DRUM BRAKE

Abstract

A drum brake is disclosed. The drum brake comprises: a drum configured to rotate together with a wheel; a pair of brake shoes positioned within the drum and configured to move through a wheel cylinder to an inner peripheral surface of the drum; and a lining attached to an outer peripheral surface of each brake shoe and configured to rub against the inner peripheral surface of the drum when the brake shoe operates outwardly, wherein the brake shoe includes an expansion part made of a material that thermally expands in a radial direction and configured to compensate for a gap formed between the lining and the thermally expanding drum.

Description

BACKGROUND1. AREA

[0001] The disclosure relates to a drum brake and, more particularly, to a drum brake for improving braking performance against thermal expansion of a drum. 2. DESCRIPTION OF THE STATE OF THE ART

[0002] Brake systems are essential for vehicles. Representative brake systems include drum brakes and caliper brakes.

[0003] The drum brake consists of a drum that rotates with a wheel and brake shoes. Accordingly, when the vehicle brakes, the drum brake generates a frictional force by compressing the brake shoes from the inside of the drum toward the inner peripheral surface of the drum, and uses the frictional force as braking force.

[0004] In contrast, the drum brake rotates the drum while driving by moving the brake shoes a certain distance away from the inner peripheral surface of the drum. Therefore, it is important to properly adjust the clearance between the drum and the brake shoes of the drum brake.

[0005] The drum is generally made of a material that expands thermally, such as iron. Because the drum brake uses frictional force as the braking force, the temperature and pressure inside the drum inevitably rise significantly when the vehicle brakes. Accordingly, the drum expands radially when the vehicle brakes, forming a gap between the inner peripheral surface of the drum and the brake shoes.

[0006] The gap prevents the brake shoes from fully contacting the drum. As a result, noise and vibration are generated when the vehicle is braking, and the braking force is reduced, which can endanger the lives of vehicle occupants and nearby pedestrians.

[0007] For this reason, a method for dealing with a thermally expanding drum in a drum brake is needed. PUBLICATIONS ON THE STATE OF THE ART

[0008] The publication KR 10 2017 0 041 028 A shows a drum brake known from the state of the art.

[0009] US Pat. No. 1,794,348 A teaches a movement-restraining mechanism with a brake shoe having opposing sections, one section being provided for frictional engagement with a movable element whose movement is to be braked. The friction-imparting section comprises a part with a relatively low coefficient of expansion and a non-metallic coating attached thereto, while the other section is designed to have a relatively high coefficient of expansion.

[0010] DE 42 12 356 A1 discloses an integrated carrier plate for a drum brake, wherein at least one anchoring component and a dust cover are formed integrally by die casting using an aluminum alloy or an aluminum-based composite material. DEMOLITION

[0011] The invention is defined in the independent claims.

[0012] It is an embodiment of the disclosure to provide a drum brake that prevents deterioration of braking performance.

[0013] It is an embodiment of the disclosure to provide a drum brake to prevent deterioration of braking performance caused by thermal expansion of the drum brake.

[0014] One embodiment of the disclosure is the provision of a drum brake to prevent vibrations and noise caused by thermal expansion of the drum brake.

[0015] It is an embodiment of the disclosure to provide a drum brake for improving productivity and economy of the brake by preventing deterioration of braking performance by a simple structure.

[0016] Additional aspects of the disclosure will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice of the disclosure.

[0017] According to one aspect of the disclosure, a drum brake comprises: a drum configured to rotate together with a wheel; a pair of brake shoes positioned within the drum and configured to move through a wheel cylinder to an inner peripheral surface of the drum; and a lining attached to an outer peripheral surface of each brake shoe and configured to rub against the inner peripheral surface of the drum when the brake shoe operates outward, wherein the brake shoe includes an expansion part made of a material that thermally expands in a radial direction and configured to compensate for a gap formed between the lining and the thermally expanding drum.

[0018] The brake shoe may further comprise a body portion made of a different material than the material of the expansion portion.

[0019] The expansion part may be made of a material that has a relatively lower stiffness and a relatively larger coefficient of thermal expansion than the material of the body part.

[0020] The body portion may be made of a material including iron, and the expansion portion may be made of a material including at least one of aluminum or copper.

[0021] The body part may have a semicircular shape, and the expansion part may extend in a circumferential direction to be positioned along a circumferential surface of the body part.

[0022] The expansion part can be arranged inside the body part.

[0023] A circumferential length of the expansion part may be shorter than a circumferential length of the body part, and a first gap may be formed at one end of the expansion part.

[0024] The expansion part may comprise a plurality of expansion parts.

[0025] The majority of the expansion parts can be arranged in the radial direction.

[0026] The plurality of expansion parts may be spaced apart from each other so that the body part is arranged between the plurality of expansion parts.

[0027] The majority of the expansion parts may be arranged in the circumferential direction.

[0028] The plurality of expansion parts may be spaced apart from each other so that a second space is formed between the plurality of expansion parts.

[0029] The body part may have a semicircular shape, and the expansion part may extend in a radial direction to be perpendicular to an outer peripheral surface of the body part.

[0030] The expansion part may be in contact with the brake pad at one end facing the brake pad.

[0031] The expansion part may comprise a plurality of expansion parts with different lengths in the radial direction.

[0032] The majority of expansion parts can each be made of materials with different thermal expansion coefficients.

[0033] The majority of expansion parts can be made of materials of different thicknesses.

[0034] The entire brake shoe can be the expansion part. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] 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 of an existing drum brake; Fig. 2 is a front view of the existing drum brake during the running of a vehicle; Fig. 3 is a front view of the existing drum brake when braking the vehicle; Fig. 4 is an enlarged view of an area A of Fig. 2; Fig. 5 is a front view of a drum brake according to a first embodiment of the disclosure; Fig. Figure 6 is an enlarged view of an area corresponding to the A area of ​​the Fig. 2 in the drum brake according to the first embodiment of the disclosure; Fig. 7 is a front view of a drum brake according to a second embodiment of the disclosure; Fig. Figure 8 is an enlarged view of an area corresponding to the A area of ​​the Fig. 2 in the drum brake according to the second embodiment of the disclosure; Fig. 9 is an enlarged view of an area corresponding to area A in Fig. 2, in a drum brake according to a third embodiment of the disclosure; Fig. 10 is a front view of a drum brake according to a fourth embodiment of the disclosure; and Fig. 11 is an enlarged view of an area corresponding to the A area of ​​the Fig. 2 in the drum brake according to the fourth embodiment of the disclosure. DETAILED DESCRIPTION

[0036] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The following embodiments are intended to convey the technical concepts of the present disclosure to those skilled in the art. However, the present disclosure is not limited to these embodiments and may be implemented in other forms. In the drawings, parts irrelevant to the descriptions may be omitted in order to clarify the present disclosure, and also, to facilitate understanding, the sizes of the components are more or less exaggerated.

[0037] Fig. 1 is a front view of an existing drum brake.

[0038] As in Fig. 1, the existing drum brake may comprise a drum 100, a brake shoe 200 and a brake pad 300.

[0039] The drum 100 may be incorporated into a wheel hub and rotate together with a wheel. Generally, the drum 100 may have a cylindrical shape and be made of cast iron.

[0040] A pair of brake shoes 200 may be provided and installed in the drum 100. The brake shoe 200 may move toward an inner peripheral surface of the drum 100 upon application of the brake by a wheel cylinder.

[0041] The lining 300 may be a friction material component that contacts the drum 100, also referred to as a liner. The lining 300 may be attached to an outer peripheral surface of the brake shoe 200 to rub against the inner peripheral surface of the drum 100 when the brake shoe 200 operates outward.

[0042] The drum 100, the brake shoe 200, and the brake pad 300 may be common components of a drum brake and can be easily implemented by a person skilled in the art using known technology. Accordingly, a detailed description of the drum 100, the brake shoe 200, and the pad 300 is omitted.

[0043] Fig. 2 is a front view of the existing drum brake while a vehicle is driving, Fig. 3 is a front view of the existing drum brake when the vehicle is braking, and Fig. 4 is an enlarged view of an area A of Fig. 2.

[0044] When a vehicle is driving or braking, the existing drum brake can check the positions of the drum 100, the brake shoe 200 and the brake pad 300 (see Fig. 2 and Fig. 4).

[0045] During driving, the brake shoe 200 may be adjusted such that an outer peripheral surface of the pad 300 attached to the brake shoe 200 is spaced from the inner peripheral surface of the drum 100 by a preset distance. Accordingly, the drum 100 attached to the wheel can rotate freely.

[0046] To decelerate the moving vehicle, the brake shoe 200 can move outward by a predetermined distance. Accordingly, the outer peripheral surface of the pad 300 attached to the brake shoe 200 can be in close contact with the inner peripheral surface of the drum 100 and rub against the inner peripheral surface of the drum 100.

[0047] However, when the lining 300 rubs against the drum 100, the internal temperature and pressure in the drum 100 may inevitably increase significantly. Accordingly, the drum 100 made of a thermally expanding material may expand, as shown by the dashed lines in Fig. 3, while the brake shoe 200 made of a different material cannot expand to the extent that the drum 100 thermally expands. Specifically, when the pad 300 rubs against the drum 100 during vehicle braking, a side wall of the drum 100 that rubs against the pad 300 may expand outward, forming a gap between the inner peripheral surface of the drum 100 and the outer peripheral surface of the pad 300.

[0048] Due to the gap that forms between the pad 300 and the drum 100 during vehicle braking, the pad 300 may not fully engage the drum 100, and vibrations of the components may occur. These vibrations may generate brake noise and degrade the braking force of the brake.

[0049] According to one embodiment of the disclosure, the brake shoe 200 may include an expansion portion 210 that thermally expands to accommodate the gap formed between the pad 300 and the drum 100, which thermally expands.

[0050] Fig. 5 is a front view of a drum brake according to a first embodiment of the disclosure, and Fig. Figure 6 is an enlarged view of an area corresponding to the A area of ​​the Fig. 2 in the drum brake according to the first embodiment of the disclosure, wherein the A-range of Fig. 2 can be an area where the drum 100 contacts the pad 300.

[0051] With reference to the Fig. 5 and Fig. 6, a brake shoe 200 according to a first embodiment of the disclosure may include a body portion 220 and an expansion portion 210 made of different materials, in contrast to the brake shoe 200, which is made of one material in the existing drum brake.

[0052] The body part 220 may be a component that forms the external appearance of the brake shoe 200 and may be made of a material different from the material of the expansion part 210.

[0053] The expansion part 210 may be made of a material different from the material of the body part 220, wherein the material of the expansion part 210 may be a material that thermally expands in the radial direction under high temperature and high pressure conditions.

[0054] More specifically, the material constituting the expansion part 210 may be selected to compensate for a gap that occurs between the inner peripheral surface of the drum 100 and the outer peripheral surface of the pad 300 due to an increase in the internal temperature of the drum 100 during braking of the vehicle according to the degree of thermal expansion of the drum 100.

[0055] The expansion part 210 may be made of a material having relatively low rigidity and a relatively large thermal expansion coefficient compared to the body part 220. Accordingly, the brake shoe 200 can ensure durability through the body part 220 and prevent deterioration of the braking performance of the brake due to the expansion part 210.

[0056] For example, the body portion 220 may be made of a material containing iron, and the expansion portion 210 may be made of a material containing at least one of the following materials: aluminum, copper, zinc, or a nickel-iron alloy.

[0057] The expansion part 210 may be disposed on one side of the body part 220. More specifically, according to the first embodiment of the disclosure, the body part 220 may have a semicircular shape, and the expansion part 210 may extend in a circumferential direction to be positioned along an outer peripheral surface of the body part 220 and in contact with an inner peripheral surface of the body part 220.

[0058] However, the body part 220 and the expansion part 210 according to the disclosure are not limited to the shape and arrangement structure according to the first embodiment, and the body part 220 and the expansion part 210 may include shapes and arrangement structures of all the body parts 220 and expansion parts 210 provided in the brake shoe 200 to accommodate a gap between the pad 300 and the drum 100 that thermally expands during vehicle braking. For example, the expansion part 210 may be disposed within the body part 220, or an entire brake shoe 200 may be provided as the expansion part 210.

[0059] Fig. 7 is a front view of a drum brake according to a second embodiment of the disclosure, and Fig. Figure 8 is an enlarged view of an area corresponding to the A area of Fig. 2 in the drum brake according to the second embodiment of the disclosure.

[0060] With reference to the Fig. 7 and Fig. 8, in the drum brake according to the second embodiment of the disclosure, the brake shoe 200 may have a plurality of expansion parts 210, in contrast to the first embodiment.

[0061] The following descriptions of the drum brake according to the second embodiment of the disclosure may be the same as those of the drum brake according to the first embodiment described above, except for the descriptions given with reference to different reference numerals. Accordingly, the same content of the second embodiment as that of the first embodiment will not be described to avoid duplication.

[0062] A plurality of expansion parts 210 may be provided. The plurality of expansion parts 210 may have different thicknesses and each be made of materials with different thermal expansion coefficients. Since the internal temperature of the brake shoe 200 increases to different degrees during vehicle deceleration depending on its components, the plurality of expansion parts 210 may be designed to effectively compensate for a gap compared to the expansion part 210 provided as a single body.

[0063] All of the plurality of expansion parts 210 can be arranged inside the body part 220. The plurality of expansion parts 210 can be arranged in a radial direction. In this case, the plurality of expansion parts 210 can be stacked or spaced apart from each other. The expansion parts 210 can be arranged at regular or irregular intervals.

[0064] Fig. 9 is an enlarged view of a part corresponding to the area A in Fig. 2, in a drum brake according to a third embodiment of the disclosure.

[0065] Referring to Fig. 9, in the drum brake according to the third embodiment of the disclosure, an expansion part 210 of a brake shoe 200 may include a first space 211 and a second space 212, in contrast to the first embodiment.

[0066] The following descriptions of the drum brake according to the third embodiment of the disclosure may be the same as those of the drum brake according to the first embodiment described above, except for the descriptions given with reference to different reference numerals. Accordingly, the same content of the third embodiment as that of the first embodiment will not be described to avoid duplication.

[0067] A plurality of expansion parts 210 may be arranged in the circumferential direction. In this case, the plurality of expansion parts 210 may be spaced apart from each other. That is, the second space 212 may be provided between adjacent expansion parts 210.

[0068] The first space 211 may be provided at one end of an expansion part 210 positioned on one side because a circumferential length of the expansion part 210 is shorter than a circumferential length of the body part 220. The first space 211 may be provided even when only a single expansion part 210 is provided or when a plurality of expansion parts 210 are arranged in the radial direction.

[0069] Specifically, in the drum brake according to the third embodiment of the disclosure, two expansion parts 210 may be arranged in the circumferential direction. In this case, the second space 212 may be provided on the inner sides of the two expansion parts 210, and the first space 211 may be provided on the outer sides of the two expansion parts 210.

[0070] Accordingly, the expansion portion 210 may heat up and thermally expand during vehicle deceleration. At this time, the radial expansion of the expansion portion 210 may compensate for a gap formed between the inner peripheral surface of the drum 100 and the outer peripheral surface of the pad 300, and the expansion portion 210 may expand circumferentially toward the first space 211 or the second space 212.

[0071] However, the body part 220 forming the first space 211 or the second space 212 according to the disclosure is not limited to the shape, number, and arrangement structure according to the third embodiment, and may include any shapes, numbers, and arrangement structures forming the first space 211 or the second space 212 and capable of compensating for the thermal expansion of the expansion part 210 in the circumferential direction.

[0072] Fig. 10 is a front view of a drum brake according to a fourth embodiment of the disclosure, and Fig. 11 is an enlarged view of an area corresponding to the A area of ​​the Fig. 2 in the drum brake according to the fourth embodiment of the disclosure.

[0073] With reference to the Fig. 10 and Fig. 11, in the drum brake according to the fourth embodiment of the disclosure, an expansion part 210 of a brake shoe 200 can expand in the radial direction, in contrast to the first embodiment.

[0074] The following descriptions of the drum brake according to the fourth embodiment of the disclosure may be the same as those of the drum brake according to the first embodiment described above, except for the descriptions given with reference to different reference numerals. Accordingly, the same content of the fourth embodiment as that of the first embodiment will not be described to avoid duplication.

[0075] The expansion part 210 may extend in a radial direction perpendicular to the outer peripheral surface of the body part 220. In this case, one end of the expansion part 210 toward the pad 300 may be in contact with an inner surface of the pad 300.

[0076] A plurality of expansion parts 210 may be provided with different lengths in the radial direction. In other words, each of the expansion parts 210 may be in contact with the pad 300 at one end while being in contact with the body part 220 at another end, and each of the expansion parts 210 may be in contact with the pad 300 at one end while penetrating the body part 200 at another end.

[0077] Accordingly, the expansion parts 210 can be in contact with the body part 220 on both sides, and when the expansion parts 210 and the body part 220 thermally expand, the expansion parts 210 can thermally expand more than the body part 220 to be easily attached to the inside of the body part 220.

[0078] Each expansion part 210 may extend in the radial direction with a different width. In other words, each expansion part 210 may have a narrow width at one end facing the pad 300 and a wide width at the opposite end. Accordingly, the expansion part 210 can be more securely attached to the inside of the body part 220.

[0079] A plurality of expansion parts 210 may be provided along the side wall of the drum 11, as shown in Fig. 11. The plurality of expansion parts 210 may be stacked along the side wall or spaced apart from each other, as shown in Fig. 11 shown.

[0080] Since the drum brake according to an embodiment includes the expansion part 210, the drum brake according to an embodiment can compensate for a gap that occurs between the inner peripheral surface of the drum 100 and the outer peripheral surface of the pad 300 provided in the brake shoe 200 due to thermal expansion of the drum 100 during vehicle braking. Accordingly, the drum brake according to an embodiment of the disclosure can prevent the drum 10, which is thermally expanded during braking, from completely contacting the brake pad 300, thereby preventing deterioration in braking performance and life-time damage, avoiding brake vibration and noise, and improving brake productivity and economy through a simple structure.

[0081] An embodiment of the disclosure may provide a drum brake that prevents deterioration of braking performance.

[0082] An embodiment of the disclosure may provide a drum brake to prevent deterioration of braking performance caused by thermal expansion of the drum brake.

[0083] An embodiment of the disclosure may provide a drum brake for preventing vibrations and noise caused by thermal expansion of the drum brake.

[0084] An embodiment of the disclosure may provide a drum brake for improving productivity and economy of the brake by preventing deterioration of braking performance through a simple structure.

Claims

[1] Drum brake, comprising: a drum (100) arranged to rotate together with a wheel; a pair of brake shoes (200) disposed within the drum (100) and adapted to move through a wheel cylinder to an inner peripheral surface of the drum (100); and a lining (300) attached to an outer peripheral surface of each brake shoe (200) and arranged to rub against the inner peripheral surface of the drum (100) when the brake shoe (200) operates outward, wherein the brake shoe (200) comprises an expansion part (210) made of a material that expands thermally in a radial direction and is adapted to compensate for a gap formed between the lining (300) and the drum (100) that expands thermally, and a body part (220) made of a material that is different from a material of the expansion part (210), wherein the expansion part (210) has a plurality of expansion parts (210), wherein the plurality of expansion parts (210) are arranged in the radial direction. [2] A drum brake according to claim 1, wherein the plurality of expansion parts (210) are made of a material having a relatively lower rigidity and a relatively larger coefficient of thermal expansion than the material of the body part (220). [3] Drum brake according to one of claims 1 or 2, wherein the body part (220) is made of a material containing iron, and the plurality of expansion parts (210) are made of a material containing at least one of the elements aluminum or copper. [4] A drum brake according to any one of claims 1 to 3, wherein the body part (220) has a semicircular shape and the plurality of expansion parts (210) extend in a circumferential direction to be positioned along a circumferential surface of the body part (220). [5] Drum brake according to one of claims 1 to 4, wherein the plurality of expansion parts (210) are arranged within the body part (220). [6] A drum brake according to any one of claims 1 to 5, wherein a circumferential length of at least one of the plurality of expansion parts (210) is shorter than a circumferential length of the body part (220), and a first gap (211) is formed at one end of the expansion part (210). [7] Drum brake according to one of claims 1 to 6, wherein the plurality of expansion parts (210) are spaced from each other so that the body part (220) is arranged between the plurality of expansion parts (210). [8] Drum brake, comprising: a drum (100) arranged to rotate together with a wheel; a pair of brake shoes (200) disposed within the drum (100) and adapted to move through a wheel cylinder to an inner peripheral surface of the drum (100); and a lining (300) attached to an outer peripheral surface of each brake shoe (200) and arranged to rub against the inner peripheral surface of the drum (100) when the brake shoe (200) operates outward, wherein the brake shoe (200) comprises an expansion part (210) made of a material that expands thermally in a radial direction and is adapted to compensate for a gap formed between the lining (300) and the drum (100) that expands thermally, and a body part (220) made of a material that is different from a material of the expansion part (210), wherein the body part (220) has a semicircular shape and the expansion part (210) extends in a radial direction to be perpendicular to an outer peripheral surface of the body part (220), wherein the expansion part (210) has a plurality of expansion parts (210) formed with different lengths in the radial direction. [9] A drum brake according to claim 8, wherein the plurality of expansion parts (210) are in contact with the lining (300) at one end toward the lining (300). [10] Drum brake, comprising: a drum (100) arranged to rotate together with a wheel; a pair of brake shoes (200) disposed within the drum (100) and adapted to move through a wheel cylinder to an inner peripheral surface of the drum (100); and a lining (300) attached to an outer peripheral surface of each brake shoe (200) and arranged to rub against the inner peripheral surface of the drum (100) when the brake shoe (200) operates outward, wherein the brake shoe (200) comprises an expansion part (210) made of a material that expands thermally in a radial direction and is adapted to compensate for a gap formed between the lining (300) and the drum (100) that expands thermally, and a body part (220) made of a material that is different from a material of the expansion part (210), wherein the expansion part (210) has a plurality of expansion parts (210), wherein the plurality of expansion parts (210) are each made of materials having different thermal expansion coefficients. [11] Drum brake, comprising: a drum (100) arranged to rotate together with a wheel; a pair of brake shoes (200) disposed within the drum (100) and adapted to move through a wheel cylinder to an inner peripheral surface of the drum (100); and a lining (300) attached to an outer peripheral surface of each brake shoe (200) and arranged to rub against the inner peripheral surface of the drum (100) when the brake shoe (200) operates outward, wherein the brake shoe (200) comprises an expansion part (210) made of a material that expands thermally in a radial direction and is adapted to compensate for a gap formed between the lining (300) and the drum (100) that expands thermally, and a body part (220) made of a material that is different from a material of the expansion part (210), wherein the expansion part (210) has a plurality of expansion parts (210), wherein the plurality of expansion parts (210) are each made of materials having different thicknesses.

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