KR102453367B1 - Machine tool and method for controlling the same - Google Patents

Abstract

The present invention relates to each machining parameter input to the numerical control unit by the error value of the current position coordinate data and the command coordinate data generated in each bend of the pattern according to the driving of the standard pattern operation program stored in the standard pattern operation program before machining the workpiece. It relates to a machine tool and a control method of a machine tool that can maximize machining precision, increase productivity, improve machine tool reliability, and promote user convenience by compensating for addition or loss.

Description

Machine tool and method for controlling the machine tool {Machine tool and method for controlling the same}

The present invention relates to a machine tool and a method for controlling a machine tool, and more particularly, by correcting the increase or decrease of the processing parameters by the error value generated in each bend of the pattern according to the driving of the standard pattern operation program before processing the workpiece. It relates to a machine tool capable of improving precision and a method for controlling a machine tool.

In general, a machine tool refers to a machine used for the purpose of machining a metal/non-metal workpiece into a desired shape and size using an appropriate tool by various cutting or non-cutting methods.

Various types of machine tools, including turning centers, vertical/horizontal machining centers, door machining centers, Swiss turns, electric discharge machines, horizontal NC boring machines, CNC lathes, etc., are widely used in various industrial sites for their respective purposes.

In general, various types of machine tools currently used have an operation panel to which a numerical control (NC) or computerized numerical control (CNC) technology is applied. Such an operation panel is provided with various function switches or buttons and a monitor.

In addition, the machine tool is a table on which a workpiece material is seated and transferred for processing the workpiece, a pallet for preparing the workpiece before processing, a spindle that rotates with a tool or workpiece combined, a tailstock for supporting the workpiece, etc. during processing, a vibration isolator etc. are provided.

In general, in a machine tool, a table, a tool rest, a main shaft, a tailstock, a vibration isolator, etc. are provided with a conveying unit conveying along a conveying axis in order to perform various machining.

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

In addition, in general, a machine tool is provided with an automatic tool changer (ATC, Automatic Tool Changer) for withdrawing or receiving a specific tool from the tool magazine by the command of the numerical control unit in order to improve the productivity of the machine tool.

In addition, in general, a machine tool is provided with an automatic pallet changer (APC, Automatic Palette Changer) in order to minimize the non-working time. The automatic pallet changer (APC) automatically exchanges pallets between the workpiece machining area and the workpiece installation area. Pallets may be loaded with workpieces.

In general, in a machine tool, a tool path is created directly by an operator or through a method such as CAM or an interactive system.

When a tool path is created through an automation system such as CAM or an interactive system, the user enters various parameter information about the dimensions of the cutting part required for thread cutting, the cutting tool, the processing sequence, and the processing method. Additional parameters required to create a movement path for movement between cuttings are input. At this time, the user inputs parameters in consideration of machining stability and avoiding collision between the tool and the workpiece or tool and other components as well as the machining efficiency of the generated tool path, and the automation system creates the tool path based on the input parameters. .

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

However, in the conventional machine tool and its control method, the same parameters were input and used because the assembly state of various equipment of the machine tool and the precision of the assembled parts were not constant, but there was a problem in that the processing precision was reduced accordingly.

In addition, in the conventional machine tool and its control method, although the driving part and the conveying part can change depending on the temperature (season) or wear state according to the usage environment, simply use the processing parameters without setting the standard, or use the processing parameters during operation. There was a problem in that processing precision and reliability of the machine tool were reduced by performing only position compensation, and resources were 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 the parameter in real time and automatically, so it consumes a lot of money and time for optimal parameter correction, causes inconvenience to the operator, and increases the non-working time. There was a problem that deteriorated the productivity of the machine.

Korean Patent Publication No. 10-2017-0067265 Korean Patent Publication No. 10-2015-0067530

The present invention is to solve the above problems, and an object of the present invention is the current position coordinate data and command coordinate data generated in each bend of the pattern according to the driving of the standard pattern operation program stored in the standard pattern operation program before machining the workpiece. Machine tool and machine tool control that can maximize machining precision, increase productivity, and improve machine tool reliability by automatically and real-time correction of the addition/decreased amount of each machining parameter input to the numerical control unit by the error value of to provide a way

In order to achieve the object of the present invention, a machine tool according to the present invention includes an HMI unit for inputting a machining program for machining a work; a numerical control unit receiving the machining program input to the HMI unit, inputting parameters for machining the work, and generating a machining path; PLC for driving a driving unit according to the machining path through communication with the HMI unit and the numerical control unit; and a control unit that corrects the increase or decrease amount of the parameters input to the numerical control unit according to an error value generated in each bent portion of the pattern when the standard pattern operation program is driven.

In addition, in another preferred embodiment of the main shaft compensation device of the machine tool according to the present invention, the control unit of the machine tool is a standard pattern operation program storage unit for storing the standard pattern operation program; a basic data storage unit for storing types of the parameters and decreasing and increasing amounts of each parameter; a reference value storage unit for storing a reference value and a minimum value; a detection unit configured to detect current command coordinate data and position coordinate data of the driving unit in each bending unit when the standard pattern operation program is driven; a calculation unit for calculating an error range based on the command coordinate data and the position coordinate data detected by the detection unit; a determination unit for determining whether the calculated value of the calculation unit is within the 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 amount of the parameters according to the determination result of the determination unit.

In addition, in another preferred embodiment of the main shaft compensation device of the machine tool according to the present invention, the compensation unit of the control unit of the machine tool, when the calculated value is greater than or equal to the reference value, the parameters are reduced to the amount stored in the basic data storage unit. When the calculated value is smaller than the reference value and greater than the minimum value, the parameters are increased by the increment stored in the basic data storage unit, and when the calculated value is less than or equal to the minimum value, the previous state is maintained. can be performed.

In addition, in another preferred embodiment of the main shaft compensation device of the machine tool according to the present invention, the standard pattern operation program stored in the standard pattern operation program storage unit of the control unit of the machine tool is a pattern operation to form an N-shaped or S-shaped pattern It can be a program.

In order to achieve another object of the present invention, there is provided a method for controlling a machine tool according to the present invention, comprising: inputting a machining program for machining a work; inputting parameters for machining the workpiece and generating a machining path; storing a standard pattern operation program; storing the types of the parameters and decreasing and increasing amounts of each parameter; storing a reference value and a minimum value; detecting current command coordinate data and position coordinate data of the driving unit at each bent part 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 the calculated value is within the range of the reference value and the minimum value; and correcting an increase or decrease amount of the parameters, wherein the correcting includes reducing the parameters to a decrease amount stored in the basic data storage unit 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 greater than the minimum value, the parameters are increased by the increment stored in the basic data storage unit, and when the calculated value is less than or equal to the minimum value, correction is performed to maintain the previous state.

The machine tool and the control method of the machine tool according to the present invention are based on the error value of the current position coordinate data and the command coordinate data generated in each bend of the pattern according to the driving of the standard pattern operation program stored in the standard pattern operation program before processing the workpiece. It has the effect of maximizing processing precision and reliability by correcting the addition/decreasing amount of each processing parameter input to the numerical control unit in real time and automatically.

In addition, the machine tool and the control method of the machine tool according to the present invention reduce the occurrence of defective products by maintaining the optimum machining precision regardless of the use environment or the degree of wear, etc. It has the effect of preventing wastage of resources.

Furthermore, the machine tool and the control method of the machine tool according to the present invention minimize the time and cost required for the correction by correcting the addition/decreasing amount of the processing parameter in real time and automatically, thereby promoting user convenience and reducing the non-working time. This has the effect of increasing the productivity of the machine tool.

Fig. 1 shows the occurrence of errors in each bent portion when an S-shaped pattern operation program is driven.
2 shows the generation of errors in each bent portion when the N-shaped pattern operation program is driven.
FIG. 3 shows an error generation relationship in each bent portion of FIG. 1 .
Figure 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.
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.
8 is a graph showing an error amount of each axis after correction by a machine tool and a control method thereof according to an embodiment of the present invention.

Hereinafter, with reference to the drawings of the machine tool and the control method of the machine tool according to an embodiment of the present invention will be described in detail. The embodiments introduced below are provided as examples so that the spirit of the present invention can be sufficiently conveyed to those skilled in the art. Accordingly, the present invention is not limited to the embodiments described below and may be embodied in other forms. And, in the drawings, the size and thickness of the device may be exaggerated for convenience. Like reference numbers refer to like elements throughout.

Advantages and features of the present invention, and a method of achieving them will become 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 will be embodied in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout. The sizes and relative sizes of layers and regions in the drawings may be exaggerated for clarity of description.

The terminology used herein is for the purpose of describing the embodiments, and therefore is not intended to limit the present 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 the presence of one or more other components, steps, operations and/or elements mentioned. or addition is not excluded.

Fig. 1 shows the occurrence of errors at each bend when the S-shaped pattern operation program is driven, Fig. 2 shows the error occurrence at each bend when the N-shaped pattern operation program is driven, and Fig. 3 shows the error occurrence at 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 shows a graph of the error amount of each axis before correction by the machine tool and its control method according to an embodiment of the present invention, and FIG. 8 is a machine tool and its control according to an embodiment of the present invention. The graph of the error amount of each axis after correction by the method is shown.

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

The HMI unit 10 provides a user-machine interface (Human-Machine Interface) for the operator to input a machining program for machining the 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 creates a machining path. The numerical control unit 20 includes a numerical control (NC) or a computerized numerical control (CNC), and various numerical control programs are built-in. That is, the numerical control unit 20 has a built-in driving program for the driving unit, a tool operation program, and the like, and automatically loads and operates the corresponding program 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 main operation unit, and this main operation unit includes a screen display program and a data input program according to screen display selection, , displays the software switch on the display screen according to the output of the screen display program, recognizes the ON/OFF of the software switch, and gives an input/output command for machine operation.

In addition, although not necessarily limited thereto, the main operation unit includes a monitor that is installed on the housing, case, or one side of the machine tool to display various function switches or buttons and various information.

PLC (30, Programmable Logic Controller) drives the driving unit 31 according to 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 according to a predetermined protocol, and performs a function of executing 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 control unit 20 or the control unit 40 . In addition, the PLC 30 may measure the number of rotations and torque by using the encoder of the driving unit 31 , and may detect the real-time current position coordinate data Yn of the driving unit 31 . Although not necessarily limited thereto, the driving unit 300 is formed of a motor or a servo motor, and driving is controlled by the PLC 30 and the correction unit 47 of the control unit 40 . Accordingly, the present invention is easily installed and operated even for a low-cost machine tool by the PLC 30, thereby maximizing compatibility and minimizing the installation cost. That is, the real-time current position coordinate data Yn of the driving unit 31 of each axis is transmitted by the PLC 30 to the detection unit 44 to be described later by a 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 touch button on the operation panel, etc., and the control unit 40 drives the standard pattern operation program before processing the workpiece to correct the increase or decrease of the parameters (P) according to the error value generated in each bend. Perform a correction function.

That is, by the input unit, the operator can arbitrarily select the automatic correction function of the parameters of the machine tool. As shown in FIG. 7 , if the automatic correction function of the machine tool parameters is not selected in the input unit, the 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 depending on the assembly state of the equipment, the difference in precision of the assembled parts, and the temperature or wear state of the transfer part and the driving part, as shown in Fig. 7 As shown in the graph, the amount of error increases and the processing precision and reliability decrease.

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 result of the judgment unit and the correction unit, the parameter (P) input to the numerical control unit, the currently running processing program and the standard pattern operation program, etc. . Accordingly, it is possible to reduce maintenance costs and prevent safety accidents in advance as the operator visually determines whether or not there is an automatic correction, processing precision, error amount, etc. to determine whether the equipment is abnormal and inspects it.

In addition, the display unit displays an alarm when the calculated value of the calculation unit is too large or correction is not performed, and informs the operator of whether the machine tool is abnormal, thereby promoting operator convenience and immediately checking whether the machine tool is damaged. This prevents secondary damage and maximizes reliability and safety. In this case, the alarm may be displayed in a form displayed on a monitor, a warning sound or a warning light. Although not necessarily limited thereto, the display unit may be composed of an LCD, an LED, a PDP monitor, and the like.

The control unit 40 controls the amount of addition (A, B) of the parameters (P) input to the numerical control unit 20 according to the error value generated in each bent portion (R) of the N-shaped or S-shaped pattern when the standard pattern operation program is driven ) is corrected.

As shown in FIGS. 1 to 3 , the bent portion R refers to a place where the positive and negative values 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 changes to a negative value. It means where the slope at each coordinate changes to a positive value.

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

Specifically, a predetermined number of coordinates having a slope of a negative value adjacent to the coordinates whose slope changes from a positive value to a negative value or from a negative value to a positive value, and a predetermined number having a slope of a positive value Up to the coordinate of the bend (R), the operator in the basic data storage, based on the coordinates where the slope changes from positive to negative or from negative to positive, the slope and positive The number of slope coordinates of the value of can be set variously as needed.

Although not necessarily limited thereto, according to an embodiment of the present invention, in order to secure reliability and to process quickly, it is adjacent based on the coordinates in which the slope changes from a positive value to a negative value or from a negative value to a positive value. It is preferable that the predetermined number of coordinates having a negative slope and the predetermined number of coordinates having a positive slope are set to 2 or more and 10 or less.

In this way, the machine tool according to the present invention is input to the numerical control unit by the error value of the current position coordinate data and the command coordinate data generated in each bend of the pattern according to the driving of the standard pattern operation program stored in the standard pattern operation program before processing the workpiece It is possible to maximize processing precision and reliability by automatically and real-time correction of the addition or decrease of each processing parameter.

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

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

As shown in Figures 1 and 2, the machine tool 1 has a larger error value in the bent portion R when the S-shaped pattern operation program (Fig. 1) is driven or the N-shaped pattern operation program (Fig. 2) is driven. will occur These error values vary depending on the operating temperature of the machine tool or the ambient temperature in which the machine tool is installed, the wear condition of the machine tool, the assembly condition of the equipment, or the precision of the assembled parts. That is, by simply inputting only the parameters P to the numerical control unit 20 , the error in the bent 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 for forming 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 for an S-shaped pattern operation program, it is suitable for a shape with many continuous acceleration and deceleration. In the case of an N-shaped pattern operation program or an S-shaped pattern operation program, it is a basic pattern operation for checking shapes with many accelerations or continuous acceleration and deceleration. Therefore, it is easy to expand the product, and it is possible to reduce the cost and time due to the addition of the program.

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

The basic data storage unit 42 stores the types of the parameters P and the decreasing amounts B and increasing amounts A of each parameter P. That is, the basic data storage unit 42 stores the acceleration/deceleration time constant before interpolation, acceleration change time, allowable acceleration change amount, continuous straight line allowable acceleration change amount, ratio of acceleration/deceleration change time, allowable acceleration, acceleration/deceleration time constant after interpolation, corner speed It is possible to store the parameters (P) for the difference, the maximum machining speed. These parameters (P) may be different from the type of the machine tool, the workpiece to be processed, the tool, and the like. In addition, the basic data storage unit 42 stores the decrease amount (B) and the increase amount (A) for each parameter (P). The decrease (B) and increase (A) are also different depending on the type of each parameter (P), the type of work, tool, and machine tool, and the user can select and input the corresponding data. Also, although not necessarily limited thereto, the increase A and the decrease B may have opposite values. That is, when the increase amount (A) for one parameter (P) is 10, the decrease amount (B) may be formed as -10 for the same parameter (P).

As a result of the determination of the calculation unit 45 and the determination unit 46 to be described later, when the calculated value (K) is smaller than the reference value (C) and the calculated value is larger than the minimum value (D), D < K in the bending portion R When <C), the correction unit 47 increases each parameter (P) by the increase amount (A) for the corresponding parameter (P) and corrects it. Conversely, if the calculation result of the calculation unit 45 and the determination unit 46 results in an overcut (if the calculated value K is greater than or equal to the reference value C, K≥C) in the bent portion R, the correction unit 47 is Correct by decreasing each parameter (P) by the amount of decrease (B) for the corresponding parameter (P). In addition, if it moves along the curved portion R, it is determined to be within the corresponding error range, and the existing state is maintained.

The reference value storage unit 43 stores the reference value C and the minimum value D for comparison with the calculated value K. Although not necessarily limited thereto, it is preferable that the reference value (C) is 5 and the minimum value (D) is 2. This is because, when the reference value (C) is greater than 5, the error is excessively corrected and processing precision is rather reduced, and when the reference value (C) is less than 5, an error in determining the degree of error may occur. In addition, when the minimum value is greater than 2, the processing precision may be reduced by the correction exceeding the error range, and if it is less than 2, the accuracy of judging whether an error occurs or the number of occurrences of the judgment error is increased. The reference value (C) and the minimum value (D) can be specified by the user, or calculated and modified by an automatic program in consideration of various factors such as the type of machine tool, the type of the workpiece, the type of tool, temperature, environment, and the life of the machine tool. may be

The detection unit 44 detects the current command coordinate data Xn and the position coordinate data Yn of the driving unit 31 in each bending portion R when the standard pattern operation program is driven. Although not necessarily limited thereto, the detection unit 44 classifies the command coordinate data Xn as data calculated by a machining path generated by the numerical control unit 20 or data of a machining program input to the HMI unit 10 . It is calculated by searching, and the position coordinate data Yn is calculated as a value read by the encoder of the driving 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 and in real time perform a correction to improve processing precision in real time, thereby 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 unit 45 calculates position coordinate data (Xn) from the command coordinate data (Xn) on each axis (X-axis, Y-axis, Z-axis, A-axis, C-axis) in each bending part R. A calculated value K, which is an average value obtained by subtracting Yn), is calculated. As an example, as shown in FIG. 3 , the calculated value K _X on 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 other than 3-axis, the calculated value K _A for A-axis and K _C for 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 formula (1).

[Equation 1]

K = (K1 + K2 + K3 ... + Kn) / n

Calculation of the deformed part at the bent part R required for error correction or multiple measurements at each bent part R can be changed by the operator as needed, such as the state or environment of the machine tool. As a result, it can be applied to various machine tools, increasing compatibility and maximizing user convenience.

As the calculated value is applied to the average value of the various deformed parts in each bend (R), it is possible to maximize processing precision through accurate error compensation 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 the 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 . For example, when the calculated value Kx of the X-axis calculation unit is greater than or equal to 5, which is the reference value C, the correction unit 47 performs correction to decrease each parameter P by the decrease amount B. Conversely, when the calculated value Kx of the X-axis calculation unit is less than 5, which is the reference value C, the correction unit 47 performs correction to increase each parameter P by the increment A. Accordingly, it is possible to maximize the machining precision and reliability of the machine tool by reducing the occurrence of errors by forming a machining path for machining the workpiece after each parameter (P) is corrected to an optimal state.

More preferably, the correction unit 47 converts the parameters (P) into the basic data storage unit (42) by the reduction amount ( 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 cut state), the parameters (P) are stored in the basic data storage unit (42). It increases by the stored increment (A), and when the calculated value (K) is less than or equal to the minimum value (D) (K≤D), correction is performed to maintain the previous state.

Therefore, the machine tool according to the present invention is a numerical control unit by the average of the error values of the current position coordinate data and the command coordinate data generated in each bend of the pattern according to the driving of the standard pattern operation program stored in the standard pattern operation program before processing the workpiece. It is possible to maximize processing precision and reliability by automatically and real-time correction of the addition or decrease of each processing parameter input to the .

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

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

After the machining program input step (S1), parameters (P) for machining the workpiece are input to the numerical control unit 20 and a machining path is generated. 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 built-in. 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 machining path generation step (S2), the standard pattern operation program is stored in the standard pattern operation program storage unit 41 of the control unit 40 . 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 for forming 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 for an S-shaped pattern operation program, it is suitable for a shape with many continuous acceleration and deceleration. In the case of an N-shaped pattern operation program or an S-shaped pattern operation program, it is a basic pattern operation for checking shapes with many accelerations or continuous acceleration and deceleration. Therefore, it is easy to expand the product, and it is possible to reduce the cost and time due to the addition of the program.

After the standard pattern operation program storage step (S3), the basic data storage unit 42 stores the types of the parameters (P) and the decreasing amounts (B) and increasing amounts (A) of each parameter. 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 C and the minimum value D are stored in the reference value storage unit 43 . As described above, the user can set the reference value (C) and the minimum value (D) arbitrarily according to the condition of the equipment, and the optimal reference value (C) and the minimum value (D) are automatically set and processed through repeated measurement of the equipment. precision can be maximized.

After the reference value/minimum value storage step (S5), the current command coordinate data (Xn) and the position coordinate data (Yn) of the driving unit 31 at each bent portion R of the pattern when the standard pattern operation program is driven in the detection unit 44 to detect The detection method is the same as the above-described method, and thus will be omitted below.

After the detection step S6, the calculation unit 45 calculates an error range 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 thus 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 increase or decrease of the parameters (P) is corrected.

That is, in the correction step (S9), as described above, when the calculated value (K) is greater than or equal to the reference value (C) (K≥C), the reduction amount (B) stored in the basic data storage unit (42) of the parameters (P) ), and when the calculated value (K) is smaller than the reference value (C) and greater than the minimum value (D) (D<K<C), the increment (A) stored in the basic data storage unit 42 for the parameters (P) , and when the calculated value (K) is less than or equal to the minimum value (D) (K≤D), 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 is applied, the amount of error of the X-axis, Y-axis, Z-axis, A-axis, and C-axis is large, and the processing precision is reduced, The occurrence of defective products increases, resulting in wastage 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 amount of error of the X-axis, Y-axis, Z-axis, A-axis, and C-axis is significantly reduced, so that the processing precision is reduced. increase and reliability may increase.

Therefore, the machine tool according to the present invention maintains optimum machining precision regardless of the type of machine tool, the use environment or the degree of wear, as the amount of addition or reduction of the machining parameter is corrected in real time and automatically, thereby reducing the occurrence of defective products and reducing resources. It is possible to prevent waste and to improve the convenience of users by minimizing the time and cost required for correction by real-time and automatic correction of the addition or decrease of the machining parameters, and to increase the productivity of the machine tool by reducing the non-machining time. .

In the detailed description of the present invention described above, although it has been described with reference to preferred embodiments of the present invention, those skilled in the art or those having ordinary skill in the art will It will be understood that various modifications and variations of the present invention can be made without departing from the spirit and scope of the present invention. Accordingly, 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 part
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: detection unit, 45: calculation unit,
46: judgment unit, 47: correction unit.

Claims (5)

HMI unit for inputting a machining program for machining the workpiece;
a numerical control unit receiving the machining program input to the HMI unit, inputting parameters for machining the work, and generating a machining path;
PLC for driving a driving unit according to the machining path through communication with the HMI unit and the numerical control unit; and
When the standard pattern operation program for forming an N-shaped or S-shaped pattern is driven, the slope at each coordinate in the N-shaped pattern or S-shaped pattern changes to a negative value while the slope at each coordinate has a positive value. Conversely, the amount of addition or subtraction of the parameters input to the numerical control unit according to the error value occurring in each bend where the slope at each coordinate has a negative value and the slope at each coordinate changes to a positive value. a control unit for correcting; and
The control unit is
a standard pattern operation program storage unit for storing a standard pattern operation program that is a pattern operation program for forming an N-shaped or S-shaped pattern;
a basic data storage unit for storing types of the parameters and decreasing and increasing amounts of each parameter;
a reference value storage unit for storing a reference value and a minimum value;
a detection unit configured to detect current command coordinate data and position coordinate data of the driving unit in each bending unit when the standard pattern operation program is driven;
a calculation unit for calculating an error range based on the command coordinate data and the position coordinate data detected by the detection unit;
a determination unit for determining whether the calculated value of the calculation unit is within the 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 amount of the parameters according to the determination result of the determination unit.
delete According to claim 1,
The correction unit,
When the calculated value is greater than or equal to the reference value, the parameters are reduced to the amount stored in the basic data storage unit, and when the calculated value is smaller than the reference value and greater than the minimum value, the parameters are stored in the basic data storage unit. It increases by the stored increment, and if the calculated value is less than or equal to the minimum value, the machine tool, characterized in that it maintains the previous state.
delete 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, which is a pattern operation program for forming an N-shaped or S-shaped pattern;
storing the types of the parameters and decreasing and increasing amounts of each parameter;
storing a reference value and a minimum value;
When the standard pattern operation program for forming the N-shaped or S-shaped pattern is driven, the slope at each coordinate has a positive value in the N-shaped pattern or S-shaped pattern, and the slope at each coordinate changes to a negative value. or conversely, detecting the current command coordinate data and the position coordinate data of the driving unit at each bend in which the slope at each coordinate has a negative value and the slope at each coordinate changes to a positive value;
calculating an error range based on the detected command coordinate data and the position coordinate data;
determining whether the calculated value is within the range of the reference value and the minimum value; and
Including; correcting the addition or decrease of the parameters;
The correcting step is
When the calculated value is greater than or equal to the reference value, the parameters are reduced to the amount stored in the basic data storage unit, and when the calculated value is smaller than the reference value and greater than the minimum value, the parameters are stored in the basic data storage unit. The control method of a machine tool, characterized in that by increasing the increase amount, and maintaining the previous state when the calculated value is less than or equal to the minimum value.

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