JP2012171020A - Gear manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gear manufacturing method by which burrs can be removed, the burrs being generated in the end face on the lower side of a workpiece, namely, on the lower side of the feeding operation of a cutter in skiving, without causing for example increase in cost, deterioration in machining accuracy, and interference between the cutter and other members.SOLUTION: The gear manufacturing method using skiving is provided in which a pinion type cutter 1 is used that has an inclined rotary axis Ac relative to the rotary axis Aw of the workpiece 10 to be machined into a gear and, while the cutter 1 is rotated synchronously with the workpiece 10, feeding operation of the cutter is conducted in the tooth line direction of the workpiece 10. In this method, deburring is performed by differentiating, from conditions of cutting a region other than the end face 10c on the lower side, at least any one of the following: feeding speed of the cutter 1; cutting depth; and a relative rotary phase between the cutter 1 and the workpiece 10, in the end face 10c on the lower side of the workpiece 10 that becomes the lower side in the feeding operation.

Description

  Gear manufacturing using skiving processing that uses a pinion-type cutter that has a rotation axis inclined with respect to the rotation axis of the workpiece to be processed into a gear and feeds it in the direction of the teeth of the workpiece while rotating the cutter synchronously with the workpiece. Regarding the method.

  The skiving process is described with reference to FIG. 1. A pinion-type cutter having a rotation axis Ac inclined with respect to the rotation axis Aw of the workpiece 10 to be processed into a gear and provided with a number of cutting blades 2. 1 is a processing method in which a feed operation (here, a feed operation from the upper side to the lower side along the rotation axis Aw) is performed in a gearing direction of the workpiece 10 while rotating 1 in synchronization with the workpiece 10.

  In such skiving processing, cutting is performed by the rotational motion of the cutter and the workpiece, so that smooth cutting is possible as compared with other processing methods in which the cutter is simply reciprocated for cutting. Further, high speed cutting can be easily realized by increasing the rotation speed of the cutter and the workpiece. Therefore, skiving is a particularly advantageous machining method when machining a gear having a large number of fine teeth, such as a wave gear.

  In skiving processing, as described above, the cutter is fed in the direction of the teeth of the workpiece. Therefore, when the cutter is separated from the workpiece, it is shown in FIG. Such burrs B are generated. When the gear to which the burrs B are attached is assembled with other parts, the assembling accuracy may be deteriorated, or the burrs B dropped after the assembling may hinder the smooth operation of each part. In particular, in the case of the gear used for the above-mentioned wave gear, since the teeth are fine, the influence is likely to be increased even with a small burr.

  As an apparatus for removing burrs from a workpiece after gear cutting, for example, there is a gear machining apparatus described in Patent Document 1. This apparatus is configured so that a workpiece that has been subjected to gear cutting by a gear cutting mechanism can be moved by an autoloader to an edge processing mechanism provided at a position different from the gear cutting mechanism. Since the gear cutting mechanism and the edge processing mechanism are provided separately, the gear cutting processing in the gear cutting mechanism and the edge processing such as deburring in the edge processing mechanism can be performed simultaneously. As a result, it is said that the work efficiency of the gear manufacturing process can be greatly improved.

  Patent Document 2 discloses a chamfering and shaving device. This apparatus includes a chamfering cutter and a shaving cutter, one of the cutters is supported by the head body, and the other cutter is supported by a movable part that moves up and down relatively with respect to the head body. Further, this apparatus is provided with a pair of deburring cutters, and is configured so that shaving processing, chamfering processing and deburring processing can be performed with a single device.

JP 2006-224228 A JP-A-7-1231

  However, since the apparatus described in Patent Document 1 is provided with a plurality of mechanisms at remote locations, the apparatus is increased in size and requires a plurality of tools, resulting in an increase in cost. Moreover, since it is necessary to enlarge the length of a double movable part, the apparatus of patent document 2 may reduce the rigidity of the cutter periphery provided in the double movable part, and may cause a reduction in processing accuracy. Furthermore, when an internal gear such as a wave gear is manufactured by skiving, there is a cutter that is inclined with respect to the workpiece in the inner space of the workpiece. It becomes a problem.

  In view of the above problems, the present invention provides a lower end surface of the workpiece that is the lower side of the cutter feeding operation in skiving without incurring cost increase, reduction in processing accuracy, interference between the cutter and other members, etc. An object of the present invention is to provide a gear manufacturing method capable of removing burrs generated in the above.

  The characteristic means of the gear manufacturing method according to the present invention uses a pinion-type cutter having a rotation axis inclined with respect to the rotation axis of the workpiece to be processed into a gear, and rotates the cutter synchronously with the workpiece while In the gear manufacturing method using skiving processing for feeding operation in the tooth trace direction, the feed speed of the cutter on the lower side end surface of the workpiece that is the lower side in the feeding operation, the cutting amount, and the cutter and the workpiece The deburring process is performed by making at least one of the relative rotational phases different from the conditions for cutting the region excluding the lower end surface.

  In normal skiving processing, the entire area from the upper end surface to the lower end surface of the workpiece is cut and processed while maintaining the cutter feed speed, depth of cut, and relative rotation phase between the cutter and the workpiece. Therefore, burrs generated on the lower end face cannot be removed. According to this characteristic means, at least one of the feed speed of the cutter, the cutting amount, and the relative rotation phase between the cutter and the workpiece is cut on the lower end surface of the workpiece in the region excluding the lower end surface. Deburring is performed under different conditions. According to this characteristic means, it is not necessary to prepare a separate deburring tool, and it is possible to perform deburring only by changing the program that controls the operation of the cutter and workpiece. Interference does not occur, and there is no increase in cost or reduction in processing accuracy. Note that changing the feed speed of the cutter and the relative rotation phase between the cutter and the workpiece includes not only changing the speed but also reversing the feed operation direction and the relative rotation direction. And

  Here, as the deburring process, it is preferable that the feeding operation of the cutter is temporarily stopped at the lower end surface.

  As in this feature, when the cutter feeding operation is temporarily stopped at the lower end surface of the workpiece, the synchronous rotation of the cutter and the workpiece is continued at the lower end surface, and the cutter blade is formed on the workpiece processing surface. May contact the surface of the formed tooth space. As described above, even after the cutting process is finished, the cutter and the workpiece come into contact with each other, so that the burr generated on the lower end surface of the workpiece can be dropped due to an impact at the time of contact or the like.

  Further, as the deburring process, it is preferable that the cutter is reciprocated in the tooth trace direction on the lower end surface.

  As in this feature, when the feed operation is performed so that the cutter reciprocates in the tooth trace direction on the lower end surface of the workpiece, the cutter blade contacts the surface of the tooth groove formed on the workpiece surface multiple times. Can do. As described above, even after the cutting process is finished, the cutter and the workpiece come into contact with each other, so that the burr generated on the lower end surface of the workpiece can be dropped due to an impact at the time of contact or the like. In particular, when the cutter moves in the direction from the lower end surface to the upper end surface, during normal feeding operations that move the cutter from the upper end surface to the lower end surface, contact between the cutter blade and the workpiece is normal. The form (contact location, contact direction, contact force, etc.) is different. For this reason, during the reciprocating motion of the cutter, various impacts act on the workpiece, and the burr removal effect is improved.

  In addition, as the deburring process, it is preferable to cut the lower end surface again with a larger cutting amount after cutting the entire region of the workpiece in the tooth line direction.

  According to this feature means, when the entire region in the tooth trace direction of the workpiece is first cut, burrs are generated on the lower end surface of the workpiece. However, it is possible to remove the burrs from the lower end surface by cutting the lower end surface of the workpiece again with a cutting amount larger than the first cutting amount. If a new burr is generated by the second cutting, the lower end face can be cut again with a larger cutting amount in order to further remove the burr. According to this feature means, the amount of cutting after the second time is merely the difference in the amount of cutting between that time and the previous time, so the load acting on the cutter can be suppressed.

  In the deburring process, it is preferable that the rotational speed of the cutter is relatively accelerated or decelerated from the state of the synchronous rotation with the workpiece on the lower end surface.

  As in this feature means, when the rotation speed of the cutter is relatively accelerated or decelerated from the state of continuous synchronous rotation with the workpiece, the relative rotation phase between the cutter and the workpiece is shifted. When the rotational speed of the cutter is accelerated or decelerated relative to the workpiece and then returned to the original speed, the synchronous rotation is maintained with the relative rotational phase of the cutter and the workpiece deviating from the initial relative rotational phase. To do. When the cutter is accelerated, the lower side of the workpiece rotation direction is cut, and when the cutter is decelerated, the upper side of the workpiece rotation direction is cut to remove burrs from the cutting portion. It can be expected to drop out. Also, keep the cutter rotation speed accelerated or decelerated relative to the workpiece and gradually shift the synchronous rotation between the workpiece and the cutter so that the cutting area expands along the rotation direction. However, the same effect can be obtained. According to this characteristic means, the shape of the tooth groove is different from the area other than the vicinity of the lower end face near the lower end face of the work. If it is not a part that contributes to transmission, there is no particular problem.

It is a figure which shows the outline | summary of the gear manufacturing method by skiving processing. It is a figure which shows feed operation of the cutter which concerns on 1st Embodiment of this invention. It is a figure which shows feed operation of the cutter which concerns on 2nd Embodiment of this invention. It is a figure which shows feed operation of the cutter which concerns on 3rd Embodiment of this invention. It is a figure which shows feed operation of the cutter which concerns on 4th Embodiment of this invention. It is a figure which shows the locus | trajectory of the cutting blade of the cutter which concerns on 5th Embodiment of this invention. It is a figure which shows generation | occurrence | production of the burr | flash by the conventional skiving process. It is a figure which shows the feed operation of the cutter which concerns on the conventional skiving process.

  Hereinafter, an embodiment in which a gear manufacturing method according to the present invention is applied to manufacture of an internal gear used for a wave gear will be described with reference to the drawings.

  FIG. 1 is a diagram showing an outline of a gear manufacturing method according to an embodiment of the present invention using skiving. Skiving is performed using a pinion-type cutter 1 having a rotation axis Ac inclined with respect to the rotation axis Aw of the workpiece 10 to be processed into a gear and provided with a number of cutting blades 2. While the cutter 1 is rotated synchronously with the workpiece 10, the cutting operation is performed by feeding the workpiece 10 in the direction of the teeth of the workpiece 10 (here, a feeding operation from above to below along the rotation axis Aw).

  Here, since the manufacturing method of an internal gear is demonstrated, the internal peripheral surface of the cyclic | annular workpiece | work 10 becomes the process surface 10a. The tooth groove 12 is formed on the processed surface 10 a by skiving, and the portion that has not been cut becomes the tooth 11. Of the upper and lower surfaces of the workpiece 10 orthogonal to the machining surface 10a, the upper side surface in the feed direction of the cutter 1 is referred to as the upper side end surface 10b, and the lower side surface is referred to as the lower side end surface 10c.

  FIG. 7 shows the workpiece 10 in which the entire region from the upper end surface 10b to the lower end surface 10c of the workpiece 10 is cut by conventional skiving. FIG. 3A is a front view of the work surface 10a of the work 10 as viewed from the front, FIG. b is a cross-sectional view of the work surface 10a as viewed from the side, and FIG. . FIG. 8 is a graph showing the feed position of the cutter 1 in the conventional skiving process in time series. Here, z1 indicates the position of the upper side end face 10b, and z2 indicates the position of the lower side end face 10c.

  In the conventional skiving process, as shown in FIG. 8, the cutter 1 is fed from the upper end surface 10b of the work 10 to the lower end face 10c at a constant speed, and the processed surface of the work 10 with a constant depth of cut. 10a was cut. As a result, when the cutter 1 was separated from the lower end surface 10c of the workpiece 10, the burrs B were generated on the lower end surface 10c. As shown in each drawing of FIG. 7, the burr B is generated along the contour of the tooth groove 12 of the lower side end face 10 c. The present invention aims to remove this burr B.

[First Embodiment]
A first embodiment of the gear manufacturing method according to the present invention will be described with reference to FIG. FIG. 2A is a graph showing the feed position of the cutter 1 in time series, and FIG. 2B is a cross-sectional view of the workpiece 10 at times t1 and t2. In this embodiment, after the cutter 1 is fed from the feed position z1 (upper side end face 10b) to z2 (lower side end face 10c), the feed operation of the cutter 1 is performed on the lower side end face 10c from time t1 to time t2. Pause.

  According to this embodiment, the burr | flash B has generate | occur | produced at the time of the time t1 when the cutting to the lower end surface 10c was finished. However, when the feeding operation of the cutter 1 is temporarily stopped on the lower end surface 10c of the workpiece 10, the synchronous rotation of the cutter 1 and the workpiece 10 is continued on the lower end surface 10c during that time, and the cutting edge 2 of the cutter 1 is moved to the workpiece 10. Can contact the surface of the tooth groove 12 formed on the processed surface 10a. As described above, the cutter 1 and the workpiece 10 are in contact with each other even after the cutting process is finished, and the burr B generated on the lower end surface 10c of the workpiece 10 can be dropped due to an impact at the time of contact or the like.

  In the present embodiment, the feeding operation of the cutter 1 is temporarily stopped at the lower end surface 10c, but instead of completely stopping temporarily, the feeding speed when cutting the vicinity of the lower end surface 10c may be reduced. Is possible. By making the feed speed of the cutter 1 low, the generation of burrs B on the lower end surface 10c of the workpiece 10 can be suppressed, and removal of the generated burrs B can be expected.

[Second Embodiment]
A second embodiment of the gear manufacturing method according to the present invention will be described with reference to FIG. FIG. 3 is a graph showing the feed position of the cutter 1 in time series. In the present embodiment, after the cutter 1 is fed from the feed position z1 (upper side end face 10b) to z2 (lower side end face 10c), the cutter 1 is driven in the lower end face 10c from time t1 to t2. To reciprocate. Here, reciprocating the cutter 1 with the lower end surface 10c means reciprocating in a narrow region including the lower end surface 10c.

  According to this embodiment, the burr | flash B has generate | occur | produced at the time of the time t1 when the cutting to the lower end surface 10c was finished. However, when the feed operation is performed so that the cutter 1 reciprocates in the tooth trace direction on the lower end surface 10c of the workpiece 10, the cutting edge 2 of the cutter 1 is the surface of the tooth groove 12 formed on the machining surface 10a of the workpiece 10. Can be contacted multiple times. As described above, the cutter 1 and the workpiece 10 are in contact with each other even after the cutting process is finished, and the burr B generated on the lower end surface 10c of the workpiece 10 can be dropped due to an impact at the time of contact or the like.

  In particular, when the cutter 1 moves in the direction from the lower-side end surface 10c to the upper-side end surface 10b, the normal feeding operation for moving the cutter 1 from the upper-side end surface 10b to the lower-side end surface 10c means that the cutter 1 The contact form (contact location, contact direction, contact force, etc.) between the cutting blade 2 and the workpiece 10 is different. For this reason, during the reciprocating motion of the cutter 1, various impacts act on the workpiece 10, and the burr B removal effect is improved.

[Third Embodiment]
A third embodiment of the gear manufacturing method according to the present invention will be described with reference to FIG. 4A is a graph showing the feed position of the cutter 1 in time series, FIG. 4B is a graph showing the cutting amount by the cutter 1 in time series, and FIG. 4C is the time t1, t2, t3 and t4. 1 is a cross-sectional view of a workpiece 10. In this embodiment, the cutter 1 is fed at a constant speed from the feed position z1 (upper side end face 10b) to z2 (lower side end face 10c), of which z3 to z2 in the vicinity of the lower side end face 10c. From time t1 to time t2, the cutting amount by the cutter 1 is gradually reduced from r1 to r2. Thereafter, the cutting amount by the cutter 1 is gradually increased from r2 to r1 until the time when the cutter 1 is returned from z2 to z3 and from time t2 to time t3. Finally, the region from z3 to z2 is cut again with the cutting amount by the cutter 1 maintained at r1.

  According to the present embodiment, when the entire region of the workpiece 10 in the tooth line direction is first cut, that is, at time t2, burrs B are generated on the lower end surface 10c. However, since the cutting position r3 is used to cut the region from z3 to z2 after the feed position of the cutter 1 is returned to z3, the burr B on the lower end surface 10c is removed. If a burr is newly generated by the second cutting, the lower end surface 10c may be cut again with a larger cutting amount in order to further remove the burr. According to the present embodiment, the second cutting amount is merely the difference in the cutting amount between the first time and the second time, so that the load acting on the cutter 1 can be suppressed.

[Fourth Embodiment]
A fourth embodiment of the gear manufacturing method according to the present invention will be described with reference to FIG. 5A is a graph showing the feed position of the cutter 1 in time series, FIG. 5B is a graph showing the cutting amount by the cutter 1 in time series, and FIG. 5C is a work 10 at times t1, t2, and t3. FIG. In the present embodiment, after cutting the cutter 1 by feeding from the feed position z1 (upper side end face 10b) to z2 (lower side end face 10c) at a constant speed and with a constant cutting amount r1, the cutter 1 is moved to the lower side. Return to z3 in the vicinity of the end face 10c. Thereafter, cutting is performed while gradually increasing the cutting amount by the cutter 1 from r1 to r2 from z3 to z2, and from t2 to t3 in time.

  According to the present embodiment, when the entire region of the workpiece 10 in the tooth line direction is first cut, that is, at time t1, burrs B are generated on the lower end surface 10c. However, since the cutting of the region from z3 to z2 is performed while the cutting amount is gradually increased from r1 to r2 after the feed position of the cutter 1 is returned to z3, the burr B on the lower end surface 10c is removed. If a burr is newly generated by the second cutting, the lower end surface 10c may be cut again with a larger cutting amount in order to further remove the burr. According to the present embodiment, the second cutting amount is merely the difference in the cutting amount between the first time and the second time, so that the load acting on the cutter 1 can be suppressed. According to the present embodiment, the tooth gap 12 is formed deeper in the vicinity of the lower end surface 10c of the work 10 than the other region in the tooth trace direction. If the vicinity of 10c is not a part that contributes to force transmission, there is no particular problem.

[Fifth Embodiment]
Based on FIG. 6, 5th Embodiment of the gear manufacturing method which concerns on this invention is described. In the present embodiment, the feed operation of the cutter 1 is temporarily stopped on the lower end surface 10c as in the first embodiment. In the meantime, after maintaining the relative rotational phase of the cutter 1 relative to the workpiece 10 for a while, the operation is performed for a while while the relative rotational phase is advanced. FIG. 6 is a plan view showing the cutting trajectory by the cutting blade 2. The solid line arrow in FIG. A shows the cutting trajectory before the relative rotational phase is changed, and the cutting when the chain line arrow in FIG. B slows the relative rotational phase. The locus, the chain line arrow in the figure c shows the cutting locus when the relative rotational phase is increased.

  When the cutter 1 is temporarily stopped at the lower end surface 10c of the workpiece 10, the cutting blade 2 of the cutter 1 rotates clockwise in the drawing along the contour of the tooth gap 12 already formed as shown in FIG. Continue to rotate. In this state, burrs B are generated on the lower end surface 10 c along the outline of the tooth gap 12. In the first embodiment, the feeding operation of the cutter 1 is temporarily stopped in this state, and the burr B is removed by the cutting blade 2 coming into contact with the surface of the tooth gap 12 by continuing only the rotating operation of the cutter 1. It was something to do.

  In the present embodiment, the burr B is more actively removed by changing the relative rotational phase between the cutter 1 and the workpiece 10 while the feeding operation of the cutter 1 is temporarily stopped. First, the relative rotation phase is delayed while the cutter 1 is temporarily stopped at the lower end surface 10c. Then, as shown in FIG. B, the cutting locus by the cutting edge 2 shifts to the upper side in the rotational direction (left side in the figure). At this time, the upper side in the rotational direction of the tooth gap 12 is further cut, and the burr B on the upper side in the rotational direction is removed. Thereafter, the relative rotational phase is made faster than the original relative rotational phase. Then, as shown in FIG. C, the cutting locus by the cutting edge 2 changes to the lower side (right side in the figure) in the rotational direction. At this time, the lower side in the rotational direction of the tooth gap 12 is further cut, and the burr B on the lower side in the rotational direction is removed.

  By manipulating the relative rotation phase between the cutter 1 and the workpiece 10 in this way, the burr B generated along the contour of the tooth gap 12 as shown in FIG. Anything that was present in is removed. FIG. d shows an example in which the burr B at the bottom portion of the tooth gap 12 remains. However, the burr B at this portion also falls off due to an impact when a new cutting is performed by changing the relative rotational phase. It is possible to do. In order to remove the burr B remaining on the bottom portion of the tooth gap 12, for example, the cutting amount by the cutter 1 may be increased and the lower end surface 10c may be cut. However, since the bottom portion of the tooth groove 12 is not a portion that normally functions in meshing the gear, it can function as a gear even if left as it is. Further, if the tip shape of the cutting edge 2 is pointed or arcuate, burrs B as shown in FIG.

  In order to delay the relative rotation phase of the cutter 1 with respect to the workpiece 10, the rotation speed of the cutter 1 is temporarily reduced with respect to the workpiece 10 and then returned to the original rotation speed, or the cutter 1 is temporarily stopped, or What is necessary is just to make the rotational speed of the workpiece | work 10 high with respect to the cutter 1 for a moment, and to return to the original rotational speed. On the contrary, when the relative rotation phase is increased, the rotational speed of the cutter 1 is increased with respect to the workpiece 10 for a moment and then returned to the original rotational speed, or after the rotational speed of the workpiece 10 is decreased with respect to the cutter 1 for a moment. Or the workpiece 10 may be temporarily stopped temporarily.

  If the burr B at a desired location can be removed, it is not necessary to perform both the operation of delaying and accelerating the relative rotation phase as in this embodiment, and only one of them may be performed. . Further, for example, if the rotation speed of the cutter 1 is slowed down relative to the workpiece 10 and is not returned to the original rotation speed, the synchronous rotation of the cutter 1 and the workpiece 10 is gradually shifted, and the cutting trajectory is caused by the cutting blade 2. Keep moving. As a result, the lower end surface 10c of the workpiece 10 has a shape as if chamfered, but such deburring can also be performed. Furthermore, by making the synchronous rotation direction of the cutter 1 and the workpiece 10 opposite, it is possible to apply an impact to the workpiece 10 and remove the burr B.

  As mentioned above, although each embodiment has been described, the present invention is not limited to these embodiments. For example, while the cutter 1 is temporarily stopped in the first embodiment, or while the cutter 1 is reciprocating in the second embodiment, the cutting amount by the cutter 1 can be gradually increased. In the fifth embodiment, the relative rotational phase is changed while the cutter 1 is temporarily stopped. However, even if the relative rotational phase is changed while the cutter 1 is reciprocating as in the second embodiment, the relative rotational phase is changed. Good.

  The gear manufacturing method according to the present invention can be applied not only to manufacturing internal gears but also to manufacturing external gears.

DESCRIPTION OF SYMBOLS 1 Cutter 2 Cutting edge 10 Workpiece 10c Lower end surface Aw Workpiece rotation axis Ac Cutter rotation axis

Claims (5)

Using a pinion-type cutter having a rotation axis inclined with respect to the rotation axis of the workpiece to be processed into a gear, and using skiving processing in which the cutter is fed in the direction of the teeth of the workpiece while rotating in synchronization with the workpiece In the manufactured gear manufacturing method,
In the feeding operation, at least one of the feeding speed of the cutter on the lower side end surface of the workpiece, which is the lower side, the cutting amount, and the relative rotation phase of the cutter and the workpiece, the lower side end surface is used. A gear manufacturing method in which deburring is performed under different conditions when cutting the excluded region.   The gear manufacturing method according to claim 1, wherein as the deburring process, the feeding operation of the cutter is temporarily stopped at the lower end surface.   The gear manufacturing method according to claim 1, wherein, as the deburring process, the cutter is reciprocated in the tooth trace direction on the lower end surface.   The gear manufacturing method according to claim 1, wherein, as the deburring process, after cutting the entire region of the workpiece in the tooth line direction, the lower end surface is cut again with a larger cutting amount.   The said deburring process WHEREIN: The rotational speed of the said cutter is accelerated or decelerated relatively from the state of the said synchronous rotation with the said workpiece | work in the said lower end surface. Gear manufacturing method.

Images