KR20230115691A - Active body control - Google Patents

Abstract

The present invention relates to an active suspension system. The active suspension system of the present invention comprises: a motor; a gear connected to a shaft of the motor by a belt, and rotated in conjunction with the shaft of the motor; a lever arm connected to the gear; a stabilizer link wherein one side is connected to the lever arm and the other side is connected to a suspension; and a smart damper provided between the lever arm and the stabilizer link or between the stabilizer link and the suspension, and configured to generate a damping force according to a frequency transmitted from the road surface. Provided is the active suspension system which can improve safety and ride comfort.

Description

Active suspension {ACTIVE BODY CONTROL}

The present invention relates to an active suspension device, and more particularly, to an active suspension device provided to reduce vibration generated by an impact transmitted from a road surface during driving of a vehicle.

In general, a suspension system of a vehicle connects an axle and a vehicle body to control vibration or shock received from a road surface by an axle during driving from being directly transmitted to the vehicle body. Such a suspension device is a device that prevents damage to a vehicle body and cargo and improves riding comfort.

The suspension system includes a chassis spring, a shock absorber, and a stabilizer bar that controls rolling of the vehicle. Both sides of the stabilizer bar are connected to the vehicle body, and both ends are mounted to a lower arm or strut bar by a stabilizer link.

The suspension does not act when the left and right wheels move up and down simultaneously, but plays an anti-roll role to suppress the roll of the vehicle body with torsional restoring force when the left and right wheels move up and down relative to each other.

That is, the stabilizer bar is twisted when the turning outer side of the vehicle body is tilted by centrifugal force during turning of the vehicle or when the left and right wheels have a relative phase difference due to a bump or rebound during driving, thereby stabilizing the posture of the vehicle body with the restoring force. do.

Recently, an active body control system has been developed to increase driving comfort by independently controlling four corners of a vehicle. In the active suspension system, the left and right sides of the stabilizer bar are separated, and power is transmitted through the stabilizer bar when controlling the vehicle through the actuator.

On the other hand, the active suspension system requires fast forward/reverse rotation of the actuator when the vehicle is driving on a road surface where high frequency vibration is transmitted, such as a gravel field. , which will soon cause damage to the actuator.

Therefore, it is necessary to develop an auxiliary device capable of absorbing high-frequency vibration and further improving gear protection and riding comfort.

Korean Patent Publication No. 10-2006-0126704

SUMMARY OF THE INVENTION An aspect of the present invention is to provide an active suspension device capable of improving safety and riding comfort by generating a damping force by adjusting the pressure of a fluid according to the frequency of an impact transmitted from a road surface during driving of a vehicle.

According to one embodiment of the present invention, the present invention provides a motor; a gear connected to the shaft of the motor by a belt and rotated in conjunction with the shaft of the motor; a lever arm connected to the gear; a stabilizer link having one side connected to the lever arm and the other side connected to the suspension; and a smart damper provided between the lever arm and the stabilizer link or between the stabilizer link and the suspension and generating a damping force according to a frequency transmitted from a road surface.

In addition, the smart damper includes a cylinder in which fluid is stored; a piston having one side inserted to reciprocate inside the cylinder; and a valve unit connected to one side of the piston and generating a damping force according to a frequency transmitted from a road surface while the vehicle is running while the fluid in the cylinder is introduced.

In addition, the valve unit may include a sub-piston rod coupled to the piston end; a valve member coupled to the sub-piston rod and configured to generate a damping force by flowing the fluid introduced from the sub-piston rod; and a fixing nut coupled to an end of the sub-piston rod to fix the valve member.

Further, the sub-piston rod has a fluid flow path formed therein so that the fluid filled in the cylinder can flow in and flow into the valve member.

In addition, the fluid flow path may include a first fluid flow path formed by a set length along the longitudinal direction of the sub-piston rod; and a second fluid passage formed below the first fluid passage in a direction crossing the first fluid passage.

In addition, the valve member may include a housing in which a hollow is formed so that the sub-piston rod can be penetrated, and pilot chambers are formed at upper and lower sides of a set depth, respectively; a retainer through which the sub-piston rod is coupled and located at a lower side of the housing; a first pilot valve provided between the housing and the retainer; and a second pilot valve provided on an upper side of the housing.

In addition, the housing may include a first pilot chamber concavely formed by a set depth from the upper side to the lower side; and a second pilot chamber concavely formed from the lower side to the upper side by a set depth.

In addition, the retainer includes a main chamber concavely formed by a set depth in a direction from top to bottom.

Also, the first pilot valve partitions between the second pilot chamber and the main chamber, and closes or opens the main chamber according to pressures of the first pilot chamber and the second pilot chamber.

Also, the first pilot valve opens the main chamber while being deformed when a pressure inequality between the first pilot chamber and the second pilot chamber is formed.

Also, the first pilot valve closes the main chamber when pressure equilibrium is established between the first pilot chamber and the second pilot chamber.

Details of other embodiments are included in the detailed description and drawings.

The active suspension device according to the present invention has the following effects.

By providing a smart damper, it is possible to protect the gear and improve stability by generating a damping force according to the frequency of the impact transmitted to the vehicle.

In addition, by reducing the vibration of the vehicle by the damping force generated by the smart damper, it is possible to improve the riding comfort of passengers in the vehicle.

1 and 2 are schematic diagrams briefly showing the configuration of an active suspension device according to the present invention.
3 is a cross-sectional view showing a smart damper structure of an active suspension system according to the present invention.
FIG. 4 is a partial enlarged cross-sectional view of part “A” in FIG. 3 .
5 is a cross-sectional view illustrating the flow of fluid in a smart damper upon high-frequency impact.
6 is a cross-sectional view showing the flow of fluid in the smart damper during low-frequency impact.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. This invention may be embodied in many different forms and is not limited to the embodiments set forth herein.

It is advised that the drawings are schematic and not drawn to scale. Relative dimensions and proportions of parts in the drawings are shown exaggerated or reduced in size for clarity and convenience in the drawings, and any dimensions are illustrative only and not limiting. In addition, the same reference numerals are used to indicate similar features in the same structural elements or parts appearing in two or more drawings.

The embodiments of the present invention specifically represent ideal embodiments of the present invention. As a result, various variations of the diagram are expected. Therefore, the embodiment is not limited to the specific shape of the illustrated area, and includes, for example, modification of the shape by manufacturing.

Hereinafter, the active suspension device according to the present invention will be described in detail with reference to FIGS. 1 to 6 .

An active suspension device according to the present invention includes a motor 10, a gear 30, a lever arm 40, a stabilizer link 50 and a smart damper 100. The active suspension device according to the present invention independently performs rolling control and shock absorption for each wheel of a vehicle.

The motor 10 provides power. The suspension 60 is actively moved through the power provided by the motor 10 to adjust rolling, pitch, and height of the vehicle body.

The gear 30 is connected to the shaft 11 of the motor by a belt 20. The gear 30 is rotated in communication with the shaft 11 of the motor. The power provided by the motor 10 is transmitted to the gear 30 through the belt 20 .

The lever arm 40 is connected to the gear 30. The power provided by the motor 10 is transmitted to the gear 30 and is transmitted to the lever arm 40 through the gear 30 .

One side of the stabilizer link 50 is connected to the lever arm 40 and the other side is connected to the suspension 60 . The power of the motor 10 is transmitted to the stabilizer link 50 through the lever arm 40 .

Meanwhile, an impact transmitted from the road surface while the vehicle is running is input through the wheel and transmitted to the stabilizer link 50 through the suspension 60 . That is, both the impact of the road surface and the power of the motor 10 are transmitted to the stabilizer link 50 .

The suspension 60 may be vertically displaced according to the movement of the stabilizer link 50 to which both the impact of the road surface and the power of the motor 10 are transmitted, and through the vertical displacement of the suspension 60, the vehicle Rolling (rolling), pitching (pitching), height, etc. can be adjusted.

The smart damper 100 is provided between the lever arm 40 and the stabilizer link 50 or between the stabilizer link 50 and the suspension 60 .

The smart damper 100 is provided to generate a damping force according to the frequency of the impact of the road surface independently of the operation of the suspension 60 .

1 shows that the smart damper 100 is provided between the lever arm 40 and the stabilizer link 50. 2 shows that the smart damper 100 is provided between the stabilizer link 50 and the suspension 60.

The smart damper 100 includes a cylinder 110, a piston 120 and a valve unit 200.

The cylinder 110 stores fluid therein. In this embodiment, as shown in the drawing, the cylinder 110 is formed in a cylindrical shape as an example, but is not limited thereto and may be formed in various shapes.

The inside of the cylinder 110 is divided into an upper chamber 111 and a lower chamber 112 based on the valve unit 200 .

One side of the piston 120 is inserted to reciprocate inside the cylinder 110 . 1, when the smart damper 100 is located between the stabilizer link 50 and the lever arm 40, one side of the stabilizer link 50 serves as the piston 120 You may. However, since this is an example, a separate piston may be connected to the stabilizer link 50.

Although not specifically shown in the drawing, a flow path (not shown) through which fluid flows is formed inside the piston 120 . The piston 120 reciprocates due to impact transmitted from the road surface while the vehicle is driving. At this time, when the piston 120 performs a tension stroke moving in a direction toward the upper chamber 111, the fluid stored in the upper chamber 111 flows into the flow path 121 of the piston 120. . The fluid introduced into the flow path 121 of the piston 120 is transferred to the valve unit 200, which will be described in detail later.

The valve unit 200 is connected to one side of the piston 120. Specifically, it is connected to one side of the piston 120 located inside the cylinder 110. The valve unit 200 generates a damping force according to the frequency of the vibration transmitted during driving of the vehicle. That is, the component that substantially generates a damping force in the smart damper 100 is the valve unit 200 .

The valve unit 200 has the following configuration to generate damping force.

The valve unit 200 includes a sub piston rod 210, a valve member 220 and a fixing nut 230.

The sub-piston rod 210 is coupled to an end of one side of the piston 120. As shown in FIG. 3 , one side of the piston 120 is coupled to the upper side of the sub-piston rod 210 . To this end, a piston insertion groove 213 is formed on the upper side of the sub-piston rod 210.

The sub-piston rod 210 has fluid passages 211 and 212 formed inside the cylinder 110 . The fluid passages 211 and 212 are formed so that the fluid stored in the cylinder 110 flows in and flows into the valve member 220 .

The fluid flow path includes a first fluid flow path 211 and a second fluid flow path 212 . The first fluid passage 211 is formed by a set length along the longitudinal direction of the sub-piston rod 210 . The second fluid passage 212 is formed below the first fluid passage 211 in a direction crossing the first fluid passage 211 .

The fluid delivered from the flow path 121 of the piston 120 flows along the first fluid flow path 211, branches to the second fluid flow path 212, and is delivered to the valve member 220.

The valve member 220 is coupled to the sub piston rod 210 . The valve member 220 generates a damping force by the fluid introduced from the sub-piston rod 210 .

The valve member 220 includes a housing 221, a retainer 222, a first pilot valve 223 and a second pilot valve 224.

The housing 221 is formed with a first hollow 221a penetrating along the longitudinal direction. The sub-piston rod 210 penetrates and is coupled to the housing 221 as it passes through the first hollow 221a.

The housing 221 includes a first pilot chamber 221b and a second pilot chamber 221c. The first pilot chamber 221b is concave from the upper side of the housing 221 to the lower side by a set depth. The second pilot chamber 221c is concave from the lower side of the housing 221 to the upper side by a set depth.

The first pilot chamber 221b and the second pilot chamber 221c form a space in which the fluid introduced through the sub-piston rod 210 is stored.

The retainer 222 is provided on the lower side of the housing 221 . The retainer 222 is formed with a second hollow 222a penetrating along the longitudinal direction. Therefore, the sub-piston rod 210 is coupled through the second hollow 222a.

The retainer 222 includes a main chamber 222b. The main chamber 222b is concave from the upper side of the retainer 222 to the lower side by a set depth. The main chamber 222b forms a space in which the fluid introduced from the sub-piston rod 210 is stored.

The first pilot valve 223 is provided between the housing 221 and the retainer 222 . The first pilot valve 223 is also through-coupled with the sub-piston rod 210 . The first pilot valve 223 partitions between the second pilot chamber 221c and the main chamber 222b.

The first pilot valve 223 is made of rubber or synthetic resin. Accordingly, the first pilot valve 223 is elastically deformed by a pressure difference between the first pilot valve 221b and the second pilot valve 221c.

The first pilot valve 223 is in contact with the upper end of the retainer 222 when the frequency of the impact transmitted from the road surface to the vehicle is low. Conversely, when the frequency of the impact transmitted from the road surface to the vehicle is high, the first pilot valve 223 is deformed so as not to come into contact with the upper end of the retainer 222 and opens the main chamber 222b. This will be described in detail later.

Meanwhile, an inlet disk 225 is provided between the housing 221 and the first pilot valve 223 . The sub-piston rod 221 is penetrated through the inlet disk 225 . The inlet disk 225 induces a flow of fluid such that the fluid introduced through the second fluid passage 212 flows into the second pilot chamber 221c.

If the inlet disk 225 is not provided, the horizontal surface (not shown) of the first pilot valve 223 is in close contact with the lower surface of the inner wall 221d forming the second pilot chamber 221c. Therefore, the fluid introduced from the sub-piston rod 210 may not flow into the second pilot chamber 221c.

A slit (not shown) is formed in the inlet disk 225 along a radial direction from the center. Therefore, when the inlet disk 225 is provided between the housing 221 and the first pilot valve 223, fluid flows into the second pilot chamber 222c through the slit (not shown).

The second pilot valve 224 is located on the upper side of the housing 221 . The second pilot valve 224 is also through-coupled with the sub-piston rod 221 . The second pilot valve 224 shields the first pilot chamber 222b and is elastically deformed according to pressure changes in the first pilot chamber 222b and the second pilot chamber 222c. Specifically, the fluid is elastically deformed according to the pressure according to the inflow amount of the fluid flowing into the first pilot chamber 222b and the second pilot chamber 222c.

Like the first pilot valve 223, the second pilot valve 224 is made of a rubber material or a synthetic resin material.

The fixing nut 230 is coupled to an end of the sub piston rod 210 . The fixing nut 230 fixes the valve member 220 by being coupled to the end of the sub-piston rod 210 .

Hereinafter, with reference to FIGS. 5 and 6 , a process in which the active suspension system according to the present invention generates a damping force according to the frequency of an impact transmitted from a road surface will be described.

First, FIG. 5 shows a case where the frequency of an impact transmitted from a road surface is high. When a vehicle travels on a road surface such as a gravel field, a high-frequency shock is transmitted to the vehicle. At this time, in the smart damper 100, the fluid acts as follows.

The fluid stored in the cylinder 110 flows into the flow path 121 of the piston 120 and is delivered to the valve unit 200 . The fluid flows along the first fluid passage 211 and the second fluid passage 212 and flows into the valve member 220 .

A part of the fluid flows into the second pilot chamber 221c, and the rest of the fluid flows into the main chamber 222b. When a high-frequency impact is transmitted to the vehicle, the fluid flows in at high speed, so the fluid pressure first fills the second pilot chamber 221c before the fluid pressure fills the first pilot chamber 221b.

Accordingly, a pressure imbalance is formed between the first pilot chamber 221b and the second pilot chamber 221c. As a result, the first pilot valve 223 is deformed and opens the main chamber 222b.

When the main chamber 222b is opened, the fluid introduced into the main chamber 222b flows into the lower chamber 112 . When a high-frequency impact is transmitted to a vehicle due to the action of the fluid, a damping force is generated to protect the gear 30 and improve riding comfort.

6 illustrates a case where the frequency of an impact transmitted from a road surface is a low frequency. When a vehicle travels on a road surface such as a large puddle, a low-frequency shock is transmitted to the vehicle. At this time, in the smart damper 100, the fluid acts as follows.

The fluid stored in the cylinder 100 flows into the flow path 121 of the piston 120 and is delivered to the valve unit 200 . The fluid flows along the first fluid passage 211 and the second fluid passage 212 and flows into the valve member 220 .

A part of the fluid flows into the second pilot chamber 221c, and the rest of the fluid flows into the main chamber 222b. When a high-frequency impact is transmitted to the vehicle, the fluid flows in at a low speed, so that the fluid pressure is sufficiently filled in the first pilot chamber 221b and the fluid pressure is also filled in the second pilot chamber 221c. That is, the pressure equilibrium between the first pilot chamber 221b and the second pilot chamber 221c is established.

While pressure equilibrium is established between the first pilot chamber 221b and the second pilot chamber 221c, the first pilot valve 223 shields the main chamber 222b without being deformed, thereby forming the main chamber 222b. ) maintains pressure equilibrium while preventing the fluid introduced into the lower chamber 112 from flowing. When a low-frequency impact is transmitted to the vehicle due to the action of the fluid, a damping force is generated to protect the gear 30 and improve riding comfort.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art to which the present invention pertains can understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. will be.

Therefore, the embodiments described above should be understood as illustrative and not restrictive in all aspects, and the scope of the present invention is indicated by the claims to be described later, from the meaning and scope of the claims and their equivalent concepts. All changes or modified forms derived should be construed as being included in the scope of the present invention.

10: motor
20: belt
30: gear
40: lever arm
50: link unit
60: Suspension
100: smart damper
110: cylinder
120: piston
200: valve unit
210: sub piston rod
220: valve member
221 housing
222: retainer
223: first pilot valve
224: second pilot valve
225: inlet disk
230: fixing nut

Claims (11)

motor;
a gear connected to the shaft of the motor by a belt and rotated in conjunction with the shaft of the motor;
a lever arm connected to the gear;
a stabilizer link having one side connected to the lever arm and the other side connected to the suspension; and
An active suspension device including a smart damper provided between the lever arm and the stabilizer link or between the stabilizer link and the suspension and generating a damping force according to a frequency transmitted from a road surface. According to claim 1,
The smart damper,
A cylinder with fluid stored therein;
a piston having one side inserted to reciprocate inside the cylinder;
and a valve unit connected to one side of the piston and generating a damping force according to a frequency transmitted from a road surface while the vehicle is running while the fluid in the cylinder is introduced. According to claim 2,
The valve unit,
a sub-piston rod coupled to the piston end;
a valve member coupled to the sub-piston rod and configured to generate a damping force by flowing the fluid introduced from the sub-piston rod; and
An active suspension comprising a fixing nut coupled to an end of the sub-piston rod to fix the valve member. According to claim 3,
The sub piston rod,
An active suspension device having a fluid flow path formed therein so that the fluid filled in the cylinder can flow in and flow into the valve member. According to claim 4,
The fluid flow path,
a first fluid passage formed by a set length along the longitudinal direction of the sub-piston rod; and
An active suspension comprising a second fluid passage formed below the first fluid passage in a direction crossing the first fluid passage. According to claim 3,
The valve member,
a housing in which a hollow is formed so that the sub-piston rod can be through-coupled, and pilot chambers are formed at upper and lower sides of a set depth;
a retainer through which the sub-piston rod is coupled and located at a lower side of the housing;
a first pilot valve provided between the housing and the retainer; and
An active suspension device including a second pilot valve provided on the upper side of the housing. According to claim 6,
the housing,
a first pilot chamber formed concavely by a set depth from the upper side to the lower side; and
An active suspension system including a second pilot chamber concave from the lower side to the upper side by a set depth. According to claim 7,
The retainer,
An active suspension system including a main chamber concave from the upper side to the lower side by a set depth. According to claim 8,
The first pilot valve,
An active suspension device that partitions between the second pilot chamber and the main chamber and closes or opens the main chamber according to pressures of the first pilot chamber and the second pilot chamber. According to claim 9,
The first pilot valve,
An active suspension device that opens the main chamber while being deformed when pressure inequality between the first pilot chamber and the second pilot chamber is formed. According to claim 9,
The first pilot valve,
An active suspension device for shielding the main chamber when pressure equilibrium is established between the first pilot chamber and the second pilot chamber.

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