Suspension structure

Abstract

To provide a suspension structure capable of remarkably reducing weight and cost while maintaining a function required for a suspension.SOLUTION: A suspension structure includes suspension members and a steering gear box 10 for steering a wheel. The suspension members are constituted by left and right suspension members 40 and 50 which are spaced apart from each other in a vehicle width direction, are attached to front side members at both end portions in the vehicle width direction, respectively, and swingably support left and right lower arms 81 and 83, respectively. The left suspension member 40 and the right suspension member 50 are connected to each other via a steering gear box 10 extending in the vehicle width direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a suspension structure including a suspension member that supports a lower arm so that the lower arm can swing freely. [Background technology]

[0002] Conventionally, a typical suspension structure has been known that includes a suspension member that supports a lower arm so that it can swing freely, a stabilizer that connects the left and right suspension members to suppress roll, and a steering gearbox that transmits steering input from the steering shaft to turn the wheels (for example, Patent Document 1).

[0003] In such a general suspension structure, the suspension members are constructed as hollow bodies rather than solid bodies in order to reduce weight; specifically, they are generally formed by joining multiple divided members to form a hollow structure that extends in the vehicle width direction between the left and right wheels (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-131221 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-344130 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, in conventional vehicles including those disclosed in Patent Documents 1 and 2, it is common to design each component that constitutes the suspension structure separately, for example by designing the steering gear box, which is a chassis component, as a standalone unit and the suspension members, which are body components, as a standalone unit.

[0006] This is because the conventional design method is based on the idea that an optimal suspension structure can be achieved by combining optimally designed parts (such as suspension members, stabilizers, steering gear boxes, etc.) designed as individual units.

[0007] However, such a conventional design method can be evaluated as an optimal design method when viewed as a single steering gear box or a single suspension member, but it is difficult to say that it is an optimal design method when viewed as the entire suspension structure.

[0008] For example, in Patent Document 2, in order to reduce the weight of the suspension member, bending is adopted instead of drawing to reduce the plate thickness, and the flanges are omitted by joining the edges of the divided members in a butted state (or overlapping state). However, such improvements in the suspension member alone do not necessarily lead to a significant reduction in weight and cost of the entire suspension structure.

[0009] Also, when the steering gear box is assembled (attached) to the suspension member, the rigidity in the vehicle width direction of the entire suspension structure increases. However, in view of this, a design to reduce the rigidity in the vehicle width direction of the suspension member alone (to achieve weight reduction and cost reduction) is not carried out.

[0010] Thus, the conventional design method of designing each part constituting the suspension structure separately is difficult to be said to be an optimal design method, especially from the viewpoints of weight reduction and cost reduction, and there is room for improvement.

[0011] The present invention has been made in view of this point, and an object thereof is to provide a suspension structure capable of achieving significant weight reduction and cost reduction while maintaining the functions required for the suspension.

Means for Solving the Problems

[0012] To achieve the above object, in the suspension structure according to the present invention, other parts of the suspension member are boldly omitted, leaving only the parts that support the lower arm and the parts that are attached to the vehicle body, and each component constituting the suspension structure is treated as if it were a single component.

[0013] Specifically, the present invention is directed to a suspension structure including a suspension member and a steering gear box for steering a wheel.

[0014] And this suspension structure includes, as the above suspension member, left and right suspension members that are spaced apart in the vehicle width direction and are respectively attached to the vehicle body at both ends in the vehicle width direction and swingably support the left and right lower arms, and the left suspension member and the right suspension member are connected via the steering gear box extending in the vehicle width direction. and further includes a stabilizer supported by the left and right suspension members via a support member in front of the steering gear box in the vehicle longitudinal direction. The steering gear box has a pair of left and right mounting portions on the front side and the rear side in the vehicle longitudinal direction. The rear mounting portion is directly bolted to the left and right suspension members in the vertical direction, and the front mounting portion is attached to the left and right suspension members via the support member. The front mounting portion is configured to be bolted to the support member in the vertical direction or the horizontal direction. It is characterized by the above.

[0015] According to this configuration, by leaving the left and right suspension members that are attached to the vehicle body and swingably support the left and right lower arms respectively, and boldly omitting the parts between these left and right suspension members, significant weight reduction and cost reduction of the entire suspension structure can be achieved.

[0016] Thus, the left and right suspension members, which are spaced apart in the vehicle width direction, are connected via the steering gear box extending in the vehicle width direction without adding new members, so that while enjoying significant weight reduction and cost reduction, the steering gear box can compensate for the rigidity in the vehicle width direction and the like that the omitted parts were responsible for.

[0017] Thus, according to the suspension structure of the present invention, each component (suspension member and steering gear box) constituting the suspension structure is treated as if it were a single component, and by compensating for the insufficient part (function), it is possible to achieve a significant weight reduction and cost reduction while maintaining the functions required for the suspension. Also, in this configuration, for example, if both of the pair of left and right front mounting portions are bolted to the support member in the vertical direction, in other words, if all of the four front and rear mounting portions are bolted in the vertical direction, the assemblability of the steering gear box can be improved. On the other hand, in an engine vehicle, for example, various devices are arranged in the engine room on the front side of the steering gear box in the vehicle longitudinal direction. By appropriately setting the bolt fastening direction of the front mounting portion in the vertical direction or the horizontal direction, interference between the support member, bolts, etc. and the devices in the engine room can be suppressed.

[0018] By the way, even with the above configuration in which the left suspension member and the right suspension member are connected via a steering gear box, it is possible to maintain the functions required for the suspension. However, in the above configuration, since the height at which the reaction force from the tire is received (the support height of the lower arm) and the height at which the left and right suspension members are connected (the installation height of the steering gear box) are different, there is a possibility that a bending moment will occur in the left and right suspension members. Therefore, from the viewpoint of vehicle handling stability, it is preferable to connect the left suspension member and the right suspension member at a height as close as possible to the height at which the reaction force from the tire is received.

[0019] Here, if a reinforcing member is deliberately added, it will increase the weight and cost, and the meaning of omitting the part between the left suspension member and the right suspension member will be diminished. However, when an existing component is near the suspension member, there is no choice but to use it.

[0020] Therefore, in the above suspension structure, a brace for supporting an under cover that covers the underfloor of the vehicle may be attached to the left and right suspension members from below.

[0021] In a vehicle, an under cover for rectifying the running wind under the floor is usually provided in order to improve fuel efficiency. According to this configuration, since an existing brace for supporting such an under cover is attached to the left and right suspension members from below, it is possible to increase the planar rigidity in the vicinity of the height for supporting the lower arm (receiving the reaction force from the tire).

[0022] In this way, by using the existing brace, it is possible to improve the handling stability of the vehicle while maintaining significant weight reduction and cost reduction.

[0023] By the way, in an engine vehicle, usually, in order to suppress the driving reaction force of the engine, the engine is connected to the central portion in the vehicle width direction of the suspension member via a torque rod. However, in a suspension structure in which the portion between the left suspension member and the right suspension member is omitted, such a configuration cannot be adopted.

[0024] Therefore, in the above suspension structure, a torque rod attachment portion for attaching a torque rod connected to the engine is formed at the center in the vehicle width direction of the steering gear box, and the torque rod may be sandwiched vertically between the torque rod attachment portion and the brace.

[0025] According to this configuration, even in a structure in which the portion between the left suspension member and the right suspension member is omitted, the torque rod can be firmly supported with a simple configuration in which the torque rod is sandwiched vertically by the torque rod attachment portion and the brace without adding new members. Thereby, the driving reaction force of the engine can be suppressed.

[0026] Further, in the above suspension structure, the left and right suspension members may be configured as solid members made of aluminum die-cast.

[0027] According to this configuration, by adopting a solid suspension member made of aluminum die-cast with higher rigidity compared to a hollow suspension member, it is possible to increase the rigidity of the force application points, for example, at the support points of the lower arm and the vehicle body attachment points.

[0028] Moreover, even when using a solid suspension member made of aluminum die-cast, which is heavier than an iron-made hollow suspension member, since the part between the left and right suspension members is omitted, it is possible to suppress an increase in the weight of the entire suspension structure.

[0032] As described above, in the suspension structure according to the present invention, the left and right suspension members spaced apart in the vehicle width direction are connected by a substantially rod-shaped steering gear box or a flat beam-shaped brace. In other words, it can be said that the left and right suspension members spaced apart in the vehicle width direction are connected in the vehicle width direction by the skeletal members.

[0033] Therefore, the present invention can also be defined as a suspension structure including suspension members, wherein the suspension members are configured by left and right suspension members that are spaced apart in the vehicle width direction, attached to the vehicle body at both ends in the vehicle width direction, and each swingably support the left and right lower arms, and the left suspension member and the right suspension member are connected in the vehicle width direction via a skeletal member.

Effect of the Invention

[0034] As described above, according to the suspension structure of the present invention, it is possible to achieve significant weight reduction and cost reduction while maintaining the functions required for the suspension.

Brief Description of the Drawings

[0035]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

MODE FOR CARRYING OUT THE INVENTION

[0036] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In each figure, arrow Fw indicates the front side in the vehicle longitudinal direction, arrow Lf indicates the left side in the vehicle width direction, and arrow Up indicates the upper side in the vertical direction.

[0037] (Embodiment 1) FIG. 1 is a perspective view schematically showing a suspension structure according to the present embodiment, and FIG. 2 is an exploded perspective view schematically illustrating a suspension structure and an attachment mode to a vehicle body. In FIG. 2, only the right suspension member 50 among the suspension members is shown for easy viewing of the figure, and a part of the beam constituting the brace 30 is omitted from the illustration.

[0038] This suspension structure is applicable to the front suspension of vehicles equipped with engines, such as so-called conventional vehicles and hybrid vehicles. As shown in FIG. 1, this suspension structure includes suspension members 40 and 50 that connect a front wheel (not shown) and a vehicle body (front side member 90), a steering gear box 10 for steering the front wheel, a stabilizer 20 for suppressing roll, and a brace 30 for supporting an under cover (not shown).

[0039] - Suspension Member - As shown in FIG. 1, the suspension member is composed of a left suspension member 40 and a right suspension member 50 that are spaced apart in the vehicle width direction. That is, unlike a general suspension member that extends in the vehicle width direction between the left and right front wheels, the suspension member of this embodiment has a configuration in which the portion between the left suspension member 40 and the right suspension member 50 is boldly omitted. Also, unlike a general suspension member configured as an iron hollow structure, both the left and right suspension members 40 and 50 are configured as solid members made of aluminum die-cast.

[0040] The left and right suspension members 40 and 50 each include a main body portion 41 and 51, a front support portion 42 and 52, a rear support portion 43 and 53, a front attachment portion 44 and 54, and a rear attachment portion 45 and 55. They are attached to the front side member 90 at both ends in the vehicle width direction and swingably support the left and right lower arms 81 and 83, respectively. Since the left suspension member 40 and the right suspension member 50 are formed symmetrically, the right suspension member 50 will be described below as a representative.

[0041] The main body portion 51 extends in the vehicle longitudinal direction at approximately the same height as the right lower arm 83. As shown in FIG. 2, the main body portion 51 is formed such that the portion 51b where the steering gear box 10 is attached is higher than the portion 51a where the bracket 25 of the stabilizer 20 is attached. Two bolt holes penetrating vertically are formed in the relatively lower portion 51a, and the bracket 25 of the stabilizer 20 is bolted. Further, in the relatively higher portion 51b, a front bolt hole 51c and a rear bolt hole 51d penetrating vertically are formed, and the steering gear box 10 is fastened via bolts 18 and 19.

[0042] The front support portion 52 is provided at the front end portion of the main body portion 51 and swingably supports the right lower arm 83 about an axis extending in the vehicle longitudinal direction via a lower arm bush (not shown). On the other hand, the rear support portion 53 is provided at the rear end portion of the main body portion 51 and swingably supports the right lower arm 83 about an axis extending in the vertical direction via a lower arm bush (not shown). Thereby, while suppressing the action of a crosstalk direction force on the lower arm bush of the front support portion 52 by the lower arm bush of the rear support portion 53, the front support portion 52 absorbs the impact received by the tire (front wheel) and displaces the front wheel in the vertical direction with respect to the vehicle body.

[0043] As shown in Fig. 2, the right suspension member 50 is attached to the front side member 90 at the front and rear attachment portions 54 and 55. More specifically, the front side member 90 has a front portion 91 extending in the vehicle longitudinal direction and a rear portion 93 that is lower than the front portion 91 and extends in the vehicle longitudinal direction inside the vehicle width direction. The front attachment portion 54 extends obliquely upward toward the outside in the vehicle width direction (right side) from the rear side of the front support portion 52 in the main body portion 51, and its upper end portion is bolted to the front portion 91 of the front side member 90 from below. On the other hand, the rear attachment portion 55 extends further rearward from the rear support portion 53 in the main body portion 51, and its rear end portion is bolted to the rear portion 93 of the front side member 90 from below.

[0044] -Steering Gear Box- The steering gear box 10 constitutes an electric power steering system that assists the driver's steering operation. As shown in Fig. 1, it includes a housing 11 extending in the vehicle width direction, a pinion shaft 12 connected to a steering shaft (not shown), a tie rod 13, and a boot 14 that covers the portion of the tie rod 13 extending from the housing 11. This steering gear box 10 is connected to a steering wheel (not shown) via a steering shaft. When an input is made to the steering wheel by the driver's steering operation, the rotational displacement with assist torque added by an electric motor (not shown) is converted into a displacement in the vehicle width direction of the tie rod 13 to change the direction of the front wheels.

[0045] In this embodiment, as the electric power steering system, a column assist type is adopted in which an electric motor and a reduction gear (not shown) are provided in the column portion of the steering shaft in the passenger compartment to drive the column shaft. However, the present invention is not limited to this, and a pinion assist type in which an electric motor is provided in the housing 11 to drive a pinion gear (not shown) may also be adopted.

[0046] The steering gear box 10 has a pair of left and right mounting portions 15 and 16 on the front side and the rear side in the vehicle longitudinal direction. Specifically, on the front side in the vehicle longitudinal direction of the housing 11 of the steering gear box 10, as shown in FIG. 2, a pair of left and right front mounting portions 15 are provided at positions corresponding to the portions 51b (front bolt holes 51c) of the main body portions 41 and 51 of the left and right suspension members 40 and 50. Further, on the rear side in the vehicle longitudinal direction of the housing 11 of the steering gear box 10, as shown in FIGS. 1 and 2, a pair of left and right rear mounting portions 16 are provided at positions corresponding to the portions 51b (rear bolt holes 51d) of the main body portions 41 and 51 of the left and right suspension members 40 and 50.

[0047] A bolt hole penetrating in the vertical direction is formed in each of the pair of left and right front mounting portions 15 and the pair of left and right rear mounting portions 16. Then, the pair of left and right front mounting portions 15 are directly fastened in the vertical direction to the left and right suspension members 40 and 50 by bolts 18 inserted through the front bolt holes 51c, and the pair of left and right rear mounting portions 16 are directly fastened in the vertical direction to the left and right suspension members 40 and 50 by bolts 19 inserted through the rear bolt holes 51d. That is, the steering gear box 10 is fastened (supported) at four points to the left and right suspension members 40 and 50 via bolts 18 and 19.

[0048] Thereby, in the steering structure of the present embodiment, the left suspension member 40 and the right suspension member 50 are connected via the steering gear box 10 extending in the vehicle width direction. In other words, in the steering structure of the present embodiment, the steering gear box 10 functions as a skeletal member that connects the left suspension member 40 and the right suspension member 50 in the vehicle width direction.

[0049] Further, at the center in the vehicle width direction in the housing 11 of the steering gear box 10, as shown in FIGS. 1 and 2, a torque rod mounting portion 17 having a bolt hole penetrating in the vertical direction for mounting a torque rod 85 connected to an engine (not shown) is formed.

[0050] -Stabilizer- The stabilizer 20 has a torsion bar 21 extending in the vehicle width direction and arm portions 22 that are bent substantially L-shaped from both ends in the vehicle width direction of the torsion bar 21 and extend forward in the vehicle longitudinal direction. The tip ends of the arm portions 22 are connected to the left and right lower arms 81 and 83 via bushings (not shown). The stabilizer 20 is configured to suppress rolling and maintain horizontal stability by generating a torsional stress in the torsion bar 21 when there is a difference in the stroke amounts on the left and right during cornering or the like and correcting the stroke amounts on the left and right in the direction to make them the same by the restoring force.

[0051] The stabilizer 20 is supported by the left and right suspension members 40 and 50 via brackets 25 on the front side in the vehicle longitudinal direction with respect to the steering gear box 10. More specifically, a pair of left and right stabilizer bushings 23 are fitted to the torsion bar 21 of the stabilizer 20, and brackets 25 attached to cover these stabilizer bushings 23 are bolted to portions 51a of the main body portions 41 and 51, respectively, so that the stabilizer 20 is supported by the left and right suspension members 40 and 50.

[0052] <\ -Brace- The brace 30 suspends and supports an under cover (not shown) that covers the underfloor of the vehicle for rectifying the running wind under the floor. As shown in FIG. 2, the brace 30 is attached to the left and right suspension members 40 and 50 from below by being partly fastened with dedicated bolts 35 and partly co-fastened with bolts 18 for fastening the steering gear box 10.

[0053] In this way, since the brace 30 is attached to the left and right suspension members 40 and 50 from below, it is possible to increase the planar rigidity in the vicinity of the height that supports (receives the reaction force from the tire) the left and right lower arms 81 and 83 in the suspension structure. Note that the brace 30 is not a simple flat plate, but as shown in FIG. 1, it is formed in a shape that combines a substantially linear beam 31 extending in the vehicle width direction, a substantially linear beam 32 extending obliquely, etc., with the minimum number of beams considering the direction of the force acting on the left and right suspension members 40 and 50, thereby achieving weight reduction. In this way, in the steering structure of the present embodiment, in addition to the steering gear box 10, the brace 30 also functions as a framework member that connects the left suspension member 40 and the right suspension member 50 in the vehicle width direction.

[0054] Also, since the brace 30 is attached to the left and right suspension members 40 and 50 from below, the torque rod 85 connected to the engine is firmly supported in a state of being sandwiched vertically between the torque rod attachment portion 17 of the steering gear box 10 and the brace 30.

[0055] -Function and Effect- According to the present embodiment, while being attached to the front side member 90 and leaving the left and right suspension members 40 and 50 that swingably support the left and right lower arms 81 and 83 respectively, the portion between the left suspension member 40 and the right suspension member 50 is boldly omitted. Therefore, compared with the case of using a suspension member extending in the vehicle width direction between the left and right front wheels, significant weight reduction and cost reduction can be achieved.

[0056] Moreover, the left suspension member 40 and the right suspension member 50, which are spaced apart in the vehicle width direction, are connected via the steering gear box 10 extending in the vehicle width direction without adding a new member. Thus, while enjoying significant weight reduction and cost reduction, the steering gear box 10 can compensate for the rigidity in the vehicle width direction and other properties that the omitted part was responsible for.

[0057] Thus, in the suspension structure of the present embodiment, the left and right suspension members 40 and 50 swingably support the left and right lower arms 81 and 83, the steering gear box 10 changes the direction of the front wheels, the stabilizer 20 suppresses rolling, and the brace 30 suspends and supports the under cover. Therefore, it is possible to achieve significant weight reduction and cost reduction while maintaining the functions required for the suspension.

[0058] Here, even with only the configuration in which the left suspension member 40 and the right suspension member 50 are connected via the steering gear box 10, it is possible to maintain the functions required for the suspension. However, in the suspension structure of the present embodiment, since the height at which the reaction force from the tire is received (the support height of the left and right lower arms 81 and 83) and the height at which the left and right suspension members 40 and 50 are connected (the installation height of the steering gear box 10) are different, a bending moment may occur in the left and right suspension members 40 and 50.

[0059] Therefore, from the viewpoint of the vehicle's handling stability, it is preferable to connect the left suspension member 40 and the right suspension member 50 at a height as close as possible to the height at which the reaction force from the tire is received. In the present embodiment, since the brace 30 for supporting the under cover is attached to the left and right suspension members 40 and 50 from below, it is possible to increase the planar rigidity in the vicinity of the height at which the left and right lower arms 81 and 83 are supported (receiving the reaction force from the tire).

[0060] In this way, by using the brace 30 for suspending and supporting the under cover that is normally provided for improving fuel efficiency without specially adding a new reinforcing member, it is possible to improve the handling stability of the vehicle while maintaining significant weight reduction and cost reduction.

[0061] Further, since the torque rod 85 is sandwiched vertically between the torque rod mounting portion 17 of the steering gear box 10 and the brace 30, even in a structure in which the portion between the left suspension member 40 and the right suspension member 50 is omitted, the torque rod 85 can be firmly supported without adding a new member, and thereby, the driving reaction force of the engine can be suppressed.

[0062] Furthermore, by adopting the solid suspension members 40 and 50 made of aluminum die-cast with higher rigidity compared to the hollow suspension members, the bearing point rigidity can be increased at the front support portions 42 and 52 and the rear support portions 43 and 53 which are the support points of the lower arms 81 and 83, the front attachment portions 44 and 54 and the rear attachment portions 45 and 55 which are the attachment points to the front side member 90, the main body portions 41 and 51 which are the attachment points of the steering gear box 10, etc.

[0063] Moreover, even when using the solid suspension members 40 and 50 made of aluminum die-cast which are heavier than the iron-made hollow suspension members, since the portion between the left suspension member 40 and the right suspension member 50 is omitted, an increase in the vehicle body weight can be suppressed.

[0064] (Modification 1) In this modification, the mounting manner of the steering gear box to the left and right suspension members is different from that in the above-described Embodiment 1. Hereinafter, the description will focus on the differences from Embodiment 1.

[0065] FIG. 3 is a perspective view schematically showing the suspension structure according to this modification. In the first embodiment, as described above, the front mounting portion 15 and the rear mounting portion 16 of the steering gear box 10 are directly bolted in the vertical direction to the left and right suspension members 40 and 50. On the other hand, in this modification, as shown in FIG. 3, similar to the first embodiment, the rear mounting portion 16 of the steering gear box 10' is directly bolted in the vertical direction to the left and right suspension members 40' and 50'. However, different from the first embodiment, the front mounting portions 15A and 15B of the steering gear box 10' are bolted to the left and right suspension members 40' and 50' via brackets 26 and 27.

[0066] More specifically, the left and right suspension members 40' and 50' have substantially the same configuration as the above-described left and right suspension members 40 and 50, except that the front bolt holes 51c are not formed.

[0067] Also, the steering gear box 10' has substantially the same configuration as the above-described steering gear box 10, except that front mounting portions 15A and 15B are formed in the housing 11' instead of the front mounting portion 15 as shown in FIG. 3. The front mounting portions 15A and 15B are formed so as to project forward in the vehicle longitudinal direction from the housing 11' and extend above the stabilizer 20. A bolt hole penetrating in the vehicle width direction is formed in the front mounting portion 15A, while a bolt hole penetrating in the vertical direction is formed in the front mounting portion 15B.

[0068] Furthermore, similar to the bracket 25, the bracket 26 is attached to cover the stabilizer bush 23 and bolted to the left suspension member 40'. However, different from the bracket 25, it has an attachment portion 26a that protrudes upward and has a bolt hole penetrating in the vehicle width direction. Also, similar to the bracket 25, the bracket 27 is attached to cover the stabilizer bush 23 and bolted to the right suspension member 50'. However, different from the bracket 25, it has an attachment portion 27a that protrudes inward (left side) in the vehicle width direction and has a bolt hole penetrating in the vertical direction.

[0069] Thus, as shown in FIG. 3, the steering gear box 10' is directly bolted in the vertical direction to the left and right suspension members 40', 50' at the rear attachment portion 16, the front attachment portion 15A is bolted horizontally to the attachment portion 26a of the bracket 26, and the front attachment portion 15B is bolted vertically to the attachment portion 27a of the bracket 27, so that it is supported at four points with respect to the left and right suspension members 40', 50'.

[0070] -Function and Effect- In a vehicle equipped with an engine, various devices are arranged in the engine room located in front of the steering gear box 10' in the vehicle longitudinal direction. According to this modified example, by omitting the bolt 18 or setting the bolt fastening direction of the front attachment portion 15A horizontally, it is possible to suppress interference between the bracket 26, bolts, etc. and the devices in the engine room.

[0071] (Modified Example 2) This modified example is different from the above-described Embodiment 1 in that the suspension structure does not include the brace 30. Hereinafter, the description will focus on the differences from Embodiment 1.

[0072] FIG. 4 is a perspective view schematically showing the suspension structure according to this modified example. This suspension structure is applied to, for example, the front suspension of a vehicle not equipped with an engine such as an electric vehicle. In a vehicle not equipped with an engine, of course, the torque rod 85 is not necessary (it is not necessary to sandwich the torque rod 85 vertically between the steering gear box 10 and the brace 30), so in the suspension structure of this modified example, the brace 30 is omitted.

[0073] Therefore, as shown in FIG. 4, the suspension structure of this modified example has a simple structure in which the stabilizer 20 is supported via the bracket 25 on the left and right suspension members 40 and 50 that are spaced apart in the vehicle width direction and are connected via the steering gear box 10.

[0074] Note that this modified example only means that the suspension structure does not include the brace 30, and does not deny that the vehicle itself includes the brace 30 for supporting the under cover.

[0075] -Function and Effect- According to this embodiment, even in a vehicle not equipped with an engine such as an electric vehicle, it is possible to achieve a significant weight reduction and cost reduction in the entire suspension structure while maintaining the functions required for the suspension.

[0076] (Embodiment 2) This embodiment is different from the above Embodiment 1 in that the left and right suspension members are made of iron hollow members. Hereinafter, the description will focus on the differences from Embodiment 1.

[0077] FIG. 5 is a perspective view schematically showing the suspension structure according to this embodiment, and FIG. 6 is an exploded perspective view schematically explaining the suspension structure and the mounting mode to the vehicle body. The left and right suspension members 60 and 70 are configured as hollow structures extending in the vehicle width direction, which are formed by joining a plurality of iron plates that have been drawn or bent.

[0078] As shown in FIG. 5, the left and right suspension members 60 and 70 each include a main body portion 61, 71, a front support portion 62, 72, a rear support portion 63, 73, a front attachment portion 64, 74, and a rear attachment portion 65, 75. Note that the main body portion 61, the front support portion 62, the rear support portion 63, the front attachment portion 64, and the rear attachment portion 65 of the left suspension member 60 have the same configuration as the main body portion 41, the front support portion 42, the rear support portion 43, the front attachment portion 44, and the rear attachment portion 45 of the left suspension member 40, respectively, except for the difference between a hollow body and a solid body, so the description thereof will be omitted. Similarly, the main body portion 71, the front support portion 72, the rear support portion 73, the front attachment portion 74, and the rear attachment portion 75 of the right suspension member 70 have the same configuration as the main body portion 51, the front support portion 52, the rear support portion 53, the front attachment portion 54, and the rear attachment portion 55 of the right suspension member 50, respectively, except for the difference between a hollow body and a solid body, so the description thereof will be omitted.

[0079] As shown in FIG. 6, for these left and right suspension members 60 and 70, the upper end portion of the front attachment portion 74 is bolted to the front portion 91 of the front side member 90 from below, and the rear end portion of the rear attachment portion 75 is bolted to the rear portion 93 of the front side member 90 from below. Further, as shown in FIG. 5, for the left and right suspension members 60 and 70, the front support portions 62 and 72 support the left and right lower arms 81 and 83 so as to be swingable about an axis extending in the vehicle front-rear direction, while the rear support portions 63 and 73 support the left and right lower arms 81 and 83 so as to be swingable about an axis extending in the vertical direction.

[0080] Furthermore, as shown in FIG. 6, the steering gear box 10 is supported at four points on the left and right suspension members 60 and 70 by fastening the front mounting portion 15 and the rear mounting portion 16 to the main body portions 61 and 71 via bolts 18 and 19. Also, the stabilizer 20 is supported on the main body portions 61 and 71 of the left and right suspension members 60 and 70 via brackets 25. Furthermore, the brace 30 is attached to the left and right suspension members 60 and 70 from below.

[0081] -Function and Effect- According to the present embodiment, by boldly omitting the portion between the left and right suspension members 60 and 70 while leaving the left and right suspension members 60 and 70, compared with the case of using a hollow iron suspension member extending in the vehicle width direction between the left and right front wheels, a significant weight reduction and cost reduction in the entire suspension structure can be achieved.

[0082] (Modification Example) In this modification example, the mounting manner of the steering gear box to the left and right suspension members is different from that in the second embodiment. Hereinafter, the description will focus on the differences from the second embodiment.

[0083] FIG. 7 is a perspective view schematically showing the suspension structure according to this modification example. In this modification example, as shown in FIG. 7, the rear mounting portion 16 of the steering gear box 10' is directly bolted in the vertical direction to the left and right suspension members 60' and 70', while the front mounting portions 15A and 15B of the steering gear box 10' are bolted to the left and right suspension members 60' and 70' via brackets 26 and 27.

[0084] More specifically, the left and right suspension members 60’, 70’ have the same configuration as the above-described left and right suspension members 60, 70, except that no front bolt holes corresponding to the front attachment portion 15 of the steering gear box 10 are formed. Then, the steering gear box 10’ is bolted directly in the vertical direction to the left and right suspension members 60’, 70’ at the rear attachment portion 16, and as shown in FIG. 7, the front attachment portion 15A is bolted horizontally to the attachment portion 26a of the bracket 26, and the front attachment portion 15B is bolted vertically to the attachment portion 27a of the bracket 27, so that the left and right suspension members 60’, 70’ are supported at four points.

[0085] According to this modification example, the same effects as those of Modification Example 1 of the above-described Embodiment 1 can be obtained.

[0086] (Other Embodiment Forms) The present invention is not limited to the embodiment forms, and can be implemented in various other forms without departing from its spirit or main features.

[0087] In each of the above-described embodiment forms, the suspension structure of the present invention is applied to the front suspension, but the present invention is not limited thereto, and the suspension structure of the present invention may also be applied to the rear suspension.

[0088] Also, in Modification 1 of the above-described Embodiment 1 and the modification of the above-described Embodiment 2, while the front attachment portion 15A is bolted to the bracket 26 in the lateral direction, the front attachment portion 15B is bolted to the bracket 27 in the vertical direction. However, the present invention is not limited to this. For example, both the front attachment portions 15A and 15B may be bolted to the bracket in the vertical direction, or both the front attachment portions 15A and 15B may be bolted to the bracket in the lateral direction. For example, if both the front attachment portions 15A and 15B are configured to be bolted to the bracket in the vertical direction, in other words, if all four points are configured to be bolted in the vertical direction, the assemblability of the steering gear box 10' can be improved.

[0089] In each of the above-described embodiments, the left suspension members 40 and 60 and the right suspension members 50 and 70 are connected via the steering gear box 10 and the brace 30. However, the present invention is not limited to this. In addition to the steering gear box 10 and the brace 30, for example, lightweight skeletal members extending in the same direction as the beams 31 and 32 of the brace 30 may be used to connect the left suspension members 40 and 60 and the right suspension members 50 and 70.

[0090] Thus, the above-described embodiments are merely illustrative in all respects and should not be construed in a limiting sense. Further, modifications and changes belonging to the equivalent scope of the claims are all within the scope of the present invention.

Industrial Applicability

[0091] According to the present invention, it is possible to achieve a significant weight reduction and cost reduction while maintaining the functions required for the suspension. Therefore, it is extremely beneficial when applied to a suspension structure including a suspension member that swingably supports a lower arm.

Explanation of Reference Numerals

[0092] 10, 10' Steering gear box (skeletal member) 15 Front mounting part 16 Rear mounting part 17 Torque rod mounting part 20 Stabilizer 26 Bracket (support member) 27 Bracket (support member) 30 Brace (skeleton member) 40, 40’ Left suspension member 50, 50’ Right suspension member 60, 60’ Left suspension member 70, 70’ Right suspension member 81 Left lower arm 83 Right lower arm 85 Torque rod 90 Front side member (vehicle body)

Claims

1. A suspension structure comprising a suspension member and a steering gear box for steering a wheel, As the suspension member, left and right suspension members are provided which are spaced apart in the vehicle width direction and attached to the vehicle body at both ends in the vehicle width direction, and which swingably support the left and right lower arms respectively, The left suspension member and the right suspension member are connected via the steering gear box extending in the vehicle width direction, A stabilizer supported by the left and right suspension members via a support member is further provided on the front side in the vehicle longitudinal direction with respect to the steering gear box, The steering gear box has a pair of left and right attachment portions on the front and rear sides in the vehicle longitudinal direction, the rear attachment portion is directly bolted to the left and right suspension members in the vertical direction, and the front attachment portion is attached to the left and right suspension members via the support member, The front attachment portion is configured to be bolted to the support member in the vertical direction or the horizontal direction. A suspension structure characterized by this.

2. In the suspension structure according to Claim 1 above, A brace for supporting an under cover that covers the floor of the vehicle is attached to the left and right suspension members from below. A suspension structure characterized by this.

3. In the suspension structure according to Claim 2 above, A torque rod attachment portion for attaching a torque rod connected to the engine is formed at the center in the vehicle width direction of the steering gear box, The torque rod is sandwiched vertically by the torque rod attachment portion and the brace. A suspension structure characterized by this.

4. In the suspension structure according to Claim 1 above, The left and right suspension members are configured as solid members made of aluminum die-cast. A suspension structure characterized by this.

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