Drum brake structure, wheel and vehicle

Abstract

The utility model relates to a drum brake structure, a wheel and a vehicle. The drum brake structure comprises a shell, a driving shaft and two brake shoes, and a shifting piece is arranged in the shell; the driving shaft comprises a driving part and a cam part which are distributed in the axial direction. The end, close to the cam part, of the driving part is connected to the stirring piece, and the driving shaft is driven to rotate through the stirring piece, so that the brake shoe abuts against the brake face or the unlocking face. When the brake shoes abut against the brake face on the cam part, the two brake shoes expand outwards and make contact with the shell, so that the friction force between the brake shoes and the shell is increased, and braking is achieved through the friction force. Due to the fact that the shifting piece is connected to the end, close to the cam part, of the driving part, namely the shifting piece is connected to the position close to the brake shoe, the distance between the shifting piece and the brake shoe is shorter, the brake torque is reduced, the brake sensitivity is improved, the sliding distance of a vehicle is reduced, and rapid brake is achieved. Meanwhile, abrasion to the driving shaft is reduced due to reduction of the braking torque, and the service life of the drum brake structure is prolonged.

Description

Technical Field

[0001] The present application relates to the field of braking technology, and in particular to a drum brake structure, a wheel and a vehicle. Background Art

[0002] Existing vehicle brakes are generally divided into brakes with a drum brake structure and brakes with a disc brake structure. Compared with brakes with a disc brake structure, brakes with a drum brake structure have the advantages of lower maintenance costs and easier installation.

[0003] In the related art, the brake of the drum brake structure has disadvantages such as a long braking torque resulting in a large sliding distance of the vehicle. Utility Model Content

[0004] Based on this, it is necessary to provide a drum brake structure to address the problem of long braking torque in existing drum brake structures.

[0005] A drum brake structure, comprising:

[0006] A housing, wherein a toggle member is disposed in the housing;

[0007] A brake assembly, comprising a drive shaft and two brake shoes; the drive shaft comprises a drive portion and a cam portion distributed along the axial direction; one end of the drive portion close to the cam portion is connected to the toggle member; the cam portion has two braking surfaces and two unlocking surfaces distributed along the circumferential direction, and the braking surfaces and the unlocking surfaces are alternately arranged; the spacing between the two braking surfaces is greater than the spacing between the two unlocking surfaces;

[0008] In the braking state, the brake shoe abuts against the braking surface; in the unlocking state, the brake shoe abuts against the unlocking surface;

[0009] Wherein, the toggle member is configured to be operably rotated to drive the drive shaft to rotate around its own axis, so that the brake shoe abuts against the braking surface or the unlocking surface.

[0010] In one embodiment, a receiving groove is provided in the housing, and the toggle member is provided with a bent portion, and the bent portion is located in the receiving groove;

[0011] In the unlocking state, there is a gap between the bent portion and the groove wall of the accommodating groove; in the braking state, the bent portion can abut against the groove wall of the accommodating groove.

[0012] In one embodiment, a threading hole is provided on the side wall of the housing, and the threading hole is communicated with the receiving groove;

[0013] The drum brake structure also includes a brake line, which is sequentially passed through the wire threading hole and the accommodating groove and connected to the shifting member.

[0014] In one embodiment, a sleeve is disposed in the housing, and the driving part is sleeved in the sleeve;

[0015] A baffle is provided between the driving portion and the cam portion, and the shifting member is connected between the baffle and the sleeve.

[0016] In one embodiment, the brake assembly also includes a connecting rod and a gap adjustment mechanism abutting between the two brake shoes; the two ends of the connecting rod are respectively connected to the drive shaft and the gap adjustment mechanism; the connecting rod is used to transmit the power of the drive shaft to the gap adjustment mechanism, so that the gap adjustment mechanism can drive the two brake shoes to move away from or closer to each other.

[0017] In one embodiment, the clearance adjustment mechanism includes a sliding portion, a ratchet, and two abutment portions that are transmission-connected to the ratchet and located on both sides of the ratchet along the axial direction, and the abutment portions abut against the brake shoe;

[0018] The sliding portion is connected to the connecting rod and abuts against the ratchet teeth of the ratchet wheel; the connecting rod can drive the sliding portion to move, so as to drive the ratchet wheel to rotate through the sliding portion, and drive the abutting portion to move closer to or farther from the ratchet wheel through the ratchet wheel.

[0019] In one embodiment, the gap adjustment mechanism further includes a protective shell, and the ratchet is disposed in the protective shell.

[0020] In one of the embodiments, the gap adjustment mechanism further includes a pressing plate, wherein the pressing plate is connected between the abutting portion and the protective shell, and the pressing plate abuts against an end surface of the sliding portion close to the connecting rod.

[0021] A wheel comprises a wheel hub and the drum brake structure as described above mounted on the wheel hub.

[0022] A vehicle comprises a frame and the above-mentioned wheel mounted on the frame.

[0023] The drum brake structure mentioned above drives the drive shaft to rotate through the toggle member, so that the brake shoe abuts against the braking surface or the unlocking surface. Since the distance between the two braking surfaces is greater than the distance between the two unlocking surfaces, when the brake shoe abuts against the braking surface on the cam portion, the two brake shoes will expand outward and contact the outer shell, thereby increasing the friction between the brake shoe and the outer shell, and braking is achieved through friction. Since the toggle member is connected to one end of the driving portion close to the cam portion, that is, the toggle member is connected to a portion close to the brake shoe, the distance between the toggle member and the brake shoe is shorter, reducing the braking torque, thereby improving the braking sensitivity, reducing the vehicle's sliding distance, and achieving rapid braking. At the same time, the reduction in braking torque also reduces the wear on the drive shaft and extends the service life of the drum brake structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG. 1 is a schematic diagram of a drum brake structure provided in an embodiment of the present application.

[0025] FIG. 2 is an exploded view of the drum brake structure shown in FIG. 1 .

[0026] FIG. 3 is a schematic diagram of a brake assembly in the drum brake structure shown in FIG. 2 .

[0027] FIG. 4 is a schematic diagram of the drum brake structure shown in FIG. 2 without the brake assembly.

[0028] FIG. 5A is a schematic diagram of a gap adjustment mechanism in the drum brake structure shown in FIG. 2 .

[0029] FIG. 5B is a schematic diagram of the gap adjustment mechanism in the drum brake structure shown in FIG. 5A without the protective shell.

[0030] FIG6 is a schematic block diagram of a vehicle provided in accordance with an embodiment of the present application.

[0031] Figure numbers: 1. drum brake structure; 2. vehicle; 10. shell; 11. brake assembly; 12. toggle member; 13. drive shaft; 14. brake shoe; 15. brake line; 16. gap adjustment mechanism; 17. connecting rod; 18. reset member; 20. frame; 21. wheel; 100. accommodating groove; 101. sleeve; 102. threading hole; 110. gap; 120. bending part; 121. through hole; 130. cam part; 131. driving part; 132. baffle; 160. ratchet; 161. abutment part; 162. protective shell; 163. pressing piece; 1300. unlocking surface; 1301. braking surface; 1600. sliding part. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0033] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0034] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0035] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0036] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0037] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0038] Referring to FIGS. 1 to 3 , a drum brake structure 1 provided in an embodiment of the present application includes a housing 10 and a brake assembly 11, wherein a toggle member 12 is disposed in the housing 10; the brake assembly 11 includes a drive shaft 13 and two brake shoes 14; the drive shaft 13 includes a drive portion 131 and a cam portion 130 distributed along the axial direction; one end of the drive portion 131 close to the cam portion 130 is connected to the toggle member 12; the cam portion 130 has two braking surfaces 1301 and two unlocking surfaces 130 distributed along the circumferential direction. 0, and the braking surface 1301 and the unlocking surface 1300 are arranged alternately; the spacing between the two braking surfaces 1301 is greater than the spacing between the two unlocking surfaces 1300; in the braking state, the brake shoe 14 abuts against the braking surface 1301; in the unlocking state, the brake shoe 14 abuts against the unlocking surface 1300; wherein the toggle member 12 is configured to be operably rotated to drive the drive shaft 13 to rotate around its own axis so that the brake shoe 14 abuts against the braking surface 1301 or the unlocking surface 1300. As shown in FIG. 2, the braking surface 1301 is a side with a narrower lateral width, and the unlocking surface 1300 is a side with a wider lateral width.

[0039] The drum brake structure 1 drives the driving shaft 13 to rotate through the toggle member 12, so that the brake shoe 14 abuts against the braking surface 1301 or the unlocking surface 1300. Since the spacing between the two braking surfaces 1301 is greater than the spacing between the two unlocking surfaces 1300, when the brake shoe 14 abuts against the braking surface 1301 on the cam portion 130, the two brake shoes 14 will expand outward and contact the housing 10, thereby increasing the friction between the brake shoe 14 and the housing 10, and braking is achieved through friction. Since the toggle member 12 is connected to one end of the driving portion 131 close to the cam portion 130, that is, the toggle member 12 is connected to the part close to the brake shoe 14, the distance between the toggle member 12 and the brake shoe 14 is shorter, the braking torque is reduced, the braking sensitivity is improved, the sliding distance of the vehicle 2 is reduced, and rapid braking is achieved. At the same time, the reduction of the braking torque also reduces the wear on the driving shaft 13, extending the service life of the drum brake structure 1.

[0040] Among them, the lateral width of the end face where the brake shoe 14 abuts against the cam portion 130 is not less than the lateral width of the unlocking surface 1300, so that when the toggle member 12 drives the cam portion 130 on the drive shaft 13 to rotate, the braking surface 1301 can smoothly abut against the brake shoe 14, thereby ensuring the expansion effect of the brake shoe 14 and further ensuring the braking reliability.

[0041] As shown in FIG. 4 , in one embodiment, a receiving groove 100 is provided in the housing 10, and a bending portion 120 is provided in the toggle member 12. The bending portion 120 is located in the receiving groove 100. In the unlocked state, a gap 110 is provided between the bending portion 120 and the groove wall of the receiving groove 100. In the braking state, the bending portion 120 can approach the groove wall of the receiving groove 100 until it abuts against the groove wall of the receiving groove 100. By arranging the bending portion 120 of the toggle member 12 in the receiving groove 100, the movement range of the toggle member 12 is limited to prevent excessive braking.

[0042] As shown in FIG4 , in one embodiment, the side wall of the housing 10 is provided with a threading hole 102, and the threading hole 102 is connected to the receiving groove 100; the drum brake structure 1 also includes a brake line 15, and the brake line 15 extends from the outside of the housing 10 into the receiving groove 100 through the threading hole 102, and is connected to the toggle member 12. The movement of the toggle member 12 is controlled by the brake line 15, thereby driving the cam portion 130 on the drive shaft 13 to rotate, and the unlocking state and the braking state are switched. By placing the brake line 15 in the receiving groove 100 and connecting it to the toggle member 12, the structure is simplified and the receiving space in the housing 10 is fully utilized.

[0043] As shown in FIG. 2 , in one embodiment, the toggle member 12 is provided with a through hole 121 for inserting the driving portion 131 on the driving shaft 13. The through hole 121 may be a rectangular block or a polygonal hole, and the shape of the through hole 121 is adapted to the shape of the driving portion 131, so that the toggle member 12 can drive the driving shaft 13 to rotate through the driving portion 131.

[0044] As shown in FIGS. 2 to 4 , in one embodiment, a sleeve 101 is provided in the housing 10, and the sleeve 101 extends to one end of the housing 10 where the receiving groove 100 is provided; the driving portion 131 is sleeved in the sleeve 101; a baffle 132 is provided between the driving portion 131 and the cam portion 130, and the toggle member 12 is connected between the baffle 132 and the sleeve 101. By providing the sleeve 101, the driving shaft 13 is protected to prevent wear from affecting the reliability of power transmission. Among them, lubricating materials such as grease can be applied inside the sleeve 101 to reduce transmission resistance. By providing the sleeve 101 and the baffle 132, the toggle member 12 can be limited to prevent the toggle member 12 from moving along the axial direction of the driving portion 131.

[0045] As shown in FIG. 2 and FIG. 3 , in one embodiment, the brake assembly 11 further includes a connecting rod 17 and a gap adjustment mechanism 16 abutting between two brake shoes 14; the two ends of the connecting rod 17 are respectively connected to the drive shaft 13 and the gap adjustment mechanism 16, and the connecting rod 17 is used to transmit the power of the drive shaft 13 to the gap adjustment mechanism 16, so that the gap adjustment mechanism 16 can drive the two brake shoes 14 to move away from or close to each other. Specifically, the brake shoes 14 will wear out after long-term use, resulting in loss of brake material on the surface of the brake shoes 14. The gap adjustment mechanism 16 will open the two brake shoes 14, so that the brake shoes 14 expand, increase the friction between the brake shoes 14 and the housing 10, and automatically perform brake compensation, which plays a role in enhancing the braking effect.

[0046] As shown in Figures 3 to 5B, in one embodiment, the gap adjustment mechanism 16 includes a sliding portion 1600, a ratchet 160, and two abutment portions 161 that are transmission-connected to the ratchet 160 and located on both sides of the ratchet 160 along the axial direction, and the abutment portion 161 abuts against the brake shoe 14; the sliding portion 1600 is connected to the connecting rod 17 and abuts against the ratchet teeth of the ratchet 160.

[0047] Since one end of the connecting rod 17 is connected to the driving shaft 13, when the toggle member 12 drives the driving shaft 13 to rotate, the connecting rod 17 will also be deflected, so that the other end of the connecting rod 17 can drive the sliding part 1600 to move forward and backward. When the sliding part 1600 moves forward and backward, since the sliding part 1600 is in contact with the ratchet 160, it will drive the ratchet 160 to rotate, thereby driving the abutting part 161 connected to the ratchet 160 to move closer to or away from the ratchet 160, thereby causing the brake shoe 14 abutting against the abutting part 161 to move. The ratchet 160 and the abutting part 161 can be threadedly connected, that is, the inner ring of the ratchet 160 is provided with an internal thread, and the outer ring of the abutting part 161 is provided with an external thread. When the ratchet 160 rotates, the abutting part 161 will simultaneously move along the axial direction of the ratchet 160. Through this arrangement, the rotational torque transmitted by the connecting rod 17 is converted into an axial force of the abutting portion 161 to open the two brake shoes 14 so that the two brake shoes 14 expand, which has the advantages of stable force transmission and wear resistance.

[0048] As shown in FIGS. 5A to 5B , in one embodiment, the gap adjustment mechanism 16 further includes a protective shell 162, and the ratchet 160 is disposed in the protective shell 162. By disposing the ratchet 160 in the protective shell 162, the protective shell 162 can slow down the oxidation wear of the ratchet 160 inside, thereby extending the service life of the ratchet 160.

[0049] As shown in Fig. 5A to Fig. 5B, in one embodiment, the gap adjustment mechanism 16 further includes a pressing piece 163, which is connected between the abutting portion 161 and the protective shell 162, and the pressing piece 163 abuts against the end surface of the sliding portion 1600 close to the connecting rod 17. By providing the pressing piece 163, the sliding portion 1600 is prevented from moving in the vertical direction driven by the connecting rod 17, which not only ensures that the sliding portion 1600 performs a smooth horizontal movement, but also ensures the stability of the contact between the sliding portion 1600 and the ratchet 160, thereby improving the reliability of the gap adjustment mechanism 16 and enhancing the working stability of the drum brake structure 1.

[0050] As shown in FIGS. 2 and 3 , in one embodiment, two reset members 18 are connected between the two brake shoes 14, one of which is disposed at one end of the brake shoe 14 close to the drive shaft 13, and the other is disposed at one end of the brake shoe 14 close to the gap adjustment mechanism 16. When in the braking state, the reset member 18 is in a deformed state; when the braking is completed, the two reset members 18 can drive the two brake shoes 14 to automatically return to the initial position, that is, the position before the brake shoe 14 expands, to prevent the gap adjustment mechanism 16 and the drive shaft 13 from being automatically reset inaccurately, resulting in excessive wear of the brake shoe 14. Specifically, the reset member 18 can be a reset spring, a polygonal structure spring or a circular ordinary spring, which is not limited here.

[0051] Furthermore, an embodiment of the present application also provides a wheel 21, including a wheel hub and the drum brake structure 1 as described above mounted on the wheel hub. Since the wheel 21 includes the drum brake structure 1 as described above, the distance between the shifting member 12 and the brake shoe 14 is shorter, the braking torque is reduced, the braking sensitivity is improved, the sliding distance of the vehicle 2 is reduced, and rapid braking is achieved. At the same time, the reduction of the braking torque also reduces the wear on the drive shaft 13, extending the service life of the drum brake structure 1.

[0052] As shown in Fig. 6, on the other hand, an embodiment of the present application further provides a vehicle 2, comprising a frame 20 and the above-mentioned wheel 21 mounted on the frame 20. The wheel 21 has the same beneficial effects as the above-mentioned drum brake structure 1, which will not be described in detail here.

[0053] It should be noted that the above-mentioned drum brake structure is not only applicable to traditional two-wheeled vehicles, but can also be applied to electric bicycles, tricycles, motorcycles or other vehicles that require braking, etc., provided that the strength and load requirements are met, and no limitation is made here.

[0054] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0055] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A drum brake structure, characterized in that: The drum brake structure comprises: A housing (10), wherein a toggle member (12) is disposed inside the housing (10); A brake assembly (11), comprising a drive shaft (13) and two brake shoes (14); the drive shaft (13) comprises a drive portion (131) and a cam portion (130) distributed along the axial direction; one end of the drive portion (131) close to the cam portion (130) is connected to the toggle member (12); the cam portion (130) has two braking surfaces (1301) and two unlocking surfaces (1300) distributed along the circumferential direction, and the braking surfaces (1301) and the unlocking surfaces (1300) are arranged alternately; the spacing between the two braking surfaces (1301) is greater than the spacing between the two unlocking surfaces (1300); The shifting member (12) is configured to be operably rotated to drive the driving shaft (13) to rotate around its own axis, so that the brake shoe (14) abuts against the braking surface (1301) or the unlocking surface (1300).

2. The drum brake structure according to claim 1, characterized in that: The housing (10) is provided with a receiving groove (100), the toggle member (12) is provided with a bent portion (120), and the bent portion (120) is located in the receiving groove (100); In the unlocked state, a gap (110) is provided between the bent portion (120) and the groove wall of the accommodating groove (100); in the braked state, the bent portion (120) can abut against the groove wall of the accommodating groove (100).

3. The drum brake structure according to claim 2, characterized in that: A threading hole (102) is provided on the side wall of the housing (10), and the threading hole (102) is in communication with the containing groove (100); The drum brake structure further comprises a brake wire (15), wherein the brake wire (15) is sequentially passed through the wire threading hole (102) and the accommodating groove (100) and connected to the shifting member (12).

4. The drum brake structure according to claim 1, characterized in that: A sleeve (101) is disposed in the housing (10), and the driving portion (131) is sleeved in the sleeve (101); A baffle (132) is provided between the driving portion (131) and the cam portion (130), and the shifting member (12) is connected between the baffle (132) and the sleeve (101).

5. The drum brake structure according to claim 1, characterized in that: The brake assembly (11) further comprises a connecting rod (17) and a clearance adjustment mechanism (16) abutting between the two brake shoes (14); The two ends of the connecting rod (17) are respectively connected to the drive shaft (13) and the clearance adjustment mechanism (16); the connecting rod (17) is used to transmit the power of the drive shaft (13) to the clearance adjustment mechanism (16), so that the clearance adjustment mechanism (16) can drive the two brake shoes (14) to move away from or closer to each other.

6. The drum brake structure according to claim 5, characterized in that: The clearance adjustment mechanism (16) comprises a sliding portion (1600), a ratchet (160), and two abutment portions (161) drivingly connected to the ratchet (160) and located on both sides of the ratchet (160) along the axial direction, wherein the abutment portions (161) abut against the brake shoe (14); The sliding portion (1600) is connected to the connecting rod (17) and abuts against the ratchet teeth of the ratchet wheel (160); the connecting rod (17) can drive the sliding portion (1600) to move, so as to drive the ratchet wheel (160) to rotate through the sliding portion (1600), and drive the abutting portion (161) to move closer to or farther away from the ratchet wheel (160) through the ratchet wheel (160).

7. The drum brake structure according to claim 6, characterized in that: The gap adjustment mechanism (16) further comprises a protective shell (162), and the ratchet (160) is arranged in the protective shell (162).

8. The drum brake structure according to claim 7, characterized in that: The gap adjustment mechanism (16) further comprises a pressing plate (163), wherein the pressing plate (163) is connected between the abutment portion (161) and the protective shell (162), and the pressing plate (163) abuts against an end surface of the sliding portion (1600) close to the connecting rod (17).

9. A wheel, characterized in that: The invention comprises a wheel hub and a drum brake structure (1) as claimed in any one of claims 1 to 8 mounted on the wheel hub.

10. A vehicle, characterized in that: The invention comprises a frame (20) and a wheel (21) as claimed in claim 9 mounted on the frame (20).

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