JP2011112199A - Machining method of brake shoe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a machining method of a brake shoe, by which a punching method is improved to reduce the costs by shortening the time of machining a workpiece or dressing a machining tool, etc. <P>SOLUTION: The method for machining a contact surface of a brake shoe body 20 brought in contact with an anchor member using a punching member 30 and a die member 40 includes the process for forming the brake shoe body 20 so that the contact surface is T-shaped by a shoe web 20a and a shoe rim 20b, the process for preparing the punch member 30 in which a punching blade 32 having a wed side cutting edge 33 for punching one end of the shoe web 20a and a rim side cutting blade 34 for punching one end of the shoe rim 20b is provided in a punching body 31, and the process for punching the shoe rim 20b by the rim side cutting blade 34 of the punch member 30 and for punching the shoe web 20a by the web side cutting edge 33. The contact surface is machined with a predetermined machining tolerance by the punching blade 32. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for processing a brake shoe used in a drum brake.

  A drum brake mounted on a vehicle has an abutment surface of one end of a pair of brake shoes in contact with an anchor member provided between one end of a pair of brake shoes to be expanded so that an anchor reaction from the brake shoe is reversed. A structure that holds and receives force is known (see Patent Document 1).

JP 2007-127187 A

  In such a drum brake, in order to reduce the wear and deformation of the contact surface of the brake shoe as a workpiece that contacts the anchor member, and to make the sliding state with the anchor member smooth, As the processing of the contact surface at one end, a milling tool 101 such as a cutter having a plurality of cutting blades 100 on the circumference as shown in FIG. 13 is used to cut the contact surface 103 of the brake shoe 102. Yes.

  However, the cutting with the milling tool 101 can satisfy the surface finish state of the contact surface 103, but the processing time becomes long because of the continuous fine grinding, and the cutting tool 100 of the milling tool 101 is also dressed. Therefore, there is a need for a proposal of a new processing technique for reducing the cost by reducing the processing time, the dressing time, and the like.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a brake shoe machining method in which a punching method is improved in order to shorten the time required for machining a workpiece or dressing a machining tool to reduce costs.

  In order to solve the above-described problems, the present invention provides a brake shoe machining method in which a contact surface of one end portion of a brake shoe body that is in contact with an anchor member of a drum brake is processed using a punch member and a die member. The brake shoe so that the abutment surface of the one end is formed into a T shape by a belt-like shoe web curved in an arc shape and a belt-like shoe rim projecting in the thickness direction from the outer circumference of the shoe web in the thickness direction. A step of forming a main body, a web-side cutting edge for punching one end of the shoe web, which is one side of the T shape on the contact surface, in a thickness direction thereof, and a T-shape on the contact surface. The punch member in which a punching blade portion having a rim side cutting edge for punching one end of the shoe rim on the other side in the width direction is provided on the punch body portion is used. And after holding the brake shoe main body with the die member, the punch member is moved in the punching direction, and the shoe rim is punched by the rim side cutting edge of the punching blade portion of the punch member, and A step of punching the shoe web with the web-side cutting edge, wherein the contact surface of one end portion of the brake shoe body is processed with a predetermined cutting allowance by the punching blade portion.

  With the above configuration, punching with a punch member completes the processing of the T-shaped contact surface by a single punching operation, so that the processing time can be reliably shortened compared to milling. Since the punching blade part of the punch member is also a single body, it can be simplified compared to dressing of a milling tool having a plurality of cutting edges, so that the processing cost of the contact surface of one end of the brake shoe body can be reduced. Can provide a method.

  In order to solve the above problems, in the brake shoe processing method according to the present invention, the rim side shear is inclined so that scrap generated by punching is discharged to the rim side cutting edge on the side opposite to the shoe web in the punching direction. In addition to the above-mentioned effects, scrap generated by the rim side cutting edge can be discharged, and at the same time, by reducing the offset load on the shoe rim, It is possible to provide a processing method capable of preventing deformation.

  In order to solve the above-described problem, in the brake shoe processing method of the present invention, a connection point between the rim side cutting edge and the web side cutting edge of the punching blade portion is a T-shaped side on the contact surface. By being punched so as to pass through the connection point with the other side, scrap generated by the rim side cutting edge does not become an obstacle such as biting when the shoe web is punched by the web side cutting edge. Therefore, the finish of the processed surface of the contact surface becomes good.

  In order to solve the above-mentioned problem, in the brake shoe processing method of the present invention, the shaving body having the web-side cutting edge and the rim-side cutting edge in the punch body portion upstream of the punching blade portion in the punching direction. By providing a blade portion and shaving the punching surface processed by the punching blade portion with the shaving blade portion, the processing accuracy (surface state) of the contact surface by the shaving processing is increased. Is made possible by a single punching operation.

  In order to solve the above-mentioned problems, in the brake shoe machining method of the present invention, the shaving blade portion is provided in a plurality of stages in the punching direction. It is possible to raise the surface state in steps by a single punching operation.

  In order to solve the above-described problem, in the brake shoe processing method of the present invention, during the punching of the contact surface of the brake shoe body by the punching blade, the next shaving blade is the punching blade. Since it is characterized by starting shaving processing of the processed punched surface, it can be processed with a single punching operation from the processing with the punching blade to the shaving processing to be finished, so the processing time can be shortened It will be beneficial.

  In order to solve the above problems, in the brake shoe processing method of the present invention, the contact surface of the brake shoe body is formed in a convex shape, and specifically, with the anchor member. Since the sliding resistance can be reduced and smooth sliding can be ensured, the rotation function centered on one end side of the pair of brake shoes can be improved.

1 is a schematic plan view of a drum brake having a brake shoe according to the present invention. AA schematic sectional drawing of FIG. The top view of a brake shoe. The fragmentary sectional view of an expansion apparatus. The schematic diagram of the contact part of an anchor member and a brake shoe main body. The schematic diagram of the contact surface of the one end part of a brake shoe main part. The schematic diagram of the state which processes a contact surface same as the above with a punch member. The outline perspective view of a punch member same as the above. The side view of a punch member same as the above. The top view of a punch member same as the above. The schematic diagram of the processing state in a shaving blade part and a punching blade part. The schematic diagram of the processing state of the contact surface of a brake shoe main body. The schematic diagram of the example of processing of the brake shoe by a milling tool.

  Hereinafter, embodiments of the invention will be described with reference to the drawings. First, when explaining the processing method of a brake shoe of the present invention, a drum brake using a brake shoe which is a target product of the processing method will be described. 1 is a schematic plan view of a drum brake having a brake shoe, and FIG. 2 is a schematic cross-sectional view taken along line AA of FIG.

  1 and 2, the drum brake 1 is a duo-servo type having an internally expanded brake shoe 2 used as a parking brake in the center, and includes a hat-type brake disk 3. The brake disk 3 has a disc-shaped outer peripheral portion 3a and a bottomed cylindrical central portion 3b, and the disc-shaped outer peripheral portion 3a serves as a frictional part, exhibits a disc brake function, and has a bottomed cylindrical shape. The central portion 3b serves as a friction portion and is configured to exhibit a brake drum function.

  The drum brake 1 is formed in a substantially disc shape, and includes a backing plate 4 that is integrally fixed to a vehicle body side member that is a non-rotating member such as an axle housing (not shown) or a suspension device. A disc cover 4 a for protecting the disc-like outer peripheral portion 3 a of the brake disk 3 is fixed to the outer peripheral portion of the backing plate 4.

  The above-described brake shoe 2 is disposed on the backing plate 4. The brake shoes 2 are symmetrically disposed on the outer peripheral side of the backing plate 4 so as to be close to and away from each other in a posture in which the convex side is outward toward the bottomed cylindrical central portion 3b that exhibits the brake drum function. .

  As shown in FIG. 3, the brake shoe 2 has a flat plate shape substantially parallel to the plate surface 4 b of the backing plate 4, and the brake shoe main body 20 having a shape that is curved in an arc shape as a whole. And a lining 21 made of a friction material which is integrally fixed to the outer peripheral side with a thermosetting resin adhesive or the like.

  The brake shoe main body 20 is curved in a circular arc shape that is integrated with the shoe web 20a that is curved in an arc shape and protrudes in the thickness direction T of the shoe web 20a along the arc shape of the outer peripheral edge thereof. And a belt-like shoe rim 20b. Specifically, a resistance is generated between the edge of the belt-like shoe web 20a made of a steel plate punched into a circular arc shape and the inner peripheral surface of the belt-like shoe rim 20b bent in a circular arc shape. They are integrated by joining together by welding or fillet welding to form a T-shaped cross section.

  In order to dispose the brake shoe 2 on the backing plate 4, the expansion device 5 that expands the pair of brake shoes 2 and the one end portions 2 a of the pair of brake shoes 2 are always urged toward each other. In order to come into contact with the expansion device 5, it is interposed between a return spring 6 stretched between its one end 2 a and the other end 2 b of the pair of brake shoes 2. Is changed (elongated), and the gap adjusting device 8 that adjusts the gap between the pair of brake shoes 2 and the other end 2b are always urged in the direction approaching each other to sandwich the gap adjusting device 8. In order to generate an urging force, a coiled spring 9 is provided which is stretched between the other ends 2b of the pair of brake shoes 2.

  An intermediate portion of the spring 9 is brought into contact with the adjustment wheel 7 of the gap adjusting device 8 so that the adjustment wheel 7 does not rotate due to vibration or the like. The gap adjusting device 8 and the spring 9 connect the other end portions 2b of the pair of brake shoes 2 so as to be relatively rotatable, and function as a connecting device having a gap adjusting function.

  The return spring 6 is made of a spring steel wire rod, and hook portions 6a bent in a hook shape are formed at both ends thereof. The hooking portion 6a is hooked in a through hole 20a1 formed in the shoe web 20a, thereby being stretched between the one end portions 2a of the pair of brake shoes 2 with a predetermined tension. When the return spring 6 is stretched in such a posture, the one end portions 2a of the pair of brake shoes 2 are urged toward each other, and the pair of brake shoes 2 are centered on the one end portion 2a. Rotational force that tries to rotate in the direction in which the middle parts of the two come closer to each other works.

  The backing plate 4 is provided with a shoe hold-down device 4c for holding the pair of brake shoes 2 so as to be able to move relative to the backing plate 4 in the surface direction.

  Further, as shown in FIG. 4, the spreading device 5 is a floating type that can move in the surface direction with respect to the backing plate 4. Specifically, the lever 12 and the strut 13 are connected to each other so as to be relatively rotatable by a connecting pin 11 disposed in a posture substantially parallel to the plate surface 4 a of the backing plate 4.

  The lever 12 is composed of two metal plates, and one end side connected to the connecting pin 11 is integrally overlapped so as to be in close contact with each other, and on the one end 2a side of one brake shoe 2 An engaging recess 12a is provided to be engaged with the shoe web 20a. Further, the other end side of the lever 12 is separated from each other by a predetermined dimension, and a bifurcated plate-like cable hooking portion 12b is provided. A hooking member 14 a fixed to the tip of the parking brake cable 14 is hooked on the cable hooking portion 12 b.

  The strut 13 is also composed of two metal plates, and is provided with a bifurcated arm plate portion 13a that is separated from each other by a predetermined dimension. The lever 12 is disposed inside the arm plate portion 13a, and the other end side 13c opposite to the connecting pin 11 is bent inward so as to be in close contact with each other, and is integrally overlapped. The other end 13c is provided with an engaging recess 13b that is engaged with the shoe web 20a on the one end 2a side of the other brake shoe 2.

  The lever 12 is provided with a leaf spring 12c bent in a predetermined shape, guides the latching member 14a of the parking brake cable 14 to the cable latching portion 12b, and is once inserted into the cable latching portion 12b. The latch member 14a is prevented from being detached.

  In addition, on the plate surface 4a of the backing plate 4 on which the pair of brake shoes 2 are disposed, a plurality of pieces are provided between the one end portions 2a of the pair of brake shoes 2 and on the backing plate 4 side of the spreading device 5. The anchor member 16 and the backing plate 4 are integrally fixed to a vehicle body side member such as an axle housing or a suspension device by the bolt 15.

  As shown in FIG. 5, the anchor member 16 includes a plate-like base portion 16 a and a thick plate that is a part of the base portion 16 a and is erected in a direction away from the backing plate 4 from the outer peripheral side position of the spreading device 5. And an anchor block portion 16b. The base portion 16a is fixed to the backing plate 4.

  The base portion 16a of the anchor member 16 is provided with a guide surface 16c for contacting the side surface of the shoe rim 20b located at one end portion 2a of the pair of brake shoes 2 and guiding it in a direction parallel to the backing plate 4, The side surface of the shoe rim 20b is received by the guide surface 16c.

  The anchor block portion 16b of the anchor member 16 receives and holds the anchor reaction force from the brake shoe 2, and the pair of circumferential end surfaces 16b1 of the anchor block portion 16b are subjected to the urging force of the return spring 6. Therefore, the contact surface 2a1 of the one end 2a of the pair of brake shoes 2 (brake shoe main body 20) is in contact. As shown in FIG. 6, the contact surface 2a1 has a T-shape and is formed in a convex shape (R-shaped) in the width direction of the shoe web 20a. The end surface 16b1 of the anchor block portion 16b is formed. The sliding resistance is reduced to ensure smooth sliding.

  As shown in FIG. 4, the spreading device 5 is supported in contact with the head portion 15 a of the bolt 15, and the parking brake cable 14 is inserted into the base portion 16 a of the anchor member 16 and the backing plate 4. Insertion holes 17 and 18 are provided. A guide pipe 19 that accommodates the parking brake cable 14 on the inner peripheral side is inserted through the insertion holes 17 and 18 and is crimped thereto.

  In the drum brake 1 configured as described above, when the operation force from the parking brake lever in the pulling direction is transmitted to the expansion device 5 via the parking brake cable 14, the connecting pin 11 is moved closer to the backing plate 4 side. As a result, the distance between the engagement recess 12a and the engagement recess 13b, that is, the upper end side of the pair of brake shoes 2 is expanded, and a braking force is generated. On the other hand, when the operating force is returned, the brake shoe 2 is reduced in diameter according to the urging force of the return spring 6 and the braking force is released.

  Thus, the brake shoe 2 according to the present invention used for the drum brake 1 includes a belt-like shoe web 20a curved in an arc shape, and a belt-like shoe rim 20b protruding in the thickness direction from the arc outer periphery side of the shoe web 20a. Thus, the brake shoe main body 20 is formed in a T-shaped cross section.

  And since the contact surface 2a1 of the one end part 2a of the brake shoe main body 20 is contact | abutted to the side surface 16b1 of the anchor block part 16b, it is formed in convex surface shape (Ru surface shape) in the width direction of the shoe web 20a. . And in order to make this contact state favorable, the processing method by the punching process for processing the surface form of the contact surface 2a1 precisely is employ | adopted.

  As shown in FIGS. 7 to 10, this punching method is punched to create a contact surface 2a1 in which the punching direction F is the thickness direction T of the shoe web 20a and the width direction W of the shoe rim 20b. A punching member 30 for processing is used. The punch member 30 is punched (given a shearing force) in cooperation with a die member 40 fixed as a lower die. The punch member 30 is moved up and down by a crank or hydraulic force of a press machine (not shown), and the slide portion 50 for transmitting the driving force of the press to the punch member 30 moves up and down so as to push the punch member 30 downward. Yes.

  The punch member 30 includes a punching blade portion 32 that protrudes from the punch main body portion 31 moving in the punching direction F to the contact surface 2a1 side of the one end portion 2a of the brake shoe main body 20 so as to intersect the punching direction F. The portion 32 has a web-side cutting edge 33 and a rim-side cutting edge 34 for punching the shoe web 20a and the shoe rim 20b of the brake shoe main body 20, respectively.

  The connection point P1 between the web side cutting edge 33 and the rim side cutting edge 34 is, at one end 2a of the brake shoe body 20, a shoe web 20a on one side of the T shape and a shoe rim 20b on the other side of the T shape. The connecting point P1 is punched so that the connecting point P1 passes through the connecting point P2.

  The rim side cutting edge 34 has a predetermined rim side shear angle θ1 that is inclined with respect to the punching direction F. The rim side shear angle θ1 is provided so as to be tapered in the punching direction F as the overall shape of the punching blade portion 32. The rim side shear angle θ1 is configured so that scrap generated during punching with the rim side cutting edge 34 can be discharged to the outside of the punch member 30.

  Further, as shown in FIG. 9, for example, the web-side cutting edge 33 of the shaving blade portion 35 and the shaving blade portion 36 (which can also be provided in the punching blade portion 32) has a predetermined web-side shear angle θ2. It may be. The web-side shear angle θ2 is inclined downward toward the contact surface 2a1 side of the workpiece, and scrap generated during punching with the web-side cutting edge 33 can be discharged into the gaps X1 and X2.

  Further, other blade portions can be provided in multiple stages upstream of the punching blade portion 32 in the punching direction F. Specifically, the punching blade portion 32, the shaving blade portion 35, and the shaving blade portion 36 are provided in this order from the most downstream side to the upstream side in the punching direction F. Each blade portion has a web-side blade edge 33 and a rim-side blade edge 34, respectively.

  Further, the interval X1 between the punching blade portion 32 and the shaving blade portion 35 and the interval X2 between the shaving blade portion 35 and the shaving blade portion 36 are the stroke of the slide portion 50 that drives the punch member 30 and the workpiece. It is set in relation to the size of the brake shoe main body 20. Further, as shown in FIGS. 9 and 10, the end surface 37 of each blade portion is formed in a concave shape so as to form the contact surface 2a1 of the one end portion 2a of the brake shoe main body 20 in a convex shape (R-shaped shape). Yes.

  Then, with respect to a predetermined machining allowance by the punching blade part 32, the machining allowance is sequentially reduced as moving to the shaving blade part 35 and the next shaving blade part 36. The shaving blade portions 35 and 36 are for shaving. In this shaving process, as shown in FIG. 11A, which is a schematic diagram of the processed state, the amount of scrap S attached to the shaving blade portions 35 and 36 and the machining allowance so that the thickness of the scrap S does not increase beyond a certain amount. As a result, a steady flow is produced during machining, and an apparently clean punched surface is created. In addition, although the length of the scrap S to show in figure becomes long as a process progresses, it is the schematic diagram which abbreviate | omitted the front side of this figure.

  As shown in FIG. 11 (b), in the machining allowance by the punching blade portion 32, since the amount of the scrap S is large, the resistance is large, the scrap S stops moving, and then the scrap S is lowered when the punch member 30 is lowered. It is considered that the surface rotated as it fits and cracks K enter the surface necessary as a workpiece, and the processed surface becomes rough.

  Here, the shaving process means that a punched portion formed by punching with the punching blade portion 32 of the punch member 30 is punched with the shaving blade portions 35 and 36 in the same manner as the punching blade portion 32, so that a small amount of the punched portion is scraped off and punched. This is a process for removing the rough surface and sagging generated when the blade portion 32 is punched to improve the surface roughness and surface accuracy of the punched portion.

  Further, the die member 40 is for punching the contact surface 2a1 of the one end 2a of the brake shoe main body 20 with a predetermined allowance in cooperation with the punch member 30, and the die member 40 is shown in FIG. As shown, while holding a part or all of the lower side surface 20a1 of the shoe web 20a and the lower side surface 20b1 of the shoe rim 20b of the brake shoe main body 20, the punch member 30 is lowered and punched as shown in FIG. In this case, a passing area space SP is provided so as not to interfere with the punching blade portion 32 and the shaving blade portions 35 and 36 of the punch member 30. This passage area space SP enables the scrap to be discharged to the outside.

  Next, the details of the brake shoe processing method according to the present invention will be described. In this processing method, a brake for processing the contact surface 2a1 of the one end 2a of the brake shoe main body 20 that contacts the anchor member 16 of the drum brake 1 using a punch member 30 and a die member 40 as shown in FIG. A method of processing a shoe, which is a contact surface 2a1 of one end 2a by a belt-like shoe web 20a curved in an arc shape and a belt-like shoe rim 20b protruding in the thickness direction T from the arc outer periphery side of the shoe web 20a. Includes a step of forming the brake shoe main body 20 so as to form a T shape.

  Further, a web-side cutting edge 33 for punching one end of the shoe web 20a, which is one side of the T shape in the contact surface 2a1, in the thickness direction T, and the other side of the T shape in the contact surface 2a1. In order to punch one end of the shoe rim 20b in the width direction W, a punching blade portion 32 having a rim side cutting edge 34 having a rim side shear angle θ1 inclined with respect to the punching direction F is a punch body. A step of preparing a punch member 30 provided in the portion 31 is included.

  Then, after holding the brake shoe body 20 with the die member 40, the punch member 30 is moved in the punching direction F, and the shoe rim 20b is punched by the rim side cutting edge 34 of the punching blade portion 32 of the punch member 30, and the web side It includes a step of punching the shoe web 20a with the cutting edge 33.

  Specifically, after the brake shoe main body 20 is held by the die member 40, the thickness direction T of the shoe web 20a and the width direction W of the shoe rim 20b are punched in the direction of the brake shoe main body 20 set on the die member 40. F is set, and punching is started while the punch member 30 is lowered.

  In this processing method, first, as shown in FIG. 12A, the connection point P1 between the web side cutting edge 33 and the rim side cutting edge 34 of the punching blade portion 32 is the connection point P2 between the shoe web 20a and the shoe rim 20b. Machining starts when the upper end of the shoe rim 20b on the extension line is reached.

  Then, the punch member 30 advances, and the upper side of the shoe rim 20b is punched and processed by the rim side cutting edge 34 of the punching blade portion 32 as shown in FIG. Next, as shown in FIG. 12C, after the connection point P1 of the punching blade portion 32 reaches the connection point P2 of the brake shoe main body 20, the shoe web 20a is punched by the web side cutting edge 33 and processed. Is done. Thus, since the processing of the shoe web 20a starts from the point where the connection point P2 and the connection point P1 match, the scrap generated by the rim side cutting edge 34 does not become an obstacle such as biting during the punching processing by the web side cutting edge 33. Since it is discharged, the finish of the processed surface is good.

  Then, as shown in FIG. 12D, the lower side of the shoe rim 20b is punched by the rim side cutting edge 34 of the punching blade 32, and when the punching by the punching blade 32 reaches a predetermined position, By the web side cutting edge 33 and the rim side cutting edge 34 of the shaving blade portion 35, the shaving processing of the punched surface of the shoe web 20a and the shoe rim 20b previously processed by the punching blade portion 32 is started. Note that the hatched portion in the figure indicates the machining location.

  In the case where the blade portion has a three-stage configuration, the punching process is performed by the front shaving blade portion 35 on the shoe web 20a and the shoe rim 20b by the web side blade edge 33 and the rim side blade edge 34 of the next shaving blade portion 36. The surface is shaved. In this process, the punching process by the next shaving blade part 36 may be started during the punching process by the shaving blade part 35.

  The rim side cutting edge 34 in each blade portion is inclined with respect to the punching direction F (inclined so that scrap generated by punching is discharged on the opposite side to the shoe web 20a with respect to the punching direction F). By providing the shear angle θ1, it is possible to make it easier for the scrap generated during processing to escape, and to reduce the unbalanced load on the shoe rim 20b, so that deformation of the shoe rim 20b does not occur during punching (shear processing). Can be.

  As mentioned above, although embodiment of this invention is described, this invention is not limited to said embodiment, A various change is possible based on the technical idea of this invention.

DESCRIPTION OF SYMBOLS 1 Drum brake 2 Brake shoe 2a One end part 2a1 Contact surface 16 Anchor member 20 Brake shoe main body 20a Shoe web 20b Shoe rim 30 Punch member 31 Punch main body part 32 Punching blade part 33 Web side cutting edge 34 Rim side cutting edge 35, 36 Shaving blade part F Punching direction T Thickness direction W Width direction θ1 Rim side shear angle

Claims (7)

A brake shoe processing method of processing a contact surface of one end portion of a brake shoe body that contacts an anchor member of a drum brake using a punch member and a die member,
The brake shoe main body so that the contact surface of the one end is formed into a T shape by a belt-like shoe web curved in an arc shape and a belt-like shoe rim projecting in the thickness direction from the outer circumferential side of the shoe web. Forming a step;
A web-side cutting edge for punching one end of the shoe web on one side of the T shape in the contact surface in the thickness direction, and the shoe rim on the other side of the T shape in the contact surface A step of preparing the punch member in which a punching blade portion having a rim side cutting edge for punching one end of the punch in the width direction thereof is provided in the punch body portion;
After holding the brake shoe main body with the die member, the punch member is moved in the punching direction, the shoe rim is punched by the rim side cutting edge of the punching blade portion of the punch member, and the web side cutting edge is formed. And punching the shoe web by
A method for processing a brake shoe, wherein the contact surface of one end portion of the brake shoe body is processed with a predetermined cutting allowance by the punching blade portion.   2. The brake according to claim 1, wherein the rim side cutting edge has a rim side shear angle inclined so that scrap generated by punching is discharged on a side opposite to the shoe web with respect to the punching direction. Shoe processing method.   The punching blade part is punched so that the connection point between the rim side cutting edge and the web side cutting edge passes through the connection point between the T-shaped one side and the other side on the contact surface. The method for processing a brake shoe according to claim 1 or 2, characterized in that:   The punch main body portion upstream of the punching blade portion in the punching direction is provided with a shaving blade portion having the web side blade edge and the rim side blade edge, and is processed by the punching blade portion by the shaving blade portion. 4. The brake shoe machining method according to claim 1, wherein the punched surface is shaved.   The brake shoe processing method according to claim 4, wherein the shaving blade portion is provided in a plurality of stages in the punching direction.   During the punching process of the contact surface of the brake shoe main body by the punching blade part, the next shaving blade part starts shaving processing of the punching process surface processed by the punching blade part. A method for processing a brake shoe according to claim 4 or 5.   The brake shoe processing method according to claim 1, wherein the contact surface of the brake shoe body is formed in a convex shape.

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