KR101938358B1 - Regenerative active suspension apparatus for vehicle - Google Patents

Abstract

The present invention provides a regenerative active suspension apparatus for a vehicle, which comprises: a cylinder defining a fluid chamber; a piston arranged to reciprocate in the cylinder, separating the fluid chamber to a tension chamber and a compression chamber, and connected to a piston rod; and a control system arranged in the outside of the cylinder, generating a damping force for a suspension system, and enabling a fluid to flow through the tension chamber and the compression chamber. The control system enables the fluid to flow through the tension chamber and the compression chamber, applies hydraulic pressure to the tension chamber and the compression chamber, and has a motor pump for the fluid to bidirectionally flow.

Description

[0001] REGENERATIVE ACTIVE SUSPENSION APPARATUS FOR VEHICLE [0002]

The present invention relates to a regenerative active suspension for a vehicle. More specifically, the present invention relates to a regenerative active suspension for a vehicle that reduces manufacturing costs, contributes to fuel efficiency improvement, and reduces negative pressure.

In a vehicle, a suspension device senses various inputs coming from a road surface through a sensor and effectively controls the roll behavior of the vehicle based on the sensed input. More particularly, the present invention relates to an actuator for compensating a displacement of a coil spring connected to a wheel of a vehicle and appropriately controlling the amount of fluid supplied to the actuator to detect changes in the roll and pitch of the vehicle, So as to improve the ride comfort and the road surface force of the vehicle. Furthermore, the level control (Level Control) of the garage allows the driver to set the height of the garage according to the condition of the road surface. By lowering the garage at high speed and reducing the air resistance, Can be performed.

In recent years there has been a growing interest in suspension devices that can provide improved comfort and road operability compared to conventional passive suspension devices. Accordingly, there has been developed an active suspension capable of controlling and generating the damping force based on the dynamic force against the movement of the piston. Recently, as the concern about environment friendliness has increased, we have added regeneration function to active suspension system.

Accordingly, it is necessary to develop an active suspension device that can be manufactured at a reasonable cost, and can operate efficiently and stably.

An object of the present invention is to provide an active suspension device which can be manufactured at a reasonable cost.

Another object of the present invention is to provide an active suspension which is efficient in terms of fuel economy by performing a regenerative function.

Further, it is an object of the present invention to provide an active suspension device capable of reducing the occurrence of negative pressure and stably operating.

According to an aspect of the present invention, there is provided a regeneration active suspension for a vehicle, comprising: a cylinder defining a fluid chamber; a piston arranged to reciprocate in a cylinder, separating the fluid chamber into a tension chamber and a compression chamber, A piston connected to the piston rod and a control system disposed outside the cylinder and generating a damping force for the suspension and in fluid communication with the tension chamber and the compression chamber, And a motor pump which applies hydraulic pressure to the tension chamber and the compression chamber and through which the fluid can flow in both directions.

Preferably, the control system includes an accumulator for storing the fluid entering the tension chamber and the compression chamber, a first check valve for allowing fluid to flow from the accumulator to the tension chamber, and a second check for allowing fluid to flow from the accumulator to the compression chamber. And may further include a valve.

Preferably, the control system may further comprise one solenoid valve through which current flows, the size of the fluid passage is controlled according to the magnitude of the current, and the fluid communicates with the compression chamber and the accumulator through the fluid passage.

Preferably, the control system includes a first blow-off valve for allowing fluid to flow when a hydraulic pressure greater than a predetermined first value is applied from the compression chamber to the tension chamber, and a second blow- And a second blow-off valve for allowing the fluid to flow when it is applied.

Preferably, the motor pump is capable of actively rotating and consuming energy, or rotating by the motion of the suspension to generate energy.

Preferably, the accumulator can maintain a positive (+) hydraulic pressure below a predetermined second value.

Preferably, the tension chamber and the compression chamber may have a positive hydraulic pressure.

Preferably, the diameter of the piston rod may be less than half the diameter of the piston.

Preferably, when either one of the tension chamber and the compression chamber has a hydraulic pressure higher than a predetermined third value, the other one may have a hydraulic pressure lower than the third value.

Preferably, when the suspension is tensioned and generates a damping force, fluid flows from a tension chamber having a hydraulic pressure of a predetermined third value or higher through a motor pump to a compression chamber having a hydraulic pressure of a third value or less, To generate the energy and to flow the volume of the piston rod from the accumulator through the second check valve to the compression chamber.

Preferably, when the suspension compresses and generates an active force, fluid flows from a compression chamber having a hydraulic pressure of a predetermined third value or less to a tension chamber having a hydraulic pressure of a third value or higher through a motor pump, The solenoid valve opens the fluid passage to a size larger than a predetermined fifth value so that the hydraulic pressure of the compression chamber can be maintained at a third value or less.

Preferably, when the suspension compresses and generates a damping force, the fluid flows from the compression chamber having a hydraulic pressure of a predetermined third value or higher to the tension chamber with a hydraulic pressure of the third value or less through the motor pump, And the solenoid valve opens the fluid passage to a size smaller than a predetermined fifth value so that the damping force can be controlled.

Preferably, when the suspension is tensioned and generates an active force, fluid flows from a tension chamber having a hydraulic pressure of a predetermined third value or less to a compression chamber having a hydraulic pressure of a third value or higher through a motor pump, The solenoid valve can be closed by applying a torque equal to or higher than a predetermined fourth value to control the power.

Preferably, the tension chamber and the compression chamber may each comprise a pressure sensor.

The present invention can provide an active suspension that can be manufactured at a reasonable cost.

In addition, the present invention can provide an active suspension device that is efficient in terms of fuel economy by performing a regenerative function.

Furthermore, the present invention can provide an active suspension capable of reducing the occurrence of negative pressure and stably operating.

1 is a quadrant graph for the force / speed range of a conventional semi-active suspension.
2 is a quadrant graph of the force / speed range of an active suspension according to an embodiment of the present invention.
3 shows an example of an active suspension system for a vehicle.
4 shows an example of an active suspension system for a vehicle.
5 illustrates a regenerative active suspension for a vehicle according to an embodiment of the present invention.
Figure 6 illustrates system operation at four quadrants in accordance with one embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

1 is a quadrant graph for the force / velocity range according to a typical semi-active suspension. 2 is a quadrant graph of the force / speed range of an active suspension according to an embodiment of the present invention.

Figures 1 and 2 provide a plot of the various ways to control the suspension within the force velocity domain. The damping rate is defined as (+) and the direction of compression is (-), and the damping force is defined as damping force at tension (+) and damping force at compression (-) as damping rate. Therefore, the first quadrant represents the damping force at the time of tension, the second quadrant represents the force at the time of compression, the third quadrant represents the damping force at the time of compression, and the fourth quadrant represents the force at the time of tension.

FIG. 1 is a graph of the four quadrant of the force / speed range according to a typical semi-active suspension. Referring to FIG. 1, a semi-active suspension is positioned within quadrants 1 and 3 corresponding to attenuation and attenuation compression. Thus, such a device only applies force, i.e., reaction force, to offset movement. Typically, the performance of a semi-active suspension can be varied between attenuation characteristic curves corresponding to total ductility and total stiffness through opening and closing of simple electronically controlled valves to adjust fluid flow through the system. Systems incorporating electronically controlled valves typically consume energy for operation, and the energy associated with the damping of the hydraulic actuator dissipates as heat. In addition, the operating range of the semi-active suspension is limited due to leakage at high forces and experiences fluid loss and friction effects at lower forces.

2 is a quadrant graph of the force / speed range of an active suspension according to an embodiment of the present invention. In the first quadrant, the active suspension can provide a damping tension that can respond to the reaction force of the vehicle wheel recoil. In the third quadrant, the active suspension can provide attenuation compression that can accommodate the reaction force to the compression of the vehicle wheel. Further, unlike the above-described semi-active suspension, the active suspension is capable of responding to active compression, which may correspond to towing the car wheel up, and to active tension, which may correspond to applying a force to propel the wheel downward The force can be generated in at least one of the second quadrant and the fourth quadrant.

3 shows an example of an active suspension system for a vehicle.

The active suspension 100 of Figure 3 includes a cylinder 120 defining a fluid chamber, a piston 130, a piston rod 131, a tension chamber 121 separated by a piston 130, and a compression chamber 122, A motor 141 for driving the bidirectional pump 140, a tension chamber 121, and an accumulator 150 for storing the fluid flowing into the compression chamber 122. The bidirectional pump 140, the bidirectional pump 140, The bidirectional pump 140 and the motor 141 can be regarded as one motor pump element for a simple understanding of the configuration.

The active suspension device 100 can control the roll control of the vehicle and the attitude of the vehicle by actively controlling the flow of the fluid through the driving of the bidirectional pump 140 and the motor 141. In addition, the active suspension device 100 may rotate the bidirectional pump 140 and the motor 141 to regenerate energy in a period where kinetic energy is generated. That is, the active suspension device 100 can perform both active attenuation and regeneration. In addition, the active suspension device 100 has a simple structure because the bi-directional pump 140 and the motor 141 are constituted by only one.

However, since the active suspension device 100 is composed solely of a single bidirectional pump 140 and a motor 141 without any proportional control valve, the accumulator 141 is directly connected to the tension chamber 121 and the compression chamber 122 So that there is a disadvantage that the neutral pressure is increased. Specifically, in the case of a general damper which does not perform active operation, the neutral pressure has about 3 to 5 bar which is close to zero. However, the active suspension 100 maintains a high neutral pressure of 35 bar or more. Therefore, the active suspension apparatus 100 has a problem that the durability of the system is poor.

In addition, the active suspension 100 does not have a check valve and can not prevent the flow of fluid in an undesired direction. However, the active suspension device 100 has a structure in which a check valve can not be installed because all the fluid passages are united and the check valve can not flow in one direction. The check valve prevents the flow of fluid in the undesired direction, so that negative pressure can be avoided. Therefore, the active suspension device 100 having no check valve has a problem that a negative pressure is generated and a negative pressure lower than the atmospheric pressure is generated. If a negative pressure is generated, a lot of noise is generated and the function as a suspension device may be lost.

Therefore, there is a need for a new active suspension that can improve the problem of the active suspension 100.

4 shows an example of an active suspension system for a vehicle.

The active suspension 200 of Figure 4 includes a cylinder 220 defining a fluid chamber, a piston 230, a piston rod 231, a tension chamber 221 separated by a piston 230 and a compression chamber 222, A motor 241 for driving the pump 240, an accumulator 250 for storing the fluid flowing into the tension chamber 221 and the compression chamber 222, three check valves 261, 262, 263, two blow-off valves 271, 272, and two solenoid proportional control valves 281, 282. The bidirectional pump 240 and motor 241 can be viewed as a single motor pump element for a simple understanding of the configuration.

The blow-off valves 271 and 272 are safety valves that prevent the tension chamber 221 or the compression chamber 222 from being pressurized to a specific pressure or higher,

The solenoid proportional control valves 281 and 282 are valves that control the flow of the fluid by utilizing the difference in degree of opening of the orifice depending on the magnitude of the current applied to the solenoid. Specifically, when a current of 0.3 A flows, the fluid passage of the valve as a hard mode is almost not opened to a predetermined value or less, and when the current of 1.6 A flows, the fluid passage of the valve as a soft mode is fully opened to a predetermined value or more .

The active suspension 200 includes solenoid proportional control valves 281 and 282 disposed between the tension chamber 221 and the compression chamber 222 and between the compression chamber 222 and the accumulator 250, Damping force and damping force during compression are controlled. In addition, the active suspension 200 can further control the attitude of the vehicle by generating an active power by further connecting the pump 240 and the motor 241.

However, the active suspension 200 requires a pump 240, a motor 241, and two solenoid proportional control valves 281 and 282, which increases the manufacturing cost of the apparatus and makes it impossible to regenerate the apparatus . In addition, when the vehicle body is raised by generating an active force, since both chambers 221 and 222 are pressurized at a high pressure, a force corresponding to the area of the piston rod 231 must be generated, have.

Therefore, there is a need for a new active suspension that can improve the problem of the active suspension 200.

5 illustrates a regenerative active suspension for a vehicle according to an embodiment of the present invention.

The active suspension 300 of Figure 5 includes a cylinder 320 defining a fluid chamber, a piston 330, a piston rod 331, a tension chamber 321 and a compression chamber 322 separated by a piston 330, A motor 341 for driving the bidirectional pump 340, an accumulator 350 for storing the fluid flowing into the tension chamber 321 and the compression chamber 322, a check valve (not shown) 361, 362, two blow-off valves 371, 372, and two solenoid proportional control valves 381, 382. The bidirectional pump 340 and motor 341 can be viewed as a single motor pump element for a simple understanding of the configuration.

The active suspension 300 of Figure 5 is similar to the active suspension 200 of Figure 4 except that there is no check valve and solenoid proportional control valve between the tension chamber 321 and the compression chamber 322 and instead a bi- 340 and the motor 341 are located. The active suspension device 300 of FIG. 5 has a solenoid proportional control valve 381, which is different from the active suspension device 200 of FIG. The active suspension 300 of Figure 5 also includes a bi-directional pump 340 and a motor 341 positioned between the tension chamber 321 and the compression chamber 322. Accordingly, when the kinetic energy is generated, the bidirectional pump 340 rotates by the motion of the active suspension 300 and rotates the motor 341 Rotate to revitalize the energy. The active suspension device 300 of FIG. 5 can increase the energy efficiency and operate more environmentally by energy recovery.

The active suspension 300 of Figure 5 has two blowoff valves 371 and 372 similar to the active suspension 200 of Figure 4 and the blowoff valves 371 and 372 are connected to the tension chamber 32 or When pressed beyond the compression chamber 322, flows fluid to prevent the tension chamber 321 or the compression chamber from being pressurized above a certain pressure and protects the active suspension 500.

5 differs from the active suspension apparatus 100 of FIG. 3 and the active suspension apparatus 200 of FIG. 4 in that the compression chamber 322 and the accumulator 350 and the tension chamber 321 And check valve 361 and 362 are located between accumulator 350 and accumulator 350. [ The check valve 361 allows fluid to flow from the accumulator 350 to the compression chamber 322 and the check valve 352 allows fluid to flow from the accumulator 350 to the tension chamber 321. The check valve 352 is disposed between the tension chamber 321 and the accumulator 350 to prevent negative pressure from being formed in the tension chamber 321 unlike the active suspension 200 of FIG. In addition, the neutral pressure of the accumulator 350 can be maintained at a low pressure, thereby solving the problem of the durability of the active suspension device 100 of Fig.

The active suspension 300 of FIGURE 5 is different from the active suspension 200 of FIGURE 4 in that the tension chamber 321 and the compression chamber 322 are connected to the check valves 352, When one of the two is high pressure, the other can be low pressure, so that the force of the active suspension 300 can be made larger when the same pressure is applied. 5 can reduce the area of the piston rod 331 compared to the case where the tension chamber 221 and the compression chamber 222 are both at a high pressure in the active suspension 200 of FIG. have. 4, when the diameter of the piston 230 is 32, the diameter of the piston rod 231 corresponds to 22. That is, the diameter of the piston rod 231 is at least half the diameter of the piston 230. [ On the other hand, when the diameter of the piston 330 is 40 in the active suspension 300 of FIG. 5, the diameter of the piston rod 331 is only 15. That is, the diameter of the piston rod 331 is less than half the diameter of the piston 330. [ Accordingly, the active suspension 300 of FIG. 5 can save a force corresponding to an area of the piston rod 331 which is reduced in diameter.

Further, the active suspension 300 of FIG. 5 is easy to control because it controls the pressure difference between the tension chamber 321 and the compression chamber 322. Therefore, a pressure sensor can be attached to each of the tension chamber 321 and the compression chamber 322 to perform feed-back control according to the pressure difference.

Figure 6 illustrates system operation at four quadrants in accordance with one embodiment of the present invention.

When the active suspension 300 is tensioned and produces a damping force as in Quadrant 1, fluid flows from the high pressure tension chamber 321 through the bidirectional pump 340 to the low pressure compression chamber 322. The bidirectional pump 340 can apply torque below a predetermined value to control the damping force and to generate energy. Further, the fluid corresponding to the volume of the piston rod 331 flows from the accumulator 350 to the compression chamber 322 through the check valve 361. [ The solenoid proportional control valve 381 is opened as a soft mode with a magnitude greater than a predetermined value.

The fluid flows from the low-pressure compression chamber 322 through the bidirectional pump 340 to the high-pressure tension chamber 321 when the active suspension 300 compresses and generates an active force as in the second quadrant. The bidirectional pump 340 driven by the motor 341 can control the power by applying a torque greater than a predetermined value. Further, the solenoid proportional control valve 381 is opened in a soft mode with a size larger than a predetermined value, thereby making the compression chamber 322 low in pressure.

When the active suspension 300 compresses and generates a damping force as in Quadrant 3, the fluid flows from the high pressure compression chamber 322 through the bidirectional pump 340 to the low pressure tension chamber 321. The motor 341 generates electricity by allowing the fluid to flow smoothly without any control. The fluid corresponding to the volume of the piston rod 331 flows from the compression chamber 322 to the accumulator 350 via the solenoid proportional control valve 381. [ The solenoid proportional control valve 381 controls the magnitude of the fluid passage to a predetermined value or less by the current to control the damping force as desired.

When the active suspension 300 is tensioned and generates an active force as in Quadrant 4, the fluid flows from the low pressure tension chamber 321 through the bidirectional pump 340 to the high pressure compression chamber 322. The bidirectional pump 340 driven by the motor 341 is capable of controlling the power of the vehicle by applying a torque equal to or higher than a predetermined value and further controlling the behavior of the vehicle body. The solenoid proportional control valve 381 is almost closed as a hard mode.

As described above, the active suspension 300 can control the damping force and the power using the motor 341, the bidirectional pump 340, or the solenoid proportional control valve 381 at each upper limit. Since the active suspension 300 requires only the motor 341, the bidirectional pump 340 and one solenoid proportional control valve 381, the system cost can be reduced. In addition, since the active suspension 300 can perform the function of regeneration, it can contribute to the improvement of the fuel efficiency of the vehicle. In addition, the accumulator 350 can be maintained at a low pressure, which is excellent in durability. In addition, the tension chamber 321 and the compression chamber 322 are directly connected to the accumulator 350 via the check valves 362 and 361 to receive the fluid, so that no negative pressure is generated. Further, since the pressure difference between the tension chamber 321 and the compression chamber 322 is controlled, the active suspension 300 can be easily controlled. Further, the active suspension 300 can generate a large force even at a low pressure when the one chamber is at high pressure and the other chamber is at low pressure at the time of generating active power.

The embodiments described above are those in which the elements and features of the present invention are combined in a predetermined form. Each component or feature shall be considered optional unless otherwise expressly stated. Each component or feature may be implemented in a form that is not combined with other components or features. It is also possible to construct embodiments of the present invention by combining some of the elements and / or features. The order of the operations described in the embodiments of the present invention may be changed. Some configurations or features of certain embodiments may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments. It is clear that the claims that are not expressly cited in the claims may be combined to form an embodiment or be included in a new claim by an amendment after the application.

It will be apparent to one skilled in the art that the present invention may be embodied in other forms without departing from the spirit or essential characteristics thereof. Accordingly, the above embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the present invention should be determined by reasonable interpretation of the appended claims and all possible variations within the scope of the invention.

100, 200, 300: active suspension device 120, 220, 320: cylinder
121, 221, 321: tension chambers 122, 222, 322:
130, 230, 330: Pistons 131, 231, 331: Piston rod
140, 240, 340: pumps 141, 241, 341: motors
150, 250, 350: accumulators 261, 262, 263, 361, 362: check valves
271, 272, 371, 372: blow-off valves
281, 282, 381: Solenoid proportional control valve

Claims (14)

In a vehicle regeneration active suspension,
A cylinder defining a fluid chamber;
A piston arranged to be reciprocatable in the cylinder, the piston separating the fluid chamber into a tension chamber and a compression chamber, the piston being connected to the piston rod; And
A control system disposed outside the cylinder and generating a damping force for the suspension and in fluid communication with the tension chamber and the compression chamber,
Wherein the control system includes a motor pump that is in fluid communication with the tension chamber and the compression chamber and applies hydraulic pressure to the tension chamber and the compression chamber and is capable of flowing fluid in both directions,
Wherein when one of the tension chamber and the compression chamber has an oil pressure of a predetermined third value or more, the other of the tension chamber and the compression chamber has an oil pressure of the third value or less. The method according to claim 1,
The control system includes:
An accumulator for storing the fluid entering the tension chamber and the compression chamber;
A first check valve for allowing fluid to flow from the accumulator to the tension chamber; And
Further comprising a second check valve for allowing fluid to flow from the accumulator to the compression chamber,
Active regeneration active suspension system for vehicles. 3. The method of claim 2,
The control system includes:
Further comprising one solenoid valve through which current flows, the size of the fluid passage is controlled according to the magnitude of the current, and the fluid passage communicates with the compression chamber and the accumulator.
Active regeneration active suspension system for vehicles. 3. The method of claim 2,
The control system includes:
A first blow-off valve for allowing the fluid to flow when a hydraulic pressure greater than a first predetermined value is applied from the compression chamber to the tension chamber; And
Further comprising a second blow-off valve for allowing fluid to flow when a hydraulic pressure greater than the first value is applied to the accumulator from the compression chamber.
Active regeneration active suspension system for vehicles. The method according to claim 1,
The motor pump includes:
The active rotation and energy consumption,
Or rotate by the motion of the suspension to generate energy,
Active regeneration active suspension system for vehicles. 3. The method of claim 2,
The accumulator includes:
And a positive (+) hydraulic pressure is maintained below a predetermined second value.
Active regeneration active suspension system for vehicles. 3. The method of claim 2,
Wherein the tension chamber and the compression chamber comprise:
And has a positive (+) hydraulic pressure.
Active regeneration active suspension system for vehicles. The method according to claim 1,
Characterized in that the diameter of the piston rod is less than half the diameter of the piston.
Active regeneration active suspension system for vehicles. delete The method of claim 3,
When the suspension is tensioned and produces a damping force,
The fluid flows from the tension chamber having a hydraulic pressure of a predetermined third value or more to the compression chamber having the hydraulic pressure of the third value or less via the motor pump,
Wherein the motor pump applies torque less than a predetermined fourth value to control the damping force and to generate energy,
Wherein a volume of said piston rod flows from said accumulator to said compression chamber through said second check valve,
Active regeneration active suspension system for vehicles. The method of claim 3,
When the suspension device compresses and generates an active power,
The fluid flows from the compression chamber having an oil pressure lower than a predetermined third value to the tension chamber having the hydraulic pressure of the third value or higher through the motor pump,
Wherein the motor pump controls the operating force by applying a torque equal to or greater than a predetermined fourth value,
Wherein the solenoid valve opens the fluid passage to a size greater than or equal to a predetermined fifth value to maintain the hydraulic pressure in the compression chamber below the third value,
Active regeneration active suspension system for vehicles. The method of claim 3,
When the suspension is compressing and generating a damping force,
The fluid flows from the compression chamber having an oil pressure of a predetermined third value or higher to the tension chamber having the oil pressure lower than the third value through the motor pump,
The motor pump generates energy without applying torque,
Wherein a volume of the piston rod flows from the compression chamber through the solenoid valve,
Wherein the solenoid valve controls the damping force by opening the fluid passage to a size smaller than a predetermined fifth value,
Active regeneration active suspension system for vehicles. The method of claim 3,
When the suspension is tensioned and generates an active force,
The fluid flows from the tension chamber having a hydraulic pressure lower than a predetermined third value to the compression chamber having the hydraulic pressure of the third value or higher through the motor pump,
Wherein the motor pump controls the operating force by applying a torque equal to or greater than a predetermined fourth value,
The solenoid valve is closed,
Active regeneration active suspension system for vehicles. The method according to claim 1,
Wherein the tension chamber and the compression chamber each comprise a pressure sensor,
Active regeneration active suspension system for vehicles.

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