JP3443819B2 - Lower body structure of vehicle - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lower body structure of a vehicle, and more particularly to a rear body structure.

[0002]

2. Description of the Related Art In the rear structure of a vehicle, there is a demand for lowering the floor level of the vehicle as much as possible in order to widen the vehicle interior space. However, in order to achieve a low floor, the space under the floor is pressed, so that interference with the fuel tank, the exhaust system, the suspension device, etc. becomes a problem. When considering a layout in the above-mentioned restricted space, an axle type suspension device is preferable as an independent suspension system because it can reduce the number of parts and is relatively simple in structure as compared with independent suspension. . For example, Japanese Patent Application Laid-Open No. 64-28012 discloses a so-called four-link axle type suspension device. However, in the case of such an axle type suspension device, since the wheel drive system, that is, the diff and the axle supporting the wheels are integrated, this portion becomes large, and since this portion is displaced integrally during traveling,
It becomes difficult to support the axle while avoiding the interference with the vehicle body, which hinders the reduction of floor. There is also known a so-called dodeon type suspension device in which a drive system, that is, a differential, and an axle, that is, an axle, are individually supported. In this suspension device, displacement of the drive system can be restrained, but the number of parts is increased as compared with the above-mentioned axle type device, so that interference with other devices to be arranged in the lower part of the vehicle becomes a problem.

The present invention is constructed in view of the above circumstances, and an object thereof is to provide a lower body structure of a vehicle having a compact structure. Further, the present invention is to provide a vehicle that can be made to have a large floor space by reducing the floor.

[0004]

The present invention is configured as follows to achieve the above object. That is, the lower vehicle body structure of the vehicle of the present invention includes a rear differential fixed to the vehicle body, a rear wheel connected via a drive shaft extending in the left-right direction from the rear differential, and a left-right rear wheel extending in the left-right direction. And a link member extending in the left-right direction so as to connect the axle and the vehicle body ,
The axle is offset rearward with respect to the rear differential
And is placed at a position above the lower end of the rear differential and overlapping.
A damper is disposed between the vehicle body and the rear wheel,
The dampers are arranged so as to be inclined rearward and downward . In a preferred mode, each rear wheel is supported by the vehicle body via two link members extending in the front-rear direction. In yet another aspect, the left-right direction link member is composed of two lateral links, one end of which is coupled to the vehicle body and the other end of which is connected to the axle. Further, both ends of the vehicle body and the axle may be connected by a coil spring, and the upper end of the coil spring may be attached to the vehicle body so as to be located below the floor level. In this case, of the two front-rear direction link members supporting the rear wheels, the upper link is connected to the upper portion of the hub supporting the vehicle body frame and the rear wheels, and the exhaust device is arranged between the upper link and the axle. preferable.

Further, the cross member extending in the left-right direction is provided in the above-mentioned 2
It is desirable to attach the lateral link of the book to the vehicle body by attaching it to the cross member.
In a preferred aspect, a mounting portion of the two lateral links to the axle is located near an intersection with a longitudinal centerline of the vehicle body, and the cross member has a shape in which a rear portion of a middle portion in the left-right direction is cut out. By arranging the mounting portion so as not to overlap the cross member in a plan view, it is configured to avoid interference between the two lateral links and the cross member.

[0006]

According to the present invention, in constructing the rear wheel suspension device, the rear wheel drive system including the rear differential and the both axles are separately supported. Therefore, the supporting component can be made smaller than that of the axle type. Further, the number of parts can be reduced as compared with the independent suspension type. In this case, the axle
The left and right rear wheel hubs extend in the lateral direction of the vehicle, that is, in the left-right direction so as to be coupled to each other, and are coupled to two lateral links at a substantially central portion. The lateral links extend outward and are coupled to the vehicle body. By connecting the vehicle body and the axle via the lateral link, displacement in the left-right direction is mainly supported. Furthermore, in the front-back direction, each rear wheel is supported by two links, and in the up-down direction, a coil spring is provided and the upper end is attached to the vehicle body at a position lower than the floor level, and the lower end is a hub that supports the rear wheel. It supports the lower end. According to the above configuration of the present invention, while lowering the floor, while maintaining the degree of freedom in the layout of other devices, for example, the fuel tank and the exhaust device, the suspension device of the lower body structure of the vehicle, in particular, is made compact. be able to.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view of a lower body structure of a vehicle according to an embodiment of the present invention. In the vehicle of this example, rear side frames 1 forming a lower part of the vehicle body extend in parallel to the front and rear directions on both left and right sides. Referring also to FIG. 2, the rear side frame 1 includes a front horizontal portion 3 that extends straight rearward at a relatively low level slightly forward of the rear wheel 2.
And an inclined portion 4 which is continuous with the front horizontal portion 3 and which is curved slightly inward in the front of the rear wheel and curved upward, and the inclined portion 4
It is composed of a rear horizontal portion 5 which is continuous to the rear end and the upper end and extends substantially horizontally rearward. The rear side frame 1 is joined by a cross member 6 extending left and right in front of the rear wheel 2 just before bending inward and upward, and another cross member extending right and left immediately behind the rear wheel 2. Bound by 7. Further referring to FIG. 3, the rear side frame 1 extends to a rear end portion of the vehicle, a floor panel 8 is attached to an upper end surface of the rear side frame 1, and a passenger compartment 9 is formed above the floor panel 8. In the vehicle of this example, the seat 10 is located above the front cross member 6, and slightly behind it, the floor panel 8 is located above as the rear side frame 1 curves upward. . That is,
The rear wheel 2 has a floor-up structure. The rear seat 11 is provided at the position of the rear wheel 2.
Further, the rear body panel 12 is located at the rear end of the rear side frame 1. In addition, a rear bumper 1 extending in the left-right direction at a position slightly separated from the rear end of the rear side frame 1.
3 is located.

A propeller shaft 14 extends in the front-rear direction in the center of the vehicle below the rear side frame 1.
And at the rear end of the universal joint 15
A rear differential gear device 16 (hereinafter referred to as a rear differential) is connected via the. A drive shaft 17 extends from the rear differential 16 to the left and right, and is connected to the rear wheel 2 so that power can be transmitted. The differential case 18 of the rear differential 16 is connected to a bracket 19 at the upper end thereof, and the bracket 19 extends in a bifurcated shape slightly rearward, outward and upward. Both ends thereof are coupled to the cross member 7 via the differential mount 20. That is, the rear wheel drive system is connected to the cross member 7, that is, the vehicle body at two points via the rear differential case 18. Further, below the propeller shaft 14, a power plant frame 21 extending in the front-rear direction with a width protruding in the left-right direction from the diameter of the shaft 14 is arranged, and the rear end side of the power plant frame 21 is the above-mentioned. The front end of the power plant frame 21 is connected to the lower part of the front end of the rear differential case 18, and the cross member 6 is connected to the front end of the power plant frame 21 via an arm 22 extending upward.
Is attached to the underside of. Therefore, the power plant frame 21 is interposed between the propeller shaft 14 and the road surface and extends in the front-rear direction, and also has a role of protecting the propeller shaft 14 from directly confronting the road surface. Therefore, the rear wheel drive system includes the cross member 7 at the rear of the differential 16.
Are supported at two points, and the front end side of the differential 16 is supported by the front cross member 6 via the power plant frame 21.

The rear wheel 2 is attached to the tip of the drive shaft 17.
A hub 23 for rotatably supporting is coupled. The hubs 23 of the left and right rear wheels 2 are connected to both ends of an axle 24 extending in the left and right direction, whereby the lateral relative displacement of the left and right rear wheels is restrained. Further, one end of two lateral links 25, 26 extending in the left-right direction is rotatably attached to the center of the axle 24 in the left-right direction via a bush. In this case, referring also to FIG. 4, a mounting bracket 27 protruding upward is provided at the center portion of the axle 24 in the left-right direction, and the mounting bracket 27 is rotatably mounted in another substantially triangular shape. Member 2
8 are connected. Then, the inner ends of the two lateral links 25 and 26 have the triangular mounting member 28.
Are rotatably coupled to the positions of the two apexes via bushes, and the remaining apexes are rotatably coupled to the bracket 27 of the axle 24. The lateral links 25, 26 of the lateral links 25, 26 that extend to the left in FIG. 4 extend substantially horizontally from the upper end of the mounting member 28, and extend downward from the lower portion in the vicinity of the joint between the cross member 7 and the rear side frame 1. It is pivotally supported at the lower end of 29. The lateral link 26 extending to the right extends substantially horizontally from the lower end of the mounting member 28 in the central portion, and similarly extends from the lower portion of the cross member 7 to the lower end of the bracket 30 extending downward about the rotational axis in the front-rear direction. It is pivoted through the bush. That is, the two lateral links 25 and 26 alternately and horizontally extend from the central bracket 27 outward.

Referring to FIGS. 2 and 4, the cross member 7 has a shape in which a rear portion and a lower portion of the middle portion in the left-right direction are cut out. When the mounting member 28 is displaced relative to the vehicle body along with the displacement of the axle 24 by being positioned so as not to overlap the cross member 7 in a plan view and an elevation view, the two lateral links are It is possible to avoid interference with cross members. Further, rear ends of an upper link 31 and a lower link 32 extending in the front-rear direction are attached to the hub 23 via a bush, and the two front-rear links 31, 32 restrain movement of the wheel 2 in the front-rear direction. . In this case, the hub 23 is provided with an upper arm 33 extending upward, and the rear end of the upper link 31 is rotatably connected to the tip end of the upper arm 33 via a bush. The upper link 31 extends forward inwardly and slightly inward, and extends inwardly and upwardly of the rear side frame 1 and the rear horizontal portion 5 is provided.
It is pivotally supported on the outer surface in the vicinity of the connection point with and so as to be rotatable in the vertical direction around the axis in the horizontal direction. Also, the lower link 32
The rear end is supported on the front side of the hub 23 so as to be pivotable about an axis in the left-right direction. The lower link 32 extends forward substantially parallel to the horizontal portion of the rear side frame 1 and horizontally, and the front end thereof rotates around the left-right axis like the bracket 34 extending downward from the rear end portion of the front horizontal portion 3 of the rear side frame 1. Is rotatably connected to.

Further, the hub 23 is coupled to the rear side frame 1 via a coil spring 35 in the vertical direction, and due to the presence of the coil spring 35, road surface vibration is transmitted to the rear side frame 1 or the vehicle body via the rear wheels. Is designed to buffer. Further, a lower end of a damper 36 is attached to the hub 23, and the damper 36 extends rearward and upward and extends toward the rear side frame 1.
Is pivoted to. Further, in the configuration of this example, in the front-rear direction, in the space in front of the axle 24, behind the cross member 1 and in the up-down direction, in the space above the propeller shaft 14 and below the floor panel 8, the fuel tank 37 is provided. Are placed. A central portion of the fuel tank 37 is formed at a lower portion in order to avoid interference with the propeller shaft 14, and a recess corresponding to the lower portion is formed so as to extend in the front-rear direction. Therefore, as shown in FIG. 5, the propeller shaft 14 is positioned so as to be surrounded by the fuel tank 37 on the upper side and the power plant frame 21 on the lower side. As shown in FIG. 2, the fuel tank 37 is supported on the vehicle body side by a pair of tank bands 38 extending in the front-rear direction and fixed to the two cross members 6 and 7. A refueling pipe 39 is connected to the fuel tank 37 from one side surface of the vehicle body.

Further, in the lower body structure of the vehicle of this example, an exhaust device 40 is provided. Since the exhaust pipe 41 of the exhaust device 40 is provided at a level that interferes with the fuel tank 37 in the vertical direction, in the configuration of this example, the exhaust pipe 41 is curved toward the rear side frame 1 in front of the fuel tank 37 to avoid the fuel tank 37. Then, it extends rearward along the inside of the rear side frame 1. Then, it extends slightly inward and rearward through the space between the upper link 31 and the lower link 32, and further above one lateral link 25 that extends horizontally above the axle 24 as shown in FIG. In addition, it extends rearward through a space formed below the cross member 7. In this case, as shown in FIG. 2, since the fuel tank 37 and the exhaust pipe interfere with each other in a plan view, the lower portion of the fuel tank has a notched shape. In this way, the fuel tank 37 is extended to the rear side frame 1 so as to be disposed to the limit and only the interference portion with the exhaust pipe 41 is avoided, so that the capacity of the fuel tank 37 can be secured as much as possible. After that, the exhaust pipe 41 extends slightly below the rear side frame 1 to the rear, and inside the rear horizontal part 5 slightly below, a silencer 42 extending in the front-rear direction is provided in the front-rear direction.

With respect to the left-right direction, the silencer 42 and
An underfloor storage portion 43 is formed in the space between the other rear side frame 41. In addition, above the fuel tank, reinforcing frames 44 and 45 fixed to the rear side frame 1 at both ends extend in the left-right direction. In the above structure, the drive system is supported by the vehicle body at three points, the axle is connected to the wheel hub at both ends, and is supported in the vertical and horizontal directions by the two lateral links. In addition, the hub is supported in the vehicle body by so-called four links including the upper link 31 and the lower link 32, so that the front and rear directions are restrained. The rear differential 16 is supported at two points on the rear end side, and the center of gravity is located in front of the support point. Therefore, when a rear collision occurs, the rear differential 16
When the fuel tank 37 is separated at the universal joint 15, the fuel tank 37 moves horizontally because it is displaced downward.
It is in a supporting state with high safety without colliding with.

[0014]

According to the present invention, a rear suspension device having a relatively simple structure is provided without impairing the suspension function, and the overall lower body structure of a vehicle can be made compact. In particular, since the drive system and the axle are separately supported on the vehicle body, the component can be made smaller than a so-called axle type suspension device in which the drive system and the axle are integrally supported. As a result, other equipment such as
The degree of freedom in layout of the fuel tank, exhaust system, etc. is improved. Since the axle is supported by the two relatively short lateral links, the exhaust system can be passed through by utilizing the space above it. The lower body structure of the vehicle can be made compact without inviting deterioration of the suspension function. In this way, since the lower structure of the lower body structure of the vehicle can be made compact, it is possible to achieve a low floor and a large passenger compartment.

[Brief description of drawings]

FIG. 1 is a perspective view of a lower body structure of a vehicle according to an embodiment of the present invention,

2 is a plan view of the lower body structure of FIG. 1,

FIG. 3 is an elevation view of the lower body structure of FIG. 1 seen from the lateral direction,

FIG. 4 is an elevation view of the lower body structure of FIG. 1 as seen from the rear side.

FIG. 5 is a sectional view showing a positional relationship between a propeller shaft, a fuel tank, and a power plant frame.

[Explanation of symbols]

1 rear side frame, 2 rear wheels 6 cross members 7 cross members 16 Rear differential 23 Hub 24 Axle 25 Lateral Link 26 Lateral Link 31 Aperlink 32 Lower Link 37 Fuel tank

Continuation of the front page (56) Reference JP-A-61-50812 (JP, A) JP-A-5-178239 (JP, A) Actual opening 62-151107 (JP, U) Actual opening 62-182810 (JP , U) Actual development Sho 62-49405 (JP, U) Actual development Sho 53-30618 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B62D 25/20

Claims (7)

(57) [Claims] 1. A rear differential fixed to a vehicle body, a rear wheel connected to the rear differential via a drive shaft extending in the left-right direction, an axle extending in the left-right direction to connect the left and right rear wheels, and the axle. and a link member extending in the lateral direction so as to connect the vehicle body, the axle is offset rearwardly relative to the rear differential
The rear differential is placed at an overlapping position above the lower end of the rear differential.
And a damper is provided between the vehicle body and the rear wheel.
Is a lower body structure of a vehicle, which is arranged so as to be inclined rearward and downward . 2. A lower vehicle body structure for a vehicle according to claim 1, wherein each rear wheel is supported on the vehicle body via two link members extending in the front-rear direction. 3. A lower vehicle body structure for a vehicle according to claim 2, wherein the left-right direction link member is composed of two lateral links, one end of which is connected to the vehicle body and the other end of which is connected to the axle. . 4. The lower body structure for a vehicle according to claim 1, wherein both ends of the vehicle body and the axle are connected by a coil spring, and the upper end of the coil spring is attached to the vehicle body so as to be located below a floor level. 5. The device for supporting the rear wheel according to claim 2,
Of the front-rear direction link members, an upper link is connected to an upper portion of a hub that supports a vehicle body frame and a rear wheel, and an exhaust device is disposed between the upper link and the axle. 6. The lower body structure for a vehicle according to claim 1, wherein a laterally extending cross member is provided, and the two lateral links are attached to the vehicle body by being attached to the cross members. 7. The attachment part of the two lateral links to the axle is located near an intersection with a vehicle body centerline in the front-rear direction, and the cross member has a notch in a rear part in the left-right direction. It is configured to avoid interference between the two lateral links and the cross member by arranging the mounting portion so as not to overlap the cross member in a plan view and having a bent shape. The lower body structure of the vehicle.