JP5458978B2 - Seat cross member structure - Google Patents

Description

  The present invention relates to a seat cross member structure disposed under a vehicle seat, and belongs to the field of vehicle body structure technology.

  Patent Document 1 discloses a specific example of a structure below a third row seat in a vehicle having three rows of seats in the front-rear direction. In the structure of Patent Document 1, a storage recess for storing a spare tire is formed in the floor panel below the seat cushion of the third row seat. A seat cross member for supporting the seat and fixing the seat belt anchor is disposed below the seat cushion of the third row seat so as to extend in the vehicle width direction.

  The seat cross member disclosed in Patent Document 1 is composed of a metal tube. The seat cross member is bent so that the vehicle width direction intermediate portion is located on the upper side of the vehicle width direction both ends fixed to the floor panel via the bracket, thereby preventing interference with the spare tire. It can be prevented.

  By the way, Patent Document 2 discloses a technique for performing quenching while bending a metal tube. Specifically, bending is performed while heating at a temperature at which plastic deformation is possible and quenching, and quenching is performed by rapidly cooling the heated portion immediately after heating. According to the technique of Patent Document 2, even if the plate thickness of the bent metal tube is reduced, high strength can be obtained for the metal tube. In other words, the bent metal tube can be reduced in weight while ensuring high strength.

  Therefore, by manufacturing the above-described seat cross member using the technique of Patent Document 2, the seat cross member is reduced in weight while maintaining its strength, and contributes to the weight reduction of the vehicle body that has been increasingly required in recent years. It is possible.

JP 2004-291682 A JP 2006-240441 A

  However, the seat cross member that has been reduced in thickness and weight is reduced in rigidity in a specific direction depending on the cross-sectional shape. When this is used, the seat cross member floats mainly above the floor panel due to vibration transmitted from the floor panel. The intermediate portion is likely to resonate, and accordingly, there is a concern that the vibration transmitted to the seat increases and the ride comfort deteriorates.

  Therefore, the present invention pays attention to the fact that this type of member can be adjusted in rigidity by twisting, thereby changing the resonance characteristics against vibration, and transmitted from the floor panel to the seat while reducing the weight. It is an object to provide a seat cross member structure capable of suppressing vibration.

  In order to solve the above problems, the seat cross member structure according to the present invention is configured as follows.

First, the invention described in claim 1 of the present application is configured by a tubular member that extends in the vehicle width direction below the seat cushion of the vehicle and has a flat cross-sectional shape over the entire length in the length direction. The seat has both ends as fixed parts to the floor panel, and the intermediate part is a raised part positioned above the floor panel via the rising parts from the fixed parts on both sides. Cross member structure,
The rising portion is twisted so that an upper portion of the fixed portion faces frontward or rearward at the raised portion.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, the trailing edge of the raised portion is located in front of the trailing edge of the fixed portion.

  Furthermore, the invention described in claim 3 is characterized in that, in the invention described in claim 2, the rising portion is twisted so that the upper portion of the fixed portion faces forward in the raised portion. To do.

  Still further, the invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the fixed portion has a dimension in the front-rear direction larger than a dimension in the vertical direction. The raised portion is characterized in that the vertical dimension is larger than the longitudinal dimension.

  The invention according to claim 5 is the invention according to claim 4, wherein the raised portion is arranged such that a longitudinal direction of the flat cross-sectional shape is perpendicular to the floor panel. It is characterized by being.

  Furthermore, the invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the raised portion has a substantially horizontal lower surface to which a seat belt anchor mounting member is fixed. And the lower surface has a width greater than or equal to the width of the mounting member in the vehicle width direction.

  Still further, the invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the rising edge on both sides and the trailing edge of the raised part are It is formed so as to correspond to the front edge part of the recessed part for storage formed in the floor panel.

  First, according to the first aspect of the present invention, the seat cross member having a flat cross-sectional shape over the entire length in the longitudinal direction is such that the upper portion of the fixed portion at both ends thereof is the front or Since the rising portion is twisted so as to face rearward, this makes it possible to adjust the rigidity of the seat cross member. Therefore, according to the vehicle to which the seat cross member is attached, the resonance characteristics of the seat cross member can be appropriately changed so that the resonance of the seat cross member with respect to vibration from the floor panel is prevented. Therefore, even if the plate thickness of the seat cross member is reduced, the resonance of the seat cross member can be effectively prevented. Therefore, vibration transmitted from the floor panel to the seat can be suppressed while reducing the weight of the seat cross member.

  According to the second aspect of the present invention, the rear edge of the lifted portion is located in front of the rear edge of the fixed portion, so that the space behind the lifted portion can be enlarged.

  Furthermore, when the invention according to claim 3 is applied to the invention according to claim 2, the rising edge is twisted so that the upper part of the fixed part faces forward in the floating part, so that the trailing edge of the lifting part is covered. The twisting process for positioning the front portion of the fixing portion in front of the rear edge can be performed relatively easily.

  According to the fourth aspect of the present invention, since the dimension of the fixed part in the front-rear direction is larger than the dimension in the vertical direction, the fixed part can be stably attached to the floor panel. In addition, since the vertical dimension of the lifted portion is larger than the dimension in the front-rear direction, the vertical rigidity of the lifted portion can be increased. This can effectively prevent the resonance of the seat cross member particularly with respect to the vibration in the vertical direction. Therefore, if the vibration in the vertical direction is easily transmitted from the floor panel to the seat in the vehicle to which the seat cross member is attached, the vibration Can be effectively suppressed to improve riding comfort.

  Furthermore, if the invention according to claim 5 is applied to the invention according to claim 4, the longitudinal direction of the cross-sectional shape of the lifted portion is along the vertical direction, so that the vertical rigidity of the lifted portion is maximized. The vibration in the vertical direction transmitted from the floor panel to the seat can be more effectively suppressed.

  Further, according to the invention described in claim 6, since the attachment member of the seat belt anchor is fixed to the substantially horizontal lower surface of the raised portion, an upward external force is applied to the attachment member when the seat belt is pulled. In this case, the mounting member can be reliably supported by the raised portion. Moreover, since the lower surface of the raised portion has a width equal to or larger than the width of the mounting member in the vehicle width direction, the mounting member can be securely fixed to the lower surface of the raised portion.

  According to the seventh aspect of the present invention, the rising edge on both sides and the rear edge of the raised portion are formed so as to correspond to the front edge of the recess for storage formed on the floor panel in plan view. Therefore, a space necessary for storing and taking out the stored items from the storing concave portion can be efficiently secured behind the seat cross member.

It is the perspective view which looked at the seat cross member which concerns on one Embodiment of this invention, and its peripheral member from back. It is a top view which shows the seat cross member shown in FIG. 1, and its peripheral part. It is the sectional view on the AA line of FIG. It is a perspective view which shows the metal tube used for the CAE analysis. It is a graph which shows the result of CAE analysis.

  Hereinafter, embodiments of the present invention will be described.

  FIG. 1 shows a lower portion of a third row seat 2 in a vehicle having three rows of seats in the front-rear direction. The seat 2 includes a seat cushion 4 and a seat back 6, and a storage recess 62 for storing a spare tire 70 is formed in a floor panel 60 disposed below the seat cushion 4 ( (See FIG. 2).

  As shown in FIG. 1, below the seat cushion 4, a seat cross member 10 that supports the seat 2 and fixes a later-described seat belt anchor 90 extends in the vehicle width direction.

  The seat cross member 10 is formed of a metal tube having a flat cross-sectional shape over the entire length in the length direction. Specifically, the cross-sectional shape of the seat cross member 10 is substantially rectangular. However, in the present invention, the specific cross-sectional shape of the seat cross member 10 is not particularly limited as long as it is flat. It may be oval.

  The seat cross member 10 has both ends in the length direction to be fixed portions 12 (12a, 12b) to the floor panel 60, and an intermediate portion is a rising portion 14 (14a from the fixed portions 12a, 12b on both sides. , 14b) and the raised portion 16 is located above the floor panel 60 with a space therebetween.

  The fixed part 12 is formed so that the long side direction of the cross-sectional shape is parallel to the floor panel 60. That is, in the fixed part 12, the dimension in the front-rear direction is larger than the dimension in the vertical direction. Therefore, the fixed part 12 can be stably attached to the floor panel 60.

  A fixed member 20 (20a, 20b) for fixing the seat cross member 10 to the floor panel 60 is attached to the fixed portion 12 in front of the seat cross member 10. The fixing member 20 includes a pair of left and right plate portions 22 and 24 fixed to the outer peripheral surface of the seat cross member 10 by welding, for example, so as to be perpendicular to the length direction of the seat cross member 10, and the pair of The front end portions of the plate portions 22 and 24 are coupled to each other and the arm portion 26 extends forward from the coupling portion. The front end portion 28 of the arm portion 26 is fixed to the floor panel 60 with bolts or the like. A support member 42 (42a, 42b) that fixes the fixed portion 12 to the floor panel 60 and supports the seat 2 is fixed to the plate portion 22 on the outer side in the vehicle width direction by, for example, welding. The support member 42 is provided across the floor panel 60 and the seat cushion 4. Although not shown in FIG. 1, in addition to the support member 42, a plurality of support members that support the sheet 2 are provided.

  The rising portion 14 is formed to rise obliquely upward from one end in the vehicle width direction of the fixed portion 12. The rising portion 14 is twisted so that the upper surface of the fixed portion 12 faces the front at the raised portion 16, thereby adjusting the rigidity of the seat cross member 10 as will be described later.

  In the floating portion 16, the long side direction of the cross-sectional shape is perpendicular to the floor panel 60, unlike the fixed portion 12. In other words, the lifted portion 16 has a larger vertical dimension than a longitudinal dimension. For this reason, the vertical rigidity of the raised portion 16 and the entire seat cross member 10 is enhanced. Therefore, even if the plate thickness of the seat cross member 10 is reduced, the rigidity of the seat cross member 10 in the vertical direction can be increased, and the vibration of the seat cross member 10 is caused by the vibration in the vertical direction transmitted from the floor panel 60. It can be effectively suppressed. Therefore, even if the structure of the vehicle to which the seat cross member 10 is attached is such that vertical vibration from the floor panel 60 is easily transmitted to the seat 2, the weight of the seat cross member 10 can be reduced and the floor panel 60 can be reduced. Vibration transmission to the seat 2 can be effectively suppressed, and riding comfort can be improved.

  Although the seat cross member 10 according to the present embodiment has a structure capable of suppressing vibration transmission in the vertical direction, in the present invention, the specific structure of the seat cross member is appropriately changed according to the vibration characteristics of the vehicle. Thus, vibration transmission in directions other than the vertical direction can also be suppressed.

  Further, the front surface and the rear surface of the raised portion 16 are arranged along a substantially vertical direction, and the upper surface and the lower surface of the raised portion 16 are arranged along a substantially horizontal direction. The lower surface of the lifted portion 16 has a width equal to or greater than the width of a mounting member 50 of a seat belt anchor 90 described later in the vehicle width direction.

  A fixing member 30 for fixing the seat cross member 10 to the floor panel 60 is attached to the raised portion 16 in front of the seat cross member 10. The fixing member 30 includes a base portion 32 fixed to the rear surface of the floating portion 16 via, for example, a mounting plate 40, and an arm portion 36 extending forward and downward from the upper end of the base portion 32. The front end 38 is fixed to the floor panel 60 with bolts or the like.

  An attachment member 50 for the seat belt anchor 90 is fixed to the lifted portion 16.

  As shown in FIG. 3, the seat belt anchor 90 includes a base portion 92 fixed to the attachment member 50, and a belt member 94 having one end attached to the base portion 92 and the other end attached to a buckle (not shown). Have.

  The attachment member 50 includes a lower surface fixing portion 52 that is fixed to the lower surface 80 of the floating portion 16 of the seat cross member 10, and a support that extends rearward and upward from the rear end of the lower surface fixing portion 52 to support the seat belt anchor 90. Part 54, a pair of rib plate parts 56 extending forward from the both ends of the support part 54 in the vehicle width direction toward the rear surface 82 of the floating part 16, and a vehicle from the front ends of the pair of rib plate parts 56, respectively. It has a pair of rear surface fixing portions 58 that extend outward in the width direction and are fixed to the rear surface 82 of the floating portion 16.

  The base portion 92 of the seat belt anchor 90 is fixed to the outer surface of the support portion 54 of the attachment member 50 by, for example, bolts 96 and nuts 98, whereby the seat belt anchor 90 is attached to the attachment member 50. Yes.

  The lower surface fixing portion 52 of the mounting member 50 is fixed to the substantially horizontal lower surface 80 of the raised portion 16 by welding, for example. On the other hand, the rear surface fixing portion 58 of the attachment member 50 is fixed to the substantially vertical rear surface 82 of the raised portion 16 by welding, for example. Therefore, even if an external force in the front obliquely upward direction is generated on the attachment member 50 by pulling a seat belt (not shown), the attachment member 50 can be reliably supported by the lifted portion 16.

  Further, since the lower surface 80 of the lifted portion 16 has a width equal to or larger than the width of the mounting member 50 in the vehicle width direction, the mounting member 50 can be reliably fixed to the lower surface 80 of the lifted portion 16.

  Further, since the floating portion 16 is arranged such that the long side direction of the cross-sectional shape extends in the vertical direction, the vertical dimension of the rear surface of the floating portion 16 is ensured to be large. Therefore, a large adhesion area between the rear surface 82 of the raised portion 16 and the rear surface fixing portion 58 of the attachment member 50 can be ensured, and thereby the attachment strength of the attachment member 50 to the lift portion 16 can be increased.

  FIG. 2 is a plan view showing the seat cross member 10 and the storage recess 62 of the floor panel 60.

  The storage recess 62 is provided below the rear row of the third row seat 2 so that the spare tire 70 can be stored in and taken out of the storage recess 62 from the rear of the third row seat 2. The storage recess 62 is formed so that the front end portion is deeper than the rear end portion, so that the spare tire 70 is stored in a state where the rear end portion is inclined higher than the front end portion. 62 is housed. Further, in plan view, the front edge of the storage recess 62 is formed to bulge forward in a semi-elliptical shape, for example, and the rear edge of the storage recess 62 is formed to bulge backward in a semi-elliptical shape, for example. Yes.

  The seat cross member 10 is disposed so as to straddle the front edge of the storage recess 62. Specifically, in the seat cross member 10, the fixed portions 12a and 12b are fixed to the floor panel 60 in the vicinity of the outside of the storage recess 62, and the rising portions 14a and 14b are the front edge portions of the storage recess 62 in plan view. Arranged along the part, the raised portion 16 is arranged above the front end portion of the spare tire 70 stored in the storage recess 62.

  The rear edge of the raised portion 16 is located in front of the rear edge of the fixed portion 12. Further, the rear edges of the rising portions 14 a and 14 b on both sides of the seat cross member 10 and the rear edge of the raised portion 16 are formed so as to correspond to the front edge of the storage recess 62 in plan view. That is, the entire rear edges of the rising portions 14 a and 14 b and the floating portion 16 on both sides have a planar shape that bulges forward like the front edge portion of the storage recess 62. Therefore, the space behind the raised portion 16 and the rising portions 14a and 14b can be enlarged. Therefore, a sufficient space can be secured behind the seat cross member 10 for storing and taking out the spare tire 70 from the storage recess 62 while avoiding interference between the seat cross member 10 and the spare tire 70. .

  The sheet cross member 10 is manufactured by hot bending or cold bending a metal tube. Preferably, the sheet cross member 10 is manufactured by performing bending while heating the metal tube at a plastically deformable and quenchable temperature, and quenching the heated portion immediately after heating. The According to this manufacturing method, even if the seat cross member 10 is formed of a thin metal pipe, it is possible to obtain high strength for the seat cross member 10. That is, the seat cross member 10 can be reduced in weight while ensuring high strength. Even when the weight is reduced by this manufacturing method, the seat cross member 10 has the above-described twisted structure, so that the rigidity in the vertical direction is enhanced.

  In addition, this inventor performed the CAE analysis for confirming the rigidity of the up-down direction of the sheet | seat cross member 10 which concerns on this embodiment using the metal pipe shown in FIG. 4, and obtained the result shown in FIG.

  This CAE analysis was performed on each metal tube of Comparative Example 1, Comparative Example 2, and Example 1. Each metal tube of Comparative Example 1 and Comparative Example 2 is bent so that the intermediate portion in the length direction is disposed above the both ends as shown in FIG. This is a horizontally long metal tube, and the metal tube of Example 1 is the same metal tube as the seat cross member 10 of this embodiment as shown in FIG. 4B. Further, in Comparative Example 1, the dimension of the long side direction of the cross-sectional shape was 50 mm, the dimension of the short side direction was 30 mm, and the plate thickness was 3.2 mm. In Comparative Example 2 and Example 1, the long side direction of the cross-sectional shape and About the short side direction, it was set as the same dimension as the comparative example 1, and plate | board thickness was 1.6 mm of the half of the comparative example 1. FIG.

  As shown in the analysis result of FIG. 5, in Comparative Example 2 in which the plate thickness is half that of Comparative Example 1, the vertical rigidity was reduced by about 41% compared to Comparative Example 1. On the other hand, in Example 1, although the plate thickness was the same as that of Comparative Example 2, the vertical rigidity was increased by about 7% compared to Comparative Example 1. From this, it has been confirmed that if the torsion structure according to the above embodiment is adopted for the seat cross member, it is possible to increase the rigidity in the vertical direction while reducing the weight by reducing the plate thickness.

  While the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the above-described embodiments.

  For example, in the above-described embodiment, the configuration in which the rising portion 14 is twisted so that the upper portion of the fixed portion 12 faces the front in the floating portion 16 is described. However, in the present invention, the upper portion of the fixed portion 12 is lifted. It is assumed that the rising portion 14 is twisted so as to face rearward in the portion 16. In this case as well, the resonance characteristics of the seat cross member 10 can be appropriately changed, and vibration transmission from the floor panel 60 to the seat 2 can be performed. Can contribute to restraint.

  In the above-described embodiment, the case where the dimension in the front-rear direction is larger than the dimension in the vertical direction in the fixed portion 12 and the dimension in the vertical direction is larger than the dimension in the front-rear direction in the lifted portion 16 has been described. The present invention includes a configuration in which the dimension in the vertical direction is larger than the dimension in the front-rear direction in the fixed portion 12 and the dimension in the front-rear direction is larger in the lifted portion 16 than in the vertical direction. In this case, the rigidity in the horizontal direction of the seat cross member can be increased, and in particular, in a vehicle that has a problem of suppressing vibration transmission in the horizontal direction, vibration transmitted from the floor panel 60 to the seat 2 can be effectively suppressed. it can.

  Further, in the above-described embodiment, the case where the spare tire 70 is stored in the storage recess 62 of the floor panel 60 has been described. However, in the present invention, the member stored in the storage recess 62 is limited to the spare tire 70. Not a thing.

  As described above, according to the present invention, it is possible to suppress the vibration transmitted from the floor panel to the seat through the seat cross member while reducing the weight of the seat cross member. It may be suitably used in the vehicle manufacturing industry.

2 Seat 4 Seat cushion 6 Seat back 10 Seat cross member 12 Seat cross member fixed portion 14 Seat cross member rising portion 16 Seat cross member raised portion 50 Seat belt anchor mounting member 60 Floor panel 62 For storing floor panel Recess 70 Spare tire 90 Seat belt anchor

Claims (7)

A tubular member that extends in the vehicle width direction below the seat cushion of the vehicle and has a flat cross-sectional shape over the entire length in the length direction, and both ends are fixed portions to the floor panel. And the structure of the seat cross member in which the intermediate part is a raised part located above the floor panel via the rising parts from the fixed parts on both sides,
The seat cross member structure, wherein the rising portion is twisted so that an upper portion of the fixed portion faces frontward or rearward in the floating portion.   The seat cross member structure according to claim 1, wherein a rear edge of the raised portion is positioned in front of a rear edge of the fixed portion.   3. The seat cross member structure according to claim 2, wherein the rising portion is twisted so that an upper portion of the fixed portion faces forward in the floating portion. The fixed part has a dimension in the front-rear direction larger than the dimension in the vertical direction,
The seat cross member structure according to any one of claims 1 to 3, wherein the lifted portion has a size in a vertical direction larger than a size in a front-rear direction.   5. The seat cross member structure according to claim 4, wherein the floating portion is disposed such that a longitudinal direction of the flat cross-sectional shape is perpendicular to the floor panel.   The lifted portion has a substantially horizontal lower surface to which a seat belt anchor mounting member is fixed, and the lower surface has a width equal to or greater than the width of the mounting member in the vehicle width direction. The seat cross member structure according to claim 5.   2. The rear edge of the rising part on both sides and the rear edge of the floating part are formed so as to correspond to the front edge part of the recess for storage formed in the floor panel in plan view. The seat cross member structure according to claim 6.

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