Belt anchor fixing structure

Abstract

This invention provides a belt anchor fixing structure that simplifies the structure of the belt anchor. [Solution] The fixing structure for the belt anchor 52 comprises a rear seat 10 mounted on a vehicle, a cross member 16 extending in the vehicle width direction near the rear end of the rear seat 10, a belt anchor 52 fixed to the cross member 16, and a seat belt 42 connected to the belt anchor 52. The belt anchor 52 is fixed on a straight line La parallel to the tension direction At of the seat belt 42 and passing through the centroid Pc of the cross member 16.

Description

Technical Field

[0001] This specification discloses a fixing structure of a belt anchor fixed to a cross member.

Background Art

[0002] As is well known, a seat belt device for restraining the body of an occupant during a vehicle collision is provided on a vehicle seat. Usually, a part of the seat belt of the seat belt device can be connected to a buckle. Further, the buckle is often fixed to the vehicle via a belt anchor. For example, Patent Document 1 discloses a configuration in which a belt anchor is fastened to a lower arm that is a part of a seat frame.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, due to a sudden stop or collision of the vehicle, the occupant may fall forward into the vehicle and the belt may be strongly pulled. At this time, of course, a large pulling force also acts on the belt anchor. In the case of a conventional structure, this large pulling force is received only by the fastening portion of the belt anchor. Therefore, it is necessary to make the fastening portion of the belt anchor have a strong structure so as not to be damaged by the pulling force. As a result, there is a problem that the fixing structure of the belt anchor becomes large-sized or expensive.

[0005] Therefore, this specification discloses a belt anchor fixing structure that can simplify the structure of the belt anchor.

Means for Solving the Problems

[0006] The belt anchor fixing structure disclosed herein comprises a seat mounted on a vehicle, a cross member extending in the vehicle width direction near the rear end of the seat, a belt anchor fixed to the cross member, and a seat belt connected to the belt anchor, wherein the belt anchor is fixed on a straight line parallel to the tension direction of the seat belt and passing through the centroid of the cross member.

[0007] With this configuration, the load applied to the belt anchor is efficiently transmitted to the cross member, thereby effectively preventing the belt anchor from peeling off or being damaged.

[0008] In this case, the cross member is part of a die-cast component formed by integrally casting the cross member and a pair of left and right wheelhouses, and the belt anchor may be integrally cast with the cross member as part of the die-cast component.

[0009] In die casting, complex shapes can be easily molded. Therefore, with die casting, the cross member and belt anchor can be easily cast as a single unit. Furthermore, by integrally casting the cross member and belt anchor, the force acting on the belt anchor can be transmitted to the cross member more reliably.

[0010] Furthermore, the cross member may be part of a die-cast component formed by integrally casting the cross member and a pair of left and right wheelhouses, and the cross member may have a fixing portion to which the belt anchor is fixed, and a plurality of ribs that radiate outward from the vicinity of the fixing portion.

[0011] By providing multiple ribs that radiate outwards from the vicinity of the fixed part, the load applied to the belt anchor can be distributed more effectively. Furthermore, by making the cross member part of a die-cast component, a complex shape with ribs and other features can be realized.

[0012] Furthermore, the vehicle may also be equipped with a battery pack located under the vehicle floor, the end of which may be fastened to the cross member.

[0013] With this configuration, a portion of the load transmitted from the belt anchor to the cross member is further transmitted to the battery pack. This allows for more efficient load distribution. [Effects of the Invention]

[0014] The technology disclosed herein allows for a simpler structure of the belt anchor. [Brief explanation of the drawing]

[0015] [Figure 1] This is an exploded perspective view showing the arrangement of the main components. [Figure 2] This is a schematic diagram of the rear seat. [Figure 3] This is a cross-sectional view AA in Figure 2. [Figure 4] This is a perspective view of the area around the lower belt anchor. [Figure 5] This is a schematic plan view of the area around the belt anchor. [Modes for carrying out the invention]

[0016] The fixing structure of the belt anchor 52 will be described below with reference to the drawings. Figure 1 is an exploded perspective view showing the arrangement of the main components. In each figure, Fr, Up, and Rh indicate the front, top, and right side of the vehicle, respectively.

[0017] The vehicle illustrated in this example is an electric vehicle having a driving motor (not shown) as a power source. Note that this electric vehicle may be a hybrid electric vehicle or a battery electric vehicle. As shown in FIG. 1, such a vehicle has a rear seat 10, a die-cast part 12, a side member 30, and a battery pack 34. The rear seat 10 is a seat disposed at the rear of the vehicle. The rear seat 10 is, for example, a bench seat on which three people can sit. A seat belt device described later is incorporated in this rear seat 10. Such a rear seat 10 is connected to the vehicle body or frame via a seat frame and seat rails not shown.

[0018] The die-cast part 12 and the side member 30 constitute the vehicle frame. The side member 30 is a frame member extending in the vehicle front-rear direction at the vehicle-width direction end of the passenger compartment. The side member 30 is, for example, a hollow member having a substantially rectangular cross section. A sub-cross member 32 is connected to the rear end of the side member 30. The sub-cross member 32 extends in the vehicle-width direction and connects the rear ends of the two side members 30. In this example, the sub-cross member 32 is a substantially trapezoid protruding rearward of the vehicle as shown in FIG. 1. Further, the front ends of the two side members 30 are connected by a front cross member not shown.

[0019] The die-cast part 12 is made of a light metal such as aluminum and is manufactured by a casting technique called "gigacasting" or "megacasting". "Gigacasting" or "megacasting" is a technique for integrally casting large parts using a large mold. In the die-cast part 12 of this example, a pair of left and right wheel houses 14 and a cross member 16 are integrally cast.

[0020] The cross member 16 is a frame member extending in the vehicle width direction. The cross member 16 is located near the rear end of the rear seat 10. Also, in FIG. 1, the cross member 16 is shown in a simplified manner, but as shown in FIGS. 3 and 4, the cross member 16 has a U-shaped or groove-shaped cross section that opens upward. Further, as shown in FIGS. 4 and 5, a plurality of ribs 24 are formed inside the groove of the cross member 16. This cross member 16 is placed on the sub-cross member 32 and is connected to the rear end of the side member 30 and the sub-cross member 32.

[0021] Below the side member 30 and the cross member 16, that is, under the floor of the passenger compartment, a battery pack 34 is arranged. The battery pack 34 is a secondary battery capable of charging and discharging electric power. The battery pack 34 has a flat shape with a thickness dimension smaller than its planar size. A flange 38 extending in the horizontal direction is provided at the periphery of the battery pack 34. The outer shape of the battery pack 34 including the flange 38 is approximately the same size as a substantially rectangular shape formed by the side member 30, the cross member 16, and a front cross member (not shown). The flange 38 of the battery pack 34 is overlapped with and fastened to the lower sides of the side member 30, the cross member 16, and the front cross member.

[0022] Next, the seat belt device will be described. FIG. 2 is a schematic view of the rear seat 10. Also, FIG. 3 is a cross-sectional view taken along the line A-A of FIG. 2. Further, FIG. 4 is a perspective view around the lower belt anchor 52, and FIG. 5 is a schematic plan view around the belt anchor 52.

[0023] The rear seat 10 incorporates seat belt devices for three persons. Each seat belt device has a seat belt 42 for restraining the body of the occupant. The seat belt 42 is passed through the belt hole of the tongue plate 43 (see FIG. 3). The seat belt 42 is folded back by the tongue plate 43, and is divided into a shoulder belt 42a that extends obliquely upward from the tongue plate 43 and a lap belt 42b that extends laterally from the tongue plate 43.

[0024] The upper end of the shoulder belt 42a (i.e., the end opposite the tongue plate 43) is secured to the vehicle body via an upper belt anchor 46. A retraction device (not shown) that controls the retraction and extension of the seat belt 42 is also connected to the shoulder belt 42a. The end of the lap belt 42b opposite the tongue plate 43 is secured to the vehicle body or cross member 16 via an outer belt anchor 47 or a lower belt anchor 52.

[0025] Near the rear end of the seat surface of the rear seat 10, a buckle 48 (see Figure 3) is provided to which a tongue plate 43 is releasably connected. The buckle 48 is fixed to the cross member 16 via a connecting belt 50 and a lower belt anchor 52, which will be described later. In this example, the mounting position and orientation of the lower belt anchor 52 are adjusted to reduce the load acting on the lower belt anchor 52. This will be explained in detail below. In the following, the lower belt anchor 52 will be referred to as "belt anchor 52".

[0026] The connecting belt 50 is fastened to the belt anchor 52 by fastening bolts 54. The belt anchor 52 is fixed to the cross member 16, as shown in Figures 3 and 4. More specifically, the cross member 16 has a roughly grooved shape with a front wall 18, a bottom wall 20, and a rear wall 22. The belt anchor 52 is fixed to the front wall 18 of this cross member 16. The belt anchor 52 may be integrally molded with the cross member 16. That is, in this example, the cross member 16 is manufactured by die casting. With die casting, complex shapes can be easily manufactured. Therefore, with die casting, the belt anchor 52 shown in Figure 4 can be integrally cast with the cross member 16. Alternatively, the belt anchor 52 may be manufactured as a separate part from the cross member 16 and attached to the cross member 16 by fastening or welding.

[0027] In any case, a fastening hole 55 is formed in the center of the belt anchor 52 through which a fastening bolt 54 is inserted. A nut 53 is welded to the back of this fastening hole 55 to engage with the fastening bolt 54. The fastening bolt 54 is screwed into the nut 53 with the connecting belt 50 sandwiched between its head and the belt anchor 52. This secures the connecting belt 50, and consequently the seat belt 42, to the cross member 16.

[0028] Here, as shown in Figure 3, the belt anchor 52 is positioned parallel to the tension direction At of the seat belt 42 and on a straight line La passing through the centroid Pc of the cross member 16. The tension direction At is the direction in which the buckle 48 is pulled when an occupant falls forward due to a sudden stop or collision of the vehicle. Such a tension direction At is the direction specified, for example, in "6.3.2" of "JIS D 4609:1993 Seat belt mounting parts for passenger cars - position and strength" or in "6.3.2" of Agreement Regulation No. 14 of the "Equivalent Agreement for the Reciprocal Recognition of Type Approvals of Vehicles, etc." (ECE) "Uniform provisions relating to the approval of vehicles relating to seat belt mounting devices, ISOFIX mechanism mounting devices and ISOFIX top tether mounting devices". In other words, the direction of the tensile force used in the test specified in the standard, which involves "applying a tensile force in a direction corresponding to the seating position, on a plane parallel to the central longitudinal section of the vehicle and at an angle of 10°±5° upward from the horizontal plane," is the tensile direction At.

[0029] By positioning the belt anchor 52 on the straight line La, the tensile force Ft transmitted to the belt anchor 52 can be efficiently distributed to the cross member 16. In this case, the tensile force Ft acting on the belt anchor 52 is transmitted to the centroid Pc of the cross member 16. At the centroid Pc, a reaction force Fr is generated in response to the tensile force Ft. Furthermore, this reaction force Fr is distributed in the horizontal and vertical directions, as shown by the thick arrows in Figure 3. As a result, force concentration is suppressed, and deformation or damage to the belt anchor 52 and the cross member 16 is effectively prevented. This improves the load-bearing capacity of the belt anchor 52.

[0030] Conventionally, to improve the load-bearing capacity of the belt anchor 52, the strength of the belt anchor 52 alone was increased. However, this resulted in the belt anchor 52 becoming larger and more expensive. In contrast, in this example, since the belt anchor 52 is positioned on the straight line La described above, the tensile force Ft acting on the belt anchor 52 can be efficiently distributed to the cross member 16. As a result, the load-bearing capacity of the belt anchor 52 can be improved without increasing the cost or size of the belt anchor 52 itself.

[0031] Furthermore, in this example, in order to more efficiently distribute the tensile force Ft, ribs 24 are provided in the grooves of the cross member 16, as shown in Figures 4 and 5. These ribs 24 are arranged substantially radially from the fixing portion of the belt anchor 52 to the cross member 16 in a plan view. More specifically, the cross member 16 has a first rib 24f and a pair of second ribs 24s. The first rib 24f is a rib 24 that connects the front wall 18 and the rear wall 22, and in a plan view, it is a rib that extends straight backward. Two second ribs 24s are arranged on both the left and right sides of the first rib 24f. The second ribs 24s are also ribs 24 that connect the front wall 18 and the rear wall 22. However, in a plan view, the second ribs 24s move diagonally backward so as they move backward, they move away from the first rib 24f.

[0032] The front ends of the two second ribs 24s are located near the front end of the first rib 24f. Furthermore, the front ends of all three ribs 24f and 24s are located near the fastening holes 55 of the belt anchor 52. As a result, the front wall 18, the first ribs 24f, and the second ribs 24s form a wall that radiates outwards from the fastening holes 55.

[0033] In this configuration, the force transmitted from the belt anchor 52 to the front wall 18 is further transmitted to the front wall 18 and the ribs 24f and 24s, as shown by the dashed arrows in Figure 5. This ensures that the tensile force Ft is more reliably distributed, thereby suppressing force concentration. As a result, deformation and damage to the belt anchor 52 and the cross member 16 are effectively prevented. The ribs 24, which distribute the force acting on the belt anchor 52, only need to extend radially from near the fixing point of the belt anchor 52 to the cross member 16. Here, the "fixing point" is the part where the belt anchor 52 and the cross member 16 are connected, and where force is transmitted from the belt anchor 52 to the cross member 16. In the examples in Figures 4 and 5, the thick lines represent the "fixing point".

[0034] Furthermore, as mentioned above, in this example, the battery pack 34 is fastened to the underside of the cross member 16. In this case, a portion of the force transmitted to the cross member 16 is also transmitted to the battery pack 34 through the fastening portion between the cross member 16 and the battery pack 34. The battery pack 34 is a large and heavy component. By having the battery pack 34 absorb a portion of the force, deformation or damage to the belt anchor 52 and the cross member 16 is more effectively prevented.

[0035] As is clear from the above explanation, in this example, the force acting on the belt anchor 52 is efficiently distributed to the cross member 16 and the battery pack 34. As a result, the buckle 48 and, consequently, the seat belt 42 can be properly held without excessively increasing the strength of the belt anchor 52 itself. Consequently, the structure of the belt anchor 52 can be simplified compared to conventional technology.

[0036] It should be noted that the configurations described so far are all examples, and other configurations may be changed as long as the configuration described in claim 1 is met. For example, in the above description, the cross member 16 is part of the die-cast part 12 which includes a pair of wheelhouses 14. However, the cross member 16 may be a separate part that is separate from the wheelhouses 14. For example, the cross member 16 may be constructed by welding together a plurality of sheet metal members. Also, in the above description, the battery pack 34 is fastened to the lower side of the cross member 16, but the battery pack 34 may be fastened to another location. [Explanation of Symbols]

[0037] 10 Rear seat, 12 Die-cast parts, 14 Wheelhouse, 16 Cross member, 24 Rib, 30 Side member, 32 Sub-cross member, 34 Battery pack, 38 Flange, 42 Seat belt, 43 Tongue plate, 48 Buckle, 50 Connecting belt, 52 Belt anchor, 53 Nut, 54 Fastening bolt, 55 Fastening hole, At: Tension direction, Pc: Centroid.

Claims

1. The seats installed in the vehicle, Near the rear end of the aforementioned seat, a cross member extending in the vehicle width direction, A belt anchor fixed to the aforementioned cross member, A seat belt connected to the aforementioned belt anchor, The belt anchor is fixed on a straight line parallel to the pulling direction of the seat belt and passing through the centroid of the cross member. A belt anchor fixing structure characterized by the following features.

2. A belt anchor fixing structure according to claim 1, The aforementioned cross member is part of a die-cast component formed by integrally casting the cross member and a pair of left and right wheelhouses. The belt anchor is integrally cast with the cross member as part of the die-cast component. A belt anchor fixing structure characterized by the following features.

3. A belt anchor fixing structure according to claim 1, The aforementioned cross member is part of a die-cast component formed by integrally casting the cross member and a pair of left and right wheelhouses. The aforementioned cross member is The fixing part to which the belt anchor is fixed, Multiple ribs radiating outwards from the vicinity of the fixed portion, Having, A belt anchor fixing structure characterized by the following features.

4. The belt anchor fixing structure according to claim 1, further, Equipped with a battery pack located under the vehicle floor, The end of the battery pack is fastened to the cross member. A belt anchor fixing structure characterized by the following features.

5. The seats installed in the vehicle, Near the rear end of the aforementioned seat, a cross member extending in the vehicle width direction, A belt anchor fixed to the aforementioned cross member, A seat belt connected to the aforementioned belt anchor, The cross member is equipped with, The fixing part to which the belt anchor is fixed, Multiple ribs radiating outwards from the vicinity of the fixed portion, A belt anchor fixing structure characterized by having the following features.

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