JPS63139613A - Gear cutting machine - Google Patents

Abstract

PURPOSE:To compact a cutter head and to reduce production of torque during cutting, by a method wherein a pinion type cutter is moved in parallel to the direction of the axis of a gear element while rotating around its axis. CONSTITUTION:A title gear cutting machine is provided with a headstock 2 rotating a cylindrical gear element 4 around its axis, and a cutter head 6, supporting a pinion type cuter 5 cutting the outer peripheral surface of a gear element 4, and moving the cutter 5 in parallel to the axial direction of a gear element 14 while rotating around its axis. Thus, the intersection angle between the two axes of the gear element 4 and the cutter 5 is also made approximately equal to right angles, the headstock 2 and a tailstock 3 are prevented from interference with the cutter head 6, the structure is compacted, and the formation of a worm and a screw gear at low cutting torque becomes practicable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a gear cutting machine for creating a worm or screw gear having multiple worm teeth.

(Prior art) The above-mentioned worms and screw gears are mainly used as parts of automobile transmissions, main engines, gears, other speed changes, reduction gears, etc. For example, when creating a worm among the above, a hob cutter is used. Automatic gear splitting is performed to cut cylindrical gear material.

It has been common practice in the past to create worm teeth in this way.

This will be explained with reference to FIG. 5. In the figure, reference numeral 11 is a hobbing machine which is a gear cutting machine, and this hob fill has a headstock 12 and a tailstock 13 installed on the same horizontal axis.
Jt12, 13 supports the gear material 14. This gear material 14 is a material for creating a worm having multiple worm teeth 14a, and is rotated around its axis by the headstock 12. - Also provided is a hob cutter 15 for cutting the outer peripheral surface of the gear material 14. This hob cutter 15 is supported at both ends by a cutter head 16. This cutter head 16 drives the hob cutter 15 to rotate around its axis.

As described above, the hob cutter 15 is supported and rotated while being translated in parallel to the axial direction of the gear material 14.

When creating worm teeth 14a on the outer peripheral surface of the gear blank 14, first, the gear blank 14 and the hob cutter 15 are rotated in opposite directions as shown by arrows A and B in the figure. Then, move the hob cutter 15 to the gear material 1.
4 in the direction of arrow C in the figure parallel to the axis of the gear blank 14, and the outer circumferential surface of the gear blank 14 is cut from one axial end side of the gear blank 14 to create worm teeth 14a. When the hobber 15 reaches the other end of the gear material 14 in the axial direction, the creation of the worm teeth 14a in the gear material 14 is completed. In the example shown in FIG. 0, the number of worm teeth 14a is 40.

In the above case, the rotational direction of the cutting blade 15a of the hob cutter 15 in the portion where the gear material 14 is being cut corresponds to the tooth trace direction of the worm tooth 14a to be created. Therefore, the intersection angle between the axes of the gear blank 14 and the hob cuffer 15 when viewed from the front in the direction of the arrow in the figure is an angle equal to the sum of the lead angle α of the worm tooth 14a and the lead angle of the hob cutter 15.

(Problems to be Solved by the Invention) By the way, since the lead angle α of the worm tooth 14a and the lead angle of the hob cuffer 15 are relatively small,
In the conventional example described above, the intersection angle between the axes of the gear material 14 and the hob cutter 15 is small, and therefore, these axes are nearly parallel.

In the above configuration, if the worm to be created has a small diameter, when cutting the cutting teeth of the hob cutter 15 into the outer peripheral surface of the gear material 14, the axes of the gear material 14 and the hob cuffer 15 need to be brought close to each other. . However, in this case, since the gear material 14 and the hob cutter 15 are substantially parallel as described above, these gear materials 14
There is a possibility that the headstock 12 or the center stand 13 supporting the hob cutter 15 and the cutter blade 16 may interfere with each other.

In the above case, in order to prevent the headstock 12, the shin rest 13, and the cutter radius 16 from interfering with each other, it is conceivable to increase the diameter of the hob cutter 15. But if you do it like this.

It is necessary to increase the radius 16 of the cutter supporting the hob cutter 15 accordingly, and the torque during cutting increases, which is undesirable.

(Purpose of the Invention) This invention was made in view of the above-mentioned circumstances, and even if the worm or screw gear to be created has a small diameter, the cutter head can be made compact,
It is also an object of the present invention to reduce the torque during cutting so that the above-mentioned worm and screw gear can be created.

(Structure of the Invention) To achieve the above object, the present invention is characterized by a headstock that rotates a cylindrical gear material around its axis, and a pinion type cutter that cuts the outer peripheral surface of the gear material. and a cutter head that supports the cutter and moves the cutter in parallel to the axial direction of the gear material while rotating the cutter around its axis.

(Example) Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 4.

In FIGS. 1 to 3, l is a gear cutting machine, and this gear cutting machine l has a headstock 2 and a headstock 3 installed on a horizontal coaxial shaft, and both of these 2 and 3 are connected to a gear material 4. is supported. This gear material 4 is a material for creating a worm having multiple worm teeth 4a, and is rotated around its axis by the Shinshindai 3. Further, a binion type cutter 5 for cutting the outer circumferential surface of the gear material 4 is provided. The base end of the cutter 5 is supported in a cantilever manner by the cutter head 6, and the end of the cutter 5 on the side of the cutting blade 5a is a free end. In this case, the cutter rod 6 may support the cutter 5 on both sides.

The cutter rod 6 drives the cutter 5 to rotate around its axis. Further, the cutter rad 6 supports and rotates the cutter 5 as described above, and moves the cutter 5 in parallel in the axial direction of the gear material 4.

When creating the worm teeth 4a on the outer circumferential surface of the gear blank 4, the gear blank 4 and cutter 5 are first rotated as shown by arrows A and B in the figure. Then, the cutter 5 is moved in the direction of arrow C in Figures WS1 and 2 parallel to the axis of the gear material 4, and the outer circumferential surface of the gear material 4 is cut from one end in the axial direction of the gear material 4. Worm tooth 4a
to cut. In this case, the free end side end surface of the cutter 5,
The cut portion is substantially perpendicular to the outer peripheral surface of the gear material 4. When the cutter 5 reaches the other end of the gear blank 4 in the axial direction, the creation of the worm teeth 4a in the gear blank 4 is completed.

According to the above cutting method, the worm teeth 4a can be created by rotating the gear material 4 at high speed and cutting the outer peripheral surface thereof. And since this is a processing method similar to normal lathe processing.

In the example shown in FIG. 0, the number of worm teeth 4a is 40, which allows the worm teeth 4a to be created more quickly and easily than in conventional machining using a hobbing machine.

In the above case, the direction of the cutting blade 5a of the cutter 5 in the part where the gear material 4 is being cut matches the direction of the tooth trace of the worm tooth 4a to be created. Therefore, the intersecting angle β of the two axes of the gear material 4 and the cutter 5 in plan view has a value close to a right angle since the lead angle α of the worm is small. Therefore, regardless of the diameter of the worm to be created, interference between the headstock 2, the psychological table 3, and the cutter radius 6 is prevented.

Although the above is based on the illustrated example, the headstock 2 and the psychological table 3 may be provided vertically or on other inclined axes.
Instead of creating the worm teeth 4a, a screw gear may be created from the gear material 4.

FIG. 4 shows another embodiment.

In the figure, the free end side end face of the cutter 5 is offset by a dimension from an imaginary line 7 parallel to this end face and perpendicular to the axis of the gear blank 4. If the front clearance angle of the cutter 5 with respect to the gear material 4 at this time is γ, and the rake angle is φ, it is preferable to set the γ diameter to 26 degrees and the φ point to 5 degrees. The same is true.

When the cutter 5 is used in the above state, the cutter 5 can be created as follows. That is, first, a normal spur gear is formed, which is hardened and then polished using a Reishauer grinder or a matrix tooth grinder to create the cutter 5.

According to the above creation, the cutter 5 can be made highly accurate,
Moreover, mass production becomes possible.

(Effects of the Invention) According to the present invention, a headstock for rotating a cylindrical gear material around its axis, and a pinion type cutter for cutting the outer peripheral surface of the gear material are supported, and the cutter is rotated around its axis. The cutter head is provided with a cutter head that moves parallel to the axial direction of the gear material while rotating around the gear material, and in this case, the direction of the cutting blade of the cutter in the part where the gear material is being cut is created. This corresponds to the tooth trace direction of the worm teeth. Therefore, since the lead angle of the worm is small, the intersecting angle between the axes of the gear material and the cutter has a value close to a right angle.

That is, the positions of the headstock or psychological stand that support the gear material and the cutter, respectively, and the cutter head are shifted by approximately 90 degrees. Therefore, if the diameter of the worm to be created is small, even if the diameter of the cutter is made smaller and the axes of the gear material and the cutter are brought closer together, the headstock, psychological table, and cutter head will not fit together. are prevented from interfering with each other.

Therefore, even if the worm to be created has a small diameter, the diameter of the cutter can be made small, so the cutter head that supports it can be made compact.
The above worm can be created. Furthermore, since the diameter of the cutter can be reduced, the torque during cutting can also be reduced.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention, in which FIG. 1 is a plan view, FIG. 2 is a front view, FIG. 3 is a side cross-sectional view taken along line mm in FIG. 1, and FIG. The figure shows another example, and FIG. 15 is a partially enlarged cross-sectional view of the figure corresponding to FIG. 3, which is a plan view showing a conventional example. L・Fist gear cutting machine, 2・φ headstock, No. 4 fist gear material, 4a...
Worm tooth, 5... cutter, 6φ cutter head. Patent applicant: Mizoguchi Machine Manufacturing Co., Ltd.
Matsuki Seiki Co., Ltd.

Claims (1)

[Claims] 1. A gear cutting machine that creates a worm or screw gear with multiple worm teeth from a cylindrical gear material, which includes a headstock for rotating the gear material around its axis, and an outer circumferential surface of the gear material. A gear cutting machine characterized by being provided with a cutter head that supports a pinion type cutter for cutting and moves the cutter parallel to the axial direction of the gear material while rotating the cutter around its axis.