TW201315564A - Vibration-damping mechanism - Google Patents

Abstract

This invention provides a vibration-damping mechanism configured to absorb a large amount of vibration energy and avoid the high production costs of the vibration-damping weight member and a reduction in the strength of the shaft section. A cylindrical hollow section (6) formed within a shaft section (1) is received with heavy weight members (14) which are separated circumferentially about the axis of the hollow section. Pressing members (16) are provided in the hollow section pressing the weight members toward the axis so that the separation surfaces (15) of the adjacent heavy weight members are in surface contact with each other.

Description

Damping mechanism

According to the present invention, the cylindrical hollow portion formed in the shaft portion of the tool holder or the like is housed in a vibration-damping mechanism for the vibration-damping weight so as to be concentric with the axial center of the hollow portion.

In the cutting process of the metal, the tool holder that fixes the cutting blade on the distal end side is attached to the machine tool in a cantilever state, and the tool holder rotates to perform metal cutting. Flutter can cause problems with reduced machining accuracy.

In the damper mechanism, the vibration is generated in the machining process, and the vibration damping weight accommodated in the hollow portion vibrates to cancel the chatter vibration while absorbing the energy of the chatter vibration, thereby suppressing the chatter vibration. Seek to improve processing accuracy.

The conventional vibration damping mechanism absorbs chattering energy by rubbing and colliding with one of the damping weights accommodated in the hollow portion and the inner surface of the hollow portion (see, for example, Patent Document 1).

[Patent Document 1] Japanese Patent Publication No. 2003-521381

Therefore, the amount of absorption of the vibration energy corresponds to the weight of the weight for vibration suppression, and in order to increase the absorption amount of the vibration energy, it is necessary to accommodate the weighted weight in the hollow portion.

When the heavy weight damping hammer is accommodated in the hollow portion, the production cost of the vibration hammer for heavy vibration may be increased if a heavy hammer made of a high-priced super-hard alloy or a heavy metal is accommodated. Further, if a weight of a low-cost metal having a small specific gravity is accommodated, the hollow portion may be increased in size and the strength of the tool holder may be lowered.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a vibration damping mechanism which can avoid an increase in the manufacturing cost of the weight for vibration damping and a decrease in the strength of the shaft portion, and can increase the absorption amount of the vibration energy.

The first characteristic structure of the vibration-damping mechanism of the present invention is a cylindrical hollow portion formed inside the shaft portion, and accommodates a plurality of weight members that are divided into a plurality of circumferential directions around the axial center of the hollow portion, and The elastic member is biased toward the axial center so that the divided surfaces of the adjacent weight members are in surface contact with each other.

The vibration damping mechanism of the present configuration is a cylindrical hollow portion formed inside the shaft portion, and accommodates a plurality of weight members divided into a plurality of pieces.

Therefore, with the chattering of the shaft portion, the split surfaces of the adjacent weight members can slide each other, so that the vibration energy can be absorbed in the form of friction energy and collision energy between the split surfaces.

In addition, since the weight member divided into a plurality of weight members in the circumferential direction around the axial center of the hollow portion is accommodated in the hollow portion, the divided surfaces of the weight members can slide along each other in the radial direction of the shaft portion, and the weight portion can be effectively reduced. Flutter generated in the direction of the shaft diameter.

In addition, since the elastic member that is biased toward the axial center of the hollow portion so that the divided surfaces of the adjacent weight members are in surface contact with each other is provided, it is possible to positively impart resistance to the sliding between the divided surfaces, and to allow the divided surfaces to be mutually The friction energy between them increases, and the absorption amount of the vibration energy is further increased.

Therefore, according to the vibration damping mechanism of the present configuration, it is possible to avoid an increase in the manufacturing cost of the weight for vibration making and a decrease in the strength of the shaft portion, and it is possible to increase the absorption amount of the vibration energy.

According to a second aspect of the invention, the elastic member is an annular elastic member that is disposed between the outer peripheral surface of the plurality of weight members and the inner peripheral surface of the hollow portion.

According to this configuration, a plurality of weight members can be biased in a uniform and simple manner to move toward the axial side.

According to a third aspect of the present invention, a restriction member for restricting a displacement amount of the plurality of weight members away from the axial center side is provided.

According to this configuration, since the amount of displacement of the plurality of weight members away from the axial center side can be restricted, it is easy to quickly move the weight member displaced toward the axial center side toward the axial center side as the shaft portion vibrates. The rotation of the shaft portion is stabilized, and the vibration energy absorbing effect by the sliding between the divided surfaces can be improved.

Embodiments of the present invention will be described below based on the drawings.

[First Embodiment]

Fig. 1 and Fig. 2 show a tool holder (an example of a shaft portion) 1 provided with the vibration damping mechanism 2 of the present invention.

The damper mechanism 2 is mounted inside a steel tool holder 1 having a circular cross section and having an outer peripheral portion concentric with the rotation axis X.

The tool holder 1 is concentrically and integrally provided with a shaft portion main body 1a for tool mounting and a tapered portion 1b for coupling to a rotating shaft (not shown) of the machine tool, and is coupled to the tapered portion 1b. The rotary shaft is driven to rotate.

A mounting hole 4 of the tool head 3 is formed at a front end portion of the shaft main body 1a, and the tool head 3 is fixed to the mounting hole 4 in a state in which it cannot be detached, as shown by the imaginary line in Fig. 1, on the tool head 3. A disposable blade 5 having a cutting edge portion is fixed.

Inside the shaft main body 1a, a hollow portion 6 which is concentric with the rotation axis X of the tool holder 1 and has a circular cross section is formed, and the vibration damping mechanism 2 is installed in the hollow portion 6.

The hollow portion 6 is formed on the tapered portion 1b side of the plug member 8 by being partitioned by the plug member 8 screwed to the inner peripheral surface of the shaft hole 7. The shaft hole 7 is open to the front end side of the shaft portion main body 1a and has a circular cross-sectional shape.

A mounting hole 4 is formed in the shaft hole 7 at a front end side of the plug member 8.

The tool holder 1 is formed with a refrigerant supply path 9 for supplying a refrigerant such as cutting oil to the tool through the mounting hole 4 so as to be concentric with the rotation axis X throughout the shaft main body 1a and the tapered portion 1b. Head 3.

The refrigerant supply line 9 is connected to the refrigerant pipe 10 which is concentric with the rotation axis X and penetrates the hollow portion 6. The refrigerant pipe 10 is connected to the through hole 8a of the plug member 8 and communicates with the mounting hole 4.

The vibration damping mechanism 2 is a vibration mass 11 made of a superhard alloy obtained by sintering WC (tungsten carbide) or the like, and a gap 12a, 12b is interposed between the outer circumferential surface of the refrigerant pipe 10 and the inner circumferential surface of the hollow portion 6. It is accommodated in such a manner that it is concentric with the rotation axis X.

The elastic O-ring 13 is attached to the connection portion between the refrigerant pipe 10 and the refrigerant supply path 9 and the connection portion with the through hole 8a of the plug member 8. Therefore, it is possible to prevent the liquid such as the refrigerant from flowing into the vibration mass 11 and The gaps 12a and 12b between the outer circumferential surface of the refrigerant pipe 10 and the inner circumferential surface of the hollow portion 6 can prevent the vibration damping effect from being lowered.

As shown in FIG. 2 and FIG. 3, the weight-increasing weight 11 is divided into a plurality of weight members 14 that are fan-shaped in cross-sectional shape along the circumferential direction around the rotation axis X, and will be divided into a plurality of weight members 14 having a fan shape in a cross-sectional shape. The weight members 14 are arranged in a cylindrical shape around the refrigerant pipe 10 and housed in the hollow portion 6.

Further, the plug member 8 is locked with force toward the vibration-damping weight 11 side, whereby the weight member 14 is given a compressive force in the direction of the rotation axis X.

In order to allow the split faces 15 of the adjacent weight members 14 to strongly slide with each other with the chattering of the tool holder 1, the elastic members 16 are provided at both end portions in the X-direction of the rotation axis; the elastic members In a state in which the plurality of weight members 14 are arranged in a cylindrical shape and housed in the hollow portion 6, the plurality of weight members 14 are biased so that the divided faces 15 of the adjacent weight members 14 are in surface contact with each other.

The elastic member 16 is configured by an annular elastic member (elastic O-ring) that is disposed between the outer peripheral surface of the plurality of weight members 14 and the inner peripheral surface of the hollow portion 6.

[Second Embodiment]

Fig. 4 and Fig. 5 show other embodiments of the vibration damping mechanism of the present invention.

The vibration damping mechanism of the present embodiment is disposed at a central position in the X direction of the rotation axis of the damping weight 11 divided into a plurality of weight members 14, and is provided to restrict the plurality of weight members 14 from moving away from the rotation axis. The restriction member 17 of the shift amount on the side of the heart X.

The restricting member 17 is formed of a metal ring body having an inner diameter smaller than the inner diameter of the hollow portion 6 and having an outer diameter larger than the inner diameter of the hollow portion 6, and the outer peripheral side thereof is fitted into the inner peripheral surface of the hollow portion 6. The circumferential groove 18 is mounted on the side of the weight member 14 so as not to fall off.

The other structure is the same as that of the first embodiment.

[Other Embodiments]

1. The vibration damping mechanism according to the present invention is divided into a plurality of weight members at equal intervals in the circumferential direction around the axial center of the hollow portion, and may be further divided into a plurality of members along the axial direction of the hollow portion.

In this case, as the chattering of the shaft portion allows the split surfaces of the adjacent weight members to slide each other in the axial direction of the hollow portion, the vibration energy can be used as the friction energy and the collision energy between the split surfaces. The form is absorbed.

Further, if an annular elastic member is interposed between the outer peripheral surface of each of the weight members and the inner peripheral surface of the hollow portion, the weight members can be biased so as to move toward the axial center side of the hollow portion. By reducing the moment of inertia of the shaft and allowing the shaft to rotate smoothly, it is possible to prevent the vibration-damping effect from deteriorating.

2. The vibration damping mechanism according to the present invention is configured such that the weight members are divided into a plurality of weight members at equal intervals in the circumferential direction around the axial center of the hollow portion, but are not limited thereto, and are not equally spaced. The weight member divided into a plurality of members may be accommodated in the hollow portion.

3. The vibration damping mechanism of the present invention is divided into a plurality of weight members in the circumferential direction around the axial center of the hollow portion, and is divided into a plurality of weight members in the axial direction of the hollow portion and accommodated in the hollow portion. For example, both end sides or one end side in the axial direction may be used.

4. The vibration damping mechanism of the present invention may be divided into a plurality of weight members in a circumferential direction around the axial center of the hollow portion in a hollow portion formed in a shaft portion other than the tool holder.

5. In the vibration damping mechanism of the present invention, the shaft portion may not be a rotating body, and the center of the hollow portion may not coincide with the axial center of the shaft portion.

The present invention can be widely applied to a hollow portion formed on a shaft portion of a member that generates vibration such as a tool holder.

1. . . Tool holder (an example of a shaft)

1a. . . Shaft body

1b. . . Cone

2. . . Damping mechanism

3. . . Tool head

4. . . Mounting holes

5. . . Disposable blade

6. . . Hollow part

7. . . Shaft hole

8a. . . Through hole

9. . . Refrigerant supply road

10. . . Refrigerant pipe

11. . . Heavy hammer

12a, 12b. . . gap

13. . . Elastic O-ring

14. . . Heavy hammer component

15. . . Split plane

16. . . Elastic member

17. . . Restricting member

18. . . Week slot

X. . . Rotating axis

Fig. 1 is a longitudinal sectional view of a tool holder provided with a vibration damping mechanism.

Fig. 2 is a sectional view taken along line II-II of Fig. 1.

Fig. 3 is a perspective view of the vibration damping mechanism.

Fig. 4 is a longitudinal sectional view showing the vibration damping mechanism of the second embodiment.

Fig. 5 is a cross-sectional view taken along line V-V of Fig. 4.

1. . . Tool holder (an example of a shaft)

1a. . . Shaft body

2. . . Damping mechanism

6. . . Hollow part

7. . . Shaft hole

10. . . Refrigerant pipe

11. . . Heavy hammer

12a, 12b. . . gap

14. . . Heavy hammer component

15. . . Split plane

16. . . Elastic member

X. . . Rotating axis

Claims (3)

A vibration-damping mechanism is a cylindrical hollow portion formed inside the shaft portion, and accommodates a plurality of weight members that are divided into a plurality of circumferential members along the circumferential direction around the axial center of the hollow portion, and is provided to allow adjacent weights The elastic pressing member that is biased toward the axial center is formed in such a manner that the dividing faces of the hammer members are in surface contact with each other. The vibration-damping mechanism according to the first aspect of the invention, wherein the elastic member is an annular elastic member that is disposed between an outer circumferential surface of the plurality of weight members and an inner circumferential surface of the hollow portion. The vibration damping mechanism according to claim 1 or 2, wherein a restraining member for restricting a displacement amount of the plurality of weight members away from the axial center side is provided.