WO2025057557A1 - Swarf-dividing lathe-turning control device and machine tool provided with same - Google Patents

Abstract

[Problem] To provide: a swarf-dividing lathe-turning control device capable of easily controlling division of swarf during lathe-turning and providing stable cutting quality; and a machine tool using the same. [Solution] This lathe-turning control device is characterized by comprising: a means for controlling lathe-turning in a spiral shape for N times, which is a natural number, until a cut depth d (mm) is achieved while causing the same to gradually move proportionally in an X direction, when F (mm/rev) represents the feed amount in a Z direction per revolution, X represents the cutting direction, and d (mm) represents the cut depth; a means for controlling the lathe-turning in a spiral shape for N times until a cut depth -d (mm) is achieved while causing the same to gradually move proportionally in the -X direction; and a means for controlling reversal of the feeding by said feeding amount F (mm/rev).

Description

Chip-cutting turning control device and machine tool equipped with same

The present invention relates to a control device for turning, and in particular to a control device for breaking up chips.

Turning is a cutting method in which a turning tool is pressed against a rotating workpiece.
In this case, the chips cut by the turning tool are generated continuously and elongated, and therefore there is a risk that they may wrap around the surrounding area or scratch the workpiece.

For example, Patent Document 1 discloses a technique in which cutting is stopped once at a point where the tool has moved a distance L2 along the Z axis, then reversed a distance shorter than this distance L2, and the process of moving forward a distance L2 from that point is repeated.
However, in the NC-controlled turning process disclosed in this publication, the forward stop position and reverse stop position change depending on the cutting speed and the depth of cut, resulting in a technical problem in that the quality of the turned surface is not stable.

Japanese Patent Application Publication No. 6-285701

The present invention aims to provide a chip breaking control device that can easily control chip breaking during turning and achieve stable cutting quality, and a machine tool using the same.

The chip breaking control device of the present invention is a control device for turning processing, and is characterized in having: a means for controlling spiral cutting N times in a natural number up to the cutting amount d (mm) while gradually moving proportionally in the X direction, where the Z direction feed amount per rotation is F (mm/rev), the cutting direction is X, and the cutting amount is d (mm); a means for controlling spiral cutting N times up to the cutting amount -d (mm) while gradually moving proportionally in the -X direction; and a control means for reverse-referencing the feed amount F (mm/rev).
Here, the natural number N is preferably in the range of 3 to 6.

Here, turning in a spiral N times means cutting while linearly changing the cutting amount by the processing length NF (mm) until the cutting amount becomes d (mm), and then cutting by NF (mm) while linearly changing the cutting amount in the -X direction until the cutting amount becomes -d (mm).
Next, by reversing the feed by the same feed amount F (mm), the position and phase of the spiral caused by the rotational feed become the same, which has the effect of stabilizing the cutting position (cutting point) of the chips.
When this type of control is expressed in an NC program, the phase determination function of the spindle that holds the workpiece in the chuck is used to specify the spindle angle at the starting point, and the two-axis linear motion is performed alternately at a specified command speed on the XZ cross section.

This type of control can be performed by an NC program and can be applied to NC-controlled machine tools.

In the control device according to the present invention, the cutting edge is turned in a spiral shape with a biaxial linear motion in an XZ cross section toward the X direction, then the same machining length is turned in a spiral shape in the -X direction in a similar manner, and then turning is performed in a reverse direction by a feed amount F (mm) while repeating this process for cutting, so that the chips are divided at regular machining lengths.
Such a control device can be applied to a machine tool such as a multi-tasking machine having a turning function.

An explanatory diagram of a cutting path is shown. An explanatory diagram of the cutting points of turning chips is shown. The cutting edge nose R0.4 is used to break off chips. (a) shows normal cutting, and (b) shows the workpiece during cutting operation. The measurement results of the surface roughness of the cut surface using a cutting edge nose R0.4 are shown. (a) shows normal cutting, and (b) shows cutting by division. The diagram shows how the cutting edge nose R0.8 breaks the chips. (a) shows normal cutting, and (b) shows cutting with chip-breaking action. The results of measuring the surface roughness of the cut surface using a cutting edge nose R0.8 are shown in Fig. 1. (a) shows normal cutting, and (b) shows disruptive cutting.

　ここで、Ｎ回は３～６の自然数が好ましい。
　これにより、図２の切屑の分断ポイントを○印で示すように、所定の加工長さ毎に分断ポイントを有することが分かる。 An example of chip-breaking turning control according to the present invention will now be described with reference to the drawings.
FIG. 1 shows an explanatory diagram of the cutting path.
The cutting direction is X, the cutting depth is d (mm), and the feed rate per revolution is F (mm/rev).
The spindle angle at the start point is specified using the spindle phase determination function, and a two-axis linear motion movement command is issued for the XZ cross section, and cutting is performed with a cutting depth of d mm in the X direction.
Under these conditions, the spiral cutting is performed N times.
Next, a movement command is issued in the same manner so that the distance becomes -d (mm) in the -X direction, and spiral cutting is performed N times.
Next, the cutting is performed in reverse by a feed rate F (mm/rev).
This operation is shown in FIG. 1 with the oblique turning indicated by the α hypotenuse and the reverse pull indicated by the F feed arrow.
The relational expression at this time is as follows:

Here, N is preferably a natural number from 3 to 6.
As a result, it can be seen that there are chip break points at every predetermined machining length, as shown by circles in FIG.

Next, a comparison was made between normal cutting (a) consisting of continuous turning and dividing cutting (b) according to the present invention using a non-breaker type cutting tip, which will be described.
The cutting conditions are as follows:
The cutting speed V was 200 m/min, the feed rate F was 0.1 mm/rev, the cutting length was 31 mm, and the finishing allowance ap was 0.1 mm.
Example 1
When a non-breaker tip with a cutting edge nose radius of 0.4 mm was used, normal cutting produced continuous chips that were wrapped around each other as shown in FIG. 3(a), whereas the cutting operation according to the present invention produced chips that were broken into pieces of a uniform size as shown in FIG. 3(b).
The measurement results of the surface roughness of the cut surface are shown in FIG.
There was no significant difference between normal cutting and split cutting.
Example 2
A non-breaker tip with a cutting edge nose radius of 0.8 mm was used to compare normal cutting with breaking cutting.
FIG. 5 shows the state of the chips, which have been cut into chips of a predetermined size during the cutting operation.
FIG. 6 shows the results of measuring the surface roughness of the cut surface.
No significant difference was observed between normal cutting and segmented cutting.

The present invention can perform turning while breaking up chips, so it can be used in machine tools such as multitasking machines.

Claims (3)

In a control device for turning, if the Z-direction feed amount per revolution is F (mm/rev), the cutting direction is X, and the cutting amount is d (mm), then
a means for controlling the lathe cutting in a spiral manner N times (where N is a natural number) up to a cutting depth d (mm) while moving the lathe proportionally and gradually in the X direction;
A chip-breaking turning control device comprising: a means for controlling spiral cutting N times to a cutting depth of -d (mm) while gradually moving proportionally in the -X direction; and a control means for reversing the feed amount F (mm/rev). The chip breaking turning control device according to claim 1, characterized in that the natural number N is 3 to 6. A machine tool equipped with the chip-breaking turning control device according to claim 1 or 2.

Images