JP2020019096A - Gear processing method - Google Patents

Abstract

To provide a gear processing method by a skiving cutter, capable of applying a crowning treatment to a tooth flank of a gear, or creating a bias tooth flank, even if an evacuation space of a tool is very small after finish of processing, by using a conventional machine tool and the skiving cutter (tool).SOLUTION: In a gear processing method for processing a gear to either of an inner peripheral surface and an outer peripheral surface of a work material W, while rotating mutually the work material W and a skiving cutter 10 in the state where a revolving shaft Oof the work material W and a revolving shaft Oof the skiving cutter 10 are crossed mutually, the gear is processed, while moving the skiving cutter 10 along an axial direction and a circumferential direction of the work material W.SELECTED DRAWING: Figure 2

Description

The present invention relates to a gear processing method using a gear cutting tool (skiving cutter).

2. Description of the Related Art In recent years, crowning processing for bias tooth profiles and tooth surfaces has been receiving attention in order to reduce noise generated by contact between tooth surfaces of gear components incorporated in a reduction gear or the like (see Patent Documents 1 and 2).

Here, the bias tooth profile refers to a tooth profile in which the curved shape of the tooth surface is changed without changing the tooth height. In addition, the crowning processing refers to a processing mode in which a curved surface shape of a tooth surface is changed by providing a height difference in a tooth trace direction.

Heretofore, it has been possible to easily and reliably create a complex tooth surface such as a bias tooth surface by using a worm-shaped tool such as a hob when performing a crowning process on a gear component. Reference 3). In addition, when a bias tooth surface is applied to a gear component, it can be created using a shaving cutter or a honing grindstone.

However, with a worm-like tool such as a hob, a so-called external gear having a tooth surface on the outer periphery can be created, but an internal gear can be created on the inner peripheral surface of the work material. Did not. In addition, an external gear cannot be created using a tool such as a hob for a stepped work material having a different outer diameter even if the work material is an external gear.

Therefore, when creating a tooth surface using a skiving cutter, if a machine tool with five or more axes is used, in addition to creating an internal gear, it is also possible to correct the shape of the tooth profile and tooth traces and improve the accuracy of the tooth surface. It is now possible. (See Patent Documents 4 and 5 and Non-Patent Document 1).

JP-A-10-89442 JP-T-2002-530211 JP-A-2002-144148 JP-A-2017-124472 JP 2017-144502 A

Yasushi Kasai, "Features of skiving processing and tool technology", Mechanical technology, Nikkan Kogyo Shimbun, Vol. 66, No. 7, p. 52-55

However, the stepped gear built into the reduction gear etc. requires more complicated processing than the processing of ordinary spur gears and helical gears in order to avoid interference between the stepped part of the work material and the tool. Become.

In particular, when the allowance of the stepped gear (space for retracting the tool after the completion of the gear cutting) is very narrow, even if a 5-axis or more machine tool is used, ordinary gear cutting with a skiving cutter is not possible. It has been difficult to apply a crowning treatment to the tooth surface or create a bias tooth surface.

Therefore, in the present invention, a conventional machine tool and skiving cutter can be used to perform a crowning process on a tooth surface or to create a bias tooth surface even when the removal allowance after processing of a stepped gear is very narrow. It is an object to provide a gear processing method using a bing cutter.

In order to solve the above-described problem, the gear machining method of the present invention is a method of rotating a work material and a skiving cutter while rotating the work material and the skiving cutter in a state where the rotation axis of the work material and the rotation axis of the skiving cutter cross each other. In a gear machining method for machining a gear on either the inner peripheral surface or the outer peripheral surface of a work material, a method is employed in which a gear is machined while moving a skiving cutter along the axial direction and the circumferential direction of the work material. Further, the gear may be processed while the skiving cutter is moved in the radial direction in addition to the axial direction and the circumferential direction of the work material.

With the gear machining method of the present invention, crowning processing and creation of bias tooth surfaces can be freely performed not only on normal external gears and internal gears but also on bevel gears and stepped work materials (internal gears and external gears). This has the effect of being able to perform

FIG. 4 is a schematic plan view showing the movement of the skiving cutter 10 during gear processing according to the present invention. FIG. 2 is a view on arrow P shown in FIG. 1. It is a schematic plan view showing movement of skiving cutter 20 at the time of conventional gear processing. FIG. 4 is a view as viewed from an arrow N shown in FIG. 3. It is a schematic perspective view which shows the tooth surface of a work material after gear processing of this invention. (A)-(c) is a schematic cross section of each tooth profile in the tooth surface shown in FIG. (D)-(f) is a schematic cross section of each tooth trace in the tooth surface shown in FIG.

The gear processing method of the present invention will be described with reference to the drawings. FIG. 1 is a schematic plan view at the time of processing a gear (stepped gear) according to an embodiment of the present invention, and FIG. FIG. 3 is a schematic plan view of a conventional gear during machining, and FIG.

In the conventional gear (external gear) during processing, skiving cutter 20 and the work material W is being rotated about a respective rotation axis O _20, O _W, skiving cutter 20, as shown in FIGS. 3 and 4 The workpiece W is directly moved vertically downward from above. That skiving cutter 20 is moved along the rotational axis O _W of the workpiece W. At this time, when the position of the skiving cutter 20 moves vertically downward as shown in FIG. 4, the skiving cutter 20 does not move the work W in the circumferential direction.

In contrast, skiving cutter 10 and the work material W in the gear (stepped gears) processing steps of the present invention while rotating around a respective rotation axis O _10, O _W, skiving cutter 10 is gear-cutting process As it proceeds, it also moves in the circumferential direction of the workpiece W as shown in FIGS. The movement of the skiving cutter 10 in the axial direction of the workpiece W moves obliquely downward as shown in FIG.

Next, the form of the tooth surface of the gear manufactured by the gear working method of the present invention shown in FIGS. 1 and 2 will be described with reference to the drawings. FIG. 5 is a schematic perspective view of a tooth surface of a gear manufactured by the gear processing method of the present invention. 6 (a) to 6 (c) are schematic sectional views of each tooth profile on the tooth surface shown in FIG. 5, and FIGS. 7 (d) to 7 (f) are schematic sectional views of each tooth trace. The hatched portions in FIG. 5 indicate portions where the tooth surface manufactured by the gear machining method of the present invention has changed compared to the form of the tooth surface manufactured by the conventional gear machining method.

First, as for the gear (work material) manufactured by the gear machining method of the present invention shown in FIGS. 1 and 2, the ridge line on the obtuse angle side (the back side in the drawing) of the gear is A1-Q as shown in FIG. −D1, and the ridge of the tooth profile of the gear (work material) manufactured by the conventional gear machining method shown in FIGS. 3 and 4 is AQD. In the tooth profile manufactured by the gear machining method of the present invention, as shown in FIGS. 6A and 7D and 7F, the position A1 of the tooth tip moves outward from the position A of the conventional tooth tip. However, the tooth root position D1 moves inward from the conventional tooth root position D.

The ridge line on the acute angle side (front side in the drawing) of the gear manufactured by the gear processing method of the present invention is C1-TF1, which is the tooth profile of the gear (work material) manufactured by the conventional gear processing method. Is CTF. That is, as shown in FIG. 6C and FIGS. 7D and 7F, the tooth tip position C1 is moved inward from the conventional tooth tip position C, and the tooth root position F1 is Move to the outside of the tooth root position F. The intermediate position of the tooth profile (ridge line BE) does not move from the positions of the points Q and T before and after the gear machining as shown in FIGS. No change.

As described above, it is possible to create a so-called bias tooth profile in which the positions of the tooth tip and the tooth root can be freely adjusted at an arbitrary position on the tooth surface with respect to the external gear and the internal gear by the gear machining method of the present invention.

10,20 Skiving cutter W Work material (gear)
O _{10, O 20} rotation axis of the skiving cutter _{O W} rotary axis of the workpiece

Claims (2)

While rotating the work material and the skiving cutter in a state where the rotation axis of the work material and the rotation axis of the skiving cutter intersect each other, a gear is provided on either the inner circumferential surface or the outer circumferential surface of the work material while rotating the work material and the skiving cutter with each other. A gear processing method for processing
A gear machining method, wherein the gear is machined while moving the skiving cutter in an axial direction and a circumferential direction of the work material. The gear cutting method according to claim 1, wherein the skiving cutter is also moved in a radial direction of the work material.

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