JP5544698B2 - Gear cutting method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear cutting method using a gear cutting tool such as a hob cutter, a pinion cutter, or an electrodeposition worm-shaped tool that forms a tooth by cutting gears.

As such a gear cutting tool, for example, a cutter provided with a blade portion having a cutting edge such as a hob cutter described in Patent Document 1 and a pinion cutter described in Patent Document 2, or described in Patent Document 3. There is known an electrodeposition worm-like tool in which diamond abrasive grains or the like are electrodeposited on such a worm-like blade portion. In these gear cutting tools, in hob cutters and electrodeposition worm-like tools, the rotation axis of the tool body is positioned on a plane intersecting the central axis of the gear to be cut, and in pinion cutters, the rotation axis Are parallel to the center axis of the work gear, and the tool body is forcibly rotated around the center axis, and the tool body is also synchronized with the rotation of the work gear. The tooth surface of the tooth of the work gear is formed by this blade part by forcibly rotating it independently and engaging with the tooth face of the tooth of the work gear so that the face of the blade part comes into contact. I will do it. In the following description, the tooth (surface) is related to the work gear, and the blade (surface) is related to the tool.
JP 2003-178015 A JP 2004-160645 A JP 2003-266241 A

  By the way, when a tooth formation error occurs in gear cutting with such a hob cutter, pinion cutter, electrodeposition worm-like tool, etc., the cutter and the gear to be cut are forcibly rotated so that they are synchronized with each other independently. Since it is driven, it is considered that the influence of the mounting error on at least one of the rotating shafts is large. However, in recent years, along with the demand for higher precision in gear cutting, in addition to such mounting errors of the work gear and tool body, the work gear is used in processing devices such as hobbing machines and gear cutting machines. When the mechanical rigidity of the device itself such as the rotating shaft to be mounted is low, or when the rigidity of the work gear itself is low, the influence of the error due to fluctuation of the meshing state of the blade surface and the tooth surface can be ignored. If such an error becomes large, the formed tooth profile may swell even if the mounting error on the rotating shaft is minimized.

The present invention has been made under such a background. Even when the mechanical rigidity of the machining apparatus is low or the rigidity of the work gear itself is low as described above, the tooth of the work gear and the blade of the tool body are provided. An object of the present invention is to provide a gear cutting method capable of stabilizing the meshing state with the portion and preventing the tooth profile from generating undulations and forming a highly accurate tooth on the work gear.

To solve the above problems, in order to achieve the above object, the present invention is the first, gear cutting method for performing gear cutting by engaging the blade portion of the hob with the teeth of workpiece gear a is, the hobs is hob or electrodeposited worm-shaped tool, by driving in synchronization the hob with respect to the workpiece gear to be rotated, the blade surface of the hob And the tooth surface of the gear to be cut and brought into contact with each other, and the dislocation pressure angle is adjusted to adjust the shift pressure angle so that the right blade surface of the gear cutting tool meshes with the workpiece gear in the state of being meshed in this way. And the left blade surface of the gear cutting tool are always in contact with each other so that the number of tooth surfaces meshing with the work gear is always the same. in contact with the surface and the left edge surface that processing is performed And features. Further, the present invention is secondly a gear cutting method for performing gear cutting by meshing a tooth of a gear to be cut with a tooth of a work gear, wherein the gear cutting tool is a pinion cutter, By driving the gear cutting tool in synchronization with the driven gear to be driven, the blade surface of the gear cutting tool and the tooth surface of the gear to be cut are brought into contact with each other, and the shift coefficient is set. By adjusting, in the state of meshing in this way, the number of tooth surfaces with which the right blade surface of the gear cutting tool meshes with the work gear, and the tooth surface with which the left blade surface of the gear cutting tool meshes with the work gear. The left and right tooth surfaces of one tooth are always in contact with the right blade surface and the left blade surface, and machining is performed. In this specification, when the gear cutting tool has a rake face such as a hob cutter or a pinion cutter, the right edge face on the right side and the left edge face on the left side when the tool is viewed from the rake face to the mountain center. When the gear cutting tool does not have a rake face like an electrodeposited worm-like tool, the right side is the right blade face and the left side is the left blade face when viewed from the direction opposite to the rotation direction of the tool from the center of the mountain .

In the gear cutting method configured in this way, the teeth of the gear to be cut are always equal in number to the left and right blade surfaces of the right and left tooth surfaces of the tooth cutting tool. Since it is engaged with the blade portion and geared while being brought into contact with each other, the stress and resistance acting on the teeth of the work gear due to contact with the blade surface of this blade portion act from the right tooth surface. And the one acting from the left tooth surface cancel each other. Therefore, even if the rigidity of the processing device such as a rotating shaft to which the work gear is mounted and the rigidity of the teeth of the work gear are low, they act on both the left and right tooth surfaces of the work gear teeth. It is possible to prevent the teeth from being biased and biased to either the left or right tooth surface due to pressure or resistance imbalance, and this changes the meshing state of the tooth surfaces with the blade part of the gear cutting tool. Therefore, it is possible to prevent waviness and the like from occurring in the tooth profile of the work gear formed by the gear cutting tool, and to promote high-precision gear cutting. In the present specification, the tooth surface of the gear to be cut that contacts the right blade surface of the tool is defined as the left tooth surface, and the tooth surface of the gear that contacts the left blade surface of the tool is defined as the right tooth surface.

Figures 1 and 2 show a first embodiment of the gear cutting method of the present invention in the case hobs are the hob. Hob in the present embodiment, the axis O around the rotational direction T tool body is rotated in the first outer circumference as shown in FIG. 1, a helical screw-like portion 2 twist to the axis O around the circumferential direction A plurality of grooves 3 extending in the direction of the axis O with a space therebetween are formed so as to intersect each other, and the rotation direction of the blade 4 formed by these grooves 3 intersecting the screw-like part 2 A surface facing the T side is a rake surface 5. When viewed from the rotational direction T facing the rake face 5, the rake face 5 has a substantially isosceles trapezoidal shape that tapers toward the outer peripheral side, and the right side edge is the right cutting edge. The side surface of the blade portion 4 that is connected to the rear side in the rotational direction T of the right cutting blade 6 is the right blade surface 7, and the left side edge of the rake surface 5 is the left cutting blade 8. The side surface of the blade portion 4 that continues to the rear side in the rotation direction T of the blade 8 is the left blade surface 9.

  Such a hob cutter is attached to a rotating shaft 10 of a hobbing machine that is a gear cutting device, and is forcibly driven to rotate in the rotational direction T around the axis O, and the toothed direction (covered) of the gear 11 to be cut. When the cutting gear 11 is a spur gear, it is fed in a direction orthogonal to the drawings in FIGS. 1 and 2 to form teeth 12 on the workpiece gear 11. That is, by the rotation of the tool body 1 of the hob cutter, the blade portions 4 formed on the screw-like portion 2 appear on the surface that sequentially forms the tooth profile, and the locus of the blade portion 4 on the tooth profile generating surface is shown in FIG. Is projected as a rack R that travels straight in the direction of travel indicated by symbol A. On the other hand, the work gear 11 is also attached to the other rotary shaft 13 of the hobbing machine so that the center axis C forms a predetermined attachment angle with respect to the axis O, and follows the traveling direction A of the rack R. Thus, the rotation of the work gear 11 and the rotation of the tool body 1 of the hob cutter are forced to rotate around the central axis C in the rotation direction B. Are driven to be synchronized so as to mesh with each other.

  Therefore, the cutting edge 4 of the tool body 1 has its right cutting edge 6 cutting the left tooth surface 14 of the tooth 12 so that the right blade surface 7 of the blade 4 contacts the left tooth surface 14 of the tooth 12. Further, the left cutting edge 8 cuts the right tooth surface 15 of the tooth 12, and the left blade surface 9 of the blade portion 4 is brought into contact with the right tooth surface 15 of the tooth 12. That is, in this embodiment, as shown in FIG. 1, the portion where the tooth 12 of the work gear 11 and the blade portion 4 of the tool body 1 are in contact with each other, with the central axis C of the work gear 11 facing down, When viewed in the rotation direction T of the tool body 1 along the central axis C, the left tooth surface of the tooth 12 at this contact portion is the left tooth surface 14 and the blade portion 4 that contacts this tooth surface 14. The right blade surface is the right blade surface 7, and the tooth surface located on the right side of the tooth 12 at the contact portion with the blade portion 4 is the right tooth surface 15. The left blade surface is a left blade surface 9. The right and left blade surfaces 7 and 9 of the blade portion 4 and the left and right tooth surfaces 14 and 15 of the teeth 4 thus meshed and brought into contact with each other are such that the right blade surface 7 of the blade portion 4 contacts the left tooth surface 14 of the teeth 12. The number of places and the place where the left blade surface 9 of the blade part 4 contacts the right tooth surface 15 of the tooth 12 are the same.

  Here, FIGS. 2A to 2L show the left and right blade surfaces 7 and 9 of the blade portion 4 while the rack R is linearly moved by one pitch of the blade portion 4 in the traveling direction A in the present embodiment. The contact state of the teeth 12 with the left and right tooth surfaces 14 and 15 is sequentially shown. As shown in FIG. 2, the tool body 1 and the work gear 11 are driven to rotate synchronously, and the rack R is rotated. As the work gear 11 is rotated in the rotation direction B on the circumference while being advanced in a straight line along the traveling direction A, the left and right blade surfaces 7 and 9 of the blade portion 4 and the left and right teeth of the tooth 12 The locations P and Q where the surfaces 14 and 15 come into contact also change along the tooth height direction of the teeth 12. In addition, the contact location shown with the code | symbol P in a figure is a location where the right blade surface 7 of the blade part 4 contacts the left tooth surface 14 of the tooth | gear 12, and the contact location shown with the code | symbol Q is the left blade surface 9 of the blade part 4. FIG. Is a portion that contacts the right tooth surface 15 of the tooth 12.

In the gear cutting method according to the present embodiment, the contact point P between the right blade surface 7 of the blade portion 4 and the left tooth surface 14 of the tooth 12 that are in contact with each other, the left blade surface 9 and the tooth 12 of the blade portion 4. The number of the contact points Q with the right tooth surface 15 is the same as described above, although it changes in the tooth height direction of the teeth 12 as described above. That is, the trajectory of one blade portion 4 in the rack R is a straight line along the traveling direction A of the rack R and a circumference along the rotational direction B of the work gear 11 as shown in FIG. As shown in FIGS. 2 (b) to 2 (f), the contact points P and Q change in the tooth height direction from the state at the contact point position of the contact point P and Q, respectively. The right blade surface 7 of one blade portion 4 and the right blade surface 7 of the next blade portion 4 on which the locus is projected on the rear side in the traveling direction A of the one blade portion 4 are these right blade surfaces 7. The left tooth surfaces 14 of the two teeth 12 facing each other are in contact with each other at one contact point P, and the left blade surface 9 of the one blade portion 4 and one traveling direction A of the one blade portion 4 The left blade surface 9 of the blade part 4 before the locus is projected to the side and the right tooth surface 15 of the two teeth 12 respectively opposed to the left blade surface 9 are also connected one by one. In contact with the contact portion Q.

  Next, when one tooth 12 of the work gear 11 is located at the contact position as the rack R advances and the work gear 11 rotates, the left side of the one tooth 12 as shown in FIG. On the tooth surface 14, the right blade surface 7 of the next blade portion 4 located on the rear side in the traveling direction A of the one tooth 12 is a contact point P, and the right tooth surface 15 of the one tooth 12 is on the right tooth surface 15. The left blade surface 9 of the first blade portion 4 located on the side of the one tooth 12 in the traveling direction A is in contact with the contact portion Q, that is, in this state, the left and right blade surfaces 7 and 9 of the blade portion 4. And the left and right tooth surfaces 14 and 15 of the tooth (1 tooth) 12 of the work gear 11 come into contact at the contact points P and Q, respectively. Further, when the rack R advances from this state and the work gear 11 rotates, the contact points P and Q are changed in the tooth height direction as shown in FIGS. The left blade surface 9 of the first blade portion 4 and the right blade surface 7 of the next blade portion 4 are brought into contact with the left and right tooth surfaces 14, 15 of the first tooth 12, respectively, and the rotation direction of the first tooth 12 is B is the left tooth surface 9 of the next blade portion 4 on the right tooth surface 15 of the next tooth 12 located on the rear side, and the left tooth surface 14 of the next tooth 12 is further provided with the next blade portion 4. The right blade surface 7 of the blade portion 4 located on the rear side in the traveling direction A is brought into contact with each other, and when the next blade portion 4 reaches the contact point position, the state returns to the state of FIG.

Therefore, in this embodiment, as shown in FIG. 2G, only one tooth 12 has its right tooth surface 15 in contact with the left blade surface 9 of the first blade portion 4 on the traveling direction A side and the contact point Q. In addition, the left and right tooth surfaces 14 of the two teeth 12 except that the left tooth surface 14 is brought into contact with the right blade surface 7 of the next blade portion 4 on the rear side in the traveling direction A at the contact point P. , 15 are in contact with the right and left blade surfaces 7 and 9 of the blade portion 4 at a total of two contact points P and Q, respectively, that is, in all states, as described above, The contact point P between the right blade surface 7 and the left tooth surface 14 of the tooth 12 is equal to the contact point Q between the left blade surface 9 of the blade part 4 and the right tooth surface 15 of the tooth 12. In addition, with respect to one tooth 12 that is in contact with the blade portion 4, the left and right tooth surfaces 14 and 15 are always adjacent to each other at the contact points P and Q. That is the two are in contact with the right edge surface 7 and Hidariha surface 9 of the blade 4. However, in a gear cutting tool such as a hob cutter used in the present embodiment, the blade portion 4 is a rack R having a rotation locus around the axis O as described above, and the left and right blade surfaces 7 and 9 are teeth 12. The left and right tooth surfaces 14 and 15 are brought into contact with each other.

According to the gear cutting method configured as described above, the work gear 11 thus contacts the left and right tooth surfaces 14 and 15 of the teeth 12 with the same number of right and left blade surfaces 7 and 9 of the blade portion 4 of the tool body 1. Since the processing is performed while making contact at the points P and Q, the cutting resistance and stress acting on the teeth 12 from the left and right tooth surfaces 14 and 15 are canceled with each other at the time of the processing, and the contact surface pressure becomes substantially equal. For this reason, even when the mechanical rigidity of the apparatus itself such as the rotary shaft 13 to which the work gear 11 is attached and driven to rotate is low, or when the work gear 11 itself has low rigidity, the teeth 12 are left or right. By being strongly biased toward the side, fluctuations in the meshing state with the blade portion 4 can be suppressed and stabilized, and the meshed tooth surfaces 14 and 15 of the machined work gear 11 have such meshing. It is possible to prevent the occurrence of undulation due to the change of the state and to improve the processing accuracy.

Moreover, in this embodiment, the left and right tooth surfaces 14 and 15 of one tooth 12 are always in contact with the right blade surface 7 and the left blade surface 9 of the pair of blade portions 4 for processing. For this reason, even in the case where the tooth 12 itself has low rigidity among the work gears 11, the contact surface pressures acting on the left and right tooth surfaces 14 and 15 are made equal to prevent the occurrence of waviness more reliably. be able to. In the first embodiment, the case where the present invention is applied to the gear cutting method using a hob cutter as described above has been described. However, in addition to the above, the present invention can be applied, for example, around the axis of the blade portion. An electrodeposited worm-like tool that forms a rack R that travels straight in the traveling direction A by rotation, and the axis O while being driven to rotate around the axis O parallel to the center axis C of the work gear 11 while being driven to rotate in synchronization with each other. It is also possible to apply to a gear cutting method using a pinion cutter that is fed in the direction.

Here, FIG. 3 is thus shows a second embodiment of the gear cutting method of the present invention in the case hobs are pinion cutter. The pinion cutter is formed such that a plurality of (many) blade portions 22 form a gear shape on the outer periphery of a tool body 21 having a substantially disk shape rotated in the rotation direction T around an axis O. The end surface of the blade portion 22 facing the front end side in the direction of the axis O (the lower side in FIGS. 3A and 3C) is a rake face 23, and the axis line as shown in FIGS. 3B and 3D. When viewed from the front end side in the O direction, the side ridge portion on the rear side in the rotational direction T of the rake face 23 is a right cutting edge 24, and the side face of the cutting edge 22 connected to the rear end side of the right cutting edge 24 is the right side. The side edge of the rake face 23 on the rotation direction T side is a left cutting edge 26, and the side face of the cutting edge 22 connected to the rear end side of the left cutting edge 26 is a left cutting edge 27. .

  In such a gear cutting method using a pinion cutter, the tool body 21 is arranged so that its axis O is parallel to the central axis C of the workpiece gear 11 as described above, and in the rotational direction T around the axis O. The blade portion 22 meshes with the teeth 12 of the work gear 11 that is reciprocatingly driven in the direction of the axis O while being forcibly rotated, and is forcibly rotated by the rotation shaft 13 in the rotation direction B around the central axis C. However, the tool main body 21 and the work gear 11 are relatively moved so that the axis O and the central axis C approach each other, and when the tool main body 21 moves forward in the axis O direction, The left and right tooth surfaces 14 and 15 of the tooth 12 of the work gear 11 are cut by the left and right cutting edges 24 and 26. That is, in this embodiment, the portion where the tooth 12 of the work gear 11 and the blade portion 22 of the tool body 21 are in contact with each other is scooped along the central axis C with the axis O of the tool body 21 facing down. When viewed from the side facing the surface 23 (when viewed from the top of the cutting gear 11 and the tool body 21 downward in FIG. 3D), the blade surface on the right side of the blade portion 22 at this contact portion Is the right blade surface 25, the left tooth surface of the tooth 12 in contact with this is the left tooth surface 14, and conversely the left blade surface of the blade portion 22 is the left blade surface 27. The tooth surface located on the right side of the tooth 12 in contact with the right tooth surface 15 is the right tooth surface 15.

  And at this time, also in this embodiment, the location where the right blade surface 25 of the blade portion 22 and the left tooth surface 14 of the tooth 12 contact, the left blade surface 27 of the blade portion 22 and the right tooth surface 15 of the tooth 12. Therefore, in the second embodiment, as in the case of the hob cutter of the first embodiment, the blade portion 22 and the teeth 12 are engaged with each other. It is possible to prevent fluctuations from occurring and prevent waviness from occurring on the tooth surfaces 14 and 15 of the work gear 11, thereby improving machining accuracy.

In addition, as in these embodiments, the position where the right blade surface of the blade portion of the gear cutting tool and the left tooth surface of the tooth of the gear to be cut are in contact with the left blade surface of the blade portion of the gear cutting tool and the workpiece. In order to bring the blade portion and the teeth into contact with each other so that the same number of locations of contact with the right tooth surface of the gear teeth are used, the gear cutting tool is a hob cutter or electrodeposition as in the first embodiment. If it is a worm-like tool, adjust the dislocation pressure angle . Further, when the gear cutting tool is a pinion cutter as in the second embodiment , the dislocation coefficient is adjusted .

Examples of the present invention will be given below to demonstrate the effects of the present invention. In this embodiment, hobs as in the second embodiment when a pinion cutter, for the left and right tooth surfaces of the workpiece gear which is processed to measure the waviness of the tooth. The result is shown in FIG. In addition, as a comparative example to this embodiment, the present invention is not applied, that is, the position where the right tooth surface of the engaged blade portion and the left tooth surface of the tooth contact each other, the left tooth surface of the blade portion, and the right tooth of the tooth The gears of the work gear are cut under the same conditions as in the embodiment, except that the number of places in contact with the surface is not the same, and there are different states. The undulation of the tooth profile was measured. The result is shown in FIG.

  In these examples and comparative examples, the work gear has a module of 2.4848 mm, the number of teeth of 13, a pressure angle of 19 °, a torsion angle of 0 °, an outer diameter of 39.9 mm, a pitch circle diameter of 32.2998 mm, a tooth bottom. This is a spur gear with a diameter of 29.65 mm, tooth width of 16.8 mm, straddle tooth thickness of 19.808 mm, the number of straddles of 3 and a shift coefficient of 0.599, 4 of 13 teeth (any one tooth is the first) FIG. 4 and FIG. 5 show the undulations and averages of the respective tooth profiles and the variations thereof for the first, fourth, eighth and eleventh teeth). In the scales of FIGS. 4 and 5, one scale in the horizontal axis direction of the broken mesh is 0.625 mm, and one scale in the vertical direction is 10 μm. In addition, the pinion cutter used in these examples and comparative examples has the same number of teeth, 72 torsion angles, 0 ° torsional angle, and 9 pieces, and in the comparative example, the outer diameter is 186.3782 mm and the tooth thickness is 65.2538 mm. In contrast, in the embodiment, the outer diameter is 181.311 mm and the tooth thickness is 63.524 mm.

  From these results shown in FIGS. 4 and 5, in the comparative example to which the present invention is not applied, the left and right tooth surfaces and the undulation are large for all measured teeth, and this tendency is particularly remarkable in the left tooth surface. The grade specified in JIS B 1702 was about 5-7. On the other hand, in the example to which the present invention is applied, the undulation is clearly suppressed on both the left and right tooth surfaces as compared with the comparative example, and the above JIS grade is particularly high at 1-2 on the left tooth surface. It can be seen that precision gear cutting is performed.

It is a figure which shows 1st Embodiment of the gear cutting method of this invention. In the embodiment shown in FIG. 1, it is a figure which shows the contact state of the left and right blade surfaces 7 and 9 of the blade part 4 of the tool main body 1, and the left and right tooth surfaces 14 and 15 of the tooth | gear 12 of the to-be-cut gear 11. FIG. (A) A schematic side view of a gear cutting tool (pinion cutter) showing a second embodiment of the gear cutting processing method of the present invention, (b) the blade portion 22 of the gear cutting tool shown in FIG. An enlarged view seen from the tip side (rake face 23 side), (c) a partially broken longitudinal sectional view for explaining the gear cutting method, and (d) FIG. (C) from the tip side (rake face 23 side) in the axis O direction. FIG. It is a figure which shows the wave | undulation of the tooth surface of the cut gear by the Example of this invention. It is a figure which shows the wave | undulation of the tooth surface of the cut gear by the comparative example with respect to the Example shown in FIG.

Explanation of symbols

1,21 Tool body 4,22 Blade portion 5,23 Rake surface 7,25 Right blade surface of blade portions 4,22 9,27 Left blade surface of blade portions 4,22 11 Work gear 12 Tooth 14 Left of tooth 12 Tooth surface 15 Right tooth surface of tooth 12 O Axis of tool bodies 1 and 21 T Rotation direction of tool bodies 1 and 21 R Rack formed by projecting blade 4 A Rack R traveling direction C Workpiece gear 11 Central axis B Rotation direction of work gear 11 P Contact point between right blade surface 7 of blade portion 4 and left tooth surface 14 of tooth 12 Q Left blade surface 9 of blade portion 4 and right tooth surface 15 of tooth 12 Contact point

Claims (2)

A gear cutting method for performing gear cutting by meshing a tooth of a gear to be cut with a tooth of a work gear, wherein the gear cutting tool is a hob cutter or an electrodeposition worm-like tool, and is rotated and driven. By driving the gear cutting tool synchronously with the cutting gear, the blade surface of the gear cutting tool and the tooth surface of the gear to be cut are brought into contact with each other, and the shift pressure angle is adjusted. thus the engaged condition, the number of tooth surface right edge surface of the hob is meshing with該被cutting gear, the number of tooth surfaces that left blade surface meshes with該被cut gear of the gear cutting tool always A gear cutting method characterized in that the same number of teeth are contacted and the left and right tooth surfaces of one tooth are always in contact with the right blade surface and the left blade surface . A gear cutting method for performing gear cutting by engaging a tooth of a gear cutting tool with a tooth of a workpiece gear, wherein the gear cutting tool is a pinion cutter, When the gear cutting tool is driven in synchronization, the blade surface of the gear cutting tool and the tooth surface of the work gear are brought into contact with each other and meshed, and the dislocation coefficient is adjusted, thereby being meshed. In this case, the number of tooth surfaces with which the right blade surface of the gear cutting tool meshes with the workpiece gear and the number of tooth surfaces with which the left blade surface of the gear cutting tool meshes with the workpiece gear are always the same. In addition , the tooth cutting method is characterized in that the processing is performed with the right and left tooth surfaces always contacting the right blade surface and the left blade surface with respect to one tooth.

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