JP2007090387A - Method for manufacturing brake piston - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a brake piston without developing the burr into a groove part formed on the outer peripheral surface in the edge part at the opening hole side. <P>SOLUTION: A bottomed cylindrical blank W whose opening end part W1 has smaller diameter than a barrel part W2, is concentrically fitted to a main shaft 2, and a pushing roller R1 having a projecting part (a) is pushed against the blank peripheral part while rotating the blank W together with the main shaft 2 and thus, the brake piston Wa having a groove part on the peripheral part, is manufactured. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a brake piston, and relates to a method for manufacturing a brake piston by subjecting an opening-side end portion of a bottomed cylindrical material to plastic processing.

  Conventionally, as a method for manufacturing a brake piston, a method has been proposed in which a disk material is plastically processed into a bottomed cylindrical shape, and a groove is plastically processed at an end portion of the outer peripheral surface (see, for example, Patent Document 1).

  By the way, as shown in FIG. 4, the spinning machine 50 used in the brake piston manufacturing method includes a squeeze roller 52, a pressing roller 53, a rotary mold 54, and a pressing mold 55 as main components.

  And the manufacturing method of the brake piston using this spinning machine 50 arrange | positions the disk-shaped raw material 51 in the rotation molding die 54, and presses and fixes it with the pressing die 55, thereby making the disk-shaped raw material 51 and the rotation molding die 54. While rotating in a state of being sandwiched between the holding dies 55, the squeezing roller 52 is brought into contact with the bottomed cylindrical semi-finished material 51a. Next, the pressure roller 53 is pressed against the peripheral surface of the semi-finished material 51a to complete the brake piston 51b in which the groove portion 51c is formed on the outer peripheral surface of the end portion.

  However, the brake piston formed by the spinning machine 50 has a problem in terms of strength because the thickness n2 of the groove formed by plastic working is thin on the outer peripheral surface of the end portion on the opening side of the material. When it is necessary to make the inner diameter of the side end portion smaller than the inner diameter of the body portion, there is a problem that the spinning machine 50 cannot be used for molding.

  In such a case, it is possible to cut the bottomed cylindrical material by cutting without using a spinning machine, but in this case, in order to reduce the cutting amount There was a problem that the material shape had to be complicated.

  In addition, the manufacturing method of the brake piston performed by the spinning machine 10 previously proposed as Japanese Patent Application No. 2004-361247 by the present applicant is as shown in FIGS. 5 to 7 at the tip of the main shaft 2 connected to the rotating mechanism 6. A chuck 21 for holding the material W is disposed, and a mandrel 3 having the same shaft center is disposed at a position opposite to the chuck 21, and the tip of the holder 4 is disposed on the outer peripheral surface of the end of the material W. A pressing roller R4 having a concavo-convex portion for performing a desired concavo-convex plastic working is rotatably attached. The holder 4 is configured to move in a direction perpendicular to the axis of the main shaft 2 (in the direction of the arrow Y2) and in the direction of the arrow P by a control signal from a control device (not shown) (see FIG. 7B). ).

In the spinning machine 10, a regulation roller R <b> 3 that regulates the end surface of the end of the material W is attached to the tip of the holder 5 so as to be rotatable. This regulating roller R3 is attached to the holder 5 in order to adjust the distance between the main shaft 2 and the axial direction of the main shaft 2 (arrow X direction) by a control signal from a control device (not shown). It moves in the direction perpendicular to the core (arrow Y direction).
The chuck 21 is configured so that it can be removed from the main shaft 2 together with the clamping member 22 and the regulating member 23 and replaced with the chuck 21 corresponding to the product shape (material W).
The mandrel 3 has a cylindrical shape in which the axial center is the same as that of the main shaft 2 and is smaller than the inner diameter of the body portion of the material W. The material W pressed in the axial direction by the pressing roller R4 comes into contact with the peripheral surface of the mandrel 3 and the roller surface of the regulating roller R3.

  Similarly to the chuck 21, the mandrel 3 is also mounted on the tip of the driven mechanism 7 that can move in the axial direction of the main shaft 2 according to the product shape (inner diameter of the material W, inner diameter of the processed product end). Attaching to 71 is possible.

  Thus, the mandrel 3 is made to enter the material W fixed by the chuck 21 with a gap d3 from the inner peripheral surface of the material W (in the direction of the arrow X), and the regulating roller R3 is made to be the material. Transition to the distance d4 (arrow X direction) with respect to the end face of W (see FIG. 7A). The values of the gaps d3 and d4 are determined by calculating the end flow caused by plastic working.

  Further, the regulating roller R3 is plastically processed while generating a thickness flow so as to increase the thickness of the end portion by pressing toward the mandrel side in the axial direction (arrow X direction) in which the gap d4 becomes small. The wall thickness n1 of the final product can be sufficiently secured.

  Next, the pressing roller R4 is pressed in the direction of the arrow Y2, and the end portion of the material W is brought into contact with the concavo-convex shape of the pressing roller R4, the peripheral surface of the mandrel 3 and the regulating roller R3, and is subjected to plastic working, and the inner diameter of the end portion Is smaller than the inner diameter of the body portion of the material W, and the outer peripheral surface thereof is subjected to plastic working into a desired uneven shape.

However, in this case, the pressure roller is formed on the wall surface of the concave and convex groove portion on the outer peripheral surface when the large-diameter peripheral surface portion a1 of the stepped convex portion a of the pressing roller R4 bites into the material W while performing the groove processing. As R4 enters, the thickness of the contact portion of the pressure roller R4 moves to both sides of the groove at the same time as the diameter is reduced, and the moved meat is further pulled by the meat on both sides, away from the side surface of the pressure roller R4, and the side surface of the groove becomes tapered. Become. At this time, the excess meat becomes “locally too much”, and as shown in FIG. 8D, too much portion b1 is formed on the outer diameter side of both sides of the groove (only the material end face side is shown in the figure), and the pressing roller As the pressing of R4 progresses, it is pressed against the small-diameter peripheral surface portion a2 of the stepped convex portion a, and as a result, as shown in FIG. There was a problem.
JP 2002-70902 A

  The present invention provides a method for manufacturing a brake piston that does not cause overturning in the groove formed on the outer peripheral surface of the opening side end in view of the problems of the method for manufacturing a brake piston using the conventional spinning machine. The purpose is to do.

  In order to achieve the above object, the manufacturing method of the brake piston of the present invention attaches a bottomed cylindrical material having an opening end smaller in diameter than the body part concentrically with the main shaft, and rotates the material together with the main shaft, A pressure roller having a convex portion is pressed against the peripheral portion of the material, and a brake piston having a groove portion on the peripheral portion is manufactured.

  In this case, it is possible to use a bottomed cylindrical material whose outer diameter of the material opening end is substantially equal to the outer diameter of the product opening end.

  According to the method for manufacturing a brake piston of the present invention, since plastic processing is performed by a spinning machine using a material whose opening end is smaller in diameter than the body, the case where the body and the opening end are of the same diameter and On the other hand, it is possible to provide a manufacturing method in which “not so much local” does not occur even when the processing by the pressing roller is started, and a flare-up portion does not occur in the groove portion of the brake piston which is the final product.

  Moreover, when using a bottomed cylindrical material whose outer diameter of the material opening end is substantially equal to the outer diameter of the product opening end, the flow of the material by the pressing roller can be kept good.

  Embodiments of a method for manufacturing a brake piston according to the present invention will be described below with reference to the drawings.

  1 to 2 show a first embodiment of a method for manufacturing a brake piston according to the present invention.

  The manufacturing method of the brake piston of the present invention is performed by using the spinning machine 1, and the shape of the material to be used is compared with the case of forming by the spinning machine 10 previously proposed by the present applicant as Japanese Patent Application No. 2004-361247. Otherwise, the configuration is the same, and the same structure is denoted by the same reference numeral and a series of reference numerals, and description thereof is omitted.

  The brake piston manufacturing method of the present invention is characterized in that the open end W1 of the bottomed cylindrical material W formed by forging is made smaller in diameter than the body W2, and plastic processing is performed from the material W. Thus, the present invention provides a method for manufacturing a brake piston that suppresses the occurrence of “too much locality” that occurs during processing, and as a result, does not cause overturning in the groove portion of the final product Wa.

And, as shown in FIG. 1, the opening end outer diameter φA and the trunk outer diameter φB of the material W are:
φA <φB
The opening end W1 is made smaller than the outer diameter of the body W2. It is desirable that the opening end W1 is connected to the body W2 by an inclined surface W3.
And the relationship between the outer diameter φC of the opening end of the final product Wa and the outer diameter φA of the opening W of the material W is configured to be substantially equal,
0.5mm <φA-φC <1mm
This range is configured to be
0 <φA-φC <0.5mm
Is desirable. According to the experiments by the inventors, when the plastic working was performed using the material W in such a range, a good final product was successfully formed.

  Further, the starting position of the diameter reduction of the material W (the position L1 from the bottom in FIG. 1A) is slightly more distal than the groove processing position of the final product Wa (the position L2 from the bottom in FIG. 1B). It is desirable that L1> L2).

  The manufacturing method of the brake piston of the present invention is the same as that of the spinning machine previously proposed as Japanese Patent Application No. 2004-361247 by the spinning machine 1 shown in FIG. 7) with respect to the material W fixed by the chuck 21, the mandrel 3 is made to enter the inner peripheral surface of the material W with a gap (arrow X direction), and the regulating roller R3 is moved to the material W. Transition to the distance that becomes the gap d4 with respect to the end face (arrow X direction) (see FIGS. 5 to 7).

  Thereafter, as shown in FIGS. 1B and 2B, the pressing roller R1 is pressed against the end surface of the material W to form the final product Wa. At this time, since the outer diameter φA of the opening end W1 is previously made smaller than the outer diameter φB of the body W2, the material to be used does not have any flesh in the local area, and the meat burr b2 as shown in FIG. Will not occur.

  At this time, the inner peripheral surface of the material W is brought into contact with the peripheral surface of the mandrel 3 as in the case of manufacturing a brake piston using the spinning machine previously proposed as Japanese Patent Application No. 2004-361247. The inner diameter of the final product may be regulated, and when the accuracy of the inner diameter of the final product is not necessary or when cutting is performed, the material W needs to be brought into contact with the mandrel 3 as shown in FIG. There is no. Further, when the gripping force by the chuck 21 can be sufficiently secured, it is not necessary to press the mandrel 3 against the inner bottom surface of the material W.

  FIG. 3 shows a second embodiment of the present invention. The manufacturing method of this brake piston is the same as that of the first embodiment in that it is manufactured by using the spinning machine 1, and the mandrel 3 has a small diameter portion 31 in which the tip portion is smaller than the inner diameter of the material W, and the material W A step wall portion 33 is formed by a step between the small-diameter portion 31 and the large-diameter portion 32 of the mandrel 3, and is formed by pressing the pressing roller R1. The difference is that the step wall portion 33 regulates the stretching of the material instead of the regulating roller R3 of the first embodiment that regulates the flow of the meat in the axial direction.

  The opening end W1 of the material W is subjected to plastic working following the uneven shape of the pressing roller R1 and the inner peripheral surface of the small diameter portion 31 of the mandrel 3 and the step wall portion 33, thereby forming the final product Wa.

  As mentioned above, although the manufacturing method of the brake piston of this invention was demonstrated based on several Example, this invention is not limited to the structure described in the said Example, In the range which does not deviate from the meaning, the The configuration can be changed.

  Since the manufacturing method of the brake piston of the present invention uses a bottomed cylindrical material whose opening end is smaller in diameter than the body, it can be plastically processed without causing overturning in the groove, It can be suitably used for processing a product that requires a sufficient thickness of the groove formed on the outer peripheral surface of the end.

In relation to the method for manufacturing a brake piston of the present invention, (a) shows a cross-sectional view of a material, and (b) shows a cross-sectional view of a final product. The process of the manufacturing method of the brake piston of this invention is shown, (a) shows the state which attached the raw material, (b) shows the final product, respectively. It is a partially cutaway top view which shows the 2nd Example of the spinning machine used for the manufacturing method of the brake piston of this invention. It is the front view of the partial cross section which shows the outline of the spinning machine used for the manufacturing method of the conventional brake piston, (a) is the state where the material was attached and the processing to the semi-finished product was completed, (b) was processed to the final product Shows the completed state. 1 is a partially cutaway front view showing a spinning machine previously proposed as Japanese Patent Application No. 2004-361247 by the present applicant. It is a partially cutaway plan view showing a spinning machine previously proposed by the present applicant as Japanese Patent Application No. 2004-361247. FIG. 2 is a partially cutaway cross-sectional view for explaining the processing procedure of a spinning machine previously proposed by the present applicant as Japanese Patent Application No. 2004-361247, in which (a) shows a state in which a material is attached, and (b) shows processing. Each completed state is shown. It is the schematic explaining generation | occurrence | production of the meat turnover, (a) is the state immediately after the start of processing, (b) is during processing, (c) is processing completion, (d) is of (a) The enlarged view of m1 part, (e) shows the enlarged view of m2 part of (c), respectively.

Explanation of symbols

1 Spinning Machine 2 Spindle R1 Pressing Roller a Convex W Material W1 End W2 Body

Claims (2)

  A bottomed cylindrical material whose opening end is smaller in diameter than the body part is attached concentrically with the main shaft, and while the material is rotated together with the main shaft, a pressing roller having a convex portion is pressed against the material peripheral portion, A brake piston manufacturing method comprising manufacturing a brake piston having a groove.   2. The method of manufacturing a brake piston according to claim 1, wherein the outer diameter of the material opening end is a bottomed cylindrical material substantially equal to the outer diameter of the product opening end.

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