KR20210121490A - Electronic parking brake device - Google Patents

Abstract

The present invention relates to an electronic parking brake apparatus, comprising: a plate unit on which a brake shoe having a lining in contact with a brake drum installed on the outer surface thereof is rotationally mounted; a housing unit mounted on the plate unit; a motor unit mounted on the housing unit and driven when a power is applied; an operation unit provided in the housing unit and driven by the motor unit; an operation piston unit provided in the housing unit and including a pair of pistons which are moved by the operation unit to operate the brake shoe; and a gap adjusting unit mounted on the operation piston unit and provided to adjust a gap between the brake drum and the lining by interaction with any one of the pair of pistons. An object of the present invention is to provide the electronic parking brake apparatus which increases a utilization level of a space during design.

Description

ELECTRONIC PARKING BRAKE DEVICE

The present invention relates to an electronic parking brake device, and more particularly, to an electronic parking brake device having improved space utilization.

In general, the electronic drum brake is designed to separate the hydraulic piston, which is the main moving part, and the parking part. And, when the hydraulic pressure is applied to the hydraulic piston during main synchronization, the vehicle is decelerated by pressing the drum by Shuasei. Meanwhile, when the vehicle is parked, when the actuator operates to rotate the worm gear and the bolt screw while the hydraulic piston is pressurized, the parking piston pressurizes the shoe-say to additionally generate a parking force.

However, in the case of the conventional electronic drum brake, the hydraulic piston and the parking part, which are the main engine parts, are separated in two rows, and the wheel cylinder located between the disc and the hub bearing of the vehicle occupies most of the internal space of the drum brake. Due to this, there is a problem in that the space where the adjust part, which is a device for compensating for lining wear, is located is narrow. Therefore, there is a need to improve it.

The background technology of the present invention is disclosed in Korean Patent Publication No. 2013-0123787 (published on November 13, 2013, title of the invention: Electronic Parking Brake Device).

The present invention has been devised to solve the above problems, and an object of the present invention is to provide an electronic parking brake device that increases the utilization of space during design by including a gap adjusting unit in a mechanism for parking.

In order to achieve the above object, an electronic parking brake apparatus according to the present invention includes a plate portion on which a brake shoe, the lining in contact with a brake drum is installed on an outer surface, is rotatably mounted, a housing portion mounted on the plate portion, and the A motor unit mounted on the housing and driven when power is applied, an operating unit provided in the housing unit and driven by the motor unit, provided in the housing unit, and moved by the operating unit to move the brake an actuating piston part including a pair of pistons for actuating a shoe, and mounted on the actuating piston part, to adjust a gap between the brake drum and the lining by interaction with any one of the pair of pistons It is characterized in that it includes a gap adjustment unit provided.

The housing portion may include a body portion on which the motor portion is mounted, and an operation piston mounting portion formed on the body portion and mounted with the operation portion, the operation piston portion, and the gap adjusting portion.

The piston part includes a first piston body inserted into one side of the housing part and moved by the operation part, and a first piston having a rod insertion groove formed inside the first piston body to open toward the other side of the housing part; , A second piston body inserted into the other side of the housing part and moved by the operation part, and a bolt insertion groove formed inside the second piston body to open in a direction opposite to the direction toward the first piston. It may be characterized in that it comprises a second piston.

The piston part includes a first pressure rod coupled to the first piston and the brake shoe and moved by the first piston to push the brake shoe, and the second piston and the brake shoe coupled to the second piston It may further include a second pressure rod provided to push the brake shoe while being moved by the piston.

The gap adjusting part is inserted into the bolt insertion groove, and is screwed to the inner circumferential surface of the bolt insertion groove so as to move in the opposite direction to the direction toward the first piston when rotating in one direction, and is coupled with the second pressure rod. A bolt, a toothed portion formed on an outer circumferential surface of the adjustment bolt, and a locking portion connected to the brake shoe and caught on the toothed portion, and rotating the adjustment bolt to adjust a gap between the brake drum and the brake shoe It may be characterized in that it includes an adjustment spring part.

The adjustment spring part may include a first adjustment spring mounted on the brake shoe and having the locking part, and a second adjustment spring installed on the brake shoe and providing an elastic force to the first adjustment spring. .

The operation unit includes a worm shaft provided in the housing unit and rotated by the motor unit and having a worm on an outer peripheral surface thereof, a worm wheel unit inserted into the housing unit and provided to rotate in engagement with the worm shaft, and the worm wheel unit It may be characterized in that it includes an operating rod that is installed through and is provided to push the piston part while rotating with the rotation of the worm wheel part.

The worm wheel unit may include a worm wheel body, a rod through hole formed in the worm wheel body to pass through the operation rod, and a worm wheel formed on an outer peripheral surface of the worm wheel body to engage the worm shaft.

The actuating rod part has a rod center part that is movably fitted in the longitudinal direction of the actuating rod part into the rod through-hole, extends from one side of the rod center part and is inserted into the rod insertion groove, and when the actuating rod part rotates, the first 1 A rod rotating part screwed to the inner circumferential surface of the rod insertion groove so that the piston and the operation rod part move in opposite directions, and extending from the other side of the rod center part, to push the second piston body when the operation rod part rotates It may be characterized in that it includes a rod pressing unit provided to be out.

The rod pressing part and the second piston body may be provided in point contact.

The rod center portion may be spline-coupled to the inner circumferential surface of the rod through hole.

The electronic parking brake device according to the present invention may be included in a mechanism for parking including the actuating piston part by providing the gap adjusting part to share an installation space with the actuating piston part and to interact with each other. Accordingly, the present invention can increase the utilization of space when designing the electronic parking brake compared to the case in which the conventional gap adjusting part and the operating piston part are separately arranged.

1 is a front view schematically showing an electronic parking brake device according to an embodiment of the present invention.
2 is an enlarged view showing a part of an electronic parking brake device according to an embodiment of the present invention.
Figure 3 is an enlarged perspective view showing the operation portion, the operation piston portion and the gap adjustment portion in Figure 2;
4 is a view showing a gap adjustment state of the electronic parking brake device according to the present invention.
5 is a view showing a parking state of the electronic parking brake device according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, the embodiments described below are suitable for understanding the technical characteristics of the electronic parking brake apparatus according to the present invention. However, the present invention is not limited to the embodiments described below, or the technical features of the present invention are not limited by the described embodiments, and various modifications are possible within the technical scope of the present invention.

1 to 3 , the electronic parking brake apparatus 100 according to an embodiment of the present invention includes a plate part 101 , a housing part 200 , a motor part 300 , and an operation part 600 . ), and an operating piston unit 500 , and a gap adjusting unit 700 .

The plate part 101 is rotatably mounted with a brake shoe 10 having a lining 20 in contact with a brake drum (not shown) installed on an outer surface thereof. Specifically, the plate part 101 may be mounted on a vehicle body, and a brake drum may be coupled thereto. The pair of brake shoes 10 may be mounted on the plate portion 101 and accommodated in the inner space of the brake drum. The brake shoes 10 may be disposed symmetrically to each other, and a lower end may be rotatably mounted to the plate part 101 . A lining 20 in contact with the brake drum may be attached to the outer surface of the brake shoe 10 . When the lining 20 wears out according to the usage state of the vehicle, a gap is generated between the lining 20 and the brake drum.

The housing part 200 is mounted on the plate part 101 . For example, the housing 200 may be bolted to the plate 101 .

The motor unit 300 is mounted on the housing unit 200 and is driven when power is applied. For example, the motor unit 300 may be bolted to the housing unit 200 , and a part of the motor unit 300 is embedded in the housing unit 200 , such as the operation unit 600 , the operation piston unit 500 , and the like. It can provide rotational force.

The operation unit 600 is provided in the housing unit 200 and is driven by the motor unit 300 . For example, the operation unit 600 may be built into the housing unit 200 , and may receive the rotational force of the motor unit 300 by passing through the housing unit 200 and being connected to the motor unit 300 . .

The operating piston unit 500 is provided in the housing unit 200 , and includes a pair of pistons 510 and 520 that are moved by the operating unit 600 to operate the brake shoe 10 . For example, the actuating piston unit 500 may be disposed on both left and right sides of the housing unit 200 , and may generate a braking force by pushing the upper end of the brake shoe 10 toward the inner surface of the brake drum.

1 and 2 , the electronic parking brake apparatus 100 according to the present invention may include a hydraulic piston unit 400 and an operating piston unit 500 . That is, the hydraulic piston unit 400 and the working piston unit 500 may be provided to be separated from each other, and for example, may be installed vertically in the housing unit 200 .

The hydraulic piston unit 400 may be mounted on the housing unit 200 , and may include a hydraulic piston 410 , a spring member 420 , and a push rod 430 . For example, the housing 200 may be connected to a flow path of a hydraulic brake device (not shown) to supply hydraulic pressure for main operation. The hydraulic pistons 410 may be provided as a pair to be spaced apart from each other, and may be moved by hydraulic pressure guided by the housing unit 200 . The push rod 430 may be coupled to the hydraulic piston 410 and the brake shoe 10 to push the upper end of the brake shoe 10 when the hydraulic piston 410 moves.

In the conventional electronic parking brake device, the hydraulic piston part 400 for main braking and the operating piston part 500 providing additional parking force are arranged in two rows separated from each other, and thus occupy most of the installation space. Due to this, the conventional apparatus has a problem of insufficient space for installing the gap adjusting unit 700 for correcting the wear of the lining 20 .

To solve this problem, the gap adjusting unit 700 according to the present invention may be included in the mechanism of the working piston unit 500 . Specifically, the gap adjusting unit 700 according to the present invention is mounted on the working piston unit 500 and adjusts the gap between the brake drum and the lining 20 by interaction with any one of the pair of pistons 510 and 520 . is provided

There is some gap between the brake drum and the lining 20 attached to the brake shoe 10, and this gap is a factor affecting the braking operation. If the gap is large, problems such as a delayed cracking action may occur, and if the gap is small, wear of the lining 20 may be promoted. The gap adjusting unit 700 may adjust the gap to be maintained within an appropriate range.

Also, the gap adjusting unit 700 is mounted on the working piston unit 500 , and is provided to adjust the gap between the brake drum and the lining 20 by interaction with any one of the pair of pistons. For example, the working piston unit 500 may include a first piston 510 and a second piston 520 , and the gap adjusting unit 700 is mounted on the second piston 520 and the second piston 520 . The gap between the lining 20 and the brake drum can be adjusted by moving the brake shoe 10 by interaction with the brake shoe 10 . In this case, the second piston 520 may serve to push the brake shoe 10 for parking and to adjust the gap.

As described above, the gap adjusting unit 700 according to the present invention is provided to share an installation space with the working piston unit 500 and to interact, and thus may be included in a mechanism for parking including the working piston unit 500 . Accordingly, the present invention can increase the utilization of space when designing the electronic parking brake compared to the case in which the conventional gap adjusting unit 700 and the operating piston unit 500 are separately disposed.

Referring to FIGS. 1, 2 and 4 , the housing part 200 may include a moving part and an operating piston mounting part 230 . In addition, the housing 200 may further include a hydraulic piston mounting unit 220 .

The body 210 may be equipped with a motor 300 . For example, the body 210 may be installed through the plate, and the motor 300 may be bolted to the rear surface of the body 210 .

The actuating piston mounting part 230 may be formed in the body part 210 , and may be a space in which the actuating part 600 , the working piston part 500 , and the gap adjusting part 700 are mounted. That is, the gap adjusting unit 700 may be mounted together in a space in which the operating piston unit 500 is mounted. An operation hole 212 may be formed in the housing 200 adjacent to the operation piston mounting portion 230 .

The hydraulic piston mounting part 220 may be formed in the body part 210 and may be a space in which the hydraulic piston part 400 is mounted. A hydraulic hole 211 may be formed in the housing unit 200 adjacent to the hydraulic piston mounting unit 220 , and hydraulic pressure may be supplied to the hydraulic piston unit 400 through the hydraulic hole 211 .

3 to 5 , the working piston part 500 may include a first piston 510 and a second piston 520 .

The first piston 510 may include a first piston body 511 and a rod insertion groove 512 . The first piston body 511 may be inserted into one side of the housing part 200 and moved by the operation part 600 . And the rod insertion groove 512 may be formed to open toward the other side of the housing portion 200 in the interior of the first piston body (511).

The second piston 520 may include a second piston body 521 and a bolt insertion groove 522 . The second piston body 521 may be inserted into the other side of the housing unit 200 and moved by the operation unit 600 . And the bolt insertion groove 522 may be formed to be opened in the direction opposite to the direction toward the first piston 510 in the inside of the second piston body 521 .

For example, as in the illustrated embodiment, the first piston 510 may be inserted into the right side of the working piston mounting unit 230 , and the rod insertion groove 512 is formed to be opened toward the center of the working piston mounting unit 230 . can be The second piston 520 may be inserted into the left side of the operating piston mounting part 230 , and the bolt insertion groove 522 may be formed to open in a direction from the second piston 520 toward the brake shoe 10 . .

Also, the working piston unit 500 may include a first pressure rod 515 and a second pressure rod 525 .

The first pressure rod 515 may be provided to be coupled to the first piston 510 and the brake shoe 10 and moved by the first piston 510 to push the brake shoe 10 . In addition, the second pressure rod 525 may be coupled to the second piston 520 and the brake shoe 10 and may be provided to push the brake shoe 10 while being moved by the second piston 520 . The first pressing rod 515 and the second pressing rod 525 may move away from each other to push the brake shoe 10 to achieve parking.

Meanwhile, referring to FIGS. 1 to 3 , the gap adjustment unit 700 may include an adjustment bolt 710 , a toothed portion 720 , and an adjustment spring portion 730 .

The adjustment bolt 710 is inserted into the bolt insertion groove 522, and is screwed to the inner circumferential surface of the bolt insertion groove 522 so as to move in the opposite direction to the direction toward the first piston 510 when rotating in one direction. Also, the adjustment bolt 710 may be coupled to the second pressing rod 525 .

Specifically, a thread may be formed on the inner surface of the bolt insertion groove 522 , and a corresponding thread may be formed on the outer surface of the adjustment bolt 710 . As a result, the adjustment bolt 710 can be rotated and moved linearly in the axial direction by screwing. For example, when the adjustment bolt 710 rotates in one direction, the adjustment bolt 710 may be provided to move in a direction away from the first piston 510 , and at this time, the second pressure rod 525 coupled to the adjustment bolt 710 . ) moves and pushes the brake shoe 10 so that the gap between the lining 20 and the brake drum can be adjusted.

The toothed portion 720 is formed on the outer peripheral surface of the adjustment bolt (710). For example, the toothed portion 720 may be formed to protrude from the outer circumferential surface of the adjustment bolt 710 and may be formed along the periphery of the outer circumferential surface.

The adjustment spring portion 730 is connected to the brake shoe 10 and has a locking portion caught on the toothed portion 720 , and is provided to rotate the adjustment bolt 710 to adjust the gap between the brake drum and the brake shoe 10 . can be

Specifically, the adjustment spring part 730 may include a first adjustment spring 731 and a second adjustment spring 732 . The first adjustment spring 731 may be mounted on the brake shoe 10 and include a locking portion. In addition, the second adjustment spring 732 may be installed on the brake shoe 10 and provide an elastic force to the first adjustment spring 731 .

For example, the first adjustment spring 731 may be pivotally installed on the brake shoe 10 so that the engaging portion provided at one end may be caught by the toothed portion 720 or spaced apart. For example, the first adjustment spring 731 may be a leaf spring, but is not limited thereto. The second adjustment spring 732 has one end fixed to the brake shoe 10 and the other end fixed to the first adjustment spring 731 , thereby providing an elastic force to the first adjustment spring 731 . The second adjustment spring 732 may be a coil spring, but is not limited thereto.

When a gap exceeding a predetermined range is generated between the brake drum and the lining 20 , the adjustment bolt 710 rotates by the adjustment spring 730 and moves in a straight line. Accordingly, the gap between the brake drum and the lining 20 may be adjusted and maintained within a predetermined range.

Meanwhile, referring to FIGS. 3 to 5 , the operation unit 600 may include a worm shaft 610 , a worm wheel unit 620 , and an operation rod unit 630 .

The worm shaft 610 may be provided in the housing 200 and rotated by the motor 300 , and a worm 611 may be provided on an outer circumferential surface. Here, the worm shaft 610 may be integrally formed with the motor shaft provided in the motor unit 300 or may be coupled to the motor shaft.

The worm wheel part 620 may be inserted into the housing part 200 and provided to rotate in engagement with the worm shaft 610 . The worm wheel unit 620 is inserted into the housing and installed to be engaged with the worm shaft 610 installed through the housing to receive the driving force of the motor unit 300 .

The actuating rod part 630 may be installed to pass through the worm wheel part 620 , and may be provided to push the working piston part 500 while rotating together with the rotation of the worm wheel part 620 .

Specifically, the worm wheel unit 620 may include a worm wheel body 621 , a rod through hole 622 , and a worm wheel 623 .

The worm wheel body 621 may be installed in the center of the operating piston mounting part 230 . The rod through hole 622 may be formed in the worm wheel body 621 , and the operation rod 630 may pass therethrough. In addition, the worm wheel 623 may be formed on the outer circumferential surface of the worm wheel body 621 to engage the worm shaft 610 .

Specifically, the worm wheel body 621 may be formed in a pipe shape such that the rod through hole 622 penetrates in the longitudinal direction of the operating piston mounting part 230 . The worm wheel 623 formed on the outer circumferential surface of the worm wheel body 621 may be provided to engage the worm 611 of the worm shaft 610 . When the worm wheel body 621 rotates, the operation rod 630 penetrating through the rod through hole 622 may rotate together.

The operation rod part 630 includes a rod center part 631 , a rod rotating part 632 , and a rod pressing part 633 .

The rod center portion 631 may be movably fitted in the rod through hole 622 in the longitudinal direction of the operation rod portion 630 . Specifically, the rod center portion 631 may be spline-coupled to the inner circumferential surface of the rod through hole 622 . For example, the rod center portion 631 may have a polygonal cross-section, and the rod through hole 622 may be formed to correspond thereto. Accordingly, the rod center portion 631 may rotate together when the worm wheel portion 620 rotates, and may move in the longitudinal direction of the operation rod portion 630 .

The rod rotating part 632 may extend from one side of the rod center part 631 and be inserted into the rod insertion groove 512 . In addition, the rod rotating part 632 may be screwed to the inner circumferential surface of the rod insertion groove 512 so that the first piston 510 and the operation rod part 630 move in opposite directions when the operation rod part 630 rotates. have.

The rod pressing part 633 may extend from the other side of the rod center part 631 , and may be provided to push the second piston body 521 when the operation rod part 630 rotates.

Specifically, when the worm wheel part 620 rotates, the rod center part 631 rotates together, and the rod rotation part 632 and the rod insertion groove 512 may be screwed together. By this screwing, the operation rod 630 and the first piston 510 may move linearly in opposite directions. Accordingly, the rod pressing unit 633 may push the second piston body 521 .

Here, the rod pressing part 633 and the second piston body 521 may be provided in point contact. For example, the front end of the rod pressing unit 633 facing the second piston body 521 is formed in a spherical shape, so that the portion in which the rod pressing unit 633 and the second piston body 521 are in contact is in point contact. can Accordingly, when the second piston body 521 is pressed while the rod pressing unit 633 rotates, the frictional force between the rod pressing unit 633 and the second piston body 521 can be reduced.

However, the shape of the rod pressing part 633 is not limited thereto, and various modifications are possible if the rod pressing part 633 and the second piston body 521 can be in point contact with each other. For example, the shape of a portion in contact with the rod pressing part 633 in the second piston body 521 may be changed.

4 is a view showing a gap adjustment operation of the electronic parking brake apparatus 100 according to the present invention. Referring to FIG. 4 , when a gap occurs between the brake drum and the lining 20 , the adjustment bolt 710 may be rotated by the engaging portion of the adjustment spring 730 rotating the toothed portion 720 . When the adjustment bolt 710 is rotated, by screwing the adjustment bolt 710 and the bolt insertion groove 522, the adjustment bolt 710 moves away from the first piston 510 (refer to the direction A in FIG. 4). It protrudes from the second piston 520 while moving. At this time, the gap between the lining 20 and the brake drum may be adjusted by pushing the brake shoe 10 while the second pressure rod 525 coupled to the adjustment bolt 710 moves.

5 is a view showing a parking operation of the electronic parking brake apparatus 100 according to the present invention. Referring to FIG. 5 , when power is applied to the motor unit 300 during parking, the worm shaft 610 is rotated, and the worm wheel unit 620 engaged with the worm shaft 610 is rotated. When the worm wheel part 620 is rotated, the worm wheel body 621 and the spline-coupled rod center part 631 are rotated. When the rod center portion 631 is rotated in one direction, the rod rotating portion 632 screwed to the rod insertion groove 512 of the first piston 510 rotates to rotate the first piston 510 in the right direction (B in FIG. 5 ). ' direction). At this time, since the operation rod 630 moves in the left direction (see direction C in FIG. 5 ), the rod press unit 633 moves the second piston 520 in the left direction (see direction B in FIG. 5 ). Due to this, while the first piston 510 and the second piston 520 move in directions away from each other at the same time (refer to B and B' directions), a pair of brake shoes 10 are simultaneously operated to perform braking for parking do.

The electronic parking brake device according to the present invention may be included in a mechanism for parking including the actuating piston part by providing the gap adjusting part to share an installation space with the actuating piston part and to interact with each other. Accordingly, the present invention can increase the utilization of space when designing the electronic parking brake compared to the case in which the conventional gap adjusting part and the operating piston part are separately arranged.

As mentioned above, specific embodiments of the present invention have been described above, but the spirit and scope of the present invention are not limited to these specific embodiments, and those described in the claims by those of ordinary skill in the art to which the present invention pertains Various modifications and variations are possible without changing the gist of the present invention.

10: brake shoe 20: lining
100: electronic parking brake device
101: plate part 200: housing part
210: body 211: hydraulic hole
212: operation hole 220: hydraulic piston mounting part
230: working piston mounting unit 300: motor unit
400: hydraulic piston part 410: hydraulic piston
420: spring member 430: push rod
500: working piston unit 510: first piston
511: first piston body 512: rod insertion groove
515: first pressure rod 520: second piston
521: second piston body 522: bolt insertion groove
525: second pressure rod 600: operation unit
610: worm shaft 611: worm
620: worm wheel part 621: worm wheel body
622: rod through hole 623: worm wheel
630: operation rod portion 631: rod center portion
632: rod rotating part 633: rod pressing part
700: gap adjustment unit 710: adjustment bolt
720: toothed portion 730: adjustment spring portion
731: first adjustment spring 732: second adjustment spring

Claims (11)

a plate portion on which a brake shoe having a lining in contact with the brake drum installed on an outer surface thereof is rotatably mounted;
a housing part mounted on the plate part;
a motor unit mounted on the housing unit and driven when power is applied;
an operation unit provided in the housing unit and driven by the motor unit;
an actuating piston part provided in the housing part and including a pair of pistons moving by the actuating part to operate the brake shoe; and
and a gap adjusting part mounted on the working piston part and provided to adjust a gap between the brake drum and the lining by interaction with any one of the pair of pistons.
According to claim 1,
the housing part
a body part on which the motor part is mounted; and
and an actuating piston mounting part formed in the body part and mounted with the actuating part, the actuating piston part, and the gap adjusting part.
According to claim 1,
the piston part
a first piston having a first piston body inserted into one side of the housing part and moved by the operation part, and a rod insertion groove formed inside the first piston body to be opened toward the other side of the housing part; and
A second piston body inserted into the other side of the housing part and moved by the operation part, and a bolt insertion groove formed inside the second piston body to be opened in a direction opposite to the direction toward the first piston. An electronic parking brake device comprising two pistons.
4. The method of claim 3,
the piston part
a first pressure rod coupled to the first piston and the brake shoe and moved by the first piston to push the brake shoe; and
and a second pressure rod coupled to the second piston and the brake shoe and provided to push the brake shoe while being moved by the second piston.
5. The method of claim 4,
The gap adjusting unit
an adjustment bolt inserted into the bolt insertion groove and screwed to the inner circumferential surface of the bolt insertion groove to move in the opposite direction to the direction toward the first piston when rotating in one direction, and coupled to the second pressing rod;
Toothed portion formed on the outer peripheral surface of the adjustment bolt; and
The electronic parking brake device comprising: an adjustment spring connected to the brake shoe and provided with a locking portion caught by the toothed portion, and configured to rotate the adjustment bolt to adjust a gap between the brake drum and the brake shoe .
6. The method of claim 5,
The adjustment spring part
a first adjustment spring mounted on the brake shoe and having the locking part; and
and a second adjustment spring installed on the brake shoe and providing an elastic force to the first adjustment spring.
4. The method of claim 3,
the working part
a worm shaft provided in the housing unit and rotated by the motor unit, the worm shaft having a worm on an outer circumferential surface;
a worm wheel part inserted into the housing part and provided to rotate in engagement with the worm shaft; and
and an actuating rod part installed through the worm wheel part and provided to push the piston part while rotating together with the rotation of the worm wheel part.
8. The method of claim 7,
The worm wheel part
worm wheel body;
a rod through hole formed in the worm wheel body to pass through the operation rod; and
and a worm wheel formed on an outer circumferential surface of the worm wheel body and engaged with the worm shaft.
9. The method of claim 8,
The operation rod part
a rod center portion that is movably fitted in the rod through hole in the longitudinal direction of the operation rod;
A rod rotating part extending from one side of the rod center part and inserted into the rod insertion groove, which is screwed to the inner circumferential surface of the rod insertion groove so that the first piston and the operation rod part move in opposite directions when the operation rod part rotates. ; and
and a rod pressing part extending from the other side of the rod center part and configured to push the second piston body when the operation rod part rotates.
10. The method of claim 9,
The electronic parking brake device, characterized in that the rod pressing part and the second piston body are provided in point contact.
10. The method of claim 9,
The electronic parking brake device, characterized in that the rod center portion is spline-coupled to the inner circumferential surface of the rod through hole.

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