WO2023159731A1

WO2023159731A1 - Self-adjusting drum brake for electric vehicle

Info

Publication number: WO2023159731A1
Application number: PCT/CN2022/087578
Authority: WO
Inventors: 孙浙勇; 唐文贵; 曹玉荣; 陈双秋
Original assignee: 唐泽交通器材(泰州)有限公司
Priority date: 2022-02-25
Filing date: 2022-04-19
Publication date: 2023-08-31
Also published as: CN114412942A

Abstract

A self-adjusting drum brake for an electric vehicle, comprising a brake chamber housing assembly (10), a friction shoe assembly (20), a camshaft (30), a rocker arm (40), a toggle mechanism (50), and a self-adjusting mechanism (60). The friction shoe assembly (20) is provided on the inner side of the brake chamber housing assembly (10); tooth-shaped structures (33) are provided on the outer side of a cam body (32); the toggle mechanism (50) toggles the camshaft (30) to rotate; the self-adjusting mechanism (60) remains in the original position and rotates at the same angle relative to the toggle mechanism (50); a reset spring (70) is further provided between the toggle mechanism (50) and the brake chamber housing assembly (10); the toggle mechanism (50) is reset under the action of the reset spring (70); and the camshaft (30) is kept at an angle under the adjustment of the self-adjusting mechanism (60). The toggle mechanism (50) and the self-adjusting mechanism (60) are adjusted to adapt to the tooth-shaped structures (33) provided on the outer side of the cam body (32) by means of arranged ratchet wheels (51, 62). Problems of untimely and accurate adjustment of a braking gap and heavy hand feeling as the gap between a shoe assembly of the existing brake and a hub becomes larger after long-term wear are solved.

Description

A self-adjusting electric vehicle drum brake

technical field

The invention relates to the field of motor vehicle or electric vehicle brakes, in particular to a self-adjusting electric vehicle drum brake.

Background technique

The drum brake drives the camshaft to rotate through the rotation of the rocker arm, and drives the shoe assemblies on both sides to open and close to the brake drum, and the friction force between the brake drum and the shoe block group stops the wheel from rotating. After a long time of use, the brake line will become longer under the action of the elastic force, and the gap between the shoe assembly and the hub will become larger after a long period of wear. At this time, the braking performance will usually decrease and the brake will fail. Adjust the brake cable screw to tighten the brake cable or replace the brake. When adjusting the brake clearance manually, it is difficult to ensure timeliness and accuracy.

Automatic brake clearance adjustment devices are widely used in the automotive field. But use seldom in the drum brake of electric vehicle, tricycle and motorcycle in the prior art at present.

For example, the announcement number is: CN106050999B A bellcrank device with the function of automatically adjusting the brake clearance: the bellcrank is composed of a driving arm and a driven arm, the driven arm and the driving arm are both sleeved on the camshaft, and the driven arm is fixedly connected to the camshaft. The active arm and the camshaft are movably connected. There is a ratchet mechanism on the active arm. A threaded hole is provided in the center of the ratchet. An adjusting screw is provided on the driven arm. The adjusting screw is screwed into the threaded hole of the ratchet. The limit block on the cover cooperates to realize the automatic adjustment of the brake clearance of the hub brake. When the active arm moves to the set angle, the head of the pawl rocker on the active arm touches the limit block, and the pawl rocker produces Turn so that the pawl moves one tooth on the ratchet.

The structure of the ratchet device designed by the main and slave crank throws is complicated and heavy, and then adjusted with the limit block, the resistance is very large during braking, and the hand feels very heavy; and the adjusting screw is a straight rod-shaped part, the main, The rotation from the crankshaft around the camshaft is a circumferential movement, and stagnation will occur during the adjustment of the rotation angle, and it is inconvenient to adjust the wear gap of the shoe group later.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention provides a self-adjusting drum brake for electric vehicles, which solves the problem that the gap between the shoe assembly of the existing brake and the wheel hub becomes larger after a long period of wear, and the adjustment of the braking gap is not timely. , accuracy, and the problem of heavy hand feeling.

In order to achieve the above object, the present invention is achieved through the following technical solutions:

The invention is a drum brake for self-adjusting electric vehicles, which comprises a brake box shell assembly, a friction shoe assembly, a camshaft and a rocker arm, the inner side of the brake box shell assembly is provided with a friction shoe assembly, and the friction shoe The first end of the assembly is rotatably mounted on the fixed core shaft of the housing assembly of the gate box, the second end abuts against the cam portion at one end of the camshaft, and the cam body at the other end of the camshaft is pivotally connected to the through hole of the housing assembly of the gate housing Inside, the rocker arm and the end of the cam body are detachably fixed on the outside of the housing assembly of the brake box. The outside of the cam body is provided with a toothed structure, and also includes a toggle mechanism and a self-adjusting mechanism. The toggle mechanism toggles the cam When the shaft rotates, the self-adjusting mechanism remains in its original position and slides at the same angle relative to the toggle mechanism. There is also a return spring between the toggle mechanism and the housing assembly of the brake box. Reset, the camshaft maintains an angle under the adjustment of the self-adjusting mechanism.

The further improvement is: the toggle mechanism is a first ratchet device arranged on the rocker arm, the self-adjusting mechanism is a second ratchet device arranged on the housing assembly of the brake box, and the first ratchet device includes a first ratchet and a first compression spring, the second ratchet device includes a second ratchet and a second compression spring, and the first ratchet and the second ratchet are adapted to the toothed structure respectively; one end of the rocker arm is provided with a brake wire connecting portion , the other end is provided with a fixing hole, a first special-shaped groove is opened inside the fixing hole, one side opening of the first special-shaped groove communicates with the fixing hole, and a second special-shaped groove is provided on one side of the gate box shell assembly, One side opening of the second special-shaped groove communicates with the through hole; the first ratchet device is installed in the special-shaped groove, and the second ratchet device is installed in the second special-shaped groove.

The further improvement is: the first ratchet and the second ratchet are respectively provided with ratchets and positioning pivots, the ratchets are engaged with the toothed structure, and positioning holes are provided in the first special-shaped groove and the second special-shaped groove The slot structure, the positioning pivot is adapted to the slot structure of the positioning hole.

A further improvement is that: the first side of the first ratchet is in contact with one side of the first special-shaped groove, the second side of the first ratchet is provided with a compression spring limiter, and the first compression spring abuts against the compression spring limiter. Between the position part and the first special-shaped groove, the second ratchet is provided with a first side, a second side and a compression spring limiting part.

A further improvement is that: the first special-shaped groove is further provided with a first baffle plate, the first baffle plate is adapted to cover the first special-shaped groove, and the second special-shaped groove is fitted to be covered with a second baffle plate.

A further improvement is that: the first ratchet and the second ratchet are disposed along the camshaft in a mirror-symmetrical structure up and down.

A further improvement is that: the cam body is set in an upper and lower tooth-shaped structure, the middle section is a cylindrical structure, and the end is provided with a circumferential annular groove, and a buckle and a rocker arm are arranged in the annular groove. Snap connection.

A further improvement is that: the brake box assembly is also provided with a lug structure, and the lug structure is provided with a brake wire threading structure and a rocker arm pressure wire structure to form a manual wear gap adjustment structure.

The beneficial effects of the present invention are:

1. The interaction between the combined toggle mechanism and self-adjusting mechanism, the return spring and the camshaft is adopted, so that the camshaft does not reset after the friction shoe assembly wears out, and the rocker arm resets to compensate for the wear and tear of the friction shoe assembly. The gap between the brake drum keeps the gap constant, ensures that the brake rocker arm is always within the effective and controllable range, and always maintains the normal gap between the friction shoe assembly and the hub. After the friction shoe assembly is worn out, it can be achieved by braking in the forward direction Automatic adjustment, flexible, fast, accurate and timely adjustment of the wear gap; ensures the safety of the rider and is more humane.

2. The toggle mechanism and the self-adjusting mechanism. The ratchet device arranged on the rocker arm and the housing assembly of the brake box is adapted to the tooth structure on the camshaft, and the adjustment and braking process is flexible, fast, accurate and timely. The ratchet device is matched with the ratchet and the pressure spring in the special-shaped groove of the opening, which has the functions of firm and stable structure, vibration and buffering. Keeping the gap constant can effectively prevent the stagnation caused by the gap adjustment being too small.

Description of drawings

Fig. 1 is a structural schematic diagram of a self-adjusting electric vehicle drum brake.

Fig. 2 is a sectional view of a self-adjusting electric vehicle drum brake.

Fig. 3 is a schematic diagram of an explosion of a self-adjusting electric vehicle drum brake.

Fig. 4 is a schematic diagram of the positions of the toggle mechanism and the self-adjusting mechanism of a self-adjusting electric vehicle drum brake.

Fig. 5 is a structural schematic diagram of a toggle mechanism and a self-adjusting mechanism of a self-adjusting electric vehicle drum brake.

Fig. 6 is a structural schematic diagram of a drum brake rocker arm for a self-adjusting electric vehicle.

Fig. 7 is a schematic structural diagram of a drum brake housing for a self-adjusting electric vehicle.

Fig. 8 is a structural schematic diagram of a drum brake camshaft for a self-adjusting electric vehicle.

Reference signs: brake box housing assembly 10, friction shoe assembly 20, camshaft 30, rocker arm 40, toggle mechanism 50, self-adjusting mechanism 60, return spring 70, buckle 80, fixed core shaft 11, through hole 12. The second special-shaped groove 13, the second baffle plate 14, the lug structure 15, the cam part 31, the cam body 32, the tooth-shaped structure 33, the annular groove 34, the brake line connection part 41, the fixing hole 42, the first special-shaped Groove 43, first baffle plate 44, first ratchet device 51, first ratchet 52, first compression spring 53, first side 521, second side 522, compression spring limiting part 523, second ratchet device 61, the first Two ratchets 62 , a second compression spring 63 , a first side 621 , a second side 622 , a compression spring stopper 623 ,

ratchets

524 , 624 ,

positioning pivots

520 , 620 , and

positioning hole structures

430 , 130 .

Detailed ways

In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings. This embodiment is only used to explain the present invention, and does not constitute a limitation to the protection scope of the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts belong to the protection scope of the present invention.

The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments.

Figure 1-3 shows an embodiment self-adjusting electric vehicle drum brake, including brake box housing assembly 10, friction shoe assembly 20, camshaft 30 and rocker arm 40, the inside of the brake box housing assembly 10 A friction shoe assembly 20 is provided, the first end of the friction shoe assembly 20 is rotatably mounted on the fixed core shaft 11 of the brake box housing assembly 10, and the second end abuts against the cam portion 31 at one end of the camshaft 30, The cam body 32 at the other end of the camshaft 30 is pivotally connected in the through hole 12 of the housing assembly 10 of the brake box. 32 is provided with a toothed structure 33, which also includes a toggle mechanism 50 and a self-adjusting mechanism 60. The toggle mechanism 50 toggles the camshaft 30 to rotate, and the self-adjusting mechanism 60 remains in its original position, relative to the toggle mechanism. 50 slides at the same angle, and a reset spring 70 is also provided between the toggle mechanism 50 and the brake box housing assembly 10, and the toggle mechanism 50 is reset under the action of the reset spring 70, and the camshaft 30 is in the position of the self-adjusting mechanism 60 An angle is maintained under adjustment; under the combined action of the toggle mechanism, self-adjusting mechanism and camshaft in such a structure, the friction shoe assembly 20 is kept at a certain point, and the brake clearance of the friction shoe assembly 20 due to wear is compensated and adjusted , so as to realize the adjustment-free function without manual adjustment.

As shown in Figures 4 and 5, the toggling mechanism 50 is a first ratchet device 51 arranged on the rocker arm 40, the first ratchet device 51 includes a first ratchet 52 and a first compression spring 53, and the self-adjusting The mechanism 60 is a second ratchet device 61 arranged on the brake box housing assembly 10, the second ratchet device 61 includes a second ratchet 62 and a second compression spring 63, and the first ratchet 52 and the second ratchet 62 are respectively provided with There are

ratchets

524, 624 meshing with the tooth-shaped structure 33; one end of the rocker arm 40 is provided with a brake cable connecting portion 41, and the other end is provided with a fixing hole 42, and a first special-shaped groove 43 is opened inside the fixing hole 42 The opening on one side of the first special-shaped groove 43 communicates with the fixing hole 42, the first ratchet device 51 is installed in the special-shaped groove 43, and the ratchet 524 passes through the opening to mesh with the tooth-shaped structure 33 of the camshaft 30. One side of the housing assembly 10 of the brake box is provided with a second special-shaped groove 13 , and one side opening of the second special-shaped groove 13 communicates with the through hole 12 ; the second ratchet device 61 is installed in the second special-shaped groove 13 .

Through the interaction between the combined ratchet device, torsion spring and the toothed structure of the camshaft, the camshaft 30 is rotated at an angle, and the friction shoe assembly 20 is stretched for braking. Reset, and the camshaft does not reset under the action of the self-adjusting mechanism after the friction shoe assembly is worn, so as to realize the self-adjustment compensation of the increased braking clearance of the shoe assembly due to wear. One side opening of the second special-shaped groove 13 communicates with the through hole 12, and one side opening of the first special-shaped groove 43 communicates with the fixing hole 42; the ratchet mounted therein can be reliably engaged with the toothed structure of the camshaft.

As shown in Figure 4-7, the first ratchet 52 and the second ratchet 62 are respectively provided with positioning pivots 520, 620, and the first special-shaped groove 43 and the second special-shaped groove 13 are provided with

positioning hole structures

430, 130, The positioning pivots 520, 620 are adapted to the

positioning hole structures

430, 130; the first side 521 of the first ratchet 52 is attached to one side of the first special-shaped groove 43, and the second side 522 of the first ratchet 52 A compression spring limiting portion 523 is provided, the first compression spring 53 abuts between the compression spring limiting portion 523 and the other side of the first special-shaped groove 43, and the second ratchet 62 is provided with a first side 621, The second side 622 and the compression spring limiting portion 623 correspond to the first ratchet 52 . The first ratchet 52 and the second ratchet 62 are disposed along the camshaft 30 in a symmetrical mirror image structure up and down.

In this way, the connection between the ratchet and the special-shaped groove can be made firm, and the braking and reset are reliable; when braking, the first compression spring abuts between the compression spring stopper 523 and the other side of the first special-shaped groove 43, and the first The first side 521 of the ratchet 52 fits with one side of the first special-shaped groove 43, and the ratchet 520 is driven by the rocker arm 40 to move the tooth-shaped structure 33 of the camshaft 30 to make the camshaft 30 rotate. At this time, the first compression spring 53 stabilizes and supports the ratchet 52; the second ratchet 62 is installed in the second special-shaped groove 13 of the brake box housing assembly 10 and is symmetrical with the first ratchet 52 up and down. When braking, the rocker arm 40 drives the camshaft 30 Rotate together, the brake box housing assembly 10 does not move, so the second ratchet 62 will maintain the original position, and it will need to slide the teeth relative to the camshaft 30 to maintain the original position. Play the role of vibration sliding teeth.

At the end of the braking, the rocker arm 40 resets under the reaction force of the return spring 70, and the first ratchet 52 is reset by the sliding teeth under the action of the first compression spring 53 and the return spring 70. 52 plays the role of vibrating sliding teeth; the second ratchet 62 engages with the tooth structure of the camshaft 30 after the camshaft 30 rotates a small angle with the reset of the rocker arm 40 and fits one side of the second special-shaped groove 13 , to prevent the camshaft 30 from rotating and resetting, so that the friction shoe assembly 20 is compensated for the wear gap caused by braking. Here, the second compression spring 63 engages with the second ratchet 63 after rotating a small angle when the rocker arm is reset. It acts as a buffer, that is, when the wear gap is too small and less than one tooth pitch, the teeth will not slip, but the compression spring is used for buffering, so as to keep the braking gap constant, and can effectively prevent the stagnation caused by the gap adjustment being too small; therefore , here the structural dimensions of the second ratchet 62 , the second compression spring 63 and the second special-shaped groove 13 are set as required.

As shown in Figure 3: the first special-shaped groove 43 is also provided with a first baffle plate 44, and the first baffle plate 44 is adapted to cover the first special-shaped groove 43, and the second special-shaped groove 13 is fitted with a cover A second baffle plate 14 is combined. Such design makes the structure more firm, reliable and not easy to scatter.

As shown in Figure 8: the cam body 32 is set as an upper and lower tooth-shaped structure 33, the middle section is a cylindrical structure, and the end is provided with a circumferential annular groove 34, and the annular groove 34 is provided with a buckle 80 and The rocker arm 40 is connected by a buckle; the overall connection of the brake is firm and reliable, and the assembly and maintenance are convenient.

The two-stage tooth structure 33 can be set as ratchet teeth in opposite directions, which are compatible with the

ratchet teeth

524, 624 of the first ratchet wheel 52 and the second ratchet wheel 62; Convenient and reasonable, reliable transmission. It is also possible to set the cam body 32 as a full-tooth structure, and the full teeth are divided into two sections of ratchets in opposite directions; or the

ratchets

524, 624 of the first ratchet 52 and the second ratchet are set as teeth in the opposite direction and the same direction on the camshaft. Shaped structure used together.

More preferably: the brake box assembly 10 is further provided with a lug structure 15, and the lug structure 15 is provided with a brake wire threading structure and the wire pressing structure 41 of the rocker arm 40 to form a manual wear gap adjustment structure. With such a setting, manual clearance adjustment and automatic clearance adjustment are combined to adjust, and the adjustment performance of the product is more convenient and superior, ensuring the safety of riders and making it more humanized and rational.

Action principle of the present invention is as follows:

When braking: move the rocker arm 40, the first side 521 of the first ratchet 52 is attached to the side of the first special-shaped hole 43 after being stressed, and the ratchet 524 on the first ratchet 52 and the external gear on the camshaft 30 The meshing structure 33 is under force, driving the camshaft 30 to rotate, and the second ratchet 62 rotates with the camshaft 30 under the action of the second pressure spring 63. The sliding gear does not move relative to the brake box housing assembly 10, and does not affect the rotation of the camshaft 30. , so that the friction shoe assembly 20 is stretched apart with the rotation of the camshaft 30 to achieve the braking effect;

After the brake is finished: loosen the rocker arm 40, and the rocker arm 40 is driven by the return spring 70 torsion spring to reset. At this time, the second side 522 of the first ratchet contacts with the first compression spring 53. , the first ratchet will rotate and reset with the sliding teeth of the rocker arm 40, and the rocker arm 40 will return to the position before braking; The second ratchet 624 meshes with the tooth-shaped structure 33 of the camshaft 30 to prevent the camshaft 30 from resetting, and the camshaft 30 is in a state of opening an angle without resetting the shoe, so that the friction shoe assembly 20 is worn due to braking. Resulting in increased brake clearance to be compensated for adjustment;

Reciprocating in this way: after the next shoe wears out, the operation principle of the drum brake is the same as above, the rocker arm automatically resets, and the shoe is always stretched to achieve the purpose of maintenance-free.

The embodiments of the present invention disclose preferred embodiments, but are not limited thereto. Those skilled in the art can easily comprehend the spirit of the present invention based on the above-mentioned embodiments, and make different extensions and changes. But as long as it does not deviate from the spirit of the present invention, it is within the protection scope of the present invention.

Claims

A drum brake for a self-adjusting electric vehicle, comprising a brake box housing assembly (10), a friction shoe assembly (20), a camshaft (30) and a rocker arm (40), the inner side of the brake box housing assembly (10) A friction shoe assembly (20) is provided, the first end of the friction shoe assembly (20) is rotatably installed on the fixed core shaft (11) of the brake box housing assembly (10), and the second end abuts against the cam The cam part (31) at one end of the shaft (30), the cam body (32) at the other end of the camshaft (30) is pivotally connected in the through hole (12) of the brake box housing assembly (10), and the rocker arm (40 ) and the end of the cam body (32) are detachably fixed on the outside of the brake box housing assembly (10), and the outside of the cam body (32) is provided with a toothed structure (33), which is characterized in that: it also includes a toggle mechanism (50 ) and the self-regulating mechanism (60), the toggling mechanism (50) turns the camshaft (30) to rotate, the self-regulating mechanism (60) remains in place, and the relative toggling mechanism (50) slides the same Angle, a return spring (70) is also provided between the toggle mechanism (50) and the brake box housing assembly (10), the toggle mechanism (50) resets under the action of the return spring (70), and the camshaft (30) maintain an angle under the adjustment of the self-adjusting mechanism (60).
A self-adjusting electric vehicle drum brake according to claim 1, characterized in that: the toggle mechanism (50) is a first ratchet device (51) arranged on the rocker arm (40), and the self-adjusting The adjustment mechanism (60) is a second ratchet device (61) arranged on the housing assembly (10) of the brake box, and the first ratchet device (51) includes a first ratchet (52) and a first compression spring (53), The second ratchet device (61) includes a second ratchet (62) and a second compression spring (63), and the first ratchet (52) and the second ratchet (62) are adapted to the toothed structure (33) respectively ; One end of the rocker arm (40) is provided with a brake wire connecting portion (41), and the other end is provided with a fixing hole (42), and a first special-shaped groove (43) is provided inside the fixing hole (42). The opening on one side of the first special-shaped groove (43) communicates with the fixing hole (42), the second special-shaped groove (13) is provided on one side of the gate box housing assembly (10), The opening communicates with the through hole (12); the first ratchet device (51) is installed in the special-shaped groove (43), and the second ratchet device (61) is installed in the second special-shaped groove (13).
A drum brake for self-adjusting electric vehicles according to claim 2, characterized in that: the first ratchet (52) and the second ratchet (62) are respectively provided with ratchets (524), (624) and positioning pivot (520), (620), the ratchets (524), (624) are engaged with the toothed structure (33), and the first special-shaped groove (43) and the second special-shaped groove (13) are provided with There are positioning hole structures (430), (130), and the positioning pivots (520), (620) are adapted to the positioning hole structures (430), (130).
A self-adjusting electric vehicle drum brake according to claim 2, characterized in that: the first side (521) of the first ratchet (52) is attached to one side of the first special-shaped groove (43), and the The second side (522) of the first ratchet (52) is provided with a compression spring limiting portion (523), and the first compression spring (53) abuts against the compression spring limiting portion (523) and the first special-shaped groove (43 ), the second ratchet (62) is provided with a first side (621), a second side (622) and a pressure spring limiting portion (623).
A self-adjusting electric vehicle drum brake according to claim 2, characterized in that: the first special-shaped groove (43) is also provided with a first baffle (44), and the first baffle (44) The fitting cover fits on the first special-shaped groove (43), and the second special-shaped groove (13) fits on the cover with the second baffle plate (14).
A self-adjusting electric vehicle drum brake according to claim 2, characterized in that: the first ratchet (52) and the second ratchet (62) are arranged along the camshaft (30) in a symmetrical mirror image structure up and down .
A self-adjusting drum brake for electric vehicles according to claim 1, characterized in that: the cam body (32) is set in two upper and lower tooth-shaped structures, the middle section is a cylindrical structure, and the end is provided with a circumferential An annular groove (34), the said annular groove (34) is provided with a buckle (80) for buckle connection with the rocker arm (40).
A self-adjusting drum brake for electric vehicles according to claim 1, characterized in that: the brake box assembly (10) is also provided with a lug structure (15), and the lug structure (15) is provided with The thread-pressing structure (41) of brake line threading structure and rocking arm (40) is arranged to form manual wear gap adjustment structure.