CN110102680A - The piston of disk brake for vehicle, its manufacturing method and its spinning processing device - Google Patents

Abstract

The present invention provides a method of manufacturing a piston of a disc brake for a vehicle, which does not require preforming a straight cylindrical base material, and uses a pressure roller to perform spinning, so that the outer peripheral end on the side of the opening end and the opening end are formed. The corners between are shaped into the desired rounded shape. In this method, a bottomed cylindrical substrate is rotated, and an annular groove is formed by pressing a groove forming roll having a convex groove forming portion from the outer peripheral surface of the substrate, and the outer peripheral face to push the corner forming roller to form the outer peripheral end on the side of the opening end, the opening end and the corner, wherein the corner forming roller has: The outer peripheral end of the opening end side of the material is in contact; the opening end forming part is in contact with the opening end of the base material; The corner between the end and the open end is shaped.

Description

Piston of disc brake for vehicles, manufacturing method thereof, and spinning device thereof

technical field

The present invention relates to a method for manufacturing a piston of a disc brake for a vehicle, a spinning device for a piston of a disc brake for a vehicle, and a piston for a disc brake for a vehicle.

Background technique

A piston (hereinafter simply referred to as a piston) of a disc brake for a vehicle has a cylindrical shape with a bottom, and has an outer peripheral surface capable of sliding relative to an inner peripheral wall of a cylinder body; and an open end capable of abutting against a friction pad. . An annular groove is formed in the outer peripheral end of the piston on the opening end side of the outer peripheral surface, and a rubber sheath for waterproof and dustproof is attached to the annular groove.

Conventionally, as a spinning device for pistons, there is known a spinning device that can rotate a base material (raw material) produced by forging iron, aluminum, etc. Plastic working is performed on the base material (Patent Document 1: JP-A-2014-61534).

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2014-61534

Contents of the invention

The problem to be solved by the invention

The piston spinning device described in Patent Document 1 includes: a collet capable of rotating a base material; a first roller for forming an annular groove in the base material; and a second roll for forming an annular groove on the base material. forming an opening end; and a core pusher capable of pressing and supporting the bottom of the base material from the opening side of the base material. In Patent Document 1, a straight cylindrical base material is preformed into a shape with a narrowed opening, and then the base material having a narrowed opening is formed using the first roll and the second roll. material for spinning. The conventional second roll has a simple straight cylindrical shape, and the shape of the corner portion of the base material formed by forging is left as it is. However, when the above-mentioned corner is a needle point corner, stress concentrates on the needle point corner, resulting in impaired durability of the needle point corner. Therefore, in order to prevent the above-mentioned corners from becoming needle point corners, preforming is required, and there is a problem that processing costs increase because preforming increases the number of processing steps.

What is not conceived in Patent Document 1 is that the corner portion of the piston between the outer peripheral end portion on the opening end side and the opening end portion is formed by spinning. Furthermore, the second roll has a structure that does not receive a load in a direction perpendicular to the rotation axis when the annular groove is formed on the base material by the first roll. A core pusher that presses and supports the bottom of the substrate on the opening side. However, there are problems in that the installation of the core push rod and its peripheral mechanism increases the cost of equipment, and that the cycle time becomes longer when the core push rod enters and exits.

solutions to problems

The present invention has been made in view of the above circumstances, and its object is to provide the following: a method for manufacturing a piston of a disc brake for a vehicle, by which method, there is no need to preform a straight cylindrical base material, and by using Predetermined pressure rollers perform spinning on a base material, thereby forming a corner between an opening end side outer peripheral end and an opening end into a desired fillet shape; a spinning of a piston of a disc brake for a vehicle A press working device capable of forming a corner between an open end side outer peripheral end and an open end into a desired rounded shape; and a piston for a disc brake for a vehicle, in which The corner between the outer peripheral end on the opening end side and the opening end has a desired rounded shape.

As a technical solution, the above-mentioned problem is solved by a solution disclosed below.

The present invention is a method of manufacturing a piston of a disc brake for a vehicle. The manufacturing method is carried out by spinning. The outer peripheral surface of the base material is pressed by a groove forming roll having a convex groove forming portion to form an annular groove on the outer peripheral surface, and a corner portion is formed from the opening end and the outer peripheral surface. The roller is pressed to form the outer peripheral end on the side of the opening end, the opening end, and the corner, wherein the corner forming roller has an outer peripheral end forming portion that is connected to the base The outer peripheral end of the opening end side of the base material is in contact with; the opening end forming part is in contact with the opening end of the base material; A corner between the end-side outer peripheral end and the opening end is shaped.

According to the present invention, the shape of the concave corner forming portion formed on the corner forming roll is transferred to the corner between the opening end side outer peripheral end portion and the opening end portion. Therefore, it is not necessary to preform into a shape with a narrow opening as in the prior art, and the processing steps can be reduced, so that the processing cost can be suppressed. Furthermore, even for a straight-cylindrical substrate, the corner can be formed into a desired convex shape by the corner forming roller.

In the present invention, it is preferable that, when the corner forming roll contacts the substrate and the corner forming roll forms the opening end side outer peripheral end, the opening end, and the After the corner, the annular groove is formed by the groove forming roller without the groove forming roller abutting against the outer peripheral end on the opening end side. After the opening end side outer peripheral end is formed by the corner forming roll, it is not formed by the groove forming roll, so that the opening end side outer peripheral end, the Dimensional accuracy of the opening end and the corner.

In the present invention, it is preferable to support the base material not from the opening side of the base material but to support the base material from the outer peripheral surface side of the base material, and to use the groove forming roll and The corner forming rollers are used to shape the substrate. By pressing the corner forming roller from the opening end and the outer peripheral surface, the base material is supported from the opening side of the base material. By side supporting the bottom of the substrate, it is possible to omit a core pusher as in the prior art, thereby enabling a shorter cycle time.

The present invention is a spinning device for a piston of a disc brake for a vehicle, characterized in that the spinning device for a piston of a disc brake for a vehicle has: The bottom of the substrate is supported by the opening side of the substrate, and the substrate is supported from the outer peripheral surface of the substrate, and the rotating part can rotate the substrate around the first rotation axis; the groove forming roller is a cylindrical shape, the groove forming roller rotates around the second rotation axis, and has a convex groove forming portion for forming an annular groove on the outer peripheral surface of the base material; and a corner forming roller, which It is cylindrical, and the corner forming roller rotates around the third rotation axis, and has an outer peripheral end forming part, an opening end forming part and a corner forming part, and the outer peripheral end forming part is used for forming the The outer peripheral end on the side of the opening end of the base material is formed, the opening end forming part is used to form the opening end of the base material, and the corner forming part is in a rounded shape and is used to align with the opening The corner between the end-side outer peripheral end and the opening end is shaped, the second rotation axis is in a direction parallel to the first rotation axis, and the third rotation axis is in a direction parallel to the first rotation axis. The direction perpendicular to the rotation axis, and the groove forming roller moves in a direction that brings the groove forming portion closer to the first rotation axis, so that the groove forming portion abuts against the outer peripheral surface, and the The corner forming roller moves in a direction to bring the open end forming portion closer to the opening end of the substrate, and toward bringing the outer peripheral end forming portion and the corner forming portion closer to the first rotation axis. moving in the direction of the opening end so that the opening end forming part abuts against the opening end.

With the present invention, the substrate rotates about the first axis of rotation. The groove forming roller moves toward the direction of bringing the groove forming portion closer to the first rotation axis to abut against the outer peripheral surface, rotates about the second rotation axis, and moves toward the outer periphery. Pressing against the groove forming portion forms an annular groove on the outer peripheral surface. And, the corner forming roller moves in a direction to bring the opening end forming part closer to the opening end of the base material, and the corner forming roll moves the outer peripheral end forming part and the The corner forming portion is moved in a direction closer to the first rotation axis so that the opening end forming portion abuts against the opening end. In addition, the outer peripheral end forming portion is in contact with the opening end side outer peripheral end, and the corner forming portion is in contact with the corner, and the corner forming roller rotates around the third rotation axis. The opening end forming portion is pressed toward the opening end while rotating about the axis. Then, the outer peripheral end forming portion is pressed toward the opening end side outer peripheral end. And, the corner forming part is pressed against the corner. Thus, the outer peripheral end portion on the side of the opening end is formed, the opening end portion is formed, and the corner portion is formed.

Here, in a front view with the first rotation axis as an axis, the outer peripheral end on the side of the opening end, the opening end, and the corner of the base material respectively form the base. The outline of the material. The corner forming roller moves the open end forming portion closer to the open end of the base material with respect to the open end and closer to the first axis of rotation so as to be compatible with the open end forming portion. The opening end is abutted against, and the outer peripheral end forming part is moved to a direction closer to the opening end of the base material with respect to the opening end side of the outer peripheral end and to a direction closer to the first rotation axis. moving so as to come into contact with the outer peripheral end on the side of the opening end, and move the corner forming portion closer to the opening end of the base material relative to the corner and closer to the first rotation. The direction of the axis moves to abut against the corner. As a result, the corner forming roll comes into line contact with the base material along the contour line of the base material, so the load on the corner forming roll can be reduced, and the durability of the corner forming roll can be improved. Sex has improved. Moreover, by pressing the corner forming roller from the opening end and the outer peripheral surface, the base material can be supported from the opening side of the base material. The opening side of the substrate supports the bottom of the substrate, and the core push rod in the prior art can be omitted, thereby reducing equipment cost and maintenance cost.

In the present invention, it is preferable that the corner forming roller is brought into contact with the base material, and the corner forming roller makes the outer peripheral end on the side of the opening end, the opening end, and the corner The annular groove is formed by the groove forming roller under the premise that the groove forming roller does not come into contact with the outer peripheral end portion on the side of the opening end. The opening end side outer peripheral end is not formed by the groove forming roll, so the opening end side outer peripheral end formed by the corner forming roll, the opening end and The dimensional accuracy of the corners.

In the present invention, preferably, the groove forming roll has a symmetrical shape on one side in the axial direction and on the other side in the axial direction with respect to the center of the second rotation axis in the axial direction. The use of both the one side in the axial direction and the other side in the axial direction for the groove forming rolls can halve the number of the groove forming rolls in stock, thereby reducing equipment costs.

In the present invention, preferably, the corner forming roller has a symmetrical shape on one side in the axial direction and on the other side in the axial direction based on the center of the third rotation axis in the axial direction. The corner forming rolls use both sides, one in the axial direction and the other in the axial direction, so that the number of the corner forming rolls in stock can be halved, thereby reducing equipment cost.

The piston of the disc brake for vehicles according to the present invention is characterized in that the piston of the disc brake for vehicles has a bottomed cylindrical shape and has an open end, an outer peripheral surface, an inner peripheral surface and a bottom. An annular groove is formed at the outer peripheral end on the opening end side, a protruding portion is formed at a position corresponding to the annular groove in the inner peripheral surface, and a protruding portion is formed at the outer peripheral end on the opening end side and the The corners between the opening ends are rounded, and the outer peripheral end on the side of the opening, the opening end, and the corners are continuous spinning surfaces.

According to the present invention, since the outer peripheral end portion on the opening end side, the opening end portion, and the corner portion are continuous spinning surfaces, it is possible to improve dimensional accuracy.

The effect of the invention

According to the method for manufacturing a piston of a disc brake for a vehicle disclosed in the present invention, the shape of the concave corner forming portion formed on the corner forming roller is transferred to the outer periphery on the side of the opening end. At the corner between the end portion and the opening end portion, a desired convex round shape can be formed, therefore, it is not necessary to preform into a shape in which the opening portion is narrowed as in the prior art, and the processing steps can be reduced. Therefore, Processing cost can be suppressed. Furthermore, even for a straight-cylindrical substrate, the corner can be formed into a desired convex shape by the corner forming roller. Furthermore, the corner forming roller can function to support the base material from the opening side of the base material, and therefore, it is not necessary to support the bottom of the base material from the opening side of the base material. Therefore, it is possible to omit the core pusher as in the prior art, and the operation of the core pusher is unnecessary, so that the cycle time can be shortened.

According to the manufacturing apparatus of the piston of the disc brake for vehicles disclosed in the present invention, the corner forming roller is in line contact with the base material along the contour line of the base material, so the pressure of the corner forming roller can be reduced. The durability of the corner forming roll can be improved due to the received load. Moreover, since the corner forming roller is pressed from the opening end and the outer peripheral surface, the base material is supported from the opening side of the base material, and therefore, there is no need to press the corner forming roller from the opening side of the base material. The opening side of the substrate supports the bottom of the substrate, and the core push rod in the prior art can be omitted, thereby reducing equipment cost and maintenance cost.

According to the piston of the disc brake for vehicles disclosed in the present invention, the outer peripheral end portion on the side of the opening end, the opening end portion, and the corner portion are continuous spinning surfaces, so that the dimensional accuracy can be improved. improve.

Description of drawings

FIG. 1 is a schematic configuration diagram showing a main part of a spinning device for a piston of a disc brake for a vehicle according to an embodiment of the present invention, and is a perspective view.

2A is a front view showing an example of a groove forming roller in a spinning device for a piston of a disc brake for a vehicle according to the above-mentioned embodiment, and FIG. 2B is a view showing spinning of a piston for a disc brake for a vehicle according to the above-mentioned embodiment. Plan view of an example of groove forming rolls in the apparatus.

3A is a front view showing an example of a corner forming roller in a spinning device for a piston of a disc brake for a vehicle according to the above-mentioned embodiment, and FIG. 3B is a diagram showing spinning of a piston for a disc brake for a vehicle according to the above-mentioned embodiment. A plan view of an example of a corner forming roll in a processing device.

Fig. 4 is a schematic structural view showing an example of a base material before being spun, and is a one-sided cross-sectional view.

FIG. 5 is a schematic configuration diagram showing an example of a piston of a disc brake for a vehicle according to the present invention, and is a one-sided cross-sectional view.

Fig. 6 is a partially enlarged view of the above-mentioned piston.

Fig. 7 is a schematic configuration diagram showing the operation of spinning the above-mentioned base material by the spinning device for the piston of the disc brake for vehicles according to the above-mentioned embodiment, and is a cross-sectional view showing a state immediately before spinning .

Fig. 8 is a schematic structural view showing the spinning operation of the base material by the spinning device for the piston of the disc brake for vehicles according to the above embodiment, showing the state immediately after the spinning is completed; cutaway view.

9 is a schematic configuration diagram showing the operation after spinning the base material by the spinning device for the piston of the vehicle disc brake according to the embodiment, and is a cross-sectional view showing a state immediately after the spinning is completed. .

Detailed ways

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a main part of a spinning machine 1 according to this embodiment, and is a perspective view. In addition, in all the drawings for describing the embodiments, members having the same functions are given the same reference numerals, and overlapping descriptions thereof may be omitted.

The spinning device 1 of the present embodiment is a spinning device 1 for a piston of a disc brake for a vehicle which spins a bottomed cylindrical base material 15 (hereinafter abbreviated as a spinning device 1 ). . As an example, the base material 15 is a forged product made of carbon steel for machine structure or the like.

As a specific structure, the spinning apparatus 1 has: a rotating part 2 that rotates around a first rotation axis P1 while holding a base material 15; and a groove forming roller 3 that is synchronized with the base material 15 around a second rotation axis P2. rotation, the second axis of rotation P2 is at a position parallel to the first axis of rotation P1; and the corner forming roller 4 is rotated synchronously with the substrate 15 about the third axis of rotation P3, which is at a position parallel to the axis of rotation P3. The position where the first axis of rotation P1 is vertical. The third axis of rotation P3 is at a position perpendicular to the second axis of rotation P2. The groove forming roll 3 and the corner forming roll 4 are arranged at positions opposite to each other at an angle of 180° around the first rotation axis P1.

The groove forming roll 3 processes the base material 15 by moving in the direction a1 in which the second rotation axis P2 approaches the first rotation axis P1.

The corner forming roller 4 processes the base material 15 by moving in the b1 direction that brings the third rotation axis P3 closer to the rotary unit 2 and then moves in the a2 direction that brings the third rotation axis P3 closer to the first rotation axis P1. Alternatively, the corner forming roller 4 processes the base material 15 by simultaneously moving in the b1 direction that brings the third rotation axis P3 closer to the rotary unit 2 and the a2 direction that brings the third rotation axis P3 closer to the first rotation axis P1.

2A and 2B are diagrams showing an example of the groove forming roll 3 in the spinning apparatus 1, FIG. 2A is a front view, and FIG. 2B is a plan view. The groove forming roll 3 is formed of hard metal such as tool steel, and has a cylindrical shape that is rotationally symmetrical about the second rotational axis P2. The groove forming roll 3 forms a flat portion 31 , a groove forming portion 32 , a flat portion 33 , a groove forming portion 32 , and a flat portion 31 sequentially from the side closer to the rotating portion 2 . Bearings (not shown) are incorporated in the groove forming roll 3, and are configured to be rotatable by an external force. The groove forming portion 32 has a cylindrical shape slightly larger than both the flat portion 31 and the flat portion 33 , and is convex in front view.

The outer surface of the groove forming roll 3 has a shape in which one side is symmetrical to the other side with respect to a center line S1 perpendicular to the center of the second rotation axis P2 in the axial direction. In FIG. 2A , one side and the other side have a line-symmetrical shape with respect to the center line S1 . According to this configuration, both sides of the groove forming roll 3 can be used, so that the equipment cost can be reduced, and the number of the groove forming rolls which are consumables in stock can be halved.

3A and 3B are diagrams showing examples of corner forming rolls 4 in the spinning apparatus 1 , wherein FIG. 3A is a front view, and FIG. 3B is a plan view. The corner forming roll 4 is formed of hard metal such as tool steel, and has a cylindrical shape that is rotationally symmetrical about the third rotational axis P3. The corner forming roller 4 starts from the side closer to the first rotation axis P1, and sequentially forms an opening end forming portion 41, a corner forming portion 47, an outer peripheral end forming portion 42, a corner forming portion 47, and an opening end forming portion. Part forming part 41. Bearings (not shown) are incorporated in the corner forming roller 4, and are configured to be rotatable by an external force. The outer peripheral end forming portion 42 has a cylindrical shape slightly larger than the opening end forming portion 41 , and is convex in front view. The corner forming portion 47 has a concave rounded shape for forming the convexly rounded corner 21 on the base material 15 .

The outer surface of the corner forming roll 4 has a shape that is symmetrical with respect to a center line S2 perpendicular to the center of the third rotation axis P3 in the axial direction. In FIG. 3A , one side and the other side have a line-symmetrical shape with respect to the center line S2 . According to this structure, both sides of the corner forming roller 4 can be used, so that the equipment cost can be reduced, and the number of corner forming rollers as consumables in stock can be halved.

FIG. 4 is a schematic structural view showing an example of the base material 15 before spinning, and is a one-sided cross-sectional view. The base material 15 has a bottomed cylindrical shape. The base material 15 has a bottom 22 , an inner bottom surface 55 , an outer peripheral surface 18 , and an inner peripheral surface 53 . The outer peripheral surface 18 of the base material 15 has a straight cylinder shape in a front view. The base material 15 has an opening end 19 on the opening side, and an outer peripheral end 20 (opening end side outer peripheral end in this application) on the side of the outer peripheral surface 18 closer to the opening end 19 . Furthermore, a corner portion 21 is provided between the opening end portion 19 and the outer peripheral end portion 20 . The corner portion 21 has an inconspicuous convex rounded shape, but is not limited thereto.

FIG. 5 is a schematic configuration diagram showing an example of the piston 5 according to the present embodiment, and is a one-sided cross-sectional view. The piston 5 is manufactured by spinning the base material 15 with the spinning device 1 . The piston 5 has a bottom 22 , an inner bottom surface 55 , an outer peripheral surface 18 and an inner peripheral surface 53 . Furthermore, an annular groove 54 is formed in a boundary portion between the outer peripheral surface 18 and the outer peripheral end portion 20 .

FIG. 6 is a partial enlarged view of the piston 5 shown in FIG. 5 encircled by a dashed-dotted line V. FIG. Protrusions 59 are formed on the inner peripheral surface 53 of the piston 5 at positions corresponding to the annular grooves 54 . Furthermore, a corner portion 21 located between the opening end portion 19 and the outer peripheral end portion 20 has a convex rounded shape. The shape of the piston 5 will be described later.

FIG. 7 is a schematic configuration diagram showing the operation of the groove forming roll 3 and the corner forming roll 4 when spinning the base material 15 by the spinning device 1 according to this embodiment, and shows the operation immediately before the spinning process. cutaway view of the state. FIG. 8 is a cross-sectional view showing a state immediately after spinning the base material 15 , and is a cross-sectional view showing a state when the piston 5 is configured. 9 is a schematic structural view showing the operation of the groove forming roll 3 and the corner forming roll 4 after spinning the base material 15, and is a cross-sectional view showing the state immediately after the piston 5 is formed.

Next, the manufacturing steps of the piston 5 will be described based on FIGS. 7 to 9 .

First, the outer peripheral surface 18 of the base material 15 is gripped by the clamping mechanism provided in the rotation unit 2 , and the rotation unit 2 is rotated about the first rotation axis P1 while holding the base material 15 . At this time, the bottom portion 22 of the base material 15 is not supported from the opening side of the base material 15 , but the rotation unit 2 is rotated while holding the base material 15 . The rotating part 2 rotates about the 1st rotation axis|shaft P1, for example, about the direction of the arrow c1 which becomes a clockwise direction in planar view. The groove forming roll 3 and the corner forming roll 4 are arranged at positions opposite to each other at an angle of 180° with the first rotation axis P1 as the middle position.

The corner forming roller 4 moves the opening end forming portion 41 in the b1 direction close to the opening end 19 of the base material 15, so that the opening end forming portion 41 abuts against the opening end 19 of the base material 15, and contacts the base material 15. The material 15 rotates synchronously, so that, viewed from the groove forming roll 3 side, the corner forming roll 4 rotates in the direction of the arrow d1 in the counterclockwise direction. Then, in a state of rotating synchronously with the base material 15, the opening end forming part 41 and the outer peripheral end forming part 42 are moved in the a2 direction close to the first rotation axis P1, thereby passing through the opening to the base material 15. The end portion 19 presses the opening end portion forming portion 41 and at the same time presses the outer peripheral end portion forming portion 42 toward the outer peripheral surface 18, thereby forming the opening end portion 19 and the outer peripheral end portion on the side of the opening end portion 19 on the base material 15. 20, and at the same time transfer the concave fillet shape formed on the corner forming portion 47 of the corner forming roll 4 to the corner portion 21 between the opening end portion 19 and the outer peripheral end portion 20, thereby, the base material 15 The corner portion 21 is made into a convex fillet shape. Here, the opening end forming portion 41 is pressed so as to approach the first rotation axis P1 so that a dimension difference ΔH exists between the outer peripheral end portion 20 and the outer peripheral surface 18 .

Alternatively, the corner forming roller 4 moves in the b1 direction that brings the opening end forming portion 41 closer to the opening end 19 of the base material 15, and makes the opening end forming portion 41 and the outer peripheral end forming portion 42 approach the first rotation. The a2 direction of the axis P1 moves so that the opening end forming part 41 abuts against the opening end 19 of the base material 15, and the outer peripheral end forming part 42 abuts against the outer peripheral surface 18, and rotates synchronously with the base material 15, Therefore, when viewed from the groove forming roll 3 side, the corner forming roll 4 rotates in the direction of the arrow d1 in the counterclockwise direction. And, under the state that rotates synchronously with base material 15, corner forming roller 4 moves to b1 direction and a2 direction at the same time, thereby, by pressing opening end forming part 41 toward opening end 19 of base material 15, The outer peripheral end forming part 42 is pushed toward the outer peripheral surface 18, thereby forming the opening end 19 and the outer peripheral end 20 on the side of the opening end 19 on the base material 15, and forming the corner forming roller 4 The concave fillet shape of the corner forming portion 47 is transferred at the corner portion 21 between the opening end portion 19 and the outer peripheral end portion 20 , thereby making the corner portion 21 of the base material 15 into a convex fillet shape. Here, the opening end forming portion 41 is pressed so as to approach the first rotation axis P1 so that the dimension difference ΔH exists between the outer peripheral end portion 20 and the outer peripheral surface 18 . In addition, other than the above cases, the corner forming roll 4 may move in the b1 direction after moving in the a2 direction.

After the corner forming roll 4 comes into contact with the base material 15 and forms the opening end 19, the outer peripheral end 20, and the corner 21, the groove forming roll 3 moves the convex groove forming portion 32 closer to the first rotation axis P1. Direction movement, so that the groove forming part 32 contacts the outer peripheral surface 18 of the substrate 15 and rotates synchronously with the substrate 15, so that the groove forming roller 3 rotates in the direction of the arrow c2 around the counterclockwise direction from a plan view. Further, the convex groove forming portion 32 is further pressed against the outer peripheral surface 18 in a state of synchronous rotation with the base material 15 to form the annular groove 54 . Here, when the groove forming portion 32 is pressed against the outer peripheral surface 18, the flat portion 33 does not come into contact with the outer peripheral end portion 20 and has a gap ΔH'. Then, when forming the annular groove 54, the corner forming roller 4 is moved in the b1 direction to press the opening end 19, the outer peripheral end 20, and the corner 21, thereby forming the piston 5 into a desired size. .

Then, after forming the piston 5 , the groove forming roller 3 moves in the direction a2 that separates the convex groove forming portion 32 from the first rotation axis P1 , thereby leaving the base material 15 . Then, the corner forming roller 4 moves in the direction b2 that separates the opening end forming portion 41 from the opening end 19 of the substrate 15, and moves the opening end forming portion 41 and the outer peripheral end forming portion 42 away from the first rotation axis. The a1 direction of P1 moves away from the substrate 15 . In addition to the above, the corner forming roller 4 may move in the b2 direction first and then move in the a1 direction, or may move in the a1 direction first and then move in the b2 direction. According to this embodiment, the operation of the conventional core pusher (the step of supporting the core pusher before processing and the step of releasing the support of the core pusher after processing) is unnecessary, and cycle time can be shortened. Make the corner forming roll 4 abut against the base material 15 prior to the groove forming roll 3, and form the outer peripheral end 20, the opening end 19 and the corner 21, after that, the groove forming roll 3 forms the ring groove 54 and the outer peripheral edge. surface 18 is formed, at this time, the outer peripheral end 20, the opening end 19 and the corner 21 will not be in contact with the groove forming roll 3, so they will not be affected by the groove forming roll 3, and the outer peripheral end can be well maintained. The dimensional accuracy of the part 20, the opening end part 19 and the corner part 21.

By the spinning of the above-described embodiment, the piston 5 can be formed into a desired shape.

According to the present embodiment, it is not necessary to preform the opening into a narrowed state as in the prior art, and it is possible to reduce the processing steps and suppress the processing cost. Furthermore, even with respect to the base material 15 of a straight cylindrical forged product, the corner portion 21 can be formed into a desired convex corner portion 21 by the corner portion forming roll 4 . In addition, the corner forming roll 4 is in line contact with the base material 15 along the contour line of the base material 15 , so the load on the corner forming roll 4 can be reduced, and the durability of the corner forming roll 4 can be improved. And, utilize corner forming roller 4, can play the effect of supporting this base material 15 from the opening side of base material 15, therefore, can save the core push pin like prior art, do not need the action of core push pin, therefore , which can shorten the cycle time. Furthermore, since the base material 15 can be supported from the opening side of the base material 15 by the corner forming roller 4, a conventional core pusher can be omitted, thereby reducing equipment cost and maintenance cost.

According to this embodiment, since the opening end 19, the outer peripheral end 20, and the corner 21 of the piston 5 are continuous spinning surfaces, it is possible to improve dimensional accuracy.

As shown in FIGS. 7 and 8 , the opening end forming portion 41 in the corner forming roll 4 is configured such that when the corner forming roll 4 abuts against the substrate 15, the opening end forming portion 41 rotates in the third rotation. The length L1 in the direction of the axis P3 is greater than the wall thickness T2 at the open end 19 in the piston 5 .

The size of the outer peripheral end forming portion 42 in the corner forming roller 4 meets: when the corner forming roller 4 abuts against the base material 15, exceeds the size of the annular groove 54 in the piston 5 near the opening end 19 side, And it does not reach the size of the annular groove 54 in the piston 5 on the inner bottom surface 55 side.

As shown in FIGS. 5 and 6 , a protruding portion 59 is formed on the inner peripheral surface 53 of the piston 5 at a position corresponding to the annular groove 54 .

Moreover, in the piston 5, the portion of the inner peripheral surface 53 on the side of the opening end 19 utilizes the first rounded portion (rounded shape) 61 on the side of the inner bottom surface 55 of the protruding portion 59 and the opening end portion. The second rounded portion (rounded shape) 62 on the 19 side is connected smoothly.

Also, the piston 5 is formed such that the wall thickness T2 at the opening end portion 19 is larger than the wall thickness T1 of the outer peripheral surface 18 . According to this configuration, the area of the opening end 19 receiving the external force from the external friction pad abutting on the opening end 19 can be made sufficiently large, and the durability can be further improved. Furthermore, in the piston 5 , there is a dimension difference ΔH between the outer peripheral surface 18 and the outer peripheral end portion 20 .

Compared with conventional machined products, the piston 5 obtained by spinning as described above can secure mechanical strength and achieve weight reduction. In addition, the piston 5 can be finished by appropriately performing surface treatment such as hard chrome plating.

The present invention is not limited to the embodiments described above, and various changes can be made without departing from the scope of the present invention. For example, the dimensions of each part of the piston 5 can be appropriately changed in accordance with the specifications of the sheath combined therewith, the external friction pad abutting against it, and the like on the premise of ensuring mechanical strength. And, for example, in the above-mentioned embodiment, the outer surfaces of the groove forming roll 3 and the corner forming roll 4 are all symmetrical shapes on one side and the other side, but sometimes it is also possible to form the groove forming roll 3 and the corner The outer surfaces of either or both of the rollers 4 are asymmetrically formed on one side and the other side.

Claims (8)

1. a kind of manufacturing method of the piston of disk brake for vehicle, the manufacturing method are carried out by rotary pressing processing, special Sign is,

The substrate of bottomed cylindrical is rotated,

It is pushed by slot forming rolls of the outer peripheral surface from the substrate to the slot forming section with convex, thus described outer Circumferential surface shapes endless groove,

It is pushed by open end from the substrate and the outer peripheral surface diagonal section forming rolls, thus to the substrate Open end side peripheral end, the open end and corner are formed, wherein the corner forming rolls includes outer circumference end Portion's forming section is in contact with open end side peripheral end；Open end forming section connects with the open end Touching；And corner forming section, it is rounded shapes, for positioned at open end side peripheral end and the open end Between the corner be formed.

2. the manufacturing method of the piston of disk brake for vehicle according to claim 1, which is characterized in that

It is abutted against in the corner forming rolls and the substrate and the corner forming rolls shapes open end side periphery After end, the open end and the corner,

In the case where the slot forming rolls is not abutted against with open end side peripheral end, the slot forming rolls is shaped The endless groove.

3. the manufacturing method of the piston of disk brake for vehicle according to claim 1 or 2, which is characterized in that

The not bottom of substrate described in the opening side bearing from the substrate, and base described in the outer peripheral surface side bearing from the substrate Material, and the substrate is formed using the slot forming rolls and the corner forming rolls.

4. a kind of spinning processing device of the piston of disk brake for vehicle, which is characterized in that

The spinning processing device of the piston of the disk brake for vehicle includes

Rotating part, not from the bottom of the opening side bearing substrate of the substrate of bottomed cylindrical, and from the outer peripheral surface branch of substrate The substrate is held, also, the rotating part can be such that the substrate is rotated with first rotation axis；

Slot forming rolls, for cylindrical shape, which is rotated using the second rotation axis as axis, and is had in institute State the slot forming section of the convex of the outer peripheral surface shaping loop slot of substrate；And

Corner forming rolls, for cylindrical shape, which is rotated using third rotation axis as axis, and has periphery End formation, open end forming section and corner forming section, the peripheral end forming section are used for the opening to the substrate End side peripheral end is formed, and the open end forming section is for being formed the open end of the substrate, the angle Portion's forming section be rounded shapes, for the corner between open end side peripheral end and the open end into Row forming,

Second rotation axis is in the direction parallel with the first rotation, and the third rotation axis is in and institute The orthogonal direction of first rotation is stated, also,

The slot forming rolls makes the slot forming section to keeping the direction of the close first rotation of the slot forming section mobile It is abutted with the outer peripheral surface, also,

The corner forming rolls is to keeping the direction of the close open end of the open end forming section mobile, and to making It is mobile close to the direction of the first rotation to state peripheral end forming section and the corner forming section, makes the open end Forming section is abutted with the open end.

5. the spinning processing device of the piston of disk brake for vehicle according to claim 4, which is characterized in that

Abut against the corner forming rolls with the substrate, the corner forming rolls to open end side peripheral end, The open end and the corner are formed, also,

Under the premise of abutting against the slot forming rolls and open end side peripheral end, the slot forming rolls is to institute Endless groove is stated to be formed.

6. the spinning processing device of the piston of disk brake for vehicle according to claim 4 or 5, which is characterized in that

The slot forming rolls is in axis direction side and axis on the basis of the center of the axis direction of second rotation axis The symmetrical shape in the direction other side.

7. the spinning processing device of the piston of disk brake for vehicle according to claim 4 or 5, which is characterized in that

The corner forming rolls is in axis direction side and axis on the basis of the center of the axis direction of the third rotation axis The symmetrical shape in the line direction other side.

8. a kind of piston of disk brake for vehicle, which is characterized in that

The piston of the disk brake for vehicle is bottomed cylindrical, and has open end, outer peripheral surface, inner peripheral surface and bottom Portion,

Open end side peripheral end in the outer peripheral surface is formed with endless groove,

Position corresponding with the endless groove in the inner peripheral surface is formed with protruding portion,

The rounded shape in corner between open end side peripheral end and the open end,

Open end side peripheral end, the open end and the corner are consecutive rotary pressing processing face.