disc brake

Abstract

Disc brake, with: a fastening component (2, 51) which is designed to be fixed to a non-rotating section of a vehicle and which is designed to extend over an outer circumferential side of a disk (1), a saddle (5) which is arranged on the fastening component (2, 51) such that it is movable in an axial direction of the disk (1), a pair of brake pads (6) which are movably provided on the mounting component (2, 51) and are designed to be pressed against both surfaces of the disc (1) by the caliper (5), a lining spring (11, 31, 61) which is provided on the fastening component (2, 51) and is arranged between the fastening component (2, 51) and the pair of brake linings (6), and a return spring (21, 41) which is arranged between the brake pad (6) and the fastening component (2, 51) and is designed to tension the brake pad (6) in a return direction to separate the brake pad (6) from the disc (1), and wherein the return spring (21, 41) has a proximal end section (22) and a distal end section (25), and the return spring (21, 41) is arranged such that the proximal end section (22) is fixed to a back plate (7) of the brake pad (6) and the distal end section (25) is in elastic contact with the side of the fastening component (2, 51) on an outer side in the disc radial direction relative to the proximal end section (22), characterized in that the lining spring (11, 31, 61) has a guide section (18, 32) which extends in the axial direction of the disk in a direction away from the disk (1) and, as it moves further away from the disk (1), is bent inwards in the disk radial direction, and wherein a part of the guide section (18, 32) is provided on a central side of the brake pad (6) in the disc circumferential direction at the intermediate section of the return spring (21, 41).

Description

Technical area

[0001] The present invention relates to a disc brake capable of applying braking force to a vehicle such as an automobile. State of the art

[0002] Generally, a disc brake mounted on a vehicle such as an automobile includes a fixing member fixed to a non-rotatable portion of the vehicle and formed to extend over the outer peripheral side of a disc, a caliper provided on the fixing member movable in an axial direction of the disc, a pair of brake pads movably installed on the fixing member and pressed against both surfaces of the disc by the caliper, and return springs provided between the brake pads and the fixing member for urging the brake pads in a return direction to separate the brake pads from the disc, and made of metallic plates (for example, refer to Japanese Patent Application Laid-Open No. 2010-169149).

[0003] When a braking operation is performed by a vehicle driver or the like, a piston provided in the caliper is slidably displaced toward the disc side by an external hydraulic supply, thereby pressing the brake pads against the disc, thereby applying braking force to the disc. Conversely, when the braking operation is released, the hydraulic pressure in the caliper is reduced such that the piston is displaced into the caliper, and the brake pads are returned to their return positions away from the disc by the return springs.

[0004] Furthermore, DE 102 38 734 A1 is known, which relates to a floating caliper disc brake for a motor vehicle, with a vehicle-fixed brake holder, on which brake pads arranged on both sides of an associated brake disc are slidably guided, with a floating caliper which overlaps the brake disc and the brake pads and is slidably mounted on the brake holder, and with at least one brake pad spring which is effective at least axially between the brake holder and the brake pad to adjust a clearance between the brake disc and the brake pad.

[0005] Furthermore, US 2004 / 0195057 A1 and DE 11 2010 003 825 T5 are known. Subject of the invention

[0006] According to the technique discussed in the above-described patent literature, Japanese Patent Application Publication No. JP 2010-169149, the return spring is configured such that a distal end side thereof is fixed to a back plate of the brake pad in elastic engagement with the fastening member side at an inner side in a disc radial direction relative to a proximal end side thereof. In this case, the return spring tends to position the brake pad at the return position in such a manner that an outer side of the brake pad is inclined toward the disc in the disc radial direction, which may easily cause a drag phenomenon to occur between this portion and the disc.

[0007] As a possible solution to this problem, a structure was considered that allows the distal end of the return spring to elastically abut against the fastening component side on the outer side of the disc radial direction relative to the proximal end fixed to the back plate of the brake pad. According to this structure, the distal end can be easily displaced from a desired abutment position depending on the abutment position of the distal end of the return spring. Therefore, manufacturing the disc brake may become laborious and complicated.

[0008] The present invention has been considered in view of the above-described problems with the conventional art, and an object of the present invention is to provide a disc brake that allows a distal end side of the return spring to be easily arranged in a desired position to thereby improve manufacturing efficiency.

[0009] To achieve the above-described object, the present invention provides a disc brake having the features of claims 1, 8 and 15.

[0010] According to the present invention, it is possible to improve the manufacturing efficiency of the disc brake. Short description of the drawings Fig. 1 is a plan view of a disc brake according to a first embodiment viewed from an outer side in a disc radial direction. Fig. 2 is a front view of the disc brake viewed from an outside. Fig. 3 is a rear view of the disc brake viewed from an inside. Fig. 4 is a side view of the disc brake viewed from a direction defined by the Fig. 3 is marked by arrows IV and IV. Fig. Figure 5 is an enlarged view of a section (V) shown in Fig. 2 is shown. Fig. Figure 6 is an enlarged view of a section (VI) shown in Fig. 3 is shown. Fig. 7 is a perspective view of the brake pads, pad springs and spring structures taken out of the disc brake, from an upper left side in Fig. 3 viewed (from above the inside). Fig. 8 is a perspective view of the inside brake pad and spring structure used by Fig. 7 was taken in the same direction as Fig. 7 considered. Fig. 9 is a rear view of the inside brake pad and spring structure viewed from the inside. Fig. 10 is a side view of the inside brake pad and the spring structure viewed from a direction defined by the Fig. 9 is marked with arrows XX. Fig. 11 is a perspective view of the spring structure used by Fig. 8, from the same direction as Fig. 8 considered. Fig. 12 is a perspective view of the pad spring on the right side in Fig. 7 (a trailing edge side) which is Fig. 7, from the same page as Fig. 7 considered. Fig. 13 is a perspective view of the pad spring on the left side in Fig. 7 (a leading edge side) which is Fig. 7, from the same direction as Fig. 7 considered. Fig. 14 is a front view of a pad spring according to a modification viewed from a disc rotation direction. Fig. 15 is a plane view of the pad spring according to the modification viewed from the outside in the disc radial direction. Fig. 16 is a perspective view of the pad spring according to the modification from the same direction as Fig. 13 considered. Fig. 17 is a perspective view of a spring structure according to a second embodiment from the same direction as Fig. 11 considered. Fig. 18 is a plan view of the spring structure shown in Fig. 17, viewed from above. Fig. 19 is a perspective view of the main parts of a disc brake according to a third embodiment, viewed from the outside. Fig. Fig. 20 is a front view of the main parts of the disc brake according to the third embodiment, taken from the same direction as Fig. 19 considered. Fig. 21 is a perspective view of a half section of the pad spring according to a fourth embodiment. Detailed description of the preferred embodiments

[0011] Hereinafter, disc brakes according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0012] Fig. 1 to 13 show a first embodiment. A disc 1 (referring to Fig. 2 and Fig. 3), which can rotate together with the vehicle wheel (not shown), rotates, for example, in a direction indicated by an arrow A (referring to Fig. 2 and Fig. 3) when the vehicle is moving forward and turns in a direction indicated by arrow B (referring to Fig. 2 and Fig. 3) marked direction when the vehicle is reversing.

[0013] A fixing member 2, referred to as a bracket, is fixed to a non-rotatable portion (not shown) of the vehicle and is formed to extend over an outer peripheral side of the disk 1. The fixing member 2 generally includes a pair of arm portions 2A and 2A, a bracket portion 2B, and a reinforcement beam 2C. The respective arm portions 2A and 2A are spaced apart from each other in a rotational direction of the disk 1 (the left-right direction in Fig. 2 and Fig. 3; in the present disclosure hereinafter referred to as a disk rotation direction, a disk tangential direction or a disk circumferential direction), and extend in an axial direction of the disk 1 (the front-back direction in Fig. 2 and Fig. 3; hereinafter referred to as a disk axial direction in the present disclosure) to extend over an outer periphery of the disk 1.

[0014] The support portion 2B is provided to integrally connect proximal end sides of the respective arm portions 2A to each other, and is fixed to the non-rotatable portion of the vehicle at a portion on an inner side of the windshield 1. The reinforcing beam 2C couples distal end sides of the respective arm portions 2A to each other at a position on an outer side of the windshield 1. As a result, the respective arm portions 2A of the fixing member 2 are integrally coupled to each other by the support portion 2B on the inner side of the windshield 1, and are integrally coupled to each other by the reinforcing beam 2C on the outer side of the windshield 1.

[0015] A disk path portion (not shown) extending in an arc along the outer periphery (a pivot point) of the disk 1 is formed at intermediate positions of the corresponding arm portions 2A of the fixing member 2 in the disk axial direction. Inner and outer guides 3 and 3 are provided on both sides of the disk path portion (both sides in the disk axial direction) in the fixing member 2, respectively.

[0016] In other words, the pad guides 3 and 3 are formed as support portions on the inner and outer sides of disk peripheral portions (both sides in the disk circumferential direction) of the mounting member 2, respectively. These respective pad guides 3 and 3 are formed such that cross-sectional surfaces of the pad guides 3 and 3, which are parallel to the disk 1, are formed into rectangular recessed grooves opened on mutually facing surfaces, and extend in a direction of sliding displacement of the brake pads 6, which will be described below, that is, in the disk axial direction.

[0017] The respective pad guides 3 serve to guide the brake pads 6 in the disc axial direction via ear portions 7B and 7C of the back plates 7 included in the brake pads 6. Therefore, the ear portions 7B and 7C of the brake pads 6 (the back plates 7) are fitted into the respective pad guides 3 (forming recess-projection fits therebetween) so as to be layered in a radial direction of the disc 1 (the vertical direction in Fig. 2 and Fig. 3; hereinafter referred to as a disk radial direction in the present disclosure).

[0018] Wall surfaces of the corresponding pad guides 3 on the bottom sides form torque-absorbing surfaces 4, referred to as torque-absorbing sections. The torque-absorbing surfaces 4 carry braking torques that the brake pads 6 absorb from the disc 1 when the brake is applied, via ear portions 7B and 7C of the brake pads 6 and the guide plate portions 15 of the pad springs 11, which are described below.

[0019] A saddle 5 is arranged on the fastening member 2 so as to be movable in the disk axial direction. The saddle 5 includes an inner leg portion 5A, a bridge portion 5B, and an outer leg portion 5C. The inner leg portion 5A is located on the inner side, which is one axial side of the disk 1. The bridge portion 5B extends from the inner leg portion 5A to the outer side, which is another axial side of the disk 1, to straddle the outer peripheral side of the disk 1 between the respective arm portions 2A of the fastening member 2. The outer leg portion 5C extends inward in the disk radial direction from an outer side of the bridge portion 5B, which corresponds to a distal end side of the bridge portion 5B, and has a two-forked distal end side as a claw portion.

[0020] For example, a single cylinder (not shown) serving as a single bore is formed at the inner root portion 5A of the caliper 5. A piston 5 (referring to Fig. 2) is slidably inserted into this cylinder. As shown in Fig. 1 and Fig. 3, a pair of fixing portions 5E and 5E projecting in the disc rotation direction are integrally formed on the inner leg portion 5A. These respective fixing portions 5E and 5E slidably support the entire saddle 5 on the respective arm portions 2A of the fixing member 2 via sliding pins (not shown).

[0021] The inner and outer brake pads 6 and 6 are arranged to face surfaces of the disc 1 on both sides in the disc axial direction. The respective brake pads 6 and 6 are installed on the mounting member 2 so as to be movable in the disc axial direction and are pressed against the two surfaces of the disc 1 by the caliper 5. As shown in Fig. As shown in Figures 7 to 10, each of the brake pads 6 and 6 generally includes the flat back plate 7 extending in the disc rotation direction, and a filler 8 fixed (fixed) to a disc-facing surface 7A as one of the surfaces of the back plate 7, and serving as a friction material in frictional contact with the surface of the disc 1 (a side surface in the axial direction). The back plate 7 may be made of a metal, plastic, and the like.

[0022] The back plate 7 of the brake pad 6 includes ear portions 7B and 7C as fitting portions, which protrude from side edges of both sides in the disc circumferential direction, respectively. These respective ear portions 7B and 7C are slidably fitted into the pad guides 3 of the mounting member 2 via the corresponding guide plate portions 15 of the pad springs 11, which will be described below, respectively. Then, the respective ear portions 7B and 7C serve as torque transmission portions capable of transmitting the braking torque, which the brake pad 6 receives from the disc 1 when the vehicle is braked, to the torque receiving surfaces 4 of the mounting member 2 (via the pad springs 11).

[0023] For example in Fig. 9, the ear portions 7B and 7C of the brake pad 6 (the back plate 7) are formed symmetrically on both sides and have identical shapes to each other. Fig. 8 to 10 show the inside brake pad 6. The ear section 7B, which is one (the left one in Fig. 9) of the ear sections is arranged at an input side (a front side edge) in the direction of rotation with respect to the disc 1, which rotates in the direction shown by the arrow A when the vehicle travels forward. The ear section 7C, which is the other (the right one in Fig. 9) of the ear portions is located on an output side (a trailing edge side) in the rotation direction with respect to the disk 1. A spring structure 20 including a return spring 21, which will be described below, is attached to the ear portion 7B, which is one of the ear portions 7B and 7C located on the leading edge side of the disk 1. In the present embodiment, the spring structure 20 is provided only on the leading edge side of the disk 1, and is not provided on the trailing edge side of the disk 1. However, the spring structure 20 may also be provided on the trailing edge side if necessary.

[0024] Projections 9 and 9 are provided on the back plate 7 of the brake pad 7 at positions near proximal end sides (base sides) of the ear portions 7B and 7C, respectively. These projections 9 are formed to protrude from a back surface 7D (a surface opposite to the disk-facing surface 7A attached to the filler 8, a back surface) of the back plate 7, and are formed in non-circular shapes (partially cut-out circles) in cross section. One of the projections 9, located on the front edge side of the disk 1, is used to position the spring structure 20, which will be described later, relative to the back plate 7. In other words, a pressing recess 22A of the spring structure 20 is engaged (compressedly coupled) with the one projection 9.

[0025] Step portions 10 and 10 are formed on surfaces 7E of the ear portions 7B and 7C of the back plate 7, which face the moment-receiving surfaces 4 of the pad guides 3, respectively. These step portions 10 and 10 are formed by partially cutting out the facing surfaces 7E, which are end surfaces of the ear portions 7B and 7C at distal end sides (protruding sides) thereof, in L-shapes. The respective step portions 10 are formed at radially outer positions relative to center positions (referring to a point Q in Fig. 9) of the ear portions 7B and 7C in width directions thereof (the vaginal radial direction).

[0026] One of the step portions 10, located on the leading edge side of the disk 1, provides a receiving space for receiving a part of a side pressure spring 26 formed integrally with the return spring 21, which will be described later. The side pressure spring 26 is arranged on this step portion 10 so as to extend in the disk axial direction. In this case, a part (projection portion 28B) of a vibration portion 28, which is a distal end of the side pressure spring 26, enters between the disk-facing surface 7A of the back plate 7 and the disk 1. In the present embodiment, the distal end of the side pressure spring 26 is also used as a function of detecting wear of the filler 8, whereby the distal end of the side pressure spring 26 extends between the disk-facing surface 7A and the disk 1.However, if the distal end of the side compression spring 26 is not used to detect the wear of the filler piece 8, it does not necessarily have to extend between the disc-facing surface 7A and the disc 1. .

[0027] Pad springs 11 and 11 are installed on the arm portions 2A of the mounting member 2, respectively. These respective pad springs 11 are arranged between the mounting member 2 and the inner and outer side brake pads 6. The pad springs 11 elastically support the respective brake pads 6 and dampen sliding displacements of these respective brake pads. In addition, one of the pad springs 11 regulates the positions of the side surfaces of the intermediate portions of the return springs 21, which will be described below, in the disc rotation direction. Each of the pad springs 11 is formed by bending (stamping) a metal plate material, such as a stainless steel plate, having a spring property.

[0028] As in Fig. 12 and Fig. 13, each of the pad springs 11 includes a connecting plate portion 12, flat plate portions 13, an engaging plate portion 14, guide plate portions 15, radially biasing plate portions 16, abutment plate portions 17, and guide plate portions 18, which will be described below. These portions are integrally formed. The connecting plate portion 12 is formed to extend in the disk axial direction while spanning the outer peripheral side of the disk 1 to integrally connect the corresponding guide plate portions 15, which will be described below, on the inner and outer sides of the disk 1. The pair of flat plate portions 13 and 13 are integrally formed on both end sides of the connecting plate portion 12 in a longitudinal direction thereof so as to extend inward in the disk radial direction.

[0029] The engagement plate portion 14 is located between the pair of flat plate portions 13 and 13 and is integrally formed with the connecting plate portion 12. The engagement plate portion 14 is attached to the fixing member 2 to engage with the pulley path portion of the arm portion 2A from the inside in the pulley radial direction. As a result, the pad spring 11 is positionally fixed relative to the arm portion 2A of the fixing member 2 in the axial direction of the pulley 1 and is prevented from displacing in the rotational direction of the pulley 1.

[0030] The pair of guide plate portions 15 and 15 are formed on both end sides of the connecting plate portion 12 via the corresponding flat plate portions 13. The corresponding guide plate portions 15 are formed by bending the flat plate portions 13 from inner end sides thereof in the disc radial direction to correspond to the shapes of the pad guides 3 (substantially U-shapes or substantially square U-shapes). One of the pair of guide plate portions 15 is attached by being fitted into the inner side pad guide 3. The other of the pair of guide plate portions 15 is attached by being fitted into the outer side pad guide 3. The corresponding guide plate portions 15 serve to guide the back plates 7 of the brake pads 6 in the disc axial direction via the projecting ear portions 7B and 7C.

[0031] The radially biasing plate portions 16 are formed integrally with the inner sides of the corresponding guide plate portions 15 in the disc radial direction. The corresponding radially biasing plate portions 16 extend in the disc axial direction from the inner sides of the guide plate portions 15 in the disc radial direction, and are arcuately rotated by approximately 360 degrees. Distal ends thereof extend to reach inner sides of the ear portions 7B and 7C in a disc radial direction to abut against the ear portions 7B and 7C of the corresponding brake pads 6 (the back plates 7). The corresponding radially biasing plate portions 16 are in elastic abutment with the ear portions 7B and 7C of the corresponding brake pads 6 (the back plates 7) in the corresponding pad guides 3 of the mounting member 2, and bias the back plates 7 of the corresponding brake pads 6 outward in the disc radial direction.As a result, the respective radially preloading plate portions 16 can prevent the respective brake pads 6 from rattling and can smoothly guide the brake pads 6 along the guide plate portions 15 in the disc axial direction when a braking operation is performed.

[0032] The abutment plate portions 17 of the abutment plates are provided on outer sides of the corresponding flat plate portions 13 in the disk axial direction, and are integrally formed to be bent from the corresponding flat plate portions 13 by approximately 90 degrees to extend in the disk rotation direction. The abutment plate portions 17 serve as receiving seat portions in abutment with distal end sides (abutment portions 25) of the return springs 21, which will be described later, in an elastically deformed state. In other words, the present embodiment is configured such that the return springs 21 are in abutment with the fastening member side via the abutment plate portions 17 serving as metallic abutment plates. In this case, the abutment plate portions 17 are configured to extend from the pad spring 11.Furthermore, the distal end guide portions 17A are formed on distal end sides of the abutment plate portions 17 by bending the abutment plate portions 17 obliquely or perpendicularly in corresponding directions away from the disc 1. The distal end guide portions 17A limit or prevent movements of the distal end sides of the return springs 21, particularly the abutment portions 25 of the return springs 21, in a direction away from the brake pads 6 in the disc rotation direction.

[0033] The guide plate portions 18 as guide portions are provided on both end sides of the connecting plate portion 12 in the longitudinal direction (or on outer sides of the corresponding flat plate portions 13 in the disk axial direction and outer sides of the abutment plate portions 17 in the disk radial direction). Each of the guide plate portions 18 extends from the connecting plate portion 12 (or each of the flat plate portions 13) in the direction away from the disk 1 in the disk axial direction and is formed in a substantially quarter-circular arc that curves inward in the disk radial direction as it moves farther away from the disk 1. The guide plate portions 18 support the side surfaces of the intermediate portions of the return springs 21, specifically, the side surfaces of the second extension portions 24 of the return springs 21.Therefore, the guide plate portions 18 extend in the disk axial direction on the same planes as the flat plate portions 13, and extend from the outer sides to the inner sides in the disk radial direction (while being curved) along portions where the flat plate portions 13 and the abutment plate portions 17 are connected to each other (portions where the flat plate portions 13 and the abutment plate portions 17 are bent from each other by approximately 90 degrees).

[0034] As a result, the guide plate portions 18 are configured to limit or prevent the movements of the distal end sides of the return springs 21, that is, the portions extending from the second extension portions 24 to the abutment portions 25 to the brake pads 6 in the disc rotation direction. In other words, the movements of the distal end sides of the return springs 21 away from the brake pads 6 in the disc rotation direction are limited or prevented by the distal end guide portions 17A of the abutment plate portions 17 of the pad springs 11, and the movements of the distal end sides of the return springs 21 toward the brake pads 6 are limited or prevented by the guide plate portions 18. As a result, the distal end sides of the return springs 21 can be placed in abutment with the desired positions (the abutment plate portions 17).

[0035] The present embodiment has been described based on the example in which the guide plate portions 18 are formed in circular arcs. However, the present invention is not limited to this. For example, each of the guide plate portions 18 may be configured to have an axially extending portion extending linearly from the connecting plate portion 12 (or each of the flat plate portions 13) in the disk axial direction, and a radially extending portion extending inward from a distal end of the axially extending portion in the disk radial direction, that is, formed into a substantially L-shaped configuration as a whole. In other words, the guide plate portions 18 may be formed to extend to support target portions of the side portions of the intermediate portions of the return springs 21.

[0036] Furthermore, the present embodiment is configured such that the abutment plate portions 17 and the guide plate portions 18 are provided on both the leading edge side and the trailing edge side pad springs 11. However, the present embodiment may be configured such that the abutment plate portions 17 and the guide plate portions 18 are provided on only the leading edge side pad spring 11 where the return springs 21 are installed. In other words, the abutment plate portions 17 and the guide plate portions 18 may be omitted from the trailing edge side pad spring 11 where the return springs 21 are not installed.However, it is preferable that the disc brake is constructed such that the pad spring 11 is provided with the abutment plate portions 17 and the guide plate portions 18 therein on both the leading edge side and the trailing edge side, as in the present embodiment, in order to use the same parts for the pad springs 11 on the leading edge side and the trailing edge side and to facilitate assembling.

[0037] Next, the return spring 21, which biases the brake pad 6 in a reverse direction to separate the brake pad 6 from the disc 1, will be described. The present embodiment is configured such that the side pressure spring 26 is provided on the return spring 21, and this return spring 21 and side pressure spring 26 are integrally formed with each other. The side pressure spring 26 according to the present embodiment serves to bias the brake pad 6 in the disc circumferential direction (the disc tangential direction), and also to inform the driver or the like that it is time to replace the brake pad 6 (the filler 8 has been worn to a wear limit).

[0038] In other words, the return spring 21 forms the spring structure 20 together with the side pressure spring 26. Then, the spring structure 20 is formed as a metallic, integrally formed spring component, which has a total of three functions, wherein the return spring 21 has a function of returning the brake pad 6 to a return position where the brake pad 6 is separated from the disc 1 (a return function), and the side pressure spring 26 has two functions, a function of pressing the brake pad 6 in the disc tangential direction (the disc rotation direction) (a side pressure function) and a function of warning the driver of the wear limit of the filler 8 (a wear detection function).The present embodiment has been described based on the example in which the spring structure is provided as a metallic, integrally formed spring component with all three functions, thereby reducing costs and improving installability. However, they may be provided separately. Furthermore, the side-pressing function and the wear detection function may be omitted.

[0039] The spring structure 20 is fixed to the side edge portion (the ear portion 7B) located on the disc front edge side when the vehicle travels forward, which is one with the corresponding side edge portions (the ear portions 7B and 7C) of the back plate 7 included in each of the inside and outside brake pads 6. The spring structure 20 includes the return spring 21 and the side pressure spring 26, which are integrally formed by bending a spring material formed from a metallic plate having a spring property, such as a stainless steel plate, using a metal stamping method or the like. The inside spring structure 20 and the outside spring structure 20 are identical in structure except for one difference: they are formed symmetrically (plane-symmetrically) around the disc 1.In the following description, the spring structure 20 is described mainly with regard to the inner side spring structure 20.

[0040] The return spring 21 included in the spring structure 20 is arranged between the brake pad 6 and the fastening member 2, specifically between the ear portion 7B on the disc leading edge side and the pad spring 11 arranged on the fastening member 2. The return spring 21 biases the brake pad 6 in the return direction to separate the brake pad 6 from the disc 1, and is formed by bending the metallic spring material together with the side pressure spring 26.

[0041] The return spring 21 is constructed such that a proximal end thereof is fixed to the back plate 7 of the brake pad 6, and the distal end thereof is in elastic contact with the fastening member 2 on the outer side in the disc radial direction relative to the proximal end thereof. Therefore, the return spring 21 includes a fixing portion 22, a first extension portion 23, a second extension portion 24, and an abutment portion 25.

[0042] The fixing portion 22, as a flat plate, is tightly crimped to the protrusion 9 of the ear portion 7B of the brake pad 6 (the back plate 7), thereby being positionally fixed while also being positioned in the rotational direction. Therefore, the non-circular crimping recess 22A is penetrated by a substantially central position of the fixing portion 22. The protrusion 9 of the ear portion 7B is fitted into this recess 22A. The present embodiment has been described based on the example in which the spring structure 20 is crimped. However, the present invention is not limited to this. The spring structure 20 can be fixed by clamping the ear portions 7B and 7C of the back plate 7 of the brake pad 6 to each other. The fixing method can be appropriately designed.

[0043] The first extension portion 23 is formed by bending the fixing portion 22 in an L-shaped manner as if the first extension portion 23 is aligned perpendicularly from the fixing portion 22, and a distal end side thereof extends in a direction perpendicularly separated from the surface of the disk 1. In other words, the proximal end side of the first extension portion 23 extends in the disk axial direction like the erected portion 23A, and a portion from an intermediate position to a distal end side of the first extension portion 23 extends obliquely relative to the disk axial direction, specifically obliquely to the moment-receiving surface 4 of the fixing member 2, thereby forming an inclined portion 23B.

[0044] The second extension portion 24 is bent at an acute angle or a right angle (approximately 45 to 90 degrees) from the distal end side of the first extension portion 23 outward in the disc radial direction to the abutment plate portion 17 of the pad spring 11, and extends outward in the disc radial direction to the abutment plate portion 17 of the pad spring 11. The abutment portion 25 is bent substantially perpendicularly (70 to 90 degrees) from a distal end side of the second extension portion 24 to the abutment plate portion 17 of the pad spring 11, and includes a folded portion 25A formed by folding a distal end side thereof in a U-shaped manner. The folded portion 25A is in elastic abutment with the abutment plate portion 17 of the pad spring 11.As a result, the return spring 21 is constructed such that the distal end side (the abutment portion 25) thereof is in elastic abutment with the fixing member side (the pad spring 11) on the outer side in the disk radial direction relative to the proximal end side (the fixing portion 22).

[0045] Specifically, the proximal end side of the first extension portion 23 of the return spring 21 is formed integrally with the fixing portion 22, and a direction of a plate thickness t (referring to Fig. 10) thereof is aligned in a Y-axis direction, which is Fig. 9 to 11 to substantially match the radial direction of the disk 1. In other words, assuming that an X-axis is an axis extending perpendicular to the Y-axis in the left-right direction, and a Z-axis is a direction perpendicular to both the X-axis and the Y-axis, the return spring 21 is formed such that the first extension portion 23 extends as if erected from the fixing portion 22 in the Z-axis direction, with its disk width direction matching the X-axis direction and the direction of the disk thickness t matching the Y-axis direction.

[0046] In this case, the X-axis direction corresponds essentially to the circumferential direction (more precisely, the left-right direction or the tangential direction) of the disc 1, which rotates in the direction indicated by arrow A or the direction indicated by arrow B in Fig. 2 and Fig. 3 marked direction.

[0047] The Y-axis direction substantially corresponds to the radial direction of the disk 1. The Z-axis direction corresponds to the axial direction of the disk 1. Then, the fixing portion 22 of the return spring 21 is arranged in parallel with a plane defined by the X-axis and Y-axis, and a plate thickness direction thereof is aligned in the Z-axis direction.

[0048] The first extension portion 23 includes the inclined portion 23B on the distal end side from the intermediate position thereof, which extends obliquely relative to the erected portion 23A on the proximal end side. As a result, the proximal end side of the return spring 21 (the portion where the fixing portion 22 and the erected portion 23A are connected to each other) is offset (displaced) from the distal end side (the abutment portion 25) in the tangential direction of the disk 1 (the X-axis direction), thereby preventing it from interfering with the side pressing spring 26 described below and adjusting a spring force of the return spring 21.

[0049] Furthermore, the second extension portion 24 is bent from the distal end of the first extension portion 23 in the Y-axis direction at a right angle or an acute angle (in a direction partially having a Z-axis direction component) and is formed to extend toward the abutment plate portion 17 of the pad spring 11. As a result, the second extension portion 24 is formed to extend outside the side compression spring 26 in the disk axial direction, thereby preventing it from interfering with the second compression spring 26. Further, the abutment portion 25 is bent from the distal end of the second extension portion 24 in a substantially L-shaped configuration in the Z-axis direction.The folded portion 25A formed by folding the distal end side of the abutment portion 25 in a U-shaped manner is in elastic abutment with the abutment plate portion 17 of the pad spring 11 with a line contact established therebetween.

[0050] Due to this structure, the return spring 21 constantly biases the brake pad 6 (the back plate 7) in a return direction for separating the brake pad 6 from the disc 1, and can therefore constantly return the brake pad 6 to the return position (an initial position or standby position), for example, when the brake operation of the vehicle is released. In this case, the abutment portion 25 on the distal end side of the return spring 21 is in elastic abutment with the abutment plate portion 17 of the pad spring 11, which corresponds to the fastening member side, outside the fixing portion 22 on the proximal end side of the return spring 21 in the sheath radial direction. As a result, the brake pad 6 may tend to such a position at the return position that the radially outer side thereof is inclined further away from the disc 1 than the radially inner side thereof, ie, the brake pad 6 is open outwards (upwards).The return spring 21 does not necessarily have to exert a preload force strong enough to reach the outwardly (upwardly) open position, as long as the brake pad 6 is prevented from tending to an inwardly open position (downwardly) in the previously described return position.

[0051] In particular, as in Fig. 10, a load F is applied to the contact portion 25 of the return spring 21 in the disc axial direction due to the contact with the contact plate portion 17 of the pad spring 11. In Fig. In FIG. 10, a solid line indicates a free state in which the return spring 21 is outside the abutment and the abutment plate portion 17 (before assembly) (a state in which the return spring 21 is not elastically deformed), and a two-dashed line indicates a state in which the return spring 21 is elastically deformed in abutment with the abutment plate portion 17 (after assembly). A moment M is applied to the brake pad 6 around the center of gravity P where the ear portion 7B of the brake pad 6 and the fixing portion 22 are coupled to each other (a fixing portion) based on a component force F' of the load F. This moment M is a force for placing the brake pad 6 in such a posture that the radially outer side thereof is inclined farther away from the disc 1 than the radially inner side thereof.As a result, the radially outer side of the brake pad 6 tends to separate from the disc 1, whereby drag between this portion and the disc 1 can be reduced. In . Fig. 10, Q denotes a radial center position of the ear portion 7B (a center of a slidably guided portion). Furthermore, assuming that K represents a radial dimension of the filler piece 8 and L represents a distance dimension between the center of gravity P and the abutment portion 25, K is greater than L (K>L), so that the center of gravity P is included in the dimension K.

[0052] The present embodiment has been described based on the example in which the return spring 21 is disposed only on the leading edge side. The reason for this is as follows. Disc brakes tend to pull the leading edge side inward, and therefore the trailing edge side is more open than the leading edge side. Therefore, according to the conventional technique, the radially inner side of the leading edge side tends to be worn the most, resulting in the occurrence of uneven wear of the filler piece 8. Therefore, the present embodiment includes the return spring 21 only on the leading edge side, thereby solving the previously described problem of uneven wear.For example, if the disc brake has a double-bore structure with two cylinders and two pistons, and the leading edge side and the trailing edge side have similar wear tendencies, by increasing the diameter of the piston on the trailing edge side compared to the piston on the leading edge side, the return spring 21 can be provided on both the leading edge side and the trailing edge side.

[0053] In any case, according to the present embodiment, the side surface of the second extension portion 24 corresponding to the side surface of the intermediate portion of the return spring 21 is disposed close to the guide plate portion 18 of the pad spring 11 while facing it, and the spring structure 20 (the return spring 21) is installed on the fixing member 2 together with the brake pad 6. In other words, when the return spring 21 is installed on the fixing member 2 together with the brake pad 6, the side surface of the second extension portion 24 is supported (guided) by the guide plate portion 18, which limits or prevents the movements of the second extension portion 24 and the abutment portion 25 with the brake pad 6 in the disc rotation direction.As a result, after the installation is completed, the abutment position of the abutment portion 25 of the return spring 21 is adjusted to be located at the abutment plate portion 17 of the pad spring 11. Furthermore, for example, even if the distal end side of the return spring 21 is displaced from the abutment plate portion 17 due to the application of an external force to the return spring 21 from an impact or the like of a flying stone or the like when the vehicle is running on an unpaved road or the like, this displacement can also be prevented because the side surface of the intermediate portion (the side surface of the second extension portion 24) of the return spring 21 is supported by the guide plate portion 18 of the pad spring 11.

[0054] Next, the side pressure spring 26, which is formed integrally with the return spring 21, will be described.

[0055] The side pressure spring 26 forms the spring structure 20 together with the return spring 21. The side pressure spring 26 is arranged between the ear portion 7B, which is located on the disc front edge side when the vehicle travels forward, and the moment-receiving surface 4 of the fastening member 2, which faces this ear portion 7B. The side pressure spring 26 has the pressing function, such as a circumferentially biasing portion, which biases the pad guide 3 to press the brake pad 6 toward the rear edge side of the disc 1 in the disc circumferential direction. Furthermore, in addition to this, the side pressure spring 26 also has the function of warning the driver or the like that the filler 8 has reached the wear limit by generating a sound when the distal end of the side pressure spring 26, which is arranged between the back plate 7 of the brake pad 6 and the disc 1, i.e., the vibrating portion 28 (the distal end portion 28A thereof), is in contact with the disk 1.

[0056] The side pressing spring 26 generally includes the fixing portion 22 shared with the return spring 21, a pressing portion 27, and the vibration portion 28. The fixing portion 22, the pressing portion 27, and the vibration portion 28 are integrally formed. The pressing portion 27 is formed by bending the plate of the fixing portion 22 to define a U-shape in cross section on the rear surface side of the back plate 7. The pressing portion 27 includes a bent portion 27A, a folded portion 27B, and an abutment portion 27C.

[0057] The bending piece portion 27A is formed by bending the plate in an L-shape so as to be erected perpendicularly from the fixing portion 22 at a position separated from the first extension portion 23 of the return spring 21 in the X- and Y-axis directions. A distal end side of the bending piece portion 27A extends perpendicularly away from the surface of the disk 1 in the Z-axis direction. In other words, the bending piece portion 27A is arranged in a positional relationship substantially perpendicular to the first extension portion 23 and extends substantially parallel with a plane defined by the Y-axis and the Z-axis.

[0058] The folded portion 27B is formed by folding the distal end side of the bent portion 27A in a substantially U-shaped manner and extends conversely in the Z-axis direction. The abutment portion 27C is connected to a distal end side of the folded portion 27B and extends from this distal end side toward the disk-facing surface 7A of the back plate 7 toward the disk 1.

[0059] The abutment portion 27C includes a tapered portion 27C1 with a width dimension that decreases toward the disk 1, and a constant width portion 27C2 that extends toward the disk 1 without changing the width dimension (constant). Furthermore, the abutment portion 27C includes a projection portion 27C3 that extends beyond the tapered portion 27C1 to the constant width portion 27C2.

[0060] The abutment portion 27C (the projection portion 27C3) is in abutment (elastic contact) with the moment-absorbing surface 4 of the fastening member 2 via the guide plate portion 15 of the pad spring 11 while being elastically deformed. The abutment portion 27C is in elastic contact with the moment-absorbing surface 4 via the pad spring 11, through which the pressing portion 27 of the side pressing spring 26 preloads the brake pad 6 in the disc tangential direction, particularly toward the rear edge side of the disc 1.

[0061] The vibration portion 28 included in the side pressing spring 26 extends from a distal end side of the pressing portion 27 (the abutment portion 27C) to the disc 1. The vibration portion 28 generates a noise (an abnormal noise) due to vibration of the distal end 28A thereof from contact with the side surface (the face) of the disc 1 in the disc axial direction when the filler 8 of the brake pad 6 has been worn to reach a certain portion (wear limit) set in advance.

[0062] In particular, as in Fig. As shown in Figure 10, when the disc-facing surface 7A of the back plate 7 is displaced closer to the disc 1 due to wear of the filler 8 during vehicle braking, the distal end 28A of the vibration portion 28 contacts the side surface of the disc 1, causing it to vibrate and generate a noise. As a result, a warning or the like can be issued to the driver indicating that it is time to replace the brake pad 6 (the filler 8 has been worn to the wear limit). Fig. 10, a solid line indicates the side pressure spring 26 in a free state before the brake pad 6 and the spring structure 20 are installed on the fastening member 2 (without the spring structure 20 being elastically deformed), and a dash-two-dash line indicates the side pressure spring 26 with the spring structure 20 being elastically deformed after installation.

[0063] As in Fig. 10, the vibrating portion 28 is formed such that a dimension W1 of the distal end 28A of the vibrating portion 28 in the disk radial direction is larger than a dimension W2 of the constant width portion 27C2 in the disk radial direction, which is the portion of the side pressing spring 26 that biases the pad guide 3, that is, the portion of the abutment portion 27C of the pressing portion 27 that overlaps with the ear portion 7B in the disk circumferential direction. Therefore, a protrusion portion 28B that protrudes inward in the disk radial direction is formed at the distal end 28A of the vibrating portion 28. As a result, the vibrating portion 28 is formed such that a part (the protrusion portion 28B) of the vibrating portion 28 can enter between the disk-facing surface 7A of the back plate 7 and the disk 1.

[0064] When the filler 8 has been worn to reach the wear limit, the distal end 28A of the vibrating portion 28 contacts the side surface of the disk 1. At this time, the vibrating portion 28 is oriented such that a plate thickness direction thereof matches the X-axis direction (approximately the circumferential direction of the disk 1). Therefore, for example, when the vibrating portion 28 contacts the disk 1, the direction indicated by arrow A or the direction indicated by arrow B in Fig. 3 rotates, the vibration section 28 naturally deforms elastically in the same direction.

[0065] Furthermore, the distal end 28A of the vibrating portion 28 has a large dimension W1 in the disk radial direction, allowing the distal end 28A to contact the disk 1 with a wide area, thereby reliably generating the warning sound, increasing the volume of the sound, and the like. Furthermore, when the distal end 28A of the vibrating portion 28 contacts the side surface of the disk 1, a part (the protrusion portion 28B) of the distal end 28A is sandwiched between the disk-facing surface 7A of the back plate 7 and the side surface of the disk 1. As a result, the distal end 28A of the vibrating portion 28 is pressed against the side surface of the disk 1, which also contributes to reliably generating the warning sound, increasing the volume of the sound, and the like.

[0066] The disc brake according to the present embodiment is constructed as described above, and an operation thereof will be described below.

[0067] First, when the braking operation is performed on the vehicle, brake hydraulic pressure is supplied to the inner leg portion 5A (the cylinder) of the caliper 5, whereby a piston 5D is slidably displaced toward the disc 1. As a result, the inside brake pad 6 is pressed against one side surface of the disc 1. Then, at this time, after the caliper 5 receives a pressure reaction force from the disc 1, the entire caliper 5 is slidably displaced to the inside relative to the arm portions 2A of the fixing member 2, whereby the outside leg portion 5C presses the outside brake pad 6 against the other side surface of the disc 1.

[0068] As a result, the inside and outside brake pads 6 can forcefully clamp the disc 1, for example, in the position indicated by the arrow A in Fig. 2 and Fig. 3 (when the vehicle is traveling forward) between both axial sides, thereby successfully providing braking force to the brake 1. Then, when the brake application is released, a stop of the hydraulic supply to the piston 5D separates the inside and outside brake pads 6 from the disc 1, thereby returning the vehicle to a non-braked state. At this time, the inside and outside brake pads 6 are stably returned by the return springs 21 to the return positions (the initial positions or standby positions) separated from the disc 1.

[0069] When the brake operation is performed or released in this way (when the vehicle is not braked), the ear portions 7B, which are those of the ear portions 7B and 7C of the brake pads 6 located on the front edge side of the disc 1, are urged by the urging portions 27 of the side urging springs 26 in a direction indicated by the arrow C in Fig. 2 and Fig. 3, and the brake pads 6 are constantly tensioned by weak forces towards the rear edge side of the disc 1 (in the direction indicated by arrow A in Fig. 2 and Fig. 3). Then, the ear portions 7C located on the trailing edge side of the disc 1 are pressed against the moment-absorbing surfaces 4 of the pad guides 3 by the preload forces at this time via the guide plate portions 15 of the pad spring 11.

[0070] Therefore, when the vehicle is traveling, the brake pads 6 can be prevented from rattling in the disc circumferential direction due to vibration and the like by the side pressure springs 26 arranged between the ear portions 7B and the torque-receiving surfaces 4 of the leading edge side of the disc 1. Then, when the vehicle is braked while traveling forward, the braking torques that the brake pads 6 receive from the disc 1 (torques in the direction indicated by arrow A) can be absorbed by the arm portion 2A (the torque-receiving surfaces 4 of the pad guides 3) on the trailing edge side.

[0071] As a result, the ear portions 7C of the brake pads 6 located on the trailing edge side of the disc 1 continue to abut against the torque-receiving surfaces 4 of the path guides 3 via the guide plate portions 15. Further, before the braking operation is performed, the ear portions 7C of the trailing edge side are in contact with the guide plate portions 15 due to the biasing forces of the pressing portions 27 of the side pressing springs 26, without creating a clearance (space) therebetween. Therefore, the brake pads 6 can be prevented from displacing to generate an abnormal noise (a rattling noise) due to the braking torque.

[0072] According to the conventional technique, the return spring is configured such that the distal end side of the return spring is in elastic engagement with the fixing member side on the inner side of the disc radial direction relative to the proximal end side of the return spring fixed to the back plate of the brake pad. According to this configuration, the posture of the brake pad may tend to open inward (downward) at the return position in response to the biasing force of the return spring. That is, the outer side of the brake pad in the disc radial direction may tend to tilt toward the disc, resulting in a slight occurrence of drag between this portion and the disc.

[0073] In other words, according to the conventional technique, the return spring is configured such that the distal end side of the return spring returns the brake pad to the return position by urging a positional offset inward in the disc radial direction from a center of gravity of the brake pad and the center of the slidably guided portion for axially guiding the brake pad in the disc radial direction. Therefore, the brake pad tends to assume a posture at the return position such that the outer side in the disc radial direction is inclined toward the disc. As a result, when dragging occurs, an effective radius of this drag increases, leading to a possible failure to sufficiently obtain a drag reduction effect by the return spring when the disc tends to be inclined toward the outer side due to, for example, thermal gradient.

[0074] Furthermore, according to the conventional technique, the return spring is configured to extend in the disc tangential direction, which leads to a possible increase in the size of the return spring, including the receiving portion on the fastening member side for receiving the return spring. Furthermore, when the brake pad with the return spring attached thereto is installed on the fastening member, the installation process may become cumbersome. In particular, when the ear portion of the brake pad and the return spring attached thereto are to be inserted into the pad guide of the fastening member, the distal end side of the return spring easily clamps the receiving surface side of the fastening member before the ear portion of the brake pad is inserted into the pad guide according to the extension of the distal end side of the return spring in the disc tangential direction. As a result, the installation process may become cumbersome.

[0075] On the other hand, according to the present embodiment, the return spring is configured such that the abutment portion 25 on the distal end side of the return spring 21 is in elastic abutment with the fastening member side (the abutment plate portion 17 of the pad spring 11) on the outer side in the disk radial direction relative to the fixing portion 22 on the proximal end side fixed to the back plate 7 of the brake pad 6. Therefore, the braking torque M is applied to the ear portion 7B of the back plate of the brake pad 6, with the fixing portion 22 of the return spring 21 fixed thereto in the direction of separating the outer side of the brake pad 6 in the disk radial direction of the disk 1, based on the abutment between the abutment portion 25 and the fastening member side made on the outer side in the disk radial direction relative to the fixing portion 22.

[0076] In particular, as in Fig. 10, the load F is applied to the abutment portion 25 of the return spring 21 in the disc axial direction due to the abutment with the abutment plate portion 17 of the pad spring 11. As a result, the moment M is applied to the brake pad 6 around the center of gravity P where the ear portion 7B of the brake pad 6 and the fixing portion 22 are connected to each other (the fixing portion) based on the component force F' of the load F. This moment M serves as a force for placing the brake pad 6 in such a posture that the outer side thereof in the radial direction is inclined farther away from the disc 1 than the inner side thereof in the radial direction.

[0077] As a result, the brake pad 6 tends to assume such a posture at the return position that the outer side thereof in the disk radial direction is inclined farther away from the disk 1 than the inner side thereof in the disk radial direction, thereby making it possible to reduce drag between the outer side of the brake pad 6 in the disk radial direction and the disk 1. Furthermore, according to this, it is also possible to prevent the filler 8 of the brake pad 6 from being worn unevenly, thereby ensuring the stability and reliability of the braking action.

[0078] Furthermore, the guide plate portions 18 are formed on the pad spring 11. Each of the guide plate portions 18 extends in the disc axial direction and supports the side surface of the intermediate portion of the return spring 21, that is, the side surface of the second extension portion 24. Therefore, the abutment position of the abutment portion 25 of the return spring 21 can be regulated to be located on the abutment plate portion 17 by the guide plate portion 18. Therefore, when the disc brake is assembled, the guide plate portion 18 can prevent the abutment portion 25 of the return spring 21 from being displaced from the abutment plate portion 17 (prevent the return spring 21 from being incompletely installed).Even if the abutment portion 25 of the return spring 21 tends to be offset from the abutment plate portion 17 due to the application of an external force to the return spring 21 or the like, the second extension portion 24 of the return spring 21 is further supported by the guide plate portion 18, thereby successfully preventing this offset. For example, if a flying stone or the like strikes the return spring 21 when the vehicle is traveling on an unpaved road or the like, the second extension portion 24 of the return spring 21 abuts against the guide plate portion 18, thereby successfully preventing the return spring 21 from being deformed more than this (positional offset of the abutment portion 25).

[0079] Furthermore, the abutment portion 25 of the return spring 21 can be adjusted to abut against a desired abutment position, making it possible to reduce (downsize) the sizes of the abutment portion 25 and the abutment plate portion 17 of the pad spring 11. As a result, it is possible to improve the shape flexibility of the return spring and the design flexibility of the pad spring 11. Even if, due to a size reduction of the disc brake, for example, only a narrow available gap (space) is created between the mounting member 2 and the caliper 5, the return spring 21 can be installed in this narrow gap.

[0080] According to the first embodiment, the guide plate portion 18 is formed in a flat plate shape. However, like the Fig. 14 to 16 as a modification, a bent portion 32A may be formed at a position of a guide plate portion 32 away from the disk 1 in the disk axial direction.

[0081] This bent portion 32A extends by being bent from the position of the guide plate portion 32 away from the disc 1 in the disc axial direction to an opposite side from the direction in which the guide plate portion 15 protrudes. In this way, the bent portion 32A is formed on the guide plate portion 32, through which the bent portion 32A guides the return spring 21 when the brake pad 6 is installed, thereby making it possible to further improve installability over the structure of the guide plate portion 18 according to the first embodiment.

[0082] According to the first embodiment and the modification, the return spring 21 is configured such that the distal end side of the return spring 21 returns the brake pad 6 to the return position by pressing the outer side in the disc radial direction relative to the pad guide 3. Therefore, the abutment plate portion 17 of the pad spring 11, which serves as the seat portion for receiving the distal end side of the return spring 21, may be formed on the outer side in the disc radial direction relative to the guide plate portion 15 of the pad spring 11.As a result, compared with the conventional technique, it is possible to prevent the pad spring 11 from being deformed, particularly to prevent the guide plate portion 15 from deforming due to the reaction force of the return spring 21, and therefore it is possible to prevent the sliding property of the brake pad 6 from deteriorating and to prevent low-pressure brake noise from increasing, which might otherwise occur due to deformation of the pad spring 11.

[0083] Furthermore, compared with the conventional technique, it is possible to reduce the size (length) of the abutment plate portion 17 serving as the seat portion for receiving the distal end side of the return spring 21. As a result, it is possible to reduce the size of the pad spring 11 (downsize the pad spring 11), thereby improving the yield strength of the pad spring 11.

[0084] According to the first embodiment and the modification, the return spring 21 is configured such that the distal end side thereof extends outward in the disk radial direction relative to the proximal end side. Therefore, when the brake pad 6 with the return spring 21 attached thereto is installed on the fixing member 2, that is, when the ear portions 7B and 7C of the brake pad 6 with the return spring 21 attached thereto are inserted into the pad guides 3 of the fixing member 2, while the outer side of the brake pad 6 is inclined farther away from the disk 1 in the disk radial direction than the inner side of the brake pad 6 in the disk radial direction, it is possible to increase a clearance (interference) between the distal end (the abutment portion 25) of the return spring 21 and the fixing member side (the abutment plate portion 17 of the pad spring 11).Therefore, it is possible to place the distal end (the abutment portion 25) of the return spring 21 in abutment with the fixing member side (the abutment plate portion 17 of the pad spring 11) after the ear portions 7B and 7C of the brake pad 6 are inserted into the pad guides 3 of the fixing member 2. As a result, it is possible to facilitate the installation process of the brake pad 6 with the return spring 21 attached thereto, improve installability, and increase the manufacturing efficiency of the disc brake. In this case, the second extension portion 24 of the return spring 21 is supported by the guide plate portion 18, by which the abutment position of the abutment portion 25 of the return spring 21 can be regulated to be located at the abutment plate portion 17 of the pad spring 11.

[0085] According to the first embodiment and the modification, the return spring 21 is formed such that the distal end side extends outward in the disk radial direction relative to the proximal end side. Therefore, it is possible to reduce (compact) the dimension in the disk tangential direction, compared with the structure in which the distal end side of the return spring extends from a proximal end side in the disk tangential direction. As a result, it is possible to prevent the moment receiving portion (the guide plate portion 15) of the pad spring 11 from being deformed because the distal end side of the return spring 21 clamps with the fixing member 2 and the pad spring 11 when the brake pad 6 with the return spring 21 attached thereto is installed on the fixing member 2.

[0086] According to the first embodiment and the modification, as shown in Fig. 12 to 16, a protrusion portion 15A1 is formed on the abutment plate 15A of the guide plate portion 15 of the pad spring 11 at a position outward in the disc axial direction (a position away from the disc). The abutment plate 15A corresponds to the portion sandwiched between a facing surface 7E of the ear portion 7B or 7C of the brake pad 6 and the torque-absorbing surface 4 of the fastening member 2. In this case, the protrusion portion 15A1 protrudes outward in the disc radial direction by a dimension T1, as shown in Fig. 13 and Fig. 14 shown.

[0087] If the brake pad 6 with the spring structure 20 attached thereto, as shown in Fig. 8, is installed on the fixing member 2 with the pad spring 11 attached thereto, the distal end side of the side pressing spring 26, that is, the vibration portion 28 or the abutment portion 27C of the pressing portion 27 is placed in abutment with the abutment plate 15A of the guide plate portion 15. At this time, the distal end side of the side pressing spring 26 is in abutment with the abutment plate 15A having the protrusion portion 15A1. Therefore, the distal end side of the side pressing spring 26 can be in abutment with the abutment plate 15A with a wider area when the brake pad 6 is installed according to the provision of the protrusion portion 15A1, whereby it is possible to improve the installability of the brake pad 6.

[0088] According to the first embodiment and the modification, each of the guide plate portions 18 and 32 of the pad spring 11 has an increased (large) width dimension across the proximal end side thereof to the curved portion (the bent portion). In particular, as shown in Fig. 13 and Fig. 14, a width dimension T2 of the proximal end side of each of the guide plate portions 18 and 32 is larger than a width dimension T3 of the curved portion of each of the guide plate portions 18 and 32. This dimensional arrangement can improve the strength of each of the guide plate portions 18 and 32.

[0089] Furthermore, an outer portion of the connecting plate portion 12 in the disk radial direction is bent in the disk circumferential direction over almost the entire longitudinal direction, which corresponds to the disk axial direction. In this case, the bent edge of the connecting plate portion 12 is positioned on the proximal end side of each of the guide plate portions 18 and 32. In other words, the outer portion of the connecting plate portion 12 in the disk radial direction is bent from the proximal end side of each of the guide plate portions 18 and 32 in the disk circumferential direction. As a result, it is possible to improve the strength of the proximal end side of each of the guide plate portions 18 and 32, and this also contributes to improving the strength of each of the guide plate portions 18 and 32.

[0090] According to the first embodiment and the modification, a guide projection portion 15B1 protruding outward in the disc axial direction is provided on an outer plate 15B of the guide plate portion 15 of the pad spring 11. An outer surface of the ear portion 7B or 7C of the brake pad 6 in the disc radial direction is in contact with the outer plate 15B. When the brake pad 6 is installed on the fastening member 2 with the pad spring 11 attached thereto, the outer surface of the ear portion 7B or 7C of the brake pad 6 in the disc radial direction is in contact with the guide projection portion 15B1, whereby the guide projection portion 15B1 guides the ear portion 7B or 7C in the disc axial direction.

[0091] In this case, a distal end side of the guide projection portion 15B1 is bent outward in the disk radial direction. Specifically, a bent portion 15B2 that is bent outward in the disk radial direction is formed on the distal end side of the guide projection portion 15B1. This may have a dimension T4 (referring to Fig. 13 and Fig. 14) increase (widen) an opening into which the ear portion 7B or 7C is inserted when the brake pad 6 is installed. As a result, it is possible to ensure the movable flexibility of the brake pad 6 in the disc radial direction when the ear portion 7B or 7C of the brake pad 6 is inserted into the guide plate portion 15, and this can also contribute to improving the installability of the brake pad 6.

[0092] According to the first embodiment and the modification, a dimension adding portion 15A2 is formed on the abutment plate 15A of the guide plate portion 15, as shown by the shadow pattern in the Fig. 13, Fig. 14 and Fig. 16. Providing this dimension addition section 15A2 may include a dimension T5 (referring to Fig. 13 and Fig. 14) of the proximal end side of the radially urging plate portion 16 compared to when the dimension-adding portion 15A2 is omitted (the abutment plate 15A having the position corresponding to the dimension-adding portion 15A2 cut out therefrom). In other words, it is possible to reduce the dimension T5 of the portion of the radially urging plate portion 16 extending in the disk axial direction from an inner portion of the guide plate portion 15 in the disk radial direction (an inner plate 15C). This can reduce the deflection amount of the proximal end side of the radially urging plate portion 16, thereby increasing an unfolding constant of the radially urging plate portion 16.

[0093] Show next Fig. 17 and Fig. 18 shows a second embodiment. The second embodiment is characterized by a return spring configured such that a width of a second portion is narrower than a width of a first portion. The second embodiment will be described, with similar elements to the previously described first embodiment being designated by the same reference numerals, and descriptions thereof will be omitted.

[0094] A return spring 41 according to the second embodiment also includes a fixing portion 42, a first extension portion 43, a second extension portion 44, and an abutment portion 45, similar to the return spring 21 according to the first embodiment. The fixing portion 42 is fixed to the ear portion 7B of the brake pad 6 (the back plate 7) and includes a compression recess 42A pierced therethrough, similar to the fixing portion 22 of the return spring 21 according to the first embodiment.

[0095] The first extension portion 43 is formed by bending the fixing portion 42 in an L-shaped manner, such as when the first extension portion 43 is erected perpendicularly from the fixing portion 42, and a distal end side thereof extends in a direction perpendicular away from the surface of the disk 1, similarly to the first extension portion 23 of the return spring 21 according to the first embodiment. Specifically, a proximal end side of the first extension portion 43 extends in the disk axial direction, thereby forming an erected portion 43A. Then, a portion extends obliquely relative to the disk axial direction from an intermediate position thereof to the distal end side, specifically obliquely to the moment-receiving surface 4 of the fixing member 2, thereby forming an inclined portion 43B.

[0096] The second extension portion 44 is bent at an acute angle and a right angle (approximately 45 degrees to 90 degrees) from the distal end side of the first extension portion 43 outward in the disc radial direction toward the abutment plate portion 17 of the pad spring 11, and extends outward in the disc radial direction toward the abutment plate portion 17 of the pad spring 11 in a similar manner to the second extension portion 24 of the return spring 21 according to the first embodiment. The second extension portion 44 corresponds to the first portion extending from the inside to the outside in the disc radial direction.In this case, the second extension portion 44 includes a proximal end portion 44A extending outwardly in the disk radial direction from the first extension portion 23, an inclined portion 44B extending obliquely from the proximal end portion 44A relative to the direction in which the proximal end portion 44A extends, that is, obliquely in a direction away from the moment receiving surface 4, and a distal end portion 44C extending from the inclined portion 44B in the same direction as the proximal end portion 44A.

[0097] The abutment portion 45 corresponds to the second portion that extends by bending from the distal end portion 44C of the second extension portion 44 in the disk axial direction. Specifically, the abutment portion 45 is bent substantially perpendicularly (70 to 90 degrees) from the distal end side (the distal end portion 44C) of the second extension portion 44 to the abutment plate portion 17 of the pad spring 11, and extends inward in the disk axial direction toward the abutment plate portion 17 of the pad spring 11. Then, a distal end side of the abutment portion 45 is folded in a U-shaped manner, thereby forming a folded portion 45A. This folded portion 45A is in elastic abutment with the abutment plate portion 17 of the pad spring 11.

[0098] As in Fig. 18, the return spring 41 is formed such that the abutment portion 45 corresponding to the second portion has a narrower width S1 than a width S2 of the second extension portion 44 corresponding to the first portion. In this case, a part of the side surface of the abutment portion 45 is defined as an inclined surface 45B where a width dimension of the abutment portion 45 decreases as it gets farther away from the second extension portion 44. This inclined surface 45B is formed on a side surface facing (opposite) the guide plate portion 18 of the pad spring 11 and is inclined further away from the guide plate portion 18 as it gets farther away from the second extension portion 44.In other words, a proximal end side of the abutment portion 45 is configured such that the wider portion (the portion having the width S2) and the narrower portion (the portion having the width S2) are connected (continuously connected) via an inclined connecting portion 45C having the inclined surface 45B.

[0099] The second embodiment constructed in this way can improve the installability of the brake pad 6. In particular, when the brake pad 6 is mounted with the spring structure 20 as shown in Fig. 8, is installed on the fastening member 2 with the pad spring 11 attached thereto, the distal end side of the return spring 41 may interfere with the guide plate portion 18. On the other hand, according to the present embodiment, the distal end side of the return spring 41, that is, the abutment portion 45 that first faces the guide plate portion 18 upon installation, has the width S1 smaller than the width S2 of the second extension portion 44. This dimensional arrangement can prevent the return spring 41 from interfering with (clamping the guide plate portion 18), thereby improving the workability when installing the brake pad 6 (the installability).

[0100] Even a reduction in the width dimension S1 of the abutment portion 45 has almost no influence on the tension of the entire return spring 41 (there is hardly any change in the tension of the return spring 41) because the tension of the distal end side of the return spring 41 is small. Furthermore, the abutment portion 45 is in contact with the abutment plate portion 17 of the pad spring 11 at a substantially slight angle, and this is also a reason why reducing the width dimension S1 of the abutment portion 45 has little influence on the tension.

[0101] The second embodiment returns the brake pad 6 to the return position, where the brake pad 6 is separated from the disc 1 by the return spring 41 as described above, and a basic operation thereof is not significantly different from the first embodiment described above. Specifically, according to the second embodiment, the return spring 41 is formed such that the width S1 of the abutment portion 45 is narrower than the width S2 of the second extension portion 44. Therefore, when the brake pad 6 is installed, it is possible to prevent the return spring 41 from interfering with (contacting or clamping the guide plate portion 18), thereby improving the workability of installing the brake pad 6 (the installability).Furthermore, at the proximal end side of the abutment portion 45, the wider portion (the portion with the width S2) and the narrower portion (the portion with the width S1) are connected (continuously connected) via the inclined connecting portion 45C including the inclined surface 45B. Therefore, when the brake pad 6 is installed, the return spring 41 can be smoothly guided along the guide plate portion 18 from the abutment portion 45 of the return spring 41 to the second extension portion 44. This can also contribute to improving the installability of the brake pad 6.

[0102] Show next Fig. 19 and Fig. 20 shows a third embodiment. The third embodiment is characterized in that it is constructed such that a guide member is provided on a support member. The third embodiment will be described with similar elements to the previously described first embodiment designated by the same reference numerals, and a description thereof will be omitted.

[0103] A fixing member 51 fixed to the non-rotatable portion of the vehicle includes a pair of arm portions 51A, a support portion 51B, and a reinforcement beam 51C similar to the fixing member 2 according to the first embodiment. Furthermore, the pad guides 52 that guide the brake pads 6 in the disc axial direction are formed on the fixing member 51 similar to the first embodiment. According to the above-described first embodiment, the guide plate portion 18 serving as the guide portion is formed on the pad spring 11. On the other hand, according to the third embodiment, a guide projection 53 serving as the guide portion is formed on the fixing member 51.

[0104] In particular, the guide projection 53 is formed to protrude on the outside of a side surface of the fastening component 51 at an outer position in the disc axial direction relative to the pad guide 52. The guide projection 53 supports the side surface of the return spring 21, in particular, the side surface of the second extension portion 24 or the side surface of the abutment portion 25 of the return spring 21, in a manner similar to the guide plate portion 18 according to the previously described first embodiment.This structure allows the side surface (the side surface of the second extension portion 24 or the side surface of the abutment portion 25) of the return spring 21 to be supported (guided) by the guide projection 53 when the brake pad 6 is installed on the fixing member 51, thereby successfully regulating the abutment position of the abutment portion 25 of the return spring 21 so that it is located on the abutment plate portion 17 of the pad spring 11 with the brake pad 6 already installed on the fixing member 51.

[0105] The third embodiment supports (guides) the return spring 21 by the guide projection 53 as described above, and a basic operation thereof is not significantly different from the first embodiment described above. According to the third embodiment, in particular, the provision of the guide projection 53 on the fixing member 51 allows the guide plate portion 18 of the pad spring 11 to be omitted from the pad spring 11. Further, according to the third embodiment, the abutment plate portion 17 is formed as a flat surface (the distal end guide portion 17A is formed no differently from the first embodiment). In this case, the distal end side of the return spring 21, that is, the folded portion 25A of the abutment portion 25, is formed to be wide in the disk rotation direction.According to this, a restriction / prevention recess 54, recessed away from the abutment portion 25, is formed at a portion of the outer foot portion 5C of the caliper 5 facing the abutment portion 25 (the folded portion 25A). The restriction / prevention recess 54 (a bottom surface thereof) restricts or prevents movement (displacement) of the abutment portion 25 (the folded portion 25A) toward the brake pad 6 (the center side of the brake pad 6) in the disc rotation direction. In other words, the third embodiment is configured to support (guide) the distal end side (the abutment portion 25) of the return spring 21 by the guide projection 53 (the side surface thereof) of the fixing member 51 and the restriction / prevention recess 54 (the bottom surface thereof) of the caliper 5.

[0106] Next, Fig.21 shows a fourth embodiment. The fourth embodiment is characterized in that it is configured such that the guide portion is provided at an inner position in the disc radial direction relative to the abutment plate portion of the pad spring. The fourth embodiment will be described with similar elements to the previously described first embodiment designated by the same reference numerals, and descriptions thereof will be omitted.

[0107] A pad spring 61 includes a connecting plate portion 62, flat plate portions 63, an engaging plate portion 64, guide plate portions 65, radially biasing plate portions 66, abutment plate portions 67, and guide plate portions 68, which are integrally formed, similarly to the pad spring 11 according to the first embodiment. The guide plate portion 68 as the guide portion employed in the fourth embodiment is used to replace the guide plate portion 18 according to the first embodiment. The guide plate portion 68 is formed at an inner position in the disk radial direction relative to the abutment plate portion 67. In this case, the guide plate portion 68 extends linearly from the flat plate portion 63 in the direction away from the disk 1 in the disk axial direction.

[0108] The fourth embodiment supports (guides) the return spring 21 by the guide plate portion 68 as described above, and a basic operation thereof does not differ significantly from the first embodiment described above. Specifically, according to the fourth embodiment, the fourth plate portion 68 is configured to extend linearly, whereby the guide plate portions 68 can be prevented from easily jamming against each other, for example, when a plurality of pad springs 61 are conveyed together, compared with the guide plate portion 18 according to the first embodiment, that is, the guide plate portion 18 formed in a substantially L-shaped configuration or a quarter-circular arc configuration.

[0109] The above-described first embodiment was described based on an example in which the return spring 21 or 41 is configured as a disc spring made of a metallic plate. However, the present invention is not limited to this, and may use various types of springs as the return spring, such as a spring made of a material other than a metallic plate (for example, a plastic material) and a wire spring made of a material other than a plate material (for example, a wire material). The same applies to other embodiments and modifications.

[0110] The above-described first embodiment was described based on the example in which the recessed pad guides 3 are formed on the arm portions 2A of the fastening member 2, and the ear portions 7B and 7C serving as the fitting portions of the back plates 7 are formed protrudingly. However, the present invention is not limited to this, and may be configured such that, for example, recessed fitting portions are formed on the back plates of the brake pads, and protruding pad guides are formed on the arm portions of the fastening member. The same applies to the other embodiments and the modification.

[0111] The above-described embodiment was described based on the example using the so-called integral pad spring 11 with the corresponding guide plate portions 15, the radially biasing plate portions 16, and the like on the inner and outer sides of the disk 1. However, the present invention is not limited to this, and may be configured, for example, to include two pad springs configured as if the pad spring is divided into pieces on the inner and outer sides of the disk, and these are arranged on the inner and outer sides of the disk, respectively. The same applies to the other embodiments and the modification.

[0112] The above-described first embodiment was described based on the example in which the single piston 5D is provided in the inner root portion 5A of the caliper 5.

[0113] However, the present invention is not limited to this, and may, for example, include a double-bore structure with two pistons in the inner base portion of the caliper, or a structure with three or more pistons in the inner base portion of the caliper. The same applies to other embodiments and modifications.

[0114] The above-described first embodiment was described based on the example of a so-called floating-caliper disc brake, which is constructed such that the piston 5 is slidably provided in the inner leg portion 5A of the caliper 5 via the cylinder, and the outer leg portion 5C of the caliper 5 is placed in contact with the outer side of the brake pad 6. However, the present invention is not limited to this, and can be applied, for example, to a so-called opposed-piston disc brake, which is constructed such that pistons are provided on the inner and outer sides of the caliper, respectively. The same applies to the other embodiments and the modification.

[0115] According to the above-described embodiments, the return spring is configured such that the distal end side of the return spring is in elastic engagement with the fixing member side on the outer side in the disc radial direction relative to the proximal end side of the return spring fixed to the back plate of the brake pad. Therefore, the moment is applied to the portion where the proximal end side of the return spring and the back plate of the brake pad are fixed to each other in the direction of separating the outer side of the brake pad in the disc radial direction from the disc based on the engagement between the distal end side and the fixing member side established on the outer side in the disc radial direction relative to the proximal end side.Therefore, the brake pad tends to assume a position at the return position such that the outer side of the brake pad in the disc radial direction is inclined farther away from the disc than the inner side of the brake pad in the disc radial direction, thereby reducing drag between the outer side of the brake pad in the disc radial direction and the disc. Furthermore, it is also possible to prevent the filler of the brake pad from wearing unevenly.

[0116] Furthermore, the guide portion supporting the side surface of the return spring (the intermediate portion) is formed on the pad spring or the like. Therefore, it is possible to regulate the position where the distal end side of the return spring abuts the side of the fixing member so that it is located at a desired position by the guide portion of the pad spring and the like. In other words, it is possible to prevent the distal end side of the return spring from shifting from the desired abutment position (prevent the return spring from being incompletely installed) when assembling the disc brake.Furthermore, even if the distal end of the return spring tends to be displaced from the desired abutment position due to, for example, the application of an external force to the return spring, the side surface of the return spring (the intermediate portion) is supported by the guide portion of the pad spring or the like, thereby preventing this displacement. For example, even if a flying stone or the like strikes the return spring when the vehicle is traveling on an unpaved road or the like, the side surface of the return spring (the intermediate portion) is in contact with the guide portion, thereby preventing the return spring from being deformed more than this (a positional displacement of the distal end side).

[0117] Furthermore, since it is possible to regulate the distal end side of the return spring so that it is located at the abutment position described, it becomes possible to reduce the sizes of the distal end side of the return spring and the portion of the side of the fixing member with which the distal end side abuts (to downsize it). As a result, it is possible to improve the flexibility of the layout of the return spring. For example, even if only a narrow available gap (space) is created between the fixing member and the caliper due to a size reduction of the disc brake, the return spring 21 can be installed in this narrow gap.

[0118] According to one embodiment of the present invention, the return spring includes the first portion extending from the inner side outward in the disc radial direction and the second portion extending while being bent from the first portion in the disc axial direction, and is formed such that the width direction of the second portion is narrower than the width direction of the first portion. Therefore, when installing the brake pad, it is possible to prevent the return spring and the guide portion from interfering with each other (clamping each other), and therefore, it is possible to improve the workability of installing the brake pad (installability).

Claims

[1] Disc brake, with: a fastening component (2, 51) which is adapted to be fixed to a non-rotatable portion of a vehicle and which is formed to extend over an outer peripheral side of a disc (1), a saddle (5) arranged on the fastening component (2, 51) so that it is movable in an axial direction of the disc (1), a pair of brake pads (6) which are movably provided on the fastening component (2, 51) and are arranged to be pressed by the caliper (5) against both surfaces of the disc (1), a pad spring (11, 31, 61) provided on the fastening member (2, 51) and arranged between the fastening member (2, 51) and the pair of brake pads (6), and a return spring (21, 41) arranged between the brake pad (6) and the fastening component (2, 51) and arranged to tension the brake pad (6) in a return direction for separating the brake pad (6) from the disc (1), and wherein the return spring (21, 41) has a proximal end side portion (22) and a distal end side portion (25), and the return spring (21, 41) is arranged such that the proximal end side portion (22) is fixed to a back plate (7) of the brake pad (6) and the distal end side portion (25) is in elastic contact with the side of the fastening component (2, 51) on an outer side in the disc radial direction relative to the proximal end side portion (22), characterized bythat the pad spring (11, 31, 61) has a guide portion (18, 32) which extends in the axial direction of the disc in a direction away from the disc (1) and, as it moves further away from the disc (1), is bent inwards in the disc radial direction, and wherein a part of the guide portion (18, 32) is provided on a center side of the brake pad (6) in the disc circumferential direction at the intermediate portion of the return spring (21, 41). [2] Disc brake according to claim 1, wherein the guide portion limits or prevents movement of the return spring (21, 41) towards the brake pad (6). [3] A disc brake according to claim 1, wherein the return spring (21, 41) has a first portion extending outward from an inner side in the disc radial direction and a second portion extending from the first portion while being bent in the axial direction of the disc, and wherein the return spring (21, 41) is formed such that a width of the second portion is narrower than a width of the first portion. [4] A disc brake according to claim 3, wherein the return spring (21, 41) is formed such that the first portion and the second portion are connected by means of an inclined surface formed on a side surface facing the guide portion, the inclined surface being inclined further away from the guide portion as it moves further away from the first portion. [5] A disc brake according to claim 1, wherein the guide portion (18, 32) of the pad spring (11, 31, 61) extends from an outer side in the disc radial direction relative to the distal end side portion (25). [6] A disc brake according to claim 1, wherein the guide portion (18, 32) of the pad spring (11, 31, 61) extends to an inner side in the disc radial direction relative to the distal end side portion (25). [7] A disc brake according to claim 1, wherein the guide portion (18, 32) of the pad spring (11, 31, 61) has a bent portion formed at a position of the guide portion (18, 32) remote from the disc (1) in the axial direction of the disc, the bent portion being bent and extending toward the center side of the brake pad (6). [8] Disc brake, with: a fastening component (2, 51) which is adapted to be fixed to a non-rotatable portion of a vehicle and which is formed to extend over an outer peripheral side of a disc (1), a saddle (5) arranged on the fastening component (2, 51) so that it is movable in an axial direction of the disc (1), a pair of brake pads (6) which are movably provided on the fastening component (2, 51) and are arranged to be pressed by the caliper (5) against both surfaces of the disc (1), a pad spring (11, 31, 61) provided on the fastening member (2, 51) and arranged between the fastening member (2, 51) and the pair of brake pads (6), and a return spring (21, 41) arranged between the brake pad (6) and the fastening component (2, 51) and arranged to tension the brake pad (6) in a return direction for separating the brake pad (6) from the disc (1), wherein the return spring (21, 41) has a proximal end side portion (22) and a distal end side portion (25), and the return spring (21, 41) is arranged such that the proximal end side portion (22) is fixed to a back plate (7) of the brake pad (6) and the distal end side portion (25) is in elastic contact with the side of the fastening component (2, 51) on an outer side in the disc radial direction relative to the proximal end side portion (22), characterized by that the pad spring (11, 31, 61) has a guide portion (18, 32) made of a plate extending in the disc radial direction, and wherein the guide portion (18, 32) is arranged such that the guide portion (18, 32) can abut against the return spring (21, 41) on an inner side in the disk radial direction relative to the distal end side portion. [9] Disc brake according to claim 8, wherein the guide portion limits or prevents movement of the return spring (21, 41) towards the brake pad (6). [10] A disc brake according to claim 8, wherein the return spring (21, 41) has a first portion extending outward from an inner side in the disc radial direction and a second portion extending from the first portion while being bent in the axial direction of the disc, and wherein the return spring (21, 41) is formed such that a width of the second portion is narrower than a width of the first portion. [11] A disc brake according to claim 10, wherein the return spring (21, 41) is formed such that the first portion and the second portion are connected by means of an inclined surface formed on a side surface facing the guide portion, the inclined surface being inclined further away from the guide portion as it moves further away from the first portion. [12] A disc brake according to claim 8, wherein the guide portion (18, 32) of the pad spring (11, 31, 61) extends from an outer side in the disc radial direction relative to the distal end side portion (25). [13] A disc brake according to claim 8, wherein the guide portion (18, 32) of the pad spring (11, 31, 61) extends to an inner side in the disc radial direction relative to the distal end side portion (25). [14] A disc brake according to claim 8, wherein the guide portion (18, 32) of the pad spring (11, 31, 61) has a bent portion formed at a position of the guide portion (18, 32) remote from the disc (1) in the axial direction of the disc, the bent portion being bent and extending toward the center side of the brake pad (6). [15] Disc brake, with: a fastening component (2, 51) which is adapted to be fixed to a non-rotatable portion of a vehicle and which is formed to extend over an outer peripheral side of a disc (1), a saddle (5) arranged on the fastening component (2, 51) so that it is movable in an axial direction of the disc (1), a pair of brake pads (6) which are movably provided on the fastening component (2, 51) and are arranged to be pressed by the caliper (5) against both surfaces of the disc (1), a pad spring (11, 31, 61) provided on the fastening member (2, 51) and arranged between the fastening member (2, 51) and the pair of brake pads (6), and a return spring (21, 41) arranged between the brake pad (6) and the fastening component (2, 51) and arranged to tension the brake pad (6) in a return direction for separating the brake pad (6) from the disc (1), a guide section (18) which carries a side surface of the return spring (21, 41), wherein the return spring (21, 41) has a proximal end side portion (22, 42) and a distal end side portion (25, 45), and the return spring (21, 41) is arranged such that the proximal end side portion (22, 42) is fixed to a back plate (7) of the brake pad (6) and the distal end side portion (25, 45) is in elastic contact with the side of the fastening component (2) on an outer side in the disc radial direction relative to the proximal end side portion (22, 42), characterized by that the return spring (41) has a first portion (44) extending from an inner side in the disc radial direction to the outside, and a second portion (45) extending from the first portion (44) while being bent in the axial direction (Z) of the disc (1), wherein the first portion and the second portion are connected by means of an inclined surface (45B) formed on a side surface facing the guide portion, the inclined surface (45B) being inclined further away from the guide portion as it gets further away from the first portion. [16] Disc brake according to claim 15, wherein the guide portion limits or prevents movement of the return spring (21, 41) towards the brake pad (6). [17] A disc brake according to claim 15, wherein the guide portion (18, 32) of the pad spring (11, 31, 61) extends from an outer side in the disc radial direction relative to the distal end side portion (25). [18] A disc brake according to claim 15, wherein the guide portion (18, 32) of the pad spring (11, 31, 61) extends to an inner side in the disc radial direction relative to the distal end side portion (25). [19] A disc brake according to claim 15, wherein the guide portion (18, 32) of the pad spring (11, 31, 61) has a bent portion formed at a position of the guide portion (18, 32) remote from the disc (1) in the axial direction of the disc, the bent portion being bent and extending toward the center side of the brake pad (6).

Images