WO2021221458A1

WO2021221458A1 - Impact type actuator and automatic eccentricity compensation system and method using same

Info

Publication number: WO2021221458A1
Application number: PCT/KR2021/005362
Authority: WO
Inventors: 노승국; 김경호; 최두선
Original assignee: 한국기계연구원
Priority date: 2020-04-28
Filing date: 2021-04-28
Publication date: 2021-11-04
Also published as: KR102619376B1; KR20210133025A; KR20230035549A

Abstract

The technique disclosed in the present specification relates to an automatic eccentricity compensation system using an impact type actuator, such that the eccentricity of a workpiece can be compensated for by applying an impact to the workpiece that is rotating. The automatic eccentricity compensation system, which compensates for the eccentricity of the workpiece that is fixed to a vacuum chuck connected to a spindle and rotated along with the vacuum chuck, comprises: an impact type actuator located at one side of the workpiece and applying an impact to the outer circumferential surface of the rotating workpiece; a displacement measurer located at one side of the workpiece and measuring the rotational displacement of the outer circumferential surface of the rotating workpiece; an eccentricity calculator for calculating the eccentricity of the workpiece on the basis of the rotational displacement of the outer circumferential surface and the rotating angle; an impact force calculator for calculating the impact force of the impact type actuator to reduce the eccentricity calculated by the eccentricity calculator; and an impact type actuator driver for driving the impact type actuator so as to apply the impact force calculated by the impact force calculator.

Description

Impact actuator and automatic eccentricity compensation system and method using the same

The technology disclosed in the present specification relates to an impact actuator and a system and method for automatic eccentricity correction using the same, and specifically, an impact actuator capable of correcting the eccentricity of a workpiece by applying an impact to a workpiece in a rotating state, and automatic correction of eccentricity using the same It relates to systems and methods.

For diamond turning of ultra-precision optical parts such as lens molds, a centering operation is required to match the center of the workpiece with the rotational center of the spindle's rotation axis when the workpiece is installed on the spindle. In particular, the more precise the mold part, the more it must be aligned to have an eccentricity of 1 μm or less.

Conventionally, an operator manually performed the centering operation, which took a lot of time, and this manual centering operation became a factor hindering automation such as pin core processing.

In particular, the conventional centering device has a structure in which the eccentricity of the workpiece is measured for one to two rotations using a sensor, the spindle is stopped at the maximum eccentricity, and the eccentricity is corrected using the X-axis of the ultra-precision machining machine. For this reason, such a conventional centering device has a problem in that it is difficult to apply to a pin-core product having a small diameter, and the rotation of the spindle must be frequently stopped for correcting the amount of eccentricity.

Although many studies have been conducted to solve these conventional problems, satisfactory results have not yet been published.

Impact actuator and automatic eccentricity compensation system and method using the same according to an embodiment of the technology disclosed in the present specification are impact actuators and automatic eccentricity compensation system using the same to compensate the eccentricity of the workpiece by applying an impact to the workpiece in a rotating state and to provide a method.

The technical problem to be achieved by the impact actuator and the automatic eccentricity correction system and method using the same according to the technical spirit of the technology disclosed in the present specification is not limited to the above-mentioned tasks, and another task not mentioned is from the description below. It will be clearly understood by a technician.

An impact actuator according to an embodiment of the technology disclosed herein is an impact actuator for correcting an eccentricity of a workpiece fixed to a vacuum chuck and rotating together with the vacuum chuck, comprising: an impact part for applying an impact to the side of the workpiece; a dummy moving part positioned to face the impact part; an excitation unit connecting the impact unit and the dummy moving unit between the shock unit and the dummy moving unit, and reciprocating linearly moving the shock unit and the dummy moving unit in opposite directions; and an elastic connection part connecting the impact part and the dummy moving part between the impact part and the dummy moving part. The dummy moving unit may include a dummy mass.

The excitation unit is connected to any one of the impact unit and the dummy moving unit, the coil holder having a cylindrical shape wound around the outer circumferential surface; It is connected to the other one of the impact part and the dummy moving part, a permanent magnet is positioned on the inner circumferential surface, and includes a cylindrical magnetic housing into which the coil holder is inserted into the inner space, but when an alternating current is applied to the coil, the coil holder and the magnetic housing can make reciprocating linear motion.

The impact actuator includes a support plate; a coil holder bracket to which the coil holder is fixed; a magnetic housing bracket to which the magnetic housing is fixed; a guide rail fixed to the support plate and extending along the reciprocating linear motion direction; a first sliding block fixed to the coil holder bracket and sliding along the guide rail; and a second sliding block fixed to the magnetic housing bracket and sliding along the guide rail.

The elastic connection part may be a coil spring having both ends connected to the coil holder bracket and the magnetic housing bracket, respectively.

The impact actuator may further include a torsion spring having both ends connected to the magnetic housing bracket and the support plate.

The automatic eccentricity compensation system according to an embodiment of the technology disclosed herein is an eccentricity automatic compensation system for correcting the eccentricity of a workpiece that is fixed to a vacuum chuck connected to a spindle and rotates together with the vacuum chuck. It is located on one side of the workpiece an impact actuator that impacts the outer circumferential surface of the rotating workpiece; Displacement measuring device positioned on one side of the workpiece to measure the rotational displacement of the outer peripheral surface of the rotating workpiece; An eccentricity calculation unit for calculating the amount of eccentricity of the workpiece based on the outer circumferential rotational displacement and rotational angle; an impact force calculation unit for calculating an impact force of the impact actuator to reduce the eccentricity calculated by the eccentricity calculation unit; and an impact actuator driving unit for driving the impact actuator to apply the impact force calculated by the impact force calculation unit.

The impact actuator driving unit may drive the impact actuator to apply an impact to the work piece only at a rotation angle at which the eccentric amount of the work piece is generated.

The impact actuator includes an impact portion that impacts the side of the workpiece; a dummy moving part positioned to face the impact part; an excitation unit connecting the impact unit and the dummy moving unit between the shock unit and the dummy moving unit, and reciprocating linearly moving the shock unit and the dummy moving unit in opposite directions; and an elastic connection part connecting the impact part and the dummy moving part between the impact part and the dummy moving part. The dummy moving unit may include a dummy mass.

The method for automatically correcting the amount of eccentricity according to an embodiment of the technology disclosed in the present specification is a method for automatically correcting the amount of eccentricity for correcting the amount of eccentricity of a workpiece fixed to a vacuum chuck connected to a spindle and rotating together with the vacuum chuck, (a) one side of the workpiece Measuring the rotational displacement of the outer peripheral surface of the rotating workpiece with a displacement measuring device located in; (b) calculating the amount of eccentricity of the workpiece based on the measured rotational displacement of the outer peripheral surface; (c) calculating the impact force of the impact actuator to reduce the amount of eccentricity calculated by the eccentricity calculation unit; and (d) driving the impact actuator to apply the calculated impact force.

The step (d) may be characterized in that the impact portion of the impact actuator reciprocates linearly to apply an impact to the work, and the dummy moving portion of the impact actuator reciprocates linearly in the opposite direction to the impact portion.

In the step (c), when the amount of eccentricity calculated in step (b) is greater than a reference value, calculating the impact force of the actuator as a relatively large first value; and when the amount of eccentricity calculated in step (b) is smaller than the reference value, calculating the impact force of the actuator as a relatively small second value.

As a computer-readable recording medium recording a program for performing an eccentricity automatic correction method for correcting the eccentricity of a workpiece that is fixed to a vacuum chuck connected to a spindle according to an embodiment of the technology disclosed herein and rotates together with the vacuum chuck , may be a computer-readable recording medium storing instructions for performing the above-described method.

An impact actuator according to an embodiment of the technology disclosed herein includes a support plate; an impact unit that is slidably positioned on the support plate and applies an impact to the impact object; a dummy moving part facing the impact part and being slidably positioned on the support plate, including a dummy mass; a cylindrical coil holder connected to any one of the impact part and the dummy moving part, and having a coil wound around an outer circumferential surface; It is connected to the other one of the impact part and the dummy moving part, and a permanent magnet is positioned on the inner circumferential surface. Enclosed cylindrical magnetic housing; a coil spring connecting the impact unit and the dummy moving unit between the shock unit and the dummy moving unit; And both ends may include a torsion spring connected to the magnetic housing and the support plate.

The impact actuator and the automatic eccentricity correction system and method using the same according to an embodiment of the technology disclosed herein have the following effects.

(1) The amount of eccentricity of the work piece can be corrected by applying an impact to the work piece in the rotating state.

(2) The amount of eccentricity can be corrected by applying the desired amount of impact to the desired rotation angle on the rotating workpiece.

(3) When an impact is applied to a rotating workpiece, the reaction force applied to the impact actuator can be absorbed.

(4) The setup time of ultra-precision turning parts can be shortened.

(5) It is possible to build automation through the automatic centering function, and the competitiveness of equipment can be strengthened.

(6) It becomes possible to construct a practical device that does not use expensive piezo parts.

However, the effects that can be achieved by the impact actuator and the automatic eccentricity correction system and method using the same according to an embodiment of the technology disclosed in the present specification are not limited to those mentioned above, and other effects not mentioned below are It will be clearly understood by those skilled in the art from the description.

In order to more fully understand the drawings cited herein, a brief description of each drawing is provided.

1 is a perspective view of an impact actuator according to one embodiment of the technology disclosed herein;

2 is a perspective view illustrating an internal structure of an impact actuator according to an embodiment of the technology disclosed herein.

3 is an exploded perspective view of an impact actuator according to an embodiment of the technology disclosed herein;

4 is a schematic diagram of an automatic eccentricity correction system according to an embodiment of the technology disclosed herein.

5 is a view for explaining the steps of the eccentricity correction method according to the present specification.

6 is a view showing measurement data according to the result of performing the eccentricity correction method according to the present specification.

7 is a view showing measurement data according to the result of performing the eccentricity correction method according to the present specification.

Since the technology disclosed in this specification can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings, and this will be described in detail through the detailed description. However, this is not intended to limit the technology disclosed herein to specific embodiments, and it is understood that the technology disclosed herein includes all modifications, equivalents and substitutions included in the spirit and scope of the technology disclosed herein. should be

In describing the technology disclosed in the present specification, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the technology disclosed herein, the detailed description thereof will be omitted. In addition, numbers (eg, first, second, etc.) used in the description process of the present specification are only identifiers for distinguishing one component from other components.

In addition, in this specification, when a component is referred to as "connected" or "coupled" to another component, the component may be directly connected or coupled to the other component, but the opposite is particularly true. Unless there is a description, it should be understood that other elements may be interposed or connected or combined therebetween.

In addition, in the present specification, two or more components may be combined into one component, or one component may be divided into two or more for each more subdivided function. In addition, each of the components to be described below may additionally perform some or all of the functions of other components in addition to the main functions that each component is responsible for, and some of the main functions of each of the components are different It goes without saying that it may be performed exclusively by the component.

Expressions such as “first”, “second”, “first”, or “second” used in various embodiments can modify various components regardless of order and/or importance, and do not limit For example, without departing from the scope of the technology disclosed herein, a first component may be referred to as a second component, and similarly, a second component may also be renamed to a first component.

Hereinafter, embodiments of the technology disclosed herein will be described in detail in turn.

1 is a perspective view of an impact actuator according to one embodiment of the technology disclosed herein; 2 is a perspective view illustrating an internal structure of an impact actuator according to an embodiment of the technology disclosed herein. 3 is an exploded perspective view of an impact actuator according to an embodiment of the technology disclosed herein;

The impact actuator 100 according to an embodiment of the technology disclosed herein may be fixed to the vacuum chuck 10 to correct the eccentricity of the workpiece 1 rotating together with the vacuum chuck 10 . The impact actuator 100 includes a shock unit 110, a dummy moving unit 120, an excitation unit 130, an elastic connection unit 140, a guide rail 151, a first sliding block 153, a second sliding block ( 154 ) and a torsion spring 155 . These may be accommodated in a space formed by the lower plate 101 , the upper plate 102 , the side cover 103 , and the support plate 150 . Here, the excitation unit 130 is a component including the coil holder 131 and the magnetic housing 132 , and may be, for example, a voice coil motor.

The support plate 150 may be a “a”-shaped wall plate, and a guide rail 151 may be fixed to each inner surface, and the guide rail 151 may be moved in the axial direction, that is, the impact unit 110 and the dummy moving unit. It may extend in the reciprocating linear motion direction of 120 .

A lower plate 101 may be connected to a lower surface of the support plate 150 , and an upper plate 102 may be connected to an upper surface of the support plate 150 . The impact part opening 105 for the impact part 110 to pass through is formed in the lower plate 101 , and the dummy movable part opening 104 for the dummy movable part 120 to pass through is formed in the upper plate 102 . can be

The side cover 103 is also a “L”-shaped plate, and may be connected to the lower plate 101 , the upper plate 102 and the support plate 150 to close the inner space.

The impact unit 110 is fixed to the coil holder bracket 133 and can be slidably positioned in the x-axis direction on the support plate 150 , passes through the impact unit opening 105 , and the workpiece 1 in a rotating state ) is a member that repeatedly applies an impact to the side. Here, the x-axis direction is a direction perpendicular to the axis of rotation of the spindle rotating the workpiece 1 . For example, when the workpiece 1 is a circular object having the same volume as a lens, it may correspond to the radial direction of the circular object. For example, the axis of rotation of the spindle may be in the y-axis direction or the z-axis direction, and the workpiece 1 may have an eccentricity with respect to the x-axis direction due to inaccurate centering. The eccentricity can be corrected.

The dummy moving unit 120 is positioned to face the impact unit 110 , and may linearly move through the dummy moving unit opening 104 . The dummy moving part 120 may be fixed to the magnetic housing bracket 134 and slidably positioned on the support plate 150 in the x-axis direction. The dummy moving unit 120 may include a dummy mass, and the dummy mass preferably has a mass greater than that of the impact unit 110 .

When the impact unit 110 applies an impact to the work piece 1, the reaction force applied to the impact unit 110 is used to move the dummy moving unit 120 connected by the elastic connection unit 140, whereby the impact is It is absorbed and it can be prevented that the reaction force is directly transmitted to the impact actuator 100 itself. That is, according to the present invention, when the impact unit 110 slides in one direction of the x-axis (+x-axis direction), the dummy moving unit 120 slides in the opposite direction of the x-axis (-x-axis direction) due to the reaction force. do. That is, since the movement direction of the impact unit 110 and the movement direction of the dummy movement unit 120 are opposite to each other, the reaction force applied to the impact actuator 100 itself may be offset.

The excitation unit 130 connects the shock unit 110 and the dummy moving unit 120 between the shock unit 110 and the dummy moving unit 120 , and the shock unit 110 and the dummy moving unit 120 . A reciprocating linear motion can be performed at a predetermined cycle.

The excitation unit 130 may be a voice coil motor, and may include a coil holder 131 and a magnetic housing 132 .

The coil holder 131 may be connected to any one of the shock unit 110 and the dummy moving unit 120 , and in this embodiment, the coil holder 131 is exemplified as being connected to the shock unit 110 . The coil holder 131 may be a cylindrical member in which a coil is wound around an outer circumferential surface, and may be fixed to the coil holder bracket 133 .

The magnetic housing 132 may be connected to the other one of the impact unit 110 and the dummy moving unit 120 , and in this embodiment, the magnetic housing 132 is exemplified as being connected to the dummy moving unit 120 . The magnetic housing 132 is a cylindrical member and may be fixed to the magnetic housing bracket 134 .

The magnetic housing 132 has a structure surrounding the coil holder 131, and the coil holder 131 is inserted into the inner space of the magnetic housing 132 or a reciprocating linear motion coming out of the inner space of the magnetic housing 132 can be made. can have an inner diameter. A permanent magnet is positioned on the inner circumferential surface of the magnetic housing 132 , and when an alternating current is applied to the coil of the coil holder 131 , the coil holder 131 and the magnetic housing 132 may reciprocate linearly.

The elastic connection unit 140 may connect the shock unit 110 and the dummy moving unit 120 between the shock unit 110 and the dummy moving unit 120 , and may be a coil spring. A first spring fixing member 161 may be installed in the coil holder bracket 133 , and a second spring fixing member 162 may be installed in the magnetic housing bracket 134 . Both ends of the elastic connection part 140 may be connected to the first spring fixing member 161 and the second spring fixing member 162, whereby the impact part 110 and the dummy moving part 120 are mutually tanned. be sexually connected.

The coil holder bracket 133 may be fixed to the first sliding block 153 , and the first sliding block 153 may slide along the guide rail 151 . The magnetic housing bracket 134 may be fixed to the second sliding block 154 , and the second sliding block 154 may slide along the guide rail 151 . Here, the first sliding block 153 and the second sliding block 154, the guide rail 151 may be formed of an LM guide.

Both ends of the torsion spring 155 may be connected to the locking member 135 of the magnetic housing bracket 134 and the locking member 136 of the support plate 150 . The torsion spring 155 may perform a function of returning the dummy moving unit 120 linearly moved by the excitation unit 130 or linearly moved by the reaction force transmitted to the impact unit 110 to its original position.

The impact actuator 100 of this configuration is fixed to the vacuum chuck 10 in the automatic eccentricity compensation system 200 and applies an impact to the workpiece 1 rotating together with the vacuum chuck 10 in one direction (x-axis direction). It is possible to perform a function of correcting the amount of eccentricity of the workpiece (1).

The automatic eccentricity correction system 200 according to an embodiment of the technology disclosed herein is fixed to the vacuum chuck 10 connected to the spindle 20 and corrects the eccentricity of the workpiece 1 rotating together with the vacuum chuck 10 . can be used to The automatic eccentricity correction system 200 includes an impact actuator 100, a displacement measuring instrument 210, a rotation angle measuring unit 220, an eccentricity calculating unit 230, an impact force calculating unit 240, and an impact actuator driving unit 250. can

The impact actuator 100 uses the first sliding block 153 , the second sliding block 154 and the guide rail 151 constituting the voice coil motor and the LM guide of the excitation unit 130 to the impact unit 110 . Since the precise guidance of the workpiece 1 is possible, the amount of eccentricity can be adjusted by applying an impact to the outer circumferential surface of the workpiece 1 positioned on one side of the workpiece 1 and rotating at a constant speed to generate a minute displacement in the impact direction. In addition, since the impact actuator 100 absorbs the reaction force according to the impact through the dummy moving part 120 , it is possible to block the impact transmitted to the impact actuator 100 or the table 40 .

The displacement measuring device 210 is located on one side of the workpiece 1 and can measure the rotational displacement of the outer circumferential surface of the workpiece 1 rotating at a constant speed, and the rotation angle measuring device 220 measures the rotation angle of the spindle 20 can be measured As the displacement measuring device 210, a known contact/non-contact displacement measuring sensor may be used without limitation.

The eccentricity calculation unit 230 may calculate the eccentricity of the workpiece based on the rotational displacement of the outer peripheral surface of the workpiece 1 and the rotational angle of the spindle 20 . As a method of detecting the amount of eccentricity in real time, a least mean square (LMS) filter for the rotation speed synchronization component can be used, and an excitation signal capable of correcting the extracted amount of eccentricity is generated.

The impact force calculation unit 240 may calculate an impact force (force or displacement) of the impact actuator 100 that will reduce the amount of eccentricity at a predetermined rotation angle calculated by the eccentricity calculation unit 230 .

The impact actuator driving unit 250 may drive the impact actuator 100 by transmitting a signal with the impact actuator 100 to apply the impact force calculated by the impact force calculation unit 240 .

The impact actuator driving unit 250 may drive the impact actuator 100 to apply an impact to the work piece 1 only at a rotation angle that exceeds the reference value by the amount of eccentricity of the work piece 1 . For example, among the rotation angles of the spindle 20 rotating at a constant speed, whenever the rotation angle at which the largest amount of eccentricity is generated, an excitation period is set to apply an impact to the work piece 1, and the impact actuator 100 is can drive Here, the impulse signal and the magnitude of the impact force may be generated at a constant frequency greater than the number of rotations of the spindle 20 .

The amount of eccentricity reduced by the impact is measured and fed back by the displacement measuring device 210 and the rotation angle measuring device 220, and a new impact force can be applied based on the fed back information. When the distance between the axis of rotation of the spindle 20 and the center of the work 1 falls below the reference value, machining with the tool 30 is possible.

An embodiment of the technology disclosed herein may include a method for automatically correcting the amount of eccentricity. The method of automatically correcting the amount of eccentricity according to the present specification will be described later with reference to FIGS. 5 to 7 .

5 is a view for explaining the steps of the method for correcting the amount of eccentricity according to the present specification, and FIGS. 6 and 7 are views showing measurement data according to the result of performing the method for correcting the amount of eccentricity according to the present specification.

The graph (1) of FIG. 6 is a graph showing the amount of eccentricity (absolute value) of the workpiece fixed to the vacuum chuck connected to the spindle. .

The graph (2) of FIG. 6 is a graph showing the distance value measured by measuring the rotational displacement of the outer peripheral surface of the workpiece based on the rotational center of the spindle. The horizontal axis is time and the unit is seconds, and the vertical axis is distance, and the unit is micrometer ( micrometer).

Graph (3) of FIG. 6 is a graph showing a calculated value of the impact force input to the excitation part of the impact actuator, the horizontal axis is time, the unit is seconds, and the vertical axis is force, the unit is Newton (N). Based on the impact force calculated according to graph (3), the excitation part of the impact actuator moves, and the motion of the impact part and the dummy moving part as shown in graphs (4) and (5) occurs according to the motion result of the excitation part. That is, the calculated impact force is a concept corresponding to the actual movement amount, but is not the same concept.

The graph (4) of FIG. 7 is a graph showing the measured value of the movement distance of the impact part of the impact actuator, and the horizontal axis is time and the unit is seconds, and the vertical axis is distance and the unit is meters.

Graph (5) of FIG. 7 is a graph showing the measured value of the moving distance of the dummy moving part of the impact actuator. The horizontal axis is time and the unit is seconds, and the vertical axis is distance and the unit is meters.

5, the eccentricity correction method according to the present specification is an eccentricity automatic correction method for correcting the eccentricity amount of a workpiece fixed to a vacuum chuck connected to a spindle and rotating together with the vacuum chuck, specifically, the displacement of the outer peripheral surface of the rotating workpiece Measuring (S510), calculating the amount of eccentricity of the workpiece based on the rotational displacement of the outer peripheral surface (S520), calculating the impact force of the impact actuator (S530) and driving the impact actuator to apply the calculated impact force (S540) may be included.

According to step S510, the workpiece to be processed is fixed by the vacuum operation of the vacuum chuck connected to the rotatable spindle, and the step of rotating the workpiece may be performed. In addition, according to this step, as described above, a sensor such as the displacement measuring device 210 may measure the rotational displacement of the workpiece. As such a sensor, a non-contact displacement measurement sensor as well as a contact displacement measurement sensor may be used. The result measured according to this step may be shown as graph (2). As shown in the graph (2) of FIG. 6, the displacement of the workpiece means the distance to the outer peripheral surface of the workpiece measured based on the rotation axis of the spindle, and 0 to 2 seconds is the initial measurement section, and actually impacts the workpiece. This applied section may be a section after 2 seconds. As shown in the graph (2) of FIG. 6 , the displacement of the workpiece may be rapidly reduced in the section from 2 seconds to about 6.2 seconds. This is because, when the amount of eccentricity (graph (1)) is equal to or greater than a reference value (eg, 5 micrometers), the impact force (graph (3)) is input as a relatively large first value (eg, 17N). As shown in the graph (2) of FIG. 6 , the displacement of the workpiece may gradually decrease in the section after about 6.2 seconds. This is because, when the amount of eccentricity (graph 1) is less than or equal to a reference value (eg, 5 micrometers), the impact force (graph 3) is input as a relatively small second value (eg, 9N). In this way, it is possible to quickly correct the amount of eccentricity through the input of the impact force through two steps, as well as to fine-tune it.

According to step S520, a step of calculating the amount of eccentricity of the workpiece based on the previously measured rotational displacement of the outer circumferential surface may be performed. As a method of detecting the amount of eccentricity in real time, the least mean square filter for the rotation speed synchronization component can be used. The amount of eccentricity calculated according to this step may be shown as graph (1) and expressed as an absolute value. As shown in graph (1) of FIG. 6, the amount of eccentricity of the workpiece rapidly decreases as above the reference value (eg, 5 micrometers) during the interval from 2 seconds to about 6.2 seconds after the initial measurement interval from 0 to 2 seconds. can be In the section after about 6.2 seconds, the eccentricity is less than the reference value and can be gradually decreased. As described above, as the first step, in the section where the eccentricity is greater than or equal to the reference value, the impact force is input as a relatively large first value (eg, 17N), and as the second step, in the section where the eccentricity is less than or equal to the reference value, the impact force is set to a relatively small second value (e.g., 9N). As shown in graph (1), when the correction is carried out according to the invention disclosed herein, the reduction in the amount of eccentricity of the workpiece to within 1 micrometer can be achieved within 20 seconds.

According to step S530, the step of calculating the impact force of the impact actuator based on the previously calculated amount of eccentricity of the workpiece may be performed. As shown in the graph (3) of FIG. 6 , in the section from 2 seconds to about 6.2 seconds in which the amount of eccentricity of the workpiece is equal to or greater than the reference value (for example, 5 micrometers), the impact force is a relatively large first value (for example, 17N) can be set to In addition, in a section after about 6.2 seconds in which the eccentricity of the work piece is equal to or less than the reference value, the impact force may be set to a relatively small second value (eg, 9N). The calculated impact force is input to the excitation unit, which may be a voice coil motor, so that the impact unit and the dummy moving unit may repeatedly reciprocate linearly as described below.

According to step S540, a step of driving the impact actuator according to the calculated impact force may be performed. Specifically, the impact unit and the dummy moving unit, which are the excitation units of the impact actuator, may perform repeated reciprocating linear motion. Referring to the graph (4) of FIG. 7 , the impact unit of the impact actuator may move forward by 5 mm and backward by -1 mm along the x-axis. That is, the impact part moves 5 mm to impact the outer peripheral surface of the workpiece, and can move by -1 mm along the x-axis by the elastic force of the elastic connection part. In addition, while the impact unit moves 5 mm, the dummy moving unit may move -6 mm along the x-axis. In addition, the impact part moves 5 mm forward for 2 to 20 seconds, which is the time before the impact is applied, because the impact part and the outer circumferential surface of the workpiece are in contact. In addition, the impact unit has a relatively large first value, and during a section from 2 seconds to about 6.2 seconds in which the impact force is input, the distance to move backward is a second value, which is a relatively small value, about 6.2 seconds, which is a section in which the impact force is input. It may be greater than the distance traveled backward during the subsequent section. In addition, the dummy moving unit has a relatively large first value, and during a section from 2 seconds to about 6.2 seconds, in which the impact force is input, the distance moving backward is about 6.2, which is a section in which the impact force is input as a second value, which is a relatively small value. It may be greater than the distance traveled backward during the interval after seconds. In addition, the moving distance of the dummy moving part may be smaller than the moving distance of the impacting part because the mass of the dummy moving part is larger than the mass of the impacting part.

Another embodiment not described herein may be a computer-readable medium in which a program is recorded, and the corresponding medium may be a medium in which instructions for implementing the method as described above are recorded. Specifically, the computer-readable medium in which the program according to this embodiment is recorded is a command for measuring the displacement of the outer circumferential surface of the rotating workpiece, a command for calculating the amount of eccentricity of the workpiece based on the rotational displacement of the outer circumferential surface, the impact actuator A command for calculating the impact force and a command for driving the impact actuator to apply the calculated impact force can be recorded.

The functional operations described in this specification and the embodiments related to the present subject matter can be implemented in a digital electronic circuit, computer software, firmware, or hardware, including the structures disclosed herein and structural equivalents thereof, or in a combination of one or more thereof do.

Embodiments of the subject matter described herein are one or more computer program products, ie one or more modules directed to computer program instructions encoded on a tangible program medium for execution by or for controlling the operation of a data processing device. can be implemented. A tangible program medium may be a radio wave signal or a computer-readable medium. A radio wave signal is an artificially generated signal, eg a machine generated electrical, optical or electromagnetic signal, that is generated to encode information for transmission to an appropriate receiver device for execution by a computer. The computer-readable medium may be a machine-readable storage device, a machine-readable storage substrate, a memory device, a combination of materials that affect a machine-readable radio wave signal, or a combination of one or more of these.

A computer program (also known as a program, software, software application, script or code) may be written in any form of programming language, including compiled or interpreted language or a priori or procedural language, and may be written as a stand-alone program or module; It can be deployed in any form, including components, subroutines, or other units suitable for use in a computer environment.

A computer program does not necessarily correspond to a file in a file system. A program may be in a single file provided to the requested program, or in multiple interacting files (eg, files that store one or more modules, subprograms, or portions of code), or portions of files that hold other programs or data. (eg, one or more scripts stored within a markup language document).

A computer program may be deployed to be executed on a single computer or multiple computers located at one site or distributed over a plurality of sites and interconnected by a communication network.

The processes and logic flows described herein may be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output.

Processors suitable for the execution of computer programs include, for example, both general and special purpose microprocessors and any one or more processors of any kind of digital computer. Typically, the processor will receive instructions and data from read-only memory, random access memory, or both.

A key element of a computer is one or more memory devices for storing instructions and data and a processor for executing instructions. Further, a computer is generally operably coupled to receive data from, transfer data to, or both of one or more mass storage devices for storing data, such as, for example, magnetic, magneto-optical disks or optical disks. or will include However, the computer need not have such a device.

The present description sets forth the best mode of the invention, and provides examples to illustrate the invention, and to enable any person skilled in the art to make or use the invention. This written specification does not limit the present invention to the specific terms presented.

Accordingly, although the present invention has been described in detail with reference to the above-described examples, those skilled in the art can make modifications, changes, and modifications to the examples without departing from the scope of the present invention.

Claims

An impact actuator for correcting an eccentricity of a workpiece fixed to the vacuum chuck and rotating together with the vacuum chuck, the impact actuator comprising:

Impact part for impacting the side of the workpiece;

a dummy moving part positioned to face the impact part;

an excitation unit connecting the impact unit and the dummy moving unit between the shock unit and the dummy moving unit, and reciprocating linearly moving the shock unit and the dummy moving unit in opposite directions; and

An impact actuator comprising an elastic connection part connecting the impact part and the dummy moving part between the impact part and the dummy moving part.
The method of claim 1,

Impact actuator, characterized in that the dummy moving part comprises a dummy mass.
The method of claim 1,

wealthy

a cylindrical coil holder connected to any one of the impact part and the dummy moving part, and having a coil wound around an outer circumferential surface;

A cylindrical magnetic housing connected to the other of the impact part and the dummy moving part, a permanent magnet is positioned on the inner circumferential surface, and the coil holder is inserted into the internal space,

An impact actuator, characterized in that when an alternating current is applied to the coil, the coil holder and the magnetic housing make reciprocating linear motion.
4. The method of claim 3, wherein the impact actuator is

support plate;

a coil holder bracket to which the coil holder is fixed;

a magnetic housing bracket to which the magnetic housing is fixed;

a guide rail fixed to the support plate and extending along the reciprocating linear motion direction;

a first sliding block fixed to the coil holder bracket and sliding along the guide rail; and

The shock actuator further comprising a second sliding block fixed to the magnetic housing bracket and sliding along the guide rail.
5. The method of claim 4,

The resilient connection part is an impact actuator, characterized in that both ends are a coil spring connected to a coil holder bracket and a magnetic housing bracket, respectively.
6. The method of claim 5, wherein the impact actuator is

Impact actuator, characterized in that both ends further include a torsion spring connected to the magnetic housing bracket and the support plate.
In the automatic eccentricity compensation system for compensating the amount of eccentricity of a workpiece which is fixed to the vacuum chuck connected to the spindle and rotates together with the vacuum chuck,

an impact actuator positioned on one side of the workpiece to apply an impact to the outer peripheral surface of the rotating workpiece;

Displacement measuring device positioned on one side of the workpiece to measure the rotational displacement of the outer peripheral surface of the rotating workpiece;

An eccentricity calculation unit for calculating the amount of eccentricity of the workpiece based on the outer circumferential rotational displacement and rotational angle;

an impact force calculation unit for calculating an impact force of the impact actuator to reduce the amount of eccentricity calculated by the eccentricity calculation unit; and

Automatic eccentricity compensation system, characterized in that it comprises a shock actuator driving unit for driving the shock actuator to apply the impact force calculated by the impact force calculation unit.
8. The method of claim 7,

The impact actuator drive unit drives the impact actuator to apply an impact to the workpiece only at a rotation angle at which the amount of eccentricity of the workpiece is generated.
8. The method of claim 7, wherein the impact actuator is

Impact part for impacting the side of the workpiece;

a dummy moving part positioned to face the impact part;

an excitation unit connecting the impact unit and the dummy moving unit between the shock unit and the dummy moving unit, and reciprocating linearly moving the shock unit and the dummy moving unit in opposite directions; and

Automatic compensation system for eccentricity, characterized in that it includes an elastic connecting part connecting the impact part and the dummy moving part between the impact part and the dummy moving part.
10. The method of claim 9,

The automatic eccentricity compensation system, characterized in that the dummy moving part includes a dummy mass.
10. The method of claim 9,

wealthy

a cylindrical coil holder connected to any one of the impact part and the dummy moving part, and having a coil wound around an outer circumferential surface;

A cylindrical magnetic housing connected to the other of the impact part and the dummy moving part, a permanent magnet is positioned on the inner circumferential surface, and the coil holder is inserted into the internal space,

When an alternating current is applied to the coil, the coil holder and the magnetic housing make a reciprocating linear motion.
12. The method of claim 11, wherein the impact actuator is

support plate;

a coil holder bracket to which the coil holder is fixed;

a magnetic housing bracket to which the magnetic housing is fixed;

a guide rail fixed to the support plate and extending along the reciprocating linear motion direction;

a first sliding block fixed to the coil holder bracket and sliding along the guide rail; and

The automatic eccentricity compensation system, fixed to the magnetic housing bracket, further comprising a second sliding block sliding along the guide rail.
13. The method of claim 12,

The elastic connection part is an automatic eccentricity compensation system, characterized in that both ends are a coil spring connected to a coil holder bracket and a magnetic housing bracket, respectively.
14. The method of claim 13, wherein the impact actuator is

Automatic eccentricity compensation system, characterized in that both ends further include a torsion spring connected to the magnetic housing bracket and the support plate.
A method for automatically correcting the amount of eccentricity for correcting the amount of eccentricity of a workpiece fixed to a vacuum chuck connected to a spindle and rotating together with the vacuum chuck, the method comprising:

(a) measuring the rotational displacement of the outer peripheral surface of the rotating workpiece with a displacement measuring device located on one side of the workpiece;

(b) calculating the amount of eccentricity of the workpiece based on the measured outer peripheral rotational displacement;

(c) calculating the impact force of the impact actuator to reduce the amount of eccentricity calculated by the eccentricity calculation unit; and

(d) automatically correcting the amount of eccentricity comprising the step of driving an impact actuator to apply the calculated impact force.
16. The method of claim 15, wherein step (d) is

The method for automatically correcting eccentricity, characterized in that the impact part of the impact actuator reciprocates linearly to apply an impact to the work, and the dummy moving part of the impact actuator reciprocates and linearly moves in the opposite direction to the impact part.
17. The method of claim 16, wherein step (c) is

when the amount of eccentricity calculated in step (b) is greater than the reference value, calculating the impact force of the actuator as a relatively large first value; and

If the amount of eccentricity calculated in step (b) is smaller than the reference value, calculating the impact force of the actuator as a relatively small second value.
As a computer-readable recording medium recording a program for performing an automatic eccentricity correction method for correcting the eccentricity of a workpiece fixed to a vacuum chuck connected to a spindle and rotating together with the vacuum chuck,

A computer-readable recording medium, characterized in that it stores instructions for performing the method according to any one of claims 15 to 17.