JPH0780702A - Vibration damping method in cutting work - Google Patents

Abstract

PURPOSE:To surely restrain chattering vibration generated in a cutting tool during cutting work by providing a weight sliding along the axis direction of a vibration damping device to constantly conform the weight sliding axis to the resultant force direction of cutting resistance exerted on the cutting edge of the cutting tool. CONSTITUTION:The weight axis of a vibration damping device 10 is directed to the direction of resultant force R, and a weight-sliding direction S and the resultant force R direction can be conformed with each other. Consequently when a relatively larger shock load is applied to a cutting tool 1 during work, a holder 4 is displaced in the resultant force R direction of main component force Fv, feed component force Ff, and back component force Fp, cutting resistant components, to produce a fine gap between a weight 11 and the head part of a bolt 12. At that time, the weight 11 slides in the resultant force R direction by the action of a spring 13 to collide with the head part of the bolt 12, and the weight 11 is sprung back to collide with the head part of the bolt 12 again. This repetetion consumes vibration energy to eliminate chattering vibration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration control method for cutting which is suitable for suppressing chatter vibration of a cutting tool during cutting of a work.

[0002]

Chatter vibration of a tool during cutting is
In recent years, this is one of the causes of significantly impairing the functions of highly efficient and highly accurate machine tools that have been improved. For example, this is the impact load when the cutting edge is inadvertently overcut into the work, the cutting edge hits the hard part of the material during cutting,
It occurs due to the action of other external forces, for example,
Machining accuracy is greatly impaired, and when it matches the natural frequency of the cutting tool, the tool confidence will be damaged, and other problems will occur.

An example of a conventional technique used for suppressing such chatter vibration of a tool is shown in FIG. 5, for example. The cutting tool 1 is fixed to a tool rest 2, and a weight 3 having a certain weight is provided on an upper surface of a holder 4. The bolt 5 extends inside the holder 4 through a counterbore hole 3 a formed in the weight 3, and the weight 3 is fixed via a spring 6. The cutting edge 7 is embedded in the work 8 and indicates that the work is being cut. In the figure, arrow Fv indicates the main component force in cutting, S indicates the weight sliding direction, and N indicates the workpiece rotation direction.

In the above construction, when an impact load is applied to the cutting tool 1, a minute gap is generated between the upper surface of the holder 4 and the weight 3, and the weight 3 acts on the upper surface of the holder 4 by the action of the spring 6. The weight 3 is pressed, and the weight 3 repeatedly collides in this process to damp the vibration.

[0005]

However, in the above-described vibration damping device, the weight sliding direction S is limited to one direction, and a sufficient vibration damping effect cannot be obtained. That is,
As is well known, the cutting resistance is the resultant force of the feed component force V including the main component force Fv and the back force component, and the holder 4 is not always displaced in the direction that coincides with the main component force Fv. In order to direct the weight sliding direction S in a direction that matches the resultant force, the above-described vibration damping device is insufficient including the arrangement of the members, and a more desirable method that does not rely on this vibration damping device is required.

Further, in order to enhance the damping effect, it is necessary to make the weight 3 larger or the spring 6 stronger in the above-mentioned vibration control device, but even if such a method is used, the device becomes large in size. However, the damping effect does not increase,
In particular, it is difficult to function effectively when processing a work having a large cutting resistance.

An object of the present invention is to provide a vibration damping method in cutting which effectively suppresses chatter vibration generated in a cutting tool.

[0008]

In order to suppress chatter vibration generated in a cutting tool during cutting of a workpiece, the present invention provides a weight that slides along the axial center method of a vibration damping device, and uses the weight sliding shaft as a cutting tool. It is characterized in that the cutting force acting on the cutting edge is always matched with the resultant direction.

In another invention, in order to suppress chatter vibration generated in a cutting tool during cutting of a workpiece, a weight provided with a vibration damping material contacting the cutting tool at each surface in cross section is provided, and the weight is used as a cutting tool. It is characterized in that it is moved in all directions including the resultant direction of the cutting resistance acting on the cutting edge.

[0010]

[Function] In order to suppress chatter vibration in cutting, it is not sufficient to consider only a part of the cutting resistance component, and attention is paid to how the resultant force of each component is involved. That is, the weight axis of the vibration damping device is arranged in the resultant direction.

By making the resultant force direction and the weight sliding direction coincide with each other in this way, the displacement direction of the cutting tool to be vibrated and the operating direction of the weight can be accurately matched, and the vibration damping effect can be made more reliable. become.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIG. A tip 9 is attached to the tip of the holder 4. The cutting edge 7 is directed toward the work 8 and a part of the cutting edge 7 bites into the work 8. At this time, the cutting resistance component generated in the cutting tool 1 can be expressed by the main component force Fv, the feed component force Ff, and the back component force Fp. From this, it is understood that the resultant force R of the cutting resistance is diagonally downward from the cutting edge 7.

The weight axis of the vibration damping device 10 of this embodiment is oriented in the direction of the resultant force R, and the weight sliding direction S and the direction of the resultant force R can be matched. The vibration damping device 10 includes a weight 11, a bolt 12, and a spring 1.
It consists of three. In fixing the bolt 12, the fixing screw 14 is carved on the holder 4 in the embodiment and the tip of the bolt 12 is screwed into the holder.

The weight 11 has a counterbore 11a formed therein, and the spring 13 is mounted in the counterbore 11a.

In the above configuration, the cutting tool 1 is being machined during machining.
When a relatively large impact load is applied to, the resultant force R of the cutting force component of the main component force Fv, the feed component force Ff, and the back component force Fp
The holder 4 is displaced in the direction, and a minute gap is formed between the weight 11 and the head of the bolt 12. At this time, the weight 11
Is slid in the same direction by the action of the spring 13, collides with the head of the bolt 12, the weight 11 bounces and collides with the head of the bolt 12 again, and by repeating this, vibration energy is consumed and chatter vibration disappears.

In the present embodiment, not only the main component force Fv but also the cutting resistance components of the feed component force Ff and the back component force Fp are taken into consideration, so that the vibration damping device 10 can be used more effectively. Is.

The vibration damping device 10 is composed of a minimum number of necessary members, has a simple structure, and has a simple fixing method, so that it can be used for any application from light cutting conditions to heavy cutting conditions. Although the above embodiment takes into consideration the three-component force of the cutting resistance component, the vibration damping device may be provided in the direction that coincides with the resultant direction of the two-component force.

FIG. 2 shows an embodiment in which the vibration damping device 10 is applied in the resultant direction R'of the two-component force. The weight axis of the vibration damping device 10 is oriented in the direction of the resultant force R'of the main component force Fv and the back force component Fp, and the weight sliding direction S and the direction of the resultant force R'are aligned.

The vibration damping device 10 includes a weight 11 and a bolt 1.
2. A universal joint 15 is added to the spring 13.

A fixing screw 14 is cut on the holder 4 ', and a main shaft 15a of a universal joint 15 is screwed into and fixed to the holder 4'. Further, the bolt 12 is connected to the base 15b and operates integrally.

In order to match the weight sliding direction S of the vibration damping device 10 with the direction of the resultant force R ', the universal joint 15 is made to match the direction and then the rotation is stopped by a fixing lever (not shown).

In this embodiment, since the universal joint 15 is fixed to the holder 4, the simple vibration damping device 1
Although the advantage of 0 is somewhat impaired, the weight sliding direction S
There is an advantage that the universal joint 15 can easily correct when the directions of the resultant force R ′ and the direction of the resultant force R ′ coincide with each other.

Further, in this embodiment, the main resultant force Fv and the back force F are
Although the resultant force R ′ with p is taken into consideration, the weight sliding direction S can be determined in consideration of the resultant force of the main component force Fv and the feed component force.

Further, an embodiment different from the above embodiment will be described with reference to FIGS. 3 and 4. In FIG. 3, a vibration damping device indicated by reference numeral 20 has a weight 22 having a square hole 21 whose inner surface is formed larger than that of the holder 4 so as to keep a space between the holder 4 and the outer peripheral surface, and the square hole 21. A vibration damping material 23 made of an elastic material, for example, synthetic rubber, which is mounted so as to fill the gap between the holder 4 and the holder 4, and a tightening bolt 24 for fixing the weight 22 to the holder 4. The weight 22 is formed with a cutout groove 22b extending from the square hole 21 to a protruding portion 22a slightly protruding to the outer surface, and a screw 22c is formed in the protruding portion 22a in a direction perpendicular to the cutout groove 22b to tighten the tightening bolt 24. Can be screwed there.

FIG. 4 shows that the holder 4 to which the vibration damping device 20 is fixed is fixed to the tool rest 2.

The damping effect of this embodiment depends on the elasticity of the vibration damping material 23 mounted in the square hole 21 of the weight 22, and the cutting resistance is actually received by the holder 4 through the cutting edge 7 of the cutting tool 1. It is necessary to compare the state of vibration occurrence.
This is carried out while changing the tightening force of the tightening bolt 24 to determine the direction of the exciting force transmitted to the weight 22 and finding a place where the vibration becomes small. In the present embodiment, the weight 22 moves in a small amount in all directions including the resultant direction of the cutting resistance, and it is possible to damp complicated cutting vibration due to variations in cutting conditions and work rigidity.

The shape of the vibration damping device 20 is such that the partition wall is provided on the holder 4 with a flat plate, and the chips generated by the cutting edge 7 are prevented from being scattered by the partition wall to ensure the safety of the operator. But it works.

Although the weight 22 of the embodiment is a square shape, it may be a circular shape, and another shape may be adopted depending on the shape of the work.

Further, in order to monitor only the cutting edge 7, it is possible to make a part of the weight 22 into a cutout shape so that only the cutting edge 7 can be seen.

[0030]

As is apparent from the above description, the present invention is provided with a weight that slides along the axial direction of the vibration damping device, and the weight sliding axis is the resultant direction of the cutting resistance that acts on the cutting edge of the cutting tool. The chatter vibration generated in the cutting tool can be surely suppressed during the work cutting, and an excellent effect such as high accuracy and high accuracy can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing a mounted state of a vibration damping device that realizes a vibration damping method according to the present invention.

FIG. 2 is a side view showing another embodiment of the vibration damping device of the invention.

FIG. 3 is a sectional view showing another embodiment of the vibration damping device of the invention.

4 is a cross-sectional view of the vibration damping device shown in FIG.

FIG. 5 is a side view showing an example of a vibration damping device according to a conventional technique.

[Explanation of symbols]

 4 ... Holder 7 ... Cutting edge 9 ... Tip 10 ... Damping device 11, 22 ... Weight 12, 24 ... Tightening bolt 13 ... Spring 15 ... Universal joint 21 ... Square hole 23 ………… Vibration damping material

Claims (2)

[Claims] 1. In suppressing chatter vibration generated in a cutting tool during work cutting, a weight that slides along a shaft center method of a vibration damping device is provided, and the weight sliding shaft acts on a cutting edge of the cutting tool. A damping method in cutting, which is characterized by always matching the resultant direction of cutting resistance. 2. In suppressing chatter vibration generated in a cutting tool during cutting of a workpiece, a weight provided with a vibration damping material that is in contact with the cutting tool at each surface in cross section is provided, and the weight is cut by the cutting tool. A vibration damping method in cutting, which comprises moving the blade in all directions including the resultant direction of the cutting resistance acting on the blade.