method different from that shown in FIG. 3. A partial vertical cross-sectional view of the bead, Figure 5 is a modification 51 at the terminal end! Figure 6 is a partial vertical cross-sectional view of the weld bead showing a treatment method different from that shown in Figure 5; Figure 7 is a partial longitudinal cross-sectional view of the weld bead showing the treatment method shown in Figures 3 to 6. A plan view of a weld bead showing an example of the treatment range, Figure 8 (a) is a m19i plane view showing the bead tangent angle of the weld bead before treatment, and Figure 8 (b) shows the bead tangent angle after treatment. A longitudinal cross-sectional view of a weld bead, FIG. 9 is a diagram showing the relationship between the bead tangent angle at the beginning and end and the durable rotation speed of the wheel, FIG. 10 is a diagram showing the relationship between the presence or absence of correction processing according to the present invention and the durable rotation speed of the wheel, Figure 11 is a side view of the test equipment showing the wheel durability test, Figure N12 is a front view of the wheel showing the stress concentration state of a conventional wheel, and Figure 13 is the stress concentration state seen from a different angle from Figure 11. FIG. 3 is a partially enlarged sectional view of the wheel. 1...Weld bead 2...Joining member 3...Starting end 4...Terminal end 5.5'...Non-welding part 6 .6'...Processing range 9...Rim 1o...Disk 11...Stress θ...Bead tangent angle Fig. 2 5 Non Welding part Fig. 3 Fig. 5 Fig. 10 (time) Fig. 12

Claims (1)

[Claims] (1) In assembly welding of the wheel that joins the rim and the disc, the weld bead is formed intermittently at the start and end of the weld bead according to the bead shape at the start and end of the bead shape line. A method for assembling and welding a wheel, characterized in that a correction process is performed locally along the line to make the bead tangential angle between the weld bead and the non-welded part of the joining member 130 degrees or more.