Drum brake

Abstract

The utility model provides a drum brake. Lightweight of an automobile is achieved through improvement of the drum brake. The drum brake comprises a brake drum and a brake bottom plate, the brake drum can rotate relative to the brake bottom plate, the brake bottom plate is provided with a groove-shaped structure, and the groove-shaped structure is matched with one end of the brake drum. The groove-shaped structure is provided with an outer groove wall part; in the radial direction of the drum brake, the outer groove wall portion is located on the outer side of the one end portion of the brake drum. According to the technical scheme, the structure of the drum brake can be improved, so that a dustproof ring structure is omitted, the drum brake is cleared, and then light weight of a vehicle is achieved.

Description

Technical Field

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

[0002] Drum brakes are widely used in the field of automobile braking technology. When the driver steps on the brake pedal, the brake shoe of the drum brake can be opened under the action of the transmission member, so as to be in close contact with the inner surface of the brake drum. At this time, since the wheel is still rotating, friction is generated between the brake drum and the friction plate on the brake shoe, so as to achieve vehicle deceleration or parking.

[0003] With the increasing global attention to environmental protection and energy efficiency, automobile lightweighting has become a major trend in current automobile design and manufacturing; in this trend, the lightweighting of drum brakes is particularly important. Utility Model Content

[0004] The purpose of the utility model is to provide a drum brake, and to achieve the lightweight of the automobile by improving the drum brake.

[0005] On the one hand, the drum brake includes a brake drum and a brake base plate, the brake drum can rotate relative to the brake base plate, the brake base plate is provided with a groove structure, the groove structure is adapted to one end of the brake drum; the groove structure has an outer groove wall portion; in the radial direction of the drum brake, the outer groove wall portion is located outside the one end of the brake drum. In the technical solution of the present application, the dust ring structure can be eliminated by improving the structure of the drum brake, thereby achieving the cleaning of the drum brake and further achieving the lightweight of the vehicle.

[0006] Optionally, the one end and the groove structure form an air passage, and the interior of the brake drum is connected to the outside through the air passage; the air passage has a first port connected to the outside, and the opening direction of the first port is toward the side where the brake drum is located. By changing the opening direction of the first port of the air passage, it is no longer necessary to set a dust ring to cover the first port, thereby eliminating the dust ring. Eliminating the dust ring not only reduces the weight of the drum brake, but also avoids the problem of deformation of the brake base plate due to welding heat caused by welding the dust ring, thereby avoiding interference between the brake base plate and the brake drum, which causes abnormal noise in the drum brake.

[0007] Optionally, the groove structure is a U-shaped groove, which is recessed axially toward the side away from the brake drum; through the drum brake of the present application, a U-shaped air path can be formed, thereby shortening the path length of external air entering the accommodating cavity, making the air circulation smoother and improving the heat dissipation effect of the drum brake.

[0008] Optionally, the outer wall of the brake drum is provided with a water guide groove structure, which is radially recessed from the outer wall of the drum; the water guide groove structure is a U-shaped groove, having a first water guide groove wall and a second water guide groove wall axially opposite to each other, and compared with the first water guide groove wall, the second water guide groove wall is closer to the brake bottom plate; the brake drum has a radially outwardly protruding water guide boss, and the second water guide groove wall is located on the water guide boss. The water guide groove structure is used to collect rainwater, and after the rainwater is collected in the water guide groove, it cannot enter the accommodating cavity through the air path to a certain extent under the stop of the water guide boss; at the same time, when the brake drum is in a rotating state, the rainwater collected in the water guide groove structure can be thrown out under the action of centrifugal force.

[0009] Optionally, the water-conducting boss is aligned with the notch of the groove-shaped structure or extends axially into the groove-shaped structure; a U-shaped air passage can be formed by the drum brake of the present application.

[0010] Optionally, the brake drum has a drum end face, the drum end face is opposite to the brake base plate in the axial direction; a first chamfer is provided at a position where the drum outer wall and the drum end face meet, and the first chamfer constitutes a wall portion of the air passage. The first chamfer can better guide external air into the air passage.

[0011] Optionally, the brake drum has a drum end face, and the drum end face is opposite to the brake base plate in the axial direction; a second chamfer is provided at a position where the drum inner wall of the brake drum and the drum end face meet, and the second chamfer constitutes a wall portion of the gas path. By providing the second chamfer and the groove structure to define the second port, the gas flow at the second port position can be increased, and the resistance of the second port to the gas flow can be reduced.

[0012] Optionally, the outer groove wall is provided with a flange portion, and the flange portion is formed by radially turning the outer groove wall portion outward. The flange portion can stop external pollutants, especially for pollutants from one side of the brake base plate, to form a better stopping effect; at the same time, the structural strength of the brake base plate can also be increased by providing the flange portion.

[0013] Optionally, the drum brake has an air passage, and the portion where the flange portion meets the outer groove wall portion has a third chamfer, and the third chamfer constitutes part of the air passage. The third chamfer can further reduce the resistance of air flowing in the air passage.

[0014] Optionally, the third chamfer is an arc-shaped chamfer, thereby further reducing the resistance to air circulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the specification and, together with the description, serve to explain the principles of the specification.

[0016] Figure 1 It is a structural schematic diagram of a drum brake in an embodiment of the utility model;

[0017] Figure 2 yes Figure 1 A cross-sectional view of a brake drum in FIG.

[0018] Figure 3 yes Figure 1 A cross-sectional view of the brake base plate in FIG.

[0019] Figure 4 yes Figure 1 A partial cross-sectional view of

[0020] Figure 5 yes Figure 4 Air circulation diagram and rainwater flow diagram;

[0021] Figure 6 It is a cross-sectional view of a drum brake of the prior art, showing the air flow direction and rain water flow direction.

[0022] Figure 1-Figure 5 middle:

[0023] 100, brake drum; 110, drum end surface; 120, drum outer wall; 130, drum inner wall;

[0024] 140. water channel structure; 141. first water channel wall; 142. second water channel wall; 143. channel bottom wall;

[0025] 150, water guide boss; 151, table top; 152, side wall surface;

[0026] 160, adapter;

[0027] 200, brake base plate; 210, groove structure; 220, outer groove wall; 221, inner surface; 222, outer surface; 230, flange portion;

[0028] 300, accommodating chamber;

[0029] 400, gas passage; 410, first opening; 420, second opening; 430, first chamfer; 440, second chamfer; 450, third chamfer;

[0030] Figure 6 middle:

[0031] 100', brake drum; 120', drum outer wall;

[0032] 200′, brake base plate;

[0033] 300′, accommodating chamber;

[0034] 400', gas passage; 410', first port; 420', second port;

[0035] 500. Dust ring. DETAILED DESCRIPTION

[0036] The utility model provides a drum brake, which realizes the lightness of an automobile by improving the drum brake.

[0037] like Figure 1-Figure 6 As shown, Figure 1 It is a structural schematic diagram of a drum brake in an embodiment of the utility model; Figure 2 yes Figure 1 A cross-sectional view of a brake drum in FIG. Figure 3 yes Figure 1 A cross-sectional view of the brake base plate in FIG. Figure 4 yes Figure 1 A partial cross-sectional view of Figure 5 yes Figure 4 Air circulation diagram and rainwater flow diagram; Figure 6 It is a cross-sectional view of a drum brake of the prior art, showing the air flow direction and rain water flow direction.

[0038] As shown in the figure, the drum brake includes a brake drum 100 and a brake base plate 200. The brake drum 100 is installed on the wheel hub and can rotate with the wheel; this means that when the vehicle is driving or the wheel is rotating, the brake drum 100 will also rotate. The brake base plate 200 is fixedly installed on the axle. It bears the rotational torque during braking and does not rotate with the wheel itself. The brake shoe, wheel cylinder, return spring, positioning pin and other components are installed on the brake base plate 200. The brake shoe can rotate around the support pin. When the driver steps on the brake pedal, the brake shoe will rotate around the support pin, so that the friction plate on it contacts the rotating brake drum 100, thereby generating a friction torque and slowing down the rotation speed of the wheel. Since the brake drum 100 rotates with the wheel and the brake base plate 200 is fixed, the brake drum 100 can rotate relative to the brake base plate 200.

[0039] In some conventional drum brakes, such as Figure 6As shown, the brake drum 100′ and the brake base plate 200′ respectively form adaptation grooves, and the adaptation grooves cooperate to enclose a part of the air path channel 400′. The accommodating cavity 300′ defined by the brake drum 100′ and the brake base plate 200′ is connected with the outside through the air path channel 400′; the air path channel 400′ has a first port 410′ for communicating with the outside and a second port 420′ communicating with the accommodating cavity 300′, and the opening direction of the first port 410′ is toward the side where the brake base plate 200′ is located, which makes it easy for external pollutants to invade into the accommodating cavity 300′ through the air path channel 400′. In order to prevent pollutants from entering the accommodating cavity 300' through the first opening 410', the drum brake is usually further provided with a dust ring 500, which is welded to the brake base plate 200' and covers the first opening 410', thereby preventing external pollutants from entering; thus, the dust ring 500 and the drum outer wall 120' of the brake drum 100' enclose another part of the air path 400', thereby forming a maze-shaped air path 400'.

[0040] In the technical solution of the present application, the dust ring 500 structure can be eliminated by improving the structure of the drum brake, thereby achieving the cleaning of the drum brake and further achieving the lightweight of the vehicle.

[0041] Specifically, as shown in the figure, the brake base plate 200 of the drum brake of the present application is provided with a groove structure 210, the groove structure 210 has an outer groove wall portion 220, and the brake base plate 200 has an outer side wall, the outer side wall of the brake base plate 200 is located at the outermost side of the brake base plate 200 in the radial direction, and extends a certain distance along the axial direction of the drum brake; the outer groove wall portion 220 has an inner surface 221 and an outer surface 222, the inner surface 221 is a part of the groove wall of the groove structure 210, and the outer surface 222 is at least a part of the outer side wall of the brake base plate 200. The brake drum 100 and the brake base plate 200 are adapted to enclose a receiving cavity 300, and one end is adapted to the groove structure 210, which is defined as an adapting end 160; in the radial direction of the drum brake, the outer groove wall portion 220 of the groove structure 210 is located outside the adapting end 160; wherein in the radial direction, the side pointing to the rotation axis of the brake drum 100 is the inner side, and the opposite side is the outer side. That is to say, in the radial direction, the outer groove wall portion 220 of the brake base plate 200 is aligned with the adapter end 160 or covers a portion of the adapter end 160; thus, the groove structure 210 and the adapter end 160 form an air path channel 400, and the air path channel 400 can connect the accommodating cavity 300 with the outside; the opening of the air path channel 400 connected to the outside faces the side where the brake drum 100 is located, so there is no need to set a dust ring 500, thereby achieving the purpose of lightweight.

[0042] Specifically, the air passage 400 also has a first port 410 communicating with the outside and a second port 420 communicating with the accommodating chamber 300; at this time, the opening direction of the first port 410 is opposite to the opening direction of the first port 410' of the conventional drum brake. The opening direction of the first port 410 of the air passage 400 in the present application is toward the side where the brake drum 100 is located, that is, toward Figure 4 and Figure 5 The right side in the figure; thus, by changing the opening direction of the first port 410 of the air path channel 400, the opening direction of the first port 410 is changed from the side where the brake drum 100 is located (the left side in the figure) to the side where the brake base plate 200 is located (the right side in the figure), and there is no need to set a dust ring 500 to cover the first port 410, thereby eliminating the dust ring 500. Eliminating the dust ring 500 not only reduces the weight of the drum brake, but also avoids the problem of deformation of the brake base plate 200 due to welding heat caused by welding the dust ring 500, thereby avoiding the interference between the brake base plate 200 and the brake drum 100 and causing abnormal noise from the drum brake.

[0043] In the above implementation, please refer to Figure 5 and Figure 6 ,exist Figure 5 and Figure 6 In the figure, the green circle represents the external air, and the red circle represents the high-temperature gas in the accommodating chamber 300; the groove structure 210 is a U-shaped groove, which is recessed on the side axially away from the brake drum 100; the adapter end 160 is located at the notch of the U-shaped groove or extends axially from the notch into the U-shaped groove; in this way, the air path 400 is approximately U-shaped; in the conventional technical solution, the adapter grooves arranged on the brake drum 100 and the brake base plate 200 are surrounded by a labyrinth-shaped air path 400, and the labyrinth-shaped air path 400 has at least one S-shaped air path 400 (it can also have more S-shaped sections); the brake drum 100 is prone to generate a higher temperature after friction with the brake shoe. Under high temperature conditions, the labyrinth-shaped air path 400 causes the heat dissipation efficiency of the traditional drum brake to be low, such as Figure 6 As shown, external air needs to pass through a longer path before it can enter the accommodating cavity 300; through the drum brake of the present application, a U-shaped air path channel 400 can be formed, thereby shortening the path length of external air entering the accommodating cavity 300, making the air circulation smoother and improving the heat dissipation effect of the drum brake.

[0044] In other embodiments, please continue to compare Figure 5 and Figure 6 ,exist Figure 5 and Figure 6In the figure, the blue arrow represents the flow direction of rainwater; the drum outer wall 120 of the adapter end 160 is provided with a water guide groove structure 140, and the water guide groove structure 140 is radially recessed from the drum outer wall 120; the water guide groove structure 140 is a U-shaped groove, having a first water guide groove wall 141 and a second water guide groove wall 142 axially opposite to each other, and compared with the first water guide groove wall 141, the second water guide groove wall 142 is closer to the brake base plate 200; the adapter end 160 is provided with a water guide boss 150, and the second water guide groove wall 142 is located on the water guide boss 150. The water-guiding boss 150 is aligned with the slot of the slot structure 210 or extends into the slot structure 210, the second water-guiding slot wall 142 and the slot are located in the same plane or the second water-guiding slot wall 142 is located in the slot structure 210; the water-guiding boss 150 protrudes radially outward and surrounds a portion of the air path 400, the water-guiding slot structure 140 is used to collect rainwater, after the rainwater is collected in the water-guiding slot, it is stopped by the water-guiding boss 150 and cannot pass through the air path 400 to enter the accommodating chamber 300 to a certain extent; at the same time, when the brake drum 100 is in a rotating state, the rainwater collected in the water-guiding slot structure 140 can be thrown out under the action of centrifugal force.

[0045] In the above embodiment, the adapter end 160 has a drum end surface 110 axially opposite to the brake base plate 200 ; a first chamfer 430 is provided at the position where the drum outer wall 120 and the drum end surface 110 meet, and the first chamfer 430 constitutes a part of the air path 400 . That is, when the water-guiding boss 150 is provided, the table 151 of the water-guiding boss 150 serves as part of the drum outer wall 120, the drum end face 110 is located at the side wall 152 of the water-guiding boss 150 away from the water-guiding groove structure 140, and serves as the axial drum end face 110 of the brake drum 100, and the first chamfer 430 is located at the position where the side wall 152 of the water-guiding boss 150 and the table 151 meet; of course, the water-guiding boss 150 may not be provided, and when the water-guiding boss 150 is not provided, the drum outer wall 120 is the groove bottom wall 143 of the water-guiding groove structure 140; the first chamfer 430 is located at the position where the groove bottom wall 143 meets the drum end face 110. The first chamfer 430 and the groove structure 210 enclose part of the air path 400. By providing the first chamfer 430, the external air can be better guided into the air path 400.

[0046] Optionally, a second chamfer 440 is provided at the position where the drum inner wall 130 of the brake drum 100 meets the drum end surface 110, and the second chamfer 440 constitutes a part of the gas path 400. By defining the second port 420 with the second chamfer 440 and the groove structure, the gas flow at the position of the second port 420 can be increased, and the resistance of the second port 420 to the gas flow can be reduced.

[0047] In the above embodiment, the outer groove wall portion 220 is provided with a flange portion 230, and the flange portion 230 is formed by radially turning outward the outer groove wall portion 220. The flange portion 230 extends a certain dimension in the radial direction and is substantially perpendicular to the outer groove wall portion 220 of the groove structure. Thus, the flange portion 230 can stop external contaminants; in particular, it forms a better stopping effect for contaminants from one side of the brake base plate 200; at the same time, the structural strength of the brake base plate 200 can also be increased by providing the flange portion 230.

[0048] The part where the inner wall of the flange portion 230 and the inner wall of the outer groove wall portion 220 are connected has a third chamfer 450, and the third chamfer 450 constitutes a part of the air path channel 400. By setting the third chamfer 450, the resistance of air flowing in the air path channel 400 can be further reduced; optionally, the third chamfer 450 is an arc chamfer, and the third chamfer 450 is opposite to the first chamfer 430. The arc chamfer can further avoid blocking the air and increase the circulation of air in the air path channel 400. The third chamfer 450 is opposite to the first chamfer 430, and the size of the blockage for external contaminants can be adjusted by adjusting the gap between the third chamfer 450 and the first chamfer 430 to avoid large particles of foreign matter from entering the working surface.

[0049] By setting the first chamfer 430, the second chamfer 440 and the third chamfer 450, it is also possible that in the technical solution of the present application, only the fitting clearance between the third chamfer 450 and the first chamfer 430 needs to be adjusted, thereby reducing the disadvantage of the traditional technical solution that the brake drum 100 and the brake base plate 200 have multiple fitting clearances, and reducing the difficulty of controlling the fitting clearance between the brake drum 100 and the brake base plate 200.

[0050] Compared with the prior art, the drum brake according to the present invention can achieve the following beneficial effects:

[0051] First, the dust ring 500 traditionally welded to the brake base plate 200 is eliminated, the number of parts of the drum brake is reduced, and the drum brake is lightweight; at the same time, the brake base plate 200 is prevented from thermal deformation during the welding of the dust ring 500, and the brake base plate 200 is prevented from interfering with the rotating brake drum 100 during the braking process of the drum brake to generate abnormal noise;

[0052] Second, the design of the labyrinth-shaped air passage 400 of the conventional brake drum 100 is changed, the structure of the drum brake is simplified to achieve lightweight; the air flow in the air passage 400 is made smoother, and the heat dissipation effect of the drum brake is optimized;

[0053] Third, it can effectively guide and throw away rainwater. At the same time, the flange portion 230 can not only cooperate with the first chamfer 430 to prevent large particles of foreign matter from entering the working surface (friction surface between the brake drum 100 and the brake shoe);

[0054] Fourth, the third chamfer 450 cooperates with the first chamfer 430 to allow air to flow quickly, thereby improving the heat dissipation effect of the drum brake.

[0055] Fifth, the difficulty of controlling the clearance between the brake drum 100 and the brake base plate 200 is reduced.

[0056] The drum brake provided by the utility model is introduced in detail above. The principle and implementation method of the utility model are described in this article using specific examples. The description of the above embodiments is only used to help understand the core idea of ​​the utility model. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the utility model, the utility model can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the utility model.

Claims

1. A drum brake, characterized in that: The invention comprises a brake drum (100) and a brake base plate (200), wherein the brake drum (100) is rotatable relative to the brake base plate (200), and the brake base plate (200) is provided with a groove structure (210), wherein the groove structure (210) is adapted to an end portion (160) of the brake drum (100); the groove structure (210) has an outer groove wall portion (220); and in the radial direction of the drum brake, the outer groove wall portion (220) is located outside the end portion (160) of the brake drum (100).

2. The drum brake according to claim 1, characterized in that: The one end portion (160) and the groove structure (210) form an air passage (400), and the interior of the brake drum (100) is connected to the outside through the air passage (400); the air passage (400) has a first port (410) connected to the outside, and the opening direction of the first port (410) is toward the side where the brake drum (100) is located.

3. The drum brake according to claim 2, characterized in that: The groove structure (210) is a U-shaped groove, which is recessed in the axial direction toward a side away from the brake drum (100).

4. The drum brake according to claim 2, characterized in that: The outer wall (120) of the brake drum (100) is provided with a water guide groove structure (140), wherein the water guide groove structure (140) is recessed radially inward from the outer wall (120); The water guide groove structure (140) is a U-shaped groove, having a first water guide groove wall (141) and a second water guide groove wall (142) axially opposite to each other, and compared with the first water guide groove wall (141), the second water guide groove wall (142) is closer to the brake bottom plate (200); The brake drum (100) has a water-conducting boss (150) that protrudes radially outward, and the second water-conducting groove wall (142) is located on the water-conducting boss (150).

5. The drum brake according to claim 4, characterized in that The water-conducting boss (150) is aligned with the notch of the groove-shaped structure (210); or, The water-conducting boss (150) extends axially into the groove-shaped structure (210).

6. The drum brake according to claim 5, characterized in that The brake drum (100) has a drum end surface (110), and the drum end surface (110) is opposite to the brake base plate (200) in the axial direction; A first chamfer (430) is provided at a position where the drum outer wall (120) and the drum end surface (110) meet, and the first chamfer (430) constitutes part of the wall portion of the gas path channel (400).

7. The drum brake according to claim 5, characterized in that The brake drum (100) has a drum end surface (110), and the drum end surface (110) is opposite to the brake base plate (200) in the axial direction; A second chamfer (440) is provided at a position where the drum inner wall (130) of the brake drum (100) meets the drum end surface (110), and the second chamfer (440) constitutes a portion of the wall of the air passage (400).

8. The drum brake according to any one of claims 1 to 7, characterized in that: The outer groove wall portion (220) is provided with a flange portion (230), and the flange portion (230) is formed by radially turning outward of the outer groove wall portion (220).

9. The drum brake according to claim 8, characterized in that The drum brake has an air passage (400), and the portion where the flange portion (230) and the outer groove wall portion (220) meet has a third chamfer (450), and the third chamfer (450) constitutes a portion of the air passage (400).

10. The drum brake according to claim 9, characterized in that The third chamfer (450) is an arc-shaped chamfer.

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