JP2022162254A - Suspension device and vehicle body structure - Google Patents

Abstract

To prevent the weight of a vehicle from increasing.SOLUTION: A suspension device according to one aspect is attached to a vehicle body frame that includes: a pair of side rails extending in a vehicle front-rear direction; a cross member extending in a vehicle width direction to connect the pair of side rails; and a pair of rear rails connected to positions in the middle of the extending direction of the cross member and extending from the cross member toward a vehicle rear side. The suspension device includes: leaf springs disposed outside in the vehicle width direction of the pair of rear rails to support a vehicle rear axle; and front spring brackets connecting front end portions of the leaf springs to the cross member.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to suspension devices and vehicle body structures.

Leaf springs are used as suspension devices for automobiles. For example, Patent Literature 1 describes a suspension device that includes a leaf spring that suspends a front wheel via a front axle tube and a shock absorber that damps vibration of the leaf spring. In this device, the front end of the leaf spring is connected to a longitudinally extending frame via a bracket, and the rear end of the leaf spring is connected to the frame via a shackle and a bracket.

JP-A-7-257129

2. Description of the Related Art In recent years, development of an electric vehicle that runs by driving a motor with electric power from a battery is underway. In an electric vehicle, electrical components such as a battery, a motor, and an inverter are mounted on a body frame of the vehicle. The required performance of electric vehicles is increasing year by year, and accordingly, the capacity of the batteries mounted on the vehicles is also increasing. In order to mount a large-capacity battery, for example, a pair of side rails extending in the longitudinal direction of the vehicle body frame and a cross member extending in the vehicle width direction and connecting the pair of side rails are provided. , and a pair of rear rails connected to a midpoint in the extending direction of the cross member and extending rearward of the vehicle from the cross member, and a space for mounting the battery is provided between the pair of side rails and the cross member. It is conceivable to form

In such a configuration, the load concentrates on the connecting portion between the cross member and the pair of rear rails. In particular, when the leaf springs are connected to the pair of rear rails as in Patent Document 1, the load of the leaf springs is applied to the pair of rear rails, so the connecting portion between the cross member and the pair of rear rails is significantly reinforced. Is required. Such reinforcement leads to an increase in the number of parts and causes an increase in the weight of the vehicle.

Accordingly, an object of the present disclosure is to suppress an increase in the weight of a vehicle.

In one aspect, a pair of side rails extending in the front-rear direction of the vehicle, a cross member extending in the vehicle width direction of the vehicle and connecting the pair of side rails, and a midway position in the extending direction of the cross member are connected. and a pair of rear rails extending from the cross member to the rear of the vehicle. This suspension device includes a leaf spring arranged outside a pair of rear rails in the vehicle width direction and supporting a rear axle of the vehicle, and a front spring bracket connecting a front end portion of the leaf spring to a cross member.

In the suspension device according to this aspect, the front end portion of the leaf spring is connected to the cross member via the front spring bracket. Therefore, the load from the leaf spring is transmitted to the cross member, and concentration of the load on the pair of rear rails is suppressed. As a result, the load transmitted to the connecting portion between the cross member and the pair of rear rails is reduced, making it possible to simplify the reinforcement of the connecting portion. Therefore, an increase in weight of the vehicle can be suppressed.

One embodiment may further include a rear spring bracket connecting the rear ends of the leaf springs to the pair of rear rails. With such a configuration, the load of the leaf spring can be distributed to the cross member and the pair of rear rails.

In one embodiment, the front spring bracket may connect the front end of the leaf spring to the cross member so as to be pivotable about an axis parallel to the extending direction of the cross member. By connecting the front end of the leaf spring to the cross member so as to be rotatable about an axis parallel to the extending direction of the cross member, the axis of the front spring bracket can be arranged close to the vehicle body frame. , and accordingly the moment acting on the front spring bracket is reduced. Therefore, the strength required for the front spring bracket is reduced, and the structure of the front spring bracket can be simplified. As a result, an increase in the weight of the vehicle can be further suppressed.

In one embodiment, the cross member has a hollow structure with a rectangular cross section including an upper surface facing the upper side of the vehicle, a lower surface facing the lower side of the vehicle, and a pair of side surfaces facing in the longitudinal direction of the vehicle. , the front spring bracket may be fastened to the side surface facing the rear side of the vehicle and the lower surface of the pair of side surfaces. With such a configuration, the front spring bracket can be firmly connected to the cross member.

A vehicle body structure according to one aspect includes a pair of side rails extending in the longitudinal direction of the vehicle, a cross member extending in the vehicle width direction of the vehicle and connecting the pair of side rails, and an extension of the cross member. a pair of rear rails connected to a position midway in the direction and extending rearward of the vehicle from the cross member; a leaf spring arranged outside the pair of rear rails in the vehicle width direction and supporting a rear axle of the vehicle; a front spring bracket connecting the front end to the cross member.

According to the vehicle body structure according to this aspect, it is possible to suppress an increase in the weight of the vehicle.

According to various aspects of the present invention, it is possible to suppress an increase in the weight of the vehicle.

1 is a plan view of a body structure including suspension devices according to one embodiment; FIG. FIG. 2 is a side view of the body structure shown in FIG. 1; It is a top view of a suspension device. It is a perspective view which expands and shows a front spring bracket periphery.

Embodiments of the present disclosure will be described below with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference numerals, and redundant description will not be repeated.

FIG. 1 is a plan view showing a body structure including a suspension device according to one embodiment. 2 is a side view of the body structure shown in FIG. 1. FIG. A vehicle body structure 1 shown in FIGS. 1 and 2 is a structure applied to a large vehicle such as a truck. The vehicle is, for example, a hybrid vehicle, an electric vehicle, a fuel cell vehicle, or an electric vehicle that runs by driving a motor with electric power from a battery. In the following description, the forward and backward directions of the vehicle are referred to as the front-rear direction of the vehicle, and the left-right direction when the vehicle is viewed from the rear is referred to as the vehicle width direction.

As shown in FIG. 1, the body structure 1 includes a body frame 10 and a suspension device 30. As shown in FIG. The body frame 10 includes a pair of side rails 2 , a pair of cross members 3 , a pair of front rails 4 and a pair of rear rails 5 . A pair of front rails 4 support a cab 8 in which a driver's seat of the vehicle is arranged, and a pair of side rails 2 and a pair of rear rails 5 support a cargo bed 9 of the vehicle.

The pair of side rails 2 are spaced apart in the left and right direction and extend parallel to each other along the longitudinal direction of the vehicle. In one embodiment, the pair of side rails 2 are positioned in the longitudinally central portion of the vehicle, more specifically between the front and rear wheels 17 and 18 of the vehicle.

A pair of cross members 3 extend in the width direction of the vehicle and connect end portions of the pair of side rails 2 to each other. The pair of side rails 2 and the pair of cross members 3 are made of elongated metal members such as I-shaped steel. A battery mounting area R1, which is a rectangular space, is formed between the pair of side rails 2 and the pair of cross members 3. As shown in FIG. A battery 21 that supplies electric power for driving the vehicle is mounted in the battery mounting region R1.

The pair of cross members 3 includes a cross member 3A arranged on the front side and a cross member 3B arranged on the rear side of the cross member 3A. A walk-through portion W may be formed on the cross member 3A between the cab 8 and the cargo bed 9 so that passengers can pass through.

A pair of front rails 4 are connected to the cross member 3A. The pair of front rails 4 are spaced apart in the vehicle width direction and extend in parallel from the cross member 3A toward the front of the vehicle. That is, the pair of front rails 4 are arranged forward of the pair of side rails 2 . The space between the pair of front rails 4 in the vehicle width direction is smaller than the space between the pair of side rails 2 in the vehicle width direction. Therefore, the pair of front rails 4 are connected to a midway position in the extending direction of the cross member 3A. Cross members 11 and 12 extending in the vehicle width direction are connected to the pair of front rails 4 . The cross member 11 connects the front end portions of the pair of front rails 4 to each other. The cross member 12 is arranged behind the cross member 11 and connects the pair of front rails 4 .

A front wheel 17 is attached to the pair of front rails 4 via a front axle (axle) 15 . A front mounting area R2 is formed between the pair of front rails 4. As shown in FIG. In the front mounting region R2, for example, electrical components such as a motor 22 and an inverter 23 and a cooling device 24 for cooling these electrical components are mounted.

Between the pair of front rails 4 and the cross member 3A, upper and lower parts connecting the pair of front rails 4 and the cross member 3A are provided so that the pair of side rails 2 are arranged at a position lower than the pair of front rails 4. A kick portion 6 is provided. The up-and-down kick portions 6 are connected to the rear end portions of the pair of front rails 4 and are continuously inclined downward toward the cross member 3A and connected to the cross member 3A. The pair of cross members 3 and the pair of rear rails 5 are arranged at positions lower than the pair of side rails 2 by interposing the vertical kick portions 6 between the cross member 3A and the pair of front rails 4 . As a result, since the loading platform 9 is supported at a low position, it is possible to increase the load capacity of the vehicle.

A pair of rear rails 5 are connected to the cross member 3B. The pair of rear rails 5 are spaced apart in the vehicle width direction and extend parallel to each other toward the rear of the vehicle from the cross member 3B. That is, the pair of rear rails 5 are arranged behind the pair of side rails 2 . The space between the pair of rear rails 5 in the vehicle width direction is smaller than the space between the pair of side rails 2 in the vehicle width direction. Therefore, the pair of rear rails 5 are connected to a midway position in the extending direction of the cross member 3B. The interval between the pair of rear rails 5 in the vehicle width direction may be the same as the interval between the pair of front rails 4 in the vehicle width direction. A cross member 13 and a cross member 14 extending in the vehicle width direction are connected to the pair of rear rails 5 . The cross member 13 connects the rear ends of the pair of rear rails 5 to each other. The cross member 14 is arranged in front of the cross member 11 and connects the pair of rear rails 5 .

A rear wheel 18 is attached to the pair of rear rails 5 via a rear axle (axle) 16 . A rear mounting region R3 is formed between the pair of rear rails 5 . Electrical components such as a junction box 25, an on-vehicle charger 26, a DC converter 27, and a cooling device 28 for cooling these electrical components are mounted in the rear mounting region R3.

As described above, the length of the pair of cross members 3 in the vehicle width direction is longer than that of the cross members 11, 12, 13, and 14. As shown in FIG. Therefore, the width of the battery mounting region R1 in the vehicle width direction is greater than the widths of the front mounting region R2 and the rear mounting region R3 in the vehicle width direction. That is, the portion of the body frame 10 where the pair of side rails 2 are arranged is wider than the portion where the pair of front rails 4 and the pair of rear rails 5 are arranged.

FIG. 3 is a plan view of the suspension device 30. FIG. The suspension device 30 is provided between the body frame 10 and the rear axle 16, and suppresses vibration of the body frame 10 during running. As shown in FIGS. 2 and 3, the suspension device 30 includes a pair of leaf springs 31, a pair of front spring brackets 32, a pair of rear spring brackets 33 and a pair of shock absorbers .

As shown in FIG. 3, the pair of leaf springs 31 are arranged outside the pair of rear rails 5 in the vehicle width direction and extend in the front-rear direction of the vehicle. The leaf spring 31 supports the rear axle 16 via the support member 16a at the central portion in the longitudinal direction.

A front end portion 31a of the leaf spring 31 is connected to the cross member 3B via a front spring bracket 32. As shown in FIG. FIG. 4 is an enlarged perspective view showing the periphery of the front spring bracket 32. As shown in FIG. As shown in FIG. 4, the cross member 3B has a rectangular cross-sectional shape including an upper surface 3u facing the upper side of the vehicle, a lower surface 3b facing the lower side of the vehicle, and a pair of side surfaces 3s facing the longitudinal direction of the vehicle. It has a hollow structure of The front spring bracket 32 is bolted to the side surface 3s facing the rear side of the vehicle and the bottom surface 3b of the pair of side surfaces 3s. Further, the front spring bracket 32 has a fixed shaft extending along an axis AX parallel to the extending direction (vehicle width direction) of the cross member 3B. A front end portion 31a of the leaf spring 31 is rounded so as to surround the fixed shaft of the front spring bracket 32, and is fastened to the front spring bracket 32 so as to be rotatable about the axis AX. That is, the front end portion 31 a of the leaf spring 31 is rotatably connected to the cross member 3 via the front spring bracket 32 .

As shown in FIG. 2 , the pair of rear spring brackets 33 are arranged behind the pair of front spring brackets 32 and fastened to the outer side surfaces of the pair of rear rails 5 . A rear end portion 31 b of the leaf spring 31 is fastened to the rear spring bracket 33 via a shackle 35 . Shackle 35 is rotatable with respect to rear spring bracket 33 . That is, the rear end portion 31 b of the leaf spring 31 is rotatably connected to the rear rail 5 via the rear spring bracket 33 .

As shown in FIG. 3 , a pair of shock absorbers 34 are provided between the pair of rear rails 5 and the rear axle 16 . The shock absorber 34 dampens vibration of the leaf spring 31 caused by vertical movement of the rear axle 16 .

As described above, in the suspension device 30, the front end portion 31a of the leaf spring 31 is connected to the cross member 3B via the front spring bracket 32, and the rear end portion 31b of the leaf spring 31 is connected to the rear rail 5 via the rear spring bracket 33. It is connected to the. Therefore, the load transmitted from the rear axle 16 to the leaf springs 31 is dispersed and transmitted to the cross member 3B and the pair of rear rails 5 . Therefore, concentration of the load on the pair of rear rails is suppressed. As a result, the load transmitted to the connection portion C between the cross member and the pair of rear rails is reduced, and the reinforcement of the connection portion C can be simplified (see FIG. 3). Therefore, an increase in weight of the vehicle can be suppressed.

In the body structure 1 described above, the distance between the pair of side rails 2 in the vehicle width direction is greater than the distance between the pair of front rails 4 in the vehicle width direction and the distance between the pair of rear rails 5 in the vehicle width direction. That is, the portion where the pair of side rails 2 are arranged has a structure wider than the portion where the pair of front rails 4 and the pair of rear rails 5 are arranged. As a result, it is possible to secure a wide battery mounting area R1 formed between the pair of side rails 2, so that it is possible to mount the battery 21 having a relatively large capacity while maintaining the wheelbase of the vehicle. Become. As a result, the cruising distance of the vehicle can be increased.

The front spring bracket 32 connects the leaf spring 31 to the cross member 3B so that the front end portion 31a of the leaf spring 31 can rotate about the axis AX parallel to the extending direction of the cross member 3B. When the leaf spring 31 is connected to the cross member 3B so that the front end portion 31a of the leaf spring 31 can rotate about the axis AX parallel to the extending direction of the cross member 3B, the front spring bracket 32 is attached to the rear rail 5. It is possible to arrange the fixed shaft of the front spring bracket 32 closer to the vehicle body frame 10 than when it is fastened. By placing the fixed shaft of the front spring bracket 32 close to the vehicle body frame 10, the moment acting on the front spring bracket 32 is reduced. Therefore, the front spring bracket 32 can be simplified, and as a result, the increase in weight of the vehicle can be further suppressed.

Although suspension devices and vehicle body structures according to various embodiments have been described above, various modifications can be made without changing the gist of the invention without being limited to the above-described embodiments.

DESCRIPTION OF SYMBOLS 1... Body structure 2... Side rail 3... Cross member 3b... Lower surface 3s... Side surface 3u... Upper surface 5... Rear rail 10... Body frame 16... Rear axle 30... Suspension device 31... Leaf spring , 31a... Front end part, 31b... Rear end part, 32... Front spring bracket, 33... Rear spring bracket.

Claims (5)

a pair of side rails extending in the longitudinal direction of the vehicle; a cross member extending in the vehicle width direction of the vehicle and connecting the pair of side rails; , and a pair of rear rails extending rearward of the vehicle from the cross member, the suspension device being attached to a vehicle body frame,
a leaf spring arranged outside the pair of rear rails in the vehicle width direction and supporting a rear axle of the vehicle;
a front spring bracket connecting the front end of the leaf spring to the cross member;
A suspension device. 2. The suspension device according to claim 1, further comprising a rear spring bracket connecting the rear end of said leaf spring to said pair of rear rails. 3. The suspension device according to claim 1, wherein the front spring bracket connects the front end of the leaf spring to the cross member so as to be rotatable around an axis parallel to the extending direction of the cross member. The cross member has a hollow structure with a rectangular cross section including an upper surface facing the upper side of the vehicle, a lower surface facing the lower side of the vehicle, and a pair of side surfaces facing the front-rear direction of the vehicle,
The suspension device according to any one of claims 1 to 3, wherein the front spring bracket is fastened to one of the pair of side surfaces facing the rear side of the vehicle and to the lower surface. a pair of side rails extending in the longitudinal direction of the vehicle;
a cross member extending in the width direction of the vehicle and connecting the pair of side rails;
a pair of rear rails connected to an intermediate position in the extending direction of the cross member and extending rearward of the vehicle from the cross member;
a leaf spring arranged outside the pair of rear rails in the vehicle width direction and supporting a rear axle of the vehicle;
a front spring bracket connecting the front end of the leaf spring to the cross member;
A vehicle body structure comprising:

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