KR102625382B1 - Parking Brake Actuator - Google Patents

Abstract

The present invention relates to the structure of a parking brake actuator, and relates to a parking actuator with a simple gear unit and a Hall sensor that optimizes the arrangement of Hall elements for detecting the speed/position of the rotor for control of the actuator.
According to one embodiment of the present invention, a housing formed with a motor accommodating part, a driven gear accommodating part, an output gear accommodating part, and a PCB accommodating part; a motor accommodated in the motor receiving portion and having a motor shaft protruding in one direction; a driven gear having a rotation axis parallel to the axis of the motor shaft and receiving output from the motor; and an output gear that receives power from the driven gear to vary the displacement of the caliper or cable.

Description

Parking Brake Actuator

The present invention relates to the structure of a parking brake actuator, and relates to a parking actuator with a simple gear unit and a Hall sensor that optimizes the arrangement of Hall elements for detecting the speed/position of the rotor for control of the actuator.

The Electric Parking Brake (EPB) is a braking system used as a substitute for a mechanical handle lever (side brake) or foot pedal, enabling parking braking using a simple button operation and motor power.

In the case of the parking brake, the control operation is performed by limiting the movement of the wheels using a separate actuator equipped with a motor. Cable puller types and motor on caliper types are mainly used as means to limit wheel movement.

In other words, the parking brake controls the caliper or cable by providing appropriate braking force to the wheel by an actuator.

Related prior art documents include Korean Patent Publication No. 10-2013-0141073 and Korean Patent Registration No. 10-1688878.

In prior art literature, a gear unit is provided along with a motor to control a caliper or cable, and a gear unit consisting of a planetary gear and/or a plurality of gear trains is mainly used.

However, in order to ensure the safety and convenience of the driver, the parking brake must be equipped with a function to prevent the car from being pushed backwards in other situations such as when trying to start again after stopping on an incline. To ensure this function, the gear unit is inevitably installed. There was no choice but to have a more complex structure, and along with the resulting cost increase, complexity increased further, and as the structure became more complex, there was a problem that the probability of the gear train being damaged in the process of power transmission increased.

Meanwhile, in recent years, there has been a continuous demand to reduce the volume of the parking brake actuator in accordance with the trend of miniaturization and compactness of vehicle structures. The volume of the parking brake actuator is the printed circuit on which the motor, gear unit, magnet, and sensor are mounted. Since it depends on the layout relationship of the printed circuit board (PCB), optimal design for these layouts is required.

Korean Patent Publication No. 10-2013-0141073 Korean Patent No. 10-1688878

The present invention was created to solve the above problems and satisfy the optimal design requirements of the parking brake actuator. It provides a motor and gear unit to minimize the volume of the parking brake actuator while providing a function to prevent slipping in an inclined section. In addition, we would like to propose the optimal arrangement structure between printed circuit boards.

According to one embodiment of the present invention, a housing formed with a motor accommodating part, a driven gear accommodating part, an output gear accommodating part, and a PCB accommodating part; a motor accommodated in the motor receiving portion and having a motor shaft protruding in one direction; a driven gear having a rotation axis parallel to the axis of the motor shaft and receiving output from the motor; and an output gear that receives power from the driven gear to vary the displacement of the caliper or cable.

According to one embodiment of the present invention, the driven gear has a spur gear part meshed with teeth formed at the end of the motor shaft, and a driven gear shaft extending from the spur gear part in a direction parallel to the axis of the motor shaft, It is characterized in that it is formed as a worm gear engaged with the output gear on the rotation axis.

Furthermore, the driven gear may have a double flange formed on the driven gear shaft to prevent separation,

Additionally, the output gear may have an output shaft forming a rotation axis in a direction perpendicular to the driven gear shaft, and a worm wheel gear on the outer periphery of the output shaft.

According to one embodiment, the worm wheel gear rotates around the rotation axis of the output shaft perpendicular to the driven gear shaft, but the rotation angle may be limited to a specific angle range.

According to one embodiment, the worm wheel gear may be formed to extend from the outer periphery of the output shaft in a fan shape.

According to one embodiment, the PCB accommodating part may be provided adjacent to the driven gear accommodating part, and the mounting surface of the PCB may be arranged to face the driven gear part.

A magnet may be coupled to the driven gear, and at least one Hall sensor for measuring changes in the magnetic field of the magnet may be mounted on the PCB.

Additionally, the magnet may be formed in a ring shape.

Compared to the parking brake of the prior art, the parking brake actuator according to an embodiment of the present invention operates with a simple gear unit included therein, thereby reducing material costs and improving durability by simplifying the structure.

Since the parking brake actuator of the present invention is provided in an optimal design shape to prevent volume loss, it has the advantage of reducing material costs by reducing the size of the housing and worm wheel.

Figure 1 is a perspective view showing the housing and internal configuration of a parking brake actuator according to an embodiment of the present invention.
FIG. 2 is a view of the parking brake actuator of FIG. 1 viewed from another side.
FIG. 3 is a top view of the parking brake actuator shown in FIGS. 1 and 2.
Figure 4 is a diagram showing the arrangement relationship between the driven gear and the hall sensor installed on the PCB in the parking brake actuator configuration of the present invention.
Figure 5 is a diagram showing an embodiment contrasting with the arrangement relationship between a PCB and a Hall sensor according to an embodiment of the present invention.

The embodiments described below are provided so that those skilled in the art can easily understand the technical idea of the present invention, and the present invention is not limited thereto. In addition, the matters expressed in the attached drawings may be different from the actual implementation form in the schematic drawings to easily explain the embodiments of the present invention.

When a component is mentioned as being connected or connected to another component, it should be understood that it may be directly connected or connected to the other component, but that other components may exist in between. Additionally, throughout this specification, when a member is said to be located “on” another member, this includes not only the case where a member is in contact with another member, but also the case where another member exists between the two members.

And here, “connection” includes direct connection and indirect connection between one member and another member, and may mean all physical and electrical connections such as adhesion, attachment, fastening, bonding, and bonding.

Singular expressions include plural expressions unless the context clearly dictates otherwise. Terms such as “includes” or “has” are intended to mean the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, including one or more other features or numbers, It can be interpreted that steps, operations, components, parts, or combinations thereof can be added.

Hereinafter, the configuration of a parking brake actuator according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3.

Figure 1 is a perspective view showing the housing and internal configuration of a parking brake actuator according to an embodiment of the present invention. FIG. 2 is a view of the parking brake actuator of FIG. 1 viewed from another side. FIG. 3 is a top view of the parking brake actuator shown in FIGS. 1 and 2.

Referring to FIGS. 1 to 3 together, the parking brake actuator of the present invention has a housing in which a motor accommodating part 11, a driven gear accommodating part 12, an output gear accommodating part 13, and a PCB accommodating part 14 are formed ( 10); A motor 110 accommodated in the motor receiving portion 11 and having a motor shaft 120 protruding in one direction; A driven gear 200 that has a rotation axis in a direction parallel to the axis of the motor shaft 120 and receives an output from the motor 110; and an output gear 300 that receives power from the driven gear 200 and changes the displacement of the caliper or cable.

For reference, detailed description of the caliper or cable, which is the final goal of power transmission of the actuator of the present invention, will be omitted.

The housing 10 includes the motor 110, the driven gear 200, the output gear 300, and the PCB 400 of the present invention. A cover not separately shown in the drawing may be provided, and the interior may be sealed through this. The housing 10 has accommodation spaces (motor accommodating part, driven gear accommodating part, output gear forming a receiving portion and a PCB receiving portion).

In conventional electronic parking brakes, the motor and gear unit are generally arranged on the same axis, so the overall volume of the actuator is considerably large. However, in the present invention, the motor accommodating part 11, the driven gear accommodating part 12, and the output gear accommodating part 13 are formed by being arranged in parallel in the horizontal direction, so that the overall volume of the actuator can be relatively reduced.

The motor 110 of the present invention may be a typical BLDC motor, and the size of the actuator housing 10 is determined depending on the size of the motor 110. Therefore, if the diameter of the motor is large, the X-direction length and Z-direction height of the actuator housing increase. When designing a parking brake actuator, the PCB receiving portion 14 is generally formed at a position spaced apart from the Z direction by a predetermined distance based on the motor, so the volume of the housing 10 becomes larger in the Z direction.

In contrast, in the present invention, in order to reduce the overall volume of the actuator, that is, the volume of the housing 10, the PCB receiving portion 14 is not provided in the circumferential direction of the motor 110. An attempt is made to reduce the volume of the housing 10 by forming the PCB receiving portion 14 in the axial direction rather than the circumferential direction of the motor.

Before explaining the solution for reducing the volume of the housing 10, the driven gear 200 and the output gear 300 of the present invention will first be described in detail.

The driven gear 200 of the present invention includes a spur gear portion 210 and a driven gear shaft 230 in which gear teeth are formed around the centrifugal direction, and a double flange 220 and a worm gear 231 formed on the driven gear shaft 230. ) is composed of.

The spur gear unit 210 is a gear structure with a large diameter, and gear teeth that mesh with the teeth of the end of the motor shaft 120 are formed on the outer periphery of the spur gear unit 210. In addition, a driven gear shaft 230 is connected from the center of the spur gear unit 210 in a direction parallel to the axial direction of the motor shaft 120. The spur gear portion 210 and the driven gear shaft 230 may be injection molded as one piece.

A worm gear 231 formed in the form of a thread is formed on the outer periphery of the driven gear shaft 230, and has the principle of transmitting driving force to the output shaft 230 through a worm wheel 320 engaged with it. In summary, the gear unit transmits the driving force generated by the motor 110 to the output shaft 230 by engaging and driving the motor, the spur gear unit 210, the worm gear 231, and the worm wheel 320, respectively.

Depending on the embodiment, a double flange 220 may be provided on the driven gear shaft 230. The double flange 220 prevents excessive vibration of the driven gear 200 during rotation of the driven gear shaft 230, and ultimately prevents the driven gear 200 from being separated. In response to this, a stepped portion 20 is formed to protrude from the housing 10 at a position between the double flanges 220. The rotation of the double flange 220 relative to the driven gear shaft 230 is not limited, but the forward and backward movement of the double flange 220 may be limited by the step portion 20.

And the output gear 300 according to an embodiment of the present invention includes an output shaft 310 forming a rotation axis in a direction perpendicular to the driven gear shaft 230, and a worm wheel gear 320 on the outer periphery of the output shaft 310. It is characterized by having.

As shown in the figure, the rotation axis of the output shaft 310 is perpendicular to the axes of the motor shaft 120 and the driven gear shaft 230.

The worm wheel gear 320 may be formed integrally with the output shaft 310, or may not be formed integrally with the output shaft 310.

It rotates around the rotation axis of the output shaft 310, which is perpendicular to the driven gear shaft 230, but the rotation angle is limited to a specific angle range.

For this purpose, the worm wheel gear 320 is formed to extend from the outer periphery of the output shaft 310 in a fan shape. More specifically, the worm wheel gear 320 is not the entire outer circumference of the output shaft 310, but a portion thereof, for example, 1/4 to 1/3 (i.e., 1/4 to 1/3) of the circumferential length (π) of the output shaft 310, as shown in FIG. It may be formed to protrude in the centrifugal direction at π/4 to π/3).

And the output shaft receiving portion 13 forms a space for accommodating the worm wheel gear 320 in an area larger than the size of the worm wheel gear 320, where the worm wheel gear 320 rotates the output shaft 310. This allows it to rotate by a predetermined angle counterclockwise or clockwise from the initial position. In particular, the worm wheel gear 320 moves only in the space formed by the output shaft receiving portion 13, so its rotation angle may be limited.

For reference, the initial position here may mean the initial position of the worm wheel gear 320 shown in FIG. 3, and at this time, it can be defined that the parking brake actuator is in the OFF state. In this state, if the parking brake actuator is turned ON, the worm wheel gear 320 rotates counterclockwise and performs an operation to control the caliper and cable. For example, assume that the maximum possible rotation angle at the initial position of the worm wheel gear 320 shown in FIG. 3 is 70°. When the parking brake actuator is turned on, the caliper and cable rotate counterclockwise, and the caliper and cable control operation is completed when rotated by 70°. When the caliper and cable control operation is completed and the vehicle is stopped, even if the parking brake actuator is released (even if it is turned off again), the worm wheel gear 320 can only rotate clockwise and cannot move further counterclockwise. Reversals are prevented.

In summary, the structure of the worm wheel gear 320 of the present invention is formed so that it can be engaged only within a limited angle range on the worm gear 231. In the case of a gear unit using the planetary gear structure of the prior art, the angle range for caliper and cable control is not limited, so the vehicle may be pushed backwards on inclined sections. However, when the parking brake actuator of the present invention is used, the vehicle can be pushed backwards on inclined sections. It is possible to prevent the vehicle from being unintentionally pushed backwards.

Next, a method for reducing the volume of the housing will be described in more detail. Figure 4 is a diagram showing the arrangement relationship between the driven gear and the hall sensor installed on the PCB in the parking brake actuator configuration of the present invention.

Referring to FIGS. 1 to 4 together, the PCB receiving portion 14 according to an embodiment of the present invention is provided adjacent to the driven gear receiving portion 12, and the mounting surface of the PCB 400 has a driven gear ( It is characterized in that it is placed opposite 200).

A magnet 211 is coupled to the driven gear 200, and at least one Hall sensor 410 for measuring changes in the magnetic field of the magnet 211 is mounted on the PCB 400. The PCB 400 may further include a parking brake actuator drive IC in addition to the Hall sensor 410.

The magnet 211 coupled to the driven gear 200 is more specifically meant to be coupled to the spur gear portion 210, and is coupled to the inner surface of the spur gear portion 210 in a protruding state, or as shown in FIGS. As shown in Figure 4, it may not protrude from the surface of the spur gear portion 210 but may be pressed into a groove formed in the spur gear portion 210.

The Hall sensor 410 is a sensor based on the Hall effect, which is an effect in which an electric field is formed when a current flows in the magnetic field area formed by the magnet 211, and is opposed to the magnet 211. It can be mounted on the PCB (400).

When the spur gear unit 210 rotates through the Hall sensor 410, information such as what direction it rotates and what the rotation angle is can be obtained, and through this, the driving state of the parking brake actuator is estimated. .

Meanwhile, the magnet 211 of the present invention may be manufactured in a ring shape.

Figure 5 is a diagram showing an embodiment contrasting with the arrangement relationship between a PCB and a Hall sensor according to an embodiment of the present invention.

Figure 5 shows an embodiment in contrast to the parking brake actuator according to an embodiment of the present invention, in which the output shaft 310' with a magnet 311' formed at the end and the rotation axis direction of the output shaft 310' are opposed to each other. Assume that the PCB 400' is formed at a position. The PCB 400' of the control example is also provided with a hall sensor 410' to measure the duty according to the rotation of the output gear 300, through which the driving state of the parking brake actuator can be estimated.

However, according to the control example shown in FIG. 5, space must be provided to accommodate the PCB in the height direction (Z) of the parking brake actuator, so the length of the housing in the height direction becomes longer, which causes volume loss. .

The better the output performance of a motor, the larger it is, and it is common for the size to vary depending on this output performance. Since the appropriate output performance is determined for each actuator, the size of the motor can also be considered determined. Therefore, to prevent the housing volume from increasing while maintaining output performance, the location where the PCB is placed must be changed.

In the present invention, the PCB accommodating part 14 is placed next to the driven gear accommodating part 12, more specifically, adjacent to the spur gear part 210, and the PCB is placed at a position facing the large-area plane of the spur gear part 210. Place it. Referring again to FIG. 3, the PCB receiving portion 14, which is a space in which the PCB is accommodated, can be prepared by adjusting the length of the motor shaft 120 and the length of the driven gear shaft 230. In this case, by simply shortening the length of the shaft slightly without changing the output performance of the motor, it is possible to secure space to accommodate the PCB and reduce volume loss compared to the control example of FIG. 5.

This specification is not intended to limit the invention to the specific terms presented. Accordingly, although the present invention has been described in detail with reference to the embodiments described above, those skilled in the art will be able to understand the embodiments of the present invention without departing from the scope of the present invention. Modifications, changes and variations may be made.

The scope of the present invention is indicated by the claims described later rather than the detailed description above, and the meaning and scope of the claims and all changes or modified forms derived from the equivalent concept are interpreted to be included in the scope of rights of the present invention. It has to be.

10: housing
11: motor receiving part
12: driven gear receiving part
13: Output gear receiving part
14: PCB receiving part
110: motor
120: motor shaft
121: motor shaft teeth
200: driven gear
210: spur gear unit
220: Double flange
230: driven gear shaft
231: Worm gear
300: Output gear
310: Output shaft
320: Worm wheel gear
400: PCB

Claims (9)

A housing formed with a motor accommodating part, a driven gear accommodating part, an output gear accommodating part, and a PCB accommodating part;
a motor accommodated in the motor receiving portion and having a motor shaft protruding in one direction;
a driven gear having a rotation axis parallel to the axis of the motor shaft and receiving output from the motor; and
It includes an output gear that receives power from the driven gear and changes the displacement of the caliper or cable,
The driven gear is,
It has a spur gear portion engaged with teeth formed at the end of the motor shaft,
A driven gear shaft extending from the spur gear unit in a direction parallel to the axis of the motor shaft toward the motor receiving unit, and a worm gear engaged with the output gear are formed on the driven gear shaft,
The PCB accommodating part is provided adjacent to the driven gear accommodating part, and the mounting surface of the PCB is arranged to face the driven gear part, and the driven gear is located between the PCB accommodating part and the motor accommodating part. A parking brake actuator. . delete According to paragraph 1,
The driven gear is,
A parking brake actuator, characterized in that a double flange for preventing separation is formed on the driven gear shaft. According to paragraph 1,
A parking brake actuator characterized in that the output gear has an output shaft forming a rotation axis in a direction perpendicular to the driven gear shaft, and a worm wheel gear on the outer periphery of the output shaft. According to paragraph 4,
The worm wheel gear rotates around the rotation axis of the output shaft, which is perpendicular to the driven gear shaft, but the rotation angle is limited to a specific angle range. According to clause 5,
The parking brake actuator, wherein the worm wheel gear extends in a fan shape from the outer periphery of the output shaft. delete According to paragraph 1,
A parking brake actuator, characterized in that a magnet is coupled to the driven gear, and at least one Hall sensor for measuring changes in the magnetic field of the magnet is mounted on the PCB. According to clause 8,
A parking brake actuator, characterized in that the magnet is formed in a ring shape.

Images