JP2625166B2 - 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. 3, 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 the amount of 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 swivel due to the movement of 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 non-linear characteristics such that the rate of increase in load increases as the gas spring flexes 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 At least a hydraulic anti-roll cylinder mechanism that removes a part of the oil from the inner suspension mechanism and supplies oil to the outer suspension mechanism so that the pair of suspension mechanisms equilibrate with each other, and at least an oil chamber inside. One auxiliary tank, an oil passage connecting the oil chambers of the pair of suspension mechanisms and the anti-roll cylinder mechanism, and an anti-roll cylinder machine provided when the vehicle turns. The oil sent from the anti-roll cylinder mechanism by cutting off the communication between the oil chamber of the suspension mechanism and the anti-roll cylinder mechanism in a state in which the suspension mechanism on the outer side of rotation reaches a predetermined neutral height by operating the structure. Is provided with a bypass control valve for releasing air into the auxiliary tank.

[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 between the inside and outside of the turn by a predetermined amount or more due to the turning of the vehicle, a part of the oil is discharged from the inside of the turning inside of the turning mechanism by operating the anti-roll cylinder mechanism, and the outside of the turning mechanism is turned. Is supplied with oil. When the suspension mechanism on the outside of the swing reaches the neutral height, the communication between the oil chamber of the suspension on the outside of the swing and the anti-roll cylinder mechanism is cut off by closing the bypass control valve. For this reason, surplus oil sent from the anti-roll cylinder mechanism to the outside of the turning is guided to the auxiliary tank. As the anti-roll cylinder mechanism continues to operate, the oil in the suspension mechanism inside the turn is discharged until the suspension mechanism reaches the neutral height, so that the left and right suspension mechanisms are balanced with each other and the height before the turn is maintained. Is done.

Embodiment An embodiment of the present invention will be described below with reference to the anti-rolling apparatus 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 unevenness of the road surface during running, 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. The reciprocating movement of the rod 6 is damped.

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

Also, oil passages 23, 2 are provided in oil chambers 7, 7 of the suspension mechanisms 2, 3, respectively.
Auxiliary tanks 26, 27 are connected via 3 and solenoid valves 24, 25. Each of the auxiliary tanks 26 and 27 has oil chambers 30 and 31 and air chambers 32 and 33 inside. The oil chambers 30, 31 and the air chambers 32, 33 are completely partitioned by partition members 34, 35 using metal bellows or the like. A compressed inert gas such as nitrogen is sealed inside the air chambers 32 and 33. The gas pressure is equal to the gas pressure of the air chamber 8 described above.

The oil chamber of the pair of left and right suspension mechanisms 2 and 3 configured as described above
7, 7 are connected to an anti-roll cylinder mechanism 40 via bypass control valves 36, 37 and oil passages 38, 39, respectively. The anti-roll cylinder mechanism 40 is a symmetrical cylinder
41, a piston 42 movably provided in the cylinder 41 in the axial direction, and a detector 43 for detecting the displacement of the piston 42. The inside of the cylinder 41 is partitioned by a piston 42 into a left oil chamber 45 and a right oil chamber 46. The left oil chamber 45 can communicate with the oil chamber 7 of the left-wheel suspension mechanism 2 via the oil passage 38 and the bypass control valve 36. The right oil chamber 46 can communicate with the oil chamber 7 of the right wheel suspension mechanism 3 via the oil passage 39 and the bypass control valve 37. A left control oil chamber 48 is provided inside the piston 42.
And a right control oil chamber 49 are provided.

The piston 42 is driven by a driving unit 54 including a servo valve 51 as an example of a servo unit and hydraulic piping 52, 53, etc.
It can be moved to the left oil chamber 45 side or the right oil chamber 46 side. That is, by controlling the servo valve 51 and selectively applying the hydraulic pressure from the hydraulic pump 20 or the accumulator 55 to the left and right control oil chambers 48 and 49, the piston 42 moves in the direction in which the hydraulic pressure is applied. ing.

The driving means 54 having the servo valve 51 is controlled by a controller 57 using a microcomputer. The controller 57 is connected to a steering wheel angle sensor 58 provided on a steering shaft portion for steering and a vehicle speed sensor 59 provided on a speedometer. The output signals of these sensors 58 and 59 are input to the controller 57, and according to the processing procedure programmed in advance,
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 fed back to the controller 57.

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

For example, when the vehicle turns left, the servo valve 51 sends the hydraulic pump 20 to the right control oil chamber 49 in response to an output signal from the controller 57 that has detected the turning state by the sensors 58 and 59.
Or move to supply oil from accumulator 55. The bypass control valves 36 and 37 are in an open state. Therefore, when the piston 42 moves to the right oil chamber 46 side, the oil in the cylinder 41 is supplied to the oil chamber 7 of the suspension mechanism 3 on the outer side of rotation, and the same amount of oil is supplied to the suspension mechanism on the inner side of the rotation. 2 flows into the oil chamber 45.

Since the suspension mechanisms 2 and 3 functioning as gas springs have a non-linear load / bending characteristic such that the spring constant gradually increases as the suspension mechanism bends toward the contraction side, the suspension mechanism 2 inside the turning mechanism is operated by the action of the anti-roll cylinder mechanism 40. When the same amount of oil moves to the suspension device 3 on the outside of rotation, the suspension device 3 on the outside of the rotation reaches a predetermined deflection first, and when the oil is fed into the suspension mechanism 3 any longer, the outside of the rotation before the rotation is turned. Will rise from the neutral position. Therefore, as shown in the flowchart of FIG. 2, when the suspension mechanism 3 on the outside of the swing exceeds a predetermined neutral position, the bypass control valve 37 on the outside of the swing is closed, so that the suspension mechanism on the outside of the swing 3 The communication with the oil passage 39 connecting the roll cylinder mechanism 40 is cut off. At the same time, the electromagnetic valve 25 connected to the auxiliary tank 27 is opened to communicate the anti-roll cylinder mechanism 40 with the auxiliary tank 27. By doing so, all excess oil sent from the oil chamber 46 of the anti-roll cylinder mechanism 40 flows into the oil chamber 31 of the auxiliary tank 27. Swivel inner bypass control valve 36
Remains open. The amount V of the oil introduced into the auxiliary tank 27 is represented by the following equation, where S is the pressure receiving area of the rod 6 of the suspension mechanism 2, and V = S · 2H (H is the vehicle height rise in FIG. 4).

Until the turning peak is reached, the piston 42 of the anti-roll cylinder mechanism 40 continues to move to the right oil chamber 46 side, so that the oil is discharged from the suspension mechanism 2 inside the turning and finally the suspension mechanism 2 inside the turning also. Maintained at neutral height. The electromagnetic valve 25 connected to the auxiliary tank 27 may be always open. In this case, when the piston 42 of the anti-roll cylinder mechanism 40 moves toward the right oil chamber 46, the oil in the oil chamber 46 simultaneously flows into the oil chamber 7 of the suspension mechanism 3 and the oil chamber 31 of the auxiliary tank 27. Therefore, only the bypass control valve 37 is closed when the suspension mechanism 3 exceeds the neutral position. Further, the flow rate of the oil flowing into the auxiliary tank 27 and the suspension mechanism 3 may be adjusted by using valves capable of controlling the flow rate for the solenoid valve 25 and the bypass control valve 37.

After the peak of the turn, the load transfer begins to decrease,
Conversely, while the oil in the auxiliary tank 27 is returned to the anti-roll cylinder mechanism 40 through the oil passage 39, the oil is returned to the suspension mechanism 2 inside the turn. In this way, the balance between the left and right suspension mechanisms 2, 3 is maintained, and the lifting of the vehicle body is prevented.

When the vehicle turns right, the anti-roll cylinder mechanism
The servo valve 51 is driven by the controller 57 so that the 40 piston 42 moves in the opposite direction to the above, and the oil in the oil chamber 45 in the cylinder 41 is fed into the oil chamber 7 of the suspension mechanism 2 for the left wheel, Part of the oil in the right wheel suspension mechanism 3 is collected in the oil chamber 46 in the cylinder 41. Then, when the suspension mechanism 2 on the outside of the swing exceeds a predetermined neutral height, the bypass control valve 36 is closed. The solenoid valve 24 is opened. In this way, excess oil flowing to the outside of the turn is guided to the auxiliary tank 26, and a predetermined amount of oil is discharged from the suspension mechanism 3 inside the turn by continuing to operate the anti-roll cylinder mechanism 40. The lifting of the center of gravity is also prevented while maintaining the degree.

The electromagnetic valve 24 of the auxiliary tank 26 may be always open.
Further, the flow rate of the oil flowing into the auxiliary tank 26 and the suspension mechanism 2 may be adjusted by using valves capable of controlling the flow rate for the solenoid valve 24 and the bypass control valve 36.

In the apparatus 1 of this embodiment, the anti-roll cylinder mechanism 40 is controlled according to the degree of turning. That is, a calculated value indicating the degree of turning calculated by the controller 57 based on the input from the steering wheel angle sensor 58 and the vehicle speed sensor 59 is compared with a previously input reference value. If the calculated value falls within a predetermined range with respect to the reference value, the piston 42 is held at the neutral position, and the anti-roll control is not performed. Only when the calculated value exceeds a predetermined range with respect to the reference value, the servo valve 51 is controlled according to the calculated degree of turning.
Is controlled so that the amount of displacement becomes large. The amount of displacement of the piston 42 is detected by the detector 43 and is fed back to the controller 57.

Further, the vehicle equipped with the present embodiment device 1 opens the solenoid valves 24 and 25 of the left and right suspension mechanisms 2 and 3 at the same time during straight traveling, thereby allowing the Suspension mechanism 2, 3
If the air chambers 8, 8 cooperate with each other, the riding comfort is improved by reducing the spring constant of the suspension mechanisms 2, 3. Also,
The steering stability can be improved by simultaneously closing the solenoid valves 24 and 25 and increasing the spring constant when traveling on a rough road with severe road surface irregularities.

Since at least one auxiliary tank 26, 27 is required,
For example, by connecting two or more auxiliary tanks to one side, the spring constant may be switched to two or more stages.

[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]

FIG. 1 is a system diagram showing an outline of the configuration of an embodiment of the present invention, FIG. 2 is a flowchart showing a part of control in the anti-rolling apparatus shown in FIG. 1, and FIG. FIG. 4 is a schematic view showing a part of a vehicle provided with an oil pressure type suspension mechanism, and FIG. 4 is a view showing a relationship between a load and a deflection of a gas spring. 2,3… Hydraulic suspension system, 5… Cylinder, 6… Rod,
7 ... oil chamber, 8 ... air chamber, 12 ... height sensor, 20 ... hydraulic pump, 26, 27 ... auxiliary tank, 31 ... oil chamber, 40 ... anti-roll cylinder mechanism, 57 ... controller, 58 ... handle angle sensor, 59… Vehicle speed sensor.

Claims (4)

(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 a suspension mechanism on the outside of rotation, at least one auxiliary tank having an oil chamber inside, and an oil that connects the oil chambers of the pair of suspension mechanisms and the anti-roll cylinder mechanism The suspension is provided on the road, and the suspension mechanism on the outside of the turn reaches a predetermined neutral height due to the operation of the anti-roll cylinder mechanism during the turn of the vehicle. Vehicle antiroll device being characterized in that anda bypass control valve to release the oil coming from the anti-roll cylinder mechanism in the auxiliary tank by breaking the communication between the oil chamber and the anti-roll cylinder mechanism structure. 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. A height sensor for detecting a relative position between the cylinder and the rod in the left and right suspension mechanisms, and a controller for operating the anti-roll cylinder mechanism based on a signal from the height sensor. The anti-rolling device for a vehicle according to claim 1, wherein 4. An anti-rolling device for a vehicle according to claim 1, wherein said bypass control valve is an electromagnetic valve capable of adjusting a flow rate.