JP2014176859A - Wheel rim manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wheel rim manufacturing method capable of more stably holding a material by a mandrel compared with the conventional methods.SOLUTION: In a spinning process, in a state where there is a gap between a recess bottom part 32 and a mandrel 66 in a radial direction of a pre-stage roll working material 30, one of a recess inclination part 33 positioned more on one of left and right in an axial direction of the pre-stage roll working material 30 from the recess bottom part 32, a flare part 21 positioned more on the other side of the left and right in the axial direction of the pre-stage roll working material 30 from the recess bottom part 32, a tip end 21a of the flare part 21, a part 36 serving as a bead seat part, and the recess inclination part 33, is held by the mandrel 66. An inner diameter of the recess part 31 of the pre-stage roll working material 30 relatively easily varies, but on the other hand, since dimension in the axial direction of the pre-stage roll working material 30 does not vary so much, the pre-stage roll working material 30 can be more stably held by the mandrel 66 compared with the conventional methods.

Description

  The present invention relates to a method for manufacturing a rim of a vehicle wheel.

Japanese Patent Laid-Open Nos. 9-271878 and 2012-245551 disclose rim manufacturing methods having the following steps (i) and (ii).
(I) First, both ends in the axial direction of the cylindrical material are made flared by flare processing and roll forming of the cylindrical material, and a concave portion that becomes a drop portion is formed in an intermediate portion in the axial direction of the cylindrical material.
(Ii) Next, the recess is held by a mandrel divided in the left and right (axial direction), and the thickness of the material is reduced by spinning.

In the technique disclosed in the above publication, the bottom of the recess is in close contact with the mandrel.

In roll forming of a wheel rim, the variation in the diameter of the material after forming the cylindrical material is relatively large. For this reason, it is difficult to hold the material in a stable state by the fixing method in which the bottom of the recess is in close contact with the mandrel. Specifically, when the inner diameter of the bottom of the recess is processed larger than the diameter of the mandrel, the holding by the mandrel becomes uncertain, and the axis of the material and the axis of the mandrel shift. When the inner diameter of the bottom of the recess is processed to be smaller than the diameter of the mandrel, there is a risk that the mandrel may be damaged by the mandrel when the mandrel is inserted into the material.

JP-A-9-271878 JP 2012-245551 A

  An object of the present invention is to provide a rim manufacturing method capable of stably holding a material with a mandrel as compared with the conventional art.

The present invention for achieving the above object is as follows.
(1) Pre-stage roll process, pre-stage roll that forms a pre-roll material by processing a cylindrical material to form a flare part, a concave part that becomes a drop part of the rim, and a part that becomes a bead sheet part of the rim There is a spinning process to form a spinning processed material by spinning the processed material, a second half roll process to form the spinning processed material into a rim shape,
Prior to the spinning step, a pre-roll process is performed to form a concave portion having a concave bottom portion and a concave inclined portion positioned on the left and right in the axial direction of the front roll processing material of the concave bottom portion,
In the spinning process, with a gap in the radial direction of the front roll processed material between the concave bottom and the mandrel, a concave inclined portion located on one of the left and right in the axial direction of the front roll processed material from the concave bottom, and the concave bottom The mandrel holds any one of the flare portion, the tip of the flare portion, the portion that becomes the beat sheet portion, and the concave inclined portion that are positioned on the other of the left and right in the axial direction of the upstream roll processed material. Rim manufacturing method in which the pre-roll processed material is positioned in the axial direction of the pre-roll processed material and the radial direction of the pre-roll processed material with respect to the mandrel, and a part of the pre-roll processed material is thinned by spinning. .
(2) The pre-roll process includes a flare process in which a cylindrical material is flared to form a flared material having a flared portion, and a flared material having a concave portion that becomes a rim drop portion and a portion that becomes a rim bead sheet portion. A rim manufacturing method according to (1), comprising: a former roll forming step of forming a former roll processed material.
(3) The recessed portion inclined portion includes a recessed portion bottom R portion, a recessed portion side wall portion, and a recessed portion upper R portion,
In the spinning step, the mandrel that holds the concave inclined portion holds at least one of the concave bottom R portion, the concave side wall portion, and the concave upper R portion. The rim manufacturing method according to (1) or (2).
(4) The mandrel is pushed in the axial direction of the front roll processed material into the concave inclined portion positioned on one of the inner and outer sides of the front roll processed material, and the concave inclined portion is moved in the radial direction of the front roll processed material by the inclined portion of the mandrel. The rim manufacturing method according to any one of (1) to (3), wherein the shaft of the mandrel and the shaft of the preceding roll processed material are aligned by being pushed outward.
(5) The mandrel is pushed in the axial direction of the preceding roll processed material into the portion that becomes the bead sheet portion positioned on one of the left and right axial directions of the preceding roll processed material, to the portion that becomes the bead sheet portion of the preceding roll processed material The mandrel shaft and the front roll processed material shaft are adjusted by expanding the portion that becomes the bead sheet portion of the front roll processed material outward in the radial direction of the front roll processed material by the corresponding portion of the mandrel. The rim manufacturing method according to any one of (1) to (3).

According to the rim manufacturing method of (1) above, in the spinning step, the axial direction left and right of the upstream roll work material from the concave bottom part with a gap in the radial direction of the front roll work material between the concave bottom part and the mandrel. A recessed portion inclined portion located on one of the above, a flare portion located on the other of the left and right in the axial direction of the preceding roll processed material from the recessed portion bottom, a tip of the flare portion, a portion serving as a beat sheet portion, and a recessed portion inclined portion, Since one of the above is held by the mandrel, the following effects can be obtained.
The inner diameter of the concave portion of the former roll processed material is relatively easy to vary, but the axial dimension of the former roll processed material is relatively small. Therefore, the former roll processed material can be stably held by the mandrel as compared with the conventional case.
In addition, since there is a gap in the radial direction of the preceding roll processed material between the bottom of the recess and the mandrel, it is possible to suppress scuffing the previous roll processed material with the mandrel when the mandrel is inserted into the previous roll processed material.

  According to the rim manufacturing method of (2) above, the pre-roll process includes a flare process in which a cylindrical material is flared to form a flare processed material having a flare portion, and a concave portion that becomes a rim drop portion on the flare processed material. And a pre-roll forming step of forming a pre-roll processed material by forming a portion that becomes a bead sheet portion of the rim, and a pre-roll processed material having a flare portion, a concave portion that becomes a drop portion, and a portion that becomes a bead sheet portion Can be formed.

  According to the rim manufacturing method of (3) above, in the spinning process, the mandrel that holds the recessed portion inclined portion holds at least one of the recessed portion bottom R portion, the recessed portion side wall portion, and the recessed portion upper R portion. Roll processed material can be fixed relatively easily with a mandrel.

  According to the rim manufacturing method of (4) above, the axis of the pre-roll processed material can be accurately aligned with the axis of the mandrel.

According to the rim manufacturing method of (5) above, the axis of the pre-roll processed material can be accurately aligned with the axis of the mandrel.

It is process drawing of the process of producing a cylindrical raw material of the rim manufacturing method of Example 1 of this invention. However, FIG. 1 is applicable to all the embodiments of the present invention. (A) shows the strip | belt-shaped member wound by the coil shape. (B) shows a flat rectangular steel plate. (C) shows the state by which a steel plate is wound cylindrically. (D) shows the state which weld-joins the both ends of winding. (E) shows a state in which the rise and burrs of the welded portion are trimmed. (F) shows a cylindrical material. It is sectional drawing of the flare apparatus in the flare process of the rim manufacturing method of this invention Example 1. FIG. Note that the hatching of the flare device is omitted for the sake of clarity of the drawing. However, FIG. 2 is applicable to all embodiments of the present invention. It is sectional drawing of the part which carries out the shaping | molding process of the pre-stage roll forming apparatus in the pre-stage roll forming process of the rim manufacturing method of Example 1 of this invention. The hatching of the former roll forming apparatus is omitted for clarity of the drawing. However, FIG. 3 is applicable to all the embodiments of the present invention. It is sectional drawing of the spinning apparatus in the spinning process of the rim manufacturing method of Example 1 of this invention. Note that hatching of the spinning device is omitted for clarity of the drawing. It is sectional drawing of the state which is inserting the mandrel in the pre-stage roll processed material in the spinning process of the rim manufacturing method of Example 1 of this invention. Note that hatching of mandrels is omitted for clarity of the drawing. It is sectional drawing of the part which carries out the shaping | molding process of the latter half roll apparatus in the latter half roll process of the rim manufacturing method of Example 1 of this invention. The hatching of the latter half roll device is omitted for clarity of the drawing. However, FIG. 6 is applicable to all the embodiments of the present invention. It is the sectional view on the AA line of FIG. However, FIG. 7 is applicable to all the embodiments of the present invention. It is a half section view of the rim manufactured by the rim manufacturing method of Example 1 of the present invention. However, FIG. 8 is applicable to all the embodiments of the present invention. It is sectional drawing of the spinning apparatus of the modification in the spinning process of the rim manufacturing method of Example 1 of this invention. Note that hatching of the spinning device is omitted for clarity of the drawing. It is sectional drawing of the spinning apparatus of the modification in the spinning process of the rim manufacturing method of Example 1 of this invention. Note that hatching of the spinning device is omitted for clarity of the drawing. It is sectional drawing of the spinning apparatus in the spinning process of the rim manufacturing method of Example 2 of this invention. Note that hatching of the spinning device is omitted for clarity of the drawing. It is sectional drawing of the spinning apparatus in the spinning process of the rim manufacturing method of Example 3 of this invention. Note that hatching of the spinning device is omitted for clarity of the drawing. It is sectional drawing of the spinning apparatus in the spinning process of the rim manufacturing method of Example 4 of this invention. Note that hatching of the spinning device is omitted for clarity of the drawing.

Below, with reference to FIGS. 1-13, the rim manufacturing method of the Example of this invention is demonstrated.
1 to 10 show a rim manufacturing method according to the first embodiment of the present invention, FIG. 11 shows a rim manufacturing method according to the second embodiment of the present invention, and FIG. 12 shows a rim according to the third embodiment of the present invention. A manufacturing method is shown, and FIG. 13 shows a rim manufacturing method according to Embodiment 4 of the present invention.
Portions common to all the embodiments of the present invention are denoted by the same reference numerals throughout the embodiments of the present invention.
First, parts common to all the embodiments of the present invention will be described.

  The manufacturing method of the rim 50 according to the embodiment of the present invention is a method of manufacturing the rim 50 from the cylindrical material 10 shown in FIG. The material of the cylindrical material 10 is, for example, a steel plate.

  As shown in FIG. 8, the rim 50 is a rim used for a passenger car or the like, and is a 5 ° DC rim. However, the rim 50 is a rim used for trucks and buses, and may be a 15 ° DC rim. The “5 ° DC rim” is a rim in which the bead seat portion is inclined 5 ° (including almost 5 °) with respect to the rim axis (wheel axis). The “15 ° DC rim” is a rim in which the bead seat portion is inclined by 15 ° (including almost 15 °) with respect to the rim axis.

  As shown in FIG. 8, the rim 50 has a left flange portion 51, a left bead seat portion 52, a rim intermediate portion 53, a right bead seat portion 54, and a right flange in order from the left side (inner side) in the rim axial direction. Part 55. The left flange portion 51 and the left bead seat portion 52 are located on the left side (inside) in the rim axial direction of the rim intermediate portion 53. The right bead seat portion 54 and the right flange portion 55 are located on the right side (outside) of the rim intermediate portion 53 in the rim axial direction. A wheel disk (not shown) is inserted into the rim 50 and welded to form a welding type wheel. The rim 50 may have a shape without either the left flange portion 51 or the right flange portion 55.

  The rim intermediate portion 53 is a portion located between the left bead seat portion 52 and the right bead seat portion 54. The rim middle part 53 includes a left side wall part 53d, a drop part 53a, and a right side wall part 53e. The rim intermediate portion 53 may further include a ledge portion 53b and a hump portion 53c.

  The manufacturing method of the rim 50 is as follows: (a) As shown in FIGS. 2 and 3, the cylindrical material 10 is processed, the flare portion 21, the recess portion 31 that becomes the drop portion 53 a of the rim 50, and the bead of the rim 50. A pre-roll process for forming a pre-roll material 30 by forming portions (hereinafter referred to as bead sheet intermediate forming portions) 36 to be sheet portions 52 and 54; and (b) a pre-roll process as shown in FIG. A spinning process of spinning the material 30 to form the spinning processed material 40, and (c) a second half roll process of forming the spinning processed material 40 into the shape of the rim 50 as shown in FIG. . The bead sheet intermediate forming part 36 may not be formed in the preceding roll process.

  The manufacturing method of the rim 50 includes a cylindrical material production process for producing a cylindrical material 10 having a constant thickness from a flat material 11 having a constant thickness, as shown in FIG. Also good. In the cylindrical material manufacturing process, as shown in FIG. 1 (a), a flat plate material (rectangular material) 11 having a constant thickness is formed, for example, from a strip member having a constant thickness wound in a coil shape. It is sequentially manufactured by drawing out and cutting every predetermined length. Next, the flat plate material 11 is wound into a cylindrical shape, both ends of the winding are butted against each other and welded by flash butt welding, butt welding, arc welding, or the like, and the rising and burrs of the welded portion 12 are trimmed to obtain a constant thickness. The cylindrical material 10 is prepared. In the cylindrical material manufacturing process, although not shown, the cylindrical material 10 may be manufactured by cutting a pipe-shaped material into a predetermined length.

  As shown in FIG. 2, the pre-roll process includes a flare process in which the cylindrical material 10 is flared to form a flared material 20 having a flared portion 21, and as shown in FIG. And a pre-roll forming step for forming the pre-roll processed material 30 by forming the bead sheet portion intermediate forming portion 36 in this order. However, the flare process may not be performed by forming the flare portion 21 in the former roll forming process.

  In a flare process, as shown in FIG. 2, only the both ends of the axial direction of the cylindrical raw material 10 are flared and expanded. Flare processing is performed using a pair of flare molds composed of first and second flare molds 60 and 61. The first flare mold 60 is inserted (inserted) into the cylindrical material 10 from one axial side of the cylindrical material 10, and the second flare mold 61 is cylindrical from the other axial side of the cylindrical material 10. The material 10 is inserted (inserted). The flare part 21 is located at both ends of the flare processed material 20 in the axial direction.

  As shown in FIG. 3, the pre-roll forming step includes sandwiching the flare processed material 20 between the pre-stage lower roll 62 and the pre-stage upper roll 63 and rotating the roll so that the flare processed material 20 has a recess 31 and a bead sheet intermediate forming portion. 36 is formed to form the former roll processed material 30. When the flare portion 21 is formed in the front roll forming step, the front lower roll 62 is divided into the left and right in the axial direction, and the front lower roll pushes and expands the portion that becomes the flare portion 21 of the cylindrical material 10. The diameter is preferably such that the diameter is increased. The two-dot chain line in FIG. 3 shows the left and right divisions of the front lower roll 62.

  The recess 31 includes a recess bottom 32 and a pair of recess slopes 33.

The recess bottom 32 extends in the axial direction of the former roll processed material 30. The shape of the bottom part 32 of the recess in the radial cross-sectional view of the former roll processed material 30 may be a straight line, or a part or all of it may be curved.

The concave inclined portion 33 is inclined with respect to the axis of the upstream roll processed material 30. The recessed portion inclined portion 33 includes a left recessed portion inclined portion 34 on the left side in the axial direction of the recessed portion bottom portion 32, and a right recessed portion inclined portion 35 on the right side in the axial direction of the recessed portion bottom portion 32. The left recessed portion inclined portion 34 includes a left recessed portion bottom R portion 34a, a left recessed portion side wall portion 34b, and a left recessed portion upper R portion 34c. The right recessed portion inclined portion 35 includes a right recessed portion bottom R portion 35a, a right recessed portion side wall portion 35b, and a right recessed portion upper R portion 35c.

The left recess bottom R portion 34 a is connected to the left end in the axial direction of the recess bottom 32. The left recess bottom R portion 34 a is a portion that is curved from the left end in the axial direction of the recess bottom portion 32 to the left side in the axial direction of the front roll workpiece 30 and outward in the radial direction of the front roll workpiece 30.
The left recess side wall 34b is a portion extending from the left end in the axial direction and the outer end in the radial direction of the left recess bottom R portion 34a to the left in the axial direction and outward in the radial direction. The shape of the left roll side wall part 34b in the radial direction sectional view of the upstream roll processed material 30 may be a straight line, or a part or all of it may be curved. When the left recessed portion side wall 34b is curved, the curvature of the left recessed portion side wall 34b is smaller than the curvature of the left recessed portion bottom R portion 34a.
The left recess upper R portion 34c is a portion that is curved from the left end in the axial direction and the outer end in the radial direction of the left sidewall portion 34b to the left in the axial direction and inward in the radial direction. The curvature of the left recessed portion upper R portion 34c is larger than the curvature of the left recessed portion side wall portion 34b. When the left recess side wall portion 34b is curved, the left recess upper R portion 34c is bent in the opposite direction to the left recess side wall portion 34b.

The right concave bottom R portion 35 a is connected to the axial right side end of the concave bottom 32. The right concave bottom R portion 35 a is a portion that is curved from the right end in the axial direction of the front roll processed material 30 of the concave bottom 32 to the right side in the axial direction of the front roll processed material 30 and radially outward of the front roll processed material 30. .
The right recess side wall 35b is a portion extending from the right end in the axial direction and the radially outer end of the right recess bottom R portion 35a to the right in the axial direction and radially outward. The shape of the right roll side wall part 35b in the radial direction cross-sectional view of the upstream roll processed material 30 may be a straight line, or a part or all of it may be curved. When the right recessed side wall portion 35b is curved, the curvature of the right recessed portion side wall portion 35b is smaller than the curvature of the right recessed portion bottom R portion 35a.
The right concave upper R portion 35c is a portion that is curved axially rightward and radially inward from the axially right end and the radial outer end of the right concave sidewall portion 35b. The curvature of the right concave upper R portion 35c is larger than the curvature of the right concave sidewall portion 35b. When the left recess side wall portion 35b is curved, the right recess upper R portion 35c is bent in the opposite direction to the right recess side wall portion 35b.

  The bead sheet intermediate forming portion 36 is provided on the left side and the right side in the axial direction of the recess 31. The bead sheet intermediate forming portion 36 is inclined by 5 ° (including almost 5 °) with respect to the axial center of the pre-roll processed material 30, and the diameter increases toward the end in the axial direction. ing. The inclination of the bead sheet intermediate forming portion 36 may be larger than 5 ° or smaller than 5 °. Further, the bead sheet intermediate forming portion 36 may be parallel to the axis of the upstream roll processed material 30.

In the spinning process, as shown in FIG. 4, the spinning process material 30 is spun and the spinning process material 40 is formed. The spinning process is performed using a mandrel 66 including first and second mandrels 64 and 65 and a spinning roll 67. As shown in FIG. 5, the first mandrel 64 is inserted (inserted) into the pre-roll material 30 from the left side in the axial direction of the pre-roll material 30. Further, the second mandrel 65 is inserted (inserted) into the front roll processed material 30 from the axial right side of the front roll processed material 30. At this time, a part of the mandrel inclined portion 66a (64a, 65a) of the mandrel 66 (64, 65) (portion 64c in FIG. 5) comes into contact with the recessed portion inclined portion 33 of the upstream roll processed material 30, and the recessed portion is inclined. The mandrel 66 is pushed into the concave inclined portion 33 of the upstream roll processed material 30 while the portion 33 is expanded outward in the radial direction. Further, the mandrel 66 is pushed into the front roll processed material 30, and the holding is completed when the mandrel inclined portion 66a of the mandrel 66 comes into contact with the left side recess side wall 34b of the front roll processed material 30 or slightly pushed in the axial direction. .
As shown in FIG. 4, the spinning roll 67 may be provided on each of the left side in the axial direction of the front stage roll processed material 30 and the right side in the axial direction of the front stage roll processed material 30 from the recess bottom 32. Only one spinning roll 67a or a plurality of spinning rolls 67a on the left side in the axial direction of the preceding-stage roll processed material 30 from the recess bottom 32 may be provided. Only one spinning roll 67b may be provided on the right side in the axial direction of the upstream roll processed material 30 from the recess bottom 32, or a plurality of spinning rolls 67b may be provided. The spinning roll 67a on the left side in the axial direction of the upstream roll processed material 30 from the recess bottom 32 and the spinning roll 67b on the right side in the axial direction of the upstream roll processed material 30 from the recessed bottom 32 may be provided in the same phase. It may be provided in the phase. For example, the spinning roll 67a and the spinning roll 67b may be provided at a phase shifted by an arbitrary angle in order to suppress mutual interference. Preferably, it may be provided at a phase shifted by 90 degrees or 180 degrees. One of the spinning rolls 67a and 67b on the left side in the axial direction and the right side in the axial direction may also serve as the other.

The mandrel 66 may or may not enter the region inside the radial direction of the upstream roll processed material 30 of the recess bottom 32. FIG. 4 shows a case where the first mandrel 64 has entered the region inside the recess bottom 32 in the radial direction and the second mandrel 65 has not entered the region inside the recess bottom 32 in the radial direction. 9 and 10 show a case where both the first mandrel 64 and the second mandrel 65 have entered the radially inner region of the recess bottom 32. When the mandrel 66 (64, 65) enters a region inside the radial direction of the front roll material 30 of the concave bottom 32, the mandrel 66 (64, 65) enters a region inside the radial roll of the front roll material 30 of the concave bottom 32. ) (The mandrel concave bottom R portion corresponding portions 64c and 65c) are tapered so that the mandrel 66 can be easily inserted from the axial direction of the pre-roll material 30 into the radially inner region of the pre-roll material 30. It is desirable to be in the shape. The portion of the mandrel 66 corresponding to the bead sheet intermediate forming portion 36 (portion that becomes the bead sheet portions 52 and 54) of the upstream roll processed material 30 has a diameter that increases toward the end of the upstream roll processed material 30. However, the diameter of the mandrel 66 corresponding to the bead sheet intermediate forming portion 36 may be constant.

  The spinning process is performed in a state where a gap is provided in the radial direction of the former roll processed material 30 between the recess bottom part 32 and the mandrel 66 (64, 65). That is, the spinning process is performed in a state where the recess bottom portion 32 (the portion that is the innermost end in the radial direction) and the mandrel 66 do not contact each other. However, when the front roll processed material 30 is held by the mandrel 66 while applying a force in the axial direction of the front roll processed material 30, the recess bottom portion 32 may be deformed to contact the mandrel 66.

In the spinning process, the recessed portion inclined portion 33 located on one of the left and right sides in the axial direction of the preceding roll processed material 30 from the recessed portion bottom portion 32 and the flare portion 21 located on the other of the left and right sides in the axial direction of the preceding roll processed material 30 from the recessed portion bottom portion 32. And the one end of the flare portion 21 (in the axial direction) 21 a, the beat sheet intermediate forming portion 36, and the concave inclined portion 33 are held by the mandrel 66, so that the pre-roll processed material 30 is held in the mandrel 66. On the other hand, it is positioned in the axial direction of the pre-roll material 30 and the radial direction of the pre-roll material 30, and a part of the pre-roll material 30 is spun and thinned. Hereinafter, the recessed portion inclined portion 33 positioned on one of the left and right sides in the axial direction of the upstream roll processed material 30 from the recessed portion bottom 32 is the left recessed portion inclined portion 34, and is positioned on the other of the left and right axial directions of the upstream roll processed material 30 from the recessed portion bottom 32. The case where the recessed part inclination part 33 to perform is the right side recessed part inclination part 35 is demonstrated.

  As shown in FIG. 4, the first mandrel 64 holds the left recess inclined portion 34. The first mandrel 64 and the left recess inclined portion 34 may be in continuous contact over the entire circumference or may be non-contact in a part of the circumferential direction. The first mandrel 64 holds at least one of the left recess bottom R portion 34a, the left recess side wall portion 34b, and the left recess upper R portion 34c. A portion (mandrel inclined portion) 64 a of the first mandrel 64 that holds the left-side recessed inclined portion 34 is inclined with respect to the axis of the upstream roll processed material 30. The inclination angle α of the portion (mandrel inclined portion) 64a that holds the left-side recessed inclined portion 34 of the first mandrel 64 with respect to the axis of the upstream roll processed material 30 is determined by spinning the first mandrel 64 after the spinning processing. It is desirable to be greater than 5 ° so that it can be easily removed from 40. As shown in FIG. 5, the mandrel inclined portion 64 a of the mandrel 64 holds the front roll processed material 30 by slightly expanding the left recessed portion inclined portion 34 outward in the radial direction. The mandrel inclined portion 64a that holds the left recessed portion inclined portion 34 of the front roll processed material 30 is a left recessed portion among the left recessed portion bottom R portion 34a, the left recessed portion side wall portion 34b, and the left recessed portion upper R portion 34c of the left recessed portion inclined portion 34. When one of the bottom R portion 34a and the left-side recess side wall portion 34b or the left-side recess side wall portion 34b and the left-side recess upper R portion 34c is held, the front roll processed material 30 is held in the axial direction and the radial direction. Easy to do. The inclination angle α of the portion of the mandrel inclined portion 64a that holds the preceding roll processed material 30 in the left recessed portion bottom R portion 34a and the left recessed portion upper R portion 34c with respect to the axial center of the preceding roll processed material 30 is 45 ° or less. More preferably, it is 26.5 ° or less at which the axial push amount is larger than the diametric push amount. In FIG. 5, when the first mandrel 64 is inserted into the front roll processed material 30 from the left side in the axial direction of the front roll processed material 30, the bead sheet intermediate forming portion 36 (left bead sheet portion) of the front roll processed material 30. The portion of the first mandrel 64 corresponding to the portion 52 becomes a bead sheet intermediate forming portion 36 (the portion that becomes the left bead sheet portion 52), and the bead sheet intermediate forming portion 36 (the left bead sheet portion 52). The first mandrel 64 is pushed to the right side in the axial direction of the front roll processed material 30 while further expanding the portion to be radially outward), and further, the first mandrel 64 is pushed into the front roll processed material 30; When the mandrel inclined portion 64a of the first mandrel 64 comes into contact with the left recessed portion inclined portion 34 of the preceding-stage roll processed material 30, or slightly in the axial direction. May be held in the elaborate and time is complete. In this case, the inclination angle with respect to the axial center of the front-stage roll processed material 30 in at least a part of the left-side recessed slope portion 34 of the front-stage roll processed material 30 that contacts the mandrel inclined portion 64a of the first mandrel 64 is expanded in the diameter direction. It is preferable that the amount is 26.5 ° or more which is larger than the pushing amount in the axial direction.

The second mandrel 65 has a flare portion 21, a tip 21a of the flare portion 21, a bead sheet intermediate forming portion 36, a right concave portion inclined portion 35, on the right side in the axial direction of the pre-roll material 30 from the concave bottom portion 32. One of these is held. The second mandrel 65, the flare portion 21, the tip 21a of the flare portion 21, the bead sheet intermediate forming portion 36, the right concave portion oblique portion 35, on the right side in the axial direction of the upstream roll processed material 30 from the concave portion bottom 32, Any one of these may be continuously in contact with the entire circumference, or may be non-contact in a part of the circumferential direction. When the second mandrel 65 holds the right recess inclined portion 35, the second mandrel 65 holds at least one of the right recess bottom R portion 35a, the right recess side wall portion 35b, and the right recess upper R portion 35c. To do. A portion (mandrel inclined portion) 65a of the second mandrel 65 that holds any one of the flare portion 21 of the upstream roll processed material 30, the tip 21a of the flare portion 21, the bead sheet intermediate forming portion 36, and the right-side concave portion inclined portion 35. Holds the pre-roll material 30 by slightly crushing the pre-roll material 30 in the axial direction. The mandrel inclined portion 65 a of the second mandrel 65 is inclined with respect to the axis of the upstream roll processed material 30. The inclination angle β of the mandrel inclined portion 65a of the second mandrel 65 with respect to the axis of the upstream roll processed material 30 is 5 so that the second mandrel 65 can be easily pulled out of the spinning processed material 40 after the spinning process. Desirably larger than °. The mandrel inclined portion 65a of the mandrel 65 holds the front roll processed material 30 by slightly pushing the right recessed portion inclined portion 35 outward in the radial direction. The mandrel inclined portion 65a that holds the right recessed portion inclined portion 35 of the front roll processed material 30 is the right recessed portion of the right recessed portion bottom R portion 35a, the right recessed portion side wall portion 35b, and the right recessed portion upper R portion 35c of the right recessed portion inclined portion 35. If one of the bottom R portion 35a and the right recessed portion side wall portion 35b or the right recessed portion sidewall portion 35b and the right recessed portion upper R portion 35c is held, the upstream roll processed material 30 is held in the axial direction and the radial direction. Easy to do. The inclination angle β of the mandrel inclined portion 65a with respect to the axis of the front roll processed material 30 at the portion holding the front roll processed material 30 in the right concave bottom R portion 35a, the right concave upper R portion 35c and the bead sheet intermediate forming portion 36. Is preferably 45 ° or less, and more preferably 26.5 ° or less, in which the axial push-in amount is larger than the diametric push-out amount. Further, the inclination angle of the tip 21a of the flare part 21 of the mandrel inclination part 65a with respect to the axis of the upstream roll processed material 30 may be about 90 °. In FIG. 5, when the second mandrel 65 is inserted into the front roll processed material 30 from the right side in the axial direction of the front roll processed material 30, the bead sheet intermediate forming portion 36 (the right bead sheet portion) of the front roll processed material 30. The part of the second mandrel 65 corresponding to the part 54 becomes a bead sheet intermediate forming part 36 (the part that becomes the right bead sheet part 54), and the bead sheet intermediate forming part 36 (the right bead sheet part 54). The second mandrel 65 is pushed to the left side in the axial direction of the front-stage roll processed material 30 while the second mandrel 65 is pushed into the front-stage roll processed material 30 When the mandrel inclined portion 65a of the second mandrel 65 comes into contact with the right recessed portion inclined portion 35 of the preceding-stage roll processed material 30, or slightly in the axial direction. May be held in the elaborate and time is complete. In this case, the inclination angle with respect to the axis of the front-stage roll processed material 30 in at least a part of the right-side recessed sloped portion 35 of the front-stage roll processed material 30 that contacts the mandrel inclined portion 65a of the second mandrel 65 is expanded in the diameter direction. It is preferable that the amount is 26.5 ° or more which is larger than the pushing amount in the axial direction.

  In the latter half roll forming step, as shown in FIG. 6, the spinning work 40 is sandwiched between the rear lower roll 68 and the rear upper roll 69 and the roll is rotated to form the spinning work 40 into a rim 50 shape. . Thereafter, sizing processing (processing to make it close to a perfect circle, processing to make the diameter close to a target dimension, and shaping of a rim cross-sectional shape) is performed using an expander and / or a shrinker to obtain a final rim shape.

Here, effects common to all the embodiments of the present invention will be described.
(A) In the spinning step, a gap is provided between the recess bottom 32 and the mandrel 66 in the radial direction of the front roll processed material 30, and is positioned at one of the left and right axial directions of the front roll processed material 30 from the recess bottom 32. A recessed portion inclined portion 33, a flare portion 21, a tip 21a of the flare portion 21, a beat sheet intermediate forming portion 36, and a recessed portion inclined position, which are located on the other of the left and right sides in the axial direction of the upstream roll processed material 30 from the recessed portion bottom portion 32. Since any one of the parts 33 is held by the mandrel 66, the following effects can be obtained.
(A1) Although the inner diameter of the recess 31 of the front roll processed material 30 is relatively easy to change, the axial dimension of the front roll processed material 30 is relatively small. The center of the axis of the mandrel 66 and the axis of the upstream roll processed material 30 is centered by the concave inclined portion 33 positioned on one of the left and right sides in the axial direction and the mandrel inclined portion 64a of the mandrel 66, and the upstream roll is rotated by the mandrel 66 from the other side. The workpiece 30 is held in the axial direction. Therefore, the former roll processed material 30 can be stably held by the mandrel 66 as compared with the conventional case. Therefore, an accurate spinning process can be performed.
(A2) Since there is a gap in the radial direction of the front roll processing material 30 between the recess bottom 32 and the mandrel 66, the mandrel 66 is used to fold the front roll processing material 30 with the mandrel 66 when the mandrel 66 is inserted into the front roll processing material 30. It can be suppressed.
(A3) Since there is a gap in the radial direction of the upstream roll processed material 30 between the bottom portion 32 of the recess and the mandrel 66, when the upstream roll processed material 30 is held by the mandrel 66, the upstream roll processed material 30 has a slight diameter. Even if there are fluctuations, the former roll processed material 30 can be fixed without brazing.
(A4) The mandrel 66 is not forcibly inserted into the recess bottom 24 having a small diameter, and it is possible to suppress the pre-rolled work material 30 from being brazed with the mandrel 66.

(B) The pre-roll process includes a flare process in which the cylindrical material 10 is flared to form a flared material 20 having a flared portion 21, and a concave portion 31 and a bead sheet intermediate forming portion 36 are formed in the flared material 20. Therefore, it is possible to form the pre-roll material 30 having the flare portion 21, the concave portion 31, and the bead sheet intermediate forming portion 36.

(C) In the spinning process, the mandrel 66 that holds the concave inclined portion 33 holds at least one of the concave bottom R portion, the concave side wall portion, and the concave upper R portion. Can be fixed relatively easily.

(D) The mandrel inclined part 64 a of the first mandrel 64 and the mandrel inclined part 65 a of the second mandrel 65 are inclined with respect to the axis of the upstream roll processed material 30. The former roll processed material 30 can be fixed by being expanded somewhat in the radial direction by the mandrel 66. Therefore, the pre-roll processed material 30 can be fixed by the mandrel 66 in both the axial direction of the pre-roll processed material 30 and the radial direction of the pre-roll processed material 30, and reliable fixing is possible.

(E) The portion of the first mandrel 64 (or the second mandrel 65) corresponding to the bead sheet intermediate forming portion 36 of the upstream roll processed material 30 pushes and fixes the bead sheet intermediate forming portion 36 radially outward. can do. Therefore, the pre-roll processed material 30 can be fixed by the mandrel 66 in both the axial direction of the pre-roll processed material 30 and the radial direction of the pre-roll processed material 30, and reliable fixing is possible.

Next, parts unique to each embodiment of the present invention will be described.
[Example 1] (FIGS. 1 to 10)
In the first embodiment of the present invention, the second mandrel 65 holds the right recess inclined portion 35. Therefore, the left and right bead sheet intermediate forming portions 36 can be effectively thinned. FIG. 9 shows that both the first mandrel 64 and the second mandrel 65 have entered the radially inner region of the recess bottom portion 32, and the left and right recess bottom R portion corresponding portions 64c of the mandrels 66 (64, 65), 65c shows the case where the recessed part bottom R part 34a, 35a of the front | former stage roll processed material 30 is hold | maintained. FIG. 10 shows that both the first mandrel 64 and the second mandrel 65 enter the radially inner region of the recess bottom portion 32, and the left and right recess bottom R portion corresponding portions 64c of the mandrels 66 (64, 65), The case where 65c is holding the recessed part side wall part 34b, 35b and the recessed part upper R part 34c, 35c, without contacting the recessed part bottom R part 34a, 35a of the front | former stage roll processed material 30 is shown. Further, in FIG. 10, the pre-roll processed material 30 is not flared.
The first and second mandrels 64 and 65 may be in contact with each other in the axial direction or may not be in contact with each other.

Example 2 (FIG. 11)
In the second embodiment of the present invention, the second mandrel 65 holds the flare portion 21. Therefore, even if the diameter of the former roll processed material 30 varies, the previous roll processed material 30 can be held with high accuracy.

Example 3 (FIG. 12)
In the third embodiment of the present invention, the second mandrel 65 holds the tip 21 a in the axial direction of the flare portion 21. Therefore, the former roll processed material 30 can be reliably held in the axial direction. The flare portion 21 may be held together with the tip portion 21a. The angle of the mandrel inclined portion 65a with respect to the axis of the upstream roll processed material 30 may be substantially vertical as shown in FIG.

Example 4 (FIG. 13)
In the fourth embodiment of the present invention, the second mandrel 65 holds the bead sheet intermediate forming portion 36. Therefore, the front roll processed material 30 can be reliably held, and the left and right bead sheet intermediate forming portions 36 can be easily made thin. The flare portion 21 may be held together with the bead sheet intermediate forming portion 36.

DESCRIPTION OF SYMBOLS 10 Cylindrical raw material 11 Flat plate raw material 12 Welding part 20 Flare processing material 21 Flare part 22 Flare part tip 30 Previous stage roll processing material 31 Concave part 32 Concave bottom part 33 Concave inclination part 34 Left concave part inclination part 34a Left concave part bottom R part 34b Left side Recess side wall portion 34c Left concave portion upper R portion 35 Right concave portion inclined portion 35a Right concave portion bottom R portion 35b Right concave portion side wall portion 35c Right concave portion upper R portion 36 Bead sheet intermediate forming portion 40 Spinning workpiece 50 Rim 51 Left flange portion 52 Left bead Seat part 53 Rim middle part 53a Drop part 53b Ledge part 53c Hump part 53d Left side wall part 53e Right side wall part 54 Right side bead sheet part 55 Right side flange part 60 First flare mold 61 Second flare mold 62 Previous lower roll 63 Upper roll 64 First mandrel 64a First man Mandrel slope 64c of the first mandrel Recess bottom R portion corresponding to the first mandrel 65 Second mandrel 65a Mandrel slope 65c of the second mandrel 66 corresponding to the bottom R portion of the second mandrel 66 Mandrel 66a Mandrel slope 67 , 67a, 67b Spinning roll 68 Rear lower roll 69 Rear upper roll

Claims (5)

A pre-roll process, a pre-roll process material that forms a pre-roll process material by processing a cylindrical material to form a flare part, a recess that becomes a drop part of the rim, and a part that becomes a bead sheet part of the rim. A spinning process for forming a spinning material by spinning, a second half roll process for forming the spinning material into a rim shape,
Prior to the spinning step, a pre-roll process is performed to form a concave portion having a concave bottom portion and a concave inclined portion positioned on the left and right in the axial direction of the front roll processing material of the concave bottom portion,
In the spinning process, with a gap in the radial direction of the front roll processed material between the concave bottom and the mandrel, a concave inclined portion located on one of the left and right in the axial direction of the front roll processed material from the concave bottom, and the concave bottom The mandrel holds any one of the flare portion, the tip of the flare portion, the portion that becomes the beat sheet portion, and the concave inclined portion that are positioned on the other of the left and right in the axial direction of the upstream roll processed material. Rim manufacturing method in which the pre-roll processed material is positioned in the axial direction of the pre-roll processed material and the radial direction of the pre-roll processed material with respect to the mandrel, and a part of the pre-roll processed material is thinned by spinning. .   The pre-roll process consists of flaring a cylindrical material into a flared material having a flared portion, and forming a concave portion to be a rim drop portion and a portion to be a rim bead sheet portion in the flared material. A rim manufacturing method according to claim 1, further comprising: a pre-roll forming step of forming a pre-roll processed material. The recessed portion inclined portion includes a recessed portion bottom R portion, a recessed portion side wall portion, and a recessed portion upper R portion,
3. The rim manufacturing method according to claim 1, wherein, in the spinning process, the mandrel that holds the concave inclined portion holds at least one of the concave bottom R portion, the concave side wall portion, and the concave upper R portion.   The mandrel is pushed in the axial direction of the front roll processed material into the concave inclined portion located on one of the left and right axial directions of the former roll processed material, and the concave inclined portion is pushed outward in the radial direction of the previous roll processed material by the inclined portion of the mandrel. The rim manufacturing method according to any one of claims 1 to 3, wherein the shaft of the mandrel and the shaft of the preceding-stage roll processed material are aligned by expanding. The mandrel is pushed in the axial direction of the front roll processed material into the portion that becomes the bead sheet portion located on one of the left and right of the front roll processed material, and the portion corresponding to the portion that becomes the bead sheet portion of the front roll processed material The mandrel portion aligns the mandrel shaft and the front roll processed material shaft by expanding the portion that becomes the bead sheet portion of the front roll processed material outward in the radial direction of the front roll processed material. The rim manufacturing method according to any one of claims 1 to 3.

Images