KR100723725B1 - Motor Driven Steering System Equipped with Zerol Bevel Gear - Google Patents

Abstract

The present invention relates to a motor driven steering apparatus having a zero roll bevel gear.

The present invention includes a steering shaft for transmitting a rotational movement of the steering wheel to which the driver applies a steering force to adjust the driving direction of the vehicle; A gear unit for converting the rotational motion of the steering shaft into a linear motion; And a rack bar connected to the gear part in a round bar phenomenon to linearly move from side to side according to the rotation of the steering shaft. A link structure that receives the linear motion of the rack bar and transfers the wheel to the wheel to steer the wheel; And a steering force assist device formed on one side of an outer circumferential surface of the rack bar and assisting steering force of the driver by assisting the linear movement of the rack bar. A second bevel gear for allowing the rack bar to move linearly when the bar penetrates the center of rotation and a predetermined rotation force is applied; A first bevel gear meshed with the second bevel gear and engaged; A motor connected to the first bevel gear and applying rotational force to the first bevel gear; And an electronic control unit connected to the motor and transmitting a driving signal to the motor to rotate the motor, wherein the first bevel gear and the second bevel gear have a bevel gear angle of 0 °. It provides a motor-driven steering device for a vehicle, characterized in that the bevel gear.

According to the present invention, there is provided a motor-driven steering apparatus having a zero roll bevel gear that simplifies the support structure and improves the performance and durability of the steering apparatus by reducing the bevel gear axial force and the bevel gear central force in the bevel gear.

Bevel Gears, Steering, Automotive

Description

Motor Driven Steering System Equipped with Zerol Bevel Gear

1 is a schematic diagram of a conventional steering apparatus;

2 is a partial schematic view of a conventional steering force assist device,

3 is a schematic view of a second bevel gear provided in a conventional steering force assist device,

4 is a partial schematic view of a second bevel gear provided in a conventional steering force assist device;

5 is a partial cross-sectional view of the bevel gear provided in the conventional steering force assist device,

6 is a partial cross-sectional view of the bevel gear provided in the conventional steering force assist device,

7 is a partial cross-sectional view of the bevel gear provided in the conventional steering force assist device,

8 is a schematic view of a zero roll bevel gear in accordance with an embodiment of the present invention;

9 is a partial cross-sectional view of a zero roll bevel gear according to an embodiment of the present invention.

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

100: steering wheel 102: torque sensor

104: steering shaft 106: pinion

108: rack bar 110: steering aid

112: link structure 114: wheel

116: electronic control unit 200: motor

202: motor shaft 204: first bevel gear

206: second bevel gear 208: first ball groove

210: second ball groove 300: rotation center

302: gear tooth circle 304: pitch circle

306: gear tooth visit 308: first circle

310: second circle 312: first reference point

314: second reference point 316: first contact point

318: second contact point 320: second bevel gear

322: second bevel gear angle 324: pitch radius

400: bevel gear tangential force 402: bevel gear center force

500: bevel gear axial force 600: right angle input angle

700: pitch angle 800: zero roll bevel gear angle

802: zero roll bevel gear tangential force 804: zero roll bevel gear center force

806: Zerol Bevel Gear 808: Zerol Bevel Gear

900: Xerol Bevel Gear Axial Force

The present invention relates to a motor driven steering apparatus having a zero roll bevel gear. More particularly, the present invention relates to a motor-driven steering apparatus having a zero roll bevel gear that reduces the bevel gear axial force and the bevel gear center force in the bevel gear, thereby simplifying the supporting structure and improving the performance and durability of the steering system.

The recent technology development trend of the steering apparatus provided in the vehicle is made in the direction of pursuing the convenience of the driver at the same time, such as a soft and comfortable steering feeling with the technology such as the stability of the steering state. In accordance with this development trend, various steering assistance devices, such as hydraulic or electric, have been developed as a method for improving the steering feeling of the driver. The steering assist device provides a light and comfortable steering condition at low speeds, while providing a heavy and stable steering condition at high speeds, and cope with sudden emergencies to allow for quick steering. Make it available. Generally, a power steering device includes hydraulically driven steering devices and motor driven steering devices.

The hydraulically driven steering system receives hydraulic power from the engine to operate the hydraulic pump and relieves the operator's power by sending the hydraulic pressure produced by the hydraulic pump to the driven piston at the right amount in a timely manner according to the rotation of the steering wheel or steering shaft. give.

The electric steering aid assists the driver's steering torque by driving the motor in the electronic control device according to the driving conditions of the vehicle detected by the vehicle speed sensor and the steering torque sensor.

 The electric steering aid can be divided into various parts according to the mounting position. The column assist electric steering aid (C-EPS) connects the steering wheel of the driver's seat and the gearbox of the lower part of the vehicle. A steering force assist device having an electric motor is installed at a tube portion for fixing the steering shaft to the vehicle body to assist the rotational force of the steering wheel operated by the driver.

Rack-Assist Type Electric Power Steering System (R-EPS) is an electric motor mounted on the outer circumferential surface of a rack bar that is connected to the gearbox and moves linearly from side to side after the driver's steering force is transmitted to the lower gearbox of the vehicle. A steering force assist device provided is provided to assist the turning force of the steering wheel operated by the driver.

On the other hand, the type of changing the rotational motion of the steering shaft to the linear motion of the rack bar is classified into a rack and pinion type steering device and a ball and nut type steering device.

The dual rack-and-pinion steering system has a structure in which the steering wheel directly responds to the movement of the steering wheel because the movement of the pinion gear directly connected to the steering shaft is directly transmitted to the rack bar. It is widely used in all-wheel drive vehicles of small cars. In general, the rotational force is transmitted to the gearbox composed of the rack bar and the pinion gear through the universal joint and the hook joint included in the steering shaft, and the rotational movement of the steering shaft is converted to the linear motion of the rack bar by the rack bar and the pinion 106 gear. do.

Some R-EPS assists the driver's steering force by transmitting the rotational force of the motor to the rack bar through the bevel gear provided between the motor and the rack bar, and the bevel gear is interposed between the rotating shaft of the motor and the rack bar to transmit a relatively high torque. Spiral bevel gears are used for the purpose, and teeth are formed along the spiral curve compared to straight bevel gears. Spiral bevel gears are relatively complex and require precise dimensional tolerances, but they are widely used as an energy shearing tool for precision mechanical components because of their low noise and vibration.

1 is a schematic diagram of a conventional steering apparatus. As shown, the steering device includes a steering wheel 100, a steering shaft 104, a pinion 106, a rack bar 108, a link structure 112, a wheel 114, a steering force assist device 110, and an electronic control unit. 116 and torque sensor 102.

When the driver rotates the steering wheel 100, the steering shaft 104 is rotated, the pinion 106 formed at the end of the steering shaft 104 is configured to rotate. Since the pinion 106 meshes with the rack bar 108, when the pinion 106 rotates, the rack bar 108 linearly moves in the horizontal direction, so that the linear motion of the rack bar 108 moves through the link structure 112. Is passed to 114.

On the other hand, the torque sensor 102 is configured on the steering shaft 104 as a sensing means for assisting the driver's steering force, as the driver rotates the steering wheel 100 to generate a predetermined torque or more on the steering shaft 104. The torque sensor 102 converts this torque into an electrical signal and transmits it to the electronic control unit 116. As a result, the electronic control unit 116 generates a driving signal to operate the steering assistance device 110 provided in the rack bar 108. Accordingly, the driver's force and the force of the steering assistance aid 110 are combined to steer the wheel 114.

2 is a partial schematic view of a conventional steering force assist device. As shown, the steering aid 110 is a rack bar 108, the electronic control unit 116, the motor 200, the motor shaft 202, the first bevel gear 204 and the second bevel gear 206 It is configured to include.

The rack bar 108 includes a second bevel gear 206 having a structure that slides the outer circumferential surface of the rack bar 108. When the second bevel gear 206 rotates, the rack bar 108 moves in a horizontal direction.

The first bevel gear 204 is engaged with the second bevel gear 206, and the first bevel gear 204 is connected to the motor shaft 202 extending out of the motor 200. Therefore, when the motor 200 rotates, the motor shaft 202, the first bevel gear 204, and the second bevel gear 206 rotate to eventually move the rack bar 108 in the left and right directions.

The rack bar 108 has a round bar shape, and a first ball groove 208 is formed in a spiral shape on the outer circumferential surface thereof, and the link structure 112 receives the linear motion of the rack bar 108 and transmits the wheel bar 114 to the wheel 114 to transfer the wheels. Steer.

A second ball groove 210 is formed on the inner circumferential surface of the second bevel gear 206 and the rack bar 108 and the second bevel gear are formed so that the first ball groove 208 and the second ball groove 210 form a space. 206 is coupled, and the ball is fitted in the space thus formed, so that when a predetermined or more rotational force is applied to the second bevel gear 206, the second bevel gear 206 rotates with the ball so that the ball is the first spiral ball. The rack bar 108 moves linearly as it moves along the groove 208.

3 is a schematic view of a second bevel gear provided in a conventional steering force assist device. 3 shows a second bevel gear 206, a first reference point 312, a second reference point 314, a rotation center 300, a first circle 308, a pitch radius 324, a second reference point 314. , The second circle 310, the second bevel gear angle 322, the second bevel gear 320, the pitch circle 304, the gear tooth circle 306, the gear tooth circle 302, the first contact ( 316 and second contact 318 are shown.

As shown, the pitch circle 304 passes through the center of the second bevel gear 320, the first circle passing through the center of rotation 300 about the first reference point 312 configured on the pitch circle 304. 308 and drawing the second circle 310 passing through the center of rotation 300 about the second reference point 314, the first circle 308 and the second circle 310 is the second bevel gear ( Pass the outer circumference of 320).

Gear tooth inner circle 306 is a circle passing through the inner end of the gear tooth and gear tooth outer circle 302 is a circle passing through the outer end of the gear tooth.

The contact between the first circle 308 and the gear tooth inner circle 306 is designated as the first contact point 316, and the contact between the second circle 310 and the gear tooth outer circle 302 is designated as the second contact point 318. In this case, a line is drawn from the rotation center 300 to the first contact point 316 and a line is drawn from the rotation center 300 to the second contact point 318, and then the angle formed by the two lines is the second bevel gear angle 322. It is called.

4 is a partial schematic view of a bevel gear provided in a conventional steering force assist device. 4 shows a pitch radius 324, a second bevel gear angle 322, a pitch circle 304, a gear tooth circle 306, a gear tooth circle 302, a first contact 316, a second contact 318. ), The second bevel gear 320, the bevel gear tangential force 400 and the bevel gear central force 402.

The bevel gear tangential force 400 is a force acting in the tangential direction of the pitch circle 304, which is a portion in which the second bevel gear 206 and the first bevel gear 204 are engaged and rotated to contact the gear teeth. The central force 402 is a force acting toward the center of rotation 300 of the second bevel gear 206 while the second bevel gear 206 and the first bevel gear 204 rotate together.

5 is a partial cross-sectional view of the bevel gear provided in the conventional steering force assistance device.

The bevel gear axial force 500 is parallel to the axis of rotation 300 of the second bevel gear 206 at the pitch circle 304 where the second bevel gear 206 and the first bevel gear 204 contact. It is a force acting in one direction.

6 is a partial cross-sectional view of the bevel gear provided in the conventional steering force assistance device.

As shown, the right angle input angle 600 is an angle indicating the inclination of the second bevel gear 320 and the gear at the outer circumferential surface of the second bevel gear 320 and the center of rotation of the second bevel gear 318. It refers to the angle formed by the straight line drawn in the tooth direction.

7 is a partial cross-sectional view of the bevel gear provided in the conventional steering force assistance device. As shown, FIG. 7 includes a second bevel gear 206, a rotation center 300, and a pitch angle 700.

As illustrated, the pitch angle 700 refers to an angle at which the second bevel gear 320 is inclined with respect to the rotation center 300 of the second bevel gear 206.

The bevel gear axial force 500 can be summarized as in Equation (1).

= 베벨기어 축방향 힘(500)

= 피치각(700)

= Bevel gear axial force (500)

= Pitch angle (700)

= 베베기어 접선 힘(400)

= 0 or 1(600)

= Bevel Gear Tangential Force (400)

= 0 or 1 (600)

= 제 2 베벨기어각(322)

= 치직각 입력각(600)

= Second bevel gear angle (322)

= Right angle input angle (600)

The bevel gear central force 402 can be summarized as in Equation 2.

= 베벨기어 중심방향 힘(402)

= Bevel gear center force (402)

는 제 1 베벨기어(204)의 회전 방향에 따라

의 크기가 변하기 때문에

의 크기도 변한다.As shown in Equations 1 and 2, P is 0 or 1 depending on the rotation direction of the first bevel gear 204. therefore,

Is in accordance with the rotation direction of the first bevel gear 204

Because the size of

The size also changes.

도

의 크기 변동만큼 변한다.Likewise

Degree

Changes by the size of.

및

이 제 1 베벨기어(204)의 회전 방향에 따라 변하기 때문에 베벨기어의 지지구조가 복잡해지고 내구성도 저하되는 문제점이 있다.therefore,

And

Since the first bevel gear 204 is changed according to the rotational direction, the support structure of the bevel gear is complicated and durability is also lowered.

In order to solve this problem, the present invention reduces the bevel gear axial force and the bevel gear center force in the bevel gear to simplify the supporting structure and improve the performance and durability of the steering system. To provide that purpose.

In order to achieve the above object, the present invention includes a steering shaft for transmitting a rotational movement of the steering wheel, the driver applies a steering force to adjust the driving direction of the vehicle; A gear unit for converting the rotational motion of the steering shaft into a linear motion; And a rack bar connected to the gear part in a round bar phenomenon to linearly move from side to side according to the rotation of the steering shaft. A link structure that receives the linear motion of the rack bar and transfers the wheel to the wheel to steer the wheel; And a steering force assist device formed on one side of an outer circumferential surface of the rack bar and assisting steering force of the driver by assisting the linear movement of the rack bar. A second bevel gear for allowing the rack bar to move linearly when the bar penetrates the center of rotation and a predetermined rotation force is applied; A first bevel gear meshed with the second bevel gear and engaged; A motor connected to the first bevel gear and applying rotational force to the first bevel gear; And an electronic control unit connected to the motor and transmitting a driving signal to the motor to rotate the motor, wherein the first bevel gear and the second bevel gear have a bevel gear angle of 0 °. It provides a motor-driven steering device for a vehicle, characterized in that the bevel gear.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals have the same reference numerals as much as possible even if displayed on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

8 is a schematic view of a zero roll bevel gear in accordance with an embodiment of the present invention. As shown, the steering aid includes a zero roll bevel gear 808, FIG. 8 shows a center of rotation 300, a pitch circle 304, a gear tooth circle 306, a gear tooth circle 302, Including one contact 316 and second contact 318, zero roll bevel gear angle 800, zero roll bevel gear tangential force 802, zero roll bevel gear central force 804 and zero roll bevel gear 806. Illustrated.

The pitch circle 304 passes through the center of the zero roll bevel gear 806 about the center of rotation 300. When the second circle 310 is drawn at the tangent of the pitch circle 304, the zero roll bevel gear 806 is formed. It coincides with the outer circumference of.

Gear tooth inner circle 306 is the inner end of the gear tooth and gear tooth outer circle 302 is the circle connecting the outer end of the gear tooth.

The contact between the second circle 310 and the gear tooth inner circle 306 is called the first contact point 316, and the contact between the second circle 310 and the gear tooth outer circle 302 is called the second contact point 318. . In addition, after drawing a line from the rotation center 300 to the first contact point 316 and drawing a line from the rotation center 300 to the second contact point 318, the angle of these two lines is referred to as a zero roll bevel gear angle 800. As shown, zero roll bevel gear angle 800 is zero.

The zero roll bevel gear tangential force 802 is a force generated in the tangential direction of the zero roll bevel gear 808, and the zero roll bevel gear center force 804 is a force generated in the direction of the rotation center 300 of the zero roll bevel gear 808. to be.

9 is a partial cross-sectional view of a zero roll bevel gear according to an embodiment of the present invention. As shown, the steering aid 110 comprises a zero roll bevel gear 808, FIG. 9 shows a center of rotation 300, pitch circle 304, zero roll bevel gear axial force 900 and zero roll bevel. The illustration includes the gear tooth 806.

The zero roll bevel gear axial force 900 acts in a direction parallel to the center of rotation 300 of the zero roll bevel gear 808 at the pitch circle 304 where the zero roll bevel gear 808 and the first bevel gear 204 contact. It is the power to do it. In addition, the rectangular input angle 600 and the pitch angle 700 have the same structure as described with reference to FIGS. 6 and 7.

The zero roll bevel gear axial force 900 can be summarized as in Equation 3.

= 제롤 베벨기어 축방향 힘

= 피치각

= X-Rol Bevel Gear Axial Force

= Pitch angle

= 제롤 베벨기어 접선 힘

= 0 or 1

= Xerol Bevel Gear Tangential Force

= 0 or 1

= 제롤 베벨기어각 = 0

= 치직각 입력각

Zero roll bevel gear angle

= Right angle input angle

The zero roll bevel gear central force 804 can be summarized as in Equation 4.

= 제롤 베벨기어 중심방향 힘(804)

= Zero roll bevel gear center force (804)

Since the zero bevel gear angle 800 of the zero bevel gear 808 described above is zero, Equations 3 and 4 may be summarized as Equations 5 and 6, respectively.

In other words, since the zero roll bevel gear angle is zero, the zero roll bevel gear central force 804 and the zero roll bevel gear axial force 900 are arranged as shown in equations (5) and (6), and the zero roll bevel gear tangential force, Only the pitch angle and the right angle input angle are affected. As a result, since the size of the equation is less than that of Equation 1 and Equation 2, which is a case of using a general bevel gear, the support structure of the Xerol bevel gear is simplified when using a Xerol bevel gear compared to a conventional bevel gear Not only can it be configured, but it also improves the durability of steering system.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

As described above, according to the present invention, the motor-driven steering with a zero roll bevel gear simplifies the support structure and improves the performance and durability of the steering system by reducing the bevel gear axial force and the bevel gear center force in the bevel gear. There is an effect to provide a device.

Claims (3)

A steering shaft which transmits a rotational movement of a steering wheel to which a driver applies steering force to adjust a driving direction of the vehicle; A gear unit for converting the rotational motion of the steering shaft into a linear motion; And a rack bar connected to the gear part in a round bar phenomenon to linearly move from side to side according to the rotation of the steering shaft. A link structure that receives the linear motion of the rack bar and transfers the wheel to the wheel to steer the wheel; And a steering force assist device formed on one side of an outer circumferential surface of the rack bar and supporting a steering force of the driver by assisting the linear movement of the rack bar. The steering power assist device, A second bevel gear for allowing the rack bar to move linearly when the rack bar penetrates the center of rotation and a predetermined rotation force is applied; A first bevel gear meshed with the second bevel gear and engaged; A motor connected to the first bevel gear and applying rotational force to the first bevel gear; And And an electronic control unit connected to the motor and transmitting a driving signal to the motor to rotate the motor, wherein the first bevel gear and the second bevel gear have a bevel gear angle of 0 °. Motor-driven steering apparatus of a vehicle, characterized in that consisting of gears. The method of claim 1, The rack bar is a motor-driven steering apparatus of a vehicle with a zero roll bevel gear, characterized in that the first ball groove is formed in a spiral shape on the outer circumferential surface. The method of claim 1, The second bevel gear A second ball groove is formed on an inner circumferential surface in contact with the rack bar, and the first ball groove and the second ball groove are coupled with the rack bar to form a space, and the ball is fitted in the space, so that a predetermined or more rotational force is applied. A motor-driven steering apparatus for a vehicle with a zero roll bevel gear, characterized in that the ball rotates along with the ball so that the rack bar moves linearly with the first ball groove.

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