JP3931970B2 - Manufacturing method of toothed product - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a toothed product, and more particularly to a method for manufacturing a highly accurate toothed product.
The present invention is particularly preferably used as a counter driven gear with a parking lock gear for an automatic transmission used in a vehicle or the like and a method for manufacturing the same.
[0002]
[Prior art]
Conventionally, a counter-driven gear with a parking lock gear formed by integrally molding a parking lock gear and a counter-driven gear (see FIG. 8, hereinafter, also simply abbreviated as a product with a parking lock gear) is known as a toothed product. . As a manufacturing method of the product 30 with the parking lock gear, a rough material obtained by starting the rough parking lock gear from the surface of the flange portion is formed by hot forging, and then the rough material is roughened by cold forging. It is known that a parking lock gear 32 is finished to form a parking lock gear 32 to obtain a product. And as finishing processing in the cold forging, conventionally, two types of processing methods of upsetting and ironing are generally used.
In the upsetting process, as shown in FIGS. 15 (a) and 15 (b), a parking lock gear 32 is set by setting a coarse parking lock gear 22 smaller than the die 19 in the die 19 and crushing the coarse parking lock gear 22. Is molded. In the ironing process, as shown in FIGS. 16A and 16B, a coarse parking lock gear 22 larger than the die 19 is set on the die 19, and the coarse parking lock gear 22 is squeezed into the die 19. The parking lock gear 32 is formed by pushing.
[0003]
[Problems to be solved by the invention]
In recent years, the above-mentioned products with parking lock gears are required to be highly accurate from the viewpoints of downsizing and ensuring the functions of the parking lock gears. In particular, as shown in FIG. 9, in the parking lock gear 32 of the product 30 with the parking lock gear, the radius of curvature R1 of the tooth tip corner portion 33, the surface roughness Rz of the tooth surface 34, and the tooth root portion 35 Strict accuracy {for example, R1 ≦ 0.4 mm, Rz (ten-point average roughness) ≦ 12.5z, R2 = 0.2 to 1.5 mm) is required for the curvature radius R2.
However, since the conventional upsetting process is a process of pressing the forming surface of the rough parking lock gear against the die surface, the radius of curvature R2 of the tooth base portion of the formed parking lock gear is compared. High accuracy (for example, R2 = 0.5 mm) can be ensured, but the surface roughness Rz of the tooth surface cannot ensure high accuracy (for example, Rz ≦ 20z), and the tip of the tooth tip is incomplete. As a result, high accuracy cannot be ensured. On the other hand, in the conventional ironing, the radius of curvature R1 of the tip corner and the surface roughness Rz of the tooth surface can ensure relatively high accuracy (for example, R1 ≦ 0.3 mm, Rz ≦ 10z). However, in this ironing process, ironing is performed in the ram moving direction toward the tooth base portion of the coarse parking lock gear, and therefore, a meat reservoir 18 of about 2 mm or more is formed at the tooth base portion of the parking lock gear to be formed {FIG. (b) reference} occurs, and high accuracy cannot be secured at the tooth base.
[0004]
This invention is made | formed in view of the said present condition, and aims at providing the manufacturing method of the product with a tooth profile which is a cold forging product which has a highly accurate tooth profile.
[0006]
The manufacturing method of the toothed product of the present invention is as follows.
1. In a state where the rough tooth profile of the coarse material is constrained by a moving mold that moves in a direction crossing the moving direction of the ram of the forging machine, the rough material is moved in the moving direction of the ram to iron the rough tooth shape of the rough material. A method for manufacturing a toothed product by processing, forming a tooth profile and obtaining a product with a tooth profile by cold forging ,
The moving type is a plurality of segment types that move in a direction intersecting with the moving direction of the ram via a cam mechanism, and a squeezed portion in which the upper end portion is slightly swollen in the width direction on the tip side of the segment type die portion There is
By the movement in the crossing direction of the movable type, the ironing portion applies ironing to a predetermined portion of the coarse tooth shape of the tooth base portion of the coarse material, and the ironing portion is not easily inserted into the tooth base portion, and the coarse tooth shape Restraint,
At the time of knockout, the roughing material is moved in the direction of movement of the ram by a knockout mold, and the ironing process is performed by the ironing portion in the tooth width direction toward the side opposite to the tooth base portion. And
2. The forging machine includes an inner punch, an outer punch, a knockout mold, a backup mold, and a cam mechanism that move in the moving direction of the ram,
The cam mechanism includes a cam mold that moves in the vertical direction by the movement of the outer punch. The cam mold integrally includes a cylindrical cam holder and a cylindrical return mold provided on the inner peripheral side of the cam holder. In preparation for
The cam mechanism further includes a plurality of segment molds arranged radially, and each segment mold includes a mold portion extending in the horizontal direction and an engagement portion extending obliquely downward from the rear end of the mold portion. And the engaging portion engages with the inner peripheral inclined surface of the cam holder and the outer peripheral inclined surface of the return mold, and the segment type is formed by these engagements. Moves in the horizontal direction perpendicular to the direction of ram movement,
The coarse material is positioned and set at a predetermined position between the inner punch and the backup mold. The manufacturing method of the product with a tooth profile of description.
3. The product with tooth profile is a product with tooth profile having a flange portion and a tooth profile rising from the surface of the flange portion,
The tooth profile has a radius of curvature of the tip corner of 0.4 mm or less, a surface roughness of the tooth surface of 10-point average roughness of 12.5 z or less, and a radius of curvature of the tooth root. Is 0.2 to 1.5 mm. Or 2. The manufacturing method of the product with a tooth profile as described in 2.
[0007]
The type, size, number, etc. of the “tooth profile” are not particularly limited. Examples of the type include rectangular teeth, involute teeth, and spline teeth. Moreover, the said tooth profile (or rectangular tooth) can connect the tooth surface and the tooth tip surface with a chamfered surface of a predetermined angle, a curved surface having a predetermined radius of curvature, or the like. Further, for example, a stepped portion can be provided on the tooth tip surface, or a meat steal can be provided on the tooth bottom portion. In addition, the tooth profile (or rectangular tooth) has, for example, a radius of curvature of the corner of the tooth tip of 0.3 mm or less, a surface roughness of the tooth surface of 10 z or less in terms of 10-point average roughness, and The radius of curvature of the root portion can be 0.3 to 1.0 mm. The “tooth surface” usually means a meshing surface of the mating member with respect to the tooth profile (or rectangular tooth). Further, the “tooth tip corner” can be, for example, an intersection of a pair of surfaces provided on the tooth tip side of the tooth surface. Further, the “tooth base part” can be, for example, an intersection part of the tooth surface and the surface of the flange part.
The “moving type” is not particularly limited as long as it can move in the direction intersecting the moving direction of the ram of the forging machine. The moving type can be, for example, a plurality of segment types that move in a direction crossing the moving direction of the ram via a cam mechanism. In addition, the segment mold is, for example, a shape in which each opposing surface of a pair of tooth shapes (or rectangular teeth) adjacent to one segment mold is ironed, or one tooth shape (or rectangular tooth) with one segment mold ) On both sides. The “crossing direction” can be, for example, a direction substantially orthogonal to the moving direction of the ram. Furthermore, the “predetermined portion” can include, for example, a tooth root portion of a tooth profile (or rectangular tooth).
[0009]
According to the method for manufacturing a toothed product of the present invention, the coarse material is moved in the moving direction of the ram while the rough tooth shape of the rough material is constrained by the moving mold that moves in the direction intersecting the moving direction of the ram. Therefore, a highly accurate value can be secured for the radius of curvature of the tip corner of the tooth profile to be molded and the surface roughness of the tooth surface. In addition, the coarse tooth profile is squeezed in the direction of ram movement toward the opposite side of the tooth root portion, so that no thickening occurs in the tooth root portion of the tooth profile, and a highly accurate value can be secured there.
Further, when ironing a predetermined portion of the coarse tooth profile of the coarse material and restraining the coarse tooth profile by the movable die, a more accurate value can be secured at the predetermined portion of the coarse tooth profile.
Further, when the coarse material is moved in the moving direction of the ram by the knockout mold, a product with a tooth profile can be manufactured efficiently.
According to the product with a tooth profile of the present invention, it is possible to provide a cold forged product having a highly accurate tooth profile, which is excellent in downsizing and ensuring the function of the tooth profile.
In addition, the manufacturing method of a product with a rectangular tooth is a product with a rectangular tooth by forming a rectangular tooth by ironing a rough rectangular tooth of a rough material by a moving mold that moves in a direction intersecting the moving direction of a ram of a forging machine. It is characterized by obtaining.
The rectangular toothed product is a rectangular toothed product having a flange part and a rectangular tooth rising from the surface of the flange part, and the rectangular tooth has a radius of curvature of a tip corner of 0.4 mm or less, The surface roughness of the tooth surface is a 10-point average roughness of 12.5 z or less, and the radius of curvature of the tooth base is 0.2 to 1.5 mm.
According to the manufacturing method of rectangular toothed products, the rough rectangular teeth of the rough material are ironed by the moving mold that moves in the direction crossing the moving direction of the ram. It is possible to secure highly accurate values for the radius of curvature and the surface roughness of the tooth surface. Further, since the coarse rectangular teeth are squeezed in a direction intersecting with the moving direction of the ram, no thickening occurs in the root portion of the formed rectangular teeth, and a highly accurate value can be secured there.
According to the rectangular toothed product, it is a cold forged product having a highly accurate rectangular tooth, and it is possible to provide a rectangular toothed product excellent in downsizing and ensuring the function of the rectangular tooth.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, the present invention will be specifically described with reference to the drawings. In the present embodiment, as will be described later, a product 30 with a parking lock gear (see FIG. 8) is illustrated as a product with a tooth profile to be molded.
As shown in FIG. 1, the forging machine 1 according to this embodiment includes an inner punch 2, an outer punch 3, a knockout die 4, a backup die 5, and a cam mechanism that move in the vertical direction (ram moving direction). 7 is basically provided. The inner punch 2 is actuated by the inner punch actuating source 2a, the outer punch 3 is actuated by the outer punch actuating source 3a, and the backup die 5 is actuated by the backup die actuating source 5a. Further, a cam mold 8 to be described later in the cam mechanism 7 is configured to be returned by a cam return operating source 8a.
[0011]
As shown in FIG. 2, the cam mechanism 7 includes a cam mold 8 that moves up and down by the movement of the outer punch 3. The cam mold 8 is integrally provided with a cylindrical cam holder 9 and a cylindrical return mold 10 provided on the inner peripheral side of the cam holder 9. The cam mechanism 7 includes a plurality of segment molds 11 arranged radially. Each segment mold 11 has a mold part 12 extending in the horizontal direction and an engagement part 13 extending obliquely downward from the rear end of the mold part 12 and is generally L-shaped as a whole. The engaging portion 13 is engaged with the inner peripheral inclined surface 9a of the cam holder 9 and the outer peripheral inclined surface 10a of the return die 10, and by these engagements, the segment die 11 is horizontal that is orthogonal to the ram moving direction. It is designed to move in the direction. Further, as shown in FIG. 3, the mold part 12 of the segment mold 11 is tapered toward the front end side in the cross section. Further, as shown in FIG. 4, in the longitudinal section on the front end side of the mold part 12, the upper end part is formed in a squeezing part 15 slightly swelled in the width direction, and this squeezing part 15 is a coarse parking lock gear of the coarse material 20. The rough parking lock gear 22 can be restrained by being inserted into the tooth base 35 of the 22.
[0012]
(2) Manufacturing method of product with tooth profile Next, a manufacturing method of the product 30 with parking lock gear according to the present embodiment using the forging machine having the above-described configuration will be described. First, a coarse material 20 formed by hot forging and having a plurality of coarse parking lock gears 22 raised from the surface of the disk-shaped flange portion 21 is prepared. Then, as shown on the left side of the center line in FIG. 5, the coarse material 20 is positioned and set at a predetermined position between the inner punch 2 and the backup die 5 with the coarse parking lock gear 22 side facing downward. Thereafter, as shown on the right side of the center line in FIG. 5, the cam die 8 is moved downward together with the outer punch 3, and each segment is engaged by the engagement between the cam holder 9 of the cam die 8 and the engaging portion 13 of each segment die 11. The mold 11 is moved in the horizontal direction toward the center side. Then, as shown on the left side of the center line in FIG. 6, the tip side of the mold part 12 of the segment mold 11 enters between the rough parking lock gears 22, and the ironing part 15 (see FIGS. 3 and 4) on the tip side is rough. The tooth lock 35 of the parking lock gear 22 is inserted into the tooth base portion 35, and the rough parking lock gear 22 is constrained (closed).
[0013]
Next, as shown on the right side of the center line in FIG. 6, when the ram starts to rise, together with the inner punch 2, the knockout die 4 and the backup die 5, the constrained coarse material 20 rises and the knockout operation starts. Is done. Then, as shown on the left side of the center line of FIG. 7, the ironing portion 15 of the segment mold 11 performs ironing processing downward on the rough parking lock gear 22 to form the parking lock gear 32. At this time, a surplus is produced at the edge of the formed parking lock gear 32 opposite to the tooth root, but this surplus can be removed by a cutting process or the like in a later step. Thereafter, as shown on the right side of the center line in FIG. 7, the inner punch 2, the outer punch 3, and the knockout die 4 are further raised, and each segment die 11 is returned to the centrifugal side in the horizontal direction by raising the return die 10. Thus, the knockout operation is completed, and the molded product 30 with the parking lock gear is taken out from the forging machine 1.
[0014]
(3) Product with parking lock gear Next, the product 30 with parking lock gear manufactured by the above-described manufacturing method will be described. As shown in FIG. 8, the product 30 with the parking lock gear includes a disk-shaped flange portion 31 and a plurality of (15 fixed in FIG. 8) parking lock gears 32 that rise from the surface of the flange portion 31. Yes. In the parking lock gear 32 of the product 30 with the parking lock gear, as shown in FIGS. 9 and 12A, the tooth surface 34 and the tooth tip surface 40 have a chamfered surface C having a predetermined angle S (for example, 18 degrees). In this embodiment, the intersecting portion of the tooth surface 34 and the chamfered surface C is a tooth tip corner portion 33, and the intersecting portion of the surface of the flange portion 31 and the tooth surface 34 is a tooth root portion 35. Yes. In the parking lock gear 32, the radius of curvature R1 of the tip corner 33 is a highly accurate value (0.3 mm), and the surface roughness Rz of the tooth surface 34 is a highly accurate value (10z). In addition, the radius of curvature R2 of the root portion 35 was a highly accurate value (0.5 mm). A counter driven gear is formed on the outer peripheral side of the flange portion 31 by a cutting process or the like in a later process.
[0015]
(4) Effects of the Embodiment As described above, in the manufacturing method of the product with the parking lock gear according to the present embodiment, the plurality of segment dies 11 are first applied to the rough material 20 set at a predetermined position in the forging machine 1. Is moved in the horizontal direction, the ironing portion 15 of the segment die 11 is inserted into the rough parking lock gear 22 and restrained by ironing, and then the coarse material 20 is knocked out in the restrained state, Since the parking lock gear 32 is formed by ironing the coarse parking lock gear 22 at the ironing portion 15 of the segment mold 11, the coarse parking lock gear 22 is opposite to the tooth root portion 35 at the time of knockout. The tooth lock 35 of the molded parking lock gear 32 does not accumulate in the teeth. Therefore, in the parking lock gear 32, highly accurate values can be secured for the curvature radius R1 of the tooth tip corner 33, the surface roughness Rz of the tooth surface 34, and the curvature radius R2 of the tooth root 35, and as a result. Therefore, it is possible to provide a product with a parking lock gear that is excellent in compactness and ensuring the function of the parking lock gear.
[0016]
The present invention is not limited to the specific examples described above, and can be variously modified examples within the scope of the present invention depending on the purpose and application. That is, in the present embodiment, the manufacturing method in which ironing is performed on the main portion of each coarse parking lock gear 22 of the coarse material 20 at the time of knockout is exemplified, but the present invention is not limited to this, for example, the horizontal direction of each segment mold 11 The main part of each coarse parking lock gear 22 of the coarse material 20 is subjected to ironing by moving to the normal material, and at the time of knockout, the normal molded product can be taken out without any ironing. Good. According to such a manufacturing method, the rough parking lock gear 22 can be ironed in the horizontal direction toward the center, and no thickening occurs in the tooth base portion 35 of the formed parking lock gear 32. In this parking lock gear 32, the radius of curvature R1 of the tip corner 33 is a highly accurate value (0.4 mm), and the surface roughness Rz of the tooth surface 34 is a highly accurate value (11.5z). ) And the radius of curvature R2 of the tooth root portion 35 is a highly accurate value (0.5 mm). Therefore, it is possible to provide a product 30 with a parking lock gear that includes the high-precision parking lock gear 32 and is excellent in weight reduction and durability.
[0017]
In this embodiment, the coarse parking lock gears are restrained by moving the segment mold 11 in the horizontal direction perpendicular to the ram moving direction. However, the present invention is not limited to this. For example, as shown in FIG. The segment mold 11 may be provided so as to be movable in a direction inclined slightly upward from the horizontal direction, and the coarse parking lock gears 22 may be restrained by the movement of the segment mold 11 in the inclination direction. Thereby, in the product 30 with the parking lock gear, the annular recess 37 is provided on the surface of the flange portion 31, and the parking lock gear 32 can be set up from the recess 37, that is, the product 30 with the parking lock gear. The axial length can be set to the minimum necessary, and the product can be made more compact and the function of the parking lock gear can be further improved.
Further, in this embodiment, the segment die 11 is exemplified by a simple tapered shape in the cross section (see FIG. 3). However, the present invention is not limited to this, for example, as shown in FIG. The segment die 11 may have a shape having multi-step portions 38 on both sides in the cross section so that the gear 22 can be ironed to the stepped corner portion 33 with a wider surface area in the gear 22.
[0018]
In addition, as the tooth profile of the present embodiment, the tooth surface 34 and the tooth tip surface 40 are connected by the chamfered surface C {see FIG. 12A}, but is not limited thereto. For example, FIG. As shown in a), the tooth surface 34 and the tooth tip surface 40 may be connected by a curved surface (fillet) R having a predetermined radius of curvature (for example, 1.0 mm). Further, as the tooth profile of the present embodiment, the tooth tip surface 40 is a gently curved surface (or flat plane) {see FIG. 12 (a)}, but is not limited to this, for example, FIG. As shown to a), the tooth | gear tip surface 40 may be provided with the level | step-difference part 41 which protrudes in a tooth tip side. Further, as shown in FIGS. 12B, 13B, and 14B, a meat stealing portion 42 may be provided at a connection portion between the tooth surface 34 and the root circle 43.
[Brief description of the drawings]
FIG. 1 is a side sectional view of a forging machine according to the present embodiment.
FIG. 2 is an enlarged view of a main part of FIG.
3 is an enlarged sectional view taken along line III-III in FIG. 2;
4 is an enlarged view taken along the line IV in FIG. 3;
FIG. 5 is an explanatory diagram of the operation of the forging machine, and the left side from the center line shows a state when the workpiece is set, and the right side from the center line shows a state in which the segment type starts to move.
FIG. 6 is also an operation explanatory diagram, in which the left side of the center line indicates the segment-type movable completion state, and the right side of the center line indicates the state of the ram rising start.
FIG. 7 is also an operation explanatory view, in which the left side from the center line shows a state when the forming is completed, and the right side from the center line shows a state when the workpiece is taken out.
FIG. 8 is a perspective view of a product with a parking lock gear according to the present embodiment.
9 is an enlarged perspective view of a main part of FIG.
FIG. 10 is a side sectional view for explaining another aspect of the cam mechanism.
FIG. 11 is a plan sectional view for explaining another embodiment of the segment type.
FIGS. 12A and 12B are explanatory diagrams for explaining the tooth profile according to the present embodiment and the tooth profile of another aspect, in which FIG. 12A shows a type without a meat stealing portion according to the present embodiment, and FIG. The type which has the meat stealing part which concerns on an aspect is shown.
FIGS. 13A and 13B are explanatory views for explaining another aspect of the tooth profile, in which FIG. 13A shows a type without a meat stealing portion, and FIG. 13B shows a type with a meat stealing portion.
14A and 14B are explanatory diagrams for explaining another aspect of the tooth profile, in which FIG. 14A shows a type without a meat stealing portion, and FIG. 14B shows a type with a meat stealing portion.
FIGS. 15A and 15B are explanatory diagrams for explaining conventional upsetting, in which FIG. 15A shows a state in which a coarse parking lock gear is set in a die, and FIG. 15B shows a state at the time when molding is completed;
FIGS. 16A and 16B are explanatory views for explaining conventional ironing, in which FIG. 16A shows a state in which a coarse parking lock gear is set on a die, and FIG. 16B shows a state at the time of completion of molding.
[Explanation of symbols]
1: Forging machine, 4: Knockout mold, 5: Backup mold, 11: Segment mold, 20: Rough material, 21: Flange, 22: Coarse parking lock gear, 30: Product with parking lock gear, 31: Flange 32: parking lock gear, 33: tooth tip corner, 34: tooth surface, 35: tooth base.

Claims (3)

In a state where the rough tooth profile of the coarse material is constrained by a moving mold that moves in a direction crossing the moving direction of the ram of the forging machine, the rough material is moved in the moving direction of the ram to iron the rough tooth shape of the rough material. A method for producing a toothed product by processing, forming a tooth profile and obtaining a product with a tooth profile by cold forging ,
The moving type is a plurality of segment types that move in a direction intersecting with the moving direction of the ram via a cam mechanism, and a squeezed portion in which the upper end portion is slightly swollen in the width direction on the tip side of the segment type die portion There is
By the movement in the crossing direction of the movable type, the ironing portion applies ironing to a predetermined portion of the coarse tooth shape of the tooth base portion of the coarse material, and the ironing portion is not easily inserted into the tooth base portion, and the coarse tooth shape Restraint,
At the time of knockout, the roughing material is moved in the direction of movement of the ram by a knockout mold, and the ironing process is performed by the ironing portion in the tooth width direction toward the side opposite to the tooth base portion. A method for manufacturing a toothed product. The forging machine includes an inner punch, an outer punch, a knockout mold, a backup mold, and a cam mechanism that move in the moving direction of the ram,
  The cam mechanism includes a cam mold that moves in the vertical direction by the movement of the outer punch. The cam mold integrally includes a cylindrical cam holder and a cylindrical return mold provided on the inner peripheral side of the cam holder. In preparation for
  The cam mechanism includes a plurality of segment molds arranged radially, and each segment mold has a mold portion extending in the horizontal direction and an engagement portion extending obliquely downward from the rear end of the mold portion. The engaging portion is engaged with the inner peripheral inclined surface of the cam holder and the outer peripheral inclined surface of the return mold, and the segment die is rammed by these engagements. It moves to the horizontal direction orthogonal to the moving direction of
  The method of manufacturing a toothed product according to claim 1, wherein the coarse material is positioned and set at a predetermined position between the inner punch and the backup mold. The product with tooth profile is a product with tooth profile having a flange portion and a tooth profile rising from the surface of the flange portion,
The tooth profile has a radius of curvature of the tip corner of 0.4 mm or less, a surface roughness of the tooth surface of 10-point average roughness of 12.5 z or less, and a radius of curvature of the tooth root. The method for producing a toothed product according to claim 1 or 2, wherein is 0.2 to 1.5 mm.

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