KR20030084139A - suspention system of vehicle - Google Patents

Abstract

PURPOSE: A suspension system of a vehicle is provided to sufficiently absorb impact energy, which is generated in traveling, at an optimum condition through a strut assembly and accordingly improve riding comfort and operation stability. CONSTITUTION: A suspension system of a vehicle is composed of an offset variation sensor mounted to vehicle wheels(1) to detect the variation of a kingpin offset(D); an ECU(Electronic Control Unit,23) for receiving signals from the offset variation sensor and discriminating the offset directions and variation of the vehicle wheels; and a strut assembly regulating device(30) forcibly moving one of both ends of a strut assembly(17) in a horizontal direction for the ground(G), wherein the strut assembly is combined to a lower arm(14) and an upper arm according to the control of the ECU when the kingpin offset is changed, and always matching an extension line of the strut assembly with a spot at which a central line(T) of a tire meets the ground.

Description

Suspension system of a vehicle

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension device for a vehicle. In particular, the end of the strut assembly may be moved together in proportion to a kingpin offset that is changed depending on driving conditions or road conditions. It is about a suspension device.

In general, the suspension system is connected to the axle and the vehicle body so that vibrations or shocks received from the road surface are not directly transmitted to the vehicle body, thereby preventing damage to the vehicle body or cargo and improving ride comfort.

Such suspensions are largely classified into front suspensions and rear suspensions, and the front suspensions and the rear suspensions are classified into various types of suspensions according to axle suspension and independent suspension, which is independent in the embodiment of the present invention. The description of the double wishbone suspension system used in the suspension type will be described.

That is, as shown in FIG. 1, the double wishbone suspension device includes knuckles 11 coupled to wheels of the left and right wheels 1, and ball joints 12 and 13 at upper and lower ends of the knuckles 11. The lower arm 14 and the upper arm 15 coupled to each other to adjust the movement of the wheel, and both ends are installed to be connected to the lower arm 14, while the body is to the side while enhancing the strength and rigidity of the underbody Cross member 16, which is to prevent from shaking, and a coil spring 17a for mitigating the impact received from the road surface, and a shock absorber 17b for suppressing free vibration of the coil spring 17a to improve ride comfort, The upper and lower ends are composed of strut assemblies 17 and the like installed in the longitudinal axis so as to be connected to the upper arm 15 and the lower arm 14, respectively.

The lower arm 14 is prevented from directly hitting the end of the lower arm 14 and the cross member 16 when the running wheel 1 springs upward and the suspension device is compressed to the maximum. The bound stopper 18 is fixedly installed by screwing, and the upper arm 15 is connected to the upper arm 15 when the running wheel 1 moves downward while the suspension device is fully extended. The rebound stopper 19 is fixedly screwed to prevent the end of the cross member 16 from directly hitting the end.

Meanwhile, the strut assembly 17 undergoes dynamic analysis to insulate the vibration received from the road surface when designing the suspension system of the vehicle and to dissipate the impact energy in the optimal condition, and then the position of the coupling point is determined. The assembly 17 is usually installed to coincide with the kingpin center line K, as shown in FIG.

Here, the distance between the point where the king pin center line K and the ground G meet and the point where the tire center line T and the ground G shown in FIG. 2 meet is referred to as a king pin offset D. In FIG. The illustrated suspension is a state in which the vehicle is traveling only without bump and rebound, that is, the king pin offset D is zero.

In addition, the angle of contact with the ground is changed according to the driving state of the vehicle and the state of the road. Accordingly, the position where the kingpin center line K and the tire center line T meet also changes. Accordingly, the king pin offset (D) is also changed while changing as shown in FIG.

On the other hand, the strut assembly 17 is installed so that when the king pin offset (D) is zero (zero) its extension line coincides with the point where the tire center line (T) and the ground (G) meet. In the optimum condition, the conventional strut assembly 17 has an extension line when the king pin offset D is changed due to the upper and lower ends of the strut assembly 17 fixed to the upper arm 15 and the lower arm 14, respectively. As shown in FIG. 2, the tire center line (T) and the ground (G) do not coincide with the point where they meet, and thus, the impact energy may not be sufficiently absorbed under optimum conditions, resulting in poor ride comfort and adjustment stability. there was.

Of course, when designing the suspension system of the vehicle, the strut assembly 17 undergoes dynamic analysis so as to respond to the change of the kingpin offset D to some extent so that both ends are fixed to the lower arm 14 and the upper arm 15. However, if the amount of change in the kingpin offset (D) is severe depending on the driving condition of the vehicle and the road surface condition of the road, the impact energy may not be absorbed sufficiently to increase the damage of the vehicle and reduce the ride comfort of the occupant. Deterioration of the coordination stability of the car caused a traffic accident.

Accordingly, the present invention has been made to solve the above problems, so that when the kingpin offset is changed according to the driving state of the vehicle and the road surface state of the road, the extension line of the strut assembly always coincides with the point where the tire center line meets the ground. The suspension position of the strut assembly enables the absorbing energy transmitted from the road surface to be optimally absorbed by the variable position of the strut assembly, thereby improving the driver's riding comfort and improving the steering stability of the vehicle. The purpose is to provide.

Suspension device of the present invention for achieving the above object, the offset change amount sensor for detecting the change amount of the kingpin offset is mounted on the wheel, and the offset direction and change amount of the wheel receiving the signal detected from the offset change amount detection sensor The electronic control unit for determining the degree of the and the one end of the strut assembly coupled to the lower arm and the upper arm, respectively, under the control of the electronic control unit when the king pin offset is changed while forcibly moving horizontally with respect to the ground And strut assembly adjusting means for always matching the extension line of the strut assembly with the point where the tire center line meets the ground.

1 to 3 is a schematic longitudinal cross-sectional view and conceptual view for explaining the structure of a double wishbone suspension system is generally used,

4 is a schematic conceptual view illustrating a suspension device according to the present invention;

5 and 6 are a schematic perspective view and a longitudinal sectional view for explaining the strut assembly adjusting means according to the present invention,

7 and 8 are longitudinal cross-sectional views for explaining the operating state of the suspension according to the present invention.

<Description of Symbols for Main Parts of Drawings>

1-wheel 14-lower arm

14a-long groove 14b-bottom

15-Upper Arm 17-Strut Assembly

21-Offset change detection sensor 23-Electronic control unit

30-strut assembly adjusting means 31-strut mounting brackets

32-1st motor 33-2nd motor

34-1st wire 35-2nd wire

36-Bearing D-Kingpin Offset

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is a schematic conceptual view illustrating a suspension device according to the present invention, which will be described with the same reference numeral to the same portion as the conventional structure.

As described above with reference to FIG. 1, the double wishbone suspension according to the present invention has a knuckle 11 coupled to a wheel of left and right wheels 1 and a ball joint 12 at upper and lower ends of the knuckle 11. 13) the lower arm 14 and the upper arm 15 coupled to each other to adjust the movement of the wheel, and both ends thereof are installed to be connected to the lower arm 14 to enhance the strength and rigidity of the underbody. The cross member 16 which prevents the vehicle body from swaying sideways, the coil spring 17a which alleviates the impact received from the road surface, and the shock absorber 17b which suppresses the free vibration of this coil spring 17a to improve ride quality. Strut assembly (17) is installed in the longitudinal axis so that the upper and lower ends are connected to the upper arm (15) and the lower arm (14), respectively, bound to the lower arm (14) and upper arm (15) The stopper 18, the rebound stopper 19, etc. are comprised.

On the other hand, the strut assembly 17 is subjected to a dynamic analysis to insulate the vibration received from the road surface in the design of the suspension system of the vehicle and to dissipate the impact energy to the optimum conditions, and then the position of the coupling point is determined. As shown in Figure 4 is installed to match the king pin center line (K).

Here, the distance between the point where the king pin center line (K) and the ground (G) meets and the point where the tire center line (T) and the ground (G) meets is called a king pin offset (D), the suspension shown in FIG. The vehicle is driving straight without bump or rebound, that is, the king pin offset D is zero.

On the other hand, the wheel 1 is in contact with the ground (G) is changed according to the driving state of the vehicle and the state of the road, accordingly, the position where the king pin center line (K) and the tire center line (T) meet and accordingly The kingpin offset (D) is also changed by increasing and decreasing, the suspension device according to the present invention even if the kingpin offset (D) is increased or decreased as the extension line (S) of the strut assembly 17 is the tire center line (T) and the ground ( It is configured to include a separate means for forcibly moving one end of the strut assembly 17 so that it always coincides with the point where G) meets.

That is, the suspension according to the present invention is offset offset amount detecting sensor for detecting the change amount of the king pin offset (D) is mounted to the wheel (1) as shown in Figures 4 to 6 in addition to the configuration described above with reference to FIG. 21, an electronic control unit 23 (ECU) for determining the offset direction of the wheel 1 and the degree of the change amount by receiving the signal detected from the offset change amount detecting sensor 21, and a king pin offset D. When changed, one end of both ends of the strut assembly 17 coupled to the lower arm 14 and the upper arm 15, respectively, under the control of the electronic control unit 23 is forcedly moved in the horizontal direction with respect to the ground G. It is configured to further include a strut assembly adjusting means 30 so that the extension line of the strut assembly 17 always coincides with the point where the tire center line T and the ground G meet.

Here, the strut assembly adjusting means 30 has a strut assembly 17, one end of which is hinged to the upper arm 15, and the other end of the strut mounting bracket 31 is wrapped around the strut mounting bracket 31, and the strut mounting bracket 31. ) Is coupled to the other end of the strut assembly 17 is coupled to the lower arm 14 is formed with a long groove (14a) to be reciprocating in the horizontal direction with respect to the wheel (1), and both ends of the long groove (14a) First and second motors 32 and 33 which are respectively installed and selectively driven according to control signals of the electronic control unit 23, and pulleys 32a and 33a and struts of the first and second motors 32 and 33, respectively. It comprises a first and second wires (34, 35) for connecting predetermined portions of the mounting bracket (31), respectively.

In addition, when the strut mounting bracket 31 is moved along the long groove 14a by the driving force of the first and second motors 32 and 33, the strut assembly 17 is connected to the upper arm 15 by the hinge coupling point. The bottom surface 14b of the long groove 14a is formed in the shape of an arc so as to rotate in the center, and thus the outer circumferential surface of the strut mounting bracket 31 also has a circular arc so as to minimize friction with the bottom surface 14b. It is a structure formed in a shape.

In addition, the strut mounting bracket 31 in contact with the bottom surface 14b of the long groove 14a has a structure in which a plurality of bearings 36 are press-fitted to allow free rotation.

On the other hand, if any one of the first and second motors (32, 33) 32 is driven to rotate in the release direction of the wire 34 by the control of the electronic control unit 21, the other one of the motor (33) ) Is driven to rotate in the winding direction of the wire 35.

Therefore, as shown in FIG. 6, when the kingpin offset D is zero, that is, the vehicle is traveling in a straight line without bump or rebound, the vehicle is driven in accordance with the driving conditions. Or a kingpin offset D is increased while rolling (bump or rebound phenomenon) occurs in the vehicle so that the wheel 1 unfolds outward with respect to the body (not shown) as shown in FIG. The offset change amount detecting sensor 21 detects the direction in which the kingpin offset D is made and the degree of the change amount, and transmits a detection signal to the electronic control unit 23. The electronic control unit 23 detects the offset change amount detecting sensor. The signals detected from 21 are discriminated to control the driving of the first and second motors 32 and 33, respectively.

That is, the first motor 32 is driven to rotate in the direction in which the first wire 34 can be wound around the pulley 32a by the control of the electronic control unit 23, and the second motor 33 is In proportion to the amount of rotation of the first motor 32, the second wire 35 is driven to rotate in a direction in which the second wire 35 can be released from the pulley 33a.

When the first wire 34 is wound by the driving of the first and second motors 32 and 33, on the contrary, the second wire 35 is unwound by the length of the winding of the first wire 34. The strut mounting bracket 31 connected to the first and second wires 34 and 35 has a bottom of the long groove 14a formed in the lower arm 14 around the hinge coupling point of the upper arm 15 and the strut assembly 17. The wheels 1 are moved along the surface 14b by the gaps spaced from the body, and thus the extension line of the strut assembly 17 is changed even if the king pin offset D is increased according to the driving condition and the road surface condition of the vehicle. S) can always coincide with the point where the tire center line T and the ground G meet.

As such, even when the king pin offset D of the vehicle is changed to increase, when the extension line S of the strut assembly 17 can always match the point where the tire center line T and the ground G meet, The impact energy is sufficiently absorbed in the optimum condition by the strut assembly 17, which not only improves the riding comfort of the occupant, but also prevents the adjustment stability from being deteriorated in advance, thereby contributing to the safe operation. do.

Here, the first and second motors 32 and 33 are not driven after the change amount of the king pin offset D is terminated, but are driven together when the king pin offset D is changed, and thus the suspension value according to the present invention. The device will always be able to respond to the amount of change in the kingpin offset D in optimum conditions.

On the other hand, when the turning drive is terminated or the rolling phenomenon is eliminated and the vehicle travels straight in the optimal state, the increased king pin offset D is decreased again and becomes zero, which coincides with the king pin center line K. In this case, the first and second motors 32 and 33 are also driven together in proportion to the amount by which the king pin offset D is reduced by the control of the electronic control unit 23 to extend the strut assembly 17. (S) always coincides with the point where the tire center line (T) meets the ground (G).

In addition, if the king pin offset D is reduced while the wheel 1 is pulled toward the body as shown in FIG. 8, the first and second motors 32 and 33 may increase the king pin offset D. When driven in the direction opposite to the driving direction, the strut mounting bracket 31 is moved toward the body along the bottom surface 14b of the long groove 14a in proportion to the interval at which the king pin offset (D) is reduced. While the extension line S of the strut assembly 17 is always coincident with the point where the tire center line T and the ground G meet, the impact energy generated during driving as described above is optimal by the strut assembly 17. It is sufficiently absorbed under the conditions, which not only improves the riding comfort of the occupant, but also prevents the adjustment stability in advance, thereby contributing to the safe operation.

As described above, according to the present invention, when the king pin offset of the vehicle is changed in the driving condition or the road surface, one end of the strut assembly is moved together in proportion to the change amount of the king pin offset, so that the extension line of the strut assembly is moved with the tire center line. Not only can it be consistent with the point where the ground meets, but also the impact energy generated during driving is sufficiently absorbed by the strut assembly under the optimal conditions, and the passenger's riding comfort and adjustment stability are improved, thereby improving the consumer's preference for the vehicle. And there is an effect of improving the marketability.

Claims (5)

The offset change detection sensor 21 mounted on the wheel 1 to detect the change amount of the king pin offset D, and the offset direction change amount of the wheel 1 by receiving the signal detected from the offset change detection sensor 21. The strut assembly coupled to the lower arm 14 and the upper arm 15 according to the control of the electronic control unit 23 when the king pin offset D is changed, and the electronic control unit 23 for determining the degree of 17. In order to make the extension line S of the strut assembly 17 coincide with the point where the tire center line T meets the ground G while forcibly moving one end of both ends of the 17) horizontally with respect to the ground G. Suspension device of the vehicle comprising a strut assembly adjusting means (30). The strut assembly adjusting unit (30) of claim 1, wherein the strut assembly adjusting means (30) is hinged to the upper arm (15) and the strut mounting bracket (31) wrapped around and coupled to a predetermined shape of the strut mounting bracket (31) at the other end thereof. The other end of the strut assembly 17 to which the mounting bracket 31 is coupled is inserted and coupled to the lower arm 14 having the long groove 14a formed to be reciprocated in the horizontal direction with respect to the wheel 1, and the long groove 14a. First and second motors 32 and 33 installed on both ends of the first and second motors 32 and 33 selectively driven according to control signals of the electronic control unit 23, and pulleys 32a and 32 of the first and second motors 32 and 33, respectively. 33a) and a first and second wires (34, 35) for connecting the predetermined portions of the strut mounting bracket (31), respectively. The strut assembly (17) with the upper arm (15) when the strut mounting bracket (31) is moved along the long groove (14a) by the driving force of the first and second motors (32, 33). Suspension device for a vehicle, characterized in that the bottom surface (14b) of the long groove (14a) is formed in an arc so as to rotate around the hinge point. 4. A suspension apparatus according to claim 3, wherein a plurality of bearings (36) are press-fitted to the strut mounting bracket (31) in contact with the bottom surface (14b) of the long groove (14a). According to claim 2, wherein any one of the first and second motors (32, 33) 32 is driven to rotate in the release direction of the wire 34, the other one motor 33 is the wire 35 Suspension of the vehicle, characterized in that driven to rotate in the winding direction of the.