Drum brake device

Abstract

To provide a drum brake device which can prevent a shaft part of a support pin from coming off from a web hole and a lever hole.SOLUTION: A support pin 4 for supporting a parking lever key 3 on a web 7a of a brake shoe 2a so as to be turnable, includes: a shaft part 21 inserted into a web hole 17 and a lever hole 18 from the web hole 17 side; a head part 22 which is constructed integrally with the shaft part 21, has an outer diameter larger than an inner diameter of the web hole 17, and is positioned opposite the web 7a. The shaft part 21 includes: a loose fitting part 23 loosely fit in the web hole 17; and a pressure-insertion part 24 pressure-inserted into the lever hole 18. An abutment position (X) of the web hole 17 and the loose-fitting part 23 and an abutment position (R) of the parking lever 3 and a strut 5 during turning of the parking lever 3 are located offset in an axial direction of the support pin 4.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to a drum brake device. [Background technology]

[0002] Drum brake devices are widely used as braking devices for automobiles because they have a self-boosting effect and can provide a large braking force.

[0003] A parking brake mechanism is incorporated in the drum brake device to keep the vehicle stationary, in addition to braking operation by the brake pedal while traveling.

[0004] A known parking brake mechanism, as disclosed in JP 2012-251626 A (Patent Document 1), for example, is one in which a parking lever is rotated using a parking cable or the like to spread a pair of brake shoes apart to obtain braking force.

[0005] Specifically, a parking lever that is rotatably supported by a support pin relative to one of a pair of brake shoes is rotated by pulling a parking cable, etc. This causes the other of the pair of brake shoes to be pressed against the inner peripheral surface of the brake drum via the strut, and also causes one of the brake shoes to be pressed against the inner peripheral surface of the brake drum via the support pin.

[0006] FIG. 7 shows a conventional example of a support structure for a parking lever 100. In FIG.

[0007] In the illustrated example, with an end of the parking lever 100 and an end of a web 102 constituting a brake shoe 101 overlapping each other, the parking lever 100 is supported by a support pin 103 so as to be rotatable relative to the web 102.

[0008] The parking lever 100 has a lever hole 104 at one end for inserting the support pin 103. The web 102 has a web hole 105 at one end for inserting the support pin 103 therethrough.

[0009] The support pin 103 is composed of a shaft portion 106 and a head portion 107. The shaft portion 106 is inserted into the lever hole 104 and the web hole 105 from the lever hole 104 side (the lower side in FIG. 7), and the shaft portion 106 is press-fitted into the lever hole 104, while the shaft portion 106 is loosely fitted into the web hole 105. For this reason, in the illustrated example, the support pin 103 is integral with the parking lever 100 and rotates relative to the web 102.

[0010] The head 107 is provided on the base end side of the shaft 106 (the lower side in FIG. 7), and has an outer diameter larger than the inner diameter of the lever hole 104. Therefore, even when the shaft 106 is inserted through the lever hole 104 and the web hole 105 from the lever hole 104 side, the head 107 is not inserted through the lever hole 104 and the web hole 105, and is disposed opposite to the surface of the parking lever 100 facing away from the web 102 (the lower side in FIG. 7).

[0011] A retaining member 108 such as an E-ring is engaged with the tip end portion of the shaft 106 that protrudes from the web hole 105. The retaining member 108 prevents the shaft 106 from coming out of the web hole 105 and the lever hole 104 due to vibrations and the like applied while the car is traveling. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] JP 2012-251626 A Summary of the Invention [Problem to be solved by the invention]

[0013] In the conventional example shown in FIG. 7, when the brake shoe 101 is pressed against the inner peripheral surface of the brake drum, the anti-slip member 108 is pressed strongly against the web 102 and damaged, which may cause the shaft portion 106 to come out of the web hole 105 and the lever hole 104.

[0014] 7, the shaft portion 106 constituting the support pin 103 is loosely fitted into the web hole 105. For this reason, the abutment position (X) between the web hole 105 and the shaft portion 106, which is the input position of the reaction force (FP) from the web 102 to the shaft portion 106 when the brake shoe 101 is pressed against the inner circumferential surface of the brake drum, and the abutment position (R) between the parking lever 100 and a strut (not shown), which is the pivot point of the parking lever 100, are misaligned in the axial direction of the support pin 103 (offset by HP).

[0015] As a result, a reaction force (FP) acting on shaft 106 from web 102 acts on support pin 103, causing a moment (MP = FP · HP) that draws the tip portion of shaft 106 (the upper portion in FIG. 7) into web hole 105. As a result, stopper member 108 engaged with the tip portion of shaft 106 may be damaged by being pressed strongly against web 102, and shaft 106 may come out of web hole 105 and lever hole 104.

[0016] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a drum brake device that can prevent the shaft portion of the support pin from slipping out of the web hole and the lever hole. [Means for solving the problem]

[0017] A drum brake device according to one aspect of the present disclosure includes a pair of brake shoes, a parking lever, a support pin, and a strut. Each of the pair of brake shoes has a web. The parking lever is rotatably supported on the web of one of the pair of brake shoes. The support pin supports the parking lever rotatably relative to the web of the one brake shoe. The strut is suspended between the other of the pair of brake shoes and the parking lever.

[0018] The web of the one brake shoe has a web hole. The parking lever has a lever hole. The support pin has a shaft portion inserted into each of the web holes and the lever hole from the web hole side, and a head portion formed integrally with the shaft portion, having an outer diameter larger than the inner diameter of the web hole, and positioned opposite the web of one of the brake shoes. The shaft portion has a loose-fit portion that is loosely fitted into the web hole, and a press-fit portion that is press-fit into the lever hole. Furthermore, when the parking lever rotates, the contact position of the web hole and the loose-fit portion and the contact position of the parking lever and the strut are shifted in the axial direction of the support pin.

[0019] In a drum brake device according to one embodiment of the present disclosure, the loose-fit portion has an outer diameter larger than the outer diameter of the press-fit portion, and the outer peripheral surface of the loose-fit portion and the outer peripheral surface of the press-fit portion can be connected via a step surface that functions as a stopper when the press-fit portion is pressed into the lever hole. In a drum brake device according to one aspect of the present disclosure, the loose-fit portion may have an outer diameter that is the same as the outer diameter of the press-fit portion, or may have an outer diameter that is smaller than the outer diameter of the press-fit portion. In addition, in a drum brake device according to one embodiment of the present disclosure, the outer diameter of the loose-fit portion can be made slightly smaller than the inner diameter of the web hole, and the axial dimension of the loose-fit portion can be made slightly larger than the plate thickness of the web of one of the brake shoes.

[0020] In a drum brake device according to one aspect of the present disclosure, the shaft portion has a protruding end portion on the axially opposite side of the head portion that protrudes from the lever hole, and a slip-out prevention member can be attached to the protruding end portion to prevent the shaft portion from slipping out of the lever hole and the web hole. In this case, the protruding end portion may have a constricted portion for engaging the retaining member. Alternatively, in the drum brake device according to one aspect of the present disclosure, the shaft portion can be prevented from slipping out of the lever hole and the web hole only by pressing the lever hole into the press-fit portion. In this case, the protruding end portion and the retaining member can be omitted, or only the retaining member can be omitted.

[0021] In the drum brake device according to one aspect of the present disclosure, the parking lever and the web of the one brake shoe can each be engaged with an engagement recess provided in the strut. Effect of the Invention

[0022] According to the drum brake device according to one aspect of the present disclosure, the shaft portion of the support pin can be prevented from coming out of the web hole and the lever hole. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a partially cutaway front view of a drum brake device according to a first embodiment, as viewed from the axially outer side (the outside of a vehicle). [Diagram 2] FIG. 2 is a cross-sectional view taken along line AOOA in FIG. [Diagram 3] FIG. 3 is a rear view of an area including a wheel cylinder in the disc brake device according to the first example of the embodiment, with the backing plate omitted, as viewed from the axially inner side (the center side in the vehicle width direction). [Figure 4]FIG. 4 is a schematic diagram showing a parking lever and a support pin taken out from the disc brake device according to the first example of the embodiment. [Diagram 5] FIG. 5 is a schematic diagram of FIG. 4 as viewed from below. [Figure 6] FIG. 6 is a schematic diagram corresponding to a cross section taken along line BB in FIG. [Figure 7] FIG. 7 is a schematic cross-sectional view showing a conventional example of a support structure for a parking lever using a support pin. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] [First Example of Implementation] A first example of the embodiment will be described with reference to FIGS. 1 to 6. FIG.

[0025] In this example, a description will be given of a case where the technical idea of ​​the present disclosure is applied to a leading-trailing type drum brake device 1. However, the technical idea of ​​the present disclosure is not limited to the leading-trailing type, and can be applied to other types of drum brake devices, such as a duo-servo type.

[0026] The drum brake device 1 of this example has a pair of brake shoes 2a, 2b, a parking lever 3, a support pin 4, and a strut 5. The pair of brake shoes 2a, 2b, the parking lever 3, the support pin 4, and the strut 5 constitute a parking brake mechanism 6.

[0027] <Brake shoes> Each of the brake shoes 2a, 2b is composed of a web 7a, 7b having an arc-shaped plate, a rim 8a, 8b having a partial cylindrical shape fixed along the outer peripheral edge of the web 7a, 7b, and a lining 9a, 9b fixed to the outer peripheral surface of the rim 8a, 8b.

[0028] The pair of brake shoes 2a, 2b are arranged spaced apart in the front-rear direction of the automobile (left-right direction in Fig. 1) and are supported by shoe-hold members 11a, 11b so as to be expandable against the outer surface (the surface facing outward in the width direction of the vehicle, the upper surface in Fig. 2) of a backing plate 10. The outer peripheral surface of each of the linings 9a, 9b is curved into a partially cylindrical surface and is arranged along the inner peripheral surface of a brake drum (not shown) that rotates together with the wheel.

[0029] A wheel cylinder 12 fixed to the outer surface of the backing plate 10 is disposed between the ends of one side (upper side in FIG. 1) of the webs 7a, 7b. One end of each of the webs 7a, 7b abuts against the tip of a piston 13 fitted in the wheel cylinder 12.

[0030] In contrast, an anchor 14 fixed to the outer surface of the backing plate 10 is disposed between the ends of the other side (lower side in FIG. 1) of the webs 7a, 7b. The ends of the other side of each of the webs 7a, 7b engage with the side surfaces of the anchor 14.

[0031] In the drum brake device 1 of this example, when the service brake is applied, brake oil is supplied from the master cylinder to the wheel cylinder 12, causing a pair of pistons 13 fitted in the wheel cylinder 12 to push one end of the webs 7a, 7b in a direction away from each other. Then, the pair of brake shoes 2a, 2b are rotated from the contact point with the anchor 14. This causes the linings 9a, 9b to be pressed against the inner peripheral surface of the brake drum, generating a braking force by the service brake.

[0032] A return spring 15 is suspended between the one side portions of the webs 7a, 7b. The return spring 15 imparts elastic force in a tensile direction to the one side portions of the webs 7a, 7b so as to separate the linings 9a, 9b from the inner peripheral surface of the brake drum.

[0033] In contrast, a tension coil spring 16 is hung between the other ends of the webs 7a, 7b. The tension coil spring 16 applies elastic force in the tensile direction to the other ends of the webs 7a, 7b so that the other ends of the webs 7a, 7b do not move away from the side surface of the anchor 14.

[0034] Of the pair of brake shoes 2a, 2b, the web 7a of one of the brake shoes 2a has a web hole 17 at one end for inserting the support pin 4. The web hole 17 is a circular through hole that penetrates the web 7a in the plate thickness direction. The brake shoe 2a functions as a trailing shoe when the vehicle moves forward.

[0035] <Parking lever> The parking lever 3 is disposed between a web 7a of one of the brake shoes 2a and a backing plate 10, and is rotatably supported by a support pin 4 on one end of the web 7a.

[0036] The parking lever 3 is a metal lever manufactured by pressing, forging, or the like. In this embodiment, the parking lever 3 has a plate thickness t 7 Plate thickness t is larger than 3 (t 3 >t 7 However, the thickness of the parking lever 3 may be smaller than the thickness of the web 7a, or may be the same as the thickness of the web 7a.

[0037] The parking lever 3 has a lever hole 18 for inserting the support pin 4 at one end (the upper end in FIG. 1) located near the wheel cylinder 12. The lever hole 18 is a circular through hole penetrating the parking lever 3 in the plate thickness direction. In this example, the inner diameter d 18 is the inner diameter d of the web hole 17 17 Smaller than (d 18 <d 17 ).

[0038] The parking lever 3 has an engagement portion 20 for engaging an end of the parking cable 19 at the other end (the lower end in FIG. 1) located near the anchor 14. The engagement portion 20 is configured by bending the other end of the parking lever 3 into a substantially U-shape in the plate thickness direction of the parking lever 3 (toward the back surface in FIG. 1). When the parking brake is operated, the parking cable 19 is pulled to the left in FIG. 4. There is no particular limit to the pulling method of the parking cable 19, and it may be a manual type or an electric type.

[0039] <Support pin> The support pin 4 supports the parking lever 3 rotatably relative to the web 7a of one of the brake shoes 2a.

[0040] The support pin 4 is made of metal and includes a shaft portion 21 and a head portion 22 connected to a base end portion of the shaft portion 21. The shaft portion 21 and the head portion 22 are integrally formed.

[0041] The shaft portion 21 is inserted through the web hole 17 and the lever hole 18 from the web hole 17 side (in this example, the outer side in the vehicle width direction, the upper side in FIG. 6 ). In other words, the shaft portion 21 is inserted through the web hole 17 and the lever hole 18 with the tip portion facing the outer surface of the backing plate 10.

[0042] The shaft portion 21 has a thickness t 7 and the thickness t of the parking lever 3 3 The sum of (t 7 +t 3 ) larger than the axial dimension L 21 (L 21 >t 7 +t 3 ) Therefore, the tip end portion of the shaft 21 protrudes from the lever hole 18 in the axial direction.

[0043] In this example, the shaft portion 21 has a stepped shape. The outer diameter of the shaft portion 21 decreases stepwise from the base end side to the tip end side (from the outside to the inside in the width direction of the vehicle) except for the portion where the constricted portion 27 described later is formed. Specifically, the outer diameter of the shaft portion 21 changes in three steps except for the portion where the constricted portion 27 is formed.

[0044] The shaft portion 21 has, in order from the base end side, a loose-fitting portion 23, a press-fitting portion 24, and a protruding end portion 25. Therefore, the outer diameters of the loose-fitting portion 23, the press-fitting portion 24, and the protruding end portion 25 are gradually reduced in this order (the outer diameter D of the loose-fitting portion 23 >Outside diameter D of press-fit portion 24 24 >Outside diameter D of protruding end 25 25 However, the outer diameter of the loose-fitting portion and the outer diameter of the press-fitting portion may be the same, or the outer diameter of the loose-fitting portion may be smaller than the outer diameter of the press-fitting portion.

[0045] The loose-fitting portion 23 is provided at the base end side portion of the shaft portion 21 and is connected to the head portion 22. Such a loose-fitting portion 23 is loosely fitted into the web hole 17. That is, the loose-fitting portion 23 is loosely fitted into the web hole 17. Therefore, the outer diameter D of the loose-fitting portion 23 is 23 is the inner diameter d of the web hole 17 17 A little smaller than (D 23 >d 17 ) In addition, the axial dimension L of the loose fitting portion 23 23 is the thickness t of the web 7a 7 Slightly larger than (L 23 >t 7 ).

[0046] The press-fit portion 24 is provided in the middle of the shaft portion 21 and is press-fitted into the lever hole 18. Therefore, the outer diameter D 24 is the inner diameter d of the lever hole 18 18 (D 24 >d 18 ) In addition, the axial dimension L of the press-fit portion 24 24 is the thickness t of the parking lever 3 3 Slightly larger than (L 24 >t 3). Therefore, the tip of the press-fit portion 24 protrudes from the lever hole 18. However, the axial dimension of the press-fit portion may be smaller than the plate thickness of the parking lever, or may be the same as the plate thickness of the parking lever. In this example, the case where the outer circumferential surface of the press-fit portion is cylindrical has been described, but the outer circumferential surface of the press-fit portion is not limited to a cylindrical surface, and may be, for example, a sawtooth serration. When the outer circumferential surface of the press-fit portion is sawtooth serration, the serration on the outer circumferential surface of the press-fit portion can be caused to bite into the inner circumferential surface of the lever hole when the press-fit portion of the support pin is press-fitted into the lever hole, so that the relative rotation of the support pin with respect to the parking lever can be more effectively prevented than when only press-fitting is performed.

[0047] In this example, the outer diameter D of the press-fit portion 24 24 The outer diameter D of the loose fitting portion 23 23 It is smaller than (D 24 <D 23 ). Therefore, the outer peripheral surface of the loose-fitting portion 23 and the outer peripheral surface of the press-fitting portion 24 are connected via a circular ring-shaped stepped surface 26. When the press-fitting portion 24 is press-fitted into the lever hole 18, the stepped surface 26 abuts against the opening edge of the lever hole 18 on the surface facing the web 7a of the parking lever 3 (the surface facing outward in the width direction of the vehicle in this example, the upper surface in FIG. 6 ), and functions as a stopper surface that prevents the press-fitting portion 24 from being pressed further into the lever hole 18.

[0048] The protruding end 25 is provided at a tip end portion of the shaft portion 21 located opposite the head portion 22 in the axial direction, and protrudes from the lever hole 18 .

[0049] The protruding end 25 has a constricted portion 27 at a base end portion connected to the press-fit portion 24. The outer diameter of the constricted portion 27 is smaller than the outer diameter of a portion of the protruding end 25 that is axially deviated from the constricted portion 27 (the tip end portion).

[0050] A retaining member 28 is attached to the constricted portion 27. In this example, the retaining member 28, such as a C-clip (retainer) or an E-ring, is engaged with the constricted portion 27. This prevents the shaft portion 21 from slipping out of the lever hole 18 and the web hole 17 to the upper side in Fig. 6. Note that Fig. 3 shows the case where a C-clip is used as the retaining member 28.

[0051] The head 22 is integral with the shaft portion 21 and has a disk shape. The head 22 has an outer diameter D larger than that of the shaft portion 21. 22 Specifically, the head 22 has an outer diameter D 23 Outside diameter D is sufficiently larger than 22 (D 22 >D 23 ).

[0052] The head 22 is also sized to have an inner diameter d 17 Outside diameter D is larger than 22 (D 22 >d 17 ). Therefore, even when shaft portion 21 is inserted through web hole 17 and lever hole 18 from the web hole 17 side, head portion 22 is not inserted through web hole 17 and lever hole 18, but is disposed to face a surface of web 7a facing away from parking lever 3 (a surface facing outward in the vehicle width direction in this example, the upper side surface in FIG. 6).

[0053] Outer diameter D of head 22 22 and the thickness t of the head 22 22 The specific values ​​of each of these can be appropriately determined depending on the type of metal material constituting the support pin 4, the magnitude of the reaction force (FP) applied from the web 7a to the loose-fit portion 23, and the offset amount (HP) between the abutment position (X) of the web hole 17 and the loose-fit portion 23 and the abutment position (R) of the parking lever 3 and the strut 5. The shape of the head 22 is not limited to a disk shape, and other shapes can be adopted as long as they cannot be inserted into the web hole 17.

[0054] Strut The strut 5 is suspended between a web 7b constituting the other brake shoe 2b and the parking lever 3. Specifically, the strut 5 is disposed in the vicinity of the wheel cylinder 12, and suspended between one side portion of the web 7b and one side portion of the parking lever 3.

[0055] The strut 5 has a first engagement recess 29 at one end (the end on the right side in FIG. 2) and a second engagement recess 30 at the other end (the end on the left side in FIG. 2).

[0056] In this example, the first engagement recess 29 engages not only with the inner circumferential portion of one side portion of the parking lever 3, but also with the inner circumferential portion of one side portion of the web 7a. Therefore, the first engagement recess 29 is composed of a web recess 31 and a lever recess 32. The second engagement recess 30 engages with the inner circumferential portion of one side portion of the web 7b.

[0057] In this example, the strut 5 has an automatic gap adjustment function that automatically adjusts the positions of the brake shoes 2a, 2b in accordance with the wear of the linings 9a, 9b. For this reason, the strut 5 is made up of a plurality of members. Specifically, the strut 5 is made up of an adjuster socket 33 with a first engagement recess 29, an adjuster nut 34 with a second engagement recess 30, and an adjuster screw 35 that screws into the adjuster nut 34 and has a gear portion.

[0058] When the pair of brake shoes 2a, 2b are spread apart, the strut 5 rotates the adjuster screw 35 relative to the adjuster nut 34 based on the engagement between the gear portion of the adjuster screw 35 and an adjuster lever 36 supported by the web 7b of the other brake shoe 2b, thereby extending the overall length. This adjusts the gap between the linings 9a, 9b and the inner peripheral surface of the brake drum. However, a strut without an automatic gap adjustment function can also be used.

[0059] In this example, when the parking brake is operated, the parking cable 19 is pulled, and the parking lever 3 is rotated clockwise in FIG. 1 around the support pin 4. This causes the other brake shoe 2b to open through the strut 5, and the outer circumferential surface of the lining 9b is pressed against the inner circumferential surface of the brake drum. When the parking cable 19 is further pulled, the parking lever 3 rotates around the abutment portion between the parking lever 3 and the strut 5 as a fulcrum. Specifically, the parking lever 3 rotates around the abutment position (R) between the inner circumferential side of one side portion of the parking lever 3 and the bottom of the lever recess 32 of the first engagement recess 29 provided on the strut 5 as a fulcrum. This causes the one brake shoe 2a to open, and the outer circumferential surface of the lining 9a is pressed against the inner circumferential surface of the drum brake. The abutment position (R) between the parking lever 3 and the strut 5 is within the range of the plate thickness of the parking lever 3 with respect to the axial direction of the support pin 4.

[0060] In this example, the loose-fit portion 23 constituting the support pin 4 is loosely fitted into the web hole 17, so that when the parking brake is operated and the lining 9a of one of the brake shoes 2a is pressed against the inner peripheral surface of the brake drum, a reaction force (FP) is input from the web 7a to the loose-fit portion 23 at the abutment position (X) between the web hole 17 and the loose-fit portion 23. For this reason, when the parking lever 3 rotates, the abutment position (R) between the parking lever 3 and the strut 5 and the abutment position (X) between the web hole 17 and the loose-fit portion 23 are shifted in the axial direction of the support pin 4 (offset by HP).

[0061] In the case of the drum brake device 1 of this example, the abutment position (R) between the parking lever 3 and strut 5 and the abutment position (X) between the web hole 17 and the loose-fit portion 23 are offset in the axial direction of the support pin 4, so that a moment (MP = FP · HP) acts on the support pin 4 due to the reaction force (FP) acting from the web 7 a to the loose-fit portion 23.

[0062] However, in the drum brake device 1 of this example, the head 22, which is formed integrally with the shaft portion 21 and has an outer diameter larger than the inner diameter of the web hole 17, is disposed facing the web 7a, so that when the moment (MP) is applied, the head 22 is pressed against the web 7a, instead of the retaining member 28 engaged with the shaft portion 21. This makes it possible to prevent damage to the retaining member 28, and effectively prevents the shaft portion 21 from slipping out of the lever hole 18 and the web hole 17.

[0063] In this example, the outer circumferential surface of the loose-fit portion 23 and the outer circumferential surface of the press-fit portion 24 are connected via a circular ring-shaped stepped surface 26. Therefore, when the press-fit portion 24 is press-fitted into the lever hole 18, the stepped surface 26 can function as a stopper surface that prevents the press-fit portion 24 from being pushed further into the lever hole 18. Therefore, the amount of press-fitting of the press-fit portion 24 into the lever hole 18 can be adjusted appropriately without using a jig or the like, thereby reducing the number of assembly steps.

[0064] Furthermore, in this example, the inner circumferential side of one side portion of the parking lever 3 and the inner circumferential side of one side portion of the web 7a are engaged with the first engagement recess 29 provided at one end of the strut 5. Therefore, the first engagement recess 29 can suppress the relative tilt of the web 7a and the parking lever 3. Therefore, the force with which the head 22 is pressed against the web 7a by the moment (MP) can be suppressed to be small. This makes it possible to reduce the diameter and thickness of the head 22.

[0065] In this example, the retaining member 28 is attached to the protruding end 25 of the shaft 21, which prevents the shaft 21 from coming out of the web hole 17 and the lever hole 18 due to vibrations applied when the car is traveling, etc. Furthermore, this example employs a configuration in which the retaining member 28 engages with the constricted portion 27 provided on the protruding end 25, which improves the workability of attaching the retaining member 28 and effectively prevents the retaining member 28 from falling off the protruding end 25 in the axial direction.

[0066] Although the embodiments of the present disclosure have been described above, the technical ideas of the present disclosure are not limited to the structures of the embodiments and can be modified as appropriate. For example, the structures and shapes of the parking lever and strut are not limited to the structures and shapes shown in the embodiments and can be modified as appropriate. [Explanation of symbols]

[0067] 1 Drum brake device 2a, 2b Brake shoes 3 Parking lever 4 Support pin 5 Strut 6 Parking brake mechanism 7a, 7b Web 8a, 8b rims 9a, 9b Lining 10 Backing Plate 11a, 11b Shoe hold members 12 Wheel cylinder 13 Piston 14 Anka 15 Return spring 16 Extension coil spring 17 Web Hole 18 Lever hole 19 Parking Cable 20 Engagement part 21 Shaft 22 Head 23 Play fitting part 24 Press-fit section 25 Protruding end 26 Step surface 27 Neck 28 Anti-slip member 29 First engagement recess 30 Second engagement recess 31 Web recess 32 Lever recess 33 Adjuster socket 34 Adjuster nut 35 Adjustable screw 36 Adjuster lever 100 Parking Lever 101 Brake shoe 102 Web 103 Support pin 104 Lever hole 105 Web Hole 106 Shaft 107 Head 108 Anti-slip member

Claims

1. a pair of brake shoes each having a web; a parking lever rotatably supported on the web of one of the pair of brake shoes; a support pin that rotatably supports the parking lever with respect to the web of the one brake shoe; a strut suspended between the other of the pair of brake shoes and the parking lever, the web of the one brake shoe has a web hole; The parking lever has a lever hole, the support pin has a shaft portion inserted into the web hole and the lever hole from the web hole side, and a head portion formed integrally with the shaft portion, having an outer diameter larger than an inner diameter of the web hole, and disposed opposite the web of the one brake shoe, The shaft portion has a loose-fit portion loosely fitted into the web hole and a press-fit portion press-fitted into the lever hole, When the parking lever is rotated, a contact position between the web hole and the loose-fitting portion and a contact position between the parking lever and the strut are shifted in the axial direction of the support pin. Drum brake device.

2. The loose-fit portion has an outer diameter larger than an outer diameter of the press-fit portion, an outer circumferential surface of the loose-fitting portion and an outer circumferential surface of the press-fitting portion are connected via a stepped surface that functions as a stopper when the press-fitting portion is press-fitted into the lever hole; 2. A drum brake device according to claim 1.

3. The outer diameter of the loose fit portion is slightly smaller than the inner diameter of the web hole, The axial dimension of the loose fitting portion is slightly larger than the plate thickness of the web of the one brake shoe.

3. A drum brake device according to claim 1 or 2.

4. The shaft portion has a protruding end portion protruding from the lever hole on an axially opposite side to the head portion, A retaining member is attached to the protruding end portion to prevent the shaft portion from slipping out of the lever hole and the web hole.

2. A drum brake device according to claim 1.

5. 5. The drum brake device according to claim 4, wherein the protruding end portion has a constricted portion for engaging the retaining member.

6. 2. The drum brake device according to claim 1, wherein the parking lever and the web of the one brake shoe are engaged with engaging recesses formed in the strut.

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