JP4844500B2 - suspension - Google Patents

Description

  The present invention relates to a vehicle suspension.

Conventionally, a suspension described in Patent Document 1 is known as a suspension for improving the riding comfort of a vehicle. This suspension is a trailing arm type rear suspension that is set so that the instantaneous center of rotation of the axle is positioned forward and above the wheel center and the wheel center trajectory is tilted backward when the unsprung strokes up and down. Thus, the longitudinal force input from the tire is reduced, and the harshness is reduced without lowering the rigidity of the bush.
JP 2001-270313 A

  However, in the above suspension, there is a problem that the longitudinal force input from the tire is not sufficiently reduced only by tilting the wheel center locus backward.

  Then, an object of this invention is to provide the suspension which can reduce the longitudinal force input from a tire more effectively.

  Here, as a result of intensive studies, the inventors have come to the knowledge that the arrangement of the attenuator also affects the reduction of the longitudinal force input from the tire, and the arrangement of the attenuator and the like are input from the tire. We succeeded in deriving the relationship with the longitudinal force.

Therefore, the suspension according to the present invention has been made based on the knowledge of the above-mentioned inventors, and extends in the vehicle longitudinal direction and extends between the vehicle body and the spindle shaft, and extends in the vehicle vertical direction. In a suspension equipped with an attenuator disposed between the vehicle body and the spindle shaft, the longitudinal force in the vehicle longitudinal direction input from the tire when the unsprung strokes up and down causes the unsprung stroke up and down. the generated by the arm member and the attenuator, the rigidity of the arm member, the spindle axis of the rigid damping coefficient of the attenuator, the attenuator formed inclination and longitudinal vehicle relative to the vehicle vertical direction of the line when as is canceled by the vehicle reaction force around the longitudinal direction rigidity of the arm member relative to the direction of the line is calculated on the basis of the dihedral angle formed by the direction of the axis to act, the a The rigidity of the arm member acts on the rigidity of the arm member, the rigidity around the spindle axis, the damping coefficient of the attenuator, the inclination angle formed by the attenuator with respect to the vehicle vertical direction line, and the vehicle longitudinal direction line. The opposite angle formed by the direction axis is set.

According to this suspension, since the suspension is set so as to cancel the longitudinal force input from the tire in consideration of the setting of the attenuator, the longitudinal force input from the tire can be effectively reduced. Further, it is possible to improve the riding comfort of the vehicle by suppressing the vibration in the vehicle front-rear direction under the spring.
And so as to cancel the longitudinal force input from the tire, the rigidity of the arm member, the rigidity around the spindle axis, the attenuation coefficient of the attenuator, and the inclination angle formed by the attenuator with respect to the vehicle vertical direction line, The opposite angle formed by the axis in the direction in which the rigidity of the arm member acts on the line in the vehicle longitudinal direction is set. For this reason, the longitudinal force input from the tire can be reduced with higher accuracy, and vibration in the vehicle longitudinal direction under the spring can be suppressed to improve the riding comfort of the vehicle.

The suspension according to the present invention is based on the knowledge of the above-described inventors, and extends in the vehicle longitudinal direction and extends between the vehicle body and the spindle shaft, and extends in the vehicle vertical direction. In a suspension equipped with an attenuator disposed between the vehicle body and the spindle shaft, the longitudinal force in the vehicle longitudinal direction input from the tire when the unsprung strokes up and down causes the unsprung stroke up and down. Generated by the arm member, the rigidity of the arm member, the rigidity around the spindle axis, the attenuation coefficient of the attenuator, the inclination angle formed by the attenuator with respect to the vehicle vertical direction line and the vehicle longitudinal direction line On the other hand, the longitudinal force in the vehicle longitudinal direction calculated based on the angle formed by the axis in the direction in which the rigidity of the arm member acts, and the damping when the unsprung strokes up and down And the resultant force of the longitudinal force in the vehicle longitudinal direction calculated based on the opposite angle formed by the axis of the direction in which the rigidity of the arm member acts on the rigidity of the arm member and the line in the longitudinal direction of the vehicle. as is canceled by the reaction force before and after the certain vehicle longitudinal direction, the rigidity of the arm member, the spindle axis of the rigid damping coefficient of the damper, the inclination attenuator forms and the vehicle vertical direction of the line An angle formed by an axis in a direction in which the rigidity of the arm member acts with respect to a line in the vehicle longitudinal direction is set.
According to this suspension, since the suspension is set so as to cancel the longitudinal force input from the tire in consideration of the setting of the attenuator, the longitudinal force input from the tire can be effectively reduced. Further, it is possible to improve the riding comfort of the vehicle by suppressing the vibration in the vehicle front-rear direction under the spring.
And so as to cancel the longitudinal force input from the tire, the rigidity of the arm member, the rigidity around the spindle axis, the attenuation coefficient of the attenuator, and the inclination angle formed by the attenuator with respect to the vehicle vertical direction line, The opposite angle formed by the axis in the direction in which the rigidity of the arm member acts on the line in the vehicle longitudinal direction is set. For this reason, the longitudinal force input from the tire can be reduced with higher accuracy, and vibration in the vehicle longitudinal direction under the spring can be suppressed to improve the riding comfort of the vehicle.

In addition, it is preferable that the rigidity and the inclination angle of the arm member are set so that the longitudinal force in the longitudinal direction of the vehicle input from the tire is canceled under predetermined vehicle speed conditions and riding weight conditions. According to this suspension, it is possible to cancel the longitudinal force input from the tire under predetermined vehicle speed conditions and riding weight conditions. For example, as the desired vehicle speed conditions and riding weight conditions, frequently used vehicle speed conditions and riding By using the weight condition, the longitudinal force input from the tire can be more efficiently reduced.

  Further, it is preferable to further include a stiffness changing means for changing the stiffness of the arm member in accordance with the change in the opposite angle or the inclination angle, and the attenuation coefficient change for changing the attenuation coefficient of the attenuator in accordance with the change in the opposite angle or the inclination angle. Preferably further means are provided. When the weight condition of the vehicle changes, the opposite angle that the axis in the direction in which the arm member's rigidity acts on the line in the vehicle longitudinal direction, or the axis in the direction in which the arm member's stiffness acts on the line in the vehicle longitudinal direction As the reaction angle changes, the front / rear reaction force also changes. Therefore, along with the change in the opposite angle, the rigidity of the arm member is changed, and the attenuation coefficient of the attenuator is changed, so that the front-rear reaction generated by the arm member and the attenuator according to the change in the weight condition of the vehicle. The force can be adjusted, and the longitudinal force input from the tire can be more effectively reduced.

  Further, it is preferable to further include a rigidity changing means for changing the rigidity of the arm member in accordance with a change in the vehicle speed or the vehicle weight, and an attenuation coefficient changing means for changing the attenuation coefficient of the attenuator in accordance with the change in the vehicle speed or the vehicle weight. It is preferable to further provide. Even if the longitudinal force input from the tire changes due to the vehicle speed or the vehicle weight, the rigidity of the arm member and the damping coefficient of the attenuator are changed as the vehicle speed or vehicle weight changes, so the longitudinal force input from the tire Can be more effectively reduced.

  According to the present invention, the longitudinal force input from the tire can be more effectively reduced, and the riding comfort of the vehicle can be improved.

  Hereinafter, embodiments of a suspension according to the present invention will be described with reference to the drawings. In the present embodiment, the suspension according to the present invention is applied to a rear suspension of a vehicle. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

[First Embodiment]
A suspension 1 according to a first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram schematically illustrating a vehicle to which the suspension according to the embodiment is applied. FIG. 2 is a diagram for explaining the arrangement of the suspension.

  The suspension 1 applied to the vehicle 2 absorbs vibration input from the rear tire 3 and suspends the vehicle body 8 and includes an arm 4 and an absorber 6. In the present embodiment, for ease of explanation, the description will be made using an example in which the suspension arm is composed of one.

  The arm 4 is a member that is connected between the vehicle body 8 and the rear tire 3 to control the movement of the rear tire 3. The arm 4 is connected to a hub (not shown) that rotatably supports the spindle shaft 7, and extends toward the front of the vehicle while slightly tilting upward from the vehicle, and is connected to the vehicle body 8.

  The connecting point between the arm 4 and the hub is arranged at a position shifted downward from the unsprung center of gravity by a distance H. In the present embodiment, the unsprung center of gravity is located on the spindle shaft 7 of the rear tire 3.

  By the way, when a force in the vehicle longitudinal direction is applied to a certain point of the suspension 1, there is a point where the direction in which this force is applied coincides with the direction in which the suspension 1 moves. It is called spindle A. In this embodiment, since the arm is constituted by one, a line connecting the point where the arm 4 and the hub are connected and the point where the arm 4 and the vehicle body 8 are connected, that is, the center of the arm 4 is used. The passing axis is the longitudinal elastic main axis A. The angle at which the longitudinal elastic main axis A is inclined upward with respect to the horizontal line D, which is a line in the vehicle longitudinal direction, is referred to as the longitudinal elastic main axis upper angle β.

In addition, a compliance bush 5 is fitted into the arm 4 at a connection portion with the vehicle body 8. The compliance bush 5 is a member that elastically connects the vehicle body 8 and the arm 4 and absorbs vibration in the vehicle longitudinal direction. For this reason, the rigidity of the arm 4, that is, the longitudinal elastic principal axis rigidity K _x of the longitudinal elastic principal axis A is determined by the spring constant of the compliance bush 5.

  The absorber 6 is a member that is connected between the vehicle body 8 and the rear tire 3 and attenuates the force input from the rear tire 3 (under the spring) while stroking in the vehicle vertical direction. The absorber 6 is connected to a hub that rotatably supports the spindle shaft 7. The absorber 6 extends upward from the vehicle while tilting forward from the vehicle and is connected to the vehicle body 8. The connection point between the arm 4 and the hub is arranged at a position shifted rearward of the vehicle by a distance L from the unsprung center of gravity (spindle shaft 7). The absorber 6 is configured by incorporating a coil spring (not shown).

  Here, the axis in the direction in which the damping force of the absorber 6 acts is referred to as a damping main axis B. In this embodiment, a line connecting a point where the absorber 6 and the hub are connected and a point where the absorber 6 and the vehicle body 8 are connected, that is, an axis passing through the center of the absorber 6 is the damping main axis B. Further, an angle at which the absorber 6 (attenuation main axis B) is inclined forward with respect to the vertical line E that is a line in the vehicle vertical direction is referred to as an attenuation main axis forward inclination angle α.

  Next, a method for setting the suspension 1 will be described.

  First, when the unsprung strokes up and down, a vehicle longitudinal force (hereinafter referred to as “front / rear force”) input from the rear tire 3 is defined as Ftv (v). Then, assuming that the specifications of the suspension 1 are as follows, the longitudinal force Ftv (v) input from the rear tire 3 is expressed by Expression (1). In Equation (1), Ftv (s) and Z (s) are obtained by Laplace transform of Ftv (v) and Z, respectively, and s is a Laplace operator. Moreover, the arrow direction of FIG. 2 is represented as a positive direction.

C: damping coefficient of the absorber K _tz: Vehicle tire vertical stiffness K _tx: the vehicle longitudinal direction rigidity of the tire P _x: driving stiffness Z: vertical displacement of the unsprung gravity position X: longitudinal displacement W of the unsprung centroid position: vertical load m: unsprung weight I _t: tires and wheels of inertia moment r _0: tire dynamic load radius epsilon: [dynamic load radius (deflection tires) variation amount] / [(deflection tires) static load radius variation amount]
V ₀ : Vehicle speed

  On the other hand, when the unsprung strokes up and down, the longitudinal force generated by the absorber 6 (damping main shaft B) is defined as Fkz. When the specifications of the suspension 1 are as follows, the longitudinal force Fkz generated by the absorber 6 (attenuation main shaft B) is expressed by the equation (2). In Equation (2), Fkz is a Laplace transform of Fkz (s).

C: Absorber damping coefficient α: Decay main shaft forward tilt angle (angle at which the absorber 6 (damping main shaft B) tilts forward of the vehicle with respect to the vertical line E in a side view of the vehicle)
β: Diagonal angle on the front-rear elastic main axis (angle at which the front-rear elastic main axis A tilts upward with respect to the horizontal line D in the vehicle side view)
K _θ : Windup rigidity (rigidity when axle carrier (not shown) rotates around the spindle axis)
K _x : Front / rear elastic main shaft rigidity H: Amount of deviation in the vehicle vertical direction between the unsprung center of gravity position and the front / rear elastic main shaft A L: Amount of deviation in the vehicle front / rear direction between the unsprung center of gravity position and the damping main axis B

Further, when the longitudinal force generated by the longitudinal elastic main shaft A when the unsprung strokes up and down is Fkx, the longitudinal force Fkx is expressed by Expression (3). In Equation (3), Fkx (s) is a Laplace transform of Fkx.

The longitudinal force Ftv (v) input from the rear tire 3 is a longitudinal reaction force Fxs (the resultant force of the longitudinal force Fkz generated by the absorber 6 (damping main shaft B) and the longitudinal force Fkx generated by the longitudinal elastic main shaft A). The suspension 1 is set so as to be canceled by (Fkz + Fkx). That is, the damping main shaft forward inclination angle α, the longitudinal elastic main shaft anti-reverse angle β, the windup stiffness K _θ , the longitudinal elastic main shaft stiffness K _x , the absorber damping coefficient C, and the unsprung center of gravity satisfying the equations (1) and (4). The displacement H in the vehicle vertical direction between the position and the longitudinal elastic main shaft A and the displacement L in the vehicle longitudinal direction between the unsprung center of gravity and the damping main shaft B are obtained, and the suspension 1 is set according to the obtained specifications. To do.

By the way, the longitudinal force Ftv (v) input from the rear tire 3 is a function that varies depending on the vehicle speed (v), and is a value that is substantially uniquely determined if the vehicle speed, unsprung weight, tire specifications, and the like are determined. Accordingly, the longitudinal elastic main shaft stiffness K _x and the damped main shaft forward tilt angle α satisfying the above formulas (1) and (4) are obtained using the vehicle speed conditions with high use frequency and the riding weight conditions with high use frequency, The suspension 1 may be set.

Thus, according to the suspension 1 according to the first embodiment, the longitudinal force Ftv (v) input from the rear tire 3 when the unsprung strokes up and down is configured by the arm 4 and the compliance bush 5. The longitudinal elastic main shaft stiffness K _x , the windup stiffness K _θ , the damping coefficient C, the longitudinal elastic main shaft anti-reverse angle β, the damping main shaft so as to be canceled by the longitudinal reaction force Fxs (Fkz + Fkx) generated by the arm member and the absorber 6 Since the forward tilt angle α, the amount of deviation H in the vehicle vertical direction between the unsprung center of gravity position and the longitudinal elastic main axis A, and the amount of deviation L in the vehicle longitudinal direction between the unsprung gravity center position and the damping main axis B are set. The longitudinal force Ftv (v) input from can be effectively reduced. Moreover, since the suspension is set in consideration of the arrangement, rigidity, and damping coefficient of the absorber 6, the longitudinal force Ftv (v) input from the rear tire 3 can be reduced with higher accuracy, and the unsprung vehicle The ride comfort of the vehicle 2 can be improved by suppressing the vibration in the front-rear direction.

Then, by using the frequency used and the frequency of use is high speed conditions is higher riding weight conditions, before and after seeking an elastic principal axis stiffness K _x and damping spindle forward inclination alpha, by setting the suspension 1, is input from the rear tires 3 The longitudinal force Ftv (v) can be reduced more efficiently.

[Second Embodiment]
Next, the suspension 11 according to the second embodiment will be described with reference to FIGS. 3 and 4 as well. FIG. 3 is a diagram showing a part of the suspension according to the second embodiment in a block configuration, and FIG. 4 is a diagram showing the relationship between the compliance bush and the arm.

The suspension 11 includes an arm 4 similar to the suspension 1 according to the first embodiment, an electronically controlled absorber 12 whose damping coefficient can be changed, and a front-rear elastic main-axis rebound angle detection sensor that detects a front-rear elastic main-axis rebound angle β. 13, a compliance bush 14 rotatably attached to the vehicle body 8, a front / rear elastic main shaft rigidity changing device 15 that changes the front / rear elastic main shaft rigidity K _x by rotating the compliance bush 14, and damping of the electronic control absorber 12 An ECU 17 that controls the longitudinal elastic main shaft stiffness changing device 15 and the damping coefficient changing device 16 based on the damping coefficient changing device 16 that changes the coefficient and the longitudinal elastic main shaft deflection angle β detected by the longitudinal elastic principal shaft deflection angle detection sensor 13. And.

  The electronic control absorber 12 can be changed in attenuation coefficient by an attenuation coefficient changing device 16. The damping coefficient changing device 16 changes the damping coefficient C by changing the damping force of the electronic control absorber 12, for example, by changing the flow resistance of the working fluid filled in the electronic control absorber 12. is there.

The compliance bush 14 is a member that elastically connects the arm 4 and the vehicle body 8. As shown in FIG. 4, the compliance bush 14 is formed in a substantially compacted cylindrical shape, and is press-fitted into a bush attachment hole 21 provided in the lower part of the vehicle body 8. The compliance bush 14 is fixed to the vehicle body 8 and formed of an elastic material such as rubber, and an arm attachment that is positioned on the inner side in the radial direction of the elastic portion 22 so as to swing the arm 4 around the axis. Part 23. The elastic portion 22 and the arm attachment portion 23 are connected via a bearing (not shown) that rotates around the axis of the compliance bush 14, and the longitudinal elastic main shaft rigidity changing device 15 attached to the vehicle body 8 It is configured to be rotated. The longitudinal elastic spindle stiffness changing device 15, such as by using a motor to rotate the compliance bush 14, by changing the direction of the spring constants of the front and rear principal elastic axis A in compliance bush 14, to change the longitudinal principal elastic axis stiffness K _x Is.

  In addition, the elastic portion 22 of the compliance bush 14 is formed with an edge (a hole provided in the elastic portion 22) 24. The tickles 24 are formed one by one in the vehicle vertical direction with the arm attachment portion 23 interposed therebetween.

  FIG. 4 (a) shows a case where the boarding weight is small and the vehicle body is not sinking, and the longitudinal elastic main axis opposite angle β is relatively large, and FIG. 4 (b) shows the boarding weight is small. It shows a case where the vehicle body is sinking and the longitudinal elastic main axis angle β is relatively small.

As shown in FIG. 4A, when the arm 4 and a part of the curl 24 overlap each other in the side view of the vehicle, the density of the elastic part 22 in the front-rear elastic main axis A direction becomes small due to the space of the curl 24. For this reason, the spring constant of the compliance bush 14 in the front-rear elastic main shaft A direction is reduced, and the front-rear elastic main shaft rigidity _Kx is reduced. On the other hand, as shown in FIG. 4B, the spring constant of the compliance bushing 14 in the front-rear elastic main shaft A direction is hardly affected by the curl 24 when the arm 4 and the curl 24 do not overlap in the side view of the vehicle. Therefore, the longitudinal elastic main shaft rigidity Kx is increased.

Thus, the front and rear principal elastic axis dihedral β varies, vary the spring constant of the front and rear principal elastic axis A direction in compliance bush 14 according to the position of the arm 4 against currants 24, before and after the elastic principal axis stiffness K _x varies .

The ECU 17 satisfies the above formula (4) and the longitudinal elastic main shaft stiffness table in which the longitudinal elastic main shaft anti-angle β is associated with the longitudinal elastic main shaft stiffness K _x and the above formula (4). It has a damping coefficient table in which the front-rear elastic main axis anti-reverse angle β and the damping coefficient C of the absorber are associated with each other. The ECU 17 refers to the front / rear elastic main shaft rigidity table and the damping coefficient table, and based on the front / rear elastic main shaft rebound angle detection sensor 13 and based on the front / rear elastic main shaft rebound angle β, The attenuation coefficient changing device 16 is controlled.

  Next, the setting operation of the suspension 11 will be described with reference to FIG. FIG. 5 is a flowchart showing the suspension setting operation.

First, similarly to the suspension 1 according to the first embodiment, the damping main shaft forward tilt angle α, the front-rear elastic main shaft anti-reverse angle β, the windup stiffness K _θ , and the front-rear elastic main shaft stiffness K that satisfy the equation (4) are satisfied. _The suspension 11 is represented by _x , the absorber damping coefficient C, the vehicle vertical displacement H between the unsprung center of gravity and the longitudinal elastic main shaft A, and the vehicle longitudinal displacement L between the unsprung gravity center and the damping main shaft B. Set.

  Thereafter, when the ignition is turned on, the following processing is repeated until the ignition is turned off. First, the ECU 17 acquires the front-rear elastic main-axis rebound angle β detected by the front-rear elastic main-axis rebound angle detection sensor 13 (step S1).

Then, ECU 17 from the front and rear principal elastic axis stiffness table to obtain the longitudinal principal elastic axis stiffness K _x the longitudinal acquired associated with a principal elastic axis dihedral β in step S1. Then, the front and rear elastic principal axis stiffness K _x before and after the elastic main axis A is such that the longitudinal principal elastic axis stiffness before and acquired from the table the principal elastic axis stiffness K _x, and controls the front and rear elastic spindle stiffness changing device 15, the front and rear principal elastic axis stiffness K _x is set and changed (step S2). Note that, in step S2, longitudinal elastic spindle stiffness changing device 15 changes the setting of the front and rear elastic principal axis stiffness K _x before and after the elastic main axis A by rotating the compliance bush 14.

  Further, the ECU 17 acquires the attenuation coefficient C associated with the attenuation main shaft forward tilt angle α acquired in step S1 from the attenuation coefficient table. Then, the attenuation coefficient changing device 16 is controlled so that the attenuation coefficient C of the electronic control absorber 12 becomes the attenuation coefficient C acquired from the attenuation coefficient table, and the attenuation coefficient C is set and changed (step S3).

Thus, according to the suspension 11 according to the second embodiment, by changing the front and rear elastic principal axis stiffness K _x with the change before and after the principal elastic axis dihedral beta, also with the change in the damping spindle anteversion α decay By changing the coefficient C, the longitudinal reaction force Fxs (Fkz + Fkx) can be adjusted according to the change in the weight condition of the vehicle 2, and the longitudinal force Ftv (v) input from the rear tire 3 can be reduced more effectively. can do.

  As mentioned above, although embodiment which concerns on this invention was described, this invention is implemented in various forms, without being limited to the said embodiment.

  For example, in the above-described embodiment, the suspension is described as being configured by one arm. However, the number of arms and the type of suspension are not particularly limited. For example, a double wishbone type suspension or a multilink type is used. A suspension type such as a suspension may be used.

In the above embodiment, each specification is described as being set independently. However, depending on the type of suspension, when one specification is changed, other specifications may be changed in conjunction with each other. . Specifically, for example, when considering a multi-link type suspension, if the longitudinal elastic main shaft rigidity _Kx , the unsprung center of gravity position and the longitudinal elastic main shaft A are changed, the longitudinal elastic main shaft vertical angle β is also changed in conjunction with it. The For this reason, in the present invention, it is preferable to set the suspension so as to satisfy the above formula (4) in consideration of the mutual interlocking and relationship in each specification.

In the above embodiment, by controlling the longitudinal principal elastic axis stiffness changing device 15 it has been described to change the front and rear elastic principal axis stiffness K _x based on β longitudinal principal elastic axis dihedral, for example, before and after the elastic principal axis Even if the opposite angle β changes, the position and shape of the corner formed on the compliance bush may be set so that the longitudinal elastic principal axis stiffness K _x satisfies the above formula (4).

In the above embodiment, the front and rear of an elastic principal axis stiffness table and damping coefficient table, the principal elastic axis stiffness K _x and damping coefficient C before and after with the change before and after the principal elastic axis dihedral β and longitudinal principal elastic axis dihedral β It has been described to vary the vehicle speed or the vehicle weight and the longitudinal elastic principal axis stiffness K _x and are associated with one another table, and, using the table speed or vehicle weight and the damping coefficient C is associated with each other, The longitudinal elastic main shaft rigidity _Kx and the damping coefficient C may be changed according to changes in the vehicle speed or the vehicle weight. By doing in this way, even if the longitudinal force input from the tire changes due to the vehicle speed or the vehicle weight, the rigidity of the arm member and the attenuation coefficient of the attenuator are changed with the change in the vehicle speed or the vehicle weight. The longitudinal force input from the tire can be more effectively reduced.

In the second embodiment, by changing the front and rear elastic principal axis stiffness K _x with the change before and after the principal elastic axis dihedral beta, it has been described so as to change the damping coefficient C according to the change of the damping spindle anteversion α In addition, either or both of the longitudinal elastic main shaft stiffness _Kx and the damping coefficient C may be changed in accordance with the change in either or both of the longitudinal elastic main shaft anti-reverse angle β and the damping main shaft forward tilt angle α. Even in this case, the same effects as those of the above-described embodiment can be obtained.

It is the figure which showed typically the vehicle to which the suspension which concerns on embodiment is applied. It is a figure for demonstrating arrangement | positioning of a suspension. It is the figure which showed the one part block configuration of the suspension which concerns on 2nd Embodiment. It is the figure which showed the relationship between a compliance bush and an arm, (a) shows the case where the inclination angle of an arm is large, (b) shows the case where the inclination angle of an arm is small. It is the flowchart which showed the setting operation | movement of a suspension.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11 ... Suspension, 2 ... Vehicle, 3 ... Rear tire, 4 ... Arm (arm member), 5, 14 ... Compliance bush (arm member), 6, 12 ... Absorber (attenuator), 7 ... Spindle shaft, 8 ... body, 15 ... longitudinal principal elastic axis stiffness changing device (rigidity changing means), 16 ... damping coefficient changing device (damping coefficient changing means), C ... attenuation coefficient, K x _... longitudinal principal elastic axis stiffness (rigidity of the arm member), K _theta ... Wind-up rigidity (attenuator rigidity around the axis), α ... Attenuation main axis forward tilt angle (inclination angle made by the attenuator with respect to the vehicle vertical direction line), β ... Longitudinal elastic main axis upside angle (vehicle longitudinal direction line) (Angle formed by the axis in the direction in which the rigidity of the arm member acts).

Claims (7)

In a suspension including an arm member that extends in the vehicle longitudinal direction and is disposed between the vehicle body and the spindle shaft, and an attenuator that extends in the vehicle vertical direction and is disposed between the vehicle body and the spindle shaft,
The longitudinal force in the vehicle longitudinal direction input from the tire when the unsprung strokes up and down is generated by the arm member and the attenuator when the unsprung strokes up and down, and the rigidity of the arm member, the spindle Rigidity around the axis, damping coefficient of the attenuator, inclination angle formed by the attenuator with respect to the vehicle vertical direction line, and anti-angle formed by the axis in the direction in which the rigidity of the arm member acts on the vehicle longitudinal direction line The rigidity of the arm member, the rigidity around the spindle axis, the damping coefficient of the attenuator, and the damping with respect to the line in the vertical direction of the vehicle so as to be offset by the longitudinal reaction force in the longitudinal direction of the vehicle calculated based on The suspension is characterized in that an inclination angle formed by the device and an angle formed by an axis in a direction in which the rigidity of the arm member acts on a line in the vehicle longitudinal direction are set. In a suspension including an arm member that extends in the vehicle longitudinal direction and is disposed between the vehicle body and the spindle shaft, and an attenuator that extends in the vehicle vertical direction and is disposed between the vehicle body and the spindle shaft,
The longitudinal force in the vehicle longitudinal direction input from the tire when the unsprung strokes up and down is generated by the arm member when the unsprung strokes up and down, and the rigidity of the arm member and the rigidity around the spindle axis , Based on the attenuation coefficient of the attenuator, the inclination angle formed by the attenuator with respect to the vehicle vertical direction line, and the opposite angle formed by the axis in the direction in which the rigidity of the arm member acts on the vehicle longitudinal direction line. Generated by the attenuator when the unsprung strokes up and down, and in the direction in which the rigidity of the arm member acts on the rigidity of the arm member and the vehicle longitudinal direction line. as offset by longitudinal force and the vehicle reaction force around the longitudinal direction, which is the resultant of the vehicle longitudinal direction is calculated based on the dihedral angle that the axis forms, of the arm member stiffness, of the spindle axis Sex, the damping coefficient of the damper, dihedral angle formed by the direction of the axis the rigidity of the arm member relative inclination and the vehicle longitudinal direction of the line in which the attenuator with respect to the vehicle vertical direction of the line acts is set Suspension characterized by that. Claim, characterized in that as the longitudinal force in the vehicle longitudinal direction are offset inputted from the tire under a predetermined vehicle speed condition and riding weight condition, rigidity and the inclination angle of the arm member is set 1 Or the suspension of 2 .   The suspension according to any one of claims 1 to 3, further comprising rigidity changing means for changing the rigidity of the arm member in accordance with a change in the opposite angle or the inclination angle.   The suspension according to any one of claims 1 to 3, further comprising rigidity changing means for changing the rigidity of the arm member in accordance with a change in vehicle speed or vehicle weight.   The suspension according to any one of claims 1 to 5, further comprising attenuation coefficient changing means for changing an attenuation coefficient of the attenuator in accordance with a change in the opposite angle or the inclination angle.   The suspension according to any one of claims 1 to 5, further comprising attenuation coefficient changing means for changing an attenuation coefficient of the attenuator in accordance with a change in vehicle speed or vehicle weight.

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