JPS60199709A - Suspension for car - Google Patents

Abstract

PURPOSE:To obtain desirable running stability and operation by providing a controller that controls the drive of first and second actuators so as to increase the toe variation in the toe-in direction. CONSTITUTION:In the shock absorber 31 of front wheels, when an air spring 35 is formed and a solenoid 39 is excited, the suspension characteristic of the front wheels is set in a hard state. Also, the suspension characteristic of rear wheels operates and control the solenoids 39 and 45a by the signals from a controller 27. A manual switch 47 switches the suspension characteristic in the suspension of the front wheels in the hard or soft state and supplies the signals to the controller 27. Control signals are also output to the solenoid 25a of a directional control valve 25 from the controller 27 and the valve 25 is switched. The pressure of a hydraulic cylinder 131 is varied and the variation in the toe-in direction is varied, then under steering is varied.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an automobile suspension, and in particular to improving running stability and steering performance by changing the toe angle according to the suspension characteristics of the wheel suspension. This relates to a suspension that aims to achieve this.

(Prior Art) Changes in toe angle in the wheels of an automobile affect steering characteristics. In this steering characteristic, driving stability is obtained when the understeering tendency is strengthened, while maneuverability is improved when the understeering tendency is weakened.

For example, regarding the rear wheels, increasing hump-in strengthens understeering and improves driving stability, and weakening reverse hump toe-in improves maneuverability. Therefore, desired running stability and maneuverability can be obtained by appropriately changing the toe angle of the wheels.

To perform such toe angle control, for example,
As shown in Japanese Patent No. 267, the suspension geometry of the suspension device may be changed. That is, in the device shown in the above-mentioned published utility model publication, the toe angle is directly changed by moving the suspension arm connected to the wheel in a direction (horizontal direction) parallel to the rotation axis of the wheel. . However, directly changing the toe angle in this manner requires a force of 100 kg to drive the suspension arm. Furthermore, directly changing one direction in this way is undesirable because it can impair running stability.

On the other hand, the suspension has the role of supporting the weight of the vehicle and buffering road surface irregularities, and has a significant impact not only on ride comfort but also on pitching and rolling during driving, as well as stability and responsiveness when turning. It shouldn't reach.

Therefore, by appropriately changing the suspension characteristics of the front and rear wheel suspensions, it is possible to improve maneuverability and ride comfort.

However, if the suspension characteristics are changed based on, for example, road conditions or riding comfort, the steering characteristics will also change accordingly.
There is a risk that running stability and steering performance will be compromised.

(Object of the Invention) The object of the present invention has been made in view of the above points, and is to control one corner of the steering wheel so that desired steering characteristics can be obtained without being affected by changes in the suspension characteristics of the suspension. The objective is to provide a suspension for automobiles that can be used.

(Structure of the Invention) According to the present invention, each wheel is supported by a plurality of suspension links attached to the vehicle body so as to be able to swing in the vertical direction of the vehicle body. The suspension of an automobile is configured to cause a toe change, and in order to change the rocking locus of at least one suspension link among the plurality of suspension links, the attachment point of the suspension link on the vehicle body side is changed. an actuator that changes the damping force ratio in the vertical direction; a second actuator that changes at least one of the damping force ratio and the spring constant ratio of the front wheels relative to the rear wheels; and at least one of the damping force ratio and the spring constant ratio. The first
and a controller that controls driving of the second actuator.

(Effects of the Present Invention) In the automobile suspension of the present invention configured as described above, the mounting point of at least one suspension arm on the vehicle body side is adjusted according to changes in the damping force ratio and spring constant ratio of the front wheels to the rear wheels. and the suspension geometry. As a result, the locus of movement of the vehicle body support point during hump or rebound of each wheel changes according to the damping force ratio and spring constant ratio, and as a result, the 1-angle can be changed. It is possible to obtain running stability and maneuverability.

Further, according to the present invention, the actual change in the angle is made using the pumping force or rebound force of the wheel, and the actuator merely changes the position of the attachment point of the suspension arm on the vehicle body side. Therefore, compared to the conventional device in which the toe angle is changed by directly steering the wheels, the force required to change the toe angle is reduced by 1/1.
It can be reduced to about 10 kg. Furthermore, compared to the case where the toe angle is directly changed, safety in the event of an abnormality in the device is improved.

(Embodiments) Hereinafter, a suspension for an automobile according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

First, with reference to FIGS. 1 to 3, the principle of l·- change in the automobile suspension of the present invention will be explained by taking the left rear wheel as an example.

In FIGS. 1 and 2, the symbol W indicates a left rear wheel (hereinafter simply referred to as a wheel) on the ground G, and this wheel W is connected to the first and second suspension links L that are swingable in the vertical direction. , l. As is clear from FIGS. 1 and 2, in this example, the first suspension link L is set longer than the second suspension link L.

The number of wheel sides of the first and second suspension links L and β is 1, , I! , are arranged on the same horizontal plane as shown in FIG. It is set at a position higher than the vehicle body side attachment point 7!21m of the suspension link I. Furthermore, this vehicle body side attachment point β2 is attached to the vehicle body B so as to be movable up and down.

In the above configuration, when the attachment point on the vehicle body side of the second suspension link L is at the position shown by 12, the number on the wheel side (Ma J point L1, width is
1 and 2 to the position indicated by LIO 1170, thus obtaining the hump toe-in/rebound toe-out characteristics as shown by the solid line in FIG. From the above state, when the vehicle body side attachment point is lowered to the position 7!21, the wheel side number (-1 point LI, β1 moves to the position indicated by L I I, ji'11 at the time of bump) However, the wheel W is in the state shown by the dashed-dotted line, and therefore, as shown by the dashed-dotted line C in FIG. ,”1
When the vehicle body side attachment point is raised to the position j''22, the wheel side attachment point L+, j2+ will now become L when bumping.
It moves to the position indicated by I2, β1□, and therefore the hump toe-out/rebound toe-in characteristics shown by the two-dot chain line in FIG. 3 are obtained. In this case, it can be considered that the hump toe-in is particularly weakened when the hump toe-out is around 1.

In the above configuration and operation, when at least one of the damping force ratio and spring constant ratio of the front wheels to the rear wheels is increased, the point 7+2 on the vehicle body side of the second suspension link 1 is set to β2. If lowered to the position , stronger toe-in/toe-out q, +r properties are obtained, which strengthens the understeering (lTi direction), thus improving driving stability.On the other hand, the damping force ratio and spring constant ratio When at least one of
If the J point I12 is raised to a position of 7+2 degrees, a toe-out/toe-in tendency is obtained, which weakens the understeering tendency or creates an oversteering tendency, thereby improving the steering performance.

Next, referring to FIG. 4 and subsequent figures, the suspension having the above structure will be explained by taking a rear wheel suspension as an example.

In Fig. 4, reference numeral 1 indicates a suspension mounting base extending in the width direction of the vehicle body.
is fixed to the vehicle body at both ends with bolts or the like.

The above number (= Axis 3R on the front IF in the longitudinal direction of the vehicle body of J vehicle 1.
L-shaped arms 5R and 5L are rotatably disposed around and 3L. Lower links 9R19L, which are second suspension links, are rotatably connected to the horizontal ends 7R and 7L of both arms 5R and 5L, respectively. This connecting portion is point 12 on the vehicle body side. The other ends of the lower links 9L and 9R are respectively connected to left and right wheel sides (not shown). Is this the connecting part?
1. Wheel side attachment point 7! , is.

On the other hand, the ends 11R and I of the vertical part of the L-shaped arm 5R15L
The IL includes plungers 15R, 151, of the actuator 13 for vertically moving the end portion 7R17L of the arm.
are rotatably connected to each other. ”1 Mounting base 1
On the rear surface IB, lower links 17R and 17L, which are first suspension links, are arranged symmetrically at one end so as to be rotatable.
7 R117I, the other end side is connected to a wheel (not shown).

The wheel side connection part of the lower link is the wheel side attachment point L1 marked -, and the car body side connection part is the number J point L2 shown above.
It is.

Next, an example of a specific structure of the actuator 13 will be explained with reference to FIG. As shown in FIG. 1, the actuator 13 is constituted by a hydraulic cylinder, and includes a central hydraulic chamber 131 and left and right hydraulic chambers 132 and 13 defined within the cylinder.
3, the plungers 15L, 15R
The screws installed at the base of 5Ll, 15R,
, and both plungers 15*1.1.5R reciprocate in the direction of the arrow.

The pressure difference between the hydraulic chambers is controlled by a hydraulic control circuit composed of a pump 21, a relief valve 23, a directional control valve 25, etc., and switching control of the directional control valve 25 is controlled by a controller 2.
7.

The suspensions on both the front and rear axles are equipped with shock absorbers consisting of springs and oleo dampers. Furthermore, as shown in ■, the front wheel shock absorber 3
1, an air spring 35 is formed around an oleo damper 33 by a diaphragm made of a suitable elastic material. Further, the orifice provided in the piston of the shock absorber 31 has a variable diameter, and in order to change the diameter, a plunger driven by the solenoid 39 is provided in the piston chrono lS' 37, and when the solenoid 39 is energized, The plunger rotates to reduce the diameter of the orifice, increasing the damping force and hardening the suspension characteristics of the front wheels. Further, the air spring 35 is connected to the control air chamber 4 by an air pipe 41.
3, and the state of communication between the air fan 35 and the control chamber 43 is controlled by the operation of a solenoid valve 45 provided at the center of this chamber 43. In this example, when the solenoid 45a of the solenoid valve 45 is activated, communication is interrupted. When the communication between the air spring 35 and the control chamber 43 is cut off, the effective volume of the air chamber decreases, so the spring constant of the air spring increases, and the suspension characteristics of the suspension of the front wheels become hard. In this way, the suspension of the rear wheels! This can be controlled by operating the solenoid 39.45a using a signal from the nn characteristic controller 27.

The manual switch 47 is a mode changeover switch for changing the suspension characteristics of the suspension of the front wheels to heart and soft, and the changeover signal is sent to the controller 2.
7.

When "bar 1" J is designated by this switch 47, the front axle suspension solenoid 39.45a is energized by a control signal from the controller 27, and the front wheel suspension characteristics are made hard.

Here, the U frame characteristics (of the rear wheels) are held constant,
Therefore, the damping force ratio and spring constant ratio of the front wheels to the rear wheels are large. On the other hand, when "hard" is designated in this way, a control signal is also output from the controller 27 to the solenoid 25H of the directional control valve 25. This control body number causes the directional control valve 25 to switch, and the pressure in the central hydraulic chamber 131 of the hydraulic cylinder 13 increases. As a result, both plungers 15I7, 15R are moved in the direction between Al1 and A1. This movement is piston 15R
,.

15L1 is the outer part of the hydraulic chamber 132.133]・Brim 1
This is repeated until rows 32a and 133a are reached.

As a result, the left and right type 17 arms rotate around the axes 3L and 3R, and their horizontal ends, lower links 9L and 9R, rotate.
The connecting portions 7L and 7R move toward the LJT by a predetermined amount. In this way, when the suspension characteristics of the front wheels become harder than the rear wheels, the amount of 1-1 change in the toe-in direction increases, thereby increasing the tendency for understeering, and ensuring suitable driving stability. be done.

Similarly, when the suspension characteristics of the front wheels are changed to soft by the manual switch 47, the direction control valve 25 is switched under the control of the controller 27, and the hydraulic chamber 13 of the hydraulic cylinder is switched.
1 becomes lower than the left and right hydraulic chambers 132, 133, both plancires 15L, 15R are moved closer to each other, and both pistons 15R+, 15L+ hit the stopper 131a in the hydraulic chamber 131. The result will be a correct state. As a result, the connecting portions 7L, 712 of the double-sided arms 5L, 5I move upward by a predetermined amount, contrary to the above.

In this way, when the suspension characteristics of the front wheels become softer than those of the rear wheels, the amount of change in the toe-in direction becomes smaller, thereby weakening the tendency of understeering and improving the controllability. will be maintained.

” 2nd Eggplant Pension Link - U-chi link 9R19L body side connection part, zuna connection part 7R17
The height of L may be switched to two stages at a predetermined damping force ratio and spring constant ratio between the front and rear wheels, as shown by the solid line a in FIG. It may be changed linearly according to the damping force ratio etc. as shown in , or it may be changed in a higher order function according to the damping force ratio etc. as shown by the dashed line C. In the above embodiment, if the position of the connection point can be adjusted continuously as shown by lines c, a hydraulic pressure holding means is required.

In the embodiment shown in FIG. 5, a hydraulic cylinder is used as the actuator, but it is also possible to use a screw mechanism as in the embodiment shown in FIG. The actuator using this screw mechanism has the advantage that it is easy to linearly control the height of the two connecting points.

In FIG. 7, threaded portions are formed over a predetermined range on the outer peripheral surfaces of both plungers 15L and 15R, and threaded onto sleeve nuts 611. sleeve nut 61
The support part 65 is rotatable via the hair ring 63.
The motor 69 is supported by the motor 69 and rotated by one motion around the motor 69, which is transmitted through the gear 1-rain 67. Here, the threaded portions of both plungers are provided with threads in opposite directions, so that rotation of the sleeve nut 61 causes these two plungers to move in opposite directions. The drive control 11 of the mokuro 9 is performed by a controller 27. The controller 1-roller 27 is constituted by, for example, a microconverter, and its ROM has developed a table corresponding to the position of the connecting portion with respect to the damping force ratio of the front wheel and the rear wheel. The drive of the motor 69 is controlled so that the connecting portion reaches a position corresponding to the position.

According to this embodiment configured in this way, more suitable steering characteristics can be obtained with respect to changes in the damping force ratio.

In this embodiment, the damping force or spring constant of the front wheels is changed, but the damping force or spring constant of the rear wheels or both may be changed.

[Brief explanation of the drawing]

1 is a schematic rear view of the suspension link mounted on a wheel for explaining the invention in detail; FIG. 2 is a schematic rear view of the suspension link shown in FIG. 1;
1! J schematic plan view, Figure 3 is a graph showing an example of change in toe angle obtained by the suspension link shown in Figures 1 and 2, Figure 4 is a diagram showing the installation of the suspension link on the vehicle body side. A schematic perspective view showing an example of a control mechanism for controlling the height position of a point, FIG. 5 shows the control shown in FIG. 4! +:・1 of 1, Figure 6 is a partial cross-sectional view showing in detail one example of an actuator. Characteristic line 1 showing an example of controlling the height of the connecting portion, and FIG. 7 are partial cross-sectional views showing other examples of the actuator. L, β-the suspension link, β2-body side connection part,
5-L-shaped arm, 7-link connection section, 9-lower link, 13-actuator, 15-plunger, 27-controller, 31-shock absorber, 35-air spring, 39.45 a-solenoid, 43-control air room,
45-Solenoid valve, 47-Manual switch. Patent applicant: Toyo Kogyo Co., Ltd.

Claims (1)

[Claims] Each wheel is supported by a plurality of suspension links attached to the vehicle body so as to be able to swing in the vertical direction of the vehicle body, and the wheel is configured to cause a toe change due to a difference in the rocking locus of each link. A first actuator for changing the attachment point of the suspension link on the vehicle body side in the vertical direction in order to change the rocking locus of at least one suspension link among the plurality of suspension links in the suspension of an automobile; a second actuator that changes at least one of a damping force ratio and a spring constant ratio of the front wheels to the rear wheels; and a second actuator that changes at least one of the damping force ratio and the spring constant ratio of the front wheels to the rear wheels; Said first and second so as to increase the change village.
An automobile suspension comprising a controller for controlling the drive of an actuator.