JPS62162421A - Shaving grinding tool - Google Patents

Abstract

PURPOSE:To eliminate the phenomenon of intermediately concave cutting in a conventional shaving system, by forming serration grinding blades in both side surfaces of each of teeth of a shaving grinding tool so that a gear to be ground is ground always in a uniform thickness. CONSTITUTION:A shaving grinding tool has serration grinding blades 12 only in the area of one widthwise side half of one side flank of each teeth. The other side flank 11b of each tooth 11 has serration grinding blades 11 only in the area of the other widthwise side half thereof. Accordingly, when the shaving grinding tool is fed in the direction of the arrow to grind on rotation a gear to be ground, only of serration blades formed in one half of the flanks 1a or 11b of the teeth 11 grinds one side tool flanks 4a, 4b of each tooth. Further, a point g1 or g2 in the substantially center part of each tooth 11 serves as a guide for the movement of the grinding tool so that the gear to be grind is ground in an uniform thickness k1 or k2.

Description

[Detailed description of the invention] 【Technical field】

The present invention relates to a shaving grinding tool, and more particularly to a shaving grinding tool suitable for a so-called conventional shaving method in which the shaving grinding tool itself is fed laterally on a gear shaft and vane row of a wave machining involute.

[Prior art]

Conventionally, when finishing involute gears, a shaving cutter with many serrated cutting edges on the tooth surface is used, and the tooth profile of the gear processed with this cutter changes depending on the meshing ratio between the shaving cutter and the gear. It is known. This is true whether the processing is by cutting or grinding; for example, the serration cutting edge is not a cutting blade, but a grinding blade in which the surface of each serration is composed of an abrasive surface. The same is true. The details will be explained below. If the tooth profile of the Soniping grinding tool itself is a true involute curve, generally when the meshing ratio with the corrugated gear is 2.0 or more, the tooth profile of the gear becomes a true involute curve, but when the meshing ratio is less than 2.0. Then,
As the tooth profile of the gear changes and the engagement ratio decreases, a large depression is created near the center of the tooth profile (on the engagement pitch circle). FIG. 6 shows the recesses 4c formed on both sides of the teeth 4 of the corrugated gear W. This tooth profile is generally called the middle incisor profile. The reason why the above-mentioned middle tooth profile occurs is that the meshing state between the shaving grinding tool and the gear changes during the aping process. This will be explained next according to FIGS. 4(I) and (n). In FIGS. 4(1) and (n), the shaving grinding tool S and the workpiece gear W rotate in the directions of the arrows shown, respectively. shall be. In the meshing state shown in FIG. 1 of the shaving grinding tool S. Therefore, when the cutting load of the shaving grinding tool S is applied to the gear W to be machined that does not have a forced transmission mechanism, the left tooth surface of the gear W to be machined is Since the contact area is 1/2 of the area of the right tooth flank, the cutting load per unit area near point C on the left tooth flank becomes relatively large, and the amount of cutting near point C on the left tooth flank increases. In other words, the constant cutting depth of the shaving grinding tool S appears as an unbalanced removal amount of the left and right tooth flanks of the gear W to be machined. The imbalance in the removal amount is noticeable near the pitch circle of the tooth surface.This is the cause of the depression 4c of the tooth 4 shown in FIG. When the meshing state shown in FIG. 4 (II) is reached (the opposite state to the state shown in FIG. 4 I), the right tooth surface 4 of the gear W to be machined
b is only point d, and the left tooth surface 4a is two points e and f.
Since it engages with the shaving grinding tool S at these locations, the situation is completely opposite to that shown in Fig. 4 (1), and the area near point d on the right flank of the gear W to be machined is ground relatively more. become. This is the cause of the depression 4c in the tooth 4 shown in FIG. To further explain this with reference to FIG.
In the meshing state shown in FIG. 1, as shown in FIG. 5, the amount C' of the tooth surface 4a of the tooth 4 ground by the serration grinding blade 2 on one side 1a of the tooth 1 of the shaving grinding tool is: Other side 1b of tooth 1 of shaving grinding tool
This value is larger than the grinding removal amount b' of the other side surface 4b of the tooth 4 which is ground by the serration grinding blade 2. Conventionally, in the case of cutting using a shaving cutter, in order to avoid the middle tooth profile of the gear to be machined, the tooth profile of each tooth of the shaving cutter is generally corrected to the middle tooth profile to obtain the desired tooth profile. Similar measures can be taken for shaving and grinding tools. However, the shaving grinding tool S and the gear W to be machined
As long as there is an imbalance in engagement as shown in Figure 4 <I) and (II>, depending on the setting of each specification, the sharpness of the serrated grinding blade will deteriorate and the shaving grinding tool will be damaged at an early stage. The effect of the incisor profile is lost, and as a result, the tooth profile of the gear to be finished is destroyed.Therefore, the service life of such a shaving and grinding tool is very short.Also, according to the above conventional solution In order to determine the middle incisor profile of the shaving grinding tool S, a so-called trial and error method must be used, which poses a problem in that the time required to set the middle incisor profile is extremely long. Analyzing the problem of the above conventional solution, the cause is that in the conventional shaving method, when the shaving grinding tool is moved in one direction along the gear axis, both tooth surfaces of each tooth of the shaving grinding tool It can be seen that the serration grinding blade simultaneously grinds the left and right tooth flanks of the gear to be machined.For this reason, the amount of removal by grinding of the tooth flank of the gear to be machined on the side that receives a larger grinding load is relatively It becomes larger.

[Technical Problem of the Present Invention] Therefore, the technical problem to be solved by the present invention is that when the shaving grinding tool is moved in one direction of the gear shaft in the conventional shaving method, one side of each tooth of the shaving grinding tool is The serration grinding blade formed on the serrated grinding blade is used to machine only the left or right tooth flank of the gear to be machined, and then when the shaving grinding tool is moved in the opposite direction of the gear axis, one of the teeth of each tooth of the shaving grinding tool is machined. To provide a shaving grinding tool capable of grinding a tooth surface on the pond side of a gear to be processed using a serrated grinding blade on the side surface. [Structure of the present invention] The present invention has been completed by paying attention to the following points. That is, the shaving grinding tool S and the gear W to be machined during the conventional shaving process are as shown in FIG. FIG. 5 shows a cross-sectional state on a meshing pitch circle based on the gear W to be machined. As shown in the figure, the teeth 1 of the shaving grinding tool S and the teeth 4 of the workpiece gear W have different helix angles.
a and 1b are convex curved surfaces, and the serration grinding blade 2 of the shaving grinding tool S is half in the advancing direction of the shaving grinding tool (the right half in the figure) from which tooth surfaces 1a and lb.
Only one half is involved in grinding, while the other half (left half)
are not in contact with the tooth surfaces 4a, 4b of the gear W to be machined. In addition, in conventional shaving processing, first a predetermined cut is made and the shaving grinding tool is moved horizontally in the gear axis direction by a length corresponding to the tooth width of the gear to be machined, and then a further cut is made and the shaving grinding tool is moved for a second time. Grinding is performed by horizontally feeding in the opposite direction to that shown in Figure 5. As shown in FIG. 1, the shaving grinding tool according to the present invention has a serration grinding blade 12 only in a half area on one side in the tooth width direction on one side of each tooth 11. The other side tooth surface Llb is characterized by having the serration grinding blade 12 only in the other half region in the tooth width direction. Incidentally, the serration grinding blade 12 is preferably a grinding blade using super abrasive grains.

[Action of the present invention]

In the above configuration, as shown in FIG. 2 (I),
When the shaving grinding tool rotates and cuts the gear to be machined while being fed laterally in the direction of the arrow in the figure, only the serrations 12 formed on the right half of the tooth surface 11a of the tooth 11 of the shaving grinding tool are formed on one side of each tooth of the gear to be machined. The tooth surface 4a is ground, and since there is no serration grinding blade on the right half of the tooth surface Llb on the other side of the tooth 11, the tooth surface 4b on the other side of the tooth of the to-be-processed gear is not ground at all. The point g+ at the approximate center of the tooth surface flb of the tooth 11 serves to guide the movement of each tooth 11 of the shaving grinding tool, and even if the meshing state changes during meshing rotation, one screen of the gear to be machined Since only 4a is ground, the tooth surface 4a has the same thickness from the tip to the root.
In other words, the grinding thickness is 1, which corresponds to the depth of cut into the gear W to be machined by the shaving grinding tool S. On the other hand, the shaving grinding tool S is shown in FIG.
When cutting a gear to be machined while traversing in the opposite direction as shown in FIG. to grind. A substantially central point g2 of the tooth surface 11a on the other side of the tooth 11 serves to guide the lateral feed of each tooth of the shaving and grinding tool similarly to the point g1. Therefore, in this case, only the tooth surface 4b of each tooth of the gear to be machined is ground to the same thickness from the tip to the base of the tooth.

[Effects of the present invention]

As described above, according to the shaving grinding tool according to the present invention, even if the meshing ratio with the gear to be machined is small and the meshing state fluctuates as a result, grinding is always performed at a constant thickness. The above-mentioned middle cutting phenomenon in which the center area of the gear tooth surface, that is, the meshing pitch circle area is relatively heavily ground, is eliminated, and if the tooth profile of the shaving grinding tool is a true involute tooth profile, the workpiece gear will have a true involute tooth profile. Teeth shape can be changed. In order to solve the above technical problem, as another method,
It is technically possible to form a serration grinding blade on only one side of each tooth of the shaving grinding tool, but in this case, first grind all of the one side of each tooth of the gear to be machined. After finishing the process, the shaving grinding tool itself needs to be rotated 180 degrees and reinstalled on the shaving machine body, resulting in poor processing efficiency. In this regard, in the shaving grinding tool according to the present invention, since serration grinding blades are formed on both sides of each tooth, by reciprocating the shaving grinding tool in the gear axis direction, both teeth of each tooth of the to-be-processed gear can be removed. Therefore, there is no need to reinstall the shaving grinding tool to the shaving machine body, resulting in high processing efficiency. Furthermore, in order to eliminate the inconvenience of reattaching the shaving grinding tool to the shaving machine body as described above, the shaving grinding tool has teeth that form serrated grinding blades only on the lead side tooth surface of each tooth, and a trailing edge. Teeth forming serration grinding teeth only on the side tooth surfaces may be arranged alternately. However, in this case as well, since grinding is performed only when the teeth of the shaving and grinding tool reciprocate in one direction, machining efficiency is still poor.

[Brief explanation of drawings]

1 and 2 show embodiments of the present invention, FIG. 1 is a perspective view of essential parts showing one tooth of a shaving grinding tool according to the present invention, and FIGS. 2 (I) and (n) are shaving grinding tools. Fig. 3 is a sectional view of a main part on a pitch circle showing a state in which shaving is performed while moving the gear to the right and left with respect to the gear to be machined that is meshed with the gear. Perspective view showing teeth, FIG. 4 (1),
(II) is an explanatory diagram showing the meshing relationship between the shaving grinding tool and the gear to be processed, respectively, and FIG. 5 is a pitch circle showing the state in which the gear to be processed is ground by the conventional shaving grinding tool shown in FIG. 3. FIG. 6 is an explanatory sectional view showing the teeth of a gear having an intermediate tooth profile. 1, 11- tooth, la, 1b, '11a, 11b-
Tooth surface, 2.12 = serration grinding blade, 4... tooth,
4a, 4b... tooth surface, 4c... hollow, S... shaving grinding tool, W... gear to be machined, a. b, c, d, e, f - meshing point, c', b', +
, k2-grinding removal m or grinding thickness, g+ +Ih...
·point.

Claims (1)

[Claims] 1. In a shaving grinding tool having serration grinding blades (12) on both tooth surfaces (11a, 11b) of each tooth (11), one tooth surface (11a) of each tooth (11) has a tooth surface (11a). The serration grinding blade (12) is applied only to half of one side in the width direction.
A shaving grinding tool characterized in that the other tooth surface (11b) of each tooth (11) has the serration grinding blade (12) only in the other half region in the tooth width direction.