JP6330443B2 - Skiving cutter and gear - Google Patents

Description

The present invention, skiving cutter, and relates to the gear, particularly, it has a pinion-like plurality of cutting portions forming the gear portion to the workpiece, and rotated around the cutter shaft center which crisscrosses the workpiece axis The present invention relates to a cutter that cuts a workpiece by relative movement while rotating synchronously with the workpiece, and a gear manufactured by the cutter.

  In the hypocycloid gear reduction mechanism and the wave gear reduction mechanism, a gear having a non-involute curve in a tooth shape is used. These reduction mechanisms can obtain a large reduction ratio, but if the center-to-center distance between the gears changes, the gears do not mesh correctly, and high accuracy is required for the gears. In addition, when accurate meshing cannot be maintained, transmission efficiency is reduced and meshing noise is generated.

  As a means for manufacturing a non-involute toothed internal gear by cutting, gear shaving in which a workpiece is cut by a pinion-like cutter can be considered. However, in this gear shaving, when the cutter is reground (re-sharpened) due to wear, the blade shape and blade thickness of the cutter change. For this reason, after regrinding, an error was caused in the tooth profile of the internal gear by cutting with a cutter. This inconvenience is also explained in Non-Patent Document 1.

  On the other hand, as a method of forming a non-involute tooth profile, there is skiving processing shown in Non-Patent Document 2. Skiving can form a tooth profile at high speed, but in this case as well, re-grinding of the cutter is required. In order to improve such an inconvenience, Patent Document 1 discloses a skiving tool having an assembly type structure in which a plurality of cutter bars are supported on a base body, although it is not a pinion-shaped cutter.

Utility Model Registration No. 3181136

Hiroshi Yamazaki, Yoshitaro Yoshida, Yoshihide Kiyosawa, Sasaki Kishi, Tomio Horiuchi, Koji Kase “Study on the design and production of pinion cutters for non-involute gears” [No.03-1] Papers of the 2003 Annual Meeting of the Japan Society of Mechanical Engineers Collection (IV) [2003.8.5-8, Tokushima] Shoichi Kojima “Study on internal gear spur gear skiving (3rd report, Cutter tooth profile design)” The Japan Society of Mechanical Engineering 40 (339), 3225-3231, 1974-11-25

  In machining by skiving, cutting is performed by "slip (slip)" generated by the rotary motion of the skiving cutter and the workpiece. Therefore, the cutter is reciprocated in the direction of the tooth trace as in the case of machining by a shaper. Compared with the processing method, smooth cutting is possible, and the tooth surface of the tooth portion formed on the workpiece is also finished smoothly.

  Further, in the machining by skiving, high speed cutting can be easily realized by increasing the rotation speed of the cutter. Accordingly, skiving is a particularly advantageous machining method when machining a gear having a large number of fine teeth such as a wave gear, for example, with a non-involute tooth profile.

  However, in skiving processing, cutting is performed in such a form that the cutter is rotated relative to the workpiece while being rotated synchronously with the workpiece, so that the blade end surface side and the outside leading in the feeding direction, that is, the cutting blade is configured. The edge of the cutting edge is easily worn.

  It is also conceivable to cope with such wear by regrinding. However, since the skiving tool of Patent Document 1 requires grinding not only to the squeeze surface but also to the flank surface with respect to a plurality of cutter bars, there is a cost and room for improvement. In particular, the skiving tool in which each cutting blade is configured independently as shown in Patent Document 1 is unsuitable for configuring a small gear tool.

  An object of the present invention is to rationally configure a skiving cutter capable of maintaining a good cutting state while suppressing a decrease in cutting performance due to wear, and a non-involute gear formed by the skiving cutter or The modified involute gear and the gear constitute the gear.

The feature of the present invention is that the workpiece is cut by driving and rotating around a cutter axis different from the workpiece axis, and relatively moving along the gear teeth of the gear portion formed on the workpiece while rotating synchronously with the workpiece. And a plurality of pinion gear-shaped cutting blade portions forming the gear portion are formed,
A squeeze surface defined by a first edge closer to the cutter axis and a second edge further away from the cutter axis than the first edge is formed on the cutting edge of the cutting edge portion with respect to the cutter axis. Formed in an inclined posture ,
When viewed in a cross-section including the cutter shaft core, the squeeze surface is formed in a concave shape that is recessed from an imaginary straight line that connects the boundary between the squeeze surface and the blade end surface that precedes in the direction of relative movement and the blade edge. There is in point.

  In skiving processing, the skiving cutter is relatively fed in the direction of the tooth trace of the workpiece, and at the same time, cutting is performed in a form that rotates around the cutter axis. In particular, the skiving cutter of the present invention enables cutting in a form in which the first edge and the second edge, which are the outer edges of the squeeze surface, are brought into contact with the workpiece. About this, the comparison of the cutting form by the specific structure of the conventional cutter 10 shown in FIG. 11 and the specific structure of the cutter 10 of this invention shown in FIG. 12 is demonstrated below.

As shown in FIG. 11, in the conventional cutter 110, the edge EX is formed only at the tip of the cutting edge. Therefore, when the cutter 110 is moved in the cutting direction with respect to the workpiece 2 at a predetermined cutting allowance D, the cutting edge is used during cutting. Cutting is performed in the straight line region L connected to the edge EX, and stress concentration on the edge EX is likely to occur. On the other hand, in the cutter 10 of the present invention, the first edge E1, the squeeze surface 13, and the second edge E2 are formed at the cutting edge as shown in FIG. When 10 is moved in the cutting direction, the cutting is performed in the bent region M that is bent at the squeeze surface 13 and the second edge E2, and the stress can be dispersed. That is, since the bending region M according to the configuration of the present invention is longer than the linear region L according to the conventional configuration, the surface pressure acting on the cutting edge can be reduced as compared with the conventional configuration, and the wear of the cutting edge can be suppressed by dispersing the stress. It becomes.
Further, in the conventional cutter 110, when the edge EX of the blade edge is set to the angle β, the cutter 10 of the present invention can make the angle γ of the portion of the first edge E1 of the blade edge larger than the angle β. Wear of the first edge E1 can be further suppressed.

Furthermore, as shown in FIG. 13, when the cutter 210 designed to have a sharp cutting edge as shown by the phantom line and the cutter 10 chamfered to form the squeeze surface 13 as shown by the solid line are compared, In the cutter 10 on which the surface 13 is formed, the blade edge portion 11T moves backward by the distance F, and the entire cutter is reduced in diameter. For this configuration, for example, in the cutter 210 in which the squib surface is simply formed by chamfering with respect to the initial design having a sharp cutting edge portion, the skiving cutter 210 is set at a position to compensate for the shortage of cutting due to the distance F. When a non-involute tooth profile or a modified involute tooth profile is cut, a large tooth profile error is caused in addition to the blade thickness error. In addition, even in the cutter 210 in which the squeeze surface 13 is formed and the shape of the cutting blade or the like is set so that an appropriate tooth profile can be cut, in the configuration in which the squeeze surface 13 is formed flat, the edge portion becomes obtuse and the cutting performance is low. It was a thing.
In the skiving cutter 10 of this configuration, as shown in FIG. 13, it is more concave than the imaginary straight line connecting the boundary (first edge E1) between the squeeze surface 13 and the blade end surface 11S and the blade edge portion 11T (second edge E2). It is formed. As a result, a sharp edge (first edge E1) is created at the boundary between the squeeze surface 13 and the blade end surface 11S, and a sharp edge (second edge E2) is also created at the blade tip 11T. Cutting performance can be further improved, and it is possible to make the blade thickness error and tooth profile error difficult to invite.
Therefore, a skiving cutter that maintains a good cutting state while suppressing a decrease in cutting performance due to wear has been constructed.

  In the present invention, the first edge is formed at the boundary between the squeeze surface and the blade end surface preceding in the direction of relative movement, and the second edge is formed at the boundary between the squeeze surface and the flank surface of the blade edge. It is in the point.

  According to this, at the time of cutting, the first edge and the second edge come into contact with the workpiece, cutting is performed at these edges, and the stress can be dispersed.

The feature of the present invention is that the workpiece is cut by driving and rotating around a cutter axis different from the workpiece axis, and relatively moving along the gear teeth of the gear portion formed on the workpiece while rotating synchronously with the workpiece. And a plurality of pinion gear-shaped cutting blade portions forming the gear portion are formed,
A squeeze surface defined by a first edge closer to the cutter axis and a second edge further away from the cutter axis than the first edge is formed on the cutting edge of the cutting edge portion with respect to the cutter axis. Formed in an inclined posture,
Among the cutting blade portions, a chamfered portion is formed in a region along the trailing side in the rotation direction around the cutter axis on the blade end surface side.

In skiving processing, the skiving cutter is relatively fed in the direction of the tooth trace of the workpiece, and at the same time, cutting is performed in a form that rotates around the cutter axis. In particular, the skiving cutter of the present invention enables cutting in a form in which the first edge and the second edge, which are the outer edges of the squeeze surface, are brought into contact with the workpiece. About this, the comparison of the cutting form by the specific structure of the conventional cutter 10 shown in FIG. 11 and the specific structure of the cutter 10 of this invention shown in FIG. 12 is demonstrated below.

As shown in FIG. 11, in the conventional cutter 110, the edge EX is formed only at the tip of the cutting edge. Therefore, when the cutter 110 is moved in the cutting direction with respect to the workpiece 2 at a predetermined cutting allowance D, the cutting edge is used during cutting. Cutting is performed in the straight line region L connected to the edge EX, and stress concentration on the edge EX is likely to occur. On the other hand, in the cutter 10 of the present invention, the first edge E1, the squeeze surface 13, and the second edge E2 are formed at the cutting edge as shown in FIG. When 10 is moved in the cutting direction, the cutting is performed in the bent region M that is bent at the squeeze surface 13 and the second edge E2, and the stress can be dispersed. That is, since the bending region M according to the configuration of the present invention is longer than the linear region L according to the conventional configuration, the surface pressure acting on the cutting edge can be reduced as compared with the conventional configuration, and the wear of the cutting edge can be suppressed by dispersing the stress. It becomes.
Further, in the conventional cutter 110, when the edge EX of the blade edge is set to the angle β, the cutter 10 of the present invention can make the angle γ of the portion of the first edge E1 of the blade edge larger than the angle β. Wear of the first edge E1 can be further suppressed.

Further, according to this, during cutting, the chamfered portion comes into contact with the workpiece on a surface wider than that of the edge, so that wear on the trailing side is suppressed. As a result, the degree of deformation of the cutting edge is reduced, and a good cutting state can be maintained over a long period of time.
Therefore, a skiving cutter that maintains a good cutting state while suppressing a decrease in cutting performance due to wear has been constructed.

In the present invention, the first edge is formed at the boundary between the squeeze surface and the blade end surface preceding in the direction of relative movement, and the second edge is formed at the boundary between the squeeze surface and the flank surface of the blade edge. It is in the point.

According to this, at the time of cutting, the first edge and the second edge come into contact with the workpiece, cutting is performed at these edges, and the stress can be dispersed.

  In the present invention, the squeeze surface may be formed as a part of a conical surface centered on the cutter axis.

  Such a squeeze surface is set so that the grindstone and grinder are inclined with respect to the cutter axis so that the outer peripheral side of the cutter edge surface is ground, and the cutter is rotated around the cutter axis. Form. Thereby, formation of a squeeze surface becomes easy.

The present invention, when viewed in cross-section including the pre-Symbol cutter axis, the rake surface, recess and the border between the rake edge preceding in the direction of the with the rake face relative movement, the virtual straight line connecting the said cutting edge It may be formed in a concave shape.

As shown in FIG. 13, when the cutter 210 designed to have a sharp cutting edge as shown by the phantom line and the cutter 10 chamfered to form the squeeze surface 13 as shown by the solid line are compared, the squeeze surface 13 In the cutter 10 in which is formed, the blade edge portion 11T moves backward by the distance F, and the diameter of the entire cutter is reduced. For this configuration, for example, in the cutter 210 in which the squib surface is simply formed by chamfering with respect to the initial design having a sharp cutting edge portion, the skiving cutter 210 is set at a position to compensate for the shortage of cutting due to the distance F. When a non-involute tooth profile or a modified involute tooth profile is cut, a large tooth profile error is caused in addition to the blade thickness error. In addition, even in the cutter 210 in which the squeeze surface 13 is formed and the shape of the cutting blade or the like is set so that an appropriate tooth profile can be cut, in the configuration in which the squeeze surface 13 is formed flat, the edge portion becomes an obtuse angle and the cutting performance is low. It was a thing.
In the skiving cutter 10 of this configuration, as shown in FIG. 13, it is more concave than the imaginary straight line connecting the boundary (first edge E1) between the squeeze surface 13 and the blade end surface 11S and the blade edge portion 11T (second edge E2). It is formed. As a result, a sharp edge (first edge E1) is created at the boundary between the squeeze surface 13 and the blade end surface 11S, and a sharp edge (second edge E2) is also created at the blade tip 11T. Cutting performance can be further improved, and it is possible to make the blade thickness error and tooth profile error difficult to invite.

  The present invention is characterized in that, in the cutting blade portion, the blade thickness in the circumferential direction of the blade end surface preceding in the direction of relative movement is set larger than the blade thickness in the circumferential direction of the portion driven in the relative movement direction. It is in.

  According to this, since the blade thickness on the opposite side of the blade end surface becomes thinner than the blade thickness on the blade end surface side, the distance between the cutting edge portion and the cutting blade portion becomes wider toward the opposite side of the blade end surface. For this reason, a favorable clearance angle is formed and smooth cutting is realized.

In the present invention, a non-involute gear or a modified involute gear may be formed by processing with the skiving cutter according to claim 1 or 3 .

  The skiving cutter not only processes the non-involute gear or the modified involute gear at a high speed, but also has a smooth finish compared to the tooth surface of the gear formed by the shaper. Therefore, by forming a non-involute gear or a modified involute gear with a skiving cutter, it is possible to achieve efficient transmission by suppressing the decrease in transmission efficiency due to friction, and to obtain a gear with excellent quietness It becomes.

In the present invention, a gear used for a hypocycloid speed reduction mechanism or a wave gear mechanism may be formed by processing with the skiving cutter according to claim 1 or 3 .

  The hypocycloid speed reduction mechanism and the wave gear mechanism enable transmission at a high speed reduction rate, and are required to have a large number of teeth. For example, when the hypocycloid speed reduction mechanism or the wave gear mechanism is constituted by a relatively small gear, it is necessary to finish the tooth surface smoothly in order to increase the transmission efficiency. In response to such demands, processing with a skiving cutter can form a gear having a smooth tooth surface even with a gear having a large number of teeth, and a hypocycloid reduction mechanism or wave gear mechanism with high transmission efficiency. Configuration is possible.

It is a perspective view which shows the processing form in a gear processing apparatus. It is a partially cutaway sectional view of a processing form in a gear processing device. It is a vertical side view which shows the state in which a tooth gap is formed in a workpiece | work by a cutting blade part. It is a cross-sectional top view which shows the state in which a tooth gap is formed in a workpiece | work by a cutting blade part. It is a partially cutaway sectional view showing a cutting state of a work by a cutter. It is sectional drawing which shows the positional relationship of a cutting blade part and a workpiece | work. It is a bottom view which shows the cutting edge part of the cutter for skiving. It is a perspective view which shows the cutter for skiving. It is sectional drawing which shows the squeeze surface of another embodiment (a). It is sectional drawing which shows the squeeze surface of another embodiment (b). It is sectional drawing which shows the cutting state by the cutter of a conventional structure. It is sectional drawing which shows the cutting state by the cutter of this invention structure. It is a figure explaining the structure of a cutter.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Outline of skiving process]
A skiving cutter (hereinafter abbreviated as a cutter 10) can produce a flat internal gear by cutting the inner peripheral surface of a ring-shaped workpiece 1 in the gear machining apparatus shown in FIGS. This gear machining apparatus has the same mechanism as that disclosed in JP 2012-45687 A and JP 2012-51049 A.

  In the gear machining apparatus, a workpiece 1 is supported on a table 2 that rotates about a workpiece axis Y, and a pinion gear-shaped cutter 10 is rotated with respect to a cutter axis X that is in a positional relationship with the workpiece axis Y. I support it. The cutter 10 has a plurality of cutting edge portions 11 on the outer periphery, and by tilting the cutter axis X with respect to the workpiece axis Y by an inclination angle α, the feeding direction of the cutter 10 with respect to the workpiece 1 changes the teeth of the cutter 10. Set to match the streak direction.

  That is, the cutting edge portion 11 of the cutter 10 is set in a posture parallel to the workpiece axis Y, and the blade end surface 11S (see FIGS. 5 and 6) side (the lower side in FIG. 2) of the cutting edge portion 11 is set. The cutter 10 is disposed so that the inner surface of the workpiece 1 is brought into contact with the blade end surface 11S and the side opposite to the blade end surface 11S (upper side in FIG. 2) is separated from the inner periphery of the workpiece 1.

  In this setting state, the workpiece 1 is rotated in the main rotation direction R around the workpiece axis Y, and the moving speed of the inner periphery of the workpiece 1 and the moving speed of the outer periphery of the cutting edge portion 11 of the cutter 10 are as follows. The cutter 10 is rotated in the secondary rotation direction S about the cutter axis X so that the speed is constant. Further, cutting is performed by moving the cutter 10 in the feed direction Z parallel to the workpiece axis Y, and a gear portion is formed on the workpiece 1.

  At the time of cutting, simultaneously with the rotation of the cutter 10, the cutting edge portion 11 of the cutter 10 moves relative to the workpiece 1 in the feed direction Z parallel to the workpiece axis Y. As a result, the moving component accompanying rotation about the cutter axis X and the moving component in the feed direction Z parallel to the workpiece axis Y are combined, and the cutting edge portion 11 is moved to the workpiece 1 in this combined direction. Relative movement. Further, during cutting, the cutter 10 moves relative to the direction combined with the workpiece 1, and the workpiece 1 rotates around the workpiece axis Y during this relative movement. Therefore, the difference between the amount of relative movement in the combined direction and the amount of rotation of the work 1 (strictly speaking, the component of the amount of rotation along the combined direction) becomes “slip”. The cutting is performed.

  Specific cutting forms are shown in FIGS. As shown in these drawings, at the time of cutting, the cutting edge portion 11 of the cutter 10 cuts the inner periphery of the work 1 by the above-mentioned “slip” to form a tooth groove 1G, and a tooth portion between each tooth groove 1G. 1T is formed. Further, in a single cutting from when one cutting edge portion 11 comes into contact with the inner periphery of the workpiece and then leaves, a tooth groove 1G having a slight length is formed in the direction of the teeth of the gear portion formed on the workpiece 1. However, as the cutter 10 operates in the feed direction Z, the tooth groove 1G is continuous in the tooth line direction, and as a result, the tooth portion 1T is formed between the plurality of tooth grooves 1G, and the gear is completed. .

〔cutter〕
As shown in FIGS. 1 to 8, the cutter 10 has a pinion gear-like shape by forming a helical groove on the outer surface of a frustoconical base material made of high-speed steel or cemented carbide having a hardness of about HRC65. A plurality of cutting edge portions 11 are provided. In this cutter 10, the large diameter side (corresponding to the side where the gear tip circle diameter is large) is referred to as a blade end surface 11S, and in the plurality of cutting blade portions 11, the blade thickness of the blade end surface 11S (in the gear tooth thickness). Equivalent) is the largest, and it is processed so that the blade thickness decreases on the opposite side. Thereby, the clearance angle with respect to the cutting surface formed in the workpiece | work 1 is formed.

  The base material of the cutter 10 of the present invention is not limited to the truncated cone shape, and may be, for example, a columnar shape or a cylindrical shape. By using the base material having such a shape, even when the cutting blade portion 11 is ground (polished), the blade shape of the cutting blade portion 11 does not change.

  As described above, the cutting blade portion 11 has a shape similar to that of a gear, and the posture of the cutter 10 is set so that the blade end surface 11S precedes when moved in the feed direction Z. When the cutter 10 is viewed along the cutter axis X, one cutting edge 11 has one cutting edge 11T, and on both sides sandwiching this, a leading-side leading surface preceded by rotation toward the secondary rotation direction S 11A and the trailing surface 11B on the trailing side opposite to this are formed.

  In particular, in this cutter 10, a squeeze surface 13 is formed on the blade end surface 11 </ b> S among the plurality of cutting blade portions 11, and is inclined so as to move away from the blade end surface 11 </ b> S with respect to the cutter axis X toward the blade tip 11 </ b> T. Yes. In the cutter 10, the blade end surface 11 </ b> S is formed in a planar shape that is orthogonal to the cutter axis X.

  In such a squeeze surface 13, an arc-shaped first edge E1 is formed at the boundary with the blade end surface 11S, and a second edge E2 is formed at the boundary with the outer edge of the cutting blade portion 11 on the blade edge 11T side. Is done. In the case of re-grinding with this cutter 10, the squeeze surface 13 is formed simply by chamfering the outer peripheral side of the blade end surface 11S, and at the same time, the first edge E1 and the second edge E2 Is formed. That is, the squeeze surface 13 is formed with the first edge E1 that has a protruding shape on the cutter shaft X side and the second edge E2 that has a protruding shape on the opposite side of the cutter shaft X as outer edges.

  As shown in FIG. 7, a center line C passing through the center of the blade width of the cutting edge portion 11 in a direction view along the cutter axis X and a reference line H in a posture orthogonal to the center line C are assumed. Further, the squeeze surface 13 is formed in a region where the intersecting angle θ between the tangent line L and the reference line H at a portion where the preceding surface 11A and the subsequent surface 11B intersect is less than 60 degrees. The intersection angle θ may be 60 degrees or an angle exceeding 60 degrees.

  Further, in the blade end surface 11S of the plurality of cutting blade portions 11, a chamfered portion 12 is provided at the boundary portion with the leading surface 11A on the trailing side that is driven by rotation in the secondary rotation direction S about the cutter axis X. Is formed. Since the chamfered portion 12 is formed in a region adjacent to the squeeze surface 13, the chamfered portion 12 is formed in a region where the first edge E1 extends in a region along the blade end surface 11S. Of these, the second edge E2 is formed in a region along the leading surface 11A.

  The chamfered portion 12 can be formed by grinding with a grindstone or a grinder, but is formed by shot blasting or shot peening techniques.

[Cutting operation]
In skiving processing, cutting is started when the cutter 10 moves relative to the workpiece 1 in the feed direction Z while the workpiece 1 and the cutter 10 rotate synchronously. At the time of cutting, the cutting edge 11T comes into pressure contact with the work 1 by movement in the feed direction Z with respect to the inner periphery of the work 1, and at the same time, the cutting edge 11T comes into pressure contact with the work 1 in the rotation direction by rotation about the cutter axis X. As a result, the “slip” is generated as described above, and cutting is performed on the cutting edge 11T and the leading surface 11A connected thereto.

  In the cutter 10 of the present invention, the squeeze surface 13 is formed as described above, and the first edge E1 and the second edge E2 are formed. Therefore, the angle formed by the cross section of the cutting edge portion 11 and the squeeze surface 13 is increased. At the same time (for example, an obtuse angle), cutting by the first edge E1 and the second edge E2 is enabled. In the cutter of the present invention, it is possible to perform cutting in a form in which the first edge E1 and the second edge E2, which are the outer edges of the squeeze surface 13, are brought into contact with the workpiece 1. In such a cutting mode, cutting can be performed using a bent region continuous from the squeeze surface 13 via the second edge as a cutting allowance, so stress is applied to a long region compared to a conventional cutter that performs cutting in a linear region. It is possible to suppress wear of the cutting edge 11T.

  Thereby, compared with the cutting edge part 11 provided with the single edge, the load which acts on the blade edge | tip 11T at the time of cutting is disperse | distributed, pressure concentration is reduced, and wear is suppressed. That is, at the time of cutting, cutting at the first edge E1 and the second edge E2 is realized in a state where the pressure is distributed to the first edge E1 and the second edge E2. Thereby, the lifetime of the cutter 10 is extended and efficient cutting can be performed continuously.

  Further, since the chamfered portion 12 contacts the workpiece 1 at the time of cutting, wear is suppressed, and cutting is also performed at the first edge E1 and the second edge E2 connected to the chamfered portion 12.

  In addition, when a single edge is formed on the cutting edge portion 11 and cutting is performed with the cutter 10, a relatively large size of chips is generated. This chip easily adheres to the inner surface of the workpiece 1 due to centrifugal force, and causes an increase in the temperature of the cutting edge portion 11. On the other hand, in the cutter 10 of the present invention, the second edge E2 comes into contact with the chips generated by cutting at the first edge E1, so that the chips are divided or curled to facilitate discharge, The heat capacity of the chips is reduced to suppress the temperature rise of the cutting blade portion 11.

  The chips are pushed out from the blade end surface 11S and discharged downward in FIGS. Further, when the cutter 10 is viewed along the cutter axis X, the blade thickness at the blade end surface 11S is the largest in each of the cutting blade portions 11, and the blade thickness decreases toward the side opposite to the blade end surface 11S. For this reason, it is possible to reduce the friction by reducing the contact area between the cutting edge portion 11 and the tooth gap formed in the workpiece 1.

[Another embodiment]
The present invention may be configured as follows in addition to the embodiment described above.
(A) As shown in FIG. 9, when viewed in a cross section including the cutter shaft X, the boundary (first edge E1) between the squeeze surface 13 and the blade end surface 11S, and the cutting edge 11T (first edge E1) May be formed in a concave surface that is recessed from a virtual straight line connecting the two. Further, in addition to this configuration, the chamfered portion 12 may be formed similarly to the embodiment. Thereby, it is also possible to form the first edge E1 in the region along the cutting edge surface 11S in the chamfered portion 12 and form the second edge E2 in the region along the leading surface 11A in the chamfered portion 12.

  By forming the squeeze surface 13 in a concave shape as in this different embodiment (a), the first edge E1 and the second edge E2 become sharp, and the cutting performance can be further enhanced.

(B) As shown in FIG. 10, the squeeze surface 13 is formed so that the first edge E1 is formed in a straight line by a process such as planar grinding of the region on the distal end side of the cutting edge portion 11. May be.
In addition, the chamfered portion 12 can be formed in this configuration. Since the chamfered portion 12 is formed in a region extending from the blade base side to the blade edge 11T in the cutting blade portion 11, the chamfered portion 12 is formed in a region continuous with the first edge E1 and the second edge E2. It will be.

  In the configuration in which the squeeze surface 13 is formed as in this alternative embodiment (b), the squeeze surface 13 is formed in a slight region in the vicinity of the cutting edge 11T in the blade end surface 11S. Is not reduced.

(C) The skiving cutter of the present invention is used to process a non-involute gear or a modified involute gear.

  The skiving cutter not only processes the non-involute gear or the modified involute gear at a high speed, but also has a smooth finish compared to the tooth surface of the gear formed by the shaper. Therefore, by forming a non-involute gear or a modified involute gear with a skiving cutter, it is possible to achieve efficient transmission by suppressing the decrease in transmission efficiency due to friction, and to obtain a gear with excellent quietness It becomes.

(D) A gear used for a hypocycloid reduction mechanism or a wave gear mechanism is formed by processing with the skiving cutter of the present invention.

  The hypocycloid speed reduction mechanism and the wave gear mechanism enable transmission at a high speed reduction rate, and are required to have a large number of teeth. For example, when the hypocycloid speed reduction mechanism or the wave gear mechanism is constituted by a relatively small gear, it is necessary to finish the tooth surface smoothly in order to increase the transmission efficiency. In response to such demands, processing with a skiving cutter can form a gear having a smooth tooth surface even with a gear having a large number of teeth, and a hypocycloid reduction mechanism or wave gear mechanism with high transmission efficiency. Configuration is possible.

(E) A gear used for a variable valve timing device is formed by processing with the skiving cutter of the present invention.

  As a variable valve timing device, a driving side rotating body that rotates synchronously with a crankshaft of an internal combustion engine and a driven side rotating body that is coupled to a camshaft are disposed so as to be relatively rotatable, and the drive side rotating body and the driven side rotating body In order to change the relative rotational phase, a configuration having a reduction transmission system that transmits a driving force of an actuator such as an electric motor by a gear is conceivable. Since this reduction transmission system requires a high reduction rate, a hypocycloid reduction mechanism and a wave gear mechanism are used. By forming the gear used in the reduction transmission system by machining with a skiving cutter, the gear is machined at high speed, and the tooth surface is smoothly finished to achieve transmission with good transmission efficiency.

  The present invention can be used for a pinion gear cutter used for skiving.

1 Workpiece 10 Skiving cutter 11 Cutting edge portion 11S Cutting edge surface 11T Cutting edge 12 Chamfering portion 13 Squee surface E1 First edge E2 Second edge X Cutter shaft core Y Work shaft core Z Feeding direction

Claims (9)

Drive and rotate around a cutter axis that is different from the workpiece axis, and cut relative to the gear part formed on the workpiece while rotating synchronously with the workpiece, thereby cutting the workpiece, A plurality of pinion gear-shaped cutting blade portions to be formed are formed,
A squeeze surface defined by a first edge closer to the cutter axis and a second edge further away from the cutter axis than the first edge is formed on the cutting edge of the cutting edge portion with respect to the cutter axis. Formed in an inclined posture ,
When viewed in a cross-section including the cutter shaft core, the squeeze surface is formed in a concave shape that is recessed from an imaginary straight line that connects the boundary between the squeeze surface and the blade end surface that precedes in the direction of relative movement and the blade edge. Skiving cutter.   The first edge is formed at a boundary between the squeeze surface and a blade end surface preceding in the direction of relative movement, and the second edge is formed at a boundary between the squeeze surface and the flank surface of the blade edge. Item 1. A skiving cutter according to item 1. Drive and rotate around a cutter axis that is different from the workpiece axis, and cut relative to the gear part formed on the workpiece while rotating synchronously with the workpiece, thereby cutting the workpiece, A plurality of pinion gear-shaped cutting blade portions to be formed are formed,
A squeeze surface defined by a first edge closer to the cutter axis and a second edge further away from the cutter axis than the first edge is formed on the cutting edge of the cutting edge portion with respect to the cutter axis. Formed in an inclined posture,
A skiving cutter in which a chamfered portion is formed in a region along the trailing side in the rotational direction around the cutter axis on the blade end surface side in the cutting blade portion . The first edge is formed at a boundary between the squeeze surface and a blade end surface preceding in the direction of relative movement, and the second edge is formed at a boundary between the squeeze surface and the flank surface of the blade edge. Item 4. A skiving cutter according to item 3 . The rake face, the skiving cutter of claim 1, wherein formed as part of a conical surface the cutter axial centered. When viewed in cross-section including the pre-Symbol cutter axis, said rake surface is formed and the border between the rake edge preceding in the direction of the relative movement between the rake surface, the concave recessed from the virtual straight line connecting the said cutting edge The skiving cutter according to claim 3 or 4 , wherein the skiving cutter is used. The blade thickness in the circumferential direction of the blade end surface preceding in the direction of the relative movement among the cutting blade portions is set to be larger than the blade thickness in the circumferential direction of a portion driven in the relative movement direction. The skiving cutter according to claim 6. A non-involute gear or a modified involute gear processed by the skiving cutter according to claim 1 or 3 . A gear which is processed by the skiving cutter according to claim 1 or 3 and used for a hypocycloid reduction mechanism, a wave gear mechanism or a variable valve timing device .

Images