JP2011126537A - Suspension device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control a camber angle at an appropriate value using a lateral force applied to wheels without accompanying displacements at the tire grounding points. <P>SOLUTION: A suspension device is provided with a link mechanism that can equivalently replace a first virtual link 11 which increases the lateral force and inclines the wheels 2 in the camber angle direction against a vehicle body 1 when the lateral force is applied to the tire grounding points with a second virtual link 12 which is virtually connected in a rotatable manner between the first virtual link 11 and the vehicle body 1 and can move wheels 2 in vertical directions against the vehicle body 1 in accordance with the changes in load of the wheels in vertical directions. An instantaneous center of rotation A in the camber angle direction of the wheels against the vehicle body and an instantaneous center of rotation B in the vertical direction are positioned to negate the lateral movement ¾Δ yl1¾ of tire grounding points in accordance with the changes in the position of the first virtual link 11 by the lateral movement ¾Δ yl2¾ of the tire grounding points in accordance with the changes in the position of the second virtual link 12 and to satisfy ¾Δ yl2¾≥¾Δ yl1¾. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle suspension apparatus capable of controlling the attitude of a vehicle body, and more particularly to a vehicle suspension apparatus configured to control a camber angle using a tire lateral force acting on a tire.

  Conventionally, as a suspension device that changes the camber angle using the tire lateral force, for example, as described in Patent Document 1, the camber angle of the wheel can be changed independently of the vertical movement of the wheel. Possible suspension devices have been proposed. In this suspension device, the instantaneous rotation center position of the movement of the wheel in the camber angle direction is set to a position lower than the ground, and when a tire lateral force is applied, a negative camber is added to the turning outer wheel and a positive camber is added to the turning inner wheel. It is configured to be possible. Further, when the instantaneous rotation center position of the movement in the camber angle direction is set to a position higher than the ground near the ground, the camber angle can be controlled by using an actuator or the like.

Special table 2003-528771 gazette

The conventional suspension device capable of changing the camber angle of the wheel independently of the vertical movement of the wheel is such that the instantaneous rotation center position of the movement in the camber angle direction of the wheel is at a desired position. This is a suspension structure with a new link layout.
Here, when the momentary rotation center position of the movement in the camber angle direction is set to a position below the ground and away from the ground, the momentary rotation center position of the movement in the camber angle direction is determined as Since the wheel moves in the camber angle direction as the center, the tire contact point also moves laterally when the camber angle is generated.

In other words, when the tire lateral force acts in a steady running state, the wheel is centered on the instantaneous rotation center position of the movement in the camber angular direction provided at a position away from the ground, the turning outer wheel is a negative camber, The turning inner ring is inclined in the positive camber direction. For this reason, the tire ground contact point moves instantaneously in the wheel turning inner direction, and the tire contact point moves at a certain speed in the vehicle turning inner direction. Due to this movement, there is a problem that tire lateral force is generated in a direction that hinders turning, that is, the direction outside the turning, and the responsiveness of the vehicle to the addition of the camber angle is lowered.
In order to make the lateral displacement of the tire contact point zero, it is possible to provide an instantaneous rotational center position of the movement in the camber angle direction near the ground. However, if the instantaneous rotational center position of the motion in the camber angle direction is provided near the ground in this way, the camber angle also approaches zero, and the effect of the camber angle is impaired.

For this reason, in order to set the camber angle to an appropriate value and reduce the lateral displacement of the tire ground contact point, an actuator for controlling the camber angle and the lateral displacement of the tire ground contact point is necessary, which increases the cost. There is a problem of being connected.
Therefore, the present invention has been made paying attention to the above-mentioned conventional problems, and controls the camber angle to an appropriate value by utilizing the lateral force acting on the tire without impairing the effect due to the camber angle change. It is an object of the present invention to provide a vehicle suspension device capable of the following.

In order to achieve the above object, in the vehicle suspension apparatus according to claim 1 of the present invention, when a lateral force acts on a tire contact point, the lateral force increases independently of the vertical displacement of the wheel. A first virtual link that tilts the wheel in a camber angle direction with respect to the vehicle body, and is connected to the first virtual link and the vehicle body so as to be virtually pivotable and in a vertical direction of the wheel. A suspension device for a vehicle comprising a link mechanism that can be equivalently replaced with a second virtual link that can move a wheel in a vertical direction with respect to a vehicle body in accordance with a load change, wherein the tire ground contact point This occurs when the position of the second virtual link changes when the tire ground contact point moves toward the inside of the turn by changing the position of the first virtual link in a state where lateral force acts on the vehicle. The camber of the wheel with respect to the vehicle body is such that the displacement of the tire contact point in the direction of turning outward is greater than or equal to the displacement of the tire contact point in the direction of turning inside caused by the change of the position of the first virtual link. An angular rotation center point and a vertical rotation center point of the wheel with respect to the vehicle body are arranged, and the camber angular rotation center point is arranged below the ground and the vertical rotation center point is When provided on the opposite left and right wheels above the ground, the amount of lateral movement Δyl1 of the tire ground contact point caused by the change in the position of the first virtual link and the position of the second virtual link change. The lateral movement amount Δyl2 and the camber angle change γ of the tire contact point generated by the above are defined by the following equations, and based on this, the rotation center point in the camber angle direction and the rotation center point in the vertical direction It is characterized in placing a.
Δyl1 = l1 · tanγ
Δyl2 = −R [cos β-cos (β-α)]
γ = [− Fy · l1 + (W + ΔW) · l3] / Kγ

  Where R is the link length of the second virtual link, β is the tilt angle of the second virtual link in the steady state, α is the change angle of the tilt angle of the second virtual link from the steady state, and l1 Is the vertical distance from the rotation center point in the camber angle direction to the ground, Fy is the lateral force acting on the tire contact point, W is the wheel load in the steady state, ΔW is the wheel load change from the steady state, and l3 is the steady state The displacement of the tire ground contact point from K, Kγ is the stiffness value in the camber angle direction by the first virtual link.

  According to the vehicle suspension apparatus of the present invention, when a lateral force acts on a tire contact point, the wheel is in a direction in which the lateral force increases and a camber angle direction with respect to the vehicle body independently of the vertical displacement of the wheel. A first virtual link that tilts the vehicle, and the first virtual link and the vehicle body are virtually pivotably connected to each other, and the wheel is moved vertically with respect to the vehicle body in accordance with a load change in the wheel vertical direction. And a second virtual link that can be moved to a link mechanism that can be equivalently replaced. Then, the position of the first virtual link changes in a state in which a lateral force acts on the tire ground contact point at the rotation center point in the camber angle direction with respect to the vehicle body of the wheel and the rotation center point in the vertical direction with respect to the vehicle body of the wheel. Since the arrangement of the tire ground contact point is canceled by the displacement of the tire ground contact point caused by the change in the position of the second virtual link, the tire ground contact point is not displaced and the lateral force is changed. The camber angle can be adjusted.

It is a schematic block diagram which shows an example of the suspension apparatus for vehicles of this invention. It is explanatory drawing for demonstrating a 1st virtual link and a 2nd virtual link. It is explanatory drawing for demonstrating the force which acts on a tire when the lateral force of a tire acts. It is explanatory drawing for demonstrating operation | movement of this invention. It is explanatory drawing for demonstrating the calculation method of lateral movement amount (DELTA) yl1, (DELTA) yl2 and the camber angle (gamma) of a tire grounding point. It is explanatory drawing for demonstrating virtual spring Kdelta. It is explanatory drawing for demonstrating the operation | movement of 1st Embodiment. It is a schematic block diagram which shows an example of the suspension apparatus in 2nd Embodiment. It is explanatory drawing for demonstrating operation | movement of 2nd Embodiment. It is explanatory drawing for demonstrating the calculation method of lateral movement amount (DELTA) yl1u of a wheel upper part position. It is explanatory drawing for demonstrating the operation | movement of 3rd Embodiment.

Embodiments of the present invention will be described below.
First, a first embodiment will be described.
FIG. 1 shows the principle of a vehicle suspension device according to the present invention, as viewed from the rear of a vehicle body.
In FIG. 1, 1 is a vehicle body, 2 is a wheel, and the wheel 2 is rotatably supported by a rotation support member 3. The rotation support member 3 is connected to the upper ends of links 4 and 5 as vertical links extending in a substantially vertical direction via rotation members 4a and 5a. The lower end is connected to a link 6 as an inverted T-shaped link. The link 6 is formed in a substantially inverted T-shape, and the lower ends of the link 4 and the link 5 are rotated at both ends of a horizontal portion 6a extending in the substantially horizontal direction of the link 6 via rotating members 4b and 5b, respectively. The link 4 and the link 5 are arranged so that the intersection of the extension lines of the axes of the link 4 and the link 5 is located below the ground.

  Further, the link 7 and the link 8 that correspond to the upper link and the lower link and extend in the vehicle width direction and that serve as the vehicle width direction link can freely turn to the vehicle body 1 via the rotating members 7a and 8a. The wheel side end portion of the link 7 is connected to the end portion of the vertical portion 6b extending in the substantially vertical direction of the link 6 via a rotating member 7b, and the wheel side end portion of the link 8 is connected to the wheel side end portion. The vertical portion 6b of the link 6 is rotatably connected to a position from the horizontal portion 6a via a rotating member 8b. And the intersection of the extension line of the axis | shaft of the link 7 and the link 8 is arrange | positioned so that it may be located inside a vehicle width direction.

A spring member 10 corresponding to a shock absorber or the like that extends substantially in the vertical direction and can support the weight of the vehicle body is rotatably connected between the link 8 and the vehicle body 1.
As a result, the link 6 is supported so as to be movable relative to the vehicle body 1 in the vertical direction by the input of the vertical force from the road surface, and the rotation support member 3 is supported by the lateral force from the road surface. Is supported so as to be movable relative to the link 6 in the lateral direction. At this time, the instantaneous rotation center A of the lateral movement of the rotation support member 3 is an intersection of the extension lines of the axes of the link 4 and the link 5, and the instantaneous rotation center B of the link 6 in the vertical direction is This is the intersection of the extension lines of the links 7 and 8.

  Therefore, the wheel 2 changes in the vertical direction with respect to the vehicle body 1 by the input of the vertical force from the road surface, and changes in the camber angle direction with respect to the vehicle body 1 by the input of the horizontal force from the road surface. Then you can think geometrically. The instantaneous rotation center B of the wheel 2 in the vertical direction is the intersection of the extension lines of the links 7 and 8, and the instantaneous rotation center A of the wheel 2 in the camber angle direction is the extension line of the links 4 and 5. Can be thought of as the intersection of

Here, since the rotation support member 3 rotatably supports the wheel 2 and determines the instantaneous rotation center A in the camber angle direction together with the link 4, the link 5 and the link 6, the rotation support member 3 in FIG. As shown in FIG. 2, the links 4, 5, and 6 can be equivalently replaced with a first virtual link 11 that connects the instantaneous rotation center A in the camber angle direction and the wheel 2. Further, the instantaneous rotation center B in the vertical direction is determined by the link 6, the link 7 and the link 8, and the link 7 and the link 8 are connected to the first virtual link 11 via the link 6. Since the link 6 and the link 7 and the link 8 are virtually connected to the first virtual link 11 at the instantaneous rotation center A in the camber angle direction, as shown in FIG. The second virtual link 12 virtually connected to the instantaneous rotation center A in the camber angle direction and the instantaneous rotation center B in the vertical direction can be replaced.
In FIG. 1, the spring member 10 is attached to the link 8. However, the spring member 10 may be attached to any one of the suspension components constituting the second virtual link 12 that determines the vertical position of the wheel 2. That's fine.

  In FIG. 2, a virtual spring 14 is provided between the first virtual link 11 and the second virtual link 12, and this virtual spring 14 is an overturning moment that is generated when the tire is displaced in the camber angle direction. It corresponds to a factor considered by the friction of the suspension link constituting the first virtual link 11 and the spring element of the rotating member, and the like, between the first virtual link 11 and the second virtual link 12. It can be considered that it is provided.

  Here, in order to describe the first virtual link 11 and the second virtual link 12, the case where a double wishbone type suspension is used as shown in FIG. 1 has been described, but the present invention is not limited to this. Instead, the link structure can be applied to a suspension system of a strut type, a multi-link type, or a trailing arm type, and can be replaced with the first virtual link 11 and the second virtual link 12. Any suspension type can be applied as long as it has a suspension.

Next, a method for setting the instantaneous rotation center A in the camber angle direction and the instantaneous rotation center B in the vertical direction will be described.
Here, in the conventional camber angle control type suspension device, as described above, the camber angle is changed when the tire lateral force is applied. Therefore, it can be considered that the first virtual link 11 of FIG. 2 is provided. Then, in order to add a camber angle by the first virtual link 11, it is determined at which position the instantaneous rotation center of the first virtual link 11, that is, the instantaneous rotation center A in the camber angle direction is determined.

  However, in this suspension device, as described above, although the camber angle can be controlled according to the lateral force, by adding the camber angle, a lateral movement of the tire ground contact point occurs, thereby adding the camber angle. This reduces the responsiveness of the vehicle. That is, as shown in FIG. 3, in the steady state where the camber angle is not controlled (FIG. 3A), when the instantaneous rotation center A in the camber angle direction of the wheel 2 is set below the ground, As shown in FIG. 3B, when a lateral force acts on the tire, the wheel 2 rotates about the instantaneous rotation center A in the camber angle direction. For this reason, the tire ground contact point instantaneously moves in the turning inner direction, and as a result, the tire contact point center moves in the vehicle turning inner direction at the speed Vy. For this reason, an angle αy is generated between the longitudinal velocity V at the center of the tire contact point and the tire traveling direction, and a tire lateral force is generated in a direction that prevents turning (FIG. 3C).

Therefore, in the first embodiment, the horizontal movement amount Δyl1 of the tire ground contact point when the camber angle is changed about the instantaneous rotation center A in the camber angle direction is set by the first virtual link 11 in the vertical direction. Is adjusted by the lateral movement amount Δyl2 of the tire ground contact point generated by the rotation of the second virtual link 12 around the instantaneous rotation center B.
Here, as described above, by providing the first virtual link 11 and the second virtual link 12, in the passive suspension, the camber angle change of the wheel 2 when the tire lateral force is generated, and the tire contact point The lateral displacement can be arbitrarily set independently.

  As shown in FIG. 4A, when the camber angle changes due to the tire lateral force, the first virtual link 11 rotates around the instantaneous rotation center A in the camber angle direction and the wheel 2 rotates. Therefore, the tire ground contact point moves laterally by Δyl1. On the other hand, when the first virtual link 11 is rotated by the tire lateral force, the second virtual link 12 that determines the vertical position of the vehicle body with a change in the wheel load accompanying the rotation of the first virtual link 11. However, since it rotates around the instantaneous vertical rotation center B in the vertical direction, as shown in FIG. 4B, it moves laterally by Δyl2 in the direction to cancel the lateral movement amount Δyl1.

Here, the lateral movement amounts Δyl1 and Δyl2 and the camber angle γ of the tire ground contact point generated by the rotation of the first virtual link 11 and the second virtual link 12 can be expressed by the following equations.
Δyl1 = l1 · tanγ (1)
γ = [− Fy · l1 + (W + ΔW) · l3] / Kγ (2)
Δyl2 = −R [cos β-cos (β-α)] (3)
R = [(l4) ² + (l2) ² ] ^1/2 (4)
β = cos ⁻¹ [(l4) / (l2)] (5)
α = β + sin ⁻¹ (ΔZ / R−sin β)] (6)
ΔZ
= R · sin [(ΔW · R · cosβ−Fy · R · cosβ + Kγ · γ) / Kδ]
...... (7)
Kδ = Kw · (R · cosβ) ² (8)
ΔW = f (Fy) (9)

  In addition, l1-l4 in the said formula is a value prescribed | regulated as shown in FIG. That is, as shown in FIG. 5A, l1 is a vertical distance from the instantaneous rotation center A of the camber angle to the tire contact point, and l3 is a tire contact point when the camber angle is added around the instantaneous rotation center A. Displacement amount. Further, as shown in FIG. 5B, l2 is the state before the second virtual link 12 moves, that is, between the instantaneous rotation center A and the instantaneous rotation center B in the vertical direction when in the steady state. The horizontal distance, l4, is the vertical distance between the instantaneous rotation center A and the instantaneous rotation center B when in a steady state.

  Further, Fy is a lateral force at the tire contact point, W is a wheel load in a steady state, ΔW is a wheel load change from the steady state, Kγ is an overturning moment, bush rigidity, and the like in the camber angle direction by the first virtual link 11 , Kw is a virtual spring corresponding to the wheel end provided in the second virtual link 12, and Kδ is provided as a spring corresponding to the wheel end in the second virtual link 12, as shown in FIG. The virtual spring Kw is a spring equivalent value provided in the second virtual link 11 around the instantaneous rotation center B, R is the length of the second virtual link 12 (distance between the instantaneous rotation center A and the instantaneous rotation center B), β Is the inclination angle of the second virtual link 12, α is the inclination angle change of the second virtual link 12, and ΔZ is the vertical displacement of the tire contact point.

  When the tire lateral force is input, the camber angle γ provided by the first virtual link 11 can be expressed by the equation (2) from the balance around the moment of the tire contact point. Here, Kγ is a spring equivalent (corresponding to the virtual spring 14 in FIG. 2) acting in a direction in which the first virtual link 11 prevents the camber angle from being generated with respect to the moment around the instantaneous rotation center A. This is the repulsive force due to tire overturning moment, suspension member deformation, and the like.

Then, due to the camber angle γ generated by the first virtual link l1, the lateral movement amount Δyl1 of the tire contact point caused by the first virtual link 11 is a geometrical relationship between the tire contact point, the instantaneous rotation center A, and the camber angle γ From the above relationship, it can be expressed by the formula (1).
Further, the lateral movement amount Δyl2 of the tire ground contact point by the second virtual link 12 is expressed by the equation (3), and R, β, and α in the equation (3) are obtained from the equation (4), respectively. (6) It represents with Formula. ΔZ in the equation (6) is expressed by the equation (7), and is generated around the instantaneous rotation center A by the wheel load of the vehicle body, the lateral force acting on the tire, and the first virtual link 11. Determined by moment.

  Here, the wheel load change ΔW can be expressed by a function value having the lateral force Fy acting on the tire as a variable, as shown in the equation (9). Therefore, since the lateral force Fy and the wheel load change ΔW acting on the tire in a certain running state are established by the relational expression, a certain running is determined from the center of gravity position of the vehicle body, roll rigidity, wheel load distribution, roll center height, and the like. In the state, the instantaneous rotation center B with respect to the instantaneous rotation center A can be set so that the camber angle and the lateral displacement of the tire ground contact point have desired values.

  That is, the camber angle γ of the wheel 2 generated by the first virtual link 11 is determined by the position of the instantaneous rotation center A and the rigidity value Kγ, and the lateral displacement of the tire ground contact point is the camber angle by the first virtual link 11. This is the sum of the lateral displacement movement of the ground contact point associated with the displacement and the lateral movement of the tire ground contact point that occurs when the second virtual link 11 rotates about the instantaneous rotation center B. That is, a desired camber angle γ in a certain state quantity is determined by the first virtual link 11, and the instantaneous rotation center B is set for the characteristic, thereby changing the camber angle and the lateral displacement of the tire ground contact point. Can be adjusted independently.

  In the first embodiment, the tire contact by the second virtual link 12 is greater than the lateral movement amount Δyl1 of the tire ground contact point inwardly caused by the inclination in the camber angle direction by the first virtual link 11. The instantaneous rotation center B with respect to the instantaneous rotation center A is set so that the lateral movement amount Δyl2 of the point becomes larger. That is, the instantaneous rotation center B is set so that | Δyl2 | ≧ | Δyl1 | is satisfied in the lateral displacement of the tire contact point defined by the equations (1) and (3).

  As a result, as shown in FIG. 7, the tire ground contact point is moved to the outside of the turn at least from the steady state. Therefore, a desired camber angle can be realized, and the tire ground contact point does not move inward of the turn from the steady state. It is possible to avoid the occurrence of a tire lateral force in a direction that hinders the vehicle, and it is possible to avoid a decrease in vehicle responsiveness to the addition of a camber angle. Then, as shown in FIG. 7, since the tire ground contact point is moved to the outside of the turn from the steady state, the tire lateral force is generated on the inside of the turn, and the response to the addition of the camber angle. Can be improved.

At this time, the lateral movement amount Δyl2 of the tire ground contact point by the second virtual link 12 is larger than the lateral movement amount Δyl1 of the tire ground contact point inward of the turning caused by the inclination in the camber angle direction by the first virtual link 11. The larger the is, the greater the tire lateral force generated on the inside of the turn, so that the responsiveness to the addition of the camber angle can be further improved.
Further, as shown in the equations (1) to (9), the camber angle γ by the first virtual link 11, the lateral movement amount Δyl 1 of the tire ground contact point by the first virtual link 11, and the second virtual link 12 Since the lateral movement amount Δyl2 of the tire contact point can be defined and numerically defined, the positions of the instantaneous rotation centers A and B are calculated so that the lateral movement amounts Δyl1 and Δyl2 satisfy a predetermined relationship. Therefore, these arrangement positions can be easily determined, and can be easily realized without using an actuator or the like.

  In addition, the camber angle can be controlled and the displacement of the tire contact point can be controlled without using an actuator or the like. Therefore, when an actuator is used, it is necessary to provide an actuator corresponding to each wheel. However, since the camber angle can be adjusted without providing an actuator as described above, significant cost reduction can be achieved. it can.

Next, a second embodiment of the present invention will be described.
FIG. 8 is a schematic configuration diagram illustrating an example of a vehicle suspension device according to the second embodiment, as viewed from the rear of the vehicle.
In FIG. 8, reference numeral 31 denotes a knuckle arm, and a wheel 32 and a brake rotor 33 are rotatably attached to the knuckle arm 31. A link 34 extending in the vertical direction is connected to the knuckle arm 31 via two bushes (elastic members) 35 and 36, and the direction of deformation of each of the two bushes 35 and 36 is defined as an axial direction. At this time, the intersection of the orthogonal axes orthogonal to the axial direction is arranged at a position below the ground.

  One end of an upper link 37 and a lower link 38 extending in the vehicle width direction is connected to the upper and lower ends of the link 34 via pillow balls 34a and 34b. The other ends of the upper link and the lower link 38 are rotatably connected to a vehicle body side member (not shown) so that the intersection of the extension lines of the upper link 37 and the lower link 38 is located on the opposite wheel side. Be placed.

When the lateral force acts on the tire, the bushes 35 and 36 are elastically deformed to change the camber angle of the wheel 32, and the wheel 32 is moved in the vertical direction by the upper link 37 and the lower link 38. Be able to. In FIG. 8, 39 is a brake caliper, and 40 is a wheel hub.
In this suspension device, the intersection of the orthogonal axes orthogonal to the axial direction of the two bushes 35 and 36 becomes the instantaneous rotation center A in the camber angular direction. Further, the intersection of the extension lines of the upper link 37 and the lower link 38 becomes the instantaneous rotation center B in the vertical direction.

  Therefore, in this second embodiment, the knuckle arm 31 holds the wheel 32 rotatably, and determines the instantaneous rotation center A in the camber angle direction together with the bushes 35 and 36 and the link 34. 35 and 36, the link 34, and the knuckle arm 31 can be equivalently replaced as the first virtual link 11 that connects the instantaneous rotation center A in the camber angle direction and the wheel 2 as shown in FIG. The upper link 37, the lower link 38, and the link 34 determine the instantaneous rotation center B in the vertical direction. The upper link 37 and the lower link 38 are connected to the first virtual link 11 via the link 34. Therefore, the upper link 37 and the lower link 38 and the link 34 are connected to the instantaneous rotation center A in the camber angle direction and the instantaneous rotation center B in the vertical direction in FIG. It can be replaced with two virtual links 12.

  In FIG. 8, when a lateral force acts on the wheel 32, the bushes 35 and 36 are deformed, and the knuckle arm 31 rotates around the instantaneous rotation center A to change the camber angle. At this time, since the instantaneous rotation center A is set at a position below the ground, the tire ground contact point moves in the lateral direction. Therefore, the instantaneous rotation center B in the vertical direction is set so that no lateral displacement of the tire ground contact point in the turning inner direction occurs.

In the second embodiment, the amount of lateral movement Δyl1 of the tire ground contact point caused by the inclination in the camber angle direction by the first virtual link 11 to the inside of the turn of the tire ground contact point by the second virtual link 12 is The instantaneous rotation center B in the vertical direction is set with respect to the instantaneous rotation center A in the camber angle direction so as to be substantially equal to the lateral movement amount Δyl2 inward of the turning. Specifically, the lateral movement amounts Δyl1 and Δyl2 of the tire contact point defined by the equations (1) and (3) are set so that | Δyl1 | = | Δyl2 |. That is, the instantaneous rotation centers A and B are set so as to satisfy the following expression (10).
R = | l1 · tanγ | / | cosα | (10)

As a result, even when a lateral force acts on the wheel 32 and a camber angle change occurs, the lateral movement amounts Δyl1 and Δyl2 cancel each other. The displacement is almost zero. Therefore, it is possible to avoid the occurrence of a lateral force in a direction that hinders turning due to the lateral movement of the tire ground contact point, and the responsiveness of the vehicle is reduced due to the occurrence of the lateral force. It can be avoided.
In addition, as described in the first embodiment, the bushes 35 and 36 are used as compared with the case where the first virtual link 11 and the second virtual link 12 are configured using a link mechanism. Therefore, it can be realized with a simple structure and at a lower cost, and the weight can be further reduced.

In the second embodiment, as shown in FIG. 9, the case where the instantaneous rotation centers A and B are set so that the lateral displacement of the tire ground contact point becomes substantially zero has been described, but the present invention is not limited thereto. However, as in the first embodiment, the lateral movement amount Δyl2 of the tire ground contact point due to the rotation of the second virtual link 12 is greater than the tire ground contact point due to the rotation of the first virtual link 11. May be set so as to be larger than the lateral movement amount Δyl1 of the tire, and the tire ground contact point may be configured to move to the outside of the turn from the steady state. Since the lateral force acts, it becomes possible to improve the response of the vehicle to the addition of the camber angle.
Moreover, although the case where a bush was used as an elastic member was demonstrated, it is not restricted to this, For example, if it is a member which elastically deforms, such as a spring member, it is applicable.

Next, a third embodiment of the present invention will be described.
The third embodiment is the same as the first embodiment except that the instantaneous rotation centers A and B are set differently. Omitted.
In the third embodiment, as shown in FIG. 10, the lateral movement amount Δyl1u when the upper portion of the wheel 2 moves in the turning inner direction due to the inclination in the camber angle direction by the first virtual link 11. However, the instantaneous rotation center B with respect to the instantaneous rotation center A is set so as to be substantially equal to the lateral movement amount Δyl2 of the tire ground contact point by the second virtual link 12.

That is, the instantaneous rotation center is set so that the lateral movement amount Δyl2 of the tire contact point defined by the equation (3) and the lateral movement amount Δyl1u of the upper position of the wheel 2 satisfy | Δyl2 | ≈ | Δyl1u |. Set A and B.
Here, the lateral movement amount Δyl1u of the upper position of the wheel 2 can be expressed by the following equation (11).
Δyl1u = l1 · tanγ + 2r · sinγ (11)
In the equation (11), r is the radius of the wheel 2.
Therefore, in order to realize | Δyl1u | ≈ | Δyl2 |, the instantaneous rotation centers A and B may be set so as to satisfy the following expression (12).
R = | l1 · tanγ + 2r · sinγ | / | cosα | (12)

  By setting the instantaneous rotation centers A and B so as to satisfy the above expression (12), as shown in FIG. 11, the tire ground contact point is prevented from moving in the turning inward direction as the camber angle changes. In addition, it is possible to avoid the upper position of the wheel 2 from changing in the turning inner direction. Therefore, it is possible to obtain the same effect as that of the first embodiment, and in the third embodiment, it is possible to avoid the change in the upper position of the wheel 2 as shown in FIG. .

  Here, when the upper position of the wheel 2 is changed, when the upper position of the wheel 2 is changed to the vehicle body 1 side in FIG. 11, the tire house clearance is changed. It may not be applicable. However, in the third embodiment, as described above, since the instantaneous rotation centers A and B are set so that the change in the upper position of the wheel 2 does not occur, there is no problem even in the conventional vehicle body structure. Can be applied.

In the third embodiment, the case has been described in which the instantaneous rotation centers A and B are set so that the upper position of the wheel 2 does not change in the turning inner direction with the change of the camber angle. However, the present invention is not limited to this. If the tire house clearance when the upper position of the wheel 2 changes in the turning inner direction is within the allowable range, the upper position of the wheel 2 changes in the turning inner direction. Can also be applied.
Moreover, in the said 3rd Embodiment, although the case where it applied to the said 1st Embodiment was demonstrated, it cannot be overemphasized that it can apply to the said 2nd Embodiment.

DESCRIPTION OF SYMBOLS 1 Car body 2 Wheel 3 Rotation support member 4, 5 Link 6 Link 7, 8 Link 10 Virtual spring 11 First virtual link 12 Second virtual link 14 Virtual spring 31 Knuckle arm 32 Wheel 33 Brake rotor 34 Link 35, 36 Bush (Elastic member)

Claims (5)

A first virtual link that tilts the wheel in a camber angle direction with respect to the vehicle body in a direction in which the lateral force increases independently of a vertical displacement of the wheel when a lateral force acts on the tire contact point; A second virtual link that is virtually pivotably connected between the first virtual link and the vehicle body and that is capable of moving the wheel up and down relative to the vehicle body in accordance with a load change in the vertical direction of the wheel. A suspension device for a vehicle having a link mechanism that can be equivalently replaced with
When a lateral force acts on the tire ground contact point, the position of the second virtual link changes when the tire ground contact point moves in the turning inner direction due to the position of the first virtual link changing. So that the displacement of the tire ground contact point in the direction of turning outward is greater than or equal to the displacement of the tire ground contact point in the direction of turning inside caused by the change in the position of the first virtual link. A rotation center point in the camber angle direction relative to the vehicle body and a rotation center point in the vertical direction relative to the vehicle body of the wheel,
Further, when the rotation center point in the camber angle direction is disposed below the ground and the rotation center point in the vertical direction is provided on the opposite left and right wheels above the ground, the first virtual link The lateral movement amount Δyl1 of the tire contact point caused by the change in position, the lateral movement amount Δyl2 of the tire contact point caused by the change of the position of the second virtual link, and the camber angle change γ are defined by the following expressions: And based on this, the rotation center point in the camber angle direction and the rotation center point in the vertical direction are arranged.
Δyl1 = l1 · tanγ
Δyl2 = −R [cos β-cos (β-α)]
γ = [− Fy · l1 + (W + ΔW) · l3] / Kγ
Where R is the link length of the second virtual link, β is the tilt angle of the second virtual link in the steady state, α is the change angle of the tilt angle of the second virtual link from the steady state, and l1 Is the vertical distance from the rotation center point in the camber angle direction to the ground, Fy is the lateral force acting on the tire contact point, W is the wheel load in the steady state, ΔW is the wheel load change from the steady state, and l3 is the steady state The displacement of the tire ground contact point from K, Kγ is the stiffness value in the camber angle direction by the first virtual link. A first virtual link that tilts the wheel in a camber angle direction with respect to the vehicle body in a direction in which the lateral force increases independently of a vertical displacement of the wheel when a lateral force acts on the tire contact point; A second virtual link that is virtually pivotably connected between the first virtual link and the vehicle body and that is capable of moving the wheel up and down relative to the vehicle body in accordance with a load change in the vertical direction of the wheel. A suspension device for a vehicle having a link mechanism that can be equivalently replaced with
In a state where lateral force acts on the tire ground contact point, the displacement of the tire ground contact point in the turning inner direction caused by the change in the position of the first virtual link and the position of the second virtual link change. A rotation center point in the camber angle direction with respect to the vehicle body of the wheel and a rotation center point in the vertical direction with respect to the vehicle body of the wheel so that the displacement of the tire ground contact point in the direction of the turning outer side caused by Place and
Further, when the rotation center point in the camber angle direction is disposed below the ground and the rotation center point in the vertical direction is provided on the opposite left and right wheels above the ground, the first virtual link The lateral movement amount Δyl1 of the tire contact point caused by the change in position, the lateral movement amount Δyl2 of the tire contact point caused by the change of the position of the second virtual link, and the camber angle change γ are defined by the following expressions: And based on this, the rotation center point in the camber angle direction and the rotation center point in the vertical direction are arranged.
Δyl1 = l1 · tanγ
Δyl2 = −R [cos β-cos (β-α)]
γ = [− Fy · l1 + (W + ΔW) · l3] / Kγ
Where R is the link length of the second virtual link, β is the tilt angle of the second virtual link in the steady state, α is the change angle of the tilt angle of the second virtual link from the steady state, and l1 Is the vertical distance from the rotation center point in the camber angle direction to the ground, Fy is the lateral force acting on the tire contact point, W is the wheel load in the steady state, ΔW is the wheel load change from the steady state, and l3 is the steady state The displacement of the tire ground contact point from K, Kγ is the stiffness value in the camber angle direction by the first virtual link.   Rotation in the camber angle direction so that the tire house clearance between the upper part of the wheel and the vehicle body is within an allowable range when the wheel is inclined toward the vehicle body by changing the position of the first virtual link. The vehicle suspension apparatus according to claim 1 or 2, wherein a center point and the rotation center point in the vertical direction are arranged. When the rotation center point in the camber angle direction is disposed below the ground and the rotation center point in the vertical direction is provided on the opposite left and right wheels above the ground, the position of the first virtual link is The lateral movement amount Δyl1u of the wheel upper portion caused by the change, the lateral movement amount Δyl2 of the tire contact point caused by the change of the position of the second virtual link, and the camber angle change γ are defined by the following expressions: 4. The vehicle suspension device according to claim 1, wherein a rotation center point in the camber angle direction and a rotation center point in the vertical direction are arranged based on this. 5.
Δyl1u = l1 · tanγ + 2r · sinγ
Δyl2 = −R [cos β-cos (β-α)]
γ = [− Fy · l1 + (W + ΔW) · l3] / Kγ
Where R is the link length of the second virtual link, β is the tilt angle of the second virtual link in the steady state, α is the change angle of the tilt angle of the second virtual link from the steady state, and l1 Is the vertical distance from the rotation center point in the camber angle direction to the ground, r is the radius of the wheel, Fy is the lateral force acting on the tire contact point, W is the wheel load in the steady state, and ΔW is the wheel load from the steady state The change, l3 is the displacement of the tire contact point from the steady state, and Kγ is the camber angle stiffness value by the first virtual link.   The vehicle suspension according to any one of claims 1 to 4, wherein the first virtual link is configured to change the camber angle by utilizing rigidity of an elastic member. apparatus.

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