JP2007230517A - Suspension device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension device for vehicle which can arbitrarily set the ratio of a damper stroke to a wheel stroke. <P>SOLUTION: A first connecting point 18 is connected with a lower arm 16 without directly connecting the lower end of a damper 26, of which the upper end is connected with a car body 13, with the lower arm 16. A second connecting point 19 is connected with a camber control arm 20, and also, a third connecting point 22 is connected with a fourth connecting point 25 of a rocker link 17 which is connected with a rocker arm 23. As a result, in a small wheel stroke region, the compression amount of the damper 26 to the increase amount of a wheel stroke becomes smaller, and a suspension spring becomes softer, and the riding comfort can be improved. In the meantime, in a large wheel stroke region, the compression amount of the damper 26 to the increase amount of the wheel stroke becomes larger, and also, the suspension spring becomes harder, and the steering stability can be increased by suppressing the rolling of the car body at the time of turning. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle suspension apparatus.

  FIG. 11 shows a conventional general double wishbone suspension device. A knuckle 02 that rotatably supports a wheel 01 is connected to a vehicle body 05 via an upper arm 03 and a lower arm 04. 05 are connected by a damper 06.

Further, in a double wishbone suspension device having an upper control arm and a lower control arm, the upper control arm is divided into a first control arm on the outer side in the vehicle width direction and a second control arm on the inner side in the vehicle width direction. A camber control arm having an intermediate portion connected to one end thereof is connected to the first control arm, and the other end is connected to a lower end of a damper (strut assembly).
US Pat. No. 5,620,199

  By the way, in the conventional double wishbone type suspension device shown in FIG. 11, the vertical stroke (wheel stroke) of the wheel 01 and the stroke of the damper 06 (and the suspension spring provided in the damper 06) are proportional to each other. If the wheel end spring rate (the spring rate of the suspension spring with respect to the stroke of the wheel) and the damping force of the damper 06 are decreased to improve the riding comfort in the region where the wheel stroke is small, the wheel end spring rate and the damper 06 are increased in the region where the wheel stroke is large. Since the damping force of the vehicle is insufficient, there is a problem that the amount of roll of the vehicle body at the time of turning increases and the steering stability is lowered. Therefore, if the wheel end spring rate and the damping force of the damper 06 are increased in the region where the wheel stroke is large to increase the steering stability, the wheel end spring rate and the damping force of the damper 06 are excessive in the region where the wheel stroke is small. Therefore, there is a problem that the ride comfort is lowered. Thus, in the conventional double wishbone suspension device, it is difficult to achieve both riding comfort and handling stability.

  Further, as shown in FIG. 12, the conventional double wishbone suspension device can change the camber angle in the negative direction at the time of bump when the upper arm 03 is inclined downwardly in the vehicle body when viewed from the front. However, when the instantaneous center of rotation of the wheel is inside the vehicle body, there is a problem that an upward load is applied by the cornering force of the turning outer wheel and the vehicle body is jacked up.

  On the other hand, as shown in FIG. 13, when the upper arm 03 is inclined to the upper side in the vehicle body when viewed from the front, there is a problem that the camber angle changes in the positive direction at the time of bumping. However, since the instantaneous center of rotation of the wheel can be set to the outside of the vehicle body, a downward load can be applied by the cornering force of the turning outer wheel, and the vehicle body can be jacked down.

  Therefore, the conventional double wishbone type suspension device has a problem that the negative camber angle and the jack-down of the vehicle body cannot be made compatible at the time of high-speed turning, and the running stability is lowered.

  Moreover, although what was described in the said patent document 1 can make a negative camber angle | corner and the jackdown of a vehicle body compatible, the 1st control arm and 2nd to which the upper control arm was connected in series in the vehicle width direction Since it is divided into control arms, not only the size of the suspension device in the vehicle width direction is increased, but also there is a problem that the arrangement of the damper is restricted.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle suspension device that can arbitrarily set the ratio of the damper stroke to the wheel stroke.

  To achieve the above object, according to the first aspect of the present invention, a knuckle for rotatably supporting a wheel, a suspension arm for coupling the knuckle to a vehicle body, and a first coupling point on the suspension arm. A connected rocker link, a camber control arm for connecting a second connection point of the rocker link to the knuckle, a rocker arm for connecting a third connection point of the rocker link to a vehicle body, and a fourth connection of the rocker link There is proposed a vehicle suspension device comprising a damper for connecting a point to a vehicle body.

  The lower arms 16 and 37 of the first and second embodiments correspond to the suspension arm of the present invention, and the rubber bush joints 18, 19, 22, and 25 of the first embodiment are respectively connected to the first connection of the present invention. The rubber bush joints 42, 43, 46, and 49 of the second embodiment correspond to the first to fourth connection points of the present invention, respectively, corresponding to the point to the fourth connection point.

  According to the configuration of the first aspect, the other end of the damper whose one end is connected to the vehicle body is not directly connected to the suspension arm, and the other end is connected to the rocker link that is swingably connected to the suspension arm. Is connected to the knuckle via the camber control arm and to the vehicle body via the rocker arm, so that when the suspension arm swings up and down as the wheel moves up and down, the rocker link swings and the damper expands and contracts. By doing so, the relationship between the damper stroke and the wheel stroke becomes non-linear.

  As a result, in a region where the wheel stroke is small, the amount of compression of the damper with respect to the increase amount of the wheel stroke becomes small and the suspension spring becomes soft, so that riding comfort can be enhanced. By increasing the amount of compression of the damper with respect to the amount of stroke increase and the suspension spring becoming harder, the roll of the vehicle body is suppressed during turning to improve steering stability, resulting in improved ride comfort and improved steering stability performance. Can be made compatible.

  Moreover, since the height of the roll center of the vehicle body can be set to a position lower than the road surface, a jackdown force that presses the vehicle body against the road surface when the vehicle turns is generated to stabilize the vehicle behavior and to the bumped wheel. A negative camber can be generated to stabilize the vehicle behavior when turning.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 9 show a first embodiment of the present invention. FIG. 1 is a perspective view of the suspension device, FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 1, and FIG. 3 is a skeleton of the suspension device. 4 is a graph showing the relationship of the damper stroke to the wheel stroke, FIG. 5 is a graph showing the relationship of the lever ratio to the wheel stroke, FIG. 6 is a graph showing the relationship of the wheel end spring rate to the wheel stroke, and FIG. FIG. 8 is a diagram for explaining the relationship between the center height and the jack-down force (jack-up force), FIG. 8 is a diagram for explaining the reason why the jack-down force is obtained by the present invention, and FIG. 9 is the reason why the negative camber is obtained by the present invention. It is a figure explaining.

  As shown in FIGS. 1 to 3, the front wheel suspension device S includes a knuckle 11 that rotatably supports a wheel W, and a lower end of the knuckle 11 that is coupled to an outer end in the vehicle width direction via a ball joint 12. In addition, a lower arm 16 including an A-type arm whose inner end in the vehicle width direction is connected to the vehicle body 13 via a pair of rubber bush joints 14 and 15 is provided.

  A first connection point at the lower end of the generally inverted triangular rocker link 17 is connected to the intermediate portion in the vehicle width direction of the lower arm 16 via a rubber bush joint 18. The second connecting point at the outer end in the vehicle width direction of the upper portion of the rocker link 17 is connected to the inner end in the vehicle width direction of the camber control arm 20 via the rubber bush joint 19, and the outer end in the vehicle width direction of the camber control arm 20 is connected. Is connected to the upper end of the knuckle 11 via the ball joint 21.

  The third connecting point at the inner end in the vehicle width direction of the upper portion of the rocker link 17 is connected to the outer end in the vehicle width direction of the rocker arm 23 via the rubber bush joint 22, and the inner end in the vehicle width direction of the rocker arm 23 is rubber. It is connected to the vehicle body 13 via the bush joint 24. A fourth connection point in the vehicle width direction intermediate portion at the upper portion of the rocker link 17 is connected to the lower end of the damper 26 via the rubber bush joint 25, and the vehicle body fixing portion 27 at the upper end of the damper 26 is fixed to the vehicle body 13. . A suspension spring 28 (see FIG. 1) that extends and contracts with the damper 26 is disposed on the outer periphery of the damper 26.

  Next, the operation of the first embodiment of the present invention having the above configuration will be described.

  As apparent from FIG. 3, the suspension device S of the present embodiment has the lower end of the damper 26 not directly connected to the lower arm 16 but connected to the rocker link 17 connected to the lower arm 16 by the rubber bush joint 18. Yes. Accordingly, when the lower arm 16 swings up and down as the wheel W moves up and down, the rocker link 17 connected to the knuckle 11 via the camber control arm 20 and to the vehicle body 13 via the rocker arm 23 is connected to the rubber bush. By swinging around the joint 18, the stroke of the damper 26 disposed between the rocker link 17 and the vehicle body 13 has a non-linear relationship with the stroke of the wheel W.

  That is, as shown in the graph of FIG. 4, the relationship between the damper stroke and the wheel stroke has been almost linear in the past, but is nonlinear in the present embodiment. Specifically, in the region where the wheel stroke is small near the neutral position, the amount of increase in the damper stroke relative to the amount of increase in the wheel stroke is small, but in the region where the wheel stroke is large, the amount of increase in the damper stroke relative to the amount of increase in the wheel stroke is small. growing.

  In other words, as shown in the graph of FIG. 5, as the wheel stroke increases from the neutral position, the lever ratio, which is the ratio of the damper stroke increase amount to the wheel stroke increase amount, gradually increases. This is because, in the region where the wheel stroke is small, the amount of compression of the damper 26 is small because the amount of increase in the damper stroke relative to the amount of increase in the wheel stroke is small, but in the region where the wheel stroke is large, the damper stroke relative to the amount of increase in the wheel stroke. This indicates that the amount of compression of the damper 26 increases due to the large increase amount of.

  Further, as shown in the graph of FIG. 6, as the wheel stroke increases from the neutral position, the wheel end spring rate gradually increases. This indicates that the suspension spring is soft in the region where the wheel stroke is small, and the suspension spring is hard in the region where the wheel stroke is large.

  As described above, in the region where the wheel stroke is small, the amount of compression of the damper 22 with respect to the increase amount of the wheel stroke becomes small, and the suspension spring becomes soft, so that riding comfort can be enhanced. On the other hand, in a region where the wheel stroke is large, the compression amount of the damper 26 with respect to the increase amount of the wheel stroke becomes large and the suspension spring becomes hard, thereby suppressing the roll of the vehicle body at the time of turning and improving the steering stability. it can. Therefore, according to the present embodiment, it is possible to achieve both improvement in ride comfort and improvement in steering stability performance.

  FIG. 7 is a view of the right wheel W of the vehicle turning left from the rear of the vehicle body. Since a large ground load acts on the right wheel W serving as a turning outer wheel, a large lateral inward in the vehicle width direction from the road surface is shown. Force F is input. At this time, when the roll center of the vehicle body is at a high position A, if the angle formed by the straight line connecting the ground contact point of the wheel W and the roll center A with the road surface is θA, a large jackup force represented by FtanθA is obtained. It acts to lift the vehicle body from the road surface.

  When the height of the roll center is at a position B lower than A, the angle θB formed by the straight line connecting the ground contact point of the wheel W and the roll center B with the road surface is smaller than the θA, so jack up The force FtanθB also decreases accordingly. However, as long as the roll center is higher than the road surface, jack-up force is generated, and jack-down force cannot be generated.

  On the other hand, when the height of the roll center is at a position C lower than the road surface, if the angle formed by the straight line connecting the contact point of the wheel W and the roll center C with the road surface is θC, −FtanθC is expressed. The jackdown force acts, and the vehicle behavior can be stabilized by pressing the vehicle body against the road surface.

  FIG. 8B is a view of a vehicle equipped with a conventional double wishbone suspension device turning left, as viewed from the rear of the vehicle body. In this case, a large leftward lateral force Fo is input to the right wheel W that is the outer turning wheel, and a small leftward lateral force Fi is input to the left wheel W that is the inner turning wheel. Since the roll center of the right wheel W, which is the outer turning wheel, is higher than the road surface, a large jackup force Fup corresponding to the large lateral force Fo acts, and the roll center of the left wheel W, which is the inner turning wheel, is also higher than the road surface. A small jackdown force Fdn corresponding to a small lateral force Fi acts. Accordingly, the sum of the jack-up force Fup and the jack-down force Fdn becomes a jack-up force, which may make the vehicle behavior unstable.

  FIG. 8 (A) is a view of the vehicle equipped with the suspension device S of the present embodiment turning left, as viewed from the rear of the vehicle body. Also in this case, a large leftward lateral force Fo is input to the right wheel W that is the outer turning wheel, and a small leftward lateral force Fi is input to the left wheel W that is the inner turning wheel. However, since the roll center of the right wheel W that is the turning outer wheel is lower than the road surface, a large jackdown force Fdn corresponding to the large lateral force Fo acts, and the roll center of the left wheel W that is the turning inner wheel is also lower than the road surface. Therefore, a small jackup force Fup corresponding to a small lateral force Fi acts. Accordingly, the sum of the jackup force Fup and the jackdown force Fdn becomes a jackdown force, and the vehicle behavior can be stabilized.

  By the way, when the camber angle of the turning outer wheel increases when the vehicle turns (that is, when it becomes a positive ground camber), the camber thrust acts in a direction opposite to the cornering force of the tire, and therefore cornering that opposes the centrifugal force acting on the vehicle body. Force decreases and turning performance decreases. Therefore, it is desirable to maintain the camber angle of the turning outer wheel at a negative value (so-called negative camber) when the vehicle body is tilted outward in the turning direction by the centrifugal force when the vehicle turns and the turning outer wheel bumps upward from the neutral position.

  FIG. 9B shows a trajectory when a vehicle wheel W equipped with a conventional double wishbone suspension device bumps and rebounds from a neutral position. As can be seen from the figure, when the wheel W bumps from the neutral position, the camber angle changes by an angle α1 in the negative direction (the left and right wheels open in a “C” shape).

  FIG. 9A shows a trajectory when a vehicle wheel W provided with the suspension device S of the present embodiment bumps and rebounds from a neutral position. As is clear from the figure, when the wheel bumps from the neutral position, the camber angle changes in the negative direction by an angle α2, which is larger than the angle α1 of the conventional double wishbone suspension device.

  Thus, according to the suspension device S of the present embodiment, the negative camber can be strengthened when the wheel W bumps, so that the vehicle behavior during turning can be stabilized.

  Next, a second embodiment of the present invention will be described with reference to FIG.

  The front wheel suspension device S includes a knuckle 31 that rotatably supports a wheel W, a knuckle arm 33 having an upper end coupled to the lower end of the knuckle 11 via a ball joint 32, and a rubber bush joint to the lower end of the knuckle arm 33. The vehicle width direction outer end is connected via 34, the vehicle width direction inner end is connected to the vehicle body 35 via a rubber bush joint 36, and the knuckle 31 is connected to the upper end of the knuckle 31 via a ball joint 38. An outer end in the width direction is connected, and an inner arm in the vehicle width direction is connected to the vehicle body 35 via a rubber bush joint 39.

  A first connection point at the upper end of the generally triangular rocker link 41 is connected to an intermediate portion in the vehicle width direction of the lower arm 37 via a rubber bush joint 42. A second connection point at the outer end in the vehicle width direction at the lower part of the rocker link 17 is connected to the inner end in the vehicle width direction of the camber control arm 44 via the rubber bush joint 43, and the outer end in the vehicle width direction of the camber control arm 44 is connected. Is connected to the intermediate portion in the vertical direction of the knuckle arm 33 through the rubber bush joint 45.

  A third connection point at the inner end in the vehicle width direction at the lower portion of the rocker link 41 is connected to the outer end in the vehicle width direction of the rocker arm 47 via the rubber bush joint 46, and the inner end in the vehicle width direction of the rocker arm 47 is rubber. It is connected to the vehicle body 35 via the bush joint 48. A fourth connection point at substantially the center of the rocker link 41 is connected to the lower end of the damper 50 via the rubber bush joint 49, and the vehicle body fixing portion 51 at the upper end of the damper 50 is fixed to the vehicle body 35. A suspension spring (not shown) that extends and contracts with the damper 50 is disposed on the outer periphery of the damper 50.

  In the suspension device S of the present embodiment, the lower end of the damper 50 is not directly connected to the lower arm 37 but is connected to a rocker link 41 connected to the lower arm 37 by a rubber bush joint 42. Accordingly, when the lower arm 37 swings up and down with the vertical movement of the wheel W, the rocker link 41 connected to the knuckle arm 33 via the camber control arm 44 and to the vehicle body 35 via the rocker arm 47 is rubber. By swinging around the bush joint 42, the stroke of the damper 50 disposed between the rocker link 41 and the vehicle body 35 has a non-linear relationship with the stroke of the wheel W, and is the same as in the first embodiment. The effect of this can be achieved.

  Further, the effect of generating a jackdown force on the vehicle body during turning and the effect of generating a negative camber on the bumping wheel W can be achieved as in the first embodiment.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

The perspective view of the suspension apparatus which concerns on 1st Embodiment 2-2 line enlarged sectional view of FIG. Suspension skeleton diagram Graph showing the relationship of damper stroke to wheel stroke Graph showing the relationship of lever ratio to wheel stroke Graph showing the relationship of wheel end spring rate to wheel stroke Diagram explaining the relationship between roll center height and jackdown force (jackup force) The figure explaining the reason why jackdown force is obtained by the present invention The figure explaining the reason for obtaining a negative camber by the present invention Skeleton diagram of the suspension device according to the second embodiment Skeleton diagram of conventional double wishbone suspension system Front view of conventional double wishbone suspension (when negative camber and jack-up occurs) Front view of conventional double wishbone suspension system (when positive camber and jackdown occurs)

Explanation of symbols

11 Knuckle 13 Car body 16 Lower arm (Suspension arm)
17 Rocker link 18 Rubber bush joint (first connection point)
19 Rubber bush joint (second connecting point)
20 Camber control arm 22 Rubber bush joint (third connection point)
23 Rocker arm 25 Rubber bush joint (4th connecting point)
26 Damper 31 Knuckle 35 Car body 37 Lower arm (Suspension arm)
41 Rocker link 42 Rubber bush joint (first connection point)
43 Rubber bush joint (second connecting point)
44 Camber control arm 46 Rubber bush joint (third connection point)
47 Rocker arm 49 Rubber bush joint (4th connecting point)
50 damper W wheels

Claims (1)

A knuckle (11, 31) for rotatably supporting the wheel (W);
Suspension arms (16, 37) for connecting the knuckle (11, 31) to the vehicle body (13, 35);
Rocker links (17, 41) connected to the suspension arms (16, 37) at first connection points (18, 42);
A camber control arm (20, 44) for connecting the second connection point (19, 43) of the rocker link (17, 41) to the knuckle (11, 31);
Rocker arms (23, 47) for connecting the third connection points (22, 46) of the rocker links (17, 41) to the vehicle body (13, 35);
A damper (26, 50) for connecting the fourth connection point (25, 49) of the rocker link (17, 41) to the vehicle body (13, 35);
A vehicle suspension apparatus comprising:

Images