JPH027769B2 - - Google Patents

Description

[Detailed Description of the Invention] Conventionally, when tapping a screw, the ejection of chips is not smooth, and the cutting tool may be damaged due to excessive cutting resistance, so the tapping process is troublesome. In particular, the latest caution is required when tapping small diameter screws.

Therefore, various studies have been conducted to facilitate the tapping process, and the vibration cutting method has been developed as the most effective method. What is this vibration cutting method?
This is a method in which tapping is performed while forcibly swinging the blade (tap) or workpiece. According to this method, cutting resistance is theoretically reduced, chip evacuation is improved, and burrs are eliminated. It is well known that it is possible to tap screws with good quality without sticking out, and it is also possible to easily tap small diameter screws.Thread tapping devices and drilling devices that incorporate such vibration cutting methods , tooling, etc. are being researched and developed.

However, currently developed devices have separate driving sources for rotating and swinging the cutter, and have a structure that rotates the cutter and swings the workpiece, resulting in a complex device structure. It is inevitable that they will become larger and larger, and they are becoming more troublesome to handle. In addition, although devices have been developed in which the cutter rotates and oscillates using the same drive source, the rotation and oscillation of the cutter lack smoothness, and the rotational speeds are similar, making it difficult to rotate and oscillate. However, they failed to produce the theoretical effects, lacked practicality, and have hardly been put into practical use.

This inventor has been researching vibration cutting methods for a long time and is one of the people who established the vibration cutting theory, but he has also continued research and development toward practical application, and has fully demonstrated the effects of vibration cutting methods. We have completed a tooling for tapping and drilling using an oscillating cutting method that is small, easy to handle, and can be used in machining centers.

That is, the present invention connects a wave generator of a reduction gear having a coaxial three-layer structure of a wave generator, a flex spline, and a circular spline to a driving shaft, and One is fixed, the other is an output part, a rotary holder is fixed to this output part, a female thread is provided on the tip of the rotary holder coaxially with the driving shaft, and a tool holder mounting main shaft is screwed into the female thread. , a crankshaft is provided on the inner wall of the rotating holder at a position eccentric to the driving shaft so as to be freely rotatable in the direction of the coaxial center, crank arms are fixed to both ends of the crankshaft, and one of the crank arms is fixed to the above-mentioned drive shaft. The wave generator and the other crank arm are engaged with the tool holder mounting spindle at eccentric positions, and the rotation of the wave generator causes the tool holder mounting spindle to swing via the crank arm and crankshaft. In addition, the tool holder attachment main shaft is rotated through the rotary holder, which rotates due to the rotation of the output section of the reduction gear.

Hereinafter, the present invention will be explained in detail based on embodiments shown in the drawings.

In the drawings, 1 is a driving shaft that rotates in response to the rotation of a main shaft 2 of a machining center, and 3 is a speed reduction device that decelerates the rotation of the driving shaft 1. This speed reducer 3
In this case, it is a flexure-mesh type speed reduction device composed of a coaxial three-layer structure of a wave generator 4, a flex spline 5, and a circular spline 6, and is capable of obtaining a large reduction ratio, and is generally used. It is known under the trade name Harmonic Drive (trade name). This speed reducer 3
A wave generator 4 is connected to the driving shaft 1 and serves as an input section. Regarding the output section, when either the flex spline 5 or the circular spline 6 is fixed, the other becomes the output section. In the embodiment, the flex spline 5 is fixed and the circular spline 6 is used as the output section. Reference numeral 7 denotes a fixing circular spline for fixing the flexspline 5, and this fixing circular spline 7 is fixed to the casing 8.

Reference numeral 9 denotes a rotary holder fixed to the circular spline 6 which serves as the output section of the speed reducer 3, and a female thread 10 is provided at the tip of the rotary holder 9 coaxially with the driving shaft 1 and the wave generator 4. The pitch of this female thread 10 is not particularly limited in the case of drilling, but in the case of tapping, it should be the same pitch as the desired thread. A tool holder attachment main shaft 11 is screwed into this female thread 10.

The crankshaft 1 is mounted on the inner wall of the rotating holder 9.
2 is provided at a position eccentric to the driving shaft 1 and the wave generator 4 so as to be freely rotatable in the coaxial direction. Crank arms 13 and 14 are fixed to both ends of this crankshaft 12, respectively, and the crank arms 13 and 14 are engaged with the wave generator 4 and the tool holder attachment main shaft 11 at eccentric positions, respectively. I'm letting you do it. Specifically, a guide groove 15 is formed in the longitudinal direction of the crank arm 13, and an eccentric pin 16 is provided in the wave generator 4 at a position eccentric to the coaxial center.
A shoe 17 is fitted onto this eccentric pin 16, and this shoe 17 is inserted into the guide groove 15 of the crank arm 13.
is engaged with. The shoe 17 is designed to slide along the guide groove 15 with little friction, and when the wave generator 4 rotates, the shoe 17 slides along the guide groove 15.
rotates while sliding in the guide groove 15 of the crank arm 13, and the rotation of the shoe 17 causes the crank arm 13 to swing at an angle proportional to the amount of eccentricity of the eccentric pin 16. In addition, an eccentric pin 18 is provided on the crank arm 14 provided at the other end of the crankshaft 12 at a position eccentric to the axis of the crankshaft 12 and the axis of the tool holder attachment main shaft 11. mate. And tool holder mounting spindle 1
A guide groove 21 parallel to the crank arm 14 is formed at the end of the motion transmission shaft 20 coaxial with the main shaft 11 and engaged with the main shaft 11, and the shoe 19 is engaged with the guide groove 21. ing. The shoe 19 is designed to slide along the guide groove 21 with little friction, and when the crankshaft 12 swings in the circumferential direction via the crank arm 13 due to the rotation of the wave generator 4, the crank arm 14
The shoe 19 also makes a swinging motion while sliding on the guide groove 21. The swinging motion of the shoe 19 causes the motion transmission shaft 20 to swing in the circumferential direction, and the tool holder attachment main shaft 11 that engages with this motion transmission shaft 20 swings. For the engagement between the tool holder attachment spindle 11 and the motion transmission shaft 20, a square hole 22 is formed in the axial direction at the end of the tool holder attachment spindle 11, while the end of the motion transmission shaft 20 is A square rod 23 having the same shape as the square hole 22 is formed, and the square rod 23 is fitted into the square hole 22 so as to be slidable in the axial direction.

Therefore, when the driving shaft 1 rotates, the speed reducer 3
The rotary holder 9 fixed to the circular spline 6, which serves as the output part, is rotated at a predetermined rotation speed, and the female thread 10 provided at the tip of the rotary holder 9 is rotated.
The tool holder attachment main shaft 11, which is screwed into the tool holder, rotates. At the same time, due to the rotation of the wave generator 4, which rotates at high speed by directly receiving the high-speed rotation of the driving shaft 1, the shaft is transferred to the tool holder mounting main shaft 11 via the crank arm 13, crank shaft 12, crank arm 14, and motion transmission shaft 20. Transmits high-speed rocking motion in the circumferential direction. As a result, the tool holder attachment main shaft 11 rotates slowly in response to the rotation of the rotary holder 9, and at the same time slides at high speed on the square bar 23 of the motion transmission shaft 20 in the lead angle direction of the female thread 10 in response to the oscillating motion. It is designed to perform a rocking motion.

24 is a pull stud, 25, 26, 27 are nuts, 28, 29 are bearings, 30, 31 are oil seals, 32 is a tool holder provided at the tip of the tool holder mounting spindle 11, and 33 is provided on the outer wall of the casing 8. When the tooling according to the present invention is set on the main shaft 2 of a machining center, the rotation stopper engages with a positioning block 34 provided on the machining center and prevents the casing 8 from rotating.

When tapping the tool with the above configuration on a machining center, the tooling is done by matching the pitch of the female thread 10 provided at the tip of the rotary holder 9, and the tool holder 32 is tapped by the rotation of the main shaft 2 of the machining center. The attached cutter rotates in the direction of the lead angle of the female thread 10 while making a high-speed rocking motion, and taps the thread by feeding the height according to the pitch of the thread required by the machining center. Further, the drilling process is carried out in the same manner as the tapping process described above, but in this case there is no need to pay attention to the pitch of the female thread 10.

As described above, according to the present invention, the rotary motion and rocking motion of the cutter are performed smoothly, and since the reduction gear used in the present invention requires a large reduction ratio, the rotary motion and rocking motion are smoothly performed. A large speed difference in dynamic motion can be determined, and the theoretical effects of rocking can be extremely effectively produced. In addition, the simple structure makes it compact and lightweight, making it easy to handle.Furthermore, since the driving shaft and the cutter are coaxially located, it can be used in machining centers, making it particularly suitable as tooling for machining centers. It has a positive effect.

[Brief explanation of drawings]

The drawings show one embodiment of the invention.
The figure is a longitudinal sectional view, and FIG. 2 is a partially exploded perspective view of FIG. 1. 1... Driving shaft, 3... Reduction device, 4... Wave generator, 5... Fukure spline, 6...
...Circular spline, 9...Rotating holder,
10... Female thread, 11... Tool holder mounting spindle, 12... Crank shaft, 13, 14... Crank arm.

Claims (1)

[Claims] 1. Connect the wave generator of a reduction gear that has a coaxial three-layer structure of a wave generator, flex spline, and circular spline to the driving shaft, and fix either the flex spline or the circular spline. , the other is an output part, and a rotary holder is fixed to this output part,
A female thread is provided at the tip of the rotary holder coaxially with the driving shaft, a tool holder mounting main shaft is screwed onto the female thread, and a crankshaft is mounted on the inner wall of the rotating holder in a coaxial direction at a position eccentric to the driving shaft. A crank arm is fixed to both ends of the crankshaft, and one crank arm of the crank arm is connected to the wave generator, and the other crank arm is connected to the tool holder mounting main shaft and their respective axes. The rotary holder is engaged at an eccentric position so that the rotation of the wave generator causes the tool holder attachment main shaft to swing through the crank arm and the crankshaft, and the rotary holder rotates due to the rotation of the output section of the reduction gear. Tooling in which the tool holder mounting spindle is rotated through the tool holder.