JPS6052220A - Semi-topping pinion cutter and its tooth profile grinding wheel - Google Patents

Abstract

PURPOSE:To improve the efficiency of tooth profile grinding, by forming the dedendum of a cutting part into a convex circular form in its central direction along a tooth trace direction as well as thinning the tooth thickness as far as a corresponding portion for an increase in addendum for that. CONSTITUTION:A chamfering part 7b, which grinds a chamfering cutting part 1a of a pinion cutter 1, is formed in the outer edge part of a grinding wheel 1. In order to grind a tooth surface, a tooth profile grinding surface 7a of the grinding wheel 7 is set down to a conic surface at a conic angle beta, and this grinding wheel 7 is attached to the tooth profile grinding surface 7a after this surface 7a is shifted in a virtual rack surface whereby gear form grinding takes place as in the same way heretofore. Since tooth thickness becomes thinned in conformity with a variation in addendum attending on wear, accurate tip chamfering is always performable.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semi-topping pinion cutter that is easy to manufacture and a tooth profile grinding wheel used for manufacturing the same.

Figure 1 is a diagram showing the principle of the conventional tooth profile generating grinding method for pinion cutters. Grinding wheels 3 and 4 are positioned on the tooth surface 2, and the tooth profile grinding surfaces 3a and 4a, which have flat side surfaces, are likened to the tooth surfaces of a rack, and are moved relative to each other to perform generating grinding of the tooth profile. On the other hand, in recent years, in order to simultaneously chamfer the tooth tip without boiling the tooth surface of the gear, semi-topping is provided with a chamfering blade part 1a with a different inclination angle of the cutting edge at the root of the tooth of the pinion cutter l. As the number of pinion cutters 1 is increased, the grinding of the peripheral cutting edge portion 1a is carried out by providing chamfered portions 3b and 4b on the outer edges of the grindstones 3 and 4. This type of pinion cutter tooth profile grinder does not move the pinion cutter l and the grinding wheels 3 and 4 relative to each other in the direction of the teeth of the pinion cutter. According to the outer shape of the tooth, it has an arcuate shape that is convex toward the center along the tooth trace direction.

FIGS. 3 and 4 show cross-sectional views of a binion cutter I created by this conventional binion cutter tooth profile grinder. Fig. 3 is a partial sectional view seen from the side, and Fig. 4 is a section 1 (J1 side view) cut on the pitch line.As shown in Fig. 3,
The blade life distance f' from the blade surface ib of the outpost and the blade 1eib,
(The tooth height from the tooth root to the tooth tip 1 at the location within L t is the same base.) If you select the value, then set these two points to 1.
The tooth root actually ground with respect to the standard tooth root heel 5 inclined at an angle θ is convex toward the center of the binion cutter 1 with a radius corresponding to the outer diameter of the grinding wheel 3.4, as described above. Since it has an arc shape, there is a distance M difference ε at a distance nWa from the cutting surface 1)). Furthermore, this distance difference ε
is determined by the radius R of the grindstones 3 and 4 and the distance t. In addition, as shown in the fourth article, the tooth trace line 1c of the pinion cutter l is the flat tooth profile grinding surface 3a of the grindstones 3 and 4.
.

4a, it has a straight line shape with a fill relief angle r. Therefore, in this case, when a new cutting surface is ground due to the wear of the cutting edge, the tooth height from the tip of the pinion tooth to the chamfering edge at the tooth root changes, and as a result, the workpiece A problem arises in that the chamfer amount of the tooth tip changes.

On the other hand, in order to solve this problem, by grinding the tooth profile of the pinion cutter while reciprocating the grindstone in the direction of the tooth trace, the chamfering edge at the base of the tooth is machined in a straight line in the direction of the tooth trace. The grinder is 1 shot, 1 shot. However, when using this through grinder, there are naturally disadvantages in that the number of machining steps increases and the tooth profile grinding efficiency decreases.

The present invention has been made in view of the above points, and allows for efficient tooth profile grinding without moving the grinding wheel in the direction of the teeth trace of the pinion cutter, and also enables grinding of tooth profiles at any position where the blade life reaches its limit. The purpose of the present invention is to provide a semi-topping pinion cutter that enables accurate chamfering of the tooth tip of a cut object, and a tooth profile grinding wheel used for manufacturing the same. In a semi-topping pinion cutter that has a chamfering blade at the base of the blade to chamfer the tooth tips at the same time as cutting the teeth, the teeth of the front ML blade. The root is formed in an inner arc shape that is convex toward the center along the tooth trace direction, and the tooth thickness is formed to be thinner by an amount corresponding to the increase in tooth height due to the circular arc shape of the tooth root. In addition, the tooth profile grinding wheel for a semi-topping semi-topping cutter of the present invention is configured such that the tooth profile grinding wheel for a binion cutter performs tooth profile generating grinding by positioning the tooth profile grinding surface on the virtual rack mouth surface that meshes with the binion cutter. A chamfer is formed on the outer edge for grinding the chamfering blade part of the cutter, and the teeth are cut by an amount corresponding to the increase in the tooth height due to the arc-shaped shape of the tooth base of the cutter. It is characterized in that the tooth-shaped ground surface is a conical surface so as to be formed thinly.

An embodiment of the present invention will be specifically described below with reference to the drawings.

FIG. 5 is a partial sectional view taken along the pitch line of a semi-topping binion cutter according to the present invention. Incidentally, the sectional view of the pinion cutter seen from the side is the same as that shown in FIG. 3 as a conventional example. As shown in Figure 3, the pinion cutter 1 according to the present embodiment has a tooth base of the blade section that is twisted in the tooth trace direction and formed in an arc shape that is convex toward the center.
The blade portion is formed into a wedge shape by curving the tooth trace mzd into an arc shape, as shown in FIG.

Here, as mentioned above, the distance t from the cutting surface ib is set as the cutting life of the pinion cutter l, and the cutting surface ib is The tooth surface at a distance a from the center is located inward by the correction amount τ, and therefore the tooth thickness becomes thinner by 2×τ at that position.

Considering that the tooth height is longer by the distance difference a at this position, the value of the correction amount τ is determined to compensate for the increase in the tooth height by reducing the tooth thickness. Induce from.

This pinion cutter I can be easily manufactured by changing the grindstone in the conventional generating tooth profile grinder shown in FIG. That is, as shown in FIG. 6, a chamfer 7b for grinding the chamfering blade part 1a of the binion cutter l is formed on the outer edge of the grindstone 7, and a tooth profile of the grindstone 7 is formed for grinding the curved tooth surface. The grinding surface 7a is a conical surface with a conical angle β, and the grinding wheel 7 is positioned and attached to the chevron-shaped grinding surface 7a'i (virtual rack surface), and generating grinding is performed in the same manner as in the prior art. FIG. 7 shows a cross-sectional view of the grinding wheel 7 and the pinion cutter 1 cut along the pitch line 8 of the virtual rack shown in FIG. The tooth line i1d of the pinion cutter l can be ground into an arc shape. Here, the cone angle β is determined so as to give the above modification amount t to the tooth surface.

In a pinion cutter that does not have such a configuration, when a new blade is ground due to wear of the cutting edge, the tooth height from the tip of the pinion cutter to the chamfering blade at the root of the tooth changes. At the same time, the tooth thickness decreases in response to this change, so in actual cutting, the depth of cut must be increased to correspond to the decrease in thickness, so that the tooth tip chamfer is always correctly chamfered. It can be carried out. Also, in its manufacture, there is no need for through grinding, and it can be manufactured using a conventional binion cutter tooth profile generating grinder.

As specifically explained above with reference to one embodiment, according to the present invention, the tooth profile can be efficiently ground without moving the grinding wheel in the direction of the teeth of the pinion cutter during manufacturing, and there is a limit to the lifespan of the blade. It is possible to provide a semi-topping semi-topping millet blade that can accurately chamfer the tooth tip of a workpiece at any position, and a tooth profile grinding wheel used for creating the same.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the principle of the conventional tooth profile generating grinding method for a binion cutter, Fig. 2 is a sectional view of a conventional binion cutter, and Fig. 3 is a partial sectional view of a conventional binion cutter seen from the side. FIG. 4 is a partial cross-sectional view taken along the pitch line, FIGS. 5 to 7 show an embodiment of the present invention, and FIG. FIG. 6 is a 111-plane view of the part of the grindstone according to the present invention, and FIG. 7 is a sectional view of the pinion cutter to be ground and the grindstone taken along the pitch line of the virtual rack. In the drawings, 2 is a binion cutter, la is a chamfering blade, 7 is a grindstone, 7a is a tooth-shaped grinding surface, and 7b is a chamfer. 1 Figure 6/b Figure 7

Claims (1)

[Scope of Claims] (Li) A semi-topping pinion cutter in which a chamfering blade is provided at the root of the blade in order to chamfer the tooth tip at the same time as cutting the tooth, With a semi-topping, the tooth trace direction KG is formed in an arc shape convex toward the center, and the tooth thickness is formed to be thinner by an amount corresponding to the increase in tooth height due to the arc shape of the tooth root. Pinion cutter. (2) For grinding the chamfering blade part of the cutter in the tooth profile grinding wheel of the pinion cutter, which performs tooth profile generating grinding by positioning the tooth profile grinding surface on the virtual rack tooth surface that meshes with the pinion cutter. A chamfer is formed on the outer edge, and the tooth profile grinding surface is made conical so that the tooth thickness is reduced by an amount corresponding to the increase in the tooth height due to the circular arc shape of the root of the tooth of the cutter being ground on the outer edge. A tooth-shaped grinding wheel for a pinion cutter with a semi-topping feature.