JPS582009B2 - Shaving cutter for gears - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The invention of this application prevents the cutter blade from sinking into the tooth surface of the gear to be cut and from slipping when cutting a high-hardness gear.
This invention relates to a shaving cutter for gears that enables efficient finishing without abrasion.In particular, the shaving cutter has only one land for cutting, and the part to be cut can surely bite into the land. , and the gear shaving cutter is based on the fact that the load on the contact tooth surface is small, and furthermore, the amount of biting is prevented from exceeding a certain amount, so that the load on the land is not excessive. This is such an invention.

Conventionally, gear shaving cutters have been widely used in gear manufacturing as tools for efficiently finishing pre-hobbed gears with high precision.

However, as shown in FIGS. 1 and 2, a commonly used shaving cutter 1 has slots 3 at appropriate pitches extending from the top 2 of the tooth portion, through the tooth surface, and toward the base.
The intersection line 5 between the slot 3 and the land 4 acts as a cutting edge, and as shown in FIG. 4, 4, 4... slightly bite into the tooth surface 7 to be cut, and the tooth surface 7 to be cut is ground by a minute amount δ1 due to the slip S1 in the axial direction (tooth line direction) that occurs when rotating on the offset shaft. Take it.

However, as the hardness of the tooth surface 7 to be cut increases, the land 4 no longer bites into the tooth surface 7 to be cut, and the tooth surface 7 to be cut is only burnished.

To deal with this, it is possible to increase the tooth surface load in order to make the land 4 bite into the tooth surface 7 to be cut, but this is due to the deflection of the teeth of the shaving cutter 1 and the gear to be cut, the deflection of the shaft, Furthermore, there is a risk that the land 4 may be damaged.

As described above, conventional shaving cutters have drawbacks that generally make it impossible to use them for finishing gears made of high-hardness materials. Although hobbing has become possible for treated gears, in order to obtain high-precision gears, the final finishing must be carried out exclusively by gear grinding. The equipment is expensive, and in addition, production efficiency is extremely low, and large gears such as reduction gears for ships are very expensive, and they are not suitable for mass-produced gears. there were.

The purpose of the invention of this application is to solve the above-mentioned problems based on the prior art, and to solve the problems of the above-mentioned prior art, and to solve the problem of high hardness gears (Brinell hardness HB = 500 or more), which are considered impossible to cut with gear shaving cutters. A gear shaving cutter that can also cut medium hard gears (Brinell hardness HB=5
The purpose of the present invention is to provide an excellent gear shaving cutter that benefits the field of gear use in the processing industry by enabling cutting equivalent to that of shaving 00 or less. It is an object of the present invention to provide an excellent gear shaving cutter that can increase the contact surface pressure of the cutting blade and improve cutting performance by using only one shaving cutter.

The structure of the invention of this application in accordance with the above-mentioned object is that only one bladed land of the gear shaving cutter is provided in the tooth surface from the top to the base in the form of a strip with a cross section of the letter ``■''. The basic idea is to ensure that the cutter bites into the workpiece material and cutting is performed reliably, and that the required contact tooth surface load is small, and that the deformation of the cutter, cut gear, and processing machine is minimized. Furthermore, a bladeless land is provided on both ends of the tooth portion of the gear shaving cutter in parallel with the bladed land, and when cutting, the bladed land has a cutting amount that is equal to or greater than the end difference between the bladeless land and the bladed land. The gist of this is that technical measures have been taken to ensure that this is not the case.

Next, an embodiment of the invention of this application will be described below based on the drawings from FIG. 3 onwards.

In the embodiment shown in FIG. 3, reference numeral 8 denotes a shaving cutter for cutting gears, which constitutes the gist of the invention of this application, and the shaving cutter 8 cuts from the center of the top 9 of the teeth along the tooth surface toward the base. Only one bladed land 10 for the purpose of cutting is provided, and the cross section is shaped like the letter ``■''. ing.

The intersecting line 12 between the edged land 10 and the cut edge 11 performs a cutting action as the cutting edge.

According to experiments, the land width of the bladed land 10 is Q.
It has been found that if it is less than 3 mm, the edged land 10 will bend and the machining accuracy will decrease, and if it is more than 1.5 mm, the load on the blade surface will increase.

In the above configuration, when the shaving cutter 8 is used for gear finish cutting as shown in FIG. Since this is only the portion formed by the above-mentioned edged land 10 and its contact area is small, the edged land 10 easily bites into the tooth surface 13 to be cut with a small tooth surface load, and the slight amount δ2 is removed by the rotational sliding S2. Therefore, the edged land 10 reliably performs gear cutting,
Accurate cutting can be performed without unnecessarily increasing the cutting force.

Further, the embodiment shown in FIGS. 5 and 6 is a shaving cutter 8'.
A bladed land 10' having a square cross section similar to that described above is provided for the purpose of cutting from the top part 9' of the tooth part 9' toward the base along the tooth surface, and at both ends of the tooth part 9'. A bladeless land 14,1 that is not intended for cutting is parallel to the bladed land 10'.
4 is provided.

A dent 11' is formed on the tooth surface between the edged land 10' and the non-edged lands 14, 14, and an intersection line 12' between the edged land 10' and the edge 11'. Only the cutting edge performs the cutting action.

That is, as shown in FIG. 6, in the cutting state, at the beginning of cutting, the contact area between the shaving cutter 9' and the tooth surface 13' to be cut is only the edged land 10' whose purpose is to cut the center of the tooth surface. As in the previous embodiment, since the contact area is small, it easily bites into the tooth surface 13' to be cut with a small tooth surface load, and a small amount is scraped off by the rotational sliding S3.

When this cutting amount reaches δ3, the bladeless lands 14, 14, which are not intended for cutting, on both ends of the tooth surface come into contact, and the toothed land 10/ will no longer bite into the tooth surface 13' to be cut. It disappears.

Therefore, the bladeless land 14, which is not intended for cutting,
14 improves the guiding performance of the shaving cutter 8' in the tooth line direction, and prevents the cutting edge from being damaged due to excessive biting of the edged land 10'.

As mentioned above, according to the invention of this application, by providing only one edged land on the tooth portion of the shaving cutter, the edged land can easily bite into the tooth with a small tooth surface load. An excellent effect of accurate finish cutting is achieved.

In addition, since the cutting edge shape of the teeth is single, cemented carbide or ceramic can be used as the cutting edge material, and this cutting edge piece (chip) can be attached to the cutter body by brazing or using a clamp mechanism. If it is attached to the teeth, it has the effect of making gear cutting more efficient.

Furthermore, this shaving cutter is ideal for shaving high-hardness gears, and allows high-precision, high-hardness gears, such as hardened and ground gears, which were previously very expensive, to be manufactured inexpensively and efficiently through shaving. It becomes possible.

In addition, by providing bladeless lands at both ends of the tooth, when performing gear cutting, the amount of cut of the bladed land can be suppressed by the end face difference between the bladeless land and the bladed land at the center of the tooth. Therefore, the cutting resistance of the edged land can be kept below a certain level, and cutting operations can be performed safely without accidentally destroying the edged land. Excellent effects are produced.

[Brief explanation of drawings]

Figures 1 and 2 are explanatory diagrams of a shaving cutter based on the prior art. Figure 1 is a perspective view of its teeth, Figure 2 is an explanatory side view showing its cutting state, and Figures 3 and below are illustrations of this shaving cutter. Embodiments of the invention of the application are shown, FIG. 3 is a perspective view of the tooth portion, and FIG.
FIG. 5 is an explanatory side view showing the cutting state, FIGS. 5 and 6 show other embodiments, FIG. 5 is a perspective view of the tooth portion, and FIG. 6 is an explanatory side view showing the cutting state. 2, 9, 9'... Top, 1, 8, 8'...
...Gear shaving cutter, 10,10'...
...Blade land, 14,14...Bladeless land.

Claims (1)

[Scope of Claims] 1. One edged land protruding from the tooth surface in the central part of the tooth part in a cross-sectional shape of the letter ``■'' and extending from the top to the base has a land width of 0.
A shaving cutter for a gear, characterized in that the cutter is formed to have a thickness of 3 to 1.5 mm. 2. At the center of the tooth part, one edged land protruding from the tooth surface in the shape of a square cross section and extending from the top to the base has a land width of 0.
A shaving cutter for a gear, characterized in that the tooth is formed to have a thickness of 3 to 1.5 mm, and a non-blade land is provided at both ends of the tooth portion in parallel to the blade land.