JP2018008295A - Weld structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a weld structure capable of readily maintaining weld quality of an end part while inhibiting concentration of stress in a weld end part.SOLUTION: A front cross member 22 is superposed with an engine mount bracket 50. A bracket lateral part 54 and a straight line extension part 56 continuously extended from the bracket lateral part 54 are disposed on a lateral part 22C of the front cross member 22. A weld line 58 is formed along a body outer edge 54A of the bracket lateral part 54 and a straight line extension outer edge 56A of the straight line extension part 56.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a welded structure.

  Conventionally, in welding by arc welding, defects are likely to occur at the end of the weld bead, and therefore various techniques have been proposed for the configuration of the end. For example, in Patent Document 1, when arc welding a mounting plate on a base plate, an extended weld bead is formed by extending a welding bead from the end of the mounting plate onto the surface of the base plate. Thus, by extending the weld bead, the end of the weld bead is moved away from the joint end of the plates where stress is concentrated.

Japanese Patent Laid-Open No. 9-253843

  However, there is no mark in the direction away from the base plate on the surface of the base plate, and it is difficult to specify the welding position. In addition, since the number of plate members is changed from two to one in the extended portion, it is necessary to adjust the amount of heat input, and it is difficult to control the welding quality to be constant.

  The present invention has been made in consideration of the above-described facts, and an object of the present invention is to obtain a welded structure that can easily maintain the weld quality of the end while suppressing stress concentration on the weld end. And

  In order to achieve the above object, a welding structure according to claim 1 according to the present invention includes a first member having a flat surface, and a main body outer edge of a main body portion disposed on the flat surface of the first member. An extended outer edge that is continuous with the outer edge of the main body and extends continuously from the main body, and the first member along the outer edge of the main body and the extended outer edge, And a second member formed with a weld line.

  In the welded structure according to the first aspect, the first member and the second member are welded. The first member has a flat surface. The second member has a main body part and an extending part continuously extending from the main body part. The main body outer edge of the main body portion is disposed on the flat surface of the first member, and the extending outer edge of the extending portion is continuous with the main body outer edge. A weld line is formed between the first member and the second member along the outer edge of the main body and the extended outer edge and is welded to each other.

  In the welded structure according to the first aspect, the weld line is formed to the extended outer edge of the extended portion extended from the main body portion of the second member. Therefore, the end portion of the weld line is disposed at a position away from the end portion of the main body portion of the second member where the stress is concentrated, and the stress concentration on the weld end portion can be suppressed. In addition, since the weld line is formed along the extended outer edge, it is easy to specify the position of welding and the welding work can be easily performed. Also, since the weld line formed on the extended outer edge is a weld line between the first member and the second member, it can be welded with the same amount of heat input as the weld line formed on the outer edge of the main body, and is easily welded. Quality can be maintained.

  In the welded structure according to claim 2, the extending outer edge extends in the same direction as the extending direction of the main body outer edge.

  Thus, by making the main body outer edge and the extended outer edge in the same direction, the weld line becomes linear, and welding can be performed easily.

  In the welding structure according to a third aspect, the extended outer edge extends in a direction intersecting with the extending direction of the main body outer edge.

  Thus, by forming the extended outer edge in a direction intersecting with the outer edge of the main body, the weld line can be arranged in an appropriate direction according to the input direction of the load, the arrangement of the surrounding members, and the like.

  According to the welded structure according to the present invention, it is possible to easily maintain the weld quality of the end portion while suppressing stress concentration on the weld end portion.

It is a perspective view which shows the suspension member of this embodiment seeing from upper direction. It is a perspective view which shows the edge part vicinity of the engine mount bracket to which the welding structure of the 1st aspect was applied. It is a front view which shows the edge part vicinity of the engine mount bracket to which the welding structure of the 1st aspect was applied. It is a perspective view which shows the edge part vicinity of the engine mount bracket to which the welding structure of the 2nd aspect was applied. It is a front view which shows the edge part vicinity of the engine mount bracket to which the welding structure of the 2nd aspect was applied.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. For convenience of explanation, an arrow UP appropriately shown in each figure is a vehicle body upward direction, an arrow FR is a vehicle body front direction, and an arrow RH is a vehicle body right direction. In addition, in the following description, when the vertical, front / rear, and left / right directions are described without special mention, the vertical direction of the vehicle body, the front / rear direction of the vehicle body, and the left / right direction of the vehicle body (vehicle width direction) are indicated. To do.

  FIG. 1 shows a suspension member 10 to which a welding structure 70 of the present invention is applied. The suspension member 10 is supported in a suspended state below the front part of a pair of left and right front side members (not shown) extending along the longitudinal direction of the vehicle body. The suspension member 10 has a pair of left and right front mounting members 24, which will be described later, which are left and right front ends thereof, attached to the front end of the front side member on the front side of the vehicle body relative to the kick portion. The fastening portion 34 is attached to the lower end portion of the kick portion.

  The suspension member 10 includes a front frame 20 and a rear frame 30 disposed behind the front frame 20. The front frame 20 includes a front cross member 22 extending in the vehicle width direction and a pair of left and right front mounting members 24 joined to both ends of the front cross member 22 in the vehicle width direction. The front mounting member 24 is substantially L-shaped when viewed from above, and extends integrally from the front body mount portion 25 joined to the front cross member 22 and the pair of left and right front body mount portions 25 toward the rear of the vehicle body. A pair of left and right front side rail portions 26 are provided.

  The rear frame 30 includes a rear cross portion 32 extending in the vehicle width direction, a pair of left and right fastening portions 34 integrally formed at both ends of the rear cross portion 32 in the vehicle width direction, and both ends of the rear cross portion 32 in the vehicle width direction. A pair of left and right rear side rail portions 36 that are integrally extended from the portion toward the front of the vehicle body.

  As shown in FIG. 2, the front cross member 22 of the front frame 20 has a long shape with a rectangular closed cross section, and includes an upper surface portion 22A constituting the upper surface, a lower surface portion 22B constituting the lower surface, and an upper surface portion 22A. It has a pair of side surface parts 22C which connect the lower surface part 22B and comprise a side surface. The side surface portion 22C is flat. The front cross member 22 is formed by extruding a light metal material such as an aluminum alloy and has high ductility. A cross plate 21 is joined to the lower side of the front cross member 22. The lower portion of the front cross member 22 is protected by the cross plate 21.

  An engine mount bracket 50 is fixed by welding at the center of the front cross member 22. The engine mount bracket 50 has an open cross-sectional shape with an open lower side (substantially inverted U-shaped cross section), and is continuously formed by bending downward from both ends of the bracket upper surface portion 52 and the bracket upper surface portion 52 constituting the upper surface. A bracket side portion 54 is provided. A ridge line 53 is formed between the bracket upper surface portion 52 and the bracket side surface portion 54. The engine mount bracket 50 is integrally formed by die-casting a light metal material such as an aluminum alloy. The welding structure of the present invention is applied to welding the engine mount bracket 50 to the front cross member 22. Details of the end structure of the engine mount bracket 50 and the welded structure will be described later.

  The front mounting member 24 is formed by pressing an aluminum plate or the like. The front mounting member 24 has a front body mount portion 25 and is arc welded to the front cross member 22 at the inner end in the vehicle width direction with the end of the front cross member 22 sandwiched from above and below. The welding structure of the present invention can also be applied to this welding. The welding structure is the same as the welding to the front cross member 22 of the engine mount bracket 50 described later. Each of the front body mount portions 25 is provided with a fixture 29, which is fastened to a front side member (not shown), and the front attachment member 24 is attached to the lower side of the front side member (not shown). It is done.

  The front side rail portion 26 extends rearward from the front body mount portion 25 on each of the right side and the left side. The front side rail portion 26 has a bent portion 27 that is convex (downwardly convex) toward the lower side of the vehicle body in a side view as viewed from the vehicle width direction at a substantially central portion in the longitudinal direction (extending direction). doing.

  The rear cross portion 32 of the rear frame 30 extends in the vehicle width direction, and fastening portions 34 are integrally formed at both ends in the vehicle width direction. An attachment hole 34A is formed in the fastening portion 34, and the fastening portion 34 is attached to a lower end portion of a kick portion (not shown) of the front side member via the attachment hole 34A. On the front side of the fastening portion 34, a lower arm attachment portion 34B for attaching a lower arm (not shown) constituting a suspension (not shown) is formed.

  A pair of left and right rear side rail portions 36 each extending forward of the vehicle body are integrally formed on both front sides of the rear cross portion 32 in the vehicle width direction. The pair of left and right rear side rail portions 36 are formed in an open cross-sectional shape (substantially U-shaped in cross section) with the lower side opened. The front end portion of the rear side rail portion 36 is overlapped with the rear end portion of the front side rail portion 26 from above, and the rear side rail portion 36 and the front side rail portion 26 are overlapped and arc-welded. The welding structure of the present invention can also be applied to this welding. The welding structure can be the same as the welding to the front cross member 22 of the engine mount bracket 50 described later.

  The rear frame 30 is die cast of a light metal material such as an aluminum alloy, and a rear cross portion 32, a fastening portion 34, and a rear side rail portion 36 are integrally formed.

  A protection member 40 is disposed below the rear frame 30. The protection member 40 extends in the vehicle width direction and covers the front side of the lower surface of the rear cross portion 32, and extends forward from both ends of the protection cross portion 42 in the vehicle width direction, and the lower surface of the rear side rail portion 36. The protective side part 44 which covers is provided. The protection member 40 is substantially U-shaped when viewed from above. The protection member 40 is integrally formed by pressing an aluminum panel. The protection member 40 can protect the rear frame 30 from road surfaces and obstacles on the road surface.

  The protective member 40 is arc welded to the rear frame 30. The welding structure of the present invention can also be applied to this welding. The welding structure can be the same as the welding to the front cross member 22 of the engine mount bracket 50 described later.

  Next, a welding structure for welding the engine mount bracket 50 to the front cross member 22 will be described.

[Welding structure of the first aspect]
First, the welding structure 70 according to the first aspect will be described. As shown in FIG. 2, a linearly extending portion 56 that extends in the same direction as the extending direction of the ridge line 53 is formed at the end of the bracket side surface portion 54 in the extending direction of the ridge line 53. The linearly extending portion 56 is formed integrally with the bracket side surface portion 54, and extends beyond the ridge line 53 from a position lowered from the ridge line 53 of the bracket side surface portion 54. 2 and 3, only one end portion of the engine mount bracket 50 is shown, but the other end side has a similar welding structure.

  The engine mount bracket 50 is placed on the front cross member 22 from the upper side, the bracket upper surface portion 52 is disposed above the upper surface portion 22A, and the bracket side surface portion 54 and the linear extension portion 56 are disposed outside the side surface portion 22B. Is done. As shown in FIG. 3, if a virtual line that crosses the bracket side surface 54 downward from the end 53A of the ridge line 53 of the engine mount bracket 50 is a boundary line 55, the ridge line 53 side (see FIG. 3, a bracket side surface 54 is formed, and a linearly extending portion 56 is formed on the extended end side (left side in FIG. 3) from the boundary line 55. In this embodiment, the end side of the bracket side surface portion 54 is referred to as “main body outer edge 54A”, and the end side of the linear extension portion 56 continuous with the main body outer edge 54A is referred to as “straight extension outer edge 56A”.

  A weld line 58 extending in parallel with the ridge line 53 is formed between the engine mount bracket 50 and the front cross member 22. The weld line 58 is continuous in a straight line along the main body outer edge 54A of the bracket side surface portion 54 and the straight extension outer edge 56A of the linear extension portion 56. The weld line 58 terminates at a linearly extending outer edge 56A. The engine mount bracket 50 is arc welded to the front cross member 22 with the weld line 58.

  When a load in the peeling direction acts on the engine mount bracket 50 of the present embodiment, the load is transmitted along the ridgeline 53, and stress concentrates in the vicinity of the terminal end 53A of the ridgeline 53 that is a cross-sectional inflection point. In the welded structure 70 of the first aspect, since the weld line 58 extends to the linearly extended outer edge 56A beyond the main body outer edge 54A, the load acting near the terminal end 53A is distributed and received by the long weld line 58. Can do. Moreover, the end of the weld line 58 can be arranged at a position away from the terminal end 53A where the stress is concentrated, thereby suppressing the stress concentration on the weld end. Furthermore, since the base portion (near the boundary line 55) of the straight extension portion 56 is bent by the load input near the terminal end 53A, the load can be released, and the load input to the weld end portion can be reduced. it can.

  Further, in the weld structure 70 of the first aspect, the weld line 58 is formed along the linearly extending outer edge 56A, so that the welding position can be easily specified and the welding work can be easily performed. Further, a weld line 58 is formed at a portion where the two members of the front cross member 22 and the engine mount bracket 50 overlap. Therefore, since the linearly extending outer edge 56A can be welded with the same amount of heat input as that of the main body outer edge 54A, the amount of heat input can be easily controlled, and the weld quality of the end can be easily maintained.

  Moreover, in the welding structure 70 of the first aspect, the engine mount bracket 50 is formed by integrally molding a light metal material such as an aluminum alloy by die casting, so that the linear extension portion 56 can be easily formed.

  Furthermore, in the welded structure 70 of the first aspect, the resistance to the input of the load is improved without increasing the thickness of the engine mount bracket 50 and the front cross member 22, which can contribute to weight reduction.

[Welding structure of second aspect]
Next, the welding structure 72 of a 2nd aspect is demonstrated. About the 2nd mode, the same numerals are given to the same portion as the 1st mode, and the detailed explanation is omitted.

  As shown in FIG. 4, a bent extending portion 60 extending in a direction orthogonal to the extending direction of the ridge line 53 is formed at the end of the bracket side surface portion 54 in the extending direction of the ridge line 53. The bent extension portion 60 is formed integrally with the bracket side surface portion 54 and extends downward beyond an end side parallel to the ridge line 53 of the bracket side surface portion 54.

  The engine mount bracket 50 is placed on the front cross member 22 from above, the bracket upper surface portion 52 is disposed above the upper surface portion 22A, and the bracket side surface portion 54 and the bent extension portion 60 are disposed outside the side surface portion 22B. Is done. As shown in FIG. 5, when a virtual line obtained by extending an end parallel to the ridge line 53 of the engine mount bracket 50 is defined as a boundary line 62, the bracket side surface portion is located above the boundary line 62 (ridge line 53 side) when viewed from the front. 54 is formed, and a bent extension portion 60 is formed below the boundary line 62. In this embodiment, the end side of the bracket side surface portion 54 is referred to as “main body outer edge 54A”, and the end side of the bent extension portion 60 continuous with the main body outer edge 54A is referred to as “bending extension outer edge 60A”. The bent and extended outer edge 60A is continuously bent from the main body outer edge 54A and forms a concave shape with the main body outer edge 54A. The bent extended outer edge 60A only needs to extend in a direction intersecting with the main body outer edge 54A at an angle.

  A weld line 64 is formed between the engine mount bracket 50 and the front cross member 22 so as to continuously extend along the main body outer edge 54A and the bent extended outer edge 60A. The weld line 58 terminates at the bent extension outer edge 60A. The engine mount bracket 50 is arc welded to the front cross member 22 by the weld line 64.

  When a load in the peeling direction acts on the engine mount bracket 50 of the present embodiment, the load is transmitted along the ridgeline 53, and stress concentrates in the vicinity of the terminal end 53A of the ridgeline 53 that is a cross-sectional inflection point. In the welded structure 72 of the second aspect, since the weld line 64 extends beyond the main body outer edge 54A to the bent and extended outer edge 60A, the load acting on the vicinity of the terminal end 53A is distributed and received by the long weld line 64. Can do. Moreover, the end of the weld line 64 can be arranged at a position away from the terminal end 53A where the stress is concentrated, thereby suppressing the stress concentration on the weld end. Furthermore, since the weld line 64 formed along the bent and extended outer edge 60A receives a load acting in the vicinity of the terminal end 53A in the shear direction, stress concentration on the weld line 64 can be suppressed.

  Further, in the weld structure 72 of the second aspect, the weld line 64 is formed along the bent and extended outer edge 60A, so that it is easy to specify the position of the weld and the welding work can be easily performed. Further, a weld line 64 is formed at a portion where the two members of the front cross member 22 and the engine mount bracket 50 overlap. Therefore, the bent extended outer edge 60A can be welded with the same amount of heat input as that of the main body outer edge 54A, so that the amount of heat input can be easily controlled and the end weld quality can be easily maintained.

  Furthermore, in the welded structure 72 of the second aspect, since resistance to load input is improved without increasing the thickness of the engine mount bracket 50 and the front cross member 22, it is possible to contribute to weight reduction.

  In the above embodiment, the engine mount bracket 50 having a U-shaped cross section is welded to the front cross member 22. However, even when a member is welded on a flat plate surface whose cross section is not bent, the end of the member is attached. The linearly extending portion 56 and the bent extending portion 60 of the first aspect and the second aspect may be formed and similarly welded.

  Furthermore, in the above-described embodiment, the example in which the welding structure of the present invention is applied to each part of the suspension member has been described. However, the present invention is suitable for other vehicle body parts, in particular, parts for welding light metal materials such as aluminum alloys. It is.

22 Front cross member (first member)
22B Side surface (flat surface)
50 Engine mount bracket (second member)
54 Bracket side surface (main body)
54A Body outer edge 56 Linear extension (extension)
56A straight extension outer edge (extension outer edge)
58 Welding wire 60 Bending extension (extension part)
60A bending extension outer edge (extension outer edge)
64 Welding lines 70, 72 Welding structure

Claims (3)

A first member having a flat surface;
A main body outer edge of the main body portion disposed on the flat surface of the first member; and an extended outer edge that is continuous with the main body outer edge and extends continuously from the main body portion. A second member in which a weld line with the first member is formed along the outer edge of the main body and the extended outer edge;
With welded structure.   The welded structure according to claim 1, wherein the extending outer edge extends in the same direction as the extending direction of the main body outer edge.   The welded structure according to claim 1, wherein the extended outer edge extends in a direction intersecting with an extending direction of the main body outer edge.