JP2015147549A - Body structure of automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the welding strength of weld zones of first and second panels constituting an upper member extending forward from a front pillar of an automobile body without increasing the size nor the weight.SOLUTION: An upper member 18 is constituted by joining automobile-width-directionally outside joint flanges 21d, 22d of a first panel 21 and a second panel 22 through seam welding W1(a), and has high strength against mouth opening deformation of the joint flanges 21d, 22d when a load is placed on a damper fitting part 14a of a damper housing 14 since a nugget width "w" of the seam welding W1(a) and a nugget diameter "d" of normal spot welding of an automobile body are so related that 0.29≤w/d≤0.36, and the same shearing strength with the normal spot welding can be obtained although the seam welding W1(a) which can reduce the weight by decreasing widths of the joint flanges 21d, 22d is employed.

Description

  The present invention relates to a vehicle body structure for an automobile in which an inner portion in a vehicle width direction of an upper member having a closed cross section extending forward from front ends of left and right front pillar uppers is connected to a damper mounting portion of a damper housing of a front suspension.

  In the case of a front pillar having a closed cross section by welding with a reinforcement between the flange of the outer panel and the flange of the inner panel, the flange of the outer panel and the flange of the inner panel are shifted and arranged. In addition to seam welding with two flanges and reinforcements, and seam welding with two flanges and reinforcements on the inner panel, it is possible to avoid three-layer seam welding to ensure welding strength. This is known from Patent Document 1 below.

JP 2009-255800 A

  By the way, in the above-mentioned conventional one, the seam welding that joins the flange and the reinforcement of the outer panel by two sheets and the seam welding that joins the flange and the reinforcement of the inner panel by two sheets are parallel to each other with a predetermined distance. Therefore, the widths of the flanges of the outer panel and the inner panel are inevitably increased, and not only the size of the welded portion is increased, but also the weight is increased by the increased width of the flange.

  The present invention has been made in view of the above circumstances, and without increasing the size and weight of the welded portions of the first and second panels constituting the upper member extending forward from the front pillar of the vehicle body, the welding strength thereof can be increased. The purpose is to increase.

  To achieve the above object, according to the first aspect of the present invention, the inner portion in the vehicle width direction of the upper member of the closed cross section that extends forward from the front ends of the left and right front pillar uppers is used as the damper of the damper housing of the front suspension. A vehicle body structure connected to a mounting portion, wherein the upper member is formed by seam welding at least a joining flange on the outer side in the vehicle width direction of the first panel and the second panel, and the nugget width w of the seam welding and the vehicle body A vehicle body structure is proposed in which the relationship with the nugget diameter d of normal spot welding is set to 0.29 ≦ w / d ≦ 0.36.

  According to the second aspect of the present invention, in addition to the configuration of the first aspect, spot welding is performed on both end portions of the portion of the upper member where the first panel and the joint flange of the second panel are seam welded. A vehicle body structure is proposed in which the relationship between the nugget width w of the seam welding and the nugget diameter d of the spot welding is set to 0.29 ≦ w / d ≦ 0.36.

  According to the invention described in claim 3, in addition to the configuration of claim 1 or 2, the lower member extending forward from the front end of the upper member is provided, and the front end of the lower member is located at the front end of the front side frame. The lower member is connected through an outrigger, and the lower member is formed by seam welding at least a joint flange on the outer side in the vehicle width direction of the first panel and the second panel. The nugget width w of the seam welding and the normal spot welding nugget of the vehicle body A vehicle body structure is proposed in which the relationship with the diameter d is set to 0.29 ≦ w / d ≦ 0.36.

  According to the invention described in claim 4, in addition to the structure of claim 3, spot welding is performed on both ends of the portion of the lower member where the first panel and the joint flange of the second panel are seam welded. A vehicle body structure is proposed in which the relationship between the nugget width w of the seam welding and the nugget diameter d of the spot welding is set to 0.29 ≦ w / d ≦ 0.36.

  According to the invention described in claim 5, in addition to the configuration of claim 3 or claim 4, the first panel of the upper member and the first panel of the lower member are common members, A vehicle body structure for an automobile is proposed in which the seam welding of the upper member and the seam welding of the lower member are continued on an extension line of each other.

  According to a sixth aspect of the invention, in addition to the configuration of the fourth or fifth aspect, the spot weld located between the seam weld of the upper member and the seam weld end of the lower member. Is proposed at a connecting portion between a front end of the upper member that is substantially horizontal and a rear end of the lower member that is forward and downward.

  Note that the second joining flanges 21d, 22d, 23d, and 24d of the embodiment correspond to the joining flange of the present invention.

  According to the configuration of the first aspect, the inner part in the vehicle width direction of the upper member of the closed cross section extending forward from the front ends of the left and right front pillar uppers is connected to the damper mounting portion of the damper housing of the front suspension. The upper member is formed by seam welding at least the outer flanges of the first panel and the second panel in the vehicle width direction, and the relationship between the nugget width w of the seam welding and the nugget diameter d of normal spot welding of the vehicle body, Since 0.29 ≦ w / d ≦ 0.36 was set, when a load was input from the damper of the front suspension to the damper mounting portion of the damper housing, the strength of the joint flange against opening deformation was high, and the joint flange A shear strength equivalent to that of normal spot welding can be obtained while using seam welding that can be reduced in weight and reduced in weight. In addition, seam welding is performed by applying pressure to the overlapped joint flanges with electrodes, which not only eliminates the gap between the joint flanges and stabilizes the welding strength, but also eliminates the need for a special welding jig, which increases productivity. improves.

  According to the construction of claim 2, both ends of the seam welded portion of the joint flange of the first panel and the second panel of the upper member are spot welded, and the nugget width w of the seam weld and the nugget diameter d of the spot weld are obtained. Is set to 0.29 ≦ w / d ≦ 0.36, so that when the bending load is applied to the upper member, the opening of the first panel and the second panel is prevented from being deformed by seam welding. In addition, since the joining flanges are joined by spot welding having higher peel strength than the seam welding at both ends of the seam welded portion, peeling at both ends of the seam welding can be prevented by spot welding.

  According to the configuration of claim 3, the lower member includes a lower member extending forward from the front end of the upper member, the front end of the lower member is connected to the front end of the front side frame via the outrigger, and the lower member is at least of the first panel and the second panel. The joint flange on the outer side in the vehicle width direction is formed by seam welding, and the relationship between the seam welding nugget width w and the normal spot welding nugget diameter d of the vehicle body is set to 0.29 ≦ w / d ≦ 0.36 Therefore, when a load is transmitted from the upper member to the lower member, the strength of the joint flange against opening deformation is high, and while using seam welding that can reduce the width of the joint flange and reduce the weight, Shear strength equivalent to welding can be obtained. In addition, seam welding is performed by applying pressure to the overlapped joint flanges with electrodes, which not only eliminates the gap between the joint flanges and stabilizes the welding strength, but also eliminates the need for a special welding jig, which increases productivity. improves.

  According to the fourth aspect of the present invention, both ends of the seam welded portion of the joint flange of the first panel and the second panel of the lower member are spot welded, and the nugget width w of the seam weld and the nugget diameter d of the spot weld are Since the relationship is set to 0.29 ≦ w / d ≦ 0.36, it is possible to prevent the first panel and the second panel from opening and deforming due to seam welding when a bending load is applied to the lower member. Moreover, since the joining flanges are joined by spot welding having higher peel strength than the seam welding at both ends of the seam welded portion, peeling at both ends of the seam welding can be prevented by spot welding.

  According to the fifth aspect of the present invention, since the first panel of the upper member and the first panel of the lower member are common members, not only the number of parts can be reduced but also the second panel of the upper member and the lower member which are separate members. The strength distribution can be arbitrarily set by changing the thickness of the second panel of the second panel, and the seam welding of the upper member and the seam welding of the lower member are continued on the extension line of each other, so that the workability of the seam welding is improved. .

  According to the construction of claim 6, spot welding located between the end portions of the seam welding of the upper member and the seam welding of the lower member is performed by connecting the front end of the substantially horizontal upper member and the rear end of the lower lower member. Therefore, it is possible to spot weld a portion that is easily deformed by a load input from the damper of the front suspension, and to prevent seam welding of the upper member and the lower member adjacent to each other from being peeled off. In addition, since the connection between the front end of the upper member and the rear end of the lower member is a three-layer weld with the addition of the first panel, it is necessary to locally change the welding conditions for seam welding by spot welding that portion. It becomes possible to improve welding quality and workability.

The figure which compares the member which carried out seam welding, and the member which carried out spot welding. Explanatory drawing of the member which used seam welding and spot welding together. The top view of the vehicle body front part of a motor vehicle. FIG. 4 is a four-direction arrow view of FIG. 3. The figure which shows the state which isolate | separated the 2nd panel from FIG. 6A-6A line of FIG. 4, 6B-6B line and 6C-6C line sectional drawing.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  FIG. 1 (A) shows a member in which a pair of hat-shaped steel plates are seam welded in a state of being overlapped at their joint flanges to form a closed cross section, and FIG. 1 (B) is also spot welded. Shows things. The pitch of spot welding is 30 mm, which is generally used for welding of automobile bodies.

  When a bending moment is applied to this member, in the case of discrete spot welding, the gap between adjacent welds is easily deformed due to opening deformation, but in the case of continuous seam welding. Since there is no opening deformation, the bending strength is improved, the steel sheet can be made thinner and lighter, and the seam weld nugget width is smaller than the spot weld nugget diameter. Further reduction in weight can be achieved by reducing the width of the flange. On the other hand, when a peeling load is applied to the member, peeling is likely to occur from the weld end in the case of seam welding with a small nugget width, but peeling is unlikely to occur in spot welding with a large nugget diameter. .

  In addition, in order to obtain a shear strength equivalent to that of spot welding at intervals of 30 mm by seam welding, when the nugget width of seam welding is set to w and the diameter of nugget of general spot welding used for automobile body welding is set to d. Including the safety factor, it is necessary that 0.29 ≦ w / d ≦ 0.36 holds. If the seam welding nugget width w is too small and w / d is less than 0.29, the shear strength will be insufficient, and if the seam welding nugget width w is too large and w / d exceeds 0.36, the base metal That is, the steel material itself breaks.

  Therefore, as shown in FIG. 2, the center part in the longitudinal direction of the joining part of two steel materials is seam welded to increase the strength against bending load, and both ends of seam welding are spot welded to increase the strength against peeling load. The advantages of seam welding and spot welding can be achieved at the same time, and a member having high bending strength and high peel strength can be obtained while being lightweight. In addition, by setting the relationship between the nugget width w of seam welding and the nugget diameter d of spot welding to 0.29 ≦ w / d ≦ 0.36, general spot welding used for automobile body welding Equivalent shear strength can be ensured.

  Next, an embodiment to which the combination of seam welding and spot welding described above is applied will be described with reference to FIGS. In the present specification, the front-rear direction, the left-right direction (vehicle width direction), and the up-down direction are defined with reference to an occupant seated in the driver's seat.

  As shown in FIGS. 3 and 4, the rear ends of a pair of left and right front side frames 13, 13 are connected to the front surface of a dash panel lower 12 standing from the front end of the floor panel 11 of the automobile. A front surface at both ends in the vehicle width direction and an outer surface in the vehicle width direction at the rear end of the front side frame 13 are connected by a damper housing 14. The damper housing 14 is connected to a flat damper mounting portion 14a formed on the upper surface of the damper housing 14 at the upper end of a damper of a front suspension device (not shown), and the left and right damper housings 14, 14 extend in the vehicle width direction. Connected to both ends of the bar 15.

  The front ends of a pair of left and right front pillar uppers 17 and 17 are connected to the upper ends of a pair of left and right front pillar lowers 16 and 16 that stand along the rear surface of the dash panel lower 12 from both ends in the vehicle width direction of the front end of the floor panel 11. The The upper member 18 extends forward from the front end of each front pillar upper 17, the lower member 19 extends forward and downward from the front end of the upper member 18, and the front end of the front side frame 13 and the front end of the lower member 19 are connected to each other by the outrigger 20. Connected in the direction.

  As shown in FIGS. 3 to 6, the upper member 18 includes an L-shaped first panel 21 having an inner wall 21a and a lower wall 21b in the vehicle width direction, and an L shape having an outer wall 22a and an upper wall 22b in the vehicle width direction. The second panel 22 having a cross section is joined to the first joining flanges 21c and 22c, and the second joining flanges 21d and 22d are joined to form a closed section. The lower member 19 includes an L-shaped first panel 23 having an inner wall 23a and a lower wall 23b, and an L-shaped second panel 24 having an outer wall 24a and an upper wall 24b. The first joint flanges 23c and 24c are joined together, and the second joint flanges 23d and 24d are joined together to form a closed cross section.

  The first panel 21 of the upper member 18 and the first panel 23 of the lower member 19 are a single plate member formed integrally. The first joining flange 21c extending in the horizontal direction of the first panel 21 of the upper member 18 and the lower member The 19th first panel 23 and the first joint flange 23c extending in the vertical direction are twisted by 90 ° relative to each other (see FIG. 5). On the other hand, the second joining flange 21d of the first panel 21 of the upper member 18 and the second joining flange 23d of the first panel 23 of the lower member 19 both extend in the horizontal direction and are continuous with each other.

  In the upper member 18, the first joining flange 21 c of the first panel 21 and the first joining flange 22 c of the second panel 22 are overlapped in the vertical direction. Joined by spot welding W2 (a). At that time, the first joining flanges 21c and 22c are overlapped on the damper mounting portion 14a of the damper housing 14 in a three-layer manner and spot-welded W2 (c), so that the inner part in the vehicle width direction of the upper member 18 is It is integrated with the damper housing 14 (see FIG. 6A).

  In the lower member 19, the first joint flange 23c of the first panel 23 and the first joint flange 24c of the second panel 24 are overlapped in the vehicle width direction. Joined by spot welding W2 (b). At this time, the front end of the first joining flange 22c of the second panel 22 of the upper member 18 and the rear end of the first joining flange 24c of the second panel 24 of the lower member 19 are the boundary portions of the first panels 21 and 23. In Fig. 6, spot welding W2 (d) is performed by overlapping three sheets (see Fig. 6B).

  In addition, the upper member 18 has the second joining flange 21d of the first panel 21 and the second joining flange 22d of the second panel 22 overlapped in the vertical direction and joined by seam welding W1 (a). And the both ends of seam welding W1 (a) are joined by spot welding W2 (e) and W2 (f), respectively. At this time, one spot weld W2 (f) on the front end side of the seam weld W1 (a) is overlapped and joined to the second joint flange 24d of the second panel 24 of the lower member 19 in a three-layer manner.

  In the lower member 19, the second joining flange 23d of the first panel 23 and the second joining flange 24d of the second panel 24 are overlapped in the vertical direction and joined by seam welding W1 (b). And both ends of seam welding W1 (b) are joined by spot welding W2 (f) and W2 (g), respectively. At this time, the seam weld W1 (a) of the upper member 18 and the seam weld W1 (b) of the lower member 19 are continuous on the extension line of each other, and two spot welds W2 (f) are interposed between them. Sandwiched.

  In the present embodiment, the nugget diameter d of each of the spot welds W2 (a) to W2 (g) is the same as the general nugget diameter d of spot welding of the vehicle body, and each of the seam welds W1 (a), W1. The nugget width w in (b) is set so that a relation of 0.29 ≦ w / d ≦ 0.36 is established with respect to the nugget diameter d.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  When the load from the front wheel is input to the damper mounting portion 14a of the damper housing 14 via the damper of the front suspension device, the load is transmitted from the damper housing 14 to the upper member 18 and from the upper member 18 to the front pillar upper 17. And transmitted to the front end of the front side frame 13 via the lower member 19 and the outrigger 20.

  The second joint flanges 21d and 22d on the outer side in the vehicle width direction of the first panel 21 and the second panel 22 of the upper member 18 are seam welded W1 (a), and the first panel 23 and the second panel 24 of the lower member 19 are mounted on the vehicle. The second joint flanges 23d and 24d on the outer side in the width direction are seam welded W1 (b), and the relationship between the nugget width w of the seam welds W1 (a) and W1 (b) and the nugget diameter d of the normal spot welding of the vehicle body Is set to 0.29 ≦ w / d ≦ 0.36, the strength of the second joint flanges 21d and 22d of the upper member 18 and the second joint flanges 23d and 24d of the lower member 19 is high against opening deformation, and While using seam welds W1 (a) and W1 (b) that can reduce the width of the second joining flanges 21d, 22d, 23d, and 24d and reduce the weight, Tsu DOO welding comparable shear strength can be obtained.

  The seam welds W1 (a) and W1 (b) are electrodes that connect the second joining flanges 21d and 23d of the first panels 21 and 23 and the second joining flanges 22d and 24d of the second panels 22 and 24, respectively. Since welding is performed while pressurizing, the gap between both the flanges is eliminated and the welding strength is stabilized, and productivity is improved because a special welding jig is not required.

  Further, the rear end of the seam weld W1 (a) of the second joint flanges 21d and 22d of the upper member 18 is spot welded W2 (e) and the front end is spot welded W2 (f), and the second joint flanges 23d and 24d seam weld W1 (b) has the rear end spot welded W2 (f) and the front end spot welded W2 (g), and the seam weld W1 (a), W1 (b) nugget width w and spot weld W2 ( e) Since the relationship between W2 (f) and W2 (g) and the nugget diameter d is set to 0.29 ≦ w / d ≦ 0.36, when a bending load is applied to the upper member 18 and the lower member 19 It is possible to prevent the first panel 21, 23 and the second panel 22, 24 from being deformed by seam welding W1 (a), W1 (b), and the seam welding W1 (a), W1 (b ) Peeling strength is high spot welding W2 (e), W2 (f), by W2 (g), seam welding W1 (a), it is possible to prevent peeling of the both end portions of W1 (b).

  In particular, in the connection portion between the upper member 18 and the lower member 19, the second joint flange 22d of the second panel 22 of the upper member 18 and the second joint flange 24d of the second panel 24 of the lower member 19 are one member. Since the portion where three sheets are overlapped with respect to one panel 21 and 23 is spot-welded W2 (f) instead of seam welding (see FIG. 6B), peeling of the portion is performed by spot welding W2 (f). Not only can this be prevented, but it is not necessary to seam weld the overlapped part of the three sheets, so there is no need to change the welding conditions of seam welding according to the welding site, and the quality of seam welding can be guaranteed. it can.

  Further, since the first panel 21 of the upper member 18 and the first panel 23 of the lower member 19 are used as a common member, not only the number of parts can be reduced, but also the second panel 22 of the upper member 18 and the second panel 24 of the lower member 19 can be reduced. The strength distribution can be arbitrarily set by using different members and varying the plate thicknesses. Moreover, since the seam weld W1 (a) of the upper member 18 and the seam weld W1 (b) of the lower member 19 are continuous on each other's extension line, the workability of the seam welds W1 (a) and W1 (b) is only improved. Without spot welding W2 (f), the welding condition of the seam welding W1 (a) and W1 (b) is locally determined by spot welding W2 (f) between the seam welds W1 (a) and W1 (b). There is no need to change, and it is possible to improve welding quality and workability.

  The spot weld W2 (f) located between the ends of the seam weld W1 (a) of the upper member 18 and the seam weld W1 (b) of the lower member 19 is composed of the front end of the substantially horizontal upper member 18 and the lower member 19 of the front and lower. Since it is disposed at the connecting portion with the rear end, a portion that is easily deformed by a load input from the damper of the front suspension is spot-welded W2 (f), and the seam weld W1 (a ), W1 (b) can be prevented from peeling off.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the number of spot welds W2 (a) to W2 (g) is not limited to the embodiment, and can be set arbitrarily.

13 Front side frame 14 Damper housing 14a Damper mounting portion 17 Front pillar upper 18 Upper member 19 Lower member 20 Outrigger 21 Upper member first panel 21d Second joining flange (joining flange)
22 Upper member second panel 22d Second joint flange (joint flange)
23 Lower panel first panel 23d Second joint flange (joint flange)
24 Lower panel second panel 24d Second joint flange (joint flange)
W1 (a) Seam welding W1 (b) Seam welding W2 (e) Spot welding W2 (f) Spot welding W2 (g) Spot welding

Claims (6)

The vehicle body of the automobile in which the inner part in the vehicle width direction of the upper member (18) having a closed cross section extending forward from the front ends of the left and right front pillar uppers (17) is connected to the damper mounting portion (14a) of the damper housing (14) of the front suspension. Structure,
The upper member (18) is formed by welding seam flanges (21d, 22d) at least on the outer side in the vehicle width direction of the first panel (21) and the second panel (22), and the seam The vehicle body structure of an automobile characterized in that the relationship between the nugget width w of welding (W1 (a)) and the nugget diameter d of normal spot welding of the vehicle body is set to 0.29 ≦ w / d ≦ 0.36 .   Spot welding (W2) is performed at both ends of the first member (21) of the upper member (18) and the joint flanges (21d, 22d) of the second panel (22) by seam welding (W1 (a)). (E), W2 (f)), and the relationship between the nugget width w of the seam welding (W1 (a)) and the nugget diameter d of the spot welding (W2 (e), W2 (f)) is 0. The vehicle body structure according to claim 1, wherein 29 ≦ w / d ≦ 0.36 is set.   A lower member (19) extending forward from a front end of the upper member (18) is provided, and a front end of the lower member (19) is connected to a front end of a front side frame (13) via an outrigger (20), and the lower member (19 ) Is formed by seam-welding (W1 (b)) the outer flanges (23d, 24d) of the first panel (23) and the second panel (24) in the vehicle width direction, and the seam welding (W1 (b) The relation between the nugget width w)) and the nugget diameter d of normal spot welding of the vehicle body is set to 0.29 ≦ w / d ≦ 0.36. Vehicle body structure described.   Both ends of the lower member (19) where the first and second panels (23) and (24) are seam welded (W1 (b)) to the first and second panels (23) and (24) are spot welded (W2 ( f), W2 (g)), and the relationship between the nugget width w of the seam welding (W1 (b)) and the nugget diameter d of the spot welding (W2 (f), W2 (g)) is 0.29. 4. The vehicle body structure according to claim 3, wherein ≦ w / d ≦ 0.36 is set.   The first panel (21) of the upper member (18) and the first panel (23) of the lower member (19) are common members, and the seam welding (W1 (a) of the upper member (18) is performed. 5) and the seam welding (W1 (b)) of the lower member (19) are continuous on each other's extension line, the vehicle body structure of an automobile according to claim 3 or 4.   The spot weld (W2 (f)) located between the seam weld (W1 (a)) of the upper member (18) and the seam weld (W1 (b)) of the lower member (19) is: 6. The vehicle body of claim 4, wherein the vehicle body is disposed at a connection portion between a front end of the upper member (18) that is substantially horizontal and a rear end of the lower member (19). Construction.

Images