JPH0357375Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is a method of cutting (turning or grinding) by continuously rotating a predetermined workpiece and applying a cutting blade to the workpiece. The present invention relates to a vibration absorbing device for a workpiece in a rotary cutting machine.

(Prior art) Conventionally, for example, when finishing cutting the outer periphery of a shaft workpiece with a length of 300 mm or more, a roller guide or the like is pressed against the center of the workpiece in the longitudinal direction to prevent the workpiece from steadying. It's summery.

(Problem to be solved by the invention) When the natural vibration of the workpiece and the vibration generated between the workpiece and the cutting blade resonate during cutting of the workpiece, as described above, However, a steady rest means such as a roller guide pressed against the longitudinal center of the workpiece is not very effective. This resonance then causes the workpiece itself to vibrate. In particular, when cutting a relatively short workpiece such as an annular cutting portion on the end face thereof, vibration (chatter vibration) of the workpiece is significant, thereby reducing the machining accuracy of the workpiece. In addition, in order to maintain this machining accuracy, machining conditions are sometimes changed by lowering the cutting feed rate and rotation speed, but in this case, it is possible to avoid a decrease in productivity. I can't.

(Means for solving the problems) In order to solve the above problems, the present invention is configured as follows. That is, a disk-shaped vibration absorbing member is fixed to a center guide nose that is fixed to the end of the spindle arbor and transmits rotational force to the workpiece. This vibration absorbing member is provided with slits extending from its outer periphery toward the center at a plurality of locations in the circumferential direction. An annular elastic body is attached to the outer periphery of the vibration absorbing member to press against the end surface of the workpiece.

(Operations of the invention and its effects) According to the above configuration, during cutting of the workpiece, the resonance between the natural vibration of the workpiece and the vibration generated between the workpiece and the cutting blade is caused by the center guide. The vibration is effectively absorbed by the vibration absorbing member fixed to the nose. As a result, vibrations (chatter vibrations) of the workpiece itself are suppressed, and the machining accuracy of the workpiece can be improved without reducing the feed rate or rotational speed for cutting.

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

First, in FIG. 1 showing the main parts of a rotary cutting machine, a hollow center guide nose 2 is fixed by bolts 3 to an end of a main shaft arbor 1 of this cutting machine. A center pin 4 extending from the spindle arbor 1 side is inserted into the hollow portion 2a of the center guide nose 2, and the tip of the center pin 4 protrudes from the end of the center guide nose 2.

On the other hand, the workpiece 20 of this embodiment has its shaft portion 21
It has a flange portion 22 at one end thereof, and an annular stepped portion 22 is formed on the end surface of this flange portion 22 . Then, the flange portion 2 of this workpiece 20
2 has an external shape as shown in FIG.

Centering holes 23 and 24 are formed in the axial center portions of both ends of the shaft portion 21 in the workpiece 20, respectively. Among these, one centering hole 23 is supported by the tip of the center pin 4 extending from the spindle arbor 1, and the other centering hole 24 is supported by the centering pin 1 of the centering stand (tail stock) 10.
It is supported by one tip. As a result, the workpiece 20 is positioned and held in a centered manner with respect to the rotary cutting machine. Further, in this state, the tip 2b of the center guide nose 2 is engaged with the drive plate 25 of the workpiece 20. As a result, the rotational force of the spindle arbor 1 is transmitted to the workpiece 20 through the center guide nose 2.
is transmitted to.

On the outer peripheral surface of the center guide nose 2 near the end, a vibration absorbing member 5 made of a material such as metal and formed into a disk shape as shown in FIG. 2 is fixed. That is, the vibration absorbing member 5 has a boss portion 6 that can be fitted onto the outer peripheral surface of the center guide nose 2, and the boss portion 6 is fixed to the center guide nose 2 with a plurality of bolts 8. Also,
Slits 7 extending from the outer periphery toward the center of the vibration absorbing member 5 are formed at a plurality of locations (six locations in the drawing) in the circumferential direction of the vibration absorbing member 5 .

Furthermore, an annular elastic body 9 made of a material such as rubber is attached to the outer periphery of the vibration absorbing member 5. (See Figure 1). This elastic body 9 can be pressed against the end surface of the flange portion 22 of the workpiece 20, and when the outer peripheral portion of the vibration absorbing member 5 is brought into direct contact with the end surface of the flange portion 22 of the workpiece 20, the workpiece 20 to prevent damage to the product.

In the rotary cutting machine configured as described above, when the spindle arbor 1 is rotationally driven, the centering state is maintained as described above by the center pin 4 of the spindle arbor 1 and the centering pin 11 of the centering table 10. The workpiece 20 that is held in position is continuously rotated through the center guide nose 2. Here, the flange portion 22 of the workpiece 20
When finishing cutting the annular stepped portion 22a formed on the end face, as shown in FIG. 22a to perform cutting.

If the natural vibration of the workpiece 20 and the vibration generated between the workpiece 20 and the cutting blade 13 resonate during this cutting process, this resonance will cause the vibration absorption member 5 fixed to the center guide nose 2 to resonate. It is effectively absorbed. As a result, the vibration of the workpiece 20 itself due to resonance is suppressed, and the finishing accuracy of the annular stepped portion 22a is maintained well. This is especially true when the finishing accuracy guarantee (flatness or surface roughness) is strict and the cutting is performed intermittently based on the external shape of the flange portion 22 of the workpiece 20 as in this embodiment. The vibration of the workpiece 20 is effectively suppressed even in cutting operations under such severe conditions.

The outer periphery of the vibration absorbing member 5 may be set to a large diameter within a range where the elastic body 9 attached thereto does not interfere with the holder 12 of the cutting blade 13, thereby improving the vibration suppression function of the workpiece 20. will be further improved.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; Fig. 1 is a sectional view showing the main parts of the rotary cutting machine, Fig. 2 is a plan view showing the vibration absorbing member, and Fig. 3 is the shape of the flange of the workpiece. FIG. 1... Spindle arbor, 2... Center guide nose, 5... Vibration absorbing member, 7... Slit, 9...
Elastic body, 20... Workpiece.

Claims (1)

[Scope of utility model registration request] In a rotary cutting machine that performs cutting by applying a cutting blade to a workpiece to which rotational force is applied through a center guide nose fixed to the end of the spindle arbor, the center guide nose has a disk shape, A rotary cutting machine comprising: a vibration absorbing member having slits formed at a plurality of locations in the circumferential direction from the outer periphery toward the center; and an annular elastic body attached to the outer periphery of the vibration absorbing member to press against the end face of the workpiece. Vibration absorption device for workpieces.