JP6442211B2 - Suspension device - Google Patents

Description

  The present invention relates to a suspension device, and more particularly to a suspension device that supports a subframe with a floating bush interposed in a vehicle body frame.

  As a suspension for supporting a rear wheel of a vehicle, a suspension device is known in which a subframe is supported on a body frame such as a left and right main frame via a floating bush, and a wheel is supported on the subframe by a suspension arm.

  For example, the sub-frame is formed in a substantially rectangular frame shape in which a pair of front and rear frame members extending in the vehicle body width direction and a pair of side frame members extending in the front-rear direction are integrally connected to the lower surface of the vehicle body. A housing that holds the wheels is supported at the distal ends of a plurality of suspension arms whose base ends are supported by the side frame members. The front frame member, the rear frame member, and the side frame member of the subframe are attached and supported on the lower surface of the vehicle body via a floating bush made of vibration-proof rubber.

  In such a suspension device, for example, when a vehicle rides on a road with a step or protrusion on the road surface, the vibration called harshness that is input to the vehicle body is suppressed to ensure riding comfort. To achieve this, it is necessary to increase the spring constant of the floating bush. On the other hand, when the spring constant of the floating bush is increased, the support rigidity of the subframe in the vehicle body width direction is lowered, which causes a decrease in steering stability during turning.

  In addition, in the subframe where the suspension arm that supports the wheels is mounted, the spring constant of the floating bush is increased with respect to the load input in the vertical direction of the vehicle in order to suppress the harshness while suppressing the influence on the steering stability. It is known to reduce the spring constant with respect to load input in the vehicle longitudinal direction (see, for example, Patent Document 1).

JP-A-8-48262

  However, in the subframe where the suspension arm that supports the wheels is mounted, if the spring constant of the floating bush is set high and the floating bush is deformed and the subframe is displaced relative to the vehicle body, the positional relationship of the wheels with respect to the vehicle body Therefore, it is necessary to ensure the rigidity of the floating bush in order to reduce the influence of the displacement.

  Here, as a result of earnest research experiments, the inventors of the present invention have seen from the side of the vehicle on the subframe supported via the floating bush when the wheel rides on a step or protrusion on the road and passes. Focusing on the fact that a so-called rear pulling force acts from the front to the rear, improving the steering stability of the vehicle while suppressing harshness by actively utilizing the displacement of the side frame due to the elastic deformation of the floating bush Has been found.

  Accordingly, it is an object of the present invention to provide a suspension device that can ensure steering stability of a vehicle while suppressing harshness.

The suspension device according to claim 1, which achieves the above object, includes a sub-frame supported on a vehicle body frame disposed on a lower surface of the vehicle body via a floating bush, a housing for rotatably supporting a wheel, and the housing A suspension arm whose front end is swingably supported and a base end is swingably supported by the subframe, and a lower end is connected to an intermediate portion between the front end and the base end of the suspension arm, and an upper end is In the suspension device including a vertical force transmission member that is connected to the lower surface of the vehicle body, the floating bushes are provided on the vehicle body front side and the rear side of the subframe in pairs on the left and right sides. includes a cylindrical inner extending axially is supported on the body frame, the outer cylinder is held by the sub-frame , And a resilient member interposed between the inner cylinder and the outer cylinder, when the external load to the outer cylinder from the front of the vehicle body is inputted, and coupling displace the outer cylinder downwardly with respect to the inner tube The sub-frame is moved downward with respect to the inner cylinder .

According to this, for example, when the vehicle travels forward and the wheel rides on a road step or protrusion, the wheel is held by the body frame of the floating bush as the subframe moves backward due to an external load. When the outer cylinder is displaced downward relative to the inner cylinder , the subframe is lowered, so that the base end of the suspension arm is lowered and the ascending stroke of the vertical force transmission member is reduced. That is, the vertical load input is reduced, and harshness can be reduced. On the other hand, steering stability can be secured by maintaining a high spring constant in the radial direction of the floating bush.

According to a second aspect of the present invention, in the suspension device according to the first aspect, the shaft center of each floating bush is in a forwardly inclined state in which it shifts to the front side of the vehicle body as it moves from below to above, and the inner cylinder The outer peripheral surface and the inner peripheral surface of the outer cylinder extend in the axial direction .

According to a third aspect of the present invention, in the suspension device according to the first aspect, the axial center of each floating bush extends in the vertical direction, and the elastic member has an annular shape with the front being downward with respect to the rear side. It is arranged .

According to a fourth aspect of the present invention, in the suspension device according to the first aspect , the shaft center of each floating bush extends in the vertical direction, and the outer peripheral surface of the inner cylinder and the inner peripheral surface of the outer cylinder are upward. As the vehicle moves downward from the vehicle, the vehicle is displaced backward .

According to a fifth aspect of the present invention, in the suspension device according to any one of the first to fourth aspects, the suspension arm includes a plurality of suspension arms, and a lower end of the vertical force transmission member is connected to any one of the suspension arms. It is characterized by being.

  This shows a specific configuration of the suspension device, and includes, for example, a plurality of suspension arms such as a front lateral link, a rear lateral link, and an upper arm, and transmits vertical force to one of the suspension arms, for example, the rear lateral link. The lower ends are connected.

A sixth aspect of the present invention is the suspension apparatus according to any one of the first to fifth aspects, wherein the vertical force transmitting member is a shock absorber. This illustrates a specific configuration in which the vertical force transmission member is a shock absorber.

  According to the present invention, when the vehicle travels forward and the wheel rides on a step or protrusion on the road surface, the outer cylinder moves downward with respect to the inner cylinder as the sub-frame moves backward. The subframe is lowered, the ascending stroke of the vertical force transmitting member is reduced, the input load to the lower surface of the vehicle body is reduced, and harshness can be reduced.

1 is a schematic plan view of a suspension device as seen from below a rear part of a vehicle body showing an outline of an embodiment of the present invention. It is II arrow directional view of FIG. It is the III-III sectional view taken on the line of FIG. It is the IV-IV sectional view taken on the line of FIG. It is a schematic diagram which shows the structure of the suspension apparatus of FIG. 1, Comprising: The state seen from the vehicle back is shown. It is a side view which shows typically the principal part of a sub-frame. It is explanatory drawing which shows an effect | action typically. It is an outline explanatory view of acceleration of input load to a floor, and vibration attenuation. It is outline | summary explanatory drawing of a floating bush. It is outline | summary explanatory drawing of a floating bush.

  Hereinafter, an embodiment of a suspension device according to the present invention will be described with reference to the drawings.

1 is a schematic plan view of the rear part of a vehicle body as viewed from below, FIG. 2 is a view taken along the line II in FIG. 1, FIG. 3 is a sectional view taken along line III-III in FIG. It is IV sectional view. In the figure, the arrow W indicates the vehicle body width direction, and the arrow F r indicates the vehicle front direction.

  As shown in FIG. 1, a vehicle body frame 1 having left and right main frames 2 disposed on both sides of a floor 5 serving as a lower surface of the vehicle body and extending in the longitudinal direction of the vehicle body and a cross member 3 extending in the vehicle body width direction is provided. And a subframe 10 extending in the vehicle body width direction is disposed on the lower surface of the vehicle body frame 1.

  The sub frame 10 is formed in a substantially rectangular frame shape by a front frame member 11 and a rear frame member 12 extending in the vehicle body width direction, and left and right side frame members 13 extending in the vehicle body front-rear direction. Front side ends of the side frame members 13 forming the front end portion of the subframe 10 are supported by the left and right main frames 2 by the floating bush 21 and the phosphorus hose 25, and the side frames forming the rear left and right end portions of the subframe 10. The rear ends of the members 13 are supported by the main frame 2 and the cross member 3 via the floating bush 31 and the phosphorus hose 35, respectively. The support structure of the subframe 10 by the floating bushes 21 and 31 and the phosphorus hoses 25 and 35 will be described later.

  The wheels 50 are supported on vehicle body members such as the subframe 10 and the main frame 2 by various suspension arms. In the present embodiment, the housing 41 that rotatably supports the wheel 50 has a shaft-like base end that is pivotably supported at the front end of the housing 41 via the floating bush 42a and extends in the vehicle body width direction. The front lateral link 42 is swingably mounted and supported near the front end of the side frame member 13 via the floating bush 42b and the bracket 42c, and the front end of the housing 41 is swingable via the floating bush 43a. A rear lateral link 43 that is supported by the shaft and extends in the vehicle body width direction and has a base end pivotably mounted and supported near the rear end of the side frame member 13 via the floating bush 43b and the bracket 43c. The front end of the housing 41 is swingably supported via a floating bush 44a so that the front side of the vehicle body A trailing link 44 that is pivotally attached to and supported by the subframe 10 or the lower surface 2a of the main frame 2 via a floating bush 44b and a bracket 44c, and a distal end of the housing 41. The base end is supported so as to be able to swing in the vertical direction by an upper arm 45 that is swingably connected and extends in the vehicle body width direction and has a base end swingably supported by the side frame member 13. Further, the lower end of the rear lateral link 43 in the axial direction, more specifically in the vicinity of the front end, is supported via a floating bush 46a, extends in the vertical direction, and the upper end is supported on the lower surface of the vehicle body such as the floor 5 by a bracket or the like. A shock absorber 46, which is a vertical force transmission member comprising a damper 46b and a spring 46c, is installed.

  As shown in FIG. 3, a front mounting portion 2A is formed on the lower surface 2a of the main frame 2 where the front portion of the subframe 10 is supported. The front mounting portion 2A is inclined so as to rise from the front to the rear of the vehicle body. The A mounting hole 2Aa is drilled in the front mounting portion 2A, and a welding nut 30 is fixedly provided corresponding to the mounting hole 2Aa.

  On the other hand, a cylindrical front bush mounting portion 14 is formed at the front end of the side frame member 13 of the subframe 10. The front bush mounting portion 14 is set to an inclination angle α that inclines forward of the vehicle and inclines forward with respect to the vertical direction a so that the central axis moves rearward as the central axis moves downward from above.

  The floating bush 21 includes an inner cylinder 22 through which a mounting bolt 28 serving as a support shaft can pass, an outer cylinder 23 formed with flanges 23a and 23b press-fitted to the front bush mounting section 14, and the inner cylinder 22 It is integrally constituted by an elastic member 24 such as rubber which is filled between the cylinders 23 and joined to the inner cylinder 22 and the outer cylinder 23 by vulcanization adhesion.

The floating bush 21 is set such that the spring constant in the axial direction A is lower than the spring constant in the radial direction B perpendicular to the axial direction A. That is, it is soft in the axial direction A, has a large deformation stroke, and is hard in the radial direction B.

  On the other hand, the phosphorus hose 25 is capable of coming into contact with the lower end 22b of the inner cylinder 22 of the floating bush 21 and has a base end portion 26 in which a mounting hole 26a is formed, and extends from the base end portion 26 to the lower surface 2a of the main frame 2. It is formed by a plate-like member having a tip portion 27 that abuts and is joined by a mounting bolt 29.

  Then, an upper end 22a of the inner cylinder 22 of the floating bush 21 in which the outer cylinder 23 is fixed to the front bush mounting part 14 of the side frame member 13 is contacted with the front mounting part 2A formed on the lower surface 2a of the main frame 2. The base end portion 26 of the phosphorus hose 25 is brought into contact with the lower end 22b of the inner cylinder 22 and positioned, and the distal end portion 27 of the phosphorus hose 25 is brought into contact with the lower surface 2a of the main frame 2 and positioned.

  It is inserted from the mounting hole 26a formed in the base end portion 26 of the positioned phosphorus hose 25 and passes through the inner cylinder 22 of the floating bush 21 and the mounting hole 2Aa of the front mounting portion 2A and is screwed into the welding nut 30. The base end portion 26 of the floating bush 21 and the phosphorus hose 25 is attached and supported on the lower surface 2 a of the main frame 2 by the attachment bolt 28.

  Further, the distal end portion 27 of the phosphorus hose 25 that is positioned in contact with the lower surface 2 a of the main frame 2 is attached to the lower surface 2 a of the main frame 2 by the mounting bolt 29.

  Thus, the inner cylinder 22 and the mounting bolt 28 of the floating bush 21 that supports the front end of the side frame member 13 on the main frame 2 are supported by the front mounting section 2A of the main frame 2 and protrude from the inner cylinder 22. The lower end of the mounting bolt 28 is supported by the main frame 2 via the phosphorus hose 25, and the floating bush 21 is held in a forward tilted state inclined forward of the vehicle body at an inclination angle α with respect to the vertical direction a.

In the floating bush 21 which is inclined forward at this inclination angle α and the spring constant in the axial direction A is set lower than the spring constant in the radial direction B, the external load P is input to the outer cylinder 23 horizontally from the front direction. Then , a radial component force P1 that relatively displaces the outer cylinder 23 in the radial direction B with respect to the inner cylinder 22 by the component action of the inclined inner cylinder 22 and outer cylinder 23, and the outer cylinder 23 with respect to the inner cylinder 22. As a result, an axial component force P2 that is displaced in the axial direction A is generated. Here, since the spring constant in the axial direction A is set lower than the spring constant in the radial direction B, the outer cylinder 23 is relatively displaced relative to the inner cylinder 22 in the axial direction A compared to the radial direction B. . In FIG. 3, the magnitudes of P1 and P2 indicate the magnitude of relative displacement due to the component force. That is, the floating bush 21 has a coupled component P3 that displaces the outer cylinder 23 downward with respect to an external load P input to the outer cylinder 23 from the front direction, that is, a so-called spring constant principal axis. The outer cylinder 23 has a descending component P4 that descends according to the coupled component P3. The descending component P4 is set to the maximum when the inclination angle α of the floating bush 21 is 45 °.

  Further, as shown in FIG. 4, a rear mounting portion 2B that is inclined to rise as it moves from the front to the rear of the vehicle body is formed on the lower surface 2a of the portion of the main frame 2 that supports the rear portion of the subframe 10. Is done. A mounting hole 2Ba is drilled in the rear mounting portion 2B, and a welding nut 40 is fixedly provided corresponding to the mounting hole 2Ba.

  On the other hand, a cylindrical rear bush mounting portion 15 is formed at the rear end of the side frame member 13 of the subframe 10. The rear bush mounting portion 15 is set so as to incline forward at an inclination angle α with respect to the vertical direction a so that the central axis moves rearward as the central axis moves from upper to lower.

The floating bush 31 is the same as the floating bush 21, and an inner cylinder 32 through which a mounting bolt 38 serving as a support shaft can pass, an outer cylinder 33 having flanges 33a and 33b formed at both ends, and the inner cylinder 32, It is integrally constituted by an elastic member 34 such as rubber interposed between the outer cylinder 33. The floating bush 31 is set such that the spring constant in the axial direction A is lower than the spring constant in the radial direction B. That is, it is soft in the axial direction A, has a large deformation stroke, and is hard in the radial direction B.

  On the other hand, the phosphorus hose 35 is in contact with the lower end 32b of the inner cylinder 32 of the floating bush 31 and has a base end portion 36 in which a mounting hole 36a is formed, and extends from the base end portion 36 to contact the cross member 3. It is formed by a plate-shaped member having a coupling portion 37 coupled by a mounting bolt 39.

  And the upper end 32a of the inner cylinder 32 of the floating bush 31 in which the outer cylinder 33 is fixed to the rear bush mounting part 15 of the side frame member 13 to the rear side mounting part 2B formed on the lower surface 2a of the main frame 2. , The base end portion 36 of the phosphorus hose 35 is abutted against the lower end 32b of the inner cylinder 32, and the attachment portion 37 of the phosphorus hose 35 is abutted against the cross member 3 for positioning.

  It is inserted from the mounting hole 36a formed in the base end portion 36 of the positioned phosphorus hose 35, penetrates through the mounting hole 2Ba to the inner cylinder 32 and the rear mounting portion 2B of the floating bush 31, and is screwed into the welding nut 40. The floating bush 31 and the base end portion 36 of the phosphorus hose 35 are attached and supported on the lower surface 2 a of the main frame 2 by the mounting bolt 38.

  Furthermore, the front end portion 37 of the phosphorus hose 35 positioned in contact with the lower surface 2 a of the main frame 2 is attached to the lower surface 2 a of the main frame 2 by the mounting bolt 39.

  Thus, the inner cylinder 32 and the mounting bolt 38 of the floating bush 31 that supports the rear end of the side frame member 13 on the main frame 2 are supported at the upper end by the rear mounting section 2B of the main frame 2 and the inner cylinder 32. The lower end of the mounting bolt 38 protruding from the main frame 2 is supported via the phosphorus hose 35, and the floating bush 31 is tilted forward and held at an inclination angle α with respect to the vertical direction a.

When the external bushing P is input to the outer cylinder 33 from the front direction, the floating bush 31 is inclined forward at this inclination angle α and the spring constant in the axial direction A is set lower than the spring constant in the radial direction B. A radial component force P1 that relatively displaces the outer cylinder 33 in the radial direction B with respect to the inner cylinder 32 by the component action of the inclined inner cylinder 32 and outer cylinder 33, and an axial center of the outer cylinder 33 with respect to the inner cylinder 32. An axial component force P2 that is displaced in the direction A is generated. Here, by setting lower than the spring constant of the spring constant radial direction B of the axial direction A, the outer tube 33 relative to the inner cylinder 32 is increased relative displacement in the axial direction A in comparison with the radial direction B. In FIG. 4, the magnitudes of P1 and P2 indicate the magnitude of relative displacement due to the component force. That is, the floating bush 31 has a so-called spring constant principal axis, which is a coupled component P3 that displaces the outer cylinder 33 rearward and downward with respect to an external load P input to the outer cylinder 33 from the front direction. On the other hand, the outer cylinder 33 has a descending component P4 that descends according to the coupled component P3. The descending component P4 is set to the maximum when the inclination angle α of the floating bush 31 is 45 °.

  The operation of the suspension device thus configured will be described with reference to FIGS.

  5 is a schematic diagram showing a schematic configuration of the suspension device of FIG. 1 as viewed from the rear, FIG. 6 is a side view schematically showing the main part of the subframe, and FIG. 7 is an action explanatory view schematically showing the action. .

  As shown in FIG. 5, the subframe 10 is supported on the left and right main frames on the lower surface of the vehicle body via floating bushes 21 and 31, and the front lateral link 42 and the rear lateral link 43 are attached to the side frame 13 of the subframe 10. The housing 41 is swingably supported by suspension arms such as the trailing link 44 and the upper arm 45, and the position of the rear lateral link 43 in the vicinity of the housing 41 of the rear lateral link 43 extending in the vehicle width direction, that is, the rear lateral link 24. A shock absorber 46, which is a vertical force transmission member, extends between the intermediate portion between the base end and the front end and the floor 5 so as to extend in the vertical direction.

Here, as shown in FIG. 6, in the floating bush 21 that supports the front side of the sub-frame 10, the inner cylinder 22 is supported by the main frame 2 and the outer cylinder 23 is supported by the sub-frame 10 in a state of being inclined forward of the vehicle body. The spring constant in the axial direction A is set lower than the spring constant in the radial direction B. Thus, when an external load P directed from the front to the rear is input to the subframe 10, a coupled component P <b> 3 is generated in the floating bush 21 in a direction that causes the outer cylinder 23 to move backward and downward with respect to the external load P. The outer cylinder 23 is displaced downward in accordance with the descending component P4.

Similarly, in the floating bush 31 that supports the rear side of the subframe 10, the inner cylinder 32 is supported by the main frame 2, the outer cylinder 33 is supported by the subframe 1, and the axial direction A Is set lower than the spring constant in the radial direction B. As a result, when an external load P directed from the front to the rear is input to the subframe 1, a coupled component P3 is generated in the floating bush 31 in a direction that causes the outer cylinder 33 to move rearward and downward with respect to the external load P. The outer cylinder 33 is displaced downward according to the descending component P4.

Therefore, for example, as shown in FIG. 7A, when the vehicle 50 travels forward and the wheel 50 rides on the step or protrusion Ra on the road surface R and passes through, the wheel 50 has a force F from the front to the rear. , so-called Atohiki force upthrust et been with receiving, front lateral link 42 from the housing 40, the rear lateral link 43, external load P is input toward the rear from the front sub-frame 10 via a suspension arm, such as the upper arm 45 Is done. When this external load P is received, the outer cylinders 23 and 33 of the floating bushes 21 and 31 are pressed backward against the inner cylinders 22 and 32 held by the vehicle body as shown in FIG. According to the coupled displacement of the TIG bushes 21 and 31, the outer cylinders 23 and 33 move down the subframe 10 together as indicated by phantom lines.

Here, as schematically shown in FIG. 7C, when the subframe 10 descends from the state indicated by the solid line as indicated by the virtual line 10a, the proximal end of the rear lateral link 43 supported by the subframe 10 is The wheel 50 is lowered and the wheel 50 is pushed up or lifted relative to the fastening point C between the shock absorber 48 and the rear lateral link 43.

  Due to the relative rise of the relative wheels 50, the rising stroke of the shock absorber 46 when getting over the step or protrusion Ra is reduced, the load input to the floor 5, that is, the vertical load input is reduced, and the vibration component is reduced. Reduced to reduce harshness.

FIG. 8 shows an outline of acceleration and vibration attenuation of the vertical load input from the shock absorber 46 to the floor 5 when passing over the step or protrusion Ra. In FIG. 8, a virtual line b indicates a vertical load input in the present embodiment, and a solid line a indicates a conventional example in which the axes of the floating bushes 21 and 31 are vertical.

On the other hand, the floating bush 21 that supports the front side of the subframe 10 and the floating bush 31 that supports the rear side are disposed in a state of being inclined forward of the vehicle body, but the spring constant in the axial direction A is the spring constant in the radial direction B. By setting it lower, rigidity with respect to a load in a direction in which the outer cylinders 23 and 33 are displaced in the vehicle width direction with respect to the inner cylinders 22 and 32 is ensured. As a result, the load in the vehicle body width direction, that is, the lateral force input to the subframe 10 from the housing 41 that supports the wheels 50 by turning or the like through each suspension arm such as the front lateral link 43 and the rear lateral link 43. When input, the load is received by the vehicle body frame 1 via the floating bushes 21 and 31 disposed at the end of the sub frame 10, and the displacement of the sub frame 10 in the vehicle width direction is suppressed, thereby improving running stability. It can be secured.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of invention. For example, in the above embodiment, the case where the shock absorber 46 is installed between the rear lateral link 43 and the floor 5 has been described as an example. However, instead of the rear lateral link 43, the subframe 10 and the housing 41 The shock absorber 46 can also be coupled to other suspension arms such as the front lateral link 42 and the upper arm 45 that are slidably mounted between them.

Further, in the above embodiment, the floating bushes 21 and 31 having the spring constant in the axial direction A set lower than the spring constant in the radial direction B are tilted toward the front side of the vehicle body and input to the outer cylinders 23 and 33 from the front. The outer cylinders 23 and 33 are configured to generate a coupled displacement that moves downward in response to an external load P. However, the shaft is input to the outer cylinder from the front with the shaft center extending in the vertical direction. The sub-frame 10 can also be supported by a floating bush that generates a coupled displacement that moves the outer cylinder downward and backward with respect to an external load. An example of this floating bush will be described with reference to FIG.

  FIG. 9A is a side view schematically showing the outline of the subframe 10 in which the floating bush 61 is mounted on the front and rear portions of the subframe 10.

As shown in a cross-sectional view in FIG. 9B, the floating bush 61 has an inner cylinder 62 that is attached to and supported by the vehicle body frame, and a cylindrical shape that extends in the vertical direction a disposed at the front end of the subframe 10. The outer cylinder 63 press-fitted to the bush mounting portions 14A and 15A and an annular elastic member 64 interposed between the inner cylinder 22A and the outer cylinder 23A are integrally formed. And it is located in the lower side of the outer cylinder 63, and is inclined and arranged in a front lowering state located on the upper side of the inner cylinder 62 and the outer cylinder 63 on the rear side of the vehicle body. The floating bush 61 is set such that the spring constant in the axial direction A is lower than the spring constant in the radial direction B. That is, it is set so that it is soft in the axial direction A, has a large deformation stroke, and is hard in the radial direction B.

  When an external load P is input from the front, the inner cylinder 62 and the outer cylinder 63 are displaced relative to each other in the axial direction, that is, the inner cylinder 62 by a component action that is inclined so that the front side of the elastic member 64 is lower than the rear side. Has a coupled component P3 for lowering the outer cylinder 63, that is, a spring constant principal axis.

  As a result, when the vehicle rides on the road step or protrusion Ra and passes while the vehicle is running, the wheel receives a force F from the front to the rear and is pushed up, and the subframe 10 is exposed to the outside from the front to the rear. The dynamic load P is input. When this external load P is received, the external load is efficiently input to the outer cylinder 63 of each floating bush 61 by the rearward movement of the subframe 10, and the inner cylinder 63 of each floating bush 61 is held in the vehicle body. When pressed against the cylinder 62 rearward, the outer cylinder 63 moves down the subframe 10 in accordance with the coupled component of the floating bush 61. As a result, the rising stroke of the shock absorber 46 is reduced in the same manner as described above. The input load is reduced, the vibration component is reduced, and a reduction in harshness can be obtained.

Moreover, there is a floating bush shown in FIG. 10 as a floating bush to be mounted on the subframe with the shaft center in the vertical direction. The floating bush 71 includes a first bush 71A and a second bush 71B. The first bush 71A includes an inner cylinder 72A extending in the vertical direction along the axis, an outer cylinder 73A, and the inner cylinder 72A. And an elastic body 74A interposed between the outer cylinder 73A. The vehicle body front side of the outer peripheral surface of the inner cylinder 72A is inclined so as to become forward as it moves from the lower end to the upper end, and the vehicle body front side of the inner peripheral surface of the outer cylinder 73A is formed in parallel with the outer peripheral surface of the inner cylinder 72A. The first bush 71A is set such that the spring constant in the axial direction A is lower than the spring constant in the radial direction B.

Similarly, the second bush 71B includes an inner cylinder 72B extending in the vertical direction along the axis, an outer cylinder 73B, and an elastic body 74B interposed between the inner cylinder 72B and the outer cylinder 53B. The vehicle rear side of the outer peripheral surface of the inner cylinder 72B is inclined so as to become rearward as it moves from the upper end to the lower end, and the rear side of the inner peripheral surface of the outer cylinder 73B is formed in parallel with the outer peripheral surface of the inner cylinder 72B. The The second bush 71B is set such that the spring constant in the axial direction A is lower than the spring constant in the radial direction B.

  The inner cylinders 72A and 72B of the first bush 71A and the second bush 71B are fixed to a vehicle body frame or the like with the shaft center extending in the vertical direction a, and the outer cylinders 73A and 73B are bush mounting portions of the subframe. 75 is attached.

Thus, when the external load P from the front side in the horizontal direction via the sub-frame is input, the inclined inner cylinder 72A, 72B of the outer peripheral surface 72Aa, 72Ba and the outer tube 7 3 A, the inner circumferential surface of the 73B 73Ba, the relative displacement of the inner cylinder and the outer cylinder 63, i.e. the inner cylinder 72A, the outer cylinder 73 a relative 72B, coupling component P3 which allowed to lowering the 73B is generated by the component force effect of the 73Ba, subframe is lowered.

1 Body frame 2 Main frame 5 Floor (underside of the body)
10 Subframe 21 Floating bush 22 Inner cylinder 23 Outer cylinder 24 Elastic member 28 Mounting bolt (support shaft)
31 Floating bush 32 Inner cylinder 33 Outer cylinder 34 Elastic member 38 Mounting bolt (support shaft)
41 Housing 42 Front lateral link (suspension arm)
43 Rear lateral link (suspension arm)
44 Trailing link (suspension arm)
45 Upper arm (suspension arm)
46 Shock absorber (vertical force transmission member)
50 wheels
61 Floating bush 62 Inner cylinder 63 Outer cylinder 64 Elastic member 71 Floating bush 71A First bush 72A Inner cylinder 73B Outer cylinder 74A Elastic member 71B Second bush 72B Inner cylinder 73B Outer cylinder 74B Elastic member

Claims (6)

A sub-frame supported on a vehicle body frame disposed on the lower surface of the vehicle body via a floating bush, a housing for rotatably supporting a wheel, a distal end of the housing supported by the housing so that the base end is swingable, and a base end of the sub-frame A suspension arm that is swingably supported by the frame, and a vertical force transmission member that is constructed with a lower end connected to an intermediate portion between the distal end and the base end of the suspension arm and an upper end connected to the lower surface of the vehicle body. In the suspension device provided,
The floating bushes are provided on the vehicle body front side and the rear side of the subframe in pairs on the left and right sides,
Each floating bush includes an inner cylinder that is supported by the body frame and extends in the axial direction, an outer cylinder that is held by the subframe, and an elastic member that is interposed between the inner cylinder and the outer cylinder. When an external load is input to the outer cylinder from the front of the vehicle body, the outer cylinder is coupled and displaced downward with respect to the inner cylinder to move the subframe downward with respect to the inner cylinder. Suspension device. The shaft center of each floating bush is in a forward tilted state that shifts to the front side of the vehicle body as it moves from below to above, and the outer peripheral surface of the inner cylinder and the inner peripheral surface of the outer cylinder extend in the axial direction. the suspension device according to claim 1, characterized in that there. 2. The suspension device according to claim 1, wherein an axis of each floating bush extends in a vertical direction, and the elastic member is disposed in an annular shape with a front side being downward with respect to a rear side. The shaft center of each floating bush extends in a vertical direction, and the outer peripheral surface of the inner cylinder and the inner peripheral surface of the outer cylinder are displaced rearward as the vehicle moves from above to below. 2. The suspension device according to 1. The suspension arm is a plurality, suspension apparatus according to any one of claims 1 to 4, characterized in that the lower end of the vertical force transmission member to one of the suspension arm is connected. The vertical force transmission member suspension device according to any one of claims 1 to 5, characterized in that a shock absorber.

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