Brake actuator and brake device comprising same

Abstract

Disclosed herein are a brake actuator and a brake device including the same. The brake actuator includes: a housing; a first motor installed in the housing; a transfer gear rotatably mounted in the housing and connected to the first motor; a first parking member configured to rotate together with the transfer gear; a second motor spaced apart from the first motor; a second parking member rotatably mounted in the housing and configured to selectively restrict rotation of the first parking member according to a rotation direction thereof; and a conversion member configured to convert a rotational force of the second motor into a linear motion to rotate the second parking member. By means of the first parking member and the second parking member, even if the operation of the first motor is released during parking braking, the brake actuator and the brake device according to the present disclosure can maintain parking braking force.

Description

Technical Field

[0001] Exemplary embodiments of the present disclosure relate to a brake actuator and a braking device including the brake actuator, and more particularly, to a brake actuator capable of ensuring stable parking brake performance and a braking device including the brake actuator. Background Art

[0002] A vehicle braking device generally functions to brake a vehicle by using frictional force between a pad and a brake disc by pushing a piston with a driving force to bring the pad into close contact with the brake disc.

[0003] Among them, an electro mechanical brake (EMB) generates braking force by directly mounting a motor-driven actuator on a caliper without using hydraulic pressure and pressing a piston through a mechanical device (such as a gear and a screw). Such an EMB can perform active braking and independent braking of a specific wheel, and thus can implement additional functions (such as an anti-lock braking system (ABS), an electronic stability control system (ESC), a traction control system (TCS), and an autonomous emergency braking (AEB)) as well as typical main braking. Since there is no delay in hydraulic transmission, the EMB can also achieve higher performance.

[0004] Conventional EMBs ensure fast piston response and high efficiency through ball screws. However, due to the structural characteristics of the ball screws, these ball screws cannot be self-locked because their own rotation cannot be restricted. Therefore, if the power supply to the motor is interrupted, the braking force can be arbitrarily released by the repulsive force between the pad and the piston.

[0005] The related art of the present disclosure is disclosed in Korean Patent Application Publication No. 10-2010-0098846 (published on September 10, 2010, titled "Disc Brake with Parking Function"). Summary of the Invention

[0006] The present Summary of the Invention is provided to introduce a selection of concepts that are further described below in the Detailed Description in a simplified form. The present Summary of the Invention is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0007] Various embodiments relate to a brake actuator capable of ensuring stable parking brake performance and a braking device including the brake actuator.

[0008] In one embodiment, a brake actuator includes: a housing; a first motor mounted in the housing; a transmission gear rotatably mounted in the housing and connected to the first motor; a first parking member configured to rotate with the transmission gear; a second motor spaced apart from the first motor; a second parking member rotatably mounted in the housing and configured to selectively restrict the rotation of the first parking member according to the rotation direction of the second parking member; and a conversion member configured to convert the rotational force of the second motor into linear motion to rotate the second parking member.

[0009] The first parking member may include: a first parking body connected to the first output shaft of the first motor; and a plurality of extending portions extending from the first parking body and arranged along the circumferential surface of the first parking body.

[0010] Each extending portion may extend obliquely with respect to the radial direction of the first parking body.

[0011] The second parking member may include: a second parking body mounted to be rotatable about a rotation axis parallel to the first output shaft; a lever extending from one side of the second parking body and configured to convert the linear motion of the conversion member into rotational motion of the second parking body; and a latch portion extending from the other side of the second parking body, and when the second parking body rotates in the first rotation direction, the latch portion is inserted between a pair of associated adjacent extending portions.

[0012] The conversion member may include: a first conversion gear connected to the second output shaft of the second motor and rotating with the second output shaft of the second motor; and a second conversion gear connected to the first conversion gear and linearly moving in a first direction or a second direction opposite to the first direction, and configured to press or release the lever. When the second conversion gear presses the lever in the first direction, the second parking body may rotate in the first rotation direction.

[0013] The first output shaft may be misaligned with the second output shaft.

[0014] The first conversion gear may be a pinion gear, and the second conversion gear may be a rack gear.

[0015] The brake actuator may further include a return member connected to the lever and configured to press the lever in the second direction.

[0016] The return member may be arranged to face the second conversion gear, and the lever is interposed therebetween.

[0017] The return member may be configured to be elastically deformable in a direction parallel to the second direction.

[0018] The return member can be a compression spring.

[0019] The second parking body can be installed to be movable in the longitudinal direction of the rotating shaft. When the load acting between one of a pair of associated adjacent extension portions and the latch portion increases beyond a set magnitude, the second parking body can move in a departure direction parallel to the longitudinal direction of the rotating shaft.

[0020] The latch portion can have a side surface inclined with respect to the longitudinal direction of the rotating shaft.

[0021] The brake actuator can further include a return member configured to press the second parking body in a direction opposite to the departure direction.

[0022] The return member can include: a return body arranged to face the second parking body; and an elastic member configured to be elastically deformable in a direction parallel to the longitudinal direction of the rotating shaft and having two ends respectively in contact with the return body and the second parking body.

[0023] The elastic member can be a compression spring.

[0024] In another embodiment, a braking device includes: a caliper body; a piston unit movably installed on the caliper body and configured to contact or separate from a brake pad according to the movement direction of the piston unit; and a brake actuator connected to the piston unit and configured to move the piston unit. The brake actuator includes: a housing; a first motor installed in the housing; a transmission gear rotatably installed in the housing and connected to the first motor; a first parking member configured to rotate together with the transmission gear; a second motor spaced apart from the first motor; a second parking member rotatably installed in the housing and configured to selectively restrict the rotation of the first parking member according to the rotation direction of the second parking member; and a conversion member configured to convert the rotational force of the second motor into a linear motion to rotate the second parking member.

[0025] It can be clearly seen from the above description that even if the operation of the first motor is released during the parking brake of the first parking member and the second parking member, the brake actuator and the braking device according to the present disclosure can maintain the parking braking force.

[0026] The brake actuator and the braking device according to the present disclosure can ensure the degree of freedom in the design of the position of the second motor by indirectly connecting the second parking member to the second motor via the conversion member.

[0027] The brake actuator and the braking device according to the present disclosure can return the second parking body to its initial position without driving the second motor through a return member, thereby controlling the operation of the second parking body only through the on / off control of the second motor.

[0028] When the braking force cannot be smoothly released due to damage or malfunction of the first parking member and the second parking member, the brake actuator and the braking device according to the present disclosure can forcibly release the braking force through the inclined structures of the latch portion, the extension portion, and the reset member to prevent the vehicle from losing its driving ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a perspective view schematically showing the configuration of a braking device according to an embodiment of the present disclosure.

[0030] Figure 2 is a cross-sectional view schematically showing the configuration of a braking device according to an embodiment of the present disclosure.

[0031] Figure 3 is a perspective view schematically showing the configuration of a brake actuator according to an embodiment of the present disclosure.

[0032] Figure 4 is a front view schematically showing the configuration of a brake actuator according to an embodiment of the present disclosure.

[0033] Figure 5 is a perspective view schematically showing the configurations of a first parking member, a second parking member, and a conversion member according to an embodiment of the present disclosure.

[0034] Figure 6 is a front view schematically showing the configurations of a first parking member, a second parking member, and a conversion member according to an embodiment of the present disclosure.

[0035] Figures 7 to 9 is a view schematically showing the process of generating a parking braking force.

[0036] Figures 10 to 12 is a view schematically showing the process of releasing the parking braking force.

[0037] Figures 13 to 15 is a view schematically showing the process of forcibly releasing the parking braking force. DETAILED DESCRIPTION

[0038] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings.

[0039] It should be considered that, for the sake of clarity and convenience of description, the thickness of each line or the size of each component in the drawings may be exaggerated. In addition, the terms used herein are terms defined in consideration of the functions of the present disclosure, and these terms may be changed according to the intention or practice of the user or operator. Therefore, these terms should be defined based on the overall disclosure set forth herein.

[0040] In the specification, it should be understood that when an element is referred to as being "connected (or coupled)" to another element, it can be "directly connected (or coupled)" to other elements, or it can also be "indirectly connected (or coupled)" to other elements, with other elements being interposed therebetween. In the specification, it should be understood that when a component is referred to as "including (or containing)" any component, it does not exclude other components and can further include (or contain) other components, unless otherwise specified.

[0041] Throughout the specification, the same reference numerals may refer to the same components. Even if the same or similar reference numerals are not mentioned or described in a particular drawing, they can be described based on other drawings. In addition, even if there are elements in a particular drawing that are not labeled with reference numerals, those elements can be described based on other drawings. Moreover, the number, shape, size, relative differences, etc. of the detailed components shown in the drawings herein are provided for ease of understanding and can be implemented in various forms without limiting the embodiments thereof.

[0042] Figure 1 is a perspective view schematically showing the configuration of a braking device according to an embodiment of the present disclosure. Figure 2 is a cross-sectional view schematically showing the configuration of a braking device according to an embodiment of the present disclosure.

[0043] Reference Figure 1 and Figure 2 , the braking device denoted by reference numeral 1 according to the present embodiment includes a caliper body 10, a piston unit 20, and a brake actuator 30.

[0044] The caliper body 10 can define a schematic appearance of the braking device and support the piston unit 20 and the brake actuator 30 as a whole.

[0045] The caliper body 10 according to the present embodiment may include a bridge member 11, finger members 12, and a cylinder 13.

[0046] The bridge member 11 can define the central appearance of the caliper body 10 and support the finger members 12 and the cylinder 13. The bridge member 11 may have a lower surface spaced a predetermined distance from the circumferential surface of the brake disc D facing the brake disc D. The bridge member 11 may have both sides extending in opposite directions along a direction parallel to the central axis of the brake disc D ( Figure 2 the X-axis direction in Figure 1 and Figure 2 shown in the figure), and the bridge member 11 is not limited to having the

[0047] A pair of brake pads P can be arranged on the lower side of the bridge member 11. The pair of brake pads P can be spaced apart from each other along the central axis of the brake disc D. The pair of brake pads P can face each other, with the brake disc D therebetween. The pair of brake pads P can be supported on the bracket 2 or the bridge member 11 so as to be slidable in a direction parallel to the central axis of the brake disc D. A friction pad made of a material having a high coefficient of friction (such as rubber) can be attached to one surface of each brake pad P facing the brake disc D.

[0048] The bridge member 11 is movably connected to the bracket 2 via a guide rod 11a, and the bracket 2 is fixed to a steering knuckle (not shown) or the like. During vehicle braking, the bridge member 11 can slide in a direction parallel to the central axis of the brake disc D by the reaction force generated between the piston unit 20 and the associated brake pad P.

[0049] The finger member 12 can extend downward from one side of the bridge member 11. The finger member 12 can be integrally connected to the bridge member 11 by welding, pressing, bending, etc. The finger member 12 can be arranged to face one of the pair of brake pads P. By sliding the bridge member 11, the finger member 12 can press one of the pair of brake pads P against the brake disc D or release one of the pair of brake pads P from the brake disc D.

[0050] The cylinder 13 can extend downward from the other side of the bridge member 11. The cylinder 13 can have a hollow cylindrical shape with an opening on one side. The central axis of the cylinder 13 can be parallel to the central axis of the brake disc D. The opening side of the cylinder 13 can be arranged to face the remaining one of the pair of brake pads P.

[0051] The piston unit 20 can be movably mounted on the caliper body 10. The piston unit 20 can contact or separate from the remaining one of the pair of brake pads P according to its movement direction. When the piston unit 20 contacts the associated brake pad P, it can press the brake pad P against the brake disc D so that the brake pad P is in close contact with the brake disc D to apply a braking force to the vehicle. When the piston unit 20 separates from the brake pad P, the piston unit 20 can release the pressing force applied to the brake pad P so that the brake pad P separates from the brake disc D to release the braking force applied to the vehicle.

[0052] The piston unit 20 can include a piston 21, a bolt 22, and a nut 23.

[0053] The piston 21 can have a cup shape with an opening on one side. The closed side of the piston 21 can point to the brake pad P that is arranged to face the cylinder 13. The opening side of the piston 21 can point to the inner space of the cylinder 13. The piston 21 can have an outer surface that is slidably supported on the inner surface of the cylinder 13. Alternatively, the outer surface of the piston 21 can also be spaced apart from the inner surface of the cylinder 13 by a predetermined distance to form a gap therebetween.

[0054] The piston 21 can move forward and backward in a direction parallel to the central axis of the cylinder 13 (in a direction parallel to the X-axis in Figure 2 ). When the piston 21 moves forward, it can protrude outside the cylinder 13 and press the brake pad P set to face the cylinder 13 against the brake disc D. In this case, the bridge member 11 can move in a direction opposite to the moving direction of the piston 21 by the reaction force generated between the piston 21 and the brake pad P. When the piston 21 moves backward, it can release the pressing force applied to the brake pad P and separate the brake pad P from the brake disc D.

[0055] The bolt 22 can be provided inside the cylinder 13 and can rotate by the driving force received from the brake actuator 30.

[0056] For example, the bolt 22 can be in the form of a rod having a substantially circular cross-section. The bolt 22 can be provided inside the cylinder 13, and its central axis can be coaxially positioned with the central axis of the cylinder 13. The bolt 22 can have one end facing the inner end surface of the piston 21, and this end is spaced apart from the inner end surface by a predetermined distance. The bolt 22 can have the other end that protrudes outside the caliper body 10 through the closed side of the cylinder 13. When the brake actuator 30 is operated, the bolt 22 can rotate clockwise or counterclockwise about its central axis.

[0057] The bolt 22 can have a groove formed on its outer peripheral surface, and half (one circumference) of the spherical rolling elements are placed in the groove. The groove can extend spirally in the longitudinal direction of the bolt 22 to provide a circulation path for the rolling elements.

[0058] The nut 23 can be provided inside the cylinder 13 and can be connected to the bolt 22. As the bolt 22 rotates inside the cylinder 13, the nut 23 linearly reciprocates in a direction parallel to the longitudinal direction of the bolt 22. Depending on its moving direction, the nut 23 can press the piston 21 against the brake pad P or release the piston 21 from the brake pad P.

[0059] For example, the nut 23 can have a hollow cylindrical shape. The nut 23 can have an inner peripheral surface facing the outer peripheral surface of the bolt 22, and this inner peripheral surface is spaced apart from the outer peripheral surface by a predetermined distance. The nut 23 can have a groove formed on its inner peripheral surface, and the other half (other circumference) of the spherical rolling elements are placed in the groove. The groove can extend spirally in the longitudinal direction of the nut 23 to provide a circulation path for the rolling elements.

[0060] The nut 23 can receive the rotational force of the bolt 22 via rolling elements. When the bolt 22 rotates, the nut 23 can move forward and backward in the longitudinal direction of the bolt 22 through the cyclic movement of the rolling elements.

[0061] When the nut 23 moves forward, it can contact the inner surface of the piston 21 to press the piston 21 toward the brake disc D. When the nut 23 moves backward, it can separate from the inner surface of the piston 21 to release the pressing force applied to the piston 21.

[0062] The brake actuator 30 can be connected to the piston unit 20 and can move the piston unit 20. In other words, the brake actuator 30 can be used as a component that generates a driving force to apply a braking force to the vehicle or release a braking force from the vehicle and transmits the generated driving force to the piston unit 20.

[0063] Figure 3 is a perspective view schematically showing the configuration of a brake actuator according to an embodiment of the present disclosure. Figure 4 is a front view schematically showing the configuration of a brake actuator according to an embodiment of the present disclosure.

[0064] Reference Figure 3 and Figure 4 , the brake actuator 30 according to the present embodiment includes a housing 100, a first motor 200, a transmission gear 300, a first parking member 400, a second motor 500, and a second parking member 600.

[0065] The housing 100 can be fixed to the caliper body 10 and can support the first motor 200, the transmission gear 300, the first parking member 400, the second motor 500, and the second parking member 600 as a whole.

[0066] The housing 100 can include a housing body 110 and a housing cover 120.

[0067] The housing body 110 can have a hollow cylindrical shape with an opening on one side. The closed side of the housing body 110 can be set to face the rear of the cylinder 13. The housing body 110 can be fixed to the rear of the cylinder 13 by various types of joining methods (e.g., bolt connection, welding, and fitting). The housing body 110 is not limited to having Figure 3 and Figure 4 the shape shown and can be designed and changed into various shapes.

[0068] The housing cover 120 can be arranged to face the housing body 110 and can enclose the internal space of the housing body 110. The housing cover 120 can have a substantially plate shape and can be arranged to face the opening side of the housing body 110. The housing cover 120 can be fixed to the opening side of the housing body 110 by various types of joining methods (such as bolt connection, welding, and fitting). The cross-sectional shape of the housing cover 120 can correspond to the cross-sectional shape of the housing body 110.

[0069] The first motor 200 is installed in the housing 100 and generates a rotational force to move the piston unit 20. As an example, the first motor 200 can be exemplified as various types of electric motors that can rotate the first output shaft 210 by receiving power from the outside. The first motor 200 can be fixed to the outside of the housing body 110 by various types of joining methods (such as bolt connection, welding, and fitting). The first output shaft 210 can protrude into its internal space through the housing body 110. The first output shaft 210 can be arranged such that its longitudinal direction is parallel to the longitudinal direction of the bolt 22 in the cylinder 13, for example, Figure 3 in the X-axis direction. The first motor 200 can be electrically connected to a battery of the vehicle or the like to receive power therefrom.

[0070] The transmission gear 300 can be rotatably installed in the housing 100. The transmission gear 300 is connected to the first motor 200 and rotates together with the rotational force generated by the first motor 200. The transmission gear 300 can be used as a component for transmitting the rotational force generated by the first motor 200 to the piston unit 20.

[0071] The transmission gear 300 can include a first transmission gear 310, a second transmission gear 320, and a third transmission gear 330.

[0072] The first transmission gear 310 can be connected to the first output shaft 210 of the first motor 200. As an example, the first transmission gear 310 can be a hollow helical gear or a spur gear, with teeth formed on its outer peripheral surface. The central axis of the first transmission gear 310 can be coaxially arranged with the central axis of the first output shaft 210 of the first motor 200. The first transmission gear 310 can have an inner peripheral surface that is spline-engaged with the outer peripheral surface of the first output shaft 210. Thus, when the first motor 200 is operated, the first transmission gear 310 can rotate at the same angular velocity as the first output shaft 210.

[0073] The second transmission gear 320 can mesh with the first transmission gear 310 and can rotate together with the rotation of the first transmission gear 310. As an example, the second transmission gear 320 can be a hollow helical gear or a spur gear, with teeth formed on its outer peripheral surface. The central axis of the second transmission gear 320 can be arranged parallel to the central axis of the first transmission gear 310. The second transmission gear 320 can be supported by a separate shaft (not shown) or the like, so as to be rotatable within the housing 100 about its central axis. The second transmission gear 320 can have an outer peripheral surface that meshes with the outer peripheral surface of the first transmission gear 310. When the first transmission gear 310 rotates, the second transmission gear 320 can rotate in a direction opposite to that of the first transmission gear 320. The second transmission gear 320 can have a larger diameter than the first transmission gear 310. Therefore, the second transmission gear 320 can amplify the magnitude of the rotational force transmitted from the first transmission gear 310.

[0074] The third transmission gear 330 can mesh with the second transmission gear 320 and can rotate together with the rotation of the second transmission gear 320. The third transmission gear 330 can be used as a component that finally transmits the rotational force generated by the first motor 200 to the piston unit 20. As an example, the third transmission gear 330 can be a hollow helical gear or a spur gear, with teeth formed on its outer peripheral surface. The central axis of the third transmission gear 330 can be arranged parallel to the central axis of the second transmission gear 320. The central axis of the third transmission gear 330 can be coaxially positioned with the central axis of the bolt 22 of the piston unit 20. The third transmission gear 330 can have an outer peripheral surface that meshes with the outer peripheral surface of the second transmission gear 320. When the second transmission gear 320 rotates, the third transmission gear 330 can rotate about its central axis in a direction opposite to that of the second transmission gear 320. The rear end of the bolt 22 protruding from the rear of the cylinder 13 can be inserted into the center of the third transmission gear 330. The bolt 22 can have an outer peripheral surface that is spline-engaged with the inner peripheral surface of the third transmission gear 330. Therefore, when the third transmission gear 330 rotates, the bolt 22 can rotate together with the third transmission gear 330 to move the nut 23 forward and backward. The third transmission gear 330 can have a larger diameter than the second transmission gear 320. Therefore, when the second transmission gear 320 rotates, the third transmission gear 330 can rotate at a lower angular velocity than the second transmission gear 320 and can amplify the magnitude of the rotational force transmitted to the piston unit 20.

[0075] When the first output shaft 210 rotates in the direction of brake application, the rotational force of the first output shaft can be sequentially transmitted to the first transmission gear 310, the second transmission gear 320, the third transmission gear 330, and the bolt 22, and the nut 23 and the piston 21 can move forward to bring the brake pad P into close contact with the brake disc D.

[0076] When the first output shaft 210 rotates in the direction of brake release, the rotational force of the first output shaft can be sequentially transmitted to the first transmission gear 310, the second transmission gear 320, the third transmission gear 330, and the bolt 22, and the nut 23 and the piston 21 can move backward to separate the brake pad P from the brake disc D.

[0077] The first parking member 400 can be used as a component that rotates together with the transmission gear 300 and holds the parking braking force together with the second parking member 600.

[0078] Figure 5 is a perspective view schematically showing the configurations of the first parking member, the second parking member, and the conversion member according to an embodiment of the present disclosure. Figure 6 is a front view schematically showing the configurations of the first parking member, the second parking member, and the conversion member according to an embodiment of the present disclosure.

[0079] Reference Figures 1 to 6 , the first parking member 400 can include a first parking body 410 and an extension part 420.

[0080] The first parking body 410 can be connected to the first output shaft 210 of the first motor 200. As an example, the first parking body 410 can be in the form of a ring having a hollow formed at its center. The central axis of the first parking body 410 can be coaxially positioned with the central axis of the first output shaft 210. The first parking body 410 can have an inner circumferential surface that is splined to the outer circumferential surface of the first output shaft 210. When the first output shaft 210 rotates, the first parking body 410 can rotate at the same angular velocity as the first output shaft 210 and the first transmission gear 310. Therefore, compared with when the first parking body 410 is connected to the second transmission gear 320 or the third transmission gear 330 (the rotational force of which is multiplied by its gear ratio), the first parking body 410 can reduce the magnitude of the load applied to the second parking member 600. When the first output shaft 210 rotates, the first parking body 410 can rotate together with the first output shaft 210 in the direction of brake application or in the direction of brake release.

[0081] The extension part 420 can be used as a component that extends from the first parking body 410 and forms an interference structure with the second parking member 600. As an example, the extension part 420 can protrude from the circumferential surface of the first parking body 410 to the outside of the first parking body 410. The extension part 420 can be composed of a plurality of extension parts. The plurality of extension parts 420 can be arranged at set intervals along the circumferential surface of the first parking body 410 around the central axis of the first parking body 410. The distances between adjacent extension parts 420 can all be the same.

[0082] Each extension portion 420 may extend obliquely with respect to the radial direction of the first parking body 410. As an example, the extension portion 420 may be inclined at a set angle, or may extend spirally in a curved shape from the circumferential surface of the first parking body 410 in the direction of brake release (i.e., in the counterclockwise direction in Figure 6 ). Thus, when the extension portion 420 is fastened to the second parking member 600, it may allow the first parking body 410 to rotate in the direction of brake release while also restricting the rotation of the first parking body 410 in the direction of brake release.

[0083] The second motor 500 is installed in the housing 100 and generates a rotational force to rotate the second parking member 600. As an example, the second motor 500 may be exemplified as various types of electric motors that can rotate the second output shaft 510 by receiving power from the outside. The second motor 500 may be spaced apart from the first motor 200. The second motor 500 may be disposed inside the housing body 110, or alternatively, may be disposed outside the housing body 110. The second motor 500 may be fixed to the housing body 110 by various types of joining methods (e.g., bolt connection, welding, and assembly). The second motor 500 may be electrically connected to a battery of the vehicle, etc., to receive power therefrom.

[0084] The second output shaft 510 may be disposed in the internal space of the housing 110. The second output shaft 510 may be arranged such that its longitudinal direction is misaligned with the longitudinal direction of the first output shaft 210. The misalignment of the first output shaft 210 and the second output shaft 510 may mean that they cross each other in the same plane or are twisted together in three-dimensional space. As an example, in Figure 6 , the second output shaft 510 may be arranged such that its longitudinal direction is parallel to the Z-axis direction, and the first output shaft 210 may be arranged such that its longitudinal direction is parallel to the X-axis direction.

[0085] The second parking member 600 may be rotatably installed in the housing 100. The second parking member 600 may be rotated by the operation of the second motor 500 and the conversion member 700, and may selectively restrict the rotation of the first parking member 400 according to its rotation direction. More specifically, the second parking member 600 may allow the first parking member 400 to rotate during normal driving of the vehicle, so that the main brake can be smoothly performed by the first motor 200. In addition, the second parking member 600 may restrict the rotation of the first parking member 400 during the main brake of the vehicle, so that even if the operation of the first motor 200 stops, the piston unit 20 can be prevented from losing the parking braking force due to any separation from the brake pad P.

[0086] The second parking member 600 may include a second parking body 610, a lever 620, and a latch portion 630.

[0087] The second parking body 610 may define the central appearance of the second parking member 600 and may support the lever 620 and the latch portion 630 as a whole. The second parking body 610 may be mounted to be rotatable about a rotation axis A parallel to the first output shaft 210. As an example, the second parking body 610 may have a cylindrical shape and may be rotatably supported on the rotation axis A that extends from the housing body 110 parallel to the first output shaft 210.

[0088] The second parking body 610 may rotate about the rotation axis A in a first rotation direction and a second rotation direction opposite to the first rotation direction. The rotation of the second parking body 610 in the first rotation direction may mean that the second parking body 610 rotates counterclockwise about the Figure 6 rotation axis A in, and the rotation of the second parking body 610 in the second rotation direction may mean that the second parking body 610 rotates clockwise about the Figure 6 rotation axis A in.

[0089] The lever 620 may extend from one side of the second parking body 610. The lever 620 may serve as a component for transmitting the driving force applied from the conversion member 700 to the second parking body 610. More specifically, the lever 620 may convert the linear motion of the conversion member 700 into the rotational motion of the second parking body 610 about the rotation axis A. As an example, the lever 620 may be in the form of a lever that extends in the radial direction of the second parking body 610 from the circumferential surface of the second parking body 610.

[0090] The latch portion 630 may extend from the other side of the second parking body 610 and may be spaced apart from the lever 620. The latch portion 630 may restrict or allow the rotation of the extension portion 420 according to the rotation direction of the second parking body 610.

[0091] As an example, the latch portion 630 may extend in the radial direction of the second parking body 610 from the circumferential surface of the second parking body 610. The longitudinal direction of the latch portion 630 may be inclined at a set angle about the rotation axis A with respect to the longitudinal direction of the lever 620. In other words, the lever 620 and the latch portion 630 may extend from the circumferential surface of the second parking body 610 in different directions.

[0092] The latch portion 630 may have an end pointing to the first parking member 400. When the second parking body 610 rotates in the first rotation direction, the latch portion 630 may be inserted between any associated pair of adjacent extension portions 420. In this case, the latch portion 630 may be latched to the associated extension portion 420 to restrict the rotation of the first parking body 410. When the second parking body 610 rotates in the second rotation direction, the latch portion 630 may be separated from the associated pair of adjacent extension portions 420. In this case, the latch portion 630 may be unlatched from the associated extension portion 420 to allow the first parking body 410 to rotate.

[0093] The width of the latch portion 630 may gradually narrow toward its end. Thus, when the second parking body 610 rotates in the first rotation direction, the latch portion 630 may be more easily inserted between any associated pair of adjacent extension portions 420.

[0094] The conversion member 700 may convert the rotational force of the second motor 500 into linear motion to rotate the second parking member 600. The conversion member 700 may be disposed between the second motor 500 and the second parking member 600. Since the second parking member 600 is indirectly connected to the second motor 500 via the conversion member 700, the second output shaft 510 may not be aligned with the first output shaft 210, thereby increasing the degree of freedom in placing the second motor 500.

[0095] The conversion member 700 may include a first conversion gear 710 and a second conversion gear 720.

[0096] The first conversion gear 710 may be connected to the second output shaft 510 and rotate together with the second output shaft 510. As an example, the first conversion gear 710 may be a pinion gear with gear teeth formed on its outer peripheral surface. The central axis of the first conversion gear 710 may be coaxially positioned with the central axis of the second output shaft 510. The first conversion gear 710 may have an inner peripheral surface that is splined to the outer peripheral surface of the second output shaft 510. Thus, when the second output shaft 510 rotates, the first conversion gear 710 may rotate at the same angular velocity as the second output shaft 510.

[0097] The second conversion gear 720 may be connected to the first conversion gear 710. The second conversion gear 720 may linearly reciprocate in a first direction and a second direction opposite to the first direction as the first conversion gear 710 rotates. The second conversion gear 720 may press or release the lever 620 according to its movement direction and may rotate the second parking body 610.

[0098] As an example, the second conversion gear 720 may be a rack gear, with gear teeth formed on one of its surfaces. One surface of the second conversion gear 720 may mesh with the outer peripheral surface of the first conversion gear 710. The second conversion gear 720 may have one end facing one surface of the rod 620. When the first conversion gear 710 rotates, the second conversion gear 720 may linearly and longitudinally reciprocate in a first direction and a second direction. The first direction may, for example, refer to a direction that is parallel to the longitudinal direction of the second conversion gear 720 and in which the end of the second conversion gear 720 linearly moves toward one surface of the rod 620. The second direction may, for example, refer to a direction that is parallel to the longitudinal direction of the second conversion gear 720 and in which the end of the second conversion gear 720 linearly moves away from one surface of the rod 620. As an example, in Figure 6 the first direction may refer to the left direction and the second direction may refer to the right direction.

[0099] The second conversion gear 720 may press the rod 620 in the first direction when it moves in the first direction. When the second conversion gear 720 presses the rod 620 in the first direction, the second parking body 610 may rotate about the rotation axis A in a first rotation direction (in the Figure 6 counterclockwise direction in

[0100] ). Figure 6 When the second conversion gear 720 moves in the second direction, it may release the pressing force applied to the rod 620 in the first direction. When the second conversion gear 720 releases the rod 620, the second parking body 610 may rotate about the rotation axis A in a second rotation direction (in the Figure 6 clockwise direction in

[0101] ).

[0102] The brake actuator 30 may further include a return member 800. The return member 800 may be connected to the rod 620 to press the rod 620 in the second direction. The return member 800 may be configured to be elastically deformable in a direction parallel to the first direction and the second direction. The return member 800 may serve as a component that, when the second conversion gear 720 releases the pressing force applied to the rod 620, returns the rod 620 to its initial position through its own elastic restoring force. Thus, without driving the second motor 500, the return member 800 may return the rod 610 to its initial position, enabling two-way rotation of the second parking body 610 only through on / off control of the second motor 500.

[0102] As an example, the return member 800 may be a compression spring that is elastically deformable in its longitudinal direction. The return member 800 may be arranged such that its longitudinal direction is parallel to the longitudinal direction of the second switching gear 720. The return member 800 may be arranged to face the other surface of the rod 620. In other words, the return member 800 may be arranged to face the second switching gear 720, with the rod 620 being between the return member 800 and the second switching gear 720. One end of the return member 800 may contact the other surface of the rod 620. One end of the return member 800 may simply contact the other surface of the rod 620, or may be otherwise fixed to the other surface of the rod 620. The other end of the return member 800 may be fixed to the housing body 110 or to a separate support device (not shown) installed in the housing body 110.

[0103] When the second parking body 610 and the rod 620 rotate in the first rotation direction about the rotation axis A, the return member 800 may be elastically deformed in its longitudinal direction, thereby accumulating elastic energy to press the rod 620 in the second direction. When the second switching gear 720 moves in the second direction to release the rod 620, the return member 800 may press the rod 620 in the second direction by the accumulated elastic energy and rotate the second parking body 610 in the second rotation direction.

[0104] Meanwhile, when the return member 800 is not installed, the end of the second switching gear 720 may be directly fixed to one surface of the rod 620. In this case, when the second switching gear 720 moves in the second direction, it may pull the rod 620 in the second direction and rotate the second parking body 610 in the second rotation direction.

[0105] The second parking body 610 may be installed to reciprocate in the longitudinal direction of the rotation axis A. As an example, the second parking body 610 may have an inner circumferential surface that is spline-engaged with the outer circumferential surface of the rotation axis A.

[0106] The side surface of the latch portion 630 may be inclined with respect to the longitudinal direction of the rotation axis A. As an example, the cross-section of the latch portion 630 may gradually narrow as it points downward in Figure 5 it.

[0107] The side surface of the extension portion 420 may also be inclined with respect to the longitudinal direction of the first output shaft 210. In this case, the side surface of the extension portion 420 may be formed at an angle corresponding to the side inclination of the latch portion 630, so as to make surface contact with the side surface of the latch portion 630. As an example, the cross-section of the extension portion 420 may gradually narrow as it points upward in Figure 5 it. Alternatively, the side surface of the extension portion 420 may be parallel to the longitudinal direction of the first output shaft 210.

[0108] A part of the reaction force acting between the extension part 420 and the latch part 630 can be transmitted in a direction parallel to the longitudinal direction of the rotation axis A through the inclination angles of the side surfaces of the extension part 420 and the latch part 630. In this case, when the reaction force acting between the extension part 420 and the latch part 630 increases beyond a set magnitude, the second parking body 610 can linearly move in the leaving direction parallel to the longitudinal direction of the rotation axis A. When the second parking body 610 moves in the leaving direction, the latch part 630 can be separated from the extension part 420. As an example, the leaving direction can refer to Figure 5 the upward direction in []. Therefore, if the second parking body 610 cannot smoothly rotate in the second rotation direction due to the clamping between the extension part 420 and the latch part 630 or the damage of the return member 800, the latch part 630 can be unlatched from the extension part 420 by the forced rotation of the first output shaft 210.

[0109] The brake actuator 30 can also include a return member 900.

[0110] After the second parking body 610 moves in the leaving direction, the return member 900 can move the second parking body 610 in a direction opposite to the leaving direction. Therefore, after the extension part 420 and the latch part 630 are forcibly separated, the return member 900 can return the second parking body 610 to its initial position, thereby preventing a permanent loss of the main brake maintaining performance of the brake actuator 30.

[0111] The return member 900 can include a return body 910 and an elastic member 920.

[0112] The return body 910 can be spaced apart from the second parking body 610 in a direction parallel to the longitudinal direction of the rotation axis A. As an example, the return body 910 can be in the form of a disk extending in the radial direction of the rotation axis A from the circumferential surface of the rotation axis A. The lower surface of the return body 910 can face the upper surface of the second parking body 610. Alternatively, the upper surface of the return body 910 can face the lower surface of the second parking body 610.

[0113] The elastic member 920 can be configured to be elastically deformable in a direction parallel to the longitudinal direction of the rotation axis A. As an example, the elastic member 920 can be a compression spring that is elastically deformable in its longitudinal direction. The elastic member 920 can be arranged such that its longitudinal direction is parallel to the longitudinal direction of the rotation axis A. The central axis of the elastic member 920 can be coaxially positioned with the central axis of the rotation axis A. The elastic member 920 can have two ends that are in contact with the respective facing surfaces of the return body 910 and the second parking body 610.

[0114] When the second parking body 610 is in its initial position, the elastic member 920 can be installed in a neutral state without being tensioned or compressed. When the second parking body 610 moves in the leaving direction, the elastic member 920 can be longitudinally tensioned or compressed to accumulate elastic energy. After the extension portion 420 and the latch portion 630 are forcibly separated, the elastic member 920 can press or pull the second parking body 610 in a direction opposite to the leaving direction by the accumulated elastic energy, so that the second parking body 610 returns to its initial position. When the second parking body 610 rotates in the first rotation direction, the initial position of the second parking body 610 can be designed and changed in various ways within the range of the position where the latch portion 630 can be inserted between a pair of adjacent extension portions 420 associated therewith.

[0115] Although the second parking body 610 has been described above as being installed to reciprocate in the longitudinal direction of the rotation axis A as an example, the present disclosure is not limited thereto. For example, the first parking body 410 may also be installed to reciprocate in the longitudinal direction of the first output shaft 210. In this case, the reset member 900 may be positioned and have a structure that presses the first parking body 410 in a direction opposite to the leaving direction.

[0116] The brake actuator 30 may further include a control module.

[0117] The control module is connected to the first motor 200 and the second motor 500 and controls the operations of the first motor 200 and the second motor 500. More specifically, the control module may control the operations of the first motor 200 and the second motor 500 based on a brake signal or a brake release signal generated by the driver's brake pedal operation or a parking brake command. The control module may be implemented as an integrated circuit (IC), a microcontroller (μC), a microprocessor, an application specific integrated circuit (ASIC), or a combination thereof, which may be electrically connected to the first motor 200 and the second motor 500, and may control whether the first output shaft 210 and the second output shaft 510 rotate, the rotational speeds of the first output shaft 210 and the second output shaft 510, etc. The control module may control the rotational directions of the first output shaft 210 and the second output shaft 510 in only one direction through on / off operations. Alternatively, the control module may bidirectionally control the rotational directions of the first output shaft 210 and the second output shaft 510 through multiple circuits. The control module may be disposed inside the housing 100, or may be otherwise engaged to the outer surface of the housing 100.

[0118] Hereinafter, the operation of the brake actuator 30 according to an embodiment of the present disclosure will be described.

[0119] Figures 7 to 9 It is a view schematically showing the process of generating a parking braking force.

[0120] Referring Figures 7 to 9 , during parking braking, with the second parking body 610 in its initial position, the first motor 200 can rotate the first output shaft 210 in the direction of brake application (in the Figure 7 counterclockwise direction in ).

[0121] When the first output shaft 210 rotates in the direction of brake application, the rotational force of the first output shaft 210 can be transmitted to the piston unit 20 through the transmission gear 300, and the brake pad P can contact the brake disc D to generate a braking force in the vehicle.

[0122] In this case, the first parking member 400 can rotate in the direction of brake application together with the first output shaft 210.

[0123] Then, the second motor 500 rotates the second output shaft 510 to move the second conversion gear 720 in the first direction (to the Figure 8 left in ).

[0124] When the second conversion gear 720 moves in the first direction, it can press the lever 620 in the first direction.

[0125] When the second conversion gear 720 presses the lever 620 in the first direction, the pressing force applied to the lever 620 in the first direction can be converted into a rotational force in the first rotational direction (in the Figure 8 counterclockwise direction in ) about the rotation axis A, and the second parking body 610 can rotate about the rotation axis A in the first rotational direction.

[0126] When the second parking body 610 and the lever 620 rotate about the rotation axis A in the first rotational direction, the return member 800 can be elastically deformed in its longitudinal direction, thereby accumulating elastic energy to press the lever 620 in the second direction.

[0127] When the second parking body 610 rotates in the first rotational direction by more than a set angle, the latch portion 630 can be inserted between any associated pair of adjacent extension portions 420.

[0128] Then, the operation of the first motor 200 stops, and a rotational force in the brake release direction (in the Figure 9 clockwise direction in ) is generated in the first output shaft 210 by the reaction force acting between the brake disc D and the brake pad P.

[0129] By applying a rotational force to the first output shaft 210 in the brake release direction, the extension part 420 and the latch part 630 are unlatched from each other.

[0130] The rotational force applied to the first output shaft 210 in the brake release direction can be offset by the latching force between the extension part 420 and the latch part 630 and the supporting force of the second stopper relative to the first stopper, and the parking brake can be maintained by restricting the rotation of the first parking body 410 and the first output shaft 210.

[0131] Figures 10 to 12 is a view schematically showing the process of releasing the parking brake force.

[0132] Reference Figures 1 to 12 , when the parking brake is released, in the Figure 9 state, the first motor 200 can rotate the first output shaft 210 in the brake application direction (in the counterclockwise direction in Figure 12 ) by a certain angle.

[0133] When the first output shaft 210 rotates in the brake application direction, the magnitude of the reaction force acting between the extension part 420 and the latch part 630 decreases.

[0134] Due to the decrease in the reaction force, the pressing force of the second parking body 610 on the rod 620 in the second direction by the return member 800 rotates the rod 620 in the second rotation direction (in the clockwise direction in Figure 11 ) around the rotation axis A.

[0135] When the second parking body 610 and the rod 620 rotate around the rotation axis A in the rotation direction, without driving the second motor 500, the second conversion gear 720 can linearly move in the second direction, and the rod 620 can return to its initial position.

[0136] When the second parking body 610 rotates in the rotation direction, the latch part 630 separates from a pair of adjacent extension parts 420, and allows the first parking body 410 and the first output shaft 210 to rotate.

[0137] Then, the first output shaft 210 can rotate in the brake release direction (in the clockwise direction in Figure 12 ), thereby releasing the parking brake force.

[0138] Figures 13 to 15 is a view schematically showing the process of forcibly releasing the parking brake force.

[0139] Reference Figures 1 to 15 , if the first output shaft 210 does not rotate in the brake application direction (in Figure 13rotates in the counterclockwise direction (in the counterclockwise direction in the figure), and the second parking body 610 does not rotate about the rotation axis A in the second rotation direction ( Figure 13 in the clockwise direction in the figure) due to damage to the clamping or return member 800 between the extension portion 420 and the latch portion 630, the first motor 200 forcibly rotates the first output shaft 210 in the direction of brake release ( Figure 13 in the clockwise direction in the figure).

[0140] When the first output shaft 210 rotates in the direction of brake release, the magnitude of the reaction force acting between the extension portion 420 and the latch portion 630 increases.

[0141] A part of the reaction force acting between the extension portion 420 and the latch portion 630 is transmitted in a direction parallel to the longitudinal direction of the rotation axis A through the inclination angles of the side surfaces of the extension portion 420 and the latch portion 630.

[0142] When the reaction force acting between the extension portion 420 and the latch portion 630 increases beyond a set magnitude, the second parking body 610 linearly moves in the direction of separation ( Figure 14 in the upward direction in the figure) parallel to the longitudinal direction of the rotation axis A.

[0143] The extension portion 420 can move relative to the latch portion 630 in the longitudinal direction of the rotation axis A, and the extension portion 420 and the latch portion 630 can be separated from each other.

[0144] During this process, the elastic member 920 is elastically deformed in the longitudinal direction of the rotation axis A to accumulate elastic energy to restore the second parking body 610 to its initial position.

[0145] When the extension portion 420 and the latch portion 630 are separated from each other, the first output shaft 210 can rotate in the direction of brake release.

[0146] Then, when the second parking body 610 returns to its initial position by the elastic restoring force of the return member 800, the driving force of the second motor 500 or manually, the first parking body 610 can move in the direction opposite to the separation direction ( Figure 15 in the downward direction in the figure) and can return to its initial position.

[0147] Although the present disclosure has been described with reference to the embodiments shown in the drawings, it will be apparent to those skilled in the art that these embodiments are provided only by way of example. Those skilled in the art will understand that various modifications and other equivalent embodiments can be made without departing from the spirit and scope of the present disclosure defined in the technical solutions of the present disclosure.

Claims

1. A brake actuator, comprising: case; a first motor mounted in the housing; a transmission gear rotatably mounted in the housing and connected to the first motor; a first parking member configured to rotate together with the transmission gear; a second motor spaced apart from the first motor; a second parking member rotatably mounted in the housing and configured to selectively restrict rotation of the first parking member according to a rotation direction of the second parking member; as well as A conversion member is configured to convert the rotational force of the second motor into a linear motion to rotate the second parking member.

2. The brake actuator according to claim 1, wherein: The first parking member comprises: a first parking body connected to a first output shaft of the first motor; and A plurality of extension portions extend from the first parking body and are arranged along a circumferential surface of the first parking body.

3. The brake actuator according to claim 2, wherein: Each of the extending portions extends obliquely with respect to a radial direction of the first parking body.

4. The brake actuator according to claim 2, wherein: The second parking member comprises: a second parking body mounted to be rotatable about a rotation axis parallel to the first output shaft; a rod extending from one side of the second parking body and configured to convert a linear motion of the conversion member into a rotational motion of the second parking body; and A latch portion extends from the other side of the second parking body and is inserted between an associated pair of adjacent extending portions when the second parking body is rotated in the first rotation direction.

5. The brake actuator according to claim 4, wherein: The conversion component comprises: a first conversion gear connected to a second output shaft of the second motor and rotating together with the second output shaft of the second motor; and a second conversion gear connected to the first conversion gear and linearly moving in a first direction or a second direction opposite to the first direction and configured to press or release the lever, and When the second conversion gear presses the rod in the first direction, the second parking body rotates in the first rotation direction.

6. The brake actuator according to claim 5, wherein: The first output shaft is not aligned with the second output shaft.

7. The brake actuator according to claim 5, wherein: The first conversion gear is a pinion gear, and the second conversion gear is a rack gear. 8 . The brake actuator of claim 5 , further comprising a return member connected to the rod and configured to press the rod in the second direction.

9. The brake actuator according to claim 8, wherein: The return member is disposed to face the second conversion gear with the rod interposed therebetween.

10. The brake actuator according to claim 8, wherein: The return member is configured to be elastically deformable in a direction parallel to the second direction.

11. The brake actuator according to claim 10, wherein: The return member is a compression spring.

12. The brake actuator according to claim 4, wherein: The second parking body is installed to be movable in the longitudinal direction of the rotation axis; and When a load acting between an associated one of the pair of adjacent extending portions and the latch portion increases beyond a set magnitude, the second parking body moves in a departure direction parallel to the longitudinal direction of the rotation shaft.

13. The brake actuator according to claim 12, wherein: The latch portion has a side surface inclined with respect to a longitudinal direction of the rotation axis. 14 . The brake actuator according to claim 12 , further comprising a return member configured to press the second parking body in a direction opposite to the departure direction.

15. The brake actuator according to claim 14, wherein: The reset member comprises: a reset body disposed to face the second parking body; and An elastic member is configured to be elastically deformable in a direction parallel to the longitudinal direction of the rotation shaft and has both ends contacting the return body and the second parking body, respectively.

16. The brake actuator according to claim 15, wherein: The elastic member is a compression spring.

17. A braking device, comprising: Caliper body; a piston unit movably mounted on the caliper body and configured to contact or separate from the brake pad according to a movement direction of the piston unit; as well as a brake actuator connected to the piston unit and configured to move the piston unit, Wherein, the brake actuator comprises: case; a first motor mounted in the housing; a transmission gear rotatably mounted in the housing and connected to the first motor; a first parking member configured to rotate together with the transmission gear; a second motor spaced apart from the first motor; a second parking member rotatably mounted in the housing and configured to selectively restrict rotation of the first parking member according to a rotation direction of the second parking member; and A conversion member is configured to convert the rotational force of the second motor into a linear motion to rotate the second parking member.

Images