JP6094380B2 - Mounting structure for vehicle seat - Google Patents

Description

  The present invention relates to a mounting structure for a vehicle seat provided in a vehicle interior.

  2. Description of the Related Art Conventionally, there is a vehicle-shaped floor pan (also referred to as a floor panel) in which a tunnel-like backbone (also referred to as a tunnel portion or a floor tunnel) extending in the vehicle front-rear direction is formed at the center in the vehicle width direction. The backbone is a tunnel-like portion that extends in the vehicle front-rear direction by projecting the center of the floor pan in the vehicle width direction, and is disposed so as to pass between the driver seat and the passenger seat, for example. . By forming such a backbone, space for various devices (exhaust system devices, power transmission system devices, etc.) disposed in the lower part of the vehicle body is secured while lowering the cabin space.

  By the way, as one of seat layouts of a vehicle, there is one in which seats are arranged so as to form a pair on the left and right in the vehicle width direction with a backbone interposed therebetween. This layout is often used especially for front seats. The front seat has a pair of left and right slide rails extending in the front-rear direction in the lower part of the vehicle width, and the fixing points at the front and rear ends of the slide rail are fixed on a seat bracket provided on the floor pan side to the floor pan. It is attached.

  On the other hand, since the backbone is extended in the vehicle front-rear direction, there is an advantage that it is difficult to deform with respect to the input in the vehicle front-rear direction and structural strength is easily secured. Therefore, the seat bracket that supports the fixed portion of the front seat on the inner side in the vehicle width direction (the fixed portion of the slide rail on the inner side in the vehicle width direction) is attached to the backbone. That is, by attaching the seat bracket to the backbone having a relatively high rigidity, the rigidity at the attachment portion of the vehicle seat is increased, and the attachment stability of the seat is improved. As an example of such a structure, there is known a structure in which brackets are fixed to the left and right sides of the backbone, and the fixing portion of the seat is supported by the brackets (see, for example, Patent Document 1).

JP 2012-111363 A

However, even when the backbone is formed on the floor pan, sufficient deformation resistance cannot always be obtained with respect to the input in the vehicle width direction or the vertical direction. In some cases, the breakage cannot be sufficiently suppressed.
For example, at the time of a frontal collision of a vehicle, an occupant and a seat try to move toward the front of the vehicle due to inertia. At this time, the occupant's body is restrained by the seat belt, and the impact force in the forward direction of the vehicle is supported by the tension of the seat belt. On the other hand, in the case of a general three-point seat belt, the fulcrum of the belt is set above (adjuster) and below (retractor) the vehicle body outside the passenger compartment and below the seat (buckle) at the center of the passenger compartment. Therefore, the impact force at the time of a frontal collision acts so as to push up the seat toward the front outer side obliquely upward via the buckle of the seat belt.

That is, due to the impact force at the time of frontal collision, rotation in the pitch direction that rotates the seat in the forward tilt direction occurs, and at the same time, rotation in the roll direction that rotates the seat outward of the vehicle occurs. For example, the right seat in the vehicle width direction rotates in the right roll direction in the traveling direction, and the left seat tries to rotate in the left roll direction in the traveling direction. Since the forces in the pitch direction and the roll direction as described above are inputted in the vertical direction with respect to the attachment portion (fixed portion) of the sheet, there is a risk of causing deformation and breakage of the sheet attachment portion and its periphery.
It is also conceivable to suppress such deformation and breakage by increasing the thickness of the backbone and floor pan. In this case, however, the weight of the vehicle body and the cost are increased.

  One of the purposes of the present invention was devised in view of the above problems, and a vehicle seat mounting structure capable of suppressing breakage and deformation of the seat mounting portion and its periphery with a simple configuration. Is to provide. The present invention is not limited to this purpose, and is a function and effect derived from each configuration shown in the embodiments for carrying out the invention described later, and other effects of the present invention are to obtain a function and effect that cannot be obtained by conventional techniques. Can be positioned.

(1) A vehicle seat mounting structure disclosed herein includes a backbone formed in a tunnel shape extending in a vehicle longitudinal direction in a vehicle width direction center portion , and a floor surface portion formed outside the backbone in the vehicle width direction, And a seat bracket that is joined to the backbone on the upper surface side of the floor surface portion of the floor pan and supports a fixed portion on the vehicle compartment center side of the vehicle seat.
Further, a reinforcing member is provided on the lower surface side of the floor pan, which is joined to a position facing the seat bracket with the floor pan interposed therebetween, and reinforces a fixed portion on the vehicle compartment center side of the vehicle seat.
Further, a joint surface joined to the floor surface portion at an end portion on the vehicle width direction outer side of the reinforcing member is integrally coupled to the seat bracket with the floor surface portion sandwiched between the seat bracket and the seat bracket. The Moreover, the curved surface part which curves toward the direction away from the said floor pan is formed in the edge of the said joint surface .

(2) It is preferable that the joining surface of the reinforcing member and the seat bracket are integrally coupled with the floor surface portion sandwiched by welding of the joining surface, the floor surface portion, and the seat bracket.
(3) Moreover , it is preferable that the said curved surface part is formed in spherical shape .

(4) The reinforcing member includes a first closed cross section extending in the vehicle width direction so as to form a closed cross section with the floor pan, and a vehicle front-rear direction of the first closed cross section. It is preferable to have a first joint surface extending from the end side in the vehicle front-rear direction and joined to the lower surface of the floor pan. In this case, it is preferable that the curved surface portion is formed on an outer edge in the vehicle width direction of the first joint surface.
That is, it is preferable that the curved surface portion is formed outside the first closed cross-section portion (at a position avoiding a portion functioning as a cross member) in the reinforcing member.

(5) The seat bracket extends in the vehicle front-rear direction from a second closed cross-sectional portion that forms a closed cross-section with the floor pan, and an end of the second closed cross-sectional portion in the vehicle front-rear direction. It is preferable to have a second joining surface joined to the upper surface of the floor pan. In this case, it is preferable that the second joining surface is joined at a position facing the first joining surface of the reinforcing member with the floor pan interposed therebetween.
That is, it is preferable that the reinforcing member and the seat bracket are provided so that the first closed cross-section portion and the second closed cross-section portion face each other across the floor pan.

  (6) Further, the vehicle seat is provided on each of the right and left sides in the vehicle width direction with the backbone interposed therebetween, and the reinforcing member is fixed to the left side of the vehicle seat center side and the right side of the vehicle seat. It is preferable that the vehicle seat is disposed so as to be connected to a fixed portion on the center side of the passenger compartment. That is, the reinforcing member may be integrally formed on the left and right sides across the backbone. In this case, the seat bracket for supporting the left vehicle seat and the seat bracket for supporting the right vehicle seat may be integrated or separate.

  In addition, it is preferable that the said seat bracket is provided separately from the seat bracket (second seat bracket) that supports the fixed portion of the vehicle seat on the side of the passenger compartment. For example, a second seat bracket may be provided that is joined or fixed to a side sill on the upper surface side of the floor pan and supports a fixed portion on the vehicle compartment end side of the vehicle seat.

  According to the disclosed vehicle seat mounting structure, by providing a curved surface portion at the end of the reinforcing member, the seat mounting portion on the vehicle center side rear side of the vehicle seat and its periphery face upward in the vehicle width direction. Even if it is displaced, stress concentration due to contact (per edge) between the edge of the reinforcing member and the floor pan can be alleviated, and breakage of the floor pan can be suppressed.

1 is an exploded perspective view of a vehicle floor to which a vehicle seat mounting structure according to an embodiment is applied. (A) is a top view of the floor of FIG. 1, and (b) is a bottom view thereof. (A)-(c) is a perspective view of the 1st back side seat bracket of FIG. 1, a 2nd back side seat bracket, and a reinforcement member, (d), (e) is a perspective view of the reinforcement member as a modification. It is. 1A is a cross-sectional view of the floor of FIG. 1, FIG. 1B is a cross-sectional view of the periphery of the reinforcing member of FIG. 1 [A-A cross-sectional view of FIG. 3C], and FIG. It is sectional drawing [BB sectional drawing of FIG.3 (c)] of a part.

  A vehicle seat mounting structure applied to a vehicle will be described with reference to the drawings. Note that the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described in the following embodiment. Each configuration of the present embodiment can be implemented with various modifications without departing from the spirit of the present embodiment, and can be selected or combined as necessary.

[1. overall structure]
The vehicle seat mounting structure of the present embodiment is applied to the vehicle front seat 10 shown in FIG. For example, a pair of left and right rails for adjusting the seating position in the vehicle front-rear direction is provided at the lower portion of the front seat 10, and these rails are fixed on the floor pan 1 with fasteners. There are four fixing points per leg of the front seat 10 at the front and rear ends of the pair of rails. In the example shown in FIG. 1, the front and rear end portions of the rail extend downward, and the fastening surface of the fastener is provided substantially horizontally near the tip portion.

  Hereinafter, when describing the fixed part of the monopod front seat 10, the position in the vehicle front-rear direction is distinguished by the expression “front, rear”, and the position in the vehicle width direction is “center side, outside”. It distinguishes with the expression. Here, “center side” means the vehicle interior side direction (vehicle center direction) when viewed from the center of the front seat 10 in the vehicle width direction, and “outside” means the vehicle interior direction. (Direction close to the side of the vehicle). For example, the position of the right front fixing location in the left seat 10a is “center front”, and the right front fixing location in the right seat 10b is “outer front”.

  The floor pan 1 (front floor pan) is a plate-like member that forms a passenger compartment floor surface from the dash panel to the vicinity of the feet of the rear seat, and horizontally between a pair of side sills 7 arranged on the left and right sides of the vehicle body. It is provided to connect in the direction. As shown in FIG. 1, a backbone 6 (tunnel portion, floor tunnel) in which a tunnel-like protrusion having a substantially trapezoidal cross section is arranged in the vehicle front-rear direction as shown in FIG. ) Is formed. The backbone 6 extends in the longitudinal direction at the approximate center in the vehicle width direction on the surface of the floor pan 1 so as to bisect the floor surface on the driver's seat side and the floor surface on the passenger seat side. A space continuous in the vehicle front-rear direction is formed below the backbone 6. This space can be used as an arrangement space for an exhaust system device, a power transmission system device, and the like. On the other hand, the floor surface portion 1a located on the left and right of the backbone 6 in the vehicle width direction is a portion that is a foot of the occupant and is substantially planar.

  The backbone 6 of the present embodiment is provided with a backbone body 6a formed by bending the floor pan 1, and a backbone reinforcement 6b joined and fixed to the upper surface side by welding such as spot welding. The backbone reinforcement 6b is a reinforcing member formed separately from the floor pan 1, and slightly covers the backbone body 6a so as to cover a portion corresponding to the upper base of the trapezoid in the backbone body 6a. Are arranged in a state of being spaced apart from each other. The range covered by the backbone reinforcement 6b is set so as to include at least the range from the front end portion of the floor pan 1 to the position where the first rear side seat bracket 2 described later is disposed.

  A pair of front side members 8 extending in the vehicle front-rear direction from the front of the passenger compartment is attached to the lower surface side of the floor pan 1 as shown in FIG. The floor pan 1 is placed on the upper surfaces of the pair of front side members 8 and fixed thereto. The front side member 8 is a main structural member that forms the skeleton of the vehicle. For example, the front side member 8 is gently bent toward the outside in the vehicle width direction in front of the dashboard, and its front end is connected to the front bumper. The rear end of the front side member 8 is connected to a main structural member such as a rear side member (not shown). The front side members 8 of the present embodiment are arranged one by one between the backbone 6 and the left and right side sills 7, that is, below the floor surface on the driver seat side and the floor surface on the passenger seat side of the floor pan 1, respectively. .

  A pair of left and right front floor cross members 9 are fixed to the upper surface side of the floor pan 1 as shown in FIG. The front floor cross member 9 is a structural member that connects the backbone 6 and the left and right side sills 7 in the vehicle width direction. The left and right front floor cross members 9 are arranged in a straight line across the backbone 6. Further, on the upper surface of the end portion of the front floor cross member 9 on the outer side in the vehicle width direction (side sill side), an attachment portion 9a for fastening a fixed portion on the front side outside the front seat 10 is provided.

  A front side seat bracket 12 for fastening a fixing portion in front of the center side of the front seat 10 is provided in the vicinity of the connecting portion between the end of the front floor cross member 9 in the vehicle width direction and the backbone 6. The front seat bracket 12 is provided on the front floor cross member 9 adjacent to the backbone 6, and is joined to the surfaces of both the backbone 6 and the front floor cross member 9 by welding.

  As shown in FIGS. 1 and 2 (a), a rear side seat bracket for fastening a fixed portion on the rear side on the center side and on the outer side of the front seat 10 on the rear side of the vehicle with respect to the front floor cross member 9. Is provided. Here, the bracket corresponding to the fixing position on the rear side on the center side is referred to as a first rear seat bracket 2 (seat bracket), and the bracket corresponding to the fixing position on the outer rear side is referred to as the second rear side seat bracket 3 (second seat bracket). ). The first rear side seat bracket 2 and the second rear side seat bracket 3 are provided as separate members (separately).

  The first rear side seat bracket 2 is a bracket joined to the backbone 6 by welding on the upper surface side of the floor pan 1. On the other hand, the second rear side seat bracket 3 is a bracket joined to the side sill 7 by welding on the upper surface side of the floor pan 1. The first rear side seat bracket 2 and the second rear side seat bracket 3 are provided independently and spaced apart from each other. Accordingly, the first rear side seat bracket 2 is not joined to the side sill 7, and the second rear side seat bracket 3 is not joined to the backbone 6.

  Reinforcing members 4 (backbone cross members) are arranged side by side on the lower surface side of the floor pan 1 that is directly below the front seat bracket 12 and the first rear seat bracket 2. These reinforcing members 4 are members for reinforcing a fixed portion on the center side of the front seat 10 and have a shape bent into a trapezoidal shape corresponding to the back surface shape of the backbone 6 as shown in FIG. Further, these reinforcing members 4 together with the front seat bracket 12 and the first rear seat bracket 2 cross the backbone 6 so as to form a cylindrical closed cross-sectional structure extending in the vehicle width direction. Bonded to the back of the.

[2. Details of seat mounting structure]
[2-1. First rear seat bracket]
FIG. 3A is a perspective view illustrating the first rear seat bracket 2. The first rear side seat bracket 2 is a member assembled by bending or welding plate members, and includes a support surface 2a, a pair of first flange surfaces 2b, a pair of second flange surfaces 2c, and a pair of first vertical wall surfaces 2d. , Has a second vertical wall surface 2e.

The support surface 2 a is a part that supports the front seat 10 by making surface contact with a fixed portion on the rear side of the center side of the front seat 10. The surface of the support surface 2a is formed substantially horizontally. A weld nut 2f for fastening a fastener is provided at the center of the support surface 2a.
The first flange surface 2b (second joint surface) is a flange surface joined to the upper surface of the floor pan 1 outside the backbone 6 in the vehicle width direction, that is, the floor surface portion 1a. On the other hand, the second flange surface 2 c is a flange surface joined to the surface of the backbone 6 and joined to the inclined surface of the trapezoidal backbone 6. The first flange surface 2b and the second flange surface 2c are formed continuously in the vehicle width direction, and are respectively disposed on the front and rear sides of the vehicle with the support surface 2a sandwiched in the vehicle front-rear direction.

The first vertical wall surface 2d is a surface connecting the end of the support surface 2a in the vehicle front-rear direction and the first flange surface 2b and the second flange surface 2c, and is disposed substantially perpendicular to the support surface 2a. Further, the second vertical wall surface 2e is a surface that connects the outer edge of the support surface 2a to the outer side of the passenger compartment and the first flange surface 2b, and is disposed substantially perpendicular to the support surface 2a.
The support surface 2 a and the first vertical wall surface 2 d (second closed cross section) form a rectangular closed cross section with the floor pan 1. When the pair of first flange surfaces 2b are joined to the floor pan 1 and the pair of second flange surfaces 2c are joined to the backbone 6, as shown in FIG. A box-shaped space is formed between the pan 1 and the weld nut 2f is accommodated in this space.

[2-2. Second rear seat bracket]
FIG. 3B is a perspective view illustrating the second rear side seat bracket 3. Similarly to the first rear side seat bracket 2, the second rear side seat bracket 3 is a member assembled by bending or welding a plate material, and includes a support surface 3a, a pair of first flange surfaces 3b, and a pair of second members. It has a flange surface 3c, a pair of first vertical wall surfaces 3d, and an inclined surface 3e.

  The support surface 3 a is a portion that supports the front seat 10 by making surface contact with a fixed portion on the outer rear side of the front seat 10. The surface of the support surface 3a is formed substantially horizontally. A weld nut 3f for fastening a fastener is provided at the center of the support surface 3a. The mounting height of the support surface 3a is substantially the same as the mounting height of the support surface 2a of the first rear seat bracket 2.

  The functions and structures of the pair of first flange surfaces 3b, the pair of second flange surfaces 3c, and the pair of first vertical wall surfaces 3d are the same as the pair of first flange surfaces 2b and the pair of first flange surfaces 2b of the first rear seat bracket 2. It is substantially the same as each of the two flange surfaces 2c and the pair of first vertical wall surfaces 2d. However, since the second rear side seat bracket 3 is a member joined to the side sill 7, the pair of second flange surfaces 3 c are joined to the side surface on the vehicle compartment center side where the surface gradient of the side sill 7 is substantially vertical. .

The inclined surface 3 e is a surface that connects the end of the support surface 3 a on the center side of the passenger compartment and the first flange surface 3 b, and is inclined gently from the support surface 3 a toward the surface of the floor pan 1. Therefore, the second rear side seat bracket 3 has a slightly elongated shape in the vehicle width direction, as shown in FIGS.
As shown in FIG. 4A, the dimension of the second rear side seat bracket 3 in the vehicle width direction is the edge of the inclined surface 3 e on the vehicle center side when the second flange surface 3 c is joined to the side sill 7. Is set to be located immediately above the front side member 8. Thereby, the load in the vehicle width direction acting on the second rear side seat bracket 3 is easily transmitted to the front side member 8, and the mounting strength of the front seat 10 is improved.

  In FIG. 4A, the side sill 7 has a side sill inner 7a and a pillar inner 7b having a closed cross-sectional structure, and the side sill reinforcement 7c further forms a closed cross-sectional structure on the outside of the vehicle. The specific structure is not limited to this. 4A is a side panel, 11a is a side panel outer, and 11b is a pillar reinforcement, but the structure on the outer plate side is not limited to this.

[2-3. Reinforcing member]
FIG. 3C is a perspective view illustrating the reinforcing member 4. The reinforcing member 4 includes a cross member surface 4a provided at a distance in the vertical direction with respect to the lower surface of the backbone 6, a flange surface 4b (first bonding surface) bonded to the lower surface of the backbone 6, and these cross members. A vertical wall surface 4c that connects the surface 4a and the flange surface 4b in the vertical direction. The cross member surface 4 a and the vertical wall surface 4 c (first closed cross section) are extended in the vehicle width direction so as to form a rectangular closed cross section with the floor pan 1. The flange surface 4b is a planar portion extending from the end side of the vertical wall surface 4c in the vehicle front-rear direction.

Flange surface 4b of the reinforcing member 4 is disposed so as provided as non-write sandwiched floor pan 1 together with the first rear seat first flange surface 2b of the bracket 2, and traversing the backbone 6 in the vehicle width direction Is done. Therefore, the first rear side seat brackets 2 provided on the left and right sides of the backbone 6 are connected to each other by the reinforcing member 4 on the lower surface side of the floor pan 1.

  The spacing dimension between the pair of vertical wall surfaces 4 c in the reinforcing member 4 is set to be approximately the same value as the spacing dimension between the pair of first vertical wall surfaces 2 d in the first rear seat bracket 2. As a result, as shown in FIG. 4B, a closed cross-sectional structure surrounded by the floor pan 1, the cross member surface 4a, and the vertical wall surface 4c is formed at the place where the reinforcing member 4 is disposed, and the floor A closed cross-sectional structure surrounded by the pan 1, the support surface 2a, and the first vertical wall surface 2d is connected to the upper portion thereof. The reinforcing member 4 functions as a cross member that connects the left and right first rear side seat mounting brackets 2 and reinforces the backbone 6 in the vehicle width direction, and also has a fixing portion at the rear side of the center side of the front seat 10 and its periphery. Functions to reinforce.

  In addition, the width dimension (dimension in the vehicle front-rear direction) of the flange surface 4 b in the reinforcing member 4 is set to be substantially the same as the width dimension of the first flange surface 2 b in the first rear seat bracket 2. That is, as shown in FIG. 4B, the pair of flange surfaces 4b are formed in a size, position, and shape corresponding to the pair of first flange surfaces 2b, and are arranged so as to face each other with the floor pan 1 interposed therebetween. The Thereby, the 1st back side seat bracket 2 and the reinforcement member 4 form one closed cross-section structure, and exhibit the rigidity and intensity | strength irrespective of the plate | board thickness of the floor pan 1. FIG.

  Further, the flange surface 4b of the reinforcing member 4 is joined to the first flange surface 2b of the first rear side seat bracket 2 by welding with the floor pan 1 interposed therebetween. That is, the three panels of the flange surface 4b, the floor pan 1, and the first flange surface 2b are integrally joined by spot welding at the joint (welding point). Thereby, the reinforcement member 4 and the 1st back side seat bracket 2 are connected more firmly, and the intensity | strength with respect to the input to a peeling direction (upper side) can be ensured.

  Further, at both ends of the flange surface 4b on the outer side in the vehicle width direction, as shown in FIG. 3C, curved surface portions 5 formed so as to bend away from the floor pan 1 are provided. In the present embodiment, the curved surface portion 5 is curved downward. The surface shape of the curved surface portion 5 is arbitrary, but is preferably a cylindrical surface shape, more preferably a spherical surface shape. In this case, only the end of the cylindrical surface may be spherical, or the entire shape may be spherical. In any case, the flange surface 4b of the reinforcing member 4 attached to the floor pan 1 is separated from the surface of the floor pan 1 toward the end in the vehicle width direction as shown in FIG. Curve towards.

  The boundary between the flange surface 4b and the curved surface portion 5 is set outside the vehicle compartment from the outermost joint portion (welding point) X where the flange surface 4b is joined to the floor pan 1. Thereby, the floor pan 1 is deformed so as to follow the curved surface portion 5 when the first flange surface 2b is displaced upward, and the end side of the curved surface portion 5, that is, the outer end in the vehicle width direction of the flange surface 4b of the reinforcing member 4 is deformed. Since it becomes difficult for the edge part of an edge to contact the floor pan 1, the stress concentration in the edge vicinity of the flange surface 4b is suppressed more reliably.

[3. Action, effect]
(1) In the vehicle seat mounting structure described above, the curved surface portion 5 is provided at the outer end of the reinforcing member 4 in the vehicle width direction. As a result, even if an upward force is applied to the fixed position on the rear side of the center side of the front seat 10, the edge of the outer end in the vehicle width direction of the reinforcing member 4 (flange surface 4b) is applied to the lower surface of the floor pan 1. There is no stress concentration in contact. Therefore, breakage of the floor pan 1 can be suppressed.

Further, in the vehicle seat mounting structure, out of the four fixing points of the front seat 10, the outer front fixing point is fastened to the mounting portion 9a of the front floor cross member 9, and the central front fixing point is the front seat. Fastened to the bracket 12. Since these fixing points are located on the front floor cross member 9, good mounting strength can be expected.
On the other hand, the center rear fixed portion is fastened to the support surface 2 a of the first rear seat bracket 2, and the outer rear fixed portion is fastened to the support surface 3 a of the second rear seat bracket 3. Since the first rear side seat bracket 2 and the second rear side seat bracket 3 are provided separately, it is easy to set the strength and rigidity of each fixing point according to the difference in characteristics between the center side and the outer side. It is.

For example, an upward force is more likely to act on the fixing portion on the rear side of the center side of the front seat 10 than on the fixing portion on the outer rear side. Accordingly, it is possible to set the plate thickness of the first rear side seat bracket 2 to be larger than the plate thickness of the second rear side seat bracket 3 to improve the mounting strength of the fixed portion on the center side. In other words, the plate thickness of the second rear side seat bracket 3 can be made smaller than the plate thickness of the first rear side seat bracket 2, and the weight reduction and the material cost can be reduced.
In addition, in the above embodiment, the reinforcing member 4 is provided below the first rear side seat bracket 2 to reinforce the fixed portion on the rear side of the center side. Even when the rotational force acts, the mounting state of the front seat 10 can be maintained.

  (2) In the mounting structure described above, the surface shape of the curved surface portion 5 is formed in a spherical shape. Thereby, irrespective of the amount of deformation of the floor pan 1 in the upward direction, it is possible to easily maintain the surface contact (the surface contact state) between the floor pan 1 and the curved surface portion 5, and the edge contact (pointing) It is possible to more reliably avoid the contacted portion). Further, as the deformation amount of the floor pan 1 increases, the contact area between the curved surface portion 5 and the floor pan 1 can be gradually increased. Thereby, the stress which floor pan 1 bears can be reduced.

  (3) As shown in FIG. 4 (c), the flange surface 4b located at the outer end in the vehicle width direction of the reinforcing member 4 is the first rear side across the floor pan 1 at the joint (welding point) X. The seat bracket 2 is integrally coupled to the first flange surface 2b. Thereby, even if it is a case where the joining of the 1st back side seat bracket 2 is strengthened and the upward load is inputted into the fixed part of the center side back, the reinforcement member 4 side from the 1st back side seat bracket 2 Since the load can be reliably transmitted, the deformation of the floor pan 1 can be suppressed.

  (4) In the mounting structure described above, the first closed cross-section portion (cross member surface 4a and vertical wall surface 4c) of the closed cross-section structure that functions as a cross member is formed on the reinforcing member 4, so that the center of the left and right front seats 10 is It is possible to improve the rigidity and strength of the floor pan 1 and the backbone 6 at the portion sandwiched between the fixed portions on the rear side. On the other hand, the curved surface portion 5 is formed at the outer end in the vehicle width direction of the flange surface 4b outside the cross member portion, and therefore does not hinder the reinforcing function of the cross member portion. Therefore, deformation and breakage of the floor pan 1 with respect to an upward load can be suppressed while increasing the rigidity and strength of the floor pan 1 and the backbone 6.

  (5) In the mounting structure described above, the interval between the first vertical wall surfaces 2 d of the first rear side seat bracket 2 is formed to be approximately the same as the interval between the vertical wall surfaces 4 c of the reinforcing member 4. That is, as shown in FIG. 4B, the first flange surface 2b of the first rear seat bracket 2 and the flange surface 4b of the reinforcing member 4 are arranged so as to face each other with the floor pan 1 interposed therebetween. Thereby, the closed cross-section structure formed by the 1st back side seat bracket 2 and the floor pan 1 and the closed cross-section structure formed by the reinforcing member 4 and the floor pan 1 are connected up and down. In other words, the fixed portion at the center rear side of the front seat 10 is reinforced by the closed cross-sectional structure formed by the first rear side seat bracket 2 and the reinforcing member 4. Therefore, regardless of the thickness of the floor pan 1, the attachment strength at the fixed location at the center rear side can be further increased.

  (6) In the above mounting structure, as shown in FIG. 1, the reinforcing member 4 connects the first rear side seat bracket 2. Thereby, the reinforcing member 4 reinforces the left and right first rear seat brackets 2 arranged on the left and right sides in the vehicle width direction across the backbone 6 by connecting them on the back side of the floor pan 1. In other words, the reinforcing member 4 extends across the backbone 6 in the vehicle width direction, and the right side (driver's seat side) front seat 10 is fixed at the center of the passenger compartment and the left side (passenger seat side) front seat 10. Is connected to the fixed part on the center side of the car. For this reason, the load which acts on the front seat 10 can be distributed in the vehicle width direction and can be equally borne. Thereby, the upward force which can act on the fixed location of the front seat 10 can be reduced, and deformation and breakage of the floor pan 1 can be efficiently suppressed.

[4. Modified example]
In the above vehicle seat mounting structure, as shown in FIG. 3C, the reinforcing member 4 having a structure that forms a closed cross section with the floor pan 1 is illustrated. The shape is not limited to this. For example, as shown in FIG. 3D, a reinforcing member 14 that does not form a closed cross section with the floor pan 1 may be used. Alternatively, as shown in FIG. 3 (e), the reinforcing member 15 that reinforces the fixed portion at the center side rear of the left seat 10a and the reinforcing member 16 that reinforces the fixed portion at the center side rear of the right seat 10b are separated. You may form in. By reinforcing at least the lower part of the first rear side seat bracket 2 with the reinforcing members 14, 15, and 16 in which the curved surface part 5 is formed at the end portion on the outer side in the vehicle width direction, the same operations and effects as in the above-described embodiment. Can be earned.

Further, in the above-described embodiment, the first rear side seat bracket 2 that supports the center rear fixed portion of the front seat 10 is provided separately on the left and right sides of the backbone 6. You may arrange | position integrally.
Furthermore, in the above-mentioned embodiment, the separate 1st back side seat bracket 2 and 2nd back side seat bracket 3 which fix the fixing location of the center side back of the front seat 10, and the fixing location of the outer back each were illustrated. However, the central rear side and the outer rear side may be fixed to the first rear side seat bracket 2. In that case, the vehicle width direction outer side of the first rear side seat bracket 2 may be joined to the side sill 7.

1 Floor pan 2 First rear seat bracket (seat bracket)
2a Support surface (part of the second closed section)
2b First flange surface (second joint surface)
2c 2nd flange surface 2d 1st vertical wall surface (a part of 2nd closed cross-section part)
2e Second vertical wall 3 Second rear seat bracket (second seat bracket)
4 Reinforcing member 4a Cross member surface (part of the first closed section)
4b Flange surface (first joint surface)
4c Vertical wall (part of the first closed section)
5 Curved part 6 Backbone 10 Front seat X Joint (welding point)

Claims (6)

A floor pan having a backbone formed in a tunnel shape extending in the vehicle longitudinal direction in the vehicle width direction center portion , and a floor surface portion formed on the vehicle width direction outer side of the backbone ;
A seat bracket that is joined to the backbone on the upper surface side of the floor surface portion in the floor pan, and supports a fixed portion on the vehicle compartment center side of the vehicle seat,
A reinforcing member that is joined to a position facing the seat bracket across the floor pan on the lower surface side of the floor pan, and that reinforces a fixed portion on the vehicle compartment center side of the vehicle seat. Mounting structure,
The joint surface joined to the floor surface portion at the end of the reinforcing member in the vehicle width direction outside is integrally coupled to the seat bracket with the floor surface portion sandwiched between the seat bracket,
A mounting structure for a vehicle seat, wherein a curved portion that curves in a direction away from the floor pan is formed at an edge of the joint surface .   The joint surface of the reinforcing member and the seat bracket are integrally coupled with the floor surface portion sandwiched by welding of the joint surface, the floor surface portion, and the seat bracket.
The vehicle seat mounting structure according to claim 1, wherein: The curved surface portion, characterized in that formed by spherically formed, according to claim 1 or 2 mounting structure of a vehicle seat according. The reinforcing member is
A first closed section extending in the vehicle width direction so as to form a closed section with the floor pan;
A first joint surface that extends in the vehicle front-rear direction from the end of the first closed cross-sectional portion in the vehicle front-rear direction and is joined to the lower surface of the floor pan;
The vehicle seat mounting structure according to any one of claims 1 to 3, wherein the curved surface portion is formed at an outer edge in the vehicle width direction of the first joint surface. The seat bracket is
A second closed cross section forming a closed cross section with the floor pan;
A second joint surface that extends in the vehicle front-rear direction from the end of the second closed cross-sectional portion in the vehicle front-rear direction and is joined to the upper surface of the floor pan;
The vehicle seat mounting structure according to claim 4, wherein the second joint surface is joined to a position facing the first joint surface of the reinforcing member with the floor pan interposed therebetween. The vehicle seat is provided on each of the right and left sides in the vehicle width direction across the backbone,
The reinforcing member is disposed by connecting a fixed portion of the left side of the vehicle seat on the center side of the vehicle compartment and a fixed portion of the right side of the vehicle seat on the center side of the vehicle compartment. The vehicle seat mounting structure according to any one of 1 to 5.

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