JP2012096251A - Method of manufacturing gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a gear which satisfies required durability and calmness by inexpensively improving durability and gear surface accuracy without a large sum of equipment investment.SOLUTION: The method of manufacturing the gear comprises: a gear cutting step of performing gear cutting on a work; a pre-heat treatment finish machining step of performing pre-heat treatment finish machining on the gear-cut work; and a heat treatment step of performing heat treatment on the work subjected to pre-heat treatment finish machining, wherein the processing of the gear is completed in the heat treatment step. The pre-heat treatment finish machining step comprises a first processing step of performing shaving on the gear-cut work; and a second processing step of performing rolling processing on the gear root portion and gear surface of the shaved work. A shaving cutter used by being attached to a shaving processing device in the first processing step is replaced by a rolling die, and the rolling processing related to the second processing step is performed by use of the rolling die.

Description

  The present invention relates to a gear manufacturing method.

  Conventionally, gears are manufactured through a raw material turning process, a gear cutting process such as a hobbing process and a gear shaper, a pre-heat treatment finishing process by shaving a rough molding material obtained in the gear cutting process, and a heat treatment process such as quenching.

  Here, as a measure for improving durability among the required characteristics of the gear, means for performing shot peening after heat treatment is known in order to improve fatigue strength. Further, as a measure for improving quietness, means for performing tooth surface grinding after heat treatment is known in order to improve tooth surface accuracy.

  As a specific example, for example, the following Patent Document 1 is provided with a surface treatment process such as shot peening or a tooth surface grinding finishing process after a shaving process as a tooth surface finishing process, a heat treatment process such as carburizing and quenching. A gear manufacturing method is described.

  Further, in Patent Document 2 below, as a means for improving the tooth surface accuracy at a low cost, after the gear cutting step of cutting the outer peripheral surface of the blank material to form a roughing gear, the roughening of the gear is performed. A gear manufacturing method is described in which a tooth surface forming step of forming a tooth surface by pressing a rolling die on a processed tooth surface is described.

JP 2000-42832 A Japanese Utility Model Publication No. 2009-233722

  Thus, in order to improve both the fatigue strength and the tooth surface accuracy of the gear, it is necessary to provide both the shot peening process and the finish grinding process after the heat treatment process, as described in Patent Document 1 above. However, if it does so, since it will be necessary to newly install a processing apparatus for each, it will raise capital investment. As described in Patent Document 2, if the method is intended to improve tooth surface accuracy by providing a rolling step after the gear cutting step, shaving processing before heat treatment and finish grinding after heat treatment can be omitted. However, since the strength improvement equivalent to shot peening cannot be expected only by rolling the tooth surface, shot peening after heat treatment cannot be omitted. Furthermore, a gear (coarse molding material) roughly formed by gear cutting has some variation in the tooth surface shape and dimensions. Therefore, even if rolling is performed with a rolling mold processed with high accuracy, the influence of variations in tooth surface shape and dimensions at the time of gear cutting remains, and all tooth surfaces are transferred and molded with high accuracy. I can't. In particular, in the gear used for the drive system of the vehicle, not only the durability but also the further improvement in quietness in the vehicle interior is required. In view of such a situation, the method described in Patent Document 2 described above is required. It is difficult to obtain the required tooth surface accuracy.

  In view of the above circumstances, it is possible to provide a gear manufacturing method that can improve fatigue strength and tooth surface accuracy at low cost and satisfy required durability and quietness without making a large capital investment. This is a technical problem to be solved by the present invention.

  The solution to the above problem is achieved by the gear manufacturing method according to the present invention. In other words, this manufacturing method includes a gear cutting process for performing gear cutting on a workpiece, a pre-heat treatment finishing process for performing a pre-heat treatment finishing process on a workpiece subjected to gear cutting, and a work subjected to a pre-heat treatment finishing process. A heat treatment step for performing heat treatment, and a gear manufacturing method that completes the processing of the gear in the heat treatment step, wherein the pre-heat treatment finish processing step includes a first processing step for performing a shaving process on the workpiece after gear cutting, A rolling die provided with a raised portion as a portion corresponding to the tooth root portion, and a second machining step for rolling the tooth root portion and the tooth surface of the workpiece subjected to the shaving process. It is characterized by the fact that the shaving cutter attached to the shaving processing device is replaced with a rolling die, and the rolling process according to the second processing step is performed with the rolling die.

  The present invention aims to improve the fatigue strength of the gear efficiently by rolling the work tooth root part with a rolling die provided with a raised part before heat treatment, and to perform the rolling process after the shaving process. By implementing it, the aim is to achieve improvement in tooth surface accuracy without requiring large capital investment. That is, before the heat treatment such as quenching, the workpiece is rolled with a rolling die provided with a raised portion as a portion corresponding to the tooth root portion, so that the tooth root portion of the workpiece is pressed by the raised portion of the rolling die. Thus, compressive residual stress can be generated in the tooth base. In this way, by generating residual compressive stress in the tooth root part, which is the part that greatly affects the fatigue strength of the gear (the part where the bending load is expected to act most when the gear is used), the gear is The fatigue strength of can be increased efficiently.

  In addition, by shaving the workpiece after the gear cutting, variations in the tooth surface shape and dimensions caused by the gear cutting can be suppressed to some extent by the shaving. Therefore, by rolling the workpiece that has been shaved, the amount of workpiece processing (plastic deformation) due to the rolling process is reduced, and all tooth surfaces of the workpiece are rolled with high accuracy. Can be molded.

  In addition, as described above, after finishing the work after the shaving process and then the rolling process as the finishing process before the heat treatment, the gear processing is completed by the heat treatment process, so that any finishing process is provided after the heat treatment. Therefore, it is possible to improve fatigue strength and tooth surface accuracy. Therefore, the shot peening process and the grinding finishing process after the heat treatment can be omitted, and the equipment investment corresponding to that can be kept low. In addition, the rolling process is a processing means having a shorter processing time than the finishing process after the heat treatment described above, and the rolling process amount (plastic deformation amount) on the workpiece by performing the rolling process after the shaving process. Therefore, the processing time can be shortened. Therefore, it is possible to reduce the manufacturing cost and mass-produce gears.

  In the gear manufacturing method according to the present invention, the shaving cutter attached to the shaving processing apparatus in the first processing step is replaced with a rolling die, and the rolling processing related to the second processing step is performed with the rolling die. It is characterized by giving.

  In this way, if the work tool (shaving cutter, rolling die) is changed and the first and second processing steps are performed, the rolling process can be performed using the shaving apparatus. it can. In this case, it is not necessary to provide an apparatus dedicated to rolling processing, so that the capital investment can be greatly reduced. In addition, shaving and rolling can be performed simply by changing the processing tool with the same processing device, so both processes can be performed continuously while the workpiece is still attached to the shaving processing device. it can. As a result, it is possible to further reduce the machining time by eliminating the trouble of removing and reattaching the workpiece.

  In addition, since the shaving process and the rolling process can be performed while the workpiece is attached to the shaving apparatus, higher processing accuracy can be obtained as compared with the case where the workpiece is once removed and reattached.

  In the second processing step, the tooth surface of the workpiece may be subjected to rolling processing in a state where the rotation axis of the rolling die is parallel to the support shaft of the workpiece.

  In the shaving process, the tooth surface of the workpiece is scraped off by the serration provided on the tooth tip of the cutter by sliding the shaving cutter with respect to the tooth surface of the workpiece. Even if the shaving cutter can be machined into a shape that incorporates, it is difficult to machine the tooth surface of the workpiece according to the shape. On the other hand, in the present invention, the rolling surface of the rolling die is parallel to the support shaft of the workpiece, and the tooth surface of the workpiece is subjected to the rolling process, so that the rotation shaft and the support shaft intersect. The rolling die can be pressed against the workpiece with the angle being substantially zero degrees. Therefore, it is possible to transfer the shape of the portion corresponding to the tooth surface of the rolling die to the work tooth surface with high accuracy by minimizing slippage during processing as described above, thereby further improving the tooth surface finishing accuracy. Further, when performing this type of shaving (shaving), as described above, in order to cause a predetermined relative slip between the shaving cutter and the work tooth surface, the shaft of the shaving cutter and the support of the work are supported. For example, when the shaving cutter is replaced with a rolling die in the same processing apparatus and the rolling process is performed, the rotation axis of the rolling die and the support shaft of the workpiece are By simply changing the crossing angle from the angle at the time of shaving to zero degrees, rolling without relative slip can be easily and quickly performed.

  In the second processing step, the tooth surface corresponding part of the rolling die is processed into a shape incorporating the three-dimensional deformation amount of the work tooth surface generated by the heat treatment, and the tooth of the workpiece is processed using the processed rolling die. You may make it give a rolling process to a surface.

  That is, in the toothing of the shaving cutter, the processing means for the specific direction of the cutter tooth surface (for example, the direction of the tooth trace) is limited due to the mechanism of the toothing process or the structure of the shaving cutter. There was a problem that precise processing to the tooth surface shape that anticipated deformation was difficult. On the other hand, rolling dies require fewer processing restrictions than shaving cutters, and therefore, as described above, the tooth surface is compatible with the shape incorporating the three-dimensional deformation of the work tooth surface caused by heat treatment. The part can be processed. Therefore, by using the rolling die subjected to the above processing, it is possible to finish the tooth surface of the workpiece into a three-dimensional shape incorporating the heat treatment deformation amount in the tooth trace direction as well as the tooth shape direction of the tooth surface. Thereby, the amount of heat treatment deformation of the workpiece tooth surface in a predetermined direction (tooth direction) that is difficult to compensate by shaving can be compensated by rolling to further improve the tooth surface accuracy of the finished product.

  As described above, according to the gear manufacturing method of the present invention, the required durability and quietness are satisfied by improving durability and tooth surface accuracy at low cost without making a large investment in equipment. Gears can be manufactured. Moreover, it becomes possible to achieve further cost reduction by performing the finishing process before heat processing using the existing equipment.

It is a manufacturing method of the gear concerning one embodiment of the present invention, and is the flow chart which shows the processing procedure. It is a front view of the shaving processing apparatus used for the shaving process shown in FIG. It is the figure which planarly viewed the workpiece | work and shaving cutter attached to the shaving processing apparatus, Comprising: It is a top view for demonstrating mesh | engagement with a workpiece | work and a shaving cutter. It is the figure which planarly viewed the workpiece | work and rolling die attached to the shaving processing apparatus, Comprising: It is a top view for demonstrating meshing | engagement of a workpiece | work and a rolling die. It is the side view to which the tooth | gear part of the workpiece | work which performed the gear cutting process was expanded. It is the side view to which the tooth tip part of the rolling die was expanded.

  Hereinafter, an embodiment of a gear manufacturing method according to the present invention will be described with reference to the drawings. In this embodiment, a case where a helical gear is manufactured will be described as an example.

  FIG. 1 is an example of a gear manufacturing method according to the present invention, and shows the processing procedure in a flow. As shown in this flowchart, the gear manufacturing method according to this embodiment is such that a blank material is obtained by forming a portion excluding the tooth surface into a predetermined shape. (B) The gear cutting process, and the workpiece 1 (see FIG. 5 to be described later) subjected to the gear cutting is subjected to a pre-heat treatment finishing process and then the tooth surface is processed. 3 is finished (c) a pre-heat treatment finishing process, and a heat treatment such as carburizing and quenching is performed on the workpiece 1 that has been subjected to the pre-heat treatment finishing process (d). Then, through these series of processing steps, the processing of the workpiece is completed, and the gear is completed by performing cleaning and inspection as necessary. In addition, (c) the finishing process before the heat treatment is a rolling process in which a shaving process is performed on the workpiece 1 after the gear cutting process (c-1) a first processing step and a raised part 34 as a tooth base corresponding part A die 30 (see FIG. 6 to be described later) has a second machining step (c-2) for rolling the tooth root part 5 and the tooth surface 3 of the work 1 subjected to the shaving process.

  Further, as an example of the layout of the processing line in this case, although not shown in the drawings, a turning processing device, a hobbing device, a shaving processing device, a quenching device (a quenching furnace, a cooling furnace) is provided on the workpiece transfer line or on the side thereof. ) Are arranged in order from the upstream side. Hereinafter, (c) the pre-heat treatment finishing process will be mainly described.

(A) Blanking process First, the steel material used as a raw material is turned with a lathe etc., and the part except the tooth surface of a gearwheel is shape | molded in a defined shape, and a blank material is obtained (blank process). In other words, the workpiece is subjected to predetermined processing so that the tooth surface can be formed by gear cutting performed thereafter. In addition, in this embodiment, although the turning process was illustrated as a blank process, you may employ | adopt other process means, for example, a forge process, for a blank process.

(B) Gear cutting process Next, the workpiece subjected to the turning process is subjected to hobbing using, for example, a hobbing apparatus equipped with a hob cutter, and a tooth surface having a shape according to the finished product on the outer periphery of the workpiece, for example, The involute tooth surface is roughly formed (tooth cutting). At this time, the tooth root portion 5 of the workpiece 1 obtained by hobbing may have a shape smoothly connected to the adjacent tooth surface 3 or the tooth bottom surface 4 as a part of the involute tooth surface as shown in FIG. And it is good also as the undercut shape 6 (The shape shown with the broken line in FIG. 5. It is also called a protubal balance shape.) Which is dented inward with respect to these adjacent tooth surfaces 3 and tooth bottom surfaces 4. These can be formed in the tooth base portion 5 simultaneously with the gear cutting by processing the tooth tip portion of the hob cutter into a corresponding shape, for example. Note that the gear cutting is not limited to the hobbing described above, but may be a creative gear cutting such as gear shaper processing, or a molding gear cutting such as milling or grinding using a disk-shaped grindstone. Processing may be employed.

(C) Finishing process before heat treatment (c-1) First processing step Shaving is performed on the work 1 that has been subjected to gear cutting as described above, and the tooth surface of each tooth 2 of the work 1 by gear cutting. The cutting lines (also referred to as tool marks) generated in 3 are removed and the tooth surface 3 is finished (first machining step). FIG. 2 shows a front view of the shaving apparatus 10 used for this shaving process. As shown in this figure, the shaving apparatus 10 includes a base 11, a table 12 attached to the base 11, and a head portion 14 attached via a column 13 standing on the base 11. It has. The table 12 is attached to the base 11 so as to be slidable in the horizontal direction, and a support device 15 for rotatably supporting the workpiece 1 is disposed on the table 12. The head unit 14 is mainly composed of a head lifting unit 16 attached to the column 13 so as to be movable up and down, and a head body 17 integrally provided below the head lifting unit 16. On one side of the head main body 17, a processing tool mounting portion 18 is provided that allows a processing tool such as a shaving cutter 20 and a rolling die 30 (see FIG. 6 described later) to be mounted. Is provided with a motor 19 for rotationally driving a shaving cutter 20 or the like mounted on the processing tool mounting portion 18. Further, the head main body 17 is configured to be rotatable about a vertical axis with respect to the head lifting / lowering unit 16. When the shaving cutter 20 or the like is mounted on the processing tool mounting unit 18, the rotation axis A of the shaving cutter 20 or the like. ₁ and a crossing angle θ (see FIG. 3 to be described later) between the support shaft A ₂ of the workpiece 1 rotatably supported by the support device 15 can be arbitrarily set.

A description will be given of one processing mode of the shaving processing using the shaving processing device 10 having the above-described configuration. First, as shown in FIG. 2, the work 1 subjected to gear cutting processing is attached to the support device 15 of the shaving processing device 10, The shaving cutter 20 is mounted on the processing tool mounting portion 18 of the head unit 14. Then, as shown in FIG. 3, the head main body 17 is placed on the vertical axis with respect to the head elevating unit 16 so that the teeth 21 of the shaving cutter 20 arranged vertically above the work 1 and the teeth 2 of the work 1 are engaged with each other. By rotating around, the crossing angle θ between the rotation axis A ₁ of the shaving cutter 20 and the support axis A ₂ of the workpiece 1 is set to a predetermined size.

After setting the crossing angle θ in this way, the head elevating part 16 is lowered with respect to the column 13, and the shaving cutter 20 mounted on the head body 17 and the processing tool mounting part 18 of the head body 17 is moved to the center of the work 1. Push in toward the side and engage both teeth 2, 21. Then, by rotating the shaving cutter 20 by driving the motor 19, the work 1 in mesh with the shaving cutter 20 is rotated. At this time, as shown in FIG. 3, since the rotation axis A ₁ of the shaving cutter 20 and the support axis A ₂ of the workpiece 1 intersect at a predetermined intersection angle θ, the shaving cutter 20 is moved as described above. By pushing into 1 and causing rotation, relative slip occurs between the tooth 21 of the shaving cutter 20 and the tooth surface 3 of the workpiece 1. Then, a plurality of serrations (not shown) provided on the tooth tips of the shaving cutter 20 by this relative sliding scrape out minute irregularities present on the tooth surface 3 of the workpiece 1, thereby finishing the workpiece 1. .

  In this way, the tooth surface 3 is smoothly finished by scraping the tooth surface 3 of the workpiece 1 with the shaving cutter 20. In addition, variations in shape and dimensions during gear cutting can be suppressed to some extent by shaving, and thereby the shape accuracy of the tooth surface 3 can be improved. Further, as described above, the shaving cutter 20 is pressed against the work 1 and the shaving process is performed so that the work 1 is rotated (only the shaving cutter 20 is rotated). An error between pitches of the teeth 2 of the workpiece 1 is corrected.

(C-2) Second processing step The workpiece 1 subjected to the shaving process as described above is subjected to a rolling process with a rolling die 30 having a predetermined shape. As shown in FIG. 6, the rolling die 30 used here includes a tooth surface corresponding portion 32 for forming the tooth surface 3 of the work 1 on each tooth 21 by rolling, and teeth of the tooth surface corresponding portion 32. On the front side and on both sides in the circumferential direction of the tooth tip surface 33, there are integrally raised portions 34 as tooth base corresponding portions for forming the tooth base 5 of the workpiece 1 by rolling. Of course, the tooth tip surface 33 of the rolling die 30 is not provided with serrations such as the shaving cutter 20 and is flat. In this embodiment, the rolling die 30 having the above configuration is used by being attached to the shaving apparatus 10 shown in FIG. That is, in the immediately preceding first processing step (shaving processing step), the shaving cutter 20 used by being attached to the shaving processing apparatus 10 shown in FIG. 2 is removed from the processing tool mounting portion 18 and a rolling die 30 is attached instead.

In this state, the rotation axis A ₁ of the rolling die 30 and the support axis A _{2 of the} work 1 are in a state of intersecting at an intersecting angle θ (see FIG. 3) at the time of shaving. 4, the head main body 17 is rotated about the vertical axis with respect to the head elevating part 16 so that the teeth 31 of the rolling die 30 and the teeth 2 of the work 1 are engaged with each other. In this embodiment, the rotation axis A ₁ of the rolling die 30 and the support axis A _{2 of the} work 1 are parallel to each other in the meshed state (as shown in FIG. ₁ and A ₂ are overlapped), and the twist angle of each tooth 21 with respect to the rotation axis A ₁ of the rolling die 30 is set. Therefore, in this case, the head body 17 and the rolling die 30 are moved around the vertical axis until the crossing angle θ between the rotation axis A ₁ of the rolling die 30 and the support axis A ₂ of the workpiece 1 becomes substantially zero degrees. Turn to.

  After positioning the rolling die 30 with respect to the workpiece 1 in this manner, the head lifting / lowering portion 16 is lowered with respect to the column 13 and the head main body 17 and the rolling tool mounted on the processing tool mounting portion 18 of the head main body 17 are mounted. The die-making die 30 is pushed toward the center side of the work 1, and the teeth 2 and 31 are engaged with each other. Then, by rotating the rolling die 30 by driving the motor 19, the teeth 2 and 31 with which the rolling die 30 and the workpiece 1 are engaged with each other are changed, and the bulge as a tooth base corresponding portion of the rolling die 30 is raised. The part 34 and the tooth surface corresponding part 32 are pressed against the tooth root part 5 and the tooth surface 3 of the workpiece 1, respectively. Thereby, compressive residual stress can be actively generated in the tooth root part 5, and as a result, the fatigue strength of a gear can be improved. Further, as shown by a broken line in FIG. 5, when the tooth root portion 5 has an undercut shape 6, a raised portion 34 having a size larger than the undercut shape 6 is provided in the rolling die 30. A sufficient pressing force may be applied to the tooth base portion 5 of the undercut shape 6 to generate a required compressive residual stress.

Further, by pressing the tooth surface 3 of the workpiece 1 with the tooth surface corresponding portion 32 of the rolling die 30, the tooth surface corresponding portion 32 is accurately transferred and formed on these tooth surfaces 3. In addition, by performing the rolling process while the workpiece 1 is attached to the shaving processing apparatus 10 as described above, a higher machining accuracy can be obtained than when the workpiece 1 is once removed and attached again. In particular, in this embodiment, the rolling surface is applied to the tooth surface 3 of the workpiece 1 in a state where the rotation axis A ₁ of the rolling die 30 is parallel to the support axis A ₂ of the workpiece 1. The rolling die 30 can be pressed against the workpiece 1 and formed by setting the crossing angle θ between the rotation axis A ₁ of the die 30 and the support axis A ₂ of the workpiece 1 to substantially zero degrees. For this reason, the shape of the tooth surface corresponding portion 32 of the rolling die 30 is transferred to the tooth surface 3 of the work 1 with high accuracy while minimizing relative slip as in the shaving process. Thereby, the finishing precision of the tooth surface 3 is further improved.

  At this time, the tooth surface corresponding portion 32 of the rolling die 30 is processed in advance into a shape incorporating a three-dimensional deformation amount of the tooth surface 3 of the work 1 generated by heat treatment, which will be described later, and this processing is performed. A rolling process may be performed on the tooth surface 3 of the workpiece 1 using the die making die 30. In this case, the toothing on the tooth surface corresponding portion 32 of the rolling die 30 can be performed by using a grinding apparatus capable of precise three-dimensional processing on the tooth surface 3 such as a Marg tooth grinder. .

  If the rolling process is performed on the workpiece 1 using the rolling die 30 that has been processed as described above, the tooth surface incorporating the heat treatment deformation amount in the tooth trace direction as well as the tooth profile direction of the tooth surface 3. A rolling finish is applied to the tooth surface 3 of the workpiece 1 at the corresponding portion 32. Therefore, even if no processing step is provided after the heat treatment, the shape of the tooth surface 3 after being deformed by the heat treatment described later can be made closer to the design shape, and the tooth surface accuracy of the finished product can be further improved. Further, by performing the rolling process described above after the shaving process, it is possible to suppress the variation in the tooth surface accuracy of the tooth 2 after the rolling process, so coupled with the above effect, when using the gear, It becomes a stable meshing state, and this makes it possible to reduce noise during use.

(D) Heat treatment step The workpiece 1 subjected to the rolling process in this manner is subjected to a heat treatment such as carburizing and quenching to increase the hardness of the gear (heat treatment). Specifically, the work 1 that has undergone the rolling process is put into a quenching furnace and then into a cooling furnace, and given a predetermined heat history, the hardness and rigidity of the work 1 are improved. Thereby, the processing of the workpiece 1 is completed, and a gear as a finished product is manufactured.

  As described above, as the finishing process before the heat treatment, the work 1 is subjected to the shaving process and then the rolling process, whereby the fatigue strength and the tooth surface accuracy can be improved without providing any finishing process after the heat treatment. Therefore, the shot peening process and the grinding finishing process after the heat treatment can be omitted, and the equipment investment corresponding to that can be kept low. In particular, as described above, if the shaving cutter 20 is replaced with the rolling die 30 and the shaving process and the rolling process are performed, the shaving apparatus 10 can be used for the rolling process. Therefore, it is not necessary to install an apparatus dedicated to rolling processing, and the capital investment can be further reduced. Further, since the shaving process and the rolling process can be performed simply by changing the processing tool, both processes can be performed continuously with the workpiece 1 attached to the shaving apparatus 10. Therefore, it is possible to further reduce the machining time and reduce the cost by removing the work 1 from being removed and reattached. Therefore, it is also suitable for mass production of gears.

In the above embodiment, the case where the shaving cutter 20 attached to the shaving processing apparatus 10 is used in place of the rolling die 30 and the workpiece 1 is subjected to rolling processing with the rolling die 30 is exemplified. It is also possible to take other forms. For example, two shaving processing apparatuses 10 are arranged in parallel on a gear processing line, a shaving cutter 20 is mounted on the upstream shaving processing apparatus 10, and a rolling die 30 is mounted on the downstream shaving processing apparatus 10. Wear. With such a configuration, it is not necessary to replace the shaving cutter 20 with the rolling die 30, and the crossing angle θ between the rotation axis A _{1 of} the shaving cutter 20 or the rolling die 30 and the support axis A ₂ of the workpiece 1. This saves you the trouble of changing the process every time.

  In any case, the gear manufacturing method according to the present invention is not limited to the above-described exemplary embodiment. The shaving process is performed on the gear cutting process and the workpiece after the gear cutting process, and then the rolling process is performed on the tooth root part and tooth surface of the work with a rolling die provided with a raised part corresponding to the tooth base part. As long as it has a pre-heat treatment finishing process for applying heat treatment and a heat treatment process, and completes the processing of the gears in the heat treatment process, it can take any form.

  In the above embodiment, the case where the present invention is applied to the production of a helical gear has been described. Of course, the manufacturing method according to the present invention can be applied to other types of gears.

DESCRIPTION OF SYMBOLS 1 Work 2 Tooth 3 Tooth surface 4 Tooth base 5 Tooth base part 6 Undercut shape 10 Shaving processing apparatus 11 Base 12 Table 13 Column 14 Head part 15 Support apparatus 16 Head raising / lowering part 17 Head main body 18 Work tool mounting part 19 Motor 20 Shaving cutter 21 Teeth 30 Rolling die 31 Teeth 32 Tooth surface corresponding portion 33 Tooth tip surface 34 Raised portion (tooth base corresponding portion)
A1 Rotating shaft (shaving cutter, rolling die)
A2 Support shaft (workpiece)
θ Crossing angle

Claims (3)

A gear cutting process for performing gear cutting on a workpiece, a pre-heat treatment finishing process for performing a pre-heat treatment finishing process on the workpiece subjected to the gear cutting process, and a heat treatment process for performing a heat treatment on the workpiece subjected to the pre-heat treatment finishing process. A gear manufacturing method that completes the processing of the gear by the heat treatment step,
The pre-heat treatment finishing process includes a first machining step in which a shaving process is performed on the workpiece after the gear cutting process, and a rolling die provided with a raised portion as a tooth base corresponding part. A second machining step for rolling the tooth root and tooth surface of
A method for manufacturing a gear, wherein a shaving cutter attached to a shaving processing apparatus in the first processing step is used for the rolling die, and the rolling processing is performed with the rolling die according to the second processing step.   2. The gear manufacturing method according to claim 1, wherein, in the second processing step, the tooth surface of the workpiece is subjected to rolling processing in a state in which a rotating shaft of the rolling die is parallel to a support shaft of the workpiece.   In the second processing step, the tooth surface corresponding portion of the rolling die is processed into a three-dimensional shape incorporating a deformation amount of the workpiece tooth surface caused by the heat treatment, and the processed rolling die is used to perform the processing. The gear manufacturing method according to claim 1, wherein a rolling process is performed on a tooth surface of the workpiece.

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