KR102218190B1 - Piston structure for electronic drum brake - Google Patents

Abstract

The present invention relates to a piston structure for an electronic drum brake, and in the piston structure for an electronic drum brake, the piston has a structure in which a single piston is assembled into one by pressing in two, and a structure for fixing an internal disk spring is a nut Unlike the conventional tightening of the nut screw, it is possible to fix it only by sequentially inserting and installing the nut screw, so there is no problem that the fixing part for fixing between internal components is loosened by rotation and abrasion, and various plating is possible. In addition, it relates to a piston structure for a magnetic drum brake with improved workability by simplifying the assembly process compared to the conventional one.

Description

Piston structure for electronic drum brake

The present invention relates to a piston structure for an electronic drum brake that is easy to manage because various plating is possible, assembly is simple, and loosening due to wear or rotation does not occur.

In general, a parking brake allows a vehicle to be stopped on the road or on the ground when parking a vehicle, and there are a foot brake method and a hand brake method, and in general, a hand brake method is used for small cars, and a medium-sized car and a large car In the case of, the foot brake method is widely used.

As is well known, in the conventional parking brake system, when the driver operates the indoor parking lever, the parking rod pulls the operating lever of the rear drum brake, and at this time, the lining connected to the operating lever is expanded and pressed toward the drum. The wheel is braked using the friction between the drum and the lining.

More specifically, in the conventional parking brake system, when the parking rod is pulled by the parking lever, the operating lever attached to one lining in the drum brake interlocks and pulls, and at this time, the lining is extended around the lining support point and the friction of the drum. It makes parking possible by coming into contact with the surface.

The conventional manual parking brake that brakes the wheel by manipulating the parking lever in this way was very inconvenient because the driver had to manually operate the parking lever each time during parking braking, and there are many cases of forgetting this, which leads to the risk of safety accidents. There was this.

Therefore, in recent years, in order to solve the inconvenience of such a manual parking brake, an electronic parking brake (EPB) is used to keep the braking state safely while simply performing the parking operation using the driving force of the motor when parking. Such an electronic parking brake typically generates an equal braking force to each wheel when a motor is driven by pressing an operation button in a vehicle interior, as the parking rod is pulled according to the rotation of the motor.

However, in the case of such an electronic drum brake, the component part that pushes the lined break shoe from the inside of the electronic drum toward the drum is loose due to frequent use or various use environments. , It caused problems such as frequent maintenance and accidents.

In addition, looking at the'electronic drum parking brake for trucks to prevent loosening' (Korean Patent Publication No. 10-1910854) previously filed by the present applicant, it was impossible to use the barrel plating of the piston due to product design (overlapping due to product design). The cost rises due to the progress of rack plating in the late period.Currently 200 won/ea -> 800 won/ea), the forgeability and workability of the piston are inefficient (the shape is very complicated and the dimensions are difficult, so the shoe contact part (diagonal angle) and the inner diameter hexagon, It was impossible to forge the inner diameter keyway at the same time, so the C/T was increased/).

In addition, the internal assembly fixing part was released by abrasion, or the holding part was rotated and loosened due to repeated APPLY/RELEASE, and the internal disk spring was damaged due to overload, and the structure for the overall assembly facility ( Temporary assembly, true assembly, height inspection, etc.) became complicated and various fixings had to be added.

In addition, in the past, the process was complicated because it was necessary to take an assembly process in which an internal nut assembly was constructed and then a piston assembly to fix it to the inside had to be performed.

Republic of Korea Patent Publication No. 10-1305120 (registered on September 02, 2013) Republic of Korea Patent Publication No. 10-1910854 (registered on October 17, 2018)

The present invention allows the piston of the parking brake used in the electronic drum to be used in one configuration by plating two separate configurations and then press-fitting each other to enable various plating fixing and fixing the internal disk spring. The nut configuration and the fastening structure for it are improved in a simple assembly form to improve workability and simplify assembly facilities, reduce the number of parts, and facilitate the control of fastening pressure and torque, while the fastening part is worn by repeated fastening. It is to provide a piston structure for an electronic drum brake that prevents the problem of loosening the nut for fixing.

Other objects and advantages of the present invention will be described below, and will be understood by examples of the present invention. Further, the objects and advantages of the present invention can be realized by means and combinations shown in the claims.

The present invention is a means for solving the above problems,

A piston case 20 having a through hole 21 formed in the longitudinal direction; A piston head 30 that is inserted into the piston case 20 and then press-fitted to protrude a predetermined length toward the front of the piston case 20 and is coupled to be integrally with the piston case 20; A disk spring 40 that is correspondingly mounted inside the piston case 20 and forms a fastening hole 41 in the center; It is mounted inside the piston case 20 at the rear end of the disk spring 40, and one end is correspondingly inserted into the fastening hole 41 in the longitudinal direction, and is located in the mounting groove 31 formed at the other end of the piston head 30, , A nut screw 50 having a screw hole 51 formed in the longitudinal direction in the center; A ring member 60 mounted inside the piston case 20 at the rear end of the nut screw 50 to position the nut screw 50 so as not to be removed to the outside; It characterized in that it consists of.

As described above, according to the present invention, in constructing a piston for an electronic drum parking brake, as the fastening part is ground and worn in the internal fastening structure, there is an effect that the holding part is not loosened.

In addition, the present invention has the effect of preventing rotation of the structure for holding the nut spring by repeating APPLY/RELEASE.

In addition, the present invention has the effect of preventing the damage of the disk spring due to the application of an overload.

In addition, the present invention has the effect of simplifying the assembly facility structure and assembly process.

1 is a view of an embodiment showing a piston consisting of a disk case and a disk head according to the present invention.
Figure 2 is a view of an embodiment showing a piston structure for an electronic drum brake according to the present invention.
Figure 3 is a view of an embodiment showing a piston case according to the present invention.
Figure 4 is a view of one embodiment showing a piston head according to the present invention.
Figure 5 is a view of an embodiment showing a nut screw according to the present invention.

Before describing various embodiments of the present invention in detail, it will be appreciated that the application is not limited to the details of configurations and arrangements of elements described in the following detailed description or illustrated in the drawings. The present invention can be implemented and practiced in different embodiments, and can be carried out in various ways. Also, the device or element orientation (eg "front", "back", "up", "down", "top", "bottom" The expressions and predicates used herein with respect to terms such as ", "left", "right", "lateral"), etc. are used only to simplify the description of the present invention, and related devices Or you may find that the element simply indicates or does not mean that it should have a specific orientation. Further, terms such as “first” and “second” are used in this application and the appended claims for purposes of explanation and are not intended to represent or imply any relative importance or spirit.

The present invention has the following features to achieve the above object.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as being limited to their usual or dictionary meanings, and the inventors appropriately explain the concept of terms in order to explain their own invention in the best way. Based on the principle that it can be defined, it should be interpreted as a meaning and concept consistent with the technical idea of the present invention.

Accordingly, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiment of the present invention, and do not represent all the technical spirit of the present invention, and thus various alternatives that can be substituted for them at the time of application It should be understood that there may be equivalents and variations.

Looking at an embodiment according to the present invention,

A piston case 20 used for an electronic drum brake and having a through hole 21 formed in the longitudinal direction; A piston head 30 that is inserted into the piston case 20 and then press-fitted to protrude a predetermined length toward the front of the piston case 20 and is coupled to be integrally with the piston case 20; A disk spring 40 that is correspondingly mounted inside the piston case 20 and forms a fastening hole 41 in the center; It is mounted inside the piston case 20 at the rear end of the disk spring 40, and one end is correspondingly inserted into the fastening hole 41 in the longitudinal direction, and is located in the mounting groove 31 formed at the other end of the piston head 30, , A nut screw 50 having a screw hole 51 formed in the longitudinal direction in the center; A ring member 60 mounted inside the piston case 20 at the rear end of the nut screw 50 to position the nut screw 50 so as not to be removed to the outside; It characterized in that it consists of.

In addition, the piston case 20 has a plurality of first key grooves 22 formed at one inner periphery, and the piston head 30 has a plurality of first keys 32 correspondingly fastened to the first key groove 22 Is formed on the outer periphery of the other side, and the piston case 20 and the piston head 30 are individually manufactured, plated, and then coupled by press-fitting.

In addition, the nut screw 50 has a first body 52 that is correspondingly inserted into the fastening hole 41 and a second body 52 extending from one end of the first body 52 to a larger diameter than the first body 52. Consisting of a body 53, wherein the second body 53 corresponds to a plurality of second key grooves 23 formed on the inner periphery of the other side of the piston case 20, and a plurality of second keys 54 It is characterized in that by protruding from the periphery to prevent rotation of the nut screw (50).

In addition, the second body 53 forms a step portion 55 whose one side is bent in all directions so as to correspond to the ring groove 24 formed in the inner circumference of the other end of the piston head 30, and the ring member It is characterized in that it is fitted locally into the ring groove 24 in a state in which the 60 is in contact with the stepped portion 55, so that removal of the nut screw 50 is prevented.

In addition, the inner diameter depth (a) of the piston case 20 to which the piston head 30 is fastened or the length (b) of the first body 52 of the nut screw 50 to which the disk spring 40 is fastened, or the disk By adjusting any one of the overall length (c) of the spring 40, it is characterized in that it is possible to control the fastening load and torque.

Hereinafter, a piston structure for an electronic drum brake according to a preferred embodiment of the present invention will be described in detail with reference to FIGS. 1 to 5.

The general structure of a general electronic drum brake is as follows. A ball screw, which is a shaft having a predetermined thickness, is formed, and a forming part for forming a worm wheel (or worm gear) is formed at the middle of the ball screw, and both ends of the forming part extend horizontally with the ground, but are threaded around the outer periphery ( G, hereafter, all threads of other configurations are also denoted by the same symbol).

When a worm wheel is formed in the formation portion of the middle, a separate worm shaft corresponding to the worm wheel is rotated by receiving a rotational force from a driving means (motor, etc.), so that the ball screw receives the rotational motion of the worm wheel from the worm wheel. It has a structure in which linear motion is performed. When the ball screw moves to one of the two sides, the piston 10 connected to the end of the ball screw has a break shoe forming a break lining on the outer periphery, and the ball screw is installed. It is pressed toward the inner circumference of the electronic drum, and the wheel is braked by using the frictional force between the drum and the lining. The configuration and operation of such an electronic drum brake is a well-known technique, and a detailed description thereof will be omitted.

The piston structure for an electronic drum brake according to the present invention includes a piston case 20, a piston head 30, a disk spring 40, a nut screw 50, and a ring member 60.

The piston case 20 is a housing in which a through hole 21 is formed in the longitudinal direction, has a circular cross section, a plurality of first key grooves 22 are formed to face each other at one inner periphery, and the other inner periphery A plurality of second key grooves 23 are formed to face each other.

At this time, the second key groove 23 has a dent depth of the second key groove 23 with an end portion forming a diagonal shape toward the insertion direction of the second key 54 to be described later that is inserted correspondingly to the second key groove 23 Try to shrink.

In addition, the ring member 60 to be described later corresponds to the inner periphery of the other side, and the ring groove 24 to be fitted is recessed in a ring shape.

After the piston head 30 is inserted into the piston case 20 described above, it is press-fitted to protrude a predetermined length toward the front of the piston case 20, and is coupled to form an integral body with the piston case 20. will be.

At this time, the piston head 30 forms a plurality of first keys 32 correspondingly fastened to the first key groove 22 on the outer periphery of the other side, and the piston case 20 and the piston head 30 are individually manufactured. And then plated, so that they can be joined by press fitting.

In addition, the seating groove 31 is formed in the other side of the piston head 30 to be recessed.

Through this structure, since the conventional piston 10 consisting of the piston case 20 and the piston head 30 consists of only one, the problem that the unplated part of the exterior occurs due to the overlapping of parts during barrel plating. However, in the present invention, two separate configurations are made so that not only rack plating but also barrel plating can be used without such a problem.

The disk spring 40 is correspondingly mounted inside the piston case 20 and forms a fastening hole 41 in the center. This is a well-known configuration as ring-shaped disks are connected to each other to form a spring form.

The nut screw 50 is mounted inside the piston case 20 at the rear end of the disk spring 40, and one end is correspondingly inserted into the fastening hole 41 in the longitudinal direction to form a seating groove formed at the other end of the piston head 30 It is located at (31), and in the center, a screw hole 51 (where a separate ball screw is inserted) is formed in the longitudinal direction.

More specifically, the first body 52 that is inserted correspondingly to the fastening hole 41 formed in the center of the disk spring 40 in the longitudinal direction, and the first body 52 at one end of the first body 52 Consisting of a plate-shaped second body 53 extending in a large diameter, the second body 53 is correspondingly fastened to a plurality of second key grooves 23 formed on the inner periphery of the other side of the piston case 20, The plurality of second keys 54 are protruded from the outer periphery to prevent rotation of the nut screw 50.

In addition, the second body 53 forms a stepped portion 55 whose one side is bent in all directions so as to correspond to the ring groove 24 formed in the inner periphery of the other end of the piston head 30, and the ring member ( 60) corresponds to the ring groove 24 through the step portion 55 and is fitted, so that the removal of the ring member 60 is prevented.

The ring member 60 is a'C' shaped ring that is mounted inside the piston case 20 at the rear end of the nut screw 50 so that the nut screw 50 is not removed to the outside.

That is, as described above, while the'C'-shaped ring member 60 is fitted into the ring groove 24 of the piston head 30 by a step on one side of the second body 53, such a step portion 55 ), it cannot be removed by human power.

Thus, in the case of the present invention, in order to fix the internal disc spring 40, assembly and fixation between the components was possible through rotational mounting of the nut at the outermost, but in the present invention, additional assembly or rotation is required. Without the configuration, simply by mutually fastening the piston 10 (piston case 20, piston head 30) and the nut screw 50, it is possible to assemble and fix the position between the components, the piston head 30 The inner diameter depth (a) of the piston case 20 is fastened or the length (b) of the first body 52 of the nut screw 50 to which the disc spring 40 is fastened, or the overall length of the disc spring 40 ( By adjusting any one of c), it is possible to control the clamping load and torque, making management easier.

As described above, although the present invention has been described by the limited embodiments and drawings, the present invention is not limited thereto, and the technical spirit of the present invention and the following by those of ordinary skill in the technical field to which the present invention belongs. It goes without saying that various modifications and changes are possible within the equivalent range of the claims to be described.

10: piston 20: piston case
21: through hole 22: first keyway
23: second keyway 24: ring groove
30: piston head 31: seating groove
32: first key 40: disc spring
41: fastening hole 50: nut screw
51: screw hole 52: first body
53: second body 54: second key
55: step portion 60: ring member

Claims (5)

Used for electronic drum brakes,
A piston case 20 having a through hole 21 formed in the longitudinal direction;
A piston head 30 that is inserted into the piston case 20 and then press-fitted to protrude a predetermined length toward the front of the piston case 20 and is coupled to be integrally with the piston case 20;
A disk spring 40 that is correspondingly mounted inside the piston case 20 and forms a fastening hole 41 in the center;
It is mounted inside the piston case 20 at the rear end of the disk spring 40, and one end is correspondingly inserted into the fastening hole 41 in the longitudinal direction, and is located in the mounting groove 31 formed at the other end of the piston head 30, , A nut screw 50 having a screw hole 51 formed in the longitudinal direction in the center;
A ring member 60 mounted in the piston case 20 at the rear end of the nut screw 50 to move the nut screw 50 to the outside so that the nut screw 50 is not removed.
The piston case 20 forms a plurality of first key grooves 22 on one inner periphery, and the piston head 30 has a plurality of first keys 32 corresponding to the first key groove 22 on the other side. Formed on the outer periphery, the piston case 20 and the piston head 30 are individually manufactured, plated, and then coupled by press-fitting.
The method of claim 1,
The nut screw 50 is
Consisting of a first body 52 that is inserted correspondingly to the fastening hole 41, and a second body 53 extending from one end of the first body 52 to a larger diameter than the first body 52,
The second body 53 is formed to protrude from the outer circumference of a plurality of second keys 54, which are fastened correspondingly to a plurality of second key grooves 23 formed on the inner circumference of the other side of the piston case 20, and the nut An electronic drum brake piston structure, characterized in that the screw 50 is prevented from rotating.
The method of claim 2,
The second body 53 is
To correspond to the ring groove 24 formed in the inner circumference of the other end of the piston head 30,
By forming a stepped portion 55 that one side is bent in all directions,
The piston structure for an electronic drum brake, characterized in that the ring member (60) is locally fitted into the ring groove (24) in contact with the stepped portion (55) to prevent the nut screw (50) from being removed.
The method of claim 2,
The inner diameter depth (a) of the piston case 20 to which the piston head 30 is fastened or
The first body 52 length (b) of the nut screw 50 to which the disk spring 40 is fastened or
Of the total length (c) of the disk spring 40
An electronic drum brake piston structure, characterized in that it is possible to control a fastening load and a torque by adjusting any one.
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