JPS62166105A - Position controller for vehicle - Google Patents

Abstract

PURPOSE:To improve a roll restraining force in the captioned controller having an unspring member coupled with a stabilizer by constitutionally converting energizing forces produced in hydraulic cylinders of front and rear wheels for front and rear wheel stabilizers to torsional rigidity different in front and rear wheel torsion bars. CONSTITUTION:A calculation processing unit 94 carries out a predetermined process according to the detecting signals of a speed sensor 96 and a steering sensor 98 to send the control signal output to a hydraulic pump 82 and an electromagnetic change-over valve 84 to change the connecting distance between connecting members 22, 56 and adjust the torsional rigidity of a stabilizer. Then, by making the rigidity of the front wheel side torsion bar 30 higher than that of the rear wheel torsion bar 50, can be offset a large energizing force for the front wheel torsion bar produced by the diameter of the front wheel hydraulic cylinder larger than that of the rear wheel hydraulic cylinder. Thus, a roll can be restrained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle attitude control device in which unsprung members of left and right wheels are connected by a stabilizer.

[Prior Art] By connecting the unsprung members of each of the left and right wheels with a stabilizer, also known as an anti-roll bar, the independent movements of the left and right wheels are linked, and the tilting and shaking of the vehicle when turning is prevented. It is known to reduce

In a stabilizer device, if the left and right wheels are at the same suspension position, the stabilizer will not twist, but if one of the left and right wheels rides over a protrusion or turns, and the suspension positions of the left and right wheels are significantly different, torsion of the stabilizer will occur. The bar is twisted, and as a reaction, an elastic force acts in a direction that cancels out the twist, working to equalize the suspension positions of the left and right wheels.

The attitude stability performance of a vehicle is evaluated based on several items, but the main factors that are important during driving are the ability to follow the road surface and the roll suppression effect when turning. If priority is given to road surface followability, it is desirable that the torsional properties of the stabilizer be small, whereas if priority is given to the roll suppression effect, it is desirable that the torsional elasticity is large.

However, in the conventional device described above, since the characteristics of the torsion bar of the stabilizer are fixed, the torsional elasticity characteristics must be set at an appropriate design value, making it difficult to achieve both characteristics.

As a means to solve this problem, it has been proposed to provide a connection member that changes the connection distance between the stabilizer and the unsprung member that holds the wheel, and to variably adjust the torsion characteristics of the torsion bar.

[Problems to be Solved by the Invention] Incidentally, in a vehicle equipped with stabilizers on each of the front and rear wheels, the torsional rigidity is set to be high because the load on the front stabilizer is greater than that on the rear wheel. . For this reason, if hydraulic cylinders with the same diameter are used for the front and rear wheels as the above-mentioned connecting members and pressure oil is supplied from the same hydraulic source, the torsional rigidity of the stabilizer on the front wheel side will be smaller than that on the rear wheel side, which will suppress the roll of the vehicle. Insufficient effect (
There is a problem that it becomes insufficient.

[Means for Solving the Problems] The present invention, which has been made to solve the above problems, includes front and rear wheel stabilizers in which unsprung members of the left and right front wheels and rear wheels are connected by torsion bars; interposed as a connecting means between at least one of the respective unsprung members and a portion of the stabilizer that transfers and receives torsional action, and a connection between the unsprung member and the portion of the stabilizer that transfers and receives torsional action; Front wheel side and rear wheel side connecting members whose distances can be adjusted by movable pistons of hydraulic cylinders, and pressure oil supply means for controlling the supply of pressure oil from the hydraulic pressure source to the two pressure cylinders, The structure is configured such that the urging force applied to the front wheel side and rear wheel side stabilizers on the connecting member by the hydraulic pressure from the single oil pressure source corresponds to the different inherent torsional rigidities of the front wheel side torsion bar and the rear wheel side torsion bar. It is characterized by:

By providing an adjustable connecting member between one end of the stabilizer and the unsprung member of either the left or right wheel, the torsional characteristics of the stabilizer can be adjusted. It is also possible to adjust the torsion characteristics by providing each of these between the unsprung members of the wheel.

The cylinder v! of the hydraulic cylinder is used as a means to apply the biasing force generated on the stabilizers of the front and rear wheels so as to correspond to the inherent torsional rigidity of the torsion bar. In addition to changing the pressure, it is also possible to provide a pressure reducing valve in the path to one of the hydraulic cylinders to reduce the pressure from the hydraulic source.

[Operation] In the present invention, when turning, pressure oil is supplied from the hydraulic source of the pressure oil supply means to the hydraulic cylinders of the connecting members of the front and rear wheels, and the distance of the connecting members is adjusted to make the torsional rigidity of the stabilizer variable. At this time, the biasing force on the stabilizer generated by the front and rear hydraulic cylinders can be generated by, for example, selecting a hydraulic cylinder diameter proportional to the rigidity of the front and rear stabilizers to generate a force proportional to the specific rigidity of the torsion bar of the front and rear wheels. do. Therefore, the roll improvement characteristics of the front and rear wheels by the stabilizer are equal, so that a stable posture of the vehicle can be obtained when turning.

[Embodiment] FIG. 1 shows the overall configuration of a vehicle attitude control device to which the present invention is applied. The front wheels of the four-wheeled vehicle designated by reference numeral 10.12 are steering wheels, and each wheel 10.12 is supported by an unsprung member 14.16, and each unsprung member is connected to the vehicle body via a shock absorber 26.28. is supported by The stabilizer 18 has a front wheel side 1 having torsional elasticity.
- the version bar 30 is rotatably supported by rubber bearings 32,34;

One end 36 of the stabilizer 18 is connected to the unsprung member 14 via a connecting member 22 whose connecting distance can be adjusted, and the connecting length between the end of the stabilizer 18 and the unsprung member 14 depends on the expansion and contraction of the connecting member 22. It is adjustable by The other end 38 of the stabilizer 18 is fixedly connected to the other unsprung member 16 by a suitable connection method. The connecting target portion of each unsprung member 14.16 that is connected to one end or the other end of the stabilizer 18 may be a lower arm, or a shock absorber 26.28 as shown in FIG.
It may also be a fixed part on the wheel side. In FIG. 2, the other end 38 of the stabilizer 18 is connected to the shock absorber 28 using a tie rod 40.

For steering the vehicle, a steering mechanism 44 coupled to a steering wheel 42 is connected to a respective unsprung member 14,16.
is combined with

Rear wheels 46 and 48 are supported by unsprung members 51 and 52, respectively, and are connected to the vehicle body via a suspension system (not shown). The rear wheel stabilizer 50 is connected at one end to an unsprung member 51 via a connecting member 56, as in the case of the front wheel, and fixedly connected to an unsprung member 52 at the other end. In the rear wheel stabilizer 50, the diameter of the torsion bar 50a is smaller than that of the front wheel so that the torsional rigidity is smaller than that of the front wheel.

As shown in FIG. 3, the connecting member 22 mainly connects the piston 5.
8 and a cylinder body 60. A piston rod 62, which is integrally constructed and fixed with the piston 58, is connected to the shock absorber 26 at a mounting portion 64. The cylinder body 60 is coupled to the stabilizer 18 at a mounting portion 66 .

The piston 58 is oil-tightly slidable within the cylinder body 60 in the vertical direction shown in the figure via a sealing o-ring 68, and the piston rod 62 is also fitted with O-rings 70, 72.
It is supported by the piston body 60 via.

The interior of the cylinder body 60 is divided by the piston 58 into a lower cylinder chamber 74 and an upper cylinder chamber 76, each of which is connected to a port 78.
．． A fluid supply device (not shown) as an operating means is connected via 80.
The hydraulic circuit shown at 24 in FIG.

In this configuration of the connecting member 22, the lower cylinder chamber 7
By applying fluid pressure to 4, the lower cylinder chamber 7
4, and together with this, the upper cylinder chamber 76
When fluid is forced out of the piston 58 , the piston 58 can be pushed upwardly relative to the cylinder body 60 . At this time, the piston rod 62 is attached by the relative distance between the part 64 and the cylinder body 60 by the relative distance between the one end 36 of the stabilizer 18 and the unsprung member 14 in FIG.
The connection distance between the two is extended.

On the other hand, if the volume of the upper cylinder chamber 76 is increased by applying fluid pressure to the upper cylinder chamber 76, the piston 58 can be moved downward relative to the cylinder body 60.

As a result, contrary to the above, the connection distance between the one end 18 of the stabilizer 18 and the unsprung member 14 is shortened.

Therefore, the connection distance by the connection member 22 can be adjusted by adjusting the amount of fluid supplied to both cylinder chambers.

On the other hand, the rear wheel side connecting member 56 is connected to the front wheel side connecting member 22.
However, as mentioned above, the torsion bar 50 on the rear wheel side is thinner than the front wheel side and has weaker torsional rigidity, so the diameter of the hydraulic cylinder (not shown) has been changed accordingly. It's getting smaller.

Hydraulic circuit 2 serving as an operating means of the present invention as a fluid supply device
4 includes a hydraulic pump 82, a four-port electromagnetic switching valve 84, and hydraulic lines 86-92. The hydraulic pump 82 is driven by an electric VJ machine that is energized and deenergized by the electric drive signal 01, but if necessary, it can be of an engine-driven type or can be used in common with the power steering device.

At the connecting portion 022.56, the lower conduit 9O communicating with each lower cylinder chamber (74 in FIG. 3) and the upper conduit 92 communicating with each upper cylinder chamber (76 in FIG. 3) are connected to four boats. It is connected before the electromagnetic switching valve 84, so that fluid can be supplied to the upper or lower cylinder chamber at the same time.

The 4-boat electromagnetic switching valve 84 is selectively switched to 3 positions by the electric drive signal 02, and in the 1st position If (neutral mode), the pump discharge m pipe 86 and the return pipe 88
and also connects the lower conduit 90 and upper conduit 92 of the connecting member 22.56. At this time, since the upper and lower cylinder chambers of each connecting member are sealed by the pipes 90, 92 and the valve 84, the connecting distance is maintained without changing.

Next, in the second position (extension mode), the pump discharge side pipe 8
6 and the lower pipe line 90, and the return pipe line 88.
and the upper pipe line 92. Therefore, the volume of the lower cylinder chamber of each connecting member is increased, and the connecting distance thereof is extended.

Next, in the third position (reduction mode), the pump discharge steel pipe line 8
6 and the upper pipe line 92, and the return pipe line 88.
and the lower pipe line 90. Therefore, the volume of the upper cylinder chamber of each communication member is increased, and the connection distance thereof is reduced.

In the configuration described above, the vehicle attitude control according to the present invention can be realized by adjusting the connection length of the connection member 22.56 by adjusting the oil pressure by the hydraulic circuit 24. This is done by controlling the hydraulic pump 82 and the electromagnetic switching valve 84 of the circuit 24 with the electric drive signal 01.02.

Next, the operation of the above configuration will be explained.

Now, when the arithmetic processing unit @ 94 determines that the torsional rigidity of the stabilizer should be adjusted by changing the connection distance of the connection member 22.56 based on the detection signals of the speed sensor 96 and the steering sensor 98, the hydraulic A control signal is sent to the pump 82 and the N magnetic switching valve 84. As a result, pressure oil from the hydraulic pump 82 is supplied to the hydraulic cylinders of the front and rear wheel coupling means 22.56 through the electromagnetic switching valves 84, respectively. At this time, since the diameter of the hydraulic cylinder on the front wheel side is larger than that on the rear wheel side, the biasing force on the torsion bar generated by the hydraulic cylinder on the front wheel side is larger than that on the rear wheel side, but the rigidity of the torsion bar 30 on the front wheel side is Since the higher is the higher setting, the two cancel each other out, and the torsional rigidity generated in the front and rear wheel stabilizers becomes almost equal.

Therefore, even if the inherent stiffness of the torsion bars of the front and rear wheels is different, the torsional characteristics of the stabilizers of the front and rear wheels are made equal by the hydraulic pressure supplied from a single hydraulic pressure source, resulting in a stable vehicle posture when turning.

Moreover, the configuration is simple because separate hydraulic power sources are not used for the front and rear wheels, that is, a single hydraulic power source supplies pressure oil to the front and rear wheels.

[Effects of the Invention] As explained above, according to the present invention, even if the torsion bars of the front and rear wheels have different inherent torsional rigidities, the stabilizers of the front and rear wheels can be stabilized with hydraulic pressure supplied from a single hydraulic source. Since the torsional characteristics are made equal, the attitude of the vehicle can be stabilized when turning.

Moreover, since a single hydraulic power source is sufficient to control the front and rear wheels, the configuration is simple.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram of an embodiment of the present invention viewed from above the vehicle, Fig. 2 is a view of the front wheel suspension part in Fig. 1 seen from the front of the vehicle, and Fig. 3 is a diagram of the connecting member. FIG. 10.12-...Wheel 14.16.51.52...Unsprung member 18.50-
... Stabilizer 22.56 ... Connection means 24 ... Hydraulic circuit as operating means 26.28 ... Shock absorber 82 ... Hydraulic pump 84 ... Electromagnetic switching valves 86 to 92 ... Pipe line 94... Arithmetic processing unit 96... Speed sensor 98... Steering sensor 100... Stroke sensor

Claims (1)

[Scope of Claims] 1. Front wheel side and rear wheel side stabilizers in which unsprung members of the left and right front wheels and rear wheels are connected by torsion bars, and torsional action between at least one of the respective unsprung members and the stabilizer is provided. A front wheel side that is interposed as a connecting means between the unsprung member and the part that gives and receives the torsional action of the stabilizer, and that the connection distance between the unsprung member and the part that gives and receives the torsional action of the stabilizer can be adjusted by movement of a piston of a hydraulic cylinder; a rear wheel side connecting member; a pressure oil supply means for controlling the supply of pressure oil from a single hydraulic source to the two hydraulic cylinders; and a front wheel side and rear wheel side and a rear wheel side that are generated in the connecting member by hydraulic pressure from the single hydraulic pressure source. 1. A vehicle attitude control device characterized in that a biasing force applied to a side stabilizer corresponds to different inherent torsional rigidities of a front wheel side torsion bar and a rear wheel side torsion bar. 2. The vehicle attitude control device according to claim 1, wherein the hydraulic cylinders of the front wheel side connecting member and the rear wheel side connecting member have different cylinder diameters.