JP2016107359A - Grindstone for gear machining - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grindstone for gear machining which prevents a defect due to load concentration.SOLUTION: The grindstone for gear machining is used for grinding of a gear tooth surface. The grindstone for gear machining is a barrel-shaped screw-like grindstone 10 having multithread grinding tooth 11 in a helical gear shape or in a screw gear shape that are twisted and formed consecutively relative to a grindstone shaft B, the outer diameter dimension of the grindstone 10 gradually increasing from a center part toward both end parts in a shaft direction of the grindstone B. An outer edge part of at least one end face 13 of the screw-like grindstone 10 is subjected to C chamfering, and on at least one end part of the grinding tooth 11 is formed a C surface 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gear processing grindstone for grinding a gear.

  In order to improve the accuracy of gears after heat treatment, there is a known technology that performs tooth surface grinding by meshing the heat-treated gear and a threaded grindstone with a crossed angle and rotating them synchronously. (Patent Document 1).

  For example, in the case of an internal gear, as shown in FIG. 7 and FIG. 8, a barrel-shaped screw-shaped grindstone 30 having a plurality of gear-shaped grinding teeth 31 is used, and the grindstone axis B1 of the thread-shaped grindstone 30 is used. And the workpiece shaft C1 of the internal gear W1 are engaged with each other in a state of giving an axis crossing angle Σ1, and synchronously rotated to perform tooth surface grinding.

  In the case of an external gear, as shown in FIG. 9, a drum-shaped threaded grindstone 40 having multiple gear-shaped grinding teeth 41 is used, and the grindstone shaft B2 of the threaded grindstone 40 and the external gear are used. The tooth surface is ground by meshing with the workpiece axis C2 of W2 in a state where the axis crossing angle Σ2 is given and rotating in synchronization.

JP 2010-149219 A

  The above-described threaded grinding wheels 30 and 40 are formed by directly inserting a tooth groove into a cylindrical grinding wheel material itself, and using the formed grinding wheel, tooth surface grinding of the internal gear W1 and the external gear W2 is performed. It is carried out. At this time, in the grinding process of the internal gear W1, the operation of feeding the screw-shaped grindstone 30 in the feed direction along the workpiece axis C1 is performed with respect to the internal gear W1, and in the grinding process of the external gear W2, the external gear An operation of feeding the threaded grindstone 40 with respect to W2 in the feeding direction along the workpiece axis C2 (or the feeding direction intersecting the workpiece axis C2 at a predetermined diagonal angle) is performed.

  Therefore, during the grinding process, load concentration occurs at the ends that become the boundaries between the end faces 32 and 42 of the grinding teeth 31 and 41 of the threaded grinding wheels 30 and 40. As a result, as shown in FIGS. Chips D are generated at the ends of the weakly ground grinding teeth 31, 41, causing cracks in the grindstone.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a gear machining grindstone that prevents a loss due to load concentration.

The grinding wheel for gear processing according to the first invention for solving the above-mentioned problems is
In the grinding wheel for gear processing that performs gear tooth surface grinding,
The gear processing grindstone is a threaded grindstone having multiple gear-shaped grinding teeth,
The outer edge of at least one end surface is subjected to C chamfering or R chamfering to form a C surface or R surface at at least one end of the grinding tooth.

A gear processing grindstone according to a second invention for solving the above-mentioned problems is as follows.
In the grinding wheel for gear processing that performs gear tooth surface grinding,
The gear processing grindstone is a threaded grindstone having multiple gear-shaped grinding teeth,
C corner chamfering processing or R chamfering processing is performed on a corner portion formed by at least one end surface and the tooth surface of the grinding tooth, and a C surface or R surface is formed at the corner portion.

A gear processing grindstone according to a third invention for solving the above-mentioned problems is as follows.
In the grinding wheel for gear processing according to the second invention,
The corner portion forming the C surface or the R surface is a corner portion having an acute angle formed by the end surface and the tooth surface.

A gear processing grindstone according to a fourth invention for solving the above-mentioned problems is as follows.
In the gear processing grindstone according to any one of the first to third inventions,
The screw-shaped grindstone is a barrel-shaped thread-shaped grindstone whose outer diameter dimension gradually decreases from the central portion in the axial direction of the grindstone shaft toward both ends.

A gear processing grindstone according to a fourth invention for solving the above-mentioned problems is as follows.
In the gear processing grindstone according to any one of the first to third inventions,
The thread-shaped grindstone is a drum-shaped thread-shaped grindstone whose outer diameter dimension gradually increases from the central portion in the axial direction of the grindstone shaft toward both ends.

  ADVANTAGE OF THE INVENTION According to this invention, the grindstone for gear processing which prevents the defect | deletion by load concentration can be provided.

It is a perspective view which shows an example (Example 1) of embodiment of the grindstone for gear processing concerning this invention. It is a perspective view which expands and shows a part of grindstone for gear processing shown in FIG. It is a perspective view which shows another example (Example 2) of embodiment of the grindstone for gear processing concerning this invention. It is a perspective view which expands and shows a part of grindstone for gear processing shown in FIG. It is another example (Example 3) of embodiment of the grindstone for gear processing concerning this invention, Comprising: It is a perspective view which expands and shows a part. It is another example (Example 4) of embodiment of the grindstone for gear processing concerning this invention, Comprising: It is a perspective view which expands and shows a part. It is a perspective view which shows a barrel-shaped screw-shaped grindstone. It is a figure explaining the grinding process of the internal gear using the barrel-shaped screw-shaped grindstone shown in FIG. It is a figure explaining grinding processing of an external gear using a drum-shaped screw-like grindstone. It is a perspective view which shows the grinding tooth of the screw-shaped grindstone shown in FIGS. It is a perspective view explaining the chip | tip of the grinding tooth shown in FIG.

  Hereinafter, an embodiment of a grinding wheel for gear processing according to the present invention will be described with reference to FIGS. In addition, although a barrel-shaped screw-shaped grindstone is illustrated here as a gear-processing grindstone, it is applicable also to a drum-shaped thread-shaped grindstone. As the barrel-shaped threaded grindstone gradually decreases from the axial center of the grindstone shaft to both ends, the outer diameter of the barrel-shaped threaded grindstone gradually decreases. The outer diameter dimension gradually increases from the central part of the direction toward both ends.

Example 1
FIG. 1 is a perspective view showing a gear processing grindstone of the present embodiment, and FIG. 2 is an enlarged perspective view showing a part of the gear processing grindstone shown in FIG.

  As shown in FIG. 1, the gear processing grindstone of the present embodiment is a barrel-shaped screw-shaped grindstone 10, and a plurality of grinding teeth 11 are formed by directly inserting a tooth groove in the cylindrical grindstone material itself. Is. As the abrasive grains constituting the grindstone, for example, CBN abrasive grains are used. In this thread-like grindstone 10, a plurality of grinding teeth 11 are formed in a gear shape (helical gear shape or screw gear shape), and from the central portion in the axial direction of the grindstone shaft B toward both ends. The outer diameter is formed into a barrel shape that gradually decreases.

  Each grinding tooth 11 is formed by continuously twisting in the right-handed direction with respect to the grindstone axis B over substantially the entire width of the grindstone width of the screw-shaped grindstone 10 (width in the axial direction of the grindstone axis B). The twist angle is set so as to gradually change from the central portion of the grinding wheel shaft B in the axial direction toward both ends.

  As apparent from comparison with the threaded grinding wheel 30 shown in FIG. 7, the outer edge of the end surface 13 of the threaded grinding wheel 10 of this embodiment is formed by performing C chamfering to flatten the corners. A surface (inclined surface) 12 is provided. Here, as an example, chamfering of about C3 (angle 45 °, width 3 mm) is performed, but can be changed as appropriate depending on the size of the threaded grinding stone 10, for example, at an angle of 30 to 60 °, It is desirable that the width is about the tooth height.

  In FIG. 2, in which a part of the threaded grinding wheel 10 of the present embodiment is enlarged and illustrated, the threaded grinding wheel 30 illustrated in FIG. 7 will be described with a dotted line. Therefore, in the grinding tooth 11 of the present embodiment, the end portion having a weak strength is cut off by providing the C surface 12 by C chamfering, and the end portion of the grinding tooth 11 has a more obtuse shape. It is said. By setting it as such a shape, the intensity | strength of the edge part of the grinding tooth 11 can be increased, and the defect | deletion by the load concentration at the time of grinding can be prevented.

  In addition, in FIG. 1, although the C surface 12 by C chamfering is provided in both the end surfaces 13 of the screw-shaped grindstone 10, when load concentration accompanying grinding processing occurs on one end surface 13 of the screw-shaped grindstone 10, You may make it provide the C surface 12 only in the direction of one end surface 13 instead of both.

(Example 2)
FIG. 3 is a perspective view showing the gear processing grindstone of the present embodiment, and FIG. 4 is a perspective view showing a part of the gear processing grindstone shown in FIG. 3 in an enlarged manner.

  As shown in FIG. 3, the gear processing grindstone of the present embodiment is also a barrel-shaped screw-shaped grindstone 20, and a plurality of grinding teeth 21 are formed by directly inserting a tooth groove in the cylindrical grindstone material itself. Is. As the abrasive grains constituting the grindstone, for example, CBN abrasive grains are used. Also in this thread-like grindstone 20, the multiple grinding teeth 21 are formed in a gear shape (helical gear shape or screw gear shape), and as it goes from the central portion in the axial direction of the grindstone shaft B toward both ends. The outer diameter is formed into a barrel shape that gradually decreases.

  Each grinding tooth 21 is formed by continuously twisting in the right-handed direction with respect to the grindstone axis B over substantially the entire width of the grindstone width of the screw-shaped grindstone 20 (width in the axial direction of the grindstone axis B). The twist angle is set so as to gradually change from the central portion of the grinding wheel shaft B in the axial direction toward both ends.

  As apparent from comparison with the threaded grinding wheel 30 shown in FIG. 7, the outer surface of the end surface 23 of the threaded grinding wheel 20 of the present embodiment is formed with an R surface (R surface chamfering rounded corners) ( (Curved surface) 22 is provided. The size of the R chamfer can also be appropriately changed depending on the size of the threaded grindstone 20 or the like.

  In FIG. 4, in which a part of the threaded grindstone 20 of the present embodiment is enlarged and illustrated, the threaded grindstone 30 illustrated in FIG. 7 will be described with a dotted line. Therefore, in the grinding tooth 21 of the present embodiment, the end portion having a low strength is cut off by providing the R surface 22 by R chamfering, and the end portion of the grinding tooth 21 is rounded. Yes. By setting it as such a shape, the intensity | strength of the edge part of the grinding tooth 21 can be increased, and the defect | deletion by the load concentration at the time of grinding can be prevented.

  In FIG. 3, both the end faces 23 of the threaded grindstone 20 are provided with R surfaces 22 by R chamfering. However, when load concentration due to grinding occurs on one end face 23 of the threaded grindstone 20, You may make it provide the R surface 22 only in the direction of one end surface 23 instead of both.

(Example 3)
FIG. 5 is a perspective view showing a gear processing grindstone of the present embodiment in an enlarged manner. Here, the description will be made on the assumption that the barrel-shaped threaded grinding wheel 30 shown in FIG. Therefore, in FIG. 5, the same code | symbol is attached | subjected to the structure equivalent to the screw-shaped grindstone 30 shown in FIG.

  When the size of the thread-shaped grindstone is large, when the grindstone width of the thread-shaped grindstone is thin, etc., when the end face of the thread-shaped grindstone has a shape that cannot perform the C chamfering and R chamfering shown in the first and second embodiments, Instead of chamfering the end surface of the grinding wheel, chamfering may be performed on the end portion of the tooth surface of the grinding tooth.

  For example, the grinding teeth 31 of the threaded grinding wheel 30 shown in FIG. 7 are formed to be twisted in the right-handed direction in the same manner as the grinding teeth 11 and 21 shown in the first and second embodiments. 5, the angle formed by the right tooth surface 31 b and the end surface 32 of the grinding tooth 31 is sharper than the angle formed by the left tooth surface 31 a and the end surface 32 of the grinding tooth 31. The loss due to the load concentration in is easy to occur.

  Therefore, in this embodiment, a C surface 35 by C chamfering is provided at a corner portion formed by the tooth surface 31b and the end surface 32. Here, as an example, chamfering of about C1 (45 °, 1 mm) is performed, but can be appropriately changed depending on the size of the threaded grindstone 30 or the like.

  Thus, in the present embodiment, in the grinding tooth 31, by providing the C surface 35 by C chamfering at the corner portion formed by the tooth surface 31 b and the end surface 32 having a sharp angle or a shape close to an acute angle and having a low strength, The said corner | angular part will be excised and the part is made into the obtuse shape. By setting it as such a shape, the intensity | strength of the edge part of the grinding tooth 31 can be increased, and the defect | deletion by load concentration at the time of grinding can be prevented.

  In addition, you may make it provide the C surface 35 by C chamfering mentioned above in the corner | angular part which the tooth surface 31a and the end surface 32 make. Moreover, it is good also as a structure combined with Example 1 or Example 2. FIG. That is, the C surface 12 and the R surface 22 are formed, and the C surface 35 by the C chamfering described above is provided at the corner formed by the tooth surface of the grinding tooth 11 or the grinding tooth 21 and the C surface 12 or the R surface 22. Anyway.

Example 4
FIG. 6 is a perspective view showing an enlarged part of the grinding wheel for gear machining of the present embodiment. Here, the description will be given on the assumption that the barrel-shaped threaded grinding wheel 30 shown in FIG. Therefore, also in FIG. 6, the same code | symbol is attached | subjected to the structure equivalent to the screw-shaped grindstone 30 shown in FIG.

  In the present embodiment, as in the third embodiment, chamfering is not performed on the end surface of the threaded grindstone, but the end portion of the tooth surface of the grinding tooth is chamfered.

  Specifically, also in the present embodiment, an R surface 36 by R chamfering is provided at a corner portion formed by the tooth surface 31 b and the end surface 32. The size of the R chamfer can also be changed as appropriate depending on the size of the threaded grindstone 30 and the like.

  Thus, in the present embodiment, in the grinding tooth 31, by providing the R surface 36 by R chamfering at the corner formed by the tooth surface 31 b and the end surface 32, which have a sharp angle or a shape close to an acute angle, and the strength is weak, The corner is cut off, and the portion is rounded. By setting it as such a shape, the intensity | strength of the edge part of the grinding tooth 31 can be increased, and the defect | deletion by load concentration at the time of grinding can be prevented.

  In addition, you may make it provide the R surface 36 by R chamfering mentioned above in the corner | angular part which the tooth surface 31a and the end surface 32 make. Moreover, it is good also as a structure combined with Example 1 or Example 2. FIG. That is, the C surface 12 and the R surface 22 are formed, and the R surface 36 by the R chamfering described above is provided at the corner portion formed by the tooth surface of the grinding tooth 11 or the grinding tooth 21 and the C surface 12 or the R surface 22. Anyway.

  The present invention is suitable for a grindstone for gear processing.

DESCRIPTION OF SYMBOLS 10 Threaded grinding wheel 11 Grinding tooth 12 C surface 13 End surface 20 Threaded grinding wheel 21 Grinding tooth 22 R surface 23 End surface 35 C surface 36 R surface

Claims (5)

In the grinding wheel for gear processing that performs gear tooth surface grinding,
The gear processing grindstone is a threaded grindstone having multiple gear-shaped grinding teeth,
A gear processing grindstone, wherein a C surface or an R surface is formed on an outer edge portion of at least one end surface to form a C surface or an R surface on at least one end portion of the grinding tooth. In the grinding wheel for gear processing that performs gear tooth surface grinding,
The gear processing grindstone is a threaded grindstone having multiple gear-shaped grinding teeth,
A gear processing grindstone, wherein a chamfering process or an R chamfering process is performed on a corner portion formed by at least one end surface and the tooth surface of the grinding tooth to form a C surface or an R surface at the corner portion. In the grindstone for gear processing according to claim 2,
The gear processing grindstone, wherein the corner portion forming the C surface or the R surface is an acute corner portion formed by the end surface and the tooth surface. In the grindstone for gear processing according to any one of claims 1 to 3,
The gear-processing grindstone is characterized in that the thread-shaped grindstone is a barrel-shaped thread-shaped grindstone whose outer diameter dimension gradually decreases from the central portion in the axial direction of the grindstone shaft toward both ends. In the grindstone for gear processing according to any one of claims 1 to 3,
The threaded grindstone is a drum-shaped grindstone whose outer diameter is gradually increased from the central portion in the axial direction of the grindstone shaft toward both ends.

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