KR20170064429A - Parking brake actuator - Google Patents

Abstract

The present invention relates to a motor, A worm gear connected to the motor so as to transmit power; A worm wheel engaged with the worm gear; A first gear coupled to a rotating shaft of the motor, and a second gear coupled to a rotating shaft of the worm gear to transmit power transmission to the first gear, And a gear ratio of the first gear and the second gear is 10:66, and the gear ratio of the worm gear and the worm wheel is 1:54, so that the parking brake actuator Lt; / RTI >

Description

[0001] The present invention relates to a parking brake actuator,

The present invention relates to a parking brake actuator, and more particularly, to a parking brake actuator including a gear that transmits a driving force of the motor.

The brake system is a device for decelerating and stopping the vehicle while it is stopped and at the same time maintaining the stopped state. The brake system has a parking brake that decelerates and stops the vehicle while the vehicle is running and keeps the vehicle in a stopped state .

The parking brake is provided so that the parking cable is pulled by the operation of the lever provided at one side of the driver's seat inside the vehicle and the braking force is applied to the wheel connected to the parking cable so that the wheel is kept stationary, Thereby releasing the braking force provided to the wheel.

These parking brakes are operated only by the driver's intention, that is, the driver has to operate the lever every time he starts parking or driving, which is very troublesome to use. Accordingly, an electronic parking brake (EPB) system has been developed which allows the parking brake to be automatically operated by the motor according to the operating state of the vehicle.

The Electronic Parking Brake (EPB) system automatically switches the parking brake in conjunction with the manual operation mode of the driver and the electronic hydraulic control unit (HECU), engine electronic control unit (ECU) and traction control unit (TCU) Release and ensure braking stability in emergency situations.

 The electronic parking brake (EPB) system includes an electronic control unit (ECU), a motor, a gear, a parking cable, and a braking force sensor. Here, the electronic control unit ECU receives relevant information from the electronic oil pressure control unit HECU, the engine electronic control unit ECU, the traction control unit TCU, etc. through the can (CAN) Activate the brake actuator.

When the motor of the parking brake actuator is operated, the gear assembly is actuated by the driving of the motor, and the driving shaft is rotated by the operation of the gear assembly, so that the parking brake is pulled so that the braking force is applied to the wheel. Here, the gear assembly may include a worm and a worm wheel connected to the rotation shaft of the motor so as to transmit power.

Worms and worm wheels have the advantage of high torque with large reduction ratio. However, in order to rotate the worm and the worm wheel, the motor must be operated. In order to operate the motor, current is consumed. There is an urgent need for a structure capable of connecting the rotational force of the motor to the drive shaft connected to the parking cable with low power and high efficiency in a situation where the electric field parts are increasing in the vehicle and the environment in which the driving force is provided through the motor is increasing rapidly.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a parking brake actuator capable of connecting a rotational force of a motor to a drive shaft to which a parking cable is connected with low power and high efficiency.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned here can be understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a worm gear device including a motor, a worm gear connected to the motor to transmit power, a worm wheel engaged with the worm gear, a drive shaft coupled to the worm wheel, And a power transmission gear including a first gear engaged with the first gear and a second gear coupled with a rotation axis of the worm gear and connected to the first gear so as to transmit power, : 66, and the gear ratio of the worm gear and the worm wheel is 1:54.

Preferably, the number of teeth of the first gear is 10, the number of teeth of the second gear is 66, and the number of teeth of the worm wheel is 54. [

Preferably, the worm gear may be disposed so that the rotation axis is spaced apart from the rotation axis of the motor.

Preferably, the rotation axis of the motor and the rotation axis of the worm gear may be arranged in parallel.

Preferably, the first gear and the second gear can be engaged with each other.

Preferably, the motor is disposed on one side of the reference line perpendicular to the rotation axis direction of the motor and the reference line passing through the first gear, and the worm gear may be disposed on the other side of the reference line.

According to an embodiment of the present invention, the gear ratio of the first gear coupled to the rotational shaft of the motor and the second gear coupled to the rotational shaft of the worm gear and engaged with the first gear is 10:66, and the gear ratio of the worm gear and the worm gear is set to 1 : 54, thereby minimizing current consumption, thereby providing a favorable effect of driving the parking brake actuator with low power consumption and high efficiency.

1 is a view showing a parking brake actuator according to a preferred embodiment of the present invention;
Fig. 2 is a view showing the motor shown in Fig. 1,
3 is a view showing a worm gear, a worm wheel, and a power transmission gear,
4 is a view showing a comparison between the strength analysis of the conventional worm wheel and the strength analysis of the worm wheel of the present invention,
Fig. 5 is a view comparing the strength analysis of the conventional first gear with the strength analysis of the first gear of the present invention,
FIG. 6 is a diagram comparing the strength analysis of the conventional second gear with the strength analysis of the second gear of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The objectives, specific advantages, and novel features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. The terms and words used in the present specification and claims should not be construed to be limited to ordinary or dictionary terms and the inventor should properly define the concept of the term in order to describe its own invention in the best way. The present invention should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

The terms including ordinal, such as second, first, etc., may be used to describe various elements, but the elements are not limited to these terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be referred to as a first component, and similarly, the first component may also be referred to as a second component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

1 is a view showing a parking brake actuator according to a preferred embodiment of the present invention. It will be apparent to those skilled in the art from this disclosure that Fig. 1 clearly shows only the main feature parts in order to clearly illustrate the invention, and as a result various variations of the illustration are to be expected and the scope of the invention There is no.

1, a parking brake actuator according to a preferred embodiment of the present invention includes a motor 100, a worm gear 200, a worm wheel 300, a drive shaft 400, a power transmission gear 500, , And a housing (600).

The worm gear 200, the worm wheel 300, and the power transmission gear 500 serve to transmit the rotational force of the motor 100 to the driving shaft 400. A parking cable may be connected to the drive shaft 400.

The worm gear 200 and the worm wheel 300 are used when the rotating shaft of the driving gear and the driven gear transmit the power in the vertical direction at right angles and the driving shaft 400 to which the parking cable is connected is perpendicular to the rotating shaft of the motor 100 And serves to transmit the rotational force of the motor 100 to the drive shaft 400 in a deployed state.

Fig. 2 is a view showing the motor shown in Fig. 1. Fig.

Referring to FIG. 2, the motor 100 may include a stator 110, a rotor 120, and a rotating shaft 130.

The stator 110 may be fixed inside the housing 140 of the motor. The rotor 120 may be disposed on the inner side of the stator 110, and the rotation axis 130 may be coupled to the center portion. The stator 110 may be wound with a coil forming a rotating magnetic field, and the rotor 120 may include a magnet. When the rotor 120 rotates due to electrical interaction between the coil and the magnet and the rotor 120 rotates, the rotation shaft 130 rotates to generate driving force for pulling or pushing the parking cable.

The rotary shaft 130 may be rotatably supported by the bearing 150.

The stator 110 may be formed of one core or a plurality of divided cores may be combined.

3 is a view showing a worm gear, a worm wheel, and a power transmission gear.

1 and 3, the worm gear 200 may be disposed such that its rotational axis C1 is parallel to the rotational axis C2 of the motor 100. [ The worm wheel 300 meshes with the worm gear 200 and the driving shaft 400 is coupled to the center shaft. The rotation axis C3 of the worm wheel 300 is orthogonal to the rotation axis C1 of the worm gear 200. [

The motor 100 and the worm gear 200 are connected via the power transmission gear 500.

The power transmission gear 500 may include a first gear 510 and a second gear 520.

The first gear 510 may be connected to the rotating shaft of the motor 100. The second gear 520 may be coupled to the rotation shaft of the worm wheel 300. The first gear 510 and the second gear 520 are arranged to mesh with each other. Since the number of teeth of the second gear 520 is greater than the number of teeth of the first gear 510, the rotation of the motor 100 is reduced and transmitted to the worm wheel 300.

When the motor 100 rotates, the first gear 510 rotates. When the first gear 510 rotates, the second gear 520 and the worm gear 200 rotate. As the worm gear 200 rotates, when the worm wheel 300 rotates about the rotation axis C3, the driving shaft 400 rotates to pull the parking cable, thereby applying the braking force to the parking brake.

The worm gear 200 and the worm wheel 300 are gear devices capable of obtaining high torque at a large reduction ratio.

The rotational force transmission process of the motor 100 is transmitted to the worm gear 200 and the worm wheel 300 via the first gear 510 and the second gear 520. In order to operate the motor 100, a current is consumed. However, in a situation where electric parts are increased in the vehicle and the environment in which the driving force is supplied through the motor is rapidly increasing, a low power and high efficiency power transmission structure is required.

Therefore, the parking brake actuator according to an embodiment of the present invention can reduce the power consumption of the worm gear 200 and the worm wheel 300 by controlling the gear ratio of the first gear 510 and the second gear 520, Implement the delivery process.

First, the gear ratio of the first gear 510 and the second gear 520 may be 10:66. For example, when the number of teeth of the first gear 510 is 10, the number of teeth of the second gear 520 may be 66.

The gear ratio of the worm gear 200 and the worm wheel 300 may be 1:54. For example, the number of teeth of the worm gear 200 is one, and the number of teeth of the worm wheel 300 to be engaged may be 54 teeth.

4A is a view showing a stress intensity imparted to the worm wheel when the gear ratio of the worm gear 200 and the worm wheel 300 is 2:54 in the conventional structure, The gear ratio of the worm gear 200 and the worm wheel 300 of the parking brake actuator according to an exemplary embodiment is an analysis of the stress intensity imparted to the worm wheel 200 when the gear ratio is 1:54.

4, when the gear ratio of the worm gear 200 and the worm wheel 300 is 2:54, the maximum stress of the worm wheel is 186 MPa, and when the gear ratio of the worm gear 200 and the worm wheel 300 is 1:54, The stress is shown to be 135 MPa. Referring to FIG. 4, when the gear ratio of the worm gear 200 and the worm wheel 300 is 1:54, the maximum stress applied to the worm gear and the worm gear is less than that of the gear ratio of 2:54, .

5 (a) is a diagram showing a stress intensity imparted to the first gear when the gear ratio of the first gear and the second gear is 10:67, and FIG. 5 (b) FIG. 5 is a graph showing stress intensity imparted to the first gear 510 of the parking brake actuator according to a preferred embodiment.

5, when the gear ratio of the first gear 510 and the second gear 520 is 10:67, the maximum stress applied to the first gear 510 is 305 MPa, and the first gear 510 and the second gear 520 When the gear ratio applied to the gear 520 is 10:66, the maximum stress applied to the first gear 510 is 275 MPa. 5, when the gear ratio of the first gear 510 and the second gear 520 is 10:66 and the gear ratio of the first gear 510 and the second gear 520 is 10:67 The current consumption can be reduced because the maximum stress applied is small.

6 (a) is a diagram showing a stress intensity imparted to the second gear 520 when the gear ratio of the first gear and the second gear is 10:67, and FIG. 6 (b) FIG. 5 is a graph illustrating stress intensity imparted to the second gear 520 of the parking brake actuator according to an embodiment of the present invention.

6, when the gear ratio of the first gear 510 and the second gear 520 is 10:67, the maximum stress applied to the second gear 520 is 68 MPa, and the first gear 510 and the second gear 520 The maximum stress applied to the second gear 520 when the gear ratio applied to the gear 520 is 10:66 is 52 MPa. Referring to FIG. 6, when the gear ratio of the first gear 510 and the second gear 520 is 10:66, the gear ratio of the first gear 510 and the second gear 520 is 10:67 The current consumption can be reduced because the maximum stress applied is small.

Thus, when the gear ratio of the first gear 510 and the second gear 520 is 10:66 and the gear ratio of the worm gear 200 and the worm wheel 300 is 1:54, the maximum stress applied to the gear is relatively small Therefore, the current consumption of the motor can be minimized.

As described above, the parking brake actuator according to one preferred embodiment of the present invention has been specifically described with reference to the accompanying drawings.

It is to be understood that one embodiment of the invention described above is to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description. It is intended that all changes and modifications that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

100: motor
110:
120: Rotor
130:
140: housing of the motor
150: Bearings
200: Worm gear
300: Worm wheel
400: drive shaft
500: Power transmission gear
510: first gear
520: second gear
600: housing

Claims (6)

motor;
A worm gear connected to the motor so as to transmit power;
A worm wheel engaged with the worm gear;
A drive shaft coupled to the worm wheel and connected to a parking cable;
And a power transmission gear including a first gear coupled to a rotating shaft of the motor and a second gear coupled to a rotating shaft of the worm gear and connected to the first gear so as to transmit power,
Wherein the gear ratio of the first gear and the second gear is 10:66, and the gear ratio of the worm gear and the worm wheel is 1:54. The method according to claim 1,
Wherein the number of teeth of the first gear is 10, the number of teeth of the second gear is 66, and the number of teeth of the worm wheel is 54. The parking brake actuator according to claim 1, 3. The method of claim 2,
Wherein the worm gear is disposed so that its rotation axis is spaced apart from a rotation axis of the motor. The method of claim 3,
Wherein the rotation axis of the motor and the rotation axis of the worm gear are arranged in parallel. 5. The method of claim 4,
And the first gear and the second gear intermesh with each other. 6. The method of claim 5,
Wherein the motor is disposed on one side of the reference line and the worm gear is disposed on the other side of the reference line, the reference line being perpendicular to a direction of a rotation axis of the motor, the reference line passing through the first gear.

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