JP2012106552A - Suspension cross member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suspension cross member advantageous in reduction of costs by reducing the number of part items.SOLUTION: The suspension cross member 10 includes two pieces of steel plate members, an upper steel plate member 32 and a lower steel plate member 34, facing each other. A lower front surface part 3404 is overlapped in front of an upper front surface part 3204 to form an opening 28 with a gap between them, and a right and a left lower projecting pieces 42 are overlapped in front of a right and a left upper projecting pieces 40 in the opening 28. A part of the lower projecting piece 42 including an upper edge extending in the right and left direction is connected to the upper projecting piece 40 by welding, and the welded part forms a projecting piece side welding part 48. The projecting piece side welding part 48 is continuously provided to a body side welding part 36, and is extended straight in extension of the body side welding part 36, and a welding end 48A is positioned at the tip of the projecting piece side welding part 48.

Description

  The present invention relates to a suspension cross member for a vehicle in which two steel plate members having a front-rear width formed by pressing are formed so as to face each other vertically, and a suspension device for supporting a steering wheel of the vehicle is assembled at both ends in the left-right direction.

2. Description of the Related Art Conventionally, a suspension cross member is disposed at a lower portion of a rear portion of an engine room, spanned between left and right side members extending in the front-rear direction of the vehicle, and a suspension device that supports a steering wheel of the vehicle is assembled at both ends thereof. .
In the suspension cross member, there are two press-formed steel plate members because a plurality of attachment portions such as fastening members to the left and right side members and members constituting the suspension device are formed in a complicated shape. It is configured by welding. More specifically, two steel plate members that are press-formed and have front and rear widths face each other in the vertical direction and extend in the left-right direction, and the front surfaces and the rear surfaces thereof are overlapped in the left-right direction of the front surface and the rear surface. The place including the extending edge part is a welded place joined by welding, and the inside thereof is formed in a hollow shape.

In such a suspension cross member, an opening that communicates with the space inside the two steel plate members may be provided at a location including the front or rear welded portion.
For example, when the rear end of the engine roll rod for mounting the engine is inserted into the inner space through the front opening of the suspension cross member and is coupled to the front and rear intermediate portions of the suspension cross member so as to be swingable in the left-right direction. There is.
The opening 60 in this case is shown in FIG. That is, the front surface 64 of the upper steel plate member 62 and the front surface 68 of the lower steel plate member 66 are overlapped, and the portion including the edge of the front surface 68 of the lower steel plate member 66 is joined by welding. It is the location 70. And the opening 60 will be provided in the location containing the welding location 70. FIG. In other words, the weld ends 70 </ b> A are located on both sides of the opening 60 in the left-right direction.

JP 2008-290539 A

On the other hand, various stresses act on the suspension cross member when the vehicle travels.
Here, focusing on the opening 60, the weld ends 70A are located on both sides of the opening 60 in the left-right direction. For this reason, the cross-sectional shape of the welded portion 70 extending linearly changes rapidly at the weld end 70A, and stress concentration is likely to occur at the weld end 70A. Further, the weld end 70A is also a place where it is difficult to stabilize the quality such as penetration.
For this reason, the durability is inevitably reduced at the locations of the weld ends 70A located on both sides of the opening 60.
Therefore, conventionally, when the opening 60 is provided in a place including the welded place 70, a reinforcing member is provided in the vicinity of the opening 60, or the thicknesses of the two steel plate members 62 and 66 are increased. The durability of the suspension cross member is ensured.
Therefore, some improvement has been demanded for reducing the number of parts of the suspension cross member and reducing the cost.
The present invention has been devised in view of the above circumstances, and an object of the present invention is to provide a suspension cross member that is advantageous in reducing the number of parts and reducing costs.

In order to achieve the above object, according to the first aspect of the present invention, two steel plate members having a front-rear width and press-formed are vertically opposed to each other and extend in the left-right direction. The place including the edge part extended in the left-right direction of the said front surface and the said rear surface is the welding location joined by welding, and the opening connected to the space part inside these two steel plate members is the said. A suspension cross member that is provided at a location including a welding location and is assembled with suspension devices that support vehicle steering wheels at both ends in the left-right direction, and is superimposed on each other at locations including the welding location on both sides of the opening. Protruding pieces projecting in the left-right direction in the opening from the front surface or the rear surface are respectively provided, and the projecting pieces are overlapped in the opening to the left of the projecting piece. Portion comprising an edge extending in a direction, characterized in that it is joined by welding so as to be continuous with the welding spot.
Further, in the invention according to claim 2, the projecting piece assembly projecting into the opening is formed by welding the projecting pieces in the opening and joining a portion including the edge of the projecting piece by welding. A bent portion is formed at the base where the upper edge and the lower edge of the projecting piece assembly intersect the edge of the opening, and the dimensions of the upper edge and the lower edge gradually decrease as the distance from the edge of the opening increases. It is characterized by.

According to the first aspect of the invention, by shifting the weld end, which is difficult to stabilize the quality due to penetration, to the tip of the protruding piece, the left and right sides of the opening where the change in the cross-sectional shape is large and the stress due to the external input is concentrated Can be separated from the edges on both sides.
Therefore, there is no need to provide a reinforcing member in the vicinity of the opening or increase the thickness of the two steel plate members, and the number of parts of the suspension cross member can be reduced while improving the durability of the suspension cross member. This is advantageous in reducing costs.
According to the second aspect of the present invention, since the cross-sectional shape of the welded portion changes more gently at the edge of the opening due to the curved portion, it is more advantageous in reducing the stress concentration at the base of the projecting piece assembly. This is even more advantageous in improving the durability of the cross member.

It is a top view of a suspension cross member. It is a perspective view of a suspension cross member seen from the front of vehicles. It is a front view of the opening part of the front surface of a suspension cross member. It is an exploded view of the opening part of the front surface of a suspension cross member. FIG. 4 is a cross-sectional view of a suspension cross member cut along a plane extending in the front-rear direction, and (A), (B), and (C) are cross-sectional views taken along lines AA, BB, and CC in FIG. 3. It is a front view of the opening part of the front surface of the conventional suspension cross member.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the suspension cross member 10 extends in the vehicle width direction of the vehicle, and both ends thereof are respectively connected to left and right side members (not shown) extending in the vehicle front-rear direction. Located in the lower rear part of the room.
The suspension cross member 10 includes a pair of arms 12 provided on the left and right sides of the upper surface 10A for connecting to the side members. The pair of arms 12 have base ends fixedly coupled to the connecting portions 1002 of the upper surface 10A at the left and right ends of the suspension cross member 10, and connecting portions for connecting to the side members are formed at the tips of the arms 12. .

A power steering unit 14 is mounted on the suspension cross member 10. An attachment portion 1004 for attaching the power steering unit 14 is formed on the upper surface 10A of the suspension cross member 10, and the support portions 1402, 1404 of the power steering unit 14 are fastened to the attachment portion 1004, whereby the power steering unit. 14 is mounted above the suspension cross member 10.
Further, left and right suspension devices 16 are mounted on the suspension cross member 10. Connection portions 1006 and 1008 for connecting the lower arm 16A of the suspension device 16 are formed at the left and right ends of the suspension cross member 10, respectively, and the base end of the lower arm 16A is pivotally attached to the connection portions 1006 and 1008. Thus, the lower arm 16A is swingably connected to the suspension cross member 10. A knuckle 18 that supports the front wheel is rotatably connected to the tip of the lower arm 16A.

The power steering unit 14 has a pair of left and right tie rods 20, which are connected to left and right knuckle arms 22, and the front wheels are steered by the tie rods 20.
A stabilizer 24 is attached to the suspension cross member 10. Attachment portions 1010 and 1012 for attaching the stabilizer 24 are formed on the upper surface 10A of the suspension cross member 10, and the stabilizer 24 is attached to the suspension cross by fastening the support portion 2402 of the stabilizer 24 to the attachment portions 1010 and 1012. Attached above the member 10, both ends of the stabilizer 24 are connected to the lower arm 16A.
Further, the suspension cross member 10 is connected to the rear end of the engine roll rod 26 for suppressing the shake of the engine in the front-rear direction. An opening 28 communicating with the space inside the suspension cross member 10 is formed in the front surface 10B of the suspension cross member 10, and the rear end of the engine roll rod 26 is inserted from the opening 28 to connect the suspension cross member 10. Part 1014 is slidably coupled.

As described above, the suspension cross member 10 is provided with various connecting portions 1002, 1006, 1008 and mounting portions 1004, 1010, 1012, and has a complicated shape. Two steel plate members, ie, an upper steel plate member 32 and a lower steel plate member 34 that extend are configured to face each other vertically.
As shown in FIG. 5, the upper steel plate member 32 includes an upper surface portion 3202 having a front-rear width and extending in the left-right direction, an upper front surface portion 3204 bent downward from front and rear ends of the upper surface portion 3202, and an upper rear portion. And a surface portion 3206.
The lower steel plate member 34 includes a lower surface portion 3402 having a front-rear width and extending in the left-right direction, a lower front surface portion 3404 and a lower rear surface portion 3406 bent upward from the front and rear ends of the lower surface portion. have.
The front surface portions 3204 and 3404 and the rear surface portions 3206 and 3406 of the upper steel plate member 32 and the lower steel plate member 34 are overlapped with each other, and extend in the left-right direction of the front surface portions 3204 and 3404 and the rear surface portions 3206 and 3406. The location including the edge portion is formed by welding.

More specifically, the upper steel plate member 32 is disposed inside the lower steel plate member 34, the lower front surface portion 3404 is overlapped in front of the upper front surface portion 3204, and the lower rear surface portion is positioned behind the upper rear surface portion 3206. 3406 are overlapped, the edge of the lower front surface portion 3404 extending in the left-right direction is joined to the upper front surface portion 3204 by welding, and the edge of the lower rear surface portion 3406 extending in the left-right direction is the upper rear surface portion. It is joined to 3206 by welding.
Therefore, a portion including an edge portion where the upper front surface portion 3204 and the lower front surface portion 3404 are overlapped and extends in the left-right direction of the lower front surface portion 3404 is a main body side welding portion 36 joined by welding. Further, a portion including an edge portion in which the upper rear surface portion 3206 and the lower rear surface portion 3406 are overlapped and extends in the left-right direction of the lower rear surface portion 3406 is a main body side welding portion 38 joined by welding.
Further, the front surface 10 </ b> B of the suspension cross member 10 is constituted by an upper front surface portion 3204 and a lower front surface portion 3404 that are joined by the main body side welded portion 36.

As shown in FIG. 3, the opening 28 of the front surface 10 </ b> B of the suspension cross member 10 is provided at a location including the main body side welding location 36, and the main body side welding location 36 is located on both sides in the left-right direction of the opening 28. ing.
On the both sides of the opening 28 in the left and right direction, including the main body side welding point 36, there are an upper protruding piece 40 and a lower protruding piece 42 that protrude in the left and right direction from the upper front part 3204 and the lower front part 3404 into the opening 28. Each is provided. The upper protruding piece 40 and the lower protruding piece 42 have a vertical width that is smaller than the vertical width of the opening 28.

More specifically, as shown in FIG. 4, an open notch 44 for forming the opening 28 is provided at a location including the edge portion 3204 </ b> A of the upper front surface portion 3204. The upper protruding pieces 40 are provided to protrude into the notch 44 in the left-right direction at locations including the edge 3204A of the upper front surface part 3204 located on both sides of the notch 44 in the left-right direction.
The lower edge 4002 of the upper protruding piece 40 is formed in a straight line that is continuous with the edge 3204A of the upper front surface portion 3204. Further, a curved portion 4006 is formed at the base portion where the upper edge 4004 of the upper protruding piece 40 intersects with the vertical edge of the notch 44, and the upper and lower protruding pieces 40 are gradually reduced in width as the distance from the vertical edge increases. The portion excluding the base is formed in a straight line parallel to the lower edge 4002 and continuing to the end of the curved portion 4006.

In addition, an open notch 46 is provided above a portion for forming the opening 28 at a location including the edge 3404A of the lower front surface portion 3404 of the lower steel plate member 34. The lower protruding pieces 42 are provided to protrude into the notch 46 in the left-right direction at locations including the edge 3404A of the lower front surface part 3404 located on both sides of the notch 46 in the left-right direction.
The upper edge 4202 of the lower protruding piece 42 is formed in a straight line that is continuous with the edge 3404A of the lower front surface portion 3404, and the lower edge 4204 of the lower protruding piece 42 is at the base that intersects the vertical edge of the notch 46. A curved portion 4206 is formed to gradually reduce the vertical width of the lower projecting piece 42 as the distance from the vertical edge increases. The portion of the lower edge 4204 excluding the base is parallel to the upper edge 4202 and is continuous with the curved portion 4206. Is formed.

  Then, by overlapping the lower front surface portion 3404 in front of the upper front surface portion 3204, an opening 28 is formed by both the notches 44 and 46, as shown in FIGS. In the opening 28, the left and right lower protruding pieces 42 are overlapped in front of the left and right upper protruding pieces 40. And the location including the upper edge 4202 extended in the left-right direction of the lower side protrusion piece 42 is joined to the upper side protrusion piece 40 by welding, and this joined location is the protrusion piece side welding location 48. The protruding one-side welded part 48 is provided continuously with the main body-side welded part 36 and extends linearly on the extension of the main body-side welded part 36.

Thus, the location including the upper edge (upper edge 4202) of the lower projecting piece 42 is joined to the upper projecting piece 40 by welding, whereby the projecting piece assembly 50 projecting into the opening 28 is formed. . The protruding piece assembly 50 has a vertical width that is smaller than the vertical width of the opening 28.
Therefore, the upper edge of the protruding piece assembly 50 is configured by the upper edge 4004 of the upper protruding piece 40, and the lower edge of the protruding piece assembly 50 is configured by the lower edge 4204 of the lower protruding piece 42. Then, at the base portion where the upper edge 4004 and the lower edge 4204 of the protruding piece assembly 50 intersect the vertical edge of the opening 28, the curved portion where the dimensions of the upper edge 4004 and the lower edge 4204 gradually decrease as the distance from the vertical edge of the opening 28 increases. 4006 and 4206 are formed.

Next, operational effects will be described.
When the vehicle travels, various stresses act on the suspension cross member 10 via various connecting portions 1002, 1006, 1008 and mounting portions 1004, 1010, 1012.
When attention is paid to the opening 28, as shown in FIG. 3, although the main body side welding points 36 are located on both sides in the left-right direction of the opening 28, the welding end 48A is interposed via the upper protruding piece 40 and the lower protruding piece 42. That is, it is located at the tip of the projecting piece assembly 50 that is displaced from the left and right edges of the opening 28 to the inside of the opening 28 via the projecting one side welding spot 48. The bases of the upper protruding piece 40 and the lower protruding piece 42 are located at the edge of the opening 28. In other words, the position of the weld end 48A and the position where the cross-sectional shape changes suddenly by the opening 28 are shifted. Yes.

Therefore, the weld end 48A, whose quality is difficult to stabilize due to penetration or the like, is located away from the left and right edges of the opening 28, where the cross-sectional change is large and stress is concentrated, so stress concentration at the weld end 48A is concentrated. Is alleviated, which is advantageous in improving the durability of the suspension cross member 10.
Therefore, there is no need to provide a reinforcing member in the vicinity of the opening 28 or increase the thickness of the two steel plate members, and the number of parts of the suspension cross member 10 is improved while improving the durability of the suspension cross member 10. This is advantageous for reducing costs and reducing costs.

In the present embodiment, the bases of the upper projecting piece 40 and the lower projecting piece 42, that is, the base of the projecting piece assembly 50, are located at the left and right edges of the opening 28. In the base portion, curved portions 4006 and 4206 are formed in which the dimensions of the upper edge and the lower edge gradually decrease as the distance from the edge of the opening 28 increases.
That is, the change in the cross-sectional shape of the upper protruding piece 40 and the lower protruding piece 42 provided with the main body side welded portion 36 is more gently caused by the curved portions 4006 and 4206 without the cross-sectional shape changing abruptly at the edge of the opening 28. This is more advantageous in reducing the stress concentration at the base of the projecting piece assembly 50, and more advantageous in improving the durability of the suspension cross member 10.

  10: Suspension cross member, 28: Opening, 32: Upper steel plate member, 3204 ... Upper front surface portion, 34 ... Lower steel plate member, 3404 ... Lower front surface portion, 36: Body side welding 40, upper projecting piece, 4006, curved portion, 42, lower projecting piece, 4206, curved portion, 44, 46, notched portion, 48, projecting one side welding location, 50, projecting piece Joined body.

Claims (2)

Two steel plate members having a front-rear width and press-formed are vertically opposed to each other and extend in the left-right direction, and the front surfaces and the rear surfaces thereof are overlapped to extend in the left-right direction of the front surface and the rear surface. The location including the edge portion is a welded location joined by welding, and an opening communicating with the space inside the two steel plate members is provided in the location including the weld location, and at both ends in the left-right direction. A suspension cross member to which a suspension device for supporting a steering wheel of a vehicle is assembled,
Protruding pieces that protrude in the left-right direction in the opening from the front surface or the rear surface, which are overlapped with each other, are provided in places including the welded portions on both sides of the opening,
In the opening, the protruding pieces are overlapped with each other and a portion including an edge extending in the left-right direction of the protruding pieces is joined by welding so as to be continuous with the welding portion.
A suspension cross member for a vehicle characterized by the above. In the opening, the protruding pieces are overlapped and a portion including the edge of the protruding piece is joined by welding, thereby forming a protruding piece assembly protruding into the opening,
A curved portion is formed at the base where the upper edge and the lower edge of the protruding piece assembly intersect the edge of the opening, and the dimensions of the upper edge and the lower edge gradually decrease as the distance from the edge of the opening increases.
The suspension cross member for a vehicle according to claim 1.

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