JP4124034B2 - Body frame material joining method and structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle body frame material coupling method and a coupling structure in which frame materials constituting a vehicle body frame are abutted and welded together.
[0002]
[Prior art]
In recent years, attempts have been made to produce a vehicle body from aluminum in order to reduce the weight of the vehicle body in an automobile. For example, Patent Documents 1 to 3 listed below describe examples.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-337722
[Patent Document 2]
JP-A-2002-361429 gazette
[Patent Document 3]
JP, 2002-356177, A In this case, aluminum has poor spot weldability as compared with steel that is usually used, and in a monocoque structure mainly made of a plate press product, it is necessary to weld several thousand points. In this case, there is a drawback that the electrode is consumed greatly. In addition, the formability of the plate material has a drawback that aluminum is worse than steel.
[0006]
Thus, a space frame structure in which a hollow pipe-like frame is applied to a vehicle body such as an automobile such as a truck or a transportation machine is proposed in Patent Document 4 below.
[0007]
[Patent Document 4]
As shown in FIG. 3, a rectangular tubular aluminum extruded material 1 is assembled into the shape of a car body of a passenger car, and the extruded materials 1 are joined to each other by welding. Thus, a so-called space frame structure is formed, and a structural plate is attached so as to cover the space frame 3 to complete the vehicle body.
[0008]
As a method of joining the extruded members 1 made of aluminum for producing the space frame 3 described above, arc welding, resistance spot welding are performed in consideration of the characteristics of the joining method and the characteristics required for the joint. Method or mechanical joining method. In particular, arc welding methods, such as TIG or MIG welding methods that have a proven record in the field of transport equipment, are applied to joint portions that require strength.
[0009]
FIG. 4 is a perspective view showing the basic structure of the vehicle body frame. In this, two side members 5 arranged in parallel to each other are connected by two cross members 7. As shown in FIG. 5, the connecting portion is welded such that the end surface of the cross member 7 is abutted against the side surface of the side member 5 to form a joint portion, and this joint portion is subjected to MIG welding using, for example, a MIG torch 9.
[0010]
[Problems to be solved by the invention]
However, since the welding quality of arc welding such as MIG welding described above is greatly affected by the gap of the joint and the plate thickness of the work piece, the frame material is required to have extremely high accuracy, leading to an increase in manufacturing cost. There is.
[0011]
Accordingly, an object of the present invention is to reduce the manufacturing cost by eliminating the need for high component accuracy in the frame material.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is configured to abut each other of frame materials constituting a light alloy body frame, and to arrange a bonding material overlapping each of a pair of both surfaces of each frame material at the abutting portion. A body frame material joining method in which laser welding is performed on an overlapping portion of the binding material with respect to each frame material , wherein the binding material includes a base portion positioned between the frame materials, and a base portion. A connecting portion that is connected and overlaps the surface of each of the frame members, and this connecting portion includes a pair for each frame material so as to sandwich each of the frame materials from both sides, and the distance between each pair of the connecting portions Is set to be larger than the outer dimension in the direction sandwiched by the connecting portions of the corresponding frame members, and the vehicle body frame member is connected by laser welding .
[0013]
【The invention's effect】
According to the present invention, the bonding material is overlapped on each of the pair of both surfaces of each frame material, and laser welding is performed on each overlapped portion, so that there is a gap between the butted portions of each frame material. Even if there is a gap or there is a gap in the overlapping portion, the frame materials can be reliably welded to each other, and the frame material does not require high component accuracy, and the manufacturing cost can be reduced. In addition, since laser welding is used, the welding speed can be increased as compared with arc welding, and the amount of heat input to the frame material can be kept low, which can contribute to improving the accuracy of the vehicle body frame.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0015]
FIG. 1 is a front view showing a vehicle body frame material joining method according to an embodiment of the present invention. As the frame material here, the side member 11 in the body of the automobile and the cross member 13 coupled to the side surface 11a of the side member 11 are used in the same manner as shown in FIGS. FIG. 2 is a perspective view showing a state in which the frame materials are coupled to each other by the laser welding apparatus 15 shown in FIG.
[0016]
The side members 11 are arranged extending in the vehicle longitudinal direction at both sides in the vehicle width direction, and the side members 11 are connected to each other by a cross member 13 extended in the vehicle width direction. Each such frame material uses a hollow extruded material made of, for example, an aluminum alloy as a light alloy.
[0017]
The end surface 13a of the cross member 13 is opposed to the side surface 11a of the side member 11 with a gap that allows the bonding material 17 to be described later to be disposed, and the bonding material 17 is disposed between the members 11 and 13. The binding material 17 is a plate-like extruded material made of an aluminum alloy similar to each frame material.
[0018]
The above-described bonding material 17 includes a plate-like base portion 17a positioned between the side member 11 and the cross member 13 and substantially parallel to the side surface 11a of the side member 11, a side member side connecting portion 17b continuous to the base portion 17a, and Cross member side coupling portions 17c are provided.
[0019]
A pair of side member side coupling portions 17b are provided so as to extend from both upper and lower ends of the base portion 17a along the upper and lower surfaces of the side member 11, and sandwich the side members 11 from above and below. Here, the distance A between the pair of side member side coupling portions 17 b is set to be larger than the upper and lower outer dimensions B of the side member 11.
[0020]
The cross member side coupling portion 17c includes a pair extending from the lower end and the center of the base portion 17a along the upper and lower surfaces of the cross member 13 so as to sandwich the cross member 13 from above and below. Here, the distance D between the pair of cross member side coupling portions 17 c is set to be larger than the upper and lower outer dimensions E of the cross member 13.
[0021]
The laser welding apparatus 15 shown in FIG. 1 supports a processing head 21 that irradiates a welded portion with a laser beam 19 on a head support 23, and holds the welded portion at the lower end of the head support 23. A gap correction roller 25 to be attached is rotatably provided via a roller support arm 27.
[0022]
On the other hand, a bracket 31 is provided at the tip of the arm of the robot 29, and the head support portion 23 is attached to the bracket 31 via a guide rail 33 so as to be movable up and down. A drive cylinder 35 is provided above the bracket 31, and a piston rod 35 a of the drive cylinder 35 is connected to the head support portion 23. That is, when the drive cylinder 35 is operated, the head support portion 23 moves up and down together with the machining head 21 and the gap correction roller 25.
[0023]
The laser beam 19 is sent to the machining head 21 through the optical fiber 39 by the laser oscillator 37.
[0024]
Next, a welding method using the bonding material 17 when the side member 11 and the cross member 13 are bonded will be described. First, as shown in FIG. 1, after fixing the side member 11 and the cross member 13 at a predetermined joining work position, the joining member 17 is disposed at the abutting portion between the side member 11 and the cross member 13.
[0025]
At this time, the base portion 17 a of the bonding material 17 is inserted between the side surface 11 a of the side member 11 and the end surface 13 a of the cross member 13. Further, the side member 11 is sandwiched from above and below by the pair of side member side coupling portions 17b, and the cross member 13 is sandwiched from above and below by the pair of cross member side coupling portions 17c.
[0026]
In other words, the side member side coupling portion 17 b of the binding material 17 is superimposed on the pair of both surfaces of the side member 11, and the cross member side coupling portion 17 c is superimposed on the pair of both surfaces of the cross member 13.
[0027]
In this state, the machining head 21 is moved over the overlapping portion as described above as a welded portion by the robot 29, pressed by a predetermined pressing force to the part by superimposing the gap correction roller 25 by the subsequent driving cylinder 35, the side member The gap between the side coupling portion 17b and the side member 11 or the gap between the cross member side coupling portion 17c and the cross member 13 is corrected. At this time, it is desirable to set the pressing force of the drive cylinder 35 so that the gap after correction is 0.3 mm or less.
[0028]
In the state where the gap is corrected, the robot 29 moves the machining head 21 together with the gap correction roller 25 along the welded portion (overlapping portion) in the direction perpendicular to the paper surface in FIG. As shown, a bead 41 is formed by laser welding. As a result, the side member 11 and the cross member 13 are fixed by welding via the bonding material 17.
[0029]
According to the above-described embodiment of the present invention, when the side member 11 and the cross member 13 are coupled, the side member side coupling portion 17b and the cross member side coupling portion 17c of the coupling material 17 are replaced with the side member 11 and the cross member. Since the laser welding is performed in a state where they are superposed on each other, even if a gap is provided between the side member 11 and the cross member 13, or between the side member 11 and the side member side coupling portion 17 b and the cross member. Even if a gap is provided between the cross member 13 and the cross member side connecting portion 17c, the side member 11 and the cross member 13 can be reliably connected by welding.
[0030]
For this reason, the high component precision of the frame material which comprises the side member 11 and the cross member 13 becomes unnecessary, and can reduce manufacturing cost. In particular, the hollow extruded material constituting the side member 11 and the cross member 13 has a lower thickness accuracy than the plate material due to its manufacturing method. A reliable welding operation can be carried out without lowering.
[0031]
Also, because laser welding is used as the frame material joining method, the welding speed can be increased compared to arc welding, and the amount of heat input to the frame material can be kept low, contributing to improved body frame accuracy. Can do.
[0032]
In the above-described embodiment, one weld bead 41 is provided for one welded portion, but the position and number can be arbitrarily set according to the structural requirements.
[Brief description of the drawings]
FIG. 1 is a front view showing a method for joining body frame members according to an embodiment of the present invention.
2 is a perspective view showing a state in which frame materials are coupled to each other by the laser welding apparatus shown in FIG. 1; FIG.
FIG. 3 is a perspective view showing a space frame structure as a vehicle body frame.
FIG. 4 is a perspective view showing a basic structure of a vehicle body frame.
5 is an explanatory diagram showing a state in which MIG welding is performed on the frame structure of FIG. 4;
[Explanation of symbols]
11 Side member (frame material)
13 Cross member (frame material)
17 binding material 17a base 17b side member side coupling portion (coupling portion)
17c Cross member side joint (joint)

Claims (7)

The frame materials constituting the light alloy body frame are abutted against each other, and a bonding material that is superimposed on each of a pair of both surfaces of each frame material is disposed at the abutting portion, and this bonding material is superimposed on each frame material. A body frame material joining method in which laser welding is performed on a portion , wherein the joining material is connected to the base portion and overlapped on the surface of each frame material. Each of the frame members so that each frame material is sandwiched from both sides, and the distance between each pair of the connection portions is determined by the connection portion of each corresponding frame material. A method for joining body frame members, characterized in that laser welding is performed with the outer dimension set larger than the sandwiched direction . 2. The method of connecting body frame materials according to claim 1, wherein laser welding is performed in a state in which a gap between each pair of connecting portions and each frame material is corrected by a gap correction roller. 3. The method for joining body frame materials according to claim 1, wherein the frame material is a hollow extruded material made of an aluminum alloy. The frame member includes a side member extending in the longitudinal direction of the vehicle body, the vehicle body frame according to any one of claims 1 to 3, characterized in that it comprises a cross member butting an end portion on the side surface of the side member How to join materials. The frame materials constituting the light alloy body frame are abutted against each other, and a bonding material that is superimposed on each of a pair of both surfaces of each frame material is disposed at the abutting portion, and this bonding material is superimposed on each frame material. A vehicle body frame material coupling structure in which laser welding is performed on a portion , wherein the coupling material is connected to the base portion between the frame materials and on the surface of each frame material. A pair of overlapping portions, each of which is provided with a pair of each of the frame members so that each of the frame members is sandwiched from both sides, and the distance between each pair of the connecting portions corresponds to the combination of the corresponding frame members. In a state where the gap between each pair of coupling parts and each frame material is corrected by a gap correction roller from a state set larger than the outer dimension in the direction sandwiched between the parts. Coupling structure of a vehicle body frame member, characterized in that over laser welding have been made. 6. The vehicle body frame material coupling structure according to claim 5 , wherein the frame material is a hollow extruded material made of an aluminum alloy. The vehicle body frame material coupling structure according to claim 5 or 6 , wherein the frame material includes a side member extending in the longitudinal direction of the vehicle body and a cross member having an end abutted against a side surface of the side member.

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