JP3709323B2 - Gear forming method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gear forming method and apparatus for forming a gear by hot forging or cold forging.
[0002]
[Prior art]
In a conventional gear forming apparatus, for example, when a gear used in a transmission of an automobile is formed by hot forging or cold forging, the gear is formed through a plurality of manufacturing steps.
[0003]
9A and 9B schematically show the gear forming process of the gear forming apparatus according to this prior art. First, as a first step, as shown in FIG. 9A, after the gear material 4 is accommodated in the mold 1 in which the tip portion 3 is formed with the tooth forming portion 2 having a substantially triangular shape, the gear material 4 is moved by a punch. The gear blank 4 is caused to flow in the tooth forming portion 2 by being pressed vertically downward. Thereafter, the gear material 4 having one end formed in a substantially triangular shape is removed from the mold 1.
[0004]
Next, as the second step, as shown in FIG. 9B, the other end portion of the gear material 4 is accommodated in a mold 5 in which a tooth forming shape portion 6 including a taper portion 7 and a straight portion 8 is formed. . Thereafter, the gear blank 4 is pressed vertically downward by a punch, and the gear blank 4 is caused to flow into the tooth forming portion 6 to form the tooth profile 9.
[0005]
[Problems to be solved by the invention]
However, since the gear forming apparatus requires a plurality of manufacturing steps such as reversing the gear material as described above until the gear is formed, the manufacturing takes a long time, the manufacturing operation is complicated, and the cost increases. It has been pointed out that the problem will be caused. Furthermore, in order to arrange different types of molds, it is necessary to install a plurality of molding apparatuses, which leads to an increase in equipment costs and an increase in installation space, making it difficult to operate the apparatus itself efficiently. .
[0006]
The present invention has been made in consideration of such a problem, and by arranging a mold in which a tooth forming portion conforming to the shape of the gear is formed, the gear can be formed in one manufacturing process. Gears that can reduce gear manufacturing time, reduce equipment costs, reduce installation space, improve operating efficiency of molding equipment, and reduce manufacturing costs for molded products. An object of the present invention is to provide a molding method and an apparatus therefor.
[0007]
[Means for Solving the Problems]
The present invention provides a first mold in which a first tooth forming shape portion is formed , a second mold in which a second tooth forming shape portion is formed , and any one of the first and second molds. A gear forming method for forming a gear using a punch facing one side,
A plurality of inclined portions that converge toward one end are provided on one of the first tooth forming shape portion and the second tooth forming shape portion, and the other one of the first tooth forming shape portion and the second tooth forming shape portion is connected to the inclined portion at the time of mold clamping and vertically Provide a straight section extending in the direction,
Supporting the gear material on one of the first mold or the second mold,
And an end portion of the second tooth forming portion of the second mold with the end of the first tooth profile forming portion of the first mold, Ru are bonded to a predetermined angle inclined to the axial direction And storing a gear material between the first mold and the second mold ,
By pressing the gear blank with the punch, the gear blank is caused to flow simultaneously in the first tooth forming portion and the second tooth forming portion to form the gear tooth portion of the gear by one punch action. It is characterized by doing.
[0009]
In addition, the present invention includes a first mold and a second mold, and is formed on the first mold and the second mold formed on the first mold. The second tooth forming portion defines a tooth forming shape portion for forming the tooth shape portion of the gear, and the first die and the end portion of the second die have a predetermined axial direction. In addition to having a joint surface that is inclined at an angle , one of the first tooth forming part and the second tooth forming part is provided with a plurality of inclined parts that converge toward one end, and the other one of the molds is clamped In this case, a linear portion that extends in the vertical direction while being connected to the inclined portion is provided .
[0010]
Further, the first tooth forming portion includes a pair of opposed chamfer portions formed in a substantially triangular shape and an undercut portion whose one main surface is inclined at a predetermined angle in a direction away from the axial direction. The second tooth forming portion includes a first linear portion whose one principal surface is parallel to the axial direction, a tapered portion in contact with the upper end of the first linear portion, and a direction away from the axial direction. A pair of chamfered portions and the underside, and a second linear portion whose upper surface is inclined at a predetermined angle and a third linear portion inclined at a predetermined angle in a direction approaching the axial direction from the second linear portion. The first joint surface including the upper end of the cut portion and the second joint surface including the lower end of the first straight portion may be joined at a predetermined angle with respect to the axial direction .
[0011]
As described above, according to the present invention, the tooth forming portion for forming the tooth portion of the gear is formed in the first tooth forming portion and the second die formed in the first die. In addition to being defined by the second tooth forming portion, the first die and the second die are arranged in one molding device, so the gear is forged in one manufacturing process. This can significantly reduce the gear manufacturing time. Moreover, since it is not necessary to install multiple molding machines with different types of molds to form gears, equipment costs can be reduced and installation space can be reduced, dramatically improving the operational efficiency of the equipment itself. As a result, the manufacturing cost of the molded product can be reduced. Further, since the first tooth forming portion and the second tooth forming portion are joined at a predetermined angle with respect to the axial direction, burrs generated in the gear tooth portion of the gear as much as possible are formed as much as possible. Can be suppressed.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The gear forming method according to the present invention will be described in detail below with reference to the attached FIG. 1 to FIG. In addition, although the use is not limited, this gear shaping | molding apparatus is preferable when it is used, for example in order to manufacture the gearwheel for transmissions of a motor vehicle.
[0013]
A gear forming apparatus 10 according to the present embodiment is for forging an annular gear material 12 (see FIG. 8A), and as shown in FIG. An annular second undercarriage 16 that is fixed on the first undercarriage 14 and has a smaller diameter than the first undercarriage 14, and is positioned above the first undercarriage 14 and the second undercarriage 16. An annular first gantry 18, an annular second gantry 20 fixed to the bottom surface of the first gantry 18 and having a smaller diameter than the first gantry 18, and the first and second A fixing portion 22 and a punch portion 24 are provided between the lower pedestals 14 and 16 and the first and second upper pedestals 18 and 20. A plurality of guide holders 26 spaced from each other at an equal angle around the axis of the second upper base 20 are fixed to the bottom surface of the second upper base 20. The guide holder 26 is provided with a tip 28 having a smaller diameter. A plurality of guides 30 are erected between the distal end portion 28 of each guide holder 26 and the second undercarriage 16, and each guide 30 includes an upper surface of the second undercarriage 16 and the front end. A coil spring 32 seated on the portion 28 is wound.
[0014]
A hole 34 communicating with the first undercarriage 14 and the second undercarriage 16 is formed at a substantially central portion of the first undercarriage 14 and the second undercarriage 16. In addition, a first opening 36 having a large diameter is formed at a substantially central portion of the first upper mount 18, and similarly, the first opening is formed at a substantially central portion of the second upper mount 20. A second opening 38 having a diameter smaller than that of the first opening 36 is formed. Claw portions 18a and 20a projecting inward are formed in the first opening portion 36 and the second opening portion 38, respectively, and the claw portion 18a has a projection length shorter than that of the claw portion 20a. ing.
[0015]
The fixing portion 22 includes an annular base 42 that is fitted in a first recess 40 formed in a substantially central portion of the second undercarriage 16 and has an opening 43 formed in a substantially central portion thereof, and the base The first cylindrical plate 44 is fixed on the first plate 44, and a substantially cylindrical punch guide 46 is erected at a substantially central portion of the upper end surface of the first plate 44. On the first plate 44 side of the punch guide 46, a second plate 48 and a first ring 50 are externally mounted. On the first ring 50, a knockout punch 52 that is externally fitted to the punch guide 46 is provided. It is fixed. In FIG. 1, the knockout punch 52 has a lower portion formed as a thick portion 52b and then an upper portion formed as a thin portion 52a through a tapered portion.
[0016]
A sleeve 54 is fixed on the first plate 44 so as to be attached to the second plate 48, and a spacer 56 and a spacer 56 are formed on the sleeve 54 so as to surround the knockout punch 52. A fixed mold 58 that fits outside is provided. A space 55 is formed between the knockout punch 52 and the sleeve 54 so as to go around the knockout punch 52. An annular mounting portion 60 is formed on the first plate 44, and a second ring 62 for centering the first plate 44 and the sleeve 54 includes the first plate 44 and the sleeve. 54 is fitted to the outer peripheral surface. The second ring 62 is held on the mounting portion 60 of the first plate 44.
[0017]
A claw portion 58a is formed on the outer peripheral surface of the fixed mold 58, and when the claw portion 64a of the holder 64 is engaged with the claw portion 58a, the base 42, the first plate 44, the The second plate 48, the sleeve 54, the spacer 56 and the fixed mold 58 are pressed vertically downward. That is, the outside of the base 42, the second ring 62, and the holder 64 is surrounded by a first holding member 68 that is seated in a second recess 66 formed in the second undercarriage 16, A screw formed on the inner periphery of the second holding member 70 is screwed into a screw formed on the outer periphery of the upper end of the first holding member 68, and the bent portion 72 of the second holding member 70 is Since it is engaged with the holder 64, the holder 64, the fixed mold 58, the sleeve 54, the first plate 44, and the base 42 are vertically moved by screwing the second holding member 70. Press down.
[0018]
Further, a knockout pin 74 is fixed to the bottom surface of the first ring 50 through the first plate 44 and the second plate 48. The knockout pin 74 extends downward in the opening 43 formed in the base 42 in FIG. 1 and in the hole 34 communicating with the first and second undercarriages 14 and 16. It is connected to the piston rod 76 of the inserted hydraulic piston for the fixed portion.
[0019]
Therefore, the knockout pin 74 is configured to be movable up and down in the axial direction by the piston rod 76 of the hydraulic piston for the fixed portion that is displaced under the action of a hydraulic mechanism for the fixed portion (not shown). The knockout punch 52 is slidable in the axial direction on the outer peripheral surface of the punch guide 46 in conjunction with the knockout pin 74.
[0020]
On the other hand, as shown in FIG. 2, a cavity 78 that circulates between the punch guide 46 and the fixed mold 58 is formed at the upper end surface of the knockout punch 52. As will be described later, the cavity 78 becomes a flow space in which the meat of the gear material 12 flows when the gear material 12 is pressed from the upper surface thereof.
[0021]
Further, as shown in FIGS. 2 and 3, the fixed mold 58 has a material placing portion 80 formed in a substantially flat shape for placing the gear material 12, and the material placing portion 80. An inclined chamfer part 81a, 81a that faces each other so as to be formed in a substantially triangular shape using the step part 83 on the outer periphery of the outer periphery of the punch guide 46 and one main surface in a direction away from the axial direction of the punch guide 46. A fixed tooth forming portion 82 formed of an inclined undercut portion 81b is formed. The step portion 83 includes a flat surface 83a parallel to the material placing portion 80, and a fixed-side joint surface 83b inclined at a predetermined angle from the flat surface 83a. The fixed side joining surface 83b includes the upper ends of the chamfer portions 81a and 81a and the undercut portion 81b.
[0022]
As shown in FIG. 1, the punch unit 24 includes a cylindrical first holder 84 and a second holder 86 that is externally mounted on the upper end of the first holder 84, and the second holder A protrusion 88 formed so as to protrude inside 86 comes into contact with the upper end surface of the first holder 84. Further, a retaining ring 90 engaged with a first claw portion 84 a formed on the outer peripheral surface of the first holder 84 is fitted to the lower end surface of the second holder 86, By holding the first holder 84 with the retaining ring 90, the first holder 84 and the second holder 86 are fixed. That is, a screw formed inside the support ring 92 is screwed to a screw on the outer periphery of the second holder 86 so as to lock the retaining ring 90 vertically upward. A bent portion 94 that protrudes outward is formed at the upper end portion of the second holder 86 in FIG. 1, and the bent portion 94 engages with a claw portion 20 a formed on the second gantry 20. . An annular movable mold 96 having a recess 98 is fixed to the second claw portion 84b formed on the inner peripheral surface of the first holder 84, and a spacer 100 is fitted into the recess 98. Yes. Of course, the movable mold 96 is disposed so as to face the fixed mold 58.
[0023]
A first pressing plate 102a is fixed to the upper surfaces of the movable mold 96 and the spacer 100 so as to include a fixing surface between the movable mold 96 and the spacer 100, and the first pressing plate 102a and the first pressing plate 102a are fixed to each other. A second pressing plate 102 b is fixed on the protrusion 88 formed on the second holder 86. Further, the third pressing plate 102c is fixed onto the second pressing plate 102b and the second holder 86 so as to include the fixing surface between the second pressing plate 102b and the second holder 86. In addition, the third pressing plate 102c is engaged with a claw portion 18a formed on the first gantry 18. The diameters of the first to third pressing plates 102a to 102c increase in the order of the first to third pressing plates 102a to 102c.
[0024]
A rod 104 extending vertically downward passes through substantially the center of each of the movable mold 96, the spacer 100, and the first to third pressing plates 102a to 102c. This rod 104 is formed in a substantially cylindrical shape whose diameter decreases in four steps as it goes downward. A punch 106 is fixed to one end of the rod 104, and the other end is connected to a movable part hydraulic mechanism (not shown). The rod 104 is axially moved under the action of the movable part hydraulic mechanism. It can be moved up and down. Therefore, the punch 106 is also movable up and down in the axial direction.
[0025]
Similar to the rod 104, the third pressing plate 102c is also connected to the movable part hydraulic mechanism. Therefore, the first to third pressing plates 102a to 102c fixed to each other under the action of the movable portion hydraulic mechanism are movable up and down in the axial direction. Along with this, the movable mold 96 fixed to the first pressing plate 102a can also move up and down in the axial direction, and can approach or be separated from the fixed mold 58.
[0026]
As shown in FIGS. 2 and 3, the movable mold 96 includes a first straight portion 108a having a principal surface parallel to the axial direction of the punch guide 46, and an upper end of the first straight portion 108a. A taper portion 110 that contacts the second straight portion 108b whose upper surface is inclined at a predetermined angle in a direction away from the axial direction of the punch guide 46, and an axial direction of the punch guide 46 from the second straight portion 108b. In the approaching direction, a movable tooth forming shape portion 112 is formed which includes a third linear portion 108c whose upper surface is inclined at a predetermined angle. The lower end of the first straight portion 108 a is included in a movable side joining surface 113 that is inclined at a predetermined angle with respect to the axial direction of the punch guide 46. In this case, the first straight portion 108 a and the tapered portion 110 terminate at the movable side joining surface 113.
[0027]
The fixed-side joining surface 83b provided on the fixed die 58 and the movable-side joining surface 113 provided on the movable die 96 are joined to each other at a predetermined angle with respect to the axial direction. A tooth forming portion 114 for forming the tooth forming portion 118 of the gear 116 (see FIG. 8B) is defined from the fixed tooth forming shape portion 82 and the movable tooth forming shape portion 112 formed in the movable mold 96. In this case, it is preferable that the inclination angle with respect to the axial direction when the fixed-side joining surface 83b and the movable-side joining surface 113 are joined is within a range of 1 ° to 33 °.
[0028]
The gear forming apparatus 10 according to the present embodiment is basically configured as described above. Next, the operation and effect will be described.
[0029]
First, under the action of a movable part hydraulic mechanism (not shown), the punch 106 and the movable mold 96 are separated from the fixed mold 58 as shown in FIG. Then, the gear material 12 is placed on the material placing portion 80 formed in the fixed mold 58. Thereafter, the movable mold 96 is moved vertically downward under the action of the movable portion hydraulic mechanism, and the movable mold 96 is brought into close contact with the fixed mold 58 (see FIG. 5).
[0030]
Next, similarly, the rod 104 is moved vertically downward under the action of the movable portion hydraulic mechanism. Thereby, the punch 106 is displaced vertically downward, and the upper surface of the gear material 12 is pressed vertically downward by the punch 106 (see FIG. 6). At this time, the pressing speed of the punch 106 that presses the gear material 12 is set in advance to a predetermined speed.
[0031]
The meat of the gear blank 12 that is pressed vertically downward by the punch 106 flows into the tooth forming portion 114 defined by the fixed tooth forming portion 82 and the movable tooth forming portion 112, and the tooth shape portion of the gear 116. 118 is molded (see FIGS. 6 and 8B). At the same time, the meat of the gear blank 12 also flows into a cavity 78 that circulates around the punch guide 46 formed between the punch guide 46 and the fixed mold 58.
[0032]
Thereafter, the rod 104 is moved vertically upward under the action of the movable part hydraulic mechanism (not shown). As a result, the punch 106 is displaced vertically upward, and the punch 106 is separated from the formed gear 118. Similarly, the movable mold 96 is moved vertically upward under the action of the movable portion hydraulic mechanism to be separated from the fixed mold 58 (see FIG. 7).
[0033]
In a state where the movable mold 96 and the punch 106 are separated from the fixed mold 58, a fixed portion hydraulic mechanism (not shown) is operated. Under the action of the fixing portion hydraulic mechanism, the piston rod 76 of the fixing portion hydraulic piston moves vertically upward, and accordingly, the knockout punch 52 fixed to the first ring 50 via the knockout pin 74 is the punch guide 46. Is slid vertically upward. As shown in FIG. 7, the knockout punch 52 slid in the vertically upward direction eventually comes into contact with the gear 116 and separates the gear 116 from the material placing portion 80 formed in the fixed mold 58. Thereafter, the gear 116 is transported to the next process by a transport device (not shown), and finally machined to a predetermined size and shape to be completed as a product.
[0034]
Here, in the present embodiment, the fixed-side joining surface 83b including the upper ends of the chamfer portions 81a and 81a and the undercut portion 81b of the fixed tooth forming portion 82 formed in the fixed die 58, and the movable die 96 In order to form the tooth profile portion 118 of the gear 116 by joining the movable side forming surface portion 112 of the formed movable tooth forming shape portion 112 to the movable side joint surface 113 including the lower end of the first straight portion 108a at a predetermined angle with respect to the axial direction. The tooth forming portion 114 is defined. Moreover, since the fixed mold 58 and the movable mold 96 are arranged in one gear forming apparatus 10, when the gear blank 12 is forged by the gear forming apparatus 10, a single punching operation is performed. The tooth profile 118 of the gear 116 can be formed. That is, the gear 116 can be forged from the gear blank 12 in a single manufacturing process.
[0035]
【The invention's effect】
As described above, according to the present invention, the tooth forming shape portion for forming the tooth profile portion of the gear includes the fixed tooth forming shape portion formed on the fixed mold and the movable tooth forming shape portion formed on the movable mold. Because the fixed mold and the movable mold are arranged in one molding device, the gear can be forged and formed in one manufacturing process, and the manufacturing time of the gear is significantly reduced. it can. Moreover, since it is not necessary to install a plurality of molding apparatuses in which different types of molds are arranged to form gears as in the prior art, it is possible to reduce equipment costs and installation space. As a result, the operational efficiency of the device itself can be dramatically improved, and as a result, the manufacturing cost of the molded product can be reduced. Furthermore, since the fixed tooth forming portion and the movable tooth forming portion are joined at a predetermined angle with respect to the axial direction, burr generated in the tooth shape portion of the gear after molding is suppressed as much as possible. A unique effect is obtained.
[Brief description of the drawings]
FIG. 1 is a partially omitted longitudinal sectional view showing a gear forming apparatus according to the present embodiment.
2 is a partially omitted enlarged vertical cross-sectional explanatory view showing a tooth forming portion in the gear forming apparatus of FIG. 1;
FIG. 3 is a partially omitted enlarged perspective explanatory view showing a tooth forming shape portion of FIG. 2;
4 is a partially omitted enlarged vertical cross-sectional explanatory view showing a state in which the punch portion is separated from the fixed portion in the gear forming apparatus of FIG. 1;
5 is a partially omitted enlarged vertical cross-sectional explanatory view showing a state in which a movable mold is in contact with a fixed mold in the gear forming apparatus of FIG. 1. FIG.
6 is a partially omitted enlarged longitudinal sectional view illustrating a state immediately after a gear material is pressed by a punch in the gear forming apparatus of FIG. 1;
7 is a partially omitted enlarged longitudinal sectional explanatory view showing a state in which the gear after forging is released from the fixed mold in the gear forming apparatus of FIG. 1; FIG.
FIG. 8A is a perspective view showing a gear material, and FIG. 8B is a perspective view showing the gear after forging.
9A and 9B are schematic operation explanatory views of a conventional gear forming apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Gear shaping | molding apparatus 12 ... Gear raw material 58 ... Fixed mold 81a ... Chamfer part 81b ... Undercut part 82 ... Fixed tooth formation part 83b ... Fixed side joining surface 96 ... Movable metal mold 106 ... Punch 108a ... 1st linear part 108b ... second straight part 108c ... third straight part 110 ... tapered part 112 ... movable tooth forming part 113 ... movable side joint surface 114 ... tooth forming part 116 ... gear 118 ... tooth part

Claims (3)

A first mold in which a first tooth forming portion is formed , a second mold in which a second tooth forming portion is formed, and a punch that faces one of the first and second molds A gear forming method for forming a gear using
A plurality of inclined portions that converge toward one end are provided on one of the first tooth forming shape portion and the second tooth forming shape portion, and the other one of the first tooth forming shape portion and the second tooth forming shape portion is connected to the inclined portion at the time of mold clamping and vertically Provide a straight section extending in the direction,
Supporting the gear material on one of the first mold or the second mold,
And an end portion of the second tooth forming portion of the second mold with the end of the first tooth profile forming portion of the first mold, Ru are bonded to a predetermined angle inclined to the axial direction And storing a gear material between the first mold and the second mold ,
By pressing the gear blank with the punch, the gear blank is caused to flow simultaneously in the first tooth forming portion and the second tooth forming portion to form the gear tooth portion of the gear by one punch action. And a gear forming method. Having a first mold and a second mold;
A tooth forming shape portion for forming a gear tooth shape portion is defined by a first tooth forming shape portion formed on the first mold and a second tooth forming shape portion formed on the second mold. Made,
The first mold and the end of the second mold have a joint surface inclined at a predetermined angle with respect to the axial direction ;
A plurality of inclined portions that converge toward one end are provided on one of the first tooth forming shape portion and the second tooth forming shape portion, and the other one of the first tooth forming shape portion and the second tooth forming shape portion is connected to the inclined portion at the time of mold clamping and vertically A gear forming apparatus comprising a linear portion extending in a direction . The gear forming apparatus according to claim 2 , wherein
The first tooth forming portion includes a pair of mutually facing chamfer portions formed in a substantially triangular shape, and an undercut portion whose one main surface is inclined at a predetermined angle in a direction away from the axial direction,
The second tooth forming portion includes a first straight portion whose one principal surface is parallel to the axial direction, a tapered portion in contact with the upper end of the first straight portion, and a direction away from the axial direction. A second linear portion whose upper surface is inclined at a predetermined angle; and a third linear portion inclined at a predetermined angle in a direction approaching the axial direction from the second linear portion;
The first joint surface including the upper ends of the pair of chamfer portions and the undercut portion and the second joint surface including the lower ends of the first straight portions are joined at a predetermined angle with respect to the axial direction. A gear forming apparatus characterized by that.

Images