Drum brake and vehicle

Abstract

The utility model provides a drum brake and a vehicle. The drum brake comprises a chassis, a rocker arm, a transmission assembly and a shoe assembly. The transmission assembly comprises a rotating shaft and a shifting piece, the rotating shaft penetrates through the chassis and is rotatably connected with the chassis, one end of the rotating shaft is fixedly connected with the rocker arm, and a cam part is arranged at the other end of the rotating shaft and abuts against the shifting piece; the shifting piece is connected with the shoe assembly and used for driving the shoe assembly to move in the direction close to or away from the brake drum. According to the drum brake, the acting force of the rotating shaft is transmitted through the cooperation of the cam part at the end of the rotating shaft and the shifting piece, large return torque can be avoided, the braking efficiency of the brake is improved, the braking torque is increased, the braking distance is shortened, and the braking effect is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of vehicle braking, in particular to a drum brake and a vehicle. Background Art

[0002] Drum brakes create a braking effect by having the shoe against the inner wall of the brake drum. Currently, most vehicle brakes use internal-pull drum brakes. However, in some cases where the drive motor is rear-mounted, if an internal-pull drum brake is used, the direction in which the brake cable appears will be greatly restricted. Therefore, external-pull drum brakes are usually used in cases where the drive motor is rear-mounted.

[0003] The action of the shoe in the external pull brake is usually realized by a lever. The lever is rotated to move the shoe, so that the shoe moves toward the brake drum to resist the brake drum, thereby achieving parking. The lever is rotated in the opposite direction, and the shoe is separated from the brake drum, thereby canceling parking. However, this method will generate a large return torque to offset the pulling force, resulting in a low efficiency factor of the brake and a small braking torque, which affects the braking effect. Utility Model Content

[0004] In view of this, the utility model provides a drum brake and a vehicle, so as to at least solve the problems of low efficiency factor and small braking torque of the drum brake in the prior art.

[0005] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0006] The utility model provides a drum brake, comprising a chassis, a rocker arm, a transmission assembly and a shoe assembly; the transmission assembly comprises a rotating shaft and a paddle, the rotating shaft passes through the chassis and is rotatably connected to the chassis, one end of the rotating shaft is fixedly connected to the rocker arm, and the other end of the rotating shaft is provided with a cam portion, the cam portion abuts against the paddle; the paddle is connected to the shoe assembly and is used to drive the shoe assembly to move in a direction close to or away from a brake drum.

[0007] Optionally, the transmission group further includes a push rod, and the shoe assembly includes a first shoe and a second shoe; the paddle is rotatably connected to the first shoe, and a side of the paddle away from the cam portion is connected to the second shoe via the push rod.

[0008] Optionally, the transmission assembly further comprises a pin shaft, and the paddle is rotatably connected to the first shoe via the pin shaft.

[0009] Optionally, the transmission assembly further comprises a limiting ring, which is sleeved on the pin shaft and is used to limit the movement of the paddle and the first shoe along the axial direction of the pin shaft.

[0010] Optionally, the limiting ring is an open retaining ring.

[0011] Optionally, a first slot is provided on one side of the push rod, and a side of the paddle away from the cam portion is clamped in the first slot.

[0012] Optionally, a second slot is provided on the other side opposite to the push rod, and the second shoe is clamped in the second slot.

[0013] Optionally, the cam portion and the rotating shaft are an integral piece.

[0014] Optionally, the cam portion is provided with a first abutting surface, the paddle is provided with a second abutting surface, the first abutting surface and the second abutting surface abut against each other, and both the first abutting surface and the second abutting surface are planes.

[0015] The utility model also provides a vehicle, comprising the drum brake described in any one of the above items.

[0016] Compared with the prior art, the drum brake and vehicle described in the utility model have the following advantages:

[0017] The drum brake of the utility model drives the rotating shaft to rotate through the rocker arm, and the rotating shaft drives the paddle to move through the cam portion at its end, and the paddle is connected to the shoe assembly, driving the shoe assembly to move in the direction of approaching or moving away from the brake drum. Therefore, by using the cooperation between the cam portion at the end of the rotating shaft and the paddle to transmit the action force of the rotating shaft, it is possible to avoid generating a large return torque, which helps to improve the braking efficiency of the brake, increase the braking torque, and thus shorten the braking distance and improve the braking effect.

[0018] The vehicle of the present invention has the same or similar advantages as the prior art and the aforementioned drum brake, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0020] Figure 1 It is a schematic diagram of a drum brake in an embodiment of the utility model;

[0021] Figure 2 It is a front view of a drum brake in an embodiment of the utility model;

[0022] Figure 3 yes Figure 2 Schematic diagram of the cross section cut along the AA direction.

[0023] Description of reference numerals:

[0024] 1-chassis, 10-through hole, 2-rocker arm, 3-rotating shaft, 30-cam portion, 4-paddle, 5-thrust rod, 51-first slot, 52-second slot, 6-first shoe, 7-second shoe, 8-pin shaft, 9-limiting ring. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0026] The terms "first", "second", etc. in the specification and claims of the present utility model are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the utility model can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0027] It should be understood that the reference to "some embodiments" throughout the specification means that specific features, structures or characteristics related to the embodiments are included in at least one embodiment of the utility model. Therefore, the "in some embodiments" appearing in various places throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner.

[0028] A drum brake and a vehicle provided by the utility model are described in detail below by listing specific embodiments.

[0029] Reference Figures 1 to 3 A drum brake provided by an embodiment of the utility model includes a chassis 1, a rocker arm 2, a transmission assembly and a shoe assembly; the transmission assembly includes a rotating shaft 3 and a paddle 4, the rotating shaft 3 passes through the chassis 1 and is rotatably connected to the chassis 1, one end of the rotating shaft 3 is fixedly connected to the rocker arm 2, and the other end of the rotating shaft 3 is provided with a cam portion 30, and the cam portion 30 abuts against the paddle 4; the paddle 4 is connected to the shoe assembly, and is used to drive the shoe assembly to move toward or away from the brake drum.

[0030] In this embodiment, the chassis 1 is mounted on a fixed position of the vehicle axle, and is mainly used to withstand the rotational torque during braking. The rocker arm 2, the transmission assembly and the shoe assembly are directly or indirectly mounted on the chassis 1. The drum brake also includes a brake drum, which is mounted on the wheel hub of the vehicle and rotates synchronously with the wheel. The brake drum can be made of cast iron of a certain weight and is shaped like a round drum. During the braking process of the drum brake, the transmission assembly is used to press the shoe assembly against the inner wall of the brake drum, so that the shoe assembly rubs against the inner wall of the brake drum, thereby generating a braking force, decelerating the wheel, and achieving the braking of the vehicle.

[0031] The transmission assembly includes a rotating shaft 3 and a paddle 4. The rotating shaft 3 and the paddle 4 can be made of metal, non-metal or composite materials, and have good strength and stiffness, and have strong ability to resist load impact. A through hole 10 for the rotating shaft 3 to pass through is provided on the chassis 1. The rotating shaft 3 passes through the through hole 10 and can rotate relative to the through hole 10. For example, the rotating shaft 3 and the through hole 10 can be clearance-fitted, or the rotating shaft 3 can be connected to the through hole 10 through a bearing. The embodiment of the utility model does not limit the rotational connection method between the rotating shaft 3 and the through hole 10. In some embodiments, a limiting portion can be provided on the rotating shaft 3, and the diameter of the limiting portion is larger than the diameter of the through hole 10. The limiting portion abuts against the surface of the chassis 1 to limit the axial movement of the rotating shaft 3 relative to the through hole 10, thereby improving the reliability of the rotational connection between the rotating shaft 3 and the chassis 1.

[0032] One end of the rotating shaft 3 is fixedly connected to the rocker arm 2, and the fixed connection between the rotating shaft 3 and the rocker arm 2 can be assembled and connected by fasteners, so as to facilitate the disassembly and maintenance of the rotating shaft 3 or the rocker arm 2. A cam portion 30 is provided at the other end of the rotating shaft 3, and the cam portion 30 has a curved surface profile. The cam portion 30 abuts against the paddle 4, and the paddle 4 also has a curved surface profile, and the curved surface profile of the paddle 4 is adapted to the curved surface profile of the cam portion 30, so as to ensure that the cam portion 30 can smoothly drive the paddle 4 to move. The paddle 4 is connected to the shoe assembly, and the paddle 4 can drive the shoe assembly to move in the direction of approaching or moving away from the brake drum. In some embodiments, the rotating shaft 3 and the cam portion 30 are an integral part processed by an integrated molding process, so as to omit the connection process between the rotating shaft 3 and the cam portion 30, simplify the process, and effectively ensure the connection reliability between the rotating shaft 3 and the cam portion 30. In other embodiments, the transmission assembly includes two components: a rotating shaft 3 and a cam. The cam is fixed to the end of the rotating shaft 3 by welding, assembly connection, etc., to form a cam portion 30 on the rotating shaft 3. In this way, the rotating shaft 3 and the cam can directly use standard parts and can be secondary processed according to the requirements of the drum brake in the embodiment of the utility model.

[0033] Specifically, Figure 1As shown, the shoe assembly consists of two shoes. During the braking process of the vehicle, the rocker arm 2 is controlled to swing by a pull wire, and the rocker arm 2 drives the rotating shaft 3 to rotate clockwise, and the cam portion 30 at the end of the rotating shaft 3 rotates clockwise accordingly, pushing the paddle 4 to move in the direction away from the rotating shaft 3. During the movement of the paddle 4, the two shoes are driven to open each other, so that the two shoes contact and rub the inner wall of the brake drum, thereby realizing the braking of the vehicle; during the process of releasing the brakes of the vehicle, the rocker arm 2 is controlled to swing in the opposite direction by a pull wire, and the rocker arm 2 drives the rotating shaft 3 to rotate counterclockwise, and the cam portion 30 at the end of the rotating shaft 3 rotates counterclockwise accordingly, driving the paddle 4 to move in the direction close to the rotating shaft 3. During the movement of the paddle 4, the two shoes are driven to retract each other, so that the two shoes are separated from the inner wall of the brake drum, thereby releasing the braking of the vehicle.

[0034] Compared with the prior art, the drum brake of the utility model embodiment drives the rotating shaft 3 to rotate through the rocker arm 2, and the rotating shaft 3 drives the paddle 4 to move through the cam portion 30 at its end, and the paddle 4 is connected to the shoe assembly to drive the shoe assembly to move in the direction of approaching or moving away from the brake drum. Therefore, by using the cooperation between the cam portion 30 at the end of the rotating shaft 3 and the paddle 4 to transmit the force of the rotating shaft 3, it is possible to avoid generating a large return torque, which helps to improve the braking efficiency of the brake, increase the braking torque, and thus shorten the braking distance and improve the braking effect.

[0035] Optionally, refer to Figures 1 to 3 The transmission group also includes a push rod 5, and the shoe assembly includes a first shoe 6 and a second shoe 7; the paddle 4 is rotatably connected to the first shoe 6, and the side of the paddle 4 away from the cam portion 30 is connected to the second shoe 7 through the push rod 5.

[0036] In the present embodiment, the shoe assembly includes a first shoe 6 and a second shoe 7, the first shoe 6 and the second shoe 7 are symmetrically arranged with the rotating shaft 3 as the center, the paddle 4 is rotatably connected to the first shoe 6, and the rotatable connection method includes but is not limited to hinge, pin 8 connection, bearing connection, etc. In some embodiments, a rotating part protruding from the surface of the paddle 4 can be provided on the paddle 4, a connecting hole is provided on the first shoe 6, and the rotating part is rotatably embedded in the connecting hole to realize the rotatable connection between the paddle 4 and the first shoe 6. Of course, in other embodiments, a connecting hole can be provided on the paddle 4, a rotating part protruding from the surface of the first shoe 6 can be provided on the first shoe 6, and the rotating part is rotatably embedded in the connecting hole to realize the rotatable connection between the paddle 4 and the first shoe 6. The embodiment of the utility model does not limit the method of rotatably connecting the paddle 4 and the first shoe 6.

[0037] The side of the paddle 4 away from the cam portion 30 is connected to the push rod 5, and the push rod 5 is connected to the second shoe 7. The connection mode of the push rod 5, the paddle 4 and the second shoe 7 includes but is not limited to fastener assembly connection, clamping, adhesive connection and other matching connections, etc., which are not limited to the embodiment of the utility model. In the process of the cam portion 30 at the end of the rotating shaft 3 driving the paddle 4 to move, the paddle 4 directly drives the first shoe 6 to move, and drives the second shoe 7 to move through the push rod 5, so as to realize the mutual opening or retraction of the first shoe 6 and the second shoe 7.

[0038] Specifically, Figure 1 As shown, during the braking process of the vehicle, the cam portion 30 at the end of the shaft 3 rotates clockwise, pushing the paddle 4 to move in the direction away from the shaft 3. At this time, the paddle 4 drives the first shoe 6 to move to the left. During the movement of the paddle 4, the paddle 4 itself rotates counterclockwise around the portion connected to the first shoe 6, so that the side of the paddle 4 away from the cam portion 30 pushes the push rod 5 to move rightward, and the push rod 5 is connected to the second shoe 7, pushing the second shoe 7 to move rightward, so that the first shoe 6 and the second shoe 7 are opened to each other, and the first shoe 6 and the second shoe 7 contact and rub the inner wall of the brake drum, thereby achieving the braking of the vehicle;

[0039] During the process of releasing the brakes of the vehicle, the cam portion 30 at the end of the shaft 3 rotates counterclockwise, driving the paddle 4 to move toward the direction close to the shaft 3. At this time, the paddle 4 drives the first shoe 6 to move to the right. During the movement of the paddle 4, it rotates clockwise around the part where it is connected to the first shoe 6, so that the side of the paddle 4 away from the cam portion 30 drives the push rod 5 to move to the left, and the push rod 5 drives the second shoe 7 to move to the left, so that the first shoe 6 and the second shoe 7 retract relative to each other, and the first shoe 6 and the second shoe 7 are separated from the inner wall of the brake drum, thereby releasing the brake of the vehicle.

[0040] Optionally, refer to Figure 1 and Figure 2 The transmission assembly also includes a pin shaft 8, and the paddle 4 is rotatably connected to the first shoe 6 via the pin shaft 8.

[0041] In this embodiment, a first connecting hole for allowing the pin shaft 8 to pass through is provided on the paddle 4, and a second connecting hole for allowing the pin shaft 8 to pass through is provided on the first shoe 6. The positions of the first connecting hole and the second connecting hole correspond to each other, and the pin shaft 8 is passed through the first connecting hole and the second connecting hole to realize the rotatable connection between the paddle 4 and the first shoe 6.

[0042] Optionally, refer to Figure 1 and Figure 2 The transmission assembly also includes a limit ring 9, which is sleeved on the pin 8 and is used to limit the movement of the paddle 4 and the first shoe 6 along the axial direction of the pin 8.

[0043] In this embodiment, the limiting ring 9 is sleeved on the pin 8. The limiting ring 9 can be one or two. If there are two limiting rings 9, one of them abuts against the surface of the side of the paddle 4 away from the first shoe 6, and the other abuts against the surface of the side of the first shoe 6 away from the paddle 4. If there is one limiting ring 9, the limiting ring 9 can be sleeved at any of the above positions. The limiting ring 9 is fixedly connected to the pin 8, which can limit the movement of the paddle 4 and the first shoe 6 along the axial direction of the pin 8, thereby improving the stability and reliability of the rotational connection between the paddle 4 and the first shoe 6.

[0044] Optionally, refer to Figure 1 and Figure 2 , the limiting ring 9 is an open retaining spring.

[0045] In this embodiment, the open retaining spring is an elastic element with good elasticity and durability. It has a simple structure and is easy to install and disassemble. It is also easy to install and can be adjusted according to actual needs. It can be applied to a variety of different fixing and connection scenarios. The open retaining spring of this embodiment can be made of alloy retaining springs, etc., to ensure the wear resistance and durability of the retaining spring. In some embodiments, a slot for installing the open retaining spring can be set at the corresponding part of the pin 8, and the open retaining spring can be installed in the slot to prevent the open retaining spring from slipping relative to the pin 8, thereby improving the installation stability of the open retaining spring.

[0046] Optionally, refer to Figure 1 A first slot 51 is provided on one side of the push rod 5 , and a side of the paddle 4 away from the cam portion 30 is clamped in the first slot 51 .

[0047] In this embodiment, the push rod 5 is connected with the paddle 4 by snapping, and a first snapping groove 51 is provided on the side of the push rod 5 close to the paddle 4, and the shape and structure of the first snapping groove 51 are adapted to the shape and structure of the paddle 4, and the side of the paddle 4 away from the cam portion 30 is snapped in the first snapping groove 51 to achieve the matching connection between the paddle 4 and the push rod 5, so that when the cam portion 30 of the rotating shaft 3 drives the paddle 4 to move, the paddle 4 drives the push rod 5 to move synchronously. Of course, in other embodiments, the first snapping groove 51 can also be provided on the side of the paddle 4 away from the cam portion 30, and the shape and structure of the first snapping groove 51 are adapted to the shape and structure of the push rod 5, and the push rod 5 is snapped in the first snapping groove 51 to achieve the matching connection between the paddle 4 and the push rod 5. In this embodiment, the push rod 5 and the paddle 4 are snapped and connected by the first snapping groove 51, which helps to simplify the structure and connection method of the push rod 5 and the paddle 4, and is more convenient for the processing design of the drum brake.

[0048] Optionally, refer to Figure 1 A second slot 52 is provided on the other side of the push rod 5 , and the second shoe 7 is clamped in the second slot 52 .

[0049] In the present embodiment, the second draw-in slot 52 is provided on the side of the push rod 5 close to the second shoe 7, the second draw-in slot 52 and the first draw-in slot 51 are arranged relatively along the length direction of the push rod 5, the shape structure of the second draw-in slot 52 is adapted to the shape structure of the second shoe 7, and the second shoe 7 is clamped in the second draw-in slot 52 to achieve the cooperation connection between the second shoe 7 and the push rod 5, so that during the movement of the push rod 5, the push rod 5 drives the second shoe 7 to move synchronously. Of course, in other embodiments, the second draw-in slot 52 can also be provided on the side of the second shoe 7 close to the push rod 5, the shape structure of the second draw-in slot 52 is adapted to the shape structure of the push rod 5, and the push rod 5 is clamped in the second draw-in slot 52 to achieve the cooperation connection between the second shoe 7 and the push rod 5. In the present embodiment, the push rod 5 and the second shoe 7 are clamped and connected by the second draw-in slot 52, which helps to simplify the structure and connection mode of the push rod 5 and the second shoe 7, and is more convenient for the processing design of the drum brake.

[0050] Optionally, the cam portion 30 is provided with a first abutting surface, and the paddle 4 is provided with a second abutting surface, the first abutting surface and the second abutting surface abut against each other, and both the first abutting surface and the second abutting surface are planes.

[0051] In this embodiment, the curved surface profile of the cam portion 30 forms a first abutting surface, and the curved surface profile of the paddle 4 forms a second abutting surface. When the cam portion 30 drives the paddle 4 to move, the first abutting surface and the second abutting surface always maintain a state of abutting each other. The first abutting surface and the second abutting surface are both planar structures to improve the reliability of the abutment between the first abutting surface and the second abutting surface and avoid slippage. When the cam portion 30 rotates clockwise and the paddle 4 rotates counterclockwise, the area of ​​the abutment between the first abutting surface and the second abutting surface gradually decreases. When the cam portion 30 rotates clockwise and the paddle 4 rotates clockwise, the area of ​​the abutment between the first abutting surface and the second abutting surface gradually increases.

[0052] An embodiment of the utility model further provides a vehicle, comprising the drum brake as described in any one of the above items.

[0053] In this embodiment, the vehicle's braking system adopts any of the aforementioned drum brakes, which helps to improve the braking capacity of the braking system, shorten the braking distance of the vehicle, and improve the braking effect.

[0054] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A drum brake, characterized in that: It comprises a chassis (1), a rocker arm (2), a transmission assembly and a shoe assembly; The transmission assembly comprises a rotating shaft (3) and a paddle (4); the rotating shaft (3) passes through the chassis (1) and is rotatably connected to the chassis (1); one end of the rotating shaft (3) is fixedly connected to the rocker arm (2); the other end of the rotating shaft (3) is provided with a cam portion (30), and the cam portion (30) abuts against the paddle (4); The paddle (4) is connected to the shoe assembly and is used to drive the shoe assembly to move in a direction close to or away from the brake drum.

2. The drum brake according to claim 1, characterized in that: The transmission group also includes a push rod (5), and the shoe assembly includes a first shoe (6) and a second shoe (7); The paddle (4) is rotatably connected to the first shoe (6), and the side of the paddle (4) away from the cam portion (30) is connected to the second shoe (7) via the push rod (5).

3. The drum brake according to claim 2, characterized in that: The transmission assembly also includes a pin shaft (8), and the paddle (4) and the first shoe (6) are rotatably connected via the pin shaft (8).

4. The drum brake according to claim 3, characterized in that: The transmission assembly further comprises a limiting ring (9), wherein the limiting ring (9) is sleeved on the pin shaft (8), and the limiting ring (9) is used to limit the movement of the paddle (4) and the first shoe (6) along the axial direction of the pin shaft (8).

5. The drum brake according to claim 4, characterized in that The limiting ring (9) is an open clip spring.

6. The drum brake according to claim 2, characterized in that: A first clamping groove (51) is provided on one side of the push rod (5), and a side of the paddle (4) away from the cam portion (30) is clamped in the first clamping groove (51).

7. The drum brake according to claim 6, characterized in that A second clamping groove (52) is provided on the other side opposite to the push rod (5), and the second shoe (7) is clamped in the second clamping groove (52).

8. The drum brake according to claim 1, characterized in that The cam portion (30) and the rotating shaft (3) are an integral part.

9. The drum brake according to claim 1, characterized in that The cam portion (30) is provided with a first abutting surface, and the paddle (4) is provided with a second abutting surface, the first abutting surface and the second abutting surface abut against each other, and both the first abutting surface and the second abutting surface are planes.

10. A vehicle, characterized in that: A drum brake comprising any one of claims 1 to 9.

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