JPS6216768B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a shaving cutter for finish cutting gears.

(Prior Art) In order to adjust the tooth profile of a gear cut by a generating gear cutter or the like, and to improve the surface roughness of the tooth surface, grinding of the tooth surface using a shaving cutter is widely performed.

The shaving cutter that has been widely used in the past has a straight or helical spur gear shape as a whole, and has many grooves formed on the tooth surface of each tooth, as shown in Figure 1. This shaving cutter has a structure with a cutting blade, and by rotating the shaving cutter while meshing with the gear material, slippage is caused between the cutter and the tooth surface of the gear material, which means that the shaving cutter is rotated while meshing with the gear material. A helical cutter is engaged with the gear material, and a helical cutter with a straight edge or a different angle of inclination is engaged with the helical gear material to create slippage, and cutting is performed by this slippage. I was doing it.

(Problems to be Solved by the Invention) In order to manufacture this shaving cutter, after cutting with a generating gear cutter etc. in the same way as gears, the tooth surface of each tooth is involute or cycloid. Grooves had to be made one by one along each curve, and this work was extremely troublesome. Therefore, this shaving cutter is not only very expensive, but if you try to manufacture a large module, the cutter and device for cutting the teeth will become extremely large, making it virtually impossible. At present, there are almost no modules larger than 16. For this reason, finish cutting is rarely performed on gears with module 16 or higher.

In addition, in order to use this shaving cutter, a special machine tool called a gear shaving machine was required to mesh the cutter with the gear material and rotate it.

Furthermore, when the shaving cutter becomes worn out, the tooth surface of each tooth must be sharpened accurately along its involute or cycloid curve, which is a very troublesome process. Due to the delicate nature of the work, special dedicated machine tools were required.

Structure of the Invention (Means for Solving Problems) The present invention integrally forms a thread 13 on the outer periphery of a base shaft 12 in a worm shape with both sides sloped and the thread thickness becoming thinner toward the outside. A configuration is adopted in which cutting edges are continuously formed on both side slopes of the base shaft 13 in the advancing direction of the screw, which is oblique with respect to a plane including the axis of the base shaft 12.

(Function) Therefore, the shaving cutter of the present invention can be easily manufactured with high precision for any size, reducing costs, and can be used for cutting and finishing large gears. Furthermore, conventional machine tools can be used for finishing cutting and resharpening, and no special dedicated machine tool is required.

(Example) <Description of Structure> Hereinafter, a first embodiment embodying the present invention will be explained with reference to FIGS. 2 to 5. The shaving cutter of this embodiment has a mounting hole 11 in the axis. A single screw thread 13 is integrally formed protruding from the outer periphery of the base shaft 12 extending through it, forming a worm shape, and the thread 13 is obliquely formed on both sides so that it becomes thinner toward the outside. A large number of curved cutting grooves 14 are continuously formed at equal intervals in the direction in which the screw advances, being oblique with respect to a plane including the axis of the screw, with the amount of inclination increasing toward the outer periphery. Therefore, each cutting edge groove 1
4 are formed with curved cutting edges 15 that are oblique with respect to a plane including the axis of the base shaft 12, and the amount of inclination becomes larger toward the outer circumference, and are continuously formed at equal intervals in the advancing direction of the screw, and In this embodiment, the cutting edge groove 14 and the cutting edge 15 are formed so as to become wider toward the outer periphery.

As shown in FIG. 5, relief grooves 16 are formed on both sides of the base of the thread 13, and the tip edges on both sides of the cutting blade 15 are slightly rounded.

Next, a second embodiment of the present invention will be explained with reference to FIGS. 6 and 7. In this embodiment, the thread 13
The cutting edge groove 14 is formed so that the cutting edge 15 forms a short straight line inclined with respect to the plane including the axis of the base shaft 12, and the cutting edge 15 extends from the inside to the outer circumferential side. The cutting edge groove 14 is formed wider on the outer peripheral side so that the width is the same.

<Description of Manufacturing Method> Now, the shaving cutter configured as described above is manufactured by rotating a primary material made of a round bar with a mounting hole 11 through it, and using a cutting tool in the shape of a screw valley. The thread 13 is cut out to form a worm-shaped secondary material. Next, this secondary material is rotated to cut an escape groove 16 at the base of the thread 13, and also to make a tertiary material by cutting so that both edges of the tip of the thread 13 are rounded.

In the case of the shaving cutter of the first embodiment, the cutting tool is moved on the slope of the thread 13 at an arbitrary oblique angle with respect to the plane including the axis while slowly rotating the tertiary material. In the case of the shaving cutter of the second embodiment, the shaving cutter of the second embodiment cuts a curved cutting groove 14, and cuts a straight line by rotating the tertiary material intermittently and moving the cutting tool at an arbitrary oblique angle when stopped. What is necessary is to cut the cutting edge groove 14 which forms a shape. In this case, in order to make the cutting groove 14 wider toward the outer circumference, as shown in FIG. 14c
If there remains, the central portion 14c can be finally removed.

Note that whether the cutting edge 15 should be curved or linear, or the degree of inclination of the cutting edge 15 may be arbitrarily selected in consideration of the cutting conditions.

Finally, the shaving cutter having the above-described structure can be obtained by sharpening the screw surface, applying an abrasive to the threaded surface, and polishing it by rotating the shaving cutter.

In this way, the shaving cutter of the present invention can be manufactured by threading a round bar and providing a cutting groove on the thread, so unlike the conventional spur gear-shaped shaving cutter described above, There is no need to cut generating gears or cut cutting grooves on each tooth along its involute or cycloid curve, and any size can be manufactured easily and quickly using a lathe, etc. This has the effect of reducing costs and making it possible to cut and finish large gears, which was previously impossible. Furthermore, since it can be manufactured without performing such complicated cutting movements, it has the effect of being able to be made with high precision.

<Description of how to use> Next, in order to finish cutting the tooth surface using the shaving cutter of the present invention, attach the shaving cutter to an axis that is perpendicular to the axis of the gear material. A part of it is meshed with the gear material, and either the gear material and the shaving cutter are freed, and only the cutter is given rotation, so that the shaving cutter is rotated as shown in Figs. 4 and 6. It is sufficient to rotate in the direction of the arrow P, that is, in the opposite direction to the direction in which the cutting blade 15 extends toward the outer circumference.In this way, the cutting blade 15, which becomes oblique as it rotates, is aligned with the tooth surface of the gear material. Perform finish cutting by shaving the edges.

Therefore, this shaving cutter can be attached to conventional gear machine tools such as hobbing machines and honing machines that have a mounting axis perpendicular to the axis of the gear material, and can be used with special dedicated machine tools. This has the effect of allowing conventional machine tools to be used as is without the need for If the part that engages with the gear material wears out and the cutting edge of that part becomes dull, you can move the shaping cutter in the direction of its axis and mesh it with the gear material in another part. . Therefore, by making the shaving cutter longer, it can have a longer lifespan.

<Explanation of repair method when worn> Furthermore, if the cutting blade 15 becomes worn and dull, rotate the shaving cutter by applying the cutting blade to the slope, or apply the cutting blade to the tip surface of the thread 13. All you have to do is place it on the shaving cutter and rotate it in the same way to cut so that the entire thread 13 moves toward the axis.Unlike conventional shaving cutters, the tooth surface of each tooth is cut along an involute or cycloid curve. There is no need to do this, and the effect is that the work can be easily done with a normal lathe or the like without using a special dedicated machine tool.

Note that if the tip edge of the cutting blade 15 is rounded as in the embodiment, the edge of the cutter can be improved during cutting. Further, unlike the first and second embodiments, the threads 13 may have multiple threads.

(Another Embodiment) The present invention is not limited to the first and second embodiments, but can also be embodied in the following embodiments.

(a) Cutting grooves should be formed by electrical discharge machining.

(b) Make the threads multi-threaded and provide each thread with a cutting edge in the same manner as above.

(c) Omit the relief groove.

Effects of the Invention As detailed above, the present invention integrally forms a worm-shaped thread on the outer periphery of the base shaft with slopes on both sides and becomes thinner toward the outside. By continuously forming cutting edges that are oblique to the plane that includes the axis of the base shaft, it is possible to manufacture any size easily and with high accuracy, reducing costs. At the same time, it can be used for cutting and finishing large gears, and for finishing cutting and self-sharpening, there is no need for a special dedicated machine tool, and the work can be easily done using conventional machine tools as is. This is an excellent invention for industrial use as a shaving cutter.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the teeth of a conventional shaving cutter, Figs. 2 to 5 show a first embodiment of the present invention, and Fig. 2 shows the entire shaving cutter. Fig. 3 is a front view showing only a part, Fig. 4 is a sectional view showing the cutting groove and the cutting blade, Fig. 5 is a partial sectional view showing the thread, Figs. 6 and 7. The figures show a second embodiment of the present invention, in which FIG. 6 is a cross-sectional view showing the cutting groove and the cutting blade, FIG. 7 is a cross-sectional view showing the thread, and FIG. 8 is a cross-sectional view showing the cutting groove. FIG. 3 is a partial side view showing the cutting order. Base shaft 12, thread 13, cutting blade 15.

Claims (1)

[Claims] 1. A screw thread 13 is integrally formed on the outer periphery of the base shaft 12 so as to form a worm shape, with slopes on both sides and the screw thread 13 becomes thinner toward the outside. A shaving cutter characterized by having an oblique cutting edge formed continuously in the direction in which the screw advances.