JP2008067724A - Seat back frame for vehicle made of ultra-high tensile strength steel plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To configure a seat back frame for a vehicle so as to reduce the number of components, reduce weight, improve strength together with dimensional precision and easily perform welding work as well. <P>SOLUTION: The seat back frame mainly includes left and right side frames 1 and 2 press-molded into a predetermined shape from an ultra-high tensile strength steel plate, an upper member 3 between the upper portions of the side frames 1 and 2 and a lower member 4 between the lower portions of the side frames 1 and 2. The side frames 1 and 2 are formed into a roughly inward U-shape in the cross-section, and the lower member 4 is provided by integrally bending a main member part 40 over the side members 1 and 2 and side member parts 41a and 41b protruding forward from both end sides of the main member part 40. The plate surfaces facing each other of the respective members are bonded by spot-welding and assembled into a roughly quadrangular frame shape with the side frames 1 and 2 are main columns. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a seat back frame for an automobile in which a framework is formed into a substantially quadrilateral shape from a component obtained by press-forming an ultra-high strength steel plate into a predetermined shape.
[0002]
[Prior art]
In general, an automobile seat back frame is a pipe member formed by bending a shaft in a substantially downward U-shape as a main frame, and an upper plate cut from a steel plate into a predetermined plane shape is arc-welded between the upper shaft portions of the main frame. The left and right side plates cut and formed from the steel plate are joined and fixed to the longitudinal axis of the main frame by arc welding, and the lower member of the pipe member is joined and secured between the longitudinal axes of the main frame by arc welding. As a result, it is assembled into a substantially quadrangular frame shape.
[0003]
In the seat back frame, not only the number of parts is large and the weight is heavy, but also each component is joined and fixed to the main frame by arc welding.
[0004]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide an automotive seat back frame made of an ultra-high-strength steel plate that can reduce the number of parts, reduce the weight, improve the strength as well as the dimensional accuracy, and can easily perform welding work.
[0005]
[Means for Solving the Problems]
In the automotive seat back frame according to claim 1 of the present invention, the left and right side frames press-formed into a predetermined shape from the ultra-high-strength steel plate, upper members extending between the upper portions of the side frames, The lower member that spans between the lower parts of the side frames is the main constituent member, and the opposing plate surfaces of each constituent member are joined together by spot welding to assemble into a substantially quadrilateral frame shape with the side frame as the main pillar,
The left and right side frames are formed in a U-shape with a substantially inward cross-section from a wide main surface portion that forms an outer shape and an overhanging flange portion that rises inward from the front and rear edges of the main surface portion,
The lower member is bent integrally from the main member part extending between the side members and the side member part projecting forward from both end sides of the main member part, and the upper end side of the side member part is sided from both end sides of the main member part. It is formed in a shape that fits within the U-shape of the frame, and is configured by fitting the upper end side of the side member part into the lower part of the side frame from both ends of the main member part and joining and fixing by spot welding. Yes.
[0006]
In the automobile seat back frame made of ultra high strength steel sheet according to claim 2 of the present invention, the cross section is substantially U-shaped across the longitudinal direction at the center of the plate surface of the main member part and over the bent base part of the side member. It is comprised by providing the lower member which joined and fixed the shape bracing member by spot welding.
[0007]
In the automotive seat back frame made of ultra high strength steel sheet according to claim 3 of the present invention, it extends in the longitudinal direction at the substantially center of the plate surface of the main member portion, and from the plate surface of the side member to the lower surface of the side frame. It is configured by including a lower member in which a bracing member having a substantially U-shaped extending cross section is joined and fixed by spot welding.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the accompanying drawings, the illustrated embodiment is applied to assembling a seat back frame of an automobile seat including a headrest that can be adjusted in height, a reclining mechanism, and a slide rail (all not shown). ing. This seat back frame is assembled by joining and fixing each constituent member obtained by press-molding an ultra-high strength steel plate into a predetermined shape by spot welding.
[0009]
As shown in FIGS. 1 and 2, the structural members include left and right side frames 1 and 2, an upper member 3 extending between the upper portions of the side frames 1 and 2, and a lower member extending between the lower portions of the side frames 1 and 2. 4 and a bracing member 5 that reinforces the lower member 4 are provided. In addition to these components, a tension spring (not shown) is provided between the side frames 1 and 2.
[0010]
The side frames 1 and 2 rise inward from the wide main surface portions 10 and 20 (see FIG. 2) that form the outer shape of the left and right side portions from the shoulder portion of the seat back, and the front and rear edges of the main surface portions 10 and 20. The protruding flange portions 11, 12, 21, 22 are formed in a substantially U shape in cross section. The side frames 1 and 2 are formed so that the upper side is curved inward to form the shoulder portion of the seat back.
[0011]
The overhanging flange portions 11, 12, 21, and 22 of the side frames 1 and 2 are formed by chamfering the upper flange portions 11a, 12a, 21a, and 22a wider than the longitudinal center flange portions 11b, 12b, 21b, and 22b. Yes. The rear overhanging flange portion 12 is formed by chamfering the upper and lower flange portions 12a, 12c, 21a, and 22c wider than the same portions 11a, 11c, 21a, and 22c of the front overhanging flange portion 11.
[0012]
The side frames 1 and 2 are formed by vertically extending substantially quadrilateral concave portions 13, 14, 23, and 24 as ribs that reinforce the wide surfaces of the main surface portions 10 and 20, respectively, by protruding the upper surface and the middle surface inward. ing. Among these, the concave portions 13 and 23 on the upper surface are formed by flattening the upper and lower sides of the bottom surface flatly by spot welding the upper member 3 as will be described later. Moreover, it can reinforce also as a base surface provided with an armrest by providing the recessed parts 14 and 24 which reinforce the wide surface of the main surface parts 10 and 20 in a middle abdominal surface.
[0013]
In addition, a bead-shaped ridge 15 (see FIG. 2) that reinforces the lower end surface of the main surface 10 and a bead-shaped ridge that reinforces the wide upper flanges 12a and 21a of the rear overhanging flange 12. 16a, 16b, 26a, 26b (see FIG. 1) are provided. Providing these bead-shaped ridges 15, 16a, 16b, 26a, and 26b can prevent not only strength reinforcement but also warpage of the plate surface when press-forming an ultra-high strength steel plate.
[0014]
As shown in FIGS. 3 to 5, the upper member 3 is formed by combining two constituent members of an upper member 3 a that forms the upper side of the seat back and a lower member 3 b that receives the upper member 3 a.
[0015]
As shown in FIG. 3, the upper member 3a is bent so that the front plate portion 30b, the bottom plate portion 30c, the lower wall plate portion 30d, and the lower flange portion 30e are continuous from the top plate portion 30a. Further, a back plate portion 30f that wraps around from the top plate portion 30a to the rear side is bent. At both ends of the top plate 30a, tongue pieces 31a and 31b for spot welding are formed by bending downward. Each tongue piece 31a, 31b is bent so that the upper side is continuous with the front plate portion 30b and the back plate portion 30f.
[0016]
Of the upper member 3a, the lower wall plate portion 30d is formed so that the lower edge is bordered so that the central portion is at a higher position and the left and right ends are at the lower positions. Along the contour of the lower wall plate portion 30d, a lower flange portion 30e is formed so as to project forward in the horizontal direction. The top plate 30a and the bottom plate 30c are provided with openings 32a and 32b for inserting and fixing a holder (not shown) for inserting and holding the headrest stay. Further, the front plate portion 30b is provided with an opening 33 for removing the meat in the center of the plate surface.
[0017]
As shown in FIG. 4, the lower member 3b is formed of a bridge plate portion 34a and a standing wall plate portion 34b. The bridge plate portion 34a is formed such that, when viewed in plan, the front side edge is curved in an arc shape and both end portions are widened. A downward flange portion 34c is provided along the front edge. Further, tongue pieces 35a and 35b for spot welding are formed at both ends by bending downward. The standing wall plate part 34b is formed with an upper edge bordered so that the central part is the lower part and the left and right end parts are the upper part. Along the contour of the standing wall plate portion 34b, the upper flange portion 34d is formed so as to project in the horizontal direction.
[0018]
As shown in FIG. 5, the upper member 3a and the lower member 3b are spaced apart from each other by abutting the lower flange portion 30e of the lower wall plate portion 30d and the upper flange portion 34d of the standing wall plate portion 34b closer to both ends. Assemble up and down in position.
[0019]
As shown in FIG. 6, the lower member 4 is integrally formed from a main member 40, left and right brackets 41a and 41b, and weld pieces 42a and 42b extending upward from the brackets 401a and 41b. Yes. The main member 40 has a belt-like shape, and is reinforced by a bead-shaped launching portion 43 whose longitudinal direction is curved forward at the approximate center of the plate surface. Further, the upper and lower edges are reinforced by inner bending flange portions 44a and 44b.
[0020]
The bracket portions 41a and 41b are for attaching a reclining device (not shown), and fixing holes 45a and 45b of the reclining device and insertion holes 46a and 46b of the connecting shaft are provided on the plate surface. Also, the lower side is curved in an arc shape in accordance with the shape of the reclining device. Around the edge, edge flange portions 47a and 47b are provided.
[0021]
The bracing member 5 is formed to be bent in a U-shaped section having a narrow width so as to cover the projecting portion 42 of the lower member 4. A plurality of spot welding tongues 50a and 50b are provided on each of the upper and lower edges. In addition, tongue pieces 51a and 51b for spot welding are provided on both the left and right sides by bending forward.
[0022]
As shown in FIG. 7, the upper member 3a of the upper member 3 has the top plate portion 30a, the front plate portion 30b, the lower wall plate portion 30d, and the back plate portion 30f near the both end portions inside the side frames 1 and 2, respectively. It fits and opposes the overhanging flange portions 11, 12, 21, 22. Further, the tongue pieces 31a and 31b are opposed to the upper side of the bottom surfaces of the concave portions 13 and 23 protruding inside the main surface portions 10 and 20, respectively.
[0023]
The upper member 3a includes a front plate portion 30b and front projecting flange portions 11 and 21, a lower wall plate portion 30d, a rear plate portion 30f, and rear projecting flange portions 12 and 22, tongue pieces 31a and 31b, and a recess portion 13, respectively. The upper side of the bottom frame 23 is joined and fixed by spot welding (see “x” in the drawing, the same applies hereinafter) between the upper portions of the side frames 1 and 2.
[0024]
In the lower member 3b, both ends of the bridging plate portion 34a from the standing wall plate portion 34b are fitted inside the side frames 1 and 2, and both ends of the standing wall plate portion 34b are fitted to the rear projecting flange portions 12, 22. Relative to Further, the tongue pieces 35a and 35b are opposed to the lower side of the bottom surface of the concave portions 13 and 23 protruding inside the main surface portions 10 and 20, respectively.
[0025]
The lower member 3b is formed by bonding the tongue wall portions 35a, 35b and the bottom bottom sides of the recessed portions 13, 23 by spot welding to the ends of the standing wall plate portion 34b and the rear projecting flange portions 12, 22. The upper member 3a is assembled between the frames 1 and 2 so as to be received from the lower side. As an assembling procedure, the lower member 3b may be joined first and the upper member 3a may be joined and fixed later.
[0026]
As shown in FIG. 8, the lower member 4 places the bracing member 5 from the main member 40 to the inside of the brackets 41a and 41b, and spots a plurality of tongue pieces 50a, 50b, 51a and 51b on the main member 40 and the brackets 41a and 41b. It is attached to the lower member 4 in advance by welding.
[0027]
As shown in FIG. 9, the lower member 4 has weld pieces 42 a and 42 b extending upward from the bracket portions 401 a and 41 b and are fitted inside the side frames 1 and 2. For this reason, the lower member 4 is assembled to the lower side of the side frames 1 and 2 by spot welding at a plurality of locations with the lower end edges of the side frames 1 and 2 to which the welding pieces 42a and 42b face each other.
[0028]
As shown in FIGS. 10 and 12, the seat back frame of the vehicle seat configured as described above has the left and right side frames 1 and 2 as main pillars, and upper members 3 (3 a and 3 b) and both ends of the lower member 4. In addition to being combined inside the side frames 1 and 2, the opposing plate surfaces of the constituent members are joined together by spot welding to assemble into a substantially quadrangular frame shape.
[0029]
In the seat back frame, at least the left and right side frames 1 and 2 and the upper member 3 and the lower member 4 can be assembled as constituent members, so that the number of parts can be reduced and each constituent member can be formed from a thin ultra high strength steel plate. Can reduce the weight. In addition, since each component is press-molded, the dimensional accuracy can be increased, and the strength can be improved from the structure in which both ends of the upper member 3 and the lower member 4 are fitted inside the side frames 1 and 2 and all are joined by spot welding. By doing so, welding work can be easily performed.
[0030]
In the above-described embodiment, as the bracing member 5, as shown in FIG. 12, a member formed from a main member 5a and left and right submembers 5b (only one side is shown) bent into an L shape can be assembled. The bracing member 5 can be formed separately or integrally with both 5a and 5b. In this bracing member 5, the left and right submembers 5 b extend between the weld piece of the lower member 4 and the lower edge of the side frames 1, 2, so that the portion can be reinforced more firmly.
[0031]
In order to configure the entire seat frame for an automobile, as shown in FIG. 13, the front side is formed with a pan frame 6 and the pan frame 6 is welded and fixed to the left and right base frames 7 and 8 to form an ultra high strength steel plate. The seat cushion frame S is assembled, and a double-sided reclining device is provided between the lower side of the seat back frame B and the rear side of the base frame S and is connected by the pivot shaft 9.
[0032]
【The invention's effect】
As described above, according to the automotive seat back frame made of the ultra-high-strength steel sheet according to claim 1 of the present invention, the left and right side frames press-formed from the ultra-high-strength steel sheet into a predetermined shape, and the upper part of the side frame. An approximately quadrilateral frame in which the upper member and the lower member extending between the lower portions of the side frames are the main constituent members, and the plate surfaces of the respective constituent members are joined to each other by spot welding. Assembling into a shape,
The left and right side frames are formed in a U-shape with a substantially inward cross-section from a wide main surface portion that forms an outer shape and an overhanging flange portion that rises inward from the front and rear edges of the main surface portion,
The lower member is bent integrally from the main member part extending between the side members and the side member part projecting forward from both end sides of the main member part, and the upper end side of the side member part is sided from both end sides of the main member part. It is formed in a shape that fits in the U-shape of the frame, and the upper end side of the side member part is fitted into the lower part of the side frame from both ends of the main member part, and is fixed by spot welding. Therefore, the weight can be reduced, the strength can be improved with the dimensional accuracy, and the welding operation can be easily performed.
[0033]
According to the automotive seat back frame made of ultra high-strength steel sheet according to claim 2 of the present invention, the cross section of the main member portion extends substantially in the longitudinal direction at the center of the plate surface and extends along the bent base portion of the side member. By providing the lower member in which the U-shaped bracing members are joined and fixed by spot welding, the strength of not only the lower member but also the entire frame can be improved.
[0034]
According to the automotive seat back frame made of ultra high-strength steel sheet according to claim 3 of the present invention, the longitudinal direction extends substantially in the center of the plate surface of the main member portion, and the lower portion of the side frame from the plate surface of the side member. By providing the lower member in which the bracing members having a substantially U-shaped cross section extending to the surface are joined and fixed by spot welding, the side frame can be reinforced together with the lower member, and the strength of the entire frame can be improved.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an explanatory view showing a front seat frame for an automobile made of an ultra-high-strength steel sheet according to the present invention as it is developed for each component member from the front.
FIG. 2 is an explanatory view showing the automobile seat back frame of FIG. 1 from the side.
3 is a perspective view showing an upper member of an upper member constituting the seat back frame of FIG. 1. FIG.
4 is a perspective view showing a lower member of an upper member constituting the seat back frame of FIG. 1. FIG.
5 is a side sectional view showing a combination of the upper member of FIG. 3 and the lower member of FIG. 4;
6 is a perspective view showing a lower member and a bracing member that constitute the seat back frame of FIG. 1 in an unfolded state. FIG.
7 is a perspective view showing an upper side of an automobile seat back frame assembled from the components shown in FIG. 1. FIG.
8 is a perspective view showing the lower member and the bracing member of FIG. 6 in an assembled state.
FIG. 9 is an explanatory view showing the lower member of FIG. 8 in a joined state with respect to the side frame.
FIG. 10 is a front view showing the automobile seat back frame according to the present invention in a completed state;
11 is a side view showing the automobile seat back frame of FIG. 10; FIG.
12 is an explanatory view showing another modification example of the lower member of FIG. 8; FIG.
13 is a perspective view showing the entire seat frame including the automobile seat back frame of FIG. 10. FIG.
[Explanation of symbols]
1, 2 Side frames 10, 20 Main surface portions 11, 12, 21, 22 of the side frames
Side frame overhang flange part 3 (3a, 3b) Upper member 4 Lower member 40 Lower member main member part 41a, 41b Lower member side member part 5 Bracing member

Claims (3)

The left and right side frames press-molded from ultra-high strength steel sheets into a predetermined shape, the upper member extending between the upper portions of the side frames, and the lower member extending between the lower portions of the side frames are the main components, and each component is opposed to each other. In the seat back frame for automobiles made of ultra high strength steel plates that are assembled into a substantially quadrilateral frame shape with the side frames as main pillars by joining the plate surfaces together by spot welding,
The left and right side frames are formed in a U-shape with a substantially inward cross-section from a wide main surface portion that forms an outer shape and an overhanging flange portion that rises inward from the front and rear edges of the main surface portion,
The lower member is bent integrally from the main member part extending between the side members and the side member part projecting forward from both end sides of the main member part, and the upper end side of the side member part is sided from both end sides of the main member part. It is formed in a shape that fits within the U-shape of the frame, and the upper end side of the side member part is fitted into the lower part of the side frame from both ends of the main member part and is fixed by spot welding. Automotive seat back frame made of ultra-high tensile steel.   It is characterized by comprising a lower member in which a bracing member having a substantially U-shaped cross section over the longitudinal direction at the center of the plate surface of the main member portion and over the bent base portion of the side member is joined and fixed by spot welding. The automobile seat back frame according to claim 1.   It has a lower member that is joined and fixed by spot welding of a substantially U-shaped bracing member that extends in the longitudinal direction at the center of the plate surface of the main member portion and extends from the plate surface of the side member to the lower surface of the side frame. The vehicle seat back frame according to claim 1, wherein

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