JP2018086688A - Gear processing method and gear fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gear processing method and a gear fixing device that are able to easily hinder occurrence of burr on a downstream end face of a processed gear in a feed direction while restricting a manufacturing cost increase.SOLUTION: In a gear processing method in which a work piece W is gear-cut by a pinion cutter 13, the lower end face Wc of each of a second and subsequent work pieces W is brought into face contact with a lower jig 22 maintained in a fixed state used when it is gear-cut together with a first work piece W; each of the second and subsequent work pieces W and the lower jig 22 maintained in the fixed state are coaxially superposed; each of the second and subsequent work pieces W is pressed and fixed toward the lower jig 22 maintained in the fixed state; while a rotation phase relation allowing engagement between the pinion cutter 13 and the lower jig 22 maintained in the fixed state is kept, the same gear-cutting operation as the gear-cutting operation performed for the first work piece W is performed for the pinion cutter 13, thereby gear-cutting only each of the second and subsequent work pieces W.SELECTED DRAWING: Figure 4C

Description

  The present invention relates to a gear machining method that suppresses the generation of burrs at the end face of a gear to be machined, and a gear fixing device used in the gear machining method.

  As one method of machining a gear, a gear machining method in which a gear to be machined is provided by cutting and feeding the cutting tool while synchronously rotating the workpiece gear and the cutting tool. Has been provided. In such a gear machining method, for example, the cutting tool is gear-cut in the forward feed step, while being retreated from the gear to be machined in the return step which is the return path. For this reason, a burr | flash will generate | occur | produce in the feed direction downstream end surface of the gear to be processed.

  Also, if a gear with burrs as described above is assembled to other parts, its assembly accuracy will be reduced, or burrs that have fallen after assembly will enter the sliding and rotating parts, hindering their operation. There is a risk of As a result, when burrs are generated after gear cutting, some kind of burring removal work is required, which requires a large number of work steps.

  Accordingly, in the technical field of gear machining in recent years, various gear machining methods are provided which are designed to take measures against burr at the same time as machining. Such conventional gear machining methods are disclosed in, for example, Patent Documents 1 and 2.

JP 2008-30162 A Japanese Unexamined Patent Publication No. 2016-32850

  In Patent Document 1, a waste washer is brought into surface contact with an end face on the downstream side in the feed direction of the external gear to be machined, and both the external gear to be worked and the waste washer are geared together, thereby downstream of the external gear to be machined in the feed direction. Generation of burrs on the side end faces is suppressed. However, in such a conventional gear machining method, since one discarded washer is required every time one external gear is cut, the manufacturing cost increases.

  Further, in Patent Document 2, when a plurality of internal gears to be integrated that are overlapped and integrated are geared at once by a pinion cutter, the workpiece is arranged at the most downstream position in the feed direction at the time of the previous gear cutting. By arranging the processing internal gear at the most upstream position in the feed direction, burrs generated on the end surface on the downstream side in the feed direction of the internal gear to be processed are removed.

  However, in such a conventional gear processing method, the internal gear to be processed in which burrs have occurred must be superimposed on another internal gear to be processed at the next gear cutting. Accordingly, in order to prevent the burr from coming into contact with the other internal gear to be processed, it is necessary to change the direction in which the burr is generated to a predetermined direction.

  Specifically, after the pinion cutter is temporarily stopped in the middle of feeding, the feeding operation is performed again while being moved radially inward from the workpiece internal gear. Thereby, the burr | flash which generate | occur | produces in a to-be-processed internal gear is protruded toward the radial inside from the internal peripheral surface. That is, in the conventional gear machining method, the pinion cutter gear cutting operation is complicated in order to define the burr generation direction.

  Furthermore, in the above conventional gear machining method, rotational phase matching between the pinion cutter and the internal gear to be machined disposed at the most upstream position in the feed direction must be performed prior to gear cutting. Furthermore, in order to prevent positional displacement in the circumferential direction when a plurality of internal gears to be processed are overlapped, it is not only necessary to preliminarily process the positional displacement prevention means for the internal gear to be processed, Along with this, an unnecessary shape is left in the finished internal gear.

  Accordingly, the present invention solves the above-described problem, and a gear machining method and a gear capable of easily suppressing the occurrence of burrs on the downstream end surface in the feed direction of the workpiece while suppressing an increase in manufacturing cost. An object is to provide a fixing device.

A gear machining method according to the first invention for solving the above-mentioned problems is as follows.
In the gear machining method of cutting the workpiece with the tool by feeding the tool in the axial direction while rotating the workpiece and the tool,
The end surface on the downstream side in the feed direction of the work piece of the first product is brought into surface contact with the lower jig,
The first workpiece and the lower jig are coaxially overlapped,
The workpiece of the initial product is pressed and fixed toward the fixed lower jig,
The first work piece and the fixed lower jig are both cut by the tool,
Maintaining the fixed state of the lower jig when geared together with the work piece of the first product as it is,
The end surface on the downstream side in the feed direction in the workpiece after the next product is brought into surface contact with the lower jig in which the fixed state is maintained,
The workpiece after the next product and the lower jig maintained in the fixed state are coaxially overlapped,
The workpiece after the next product is pressed and fixed toward the lower jig in which the fixed state is maintained,
A gear cutting operation when the first workpiece is cut with respect to the tool while maintaining a meshable rotational phase relationship between the tool and the lower jig in which the fixed state is maintained. Only the workpiece after the next product is cut by giving the same gear cutting operation.

A gear machining method according to a second invention for solving the above-mentioned problems is as follows.
When cutting the workpiece after the next product, when replacing the tool,
Prior to gear cutting with the replaced tool,
The rotation phase of the replaced tool is maintained in the fixed state so that the replaced tool and the lower jig maintained in the fixed state have a rotational phase relationship that can be engaged with each other. It is characterized by matching the rotation phase of the tool.

A gear machining method according to a third invention for solving the above-described problems is as follows.
The workpiece of the first product or the workpiece after the next product is coaxially formed from both sides in the axial direction by the upper jig disposed on the upstream side of the lower jig and the lower jig. The tool cuts the workpiece of the first product or the workpiece after the next product without cutting the upper jig.

A gear fixing device according to a fourth aspect of the present invention for solving the above problem is as follows.
When the workpiece is cut by the tool by feeding the workpiece in the axial direction while rotating the workpiece and the tool, the workpiece In the gear fixing device for fixing
A turntable supported rotatably about the axis of the workpiece;
A peripheral surface that is fixed to the rotary table and that is in surface contact with the end surface on the downstream side in the feed direction of the workpiece, and is peripherally cut by the tool together with the peripheral surface of the workpiece, or the workpiece is toothed A lower jig having a tooth profile that meshes with the tool immediately after cutting;
An upper jig that is disposed upstream of the lower jig in the feed direction, and that clamps and fixes the workpiece from both sides in the axial direction between the lower jig and the lower jig;
And a protruding portion that protrudes from the downstream end surface in the feed direction of the upper jig toward the downstream side in the feed direction and presses the upstream end surface in the feed direction of the workpiece.

A gear fixing device according to a fifth aspect of the present invention for solving the above problem is as follows.
And a fitting portion that is formed on the lower jig and is fitted to the workpiece to position the workpiece in the radial direction.

A gear fixing device according to a sixth invention for solving the above-described problem is
A connecting bolt for connecting the upper jig and the lower jig in the axial direction;
A bolt hole through which the upper jig passes in the axial direction and the connecting bolt is inserted;
The bolt hole is opened adjacent to the protrusion.

  Therefore, according to the gear machining method and the gear fixing device according to the present invention, when cutting a plurality of workpieces, the pair of upper and lower upper jigs and lower jigs can be continuously used without being exchanged. . Even if the upper jig and the lower jig are installed, they do not affect the gear cutting operation of the tool. Therefore, the generation | occurrence | production of the burr | flash in the feed direction downstream end surface of a to-be-processed object can be easily suppressed, suppressing the increase in manufacturing cost.

It is a figure which shows the outline | summary of the gear processing method and gear fixing apparatus which concern on one Example of this invention. It is a longitudinal cross-sectional view of the gear fixing apparatus which concerns on one Example of this invention. It is the perspective view which looked at the upper jig from the feed direction downstream side. It is the figure which showed the mode before processing the 1st workpiece | work. It is an operation figure following Drawing 4A, and is a figure showing a situation after processing the 1st work. It is the figure which showed the mode before processing the workpiece | work after the 2nd piece. FIG. 4C is an operation diagram subsequent to FIG. 4C, illustrating a state after processing the second and subsequent workpieces. It is a figure showing rotation phase alignment operation between a pinion cutter and a lower jig at the time of cutter exchange.

  Hereinafter, a gear machining method and a gear fixing device according to the present invention will be described in detail with reference to the drawings. In the embodiments described below, the gear machining method and the gear fixing device according to the present invention are the gear machining method for gearing the internal gear using skiving, and the gear fixing device used in the method. The case where it is applied to is specifically described.

  As shown in FIG.1 and FIG.2, the rotary table 11 is supported by the upper part of the gear cutter (illustration omitted) so that rotation around the workpiece rotating axis C used as a vertical axis is possible. The upper part of the turntable 11 has a cylindrical shape, and a ring-shaped work (workpiece, gear material) W has a pair of upper and lower parts that form a ring shape on the mounting surface 11a that is the upper surface of the cylindrical upper part. The upper jig 21 and the lower jig 22 are detachably fixed.

  That is, the upper jig 21 is arranged on the upper part of the work W, while the lower jig 22 is arranged on the lower part of the work W. Then, by fixing the workpiece W to the mounting surface 11a of the turntable 11 via the upper jig 21 and the lower jig 22, the workpiece W, the upper jig 21 and the lower jig 22 are coaxial. These center axes coincide with the workpiece rotation axis C which is the rotation center of the rotary table 11.

  Accordingly, after the workpiece W is fixed to the mounting surface 11a of the rotary table 11 via the upper jig 21 and the lower jig 22, the rotary table 11 is rotated around the workpiece rotation axis C, whereby the workpiece W, The jig 21 and the lower jig 22 can be rotated around the workpiece rotation axis C in the state in which the jig 21 and the lower jig 22 are integrated.

  Further, the main shaft 12 is supported by the gear cutter so as to be movable and tiltable with respect to the workpiece rotation axis C. The main shaft 12 is rotatable around the cutter rotation axis B. . Further, a pinion cutter (gear-like tool) 13 whose outer teeth are helical gears is detachably attached to the tip of the main shaft 12 as a cutting tool for gear cutting. By attaching the pinion cutter 13 to the tip of the main shaft 12, the central axis of the pinion cutter 13 coincides with the cutter rotation axis B that is the rotation center of the main shaft 12.

  Therefore, after the pinion cutter 13 is mounted on the main shaft 12, the pinion cutter 13 can be rotated about the cutter rotation axis B by rotating the main shaft 12 around the cutter rotation axis B. Further, by moving the spindle 12 in the radial direction of the workpiece W and in the axial direction of the workpiece W, the pinion cutter 13 can be cut in the radial direction and fed in the axial direction (workpiece rotation axis direction). it can.

  When a feed is given to the pinion cutter 13, the pinion cutter 13 reciprocates along the axial direction of the workpiece W. At this time, in the pinion cutter 13, when moving downward, both the workpiece W and the lower jig 22 are geared, while when moving upward, the pinion cutter 13 has a diameter from the workpiece W and the lower jig 22. The workpiece W and the lower jig 22 are not separated from each other by being separated toward the inner side in the direction.

  Specifically, the pinion cutter 13 cuts the inner peripheral surface Wa from the upper end surface Wb serving as the upstream end surface in the feed direction of the workpiece W to the lower end surface Wc serving as the downstream end surface in the feed direction of the workpiece W. In succession, the inner peripheral surface 22a is cut by cutting into the fitting portion 22d, which is the upstream end surface of the lower jig 22 in the feeding direction. Therefore, the tooth profile cut by the pinion cutter 13 is formed in the entire axial direction of the inner peripheral surface Wa and the inner peripheral surface 22a. The workpiece W and the lower jig 22 are, for example, an internal spur gear. To be processed.

  That is, the upper jig 21 and the lower jig 22 constitute a gear fixing device for fixing the workpiece W to the mounting surface 11 a of the rotary table 11. Of these, the lower jig 22 of the first (first product) workpiece W is used for the purpose of suppressing the occurrence of burrs on the lower end surface Wc of the workpiece W during gear cutting. At the time of gear cutting, the pinion cutter 13 cuts teeth together with the workpiece W, and at the time of gear cutting of the second and subsequent workpieces (from the next product onward), the pinion cutter 13 does not cut gears. It is possible to mesh with the cutter 13.

  2 is a longitudinal sectional view of the gear fixing device shown in FIG. 1, but in order to facilitate understanding of the gear cutting to the workpiece W and the lower jig 22, the workpiece W and the lower arm shown in FIG. The tool 22 is in a state after gear cutting, while the workpiece W and the lower jig 22 shown in FIG. 2 are in a state before gear cutting.

  Next, the configuration of the gear fixing device will be described in detail with reference to FIGS.

  As shown in FIGS. 1 and 2, the upper jig 21 has an inner diameter larger than the inner diameter of the workpiece W and an outer diameter larger than the outer diameter of the workpiece W. 21a, upper end surface 21b, lower end surface 21c, protrusion 21d, and bolt hole 21e.

  The inner peripheral surface 21 a is disposed on the radially outer side than the inner peripheral surface Wa of the workpiece W. An annular upper end surface 21 b is formed on the upstream side of the inner peripheral surface 21 a in the feed direction, which is the upstream end surface of the upper jig 21 in the feed direction. On the other hand, an annular lower end surface 21c is formed on the downstream side in the feed direction of the inner peripheral surface 21a, which is the downstream end surface of the upper jig 21 in the feed direction. The lower end surface 21c is opposed to only the outer peripheral portion in the axial direction among the upper end surface Wb of the workpiece W. Thereby, even if the pinion cutter 13 cuts the workpiece W and the lower jig 22 by the pinion cutter 13, the upper jig 21 is not cut by the pinion cutter 13.

  As shown in FIGS. 2 and 3, a plurality of projecting portions 21 d are formed on the lower end surface 21 c. These projecting portions 21d project from the lower end surface 21c toward the downstream side in the feed direction, and are formed radially about the workpiece rotation axis C. That is, the protrusions 21d extend in the radial direction and are arranged at equal intervals in the circumferential direction. Thereby, only the protrusion part 21d will be in line contact with the upper end surface Wb of the workpiece | work W among the site | parts which comprise the upper jig | tool 21, and the said protrusion part 21d will carry out the feed direction upstream of the upper end surface Wb of the workpiece | work W. It is possible to press from the side toward the downstream side.

  Further, the upper jig 21 is formed with a plurality of bolt holes 21e penetrating in the axial direction. These bolt holes 21e are arranged on the outer side in the radial direction of the protruding portion 21d and at equal intervals in the circumferential direction, and the number of the bolt holes 21e is the same as the number of the protruding portions 21d. That is, the bolt hole 21e is disposed at the same position in the circumferential direction as the protruding portion 21d, and opens so as to be adjacent to the radially outer end portion of the protruding portion 21d. And the bolt 23 for connection mentioned later can be inserted in the bolt hole 21e.

  On the other hand, as shown in FIGS. 1 and 2, the lower jig 22 has the same inner diameter as the inner diameter of the workpiece W, and the outer diameter is larger than the outer diameter of the workpiece W. , An inner peripheral surface 22a, an upper end surface 22b, a lower end surface 22c, and a fitting portion 22d.

  The inner peripheral surface 22a is disposed at the same position as the inner peripheral surface Wa of the workpiece W in the radial direction. An annular upper end surface 22b is formed on the upstream side of the inner peripheral surface 22a in the feed direction, which is the upstream end surface of the lower jig 22 in the feed direction. On the other hand, an annular lower end surface 22c is formed on the downstream side of the inner peripheral surface 22a in the feed direction, which is an end surface on the downstream side of the lower jig 22 in the feed direction.

  An annular fitting portion 22 d is formed on the radially inner side of the lower jig 22 and on the upstream side of the lower jig 22 in the feeding direction. The fitting portion 22d can be fitted with a downstream end portion in the feed direction of the workpiece W.

  That is, the fitting portion 22d is opened across the inner peripheral surface 22a and the upper end surface 22b, and can be in surface contact with the lower end surface Wc and the outer peripheral surface Wd of the workpiece W. In this way, the work W fitted to the fitting portion 22d is radially formed by forming the fitting portion 22d into a cutout shape that cuts out between the inner peripheral surface 22a and the upper end surface 22b. Deviation to is restricted. That is, the fitting portion 22d can position the workpiece W in the radial direction.

  Furthermore, by fitting the workpiece W to the fitting portion 22d of the lower jig 22, the inner circumferential surface Wa of the workpiece W and the inner circumferential surface 22a of the lower jig 22 can be matched in the radial direction. Therefore, since both the workpiece W and the lower jig 22 can be cut, the tooth profile formed on the workpiece W matches the tooth profile formed on the lower jig 22.

  As described above, when the workpiece W and the lower jig 22 are continuously cut, the blade portion of the pinion cutter 13 that has come out of the lower end surface Wc of the workpiece W always cuts into the fitting portion 22d of the lower jig 22. become. Therefore, since the lower end surface Wc of the workpiece W and the fitting portion 22d of the lower jig 22 are in close contact with each other without any gap, a burr is formed on the lower end surface Wc of the workpiece W from the lower end surface Wc to the downstream side in the feed direction. It becomes difficult to occur toward.

  That is, in order to suppress the occurrence of burrs on the lower end surface Wc of the workpiece W, the blade portion of the pinion cutter 13 that has come out of the lower end surface Wc may be cut into the fitting portion 22d of the lower jig 22. For this reason, in the present embodiment, the inner diameter of the workpiece W and the inner diameter of the lower jig 22 are the same, but the inner diameter of the lower jig 22 may be an inner diameter equal to or smaller than the inner diameter of the workpiece W.

  On the other hand, the lower end surface 22c is in surface contact with the entire area of the mounting surface 11a. Note that the attachment surface 11 a has the same inner diameter and outer diameter as the inner diameter and outer diameter of the upper jig 21. Thereby, even if the pinion cutter 13 cuts the workpiece W and the lower jig 22, the rotary table 11 is not cut by the pinion cutter 13.

  The upper jig 21 and the lower jig 22 are connected by a plurality of connecting bolts 23. These connecting bolts 23 are arranged radially outside the outer peripheral surface Wd of the workpiece W and at equal intervals in the circumferential direction, and penetrate the bolt holes 21e of the upper jig 21 in the axial direction. Screwed into the lower jig 22 from the axial direction. Note that the connecting bolt 23 may be screwed into the rotary table 11 via the lower jig 22.

  In this way, the plurality of connecting bolts 23 are passed through the bolt holes 21 e of the upper jig 21 and fastened in the lower jig 22, whereby the upper jig 21 is drawn toward the lower jig 22. . Thereby, the workpiece | work W can be pinched | interposed and fixed between the protrusion part 21d and the fitting part 22d.

  At this time, the fastening force of the connecting bolt 23 acts as a pressing force by which the protruding portion 21d presses the workpiece W toward the fitting portion 22d. Further, since the connecting bolt 23 is inserted into the bolt hole 21e adjacent to the projecting portion 21d, the head of the connecting bolt 23 is engaged with the projecting portion 21d on the upper end surface Wb at a position facing the projecting portion 21d in the axial direction. Stop. Thereby, since the fastening force by the connecting bolt 23 can be efficiently converted into the pressing force by the protruding portion 21d, the workpiece W can be pressed by a large pressing force. As a result, the workpiece W can be firmly fixed.

  This will be described while comparing the upper jig 21 having a plurality of projecting portions 21d with a conventional upper jig not having the projecting portions 21d. However, it is assumed that the shape and area of the lower end surface 21c are the same as the shape and area of the lower end surface of the conventional upper jig.

  Here, when connecting the upper jig 21 and the conventional upper jig using the plurality of connecting bolts 23, the number and the through position of the connecting bolt 23 used for each are the same quantity and the same position. To do. That is, the same fastening force is applied to the upper jig 21 and the conventional upper jig. As a result, the upper jig 21 is pressed only by the plurality of protrusions 21d, whereas the conventional upper jig is pressed by the entire lower end surface, so that the pressing force by the plurality of protrusions 21d is , It becomes larger than the pressing force by the entire lower end surface. That is, in the upper jig 21, the pressing force per unit area is increased by pressing with the plurality of protruding portions 21d rather than pressing with the entire area of the lower end surface 21c.

  Further, the lower jig 22 is fixed to the mounting surface 11 a of the turntable 11 by a plurality of fixing bolts 24. These fixing bolts 24 are arranged radially outside the outer peripheral surface Wd of the workpiece W and at equal intervals in the circumferential direction, penetrate the lower jig 22 in the axial direction, and are arranged in the rotary table 11. It is screwed in from the axial direction. The connecting bolts 23 and the fixing bolts 24 are alternately arranged in the circumferential direction.

  In this way, the lower jig 22 can be fixed to the mounting surface 11a by passing a plurality of fixing bolts 24 through the lower jig 22 and fastening them in the rotary table 11. The tool 22 can be rotated together with the rotary table 11. That is, the fixed state of the lower jig 22 is maintained as it is unless the fastening bolts 24 are released, and no deviation occurs in the rotational phase.

  Therefore, when the workpiece W is fixed to the mounting surface 11 a of the turntable 11, first, the workpiece W is sandwiched between the protruding portion 21 d of the upper jig 21 and the fitting portion 22 d of the lower jig 22. Next, the upper jig 21 and the lower jig 22 are connected by a plurality of connecting bolts 23, and the upper jig 21, the workpiece W, and the lower jig 22 are coaxially overlapped without any gap. Then, the lower jig 22 is fixed to the mounting surface 11 a by the fixing bolt 24.

  Alternatively, first, the lower jig 22 is fixed to the mounting surface 11 a by the fixing bolt 24. Next, after fitting the workpiece W to the fitting portion 22d of the lower jig 22, the protruding portion 21d of the upper jig 21 is brought into close contact with the upper end surface Wb of the workpiece W, whereby the workpiece W is fixed to the upper jig 21. Is sandwiched between the projecting portion 21d of the lower jig 22 and the fitting portion 22d of the lower jig 22. And the upper jig | tool 21 and the lower jig | tool 22 are connected with the some connecting bolt 23, and the upper jig | tool 21, the workpiece | work W, and the lower jig | tool 22 are piled up coaxially without gap.

  Therefore, regardless of which of the two fixing methods described above is employed, the upper jig 21, the workpiece W, and the lower jig 22 are overlapped on the same axis and are attached to the mounting surface 11 a of the turntable 11. The workpiece W can be pressed and fixed from the axial direction.

  Next, a gear machining method using skiving will be described in detail with reference to FIGS. 4A to 4D and FIG.

  First, as shown in FIG. 4A, the first workpiece W is fixed to the mounting surface 11 a of the turntable 11 using the jigs 21 and 22 and the bolts 23 and 24.

  Next, the main shaft 12 is tilted so that the cutter rotation axis B is inclined with respect to the workpiece rotation axis C. That is, the main shaft 12 is tilted so that the crossing angle between the cutter rotation axis B and the workpiece rotation axis C becomes a predetermined angle according to the twist angle of the pinion cutter 13. Thereby, the blade stripe direction of the pinion cutter 13 coincides with the tooth stripe direction of the workpiece W.

  Then, the workpiece W is rotated around the workpiece rotation axis C together with the jigs 21 and 22, and the pinion cutter 13 is rotated around the cutter rotation axis B. That is, the workpiece W and the pinion cutter 13 are moved to the peripheral speed of the inner peripheral face Wa, the peripheral speed of the inner peripheral face 21a, the peripheral speed of the inner peripheral face 22a, and the peripheral face (blade part) of the pinion cutter 13. Synchronous rotation is performed so that the speeds are equal.

  Next, the pinion cutter 13 is cut in the radial direction and then fed in the axial direction. That is, the workpiece W and the lower jig 22 and the pinion cutter 13 are synchronously rotated and meshed with each other, and the pinion cutter 13 is axially cut at each cutting position while the pinion cutter 13 is cut stepwise in the radial direction. Move from top to bottom.

  4B, the blade portion of the pinion cutter 13 cuts the inner peripheral surface Wa of the workpiece W and the inner peripheral surface 22a of the lower jig 22, and the inner peripheral surface Wa and the inner The same tooth profile is formed on the peripheral surface 22a.

  At this time, the workpiece W is firmly fixed with high positioning accuracy between the upper jig 21 and the lower jig 22 by the tightening force by the connecting bolt 23 or the fitting to the fitting portion 22d. Therefore, the lower end surface Wc of the workpiece W and the fitting portion 22d of the lower jig 22 are in close contact with each other without a gap. Therefore, when both the workpiece W and the lower jig 22 are cut by the pinion cutter 13, the generation of burrs on the lower end surface Wc is suppressed, while burrs are generated on the lower end surface 22c.

  Further, in the gear cutting operation of the pinion cutter 13, since the cutting position (cutting amount) at each feeding does not change, the radial positional relationship between the pinion cutter 13 and the workpiece W is constant. Thereby, the dimension of the tooth profile formed on the workpiece W and the lower jig 22 is constant from the upper end surface Wb of the workpiece W to the lower end surface 22c of the lower jig 22.

  Then, when the gear cutting for the first workpiece W is completed, only the fastening of the connecting bolt 23 is released, the upper jig 21 is removed, and then the first workpiece W is changed to the second workpiece W. Exchange for W. That is, without releasing the fastening of the fixing bolt 24, with the lower jig 22 fixed, the fastening of the connecting bolt 23 is released and the upper jig 21 is removed. Exchange from a processed product to an unprocessed product. Thereby, since the rotation phase of the spindle 12 and the rotation phase of the rotary table 11 are kept in synchronization with each other, even if the workpiece W is replaced, the rotation phase of the pinion cutter 13 and the lower jig 22 The rotational phase relationship is maintained such that the rotational phases are properly meshed with each other, and there is no change in the rotational phase relationship between them.

  Next, as shown in FIG. 4C, the second workpiece W is fixed to the mounting surface 11 a of the turntable 11 using the jigs 21 and 22 and the bolts 23 and 24. Thereafter, as shown in FIG. 4D, the same gear cutting operation as that when the first workpiece W is cut is performed. As a result, only the workpiece W is cut by the pinion cutter 13.

  That is, as shown in FIG. 4C, when cutting the second workpiece W, unlike the case of cutting the first workpiece W, the lower jig 22 has already been cut. Furthermore, since the rotational phase of the lower jig 22 and the rotational phase of the pinion cutter 13 coincide with each other, only the workpiece W is cut out of the workpiece W and the lower jig 22. At this time, the pinion cutter 13 only meshes with the lower jig 22 maintained in a fixed state when the gear is cut with the first workpiece W, and does not cut the lower jig 22. . Thereby, generation | occurrence | production of the burr | flash in the lower end surface Wc is suppressed, and a burr | flash does not generate | occur | produce in the lower end surface 22c.

  When cutting the third and subsequent workpieces W, exchanging the workpiece W and cutting the workpiece W alternately are performed in the same manner as when cutting the second workpiece W. . That is, as shown in FIG. 4C and FIG. 4D, even when cutting the third and subsequent workpieces W, the upper and lower upper jigs 21 and the lower jigs are used as jigs for fixing the workpieces W. 22 is used, and the upper jig 21 is attached and detached every time the workpiece W is replaced. However, the lower jig 22 is fixed as it is even after the first workpiece W is cut. It continues to be used while maintaining the state (rotation phase).

  Here, as described above, when the plurality of workpieces W are successively cut by the single pinion cutter 13, the blade portion of the pinion cutter 13 is worn and the sharpness thereof is lowered. In such a case, it is necessary to replace the worn pinion cutter 13 with a new pinion cutter 13 that is not worn.

  However, if the pinion cutter 13 is replaced, the rotational phase of the replaced new pinion cutter 13 and the rotational phase of the lower-cut jig 22 are shifted. If only the workpiece W is cut in such a state, even the lower jig 22 that does not require cutting is cut, and in some cases, a large burr is generated on the lower end surface Wc of the workpiece W. There is a risk of it. Therefore, when the pinion cutter 13 is replaced, it is necessary to replace the lower jig 22 accordingly, resulting in a decrease in productivity.

  Therefore, in order to solve the above problem, when the pinion cutter 13 is replaced, the rotational phase alignment between the pinion cutter 13 and the lower jig 22 is performed prior to gear cutting by the replaced new pinion cutter 13. Like to do. That is, rotational phase alignment is performed between the exchanged pinion cutter 13 and the already-cut lower jig 22 so as to have a rotational phase relationship in which they are properly meshed with each other.

  Specifically, as shown in FIG. 5, first, a plurality of workpieces W are fixed to the mounting surface 11a of the turntable 11 using jigs 21 and 22 and bolts 23 and 24, and a pinion cutter is used. Replace 13 with a new one.

  Next, while rotating the pinion cutter 13 around the cutter rotation axis B, the rotation phase is detected by the sensor 14. This sensor 14 detects the circumferential position around the cutter rotation axis B in the blade portion or blade groove of the pinion cutter 13 and can determine the rotational phase of the pinion cutter 13 based on the detection result. . On the other hand, since the lower jig 22 is fixed when the first workpiece W is geared, the rotational phase of the lower jig 22 is the first gear-cut workpiece. It remains in agreement with the rotational phase of W.

  Then, the pinion cutter 13 is rotated around the cutter rotation axis B so that the rotation phase of the pinion cutter 13 matches the rotation phase of the lower jig 22. That is, the rotational phase of the pinion cutter 13 is adjusted so that the blade portion and the blade groove of the pinion cutter 13 and the tooth groove and the tooth portion of the lower jig 22 can properly mesh with each other.

  Next, the workpiece W and the lower jig 22 and the pinion cutter 13 are rotated in synchronization with each other and engaged with each other, and the pinion cutter 13 is axially cut at each cutting position while the pinion cutter 13 is cut stepwise in the radial direction. Move from top to bottom. As a result, the pinion cutter 13 cuts only the workpiece W and meshes with the lower jig 22 without cutting.

  That is, even when the pinion cutter 13 is replaced, the lower jig 22 has already been cut, and the rotational phase of the lower jig 22 and the rotational phase of the pinion cutter 13 are matched in advance. Of the workpiece W and the lower jig 22, only the workpiece W is cut. At this time, the pinion cutter 13 only meshes with the already cut lower jig 22, and does not cut the lower jig 22. Thereby, generation | occurrence | production of the burr | flash in the lower end surface Wc is suppressed, and a burr | flash does not generate | occur | produce in the lower end surface 22c.

  In the above-described embodiment, the gear machining method and the gear fixing device according to the present invention are described as applied to an internal gear gear cutting method and an internal gear fixing device using skiving, The present invention can be applied to an internal gear gear cutting method and an internal gear fixing device that process an internal gear using a shaping machine, and an external gear gear cutting method and an external gear fixing device that process an external gear using a hobbing machine. Even if the workpiece is either an internal gear or an external gear, these gears may be spur gears or helical gears. Furthermore, when the workpiece is an internal gear, a barrel-shaped screw-shaped tool may be used as the cutting tool instead of the gear-shaped tool.

  Therefore, when cutting a plurality of workpieces W, the pair of upper and lower upper jigs 21 and lower jigs 22 can be used without being exchanged. Further, even if the workpiece W is fixed by the upper jig 21 and the lower jig 22, these do not affect the gear cutting operation of the pinion cutter 13, and the gear cutting operation in the pinion cutter 13 may be complicated. There is no. Therefore, generation | occurrence | production of the burr | flash in the lower end surface Wc of the workpiece | work W can be suppressed easily, suppressing the increase in manufacturing cost.

  Further, even when the pinion cutter 13 is replaced, the rotation of the pinion cutter 13 is set so that the replaced pinion cutter 13 and the lower jig 22 that has been cut are in a rotational phase relationship that can be engaged with each other. By making the phase coincide with the rotational phase of the lower jig 22, it is possible to eliminate the need to replace the lower jig 22.

  On the other hand, by forming the protruding portion 21d on the lower end surface 21c of the upper jig 21, the workpiece W can be pressed with a large pressing force, so that the workpiece W can be firmly fixed. Further, by fitting the workpiece W to the fitting portion 22d formed on the lower jig 22, the workpiece W can be positioned with high accuracy in the radial direction. Thereby, the fall of the processing precision of the workpiece | work W can be prevented. Further, by opening a bolt hole 21e into which the connecting bolt 23 for connecting the upper jig 21 and the lower jig 22 is inserted adjacent to the protruding portion 21d, the fastening force by the connecting bolt 23 is increased. Thus, it can be efficiently converted into a pressing force by the protruding portion 21d.

11 Rotary table 11a Mounting surface 12 Spindle 13 Pinion cutter 14 Sensor 21 Upper jig 21a Inner peripheral surface 21b Upper end surface 21c Lower end surface 21d Projecting portion 21e Bolt hole 22 Lower jig 22a Inner peripheral surface 22b Upper end surface 22c Lower end surface 22d Fitting Part 23 Connection bolt 24 Fixing bolt W Work Wa Inner peripheral surface Wb Upper end surface Wc Lower end surface Wd Outer peripheral surface B Cutter rotation axis C Work rotation axis

Claims (6)

In the gear machining method of cutting the workpiece with the tool by feeding the tool in the axial direction while rotating the workpiece and the tool,
The end surface on the downstream side in the feed direction of the work piece of the first product is brought into surface contact with the lower jig,
The first workpiece and the lower jig are coaxially overlapped,
The workpiece of the initial product is pressed and fixed toward the fixed lower jig,
The first work piece and the fixed lower jig are both cut by the tool,
Maintaining the fixed state of the lower jig when geared together with the work piece of the first product as it is,
The end surface on the downstream side in the feed direction in the workpiece after the next product is brought into surface contact with the lower jig in which the fixed state is maintained,
The workpiece after the next product and the lower jig maintained in the fixed state are coaxially overlapped,
The workpiece after the next product is pressed and fixed toward the lower jig in which the fixed state is maintained,
A gear cutting operation when the first workpiece is cut with respect to the tool while maintaining a meshable rotational phase relationship between the tool and the lower jig in which the fixed state is maintained. The gear cutting method is characterized in that only the workpiece after the next product is cut by giving the same gear cutting operation. The gear machining method according to claim 1,
When cutting the workpiece after the next product, when replacing the tool,
Prior to gear cutting with the replaced tool,
The rotation phase of the replaced tool is maintained in the fixed state so that the replaced tool and the lower jig maintained in the fixed state have a rotational phase relationship that can be engaged with each other. A gear machining method characterized by matching the rotational phase of the tool. The gear machining method according to claim 1 or 2,
The workpiece of the first product or the workpiece after the next product is coaxially formed from both sides in the axial direction by the upper jig disposed on the upstream side of the lower jig and the lower jig. A gear machining method, wherein the tool cuts the workpiece of the first product or the workpiece after the next product without cutting the upper jig. When the workpiece is cut by the tool by feeding the workpiece in the axial direction while rotating the workpiece and the tool, the workpiece In the gear fixing device for fixing
A turntable supported rotatably about the axis of the workpiece;
A peripheral surface that is fixed to the rotary table and that is in surface contact with the end surface on the downstream side in the feed direction of the workpiece, and is peripherally cut by the tool together with the peripheral surface of the workpiece, or the workpiece is toothed A lower jig having a tooth profile that meshes with the tool immediately after cutting;
An upper jig that is disposed upstream of the lower jig in the feed direction, and that clamps and fixes the workpiece from both sides in the axial direction between the lower jig and the lower jig;
A gear fixing device, comprising: a protrusion that protrudes from the downstream end surface in the feed direction of the upper jig toward the downstream side in the feed direction and presses the upstream end surface in the feed direction of the workpiece. The gear fixing device according to claim 4, wherein
A gear fixing device, comprising: a fitting portion that is formed on the lower jig, is fitted to the workpiece, and positions the workpiece in the radial direction. The gear fixing device according to claim 4 or 5,
A connecting bolt for connecting the upper jig and the lower jig in the axial direction;
A bolt hole through which the upper jig passes in the axial direction and the connecting bolt is inserted;
The said bolt hole is opened adjacent to the said protrusion part. The gear fixing apparatus characterized by the above-mentioned.

Images