JPH01164614A - Antiroll type suspension device - Google Patents

Abstract

PURPOSE:To surely suppress a car body from its rolling lowering the center of gravity in the car body by adjusting the elasticity characteristic of a suspension in a rolling direction side to a soft condition when the car body receives a rolling load. CONSTITUTION:A device main unit has each right and left suspension SR, SL, respectively interposed between a car body 8 and each right and left wheel 2R, 2L, and each right and left adjusting mechanism MR, ML, respectively adjusting each elasticity characteristic of each right and left suspension SR, SL, or the like. In this constitution, a rolling load, acting on the car body B, is detected by a transverse gravitational acceleration (G) sensor GS as the transverse G (transverse acceleration). Being based on a detection signal of the transverse G sensor GS, the right and left adjusting mechanisms MR, ML are respectively controlled by a controller C driving an actuator 18. Now, when the car body B receives a rolling load, the suspension in the rolling direction side adjusts its elasticity characteristic to a soft condition.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a suspension device provided for a pair of left and right wheels, and in particular to an anti-roll suspension device that can prevent rolling of a vehicle body while adjusting elastic properties separately for the left and right wheels. The present invention relates to a type suspension device.

[Prior Art] Generally, in order to improve the running performance of a vehicle, it is necessary to suppress rolling of the vehicle body due to rolling loads such as cornering loads and crosswinds. As a means to reduce this rolling (anti-roll), there are devices that increase suspension rigidity (i.e., anti-roll suspension devices) by setting the elastic properties of coil springs or absorbers to be harder, or by providing stabilizers. ) is considered.

[Problems to be Solved by the Invention] In general, the running stability of a vehicle is better as the center of gravity of the vehicle is lower. This is because the lower the center of gravity of the car body, the closer the center of gravity is to the roll center below the center of gravity, which reduces the roll moment (moment around the roll center) applied to the car body, suppressing rolling of the car body. This is to be done. Therefore, if some means is provided to lower the center of gravity of the vehicle when the vehicle body attempts to roll, the running stability of the vehicle can be significantly improved.

However, in the conventional anti-roll suspension system described above, the elasticity of the left and right suspensions is always set to be equal, as is the case with general suspension systems, so the center of gravity of the vehicle is not adjusted when the vehicle rolls. .

In other words, as shown in FIG. 8, in the conventional suspension system, the vehicle body B suspended on the left and right vehicles 12L and 2R via the left suspension SL and the right suspension sR normally has a center of gravity G. It is located on the center lines C and L (in this example, the height of the center of gravity G is L). In addition, the rigidity of each of the left and right suspensions SL+SR is equally strengthened, so as schematically shown in Figures 8 and 10, the center of elasticity of the vehicle body in the left and right direction (a position mainly determined by the elasticity of the left and right suspensions)
A□ is also located near the center of gravity G on the vehicle center lines C and L (for QL+QR shown in Fig. 10,
QL=QR). Furthermore, the roll center R is also located appropriately below the center of gravity G on the vehicle center lines C and L (in this example, the distance RI
fl 1).

As shown in FIG. 9, for example, when a rightward rolling load F is applied to the vehicle body B from the left side, the vehicle body B rotates rightward about the roll center R.

During this rolling, the vehicle body rolls to the right due to the rolling load F, the left suspension SL on the side to which the load F is applied is tensed, and the right suspension sR on the opposite side is compressed.

At this time, since the left and right suspensions SL+SR are set so that the elastic center A1 of the vehicle body in the left and right direction is located on the vehicle body center lines C and L, as shown in FIG. 10, the left suspension 5LySR is The amount of tension and the amount of compression are approximately equal, and the height of the center of gravity G hardly changes.

On the other hand, since the height of the roll center R changes little as the vehicle rolls and is considered to be almost constant, the distance of the center of gravity G during rolling from the roll center R also changes to be approximately equal to the size Ω1 before rolling. Without, vehicle weight W
does not change, so the roll moment applied to the vehicle body also does not decrease.

The present invention was devised under these circumstances, and it is an object of the present invention to provide an anti-roll suspension device that lowers the center of gravity of the vehicle and suppresses roll of the vehicle body when a rolling load is applied to the vehicle body. purpose.

[Means for Solving the Problems] Therefore, the anti-roll suspension device of the present invention has a left suspension interposed between the left wheel and the vehicle body side, and a left suspension interposed between the right wheel and the vehicle body side. A suspension device including an interposed right suspension and an elastic property adjustment mechanism that can adjust the elastic properties (including damping properties) of the left suspension and the right suspension respectively between a soft state and a hard state, The present invention is characterized in that the elastic characteristic adjustment mechanism is set to adjust the elastic characteristic of the suspension on the rolling direction side to a soft state when the vehicle receives a rolling load.

[Function] In the above-described anti-roll suspension device of the present invention, when the vehicle receives a rolling load, the elastic property adjustment mechanism softens the elastic property of the suspension on the rolling direction side of the left suspension and the right suspension. adjust.

[Embodiment] An anti-roll suspension device as an embodiment of the present invention will be explained below with reference to the drawings. Fig. 1 is a flowchart showing the control flow of the elastic property adjustment mechanism, and Fig. 2 is a flowchart showing the control flow of the elastic property adjustment mechanism. A block diagram showing the configuration of the control system of the mechanism, Fig. 3 is a schematic diagram showing the rolling state of a vehicle equipped with this suspension device, Fig. 4 is a schematic diagram showing the operating principle of this suspension device, and Fig. 5 is a schematic diagram showing the rolling state of a vehicle equipped with this suspension device. FIG. 6 is a sectional view of the elastic characteristic adjusting mechanism, and FIG. 7 is a graph showing the adjustment state of the elastic characteristic of the suspension by the elastic characteristic adjusting mechanism.

As shown in FIG. 3, this anti-roll suspension device consists of a left suspension sL interposed between the left wheel 2L and the vehicle body B, and a right suspension sL interposed between the right wheel 2R and the vehicle body B. A left suspension sR, a left side elastic property adjustment mechanism ML that can adjust the elastic properties of the left suspension sL over a soft state and a hard state, and a right suspension S.
A right side elastic property adjustment mechanism MR that can adjust the elastic properties of R between a soft state and a hard state, and controls the operation of these left and right side elastic property adjustment mechanisms ML and MR, respectively.
It is composed of a controller C.

Of these suspensions 5LPSR and elastic property adjustment mechanisms ML and MR, the left suspension SL and left elastic property adjustment mechanism ML installed on the left front wheel will be explained in detail.This left suspension SL is of a double wishbone type. As shown in FIG.
The upper arm 4 and lower arm 5 are pivotally connected to the vehicle body B side through rubber bushings 7A and 7B fitted into the base end portions, respectively. Although not shown in FIG. 5, the upper arm 4 and the lower arm 5 are both bifurcated.
The length of the upper arm 4 is set shorter than that of the lower arm 5.

Furthermore, the upper end of the knuckle 6 is pivotally attached to the tip of the upper arm 4 via a ball joint 8, and the lower end of the knuckle 6 is pivotally attached to the tip of the lower arm 5 via a ball joint 9. A wheel 2L is rotatably supported by this knuckle 6.

Furthermore, a coil spring/absorber assembly (not shown) is interposed between the Rosa arm 5 and the vehicle body B, and the upper end of this coil spring absorber assembly is attached to the vehicle body B side. The lower end portion is attached to the lower arm 5.

Note that the coil spring/absorber assembly includes a coil spring and an absorber.

The upper arm 4, the lower arm 5, the knuckle 6, and the vehicle body B that pivotally supports the upper arm 4 and the lower arm 5 form a link 4i1L having a rectangular shape (substantially parallelogram shape).

The left suspension SL configured as described above is provided with a left elastic characteristic adjustment mechanism ML consisting of a lever member 12, a reinforcing rod 11, and a variable damping force damper 13.

That is, a lever member 12 is integrally provided at the base end of the lower arm 5 in a direction substantially perpendicular to the lower arm 5, and between the tip of the lever member 12 and the tip of the lower arm 5, A triangular structure is formed by the lever member 12, the lower arm 5, and the reinforcing rod 11, which are connected by a reinforcing rod 11. The lever member 12 and the reinforcing rod 11 are connected via a pin 10.

A variable damping force damper 13 is installed which can appropriately suppress the rotational movement of the lower arm 5 around the vehicle body.

As shown in FIG. 6, this variable damping force damper 13 includes a cover member 22 supported by the vehicle body B, and advance/retreat rods 14 and 1 slidably attached to the cover member 22.
5, a main body support arm 21 fixed to the vehicle body B, and a cylindrical casing 19 fixed to this main body support arm 21.
, elastic wall members 16 and 17 attached to both ends of the cage ring 19, a partition wall 20 provided inside the casing 19, and an opening adjustment type (not shown) formed on the partition wall 20. An orifice and an orifice opening adjustment actuator 18 that adjusts the opening of the orifice.
It is composed of.

Note that a rubber material is used for the elastic wall members 16 and 17, and the casing 19 has an oil chamber 23 formed therein by these elastic wall members 16 and 17 attached to both ends. 23 is sealed with damping oil. This oil chamber 23 is connected to the left oil chamber 2 by the partition wall 20.
3a and a right oil chamber 23b.

The advancing/retracting rods 14, 15 are provided in a direction substantially perpendicular to the lever member 12, and each advancing/retracting rod 14, 15
The inner end of the elastic wall member 16, 17 is embedded and fixed.

The outer end of the reciprocating rod 14 is pivotally connected to the connecting portion between the lever member 12 and the reinforcing rod 11 via the pin 10.

The opening-adjustable orifice whose opening is adjusted by the actuator 18 is set to be fully open, half-open, and fully closed, and the elastic characteristics of the suspension 5L (SR) are as shown in Figure 7 when the orifice is fully open. When the orifice is half-open, it is in a "middle elastic state" (hereinafter referred to as "medium state") as shown by straight line a2 in Figure 7, and then when the orifice is fully open. The elastic properties of coil springs, absorbers, etc. are sometimes set so that they are in a "hard fall state" as shown by straight line a in FIG. 7.

Further, the orifice opening adjustment actuator 18 is connected to the controller C as shown in FIG.
The operation of the actuator 18 is appropriately controlled in accordance with a control signal issued from a controller C based on an input signal from a lateral G sensor (lateral acceleration sensor) GS installed on the vehicle body.

Specifically, a rolling load is applied to the vehicle body B when the vehicle turns or when the vehicle receives a crosswind, but this rolling load is caused by the lateral G of the vehicle detected by the lateral G sensor OS (
(lateral acceleration).

The right elastic characteristic adjustment mechanism MR is also configured in the same manner as the left elastic characteristic adjustment mechanism ML described above, and for example, when a rolling load F to the right is generated due to an external force from the left side, the lateral G in the right direction is An operation command to fully open the orifice is output to the actuator 18 of the right elastic characteristic adjustment mechanism MR, which is the direction in which rolling is attempted based on the direction of the lateral G applied to the vehicle body, and the left elastic characteristic on the opposite side is output. It is set so that an operation command to fully close the orifice is output to the actuator 18 of the adjustment mechanism ML.

Conversely, if the vehicle attempts to roll to the left due to a rolling load to the left, lateral G in the left direction is applied to the vehicle body, causing the left side elastic characteristic adjustment mechanism M1. An operation command to fully open the orifice is output to the actuator 18 of
It is set so that an operation command to fully close the orifice is output to the actuator 18 of the right elastic characteristic adjustment mechanism MR.

In addition, when lateral G to the left and right is not detected, a control signal is output from the controller to the actuator 18 to maintain the orifice opening in the half-open state, and the elastic characteristics of the left and right suspensions 5LySR are set to the "medium state". It is designed to be held in

Note that the reference numeral 1 in Fig. 5 indicates the axle shaft;
This axle shaft 1 is rotatably supported by a knuckle 6 when the front wheel is a driving wheel as in a front wheel drive, and is fixedly attached to the knuckle 6 when the front wheel is an axle as in a rear wheel drive.

Since the anti-roll suspension device as an embodiment of the present invention is configured as described above, the actuator 18 The operation of the suspension is appropriately controlled, and the elastic properties of the suspension are adjusted.

That is, as shown in the flowchart of FIG.

The lateral G sensor GS detects the lateral G applied to the vehicle, and
By comparing G with a predetermined value, it is determined whether a rolling load is applied to the vehicle (step S1), and if the lateral G is less than a predetermined value, it is determined that a rolling load is not applied to the vehicle, The controller C outputs an operation control signal to the left and right actuators 18 to maintain the orifice in a half-open state. Then, the orifice is adjusted to a half-open state, and the elastic properties of the left suspension SL and right suspension sR are adjusted to a state suitable for normal driving.
"medium state" (step S5).

On the other hand, if the lateral G is equal to or greater than the predetermined value in step S1, it is determined that a rolling load is applied to the vehicle body B, and this lateral G
Based on the judgment as to whether the direction in which the orifice is being applied is left or right (step S2), an operation control signal is output from the controller C to the actuator 18 to immediately move the orifice to a fully open state or a fully open state ( Step S3 or Step S4). Such rolling loads applied to the vehicle body B include centrifugal force received when the vehicle turns, crosswinds received by the vehicle, and the like.

For example, rolling load F (third
(see figure) occurs, the lateral G sensor GS detects the rightward G applied to the vehicle, and outputs an operation command to fully open the orifice to the actuator 18 of the right side elastic characteristic adjustment mechanism MR in the direction in which rolling is attempted. , an operation command to fully close the orifice is output to the actuator 18 of the left elastic characteristic adjustment mechanism ML on the opposite side.

As a result, the elastic properties of the right suspension sR become "soft layer", and the elastic properties of the left suspension SL become "soft layer".
"hard state" (step S3).

Then, as shown in FIG. 4, the elastic center of the vehicle body B in the left-right direction, which is mainly determined by the elastic characteristics of the left and right suspensions 5LySH, changes to a position A2 that is deviated to the left from the vehicle center lines C and L. fiL'* QR shown in Figure 4
', QL' becomes QR'). Therefore, the vehicle body B tries to rotate around this elastic center A2 as shown by chain lines B' and B'', and rolls into a posture like B' in response to the rolling load F.

As a result, the center of gravity G of the vehicle body B is as shown in FIG.
The distance Q between the roll center R and the center of gravity G becomes n2 (Q, <Q), and the distance ′IR
It will be smaller than Q□. Therefore.

Even when a constant rolling load F is applied to body B, the rolling moment determined by ρ and F is significantly reduced, suppressing the rolling of body B, improving cornering performance, and improving resistance to crosswinds. You will be able to drive stably.

Conversely, when a rolling load to the left occurs, a lateral G to the left is detected, and based on this, an operation command is given to the actuator 18 of the left elastic characteristic adjustment mechanism ML, which is the side on which left rolling is attempted, to fully open the orifice. is output, and at the same time, an operation command to fully close the orifice is output to the actuator 18 of the right elastic characteristic adjustment mechanism MR.

As a result, the elastic properties of the left suspension SL are adjusted to a "soft layer" and the elastic properties of the right suspension sR are adjusted to a "hard state" (step S4).

As a result, the elastic center 1 moves to the right of the vehicle body centers C and L, and cornering performance and crosswind driving performance can be improved in the same way as described above.

The control flow shown in FIG. 1 is repeated at suitably short time intervals based on the input lateral G detection signal, and the suspension elasticity is constantly controlled in accordance with changes in the rolling load applied to the vehicle.

In this embodiment, the elasticity of each suspension 5LySR is set in three stages: "soft layer", "raw state", and "hard state", but it can be set in more stages.

The suspension elasticity may be finely adjusted depending on the magnitude of the rolling load, or conversely, the suspension elasticity may be set to only two levels: "soft layer" and "hard state".
- If a rolling load greater than the chamber is not applied, the left and right suspensions may be controlled so that both are in the "r soft layer" or both are in the "hard state j."

Further, the suspension elasticity changing means is the elastic characteristic adjusting mechanism M1. ．． The suspension is not limited to MR, and the suspension is not limited to the double wishbone type as in this embodiment.

In other words, in a wide range of general suspensions, for example, there is a well-known elastic characteristic adjusting means (
For example, an air spring is provided in addition to a coil spring, and air is appropriately supplied and discharged to the air spring to adjust the elastic characteristics of the air spring to adjust the suspension elasticity. By adjusting the elastic properties of the suspension to a soft layer), the anti-rolling effect can be obtained in the same way as in the embodiment.

Furthermore, in addition to controlling the elastic characteristic adjusting means based on lateral G (lateral acceleration), it is also possible to control the elastic characteristic adjusting means based on the vehicle speed detected by the vehicle speed sensor and the steering angle detected by the steering angle sensor. It is also possible to suppress the rolling of time.

In other words, when the vehicle speed reaches a predetermined speed or higher and the vehicle is in a steering state, the controller sends the actuator 18
Outputs a control signal to reduce the orifice opening,
At other times, the orifice opening degree is maintained in a large state. Note that the adjustment based on vehicle speed is based on the determination that roll control is unnecessary at low speeds. but,
Depending on the vehicle, the actuator 18 may be set to be adjusted based only on the steering angle, without depending on the vehicle speed.

Further, the actuator 18 may be adjusted in operation based on the steering angular velocity to suppress rolling of the vehicle body B during sudden steering.

Furthermore, by moving the damping center left and right instead of the elastic center, the anti-rolling effect can be obtained in the same way as in the embodiment by adjusting the damping characteristics of the suspension on the low link direction side to a soft state.

[Effects of the Invention] As described in detail above, according to the anti-roll suspension device of the present invention, the left suspension interposed between the left wheel and the vehicle body side and the left suspension interposed between the right wheel and the vehicle body side In a suspension system that includes a right suspension interposed in a vehicle and an elastic property adjustment mechanism that can adjust the elastic properties of the left suspension and right suspension, respectively, between a soft state and a hard state, when a vehicle is subjected to a rolling load. With this simple configuration, the elastic property adjustment mechanism is set to adjust the elastic properties of the suspension on the rolling direction side to a soft state when the rolling direction is applied, and the rolling of the vehicle body can be reliably suppressed, greatly improving the vehicle's driving performance. There are advantages that can be improved.

[Brief explanation of the drawing]

1 to 7 show an anti-roll type suspension device as an embodiment of the present invention, FIG. 1 is a flowchart showing the control flow of the elastic characteristic adjustment mechanism, and FIG. 2 is a flowchart showing the control flow of the elastic characteristic adjustment mechanism. 3 is a schematic rear view showing the rolling state of a vehicle equipped with this suspension device, FIG. 4 is a schematic diagram showing the operating principle of this suspension device, and FIG. 5 is a block diagram showing the configuration of the control system. 6 is a sectional view of the elastic characteristic adjustment mechanism of the present suspension device, FIG. 7 is a graph showing the state of the elastic characteristics of the suspension due to the elastic characteristic adjustment mechanism, and FIGS. 8 to 10 are 8 shows a conventional suspension device, FIG. 8 is a schematic rear view of a vehicle equipped with the suspension device, and FIG. 9 is a schematic rear view of a vehicle equipped with the suspension device in a rolling state. 10 are schematic diagrams showing the effect. 1-axle shaft, 2L-left wheel, 2R...
Right wheel, 4...-Upper arm, 5-Lower arm, 6
-・Knuckle, 7A, 7B-・Rubber butt, 8°9-
- Ball joint, 1o- Pin, 11- Reinforcing rod, 12- Lever member, 13- Variable damping force damper, 14.15- Advance/retreat rod, 16, 17- Elastic wall member, 18- ...Orifice opening adjustment actuator, 19-Casing, 20-Partition wall, 21-Body support arm, 22-Cover member, 23...-Oil chamber, 23a-
Left oil chamber, 23 b-Right oil chamber, 36--Reinforcement rod,
37: lever member, 38: pin, 40: strut assembly 41: absorber, 42: coil spring, B: body, C: controller, GS: lateral G sensor ( lateral acceleration sensor), L-link mechanism, ML-left side elastic property adjustment mechanism (elastic property adjustment mechanism), MR-right side elastic property adjustment mechanism (elastic property adjustment mechanism), SL-left suspension, sR-right suspension.

Claims (1)

[Claims] The elastic properties of the left suspension installed between the left wheel and the vehicle body side, the right suspension installed between the right wheel and the vehicle body side, and the left suspension and right suspension described above are determined as soft states. In a suspension device equipped with an elastic property adjustment mechanism that can be adjusted between a hard state and a hard state, when the vehicle receives a rolling load, the elastic property adjustment mechanism adjusts the elastic property of the suspension on the rolling direction side to a soft state. An anti-roll suspension device characterized by being set as follows.