JP2013071478A - Assembly method of frame structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a welding method of a frame structure by which, when performing welding after abutting rectangular pipe-shaped frame materials to each other, deformation due to welding is suppressed and a junction strength of a welded part can be secured.SOLUTION: According to an assembly method of the frame structure, an end face of one rectangular pipe-shaped frame material 20 (cross frame) is abutted to a side surface of another rectangular pipe-shaped frame material 10 (side frame), the abutted parts thereof are welded, thereby the frame structure 100 is assembled. When welding a longer side S1 among sides constituting a circumferential edge of an end face 21 of the cross frame 20, welding is performed by dividing a length of the longer side S1 into two or more parts.

Description

  The present invention relates to a method for assembling a frame structure such as a vehicle body frame by welding and joining rectangular tubular aluminum-based extruded materials.

  A frame structure such as a body frame of a passenger car or a truck is formed by welding and assembling a rectangular tube-shaped frame material made of an aluminum-based extruded material or the like. If the frame structure is deformed by welding, the determined dimensional accuracy cannot be obtained. Therefore, when welding each frame material, the frame structure is generated by welding by restraining each member with a jig. Suppresses body deformation.

  Further, in Patent Document 1, in order to suppress deformation when a plurality of frame members (cross members) are abutted and welded between a pair of left and right frame members (side members), the protrusion of the cross member with respect to the side members is suppressed. The direction and sequence of welding at the abutment are optimized.

  Moreover, in patent document 2, the end surface of one frame material which should be abutted against the other frame material (member to be welded) is formed in a tapered shape in advance, so that one of the four sides of the abutting portion corresponds to one side. In this example, a groove having a V-groove shape is formed between the other frame material, and one side where the groove is formed is welded first, and then the other side is welded. (Deformation amount) is offset.

JP 2002-356177 A Japanese Patent Laid-Open No. 2005-21933

  However, there is a problem that it is difficult to satisfy both the suppression of the deformation of the frame structure and the securing of the necessary bonding strength.

  The present invention has been made in view of such circumstances, and when performing welding by abutting square tube-shaped frame materials, it is possible to suppress deformation accompanying welding and to secure the joint strength of the welded portion. An object of the present invention is to provide a welding method for a frame structure.

  The present invention relates to a frame structure in which a frame structure is assembled by welding the abutting portion in a state where the end surface of the other square tube-shaped frame material is abutted against the side surface of one rectangular tube-shaped frame material. In the method of assembling the body, when welding a long side having a long length among the sides constituting the peripheral edge of the end face of the other frame member, the length of the long side is divided into two or more. And welding.

The amount of heat input and the heat melting region of the welded portion increase as the weld length increases. For this reason, as the weld length increases, the amount of heat input to the frame material increases, the temperature difference between the welded portion of the frame material and the other portions increases, the thermal melting region widens, and deformation (distortion) is likely to occur. .
By splitting the long side part into two or more parts, the amount of heat input to the frame material can be reduced and the heat melting area can be reduced, so that deformation due to welding can be suppressed and welding is performed continuously. It is possible to secure a bonding strength equivalent to or better than that of the time.

In the method for assembling the frame structure according to the present invention, the welding of the long side is performed by welding from one end of the long side to the center and then welding from the other end of the long side to the center. Good.
Thus, the deformation | transformation accompanying welding can be further reduced by arrange | positioning and joining the end part of a welding part in the center part of a long side.

  According to the present invention, by dividing the long side of the frame material having a long weld length into two or more and performing welding, the amount of heat input to the frame material can be reduced, and the heat melting region can be reduced. Therefore, it is possible to suppress the deformation accompanying welding and to secure a joint strength equal to or higher than that of continuous welding.

It is a perspective view explaining the assembly method of the frame structure of 1st Embodiment of this invention. It is A arrow directional view of the frame structure shown in FIG. It is a perspective view explaining the measuring method of deformation. It is a top view of the frame structure explaining the measurement point of deformation. It is a perspective view explaining the measuring method of joint strength. It is the table | surface which listed the conditions of each sample in an Example.

Hereinafter, an embodiment of a method for assembling a frame structure according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, the method of assembling the frame structure according to the present embodiment has a rectangular tube shape on the side surface of one frame member 10 (hereinafter referred to as a side frame) having a cross section formed into a square tube shape. The side frame 10 and the cross frame 20 are joined by welding the abutting portion in a state where the end surface of the other frame member 20 (hereinafter referred to as a cross frame) formed on the abutting surface is abutted. It is a method of assembling.

The side frame 10 and the cross frame 20 are formed in a rectangular tube shape by extrusion molding of an aluminum alloy. For example, the height H is 100 mm, the width W is 30 mm, and the thickness t is 2.5 mm.
In assembling the frame structure 100, as shown in FIGS. 1 and 2, the end surface 21 of the cross frame 20 is abutted against the side surface of the side frame 10, and the length of the side that forms the periphery of the end surface 21 of the cross frame 20 is long. It arrange | positions so that a long side (long side S1) may become perpendicular | vertical. And it restrains with jig | tool (not shown), such as a clamp, in the state arrange | positioned in a predetermined position.
Next, welding is performed on the abutting portion between the side frame 10 and the cross frame 20 by, for example, a melting welding method using electron beam welding. As the welding conditions, the setting varies depending on the conditions of the frame material to be used, but in this embodiment, the welding current is set to 160A and the welding speed is set to 100 cm / min.

Also, broken line arrows (1) to (5) shown in FIG. 2 indicate the welding sequence and the welding direction, and from the long side S1 having a long welding length among the sides constituting the peripheral edge of the end surface 21 of the cross frame 20. Weld sequentially.
At this time, the long side S1 arranged vertically is divided into two or more and welded. For example, as shown by broken line arrows (1) and (2) in FIG. 2, after welding (upward welding) from the lower end portion of the long side S1 toward the center portion, the upper end portion of the long side S1 is changed to the center portion. By welding toward the bottom (downward welding), the long side S1 is divided into two parts and welded. Next, the long side S1 opposite to the long side S1 is similarly welded from the lower end portion toward the central portion (broken line arrow (3)), and then welded from the upper end portion toward the central portion (broken line arrow). (4)) Thus, welding is performed. After the welding of both long sides S1, the upper short side S2 is welded (broken line arrow (5)), and the assembly of the frame structure 100 is completed.
Note that the short side S2 does not necessarily need to be welded if the necessary joint strength is obtained by welding the long sides S1.

As described above, according to the method for assembling the frame structure of the present embodiment, the amount of heat input to the side frame 10 and the cross frame 20 is reduced by performing the welding of the long side S1 with a long welding length in two. And the heat melting region can be reduced. Therefore, the occurrence of deformation of the frame structure 100 due to welding can be reduced, and the joint strength of the welded portion 15 can be ensured.
In the case of welding by dividing the long side into two parts, not only welding from the end part of the long side toward the central part but also welding from the central part to the end part (sample 7 in FIG. 6 described later). ), Both of which are performed in the same direction (sample 8 in FIG. 6 described later) can be employed.

Next, an embodiment according to the method for assembling the frame structure of the present invention will be described.
As shown in FIG. 5, a length L1: 300 mm formed of a rectangular tubular frame material having a height (long side) H: 100 mm, a width W (short side): 30 mm, and a thickness t: 2.5 mm. A side frame 10 and a cross frame 20 having a length L2 of 270 mm are prepared, and the frame structures 100 of the samples 1 to 9 are assembled by the welding method shown in FIG. The strength (breaking strength) was confirmed. The frame material used was aluminum of 6000 series alloy according to JIS standards. Further, the welding of each frame structure 100 was performed by a melting welding method using electron beam welding, and the welding conditions were a welding current of 160 A and a welding speed of 100 cm / min.

Arrows (1) to (4) shown in the welding method of FIG. 6 indicate the welding sequence and the welding direction.
For example, the welding conditions of samples 1 to 4 indicate that each long side is continuously welded at once. Samples 1 to 3 show that the entire region with a long side of 100 mm is welded, and Sample 4 shows that the inner 80 mm region where both ends of the long side are left is welded.
Samples 5 to 9 indicate that each long side is divided into two parts and welded. For example, the sample 5 is welded from the upper end of the long side toward the center (arrow (1)), and then welded from the lower end of the long side toward the center (arrow (2)). The sides were divided in two and welded. In addition, the sample 7 was welded from the center part of the long side toward the upper end part (arrow (1)) and then welded from the center part of the long side toward the lower end part (arrow (2)). The sides were divided in two and welded.

Further, the magnitude of the deformation is measured at each measurement point M1 before and after welding of the side frame 10 and the cross frame 20 on the side surface (measurement surface 11) of the side frame 10 opposite to the joint surface 12 with the cross frame 20. This was confirmed by measuring the displacement amount of M6.
As shown in FIG. 3, the displacement of each measurement point M1 to M6 is measured by bringing the two surfaces of the cross frame 20 into contact with the reference surfaces 31A and 31B intersecting at 90 ° of the measurement block 30. Is measured by measuring the upper surface (measurement surface 11) of the cross frame 20 with the cross frame 20 standing vertically.

The measurement of the measurement surface 11 is performed by measuring six measurement points M1 to M6 as shown in FIG. These measurement points M1 to M6 are measured using a reference point M0 set at the center of the measurement surface 11 as a reference (zero point). The reference point M0 is set to a point that overlaps the center position of the end surface 21 of the cross frame 20 disposed on the back surface side of the measurement surface 11.
Further, the “total strain” shown in FIG. 6 is obtained by calculating the total sum of absolute values of displacement amounts before and after welding at the measurement points M1 to M6.

As shown in FIG. 5, the bonding strength is obtained by fixing the side frame 10 of the frame structure 100 after bonding with a jig (not shown) in a vertically standing state, and applying a load to the cross frame 20 arranged in a horizontal state. F was added and the load F was continuously applied until the welded portion 15 between the side frame 10 and the cross frame 20 was broken, and the evaluation was made based on the magnitude of the maximum load recorded at that time. The measurement result of the maximum load of each frame structure is shown in FIG.
The load F was applied at a position of 180 mm (distance D) from the joint surface between the side frame 10 and the cross frame 20.

  Further, “rise rigidity” in FIG. 6 indicates the ratio (load / sink amount) of the load (kN) to the sink amount (mm) of the portion to which the load F is applied within the elastic range. The larger the value, the higher the rigidity.

As shown in FIG. 6, in Samples 1 to 3 that were welded continuously over the entire length of the long side, the total strain exceeded 4 mm, and the amount of deformation increased. On the other hand, although welding was performed on the entire length of the long side in the same manner, in the samples 5 to 8 which were welded by dividing the entire length of the long side, the total strain was suppressed to a level of 3 mm, and the entire length was continuously welded. The amount of deformation could be reduced compared to. Furthermore, it was confirmed that Samples 5 to 8 were able to obtain a strength equal to or higher than that of Samples 1 to 3 in which the entire length was continuously welded in the bonding strength.
In addition, among samples 5 to 8 which are welded by dividing the entire length of the long side, welding is performed from one end portion of the long side to the central portion, and then welding is performed from the other end portion of the long side to the central portion. Thus, it was found that in Sample 5 and Sample 6 in which the end portion of the welded portion is arranged at the center of the long side, the amount of deformation can be further reduced and the joint strength can be increased as compared with other cases.

Moreover, in the sample 4 which left both ends of the long side and was welded in the inner 80 mm region, and the sample 9 which left the both ends and the center of the long side and was divided and welded, The total was in the 2 mm range, and the amount of deformation could be greatly suppressed. However, since the area of the welded portion is reduced, the maximum load is reduced as compared with the case where the entire length of the long side is welded, and it has been found that the necessary joint strength cannot be obtained only by joining the two long sides.
Furthermore, it has been found that when the long side is divided into two parts and welded, the rising rigidity is higher than in the case of continuous welding.

  As described above, by performing the long side welding with a long weld length in two, the deformation of the frame structure accompanying the welding can be reduced and a joint strength equal to or higher than that of continuous welding can be secured. be able to.

In addition, this invention is not limited to the thing of the structure of the said embodiment, In a detailed structure, a various change can be added in the range which does not deviate from the meaning of this invention.
For example, in the above-described embodiment, the long side is divided into two parts and welding is performed. However, it is also possible to divide into two or more parts and perform multi-part welding.
Moreover, in the said embodiment, although welding was performed by the melt | dissolution welding method by electron beam welding, it is not limited to this. For example, it can also be performed by laser welding, arc welding, or the like.
Further, the frame material constituting the side frame and the cross frame is not limited to a rectangular tube having a mouth shape in cross section.

10 Side frame (frame material)
11 Measurement surface 12 Joint surface 15 Welded portion 20 Cross frame (frame material)
21 End face 100 Frame structure

Claims (2)

  Method of assembling a frame structure by assembling a frame structure by welding the abutting portion in a state where the end face of the other square tube-shaped frame material is abutted against the side surface of one square tube-shaped frame material And when welding the long side with a long length among the sides constituting the peripheral edge of the end face of the other frame material, the length of the long side is divided into two or more and welded. A method for assembling a frame structure. 2. The frame structure according to claim 1, wherein the long side is welded from one end of the long side to the center and then welded from the other end of the long side to the center. Body assembly method.

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