Adjustable drum brake for electric vehicle

Abstract

The present invention proposes an adjustable drum brake for electric vehicles. When the brake block is worn and thinned, the brake block moves upward along the gradually shrinking gap and can still achieve self-tightening, and then use friction to brake. There is no 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-adjustment or under-adjustment. The invention can automatically and accurately adapt to the clearance change according to the wear of the brake pad, and always maintain an effective braking effect. Moreover, since it can automatically achieve tightness, it can ensure good contact and sufficient friction between the brake pad and the brake drum during the entire process of brake pad wear, so that the braking performance will not be significantly reduced due to the wear of the brake pad. The braking effect is more stable and reliable, and can better ensure driving safety in emergency braking and other situations.

Description

Technical Field

[0001] The present 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 ensures that the brake shoe contacts the brake drum quickly and accurately during braking, generating sufficient friction, enabling the electric vehicle to brake promptly when needed and shortening the stopping 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 stopping distance. In an emergency, the vehicle may not be able to stop in time, leading to safety accidents.

[0003] Chinese patent CN118224216A discloses a progressively adjustable drum brake structure. Two arc-shaped brake shoes are symmetrically mounted on a brake disc. Friction pads are located on the outer curved surfaces of the brake shoes. The two brake shoes are connected by a return spring. A brake mechanism is located between one set of corresponding ends of the two brake shoes to control the degree of opening and closing between them. An adjustment assembly is located between the other set of corresponding ends. The adjustment assembly is adjustable vertically relative to the two brake shoes. When the adjustment assembly is adjusted downward, the adjustment assembly spreads the two brake shoes outward. When the adjustment assembly is adjusted upward, the two brake shoes contract toward the center due to the return spring. The brake mechanism is a hydraulic cylinder, with its two ends connected to the two brake shoes, respectively. One end of the hydraulic cylinder is movably connected to one of the brake shoes via a cylindrical structure. This invention allows for simple and quick adjustment of the gap between the brake drum and friction pads, fully utilizing the friction pads and improving 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 that relies on the adjuster for adjustment. If the trigger mechanism of the adjuster 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 insufficient adjustment to affect 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 depends on the trigger mechanism of the regulator. If the trigger mechanism of the regulator is not accurate 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 will affect the braking effect. The present invention proposes an adjustable drum brake for electric vehicles.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is an adjustable drum brake for electric vehicles, comprising a brake back plate, two groups of brake shoe linings are symmetrically arranged on the sides of the brake back plate, the bottom ends of the brake shoe inner linings are rotatably connected to 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 to the 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 the brake block, the outer cover of the brake block is provided with a brake drum, and the bottom end of the brake block is installed with a linkage trigger assembly, and 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 clearance-matched with the brake shoe inner lining.

[0007] Preferably, two sets of sliding limit assemblies are symmetrically provided 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 includes an ejection trigger block, the ejection trigger block is embedded in the outer wall of the brake shoe, and the ejection trigger block is slidably connected to the brake shoe.

[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 slidingly connected to an extrusion block, the extrusion block is fixedly connected to the brake back plate, and the longitudinal cross-sectional 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 return springs are symmetrically arranged inside the ejection trigger block, one end of the return spring is fixedly connected to the ejection trigger block, and the other end of the return 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 limiting assembly includes limiting sliding grooves, and the limiting sliding grooves are symmetrically arranged on both sides of the gradual extrusion block.

[0014] Preferably, the limiting sliding 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, anti-skid ribs are evenly arranged on the inner wall of the brake drum, 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, a tension spring is fixedly connected to the back of the brake shoe lining, and an end of the tension spring away from the brake shoe lining 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 pad is worn and thinned, the brake pad 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 gap 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 gap changes 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, it can ensure good contact and sufficient friction between the brake pad and the brake drum throughout the process of brake pad wear, 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 illustrated 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:

[0019] Figure 1 A schematic diagram showing the structure of an adjustable drum brake for an electric vehicle in an overall open state according to one embodiment of the present invention is shown;

[0020] Figure 2 Schematically shows the internal structure of an adjustable drum brake for an electric vehicle according to one embodiment of the present invention;

[0021] Figure 3 A schematic diagram of the internal structure of an adjustable drum brake for an electric vehicle in a braking state according to one embodiment of the present invention is shown;

[0022] Figure 4 The figure schematically shows the overall structure of an adjustable drum brake for an electric vehicle according to one embodiment of the present invention;

[0023] Figure 5Schematically shows an exploded structural diagram of a brake shoe portion of an adjustable drum brake for an electric vehicle according to one embodiment of the present invention;

[0024] Figure 6 Schematically shows an exploded structural diagram of a gradual-change extrusion block portion of an adjustable drum brake for an electric vehicle according to one embodiment of the present invention;

[0025] Figure 7 Schematically shows an exploded structural diagram of a sliding limit assembly of an adjustable drum brake for an electric vehicle according to one embodiment of the present invention;

[0026] Figure 8 Schematically shows the internal structure of a brake drum portion of an adjustable drum brake for an electric vehicle according to one embodiment of the present invention;

[0027] Figure 9 Schematically shows a three-dimensional structural diagram of a linkage trigger assembly of an adjustable drum brake for an electric vehicle according to one embodiment of the present invention;

[0028] Figure 10 The cross-sectional structure diagram of a linkage trigger assembly of an adjustable drum brake for an electric vehicle according to one embodiment of the present invention is schematically shown.

[0029] In the figure: 1. Brake back plate; 2. Brake shoe inner lining; 3. Brake shoe outer lining; 4. Gradual-change 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. Limiting slide; 702. Limiting slider. DETAILED DESCRIPTION

[0030] 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 embodiments and drawings are only exemplary descriptions of the technical solution of the present invention and should not be regarded as the entire invention or as a limitation or restriction of the technical solution of the present invention.

[0031] According to one embodiment of the present invention, Figures 1 to 10An adjustable drum brake for an electric vehicle comprises a brake back plate 1, two sets of brake shoe inner linings 2 are symmetrically arranged on the sides of the brake back plate 1, the bottom ends of the brake shoe inner linings 2 are rotatably connected to a rotating pin 8, and the rotating pin 8 is fixedly connected to the brake back plate 1, the side of the brake shoe inner lining 2 is integrally connected to a brake shoe outer lining 3, the outer wall of the brake shoe outer lining 3 is fixedly connected to a gradient extrusion block 4, the thickness of the gradient extrusion block 4 gradually increases from bottom to top, the outer wall of the gradient 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 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 gap-fitted with the brake shoe lining 2. The top of the brake shoe lining 2 is fixedly connected to the return spring 10, and the back of the brake shoe lining 2 is fixedly connected to the tension spring 13, and the end of the tension spring 13 away from the brake shoe lining 2 is fixedly connected to the brake back plate 1. The tension spring 13 is used to pull the brake shoe lining 2 and fix it on the brake back plate 1 to prevent it from falling out, and will not hinder the brake shoe lining 2 from rotating to both sides.

[0032] The brake shoe lining 2 forms a rotating structure with the brake back plate 1 through the rotating pin 8, and the two ends of the return spring 10 are respectively fixed to the top of the two groups of brake shoe linings 2. When the brake is not in use, under the action of the return spring 10, the two groups of brake shoe linings 2 are pulled inward from the top, thereby making the outermost brake block 5 disengage from the brake drum 11, so that the brake drum 11 can rotate normally. When the brake is needed, 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 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.

[0033] 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 shrinks from bottom to top. When the brake block 5 is triggered by the linkage trigger component 6 and moves upward along the brake drum 11 along the outer wall of the gradual extrusion block 4, it is stuffed 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. 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 enhancing the friction and improving the braking effect.

[0034] When the brake shoe 5 is worn and thinned after 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, 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.

[0035] When full braking is not required and the speed of the electric vehicle only 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 sufficient 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, it can rely on the friction between the brake block 5 and the inner wall of the brake drum 11 to slow it down.

[0036] When the electric vehicle is moving 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 is reversing, 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.

[0037] 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. The inclined surface 605 and the side sliding connection of the guide inclined surface 605 are provided with a guide extrusion block 606, and the guide extrusion block 606 is fixedly connected to the brake block 5. 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. The outer wall of the ejection trigger block 601 is fixedly connected with an engaging fin 607, and the engaging fin 607 is 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. Gradually increasing, 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), the bottom end of the brake block (5) is installed with a linkage trigger component (6), 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); The linkage trigger assembly (6) includes an ejection trigger block (601), 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 of the extrusion block (604) is set to be triangular, and two groups of return springs (602) are symmetrically arranged inside the ejection trigger block (601), one end of the return spring (602) is fixedly connected to the ejection trigger block (601), and the other end of the return spring (602) is fixedly connected to the brake block (5); Two sets 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, wherein: The ejection trigger block (601) is embedded in the outer wall of the brake block (5), and the ejection trigger block (601) and the brake block (5) are slidably connected.

3. The adjustable drum brake for an electric vehicle according to claim 1, wherein: A guide slope (605) is provided on the side of the ejection trigger block (601) away from the sliding pin (603), and 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).

4. The adjustable drum brake for an electric vehicle according to claim 1, wherein: The outer wall of the ejection trigger block (601) is fixedly connected with bite fins (607), and the bite fins (607) are arranged at equal intervals with respect to the outer wall of the ejection trigger block (601).

5. The adjustable drum brake for an electric vehicle according to claim 1, wherein: The sliding limiting assembly (7) comprises limiting sliding grooves (701), and the limiting sliding grooves (701) are symmetrically arranged on both sides of the gradual extrusion block (4).

6. The adjustable drum brake for an electric vehicle according to claim 5, wherein: The limiting slide groove (701) is internally slidably connected to a limiting slider, the limiting slider is fixedly connected to the side of the brake block (5), and the cross-sectional shape of the limiting slider is set to be L-shaped.

7. The adjustable drum brake for an electric vehicle according to claim 1, wherein: Anti-skid ribs (12) are evenly arranged on the inner wall of the brake drum (11), and the anti-skid ribs (12) are fixedly connected to the inner wall of the brake drum (11).

8. The adjustable drum brake for an electric vehicle according to claim 1, wherein: 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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