JP7802263B2 - Vehicle seat fixing structure - Google Patents

Description

The present invention relates to a fixing structure for a vehicle seat.

In vehicles such as automobiles, vehicle seats for occupants are fixed inside the cabin (see Patent Document 1). In the vehicle described in Patent Document 1, the sides of the vehicle seats are fixed to framework members that form part of the side walls of the cabin.

To securely secure a vehicle seat, it is preferable to secure the vehicle seat directly to the vehicle's frame. However, due to space limitations within the cabin, it may be necessary to offset the fixing portion of the vehicle seat below the frame. In this case, as shown in FIG. 9, it is possible to fix the vehicle seat (hereinafter referred to as "seat 811") to the cabin's side wall 813. As shown in FIG. 9, the vehicle 810 has a cabin-side bracket 820 and a seat-side bracket 840. The cabin-side bracket 820 and the seat-side bracket 840 extend in the vertical direction of the vehicle. The cabin-side bracket 820 has a first fixing portion 821 that is fixed to the side wall 813 of the cabin 812 (in this example, the frame), and a first fastening hole (not shown) below the first fixing portion 821 that is used to fasten the seat-side bracket 840. The seat-side bracket 840 has a second fixing portion 841 that is fixed to the side of the seat 811 (in this example, the seat frame 815), and a second fastening hole (not shown) that is used to fasten the seat-side bracket 840 to the cabin-side bracket 820 below the second fixing portion 841. In this vehicle 810, a male screw member 851 is inserted through the first fastening hole and the second fastening hole, and a female screw member 852 is screwed into the male screw member 851. This fastens the cabin-side bracket 820 and the seat-side bracket 840 together.

Patent No. 3247064

By adopting the above-described fixing structure, it is possible to fix the side of the seat 811 to the side wall 813 of the cabin 812, even when the space inside the cabin 812 is limited.

However, in the above-described fixing structure, the first fixing portion 821 on the cabin-side bracket 820 is spaced apart from the first fastening hole for fastening. Also, the second fixing portion 841 on the seat-side bracket 840 is spaced apart from the second fastening hole for fastening. Therefore, when force is applied to the seat 811 during a vehicle 810 collision, the brackets 820 and 840 are likely to deform.

In this case, as shown by arrow D in Figure 9, the first fixing portion 821 of the cabin-side bracket 820 and the second fixing portion 841 of the seat-side bracket 840 may move apart, potentially causing the brackets 820, 840 to deform. In this case, the seat 811 fixed to the seat-side bracket 840 may be displaced, collapsing inward into the cabin 812. It is desirable for the vehicle 810 to minimize displacement of the seat 811 during such a collision.

Various aspects of the device for solving the above problems will be described.
[Aspect 1] A fixing structure for a vehicle seat in which a side portion of a vehicle seat is fixed to a side wall of a cabin of a vehicle, the fixing structure comprising: a cabin-side bracket having a shape extending in the vertical direction of the vehicle and having a first fixing portion fixed to the side wall and a first fastening hole for fastening provided below the first fixing portion; a seat-side bracket having a shape extending in the vertical direction of the vehicle and having a second fixing portion fixed to the side portion and a second fastening hole for fastening provided below the second fixing portion; and a rod-shaped bracket passing through the first fastening hole and the second fastening hole. A fixing structure for a vehicle seat, comprising: a fastening fixing member having a rod-shaped portion extending in the vehicle width direction and a fastening portion provided on the rod-shaped portion in a manner that sandwiches the cabin side bracket and the seat side bracket; and a deformation control member that forms part of the side wall, located at a position above the vehicle on the side wall side of the rod-shaped portion relative to the second fastening hole, and that is positioned so that it will be pressed by the portion of the rod-shaped portion when the deformation mode during a collision of the vehicle is a deformation mode in which the end of the rod-shaped portion on the side wall side moves toward the vehicle above.

In the above configuration, if the end of the rod-shaped portion moves upward in the vehicle as the fastening member displaces during a vehicle collision, once the end has moved a certain amount, the deformation-restricting member is pressed directly or indirectly by the portion of the rod-shaped portion closest to the side wall (hereinafter referred to as the wall-side portion). According to the above configuration, the deformation-restricting member can support the rod-shaped portion in a manner that resists the pressure from the rod-shaped portion. This prevents further displacement of the rod-shaped portion of the fastening member, thereby preventing displacement of the seat-side bracket on which the fastening member is mounted and the vehicle seat. According to the above configuration, displacement of the vehicle seat during a vehicle collision can be reduced in this way.

[Aspect 2] The vehicle seat fixing structure according to aspect 1, wherein a protrusion that protrudes downward from the lower end of the deformation restricting member is provided.
According to the above configuration, the protrusion can fill a part of the gap between the wall portion of the rod-shaped portion of the fastening member and the lower end of the deformation-restricting member. Therefore, when the fastening member is displaced during a vehicle collision, the fastening member can be supported by the deformation-restricting member early, at a timing when the amount of displacement is small. Therefore, displacement of the vehicle seat during a vehicle collision can be kept small.

[Aspect 3] The fixing structure for a vehicle seat according to [Aspect 1] or [Aspect 2], wherein the deformation restricting member is a reinforcing member that reinforces the side wall.
According to the above configuration, displacement of the fastening member can be suppressed by utilizing the reinforcing member provided in the side wall of the cabin without adding a new member.

This invention makes it possible to reduce displacement of a vehicle seat during a vehicle collision.

1 is a front cross-sectional view showing a fixing structure for a vehicle seat according to an embodiment of the present invention; FIG. 10 is a side view of the seat rail, the cabin-side bracket, and the plate according to the fixing structure. FIG. FIG. 4 is a side cross-sectional view of a seat rail and a protrusion in the fixing structure. FIG. 10A and 10B are diagrams illustrating the operation of the fixing structure. FIG. 10 is a front cross-sectional view showing a fixing structure for a vehicle seat according to another embodiment. FIG. 10 is a front cross-sectional view showing a fixing structure for a vehicle seat according to another embodiment. 1 is a schematic diagram showing an example of a conventional fixing structure for a vehicle seat.

Hereinafter, a vehicle seat fixing structure according to one embodiment will be described with reference to FIGS.
<Vehicles>
As shown in FIG. 1 , a vehicle seat (hereinafter referred to as seat 11) of this embodiment is provided in a cabin 12 of a vehicle 10. In this embodiment, the vehicle 10 is a bus. The seat 11 is a passenger seat of the vehicle 10. The seat 11 is located on the right side of the vehicle inside the cabin 12. The seat 11 is located near a side wall of the cabin 12 (hereinafter referred to as cabin side wall 13).

The seat 11 is fixed to the interior wall of the cabin 12 at four locations: two on the cabin sidewall 13 side (right side of the vehicle) and two on the side furthest from the cabin sidewall 13 (left side of the vehicle). Specifically, on the right side of the seat 11, the side 14 of the seat 11 is fixed to the cabin sidewall 13 at two locations spaced apart in the fore-and-aft direction of the vehicle. On the left side of the seat 11, the lower part of the seat 11 is fixed to the bottom wall of the cabin 12, i.e., the floor of the vehicle 10, at two locations spaced apart in the fore-and-aft direction of the vehicle. Note that Figures 1 to 6 only show one of the four fixed locations, specifically the front-most of the two fixed locations on the right side of the seat 11.

In the vehicle 10 of this embodiment, a small window (not shown) is provided in the cabin side wall 13 in the area corresponding to the feet of the seat 11. In the vehicle 10, the space available for affixing the seat 11 is limited by the space required for arranging the small window. In the vehicle 10 of this embodiment, the side portion 14 of the seat 11 is affixed to the cabin side wall 13 in a situation where the space inside the cabin 12 is limited.

The fixing structure of the seat 11 will be described in detail below.
As shown in FIGS. 1 to 4, the vehicle 10 has, as members used to fasten the seat 11, a cabin-side bracket 20, a plate 30, a seat-side bracket 40, and a fastening member 50.

<Cabin side bracket>
The cabin side bracket 20 is made of a steel plate. The cabin side bracket 20 extends in the vertical direction of the vehicle. The cabin side bracket 20 has a hat-shaped cross section that opens on the right side of the vehicle (the left side in FIG. 2 ). The cabin side bracket 20 has a first fixing portion 21. The first fixing portion 21 is shaped to protrude upward from the upper end of the cabin side bracket 20 toward the vehicle. The first fixing portion 21 has a triangular plate shape that extends in the vertical direction and the longitudinal direction of the vehicle. The first fixing portion 21 is welded (fixed) to the cabin side wall 13. This fixes the upper part of the cabin side bracket 20 to the cabin side wall 13.

The cabin sidewall 13 has a panel portion 131 and a seat rail 132. The panel portion 131 and the seat rail 132 are made of steel plate. The panel portion 131 has a shape that extends in the vertical direction of the vehicle and in the longitudinal direction of the vehicle. The seat rail 132 extends in the longitudinal direction of the vehicle. The seat rail 132 has a hat-shaped cross section that opens on the right side of the vehicle (left side in Figure 2). The seat rail 132 is welded (fixed) to the portion of the panel portion 131 on the cabin 12 side so as to cover the opening on the right side of the vehicle. In this embodiment, the seat rail 132 corresponds to a reinforcing member that reinforces the cabin sidewall 13.

The first fixing portion 21 of the cabin side bracket 20 is fixed to the portion of the seat rail 132 facing inward toward the cabin 12. The lower portion of the cabin side bracket 20 is welded (fixed) to the portion of the cabin side wall 13 facing inward toward the cabin 12. In this manner, in this embodiment, the upper and lower portions of the cabin side bracket 20 are fixed to the cabin side wall 13.

The cabin-side bracket 20 has a first fastening hole 22 (Figure 2). The first fastening hole 22 is a through-hole that passes through the cabin-side bracket 20 in the vehicle width direction. The first fastening hole 22 is located at a position lower than the first fixing portion 21. The first fastening hole 22 is located at a position lower than the seat rail 132. The first fastening hole 22 is used to fasten the cabin-side bracket 20 and the seat-side bracket 40 together.

<Plate 30>
The plate 30 is made of a steel plate and extends in the vehicle up-down direction and the vehicle front-rear direction. The plate 30 is provided in a manner that covers the first fixing portion 21 of the cabin-side bracket 20 and its surrounding area from the inside of the cabin 12 (the right side in FIG. 2 ). The plate 30 is welded (fixed) to each of the cabin-side bracket 20 and the seat rail 132.

The plate 30 has fastening holes 31 (Figure 2). The fastening holes 31 are located at positions corresponding to the first fastening holes 22 of the cabin-side bracket 20. When the plate 30 is fixed to the cabin-side bracket 20, the fastening holes 31 of the plate 30 and the first fastening holes 22 of the cabin-side bracket 20 are in communication. The fastening holes 31 are used to fasten the cabin-side bracket 20 to the seat-side bracket 40.

<Seat side bracket>
The seat-side bracket 40 is made of a metal plate. The seat-side bracket 40 extends in the vertical direction of the vehicle. The seat-side bracket 40 has a U-shaped cross section that opens on the left side of the vehicle (the right side in FIG. 2 ). The portion of the seat-side bracket 40 on the upper side of the vehicle constitutes a second fixing portion 41. The second fixing portion 41 of the seat-side bracket 40 is the portion that is fixed to the side portion 14 of the seat 11.

The seat 11 has a seat frame 15 that forms its skeleton. The seat frame 15 has a pipe portion 151. The pipe portion 151 is arranged inside the seat bottom 111 of the seat 11. The pipe portion 151 extends in the vehicle width direction at the front end portion of the seat bottom 111. The right end of the pipe portion 151 is fixed integrally to the second fixing portion 41 of the seat side bracket 40. In this embodiment, the upper portion of the seat side bracket 40 is fixed to the side portion 14 of the seat 11 in this manner.

The seat-side bracket 40 has a second fastening hole 42 (Figure 2). The second fastening hole 42 is a through-hole that passes through the seat-side bracket 40 in the vehicle width direction. The second fastening hole 42 is located at a position lower than the second fixing portion 41. The second fastening hole 42 is located at a position lower than the pipe portion 151 of the seat frame 15. The second fastening hole 42 is used to fasten the seat-side bracket 40 to the cabin-side bracket 20.

<Fastening and fixing member>
As shown in FIGS. 1, 2 and 4, the fastening member 50 has a rod-shaped portion 51 and a fastening portion 52.

The rod-shaped portion 51 is rod-shaped and extends in the vehicle width direction. A male thread is formed on the outer surface of the rod-shaped portion 51. The rod-shaped portion 51 is arranged so as to pass through the first fastening hole 22 of the cabin-side bracket 20, the fastening hole 31 of the plate 30, and the second fastening hole 42 of the seat-side bracket 40. In this embodiment, a spacer 32 is provided between the cabin-side bracket 20 and the seat-side bracket 40. This spacer 32 is cylindrical. The rod-shaped portion 51 is arranged so as to pass through the center hole of this spacer 32.

The fastening portion 52 is composed of a pair of female threaded members 521, 522. The female threaded members 521, 522 are screwed into the rod-shaped portion 51 in a manner that sandwiches the cabin-side bracket 20, the plate 30, and the seat-side bracket 40.

As shown in FIG. 2, in the vehicle 10, the rod-shaped portion 51 is inserted through the first fastening hole 22 of the cabin-side bracket 20, the fastening hole 31 of the plate 30, the center hole of the spacer 32, and the second fastening hole 42 of the seat-side bracket 40. In this state, the rod-shaped portion 51, the female threaded member 521 at one end (left side in FIG. 2) of the rod-shaped portion 51, and the female threaded member 522 at the other end (right side in FIG. 2) of the rod-shaped portion 51 are tightened. In this embodiment, the cabin-side bracket 20 and the seat-side bracket 40 are fastened together by the fastening member 50.

In this embodiment, in order to reduce displacement of the seat 11 during a vehicle 10 collision, the positional relationship between the rod-shaped portion 51 of the fastening member 50 and the seat rail 132 is determined as follows:

The rod-shaped portion 51 of the fastening member 50 extends in the vehicle width direction. The portion of the rod-shaped portion 51 closer to the cabin sidewall 13 than the second fastening hole 42 of the cabin-side bracket 20 (hereinafter referred to as the wall-side portion 51W) extends to the vicinity of the panel portion 131 that forms part of the cabin sidewall 13. More specifically, the wall-side portion 51W of the rod-shaped portion 51 extends to the vicinity of the fixed portion between the panel portion 131 and the seat rail 132. The seat rail 132 is positioned above the vehicle from the wall-side portion 51W of the rod-shaped portion 51. The seat rail 132 and the end portion 511 of the rod-shaped portion 51 are spaced apart in the vertical direction of the vehicle.

Among the deformation modes that occur during a collision of the vehicle 10, a deformation mode in which the end 511 of the rod-shaped portion 51 on the cabin side wall 13 side moves toward the upper side of the vehicle is referred to as a "specific deformation mode." In the specific deformation mode, the seat rail 132 is positioned so that the wall-side portion 51W (in this embodiment, the end 511) of the rod-shaped portion 51 presses against the lower portion of the seat rail 132.

In this embodiment, the positional relationship between the rod-shaped portion 51 of the fastening member 50 and the seat rail 132 is determined so as to appropriately suppress displacement of the rod-shaped portion 51, and therefore displacement of the seat 11, during a collision of the vehicle 10. This positional relationship was determined in advance based on the results of various experiments and simulations conducted by the inventors and others. Note that in this embodiment, the seat rail 132 corresponds to the deformation-suppressing member.

<Convex part>
As shown in Figures 1, 4 and 5, the seat rail 132 is provided with a protrusion 60. The protrusion 60 is shaped to protrude from the lower end of the seat rail 132 toward the vehicle downwards. The protrusion 60 is shaped like a staircase, with a large protrusion amount at the center in the vehicle longitudinal direction and relatively small protrusion amounts at the front and rear in the vehicle longitudinal direction. The protrusion 60 is provided at a position on the seat rail 132 that corresponds to the vehicle upper side of the rod-shaped portion 51.

The protrusion 60 has a structure in which two steel plates are overlapped. More specifically, a reinforcing portion 61 is fixed to the inner portion of the hat-shaped cross section of the seat rail 132 where the protrusion 60 is provided. The reinforcing portion 61 is made of steel plate. The reinforcing portion 61 has a U-shaped cross section and extends in the fore-and-aft direction of the vehicle. The reinforcing portion 61 has a protrusion that corresponds to the shape of the protrusion 60. The reinforcing portion 61 is welded (fixed) to the inside of the seat rail 132 in such a way that the portion of the seat rail 132 where the protrusion 60 is provided and its surrounding area have a structure in which two steel plates are overlapped. In this embodiment, the protrusion 60 is reinforced by providing this reinforcing portion 61.

<Effect>
The function of the fixing structure of this embodiment will be described.
As shown in Figure 6, in the event of a collision of the vehicle 10, a force (a force indicated by arrow A in Figure 6) may act to push the front of the seat 11 downward toward the vehicle. In this case, as indicated by arrow B in Figure 6, the seat-side bracket 40 together with the seat 11 will be displaced in a manner that causes them to fall inward toward the cabin 12, with the portion fixed by the fastening member 50 as a fulcrum. Then, when the seat-side bracket 40 is displaced in this manner, as indicated by arrow C in Figure 6, the end 511 of the rod-shaped portion 51 of the fastening member 50 will be displaced in a manner that causes them to move upward toward the vehicle, with the portion fixed by the fastening member 50 as a fulcrum.

In this embodiment, when the end 511 of the rod-shaped portion 51 moves upward toward the vehicle to a certain extent, the end 511 abuts against the underside of the seat rail 132, more specifically, the underside of the protrusion 60 provided on the seat rail 132. At this time, the end 511 of the rod-shaped portion 51 presses against the protrusion 60 and the lower portion of the seat rail 132.

In this embodiment, the seat rail 132 can support the rod-shaped portion 51 in a manner that resists pressure from the end 511 of the rod-shaped portion 51. In this embodiment, the protrusion 60 is reinforced by the reinforcing portion 61, so the rod-shaped portion 51 of the fastening member 50 can be firmly supported by the protrusion 60.

In this way, the rod-shaped portion 51 of the fastening member 50 is supported by the protrusion 60 and the seat rail 132, thereby preventing the end 511 of the rod-shaped portion 51 from further displacing upward in the vehicle. This prevents the seat-side bracket 40, which is fastened and fixed by the fastening member 50, from displacing, thereby preventing the seat 11, which is fixed to the seat-side bracket 40. According to this embodiment, it is possible to prevent the seat 11 from displacing in the event of a collision of the vehicle 10.

<Action and effect>
According to the fixing structure of this embodiment, the following effects can be obtained.
(1) When the deformation mode of the vehicle 10 during a collision is a specific deformation mode in which the end 511 of the rod-shaped portion 51 moves upward toward the vehicle, the seat rail 132 is disposed at a position where the end 511 presses against the seat rail 132. Therefore, displacement of the seat 11 during a collision of the vehicle 10 can be suppressed.

(2) The lower end of the seat rail 132 is provided with a protrusion 60 that protrudes downward toward the vehicle. According to this embodiment, the protrusion 60 can fill a portion of the gap (indicated by W in FIG. 1 ) between the wall portion 51W of the rod-shaped portion 51 and the lower end of the seat rail 132. As a result, when the fastening member 50 is displaced during a vehicle 10 collision, the end 511 of the rod-shaped portion 51 presses against the seat rail 132 (the state shown in FIG. 6 ) early and at a time when the amount of displacement of the fastening member 50 is small. Therefore, the fastening member 50 can be supported by the seat rail 132 early and at a time when the amount of displacement of the fastening member 50 is small. Therefore, compared to a fixing structure without the protrusion 60, the displacement of the seat 11 during a vehicle 10 collision can be kept small.

(3) The seat rails 132, which are reinforcing members that reinforce the cabin sidewalls 13, are used as deformation-restricting members to suppress displacement of the fastening members 50. According to this embodiment, displacement of the fastening members 50 can be suppressed by utilizing the reinforcing members provided in the cabin sidewalls 13 without adding any new members.

<Example of change>
The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

- The shape of the cabin-side bracket 20 and the seat-side bracket 40 can be modified as desired, such as to have an L-shaped cross section extending in the vertical direction of the vehicle, or to have a shape with reinforcing protrusions or recesses.

The plate 30 and the spacer 32 may be omitted.
The shape of the protrusion 60 can be changed as desired, for example, to a cylindrical shape or a rectangular parallelepiped shape.

The reinforcing portion 61 can be omitted.
The protrusion 60 can be omitted. In this configuration, the positional relationship between the seat rail 132 and the rod-shaped portion 51 of the fastening member 50 can be determined as follows: The seat rail 132 can be disposed at a position above the vehicle relative to the wall-side portion 51W of the rod-shaped portion 51. Specifically, the seat rail 132 can be disposed at a position where the end 511 of the rod-shaped portion 51 abuts against the underside of the seat rail 132 when the rod-shaped portion 51 is displaced due to a collision of the vehicle 10.

As shown in an example in Figure 7, a protruding member 70 that protrudes toward the seat rail 132 may be provided on the wall portion 51W of the rod-shaped portion 51. In the example shown in Figure 7, a ring-shaped protruding member 70 is provided on the end portion 511 of the rod-shaped portion 51, with the rod-shaped portion 51 inserted into a central hole. With this configuration, the protruding member 70 can fill part of the gap (indicated by W in Figure 7) between the wall portion 51W of the rod-shaped portion 51 and the lower end of the seat rail 132. Therefore, compared to a fixed structure without a protruding member 70, it is possible to minimize displacement of the seat 11 during a vehicle 10 collision.

As shown in an example in Figure 8, an intermediate member 75 may be placed between the seat rail 132 and the wall portion 51W of the rod-shaped portion 51. The intermediate member 75 may be of any shape, such as a plate or a square pillar. With this configuration, the intermediate member 75 can fill a portion of the gap (indicated by W in Figure 8) between the wall portion 51W of the rod-shaped portion 51 and the lower end of the seat rail 132.

- Instead of using the seat rails 132 as deformation restriction members, reinforcing members other than the seat rails 132 can be used. Furthermore, in addition to using reinforcing members such as the seat rails 132 as deformation restriction members, it is also possible to use frame members of the vehicle 10.

- The fastening member 50 can be modified as desired. For example, a fastening member having a bolt and a nut can be used. In this configuration, the male threaded portion of the bolt corresponds to the rod-shaped portion, and the bolt head and nut correspond to the fastening portion.

- The vehicle seat fixing structure according to the above embodiment can also be applied to vehicles other than buses, such as passenger cars and trucks.

REFERENCE SIGNS LIST 10 Vehicle 11 Seat 111 Seat portion 12 Cabin 13 Cabin side wall 131 Panel portion 132 Seat rail 14 Side portion 15 Seat frame 151 Pipe portion 20 Cabin side bracket 21 First fixing portion 22 First fastening hole 30 Plate 31 Fastening hole 32 Spacer 40 Seat side bracket 41 Second fixing portion 42 Second fastening hole 50 Fastening fixing member 51 Rod-shaped portion 511 End portion 51W Wall side portion 52 Fastening portion 521, 522 Female thread member 60 Convex portion 61 Reinforcement portion 70 Protruding member 75 Intermediate member 810 Vehicle 811 Vehicle seat 812 Cabin 813 Side wall 815 Seat frame 820 Cabin side bracket 821 First fixing portion 840 Seat side bracket 841 Second fixing portion 851 Male thread member 852 Female thread member

Claims (3)

A vehicle seat fixing structure in which a side portion of a vehicle seat is fixed to a side wall of a cabin of a vehicle,
a cabin-side bracket having a shape extending in the vehicle up-down direction, and including a first fixing portion fixed to the side wall, and a first fastening hole for fastening and fixing provided below the first fixing portion on the vehicle;
a seat-side bracket having a shape extending in the vehicle up-down direction and including a second fixing portion fixed to the side portion and a second fastening hole for fastening and fixing the seat-side bracket and provided below the second fixing portion;
a fastening fixing member having a rod-shaped portion extending in the vehicle width direction while passing through the first fastening hole and the second fastening hole, and a fastening portion provided on the rod-shaped portion while sandwiching the cabin-side bracket and the seat-side bracket;
a deformation restriction member that constitutes a part of the side wall, the deformation restriction member being located at a position on the vehicle upper side of a portion of the rod-shaped portion that is closer to the side wall than the second fastening hole, and that is positioned so as to be pressed by the portion of the rod-shaped portion when a deformation mode in the event of a collision of the vehicle is a deformation mode in which an end of the rod-shaped portion on the side wall moves toward the vehicle upper side;
A vehicle seat fixing structure comprising: 2. The vehicle seat fixing structure according to claim 1, wherein a protrusion that protrudes downward toward the vehicle is provided at a lower end of the deformation restricting member. 3. The vehicle seat fixing structure according to claim 1, wherein the deformation restricting member is a reinforcing member that reinforces the side wall.