DRUM BRAKE

Abstract

Drum brake of a vehicle, comprising: a pair of brake shoes (100) arranged in a drum to be moved by a wheel cylinder to an inner circumferential surface of a brake drum of the drum brake; a backplate (200) attached to a vehicle body and with which each of the brake shoes (100) is rotatably coupled; and a rotation unit (300) configured to support a restoring force of the brake shoe (100), wherein the rotation unit (300) comprises a motion pin (310) attached to a side surface of the brake shoe (100) and shaped to project towards the back plate (200), a rotating plate (320) with which the motion pin (310) is coupled to receive an external force in a direction of movement of the motion pin (310), and an elastic part (330) arranged between the rotating plate (320) and the back plate (200) to elastically support the rotating plate (320), characterized in thatthat the rotating plate (320) has a curved groove (321) which is designed to be recessed in the rotating plate (320) to receive the moving pin (310), and which is curved along part of a motion path along which the moving pin (310) moves to maintain a constant distance at which the moving pin (310) moves.

Description

BACKGROUND1. Area

[0001] Embodiments of the present disclosure relate to a drum brake of a vehicle, and more particularly to a drum brake of a vehicle in which a device is provided such that a brake shoe maintains a constant distance from an inner peripheral surface of a brake drum before and after braking of the drum brake. 2. Description of the state of the art

[0002] Generally, vehicles necessarily have braking systems for braking. A drum brake is one of these braking systems. The braking principle of a drum brake is to press a brake shoe, to which a lining (a friction material) is attached, against the inner peripheral surface of a brake drum arranged inside and rotating with the wheels, to generate a frictional force and use the frictional force as braking force.

[0003] That is, when the vehicle brakes, the brake shoe comes into contact with the inner peripheral surface of the brake drum, and when the vehicle is moving, components of the brake drum are driven to maintain a constant distance between the inner peripheral surface of the brake drum and the brake shoe.

[0004] However, due to the influence of the driving direction, the pressure on the brake drum and brake shoe of the drum brake is asymmetrical. Therefore, when the drum brake repeatedly brakes and releases the vehicle, the problem arises that the clearance between the brake shoe and the brake drum is not constant. Conventionally, a return spring connecting a pair of brake shoes with an elastic part or other components to generate an external force inward has been provided to solve this problem.

[0005] However, since the existing device for maintaining the clearance between brake shoe and brake drum has a limitation, there are many disadvantages such as the complexity of the added components and the high manufacturing cost, so a new method is required. STATUS OF THE TECHNICAL PATENT DOCUMENT

[0006] Korean Patent Publication No. 10-2268683 (filed on June 17, 2021) DEMOLITION

[0007] Therefore, it is an aspect of the present disclosure to provide a drum brake in which a constant distance is maintained between a brake shoe and a brake drum by providing an external force in a direction of return of the brake shoe after deceleration of the drum brake of a vehicle.

[0008] It is another aspect of the present disclosure to provide a drum brake in which external forces acting on a pair of brake shoes are individually adjusted after deceleration of the drum brake of a vehicle.

[0009] It is another aspect of the present disclosure to provide a drum brake in which a larger interior space is provided by minimizing the size of a component capable of maintaining a clearance between a brake shoe and a brake drum after deceleration of the drum brake of a vehicle.

[0010] It is another aspect of the present disclosure to provide a drum brake whose manufacturing cost is reduced by simplifying a component capable of maintaining a clearance between a brake shoe and a brake drum after braking of the drum brake of a vehicle.

[0011] According to one aspect of the present disclosure, a drum brake of a vehicle includes a pair of brake shoes arranged in a drum to be moved by a wheel cylinder toward an inner peripheral surface of a brake drum of the drum brake, a back plate fixed to a vehicle body and to which each of the brake shoes is rotatably coupled, and a rotation unit configured to assist a restoring force of the brake shoe, wherein the rotation unit includes a moving pin fixed to a side surface of the brake shoe and configured to protrude toward the back plate, a rotary plate to which the moving pin is coupled to receive an external force in a moving direction of the moving pin, and an elastic member arranged between the rotary plate and the back plate to elastically support the rotating plate.

[0012] The rotary plate may have a curved groove shaped to be recessed into the rotary plate to receive the moving pin and curved along a portion of the path of travel on which the moving pin moves to guide a constant distance in which the moving pin moves.

[0013] The moving pin may be provided as a pair of moving pins opposite to each other in the horizontal direction on the side surface of each of the two brake shoes, and the curved groove may be provided as a pair of curved grooves opposite to each other in the horizontal direction on the rotary plate and shaped to extend in the moving direction of the moving pins.

[0014] The elastic part can be designed as a spiral torsion spring in order to generate a restoring force in a direction opposite to the direction of rotation of the rotary plate when the rotary plate rotates.

[0015] The rotary plate may be coupled to the back plate while being elastically supported by the elastic member, and a pivot may be provided in the center of the rotary plate to rotate the rotary plate.

[0016] The rotation unit can consist of at least two rotation units arranged left-right symmetrically on the back plate.

[0017] The rotation unit may comprise two pairs of rotation units, one pair of the rotation units being arranged on a horizontal diameter crossing the center of the back plate, and the other pair of the rotation units being arranged near a wheel cylinder provided in the back plate.

[0018] The rotary plate may have an insertion groove shaped to be recessed in the rotary plate by the size of one end of the moving pin so that one end of the moving pin is housed in and connected to the insertion groove.

[0019] The rotary plate may have an oval phase with a long radius in the horizontal direction and a short radius in the vertical direction.

[0020] The drum brake may be a simplex type drum brake, which has a single wheel cylinder so that the two brake shoes move in different directions when the vehicle is decelerating.

[0021] The drum brake may be a duplex type drum brake, which has two wheel cylinders so that the two brake shoes move in the same direction when the vehicle is decelerating. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] These and / or other aspects of the disclosure will become clear and better understood from the following description of the embodiments in conjunction with the accompanying drawings, in which: Fig. 1 is a front view showing the interior of a drum brake of a general vehicle; Fig. 2 is a front view showing a rotating unit of a drum brake of a vehicle according to a present embodiment; Fig. 3 is a front view illustrating a state of the rotating units when the plurality of rotating units are provided on a back plate of the drum brake of the vehicle and a brake shoe maintains a constant distance from an inner peripheral surface of a brake drum before and after braking according to the present embodiment; Fig. 4 is a cross-sectional view showing the drum brake along the line II' of Fig. 1 shows when a constant clearance is maintained between the brake shoe and the inner peripheral surface of the brake drum before and after braking of the drum brake of the vehicle according to the present embodiment; Fig. 5 is a front view illustrating a state of the rotating units when the plurality of rotating units are provided on the back plate of the drum brake of the vehicle and the brake shoe comes into contact with the inner peripheral surface of the brake drum during braking; and Fig. 6 is a cross-sectional view showing the drum brake along the line II' of Fig. 1 shows when the brake shoe comes into contact with the inner peripheral surface of the brake drum during braking of the drum brake of the vehicle according to the present embodiment. DETAILED DESCRIPTION

[0023] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The following embodiments are provided to fully convey the spirit of the present disclosure to those skilled in the art. The present disclosure is not limited to the embodiments disclosed herein and may be implemented in various forms. In the drawings, parts unrelated to the description may be omitted to make the present disclosure clearer, and components may be exaggerated to facilitate understanding of the present disclosure.

[0024] Fig. 1 is a front view showing the interior of a drum brake of a general vehicle. Referring to Fig. 1, in addition to one embodiment of the present disclosure, the drum brake of the general vehicle includes a pair of brake shoes 100 arranged in a drum, and a wheel cylinder for moving each of the brake shoes 100 toward an inner peripheral surface of the brake drum. Furthermore, a back plate 200, which is fixed to the vehicle body and to which the brake shoe 100 is pivotally connected, and a return spring 400 for connecting the pair of brake shoes 100 are provided in the drum brake. In this case, the wheel cylinder may be electronically or hydraulically driven and may be provided as one wheel cylinder or two wheel cylinders.Specifically, a brake type in which one wheel cylinder is provided in a drum brake and the pair of brake shoes 100 move in different directions when the vehicle decelerates is called a simplex drum brake, and a brake type in which two wheel cylinders are provided and the pair of brake shoes 100 move in the same direction when the vehicle decelerates is called a duplex drum brake. The embodiment of the present disclosure will be described using the simplex drum brake, but the present disclosure is not limited thereto and can also be similarly applied to the duplex drum brake. The present embodiment of the present disclosure includes a rotary plate 320 opposed to the brake shoe 100 on the back plate 200, and a moving pin 310 opposed to the rotary plate 320 on a side surface of the brake shoe 100.

[0025] Fig. Figure 2 is a front view showing a rotation unit of a drum brake of a vehicle according to a present embodiment. The drum brake of the present disclosure includes a rotation unit 300 for assisting a restoring force of the brake shoe 100 after braking, and the rotation unit 300 includes a moving pin 310, the rotating plate 320, and an elastic member 330. According to Fig. 2, the rotation unit 300 of the present embodiment includes the rotary plate 320 and a curved groove 321 and a pivot pin 322.

[0026] The rotary plate 320 is coupled to the moving pin 310 provided on the brake shoe 100 to receive an external force in a moving direction of the moving pin 310. The rotary plate 320 may be formed in an oval shape with a long radius in the horizontal direction and a short radius in the vertical direction. However, the rotary plate 320 is not limited to a specific shape and may have any rotatable plate shape. The rotary plate 320 may include the pivot pin 322, which provides a rotation axis at the center of the rotary plate 320. The pivot pin 322 contributes to stable rotation of the rotary plate 320 but need not necessarily be included in the rotation unit 300.

[0027] The curved groove 321 is formed to be recessed in the rotary plate 320 to receive the moving pin 310, and may be formed to be curved along a portion of a path of travel along which the moving pin 310 moves, to guide a constant distance for the moving pin 310 to move. Since the brake shoe 100 moves at an angle smaller than 180 degrees during braking, the curved groove 321 is provided at an angle of less than 180 degrees. The curved groove 321 may be provided as a pair of curved grooves 321 that oppose each other around the center of the rotary plate 320. In this case, instead of the curved groove 321, the rotary plate 320 may have an insertion groove (not shown) recessed to the size of one end of the moving pin 310 to receive one end of the moving pin 310 in the rotary plate 320 to receive the moving pin 310.When the curved groove 321 is provided as a component for receiving the moving pin 310, it has the advantage of not generating unnecessary external force in a direction opposite to a moving direction of the brake shoe 100 when the brake shoe 100 moves toward the inner peripheral surface of the brake drum, and improving the durability of the component because the pressure exerted on the moving pin 310 and the curved groove 321 is small. On the other hand, the insertion groove (not shown) has the advantage of making the rotary plate 320 easy to manufacture.

[0028] The rotary plate 320 of the drum brake of the vehicle according to the present embodiment has the oval shape in which the long radius in the horizontal direction is larger than the short radius in the vertical direction. The pivot pin 322 is provided in the center of the rotary plate 320, and the two curved grooves 321 are formed from the left upward and from the right downward so as to oppose each other with respect to a center of the oval shape. The curved groove 321 has a curvature along the oval shape of the rotary plate 320. However, the shape of the rotary plate 320 and a length and curvature of the curved groove 321 are not limited to the Fig. 2 and may have any shape of the rotating plate 320 capable of rotating and receiving the moving pin 310.

[0029] Fig. 3 is a front view illustrating a state of the rotating units 300 when the plurality of rotating units 300 are provided on the back plate 200 of the drum brake of the vehicle and a brake shoe 100 maintains a constant distance from the inner peripheral surface of the brake drum before and after braking according to the present embodiment, and Fig. 4 is a cross-sectional view showing the drum brake along the line II' of Fig. 1 shows when a constant distance is maintained between the brake shoe 100 and the inner peripheral surface of the brake drum before and after braking of the drum brake of the vehicle according to the present embodiment. Referring to Fig. 3 and Fig. 4, the rotation unit 300 of the drum brake of the vehicle of the present disclosure is provided as the plurality of rotation units 300, each including the elastic part 330. The moving pin 310 is attached to each of the two brake shoes 100.

[0030] The plurality of rotation units 300 may be arranged symmetrically on the left and right sides of the back plate 200. At least one pair of rotation units 300 may be provided. One pair of rotation units 300 may be arranged on a horizontal diameter crossing a center of the back plate 200, and the other pair of rotation units 300 may be arranged near a wheel cylinder provided in the back plate 200. However, since the pressure exerted on the brake drum may be asymmetric due to the driving direction, the plurality of rotation units 300 on the left and right sides may also be arranged asymmetrically to compensate for the asymmetric pressure.

[0031] The elastic member 330 is disposed between the rotary plate 320 and the back plate 200 to elastically support the rotary plate 320. The elastic member 330 is provided as a spiral torsion spring to provide a restoring force in a direction opposite to a rotation direction of the rotary plate 320 when the rotary plate 320 rotates. In this case, if the pivot pin 322 is provided at the center of the rotary plate 320, the elastic member 330 can stably support the rotary plate 320 in a state where a rotation center is provided.

[0032] The moving pin 310 is fixed to the side surface of the brake shoe 100 and shaped to protrude toward the back plate 200. The moving pin 310 may be provided as a pair of moving pins 310 horizontally opposed to each other on the side surface of each of the two brake shoes 100. In this case, the two curved grooves 321 may be provided to oppose each other in the rotary plate 320 to receive the moving pins 310 on the rotary plate 320 and shaped to extend in the direction of movement of the moving pins 310.

[0033] Four rotation units 300 of the drum brake of the vehicle according to the present embodiment are provided to be coupled to the back plate 200, and each includes the rotary plate 320 having an oval shape. Before and after the vehicle deceleration, the two moving pins 310 on the brake shoe 100 are accommodated in the curved groove 321 at the long radius of the rotary plate 320. Accordingly, the long radii of the rotary plates 320 of all the rotation units 300 are arranged parallel in the horizontal direction. The elastic member 330 is provided between the rotary plate 320 and the back plate 200, so that the rotary plate 320 is elastically supported on the elastic member 330, and the elastic member 330 is connected to the back plate 200. The pivot pin 322, located at the center of the rotary plate 320, is integrated with the elastic member 330. A return spring 400 is provided on the opposite side of the back plate 200.The return spring 400 can exert a restoring force on the brake shoe 100 together with the rotation unit 300, but the rotation unit 300 can also replace the return spring 400. However, the number and arrangement of the rotation units 300 are not limited to the . Fig. 3 and Fig. 4, but can have any number and any arrangement of rotation units 300 which are capable of exerting a restoring force on the brake shoes 100.

[0034] Fig. 5 is a front view illustrating a state of the rotating units 300 when the plurality of rotating units 300 are provided on the back plate 200 of the drum brake of the vehicle and the brake shoe 100 comes into contact with the inner peripheral surface of the brake drum during braking, and Fig. 6 is a cross-sectional view showing the drum brake along the line II' of Fig. 1 illustrates when the brake shoe 100 comes into contact with the inner peripheral surface of the brake drum during braking of the drum brake of the vehicle according to the present embodiment. Fig. 5 and Fig. 6 shows the arrangement of the rotation units 300 when braking the vehicle.

[0035] In the rotation unit 300 of the drum brake of the vehicle according to the present embodiment, the moving pin 310, which is accommodated in the curved groove 321 provided on a long radius, is rotated when the vehicle starts to decelerate. First, the moving pin 310 moves along the curved groove 321, then friction occurs between the accommodated one end of the moving pin 310 and the curved groove 321, and the rotating unit 300 starts to rotate so that the long radius points in the vertical direction. When the brake shoe 100 moves completely and a friction lining of the brake shoe 100 comes into contact with the inner peripheral surface of the brake drum, the long radius of the rotating unit 300 points in the vertical direction. Since the moving pins 310 in this case are in Fig. 6 are arranged parallel to each other and overlap each other, the movement pins 310 are seen as if a movement pin 310 is provided in the middle. When the braking of the vehicle is completed, the rotation units 300 rotate again in the states shown in the Fig. 3 and Fig. 4 are shown.

[0036] The drum brake of the vehicle according to the present embodiment with such a configuration includes the rotation unit 300 having the moving pin 310, the rotary plate 320, and the elastic member 330 to provide an external force to the brake shoe 100 in a direction of recovery after the brake application, thus maintaining a constant clearance between the brake shoe 100 and the brake drum. Furthermore, since multiple rotation units 300 can be provided, the external forces acting on the pair of brake shoes 100 can be individually adjusted.Since the rotation unit 300 is provided between the back plate 200 and the brake shoe 100 of the drum brake to have a minimal size, replacing the conventional component for maintaining a clearance between the brake shoe 100 and the brake drum, a larger internal space of the drum brake can be ensured, and the manufacturing cost can also be reduced by replacing the complex component. This can naturally improve the marketability of the drum brake.

[0037] As is apparent from the above description, according to the present embodiment, a constant clearance is maintained between a brake shoe and a brake drum by providing an external force in a direction of returning the brake shoe after deceleration of a drum brake of a vehicle.

[0038] According to the present embodiment, external forces acting on a pair of brake shoes are individually adjusted after braking a drum brake of a vehicle.

[0039] According to the present embodiment, a larger interior space is provided by minimizing the size of a member that can maintain a clearance between a brake shoe and a brake drum after braking a drum brake of a vehicle.

[0040] According to the present embodiment, manufacturing costs are reduced by simplifying a component capable of maintaining the clearance between a brake shoe and a brake drum after braking a drum brake of a vehicle. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] KR 102268683

[0006]

Claims

[1] Drum brake of a vehicle, comprising: a pair of brake shoes (100) arranged in a drum to be moved by a wheel cylinder to an inner peripheral surface of a brake drum of the drum brake; a back plate (200) secured to a vehicle body and to which each of the brake shoes (100) is rotatably coupled; and a rotation unit (300) configured to support a restoring force of the brake shoe (100), wherein the rotation unit (300) comprises a moving pin (310) fixed to a side surface of the brake shoe (100) and shaped to protrude toward the back plate (200), a rotating plate (320) to which the moving pin (310) is coupled to receive an external force in a moving direction of the moving pin (310), and an elastic member (330) disposed between the rotating plate (320) and the back plate (200) to elastically support the rotating plate (320). [2] A drum brake according to claim 1, wherein the rotary plate (320) has a curved groove (321) formed to be recessed in the rotary plate (320) to receive the moving pin (310) and curved along a part of a moving path along which the moving pin (310) moves to guide a constant distance in which the moving pin (310) moves. [3] Drum brake according to claim 2, wherein the moving pin (310) is provided as a pair of moving pins (310) which are opposite to each other in a horizontal direction on the side surface of each of the pair of brake shoes (100); and the curved groove (321) is provided as a pair of curved grooves (321) which are opposite to each other in the horizontal direction on the rotary plate (320) and are shaped to extend in moving directions of the moving pins (310). [4] A drum brake according to any one of claims 1 to 3, wherein the elastic part (330) is provided as a spiral torsion spring to provide a restoring force in a direction opposite to a rotational direction of the rotary plate (320) when the rotary plate (320) rotates. [5] A drum brake according to any one of claims 1 to 4, wherein the rotary plate (320) is coupled to the back plate (200) while being elastically supported by the elastic member (330), a pivot (322) being provided at a center of the R (320) to rotate the rotary plate (320). [6] Drum brake according to one of claims 1 to 5, wherein the rotation unit (300) is provided as at least one pair of rotation units (300) arranged left-right symmetrically on the back plate (200). [7] A drum brake according to claim 6, wherein the rotation unit (300) comprises two pairs of rotation units (300), one pair of the rotation units (300) being arranged on a horizontal diameter crossing a center of the back plate (200), and the other pair of rotation units (300) being arranged near a wheel cylinder provided in the back plate (200). [8] A drum brake according to any one of claims 1 to 7, wherein the rotary plate (320) has an insertion groove formed to be recessed in the rotary plate (320) by the size of one end of the moving pin (310) so that the one end of the moving pin (310) is accommodated in and coupled to the insertion groove. [9] A drum brake according to any one of claims 1 to 8, wherein the rotary plate (320) has an oval phase with a long radius in the horizontal direction and a short radius in the vertical direction. [10] Drum brake according to one of claims 1 to 9, comprising a drum brake of the simplex brake type in which a single wheel cylinder is provided so that the pair of brake shoes (100) moves in different directions during braking of the vehicle. [11] Drum brake according to one of claims 1 to 9, comprising a drum brake of the duplex brake type in which two wheel cylinders are provided so that the pair of brake shoes (100) moves in the same direction when the vehicle is decelerated.

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