JP2010269640A - Steering mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steering angle adjusting mechanism capable of reducing a corrected steering amount when inputting a lateral force and braking force. <P>SOLUTION: This steering angle adjusting mechanism includes a first knuckle rotatably supporting a tire, a second knuckle rotatably supporting the first knuckle and having a rotation center different from that of the first knuckle 10, a first link member for linking a first connection position formed on a vehicle body side and a second connection point formed on the second knuckle side, and a second link member for linking a third connection point formed on the vehicle body side and a fourth connection point formed on the second knuckle side. The fourth connection point is arranged at a position except a plane including the first connection point, the second connection point and the third connection point. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a mechanism for steering a vehicle.

  Conventionally, a technique described in Patent Document 1 is known as a steering mechanism. In this technique, a member having a knuckle spindle (hereinafter referred to as a knuckle member) is attached to the torsion beam, and a connecting member is provided between the knuckle member and the torsion beam. When a lateral force or a braking force is input, the knuckle member is slightly rotated in the toe-in direction by deformation of a rubber bush provided at a connection point between the knuckle member and the connection member.

JP-A-6-191248

  However, in the technique described in Patent Document 1, since the ratio of the deformation amount of the rubber bush to the length of the connecting member or the like is very small and the angle can be adjusted only in a very small range, the driver can be corrected only extremely finely. There was a problem that the steering amount was not reduced.

  The present invention has been made paying attention to the above problem, and an object of the present invention is to provide a steering angle adjustment mechanism capable of reducing the correction steering amount when a lateral force or a braking force is input.

    In order to achieve the above object, in the present invention, a first knuckle that rotatably supports a tire, and a first knuckle that rotatably supports the first knuckle and has a rotation center different from the rotation center of the first knuckle. 2 knuckle, a first link member connecting the first connection point formed on the vehicle body side and the second connection point formed on the second knuckle side, and a third connection point formed on the vehicle body side And a second link member for connecting the second connection point formed on the second knuckle side, the third connection point being the first connection point, the second connection point, and the fourth connection point. Arranged on a plane other than the plane including the connecting points.

  Therefore, roll steer can be generated, and steering correction can be performed without using an actuator or the like.

It is the schematic showing the structure of the vehicle front part by which the steering angle adjustment mechanism of Example 1 is mounted. FIG. 5 is a characteristic diagram showing a relationship of a driver's steering amount with respect to a change in roll angle when turning at a constant turning radius in a vehicle having an oversteer characteristic. FIG. 3 is a schematic diagram illustrating a configuration of an expansion / contraction mechanism according to the first embodiment. It is the schematic showing the relationship of the rotation stop link of the turning initial stage of Example 1. FIG. It is the schematic showing the relationship of the rotation stop link of the turning later stage of Example 1. FIG. It is the schematic showing the structure of the vehicle front part by which the steering angle adjustment mechanism of Example 2 is mounted, Comprising: It is a figure showing the state of the turning initial stage. It is the schematic showing the relationship of the rotation stop link of the turning latter stage of Example 2. FIG. FIG. 5 is a characteristic diagram showing a relationship of a driver's steering amount with respect to a change in roll angle when turning with a constant turning radius in a vehicle with an understeer characteristic. It is a figure showing the turning characteristic at the time of driving | running | working near a limit. It is the schematic showing the roll steer characteristic by the model which applied Example 2 concretely. It is the schematic showing the expansion-contraction mechanism provided in the rotation stop link of Example 3. It is the schematic showing the expansion-contraction mechanism provided in the rotation stop link of Example 4. It is the schematic showing the expansion-contraction mechanism provided in the rotation stop link of the other Example. FIG. 10 is a schematic diagram illustrating a configuration of an expansion / contraction mechanism according to a fifth embodiment.

  FIG. 1 is a schematic diagram illustrating a configuration of a front portion of a vehicle on which the steering angle adjusting mechanism according to the first embodiment is mounted. FIG. 1A is a bottom view seen from the bottom side of the vehicle, and FIG. 1B is a front view seen from the front of the vehicle. In addition, this vehicle is a vehicle having a so-called oversteer characteristic in which the front wheels tend to cut into the inside of the turn when the roll angle increases. Details will be described later. The front wheel steering mechanism of the first embodiment includes a first knuckle 10 having a knuckle spindle 11 that rotatably supports front wheels FR and FL, and a second knuckle that supports the first knuckle 10 via a bearing 12 so as to be relatively rotatable. 20 and a strut 50 to which the second knuckle 20 is attached. The first knuckle 10 is formed with a knuckle arm (not shown), and a rack shaft is connected to the knuckle arm via a tie rod. Basically, the rotation amount of the first knuckle 10 is determined by the rack shaft movement amount (driver's steering amount). The second knuckle 20 is rotatable about the strut 50. A lower arm 30 (first link member) and a rotation stop link 40 (second link member) for connecting the vehicle body 1 and the second knuckle 20 are provided below the second knuckle 20.

  The lower arm 30 is substantially V-shaped and includes a first arm 30a, a second arm 30b, and a knuckle arm 30c to which both arms are connected. The first arm 30a is attached to the vehicle body side and the attachment point 31 so as to be rotatable in the vertical direction, and the second arm 30b is attached to the vehicle body side and the attachment point 32 so as to be rotatable in the vertical direction. The knuckle arm 30 c is connected to the second knuckle 20 and the attachment point 33. Here, with respect to the attachment point of the lower arm 30, the center (center of gravity coordinates) of the attachment points 31 and 32 formed on the vehicle body side is representatively described as the first connection point M1, and formed on the second knuckle side. The attachment point 33 is represented as a second connection point M2. When there are a plurality of attachment points on the second knuckle side, the center (center of gravity coordinates), the rotation center coordinates, etc. may be represented as the second connection points.

  The anti-rotation link 40 has an attachment point 42 provided with an expansion / contraction mechanism 41 formed at the end of the vehicle body and extending and contracting in the link length direction, and an attachment point 43 formed on the second knuckle side. Here, regarding the attachment point of the rotation stop link 40, the attachment point 42 formed on the vehicle body side is represented as a third connection point M3, and the attachment point 43 formed on the second knuckle side is represented as a fourth connection point M4. To do.

  The first to fourth connection points M1, M2, M3, and M4 are connected to the vehicle body side and the second knuckle side via rubber bushes, respectively, and allow distortion and twist three-dimensionally within a predetermined range. It is attached as follows. The first connection point M1 can be rotated with a small resistance in the direction in which the lower arm 30 rotates in the vertical direction around the first connection point M1, and a slight amount of displacement is allowed in the front-rear and left-right directions. Is set to about. The second connecting point M2 can rotate with a small resistance in the direction in which the second knuckle 20 rotates in the turning direction around the second connecting point M2, and a slight amount of displacement in the front-rear, left-right, and up-down directions. Is set to allow The third connection point M3 is set to allow the amount of displacement that occurs when the vehicle body is rolled. The fourth connection point M4 is rotatable with a small resistance in the direction in which the second knuckle 20 rotates in the turning direction around the fourth connection point M4, and is slightly displaced in the front-rear, left-right, and up-down directions. It is set to allow the amount.

(Positional relationship of each connection point)
Next, the positional relationship of each connection point will be described. The first connection point M1 and the third connection point M3 are disposed at the same position in the vehicle width direction (left-right direction), and the third connection point M3 is disposed above the first connection point M1 in the height direction. ing. Further, the second connection point M2 and the fourth connection point M4 are at the same height position and are also arranged at the same position in the left-right direction. In other words, the lower arm 30 and the rotation stop link 40 are set to have a relative angle in a front view. This can be said that the third connection point M3 is arranged on a plane other than the plane including the first connection point M1, the second connection point M2, and the fourth connection point M4. In particular, in a vehicle having an oversteer characteristic, the third connection point M3 is disposed above the plane. In addition, the vertical dimension (B in the first embodiment) of the third connection point M3 and the fourth connection point M4 is larger than the vertical dimension (the zero in the first embodiment) of the first connection point M1 and the second connection point M2. The rotation stop link 40 is arranged so as to be large.

  In the first embodiment, in the bottom view, the length in the left-right direction between the first connection point M1 and the second connection point M2 defined by the lower arm 30 is set to A, and the third connection point defined by the rotation stop link 40 The length in the left-right direction between M3 and the fourth connection point is also set to A. Further, in the front view, the vertical length of the first connection point M1 and the third connection point M3 is set to B. It is important that the length relationship is such that a desired turning action can be applied to the second knuckle 20 when the vehicle body is rolled, and the lower arm 30 and the rotation stop link 40 are not necessarily the same length. There is no need to be.

(Relationship between the rotation center of the first knuckle and the rotation center of the second knuckle)
Next, the relationship between the rotation centers of the first knuckle 10 and the second knuckle 20 will be described. The first knuckle 10 is rotatable relative to the second knuckle 20 around a first rotation axis O <b> 1 formed on the second knuckle 20. Further, the second knuckle 20 is attached to the strut 50, and the strut 50 rotates about the second rotation axis O2. The first rotation axis O1 and the second rotation axis O2 are set in parallel. The first rotation axis O1 is disposed at a position different from the second rotation axis O2. That is, when the second knuckle 20 rotates about the second rotation axis O2, the front wheel turning angle is changed according to the rotation amount. In other words, the rotation of the second knuckle 20 is set so as to affect the turning angle, and even if the first knuckle 10 and the second knuckle 20 can be relatively rotated, The rotation of the knuckle 20 is not canceled by the relative rotation with the first knuckle 10, and the turning angle is not affected. The rotation stop link 40 is disposed on the vehicle front side with respect to the strut 50, and the lower arm 30 is disposed on the vehicle rear side with respect to the strut 50. This means that the force of the rotation stop link 40 is input to the second knuckle 20 on the opposite side to the turning direction during rolling.

(Vehicle characteristics affected by roll angle)
Next, the vehicle characteristics exerted by the roll angle according to the first embodiment will be described. FIG. 2 is a characteristic diagram showing a relationship of a driver's steering amount with respect to a change in roll angle when a vehicle turns with a constant turning radius in a vehicle with oversteer characteristics. As shown in FIG. 2, in the initial stage of turning with a relatively small roll angle, the steering amount itself does not change greatly even with the oversteer characteristic, and the steering amount is slightly reduced. However, in the latter half of the turn when a certain roll angle is reached, as shown by the dotted line in FIG. 2, the oversteer tendency tends to increase, and an operation that greatly reduces the steering amount is required to counteract this. Can be said to be large. In the first embodiment, the driver burden is reduced.

(Configuration of telescopic mechanism)
Next, the configuration of the telescopic mechanism 41 will be described. FIG. 3 is a schematic diagram showing the configuration of the expansion / contraction mechanism 41. The telescopic mechanism 41 includes a cylinder 41e, a piston 41d that is connected to the rotation stop link 40 and slides inside the cylinder 41e, a spring 41c that is an elastic member interposed between the piston 41d and the cylinder 41e, and a piston 41d. It has the expansion side stopper 41a which latches in a predetermined position, and the compression side stopper 41b which latches piston 41d in a predetermined position. The piston 41d slides in a region sandwiched between the extension side stopper 41a and the contraction side stopper 41b. The initial position of the expansion / contraction mechanism 41 of the first embodiment, that is, the position where the spring set load is 0 is set to be a substantially intermediate position between the extension side stopper 41a and the contraction side stopper 41b.
When an extension side force greater than the elastic force of the spring 41c acts on the rotation stop link 40, the distance between the vehicle body 1 and the second knuckle 20 increases against the elastic force until it abuts on the extension side stopper 41a. On the other hand, when a contraction-side force greater than the elastic force of the spring 41c is applied to the rotation stop link 40, the distance between the vehicle body 1 and the second knuckle 20 is short against the elastic force until it comes into contact with the contraction-side stopper 41b. Become. In either direction, it will not be displaced beyond the position of the stopper, and after that, the same effect as a link that does not expand and contract will be produced. The expansion / contraction amount is set so that the steering correction by roll steer is performed from the vicinity of the inflection point in the roll angle-steering amount characteristic when the vehicle is accelerated at a constant turning radius. As a result, since the polarity of the change in the steering amount of the driver does not change, the correction steering by roll steer is performed without giving the driver a sense of incongruity.

(Operation of rotation stop link)
Next, the operation of the rotation stop link 40 will be described. FIG. 4 is a schematic diagram showing the relationship of the rotation stop link 40 in the early stage of turning, and FIG. 5 is a schematic diagram showing the relationship of the rotation stop link 40 in the later stage of turning. Incidentally, the initial turning represents a region where the roll angle of the vehicle body is small, and the late rotation represents a region where the roll angle of the vehicle body is large.
When turning by steering, the vehicle body rolls so that the outside of the turn sinks due to the action of lateral acceleration. FIG. 4 shows a state when turning right. In the left front wheel FL that is the turning outer wheel, the length of the lower arm 30 does not change when the vehicle body 1 tilts. Therefore, the third connection point M3 that is separated by B above the first connection point M1 in the vertical direction of the vehicle body is the first. Trying to approach 2 knuckle 20. At this time, the telescopic mechanism 41 contracts in the early stage of turning, so that the influence of the roll of the vehicle body 1 is absorbed, and the anti-rotation link 40 does not apply excessive force to the second knuckle 20. On the other hand, in the right front wheel FR that is the turning inner wheel, when the vehicle body 1 tilts, the length of the lower arm 30 does not change, so the third connection point M3 tends to move away from the second knuckle 20. At this time, the expansion / contraction mechanism 41 extends in the early stage of turning, so that the influence of the roll of the vehicle body 1 is absorbed, and the anti-rotation link 40 does not apply excessive force to the second knuckle 20. Further, in both the outer turning wheel and the inner turning wheel, the direction in which the lateral force acts coincides with the direction in which the rotation stop link 40 contracts. Operate.

  Next, at the later stage of the turn when the roll angle is increased by the action of lateral acceleration, the piston 41d of the telescopic mechanism 41 abuts on the contraction side stopper 31b in the left front wheel FL that is the outer turning wheel, and no further contraction occurs. Become. Then, a force to approach the second knuckle 20 acts on the third connecting point M3, but the length of the lower arm 30 does not change, so the second knuckle 20 is rotated in the direction opposite to the turning direction. The force works, and the second knuckle 20 is steered to the opposite side to the turning direction according to the roll angle (hereinafter referred to as roll steer). In addition, after the expansion / contraction by the expansion / contraction mechanism 41 is completed, the direction in which the lateral force acts and the direction in which the rotation stop link 40 pushes the second knuckle 20 coincide with each other. If the third connection point M3 is arranged at a position lower than the first connection point M1 in the vertical direction, the direction in which the lateral force acts when the roll is generated and the force that the rotation stop link 40 acts on the second knuckle 20 are obtained. Since the direction is reversed, it can be said that it is difficult to generate roll steer well.

  That is, as shown in FIG. 2, in a normal vehicle without the rotation stop link 40, the vehicle tends to oversteer in the latter half of the turn, and the turn cannot be continued with the same turning radius unless the steering angle is returned. That is, the driver needs a large correction steering according to the change of the oversteer characteristic, and the burden on the driver is large. On the other hand, in the configuration of the first embodiment, the same state as normal steering is created by the action of the expansion / contraction mechanism 41 at the early stage of turning, and the action of the expansion / contraction mechanism 41 is eliminated at the later stage of turning, thereby generating roll steer. Excessive yaw rate due to the roll can be canceled, and the correction steering of the driver can be reduced.

As described above, the effects listed below can be obtained in the first embodiment.
(1) A first knuckle 10 that rotatably supports a tire, a second knuckle 20 that rotatably supports the first knuckle 10 and has a rotation center different from the rotation center of the first knuckle 10, and a vehicle body A lower arm 30 (first link member) for connecting the first connection point M1 formed on the side and the second connection point M2 formed on the second knuckle 20 side, and a third connection formed on the vehicle body side A rotation stop link 40 (second link member) that connects the point M3 and the fourth connection point M4 formed on the second knuckle 20 side, and the third connection point M3 is connected to the first connection point M1. It arrange | positioned other than the plane containing the 2nd connection point M2 and the 4th connection point M4. Therefore, roll steer can be generated by the roll of the vehicle body, and steering correction can be performed without providing an actuator or the like.

  (2) The rotation stop link 40 is provided with an expansion / contraction mechanism 41, and under an operating condition in which the roll angle of the vehicle body is not more than a predetermined value, the expansion / contraction of the expansion / contraction mechanism 41 suppresses the steering angle change caused by roll steer, and Under operating conditions larger than the value, the steering angle change due to roll steer is generated by restricting the operation of the telescopic mechanism 41. Therefore, when the roll angle is small, the normal vehicle characteristics are not hindered, and the roll steer is generated only when the roll angle is large, so that the driver's corrected steering amount can be suppressed while realizing the normal vehicle characteristics.

  (3) Since the steering correction by roll steer is performed from the vicinity of the inflection point in the roll angle-steering amount characteristic when the vehicle is accelerated at a constant turning radius, the driver's feeling of strangeness is not changed because the polarity of the steering amount change of the driver does not change. The correction steering by the roll steer can be performed without giving

  (4) The change amount of the correction steering by the roll steer is set so as to be equal to or less than the change amount of the correction steering of the driver when the vehicle is accelerated at a constant turning radius. Therefore, since the polarity of the steering amount change does not change, the correction steering by roll steer can be performed without giving the driver a sense of incongruity.

  (5) Arrange the rotation stop link 40 so that the vertical dimension of the third connection point M3 and the fourth connection point M4 is larger than the vertical dimension of the first connection point M1 and the second connection point M2. Thus, since the direction in which the lateral force acts coincides with the direction in which the rotation stop link 40 pushes out the second knuckle 20, roll steer due to action and reaction can be effectively generated.

  Next, Example 2 will be described. FIG. 6 is a schematic diagram illustrating a configuration of a vehicle front portion on which the steering angle adjusting mechanism of the second embodiment is mounted, and is a diagram illustrating a state in an initial turning. 6A is a bottom view seen from the bottom side of the vehicle, and FIG. 6B is a front view seen from the front of the vehicle. This vehicle is a vehicle having a so-called understeer characteristic in which the front wheels tend to bulge outward when the roll angle increases. Since the basic configuration is the same as that of the first embodiment, only different points will be described.

(Positional relationship of each connection point)
In the first embodiment, the rotation stop link 40 is disposed on the vehicle front side with respect to the strut 50, and the lower arm 30 is disposed on the vehicle rear side with respect to the strut 50. In other words, the third and fourth connection points M3 and M4 are arranged in front of the vehicle with respect to the first and second connection points M1 and M2. On the other hand, in the second embodiment, the rotation stop link 40 is arranged on the vehicle rear side with respect to the strut 50, in other words, the lower arm 30 is arranged on the vehicle front side with respect to the strut 50. This means that the force of the rotation stop link 40 is input to the second knuckle 20 on the side of the turning direction during rolling.

(Operation of rotation stop link)
Next, the operation of the rotation stop link 40 will be described. FIG. 6 is a schematic diagram showing the relationship of the rotation stop link 40 in the early stage of turning, and FIG. 7 is a schematic diagram showing the relationship of the rotation stop link 40 in the later stage of turning. Incidentally, the initial turning represents a region where the roll angle of the vehicle body is small, and the late rotation represents a region where the roll angle of the vehicle body is large. Since the operation of the telescopic mechanism 41 is the same as that of the first embodiment, the description thereof is omitted.

  At the later stage of the turn when the roll angle becomes larger due to the action of the lateral acceleration, the piston 41d of the telescopic mechanism 41 comes into contact with the contraction side stopper 31b in the left front wheel FL, which is the outer turning wheel, and no further contraction occurs. In addition, a force to approach the second knuckle 20 acts on the third connecting point M3, while the length of the lower arm 30 does not change, and thus a force to rotate the second knuckle 20 in the turning direction side. The second knuckle 20 is steered to the turning direction side according to the roll angle (roll steer). In addition, after the expansion / contraction by the expansion / contraction mechanism 41 is completed, the direction in which the lateral force acts and the direction in which the rotation stop link 40 pushes the second knuckle 20 coincide with each other.

  That is, as shown in FIG. 8, in a normal vehicle without the rotation stop link 40, the vehicle tends to understeer suddenly in the latter half of the turn, and the turn can be continued with the same turning radius unless the steering angle is further increased. Can not. That is, the driver needs a large correction steering according to the change in the understeer characteristic, and the burden on the driver is large. On the other hand, in the configuration of the second embodiment, the same state as normal steering is created by the action of the expansion / contraction mechanism 41 at the early stage of turning, and the action of the expansion / contraction mechanism 41 is eliminated at the later stage of turning, thereby generating roll steer. The shortage of yaw rate due to the roll can be compensated, and the correction steering of the driver can be reduced.

(Vehicle characteristics affected by roll angle)
Next, vehicle characteristics exerted by the roll angle according to the second embodiment will be described. FIG. 9 is a diagram showing the turning characteristics when traveling near the limit. As shown in FIG. 9 (a), a vehicle with a wheelbase l = 2.8m is made to make a steady circular turn counterclockwise so that the lateral acceleration becomes 0.9G on the circumference of radius ρ = 80m. As shown in FIG. 9B, the state of the tire at this time is represented by βf for the slip angle on the front wheel side and βr for the slip angle on the rear wheel side as shown in FIG. According to the design values shown, βf = 9.17 ° and βr = 5.44 ° (the numerical values in parentheses are values calculated based on the design values shown in FIG. 10). Note that βf is represented by an average of the slip angles of the left and right front wheels, and βr is studied by a so-called two-wheel model represented by an average of the slip angles of the left and right rear wheels. Further, looking at the tire ground contact load, it can be seen that the left front wheel load and the left rear wheel load are small, and the right front wheel load and the right rear wheel load are large.
From the above characteristics, the driver's steering amount δ is expressed by the following equation.
δ = 1 / ρ + βf−βr
Therefore, the driver maintains a steady state by performing a correction steering of βf−βr (= 3.7 °) in addition to the neutral steer component l / ρ (= 2 °) when performing a steady circular turn of 0.9G. Will do.

  FIG. 10 is a schematic diagram showing roll steer characteristics according to a model to which Example 2 is specifically applied. The design is such that A is 300 mm, the distance between the second connection point M2 and the fourth connection point M4 is 100 mm, and the lateral width of the vehicle body 1 is 800 mm. If the regular turning shown in FIG. 8 is performed in a normal vehicle without the rotation stop link 40, the correction steering required for the driver when the roll angle is 5 ° is 3.7 ° (see FIG. 9). On the other hand, in the case of the configuration of the second embodiment, 1.9 ° correction steering is performed by roll steer, so that the correction steering required for the driver is reduced to 1.8 °. Also from this result, it can be seen that the correction steering by roll steer can be reduced. It should be noted that the change amount of the correction steering by the roll steer is set so that the length of each link and the positional relationship of the connection points are equal to or less than the change amount of the correction steering of the driver when the vehicle is accelerated at a constant turning radius. In other words, it means that the characteristic is not set such that the steering amount has to be decreased again in the latter half of the turn like the NG characteristic indicated by the dotted line in FIG. This is because such a change in polarity results in a vehicle having an oversteer characteristic rather than a vehicle having an understeer characteristic, which gives the driver a sense of incongruity.

  As described above, in a vehicle with an understeer characteristic as in the second embodiment, the correction steering by roll steer can be similarly reduced by switching the positional relationship between the rotation stop link 40 and the lower arm 30 in the front-rear direction. Can be planned.

  Next, Example 3 will be described. Since the basic configuration is the same as that of the first embodiment, only different points will be described. FIG. 11 is a schematic diagram showing the telescopic mechanisms 41A and 41B provided in the rotation stop link 40 of the third embodiment. In the first embodiment, the telescopic mechanism 41 is provided only on the vehicle body side of the rotation stop link 40. However, the third embodiment is different in that it is also provided on the second knuckle 20 side.

  The vehicle body side expansion / contraction mechanism 41A includes a cylinder 41Ae, a piston 41Ad that is connected to the rotation stop link 40 and slides inside the cylinder 41Ae, a spring 41Ac that is an elastic member interposed between the piston 41Ad and the cylinder 41Ae, and a piston It has an extension side stopper 41Aa and a contraction side stopper 41Ab for locking 41Ad at a predetermined position. The second knuckle-side telescopic mechanism 41B includes a cylinder 41Be, a piston 41Bd that is connected to the rotation stop link 40 and slides inside the cylinder 41Be, and a spring that is an elastic member interposed between the piston 41Bd and the cylinder 41Be. 41Bc, and an expansion side stopper 41Ba and a contraction side stopper 41Bb for locking the piston 41Bd at a predetermined position. The initial positions of the expansion and contraction mechanisms 41A and B of the third embodiment, that is, the positions where the spring set load is 0 are positions where the lengths of the extension side stopper 41Ba and the piston 41Bd are substantially equal to the lengths of the contraction side stopper 41b and the piston 41Ad. Is set to Thereby, the same effect as Example 1 is acquired.

  Next, Example 4 will be described. Since the basic configuration is the same as that of the first embodiment, only different points will be described. FIG. 12 is a schematic diagram illustrating an extension / contraction mechanism 41 provided in the rotation stop link 40 of the fourth embodiment. In the first embodiment, it is configured by a combination of a piston and a spring, but in the fourth embodiment, it is accommodated in a substantially cup-shaped sliding member 41g, an extension side stopper 41a, and a recess 41g2 formed in the sliding member 41g. The elastic member 41h is made of rubber or the like. When a contraction-side force is applied to the rotation stop link 40, the end surface 41g1 of the sliding member 41g comes into contact with the cylinder end surface and functions as a contraction-side stopper. Since other operations are the same as those in the first embodiment, description thereof is omitted. FIG. 13 shows an example in which the expansion / contraction mechanism 41 using the elastic member 41g is applied to the configuration of the third embodiment. Regarding the vehicle body side expansion / contraction mechanism 41C, C is attached to each component, and for the second knuckle side extension / contraction mechanism 41D, D is attached to each component. Since the operation and the like are the same as those of the third and fourth embodiments, the description thereof is omitted.

  Next, Example 5 will be described. Since the basic configuration is the same as that of the first embodiment, only different points will be described. FIG. 14 is a schematic diagram illustrating a configuration of an expansion / contraction mechanism 41E according to the fifth embodiment. In Example 1, the same movable range was set on the expansion side and the contraction side. On the other hand, the fifth embodiment is different in that the movable range on the contraction side is narrowed and the movable range on the stretch side is widened. That is, when the steering angle is changed during turning, the slip angle changes accordingly, and the lateral force also changes. At this time, when the roll angle is large, the wheel load is different between the turning inner wheel side and the turning outer wheel side (see FIG. 2), and the sensitivity of the tire lateral force with respect to the slip angle is also the inner wheel side <the outer wheel side. Therefore, roll steer on the turning outer wheel side is generated earlier by setting a narrower movable range.

In Example 5, the following effects can be obtained.
(6) By making the movable range in the contraction direction smaller than the extension direction of the rotation stop link 40, roll steer on the turning outer wheel side with a large wheel load can be generated earlier, and the correction steering amount can be further reduced. Can do.
The configuration of the fifth embodiment can be applied to each of the expansion / contraction mechanisms described in the third and fourth embodiments, and only the movable range is adjusted, and thus detailed description thereof is omitted.

  Each embodiment has been described above, but other configurations are also included as long as the object of the present invention can be achieved. For example, in the embodiment, a swing axle type suspension device having a lower arm is shown, but the present invention can also be applied to various suspension types such as a McPherson strut type, a double wishbone type, and a multilink type.

  In the first and second embodiments, the rotation stop link is disposed above the lower arm, and the arrangement in the vehicle front-rear direction is reversed between the oversteer characteristic vehicle and the understeer characteristic vehicle. Alternatively, the same characteristic may be obtained by reversing the arrangement in the vehicle front-rear direction.

10 First knuckle 20 Second knuckle 30 Lower arm (first link member)
40 Anti-rotation link (second link member)
41 Stretch mechanism 50 Strut

Claims (6)

A first knuckle that rotatably supports the tire;
A second knuckle that rotatably supports the first knuckle and has a rotation center different from the rotation center of the first knuckle;
A first link member that connects between a first connection point formed on the vehicle body side and a second connection point formed on the second knuckle side;
A second link member for connecting a third connection point formed on the vehicle body side and a fourth connection point formed on the second knuckle side;
Have
The steering angle adjusting mechanism, wherein the third connection point is arranged on a plane other than the plane including the first connection point, the second connection point, and the fourth connection point. The steering adjustment mechanism according to claim 1,
An expansion / contraction mechanism is provided on the rotation stop link,
Under operating conditions where the roll angle of the vehicle body is less than or equal to a predetermined value, a change in the steering angle due to roll steer is suppressed by expansion and contraction of the expansion and contraction mechanism. A steering angle adjustment mechanism that generates a steering angle change due to roll steer by limiting. In the steering angle adjustment mechanism according to claim 2,
A steering angle adjusting mechanism that performs steering correction by roll steering from the vicinity of an inflection point in a roll angle-steering amount characteristic when accelerating traveling with a constant turning radius. The steering angle adjusting mechanism according to claim 2 or 3,
A steering angle adjustment mechanism that sets a change amount of correction steering by roll steer so as to be equal to or less than a change amount of correction steering of a driver when accelerating traveling with a constant turning radius. The steering angle adjusting mechanism according to any one of claims 2 to 4,
A steering angle adjustment mechanism characterized in that a movable range in a contraction direction is made smaller than an extension direction of the rotation stop link. The steering angle adjusting mechanism according to any one of claims 1 to 5,
The rotation stop link is arranged so that the vertical dimension of the third connection point and the fourth connection point is larger than the vertical dimension of the first connection point and the second connection point. Steering angle adjustment mechanism.

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