JP5203152B2 - Disc brake manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a disc brake, capable of reducing the possibility of a frictional stirring part to influence the installed condition of a piston. <P>SOLUTION: A plane part 17c is formed on the annular bottom wall 50 side of the piston 17, and a supporting member 80 having an abutting outside diameter to the annular bottom wall 50 greater than the outside diameter of the piston plane part is inserted into a bore 26 and abutted on the annular bottom wall 50 from inside the bore 26, and a lid member 43 whose annular bottom wall 50 side has the same wall thickness as the annular bottom wall 50 and which has an outside diameter approximately the same as the inside diameter of an opening 45, is inserted into the opening 45 and abutted on the supporting member 80, and the lid member 43 and the annular bottom wall 50 are joined together through frictional stirring joining. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a method for manufacturing a disc brake.

In the disc brake, there is a technique of friction stir welding between the cylinder body and the lid member so as to close the opening of the cylinder body with the lid member (see, for example, Patent Document 1).
JP 2007-225057 A

  When the friction stirrer in the softened state is pushed to the bore side and hardens during friction stir welding, there is a possibility that the assembled state of the piston will be affected.

  Accordingly, an object of the present invention is to provide a disc brake manufacturing method that can reduce the possibility that the friction stirrer affects the assembled state of the piston.

In order to achieve the above object, the present invention has an outer diameter of contact with the annular bottom wall that is larger than an outer diameter of a flat portion formed on the annular bottom wall side of the piston, and a bottom portion of the bore of the piston. a step of butting by inserting a support member having a chamfered portion of larger outside diameter than the outside diameter of the chamfered portion formed at the edge of the surface facing the side to the bore from the inside of the bore in said annular bottom wall, A step of inserting a lid member having an outer diameter substantially the same as the inner diameter of the opening into contact with the support member, the annular bottom wall side having the same thickness as the annular bottom wall; Joining the member and the annular bottom wall by friction stir welding.

Further, the present invention, the support member to the one outer edge of the surface facing the bottom side of the bore, formed by bulging than the outline of the edge of the surface facing the bottom side of the bore of the piston Ru such Ttei.

  According to the present invention, the possibility that the friction stirrer affects the assembled state of the piston can be reduced.

  An embodiment according to the present invention will be described below with reference to the drawings.

  1 to 3 show an example of a disc brake of this embodiment that is applied to a motorcycle. As shown in FIG. 1, the disc brake 1 includes a disc 12 that rotates integrally with a wheel (rotating body) to be braked, and a caliper 11 that imparts frictional resistance to the disc 12. The caliper 11 has a caliper body 16 attached to the non-rotating portion 13 of the vehicle via a bracket 14 in a state of straddling the disc 12, and a caliper body 16 so as to face each other with the disc 12 interposed therebetween as shown in FIG. And a plurality of pairs slidably provided, specifically two pairs (only one pair is shown in the cross-sectional view of FIG. 3). In the following, description will be given with the state of attachment to the vehicle, the radial direction of the disk 12 in this attachment state will be referred to as the disk radial direction, the axial direction of the disk 12 will be referred to as the disk axial direction, and the circumferential direction of the disk 12 It is called the disk circumferential direction. In FIG. 1, an arrow F indicates the direction of rotation of the disk 12 when the vehicle moves forward.

  As shown in FIG. 3, the piston 17 has a bottomed cylindrical shape having a cylindrical portion 18 and a disk-shaped bottom portion 19 that closes one end side of the cylindrical portion 18 in the axial direction. The outer peripheral surface on the radially outer side of the piston 17 is composed of a straight cylindrical surface 17 a and a chamfered portion 17 b which is on the bottom 19 side of the cylindrical portion 18 and is rounded. The outer surface of the bottom portion 19 of the piston 17 is a flat plane portion 17c that is orthogonal to the central axis of the cylindrical surface 17a. Such a piston 17 faces the bottom of the bore 26 in the flat portion 17c, and a chamfered portion 17b is formed at the edge of the flat portion 17c.

  The caliper body 16 includes an outer cylinder portion 20 disposed on the outer side (opposite to the wheel) with the disk 12 interposed therebetween, an inner cylinder portion (cylinder) 21 disposed on the inner side (wheel side), A bridge portion 22 that connects the outer side cylinder portion 20 and the inner side cylinder portion 21 on the radially outer side of the disk 12 is provided.

  The caliper body 16 includes a plurality of pad pins 24 shown in FIGS. 1 and 2 that are bridged between the outer side cylinder portion 20 and the inner side cylinder portion 21 along the disc axial direction and spaced apart in the disc circumferential direction. There are two of them.

  As shown in FIG. 3, the outer side cylinder portion 20 and the inner side cylinder portion 21 are formed with a pair of bores 26 that face each other in the disk axial direction. As shown in FIG. 1, a plurality of pairs, specifically two pairs, are provided apart from each other in the disk circumferential direction, and the above-described pistons 17 are slidably fitted into the bores 26, respectively. As a result, a plurality of pairs of bores 26 facing in the disk axial direction are formed in a plurality of pairs in the disk circumferential direction, specifically two pairs in parallel, and a plurality of pistons 17 facing in the disk axial direction are formed in a plurality of pairs in the disk circumferential direction. It is arranged in parallel, specifically two pairs in parallel.

  Here, as shown in FIG. 3, each bore 26 has a fitting inner diameter portion 27 in which the piston 17 is slidably fitted, and a rear side of the fitting inner diameter portion 27, and the fitting inner diameter portion 27. A plurality of specifically, two seal circumferential grooves for holding the piston seal 31 at a substantially intermediate position in the axial direction of the fitting inner diameter portion 27. 29 and 30 are formed. The piston 17 slides on the fitting inner diameter portion 27 on the cylindrical surface 17a. Here, the large-diameter inner diameter portion 28 is formed by casting (that is, a cast skin state). On the other hand, the fitting inner diameter portion 27 and the seal circumferential grooves 29 and 30 are formed by cutting after casting.

  A total of two pairs of brake pads 33 are supported on each pad pin 24 of the caliper body 16 so as to be movable in the disc axial direction (only one pair is shown in the sectional view of FIG. 3). These pads 33 are arranged on both sides in the axial direction of the disk 12 and are respectively pressed by the pistons 17 provided on the caliper body 16 so as to be located on the opposite side of the disk 12 with respect to the pads 33. The disc 12 is pressed against the disc 12 to generate a braking force on the vehicle. The caliper body 16 is formed with a passage for introducing brake fluid for operating the pistons 17 into the bores 26, of which the opposing bores 26 communicate with each other, as shown in FIGS. 1 and 2. The communication passages 35, 36 are bored from the outside so as to intersect each other in the caliper body 16, and an air bleeding bleeder plug 39 is attached to a mouth portion 37 that opens to the outside of one communication passage 35. The opening 38 that opens to the outside of the other communication path 36 is closed by a closing plug 40.

  In the present embodiment, as shown in FIG. 3, the caliper body 16 includes an outer side cylinder part 20, an inner side cylinder part 21, and a bridge part 22, and the outer side cylinder part 20 and the inner side cylinder part 21. The inner side cylinder portion 21 is formed by processing one side of the inner side cylinder portion 21 except for a part of the bottom portion of the inner side cylinder portion 21. A part of the bottom is a separate lid member 43.

  That is, the caliper body 16 includes an outer cylinder portion 20, an inner cylinder portion 21, and a bridge portion 22. The inner cylinder portion 21 has an opening at the bottom portion of the bore 26 as shown in FIG. A caliper body main body (cylinder main body) 46 formed by processing an integrally molded material into a shape having 45, and a lid member shown in FIGS. 4B and 4C for closing the opening 45 of the caliper body main body 46 43.

  The lid member 43 is made of, for example, an aluminum alloy and is formed in a disk shape. The lid member 43 is fitted into the opening 45 of the caliper body main body 46, and therefore has an outer diameter substantially equal to the inner diameter of the opening 45. The outer diameter is slightly smaller than 45. The lid member 43 has a disc portion 43A having a constant thickness and a convex portion 43B protruding from the center of the disc portion 43A to the one side in the axial direction with a constant diameter and a constant height.

  The opening 45 of the caliper body main body 46 has a straight cylindrical surface shape with no stepped portion on the inner peripheral surface, and the lid member 43 has a cylindrical surface shape with a straight outer peripheral surface as well.

  Here, the opening 45 of the caliper body main body 46 is formed in a circular shape coaxial with the bore 26 on the bottom side of the bore 26, and the inner diameter thereof is the inner diameter of the bore 26 (the fitting inner diameter portion 27 and the large diameter inner diameter portion 28. Smaller than the inner diameter). As a result, an annular bottom wall 50 that extends in the axial direction of the bore 26 and forms the periphery of the opening 45 is formed at the bottom of the bore 26. In other words, the annular bottom wall 50 is formed along the inner periphery of the opening 45. The wall thickness, which is the axial dimension of the annular bottom wall 50, is set to the same thickness as the disk portion 43 </ b> A of the lid member 43.

  Further, the opening 45 of the caliper body main body 46 is used as a processing hole for cutting the inner peripheral surface of the bore 26 after the caliper body main body 46 is cast. For example, the opening 45 is formed inside the bores 26 of the inner-side and outer-side cylinder portions 21 and 20 when the processing of the opening 45 itself is finished or at the stage of the pilot hole of the opening 45 immediately after casting. It is used as an insertion hole for a cutting tool when the fitting inner diameter portion 27 and the seal circumferential grooves 29 and 30 are cut on the peripheral surface.

  Further, as shown in FIG. 5, communication paths 35 and 36 for communicating the opposing bores 26 are formed in the caliper body main body 46. At this time, one communication passage 35 opens to the large-diameter inner diameter portion 28 of the inner cylinder portion 21, and the other communication passage 36 intersects the communication passage 35 while the large-diameter inner diameter portion 28 of the outer cylinder portion 20. Open to.

  When the caliper body main body 46 finishes the process of cutting the inner peripheral surface of the bore 26 and the process of cutting the opening 45 and the process of drilling the communication passages 35 and 36 after casting, The lid member 43 shown in FIG. 4 is attached to the opening 45 by friction stir welding (FSW) as follows.

  As shown in FIG. 6, a welding tool 71 used in this friction stir welding is a cylindrical large-diameter shaft portion 72 and a cylindrical shape that is smaller in diameter than the large-diameter shaft portion 72 and coaxial with the large-diameter shaft portion 72. The tip shaft portion 73 is provided. An arcuate concave portion 74 is formed on the distal end side of the large diameter shaft portion 72, and the distal end shaft portion 73 is erected from the center of the concave portion 74. Further, the tip 75 of the tip shaft portion 73 is spherical. A specific method of friction stir welding using the welding tool 71 is shown, for example, in FIGS. 12A to C of US Pat. No. 5,460,317.

  When the lid member 43 is attached to the caliper body main body 46, the pair of iron cores (support members) 80 shown in FIG. 7 are placed on the core set plate 81 as shown in FIG. The inner side cylinder portion 21 in which the opening 45 is formed is fitted to the pair of bores 26. As shown in FIG. 7, the core set plate 81 is formed with a pair of holding holes 82 for holding the core 80. On the other hand, the core 80 is formed with a main portion 83 having a substantially cylindrical shape, and a fitting convex portion 84 having a smaller diameter than the main portion 83 and protruding from the center of one end portion of the main portion 83 in the axial direction. Has been. The core 80 is fitted into the holding hole 82 at the fitting convex portion 84, and the main portion 83 is placed on the core set plate 81 on the flat placement surface 83 a around the fitting convex portion 84. Is done.

  Here, as shown in FIG. 8, in the core 80, a concave portion 85 that is recessed in the axial direction is formed at the center of the end portion of the main portion 83 opposite to the fitting convex portion 84. The periphery is a flat annular surface 83b. In addition, a chamfered portion 83c having a rounded chamfer is formed at a corner on the annular surface 83b side on the outer peripheral portion in the radial direction of the main portion 83, and a straight cylinder is formed on the opposite side of the chamfered portion 83c from the annular surface 83b. A large-diameter cylindrical surface 83d is formed, and an annular step surface 83e having a slightly smaller diameter than the large-diameter cylindrical surface 83d is formed on the opposite side of the chamfered portion 83c of the large-diameter cylindrical surface 83d. A straight large-diameter cylindrical surface 83f having the same diameter as the large-diameter cylindrical surface 83d is formed on the side opposite to the cylindrical surface 83d, and the large-diameter cylindrical surface 83f is opposite to the annular step surface 83e than the large-diameter cylindrical surface 83f. A straight small-diameter cylindrical surface 83g having a slightly small diameter is formed, and a chamfered portion 83h that is chamfered so as to be connected to the mounting surface 83a is formed at a corner of the small-diameter cylindrical surface 83g opposite to the large-diameter cylindrical surface 83f. ing. Here, the core 80 faces the bottom of the bore 26 on the mounting surface 83a as will be described later, and a chamfered portion 83c is formed at the edge of the mounting surface 83a.

  The largest diameter large diameter cylindrical portions 83 d and 83 f of the core 80 are slightly larger in diameter than the outer diameter of the cylindrical surface 17 a of the piston 17.

  Further, the outer diameter D1 of the annular surface 83b of the core 80 is larger than the outer diameter D2 of the flat portion 17c of the piston 17. That is, as will be described later, the core 80 comes into contact with the annular bottom wall 50 at the annular face 83b when fitted into the bore 26, and the annular face which is the outer diameter of contact with the annular bottom wall 50. The outer diameter D1 of 83b is made larger than the outer diameter D2 of the plane portion 17c formed on the annular bottom wall 50 side of the piston 17.

  In other words, the contact outer diameter dimension D1 of the core 80 with respect to the annular bottom wall 50 is formed to be equal to or larger than the outer diameter dimension D2 of the flat portion 17c formed on the annular bottom wall 50 side of the piston 17. The outer shape of the edge of the annular surface 83 b facing the bottom side of the bore 26 of the core 80 is formed to bulge out from the outer shape of the edge of the flat surface portion 17 c facing the bottom side of the bore 26 of the piston 17.

  In other words, the core 80 and the piston 17 are formed with chamfered portions 83 c and 17 b at the edge of the surface facing the bottom side of the bore 26, and the outer diameter of the core 80 contacting the annular bottom wall 50 is formed. D1 is formed larger than the outer diameter D2 of the flat surface portion 17c formed on the annular bottom wall 50 side of the piston 17, and the outer diameter of the chamfered portion 83c of the core 80 (the outer diameter of the large-diameter cylindrical surface 83d) is the piston 17. Is formed larger than the outer peripheral diameter of the chamfered portion 17b (the outer diameter of the cylindrical surface 17a).

  For example, the outer diameter of the large-diameter cylindrical surfaces 83d and 83f, which is the maximum outer diameter of the core 80, is substantially equal to the outer diameter of the cylindrical surface 17a of the piston 17, and the radius of the chamfered portion 83c of the core 80 is By making it smaller than the radius of the chamfered portion 17 b of the piston 17, the outer diameter of the annular surface 83 b of the core 80 may be made larger than the outer diameter of the flat portion 17 c of the piston 17.

  As shown in FIG. 9, the caliper body main body in a posture in which the inner side cylinder portion 21 is on the upper side and the outer side cylinder portion 20 is on the lower side with the pair of cores 80 being placed on the core set plate 81. 46 is inserted between the outer side cylinder part 20 and the inner side cylinder part 21 from the opposite side to the bridge part 22, and an inner part in which an opening 45 of the caliper body main body 46 is formed as shown in FIG. The pair of bores 26 of the side cylinder portion 21 are fitted from below.

  Next, from this state, the caliper body main body 46, the pair of cores 80, and the core set plate 81 are turned upside down so that the top and bottom are reversed. Accordingly, the pair of cores 80 are supported by the caliper body main body 46, and in this state, the core set plate 81 is removed as shown in FIG.

  Next, as shown in FIG. 12, a positioning plate 86 that is thicker than the core set plate 81 from the side opposite to the bridge portion 22 between the outer cylinder portion 20 and the inner cylinder portion 21 of the caliper body main body 46. Insert. Here, the positioning plate 86 is also formed with a pair of holding holes 87 for fitting the fitting convex portions 84 of the pair of cores 80. 87, the main portion 83 comes into contact with the positioning plate 86 on the mounting surface 83a.

  Next, from this state, as shown in FIG. 13, the caliper body main body 46, the pair of cores 80, and the positioning plate 86 are turned upside down so that the top and bottom are reversed, and the friction stir welding apparatus 90 receives them. It is installed on the base 91. At this time, as shown in FIGS. 13A and 13B, the positioning pins 92 provided on the positioning plate 86 are fitted into the positioning holes 93 of the receiving base 91, and as shown in FIG. 13B. Further, the caliper body main body 46 is positioned on the cradle 91 by fitting the positioning plates 86 between the both side walls 91a of the cradle 91 on both side surfaces. In this state, the pair of cores 80 inserted into the pair of bores 26 abuts the annular surface 83 b that is the top surface against the annular bottom wall 50 at the bottom of the bore 26 from the inside of the bore 26.

  Next, as shown in FIG. 14, the lid member 43 is inserted into the opening 45 from the outer surface side of the caliper body main body 46 (the bottom outer surface side of the bore 26), and the lid member 43 is inserted into the core 80 at the disk portion 43A. Is brought into contact with the annular surface 83b. At this time, the annular bottom wall 50 and the disc portion 43A of the lid member 43 abut against the flat annular surface 83b of the core 80, and are positioned in the height direction with the annular surface 83b as a reference surface. It becomes. Thereby, the annular bottom wall 50 having the same thickness and the outer surface of the disc portion 43A of the lid member 43 are flush with each other without any step.

  Next, from this state, as shown in FIG. 15, friction stir welding (FSW) is performed with respect to the joint boundary 100 between the opening 45 and the lid member 43, in other words, the joint boundary 100 between the annular bottom wall 50 and the lid member 43. )I do. At the time of this friction stir welding, the distal end shaft portion 73 of the welding tool 71 is continuously moved along the joining boundary 100 between the opening 45 and the lid member 43, and the loop is formed over the entire circumference of the lid member 43. Friction stir welding is performed. When the joining tool 71 returns to the joining start point position on the outer periphery of the lid member 43, the joining tool 71 moves a predetermined amount on the caliper body main body 46 along the circumferential tangential direction of the joining boundary 100 of the lid member 43, and the movement. When the process is completed, the caliper body 46 is pulled out. As a result, as shown in FIG. 2, the friction stirrer 105 having the circular loop part 105a and the extending part 105b extending in the tangential direction of the loop part 105a is formed in the caliper body 16 so as to remain. Become.

  Thus, the annular bottom wall 50 and the lid member 43 are joined over the entire circumference. Here, the residual shape portion 101 is formed at the end position of the extension portion 105 b of the friction stir portion 105. The residual shape portion 101 is formed only at the pulling point of the joining tool 71, and includes a central hole 102 corresponding to the tip shaft portion 73 of the joining tool 71 and a peripheral recess 103 corresponding to the large diameter shaft portion 72. Become. Although the residual shape portion 101 is recessed with the central hole 102 as the deepest portion, the extended portion 105b of the residual shape portion 101 is formed at a position deviated from the joining boundary 100 toward the caliper body main body 46. There is no such thing as a cause of strength reduction or liquid leakage at the joint. As shown in FIG. 16, the phase of the extending portion 105 b of one friction stirrer 105 substantially matches the phase of the opening in the bore 26 of the communication path 35.

  Next, with the caliper body 16 supported by the core 80 and the positioning plate 86, these are removed from the cradle 91 of the friction stir welding apparatus 90 and cooled with water.

  Next, the positioning plate 86 and the core 80 are removed from the caliper body 16 in this order in a state where the clearance between the core 80 and the bore 26 is secured by the water cooling. When removing the core 80, the core set plate 81 is used to fit the fitting convex portion 84 into the holding hole 82, and then the core set plate 81 is vibrated in the surface direction. The core 80 is removed from the caliper body 16.

  Next, milling and exterior (alumite treatment) of the friction stirrer 105 are performed for the purpose of improving the product appearance and corrosion resistance of the caliper body 16.

  Then, other parts such as the piston 17 are assembled to the caliper body 16.

  According to the present embodiment described above, the core 80 having a contact outer diameter larger than the outer diameter of the flat portion 17c formed on the annular bottom wall 50 side of the piston 17 is formed in the bore. In the state where it is inserted into the bore 26 and abuts against the annular bottom wall 50 from the inside of the bore 26, the disk portion 43A on the annular bottom wall 50 side has the same thickness as the annular bottom wall 50 and is substantially equal to the inner diameter of the opening 45. Since the lid member 43 having an outer diameter is inserted into the opening 45 and brought into contact with the core 80, the lid member 43 and the annular bottom wall 50 are joined by friction stir welding. Even if a part of the bottom wall 50 or the lid member 43 is pushed into the bore 26 by the pressure from the joining tool 71, the bottom wall 50 or the lid member 43 is pushed outside the contact outer diameter of the core 80. Therefore, the extruded portion by the friction stir welding is outside the movable range of the flat portion 17c of the bottom portion 19 of the piston 17 assembled in the bore 26, and the extruded portion of the friction stirring portion 105 interferes to cause the piston 17 to move to the bore 26. The possibility that the friction stirrer 105 affects the assembled state of the piston 17 can be reduced, for example, it becomes impossible to insert the contact portion to the convex portion 43B which is the bottom portion.

  Further, a core 80 having a contact outer diameter with respect to the annular bottom wall 50 larger than the outer diameter of the flat surface portion 17 c formed on the annular bottom wall 50 side of the piston 17 is inserted into the bore 26 from the inside of the bore 26. Extrusion received from the joining tool 71 for abutting against the annular bottom wall 50 and joining the lid member 43 and the annular bottom wall 50 by friction stir welding in a state where the annular bottom wall 50 is supported by a core 80 in a wider area. The amount of bending of the annular bottom wall 50 due to the force is small, and the amount of extrusion of the softened extruded portion can be suppressed as shown in FIG. Therefore, even if the phase of the extending portion 105b of the friction stirrer 105 substantially matches the phase of the opening in the bore 26 of the communication passage 35, the extruded portion can be prevented from reaching this opening. Therefore, the flow path by the communication path 35 can be ensured satisfactorily.

  In other words, the outer diameter dimension of the annular surface 83b, which is the outer diameter dimension of the core 80 in contact with the annular bottom wall 50, is equal to or larger than the outer diameter dimension of the flat surface portion 17c formed on the annular bottom wall 50 side of the piston 17. The outer shape of the edge of the annular surface 83b facing the bottom side of the bore 26 of the core 80 is larger than the outer shape of the edge of the flat surface portion 17c facing the bottom side of the bore 26 of the piston 17. Even if a part of the annular bottom wall 50 or the lid member 43 softened by the friction stir welding is pushed into the bore 26 by the pressure from the welding tool 71, the core 80 of the core 80 is formed. It will be pushed out of the contact outer diameter. Therefore, the extruded portion by the friction stir welding is outside the movable range of the flat portion 17c of the bottom portion 19 of the piston 17 assembled in the bore 26, and the extruded portion of the friction stirring portion 105 interferes to cause the piston 17 to move to the bore 26. The possibility that the friction stirrer 105 affects the assembled state of the piston 17 can be reduced, for example, it becomes impossible to insert the contact portion to the convex portion 43B which is the bottom portion.

  Further, the outer diameter dimension of the annular surface 83b, which is the outer diameter dimension of the core 80 in contact with the annular bottom wall 50, is equal to or larger than the outer diameter dimension of the flat portion 17c formed on the annular bottom wall 50 side of the piston 17. The outer shape of the edge of the annular surface 83b that faces the bottom of the bore 26 of the core 80 is larger than the outer shape of the edge of the flat surface 17c that faces the bottom of the bore 26 of the piston 17. Therefore, the annular bottom wall 50 can be supported in a wider area by the core 80, the amount of bending of the annular bottom wall 50 due to the extrusion force received from the joining tool 71 is reduced, and the extruded portion is softened. The amount of extrusion can be suppressed. Therefore, even if the phase of the extending portion 105b of the friction stirrer 105 substantially matches the phase of the opening in the bore 26 of the communication passage 35, the extruded portion can be prevented from reaching this opening. Therefore, the flow path by the communication path 35 can be ensured satisfactorily.

  In other words, the core 80 and the piston 17 are formed by forming the chamfered portion 83c and the chamfered portion 17b at the respective edges of the annular surface 83b and the flat surface portion 17c facing the bottom side of the bore 26. The outer diameter of the annular surface 83b, which is the outer diameter of contact with the annular bottom wall 50, is larger than the outer diameter of the flat surface portion 17c formed on the annular bottom wall 50 side in the piston 17, and the chamfered portion in the core 80 is formed. Since the outer peripheral diameter of 83 c is larger than the outer peripheral diameter of the chamfered portion 17 b of the piston 17, a part of the annular bottom wall 50 or the lid member 43 softened by friction stir welding is bored by the pressure from the welding tool 71. Even if it is pushed inward, it will be pushed outside the contact outer diameter of the core 80. Therefore, the extruded portion by the friction stir welding is outside the movable range of the flat portion 17c and the cylindrical surface 17a of the bottom portion 19 of the piston 17 assembled in the bore 26, and the extruded portion of the friction stirring portion 105 interferes to cause the piston 17 to move. The possibility that the friction stirrer 105 affects the assembled state of the piston 17 can be reduced, for example, because the friction stirrer 105 cannot be inserted to the position of contact with the convex portion 43B which is the bottom of the bore 26.

  The core 80 and the piston 17 are formed by forming a chamfered portion 83c and a chamfered portion 17b at the respective edges of the annular surface 83b and the flat surface portion 17c facing the bottom side of the bore 26. The outer diameter of the annular surface 83b, which is the outer diameter of contact with the bottom wall 50, is larger than the outer diameter of the flat portion 17c formed on the annular bottom wall 50 side of the piston 17, and the chamfered portion 83c of the core 80 is formed. Is formed larger than the outer peripheral diameter of the chamfered portion 17 b of the piston 17, the annular bottom wall 50 can be supported by the core 80 in a wider area, and the annular shape due to the pushing force received from the joining tool 71 is obtained. The amount of bending of the bottom wall 50 becomes small, and the amount of extrusion of the softened extruded portion can be suppressed. Therefore, even if the phase of the extending portion 105b of the friction stirrer 105 substantially matches the phase of the opening in the bore 26 of the communication passage 35, the extruded portion can be prevented from reaching this opening. Therefore, the flow path by the communication path 35 can be ensured satisfactorily.

It is a front view of a disc brake manufactured by one embodiment of the present invention. It is a rear view of the caliper manufactured in the embodiment. It is AA sectional drawing of FIG. 2 which shows the caliper manufactured in the embodiment. The caliper body manufactured by the embodiment is shown, (a) is a sectional view of the caliper body main body, (b) is a rear view of the lid member, and (c) is a side view of the lid member. The caliper body main body manufactured by the embodiment is shown, (a) is a sectional view, (b) is a BB sectional view of (a). It is a side view of the welding tool for friction stir welding used in the embodiment. The core and core set plate used by the embodiment are shown, (a) is a top view, (b) is CC sectional drawing of (a). It is a front view of the core used in the embodiment. It is a front sectional view showing the embodiment. It is a front sectional view showing the embodiment. It is a front sectional view showing the embodiment. It is a front sectional view showing the embodiment. The same embodiment is shown, (a) is the front view which made the caliper body main body a cross section, (b) is a top view. It is the front view which made the caliper body main body and cover member which show the same embodiment a section. It is the front view which made the caliper body main body and cover member which show the same embodiment a section. It is a fragmentary sectional view of the caliper body manufactured in the embodiment.

Explanation of symbols

1 Disc brake 12 Disc 17 Piston 17b Chamfered portion 17c Plane portion 21 Inner side cylinder (cylinder)
26 Bore 33 Brake pad 43 Lid member 45 Opening 46 Caliper body body (Cylinder body)
50 annular bottom wall 80 core (supporting member)
83c Chamfer

Claims (2)

A bore in which a piston that presses a brake pad against a disk slides, an opening formed on the bottom side of the bore with an inner diameter smaller than the inner diameter of the bore, and an annular bottom wall formed along the inner periphery of the opening Cutting the inner peripheral surface of the bore of the cylinder body having:
The piston has an outer diameter that is larger than the outer diameter of the flat portion formed on the annular bottom wall side of the piston, and is formed on the edge of the surface of the piston that faces the bottom side of the bore. Inserting a support member having a chamfered portion with an outer peripheral diameter larger than the outer peripheral diameter of the chamfered portion into the bore and abutting the annular bottom wall from the inside of the bore;
The annular bottom wall side having the same thickness as the annular bottom wall and inserting a lid member having an outer diameter substantially equal to the inner diameter of the opening portion into the opening portion to contact the support member;
Joining the lid member and the annular bottom wall by friction stir welding;
A method of manufacturing a disc brake having   The outer shape of the edge of the surface facing the bottom side of the bore is formed such that the outer shape of the edge of the surface of the piston facing the bottom side of the bore of the piston bulges. A method for manufacturing a disc brake according to claim 1.

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