Drum brake structure for vehicle

Abstract

To provide a drum brake structure for a vehicle by which a worker can easily attach a retainer to a backplate of a drum brake.SOLUTION: A drum brake structure for a vehicle comprises a housing, a bearing, a backplate and a retainer 150, and the retainer 150 has four fixing holes 152 which are formed at up-and-down two corners at a vehicle front side and up-and-down two corners at a vehicle rear side, recesses 153, 154 which are recessed to an axle shaft side between the fixing holes of the up-and-down two corners at the vehicle front side and the vehicle rear side out of the four fixing holes 152, and bulged parts 156, 158 which are bulged to the outside of a vehicle width direction along the most recessed point out of the recesses 153, 154.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a drum brake structure for a vehicle. [Background technology]

[0002] For example, Patent Document 1 discloses a drum brake structure in which a retainer is disposed inside a drum. In this drum brake structure, the retainer has a recessed portion recessed in the vehicle front-rear direction and a claw portion bent from the recessed portion and extending outward in the vehicle width direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7229635 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a vehicle drum brake structure such as that described in Patent Document 1, the presence of the claws makes it difficult to grasp the concave portion (recess) of the retainer, making it difficult for an operator to adjust the position of the retainer and difficult to attach the retainer to the back plate of the drum brake.

[0005] In view of the above problems, the present invention has an object to provide a drum brake structure for a vehicle that enables an operator to easily attach a retainer to a back plate of the drum brake. [Means for solving the problem]

[0006] In order to solve the above problems, a typical configuration of the present invention is a vehicle drum brake structure comprising a housing that is long in the vehicle width direction and accommodates an axle shaft, a bearing that is arranged within the housing and fits onto the end of the axle shaft, a drum brake backplate that is located on the vehicle width outer side of the housing and has a hole through which the bearing passes, and a plate-shaped retainer that is fixed to the vehicle width outer side of the backplate and clamps the bearing that has passed through the hole together with the housing to prevent the bearing from coming out, wherein the retainer has four fixing holes formed at the two upper and lower corners on the front side of the vehicle and the two upper and lower corners on the rear side of the vehicle, and through which predetermined fixing members are inserted to fix the retainer to the backplate, recesses that are recessed towards the axle shaft between the fixing holes at the two upper and lower corners on the front side and the rear side of the vehicle, and a bulge portion that bulges outward in the vehicle width direction along the most recessed part of the recesses. Effect of the Invention

[0007] According to the present invention, an operator can easily attach a retainer to a back plate of a drum brake. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view of a vehicle drum brake structure according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a partially enlarged perspective view of the vehicle drum brake structure of FIG. 1. [Diagram 3] 3 is a cross-sectional view of the vehicle drum brake structure of FIG. 2 excluding brake shoes and the like. [Figure 4] 3 is a perspective view of the vehicle drum brake structure of FIG. 2 with a back plate and a retainer removed. FIG. [Diagram 5] FIG. 2 is a side view of the vehicle drum brake structure of FIG. 1 with an axle shaft and a retainer removed. [Figure 6] 3 is a side view showing a state in which the retainer of the vehicle drum brake structure of FIG. 2 is attached to a back plate. FIG. [Figure 7]FIG. 7 is a cross-sectional view taken along line MM in FIG. 6. [Figure 8] FIG. 7 is a cross-sectional view taken along line NN in FIG. [Figure 9] 3 is a perspective view showing a state in which an axle shaft is removed from the vehicle drum brake structure of FIG. 2. FIG. [Figure 10] 10 is a perspective view showing a state in which the retainer of the vehicle drum brake structure of FIG. 9 is attached to a back plate. FIG. [Figure 11] FIG. 3 is a diagram of a retainer of the vehicle drum brake structure of FIG. 2. [Figure 12] FIG. 3 is a perspective view of a retainer of the vehicle drum brake structure of FIG. 2. [Figure 13] 7 is a perspective side view of the retainer of the vehicle drum brake structure of FIG. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] One embodiment of the present invention is a vehicle drum brake structure comprising a housing which is long in the vehicle width direction and which accommodates an axle shaft, a bearing which is arranged within the housing and fits onto the end of the axle shaft, a drum brake backplate which is located on the outer side of the housing in the vehicle width direction and has a hole through which the bearing passes, and a plate-shaped retainer which is fixed to the outer side of the backplate in the vehicle width direction and which clamps the bearing which has passed through the hole together with the housing to prevent the bearing from coming out, wherein the retainer is characterized in having four fixing holes formed at the two upper and lower corners on the front side of the vehicle and the two upper and lower corners on the rear side of the vehicle and through which predetermined fixing members which fix the retainer to the backplate are inserted, recesses which are recessed towards the axle shaft between the fixing holes at the two upper and lower corners on each of the four fixing holes on the front side and the rear side of the vehicle, and bulges which bulge outward in the vehicle width direction along the most recessed part of the recesses.

[0010] According to the present invention, an operator can grasp the retainer by passing the fingers of both hands through the recesses of the retainer and hooking them on the backs of the bulges, which allows the operator to easily attach the retainer to the back plate of the drum brake.

[0011] When viewed from the vehicle width direction, the bulge portion is formed in a bell shape that is curved convexly toward the axle shaft side, the deepest point of the recess is located between the outer end position and the center position of the fixing hole in the vehicle fore-and-aft direction, and the length of the bulge portion in the vehicle fore-and-aft direction is greater than the radius of the fixing hole and less than the diameter.

[0012] By forming the bulging portion in a bell shape, the bulging portion is formed long in the vehicle front-rear direction and is formed in an arch shape extending up and down. This increases the rigidity of the retainer. This further increases the rigidity of the retainer. As a result, the retainer's function of holding the bearing is improved compared to when the bulging portion is not bell-shaped.

[0013] The retainer further has an opening through which the axle shaft is inserted, an annular raised portion having a peripheral edge of the opening raised outward in the vehicle width direction in a ring shape, and a vertical raised portion which is continuous with the annular raised portion and raised outward in the vehicle width direction in the vertical direction away from the opening, and the annular raised portion is located inside the outer diameter of the bearing when viewed from the vehicle width direction, and the vertical raised portion is located outside the outer diameter of the bearing.

[0014] By forming the vertical protrusions on the retainer, the rigidity of the retainer is improved compared to a configuration in which the vertical protrusions are not formed, and the function of the retainer in pressing the bearing is improved. EXAMPLES

[0015] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific values ​​shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are given the same reference numerals to avoid repeated explanations, and elements not directly related to the present invention are not shown.

[0016] Fig. 1 is a perspective view of a vehicle drum brake structure 100 according to an embodiment of the present invention. Fig. 2 is a partially enlarged perspective view of the vehicle drum brake structure 100 of Fig. 1. In Fig. 1 and all other drawings, the vehicle front-rear direction is indicated by arrows F (Forward) and B (Backward), the left and right in the vehicle width direction are indicated by arrows L (Leftward) and R (Rightward), and the up-down direction is indicated by arrows U (Upward) and D (Downward).

[0017] The vehicle drum brake structure 100 shown in Fig. 1 includes a housing 101 that accommodates an axle shaft 105, and a bearing 102 (see Fig. 3) accommodated in the housing 101. As shown in Fig. 1, the housing 101 is a housing that is long in the vehicle width direction. As shown in Fig. 2, the vehicle drum brake structure 100 also includes a back plate 103 fixed to the housing 101, and a retainer 150 fastened to the housing 101 together with the back plate 103. The vehicle drum brake structure 100 further includes a wheel cylinder 171, a brake lining 172, a brake shoe 173, etc.

[0018] Fig. 3 is a cross-sectional view of the vehicle drum brake structure 100 of Fig. 2 excluding brake shoes and the like. As shown in Fig. 3, the housing 101 has an axle housing 111 and a housing hub 112. Fig. 4 is a perspective view of the vehicle drum brake structure 100 of Fig. 2 excluding the back plate 103 and the retainer 150. As shown in Fig. 4, the housing hub 112 has a protruding portion 112a. The protruding portion 112a is formed with four holes 112b for mounting the retainer 150 described below. The housing hub 112 also has a hole 112c for supporting the bearing 102 on the central side of the protruding portion 112a.

[0019] As shown in Fig. 3, the bearing 102 is a ball bearing. The bearing 102 includes an outer ring 102a, an inner ring 102b, and a rolling element 102c. The rolling element 102c rolls between the outer ring 102a and the inner ring 102b. Although balls are used as an example of the rolling element 102c, rollers (not shown) may be used as the rolling element 102c depending on the vehicle model. The outer ring 102a of the bearing 102 is fitted into the housing hub 112. The inner ring 102b of the bearing 102 is fitted into the end of the axle shaft 105.

[0020] As shown in Fig. 4, the bearing 102 is fitted into a hole 112c of the housing hub 112. The bearing 102 protrudes from an end face 112d of the housing hub 112. As shown in Fig. 3, when the back plate 103 is attached to the end face 112d of the housing hub 112, the bearing 102 and the back plate 103 are approximately flush with each other. Note that in Fig. 4, the back plate 103 and the retainer 150 are not shown in order to show the positional relationship between the bearing 102 and the axle shaft 105.

[0021] FIG. 5 is a side view of the vehicle drum brake structure 100 of FIG. 1 with the axle shaft 105 and the retainer 150 removed. The back plate 103 is a plate of the drum brake. As shown in FIG. 5, the back plate 103 has a hole 103a in the center. The bearing 102 is fitted into the hole 103a. The back plate 103 of FIG. 5 is disposed along the protruding portion 112a of the housing hub 112 described above, and spreads in a direction perpendicular to the vehicle width direction. The back plate 103 has four holes 103b around the hole 103a for mounting the retainer 150 described below.

[0022] The back plate 103 has a continuous opening 103c which is a continuous opening extending downward from a portion of the lower side of the hole 103a. The continuous opening 103c is an opening for draining water from within the housing 101.

[0023] FIG. 6 is a side view showing a state in which the retainer 150 of the vehicle drum brake structure of FIG. 2 is attached to the back plate 103. FIG. 7 is a cross-sectional view taken along the line MM in FIG. 6. As shown in FIG. 7, a space P is formed between the vertical raised portion 165 of the retainer 150 and the bearing 102, and between the retainer 150 and the back plate 103. Furthermore, the continuous opening 103c of the back plate 103 is disposed on the vehicle inner side of this space P. Furthermore, the recess 112e of the housing hub 112 is disposed on the vehicle inner side of this continuous opening 103c. Therefore, when water enters between the housing hub 112 and the outer ring 102a of the bearing 102, the water passes through the space P, the continuous opening 103c, and the recess 112e and is discharged to the outside.

[0024] FIG. 8 is a cross-sectional view taken along line NN in FIG. 6. As shown in FIG. 8, a space P is formed between the retainer 150 and the bearing 102. However, no space is formed between the annular protrusion 161 of the retainer 150 and the back plate 103. In addition, the continuous opening 103c of the back plate 103 is not present on the vehicle inner side of the space P. Furthermore, the recess 112e of the housing hub 112 is not present on the vehicle inner side of the continuous opening 103c. Therefore, even if water enters between the housing hub 112 and the outer ring 102a of the bearing 102, there is no drainage path for this water on the drawing of FIG. 8. However, this water flows into the drainage path of the space P, the continuous opening 103c, and the recess 112e and is discharged to the outside.

[0025] Fig. 9 is a perspective view showing a state in which the axle shaft 105 is removed from the vehicle drum brake structure 100 of Fig. 2. Fig. 10 is a perspective view showing a state in which the retainer 150 of the vehicle drum brake structure 100 of Fig. 9 is attached to the back plate 103. As shown in Figs. 9 and 10, the retainer 150 is a plate-shaped member. The retainer 150 is fastened together with the back plate 103 to the housing hub 112 by a bolt 106 and a nut 107.

[0026] Retainer 150 is fixed to the outer side of back plate 103 in the vehicle width direction, and holds bearing 102 that has passed through hole 103a together with housing hub 112 to prevent bearing 102 from falling out. In addition, retainer 150, back plate 103, and housing hub 112 are fastened together in a triple stack, so that back plate 103 is held by retainer 150 and housing hub 112.

[0027] Four holes 112b of the housing hub 112, four holes 103b of the back plate 103, and four circular fixing holes of the retainer 150 (only two of which are indicated by reference numerals 152 and 157) are aligned and fastened together by four bolts 106 and four nuts 107. As shown in Fig. 6, in this embodiment, the fixing positions of the two bolts 106 and nuts 107 on the front side of the vehicle are slightly lower than the fixing positions of the two bolts 106 and nuts 107 on the rear side of the vehicle.

[0028] FIG. 11 is a diagram of the retainer 150 of the vehicle drum brake structure 100 of FIG. 2. FIG. 11(a) is a side view of the retainer 150. FIG. 11(b) is a plan view of the retainer 150. FIG. 11(c) is a rear view of the retainer 150. FIG. 11(d) is a cross-sectional view taken along line CC of FIG. 11(a). FIG. 12 is a perspective view of the retainer 150 of the vehicle drum brake structure of FIG. 2.

[0029] As shown in FIG. 11 and FIG. 12, the retainer 150 has an opening 151. The axle shaft 105 is inserted through the opening 151. The retainer 150 has a total of four fixing holes formed at two upper and lower corners on the front side of the vehicle and two upper and lower corners on the rear side of the vehicle, and the fixing holes at the two upper and lower corners on the front side of the vehicle are given the reference numerals 152 and 157 as representatives of these. The retainer 150 has a symmetrical shape in the front and rear of the vehicle, so that hereinafter, unless otherwise specified, only the shape of the front half of the fixing holes 152, 157, etc. will be described as a representative. The bolt 106 of the bolts 106 and nuts 107 (see FIG. 10, predetermined fixing members) that fix the retainer to the back plate 103 is inserted through the fixing holes 152 and 157. The fixing holes 152 and 157 have the same size and are arranged at approximately the same position in the front-rear direction of the vehicle.

[0030] The retainer 150 has a recess 153. The recess 153 is recessed between the fixing holes 152 and 157 toward the axle shaft 105, i.e., toward the opening 151.

[0031] The recess 153 narrows in width toward the opening 151, has an inclined edge 153a that is inclined toward the opening 151, and has a bottom 153b that is the most recessed point. The bottom 153b has a first width Y1.

[0032] Here, of the ends of the fixing holes 152, 157 in the vehicle fore-aft direction, the end farthest from the opening 151 (where the axle shaft 105 fits) is defined as an outer end position A1, and the end closer to the opening 151 is defined as an inner end position A2. In this embodiment, the position of the bottom 153b, which is the most recessed part of the recess 153, in the vehicle fore-aft direction is substantially the same as the outer end positions A1 of the fixing holes 152, 157. However, the position of the bottom 153b in the vehicle fore-aft direction may be between the outer end positions A1 and the center position O of the fixing holes 152, 157.

[0033] The retainer 150 has a bulging portion 156. The bulging portion 156 bulges outward in the vehicle width direction along a bottom 153b, which is the most recessed portion of the recess 153. When viewed in the vehicle width direction, the bulging portion 156 is formed in a bell shape that is curved convexly toward the axle shaft 105 side. The length L of the bulging portion 156 in the vehicle front-rear direction is greater than the radius R of the fixing holes 152, 157 and smaller than the diameter D.

[0034] Further, the retainer 150 has an annular raised portion 161. The annular raised portion 161 is formed by raising the peripheral edge of the opening 151 in an annular shape outward in the vehicle width direction.

[0035] The retainer 150 further has vertical raised portions 162, 163, 164, and 165. The vertical raised portions 162, 163, 164, and 165 are continuous with the annular raised portion 161 and raised outward in the vehicle width direction in the up-down direction so as to move away from the opening 151.

[0036] Fig. 13 is a perspective side view of the retainer 150 of the vehicle drum brake structure 100 of Fig. 6. The annular raised portion 161 is located inside the outer diameter of the bearing 102 when viewed from the vehicle width direction. The vertical raised portions 162, 163, 164, and 165 are located outside the outer diameter (contour) of the bearing 102.

[0037] Next, a description will be given of how an operator replaces the retainer 150. With the back plate 103 attached to the bearing 102 as shown in Fig. 5, the operator grasps both bulges 156, 158 of the retainer 150 as shown in Fig. 9 and Fig. 10, passes the four fixing holes 152, 157, etc. onto the bolt 106, and tightens the nut 107 and washer 108.

[0038] According to the configuration of this embodiment, an operator can grasp retainer 150 by passing the fingers of both hands through recesses 153, 154 of retainer 150 and hooking them on the backs of bulges 156, 158. This allows an operator to easily grasp retainer 150 and easily attach retainer 150 to back plate 103 of the drum brake while easily fine-tuning the attitude of retainer 150.

[0039] Also, the worker can shorten the work time. The bulging portions 156, 158 improve the rigidity of the retainer 150. Furthermore, the configuration with the bulging portions 156, 158 of this embodiment has a higher yield than the configuration with the claw shape of the above-mentioned Patent Document 1, making it easier to manufacture good products and reducing the defect rate. Also, less material is used than with the claw shape, making it possible to reduce the weight. Also, there are no sharp protrusions such as the tips of the claws on the worker side. Since the bulging portions 156, 158 of this embodiment are gentler than the flat surface, it is possible to reduce the risk of injury to the worker compared to the claw shape.

[0040] By forming the bulging portions 156, 158 in a bell shape, the bulging portions 156, 158 are formed long in the vehicle front-rear direction and are formed in an arch shape extending up and down. This increases the rigidity of the retainer 150. As a result, the function of the retainer 150 to hold down the bearing 102 is improved compared to when the bulging portions 156, 158 are not bell-shaped.

[0041] In addition, in the vehicle front-rear direction, the area of ​​bulging portion 156 is included in the areas of fixing holes 152, 157. In other words, bulging portion 156 is formed near fixing holes 152, 157. Therefore, the worker can grasp retainer 150 in a position close to bolt 106 and nut 107 and fix it to bolt 106 and nut 107.

[0042] By forming vertical raised portions 162, 163, 164, and 165 on retainer 150, the rigidity of retainer 150 is improved compared to a configuration in which these raised portions are not formed, and the function of retainer 150 in pressing bearing 102 is improved.

[0043] Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to the above-described embodiment. It is clear that a person skilled in the art can think of various modifications or alterations within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present invention.

[0044] Furthermore, the present invention can be implemented by freely combining the inventions described in the claims and examples, regardless of the dependent relationships of the claims. [Industrial Applicability]

[0045] The present invention can be used in a drum brake structure for a vehicle. [Explanation of symbols]

[0046] 100...vehicle drum brake structure, 101...housing, 102...bearing, 102a...outer ring, 102b...inner ring, 102c...rolling element, 103...back plate, 103a...hole, 103b...hole, 103c...continuous opening, 105...axle shaft, 106...bolt (fixing member), 107...nut (fixing member), 108...washer, 111...axle housing, 112...housing hub, 112a...tension Projection part, 112b...hole, 112c...hole, 112d...end face, 150...retainer, 151...opening, 152, 157...fixing hole, 153, 154...recess, 153a...slanted edge, 153b...bottom, 156, 158...bulge Extrusion, 161...Annular raised part, 162...Vertical raised part, 163...Vertical raised part, 164...Vertical raised part, 165...Vertical raised part, A1...Outer end position, A2...Inner end position, O...Center position, P...Space, Y1...Width, Y2...Width

Claims

1. a housing that is elongated in a vehicle width direction and that accommodates an axle shaft; a bearing disposed within the housing and fitted to an end of the axle shaft; a back plate of a drum brake, the back plate being located on an outer side of the housing in the vehicle width direction and having a hole through which the bearing passes; a plate-shaped retainer fixed to the vehicle width direction outer side of the back plate, the plate-shaped retainer clamping the bearing that has passed through the hole together with the housing to prevent the bearing from coming out, The retainer includes: Four fixing holes are formed at two upper and lower corners on the front side of the vehicle and two upper and lower corners on the rear side of the vehicle, through which predetermined fixing members for fixing the vehicle to the back plate are inserted; a recessed portion recessed toward the axle shaft between fixing holes at two upper and lower corners on a vehicle front side and a vehicle rear side among the four fixing holes; a bulging portion that bulges outward in a vehicle width direction along a most recessed portion of the recess; A vehicle drum brake structure comprising:

2. The bulge portion is formed in a bell shape that is curved convexly toward the axle shaft side when viewed from the vehicle width direction, The recess has a deepest recessed portion between an outer end position and a center position of the fixing hole in the vehicle front-rear direction, The length of the bulge in the vehicle front-rear direction is greater than the radius of the fixing hole and smaller than the diameter of the fixing hole.

2. The vehicle drum brake structure according to claim 1.

3. The retainer further comprises: an opening through which the axle shaft is inserted; an annular raised portion in which a peripheral edge of the opening is raised outward in a vehicle width direction; a vertical raised portion that is continuous with the annular raised portion and raised outward in the vehicle width direction in the up-down direction so as to move away from the opening, 3. The vehicle drum brake structure according to claim 1, wherein the annular raised portion is located inside the outer diameter of the bearing when viewed in the vehicle width direction, and the vertical raised portion is located outside the outer diameter of the bearing.

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