Disc brakes

Abstract

In a disc brake device (10), a pair of brake pads (48L, 48R) each includes a friction member (58L, 58R) and a back plate (60L, 60R). At least a portion of a retainer (72) is disposed radially outward of the brake disc (16) relative to each friction member (58L, 58R). In addition, at least a portion of the retainer (72) is disposed at approximately the same height as each back plate (60L, 60R) and at approximately the same position in the circumferential direction (C) of the brake disc (16).

Description

Technical Field

[0001] The present invention relates to a disc brake device. Background Art

[0002] Conventional disc brakes use a pair of brake pads, driven by the movement of a piston housed in a brake caliper, to clamp a brake disc. This action results in the brake disc being braked by the pair of brake pads. Each of the pair of brake pads includes a friction member and a backing plate. Each friction member contacts the brake disc. Each backing plate is located on the backside of the friction member. In this case, a retaining member abuts against each backing plate, thereby retaining the pair of brake pads to the brake caliper.

[0003] International Publication No. 2019 / 049539 discloses that the width of the retainer is such that it straddles each friction member. In addition, International Publication No. 2019 / 049539 discloses that the width of the end portion of the retainer is such that it straddles each back plate. Summary of the Invention

[0004] Narrowing the retainer reduces its weight. However, narrowing the retainer increases the risk of parts accidentally entering the gap between the brake pads (the gap between the friction members) during maintenance on vehicles equipped with disc brakes. This can increase the time required for maintenance work.

[0005] Therefore, an object of the present invention is to solve the above-mentioned problems.

[0006] The disc brake device of one embodiment of the present invention comprises: a brake disc; a brake caliper which is arranged astride the brake disc; a piston which is accommodated in the brake caliper; a pair of brake pads which are accommodated in the brake caliper and which clamp the brake disc by the action of the piston; and a retainer which is arranged in the brake caliper and which holds the pair of brake pads on the brake caliper by abutting against the pair of brake pads. In the above-mentioned disc brake device, each of the pair of brake pads comprises: a friction member having a contact surface which contacts a side surface of the brake disc; and a back plate which has one surface mounted to a back surface of the friction member on a side opposite to the contact surface and has the other surface pressed against the piston, and at least a portion of the retainer is arranged radially outward of each of the friction members, at substantially the same height as each of the back plates, and at substantially the same position in the circumferential direction of the brake disc.

[0007] According to this structure, at least a portion of the retainer is provided at substantially the same height and position as the back plates, thereby making it difficult for foreign matter to enter between the pair of brake pads (the gap between the friction materials).

[0008] One circumferential end portion of the retainer and one circumferential end portion of the back plate may be provided at substantially the same height and at substantially the same circumferential position radially outward of the brake disc relative to each friction member.

[0009] According to this structure, one end of the retainer and one end of each back plate are at approximately the same height radially outward from each friction member and are disposed at approximately the same position circumferentially of the brake disc. This prevents foreign matter from entering between the pair of brake pads.

[0010] The width of the one end portion of the retainer astride the center line of the brake caliper may be substantially the same as the width of the gap between the friction members astride the center line.

[0011] According to this structure, the width of one end portion of the retainer is set to be substantially the same as the width of the gap between the friction members. This allows the retainer to be made as small and lightweight as possible, while preventing foreign matter from entering the gap between the friction members.

[0012] The above-mentioned retaining member has an abutment portion, which is arranged on the central side of the above-mentioned brake caliper in the above-mentioned circumferential direction relative to one end portion of the above-mentioned retaining member and abuts against each of the above-mentioned back plates. The width of the above-mentioned retaining member across the center line of the above-mentioned brake caliper can be narrowed as it moves from the above-mentioned abutment portion toward one end portion of the above-mentioned retaining member.

[0013] According to this structure, the width of the retaining member decreases as it moves from the abutment portion toward one end of the retaining member. This allows for a smaller and lighter retaining member, while reliably retaining the pair of brake pads to the brake caliper. Furthermore, the width of the abutment portion is wider than the width of one end of the retaining member. This reliably prevents foreign matter from entering the gaps between the friction members.

[0014] The retainer may further include a connecting portion connecting the contact portion and one end portion of the retainer, wherein a width of the connecting portion along the center line is wider than a width of a gap between the friction members along the center line.

[0015] According to this structure, the width of the connecting portion is wider than the width of the gap between the friction members, thereby reliably preventing foreign matter from entering the gap.

[0016] A width of the connecting portion straddling the center line may be narrower than a distance between the back plates.

[0017] According to this structure, the width of the connection portion is narrower than the interval between the back plates. This can avoid interference between the holder and the back plates.

[0018] It may also be that each of the above-mentioned back plates has a protrusion, which is arranged on the side of the central portion in the circumferential direction relative to one end portion of the above-mentioned back plate and protrudes radially outward from the above-mentioned brake disc relative to the above-mentioned friction member, the above-mentioned abutment portion has a shape that is bent toward each of the above-mentioned back plates and abuts against each of the above-mentioned protrusions, and the above-mentioned connecting portion is flat.

[0019] With this configuration, the abutment portions bend toward each back plate and abut against the protrusions. This allows the pair of brake pads to be held relative to the caliper in both the circumferential and radial directions of the brake disc, even if there is some play between the pair of brake pads and the caliper. Furthermore, since the connecting portion is flat, it is possible to apply markings, for example, to its surface to prevent incorrect assembly.

[0020] The retainer may be narrowed in stages from the contact portion toward one end portion of the retainer.

[0021] According to this structure, the retainer narrows stepwise from the contact portion toward one end portion of the retainer.

[0022] One end portion of the holder may be engaged with a recess provided in the brake caliper.

[0023] With this structure, one end of the retainer engages with the recess. Therefore, there's no need to widen the width of the retainer's one end to secure it to the retainer. By making the one end of the retainer narrower, the retainer can be prevented from becoming too wide. As a result, the retainer can be further miniaturized and lightweight.

[0024] Alternatively, when the inlet side of the brake disc of the brake caliper in the rotation direction is set as the disc input side and the outlet side in the rotation direction is set as the disc output side, one end portion of the retaining member and one end portion of each of the back plates are respectively arranged on one side of the disc input side and the disc output side.

[0025] According to this structure, one end portion of the holder and one end portion of each back plate are provided on either the disc entry side or the disc exit side, thereby making it possible to easily obtain the above-mentioned effects.

[0026] Alternatively, when one of the disc rotation-in side and the disc rotation-out side is the upper side of the disc brake device and the other is the lower side of the disc brake device, one end portion of the retaining member and one end portion of each of the back plates are respectively arranged on the lower side of the disc brake device.

[0027] According to this structure, one end of the retainer and one end of each back plate are respectively arranged on the lower side of the disc brake device. This effectively prevents foreign matter dropped from above during maintenance, etc. from entering the gaps between the friction members arranged on the lower side of the disc brake device.

[0028] Alternatively, the retaining member may be located radially outward of the brake disc relative to the friction members and extend along the circumferential direction so as to cover a gap formed between the friction members, and one end portion of each back plate may protrude radially outward of the brake disc relative to the friction members.

[0029] According to this structure, the retainer extends circumferentially to cover the gaps between the friction members, and one end of each back plate protrudes radially outward from the friction member in the brake disc. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a right side view of the front wheel portion of a two-wheeled vehicle equipped with the disc brake device according to this embodiment.

[0031] Figure 2 This is a rear view of the disc brake system.

[0032] Figure 3 It is a partial perspective view of a disc brake device.

[0033] Figure 4 It is a partial rear view of the disc brake device.

[0034] Figure 5 It is along Figure 2 Cross-sectional view of line VV.

[0035] Figure 6 It is along Figure 2 A cross-sectional view taken along line VI-VI.

[0036] Figure 7 It is along Figure 2 A cross-sectional view taken along line VII-VII. DETAILED DESCRIPTION

[0037] The disc brake device 10 of this embodiment is as follows Figure 1 As shown, a wheel brake device is mounted on a vehicle. As an example, Figure 1 The figure shows a case where the disc brake device 10 is applied to the brake device of the front wheel 14 of the two-wheeled vehicle 12. In addition, in the description of this embodiment, the traveling direction ( Figure 1 The front, rear, left, right, and up and down directions are described with the right direction of the disc brake device 10 being the front. Figure 1 The disc brake device 10 is provided on a wheel (front wheel 14 or rear wheel) of various vehicles such as a monocycle, a three-wheeled vehicle, and a four-wheeled vehicle.

[0038] In the following description, components on the left side of the disc brake device 10 are sometimes described by appending an "L" to the reference numerals. Also, components on the right side are sometimes described by appending an "R" to the reference numerals. Furthermore, components on the front side are sometimes described by appending an "F" to the reference numerals. Furthermore, components on the rear side are sometimes described by appending a "B" to the reference numerals.

[0039] The disc brake device 10 includes a brake disc 16. The brake disc 16 is a metal annular plate-shaped component. The brake disc 16 is provided on the right side of the front wheel 14. The brake disc 16 is connected to the front wheel 14 in a manner that is substantially coaxial with the axle 22 of the front wheel 14. Therefore, the brake disc 16 rotates integrally with the front wheel 14. In addition, the disc brake device 10 also includes a brake caliper 20. The brake caliper 20 is mounted on the front fork 18 on the right side of the front wheel 14. An axle support portion 24 is provided at the front end portion of the front fork 18. The axle support portion 24 axially supports the axle 22. The axle support portion 24 is connected to a bracket 26 that extends to the rear right side of the front wheel 14. As shown in FIG. Figures 1 to 7 As shown, the brake caliper 20 is supported on a bracket 26 in a manner straddling the brake disc 16 .

[0040] exist Figure 1 、 Figure 2 and Figure 5 In the figure, the double-headed arrow C indicates the circumferential direction of the front wheel 14 and the brake disc 16. Furthermore, the arrow Cr indicates the rotational direction of the front wheel 14 and the brake disc 16. One end of the brake caliper 20 (the one end in the rotational direction Cr) is the disc entry side 28. The other end of the brake caliper 20 (the other end in the rotational direction Cr) is the disc exit side 30. The disc entry side 28 is the side (entry side) on which the brake disc 16 enters the brake caliper 20 when the two-wheeled vehicle 12 moves forward. That is, when the two-wheeled vehicle 12 moves forward, the front wheel 14 rotates, and the brake disc 16 enters the disc entry side 28. The disc exit side 30 is the side (exit side) on which the brake disc 16 exits the brake caliper 20 when the two-wheeled vehicle 12 moves forward. That is, when the two-wheeled vehicle 12 moves forward, the front wheel 14 rotates, and the brake disc 16 exits the disc exit side 30.

[0041] The brake caliper 20 is supported by the bracket 26 on the right rear side of the front wheel 14. The brake caliper 20 extends in a substantially vertical direction along the brake disc 16. Since the brake caliper 20 is located behind the front wheel 14, the lower side of the brake caliper 20 becomes the disc rotation-in side 28. In addition, the upper side of the brake caliper 20 becomes the disc rotation-out side 30. It should be noted that, for example, in the case where the brake caliper 20 is arranged on the right front side of the front wheel 14, the lower side of the brake caliper 20 becomes the disc rotation-out side 30. In addition, in this case, the upper side of the brake caliper 20 becomes the disc rotation-in side 28. In the following description, the brake caliper 20 is described as follows. Figure 1 、 Figure 2 and Figure 5 As shown in the configuration.

[0042] like Figures 1 to 7 As shown, the brake caliper 20 has a pair of action portions 32L, 32R, a bridge portion 34B and another bridge portion 34F. Figure 2 、 Figure 6 and Figure 7 As shown, the brake disc 16 is positioned on the centerline CL of the brake caliper 20. A pair of operating portions 32L and 32R are positioned on both sides of the brake disc 16. A bridge portion 34B connects the pair of operating portions 32L and 32R on the radially outer side of the brake disc 16. One bridge portion 34B connects the pair of operating portions 32L and 32R on the disc entry side 28. Another bridge portion 34F connects the pair of operating portions 32L and 32R on the radially outer side of the brake disc 16. Another bridge portion 34F connects the pair of operating portions 32L and 32R on the disc exit side 30.

[0043] The pair of operating portions 32L and 32R extend in a generally arcuate shape along the brake disc 16. Therefore, the brake disc 16 enters the gap 35 between the pair of operating portions 32L and 32R. The brake disc 16 rotates in the rotational direction Cr at a position intermediate in the left-right direction of the gap 35. It should be noted that the left-right direction of the gap 35 also corresponds to the axial direction of the brake disc 16, the axial direction of the front wheel 14, and the width direction of the two-wheeled vehicle 12. Furthermore, this intermediate position is located on the centerline CL of the brake caliper 20.

[0044] Insertion holes 36B and 36F are formed on the disk rotation inlet side 28 and the disk rotation outlet side 30 of the right action portion 32R, respectively. The right action portion 32R is fixed to the bracket 26 by two mounting bolts (not shown) inserted through the insertion holes 36B and 36F, respectively.

[0045] Each bridge portion 34B, 34F protrudes from the pair of action portions 32L, 32R toward the radially outer side of the brake disc 16. In addition, each bridge portion 34B, 34F connects the pair of action portions 32L, 32R. Figure 2 、 Figure 4 and Figures 5 to 7 As shown, an opening 40 opened rearward is formed by the pair of acting portions 32L, 32R and the two bridging portions 34B, 34F.

[0046] like Figure 2 、 Figure 3 and Figure 5As shown, the pair of action portions 32L and 32R are formed with rearwardly bulging protrusions 42L and 42R. These protrusions 42L and 42R are formed in the center (center in the circumferential direction C) of the pair of action portions 32L and 32R. In other words, these protrusions 42L and 42R are formed in the middle of the two bridge portions 34B and 34F. A hook pin 44 extending in the left-right direction penetrates these protrusions 42L and 42R.

[0047] like Figures 2 to 7 As shown, the disc brake device 10 further includes a plurality of pistons 46L, 46R and a pair of brake pads 48L, 48R. The plurality of pistons 46L, 46R and the pair of brake pads 48L, 48R are housed in the brake caliper 20. Specifically, the gap 35 between the pair of operating portions 32L, 32R forms a brake pad housing chamber 50. The pair of brake pads 48L, 48R are housed in the brake pad housing chamber 50. Furthermore, the plurality of pistons 46L, 46R are housed in the pair of operating portions 32L, 32R.

[0048] Specifically, two cylinder bores 52L are formed in the left-side action portion 32L. The two cylinder bores 52L extend in the left-right direction. Both cylinder bores 52L open toward the brake disc 16. One cylinder bore 52L is formed between the protrusion 42L and one bridge portion 34B. The other cylinder bore 52L is formed between the protrusion 42L and the other bridge portion 34F. In other words, the two cylinder bores 52L are formed on the front and rear sides (upper and lower sides) of the left-side action portion 32L, respectively. A piston 46L is housed in each cylinder bore 52L. A hydraulic chamber 54L is formed between each cylinder bore 52L and each piston 46L.

[0049] Similarly, two cylinder bores 52R are formed in the right-side action portion 32R. The two cylinder bores 52R extend in the left-right direction. Both cylinder bores 52R open toward the brake disc 16. One cylinder bore 52R is formed between the protrusion 42R and one bridge portion 34B. The other cylinder bore 52R is formed between the protrusion 42R and the other bridge portion 34F. In other words, the two cylinder bores 52R are formed on the front and rear sides (upper and lower sides) of the right-side action portion 32R, respectively. The two cylinder bores 52R are each formed to face the two cylinder bores 52L of the left-side action portion 32L. A piston 46R is housed in each cylinder bore 52R. A hydraulic chamber 54R is formed between each cylinder bore 52R and each piston 46R.

[0050] As described above, the brake caliper 20 is an opposed-piston, four-pot caliper. It should be noted that the pair of brake pads 48L and 48R brake the brake disc 16 due to the action of the pistons 46L and 46R. Therefore, the number of pistons 46L and 46R housed in the brake caliper 20 may be any number. Furthermore, piston seals 53L and 53R are disposed on the inner wall portions of the left and right action portions 32L and 32R, respectively. Each piston seal 53L and 53R maintains a fluid-tight seal with the brake fluid in the hydraulic chamber 54L and 54R by sliding in contact with the pistons 46L and 46R, respectively. Furthermore, dust rings 55L and 55R are disposed on the inner wall portions of the left and right action portions 32L and 32R, respectively. Each dust ring 55L and 55R is disposed in proximity to the brake pad housing chamber 50 relative to the piston seals 53L and 53R. The dust rings 55L and 55R can prevent dust such as abrasion powder generated by the brake pads 48L and 48R from entering the cylinder holes 52L and 52R by sliding in contact with the pistons 46L and 46R.

[0051] The brake pad accommodation chamber 50 is formed by the inner surfaces of the pair of operating portions 32L and 32R on the brake disc 16 side, the mutually opposing inner surfaces of the two bridge portions 34B and 34F, and the bottom 56 of the brake caliper 20 located radially inward of the brake disc 16. It should be noted that the mutually opposing inner surfaces of the two bridge portions 34B and 34F are side surfaces extending in the left-right direction and perpendicular to the circumferential direction C. The bottom 56 of the brake caliper 20 extends from the bottoms of the pair of operating portions 32L and 32R (the portions of the pair of operating portions 32L and 32R located radially inward of the brake disc 16) toward the brake disc 16.

[0052] Each pair of brake pads 48L, 48R includes a friction member 58L, 58R and a backing plate 60L, 60R. Each friction member 58L, 58R has a contact surface (the side facing the brake disc 16) that contacts the side of the brake disc 16. Each friction member 58L, 58R extends in an arcuate shape along the circumferential direction C. The contact surface of each friction member 58L, 58R slides in contact with the brake disc 16. Each backing plate 60L, 60R is attached to the back surface of the friction member 58L, 58R opposite the contact surface (the side facing away from the brake disc 16). Each backing plate 60L, 60R is a roughly arcuate metal plate. One surface of each backing plate 60L, 60R is bonded to the back surface of the friction member 58L, 58R. The other surface of each backing plate 60L, 60R faces the piston 46L, 46R.

[0053] The bottom surface (radially inner surface) of each back plate 60L, 60R contacts the bottom portion 56 of the brake caliper 20. Furthermore, the side surface of each back plate 60L, 60R on the disc entry side 28 can contact the inner surface of one bridge portion 34B. Furthermore, the side surface of each back plate 60L, 60R on the disc exit side 30 can contact the inner surface of the other bridge portion 34F.

[0054] A plurality of protrusions 62L, 62R, 64L, 64R, 66L, 66R, 68L, 68R are formed on each of the back plates 60L and 60R (see Figure 3 and Figure 5 ). A plurality of protrusions 62L, 62R, 64L, 64R, 66L, 66R, 68L, 68R are formed on the back surface (radially outer surface) of each back plate 60L, 60R. The plurality of protrusions 62L, 62R, 64L, 64R, 66L, 66R, 68L, 68R protrude toward the rear of the brake disc 16 (radially outer side of the brake disc 16). In addition, the plurality of protrusions 62L, 62R, 64L, 64R, 66L, 66R, 68L, 68R protrude toward the rear of each friction member 58L, 58R (radially outer side of the brake disc 16). As Figure 2 、 Figure 3 and Figures 5 to 7 As shown, a protrusion 70L, 70R is formed in the center portion (center portion in the circumferential direction C) of the back surface of each back plate 60L, 60R. Each protrusion 70L, 70R corresponds to the protrusion 42L, 42R of each action portion 32L, 32R. Furthermore, a hook pin 44 penetrates each protrusion 70L, 70R.

[0055] Specifically, each protrusion 62L, 62R is located at the end of each back plate 60L, 60R on the disc inlet side 28. Each protrusion 62L, 62R protrudes from the back surface of each back plate 60L, 60R toward the radially outer side of the brake disc 16. Each protrusion 62L, 62R can contact the inner surface of one bridge portion 34B.

[0056] Furthermore, each protrusion 64L, 64R is located at the end of each back plate 60L, 60R on the disc exit side 30. Each protrusion 64L, 64R protrudes from the back surface of each back plate 60L, 60R toward the radially outer side of the brake disc 16. Each protrusion 64L, 64R can contact the inner surface of the other bridge portion 34F.

[0057] Furthermore, each protrusion 66L, 66R is located on the disc entry side 28 (upstream in the circumferential direction C and the rotational direction Cr) relative to a protrusion 70L, 70R located in the center of each back plate 60L, 60R. Each protrusion 66L, 66R protrudes radially outward from the back surface of each back plate 60L, 60R. The amount of radial outward protrusion of each protrusion 66L, 66R toward the brake disc 16 is smaller than the amount of radial outward protrusion of each protrusion 70L, 70R toward the brake disc 16. Furthermore, the front end surface (radially outward rear surface) of each protrusion 66L, 66R is inclined toward the front end of the protrusion 70L, 70R.

[0058] Furthermore, each protrusion 68L, 68R is located on the disc exit side 30 (downstream in the circumferential direction C and the rotational direction Cr) relative to the protrusion 70L, 70R of each back plate 60L, 60R. Each protrusion 68L, 68R protrudes radially outward from the back surface of each back plate 60L, 60R. The amount of radial outward protrusion of each protrusion 68L, 68R toward the brake disc 16 is smaller than the amount of radial outward protrusion of each protrusion 70L, 70R toward the brake disc 16. Furthermore, the front end surface (radially outward rear surface) of each protrusion 68L, 68R is inclined toward the front end of the protrusion 70L, 70R.

[0059] In this manner, the pair of brake pads 48L and 48R are positioned in the circumferential direction C by the back plates 60L and 60R (protrusions 62L, 62R, 64L, and 64R) being in surface contact with the inner surfaces of the two bridge portions 34B and 34F. Furthermore, in the pair of brake pads 48L and 48R, the back plates 60L and 60R are in surface contact with the bottom portion 56 of the brake caliper 20. Furthermore, the back plates 60L and 60R are pivotally supported by the eye pins 44. Thus, the pair of brake pads 48L and 48R are positioned in the radial direction of the brake disc 16. In this manner, the pair of brake pads 48L and 48R are housed in the brake pad housing chamber 50.

[0060] like Figures 1 to 7 As shown, the brake caliper 20 further includes a retainer 72. The retainer 72 elastically applies force to the pair of brake pads 48L and 48R. The pair of brake pads 48L and 48R are retained on the bottom 56 of the brake caliper 20 by the force applied by the retainer 72. The retainer 72 is a leaf spring component extending in the circumferential direction C. The retainer 72 covers the gap 74 between the friction members 58L and 58R on the radially outer side of the brake disc 16. Here, the width of the retainer 72 in the left-right direction (the width in the direction perpendicular to the center line CL) is denoted as Wr. In the following description, the left-right width of each part of the retainer 72 may be described by a lowercase letter after Wr.

[0061] The retainer 72 has an arcuate portion 72a. The arcuate portion 72a is locked radially inward of the center portion of the lug pin 44. The following components are sequentially connected to the portion of the arcuate portion 72a on the disk rotation side 28. The arcuate portion 72a is connected to a contact portion 72b. The contact portion 72b is located on the disk rotation side 28 relative to the arcuate portion 72a. The contact portion 72b is a portion having a large width (width Wra) that is bent and contacts the protrusions 66L, 66R of each back plate 60L, 60R. The contact portion 72b is connected to a connecting portion 72c. The connecting portion 72c is located on the disk rotation side 28 relative to the contact portion 72b. The connecting portion 72c is formed into a flat plate shape. The width Wrh of the connecting portion 72c is substantially the same as the width of the arcuate portion 72a. The connecting portion 72c is connected to a rotation-side end portion 72d. The turning-in side end portion 72d is located on the disk turning-in side 28 relative to the connecting portion 72c. The width Wre of the turning-in side end portion 72d is narrower than the width Wrh of the connecting portion 72c. A recess 76 is formed in the center (the center in the left-right direction) of the inner surface of one bridge portion 34B. The turning-in side end portion 72d is engaged with the recess 76.

[0062] In addition, the following components are sequentially connected to the portion of the circular arc-shaped portion 72a on the disk-exiting side 30. A connecting portion 72e is connected to the circular arc-shaped portion 72a. The connecting portion 72e is located on the disk-exiting side 30 relative to the circular arc-shaped portion 72a. The connecting portion 72e is formed into a flat plate. The width of the connecting portion 72e is approximately the same as the width of the circular arc-shaped portion 72a. A contact portion 72f is connected to the connecting portion 72e. The contact portion 72f is located on the disk-exiting side 30 relative to the connecting portion 72e. The contact portion 72f is a wide portion that abuts against the protrusions 64L, 64R of each back plate 60L, 60R in a bent state. The contact portion 72f is the end portion of the retaining member 72 on the exit side.

[0063] The abutment portion 72b of the retainer 72 abuts against the protrusions 66L, 66R of the back plates 60L, 60R. Furthermore, the abutment portion 72f of the retainer 72 abuts against the protrusions 64L, 64R of the back plates 60L, 60R. This forces the pair of brake pads 48L, 48R radially inward of the brake disc 16. Furthermore, the pair of brake pads 48L, 48R are also forced toward the disc-outward side 30. As a result, even if some play exists between the pair of brake pads 48L, 48R and the brake caliper 20, the pair of brake pads 48L, 48R housed in the brake pad housing chamber 50 can be retained by the brake caliper 20.

[0064] When the driver of the two-wheeled vehicle 12 operates a brake lever (not shown) while the front wheel 14 is rotating in the rotation direction Cr, the pistons 46L and 46R move axially inward (toward the brake disc 16). As the pistons 46L and 46R move axially inward, they press against the back plates 60L and 60R that form the pair of brake pads 48L and 48R. Consequently, the friction members 58L and 58R connected to the back plates 60L and 60R are pressed against the brake disc 16. As a result, the brake disc 16 and the front wheel 14 are braked by the pair of brake pads 48L and 48R.

[0065] In this case, the pair of brake pads 48L and 48R slide along the circumferential direction C (rotational direction Cr) due to the rotational force of the brake disc 16. As a result, the protrusions 64R and 64L of the back plates 60R and 60L come into contact with the inner surface of the bridge portion 34F. Therefore, the inner surface of the bridge portion 34F functions as a surface that receives the torque acting on the pair of brake pads 48L and 48R.

[0066] The disc brake device 10 of the present embodiment has the following characteristic configuration regarding the structures of the holder 72 and the back plates 60L and 60R.

[0067] That is, Figure 3 、 Figure 5 and Figure 7 As shown, at least a portion of the retainer 72 is located at approximately the same height as the back plates 60L, 60R radially outward of the brake disc 16. Furthermore, at least a portion of the retainer 72 is positioned at approximately the same position as the back plates 60L, 60R in the circumferential direction C of the brake disc 16. Specifically, the turning-in end 72d (one end) of the retainer 72 is located radially outward of the brake disc 16 relative to the friction materials 58L, 58R. In other words, the turning-in end 72d protrudes radially outward of the brake disc 16 relative to the friction materials 58L, 58R. Furthermore, the protrusions 62L, 62R (one end) of the back plates 60L, 60R are located radially outward of the brake disc 16 relative to the friction materials 58L, 58R. In other words, the protrusions 62L, 62R protrude radially outward of the brake disc 16 relative to the friction materials 58L, 58R. Furthermore, the turning-in side end portion 72d (one end portion) of the retainer 72 and the protrusions 62L, 62R (one end portion) of each back plate 60L, 60R are located at substantially the same height in the vertical direction. Furthermore, the turning-in side end portion 72d of the retainer 72 and the protrusions 62L, 62R of each back plate 60L, 60R are located at substantially the same position in the circumferential direction C.

[0068] In addition, if Figures 2 to 4 、 Figure 6 and Figure 7As shown, the width Wr of the retainer 72 (the width Wr of the retainer 72 across the center line CL) becomes narrower as it moves from the abutment portion 72b toward the turning-in side end portion 72d. Specifically, as shown in FIG. Figure 4 As shown, the retainer 72 gradually narrows from the contact portion 72b toward the transition-side end 72d in the order of Wra (width of the contact portion 72b), Wrh (width of the connecting portion 72c), and Wre (width of the transition-side end 72d). Furthermore, the width Wre of the transition-side end 72d is substantially the same as the width Wg of the gap 74 in the left-right direction (the width Wg of the gap 74 as it straddles the centerline CL) between the friction members 58L and 58R (Wre ≈ Wg).

[0069] exist Figure 2 and Figure 4 In order to illustrate the gap 74, the figure shows a case where the width Wre of the turn-in end portion 72d is slightly narrower than the width Wg of the gap 74. In this embodiment, the widths Wre and Wg can be the same. Alternatively, the width Wre of the turn-in end portion 72d can be slightly wider than the width Wg of the gap 74. In other words, the width Wre of the turn-in end portion 72d can be such that foreign matter does not enter the gap 74.

[0070] In addition, if Figures 2 to 4 、 Figure 6 and Figure 7 As shown, the width Wrh of the connecting portion 72c is wider than the width Wg of the gap 74 between the friction members 58L and 58R and narrower than the interval Wb between the back plates 60L and 60R (Wrh>Wg, Wrh<Wb). In other words, a certain interval Wi exists between the back plates 60L and 60R and the connecting portion 72c.

[0071] Moreover, if Figure 3 and Figure 5 As shown, the contact portion 72b of the holder 72 is bent toward each of the back plates 60L, 60R and contacts each of the protrusions 66L, 66R. In addition, the connecting portion 72c is formed in a flat plate shape.

[0072] Furthermore, the turned-in side end portion 72 d of the holder 72 engages with a recessed portion 76 formed in the central portion of the inner surface of one bridge portion 34B.

[0073] The disc brake device 10 of this embodiment is summarized as follows.

[0074] A disc brake device (10) includes: a brake disc (16); a brake caliper (20) arranged to straddle the brake disc (16); a piston (46L, 46R) accommodated in the brake caliper (20); a pair of brake pads (48L, 48R) accommodated in the brake caliper (20) and clamping the brake disc (16) by the action of the pistons (46L, 46R); and a retainer (72) arranged in the brake caliper (20) and holding the pair of brake pads (48L, 48R) in the brake caliper (20) by contacting the pair of brake pads (48L, 48R). In the disc brake device (10), a pair of The above-mentioned brake pads (48L, 48R) each include: a friction member (58L, 58R) having a contact surface that contacts the side surface of the above-mentioned brake disc (16); and a back plate (60L, 60R), one surface of which is mounted on the back surface of the above-mentioned friction member (58L, 58R) on the opposite side of the contact surface, and the other surface is pressed against the above-mentioned piston (46L, 46R), at least a portion of the above-mentioned retaining member (72) is arranged at approximately the same height as each of the above-mentioned back plates (60L, 60R) relative to each of the above-mentioned friction members (58L, 58R) on the radial outside of the above-mentioned brake disc (16), and is arranged at approximately the same position on the circumferential direction (C) of the above-mentioned brake disc (16).

[0075] According to this structure, at least a portion of the retainer is provided at substantially the same height and position as the back plates, thereby making it difficult for foreign matter to enter between the pair of brake pads (the gap between the friction materials).

[0076] Alternatively, one end portion (72d) of the retaining member (72) in the circumferential direction (C) and one end portion (62L, 62R) of the back plate (60L, 60R) in the circumferential direction (C) are arranged at approximately the same height relative to each of the friction members (58L, 58R) on the radial outside of the brake disc (16), and are arranged at approximately the same position in the circumferential direction (C).

[0077] According to this structure, one end of the retainer and one end of each back plate are at approximately the same height radially outward from each friction member of the brake disc and are disposed at approximately the same position circumferentially of the brake disc. This prevents foreign matter from entering between the pair of brake pads.

[0078] It is also possible that the width (Wre) of one end portion (72d) of the retaining member (72) across the center line (CL) of the brake caliper (20) is approximately the same as the width (Wg) of the gap (74) between each of the friction members (58L, 58R) across the center line (CL).

[0079] According to this structure, the width of one end portion of the retainer is substantially the same as the width of the gap between the friction members. This allows the retainer to be miniaturized and lightweight as much as possible, while preventing foreign matter from entering the gap between the friction members.

[0080] The above-mentioned retaining member (72) has a contact portion (72b), which is arranged on the central part side of the above-mentioned brake caliper (20) in the above-mentioned circumferential direction (C) relative to one end portion (72d) of the above-mentioned retaining member (72), and contacts each of the above-mentioned back plates (60L, 60R). The width (Wr) of the above-mentioned retaining member (72) across the center line (CL) of the above-mentioned brake caliper (20) can be narrowed as it moves from the above-mentioned contact portion (72b) toward one end portion (72d) of the above-mentioned retaining member (72).

[0081] According to this structure, the width of the retaining member decreases as it moves from the abutment portion toward one end of the retaining member. This allows for a smaller and lighter retaining member, while reliably retaining the pair of brake pads to the brake caliper. Furthermore, the width of the abutment portion is wider than the width of one end of the retaining member. This reliably prevents foreign matter from entering the gaps between the friction members.

[0082] Alternatively, the retaining member (72) further includes a connecting portion (72c) connecting the contact portion (72b) to one end portion (72d) of the retaining member (72), and a width (Wrh) of the connecting portion (72c) across the center line (CL) is wider than a width (Wg) of the gap (74) between each of the friction members (58L, 58R) across the center line (CL).

[0083] According to this structure, the width of the connecting portion is wider than the width of the gap between the friction members, thereby reliably preventing foreign matter from entering the gap.

[0084] The width (Wrh) of the connecting portion (72c) straddling the center line (CL) may be narrower than the interval (Wb) between the back plates (60L, 60R).

[0085] According to this configuration, the width of the connection portion is narrower than the interval between the back plates, thereby avoiding interference between the holder and the back plates.

[0086] It may also be that each of the above-mentioned back plates (60L, 60R) has a protrusion (66L, 66R), which is arranged on the central part side in the above-mentioned circumferential direction (C) relative to one end portion (62L, 62R) of the above-mentioned back plate (60L, 60R), and protrudes radially outward of the above-mentioned brake disc (16) relative to the above-mentioned friction member (58L, 58R), the above-mentioned abutment portion (72b) has a shape that is bent toward each of the above-mentioned back plates (60L, 60R) and abuts against each of the above-mentioned protrusions (66L, 66R), and the above-mentioned connecting portion (72c) is flat.

[0087] With this structure, the abutment portion bends toward each back plate and abuts against the protrusion. This allows the brake pads to be held relative to the caliper in both the circumferential and radial directions of the brake disc, even if there is some play between the brake pads and the caliper. Furthermore, since the connecting portion is flat, it can be engraved on its surface to prevent incorrect assembly.

[0088] The retaining member (72) may be narrowed in sections as it moves from the abutting portion (72b) toward one end portion (72d) of the retaining member (72).

[0089] According to this structure, the retainer narrows in stages as it moves from the contact portion toward one end portion of the retainer.

[0090] Alternatively, one end portion (72d) of the retainer (72) may be engaged with a recess (76) provided in the brake caliper (20).

[0091] With this structure, one end of the retainer engages with the recess. Therefore, there's no need to widen the width of the retainer's one end to secure it to the retainer. This allows the retainer's one end to be narrow, preventing it from becoming too wide. As a result, the retainer can be further miniaturized and lightweight.

[0092] Alternatively, when the inlet side of the brake caliper (20) in the rotation direction (Cr) of the brake disc (16) is set as the disc entry side (28) and the outlet side in the rotation direction (Cr) is set as the disc exit side (30), one end portion (72d) of the retaining member (72) and one end portion (62L, 62R) of each of the back plates (60L, 60R) are respectively arranged on one side of the disc entry side (28) and the disc exit side (30).

[0093] According to this structure, one end portion of the holder and one end portion of each back plate are provided on either the disc entry side or the disc exit side, thereby making it possible to easily obtain the above-mentioned effects.

[0094] Alternatively, when one of the disc rotation-in side (28) and the disc rotation-out side (30) is the upper side of the disc brake device (10) and the other is the lower side of the disc brake device (10), one end portion (72d) of the retaining member (72) and one end portion (62L, 62R) of each of the back plates (60L, 60R) are respectively arranged on the lower side of the disc brake device (10).

[0095] According to this structure, one end of the retainer and one end of each back plate are respectively arranged on the lower side of the disc brake device. This effectively prevents foreign matter dropped from above during maintenance, etc. from entering the gaps between the friction members arranged on the lower side of the disc brake device.

[0096] Alternatively, the retaining member (72) is located radially outward of the brake disc (16) relative to each of the friction members (58L, 58R) and extends along the circumferential direction (C) in a manner covering a gap (74) formed between each of the friction members (58L, 58R), and one end portion (62L, 62R) of each of the back plates (60L, 60R) protrudes radially outward of the brake disc (16) relative to the friction members (58L, 58R).

[0097] According to this structure, the retainer extends circumferentially to cover the gaps between the friction members, and one end of each back plate protrudes radially outward from the friction member in the brake disc.

[0098] It should be noted that the present invention is not limited to the above-described embodiment, and various configurations can be realized without departing from the gist of the present invention.

Claims

1. A disc brake device (10), comprising: A brake disc (16); a brake caliper (20) arranged to straddle the brake disc (16); a piston (46L, 46R) accommodated in the brake caliper (20); a pair of brake pads (48L, 48R) accommodated in the brake caliper (20) and clamping the brake disc (16) through the action of the pistons (46L, 46R); and a retainer (72) arranged in the brake caliper (20) and holding the pair of brake pads (48L, 48R) in the brake caliper (20) by abutting against the pair of brake pads (48L, 48R). The disc brake device (10) is characterized in that: The pair of brake pads (48L, 48R) each comprises: a friction member (58L, 58R) having a contact surface that contacts the side surface of the brake disc (16); and a back plate (60L, 60R) having one surface mounted on the back surface of the friction member (58L, 58R) opposite to the contact surface and the other surface pressed against the piston (46L, 46R). The brake caliper (20) has a lug pin (44), which extends in the axial direction of the brake disc (16) at a middle portion relative to the circumferential direction (C) of the brake disc (16) and penetrates the brake pads (48L, 48R). The retaining member (72) comprises: an abutting portion (72b) which is locked to the hook pin (44) and extends in the circumferential direction (C) of the brake disc (16) and abuts against the back plate (60L, 60R); and a circumferential end portion (72d) which is one end portion (72d) in the circumferential direction (C) of the retaining member (72) and extends from the abutting portion (72b) and is locked to the radially outer side of the brake disc (16) in the inner surface of the brake caliper (20). One end portion (62L, 62R) of the back plate (60L, 60R) in the circumferential direction (C) protrudes radially outward of the back plate (60L, 60R). The circumferential position of the circumferential end portion (72d) is substantially the same as the circumferential position of one end portion (62L, 62R) of the back plate (60L, 60R). The radial position of the circumferential end portion (72d) of the brake disc (16) in the radial direction is substantially the same as the radial position of one end portion (62L, 62R) of the back plate (60L, 60R).

2. The disc brake device (10) according to claim 1, characterized in that The width (Wre) of the circumferential end portion (72d) across the center line (CL) of the brake caliper (20) is substantially the same as the width (Wg) of the gap (74) between each of the friction members (58L, 58R) across the center line (CL).

3. The disc brake device (10) according to claim 1 or 2, characterized in that The abutment portion (72b) is provided on the central portion side of the brake caliper (20) in the circumferential direction (C) relative to the circumferential end portion (72d), and abuts against each of the back plates (60L, 60R). A width (Wr) of the retainer (72) straddling a center line (CL) of the brake caliper (20) becomes narrower as it moves from the abutment portion (72b) toward the circumferential end portion (72d).

4. The disc brake device (10) according to claim 3, characterized in that The retainer (72) further includes a connecting portion (72c) connecting the contact portion (72b) and the circumferential end portion (72d). A width (Wrh) of the connecting portion (72c) straddling the center line (CL) is wider than a width (Wg) of the gap (74) between the friction members (58L, 58R) straddling the center line (CL).

5. The disc brake device (10) according to claim 4, characterized in that A width (Wrh) of the connecting portion (72c) straddling the center line (CL) is narrower than a distance (Wb) between the back plates (60L, 60R).

6. The disc brake device (10) according to claim 4, characterized in that Each of the back plates (60L, 60R) has a protrusion (66L, 66R), which is provided on the central portion side in the circumferential direction (C) relative to one end portion (62L, 62R) of the back plate (60L, 60R) and protrudes radially outward from the brake disc (16) relative to the friction member (58L, 58R). The contact portion (72b) has a shape that is bent toward each of the back plates (60L, 60R) and contacts each of the protrusions (66L, 66R). The connecting portion (72c) is in the shape of a flat plate.

7. The disc brake device (10) according to claim 3, characterized in that The retaining member (72) narrows in stages as it moves from the abutting portion (72b) toward the circumferential end portion (72d).

8. The disc brake device (10) according to claim 1 or 2, characterized in that The circumferential end portion (72d) engages with a recess (76) provided in the brake caliper (20).

9. The disc brake device (10) according to claim 1 or 2, characterized in that When the inlet side of the brake caliper (20) in the rotation direction (Cr) of the brake disc (16) is set as the disc entry side (28) and the outlet side in the rotation direction (Cr) is set as the disc exit side (30), and when one of the disc entry side (28) and the disc exit side (30) is the upper side of the disc brake device (10) and the other is the lower side of the disc brake device (10), the circumferential end portion (72d) and one end portion (62L, 62R) of each back plate (60L, 60R) are respectively arranged on the lower side of the disc brake device (10).

10. The disc brake device (10) according to claim 1 or 2, characterized in that The retaining member (72) is located radially outside the brake disc (16) relative to the friction members (58L, 58R) and extends along the circumferential direction (C) in a manner covering a gap (74) formed between the friction members (58L, 58R). One end portion (62L, 62R) of each of the back plates (60L, 60R) protrudes radially outward of the brake disc (16) relative to the friction member (58L, 58R).

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