PARKING BRAKE ACTUATOR

Abstract

A parking brake actuator is disclosed. According to one aspect of the disclosure, a parking brake actuator includes a motor that generates a force; a reduction gear portion including a drive gear that rotates in conjunction with a drive shaft of the motor and a sun gear coupled for common rotation with the drive gear; a housing housing the motor and the reduction gear portion; and a locking portion configured to restrict rotation of the reduction gear portion.wherein the locking portion is further configured by a pair of locking elements configured to lock and release at least a part of a rotating shaft of the sun gear, a plurality of elastic elements supporting each of the locking elements in a direction of the rotating shaft of the sun gear, and an electromagnet element configured to separate the locking elements from the sun gear by generating an electromagnetic force when current is applied;

Description

[Technical field]

[0001] The disclosure relates to a parking brake actuator and, more particularly, to a parking brake actuator capable of stably maintaining a parking brake state when the parking brake is applied. [General state of the art]

[0002] Generally, a vehicle is equipped with a braking system to perform braking. Such a braking system requires a service brake function that provides braking force when the vehicle is moving, and a parking brake function that keeps the vehicle stopped when parked.

[0003] A conventional parking brake mainly uses a foot brake, which is operated by pressing a pedal with one foot, and a hand brake, which is operated by pulling a lever with one hand. With the hand brake, a user pulls the lever up with great force to engage a parking brake lever, which is why drivers who frequently stop or park a vehicle may suffer back injuries or strain their arm. Furthermore, a parking brake lever is located in the center of a console, limiting the utilization of a vehicle's interior space.

[0004] Therefore, a method is recently being developed to implement an electromechanical parking brake by using an actuator that generates a braking force through a motor when it receives the driver's intention to apply a parking brake as an electrical signal such as by pressing a button.

[0005] During a vehicle's parking brake application, a parking section, such as a piston and threaded nut spindle of a caliper brake and a parking brake shoe of a drum brake, maintains the braking force. However, even if the parking section maintains the parking brake force, if a variable exists that prevents the parking brake from being maintained, such as an external impact or a vehicle having to park on a downhill slope, the vehicle's parking brake state may be released, and the vehicle may then move. Accordingly, stones or braces are often placed between wheels or at a rear of the wheels to prevent the vehicle from moving despite the parking brake state.

[0006] In order to maintain the parking brake state when a parking brake function of the vehicle is operated as described above, various locking methods such as a separate locking gear provided in a gear portion of the actuator to maintain the fixed state of the actuator have been developed.

[0007] EP 1 058 795 B1, for example, discloses an actuating unit for an electromechanically actuated disc brake, in which an electromagnetically actuated locking mechanism serves to lock or release a sun gear of a planetary gear of an electromechanical parking brake device. [Revelation][Technical Problem]

[0008] One aspect of the disclosure is to provide a parking brake actuator capable of suppressing rollback of a vehicle during parking braking.

[0009] Another aspect of the disclosure is to provide an actuator for a parking brake capable of improving responsiveness and stability during parking braking.

[0010] Another aspect of the disclosure is to provide a parking brake actuator capable of improving the mountability of the product and improving the design freedom of the vehicle.

[0011] Another aspect of the disclosure is to provide a parking brake actuator that maintains a locked state when no power is applied to reduce vehicle power consumption and has a fail-safe function. [Technical solution]

[0012] According to one aspect of the present disclosure, an actuator for a parking brake includes a motor that generates a force; a reduction gear portion that includes a drive gear that rotates in conjunction with a drive shaft of the motor and a sun gear coupled for common rotation with the drive gear; a housing that houses the motor and the reduction gear portion; and a locking portion configured to restrict rotation of the reduction gear portion.wherein the locking portion is further configured by a pair of locking elements configured to lock and release at least a part of a rotating shaft of the sun gear, a plurality of elastic elements supporting each of the locking elements in a direction of the rotating shaft of the sun gear, and an electromagnet element configured to separate the locking elements from the sun gear by generating an electromagnetic force when current is applied;

[0013] The pair of locking members may be arranged to face the sun gear located at their center and is provided to be in close contact with the rotating shaft of the sun gear.

[0014] Each of the pair of locking members may have a friction surface having a shape corresponding to an outer peripheral surface of the rotating shaft of the sun gear, the friction surface being a surface facing the rotating shaft of the sun gear.

[0015] The actuator may further comprise a housing cover, thereby closing the housing, wherein the locking portion further comprises a body case accommodating therein the pair of locking elements, the elastic elements and the electromagnet element and is attached to the housing cover.

[0016] The body housing may include a side rib configured to slidably support the pair of locking members; and a support rib configured to restrict a range of movement of the pair of locking members.

[0017] The elastic element can be inserted between the support rib and the locking element.

[0018] One end of the elastic member may be supported by the support rib, and its other end may be inserted into an insertion hole provided in an outer surface of the locking member.

[0019] The elastic element may be provided as a coil spring.

[0020] The surface-mounted housing can be attached to an inner wall of the housing cover.

[0021] The body housing may have a hole into which at least a part of the rotating shaft of the sun gear is inserted.

[0022] The electromagnet member may be provided in a C-shape with an opening on one side, wherein the pair of locking members are arranged in the opening.

[0023] The reduction gear portion may further include a plurality of planetary gears meshed with the sun gear; and an outer gear meshed with the plurality of planetary gears and having a connecting portion connected to a locking portion.

[0024] According to another aspect of the present disclosure, an actuator for a parking brake includes a motor that generates a force; a reduction gear portion that rotates together with a drive shaft of the motor and adjusts a reduction ratio; and a locking portion configured to restrict rotation of the reduction gear portion.wherein the locking portion is further configured by at least one locking member provided to be slidably movable toward a center axis of the reduction gear portion, at least one elastic member elastically supporting the at least one locking member to be in close contact with the center axis of the reduction gear portion, and an electromagnet member configured to separate the locking member from the center axis of the reduction gear portion by generating an electromagnetic force when current is applied.

[0025] The actuator may further comprise a housing in which the motor and the reduction gear portion are housed; and a housing cover by which the housing is closed, wherein the locking portion is attached to the housing cover. [Beneficial effects]

[0026] An embodiment of the disclosure may provide a parking brake actuator capable of suppressing rollback of a vehicle during parking braking.

[0027] Furthermore, an embodiment of the disclosure may provide an actuator for a parking brake capable of improving responsiveness and stability during parking braking.

[0028] Furthermore, an embodiment of the disclosure can provide an actuator for a parking brake capable of improving the mountability of the product and improving the design freedom of the vehicle.

[0029] Furthermore, an embodiment of the disclosure may provide a parking brake actuator that maintains a locked state when no power is applied to reduce power consumption of the vehicle and has a fail-safe function. [Description of the drawings] Fig. 1 is a cutaway perspective view schematically illustrating a cross section of a parking brake actuator according to an embodiment of the disclosure. Fig. 2 is an exploded perspective view illustrating a parking brake actuator according to an embodiment of the disclosure. Fig. 3 is a perspective view schematically illustrating an actuator for a parking brake according to an embodiment of the disclosure. Fig. 4 is a perspective view illustrating a state in which a locking portion of an actuator for a parking brake is installed on a case cover according to an embodiment of the disclosure. Fig. 5 is a sectional view illustrating operation of a parking brake actuator in a lock mode according to an embodiment of the disclosure. Fig. 6 is a sectional view illustrating an operation of the parking brake actuator when the lock mode is released according to an embodiment of the disclosure. [Modes of carrying out the invention]

[0030] Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the terms used in the specification and the appended claims should not be construed as being limited to generic and lexical meanings, but should be interpreted based on the principle that the inventor may define terms appropriately for the best explanation, based on the meanings and concepts corresponding to technical aspects of the disclosure. Therefore, the description proposed in this application merely represents a preferred example for illustrative purposes and is not intended to limit the scope of the disclosure. Therefore, it should be understood that other equivalents and modifications could be made thereto without departing from the spirit and scope of the disclosure.

[0031] Fig. 1 is a cutaway perspective view illustrating a cross section of a parking brake actuator according to an embodiment of the disclosure, Fig. 2 is an exploded perspective view illustrating a parking brake actuator according to an embodiment of the disclosure, Fig. 3 is a schematic perspective view illustrating an actuator for a parking brake according to an embodiment of the disclosure, and Fig. 4 is a perspective view illustrating a state in which a locking portion of an actuator for a parking brake is installed on a case cover according to an embodiment of the disclosure.

[0032] With reference to Fig. 1 to 4, an actuator for a parking brake according to an embodiment of the disclosure may include a motor 10 that generates a force, a reduction gear portion 20 that transmits the force of the motor 10 to a parking portion that implements a parking brake of a vehicle, a housing 30 that houses the motor 10 and a gear, a housing cover 40 that closes the housing 30, and a locking portion 100 for restricting rotation of the reduction gear portion 20.

[0033] The motor 10 may generate the power by receiving an electrical signal and may be housed in an interior of the housing 30 coupled to a vehicle body (not shown) or a brake caliper (not shown).

[0034] In addition, a rotating gear 12 is coupled to one end of a drive shaft 11 of the motor 10 to be connected to a drive gear 21 of the reduction gear section 20 described later. For example, the rotating gear 12 of the motor 10 transmits power through a belt (not shown) coupled to the drive gear 21 or through at least one connecting gear (not shown) meshed with the drive gear 21.

[0035] The housing 30 may be provided to accommodate the motor 10, the reduction gear section 20, and the locking section 100, etc. Specifically, the housing 30 may accommodate and support the motor 10 on one side thereof, accommodate the reduction gear section 20 on the other side thereof, and be coupled to the housing cover 40 to close its interior.

[0036] The housing cover 40 may be provided to close the interior of the housing 30.

[0037] The housing cover 40 may be provided with the locking portion. More specifically, a mounting housing 140 may be fixed to an inner wall of the housing cover 40 by coupling with a screw 144, and a locking element 110, an elastic element 120, and an electromagnet element 130 may be housed in the mounting housing 140.

[0038] The reduction gear section 20 can transmit the power of the motor 10 to the locking section (not shown) and adjust the reduction ratio to reduce the speed while increasing the torque.

[0039] The reduction gear section 20 may include the drive gear 21 linked to the rotating gear 12, a sun gear 23 housed at a lower end of the drive gear 21 and coupled for common rotation to the same rotating shaft 23a as the drive gear 21, a plurality of planetary gears 24 externally meshed with the sun gear 23, and an external gear 25 externally meshed with the plurality of planetary gears 24 to rotate and transmit the power to the locking section (not shown).

[0040] The rotating shaft of the reduction gear section 20 may be provided in parallel with the drive shaft 11 of the motor 10, and the drive gear 21 and the sun gear 23 may be coupled to the same rotating shaft 23a so that they can rotate together.

[0041] The drive gear 21 may be provided on its lower side with a cavity for receiving the sun gear 23, the planetary gears 24, and the external gear 25. As a result, the drive gear 21 can receive the power from the motor 10 and transmit the power sequentially to the locking portion (not shown) via the sun gear 23, the planetary gears 24, and a connecting portion 25a of the external gear 25.

[0042] The locking portion 100 may be disposed on an upper side of the drive gear 21 to restrict the rotation of the reduction gear portion 20. Specifically, the locking portion 100 is provided on an inner wall of the housing cover 40, which is disposed on the upper side of the drive gear 21, and can lock and release the rotating shaft 23a of the sun gear 23, thereby restricting the rotation of the reduction gear portion 20.

[0043] The sun gear 23 is provided at the lower end of the drive gear 21, and the rotating shaft 23a extends through the drive gear 21 and projects upward. At least a portion of the rotating shaft 23a of the sun gear 23 penetrates a hole 145 of the body case 140 and is positioned inside the body case 140. The rotating shaft 23a of the sun gear 23 can be locked or released when a pair of locking members 110 are in close contact with each other or spaced apart from each other, thereby restricting or permitting the rotation of the reduction gear section 20.

[0044] The sun gear 23 may be provided to rotate together with the drive gear 21, which is coupled to a stepped portion of the rotating shaft 23a, or may be provided integrally with the drive gear 21. Furthermore, the sun gear 23 may transmit power to the external gear 25 through at least one planetary gear 24 externally meshed with the sun gear 23. At this time, the planetary gears 24 may rotate in place.

[0045] The external gear 25 is externally meshed with the planetary gears 24 from one side, and the connecting portion 25a provided on the other side of the external gear 25, which is connected to the locking portion, can transmit the power from the planetary gears 24 to the locking portion (not shown).

[0046] The connecting portion 25a may be provided in the form of a groove in which gear teeth are provided and connected to the locking portion (not shown). For example, in a caliper brake system, the locking portion (not shown) may include a threaded nut spindle, a piston, and a pad plate, and the like, and the spindle is coupled to the connecting portion 25a to transmit the force for pressing the pad plate against a disk. Since the specific operation of the parking brake is a well-known technology, a detailed description thereof will be omitted. Moreover, the parking brake actuator 1 of the disclosure is not limited to the caliper brake system but can also be applied to the locking portion (not shown) of a drum brake system.Accordingly, it should be understood in the same way even if the connecting portion 25a of the reduction gear portion 20 is connected to the parking portion (not shown) that implements the parking braking of the drum brake system.

[0047] The locking portion 100 may be arranged on the housing cover 40 and selectively provided to be in close contact with the reduction gear portion 20 to restrict the rotation of the reduction gear portion 20. In other words, to prevent the locking portion (not shown) from being released in the parking brake state, the locking portion 100 is in close contact with the reduction gear portion 20 to restrict the rotation of the reduction gear portion 20 using a friction force.

[0048] The locking portion 100 may include the pair of locking elements 110 that lock and release at least a portion of the rotating shaft 23a of the sun gear 23, a plurality of elastic members 120 that support each locking element 110 in a direction of the rotating shaft 23a of the sun gear 23, and an electromagnet element 130 that separates the locking elements 110 from the sun gear 23 by generating an electromagnetic force when current is applied. Furthermore, the locking portion further includes the body case 140 that houses the locking element 110, the elastic member 120, and the electromagnet element 130 inside and is attached to the housing cover 40.

[0049] The locking element 110 is provided as a pair and arranged inside the body case 140. The pair of locking elements 110 is arranged to face the rotating shaft 23a of the sun gear 23 at its center and is provided to be in close contact with the rotating shaft 23a.

[0050] Specifically, the pair of locking members 110 has, on a surface opposite to the rotating shaft 23a, a friction surface 111 having a shape corresponding to an outer peripheral surface of the rotating shaft 23a. Furthermore, the pair of locking members 110 can be in close contact with or spaced apart from the rotating shaft 23a by an elastic force of the elastic members 120 and an electromagnetic force of the electromagnet member 130 described later, respectively. For example, the pair of locking members 110 is provided with friction surfaces 111 each having a semicircular cross section and in close contact with or spaced apart from the rotating shaft 23a having a cylindrical shape, thereby restricting the rotation of the reduction gear section 20.

[0051] A side surface of the locking member 110 is supported by side ribs 141 so as to be slidable toward the rotating shaft 23a of the sun gear 23. Specifically, the locking member 110 is provided so as to be slidably movable only in a direction orthogonal to the rotating shaft 23a of the sun gear 23 and is guided by the side ribs 141.

[0052] A support rib 142 may be provided in a moving direction (sliding direction) of the locking members 110 to limit a moving range of the locking member 110. At this time, the elastic member 120 is interposed between the locking member 110 and the support rib 142 so that the locking member 110 can be elastically supported in the direction of the rotating shaft 23a. Furthermore, an insertion hole 112 is provided in an outer surface of the locking member 110 on the side of the support rib 142 to receive one end of the elastic member 120, thereby preventing the elastic member 120 from wobbling.

[0053] The locking element 110 may be formed of a material that can be moved by an electromagnetic force; for example, at least a portion of the locking element 110 may be formed of a metal. As a result, the locking element 110 can be separated from the rotating shaft 23a by an electromagnetic force when current is applied to the electromagnet element 130.

[0054] The plurality of elastic members 120 may be provided to elastically support each locking member 110 in the direction of the rotating shaft 23a of the sun gear 23. Specifically, the elastic member 120 is provided as a coil spring interposed between the support rib 142 and the locking member 110. One end of the elastic member 120 is inserted into a protrusion 142a of the support rib 142, and the other end is inserted and fixed into the insertion hole 112 provided in the outer surface of the locking member 110.

[0055] Accordingly, in a lock mode (or when no current is applied to the electromagnet element 130), the elastic member 120 prevents the rotation of the reduction gear section 20 by urging the lock member 110 into close contact with the rotating shaft 23a of the sun gear 23.

[0056] The electromagnet element 130 may be provided as an object that generates a magnetic field when a current flows, and may also be provided to separate the locking element 110 from the sun gear 23 using an electromagnetic force. The electromagnet element 130 may receive the current by connecting a conductive wire, but this is not shown in the drawings.

[0057] The electromagnet element 130 may be provided in a C-shape such that the pair of locking elements 110 are arranged in an opening 131 therein. The length of the opening 131 of the electromagnet element 130 is greater than that of the pair of locking elements 110, so that the pair of locking elements 110 can receive sufficient electromagnetic force from the opening 131 of the electromagnet element 130. Furthermore, the opposite ends of the electromagnet element 130 may be respectively fitted between the support ribs 142, thereby securing them without wobbling.

[0058] However, the above-described electromagnet member 130 is merely an example and can be modified in various ways and should be understood in the same way as long as separation from the rotating shaft 23a of the sun gear 23 is possible by generating an electromagnetic force in the pair of locking members 110 described above.

[0059] The body case 140 has a space on its upper surface for accommodating the locking element 110, the elastic element 120 and the electromagnet element 130 and is simultaneously attached to the inner wall of the case cover 40 to close the space.

[0060] The body case 140 may have, on its inner bottom surface, the side rib 141 that supports the pair of locking elements 110 so that they can be slidably moved, and the support rib 142 that limits the movement range of the pair of locking elements 110. In this case, the support rib 142 may be provided symmetrically around the rotating shaft 23a of the sun gear 23 and support the end of the elastic member 120. Furthermore, a projection 142a is provided on the inner surface of the support rib 142 for fitting the elastic member 120 in the form of a coil spring so that it is fixedly provided.

[0061] The hole 145 may be formed in the body case 140 so that at least a part of the rotating shaft 23a of the sun gear 23 can be inserted into the body case 140. In other words, the hole 145 has a larger diameter than the rotating shaft 23a of the sun gear 23 to allow the rotating shaft 23a of the sun gear 23 to pass therethrough. As a result, the rotating shaft 23a of the sun gear 23 is provided to be rotatable in a state where the rotating shaft 23a is inserted into the body case 140, and is locked or released when the locking member 110 is in close contact with or spaced apart from the rotating shaft 23a of the sun gear 23.

[0062] Furthermore, the mounting case 140 is provided on its outer surface with a plurality of attachment portions 143 for coupling to the inner wall of the case cover 40 by means of screws 144. Accordingly, assembly is improved because the locking portion 100 is attached to the case cover 40, which ultimately closes the case 30, thus affecting only the assembly process of the case cover 40. Furthermore, since the locking portion 100 is attached to the case cover 40, when the design of the locking portion 100 is changed, it is easy to implement the design change because no other parts are affected by the design change.

[0063] In one embodiment of the disclosure, an electronic control unit (ECU, not shown) may be provided for controlling the motor 10 and the solenoid element 130. The ECU according to an exemplary embodiment of the disclosure may be implemented by a non-volatile memory (not shown) configured to store data associated with an algorithm configured to control various components or software instructions for reproducing the algorithm, and a processor (not shown) configured to perform the operations described below using the data stored in the corresponding memory. Alternatively, the memory and the processor may be combined together as a single chip. The processor may take the form of one or more processors.

[0064] Hereinafter, an operation of the parking brake actuator 1 according to an embodiment of the disclosure will be described.

[0065] Fig. 5 is a sectional view illustrating an operation of the parking brake actuator 1 in the lock mode according to an embodiment of the disclosure, and Fig. 6 is a sectional view illustrating an operation of the parking brake actuator when the lock mode is released according to an embodiment of the disclosure.

[0066] With reference to Fig. 5 and Fig. 6, the parking brake actuator 1 according to an embodiment of the disclosure may operate in a lock mode in which the parking brake state of the vehicle is maintained and in a lock release mode following the release of the parking brake of the vehicle.

[0067] First, in the lock mode, the parking brake actuator 1 receives an electrical signal from the ECU (not shown), generates a force through the motor 10, and transmits the force through the reduction gear section 20 to the parking section (not shown), thereby implementing the parking brake. When the parking brake is completed, the lock section 100 prevents the reduction gear section 20 from rotating in the direction of braking release, thereby maintaining the braking state.

[0068] Specifically, in the parking brake actuator 1, when braking is completed, the current applied to the electromagnet element 130 is removed, and the electromagnetic force acting on the pair of locking elements 110 is extinguished. At this time, each of the pair of locking elements 110 is elastically supported toward the rotating shaft 23a of the sun gear 23 by the elastic member 120, and thereby is in close contact with the rotating shaft 23a of the sun gear, preventing the sun gear 23 and the reduction gear section 20 from rotating. Specifically, when the locking elements 110 and the rotating shaft 23a are in close contact with each other, the friction surfaces 111 respectively provided on the pair of locking elements 110 are in close contact with the rotating shaft 23a, so that rotation of the reduction gear section 20 can be prevented by frictional force.

[0069] Then, when the lock mode is released, the parking brake actuator 1 separates the lock member 110 from the rotating shaft 23a of the sun gear 23 to release the parking brake, thereby allowing the reduction gear section 20 to rotate in the brake release direction. Specifically, the ECU applies current to the electromagnet element 130 to generate an electromagnetic force, and thus, the lock member 110 is separated from the rotating shaft 23a of the sun gear 23 by the electromagnetic force. At this time, the magnitude of the electromagnetic force is greater than that of the elastic force of the elastic member 120, which elastically supports the lock member 110 in the direction of the rotating shaft 23a, so that the lock member 110 is separated from the rotating shaft 23a.Specifically, the electromagnetic forces generated from one end and the other end of the electromagnet element 130 generate attractive forces acting on the pair of locking elements 110, thereby moving the locking element 110 in the direction of separation from the rotating shaft 23a. As a result, a gap is created between the locking element 110 and the rotating shaft 23a of the sun gear 23, so that no frictional force is generated, thereby allowing the rotation of the reduction gear section 20.

[0070] When the locking member 110 is spaced apart, the motor 10, which receives an electrical signal from the ECU (not shown), generates a force in the direction in which the parking brake is released and transmits the force through the reduction gear section 20, thereby implementing the release of the brake.

[0071] As described above, the parking brake actuator 1 according to one embodiment of the disclosure can prevent the brake from being released in the parking brake state. Furthermore, since no current is applied to the locking portion 100 in the parking mode, it is possible to quickly and stably maintain the vehicle's parking position without additional power consumption. Furthermore, the parking brake actuator 1 of the disclosure can suppress the vehicle's rollback phenomenon even during parking on an incline.

[0072] Furthermore, the parking brake actuator 1 according to an embodiment of the disclosure can be manufactured without substantially changing the assembly process of the product in such a way that only the locking portion 100 is added to a conventional actuator.

Claims

[1] Actuator for a parking brake, comprising a motor (10) that generates a force; a reduction gear section (20) having a drive gear (21) rotating in conjunction with a drive shaft (11) of the motor and a sun gear (23) coupled for common rotation with the drive gear (21); a housing (30) in which the motor (20) and the reduction gear section are housed; and a locking portion (100) configured to restrict the rotation of the reduction gear portion (20); wherein the locking section (100) is further configured by: a pair of locking elements (110) adapted to hold and release at least part of a rotary shaft (23a) of the sun gear (23), a plurality of elastic members (120) supporting each of the locking members (110) in a direction of the rotating shaft (23a) of the sun gear (23), and an electromagnet element (130) configured to separate the locking elements (110) from the sun gear (23) by generating an electromagnetic force when current is applied. [2] The actuator according to claim 1, wherein the pair of locking members (110) are arranged to face the sun gear (23) located at the center thereof and are provided to be in close contact with the rotating shaft (23a) of the sun gear (23). [3] The actuator according to claim 2, wherein each of the pair of locking members (110) has a friction surface (111) having a shape corresponding to an outer peripheral surface of the rotating shaft (23a) of the sun gear (23), the friction surface (111) being a surface facing the rotating shaft (23a) of the sun gear (23). [4] The actuator according to claim 1, further comprising a housing cover (40) for closing the housing (30), wherein the locking portion (100) further comprises a body case (140) accommodating therein the pair of locking members (110), the elastic members (120) and the electromagnet member (130) and is attached to the housing cover (40). [5] The actuator according to claim 4, wherein the body case (140) has a side rib (141) configured to slidably support the pair of locking members (110); and a support rib (142) configured to restrict a range of movement of the pair of locking members (110). [6] Actuator according to claim 5, wherein the elastic element (120) is inserted between the support rib (142) and the locking element (110). [7] The actuator according to claim 6, wherein one end of the elastic member (120) is supported by the support rib (142), and the other end thereof is inserted into an insertion hole provided in an outer surface of the locking member (110). [8] Actuator according to claim 7, wherein the elastic element (120) is provided as a coil spring. [9] Actuator according to claim 6, wherein the body housing (140) is attached to an inner wall of the housing cover (40). [10] Actuator according to claim 6, wherein the body case (140) has a hole (145) into which at least a part of the rotary shaft (23a) of the sun gear (23) is inserted. [11] The actuator according to claim 1, wherein the electromagnet member (130) is provided in a C-shape with an opening on one side, the pair of locking members (110) being arranged in the opening. [12] Actuator according to claim 1, wherein the reduction gear section (20) further a plurality of planetary gears (24) which are toothed with the sun gear (23); and an outer gear which is toothed with the plurality of planetary gears (24) and has a connecting portion (25a) connected to a locking portion, has. [13] Actuator for a parking brake, comprising a motor (10) that generates a force; a reduction gear section (20) which rotates together with a drive shaft (11) of the motor (10) and adjusts a reduction ratio; and a locking portion (100) configured to restrict the rotation of the reduction gear portion (20); wherein the locking section (100) is further configured by: at least one locking element (110) provided so as to be slidably movable toward a central axis of the reduction gear section (20), at least one elastic member (120) elastically supporting the at least one locking member (110) so as to be in close contact with the central axis of the reduction gear section (20), and an electromagnet element (130) configured to separate the locking element (110) from the central axis of the reduction gear section (20) by generating an electromagnetic force when current is applied. [14] Actuator according to claim 13, further comprising a housing (30) in which the motor (10) and the reduction gear section (20) are housed; and a housing cover (40) whereby the housing (30) is closed, wherein the locking portion (100) is attached to the housing cover (40).

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