KR20190106241A - Machine tool and method for controlling the same - Google Patents

Abstract

According to the present invention, provided are a machine tool and a method for controlling the same. The machine tool corrects adjustable amounts of each of processing parameters inputted in a numerical control unit by an error value of current position coordinate data generated from each curved portion of a pattern in accordance with the driving of a standard pattern operation program stored in a standard command coordinate data before processing machine workpiece, maximizes the processing preciseness, improves the productivity, and improves the reliability of the machine tool, thereby facilitating user convenience.

Description

Machine tool and method for controlling the same}

The present invention relates to a machine tool and a method for controlling the machine tool, and more particularly, by correcting the addition and decrease of machining parameters by the error value generated in each bent portion of the pattern according to the driving of the standard pattern operation program before machining the workpiece. The present invention relates to a machine tool and a method of controlling the machine tool which can improve the precision.

In general, a machine tool refers to a machine that uses various cutting or non-cutting methods to process a metal / non-metal workpiece into a desired shape and dimension using a suitable tool.

Various types of machine tools, including turning centers, vertical / horizontal machining centers, door machining centers, swiss turns, electric discharge machines, horizontal NC boring machines and CNC lathes, are widely used for various applications in various industries.

BACKGROUND OF THE INVENTION In general, various types of machine tools currently in use include operation panels to which numerical control (NC) or computerized numerical control (CNC) technology is applied. This control panel has various function switches or buttons and a monitor.

In addition, the machine tool is a table for seating the workpiece as a workpiece and transporting it for processing the workpiece, a pallet for preparing the workpiece before processing, a tailstock for supporting a spindle or a workpiece that is rotated by combining the tool or the workpiece, and a dustproof hole. And the like.

In general, in a machine tool, a table, a tool bar, a main shaft, a tailstock, a dust shield, etc. are provided with a conveying unit for conveying along a feed shaft to perform various processing.

In addition, a machine tool generally uses a plurality of tools for various processing, and a tool magazine or a turret is used in the form of a tool storage space for storing a plurality of tools.

In general, machine tools are equipped with an automatic tool changer (ATC) for retracting or retracting a specific tool from the tool magazine by the command of the numerical control unit to improve the productivity of the machine tool.

In addition, machine tools are generally equipped with an automatic pallet changer (APC) to minimize downtime. The Automatic Pallet Changer (APC) automatically changes pallets between the workpiece machining area and the workpiece installation area. Workpieces can be mounted on pallets.

In general, tool paths in machine tools are created by the operator or by means of CAM, interactive systems, and the like.

When creating a tool path through an automated system such as a CAM or an interactive system, the user inputs various parameter information regarding the dimensions of the cutting part, the cutting tool, the processing sequence, and the processing method required for actual cutting. Additional parameters required to create a travel path for movement between cuttings are entered. At this time, the user inputs the parameters in consideration of machining stability and avoids collision between the tool and the workpiece or the tool and other components as well as the machining efficiency of the generated toolpath, and the automation system generates the toolpath based on the input parameters. .

In a conventional machine tool, various parameters are input to a numerical control unit (NC or CNC) for processing.

However, in the conventional machine tool and its control method, since the assembly state of the various equipment of the machine tool and the precision of the assembled parts are not constant, the same parameter is input, but there is a problem that the machining precision decreases accordingly.

In addition, in the conventional machine tool and its control method, although the drive unit and the transfer unit may be changed according to the temperature (seasonal) or wear condition according to the use environment, the machine tool and the transfer unit may be simply used by using machining parameters without standard setting, or by thermal deformation during operation. By performing only position correction, the machining precision and reliability of the machine tool are reduced, and there is a problem in that resources are wasted due to an increase in the incidence of defective products.

Moreover, the conventional machine tool and its control method cannot correct the error of parameters in real time and automatically, which consumes a lot of cost and time for optimal parameter correction, incurs inconvenience to the operator, There was a problem that deteriorated the productivity of the machine.

Republic of Korea Patent Publication No. 10-2017-0067265 Republic of Korea Patent Publication No. 10-2015-0067530

The present invention is to solve the above problems, the object of the present invention is the current position coordinate data and command coordinate data generated in each bent portion of the pattern according to the drive of the standard pattern motion program stored in the standard pattern motion program before machining the workpiece. Machine tool and machine tool control to maximize machining accuracy, increase productivity, and improve machine tool reliability by real-time and automatic correction of the amount of each machining parameter input to the numerical control part by the error value of To provide a way.

Machine tool according to the present invention for achieving the object of the present invention HMI unit for inputting a machining program for processing a workpiece; A numerical control unit which receives the machining program input to the HMI unit, inputs parameters for machining the workpiece, and generates a machining path; A PLC for driving a drive unit along the processing path through communication with the HMI unit and the numerical control unit; And a controller configured to correct an addition / decrease of the parameters input to the numerical controller according to an error value generated at each curved portion of the pattern when the standard pattern operation program is driven.

Further, in another preferred embodiment of the spindle compensation device of the machine tool according to the present invention, the control unit of the machine tool includes a standard pattern operation program storage unit for storing a standard pattern operation program; A basic data storage unit for storing the types of the parameters and the amount of reduction and increase of each parameter; A reference value storage unit for storing a reference value and a minimum value; A detection unit for detecting the current command coordinate data and the position coordinate data of the drive unit at each bent portion when the standard pattern operation program is driven; A calculator configured to calculate an error range based on the command coordinate data and the position coordinate data detected by the detector; A determination unit determining whether the calculated value of the calculation unit is within a range of the reference value and the minimum value stored in the reference value storage unit; And a correction unit for correcting the addition / decrease of the parameters according to the determination result of the determination unit.

Further, in another preferred embodiment of the spindle compensation device of the machine tool according to the present invention, the correction unit of the control unit of the machine tool when the calculated value is greater than or equal to the reference value to the reduction amount stored in the basic data storage unit Reduce the value, and increase the parameters to the increment stored in the basic data storage if the calculated value is less than the reference value and is greater than the minimum value, and corrects to maintain the previous state if the calculated value is less than or equal to the minimum value. Can be performed.

Further, in another preferred embodiment of the spindle compensation device of the machine tool according to the present invention, the standard pattern motion program stored in the standard pattern motion program storage of the control part of the machine tool is a pattern motion to form an N-shaped or S-shaped pattern It may be a program.

In order to achieve another object of the present invention, a method for controlling a machine tool according to the present invention includes the steps of: inputting a machining program for machining a workpiece; Inputting parameters for machining the workpiece and generating a machining path; Storing a standard pattern operation program; Storing a type of the parameters and a reduction amount and an increase amount of each parameter; Storing a reference value and a minimum value; Detecting current command coordinate data and position coordinate data of the drive unit at each bent portion of the pattern when the standard pattern operation program is driven; Calculating an error range based on the detected command coordinate data and the position coordinate data; Determining whether a calculated value is within a range of the reference value and the minimum value; And correcting the acceleration / decrease amount of the parameters, wherein the correcting step reduces the parameters to a reduction amount stored in the basic data storage when the calculated value is greater than or equal to the reference value, and the calculated value When the value is smaller than the reference value and larger than the minimum value, the parameters are increased by an increase amount stored in the basic data storage, and when the calculated value is smaller than or equal to the minimum value, correction is performed to maintain the previous state.

The control method of the machine tool and the machine tool according to the present invention is based on an error value between the current position coordinate data and the command coordinate data generated at each curved portion of the pattern according to the driving of the standard pattern motion program stored in the standard pattern motion program before the workpiece is machined. There is an effect of maximizing machining precision and reliability by correcting the acceleration / decrease amount of each machining parameter input to the numerical control part in real time and automatically.

In addition, the machine tool and the control method of the machine tool according to the present invention by reducing the amount of machining parameters in real time and automatically to reduce the occurrence of defective products by maintaining the optimum processing precision regardless of the operating environment or wear degree, It has the effect of preventing resource waste.

Furthermore, the machine tool and the method for controlling the machine tool according to the present invention can minimize the time and cost required for the correction of the machining parameters in real time and automatically to facilitate the user's convenience and to reduce the non-work time. As a result, the productivity of the machine tool can be increased.

Fig. 1 shows the occurrence of errors in each bent portion when driving an S-shaped pattern operation program.
Fig. 2 shows the occurrence of errors in each bent portion when the N-shaped pattern operation program is driven.
3 illustrates an error occurrence relationship in each bent portion of FIG. 1.
4 shows a conceptual diagram of a machine tool according to an embodiment of the present invention.
5 is a block diagram of a control unit of a machine tool according to an embodiment of the present invention.
6 is a flowchart illustrating a method for controlling a machine tool according to an embodiment of the present invention.
Figure 7 shows a graph of the error amount of each axis before correction by the machine tool and the control method according to an embodiment of the present invention.
Figure 8 shows a graph of the error amount of each axis after correction by the machine tool and the control method according to an embodiment of the present invention.

Hereinafter, with reference to the drawings of a machine tool and a method for controlling a machine tool according to an embodiment of the present invention will be described in detail. The following embodiments are provided as examples to sufficiently convey the spirit of the present invention to those skilled in the art. Therefore, the present invention is not limited to the embodiments described below and may be embodied in other forms. In the drawings, the size and thickness of the device may be exaggerated for convenience. Like numbers refer to like elements throughout the specification.

Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, only the embodiments are to make the disclosure of the present invention complete, and the general knowledge in the technical field to which the present invention belongs. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout. In the drawings, the size and relative size of layers and regions may be exaggerated for clarity.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, “comprise” and / or “comprising” refers to a component, step, operation and / or element that is present in one or more other components, steps, operations and / or elements. Or does not exclude additions.

FIG. 1 shows an error in each bend when driving an S-shaped pattern operation program, FIG. 2 shows an error in each bend when driving an N-shaped pattern operation program, and FIG. 3 shows an error in each bend in FIG. 1. Represents a relationship. Figure 4 shows a conceptual diagram of a machine tool according to an embodiment of the present invention, Figure 5 shows a block diagram of a control unit of the machine tool according to an embodiment of the present invention. 6 is a flowchart illustrating a method for controlling a machine tool according to an embodiment of the present invention. 7 is a graph showing an error amount of each axis before correction by a machine tool and a control method thereof according to an embodiment of the present invention, and FIG. 8 is a machine tool and control thereof according to an embodiment of the present invention. The graph shows the error amount of each axis after the correction by the method.

1 to 5 and 7 to 8 will be described a machine tool 1 according to the present invention. As shown in FIG. 4, the machine tool 1 according to an exemplary embodiment of the present invention includes an HMI unit 10, a numerical control unit 20, a PLC 30, and a controller 40.

The HMI unit 10 provides a human-machine interface for a worker to input a machining program for machining a workpiece. The operator inputs one or more workpiece machining programs using the HMI unit 10.

The numerical control unit 20 receives the machining program input to the HMI unit 10, inputs parameters P for machining the workpiece, and generates a machining path. The numerical control unit 20 includes a numerical control (NC) or a computerized numerical control (CNC), and includes various numerical control programs. That is, the numerical control unit 20 includes a driving program of a driving unit, a moving program of a tool, and the like, and the corresponding program is automatically loaded and operated according to the driving of the numerical control unit. The numerical control unit 20 communicates with the HMI unit 10, the PLC 30, and the control unit 40 by a predetermined protocol.

In addition, although not shown in the drawings, according to a preferred embodiment of the present invention, the numerical control unit 20 includes a casting part, such a casting part includes a display program and a data input program according to the display selection. It displays the software switch on the display screen according to the output of the screen display program, and recognizes the on / off of the software switch and executes the input / output command of the machine operation.

In addition, the present invention is not necessarily limited thereto, but the casting part is provided on a housing, a case, or one side of the machine tool, and includes a monitor capable of displaying various function switches or buttons and various information.

The programmable logic controller (PLC 30) drives the driving unit 31 along the machining path through communication with the HMI unit 10, the numerical control unit 20, or the control unit 30. The PLC 30 performs communication with the numerical control unit 20 or the control unit 40 by a predetermined protocol, and performs a control command through such communication. That is, the PLC 30 operates by receiving a control command according to the control program of the numerical controller 20 or the controller 40. In addition, the PLC 30 may measure the rotation speed and the torque by using the encoder of the driver 31 and detect the real-time current position coordinate data Yn of the driver 31. Although not necessarily limited to this, the driving unit 300 is formed of a motor or a servo motor (SERVO MOTOR), the drive is controlled by the PLC 30 and the correction unit 47 of the control unit 40. Accordingly, the present invention can be easily installed and operated even by a low cost machine tool by the PLC 30, thereby maximizing compatibility and minimizing installation costs. That is, the real-time current position coordinate data Yn of the drive part 31 of each axis is transmitted by the PLC 30 to the detection part 44 mentioned later by the predetermined protocol.

In addition, although not shown in the drawings, the machine tool 1 according to an embodiment of the present invention may further include an input unit and a display unit.

The input unit is installed in the form of a switch or a touch button on the operation panel and the like, and drives a standard pattern operation program before machining the workpiece, thereby automatically real-time automatic control of the controller 40 to correct the acceleration / decrease of the parameters P according to the error value generated in each bent portion. Perform the calibration function.

That is, the input unit allows the operator to arbitrarily select the automatic correction function of the acceleration and loss of the parameters of the machine tool. As shown in FIG. 7, when the input / output automatic correction function of the parameters of the machine tool is not selected at the input unit, machining is performed by the parameters input to the numerical control unit of the machine tool and the machining program input to the HMI unit. In this case, the error amount of each axis (X-axis, Y-axis, Z-axis, C-axis, A-axis) increases according to the assembly state of the equipment, the difference of precision of the assembled parts, the temperature and the wear state of the transfer part and the drive part. As shown in the graph, the amount of error increases, which reduces machining accuracy and reliability.

The display unit displays the progress of the automatic correction function of the control unit, the calculated value of the calculation unit of the control unit, the determination unit, the result of the correction unit and the parameters (P) input to the numerical control unit, the currently running machining program and the standard pattern operation program, etc. . As a result, the operator can determine whether there is an abnormality in the equipment by visually checking whether there is automatic correction, machining precision, and error amount, thereby reducing maintenance costs and preventing safety accidents.

In addition, the display unit displays an alarm when the calculation value of the calculation unit is too large or when the correction is not performed, and informs the operator of the abnormality of the machine tool, for the convenience of the operator, and immediately confirms the damage of the machine tool. To prevent secondary damage and maximize reliability and safety. In this case, the alarm may be displayed in the form of a monitor, a warning sound or a warning light. Although not necessarily limited thereto, the display unit may include an LCD, an LED, a PDP monitor, and the like.

The control unit 40 controls the acceleration / decrease amounts A and B of the parameters P input to the numerical control unit 20 according to an error value generated in each bent portion R of the N-shaped or S-shaped pattern when the standard pattern operation program is driven. )).

As shown in FIGS. 1 to 3, the bend R means a place where positive and negative numbers of the slope change in the corresponding coordinate graph. That is, in an S-shaped pattern or an N-shaped pattern, the slope at each coordinate has a positive value and the slope at each coordinate changes to a negative value, or conversely, the slope at each coordinate has a negative value. And where the slope at each coordinate changes to a positive value.

As such, in FIG. 1, the left first bend R is located where the slope changes from a negative slope to a positive slope, and the left second bend R is located where the slope changes from a positive slope to a negative slope.

Specifically, a predetermined number having a predetermined number of coordinates having a slope of adjacent negative values and a slope of a positive value based on coordinates in which the slope changes from a positive value to a negative value or from a negative value to a positive value With the bend (R) up to the coordinates of the operator, the operator can change the slope and the amount of the adjacent negative values based on the coordinates where the slope changes from the positive value to the negative value or from the negative value to the positive value in the basic data storage. The number of slope coordinates of the value of can be varied as needed.

Although not necessarily limited thereto, according to an embodiment of the present invention, in order to ensure reliability and speed up processing, the slope is adjacent to the coordinates of changing from a positive value to a negative value or a negative value to a positive value. It is preferable that a predetermined number of coordinates having a negative value slope and a predetermined number of coordinates having a positive value slope be set to 2 or more and 10 or less.

As described above, the machine tool according to the present invention is inputted to the numerical control unit by an error value between the current position coordinate data and the command coordinate data generated at each curved portion of the pattern according to the driving of the standard pattern motion program stored in the standard pattern motion program before the workpiece is machined. By adjusting the acceleration / decrease of each machining parameter in real time and automatically, it is possible to maximize machining precision and reliability.

3 and 4 to 5, the control unit 40 of the machine tool 1 according to an embodiment of the present invention is a standard pattern operation program storage unit 41, basic data storage unit 42, And a reference value storage section 43, detection section 44, calculation section 45, determination section 46, and correction section 47.

The standard pattern operation program storage unit 41 stores the standard pattern operation program.

As shown in Figs. 1 and 2, the machine tool 1 has a larger error value in the bent portion R when driving the S-shaped pattern operation program (Fig. 1) or when driving the N-shaped pattern operation program (Fig. 2). Will occur. These error values depend on the operating temperature of the machine tool or the ambient temperature in which the machine tool is installed, the state of wear of the machine tool, the assembly of the equipment, or the precision of the assembled parts. That is, by simply inputting only the parameters P to the numerical controller 20, the error in the curved portion R cannot be corrected.

As such, the standard pattern operation program stored in the standard pattern operation program storage unit 41 may store a pattern operation program that forms an N-shaped or S-shaped pattern. In the case of an N-shaped pattern operation program, it is suitable for a shape with many acceleration changes, and in the case of an S-shaped pattern operation program, it is suitable for a shape with many continuous accelerations and decelerations. In the case of the N-shaped pattern operation program or the S-shaped pattern operation program, it is a basic pattern operation to check the shape with high acceleration or continuous acceleration / deceleration, and it is easy to add a program to a general machine tool for the convenience of the operator and to increase the compatibility. This makes it easy to expand the product and reduce the cost and time of adding a program.

In addition, the standard pattern operation program is not necessarily limited to the S-shape or the N-shape, and may implement a repeated pattern operation, and various types of pattern operation programs may be applied as long as the curved portion R is repeatedly formed.

 The basic data storage unit 42 stores the type of the parameters P and the decrease amount B and the increase A of each parameter P. FIG. That is, the basic data storage unit 42 includes the acceleration / deceleration time constant before interpolation, the acceleration change time, the allowable acceleration change amount, the continuous linear allowable acceleration change amount, the ratio of the acceleration / deceleration change time, the allowable acceleration, the acceleration / deceleration time constant after interpolation, and the corner speed. The parameters (P) for the difference and the maximum machining speed can be stored. These parameters (P) may differ from the type of machine tool and the workpiece, tool, and the like to be machined. In addition, the basic data storage unit 42 stores the decrease amount B and the increase amount A for each parameter P. FIG. The reduction amount B and the increase amount A are also different depending on the type of each parameter P, the workpiece, the tool, and the machine tool, and the user can select and input the corresponding data. In addition, the present invention is not necessarily limited thereto, but the increase amount A and the decrease amount B may be formed to have opposite values. That is, when the increase amount A for any one parameter P is 10, the decrease amount B may be formed to -10 for the same parameter P.

As a result of the determination of the calculation unit 45 and the determination unit 46, which will be described later, if the bending portion R has reverse infeed (the calculated value K is smaller than the reference value C and the calculated value is larger than the minimum value D, D <K <C), the correction unit 47 increases and corrects each parameter P by the increase amount A with respect to the corresponding parameter P. On the contrary, when the calculation unit 45 and the determination unit 46 determine that the bending portion R is over-indented (when the calculated value K is greater than or equal to the reference value C, K≥C), the correction unit 47 Compensate by decreasing each parameter P by the decrease amount B for the parameter P. In addition, when moving along the bent portion (R) is determined to be within the error range to maintain the existing state.

The reference value storage unit 43 stores the reference value C and the minimum value D for comparison with the calculated value K. FIG. This reference value (C) is preferably 5 and the minimum value (D) is not necessarily limited thereto. If the reference value (C) is larger than 5, the error is excessively corrected to reduce the processing accuracy, and if it is smaller than 5, an error that cannot determine the degree of error may occur. In addition, when the minimum value is larger than 2, the processing precision may be reduced by the correction exceeding the error range, and when the minimum value is smaller than 2, the accuracy of the determination of the occurrence of an error or the number of occurrences of an error of determination increase. The reference value (C) and the minimum value (D) are designated by the user in consideration of various kinds of machine tools, types of workpieces, types of tools, temperature, environment, and machine tool life, or calculated and inputted by an automatic program. It may be.

The detection section 44 detects the current command coordinate data Xn and the position coordinate data Yn of the drive section 31 at each of the bends R when the standard pattern operation program is driven. Although not necessarily limited thereto, the detection unit 44 classifies the command coordinate data Xn into data calculated by the machining path generated by the numerical controller 20 or data of the machining program input to the HMI unit 10. The search results are calculated, and the position coordinate data Yn is calculated by reading the encoder of the drive unit 31 of the PLC 30. Accordingly, by quickly and easily detecting the command coordinate data (Xn) and the position coordinate data (Yn), it is possible to quickly perform the correction to improve the machining accuracy in real time, saving cost and time and maximizing user convenience. .

The calculation unit 45 calculates an error range based on the command coordinate data Xn and the position coordinate data Yn detected by the detection unit 44. As shown in Fig. 3, the calculation section 45 is a position coordinate data (Xn) in the command coordinate data (Xn) on each axis (X axis, Y axis, Z axis, A axis, C axis) in each bend portion (R) The calculated value K which is the average value obtained by subtracting Yn) is calculated. As an example, as shown in FIG. 3, the calculated value K _X in the X axis is calculated as follows.

K1 = X1-Y1, K2 = X2-Y2, K3 = X3-Y3, K4 = X4-Y4

K _X = K1 + K2 + K3 + K4 / 4

The calculated value K _Y on the Y axis is calculated as follows.

K11 = X11-Y11, K12 = X12-Y12, K13 = X13-Y13, K14 = X14-Y14

K _Y = K11 + K12 + K13 + K14 / 4

The calculated value K _Z on the Z axis is calculated as follows.

K21 = X21-Y21, K22 = X22-Y22, K23 = X23-Y23, K24 = X24-Y24

K _Z = K21 + K22 + K23 + K24 / 4

If the machine tool is a 5-axis machine in addition to the 3-axis, the calculated value K _A on the A axis and the calculated value K _{C on the} C axis are calculated as follows.

K31 = X31-Y31, K32 = X32-Y32, K33 = X33-Y33, K34 = X34-Y34

K _A = K31 + K32 + K33 + K34 / 4

K41 = X41-Y41, K42 = X42-Y42, K43 = X43-Y43, K44 = X44-Y44

K _C = K41 + K42 + K43 + K44 / 4

The calculated value K is calculated by the following equation.

[Equation 1]

K = (K1 + K2 + K3) ····· + Kn) / n

The calculation of the deformation part in the bent portion R necessary for error correction or the measurement of multiple times at each bent portion R can be changed by the operator as necessary, such as the state or environment of the machine tool. Accordingly, it can be applied to various machine tools, thereby increasing compatibility and maximizing user convenience.

As the calculated value is applied to the average value of the various deformation parts in each curved portion (R), it is possible to maximize the machining precision through accurate error correction according to the current state of the machine tool.

The determination unit 46 determines whether the calculated value K of the calculation unit 45 is within a range of the reference value C and the minimum value C stored in the reference value storage unit 43.

The correction unit 47 corrects the decrease amount B and the increase amount A of the parameters P according to the determination result of the determination unit 46. As an example, when the calculated value Kx of the calculation unit K on the X-axis is greater than or equal to 5, which is the reference value C, the correction unit 47 corrects each parameter P by the decrease amount B. FIG. On the contrary, when the calculated value Kx of the calculation unit K on the X axis is smaller than 5, which is the reference value C, the correction unit 47 corrects each parameter P by an increase amount A. Accordingly, after each parameter (P) is corrected to the optimum state, the machining path for the workpiece is formed, thereby reducing the occurrence of errors, thereby maximizing the machining precision and reliability of the machine tool.

More preferably, the correction unit 47 stores the parameters P in the basic data storage unit 42 when the calculated value K is greater than or equal to the reference value C (K≥C, over-infeed state). B), and when the calculated value K is smaller than the reference value C and larger than the minimum value D (D <K <C, reverse infeed state), the parameters P are transferred to the basic data storage 42. If the calculated value K is less than or equal to the minimum value D (K≤D), the correction is performed to maintain the previous state.

Therefore, the machine tool according to the present invention is a numerical control unit based on the average of the error value of the current position coordinate data and the command coordinate data generated in each bent portion of the pattern according to the drive of the standard pattern motion program stored in the standard pattern motion program before the workpiece machining. It is possible to maximize the processing precision and reliability by compensating the acceleration / decrease of each machining parameter input in real time and automatically.

A control method of a machine tool according to the present invention will be described with reference to FIG. 6. As shown in Figure 6, the control method of the machine tool according to an embodiment of the present invention is a machining program input step (S1), parameter input and machining path generation step (S2), standard pattern operation program storage step (S3), Basic data storage step S4, reference value / minimum value storage step S5, detection step S6, calculation step S7, determination step S8, and correction step S9.

The machining program for machining the workpiece is input to the HMI 10.

After the machining program input step S1, the numerical control unit 20 inputs parameters P for machining the workpiece and generates a machining path. As described above, the numerical control unit 20 includes a numerical control (NC) or a computerized numerical control (CNC), and various numerical control programs are embedded therein. The numerical control unit 20 communicates with the HMI unit 10, the PLC 30, and the control unit 40 by a predetermined protocol.

After the parameter input and the machining path generation step S2, the standard pattern operation program storage unit 41 of the control unit 40 is stored. Although not necessarily limited thereto, the standard pattern operation program stored in the standard pattern operation program storage unit 41 may store a pattern operation program that forms an N-shaped or S-shaped pattern. In the case of an N-shaped pattern operation program, it is suitable for a shape with many acceleration changes, and in the case of an S-shaped pattern operation program, it is suitable for a shape with many continuous accelerations and decelerations. In the case of the N-shaped pattern operation program or the S-shaped pattern operation program, it is a basic pattern operation to check the shape with high acceleration or continuous acceleration / deceleration, and it is easy to add a program to a general machine tool for the convenience of the operator and to increase the compatibility. This makes it easy to expand the product and reduce the cost and time of adding a program.

After the standard pattern operation program storage step S3, the type of the parameters P and the amount of decrease B and the amount A of the parameters P are stored in the basic data storage 42. The input parameters P, the decrease amount B and the increase amount A are the same as described above and will be omitted below.

After the basic data storage step S4, the reference value storage unit 43 stores the reference value C and the minimum value D. As described above, the reference value (C) and the minimum value (D) can be arbitrarily set by the user according to the condition of the equipment, and the optimum reference value (C) and the minimum value (D) are automatically set through repeated measurement of the corresponding equipment. Precision can be maximized.

After the reference value / minimum value storing step S5, the current command coordinate data Xn and the position coordinate data Yn of the drive unit 31 at each bent portion R of the pattern when the detection unit 44 drives the standard pattern operation program. Detect. The detection method is the same as the method described above, and will be omitted below.

After the detection step S6, an error range is calculated by the calculation unit 45 based on the detected command coordinate data Xn and the position coordinate data Yn. In the calculation step S7, the calculation method and the calculation formula are the same as described above and will be omitted below.

After the calculation step S7, the determination unit 46 determines whether the calculated value K is within the range of the reference value C and the minimum value D.

After the determination step S8, the acceleration / decrease amount of the parameters P is corrected.

That is, in the correction step S9, when the calculated value K is greater than or equal to the reference value C as described above (K≥C), the reduction amount B stored in the basic data storage 42 is stored in the parameters P. If the calculated value (K) is smaller than the reference value (C) and larger than the minimum value (D) (D <K <C), the parameters P are stored in the basic data storage 42. If the calculated value K is less than or equal to the minimum value D (K≤D), the correction is performed to maintain the previous state.

As shown in Figure 7, before the correction by the machine tool and the control method of the machine tool according to the present invention, the error amount of the X-axis, Y-axis, Z-axis, A-axis, C-axis is large, the machining precision is reduced, The incidence of rejects increases, resulting in waste of resources. However, as shown in FIG. 8, before the correction by the machine tool and the control method of the machine tool according to the present invention is applied, the error amount of the X axis, the Y axis, the Z axis, the A axis, and the C axis is significantly reduced, thereby reducing the machining accuracy. Increase and reliability may increase.

Therefore, the machine tool according to the present invention reduces the occurrence of defective products by maintaining the optimum processing accuracy regardless of the type of the machine tool, the use environment or the degree of wear, etc. according to the real-time and automatic correction of the amount of machining parameters It prevents waste and improves the productivity of machine tools by minimizing the time and cost required for the correction by real-time and automatic correction of processing parameters. .

In the detailed description of the present invention described above with reference to the preferred embodiment of the present invention, those skilled in the art or those skilled in the art having ordinary knowledge of the present invention described in the claims to be described later It will be understood that various modifications and variations can be made in the present invention without departing from the spirit and scope of the art. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

1: machine tool, 10: HMI
20: numerical control unit, 30: PLC,
40: control unit,
41: standard pattern operation program storage unit,
42: basic data storage unit, 43: reference value storage unit,
44: detector, 45: calculator,
46: determination unit, 47: correction unit.

Claims (5)

An HMI unit for inputting a machining program for machining the workpiece;
A numerical control unit which receives the machining program input to the HMI unit, inputs parameters for machining the workpiece, and generates a machining path;
A PLC for driving a drive unit along the processing path through communication with the HMI unit and the numerical control unit; And
And a controller which corrects the amount of the parameter inputted to the numerical controller according to an error value generated at each bent portion of the pattern when the standard pattern operation program is driven.
The method of claim 1,
The control unit,
A standard pattern operation program storage unit for storing a standard pattern operation program;
A basic data storage unit for storing the types of the parameters and the amount of reduction and increase of each parameter;
A reference value storage unit for storing a reference value and a minimum value;
A detection unit for detecting the current command coordinate data and the position coordinate data of the drive unit at each bent portion when the standard pattern operation program is driven;
A calculator configured to calculate an error range based on the command coordinate data and the position coordinate data detected by the detector;
A determination unit determining whether the calculated value of the calculation unit is within a range of the reference value and the minimum value stored in the reference value storage unit; And
And a correction unit for correcting the addition / decrease of the parameters according to the determination result of the determination unit.
The method of claim 2,
The correction unit,
If the calculated value is greater than or equal to the reference value, the parameters are reduced to a reduction amount stored in the basic data storage. If the calculated value is less than the reference value and larger than the minimum value, the parameters are stored in the basic data storage. Increase by a stored increment and maintain a previous state if the calculated value is less than or equal to the minimum value.
The method of claim 2,
And the standard pattern operation program stored in the standard pattern operation program storage unit is a pattern operation program for forming an N-shaped or S-shaped pattern.
Inputting a machining program for machining the workpiece;
Inputting parameters for machining the workpiece and generating a machining path;
Storing a standard pattern operation program;
Storing a type of the parameters and a reduction amount and an increase amount of each parameter;
Storing a reference value and a minimum value;
Detecting current command coordinate data and position coordinate data of the drive unit at each bent portion of the pattern when the standard pattern operation program is driven;
Calculating an error range based on the detected command coordinate data and the position coordinate data;
Determining whether a calculated value is within a range of the reference value and the minimum value; And
Correcting the acceleration / decrease of the parameters;
The correcting step,
If the calculated value is greater than or equal to the reference value, the parameters are reduced to a reduction amount stored in the basic data storage. If the calculated value is less than the reference value and larger than the minimum value, the parameters are stored in the basic data storage. Increasing by a stored increment, and maintaining the previous state if the calculated value is less than or equal to the minimum value.

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