JPH0260814A - Antirolling device for vehicle - Google Patents

Abstract

PURPOSE:To prevent rolling and rising up of the gravity center according to a method wherein a part of oil is exhausted from a suspension mechanism on the inner side of turn, while oil is supplied to a suspension device on outer side of turn with operation on an antiroll cylinder mechanism. CONSTITUTION:When a vehicle turns, for instance, to the left, a servovalve 41 moves so as to supply oil to a right control oil chamber 39 on output signal, detected with sensors 48, 49, from a controller 47. As the result thereof, a piston 32 moves to a right oil chamber 36 side, oil in a cylinder 31 is supplied to an oil chamber 7 of a suspension mechanism 3 on outer side of turn, and oil in the same quantity thereof flows into an oil chamber 35 from a suspension mechanism 2 on inner side of turn. In this way, a vehicle body can be prevented from leaning rightward. And then, when turning starts and movement on load begins to increase, an electromagnetic valve 16a for exhausting oil in the suspension mechanism 2 on inner side of turn is made to open, a part of oil is exhausted to a tank 17 from an oil chamber 7, then the electromagnetic valve 16a is closed. In such way, height before turning is maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an anti-rolling device for stabilizing the posture of a vehicle such as an automobile while it is running.

[Prior Art] When a vehicle turns, the vehicle body exhibits a rolling behavior in which the inner side of the turn rises due to centrifugal force and the outer side of the turn sinks. Conventionally, as a means to suppress rolling, a stabilizer made of a bar-shaped metal material bent into a predetermined shape has been used. In addition, as seen in Japanese Patent Publication No. 51-212i9, the hydraulic shock absorber in the suspension system has a function equivalent to a stabilizer, and has a structure that can control the amount of oil, and when turning, the hydraulic shock absorber is located on the outside of the turn. A system has been proposed in which the attitude of the vehicle body is kept constant by replenishing the hydraulic shock absorber with oil and discharging some of the oil from the hydraulic shock absorber on the inside of the turn.

However, conventional suspension mechanisms combine suspension springs such as coil springs and leaf springs with aIJ pressure shock absorbers, and the load applied to the vehicle body (for 4-suspension systems, we support -C
there was. In this case, since the suspension spring and the hydraulic shock absorber must be provided in the suspension mechanism, a relatively large space is required, and moreover, the suspension spring occupies a large amount of weight.

The present inventors have been working on the development of a hydraulic suspension mechanism as an alternative to conventional suspension systems. In the case of a hydraulic suspension mechanism, by filling the air chamber inside the cylinder with an inert gas such as nitrogen at high pressure (for example, around 100/(!7/~)), the load applied to the vehicle body is absorbed by the repulsion of the gas in the cylinder. Because it is a gas spring type that supports only by force,
There is no need to use a separate suspension spring. As conceptually shown in FIG. 4, an anti-rolling device using this type of suspension mechanism connects an oil chamber 101 of a left wheel suspension mechanism 100 and an oil chamber 103 of a right wheel suspension mechanism 102 to an oil passage 104. Along with the decoupling, a control cylinder 105 is arranged in the middle of this Uraji 104. When the vehicle turns to the left, for example, the load applied to the suspension mechanism 102 on the outside of the turn increases due to centrifugal force, and the load applied to the suspension mechanism 100 on the inside of the turn decreases. The absolute values of the increase and decrease in this load are almost equal to each other, and the gas is compressed in the suspension mechanism 102 on the outside of the turn and its volume decreases, while the load is applied in the direction that the volume of gas increases in the suspension mechanism 100 on the inside of the turn. moves. For this reason, the control cylinder 105 drains some of the oil from the suspension mechanism 100 on the inside of the turn, and replenishes the same amount of oil to the suspension mechanism 102 on the outside of the turn, thereby maintaining the balance of the vehicle body when turning. ing.

[Problem to be solved by the invention] However, the hydraulic suspension mechanism 100 having a gas spring function
, 102 was used as is in an anti-rolling device, it was found that the following problems would occur.

As mentioned above, when the vehicle turns, for example, when turning to the left, the control cylinder 105 moves the suspension mechanism 1 on the inside of the turn.
An amount of oil equivalent to the oil discharged from 00 is sent to the suspension mechanism 102 on the outside of the rotation. Therefore, the increase in gas volume in the suspension mechanism 100 on the inner side of the turn due to the movement of oil and the decrease in the gas volume in the suspension mechanism 102 on the outer side of the turn are equal to each other. Moreover, the load increase on the outside of the turn (+W
) and the absolute value of the load decrease (-W) on the inside of the turn are almost equal to each other.

However, the load/deflection characteristics of a gas spring are not linear, and as illustrated in FIG. 5, exhibit irritating nonlinear characteristics when the rate of increase in load increases as the spring deforms toward contraction. Therefore, when the load increase (+W) and load decrease (-W) are equal, the displacement m L + on the contraction side (outside turning) and the displacement ff1L2 on the extension side (inside turning) do not match. In other words, the left and right suspension mechanisms cannot be balanced simply by moving the ura from the suspension mechanism on the inside of the turn to the suspension mechanism on the outside of the turn.

In reality, the left and right suspension mechanisms become balanced when they are lifted up by H from their normal positions before turning.In other words, in the suspension mechanism on the compression side, the gas spring is deflected due to the increase in oil volume. Subtract H from the increase δ, or -(δ-
H), and in the suspension mechanism on the extension side, H is added to the decrease in deflection δ of the gas spring due to the decrease in oil amount, L2-
Balance is reached when the displacement is (δ+H). Therefore, although the balance of the vehicle body is maintained during the turn, the vehicle height on both the left and right sides becomes higher by H compared to before the turn, and a problem with running stability remains.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an anti-rolling device for a vehicle that can prevent rolling and prevent the center of gravity from rising.

[Means for Solving the Problem] In order to achieve the above object, the anti-rolling device invented by the present inventor has a cylinder and a rod, the inside of which is filled with oil and compressed gas, and the rod is connected to the cylinder. A pair of left and right hydraulic suspension mechanisms have a non-linear characteristic in which the spring constant gradually increases as the vehicle moves toward the compression side, and a suspension mechanism that responds to the shift of load that occurs between the inside and outside of the turn when the vehicle turns. An anti-roll cylinder mechanism which removes some of the oil from the suspension mechanism on the inside of the swing and supplies oil to the suspension mechanism on the outside of the swing so that the pair of suspension mechanisms are in equilibrium with each other; an oil draining means for discharging oil from the suspension mechanism in an amount that maintains the height before turning; and an oil draining means for discharging oil in an amount that maintains the height before turning from the suspension mechanism; The system also includes oil supply means for supplying oil to the suspension mechanism.

[Operation] In the device of the present invention having the above configuration, the load applied to the vehicle body is supported by the repulsive force of the high pressure gas sealed inside the suspension mechanism. Since this suspension mechanism functions as a gas spring, it exhibits nonlinear characteristics such that the spring constant gradually increases as the rod is displaced toward the contraction side with respect to the cylinder. When the load shifts by more than a predetermined value between the inside and outside of the turn due to a turn of the vehicle, the anti-roll cylinder mechanism is activated to drain some of the oil from the suspension mechanism on the inside of the turn and transfer the load to the outside of the turn. By supplying oil to the left and right suspension mechanisms, the balance is maintained.

Moreover, while the moving load increases after the turn begins (until the peak of the turn), oil is drained from the suspension mechanism so that the height before the turn is maintained. While the load fluctuations are decreasing after the peak of turning, the suspension mechanism is supplied with pressure so that the height before turning is maintained.

[Embodiment] An embodiment of the present invention will be described below with reference to the anti-rolling device 1 shown in FIG.

The hydraulic suspension mechanism 2 on the left side of the figure supports the left wheel of the vehicle, and the hydraulic suspension mechanism 3 on the right side of the figure supports the right wheel.

Since these suspension mechanisms 2 and 3 have the same configuration,
The same reference numerals are given to the common parts of both, and one suspension mechanism 2
I will explain on behalf of.

The hydraulic suspension mechanism 2 includes a cylinder 5 and a rod 6 inserted movably in the axial direction of the cylinder 5. Inside the cylinder 5, there is an oil chamber 7 filled with water and an air chamber 8 filled with an inert gas such as nitrogen.
is provided.

The gas filling pressure is high enough to support the load applied to the car body only by the repulsive force of the gas (for example, 100/(!7)
f/d). The oil chamber 7 and the air chamber 8 are separated from each other by a partition member 9 using a bellows that is expandable and retractable in the axial direction. The pressure of the gas in the air chamber 8 is controlled by the partition member 9.
The internal pressure of the air chamber 8 acts in a direction to push the rod 6 out of the cylinder 5.

A piston portion 10 is provided at the inner end of the rod 6 and located within the oil chamber 7 . The lower end of the cylinder 5 is the connecting part 11
The upper end of the rod 6 is connected to a member on the vehicle body side. Also, cylinder 5 and rod 6
In order to detect the relative axial position of the vehicle, i.e. the vehicle height,
A height sensor 12 made of, for example, a differential transformer is provided.

The damping force generating section 13 provided in the piston section 10 has an orifice. When the cylinder 5 and the rod 6 move relative to each other in the vertical direction due to unevenness of the road surface while driving, the air chamber 8
The reciprocating motion of the rod 6 is attenuated by the expansion and contraction of the partition part 9 as the volume increases and decreases, and by the oil flowing into the damping force generating part 13.

A hydraulic pipe 15 is connected to the oil chamber 7. This hydraulic piping 15 is connected to an oil tank 17 via a solenoid valve 16a as an example of oil draining means, and to a hydraulic pump 20 as a hydraulic source via a solenoid valve 18a as an example of oil feeding means. It is connected. The bearing gap of the seal portion 21 communicates with the oil tank 17 via the drain pipe 22.

The pair of left and right suspension mechanisms 2.degree. 3 configured as described above are connected to the anti-roll cylinder mechanism 30 through oil passages 24 and 25. Anti-roll cylinder mechanism 30
is a left-right symmetrical cylinder 31, and this cylinder 31.
A piston 32 is provided inside the piston 32 so as to be movable in the axial direction, and a detector 3 for detecting the amount of displacement of the piston 32.
3. The inside of the cylinder 31 is partitioned into a left oil chamber 35 and a right bending chamber 36 by a piston 32. The left oil chamber 35 communicates with the oil chamber 7 of the left wheel suspension mechanism 2 via the oil passage 24. The right bending chamber 36 is
It communicates with the oil chamber 7 of the right wheel suspension mechanism 3 via an oil passage 25 . Inside the piston 32, there is a left control oil chamber 38.
and a right control oil chamber 39.

The piston 32 can be moved to the left oil chamber 35 side or the right oil chamber 36 side by a driving means 44 consisting of a servo valve 41 as an example of a servo means, hydraulic piping 42, 43, etc. . That is, servo valve 4
1, hydraulic pump 20 or accumulator 45
By selectively applying hydraulic pressure from the left and right control oil chambers 38 and 39, the piston 32 moves in the direction in which the hydraulic pressure is applied.

The driving means 44 including the servo valve 41 is controlled by a controller 47 using a microcomputer. This controller 47 includes a steering wheel angle sensor 48 provided on the steering shaft portion for steering.
A vehicle speed sensor 49 provided on a speedometer is connected to the vehicle speed sensor 49 . The output signals of these sensors 48 and 49 are input to the controller 47, and the magnitude of the centrifugal force accompanying the turn, that is, the magnitude of the moving load, is calculated from the relationship between the steering wheel angle and the vehicle speed according to a preprogrammed processing procedure. Ru. Also, the signal from the height sensor 12 is transmitted to the controller 4.
7 is input.

Next, the operation of the anti-rolling device 1 having the above configuration will be explained.

For example, when the vehicle turns left, the servo valve 41 supplies oil from the hydraulic pump 20 or the accumulator 45 to the three right control oil chambers in response to an output signal from the controller 47 that detects a bad turning condition by the sensors 48 and 49. It moves like this. As a result, the piston 32 moves to the right oil chamber 36 side, so that the oil in the cylinder 31 is supplied to the oil chamber 7 of the suspension mechanism 3 on the outside of the rotation, and at the same time, the same amount of oil is supplied to the oil chamber 7 on the inside of the rotation. It flows from the suspension mechanism 2 into the oil chamber 35. In this way, the suspension is moved by an amount that can keep the left and right suspension mechanisms 2 and 3 in equilibrium, thereby preventing the vehicle body from leaning to the right.

In the device of this embodiment, when the movement of the load starts to increase due to the start of the turn, the suspension mechanism 2 on the inside of the turn
By opening the drain oil solenoid valve 16a,
A portion of the oil flows into the tank 1 from the oil chamber 7 of the suspension mechanism 2 on the inside of the rotation.
It is discharged at 7. The oil amount v at this time is expressed by the following formula, %, where S is the pressure-receiving cross-sectional area of the rod 6 of the suspension mechanism 2 (H is the amount corresponding to the rise in vehicle height in FIG. 5). After mV of oil is discharged, the solenoid valve 16
a closes. In this way, until the peak of the turning,
By discharging the ura so that the neutral height is maintained,
The height before turning is maintained.

The above flowchart is shown in FIG.

When the peak of the swing passes and the swing begins to subside and the movement of the load begins to decrease, the supply solenoid valve 18a opens, and an amount of oil corresponding to the above-mentioned volume mV is supplied to the suspension mechanism 2 on the inside of the swing to the hydraulic pump 2o. Alternatively, it is supplied from the accumulator 45. Then, when the suspension mechanism 2 returns to the neutral position, the solenoid valve 18a is closed. In this way, even after the peak of the turning passes and until the turning ends, the oil moves so that the neutral height is maintained, so that the height before the turning is maintained. The above flowchart is shown in FIG.

When the vehicle turns to the right, the anti-roll cylinder mechanism 3
The servo valve 41 is driven by the controller 47 so that the piston 32 of No. 0 moves in the opposite direction to that described above, and the oil chamber 35 in the cylinder 31 is fed into the oil chamber 7 of the left wheel suspension mechanism 2. Part of the oil in the right wheel suspension mechanism 3 is collected into the oil chamber 36 in the cylinder 31, thereby maintaining left and right balance. In addition, from the start of the turn until the peak of the turn, a portion of the oil in the right wheel suspension mechanism 3 is drained into the tank 17 by opening the oil draining solenoid valve 16b, contrary to when turning to the left. It is discharged.

Then, until the peak of the turning has passed and the turning is finished, the oil is returned to the suspension mechanism 3 by opening the supply solenoid valve 18b, and when the suspension mechanism 3 reaches the neutral height, the solenoid valve 18b closes. In this way, the vehicle height is kept constant.

Note that in the above device, the anti-roll cylinder mechanism 30 is controlled depending on the degree of turning. That is, a calculated value indicating the degree of turning calculated by the controller 47 based on inputs from the steering wheel angle sensor 48 and the vehicle speed sensor 49 is compared with a reference value inputted in advance. If the calculated value is within a predetermined range with respect to the reference value, the piston 32 is held at the neutral position and anti-roll control is not performed. Only when the calculated value exceeds a predetermined range with respect to the reference value, the servo valve 41 is controlled according to the calculated degree of rotation, so that when the degree of rotation is large, the amount of displacement of the piston 32 becomes large. controlled by. The amount of displacement of the piston 32 is detected by the detector 33 and fed back to the controller 47.

[Effects of the Invention] As described above, according to the present invention, in an anti-rolling device using a hydraulic suspension mechanism with a gas spring function, rolling of the vehicle body is suppressed when cornering due to curve driving or course change. It is possible to maintain balance and prevent the vehicle height from rising, which is extremely effective in increasing the running stability of the vehicle.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are flowcharts showing a part of anti-rolling control in an embodiment of the present invention, respectively;
Fig. 3 is a system diagram showing an outline of the configuration of an embodiment of the present invention, Fig. 4 is a schematic diagram showing a part of a vehicle equipped with a pair of left and right hydraulic suspension mechanisms, and Fig. 5 is a diagram showing a part of a vehicle equipped with a pair of left and right hydraulic suspension mechanisms. FIG. 3 is a diagram showing the relationship between load and deflection. 2.3... Hydraulic suspension mechanism, 5... Cylinder, 6
... Rod, 7... Oil chamber, 8... Air chamber, 1-2.
... Height sensor, 16a, 16b... Oil draining means (solenoid valve), 18a, 18b... Oil feeding means (electromagnetic valve), 20
...Hydraulic pump, 30...Anti-roll cylinder mechanism, 47...Controller, 48...Handle angle sensor, 49...Vehicle speed sensor. 11!1 S (UxietuntNbzduck)

Claims (3)

[Claims] (1) A pair of left and right cylinders that have a cylinder and a rod, are filled with oil and compressed gas, and have nonlinear characteristics such that the spring constant gradually increases as the rod is displaced toward the cylinder toward the contraction side. A portion of the oil is removed from the hydraulic suspension mechanism and the suspension mechanism on the inside of the turn so that the pair of suspension mechanisms are balanced with each other in response to the shift of load that occurs between the inside and outside of the turn when the vehicle turns. and an anti-roll cylinder mechanism that supplies oil to the suspension mechanism on the outside of the swing, and an oil draining means that discharges oil from the suspension mechanism in an amount that maintains the height before the swing while the swing starts and the moving load increases. An anti-rolling device for a vehicle, comprising: an oil supply means for supplying the suspension mechanism with an amount of oil that maintains the height before turning while the peak of turning has passed and the fluctuating load has decreased; . (2) A claim comprising means for detecting a steering wheel operating angle and vehicle speed when turning, and a controller that calculates a moving load during turning from the relationship between the steering wheel operating angle and vehicle speed and operates the anti-roll cylinder mechanism. Item 1. The anti-rolling device for a vehicle according to item 1. (3) Equipped with a height sensor to detect the relative position of the cylinder and rod in the left and right suspension mechanisms,
The anti-rolling device for a vehicle according to claim 1, further comprising a controller that operates the oil draining means and the oil feeding means based on the signal from the height sensor.