KR20040101818A - Electro-motive actuator for controling rear wheel toe angle of the vehicles - Google Patents

Abstract

PURPOSE: An electric actuator for controlling the toe angle of a rear wheel for a vehicle is provided to increase resolving power of an encoder disc and to reduce the total volume of an encoder by forming a circular disc of the encoder like a magnet ring shape by a polarizing process and detecting a magnet of a magnet disc by a hall sensor. CONSTITUTION: An electric actuator mounted at one end of a rear cross member to secure stability of a traveling vehicle by controlling toe angle of a rear wheel is composed of a DC(Direct Current) motor(40) combined to a rear end of a housing(45); a ball screw(42) joined rotatively in a hollow hole(58) of the housing by the DC motor; a bearing(46) press-fitting between the ball screw and the housing; a ball nut(61) screw-combined to the ball screw; a rod(41) disposed at the ball nut in the front end direction of the housing to rectilinearly move; and an encoder(10) installed at the end of the ball screw in the rotational direction to control displacement of the rod. The encoder comprises a magnet disc(11) having N or S pole formed alternatively around a concentric disc by a polarizing process and a hall sensor(12) for detecting a position of the rod by sensing the polarity of the magnet disc.

Description

ELECTROL-MOTIVE ACTUATOR FOR CONTROLING REAR WHEEL TOE ANGLE OF THE VEHICLES

The present invention relates to a rear wheel toe angle control device which secures stability of a vehicle while driving by varying a toe angle of a rear wheel of an automobile actively using an electric actuator according to a driving state of a vehicle, and more particularly, to an encoder. Of circular disks in the magnetizing process by magnetizing process, and the Hall sensor detects the magnet disks to increase the resolution of the encoder disks, and the electric actuator for rear wheel toe angle control that can greatly reduce the total volume of the encoder. will be.

Suspension in a vehicle exists between a vehicle body and a wheel, and is a device that connects the two rigid bodies using one or more links, and 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 should be provided, and third, it should be possible to secure the stability of the vehicle during turning and braking driving by maintaining the vertical load on the tire ground plane at an appropriate level when driving on irregular roads.

Meanwhile, in order to solve the problem of inadequate adjustment due to a tendency to toe out of the vehicle, the AGCS has recently expanded the length of the rear wheel control arm and induces the rear wheel to toe in turning to improve steering stability. A rear wheel toe angle controller with Active Geometry Controlled System has been developed.

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

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 is installed at one end of the rear cross member 31 to convert the rotational motion of the DC motor 40 into linear reciprocating motion, and the rear wheel 30 according to the driving of the electric actuator 36. And a link mechanism 37 for adjusting the toe angle of

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.

Meanwhile, the electric actuator 36 includes a DC motor 40 coupled to the rear end of the housing 45, a ball screw 42 rotatably coupled to the inside of the hollow hole 58 of the housing 45, and a ball. A ball nut 61 screwed to the screw 42, a rod 41 mounted to the ball nut 61 in the direction of the front end of the housing 45 and coupled to allow the linear movement, a limit sensor 43, The encoder 44 etc. are comprised.

One end of the ball screw 42 is splined with the motor shaft 51 of the DC motor 40 so that 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 moves in a linear direction according to the rotational movement of the ball 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. The linear motion of the rod 41 is a projection (not shown) projecting at one end of the rod 41 is slidingly coupled to the guide 62 provided at the lower end of the hollow portion 58, so that the rotational movement of the ball screw 42 is It is transmitted by the linear motion of the rod 41. The ball screw 42 is pressed into the housing 45 via the bearing 46 and rotated in a fixed state, and the bearing 46 is fixed to the housing 45 by the bearing stopper 47.

A first opening 53 for mounting a circuit board on which the photo interrupter 48 is installed is formed at the upper end of the housing 45, and the photo interrupter 48 detects a toothed slit of the encoder disk 49 to generate an electrical pulse. Output The encoder disk 49 is installed and rotated on the motor shaft 51 of the DC motor 40.

In addition, a second opening 54 for mounting a circuit board on which the limit sensor 43 is installed is formed at an upper end of the housing 45, and the limit sensor 43 is formed at the initial position (inset position) and the final position of the rod 41. It is installed in two places to limit the position (drawed position). The limit sensor 43 is composed of two optical sensors 43a and 43b, and the optical sensors 43a and 43b reflect light by scanning light to the reflecting portion 43c provided at one end of the rod 41. Detect.

On the other hand, the rod stopper 59 is installed in the hollow hole 58 of the housing 45 in the rotational orthogonal direction at the starting position of the thread forming portion of the ball screw 42 to block the rod 41 from being pulled in any further. .

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.

In the electric actuator 36 configured as described above, the motor shaft 51 is rotated forward and backward by the driving of the DC motor 40, the encoder disk 49 connected to the motor shaft 51 rotates, and the motor shaft 51 is rotated. The rod 41 linearly moves by the rotational movement of the spline-coupled ball screw 42. 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 sensor 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 by the toe angle control of the outer ring during the turning of the vehicle to the toe-in by the driving of the electric actuator 36 to stabilize the vehicle. And running stability can be obtained.

On the other hand, in order to improve the position control capability of the electric actuator 36, the diameter of the encoder disk 49 is maintained so as to form a large number of slits, but the conventional encoder disk 49 is maintained in the entirety of the electric actuator 36. Since the volume must be considered, there was a limit to increasing the diameter.

In addition, as shown in FIG. 3, the conventional photointerrupter 48 includes at least two sensors having a light emitting part and a light receiving part at both ends with respect to the encoder disk 49 in the rotation direction. 48) There was a disadvantage of increasing its volume.

Therefore, the present invention is to solve the above disadvantages, by forming the circular disk of the encoder in the magnet ring shape by the magnetizing process, by detecting the magnet of the magnet disk with a Hall sensor can increase the resolution of the encoder disk, An object of the present invention is to provide an electric actuator for controlling the rear toe angle, which can greatly reduce the total volume of the encoder.

In order to achieve the object of the present invention, an electric actuator is installed at one end of a rear cross member to adjust the toe angle of the rear wheel of the vehicle to secure stability of the vehicle being driven, and the electric actuator is provided at the rear end of the housing. A DC motor coupled to the ball screw, a ball screw rotatably coupled by the DC motor in the hollow hole of the housing, a bearing press-fitted between the ball screw and the housing, a ball nut screwed onto the ball screw, and a front end of the housing In the rear wheel toe angle control device comprising a rod installed in the ball nut in a negative direction and coupled to enable linear movement, and an encoder installed in a rotational direction at one end of the ball screw to control the displacement of the rod, wherein the encoder is a concentric circle. A magnet disk in which an N pole or an S pole is alternately formed in a magnetizing process around a disc of a shape; It characterized in that it comprises a Hall sensor that can detect the polarity of the magnet disk to determine the location of the rod.

1 is a block diagram showing a rear wheel toe angle control apparatus according to the prior art.

Figure 2 is a cross-sectional view showing the electric actuator for rear wheel toe angle control according to the prior art.

Figure 3 is a front view showing an encoder according to the prior art.

4 is a cross-sectional view showing the electric actuator for controlling the rear toe angle according to the present invention.

5 is a front view of the encoder according to the present invention.

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

10; Encoder 11; Magnet disk

12; Hall sensor 40: DC motor

41: rod 42: ball screw

43; Limit Sensor 45: Housing

46; Bearing 51: motor shaft

53: first opening 54: second opening

61: Ball Nut

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

4 is a cross-sectional view showing the electric actuator in the present invention, Figure 5 is a front view showing the encoder according to the present invention. On the other hand, since the other components except the encoder is the same configuration as the prior art will be described with the same reference numerals.

The rear wheel toe angle control device according to the present invention comprises 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, and a link mechanism for adjusting the toe angle of the rear wheel according to the driving of the electric actuator. do.

The link mechanism is hinged to one end of the rear cross member, one end of which is linked to the electric actuator, and the other end of which is connected between the control lever, which is linked to the auxiliary link, and between the other end of the control lever and the rear knuckle to drive the driving force of the electric actuator. It consists of an auxiliary link to the rear wheels.

As shown in FIG. 4, the electric actuator 36 according to the present invention is for controlling the linear displacement by using the forward and reverse rotation of the DC motor 40, and is coupled to the rear end of the housing 45. 40, a ball screw 42 rotatably coupled inside the hollow hole 58 of the housing 45, a ball nut 61 screwed into the ball screw 42, and a front end of the housing 45. The rod 41 is installed in the ball nut 61 in the negative direction, and is coupled to the linear motion so as to be able to move linearly, and the limit sensor 43, the encoder 44, the housing 45, and the like.

The rod 41 operating direction of the electric actuator 36 according to the present invention was defined as the case of operating in the direction of the body of the electric actuator 36 in the forward direction, and the opposite direction to the reverse direction.

The ball nut 61 is fixedly installed at one end of the rod 41 according to the present invention, and the male threaded portion of the ball screw 42 is engaged with the female threaded portion of the ball nut 61 to be screwed to the output shaft of the DC motor 40. It is directly connected with and has a rotation speed ratio of 1: 1. The rod 41 and the ball nut 61 are linearly moved by the ball screw 42. The ball screw 42 is pressed into the bearing 46 and rotated in a fixed state.

The rod stopper 59 is installed in the hollow hole 58 of the housing 45 in the rotational perpendicular direction at the starting position of the threaded portion of the ball screw 42 to force the rod 41 to move further in the forward direction. Restrict. The DC motor 40 is coupled to the rear end of the housing 45, and the first opening 53 for installing the hall sensor 12 and the limit sensor 43 for installing the hall sensor 12 are provided at the upper end of the housing 45. 2 openings 54 are formed.

The motor shaft 51 and the ball screw 42 of the DC motor 40 are spline-coupled so that the driving force of the DC motor 40 is transmitted to the ball screw 42.

Particularly, according to the present invention, the encoder 10 has a magnet disk 11 in which N poles or S poles are alternately formed in a magnetization process around a disk having a concentric shape, and a rod (S) sensing the polarity of the magnet disk 11. It characterized in that it comprises a Hall sensor 12 that can grasp the position of 41).

The masnet disk 11 according to the present invention is not a sawtooth slit structure that should be machined as it is conventionally, but a magnetically magnetized structure. High resolution can be ensured and precise position control of the rod 41 can be implemented.

In addition, the Hall sensor 12 according to the present invention can be much smaller in volume than the conventional photo interrupter structure, which can contribute to reducing the total volume of the electric actuator.

According to the present invention configured as described above, the electric actuator 36 rotates forward / reversely by the driving of the DC motor 40, and is connected to the ball screw 42 splined with the motor shaft 51. The rotational force is transmitted, the encoder disk 49 provided at one end of the motor shaft 51 rotates, and the rod 41 moves in a linear direction by the rotational movement of the ball screw 42. 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 sensor 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 to control the unstable posture by the toe angle control of the outer ring during the turning of the vehicle to the toe-in by the driving of the electric actuator to obtain stable posture control and running stability of the vehicle. have.

Therefore, according to the present invention, the circular disk of the encoder is formed in a magnet ring shape by the magnetizing process, and the hall sensor can detect the magnet of the magnet disk to increase the resolution of the encoder disk, and greatly reduce the total volume of the encoder. Can be.

What has been described above is just one embodiment of the electric actuator for controlling the rear toe angle according to the present invention, and the present invention is not limited to the above-described embodiment, and as claimed in the following claims, the gist of the present invention. Without departing from the technical spirit of the present invention to the extent that any person of ordinary skill in the art to which the present invention pertains various modifications can be made.

Claims (1)

An electric actuator is installed at one end of the rear cross member to adjust the toe angle of the rear wheel of the vehicle to secure stability of the vehicle being driven, and the electric actuator is a DC motor coupled to the rear end of the housing, A ball screw rotatably coupled to the inside of the hole by a DC motor, a bearing press-fitted between the ball screw and the housing, a ball nut screwed into the ball screw, and a ball nut installed in the direction of the front end of the housing, for linear movement In the rear wheel toe angle control device comprising a rod coupled to enable and an encoder installed in one rotational direction of the ball screw to control the displacement of the rod, The encoder is a magnet disk in which an N pole or an S pole is alternately formed by a magnetizing process around a disc of a concentric circle, and Hall sensor which can detect the position of the rod by sensing the polarity of the magnet disk Electric actuator for rear wheel toe angle control comprising a.