KR20030087223A - Rear wheel toe angle control systems of the vehicles - Google Patents

Abstract

PURPOSE: A toe angle control device of rear wheels for a vehicle is provided to secure stability of the traveling vehicle by varying the toe angle of the rear wheels through an electromotive actuator control unit. CONSTITUTION: A toe angle control device of rear wheels for a vehicle includes an electromotive actuator installed to one end of a rear cross member to convert the rotary motion of a DC motor(40) into the linear reciprocation motion, a linkage controlling the toe angle of the rear wheels according to the operation of the electromotive actuator, a third opening part(63) installed to a bottom of a housing of the electromotive actuator, and a guide(55) coupled to the third opening part to guide the linear motion of a rod(41).

Description

REAR WHEEL TOE ANGLE CONTROL SYSTEMS OF THE VEHICLES}

The present invention relates to a tow angle control device applied to a rear wheel of a vehicle. More particularly, the toe angle of a rear wheel of a vehicle is changed by using an electric actuator actively according to the driving state of the vehicle. It relates to a toe angle control device to ensure stability.

Suspension in a vehicle exists between a vehicle body and a wheel, and connects these two rigid bodies using one or more links. The suspension is composed of a trailing arm, a knuckle and a control arm. .

Such a suspension device firstly effectively blocks the irregular input of the road surface generated while driving the vehicle to provide a comfortable riding comfort of the occupant, and secondly, controls the vehicle body movement caused by the driver's driving behavior and the curvature of the road. Convenience must be provided, and third, the basic condition that the vertical load on the tire ground surface should be maintained at an appropriate level when driving on irregular roads must be satisfied to ensure the stability of the vehicle during turning and braking driving.

On the other hand, in order to solve the problem of toe out tendency when turning the vehicle, the rear control arm has been recently stretched to improve the steering stability by turning the rear wheel to Toe In when turning. The rear wheel toe angle control device (AGCS System; Active Geometry Controlled System) has been developed.

1 is a perspective view of a rear wheel suspension equipped with the AGCS system of the prior art, Figure 2 is a cross-sectional view showing the main components of the rear toe angle control device according to the prior art.

In FIG. 1, the knuckle 2 supporting the rear wheel 1 is connected to the rear cross member (not shown) of the vehicle body by the first and second control arms 4, 6 in the vehicle width direction, and the length of the vehicle body. It is connected by a trailing arm 8 in the direction.

The spring 3 and the shock absorber 5 are integrally assembled so that the suspension is supported by the knuckle 2 and the vehicle body to damp its own up and down vibrations.

In particular, the length of the 2nd control arm 6 in the back is comprised by the structure which can expand and contract using a hydraulic control mechanism.

The hydraulic actuator 7 consists of a cylinder 11 integrally formed on the outer arm 10 and a piston 14 disposed at the tip of the outer arm 13 that penetrates the cap 12 of the cylinder 11. .

Hydraulic ports 15 and 16 are formed at both ends of the cylinder 11, and pistons 14 are provided at the center of the cylinder 11 in the chambers 17 and 18, which are divided into two sides by the pistons 14. The elastic members 19 and 20 which exert an elastic force to be positioned are supported.

The hydraulic pressure supplied to the hydraulic ports 15 and 16 is regulated by the direction change valve 21, and the direction change valve 21 is an electronic control unit according to the input signals of the vehicle speed sensor 22 and the steering angle sensor 23. It is comprised so that it may be controlled by (ECU).

That is, by controlling the direction switching valve 21 in accordance with the logic set in the electronic control unit in accordance with the vehicle driving conditions to extend the length of the control arm 6 to control the rear wheel 1 to maintain the toe-in state when turning, Active driving stability is achieved.

However, such a conventional rear wheel toe angle control device has a disadvantage in that the response is slow and the application space is limited due to a narrow space for mounting on the vehicle by using a complicated hydraulic control mechanism.

Accordingly, the present invention is to solve the above disadvantages, it is possible to ensure the stability of the driving vehicle by varying the toe angle of the rear wheel by using a linear actuator-driven electric actuator control mechanism. It is an object of the present invention to provide a rear wheel toe angle control device.

In order to achieve the above object, the present invention provides a rear wheel toe angle control device of a vehicle for securing stability of a driving vehicle by varying a toe angle of a rear wheel of a vehicle, the rear cross member being installed at one end of a DC motor. An electric actuator for converting the rotary motion into a linear reciprocating motion, and a link mechanism for adjusting the toe angle of the rear wheel according to the drive of the electric actuator, the electric actuator is provided with a third opening at the lower end of the housing, A guide for guiding the linear motion of the rod is characterized in that it is coupled.

1 is a perspective view of a rear wheel suspension equipped with a AGCS system of the prior art.

Figure 2 is a cross-sectional view showing the main components of the rear wheel toe angle control device according to the prior art.

Figure 3 is a block diagram showing a rear wheel toe angle control apparatus according to the present invention.

4 is a partial cross-sectional view showing the electric actuator according to the present invention.

5 is a front sectional view of a housing according to the present invention;

6 is a top plan view of a housing according to the present invention;

7 is a right side view of the housing according to the invention;

8 is a perspective view of a guide according to the present invention;

<Description of the symbols for the main parts of the drawings>

30: rear wheel 31: cross member

32: knuckle 33: control arm

34: spring 35: shock absorber

36: electric actuator 37: link mechanism

38: auxiliary link 39: control lever

40: DC motor 41: rod

42: ball screw 43: limit switch

45 housing 46 bearing

47: bearing stopper 48: photo interrupter

49: encoder disc

51: motor shaft 52: coupling

53: first opening 54: second opening

58: hollow hole (housing) 59: rod stopper

60: mounting bracket 61: ball nut

63: third opening

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

3 is a block diagram showing a rear wheel toe angle control apparatus according to the present invention. As shown, the rear wheel 30 is suspended from the rear cross member 31, the knuckle 32 supporting the rear wheel 30 is supported by the control arm 33 in the vehicle width direction, and the longitudinal direction of the vehicle body. Is supported by a trailing arm, not shown, and is supported by a spring 34 and shock absorber 35 in the vertical direction.

The rear wheel toe angle control device according to the present invention is installed at one end of the rear cross member 31 and converts the rotational motion of the DC motor into a linear reciprocating motion, and the rear wheel according to the driving of the electric actuator 36 ( And a link mechanism 37 for adjusting the toe angle of 30.

The link mechanism 37 is hingedly coupled to one end of the rear cross member 31, one end thereof being coupled to the electric actuator 36, and the other end thereof to be connected to the auxiliary link 38 by a control lever 39. It is composed of an auxiliary link 38 connected between the other end of the lever 39 and the rear wheel knuckle 32 to transmit the driving force of the electric actuator 36 to the rear wheel.

The electric actuator 36 according to the present invention includes a DC motor 40 coupled to the rear end of the housing 45 as shown in FIG. The ball screw 42 rotatably coupled to the inside of the hollow hole 58 of the 45, the ball nut 61 screwed to the ball screw 42, the ball nut (in the direction of the front end of the housing 45) It is composed of a rod 41, a limit switch 43, an encoder 44, a housing 45 and the like installed on the 61 and coupled to allow a linear movement.

The electric actuator 36 can be driven with a voltage of DC 10-16V as an input, and when a load of 20kgf and 60kgf is applied in the direction of the rod 41 of the actuator 36 at a rated input voltage of 13.5V, respectively, 105 mm / s It can drive at speeds over 65mm / s.

On the other hand, the operating range is the length of the linear section operated by the rotation of the motor 40, but the controllable range is determined as the distance between both ends of the limit switch 43.

Moreover, unlike the driving force of the mechanism with respect to a load, it can endure an axial load of 260 kgf as strength with respect to an external load.

The rod 41 operating direction of the electric actuator 36 according to the present invention is defined as a positive direction when operating in the direction of the right side, that is, the actuator 36 body in Figure 3, the opposite direction was defined as the reverse direction.

As shown in FIG. 4, the rod 41 and the ball screw 42 according to the present invention have a ball nut 61 fixedly installed at one end of the rod 41 in a ball screw manner, and The male threaded portion of the ball screw 42 is engaged with the female threaded portion and screwed, and is directly connected to the output shaft of the DC motor 40 to have a rotation speed ratio of 1: 1. The rod 41 and the ball nut 61 are linearly moved by the ball screw 42. When the lead of the ball screw 42 is 2 mm, the rod 41 per revolution of the ball screw 42 moves 2 mm. The ball screw 42 is pressed into the bearing 46 and rotates in a fixed state, and the bearing 46 is fixed to the housing 45 by the bearing stopper 47 and rotates together with the ball screw 42. work out.

5 to 7 show a housing 45 according to the invention. The coupling structure of the electric actuator 36 according to the present invention will be described with reference to FIG. 3 described above.

The rear end of the housing 45 is coupled to the DC motor 40, the motor shaft 51 of the DC motor 40 is located in the center of the housing (45). The ball screw 42 is rotatably coupled inside the hollow hole 58 of the housing 45, and one end of the ball screw 42 is connected to the motor shaft 51 and the coupling 52 of the DC motor 40. Coupled to the rotational movement of the DC motor 40 is transmitted to the ball screw 42. Meanwhile, the ball nut 61 screwed with the ball screw 42 linearly moves according to the rotational movement of the lease screw 42. The linear motion of the ball nut 61 linearly moves the rod 41 protruding in the direction of the front end of the housing 45. That is, the rotational movement of the ball screw 42 is transmitted to the linear movement of the rod 41.

A first opening 53 for installing the photo interrupter 48 is formed at the upper end of the housing 45, and the photo interrupter detects the sawtooth slit of the disk of the encoder 44 and outputs an electrical pulse. The encoder 44 disc is installed and rotated on the motor shaft 51 of the DC motor 40.

In addition, a second opening 54 for installing the limit switch 43 is formed at the upper end of the housing 45, and the limit switch 43 is respectively set to limit the initial position and the maximum transfer position of the rod 41. It is installed one by one.

In particular, according to the present invention, the third opening 63 is installed at the lower end of the housing, and the guide 55 for guiding the linear movement of the rod is coupled to the third opening 63. 8 is a perspective view showing a guide according to the present invention. As shown, the concave portion 56 is formed in the longitudinal direction on the upper surface of the guide 55, the rod 55 is coupled to the concave portion 56 of the guide 55 to guide the slide 55 The protrusion part 57 is formed in the end of the rod 41 corresponding to the recessed part 56 of (circle).

On the other hand, in the hollow hole 58 of the housing 45, the rod stopper 59 is installed at the starting position of the thread forming portion of the ball screw 42 in the direction perpendicular to the rotation so that the rod 41 no longer moves in the forward direction. Forced to restrict

The mounting bracket 60 is coupled to the lower portion of the housing 45 so that the electric actuator 36 can be easily fixed to one end of the rear cross member 31.

According to the present invention configured as described above, the electric actuator 36 has the motor shaft 51 reversely rotated by the drive of the DC motor 40, the coupling 52 and the encoder disk 49 connected to the motor shaft 51. ) Rotates, and the rod 41 linearly moves by the rotational movement of the ball screw 42 connected to the coupling 52. The linear displacement measurement of the rod 41 is measured by the ratio of the amount of rotation of the encoder disk 49 and the pitch size formed in the rod 41. At this time, the limit switch 43 regulates the operating range of the rod 41 in a linear motion.

Therefore, the electric actuator 36 is connected and fixed to the auxiliary link 38 to control the unstable posture caused by the toe-out generated when the vehicle turns, to the toe-in by the driving of the electric actuator 36 to control the stable posture of the vehicle and Running stability can be obtained.

In the above description, it should be understood that those skilled in the art can only make modifications and changes to the present invention without changing the gist of the present invention as it merely illustrates a preferred embodiment of the present invention.

Therefore, according to the present invention, by employing an electric actuator in place of the conventional complicated hydraulic control mechanism, the response can be improved and the number of component parts can be drastically reduced, so that it can be easily mounted even if the vehicle mounting space is small.

Claims (3)

In the rear wheel toe angle control device of the vehicle to secure the stability of the driving vehicle by varying the toe angle of the rear wheel of the vehicle, An electric actuator installed at one end of the rear cross member and converting the rotational motion of the DC motor into a linear reciprocating motion, It includes a link mechanism for adjusting the toe angle of the rear wheel according to the drive of the electric actuator, The rear wheel toe angle control device of a vehicle, characterized in that the guide is installed on the lower end of the housing of the electric actuator is coupled to guide the linear movement of the rod. The method of claim 1, The guide is a rear wheel toe angle control device of a vehicle, characterized in that the concave portion is formed in the longitudinal direction so that the rod is unevenly coupled to slide. The method of claim 1, The rear wheel toe angle control device of a vehicle, characterized in that the protrusion is formed to be unevenly coupled to one end of the rod corresponding to the guide recess.