KR102501746B1 - Gear assembly structure of electronic parking brake - Google Patents

Abstract

The present invention relates to an electronic parking brake gear assembly structure, in which a motor and gear parts are all mounted on an inner cover assembly, the inner cover assembly is inserted into a base housing, and the housing cover is fused to the base housing.
Airtightness is improved by reducing the number of fusion points and fusion area, and operation performance is improved by not changing the installation position of gear parts during fusion, and noise is reduced by preventing axial play of the two-stage worm wheel.

Description

Gear assembly structure of electronic parking brake}

The present invention relates to an electronic parking brake gear assembly structure, and more particularly, to an electronic parking brake gear assembly structure advantageous to airtightness, operational performance, and noise reduction of a parking brake actuator.

For operation control by the electronic control unit, the actuator of the electronic parking brake generates an operating force using an electric motor, and transmits the rotational operating force generated by the motor to the parking brake mechanism by decelerating and increasing power using a gear train. there is.

For the gear train connected to the motor, a two-stage worm & worm wheel gear structure is usually applied so that the rotation can be stopped even when the motor is off, and a planetary gear is additionally applied for boosting power.

In the 2-stage worm & worm wheel gear structure, the 1-stage worm is mounted on the output shaft of the motor, and the 1-stage worm wheel meshing with the 1-stage worm is mounted on one end of the worm shaft to which the 2-stage worm is mounted. It consists of a structure in which two-stage worm wheels are engaged, and this gear train is installed inside the base housing and the housing cover, which are usually mutually coupled (fused) in the upper and lower directions. In addition, the base housing also accommodates the motor, and covers only half of the motor, and the other half is protected by a motor cover coupled (fused) to the base housing.

Therefore, since the conventional actuator requires confidential management of the two parts that are mutually fused, there is a problem in securing and maintaining the confidentiality of the actuator.

In addition, the assembly position of the worm shaft is maintained by the base housing and the housing cover. When the housing cover is fused from the top while the gear parts are placed on the lower base housing, the alignment of the gear parts is distorted, thereby activating the actuator There was a problem in that performance was deteriorated and noise was generated.

In addition, there is a vertical play in the 2-stage worm wheel, and when the actuator is operated, the 2-stage worm wheel moves upward and collides with the housing cover, resulting in noise.

Republic of Korea Patent Publication No. 2020-0012256 (2020.02.05. Publication)

Therefore, the present invention has been made to solve the above problems, the fusion area is reduced, the alignment of the gear parts is not disturbed when the housing cover is fused, and the up-down flow of the 2-stage worm wheel is suppressed during operation, thereby preventing airtightness. An object of the present invention is to provide an electronic parking brake gear assembly structure in which overoperability is improved and noise is reduced.

The present invention for achieving the above object is an inner cover assembly in which all motors and gear parts are assembled; a base housing in which the inner cover assembly is accommodated; and a housing cover coupled to the top of the base housing to seal the base housing.

The inner cover assembly includes a tubular worm shaft assembly unit and an inner cover having a motor assembly unit and a worm wheel assembly unit formed on both sides of the worm shaft assembly unit, respectively.

A worm shaft having a two-stage worm mounted on a part of the outer circumference of the worm shaft assembly part and a first-stage worm wheel mounted on one end thereof is rotatably inserted and installed.

In the worm shaft, a support member rotatably supporting the worm shaft is provided between the first stage worm wheel and the second stage worm, the support member is inserted into the inlet of the worm shaft assembly unit, and a slit formed in the worm shaft assembly unit A snap ring is inserted through to prevent separation of the support member.

A motor is fixed to the lower surface of the motor assembly unit, a rotation shaft of the motor protrudes upward from the motor assembly unit, and a first-stage worm is mounted on the rotation shaft of the motor.

A cylindrical shaft insertion part is formed in the worm wheel assembly part, a hollow shaft of a two-stage worm wheel is inserted into the shaft insertion part, and the two-stage worm wheel is rotatably installed in the worm wheel assembly part.

The hollow shaft is formed separately from the 2-stage worm wheel, the hollow shaft is inserted and fixed into the through hole of the 2-stage worm wheel, the lower flange formed at the lower end of the hollow shaft adheres to the lower end of the shaft insertion part, and the upper end of the hollow shaft is caulked Thus, an upper flange is formed, and the gap between the upper flange and the lower flange is completely filled with the shaft insertion portion and the two-stage worm wheel, so that there is no play in the axial direction.

The hollow shaft is integrally formed with the 2-stage worm wheel, a snap ring is installed at the lower end of the hollow shaft, and a washer is installed between the snap ring and the lower end of the shaft insertion portion to suppress axial behavior of the 2-stage worm wheel.

The motor assembly unit and the worm wheel assembly unit may be mounted on the base housing via a plurality of hooks.

According to the present invention as described above, the motor and gear parts are all mounted on the inner cover to form one inner cover assembly, and the inner cover assembly is embedded between the base housing and the housing cover.

Therefore, since only one point between the base housing and the housing cover is fused, the number of fused points is reduced, thereby making it easy to secure and maintain airtightness.

In addition, since all gear parts are mounted on the inner cover and their alignment is not affected by other parts, in particular, the worm shaft to which the first stage worm wheel and the second stage worm are mounted is inserted into the worm shaft assembly part formed on the inner cover Since the assembly position is not changed during the welding process between the base housing and the housing cover, the alignment of the gear parts is not displaced during the assembly process, thereby reducing the operation efficiency and operating noise of the actuator.

In addition, by applying caulking and snap rings, no axial play occurs in the 2-stage worm wheel, so that when the actuator operates, collision noise generated when the 2-stage worm wheel collides with the housing cover has an effect of being prevented.

1 is an exploded perspective view of an electronic parking brake actuator to which the present invention is applied;
2 is an exploded perspective view of an inner cover assembly, which is one component of the actuator;
3 is a plan view of a base housing in a state in which an inner cover assembly is assembled;
Figure 4 is a bottom view of Figure 3;
5 is a cross-sectional view showing a structure for preventing axial flow of a two-stage worm, which is one component of the present invention.
6 is a cross-sectional view showing an axial flow prevention structure of a two-stage worm different from the embodiment of FIG. 5;

Since the present invention can make various changes and have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. The thickness of lines or the size of components shown in the accompanying drawings may be exaggerated for clarity and convenience of description.

In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention of a user or operator or a precedent. Therefore, definitions of these terms should be made based on the content throughout this specification.

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

1 and 2, the electronic parking brake gear assembly structure according to the present invention includes an inner cover assembly 100, a base housing 200 in which the inner cover assembly 100 is embedded, and a base housing 200 ) and a housing cover 300 for sealing.

The inner cover assembly 100 refers to a state in which the motor 120 and gear parts are all assembled to the inner cover 110 . The shafts of the gear parts do not come into contact with the base housing 200 or the housing cover 300 and are installed only on the inner cover 110 to align and maintain their positions.

In the inner cover 110, a tubular worm shaft assembly 111 with one end open is formed in the middle, and the motor assembly 112 and the worm wheel assembly 113 are respectively formed on both sides of the worm shaft assembly 111 ) is formed.

The motor 120 is fixedly installed on the lower surface of the motor assembly 112, and the rotation shaft of the motor 120 protrudes above the upper surface through the through hole formed in the motor assembly 112, and the first stage worm 130 on the rotation shaft ) is installed.

A two-stage worm wheel 160 is rotatably installed on the upper surface of the worm wheel assembly unit 113.

As shown in FIG. 5, the two-stage worm wheel 160 is provided with a hollow shaft 162 at the center, and the hollow shaft 162 is inserted into the cylindrical shaft insertion portion 113 formed in the center of the worm wheel assembly portion 113. It is installed in a structure that can rotate.

A worm shaft 150 having a first-stage worm wheel 140 and a second-stage worm 151 is inserted and installed in the worm shaft assembly unit 111.

A second-stage worm 151 of a predetermined length is installed on a part of the outer circumference of the worm shaft 150, and a first-stage worm wheel 140 is installed at the opposite end of the portion where the second-stage worm 151 is installed. In addition, a circular support member 152 is provided at one end of the second stage worm 151 at a predetermined interval from the first stage worm wheel 140. The worm shaft 150 passes through the support member 152, and the worm shaft 150 is freely rotatable inside the through hole.

The worm shaft 150 is inserted into the worm shaft assembly part 111 and its insertion end is inserted into the support hole 111a formed on the end wall of the worm shaft assembly part 111 and supported in a rotatable state.

The support member 152 is inserted into the inlet of the worm shaft assembly part 111 to block the opening of the worm shaft assembly part 111, and supports the worm shaft 150 in a rotatable state as described above.

A slit 111b through which the snap ring 170 can be inserted is formed through the outer circumference of the worm shaft assembly 111 corresponding to the installation position of the support member 152, and the snap ring 170 inserted into the slit 111b ) is caught on one end of the support member 152 to prevent the separation of the support member 152, and the installation position of the worm shaft 150 and the first stage worm wheel 140 and the second stage worm 151 provided therewith keep constant

In the assembled state as described above, the first stage worm 130 and the first stage worm wheel 140, and the second stage worm 151 and the second stage worm wheel 160 are meshed with each other.

As described above, all gear parts are mounted only on the inner cover 110 and maintain their installed state, and do not come into contact with the base housing 200 or the housing cover 300 .

The base housing 200 is formed in a shape capable of covering the entirety of the inner cover assembly 100 except for the upper surface. The inner cover 110 and the housing portion 210 covering the side surfaces and bottom surfaces of the gear parts, and the motor accommodating portion protruding downward on one side of the bottom surface of the housing portion 210 and in which the motor 120 is inserted and accommodated ( 220), and a worm wheel assembly mounting portion 230 protruding upward in a gently curved shape is formed on one side of the inside of the housing portion 210.

A connector connection portion 240 for supplying power to the actuator and a mounting portion 250 having bolt holes are formed on the outer portion of the housing portion 210 to fix the actuator to the vehicle with bolts.

The inner cover 110 and the base housing 200 may be coupled to each other in a hook hanging structure. As shown in FIGS. 1 and 3, a plurality of hooks 112a are formed on the circumferential surface of the motor assembly 112, and positions corresponding to the hooks 112a are located in the housing part 210 of the base housing 200. A hook catching portion 211 is provided. The hook hooking portion 211 may be injection-formed integrally with the base housing 200, or may be manufactured as an independent member and inserted when the base housing 200 is injected, or may be installed after completion of molding.

Therefore, when the motor 120 is completely inserted into the motor accommodating part 220 and the inner cover 110 is seated on the housing part 210, the hooks 112a are inserted into the hook hooking part 211 and caught, thereby assembling the motor. The part 112 is fixed to the base housing 200.

Similarly, a plurality of hooks 112b are formed on the bottom surface of the worm wheel assembly part 113 as shown in FIGS. 4 and 5, and in correspondence with the hooks 112b, the worm wheel assembly part mounting part 230 has a coupling hole 231 ) Is formed, and a locking jaw 231a is formed on one side of the circumference of the coupling hole 231. Therefore, the hooks 112b are inserted into the coupling holes 231 and caught on the locking jaws 231a, so that the worm wheel assembly part 113 is mounted on the worm wheel assembly part mounting part 230.

As described above, the inner cover assembly 100 is firmly attached to the base housing 200 by fixing the motor assembly 112 and the worm wheel assembly 113 to one side of the enclosure 210 and the worm wheel assembly mounting portion 230. it is fitted

At this time, the motor assembly part 112 is not applied with a hook hooking structure, and a plurality of bolt holes 112a' are formed as shown in FIG. 2, and the base housing ( 200) may be fixed.

After that, the housing cover 300 having the same planar cross-sectional shape as the housing portion 210 is coupled to the upper end of the base housing 200 . The housing cover 300 is fused to the top of the housing part 210 of the base housing 200, thereby completely blocking the gap between the inner space in which the inner cover assembly 100 is built and the outside, thereby preventing moisture and dust from entering the inner space from the outside. Prevent foreign matter from penetrating.

On the other hand, in order to prevent the flow of the two-stage worm wheel 160 in the axial direction (vertical direction in the drawing), a flow suppression structure is applied as shown in FIGS. 5 and 6 .

5 is a case where the two-stage worm wheel 160 and the hollow shaft 162 are manufactured separately and assembled together, and the hollow shaft 162 is inserted and fixed into the central through-hole 161 of the two-stage worm wheel 160 to However, it rotates integrally with the worm wheel 160.

A lower flange 162b is formed at the lower end of the hollow shaft 162 and is caught on the lower end of the shaft insertion part 113a formed in the worm wheel assembly part 113. In that state, after the 2-stage worm wheel 160 is mounted on the other end (top) of the hollow shaft 162, the other end of the hollow shaft 162 is caulked outward to form an upper flange 162a.

The shaft insertion part 113a and the two-stage worm wheel 160 are installed without a gap between the upper flange 162a and the lower flange 162b of the hollow shaft 162 by caulking of the upper flange 162a. , Accordingly, the hollow shaft 162 and the second-stage worm wheel 160 are unable to flow in the axial direction (vertical direction).

In addition, the hollow shaft 162 may be integrally formed with the two-stage worm wheel 160 as shown in FIG. inserted downward from In addition, the snap ring 170 is installed in the snap ring groove 162c formed at the lower end of the hollow shaft 162 so that the snap ring 170 is caught on the lower end of the shaft insertion portion 113a, so that the two-stage worm wheel 160 moves upward to prevent At this time, if there is no gap between the snap ring 170 and the lower end of the shaft insertion portion 113a, the axial flow of the two-stage worm wheel 160 is prevented.

In addition, when there is a gap, it is possible to prevent the axial flow of the two-stage worm wheel 160 by removing the gap by installing a part such as a washer 180 between the snap ring 170 and the shaft insertion portion 113a. .

The operation of the electronic parking brake actuator according to the present invention configured as described above is performed as follows.

When the motor 120 is operated, the first-stage worm 130 mounted on the rotation shaft is rotated. Accordingly, the first-stage worm wheel 140 meshed with the first-stage worm 130 is rotated, and the second-stage worm 151 is rotated by rotating the worm shaft 150 on which the first-stage worm wheel 140 is mounted. Accordingly, the second-stage worm wheel 160 meshed with the second-stage worm 151 is rotated, and the parking brake operation force is output through an output shaft (not shown) connected to the second-stage worm wheel 160. The hollow shaft 162 of the two-stage worm wheel 160 has Torx or spline teeth formed on its inner circumferential surface so that rotational force can be transmitted to a mechanism connected to the output shaft without slipping when the output shaft is engaged.

Through the above process, the rotational force of the motor is transmitted to the parking brake mechanism to perform parking braking of the vehicle.

On the other hand, the electronic parking brake gear assembly structure according to the present invention is a motor 120 and gear parts interlocked therewith, that is, the first stage worm 130, the first stage worm wheel 140, the second stage worm 151, 2 However, all of the worm wheels 160 are mounted only on the inner cover 110, and after the assembled inner cover assembly 100 is embedded in the base housing 200, the housing cover 300 is fused to the base housing 200 do.

Therefore, since there is no separate motor cover and there is no fusion process of the motor cover, the number and area of fusion points are reduced, thereby improving the airtightness of the actuator. Such improved airtightness maintains the operating performance of the actuator smoothly, improves durability in the long term, and prevents noise caused by penetration of foreign substances.

In addition, in the present invention, all of the gear parts are mounted only on the inner cover 110 to maintain alignment, and there is no mechanical contact relationship with other parts such as the base housing 200 or the housing cover 300.

In particular, the worm shaft 150, to which the first stage worm wheel 140 and the second stage worm 151 are mounted, is inserted into the worm shaft assembly 111 formed on the inner cover 110, and the base housing 200 and the housing cover Since the position is not changed during the welding process of 300, there is an effect of reducing the operability and operating noise of the actuator.

In addition, as described above, in the case of the separate type hollow shaft 162, the upper caulking (upper flange 162a) is applied, and in the case of the integral hollow shaft 162, the snap ring 170 and the washer 180 are applied, so that the two-stage worm wheel ( 160), there is an effect of preventing collision noise generated when the 2-stage worm wheel 160 collides with the housing cover 300 when the actuator operates.

As described above, the present invention has been described with reference to the embodiments shown in the drawings, but this is only exemplary, and various modifications and other equivalent embodiments will be made by those skilled in the art in the field to which the technology belongs. You will understand that it is possible. Therefore, the true technical protection scope of the present invention should be determined by the claims below.

100: inner cover assembly 110: inner cover
111: worm shaft assembly 112: motor assembly
113: worm wheel assembly 120: motor
130: 1st stage worm 140: 1st stage worm wheel
150: worm shaft 151: 2-stage worm
160: 2-stage worm 170,171: snap ring
180: washer 200: base housing
210: housing part 220: motor accommodating part
230: worm wheel assembly mounting part 300: housing cover

Claims (9)

an inner cover assembly in which all motor and gear parts are assembled;
a base housing in which the inner cover assembly is accommodated;
a housing cover coupled to an upper portion of the base housing to seal the base housing;
including,
The electronic parking brake gear assembly structure, characterized in that the inner cover assembly includes a tubular worm shaft assembly part, and an inner cover having a motor assembly part and a worm wheel assembly part formed on both sides of the worm shaft assembly part. delete The method of claim 1,
An electronic parking brake gear assembly structure, characterized in that a worm shaft having a part of the outer periphery of a two-stage worm mounted on the worm shaft assembly part and a first-stage worm wheel mounted on one end thereof is rotatably inserted and installed. The method of claim 3,
In the worm shaft, a support member rotatably supporting the worm shaft is provided between the first stage worm wheel and the second stage worm, the support member is inserted into the inlet of the worm shaft assembly unit, and a slit formed in the worm shaft assembly unit An electronic parking brake gear assembly structure, characterized in that the snap ring is inserted through and the separation of the support member is prevented. The method of claim 1,
The electronic parking brake gear assembly structure, characterized in that the motor is fixed to the bottom surface of the motor assembly unit, the rotation shaft of the motor protrudes upward from the motor assembly unit, and a first stage worm is mounted on the rotation shaft of the motor. The method of claim 1,
An electronic parking brake gear assembly structure, characterized in that a cylindrical shaft insertion part is formed in the worm wheel assembly part, a hollow shaft of a two-stage worm wheel is inserted into the shaft insertion part, and the two-stage worm wheel is rotatably installed in the worm wheel assembly part. . The method of claim 6,
The hollow shaft is formed separately from the 2-stage worm wheel, the hollow shaft is inserted and fixed into the through hole of the 2-stage worm wheel, the lower flange formed at the lower end of the hollow shaft adheres to the lower end of the shaft insertion part, and the upper end of the hollow shaft is caulked The electronic parking brake gear assembly structure, characterized in that the upper flange is formed so that there is no axial play between the upper flange and the lower flange. The method of claim 6,
The hollow shaft is integrally formed with the two-stage worm wheel, a snap ring is installed at the lower end of the hollow shaft, and a washer is installed between the snap ring and the lower end of the shaft insertion portion to suppress the axial behavior of the two-stage worm wheel. electronic parking brake gear assembly structure. The method of claim 1,
The electronic parking brake gear assembly structure, characterized in that the motor assembly unit and the worm wheel assembly unit are mounted to the base housing via a plurality of hooks.

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