JP2625164B2 - Anti-rolling device for vehicles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an anti-rolling device for stabilizing a running posture of a vehicle such as an automobile.

[Related Art] When a vehicle turns, the vehicle body exhibits a rolling behavior such that the inside of the turn rises and the outside of the turn sinks due to centrifugal force. Conventionally, as means for suppressing rolling, a stabilizer formed by bending a rod-shaped metal material into a predetermined shape has been used. In addition, as having a function equivalent to a stabilizer, as shown in Japanese Patent Publication No. 51-21219, the structure is such that the oil amount of a hydraulic shock absorber in a suspension device can be controlled, and it is located on the outside of the turn when turning. There has been proposed an apparatus that keeps the posture of a vehicle body constant by supplying oil to a hydraulic shock absorber and discharging a part of the oil from a hydraulic shock absorber inside a turn. However, the conventional suspension mechanism is a combination of a suspension spring such as a coil spring or a leaf spring and a hydraulic shock absorber, and the load applied to the vehicle body is supported by the suspension spring. In this case, a relatively large space is required because the suspension spring and the hydraulic shock absorber must be provided in the suspension mechanism, and the weight occupied by the suspension spring is large.

The present inventors have been working on the development of an oil pressure type suspension mechanism as an alternative to the conventional suspension device. In the case of a hydraulic suspension system, inert gas such as nitrogen is sealed in the air chamber inside the cylinder at a high pressure (for example, around 100 kg / cm ² ), so that the load applied to the vehicle body is determined only by the repulsive force of the gas inside the cylinder. Since the gas spring is also used as a supporting type, it is not necessary to use a separate suspension spring. As shown conceptually in FIG. 4, an anti-rolling device using a suspension mechanism of this type includes an oil chamber 101 of a suspension mechanism 100 for a left wheel and a suspension mechanism for a right wheel.
The oil passage 103 is connected to the oil chamber 103 by an oil passage 104, and the oil passage 1
The structure is such that the control cylinder 105 is arranged in the middle of 04. When the vehicle makes a left turn, for example, the load applied to the suspension mechanism 102 outside the turn due to the centrifugal force increases, and the load applied to the suspension mechanism 100 inside the turn decreases. The absolute value of the increase and the absolute value of the decrease in the load are substantially equal to each other, and the gas is compressed and reduced in the suspension mechanism 102 on the outside of the turn, and the gas volume is increased in the direction of increase of the gas volume in the suspension mechanism 100 on the inside of the turn. Moves. For this reason, the control cylinder 105 removes a part of the oil from the suspension mechanism 100 on the inside of the turn, and supplies the same amount of oil to the suspension mechanism 102 on the outside of the turn to maintain the balance of the vehicle body during the turn. ing.

[Problems to be Solved by the Invention] However, an oil pressure type suspension mechanism 100, 10 having a gas spring function
It was found that the following problem occurred when 2 was used as it was in an anti-rolling device.

As described above, when the vehicle turns, for example, when turning left, the control cylinder 105 turns the suspension mechanism 100 inside the turn.
Suspension mechanism on the outside of the swivel for oil equivalent to the oil discharged from the
Send to 102. Accordingly, the amount of increase in the volume of gas in the suspension mechanism 100 inside the swirl due to the movement of the oil and the amount of decrease in the volume of gas in the suspension mechanism 102 outside the swirl become equal to each other. Moreover, the absolute values of the load increase (+ w) on the outside of the turn and the load decrease (-w) on the inside of the turn are substantially equal to each other.

However, the load / deflection characteristics of the gas spring are not linear, but exhibit a non-linear characteristic such that the rate of increase of the load increases as the gas spring bends toward the contraction side as illustrated in FIG. Therefore, when the increase in load (+ w) and decrement (-w) are equal to each other, coincide with the displacement amount L ₂ of the compression-side displacement amount L ₁ and extension-side (turning outside) (turning inside) do not do. In other words, the left and right suspension mechanisms cannot be balanced only by the movement of the oil from the inside suspension mechanism to the outside suspension mechanism. The fact that the left and right suspension mechanisms are actually balanced and equilibrium is the point where the suspension mechanism on the contraction side has risen by H from the normal position before turning. The displacement is L ₁ = (δ−H) obtained by subtracting H from the increase δ, and in the suspension mechanism on the extension side, L ₂ = (δ + H) where H is added to the decrease δ of the gas spring deflection due to the decrease in the oil amount. ), It becomes balanced when displaced. Accordingly, the balance of the vehicle body is maintained during the turn, but the vehicle height on both the left and right sides becomes higher by H than before the turn, and there remains a problem in running stability.

Accordingly, an object of the present invention is to provide an anti-rolling device for a vehicle that can prevent rolling and does not cause the center of gravity to rise.

[Means for Solving the Problems] An anti-rolling device invented by the present inventor to achieve the above object has a cylinder and a rod, in which oil and compressed gas are sealed, and the rod is a cylinder. A pair of left and right hydraulic pressure-type suspension mechanisms with nonlinear characteristics such that the spring constant gradually increases as the vehicle moves toward the contraction side, and according to the movement of the load generated between the inside and outside of the turn when the vehicle turns An anti-roll cylinder mechanism that removes a portion of the oil from the inner suspension mechanism and supplies oil to the outer suspension mechanism so that the pair of suspension mechanisms are balanced with each other, and that the rotation starts and the moving load increases. An oil discharging means for discharging an amount of oil for maintaining the height before turning from the suspension mechanism, and an amount for maintaining the height before turning while the turning peak has passed and the variable load has decreased. Oil supply means for supplying the above-mentioned 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 a non-linear characteristic such that the spring constant gradually increases as the rod is displaced toward the compression side with respect to the cylinder. When the load moves by a predetermined value or more between the inside and the outside of the turn due to the turning of the vehicle, a part of the oil is discharged from the inside of the turning mechanism and the suspension mechanism on the outside of the turning by operating the anti-roll cylinder mechanism. The left and right suspension mechanisms are balanced by the supply of oil. Moreover, during the period when the moving load increases after the turn starts (until the peak of the turn)
The oil is drained from the suspension mechanism so that the height before turning is maintained. Oil is supplied to the suspension mechanism so that the height before turning is maintained while the load fluctuation decreases after the turning peak.

Example An example 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 drawing 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 both common parts, and one suspension mechanism 2 will be described as a representative.

The hydraulic pressure type 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 are provided an oil chamber 7 filled with oil, and an air chamber 8 in which an inert gas such as nitrogen is sealed. The gas filling pressure is set to a high pressure (for example, around 100 kgf / cm ² ) so that the load applied to the vehicle body can be supported only by the repulsive force of the gas. Oil chamber 7 and air chamber 8
Is a partition member 9 using a bellows which can be extended and contracted in the axial direction.
Are separated from each other by Since the pressure of the gas in the air chamber 8 acts on the oil chamber 7 via the partition member 9, the internal pressure of the air chamber 8 acts in a direction in which the rod 6 is pushed out of the cylinder 5.

A piston portion 10 is provided at the inner end of the rod 6 and located in the oil chamber 7. The lower end of the cylinder 5 is connected to a member on the wheel side via a connecting portion 11, and the upper end of the rod 6 is connected to a member on the vehicle body side. In order to detect the relative position of the cylinder 5 and the rod 6 in the axial direction, that is, the height of the vehicle, a height sensor 12 including, 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 up and down relative to each other due to the unevenness of the road surface during traveling, the volume of the air chamber 8 increases and decreases, the partition member 9 expands and contracts, and the oil flows to the damping force generating section 13 so that the rod flows. 6 are damped.

A hydraulic pipe 15 is connected to the oil chamber 7. This hydraulic piping
15 is connected to an oil tank 17 via an electromagnetic valve 16a as an example of oil discharging means, and is connected to a hydraulic pump 20 as a hydraulic source via an electromagnetic valve 18a as an example of oil feeding means. I have. 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 and 3 configured as described above are connected to the anti-roll cylinder mechanism 30 via oil passages 24 and 25, respectively. The anti-roll cylinder mechanism 30 includes a left-right symmetrical cylinder 31, a piston 32 provided inside the cylinder 31 so as to be movable in the axial direction,
And a detector 33 for detecting the amount of displacement of 32. The inside of the cylinder 31 is partitioned by a piston 32 into a left oil chamber 35 and a right oil chamber 36. And left oil chamber 35
Communicates with the oil chamber 7 of the left-wheel suspension mechanism 2 via the oil passage 24. The right oil chamber 36 is connected to the right wheel suspension mechanism 3 through the oil passage 25.
The oil chamber 7 is connected to the oil chamber 7. Inside the piston 32, a left control oil chamber 38 and a right control oil chamber 39 are provided.

The piston 32 is driven by a servo valve 41 as an example of a servo unit and a driving unit 44 including hydraulic piping 42, 43, and the like.
It can be moved to the left oil chamber 35 side or the right oil chamber 36 side. That is, by controlling the servo valve 41 and selectively applying the hydraulic pressure from the hydraulic pump 20 or the accumulator 45 to the left and right control oil chambers 38 and 39, the piston 32 moves in the direction in which the oil chamber is applied. Has become.

The driving means 44 including the servo valve 41 is controlled by a controller 47 using a microcomputer. The controller 47 is connected to a steering wheel angle sensor 48 provided on a steering shaft portion for steering and a vehicle speed sensor 49 provided on a speedometer. The output signals of these sensors 48 and 49 are input to the controller 47, and in accordance with a pre-programmed processing procedure,
The magnitude of the centrifugal force associated with the turn, that is, the magnitude of the moving load, is calculated from the relationship between the steering wheel angle and the vehicle speed. Further, a signal from the height sensor 12 is input to the controller 47.

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

For example, when the vehicle makes a left turn, the servo valve 41 sends the hydraulic pump 20 to the right control oil chamber 39 in response to an output signal from the controller 47 which detects the turning state by the sensors 48 and 49.
Or move to supply oil from accumulator 45. As a result, when the piston 32 moves to the right oil chamber 36 side, the oil in the cylinder 31 is supplied to the oil chamber 7 of the suspension mechanism 3 on the outer side of rotation, and at the same time, the same amount of oil as the oil on the inner side of the rotation. The oil flows into the oil chamber 35 from the suspension mechanism 2. In this way, the amount of oil that can keep the left and right suspension mechanisms 2 and 3 in equilibrium moves, thereby preventing the vehicle body from leaning to the right.

In the apparatus of this embodiment, when the movement of the load starts to increase due to the start of the turning, the oil discharge electromagnetic valve 16a in the suspension mechanism 2 inside the turning is opened,
Part of the oil from the oil chamber 7 of the suspension mechanism 2 inside the turning
Is discharged. The oil volume V at this time is represented by the following equation, where S is the pressure receiving cross-sectional area of the rod 6 of the suspension mechanism 2, and V = S ・ 2H (H is the vehicle height rise in FIG. 5). After the oil amount V is discharged, the solenoid valve 16a
Closes. As described above, the oil is discharged such that the neutral height is maintained until the turning peak is reached, so that the height before the turning is maintained. The above flowchart is the first
Shown in the figure.

When the movement of the load starts to decrease due to the turning of the peak after the turning peaks, the supply solenoid valve 18a is opened, and the amount of oil corresponding to the oil amount V is supplied to the suspension mechanism 2 inside the turning by the hydraulic pump. Supplied from 20 or accumulator 45. When the suspension mechanism 2 returns to the neutral position, the solenoid valve 18a is closed. As described above, even before the turning is completed after the peak of the turning, 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 right, the anti-roll cylinder mechanism
The servo valve 41 is driven by the controller 47 so that the piston 32 of the cylinder 30 moves in the opposite direction to the above, and the oil in the oil chamber 35 in the cylinder 31 is fed into the oil chamber 7 of the suspension mechanism 2 for the left wheel, A part of the oil in the right wheel suspension mechanism 3 is collected in the oil chamber 36 in the cylinder 31, so that the left and right balance is maintained. In addition, from the start of the turn to the peak of the turn, a part of the oil in the right wheel suspension mechanism 3 is stored in the tank 17 by opening the drainage electromagnetic valve 16b, contrary to the left turn. Is discharged. Until the turning is completed after the peak of the turning, oil is returned to the suspension mechanism 3 by opening the supply solenoid valve 18b, and the solenoid valve 18b is closed when the suspension mechanism 3 reaches the neutral height. Thus, the vehicle height is kept constant.

In the above device, the anti-roll cylinder mechanism 30 is controlled according to the degree of turning. That is, the calculated value indicating the degree of turning calculated by the controller 47 based on the input from the steering wheel angle sensor 48 and the vehicle speed sensor 49 is compared with a reference value input 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 no anti-roll control is performed. Only when the calculated value exceeds a predetermined range with respect to the reference value, the servo valve 41 according to the calculated degree of turning.
Is controlled so that the displacement amount of the piston 32 increases as the degree of turning increases. The 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 an oil pressure type suspension mechanism having a gas spring function, rolling of a vehicle body is suppressed during turning due to curve running, course change, and the like. While maintaining the balance,
It is also possible to prevent the vehicle height from rising, which is extremely effective in improving the running stability of the vehicle.

[Brief description of the drawings]

1 and 2 are flowcharts each showing a part of anti-rolling control in an embodiment of the present invention;
FIG. 3 is a system diagram showing the outline of the configuration of an embodiment of the present invention, FIG. 4 is a schematic diagram showing a part of a vehicle provided with a pair of right and left hydraulic suspension systems, and FIG. FIG. 4 is a diagram showing a relationship between a load and a deflection of the first embodiment. 2,3… Hydraulic suspension system, 5… Cylinder, 6… Rod,
7 ... oil chamber, 8 ... air chamber, 12 ... height sensor, 16a, 16b ... oil discharging means (solenoid valve), 18a, 18b ... oil feeding means (solenoid valve), 20 ...
Hydraulic pump, 30 anti-roll cylinder mechanism, 47 controller, 48 steering wheel angle sensor, 49 vehicle speed sensor.

Claims (3)

(57) [Claims] 1. A left and right side having a cylinder and a rod and having oil and compressed gas sealed therein, and having a non-linear characteristic such that a spring constant gradually increases as the rod is displaced toward the compression side with respect to the cylinder. A pair of oil-pressure suspension mechanisms, and a portion of oil from the inside suspension mechanism so that the pair of suspension mechanisms balance each other in accordance with the movement of the load generated between the inside and outside of the turn when the vehicle turns. An anti-roll cylinder mechanism that removes oil and supplies oil to the suspension mechanism on the outside of the turn; and an oil drainage mechanism that discharges an amount of oil from the above-described suspension mechanism that maintains the height before the turn while the turn starts and the moving load increases. Means for supplying the suspension mechanism with an amount of oil that maintains the height before turning while the turning peak has passed and the fluctuating load has decreased. Rolling device. And means for detecting a steering wheel operating angle and vehicle speed during turning, and a controller for operating the anti-roll cylinder mechanism by obtaining a moving load during turning from the relationship between the steering wheel operating angle and vehicle speed. The anti-rolling device for a vehicle according to claim 1. 3. A height sensor for detecting a relative position between a cylinder and a rod in the left and right suspension mechanisms, and the oil discharging means and the oil feeding means are operated based on a signal from the height sensor. The anti-rolling device for a vehicle according to claim 1, further comprising a controller.