JP4561141B2 - Dressing method for internal gear-shaped grinding wheel - Google Patents

Description

  The present invention relates to a method of dressing an internal gear-shaped grindstone used for gear honing of a work gear with a dressing gear.

In general, in gear honing that finishes a heat-treated gear (work gear) with an internal gear-like grindstone, dressing the internal gear-like grindstone after gear honing a predetermined number of work gears with a dressing gear. Become.
The dressing gear is made by fixing (electrodepositing) hard abrasive grains such as diamond abrasive grains on the surface of a plurality of teeth of a base metal having a gear shape made of steel or the like using a plating layer as a support layer, By grinding the tooth bottom surface of the teeth of the internal gear-like grindstone with the outer peripheral surface of the teeth of the dressing gear, and grinding the tooth surface of the teeth of the internal gear-like grindstone with the tooth surface of the teeth of the dressing gear, (For example, refer to Patent Document 1).
Further, in such gear honing processing of the work gear, the shape of the dressing gear for dressing the internal gear-like grindstone is transferred as it is to the work gear via the internal gear-like grindstone. The specifications of the dressing gear are set to be substantially the same as the specifications of the work gear to be finished by the internal gear-like grindstone.
Japanese Patent No. 2668313

By the way, regarding the shape of the work gear to be gear-honed by the internal gear-like grindstone, when the tooth tip width (the width of the outer peripheral surface) is small, as described above, the specifications of the work gear and the dressing gear Since the original is set to be substantially the same, the width of the tooth tip of the dressing gear must be set small.
Then, the dressing gear constituted by fixing hard abrasive grains on the surface of the base metal teeth needs to set the tooth tip width of the base metal itself to be smaller, so the dressing life tends to be shortened. In addition to this, it is difficult to fix hard abrasive grains to the outer peripheral surface of the base metal teeth, and in particular, if hard abrasive grains having a large particle size are fixed to the outer peripheral surface, it may become impossible to manufacture a dressing gear. Even there was.

The present invention has been made in view of the above problems, and even if the tooth tip width of the gear to be machined by gear honing is set to be small, the dressing life of the internal gear-shaped grinding wheel by the dressing gear is improved. suppresses the short life, and to provide a dressing how the gear-shaped grinding wheel among without requiring difficult to manufacture the dressing gear.

  In order to solve the above-mentioned problems and achieve such an object, the dressing method for an internal gear-shaped grindstone according to the present invention is such that the internal gear-shaped grindstone used for gear honing processing of a work gear is gear-shaped. A method of dressing with a dressing gear in which hard abrasive grains are fixed to teeth of a base metal, wherein the internal gear-shaped grindstone is dressed by the dressing gear having a shift coefficient smaller than the shift coefficient of the work gear. It is characterized by this.

According to the present invention as described above, since the shift coefficient of the dressing gear is set smaller than the shift coefficient of the work gear, the tooth tip width of the dressing gear tooth is larger than the tooth tip width of the work gear tooth. Accordingly, the shortening of the dressing life can be suppressed, and the hard abrasive grains can be securely fixed to the outer peripheral surface of the base metal teeth.
In this manner, for example, the dressing gear and the internal gear-like grindstone at the time of dressing, although the specifications of the dressing gear and the specifications of the work gear are not set substantially the same. By adopting a method such as setting the crossing angle different from the crossing angle between the work gear and the internal gear-like grindstone at the time of the gear honing, the dressing gear and the internal gear-like grindstone are used. The meshing state can be satisfactorily satisfied, and the tooth profile accuracy of the work gear finished by the internal gear-like grindstone is not impaired.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
As shown in FIG. 1, the dressing gear 1 used in the present embodiment has a base metal 2 having a gear shape made of, for example, a steel material, and a plurality of dressing gears 1 are provided on the outer periphery of the base metal 2 at regular intervals. As shown in FIG. 2, hard abrasive grains 5 such as diamond abrasive grains are fixed (electrodeposited) to the outer peripheral surface 3A and the tooth surface 3B of the teeth 3 as shown in FIG. .

  As shown in FIG. 3, such a dressing gear 1 has a predetermined crossing angle α between its axis O and the axis P of the internal gear-shaped grindstone 6, so that the internal gear-shaped grindstone 6 The tooth bottom surface 7A (see FIG. 4) of the tooth 7 of the internal gear-like grindstone 6 is ground by the outer peripheral surface 3A of the tooth 3 of the dressing gear 1 and meshed with the tooth surface 3B of the tooth 3 of the dressing gear 1. By grinding the tooth surface 7B of the tooth 7 of the grindstone 6 (see FIG. 4), the internal gear-shaped grindstone 6 is dressed.

  Then, the heat-treated work gear 10 to be subjected to the gear honing process will be described by replacing the dressing gear 1 in FIG. 3. A predetermined crossing angle β between the axis O1 and the axis P of the internal gear-like grindstone 6 will be described. Thus, the work gear 10 is gear-honed by the internal gear-shaped grindstone 6 by being engaged with the dressed internal gear-shaped grindstone 6.

  Here, in this embodiment, the shift coefficient of the dressing gear 1 meshed with the internal gear-like grindstone 6 and the shift coefficient of the work gear 10 similarly meshed with the internal gear-shaped grindstone 6 are the same as in the prior art. Is set so that the shift coefficient of the dressing gear 1 is smaller than the shift coefficient of the work gear 10.

  Furthermore, in this embodiment, as in the prior art, the axis crossing angle α between the dressing gear 1 and the internal gear-like grindstone 6 at the time of dressing, and the axis of the work gear 10 and the internal gear-like grindstone 6 at the time of gear honing. The crossing angle β is not set to be the same, but the crossing angle α between the dressing gear 1 and the internal gear-like grindstone 6 is the axial crossing angle between the work gear 10 and the internal gear-like grindstone 6. It is set differently from β.

  In the present embodiment as described above, the tip width of the tooth 3 of the dressing gear 1 (the width of the outer peripheral surface 3A) is set by setting the shift coefficient of the dressing gear 1 smaller than the shift coefficient of the work gear 10. The tooth tip width of the tooth of the work gear 10 can be made larger.

  That is, as shown in the schematic explanatory diagram of FIG. 5, when the shift coefficient of the dressing gear 1 is set to be smaller than the shift coefficient of the work gear 10 (indicated by the solid line in FIG. 5). When the dressing gear 1 has a dislocation coefficient set to be the same as the dislocation coefficient of the work gear 10 (indicated by a one-dot chain line in FIG. 5), the outer diameter of the dressing gear 1 is The region used for grinding on the tooth surface 3B becomes smaller and moves from the portion indicated by reference numeral H1 in FIG. 5 to the portion indicated by reference numeral H2, and accordingly, the width of the outer peripheral surface 3A is changed to that shown in FIG. The length increases from the length indicated by the reference symbol T1 to the length indicated by the reference symbol T2.

  Thus, since the tooth tip width of the tooth 3 of the dressing gear 1 can be made larger than the tooth tip width of the tooth of the work gear 10, the tooth tip of the work gear 10 to be gear honing processed. Even when the width is set to be small, it is not necessary to set the tip width of the tooth 3 of the base metal 2 itself so small, and it is possible to suppress the dressing life from being shortened. Even the hard abrasive grains 5 having a large particle diameter can be securely fixed to the outer peripheral surface 3A of the teeth 3 of the base metal 2, and the manufacturing of the dressing gear 1 is not difficult.

  In addition, although the specifications of the dressing gear 1 and the specifications of the work gear 10 are not set substantially the same as described above, in the present embodiment, the dressing gear 1 and the internal gear shape at the time of dressing are set. Since the axis crossing angle α with the grindstone 6 is set differently from the axis crossing angle β between the work gear 10 and the internal gear-like grindstone 6 at the time of gear honing, the dressing gear 1 and the internal gear-like grindstone 6 Can be satisfactorily satisfied, and the tooth profile accuracy of the work gear 10 finished by the internal gear-like grindstone 6 can be maintained in a good state.

<Experimental example>
The dressing method of the internal gear-like grindstone 6 according to an example of the present invention and the conventional dressing method of the internal gear-like grindstone 6 will be specifically compared.
First, a dressing gear 1 (conventional example) having an internal gear-like grindstone 6 for gear honing a work gear 10 having the following specifications, having the same shift coefficient as that of the work gear 10, And dressing was performed by the dressing gear 1 (Examples 1 and 2) having a shift coefficient smaller than the shift coefficient of the work gear 10.
Here, about the specifications of the work gear 10,
-Module m = 2.55,
・ Pressure angle PA = 17.5 °,
・ Torsion angle = 32.5 °,
・ Number of teeth NT = 18
-Dislocation coefficient = 0.316,
Is set to

  As shown in Table 1, with respect to the conventional example which is the dressing gear 1 having the same shift coefficient as that of the work gear 10, a shift coefficient smaller by 0.05 than the shift coefficient of the work gear 10 is set. The dressing gear 1 according to the first embodiment has an outer diameter smaller than that of the conventional example by 0.255 mm, an engagement circle diameter with the internal gear-like grindstone 6 is increased by 0.089 mm, and the tooth tip width It can be seen that is increased by 0.061 mm. In addition, the axis crossing angle α between the dressing gear 1 and the internal gear-like grindstone 6 of Example 1 is set larger by 0.015 ° than the conventional example.

  Similarly, as shown in Table 1, with respect to the conventional example which is the dressing gear 1 having the same shift coefficient as that of the work gear 10, the shift coefficient smaller by 0.1 than the shift coefficient of the work gear 10. In Example 2, which is a dressing gear 1 having an outer diameter, the outer diameter is smaller than that of the conventional example by 0.556 m, the meshing circle diameter with the internal gear-shaped grindstone 6 is increased by 0.178 mm, and the tooth tip is further increased. It can be seen that the width is increased by 0.117 mm. Note that the crossing angle α between the dressing gear 1 of the second embodiment and the internal gear-like grindstone 6 is set to be 0.03 ° larger than that of the conventional example.

It is a perspective view which shows the dressing gear used by embodiment of this invention. It is a principal part expanded sectional view which shows the tooth | gear of the dressing gear used by embodiment of this invention. It is a schematic explanatory drawing which shows a mode that an internal gear-shaped grindstone is dressed with the dressing gear shown in FIG. It is a principal part expanded sectional view which shows the internal-gear-like grindstone dressed by the dressing gear shown in FIG. It is a schematic explanatory drawing for demonstrating notionally the dressing method of the internal-gear-like grindstone by embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Diamond dressing gear 2 Base metal 3 Tooth 3A Outer peripheral surface 3B Tooth surface 4 Plating layer 5 Diamond abrasive grain 6 Internal gear-like grindstone 7 Tooth 7A Tooth bottom 7B Tooth surface O Dressing gear axis O1 Work gear axis A P Internal gear shape Wheel axis α Crossing angle between dressing gear and internal gear wheel β Crossing angle between work gear and internal gear wheel

Claims (2)

A method of dressing an internal gear-shaped grindstone used for gear honing processing of a work gear with a dressing gear in which hard abrasive grains are fixed to teeth of a base metal having a gear shape,
A dressing method for an internal gear-shaped grindstone, wherein the internal gear-shaped grindstone is dressed by the dressing gear having a dislocation coefficient smaller than the dislocation coefficient of the work gear. In the dressing method of the internal gear-shaped grindstone according to claim 1,
An axis crossing angle between the dressing gear and the internal gear-like grindstone at the time of dressing is set differently from an axis crossing angle between the work gear and the internal gear-like grindstone at the time of the gear honing. A dressing method for an internal gear-like grindstone.

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