JPH04365512A - Shaving method for gear - Google Patents

Abstract

PURPOSE:To improve involute gear profile accuracy and surface roughness, in finishing the tooth surface of a gear to be cut with a shaving cutter. CONSTITUTION:A shaving cutter and a gear to be cut are engaged with each other at a prescribed crossing angle, and the gear surface is finished while perform-in plunge feed of the shaving cutter and traverse feed of the gear. In the first half of a cutting cycle A, what is called plunge shaving B is performed in processes 2 3, 3 4, and in the second half of the cutting cycle A, what is called conventional shaving C is performed in processes 9 10, 10 11, 11 12, 12 13, 13 14, 14 15. The cycle time is shorter than that in the case where the conventional shaving is executed after the plunge shaving, and compared with the case using either of both methods, involute gear profile accuracy and roughness of tooth surface are improved.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for shaving gears in which the tooth surface of a gear to be cut is finished by meshing the gear to be cut and a shaving cutter at a predetermined intersecting angle.

0002

2. Description of the Related Art As shown in FIG. 1, shaving involves finishing the tooth surface of the gear G by meshing the gear G and the shaving cutter C at a predetermined angle and driving the shaving cutter C to rotate. The method includes
Broadly speaking, there are plunge shaving methods and conventional shaving methods.

The plunge shaving method cuts the workpiece gear G while moving the shaving cutter C in the direction of the arrow P in FIG. 1 (plunge feeding) so as to approach the workpiece gear G. An example is shown in FIG.

That is, in steps 1→2, the shaving cutter C is rapidly moved in a direction approaching the gear to be cut G so that the shaving cutter C and the gear to be cut G are engaged with each other without backlash, and then in steps 2 to 3. , while rotating the shaving cutter C in the normal direction at a slightly high speed (for example,
Plunge feed at a rate of 0.2 mm per minute) to perform rough finishing.
Subsequently, in steps 3→4, finishing is performed while plunging the shaving cutter C at a low speed (for example, 0.1 mm per minute). Next, in steps 4→5, the plunge feed is stopped to perform a first spark out without mechanical cutting, and then in steps 5→6, the direction of rotation of the shaving cutter C is reversed to create a second spark. Do out. Next, in steps 6→7, the shaving cutter C is moved back by several μm to several tens of μm to remove the elastic strain from the gear G to be cut, and then, in steps 7→8, the shaving cutter C is rotated. The direction is rotated forward to perform a third spark out, and finally, in steps 8→9, the rotation of the shaving cutter C is stopped and reversed to complete one cycle. In this example, the time required for one cycle of shaving processing is about 80 seconds.

In the conventional shaving method, the gear to be cut G is aligned with the shaving cutter C by the arrow T in FIG.
The gear to be cut G is cut while being moved in the direction (traverse feed), and an example of the machining cycle is shown in FIG. 4.

That is, in steps 1→2, the shaving cutter C is rapidly moved in the direction approaching the gear G to be cut, so that the shaving cutter C and the gear G to be cut are engaged with each other without backlash, and in steps 2→3 After slightly large preliminary feed while rotating the cutter C in the normal direction, rough finishing is performed while the gear to be cut G is traverse fed to the left (for example, at 40 mm per minute) in steps 3→4. Subsequently, the same operations as steps 2→3 and 3→4 are repeated in steps 4→5 and 5→6 while reversing the shaving cutter C and traversing the gear G to be cut in the right direction. Note that the number of times of rough finishing is not limited to two, but can be set arbitrarily. Next, in steps 6→7, the shaving cutter C is rotated in reverse and a small preliminary feed is performed, and in steps 7→8, the workpiece gear G is traverse fed to the left (for example, at 20 mm per minute) for finishing. ,
In steps 8→9 and 9→10, the table is fed twice (the number of times is arbitrary) while reversing the rotational direction of the shaving cutter C and the traverse feed direction of the work gear G, and finally, in step 10→ At step 11, the rotation of the shaving cutter C is stopped and the shaving cutter C is fast reversed to complete one cycle. In this example, the time required for one cycle of shaving processing is approximately 180 seconds.

[0007]

[Problems to be Solved by the Invention] By the way, although the plunge shaving method described above has the advantage of short machining time because it does not involve traverse feed, it has the problem that the surface roughness of the tooth surface is poor and it is difficult to set machining conditions. be. On the other hand, the conventional shaving method has excellent surface roughness and allows easy setting of machining conditions, but since plunge feed and traverse feed are performed alternately, machining time becomes long and tooth profile accuracy is unstable.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a gear shaving method that has both the advantages of the plunge shaving method and the conventional shaving method, and can compensate for their drawbacks.

[0009]

Means for Solving the Problems In order to achieve the above object, the present invention provides a gear for finishing the tooth surface of the gear to be cut by meshing the gear to be cut and a shaving cutter at a predetermined intersection angle. In the shaving method, in the first half of the machining cycle, the tooth surface is mainly plunge-feeded while the shaving cutter approaches the gear to be cut, and in the second half of the cycle, the gear to be cut is mainly moved in the axial direction. The feature is that the tooth surface is cut while being traversed.

0010

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings.

The present invention combines the plunge shaving method and conventional shaving method described above, and the processing cycle thereof is shown in FIG.

First, in steps 1→2, the shaving cutter C is rapidly fed in the direction approaching the gear to be cut G, and then in steps 2→3, the shaving cutter C is rotated in the forward direction while being plunge fed at a slightly high speed (for example, 0 per minute). .3mm
) while traversing the gear G to be cut to the left for rough finishing. In other words, the shaving cutter C and the gear to be cut G are angularly fed diagonally in the combined direction of arrows P and T in Fig. 1, which results in a surface roughness of the tooth surface compared to when only normal plunge feeding is performed. can be improved. Subsequently, in steps 3→4, the rotational direction of the shaving cutter C and the traverse feed direction of the gear to be cut G are reversed, and finishing is performed by angular feed, but the feed rate of the shaving cutter C at this time is the same as that in the rough finishing step 2. →It will be smaller than when it is 3 (for example, 0.1 per minute)
mm). Next, in steps 4→5 and steps 5→6, the first spark out and the second spark out are performed while reversing the rotational direction of the shaving cutter C with the traverse feed stopped.
Spark-outs are performed continuously, and in the next step 6→7, the shaving cutter C is slightly retreated to remove elastic distortion, and then a third spark-out is performed in steps 7→8, and finally, the The first half of the machining cycle is completed by quickly reversing the shaving cutter C from 8 to 9.

[0013] In the second half of the machining cycle, first, process 9→1
After preliminarily feeding the shaving cutter C slightly in step 0, in steps 10→11, the workpiece gear G is traverse fed to the left while rotating the shaving cutter C in the normal direction (
For example, rough finishing is performed at a speed of 60 mm per minute). Subsequently, in steps 11→12 and steps 12→13, the shaving cutter C is rotated in the opposite direction and the gear to be cut G is traversed to the right, while rough finishing is repeated, and the next step 13 is performed.
→ In step 14, the shaving cutter C is rotated in the normal direction to make a small preliminary feed, and then in steps 14 to 15, finishing is performed while traversing the gear G to be cut to the left (for example, at a rate of 30 mm per minute). Next, process 15 → 16 and process 16 → 1
At step 7, the table is fed twice while reversing the rotational direction of the shaving cutter C and the traverse feeding direction of the gear to be cut G. Then, in steps 17→18, the shaving cutter C is moved back slightly to remove elastic distortion, and then a third spark out is performed in steps 18→19, and finally, in steps 19→20, the shaving cutter C is quickly returned. This completes the second half of the machining cycle.

Since the plunge shaving method and the conventional shaving method are combined as described above, the fast return step in the plunge shaving method (steps 8→9 in FIG. 3) and the fast forward step in the conventional shaving method (steps 1→2 in FIG. 4) ) and increasing the cutting speed, the cycle time of this shaving method is approximately 140 seconds, which is significantly shorter than the cycle time when the plunge shaving method and conventional shaving method are performed consecutively.

FIG. 5 is an enlarged view of the tooth surface of the work gear G shaved by the conventional plunge shaving method, and FIG. 6 is an enlarged view of the tooth surface of the work gear G shaved by the method of the present embodiment. They correspond to the left and right tooth surfaces of the 1st tooth, 12th tooth, 23rd tooth, 34th tooth, etc., respectively. Note that the horizontal axis dimension (circumferential direction) in the figure is 250 times larger than each vertical axis dimension (radial direction).

[0016] As is clear from the average values of the pressure angle error, undulation, ball, and nakatotsu parameters of the involute curve, which are the standards for indicating the accuracy of the tooth surface, the undulation and ball have a large effect on the involute tooth profile accuracy. , Nakatotsu's three parameters, the values of the present invention are significantly reduced, and it is understood that the accuracy of the involute tooth profile is improved.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various small modifications may be made without departing from the scope of the invention described in the claims. It is possible to make design changes.

For example, in steps 2→3 and steps 3→4 of the machining cycle of the embodiment (see FIG. 2), auxiliary traverse feed is used in addition to plunge feed.
The traverse feeding is not essential and can be omitted.

[0019]

As described above, according to the present invention, the tooth surface is cut by the so-called plunge shaving method, which has a relatively poor surface roughness in the first half of the machining cycle, and the surface roughness is relatively poor in the second half of the machining cycle. Since the tooth surface is cut using a good so-called conventional shaving method, the tooth surface of the gear to be cut is precisely cut in two stages.
Finally, it is possible to obtain a gear with better surface roughness and higher involute tooth profile accuracy than when the plunge shaving method or conventional shaving method is used alone. Moreover, the processing time can be reduced compared to the case where the plunge shaving method and the conventional shaving method are performed consecutively.

[Brief explanation of drawings]

[Figure 1] Diagram showing the state of engagement between the shaving cutter and the gear to be cut

[Fig. 2] A diagram showing a processing cycle of an embodiment of the present invention.

[Figure 3
] Diagram showing the processing cycle of the conventional plunge shaving method

[Figure 4] Diagram showing the processing cycle of conventional conventional shaving method

[Figure 5] Diagram showing the involute shape of a gear shaved by the plunge shaving method

FIG. 6 is a diagram showing the involute shape of a gear shaved by the method of the embodiment of the present invention.

[Explanation of symbols]

C...Shaving cutter G...Gear to be cut

Claims (1)

[Claims] 1. A gear shaving method in which the tooth surface of the to-be-cut gear (G) is finished machined by meshing the to-be-cut gear (G) and the shaving cutter (C) at a predetermined intersecting angle. In the first half, the shaving cutter (C) is mainly used to cut the gear (G).
) is characterized in that the tooth surface is cut while being plunge-feeded in the direction approaching the gear (G), and in the latter half of the machining cycle, the tooth surface is cut while the gear to be cut (G) is mainly traversed-feeded in the axial direction. How to shave gears.