Manufacturing method for an annular member and a pronged annular member
A workpiece 20b is formed that includes a circular bottom portion 22b having a hole 23b and an inner wall portion 24b around the hole 23b, and a skirt-shaped outer wall portion 25b that includes prong portions 26b on the outer circumference of the bottom portion 22b and linking portions 27b that link these prong portions 26b, and by cutting off the linking portions 27b and the portion that includes the inner wall portion 24b from the formed workpiece, a pronged annular member that includes the circular bottom portion 22b that has a hole 23b and the prong portions 26b on the outer circumference of the bottom portion 22b.
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The present invention relates to a manufacturing method for an annular member and a pronged annular member, and in particular, relates to a manufacturing method for an annular member in which an annular-shaped annular portion and a pronged annular member that has at least one prong formed substantially perpendicular on the outer circumference of this annular portion are manufactured, and a pronged annular member.
BACKGROUND ARTConventionally a manufacturing method for this type of annular member has been proposed in which a carrier that is used in the planetary gear mechanism is manufactured by a press process and a bending process being applied to a cylindrical base material at room temperature. In this method, a discoid workpiece that includes a central portion, four prongs that extend radially from this center portion, and linking portions that link these prongs together is formed by applying a press process to a cylindrical base material to remove the linking portions from this workpiece and to form thereby a carrier in which the four prongs are bent at 90°.
In addition, a manufacturing method for this type of annular member has been proposed (for example, refer to Patent Document 1) that includes a roughly shaped piece formation step that forms a pronged roughly shaped piece that includes a base portion, a plurality of prong portions having differing widths (thicknesses) along the outer circumferential surface of one surface side of the base portion, and a film portion that extends between each of the prongs, and a trimming step in which the film portions of the roughly shaped piece and the center portion of the bottom portion formed by the roughly shaped piece formation step are trimmed. In this manufacturing method, during the roughly shaped piece formation step, backward extrusion formation is carried out such that the thickness of the film portion adjacent to a prong portion, whose width is narrower than the other prong portions, becomes thicker than the film portion between the other prong portions. Thereby, the induction of the material flow to the prong portions having a narrow width is promoted, and prong portions having differing widths and a uniform height are formed.
Patent Document 1: Japanese Patent Application Publication No. 2001-105085
DISCLOSURE OF THE INVENTIONIn the former manufacturing method for an annular member described above, because it is necessary to provide a significant bending process to bend the four prong portions by 90° after the press process for the workpiece by a large elastic deformation of the base material, it is necessary to carry out annealing between the press process and the bending process, and this requires time from the initial press process of the base material to the completion of the carrier. In addition, in the latter manufacturing method for an annular member described above, because the material only flows in the circumferential direction of the discoid blank when backward extrusion formation is carried out, it is necessary to apply a comparatively heavy load to the discoid blank when carrying out the backward extrusion formation.
It is an object of the manufacturing method for an annular member of present invention to reduce the manufacturing steps for manufacturing the annular member from the base material. In addition, it is an object of the manufacturing method for an annular member of the present invention to manufacture an annular member from the base material without carrying out annealing. Furthermore, it is an object of the manufacturing method for an annular member of the present invention to shorten the time that is necessary to manufacture the annular member from the base material. It is an object of the manufacturing method for an annular member of the present invention to reduce the load required when carrying out the press process on the base material.
The manufacturing method for an annular member of the present invention includes the following means for attaining at least a portion of the objects described above.
The manufacturing method for an annular member of the present invention manufactures a pronged annular member that includes an annular-shaped annular portion and at least one prong formed substantially perpendicular on the outer circumference of this annular portion, includes:
(a) preparing an annular base material;
(b) forming a workpiece by applying one press process to this base material, the workpiece including a circular bottom portion having a hole in the center thereof and a skirt-shaped outer wall portion that includes prong portions that form the prongs on the outer circumference of the bottom portion and linking portions that link the prong portions; and
(c) forming the pronged annular member by removing the linking portions from the formed workpiece.
In the manufacturing method for an annular member of the present invention, a workpiece is formed by applying one press process to a prepared annular base material, the workpiece including a circular bottom portion having a hole in the center thereof and a skirt-shaped outer wall portion that includes prong portions on the outer circumference of the bottom portion and linking portions that link the prong portions, and the linking portions are removed from the formed workpiece to form the pronged annular member. Therefore, it is not necessary to carry out a bending process on the prong portions. As a result, it is possible to decrease the manufacturing steps for manufacturing the annular member from the annular base material, and additionally, it is possible to decrease the time that is necessary to manufacture the annular member from the base material. In addition, in the case in which a workpiece is formed by one press process on the annular material and has a cylindrical vertical wall portion that is concentric to the outer wall portion along the hole in the center of the bottom portion, it is possible to increase the directions of the flow of the base material (substance), and it is possible to reduce further the load (pressure) that is necessary when carrying out the press process on the base material.
The manufacturing method for such an annular member of the present invention can be characterized in that at least the steps (b) described above and after can be carried out by cold forging. Thereby, because heating is not necessary, it is possible to shorten the time that is necessary for cooling.
In addition, the manufacturing method for an annular member of the present invention can be characterized in that at least none of the steps (b) described above and after carry out annealing. Thereby, it is possible to manufacture the annular member from the base material without carrying out annealing. As a result, the annealing step and the cooling step that follows the annealing are not necessary, and it is possible to shorten the time that is necessary to manufacture the annular member from the base material.
Furthermore, in the manufacturing method for an annular member of the present invention, the step (b) described above is a step in which the workpiece is formed such that the outer diameter of the linking portions in the outer wall portion is larger than the outer diameter of the prong portions, and step (c) described above can be a step that includes a step (c1), in which the linking portions are removed such that the linking portions in the outer wall portion are sheared off by a force that acts from the prong portions toward the prongs. Thereby, it is possible to remove the linking portions readily. In this case, the step (b) described above can be a step in which the workpiece described above is formed such that the inner diameter of the linking portions in the outer wall portion is larger than the inner diameter of the prong portions. In addition, the step (b) described above can be a step in which the workpiece is formed such that the inner diameter of the linking portions in the outer wall portion is substantially identical to the outer diameter of the prong portions. Furthermore, the step (c) described above can be a step in which the linking portions are removed, and at the same time, the portion of the workpiece that includes the hole in the bottom portion is cut off. Thereby, in comparison to carrying out the step of removing the linking portions and the step of cutting off the portion that includes the hole in the bottom of the workpiece as separate steps, it is possible to reduce the number of steps, and it is possible to shorten the time that is necessary to manufacture the annular member from the base material.
Alternatively, in the manufacturing method for an annular member of the present invention, the step (b) described above can be a step in which the workpiece described above is formed such that the wall thickness of the connecting portions, which are the portions that connect the prong portions and the linking portions, is thinner than the wall thickness of the prong portions and the wall thickness of the linking portions. Thereby, in the case in which the linking portions are removed by applying a force to the portions that include the connecting portions (for example, the base of a linking portion at the bottom portion and a connecting portion), it is possible to reduce further the load that is necessary to remove the linking portions.
In the manufacturing method for an annular member of the present invention, the step (b) described above can be a step in which the workpiece is manufactured such that the wall thickness of the linking portions is thinner than the wall thickness of the prong portions. Thereby, in comparison to making the wall thickness of the linking portions and the wall thickness of the prong portions substantially identical, it is possible to reduce the amount of base material that flows toward the linking portion side when carrying out the press process. As a result, it is possible to reduce the waste of material up to the point at which the annular member has been manufactured from the base material. In addition, the step (b) described above can be a step in which the workpiece is formed such that the base of the inside of the prong portions at the bottom portion has a wall thickness that has a radius that is larger in comparison to the base of the inside of the connecting portions at the base portion. Thus, it is possible to increase the strength of the base of the prong portions, and at the same time, it is possible to suppress cracks from occurring in the base of the prong portions while being elastically deformed due to the press process.
In addition, in the manufacturing method for the annular member of the present invention, the step (c) described above can be a step that includes a step (c2), in which the inner diameter of the prong portions is widened after removing the linking portions from the formed workpiece, and step (c) described above can be a step that includes a step (c3) in which the trimming of the locations that link the prong portions and the linking portions is carried out after removing the linking portions from the formed workpiece.
In the manufacturing method for an annular member of the present invention, the step (c) described above can be a step that includes a step (c4), in which at least one of the roughness and the evenness of the surface of at least the inside of the bottom portion are adjusted after the linking portions are removed from the formed workpiece. In this case, the step (a) described above can be a step in which a base material is prepared whose surface has been subject to a phosphating treatment providing a surface coating that includes a metallic soap, and step (c4) described above can be a step in which at least one of the roughness and evenness of this surface is adjusted after providing a process in which the metallic soap is removed. Thereby, it is possible to adjust the roughness and the evenness of the surface of the inside of the bottom portion.
In addition, in the manufacturing method for an annular member of the present invention, the step (b) described above can be a step in which the workpiece is formed having a cylindrical vertical wall that is concentric to the outer wall portion along the hole in the center of the bottom portion. Thereby, it is possible to increase the directions of the flow of the base material when carrying out the press process one time, and it is possible to reduce further the load that is necessary when carrying out the press process on the base material.
In the manufacturing method for an annular member of the present invention that is a mode in which a workpiece is formed that has these vertical wall portions, the step (b) described above can be a step in which the workpiece is formed such that the length to the end portion of this vertical wall portion is adjusted by varying the wall thickness of the linking portions depending on the distance from the prong portions. Thereby, it is possible to adjust the length to the end portion of the vertical wall portion. In this case, the step (b) described above can be a step in which the workpiece is formed such that the wall thickness of the linking portions becomes continuously larger as the distance from the prong portions becomes larger. In addition, the step (b) described above can be a step in which the workpiece is formed such that the end portion of the vertical wall member becomes continuous along the circumference of the vertical wall portion.
In addition, in the manufacturing method for an annular member of the present invention that is a mode in which a workpiece is formed that has a vertical wall portion, the step (b) described above can be a step in which the workpiece is formed such that the inner circumferential surface of the vertical wall portion has a predetermined shape. In this case, the step (b) can be a step in which the workpiece is formed such that this predetermined shape is a spline shape. Thereby, the base material readily flows toward the vertical wall portion side when the press process is carried out, and it is possible to reduce further the load that is necessary when carrying out, the press process on the base material.
Furthermore, in the manufacturing method for an annular member of the present invention that is a mode in which a workpiece is formed that has a vertical wall portion, the step (b) described above can be a step in which the workpiece that is formed has vertical wall portions that include a first vertical wall portion having a direction that is identical to the direction of the outer wall portion with respect to the hole in the center of the bottom portion and a second vertical wall portion having a direction that is opposed to the direction of the outer wall portion with respect to the hole in the center of the bottom portion. In this case, the step (c) described above can be a step that includes a step (c5) in which the first vertical wall portion is removed from the workpiece after the linking portions have been removed from the formed workpiece.
In the manufacturing method for an annular member of the present invention, the annular member is a carrier in a planetary gear mechanism. Note that in addition to such a carrier, any type of annular member is satisfactory when the annular member is a pronged annular member that includes an annular-shaped annular portion and at least one prong formed substantially perpendicular on the outer circumference of the annular-shaped annular portion.
In the pronged annular member of the present invention including an annular-shaped annular portion and at least one prong that is formed substantially perpendicular on the outer circumference of the annular portion, generally,
the pronged annular member is formed by removing the linking portions from a workpiece that has been formed by one press process being applied to an annular base material, the workpiece including a circular bottom portion having a hole in the center thereof and a skirt-shaped outer wall portion that includes prong portions that form prongs on the outer circumference of the bottom portion and linking portions that link these prong portions.
The pronged annular member of the present invention is formed by removing the linking portions from the workpiece that has been formed by one press process being applied to an annular base material, the workpiece including a circular bottom portion having a hole in the center thereof and a skirt-shaped outer wall portion that includes prong portions in which prongs are formed on the outer circumference of the bottom portion and linking portions that link these prong portions. Therefore, in contrast to carrying out a bending process at the prong portions, it is possible to manufacture a pronged annular member from an annular member by using fewer manufacturing steps, and it is possible to shorten the time that is necessary to manufacture the pronged annular member from the base material.
In such a pronged annular member of the present invention, the workpiece can be formed such that the outer diameter of the linking portions in the outer wall portion is larger than the outer diameter of the prong portions, and the pronged annular member can be formed by removing the linking portions such that the linking portions in the outer wall portions are sheared off from the prong portions by a force that is applied in the direction of the prongs. In this case, the workpiece can be formed such that the inner diameter of the linking portions in the outer wall portion is larger than the inner diameter of the prong portions. In addition, the workpiece can be formed such that the inner diameter of the linking portions in the outer wall portion is substantially identical to the outer diameter of the prong portions.
In addition, in the pronged annular member of the present invention, the pronged annular member can be formed by removing the linking portions and by cutting off a portion of the workpiece that includes the hole in the bottom portion. In addition, the workpiece can be formed such that the wall thickness of the connecting portions, which are the parts that connect the prong portions and the linking portions, is made thinner than the wall thickness of the prong portions and the wall thickness of the linking portions.
Furthermore, in the pronged annular member of the present invention, the workpiece can be formed such that the wall thickness of the linking portions is made thinner than the wall thickness of the prong portions. In addition, the workpiece can be formed such that the base of the inside of the prong portions at the bottom portion has a wall thickness that has a radius that is larger in comparison to the base of the inside of the linking portions at the bottom portion.
Alternatively, in the pronged annular member of the present invention, the pronged annular member can be formed by widening the inner diameter of the prong portions after removing the linking portions from the formed workpiece. In addition, the pronged annular member can be formed by carrying out trimming of the locations that link the linking portions and the prong portions after removing the linking portions from the formed workpiece.
In the pronged annular member of the present invention, the pronged annular member can be formed by adjusting at least one of the roughness and the evenness of at least the inside surface of the bottom portion after removing the linking portions from the formed workpiece. In this case, the annular base material can be a base material whose surface has been subject to a phosphating treatment that provides a surface coating that includes a metallic soap, and the pronged annular member can be formed by adjusting at least one of the roughness and the evenness of this surface after providing a process in which the metallic soap is removed.
In addition, in the pronged annular member of the present invention, the workpiece can be a member having a cylindrical vertical wall portion that is concentric to the outer wall portion along the hole in the center of the bottom portion.
In the manufacturing method for an annular member of the present invention that is a mode in which the workpiece has a vertical wall portion, the workpiece can be formed by adjusting the length to the end portion of the vertical wall portion by varying the wall thickness of the linking portions according to the distance from the prong portions. In this case, the workpiece can be formed such that the wall thickness of the linking portions becomes continuously larger as the distance from the prong portions becomes larger.
In addition, in the pronged annular member of the present invention that is a mode in which the workpiece has a vertical wall portion, the workpiece is formed such that the inner circumferential surface of the vertical wall portion has a predetermined shape. In this case, the workpiece can be formed such that the inner circumferential surface of the vertical wall portion is a spline shape.
Furthermore, in the pronged annular member of the present invention that is a mode in which the workpiece has vertical wall portions, the workpiece can be formed such that the vertical wall portions include a first vertical wall portion having a direction that is identical to that of the outer wall portion with respect to the hole in the center of the bottom portion and a second vertical wall portion that has a direction that is opposed to that of the outer wall portion with respect to the hole in the center of the bottom portion. In this case, the pronged annular member can be formed by removing the first vertical wall portion from the workpiece after removing the linking portions from the formed workpiece.
In the pronged annular member of the present invention, the pronged annular member can be a carrier in a planetary gear mechanism.
BRIEF DESCRIPTION OF THE DRAWINGS
Next, a preferred mode for implementing the present invention will be explained by using embodiments.
The carrier 20 having such an embodiment is manufactured as follows.
When such a base material 20a has been prepared, next, a workpiece 20b, which is illustrated in
When the workpiece 20b is formed in this manner, the linking portions 27b are cut off of the formed workpiece 20b to form the pronged annular member 20c that is illustrated in
In this embodiment, such a pronged annular member 20c is formed by using the shearing apparatus 60.
The finishing process (steps S320 to S350) of the pronged annular member 20c specifically includes a process (step S320), as shown in
In this manner, to simplify the explanation, the manufacturing method for the carrier 20 of the embodiment forms a workpiece 20b by elastic deformation using one press process on a prepared base material 20a, the workpiece being structured by a circular bottom portion 22b having a hole 23b in the center thereof and a skirt-shaped outer wall portion 25b that includes the prong portions 26b on the outer circumference of the bottom portion 22b and the linking portions 27b that link these prong portions 26b. The carrier 20 is completed by removing the linking portions 27b from the formed workpiece 20b. As can be understood from the steps described above, in the steps for completing the carrier 20 from the base material 20a, the elastic deformation is carried out only one time in the press process of step S200, and thus it is not necessary to carry out annealing for subsequent elastic deformation. Specifically, annealing is not necessary in the steps for completing the carrier 20 from the base material 20a. Therefore, the time that is necessary in order to carry out an annealing step and a cooling step after annealing can be reduced, it is possible to reduce the steps for manufacturing the carrier 20 from the base material 20a, and it is possible to reduce the time that is necessary to manufacture the carrier 20 from the base material 20a.
According to the manufacturing method for the carrier 20 in the embodiment described above, a workpiece 20b is formed by one press process carried out on a prepared annular base material 20a, the workpiece being structured by a circular bottom portion 22b that has a hole 23b in the center thereof and a skirt shaped outer wall portion 25b that includes prong portions 26b on the outer circumference of the bottom portion 22b and linking portions 27b that link these prong portions 26b. Because the carrier 20 is completed by removing the linking portions 27b from the formed workpiece 20b, it is not necessary to carry out annealing in the steps for completing the carrier 20 from the base material 20a As a result, it is possible to reduce the steps for completing the carrier 20 from the base material 20a, and it is possible to shorten the time for completing the carrier 20 from the base material 20a. In addition, according to the manufacturing method for the carrier 20 of the embodiment, because the workpiece 20a is formed from a base material 20a by using cold forging, the time that is necessary to heat the base material 20a, cool the formed workpiece 20b, and the like becomes unnecessary. As a result, it is possible to shorten further the time for completing the carrier 20 from the base material 20a.
In the manufacturing method for the carrier 20 of the embodiment, the linking portions 27b and the portion that includes the inner wall portion 24b are cut off simultaneously from the workpiece 20b, but this need not be carried out simultaneously. An example of the manufacturing method for the carrier 20 in this case is shown in
In the manufacturing method for the carrier 20 of the embodiment, the linking portions 27b and the portion that includes the inner wall portion 24b are cut off of the workpiece 20b. However, only the linking portions 27b may be cut off without cutting off the portion that includes the inner wall portion 24b.
In the manufacturing method for the carrier 20 of the embodiment, when the workpiece 20b is formed by one press process, as shown in
In the manufacturing method for the carrier 20 of the embodiment, the step after the base material 20a has been prepared is carried out by cold forging. However, this is not limiting, and the steps after the base material 20a has been prepared may be carried out by warm forging, hot forging, or the like.
In the manufacturing method for the carrier 20 of the embodiment, annealing is carried out in the step after the base material 20a has been prepared, but annealing does not need to be carried out.
In the manufacturing method for the carrier 20 of the embodiment, the outer wall portion 25b is formed such that the thickness D1 of the prong portions 26b of the workpiece 20b is thicker than the thickness D2 of the linking portions 27b. However, the outer wall portion 25b may be formed such that the thickness D1 of the prong portions 26b is substantially identical to the thickness D2 of the linking portions 27b, and the outer wall portion 25 may be formed such that the thickness D1 of the prong portions 26b is slightly thinner than the thickness D2 of the linking portions 27b.
In the manufacturing method for the carrier 20 of the embodiment, the workpiece 20b is formed such that the thickness D2 of the linking portions 27b along the inner circumference of the linking portions 27b is substantially even. However, the workpiece 20b may be formed such that the thickness of the linking portions 227b becomes larger as the distance from the prong portions 26b becomes larger, that is, becomes larger toward the center of the linking portions 27b along the inner circumference of the linking portions 27b.
In the manufacturing method for the carrier 20 of the embodiment, when the workpiece 20b is formed by using the process apparatus 40, the length from the bottom portion 22b to the end portion of the boss portion 28b is limited by using the lower die punch 52. However, instead of or in addition to this, the length from the bottom portion 22b to the end portion of the inner wall portion 24b may be limited by using a member that limits the elongation of the inner wall portion 24b toward the end portion. In addition, the workpiece 20b may be one in which neither the length from the bottom portion 22b to the end portion of the boss portion 28b nor the length from the bottom portion 22b to the end portion inner wall portion 24b are limited. Below, the case will be explained in which, a member that limits the elongation of the inner wall portion 24b toward the end portion side is used instead of the lower die punch 52. In this case, contrary to the case in which the base material 20a is elongated at the end portion side of the inner wall portion 24b, the base material 20a flows more readily toward the boss portion 28b as the thickness of the outer wall portion 25b decreases. That is, in the inner wall portion 28b, the base material 20a flows more readily to positions that are opposed to the linking portions 27b than positions that are opposed to the prong portions 26b when, similar to the embodiment, the thickness D1 of the prong portions 26b is thicker than the thickness D2 of the linking portions 27b and the thickness of the prong portions 26b and the linking portions 27b is substantially constant along the outer circumference of the bottom portion 22b. Therefore, the end portion of the boss portion 28b readily forms an irregular wavy shape. In particular, at a position that is opposed to the approximate center of the linking portions 27b along the inner circumference of the linking portions 27b, because the distance from the prong portions 26b is large and the base material 20a flows readily, the distance from the bottom portion 22b to the end portion of the boss portion 28b readily becomes long. In contrast, similar to the content shown in
In the manufacturing method for the carrier 20 in the embodiment, the outer wall portion 25b is formed such that the outer diameter R6 of the prong portions 26b and the inner diameter R7 of the linking portions 27b of the workpiece 20b are substantially identical, but the outer wall portion 25b may be formed such that one among the outer diameter R6 of the prong portions 26b and the inner diameter R7 of the linking portions 27b is slightly larger than the other.
In the manufacturing method for the carrier 20 of the embodiment, a workpiece 20b was formed that includes a circular bottom portion 22b having a hole 23b in the center thereof and an inner wall portion 24b around the hole 23b, but the bottom portion 22b may be formed without the inner wall portion 24b around the hole 23b.
In the manufacturing method for the carrier 20 of the embodiment, the linking portions 27b are removed from the workpiece 20b by applying a force in a direction from the base side of the linking portions 27b of the workpiece 20b at the bottom portion 22b toward the linking portions 27b, but the linking portions 27b may be removed from the workpiece 20b by another method, such as applying a force in a direction from the inside of the linking portions 27b (the inside of the outer wall portion 25b ) toward the outside. In this case, the outer wall portion 25b may be formed such that the outer diameter R8 of the linking portions 27b is substantially identical to the outer diameter R6 of the prong portions 26b.
In the manufacturing method for the carrier 20 of the embodiment, after forming the pronged annular member 20c by cutting the linking portions 27b off of the workpiece 20b, the inner diameter of the prong portions 26b of the pronged annular member 20c is widened, trimming of the side surface of the prong portions 26c is carried out, the metallic soap that has been coated onto the surface is removed, and coining is carried out to adjust the roughness or evenness of the surface of the bottom portion 22c. However, among these steps, one or a plurality of the steps may be omitted.
In the manufacturing method for the carrier 20 of the embodiment, the carrier 20 includes a circular bottom portion 22 having a hole 23 formed in the center thereof, prong portions 26 that include four prongs that are formed on the circumference of the bottom portion 22 substantially perpendicular to the bottom portion 22, and a boss portion 28 that is formed as a hollow shaft-shaped cylinder on the side of the bottom portion 22 that is opposed to the prong portions 26. However, the boss portion 28 may be omitted.
In the embodiment, a manufacturing method for a carrier 20 for a planetary gear mechanism was explained. However, the embodiment is not limited to the case in which a carrier 20 for a planetary gear mechanism is manufactured, and may be applied to a manufacturing method for any type of pronged annular member if the pronged annular member has an annular-shaped annular member and at least one prong formed substantially perpendicular on the outer circumference of this annular-shaped annular member.
Above, the embodiment of a preferred mode for implementing the present invention was explained. However, the present invention is not limited in any manner by such embodiments, and of course various modifications are possible that do not depart from the spirit of the present invention.
INDUSTRIAL APPLICABILITYThe present invention can be used in industries that manufacture pronged annular members such as the carrier for a planetary gear mechanism.
Claims
1. A manufacturing method for an annular member that manufactures an annular member that comprises an annular-shaped annular member and at least one prong formed substantially perpendicular on the outer circumference of this annular member, wherein:
- (a) an annular base material is prepared;
- (b) a workpiece is formed by one press process applied to this base material, the workpiece including a circular bottom portion having a hole in the center thereof and a skirt-shaped outer wall portion that comprises prong portions that form prongs on the outer circumference of this bottom portion and linking portions that link these prong portions; and
- (c) a pronged annular member is formed by removing the linking portions from the formed workpiece.
2. The manufacturing method for an annular member according to claim 1, characterized in that at least the steps (b) and after are carried out by using cold forging.
3. The manufacturing method for an annular member according to claim 1, characterized in that at least the steps (b) and after do not carry out annealing.
4. The manufacturing method for an annular member according to claim 1, wherein:
- the step (b) is a step in which the workpiece is formed such that the outer diameter of the linking portions in the outer wall portion is larger than the outer diameter of the prong portions; and
- the step (c) is a step that comprises a step (c1) in which the linking portions are removed such that the linking portions in the outer wall portion are sheared off by a force that is applied in a direction from the prong portions towards the prongs.
5. The manufacturing method for an annular member according to claim 4, wherein the step (b) is a step in which the workpiece is formed such that the inner diameter of the linking portions in the outer wall portion is larger than the inner diameter of the prong portions.
6. The manufacturing method for an annular member according to claim 4, wherein the step (b) is a step in which the workpiece is formed such that the inner diameter of the linking portions in the outer wall portion is substantially identical to the outer diameter of the prong portions.
7. The manufacturing method for an annular member according to claim 4, wherein the step (c1) is a step in which the linking portions are removed and the portion of the workpiece that includes the hole in the bottom portion is cut off.
8. The manufacturing method for an annular member according to claim 1, wherein the step (b) is a step in which the workpiece is formed such that the wall thickness of connecting portions, which are the portions that connect the prong portions and the linking portions, is thinner than the wall thickness of the prong portions and the wall thickness of the linking portions.
9. The manufacturing method for an annular member according to claim 1, wherein the step (b) is a step in which the workpiece is formed such that the wall thickness of the linking portions is thinner than the wall thickness of the prong portions.
10. The manufacturing method for an annular member according to claim 1, wherein the step (b) is a step in which the workpiece is formed such that the base of the inside of the prong portions at the bottom portion has a wall thickness through the radius that is larger in comparison to the base of the inside of the linking portions at the bottom portion.
11. The manufacturing method for an annular member according to claim 1, wherein the step (c) is a step that comprises a step (c2), in which the inner diameter of the prong portions is widened after the linking portions have been removed from the formed workpiece.
12. The manufacturing method for an annular member according to claim 1, wherein the step (c) is a step that comprises a step (c3), in which the trimming of the locations that link the prong portions and the linking portions is carried out after the linking portions have been removed from the formed workpiece.
13. The manufacturing method for an annular member according to claim 1, wherein the step (c) is a step that comprises a step (c4), in which one of at least the roughness and the evenness of the surface of at least the inside of the bottom portion are adjusted after the linking portions have been removed from the formed workpiece.
14. The manufacturing method for an annular member according to claim 13, wherein:
- the step (a) is a step in which a base material is prepared whose surface has been subject to a phosphating treatment that provides a surface coating that includes a metallic soap; and
- the step (c4) is a step in which at least one of the roughness and the evenness of the surface is adjusted after providing a treatment that removes the metallic soap.
15. The manufacturing method for an annular member according to claim 1, wherein the step (b) is a step in which the workpiece is formed that has a cylindrical vertical wall portion that is concentric to the outer wall portion around the hole in the center of the bottom portion.
16. The manufacturing method for an annular member according to claim 15, wherein the step (b) is a step in which the workpiece is formed such that the length up to the end portion of the vertical wall portion is adjusted by varying the wall thickness of the linking portions according to the distance from the prong portions.
17. The manufacturing method for an annular member according to claim 16, wherein the step (b) is a step in which a workpiece is formed such that the wall thickness of the linking portions becomes continuously larger as the distance from the prong portions becomes larger.
18. The manufacturing method for an annular member according to claim 15, wherein the step (b) is a step in which a workpiece is formed such that the inner circumferential surface of the vertical wall portion has a predetermined shape.
19. The manufacturing method for an annular member according to claim 18, wherein the step (b) is a step in which a workpiece is formed such that the predetermined shape is a spline shape.
20. The manufacturing method for an annular member according to claim 15, wherein the step (b) is a step in which the workpiece is formed having vertical wall portions that comprise a first vertical wall portion that is disposed in a direction identical to that of the outer wall portion with respect to the hole in the center of the bottom portion and a second vertical wall portion that is disposed in a direction that is opposed to that of the outer wall portion with respect to the hole in the center of the bottom portion.
21. The manufacturing method for an annular member according to claim 20, wherein the step (c) is a step that comprises a step (c5), in which the first vertical wall portion is removed from the workpiece after the linking portions have been removed from the formed workpiece.
22. The manufacturing method for an annular member according to claim 1, wherein the annular member is a carrier in a planetary gear mechanism.
23. A pronged annular member that comprises an annular-shaped annular member and at least one prong formed substantially perpendicular on the outer circumference of the annular member, wherein:
- the pronged annular member is formed by removing the linking portions from a workpiece that is formed by one press process applied to an annular base material, the workpiece including a circular bottom portion that has a hole in the center thereof and a skirt-shaped outer wall portion that comprises prong portions that form prongs on the outer circumference of the bottom portion and linking portions that link the prong portions.
24. The pronged annular member according to claim 23, wherein:
- the workpiece is formed such that the outer diameter of the linking portions in the outer wall portion is larger than the outer diameter of the prong portions; and
- the pronged annular member is formed by removing the linking portions such that the linking portions in the outer wall portion are sheared off by a force that is applied in a direction from the prong portions toward the prongs.
25. The pronged annular member according to claim 24, wherein the workpiece is formed such that the inner diameter of the linking portions in the outer wall portion is larger than the inner diameter of the prong portions.
26. The pronged annular member according to claim 24, wherein the workpiece is formed such that the inner diameter of the linking portions in the outer wall portion is substantially identical to that of the outer diameter of the prong portions.
27. The pronged annular member according to claim 23, wherein the pronged annular member is formed by removing the linking portions and cutting off the portion of the workpiece that includes the hole in the bottom portion.
28. The pronged annular member according to claim 23, wherein the workpiece is formed such that the wall thickness of the connecting portions, which are the portions that connect the prong portions and the linking portions, are thinner than the wall thickness of the prong portions and the wall thickness of the linking portions.
29. The pronged annular member according to claim 23, wherein the workpiece is formed such that the wall thickness of the linking portions is thinner than the wall thickness of the prong portions.
30. The pronged annular member according to claim 23, wherein the workpiece is formed such that the base of the inside of the prong portions at the bottom portion has a wall thickness across the radius that is larger in comparison the base of the inside of the linking portions at the bottom portion.
31. The pronged annular member according to claim 23, wherein the pronged annular member is formed such that the inner diameter of the prong portions is widened after the linking portions have been removed from the formed workpiece.
32. The pronged annular member according to claim 23, wherein the pronged annular member is formed by carrying out trimming of the locations that link the prong portions and the linking portions after the linking portions have been removed from the formed workpiece.
33. The pronged annular member according to claim 23, wherein the pronged annular member is formed by adjusting at least one of the roughness and the evenness of at least the inside surface of the bottom portion after the linking portions have been removed from the formed workpiece.
34. The pronged annular member according to claim 33, wherein:
- the annular base material is a base material on which a phosphating treatment that provides a surface coating that includes a metallic soap has been carried out on the surface thereof; and
- the pronged annular member is formed by adjusting at least one of the roughness and the evenness of the surface after providing a treatment that removes the metallic soap.
35. The pronged annular member according to claim 23, wherein the workpiece is a member that has a cylindrical vertical wall portion that is concentric to the outer wall portion along the hole in the center of the bottom portion.
36. The pronged annular member according to claim 35, wherein the workpiece is formed by adjusting the length to the end portion of the vertical wall portion by varying the wall thickness of the linking portions according to the distance from the prong portions.
37. The pronged annular member according to claim 36, wherein the workpiece is formed such that the wall thickness of the linking portions becomes continuously larger as the distance from the prong portions becomes larger.
38. The pronged annular member according to claim 35, wherein the workpiece is formed such that the inner circumferential surface of the vertical wall portions has a predetermined shape.
39. The pronged annular member according to claim 38, wherein the workpiece is formed such that the inner circumferential surface of the vertical wall portions has a spline shape.
40. The pronged annular member according to claim 35, wherein the workpiece has vertical wall portions formed thereon, the vertical wall portions including a first vertical wall portion having a direction that is identical to that of the outer wall portion with respect to the hole in the center of the bottom portion and a second vertical wall portion having a direction that is opposed to that of the outer wall portion with respect to the hole in the center of the bottom portion.
41. The pronged annular member according to claim 40, wherein the pronged annular member is formed by removing the first vertical wall portion from the workpiece after the linking portions have been removed from the formed workpiece.
42. The pronged annular member according to claim 23, wherein the pronged annular member is a carrier in a planetary gear mechanism.
Type: Application
Filed: Aug 30, 2006
Publication Date: Mar 8, 2007
Applicant: Aisin AW Co., Ltd. (Anjo-shi)
Inventors: Takehiko Adachi (Anjo), Satoshi Sakai (Anjo), Masaki Nakajima (Anjo), Hiromu Sakamaki (Anjo), Ariyoshi Terao (Anjo), Hideyuki Nagai (Okazaki), Yasuyuki Takasahara (Okazaki)
Application Number: 11/512,089
International Classification: B21J 13/00 (20060101);