Adjustable drum brake for electric vehicle

Abstract

According to the adjustable drum brake for the electric vehicle, after the brake block is abraded and thinned, the brake block moves upwards along the gradually-decreased gap, abutting can still be achieved automatically, and then braking is conducted through friction force; the brake shoe does not need to be expanded outwards to adjust the gap between the brake pad and the brake drum manually or mechanically by a gap adjuster, excessive or insufficient adjustment can be effectively prevented, gap change can be automatically and accurately adapted according to abrasion of the brake pad, the effective brake effect is kept all the time, and the service life of the brake pad is prolonged. Due to the fact that abutting can be achieved automatically, in the whole abrasion process of the brake pad, good contact and sufficient friction force between the brake pad and the brake drum can be guaranteed, the braking performance cannot be obviously reduced due to abrasion of the brake pad, the braking effect is more stable and reliable, and driving safety can be better guaranteed under the conditions of emergency braking and the like.

Description

Technical Field

[0001] The invention relates to the technical field of drum brakes for electric vehicles, and in particular to an adjustable drum brake for electric vehicles. Background Art

[0002] Appropriate brake clearance can ensure that the brake shoe contacts the brake drum quickly and accurately during braking and generate sufficient friction, so that the electric vehicle can brake in time when needed and shorten the braking distance. If the clearance is too large, the contact between the brake shoe and the brake drum will be delayed, and the generation of braking force will also lag, resulting in a significant increase in braking distance. In an emergency, the vehicle may not be able to stop in time, causing a safety accident.

[0003] In Chinese patent CN118224216A, a progressive adjustable drum brake structure is disclosed, wherein two arc-shaped brake shoes are symmetrically arranged on the brake disc, friction plates are arranged on the outer arc surface of the brake shoes, the shoe bodies of the two brake shoes are connected by a reset spring, a brake mechanism for controlling the opening and closing degree between the two brake shoes is arranged between one set of corresponding ends of the two brake shoes, and an adjustment component is arranged between the other set of corresponding ends, the adjustment component can be adjusted vertically up and down with respect to the two brake shoes, when the adjustment component is adjusted downward, the adjustment component opens the two brake shoes to both sides to expand to both sides, when the adjustment component is adjusted upward, the two brake shoes shrink to the middle under the action of the reset spring, the brake mechanism is a hydraulic cylinder, the two ends of the hydraulic cylinder of the brake mechanism are respectively connected to the two brake shoes, and one end of the hydraulic cylinder is movably connected to one of the brake shoes through a cylindrical structure. The invention can simply and quickly adjust the gap between the brake drum and the friction plate, so as to make full use of the friction plate and improve resource utilization.

[0004] Brake pads will wear out after long-term use, and the gap between them and the inner wall of the brake drum will increase, resulting in insensitive braking. Existing drum brakes usually use adjustment mechanisms such as clearance adjusters to expand the two brake shoes outward to reduce the gap between the brake pads and the brake drum. There is a trigger mechanism of the regulator for adjustment. If the trigger mechanism of the regulator is not precise enough, over-adjustment may occur, resulting in too small a brake gap and unnecessary friction between the brake shoe and the brake drum, which will not only increase energy loss, but also cause problems such as insufficient adjustment affecting the braking effect. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the defect of the prior art that adjustment is performed by relying on the trigger mechanism of the regulator. If the trigger mechanism of the regulator is not precise enough, over-adjustment may occur, resulting in too small a brake clearance and unnecessary friction between the brake shoe and the brake drum, which will not only increase energy loss, but also insufficient adjustment affecting the braking effect. The present invention proposes an adjustable drum brake for an electric vehicle.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is an adjustable drum brake for an electric vehicle, comprising a brake back plate, two groups of brake shoe inner linings are symmetrically arranged on the sides of the brake back plate, the bottom ends of the brake shoe inner linings are rotatably connected with a rotating pin, and the rotating pin is fixedly connected to the brake back plate, the sides of the brake shoe inner linings are integrally connected with brake shoe outer linings, the outer wall of the brake shoe outer lining is fixedly connected with a gradient extrusion block, the thickness of the gradient extrusion block gradually increases from bottom to top, the outer wall of the gradient extrusion block is slidably connected with a brake block, the outer cover of the brake block is provided with a brake drum, and a linkage trigger assembly is installed at the bottom end of the brake block, the linkage trigger assembly is used to trigger the brake block to rotate upward with the brake drum when braking, the top end of the brake back plate is fixedly connected with a hydraulic cylinder, and the output end of the hydraulic cylinder is gap-matched with the brake shoe inner lining.

[0007] Preferably, two sets of sliding limit assemblies are symmetrically arranged on the sides of the brake block, and the sliding limit assemblies are used to guide the brake block when the brake block slides upward along the gradual extrusion block.

[0008] Preferably, the linkage trigger assembly comprises an ejection trigger block, the ejection trigger block is embedded in the outer wall of the brake block, and the ejection trigger block is slidably connected to the brake block.

[0009] Preferably, one end of the ejection trigger block is fixedly connected to a sliding pin, and the end of the sliding pin away from the ejection trigger block is slidably connected to an extrusion block, the extrusion block is fixedly connected to the brake back plate, and the longitudinal section shape of the extrusion block is set to be a triangle.

[0010] Preferably, a guide slope is provided on a side of the ejection trigger block away from the sliding pin, a guide extrusion block is slidably connected to the side of the guide slope, and the guide extrusion block is fixedly connected to the brake block.

[0011] Preferably, two groups of pull-back springs are symmetrically arranged inside the ejection trigger block, one end of the pull-back spring is fixedly connected to the ejection trigger block, and the other end of the pull-back spring is fixedly connected to the brake block.

[0012] Preferably, the outer wall of the ejection trigger block is fixedly connected with engaging fins, and the engaging fins are arranged at equal intervals with respect to the outer wall of the ejection trigger block.

[0013] Preferably, the sliding limiter assembly comprises a limiter slide groove, and the limiter slide groove is symmetrically arranged on both sides of the gradual extrusion block.

[0014] Preferably, the limiting slide groove is internally slidably connected to a limiting slider, the limiting slider is fixedly connected to the side of the brake block, and the cross-sectional shape of the limiting slider is set to be L-shaped.

[0015] Preferably, the inner wall of the brake drum is evenly arranged with anti-skid ribs, and the anti-skid ribs are fixedly connected to the inner wall of the brake drum.

[0016] Preferably, a return spring is fixedly connected to the top of the brake shoe lining plate, a tension spring is fixedly connected to the back of the brake shoe lining plate, and one end of the tension spring away from the brake shoe lining plate is fixedly connected to the brake back plate.

[0017] Compared with the prior art, the beneficial effects of the present invention include: when the brake block of the present invention is worn and thinned, the brake block moves upward along the gradually smaller gap and can still achieve self-tightening, and then use friction to brake, without the need to use manual or mechanical triggering of the clearance adjuster to expand the brake shoe outward to adjust the clearance between the brake pad and the brake drum, which can effectively prevent over-or under-adjustment. The invention can automatically and accurately adapt to the clearance change according to the wear of the brake pad, always maintain an effective braking effect, ensure that the braking system is always in the best working state, improve the safety and reliability of braking, and because it can automatically achieve tightness, during the entire process of brake pad wear, it can ensure good contact and sufficient friction between the brake pad and the brake drum, so that the braking performance will not be significantly reduced due to the wear of the brake pad, and the braking effect is more stable and reliable, providing users with a better braking experience, and better ensuring driving safety in emergency braking and other situations. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The disclosure of the present invention is described with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. In the accompanying drawings, the same reference numerals are used to refer to the same components. Among them: Figure 1 A schematic diagram of the structure of an adjustable drum brake for an electric vehicle in an overall open state according to an embodiment of the present invention is shown; Figure 2 The figure schematically shows the internal structure of an adjustable drum brake for an electric vehicle according to one embodiment of the present invention; Figure 3 A schematic diagram of the internal structure of an adjustable drum brake for an electric vehicle in a braking state according to an embodiment of the present invention is shown; Figure 4 A schematic diagram of the overall structure of an adjustable drum brake for an electric vehicle according to an embodiment of the present invention is shown; Figure 5 The exploded structural diagram of a brake shoe part of an adjustable drum brake for an electric vehicle according to one embodiment of the present invention is schematically shown; Figure 6 The exploded structural diagram of a gradual extrusion block part of an adjustable drum brake for an electric vehicle according to one embodiment of the present invention is schematically shown; Figure 7 A schematic diagram of an exploded structure of a sliding limit assembly of an adjustable drum brake for an electric vehicle according to an embodiment of the present invention is shown; Figure 8 A schematic diagram showing the internal structure of a brake drum part of an adjustable drum brake for an electric vehicle according to an embodiment of the present invention is shown; Fig. 9 A schematic diagram of the three-dimensional structure of a linkage triggering assembly of an adjustable drum brake for an electric vehicle according to an embodiment of the present invention is shown; Fig.10 The cross-sectional structure diagram of a linkage triggering assembly of an adjustable drum brake for an electric vehicle according to an embodiment of the present invention is schematically shown.

[0019] In the figure: 1. brake back plate; 2. brake shoe inner lining; 3. brake shoe outer lining; 4. gradual extrusion block; 5. brake block; 6. linkage trigger assembly; 7. sliding limit assembly; 8. rotating pin; 9. hydraulic cylinder; 10. return spring; 11. brake drum; 12. anti-skid rib; 13. tension spring; 601. ejection trigger block; 602. pull-back spring; 603. sliding pin; 604. extrusion block; 605. guide ramp; 606. guide extrusion block; 607. engaging fin; 701. limit slide groove; 702. limit slide block. DETAILED DESCRIPTION

[0020] It is easy to understand that according to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art can propose a variety of interchangeable structural modes and implementation modes. Therefore, the following specific implementation modes and drawings are only exemplary descriptions of the technical solution of the present invention, and should not be regarded as the whole of the present invention or as a limitation or restriction to the technical solution of the present invention.

[0021] According to one embodiment of the present invention, Figures 1 to 10An adjustable drum brake for electric vehicles comprises a brake back plate 1, two groups of brake shoe inner lining plates 2 are symmetrically arranged on the sides of the brake back plate 1, the bottom ends of the brake shoe inner lining plates 2 are rotatably connected with a rotating pin shaft 8, and the rotating pin shaft 8 is fixedly connected to the brake back plate 1, the side of the brake shoe inner lining plate 2 is integrally connected with a brake shoe outer lining plate 3, the outer wall of the brake shoe outer lining plate 3 is fixedly connected with a gradual extrusion block 4, the thickness of the gradual extrusion block 4 gradually increases from bottom to top, the outer wall of the gradual extrusion block 4 is slidably connected with a brake block 5, the outer cover of the brake block 5 is provided with a brake drum 11, and the bottom end of the brake block 5 is equipped with a linkage trigger Component 6, the linkage trigger component 6 is used to trigger the brake block 5 to rotate upward with the brake drum 11 when braking. The top of the brake back plate 1 is fixedly connected to the hydraulic cylinder 9, and the output end of the hydraulic cylinder 9 is clearance-matched with the brake shoe lining plate 2. The top of the brake shoe lining plate 2 is fixedly connected to the return spring 10, and the back of the brake shoe lining plate 2 is fixedly connected to the tension spring 13, and the end of the tension spring 13 away from the brake shoe lining plate 2 is fixedly connected to the brake back plate 1. The tension spring 13 is used to pull the brake shoe lining plate 2 and fix it on the brake back plate 1 to prevent it from falling out, and will not hinder the brake shoe lining plate 2 from rotating to both sides.

[0022] The brake shoe lining plate 2 forms a rotating structure with the brake back plate 1 through the rotating pin shaft 8, and the two ends of the return spring 10 are respectively fixed to the top of the two groups of brake shoe lining plates 2. When the brake is not in use, under the action of the return spring 10, the two groups of brake shoe lining plates 2 are pulled inward from the top, so that the outermost brake block 5 is separated from the brake drum 11, so that the brake drum 11 can rotate normally. When braking is required, the hydraulic oil enters the interior of the hydraulic cylinder 9, and the two output ends of the hydraulic cylinder 9 extend outward, pushing the brake shoe lining plate 2 to expand outward on both sides, so that the outermost brake block 5 is tightly pressed against the inner wall of the brake drum 11, and the friction force is used to brake the brake drum 11, thereby braking the electric vehicle.

[0023] Since the shape of the gradual extrusion block 4 is a progressive design that gradually thickens from bottom to top, the gap between the outer wall of the gradual extrusion block 4 and the inner wall of the brake drum 11 gradually decreases from bottom to top. When the brake block 5 is triggered by the linkage trigger component 6 and moves upward along the outer wall of the gradual extrusion block 4 along the brake drum 11, it is inserted into the gradually shrinking gap. When the thickness of the brake block 5 is greater than the thickness of the gap, the brake block 5 cannot continue to slide upward, and then the gradual extrusion block 4 and the brake block 5 will be tightly pressed against the inner wall of the brake drum 11, and the brake drum 11 can be braked by utilizing the friction between the brake block 5 and the brake drum 11. Moreover, as the brake block 5 moves upward, the smaller the gap is, and the greater the pressure between the brake block 5 and the inner wall of the brake drum 11 is, which facilitates the enhancement of friction and improves the braking effect.

[0024] When the brake shoe 5 is worn and thinned due to long-term use, there is no need to rely on manual or mechanical triggering of the clearance adjuster to push the two brake shoes outward to narrow the gap between the brake shoe 5 and the brake drum 11. When the brake shoe 5 moves upward along the gradually narrowing gap between the gradual extrusion block 4 and the inner wall of the brake drum 11, when the gap thickness is less than the thickness of the brake shoe 5, the brake shoe 5 can still press against the inner wall of the brake drum 11 and brake the brake drum 11 by friction. In other words, there is no need for manual or mechanical triggering and adjustment. When the brake shoe 5 is worn and thinned, effective braking can be achieved by simply increasing the distance the brake shoe 5 moves upward a little, and this increased distance is extremely small, that is, the brake drum 11 rotates a few degrees or so, which is almost negligible. The braking effect will not be affected by the wear and thinning of the brake shoe 5, and the brake shoe 5 is adaptively adjusted along the gradual extrusion block 4, which can effectively prevent over-adjustment or under-adjustment, which affects normal driving or timely braking.

[0025] When there is no need to brake completely and only the speed of the electric vehicle needs to be reduced by brake control, the output end of the hydraulic cylinder 9 can be extended outward by a short distance through the brake control at the handle. At this time, the two brake shoes are opened outward at a smaller angle, and the gap between the gradient extrusion block 4 and the inner wall of the brake drum 11 is enough for the brake block 5 to continue to move upward without being completely stuck. When the brake block 5 slides to the top of the gradient extrusion block 4, the friction between the brake block 5 and the inner wall of the brake drum 11 can be used to slow it down.

[0026] When the electric vehicle moves forward, the tire drives the brake drum 11 to rotate clockwise, and the braking is mainly performed by the left brake block 5 pressing against the inner wall of the brake drum 11. When the electric vehicle reverses, the tire drives the brake drum 11 to rotate counterclockwise, and the braking is mainly performed by the right brake block 5 pressing against the inner wall of the brake drum 11.

[0027] The linkage trigger assembly 6 includes an ejection trigger block 601, which is embedded in the outer wall of the brake block 5, and the ejection trigger block 601 is slidably connected to the brake block 5, one end of the ejection trigger block 601 is fixedly connected to a sliding pin 603, and the end of the sliding pin 603 away from the ejection trigger block 601 is slidably connected to an extrusion block 604, the extrusion block 604 is fixedly connected to the brake back plate 1, and the longitudinal section shape of the extrusion block 604 is set to be triangular, and a guide is set on the side of the ejection trigger block 601 away from the sliding pin 603. Inclined surface 605, the side of the guiding inclined surface 605 is slidably connected with a guiding squeeze block 606, and the guiding squeeze block 606 is fixedly connected to the brake block 5, and two groups of pull-back springs 602 are symmetrically arranged inside the ejection trigger block 601, one end of the pull-back spring 602 is fixedly connected to the ejection trigger block 601, and the other end of the pull-back spring 602 is fixedly connected to the brake block 5, and the outer wall of the ejection trigger block 601 is fixedly connected with a bite fin 607, and the bite fins 607 are arranged at equal intervals about the outer wall of the ejection trigger block 601.

Claims

1. An adjustable drum brake for an electric vehicle, characterized in that: The invention comprises a brake back plate (1), two groups of brake shoe inner lining plates (2) are symmetrically arranged on the side of the brake back plate (1), the bottom end of the brake shoe inner lining plate (2) is rotatably connected with a rotating pin shaft (8), and the rotating pin shaft (8) is fixedly connected to the brake back plate (1), the side of the brake shoe inner lining plate (2) is integrally connected with a brake shoe outer lining plate (3), the outer wall of the brake shoe outer lining plate (3) is fixedly connected with a gradual extrusion block (4), and the thickness of the gradual extrusion block (4) gradually increases from bottom to top. The outer wall of the gradual extrusion block (4) is slidably connected to a brake block (5), the outer cover of the brake block (5) is provided with a brake drum (11), and a linkage trigger component (6) is installed at the bottom end of the brake block (5). The linkage trigger component (6) is used to trigger the brake block (5) to rotate upward along with the brake drum (11) when braking. The top end of the brake back plate (1) is fixedly connected to a hydraulic cylinder (9), and the output end of the hydraulic cylinder (9) is clearance-matched with the brake shoe inner lining plate (2); Two groups of sliding limit assemblies (7) are symmetrically arranged on the sides of the brake block (5), and the sliding limit assemblies (7) are used to guide the brake block (5) when the brake block (5) slides upward along the gradual extrusion block (4).

2. The adjustable drum brake for an electric vehicle according to claim 1, characterized in that: The linkage trigger component (6) comprises an ejection trigger block (601), the ejection trigger block (601) is embedded in the outer wall of the brake block (5), and the ejection trigger block (601) is slidably connected to the brake block (5).

3. The adjustable drum brake for an electric vehicle as claimed in claim 2, characterized in that: One end of the ejection trigger block (601) is fixedly connected to a sliding pin (603), and one end of the sliding pin (603) away from the ejection trigger block (601) is slidingly connected to an extrusion block (604), the extrusion block (604) is fixedly connected to the brake back plate (1), and the longitudinal section shape of the extrusion block (604) is set to be a triangle.

4. The adjustable drum brake for an electric vehicle as claimed in claim 2, characterized in that: A guide slope (605) is provided on one side of the ejection trigger block (601) away from the sliding pin (603), a guide extrusion block (606) is slidably connected to the side of the guide slope (605), and the guide extrusion block (606) is fixedly connected to the brake block (5).

5. The adjustable drum brake for an electric vehicle as claimed in claim 2, characterized in that: Two groups of pull-back springs (602) are symmetrically arranged inside the ejection trigger block (601), one end of the pull-back spring (602) is fixedly connected to the ejection trigger block (601), and the other end of the pull-back spring (602) is fixedly connected to the brake block (5).

6. The adjustable drum brake for an electric vehicle as claimed in claim 2, characterized in that: The outer wall of the ejection trigger block (601) is fixedly connected with engaging fins (607), and the engaging fins (607) are arranged at equal intervals with respect to the outer wall of the ejection trigger block (601).

7. The adjustable drum brake for an electric vehicle according to claim 1, characterized in that: The sliding limit assembly (7) comprises a limit slide groove (701), and the limit slide groove (701) is symmetrically arranged on both sides of the gradual extrusion block (4).

8. The adjustable drum brake for an electric vehicle as claimed in claim 7, characterized in that: The limiting sliding groove (701) is internally slidably connected to a limiting sliding block, the limiting sliding block is fixedly connected to the side of the brake block (5), and the cross-sectional shape of the limiting sliding block is set to be L-shaped.

9. The adjustable drum brake for an electric vehicle according to claim 1, characterized in that: The inner wall of the brake drum (11) is evenly arranged with anti-skid ribs (12), and the anti-skid ribs (12) are fixedly connected to the inner wall of the brake drum (11).

10. The adjustable drum brake for an electric vehicle according to claim 1, characterized in that: The top of the brake shoe lining plate (2) is fixedly connected to a return spring (10), the back of the brake shoe lining plate (2) is fixedly connected to a tension spring (13), and the end of the tension spring (13) away from the brake shoe lining plate (2) is fixedly connected to the brake back plate (1).

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