KR20170010607A - System and method for controlling working speed of machine tool - Google Patents

Abstract

The present invention provides a system and a method of controlling a processing speed of a machine tool. According to the present invention, the system to control a processing speed of the machine tool comprises: a tool to process a parent metal; a spindle unit rotating the tool; a transfer unit transferring the spindle unit or the parent metal; and a control unit coupled to the spindle unit and the transfer unit, controlling a processing speed by determining a processing load and shape.

Description

TECHNICAL FIELD [0001] The present invention relates to a machining speed control system and a control method for a machine tool,

The present invention relates to a machining speed control system and a control method of a machine tool.

A machine tool is a machine that is used for machining metal or nonmetal materials (hereinafter referred to as "base material") into shapes and dimensions by using various cutting or non-cutting machining methods, or for adding more precise machining.

Such machine tools are rapidly progressing in automation and numerical control throughout the industry. In addition, computerized numerical control (PC) has been applied, and the market is rapidly increasing The trend is expanding.

In such a machine tool, processing of the base material is performed by a machining program generated by an operator, and the machining program includes a tool to be used in machining, a feed speed of the tool, a spindle rotational speed, and a machining path.

Here, the portion to be processed by one tool without changing the tool is called a machining process, and in general, machining proceeds at a constant tool feed rate and a constant spindle rotational speed in this one machining process.

In this case, the amount of cutting per unit time of the tool depends on the machining path and the shape of the workpiece.

For example, when machining a shape that is formed with a corner or a non-uniform thickness, the amount of cut is not constant. Variations in the amount of machining per unit time result in variations in the machining load on the tool, which causes the tool to be subjected to excessive load or impact loads, thereby promoting tool wear and tear.

In order to solve such a problem, an adaptive speed control system which changes the machining speed (feed rate) according to the machining load applied to the tool has been proposed. However, these conventional control systems have problems in that the feed speed is automatically adjusted according to the machining load, but the straight machining in which the speed needs to be changed smoothly and the corner machining part in which the speed needs to be changed quickly can not all be satisfied.

In other words, the existing machining speed control system can be applied differently depending on the roughing, finishing, and pocket machining of the machining process unit, but it is differently applied according to the contour unit in the process such as straight machining, curve machining, corner machining I can not.

The rapid speed change in the linear machining by the conventional machining speed control system adversely affects the roughness and the slow speed change at the corner leads to the breakage of the tool because the speed deceleration does not occur in time, System is necessary.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide an apparatus and a method for controlling the machining speed (feed rate) And to provide a machining speed control system and a control method of a machine tool capable of improving machining reliability and precision.

According to an aspect of the present invention, A spindle portion for rotating the tool; A transferring part for transferring the spindle part or the base material; And a control unit coupled to the spindle unit and the transfer unit for determining a machining load and a shape to adjust a machining speed.

Further, the control unit may include: a load collecting unit for detecting a machining load of the tool during machining; A shape determining unit that determines whether the shape of the base material processing portion varies depending on a change in the load detected by the load collecting unit and a transfer distance; And a machining speed calculator for calculating a machining speed based on the data of the shape determining unit, the current machining speed, the instructed machining speed, and the setting data.

In addition, the shape determination unit may determine that the corner has started by the following conditional expression 1, and may determine that the corner is out of the conditional expression (2).

<Conditional Expression 1>

E> e

<Conditional expression 2>

E <s

Where E is a distance obtained by subtracting the distance at which the tool is located at a moment when the tool load is rapidly increased by the load collecting unit at a predetermined straight distance, e is a distance to be traversed at a predetermined straight distance, and s is a predetermined straight distance Represents a distance.

Further, the shape determination unit may determine that the corner has started by the following conditional expression (3), and may determine that the corner is out of order by the following conditional expression (2).

<Conditional expression 3>

E> e

<Conditional expression 2>

E <s

Where E is the distance obtained by subtracting the tool diameter distance from 1/3 of the tool diameter at the preset straight distance, e is the distance to be traversed at the predetermined straight distance, and s is the distance traveled from the preset straight distance.

In addition, the shape determination unit may determine that the corner has started by the following conditional expression (4), and may determine that the corner is out of order by the following conditional expression (2).

<Conditional expression 4>

E> e, E = D / 3 / sin? + D / 2 / sin?

<Conditional expression 2>

E <s

Where D is the diameter of the tool, θ is the corner angle, e is the distance to be traversed at the preset straight distance, and s is the distance traveled from the preset straight distance.

Further, the machining speed calculator may calculate the machining speed using the following conditional expression (5).

<Conditional expression 5>

Vc = Kp * Lc + Ki * Lc * t + Kd * (Lc-Lp) / t

Where Kc is the proportional gain, Ki is the integral gain, Kd is the differential gain, Lc is the current load value, Lp is the previous load value, t is the calculation period .

Also, the machining speed calculator may apply Kp, Ki, and Kd values set differently in the straight line portion and the corner portion, respectively.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, the method comprising: collecting a machining load with a load collection unit if a speed control function is on; And calculating a machining speed on the basis of the data of the shape determining unit, the current machining speed, the instructed machining speed, and the setting data as the machining speed calculator, and a machining speed controlling method of the machine tool.

The step of determining whether the machining area is a corner may include determining whether the machining area is a micro block; Thereafter, if not a small block, calculating an angle between the current block and the next block; Determining whether the angle is within a predetermined angle range; And then applying a different speed control gain value depending on whether or not it is a predetermined angle range.

In the step of determining whether the machining area is a corner part, it is determined that the corner has been started by the following conditional expression 1 in the shape determining part and it can be determined that the corner is out of the following conditional expression 2.

<Conditional Expression 1>

E> e

<Conditional expression 2>

E <s

Where E is a distance obtained by subtracting the distance at which the tool is located at a moment when the tool load is rapidly increased by the load collecting unit at a predetermined straight distance, e is a distance to be traversed at a predetermined straight distance, and s is a predetermined straight distance Represents a distance.

In the step of determining whether the machining area is a corner, it is determined that the corner has been started in the shape determining unit according to the following conditional expression (3), and it can be determined that the corner is out of the following conditional expression (2).

<Conditional expression 3>

E> e

<Conditional expression 2>

E <s

Where E is the distance obtained by subtracting the tool diameter distance from 1/3 of the tool diameter at the preset straight distance, e is the distance to be traversed at the predetermined straight distance, and s is the distance traveled from the preset straight distance.

In the step of determining whether the machining area is a corner, it is determined that the corner has been started by the following conditional expression (4) in the shape determination section, and it can be determined that the corner is out of the following conditional expression (2).

<Conditional expression 4>

E> e, E = D / 3 / sin? + D / 2 / sin?

<Conditional expression 2>

E <s

Where D is the diameter of the tool, θ is the corner angle, e is the distance to be traversed at the preset straight distance, and s is the distance traveled from the preset straight distance.

Further, in the step of calculating the machining speed, the machining speed calculating unit may calculate the machining speed by the following conditional expression (5).

<Conditional expression 5>

Vc = Kp * Lc + Ki * Lc * t + Kd * (Lc-Lp) / t

Where Kc is the proportional gain, Ki is the integral gain, Kd is the differential gain, Lc is the current load value, Lp is the previous load value, t is the calculation period .

According to the present invention, it is possible to improve the surface roughness of the plane surface and improve the tool and spindle protection function at the corner by controlling the speed response speed (gain) by judging the machining load and the machining shape, .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a machining speed control system for a machine tool according to an embodiment of the present invention; FIG.
FIG. 2 is an exemplary diagram for explaining a determination process of a shape determination unit according to an embodiment of the present invention; FIG.
3 is a flowchart of a machining speed control method of a machine tool according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Unless defined otherwise, all terms used herein are the same as the generic meanings of the terms understood by those of ordinary skill in the art, and where the terms used herein contradict the general meaning of the term, they shall be as defined herein.

It is to be understood, however, that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to be &

FIG. 1 is a view schematically showing a machining speed control system of a machine tool according to an embodiment of the present invention, and FIG. 2 is an exemplary diagram for explaining a process of determining a shape determining unit according to an embodiment of the present invention.

Referring to FIG. 1, the embodiment may include a tool 100, a spindle unit 200, a transfer unit 300, and a control unit 400.

The tool 100 is for machining the base material 10 and is mounted on a spindle portion 200 to be described later. The tool 100 may be variously provided.

The spindle unit 200 rotates the tool 100 to provide a driving force for machining the base material 10.

The transfer unit 300 is a component for transferring the spindle unit 200 or the base material 10.

The control unit 400 controls the driving of the machine tool, and more specifically, the spindle unit 200 and the transfer unit 300, and controls the machining speed by determining the machining load and shape.

That is, the control unit 400 according to the embodiment can control the machining speed by dividing the straight portion and the corner portion of the machined portion of the base material 10, unlike the conventional control unit.

To this end, the control unit 400 according to the embodiment includes a load collecting unit 410 for detecting a machining load of the tool 100 during machining, a change in load detected by the load collecting unit 410, Based on the data of the shape determining unit 420, the current machining speed, the instructed machining speed, and the setting data, the machining position determining unit 420 determines whether the machining area shape of the workpiece 10 is changed, And a processing speed meter section 430 for calculating the speed.

The load collecting unit 410 may receive a load of the tool 100 detected by the tool 100 or a sensor disposed on the spindle unit 200.

The shape determination unit 420 can determine corner portions of the machining area by a variety of methods as follows. Such determination will be described with reference to FIG.

Referring to Fig. 2, an example of the machining area of the base material 10 is shown. This machining area has two corner parts, for example, the machining coordinates can be set by the user in the control part 400 as shown in the following table.

Type of tool (100) X-axis coordinate Y-axis coordinate G1 X0 Y0 G1 X100 Y0 G1 X100 Y100 G1 X50 Y50

2, the tool 100 can be sequentially moved from No. 1 to No. 5 and the base material 10 can be machined. When the tool 100 is positioned at No. 3, the angle obtained from the NC is 270 DEG, and when the tool 100 is positioned at the fourth position, the angle obtainable from the NC is 315 DEG.

The angle of the block means an angle formed by two line segments in a plane formed by two segment segments.

First, the shape determining unit 420 determines that the corner has been started by the following conditional expression 1 and can determine that the corner is out of the following conditional expression (2).

<Conditional Expression 1>

E> e

<Conditional expression 2>

E <s

Here, E is a distance obtained by subtracting the distance at which the tool 100 is located at a moment when the load of the tool 100 is suddenly increased by the load collecting unit 410 at a predetermined straight line distance, and e is a predetermined straight line distance The distance, s, represents the distance traveled from the preset straight line distance.

That is, when the second position is converged to the third position in FIG. 2, the tool 100 meets another wall surface, so that the load of the tool 100 increases sharply, and the remaining distance at this moment becomes E. s is gradually increased from 0 when the tool 100 passes through No. 3, and it can be judged that it is out of the corner if the value is larger than E.

Secondly, the shape determining unit 420 may determine that the corner has been started by the following conditional expression 3, and may determine that the corner is out of order by the following conditional expression (2).

<Conditional expression 3>

E> e

<Conditional expression 2>

E <s

Here, E is a distance obtained by subtracting the diameter of the tool (100) from 1/3 of the diameter of the tool (100) at a predetermined straight distance, e is a distance to be traversed at a predetermined straight distance, s is a distance .

That is, in general, since the cutting width at the time of machining is 1/3 of the diameter of the tool 100 to the diameter of the tool 100, E can be set as a constant as described above. s is gradually increased from 0 when the tool 100 passes through No. 3, and it can be judged that it is out of the corner if the value is larger than E.

Thirdly, the shape determining unit 420 may determine that the corner has been started by the following conditional expression 4, and may determine that it is out of the corner by the following conditional expression (2).

<Conditional expression 4>

E> e, E = D / 3 / sin? + D / 2 / sin?

<Conditional expression 2>

E <s

Where D is the diameter of the tool 100,? Is the corner angle, e is the distance to be traversed at the predetermined straight distance, and s is the distance traveled at the predetermined straight distance.

That is, the block angle at the point 3 in FIG. 2 is 270 °, so that the value of E should be larger than 1/3 of the diameter of the tool 100 if the cutting width is 1/3 of the diameter of the tool 100. s is gradually increased from 0 when the tool 100 passes through No. 3, and it can be judged that it is out of the corner if the value is larger than E.

That is, in any one of the above-described methods, the embodiment can effectively determine the point where the contour changes.

The machining speed calculator 430 can calculate the machining speed based on the data generated by the determination of the shape determining unit 420, the current machining speed, the instructed machining speed, and the setting data.

Specifically, the machining speed meter 430 can calculate the machining speed by the following conditional expression (5).

<Conditional expression 5>

Vc = Kp * Lc + Ki * Lc * t + Kd * (Lc-Lp) / t

Where Kc is the proportional gain, Ki is the integral gain, Kd is the differential gain, Lc is the current load value, Lp is the previous load value, t is the calculation period .

Here, the control unit 400 according to the embodiment may apply the Kp, Ki, and Kd values differently in the straight line portion and the corner portion. This is attributable to the accurate determination of the shape determining unit 420.

Specifically, when the machining position is a corner portion through the determination of the shape determining unit 420, an increase in the Kd value is required unlike the straight portion. This is because, in the case of the plane machining, the load values which can be called noise are inputted instantaneously at the moment of the load value input, so it is not necessary to adjust the speed sensitively, so the Kd value is lowered much, This is because it is expected that the Kd value should be increased to speed up the speed control.

In addition, the Kp and Ki values should also be appropriately adjusted at the corner portions, and an appropriate function can be obtained by experiment.

Therefore, in the embodiment, Kp, Ki and Kd values in the case of the straight line section and Kp, Ki and Kd values at the corner can be applied differently. The values of Kp, Ki, and Kd can be stored in advance in the controller 400 in advance.

A processing speed control method of a machine tool according to this embodiment will be described as follows.

Referring to FIG. 3, it is determined whether the speed control function according to the load is ON (S100).

If the speed control function according to the load is ON, the load collecting unit 410 collects information as to whether the load increases or not (S200). If the shape determining unit 420 determines that the machining area is a straight line portion or a corner portion, (S300).

Thereafter, the machining speed calculator 430 calculates the machining speed according to the determination of the shape determining unit 420 and controls the rotational speed of the spindle unit 200 or the moving speed of the transfer unit 300 (S400) .

Here, the determination step S300 of the shape determination unit 420 determines whether the current transport block is a small block (S310).

Kp, Ki, and Kd values corresponding to the straight line portion are applied (S320), and the machining speed is calculated (S400). This processing speed calculation can be performed through the above-described conditional expression (5).

If it is determined that the angle is not within the predetermined range (S340), the angle between the current block and the next block is calculated (S330). If the angle is within the predetermined range (S340), Kp, Ki and Kd (S350). If it is not within the predetermined range, Kp, Ki, and Kd according to the straight line portion are applied (S320).

Of course, the above method is a third method using conditional expression 4 and conditional expression 2 among the judging methods of the above-mentioned three shape judging section 420, and it is possible to apply the values of Kp, Ki and Kd according to two other judging methods have.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined by the appended claims. Range and its equivalent range.

10: Base material 100: Tool
200: spindle part 300: transfer part
400: control unit 410: load collecting unit
420: shape determining unit 430: machining speed meter

Claims (13)

Tools for working base metal;
A spindle portion for rotating the tool;
A transferring part for transferring the spindle part or the base material;
And a control unit coupled to the spindle unit and the transfer unit for determining a machining load and a shape to adjust a machining speed.
The method according to claim 1,
Wherein,
A load collector for detecting a machining load of the tool during machining;
A shape determining unit that determines whether the shape of the base material processing portion varies depending on a change in the load detected by the load collecting unit and a transfer distance; And
And a machining speed measuring section for calculating a machining speed based on the data of the shape determining section, the current machining speed, the instructed machining speed, and the setting data.
3. The method of claim 2,
Wherein the shape determining unit determines that the corner has started by the following conditional expression 1 and determines that the corner is out of the corner by the following conditional expression (2).
<Conditional Expression 1>
E> e
<Conditional expression 2>
E <s
Where E is a distance obtained by subtracting the distance at which the tool is located at a moment when the tool load is rapidly increased by the load collecting unit at a predetermined straight distance, e is a distance to be traversed at a predetermined straight distance, and s is a predetermined straight distance Represents a distance.
3. The method of claim 2,
Wherein the shape determining unit determines that the corner has started by the following conditional expression (3) and determines that the corner is out of the corner according to the following conditional expression (2).
<Conditional expression 3>
E> e
<Conditional expression 2>
E <s
Where E is the distance obtained by subtracting the tool diameter distance from 1/3 of the tool diameter at the preset straight distance, e is the distance to be traversed at the predetermined straight distance, and s is the distance traveled from the preset straight distance.
3. The method of claim 2,
Wherein the shape determining unit determines that the corner has started by the following conditional expression (4) and determines that the corner is out of the corner according to the following conditional expression (2).
<Conditional expression 4>
E> e, E = D / 3 / sin? + D / 2 / sin?
<Conditional expression 2>
E <s
Where D is the diameter of the tool, θ is the corner angle, e is the distance to be traversed at the preset straight distance, and s is the distance traveled from the preset straight distance.
3. The method of claim 2,
Wherein the machining speed calculation unit calculates a machining speed by the following conditional expression (5).
<Conditional expression 5>
Vc = Kp * Lc + Ki * Lc * t + Kd * (Lc-Lp) / t
Where Kc is the proportional gain, Ki is the integral gain, Kd is the differential gain, Lc is the current load value, Lp is the previous load value, t is the calculation period .
The method according to claim 6,
Wherein the machining speed calculator applies Kp, Ki and Kd values differently set in the straight line portion and the corner portion, respectively.
If the speed control function is on, collecting the machining load by the load collecting unit and determining whether the machining area is a corner by the shape determining unit; And
And calculating a machining speed based on the data of the shape determining unit, the current machining speed, the instructed machining speed, and the setting data as the machining speedometer arithmetic unit.
9. The method of claim 8,
Wherein the step of determining whether the machining area is a corner part comprises:
Determining whether the current machining area is a micro block;
Thereafter, if not a small block, calculating an angle between the current block and the next block;
Determining whether the angle is within a predetermined angle range; And
And then applying a different speed control gain value depending on whether the range is a predetermined angle range or not.
9. The method of claim 8,
Wherein the step of judging whether the machining area is a corner part judges that the corner has started by the following condition equation 1 in the shape judging part and judges that the corner is out of the corner by the following condition equation 2:
<Conditional Expression 1>
E> e
<Conditional expression 2>
E <s
Where E is a distance obtained by subtracting the distance at which the tool is located at a moment when the tool load is rapidly increased by the load collecting unit at a predetermined straight distance, e is a distance to be traversed at a predetermined straight distance, and s is a predetermined straight distance Represents a distance.
9. The method of claim 8,
Wherein the step of determining whether the machining area is a corner portion determines that the corner is started by the following conditional expression (3) in the shape determination section and that the corner is out of the corner by the following conditional expression (2).
<Conditional expression 3>
E> e
<Conditional expression 2>
E <s
Where E is the distance obtained by subtracting the tool diameter distance from 1/3 of the tool diameter at the preset straight distance, e is the distance to be traversed at the predetermined straight distance, and s is the distance traveled from the preset straight distance.
10. The method of claim 9,
Wherein the step of judging whether the machining area is a corner part judges that the corner has started by the following condition equation 4 in the shape judging part and judges that the corner is out of the corner by the following condition equation 2:
<Conditional expression 4>
E> e, E = D / 3 / sin? + D / 2 / sin?
<Conditional expression 2>
E <s
Where D is the diameter of the tool, θ is the corner angle, e is the distance to be traversed at the preset straight distance, and s is the distance traveled from the preset straight distance.
9. The method of claim 8,
Wherein the machining speed calculating unit calculates the machining speed at the machining speed calculating step using the following conditional expression (5).
<Conditional expression 5>
Vc = Kp * Lc + Ki * Lc * t + Kd * (Lc-Lp) / t
Where Kc is the proportional gain, Ki is the integral gain, Kd is the differential gain, Lc is the current load value, Lp is the previous load value, t is the calculation period .

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