Machine tool warm-up control apparatus and method

Abstract

The present invention allows a warm-up program to be created by freely selecting either a manual or automatic mode. When the automatic input mode is selected during warm-up program creation, a warm-up program corresponding to the current temperature conditions of the machine tool spindle and shaft system can be automatically generated. Furthermore, by creating a warm-up program tailored to the characteristics of each shaft system as well as the spindle and executing the warm-up, the decrease in machine tool precision or the waste of warm-up time caused by insufficient or excessive warm-up is eliminated. By performing optimal warm-up, machining precision is improved, and furthermore, productivity can be enhanced through the optimization of warm-up time.

Description

Technology Field

[0001] The present invention relates to a warm-up control device and a control method for a machine tool, and more specifically, to a device and method for easily creating a warm-up program and automatically implementing it. Background Technology

[0002] In general, machine tools are devices for precisely processing metal materials; to prevent a decrease in processing precision caused by thermal deformation of machine tool components, the machine tool must be warmed up before processing so that the workpiece is processed only after the thermal deformation has been resolved.

[0003] Conventionally, as a warm-up method to prevent thermal deformation, Patent Document 1 provides a method of warming up by providing a timer means for determining whether a predetermined time has elapsed after a machine tool spindle has stopped, and rotating the spindle at a faster speed for a certain period of time after the spindle has stopped at a first speed, a second speed, and a third speed, respectively.

[0004] However, this method warms up by merely increasing the spindle rotation speed in stages over a certain period of time, and ignores warming parameters due to the difference with the ambient temperature or warming parameters of feed axes other than the spindle, and warms up under uniform conditions only for the spindle. As a result, not only is it impossible to implement appropriate warming corresponding to the ambient temperature and feed axis systems requiring warming in the machine tool, but excessive or insufficient warming can also lead to thermal expansion or contraction of machine tool components, which can cause a decrease in machining precision.

[0005] In addition, Patent Document 2 discloses a method for preheating a machine tool spindle by receiving feedback on the spindle motor temperature to determine whether preheating is complete, wherein the current temperature and maximum temperature of the motor connected to the spindle are detected, the difference between the maximum temperature and the current motor temperature is substituted into a mathematical formula to calculate the preheating time, and the calculated preheating time is input into a preheating device to preheat the machine tool spindle.

[0006] However, this method only considers the temperature of the spindle motor and disregards the preheating of the machine tool shaft system, which has the greatest impact on the precision of the workpiece due to thermal expansion or contraction; therefore, it cannot be considered that sufficient and appropriate preheating can be achieved for each component of the machine tool, including the shaft system. Prior art literature

[0007] Korean Published Patent Application No. 10-2008-0044987 Korean Patent Application No. 10-1521387 The problem to be solved

[0008] The objective of the present invention, which aims to solve the aforementioned problems, is to provide an apparatus and method for creating an optimized warm-up program not only for machine tool spindles but also for shaft systems, and furthermore, to provide an apparatus and method for creating a warm-up program more easily.

[0009] In addition, another objective of the present invention is to improve the precision and productivity of machine tools through optimal warm-up in a short time. means of solving the problem

[0010] The warm-up control device of the machine tool according to the present invention for solving the above-mentioned problems is

[0011] A selection unit (10) equipped with a manual input mode and an automatic input mode for selecting whether to manually input parameters for writing a warm-up program or to input them automatically;

[0012] A parameter setting unit (20) for setting the spindle rotation speed and rotation time, shaft system feed speed, shaft system feed distance, shaft system reciprocating feed count, and shaft system feed priority for creating a warm-up program;

[0013] A program creation unit (50) that creates a warming program in a processing program format that the spindle and shaft system can recognize by activating the processing program creation function provided by the numerical control device based on the warming program parameters entered in the above parameter setting unit (20);

[0014] A program storage unit (60) that stores the warm-up program written in the above program writing unit (50) in a memory device;

[0015] It includes a program driving unit (70) that enables the operation of the spindle and the shaft system through a warm-up program created in the program writing unit (50).

[0016] In a preferred embodiment of a machine tool warm-up control device, the selection unit (10) is characterized by being configured as a touchscreen method for selecting a manual input mode or an automatic input mode on an operable display screen.

[0017] In a preferred embodiment of a machine tool warm-up control device, the program driving unit (70) is characterized by calling and activating a warm-up program stored in the program storage unit (60) to perform the operation of the spindle and the shaft system.

[0018] In a preferred embodiment, the machine tool warm-up control device further includes a data acquisition unit (30) that pre-determines and stores the rotational speed of the spindle to be warmed up, the feed speed and feed distance of the shaft system, and a temperature detection unit (40) that detects the temperature of the machine tool body.

[0019] The above program creation unit (50) is characterized by creating a warm-up program as a processing program that the spindle and shaft system can recognize based on the parameters stored in the data acquisition unit (30) and the temperature detected by the temperature detection unit (40) when the automatic input mode is selected in the selection unit (10).

[0020] In a preferred embodiment of the machine tool warm-up control device, the data acquisition unit (30) records the average feed speed of the shaft system for processing an actual workpiece from the time the machine tool starts operating until it ends operating, and calculates and stores the feed speed value of the shaft system for warm-up by performing a moving average of the past average feed speeds of the shaft system over a predetermined number of times.

[0021] In a preferred embodiment, the machine tool warm-up control device is characterized in that the feed speed of the shaft system in the data acquisition unit (30) is calculated and stored as a value corresponding to two-thirds of the maximum allowable feed speed of the shaft system.

[0022] In a preferred embodiment of the machine tool warm-up control device, the temperature detection unit (40) is characterized by being a temperature sensor installed on the machine tool body surrounding the spindle motor and a temperature sensor installed on one side of the ball screw nut constituting the shaft system.

[0024] In addition, the warm-up control method of the machine tool of the present invention for solving the above-mentioned problems is

[0025] A step for selecting a method for writing a warm-up program (S20) for selecting whether to input parameters for writing a warm-up program in manual input mode or automatic input mode;

[0026] In the step of selecting the method for creating the warm-up program (S20) above, if the manual input mode is selected, the spindle rotation speed, spindle rotation time, shaft system feed speed, shaft system feed distance, number of shaft system feeds, and shaft system feed priority are set as parameters for creating the warm-up program, and

[0027] When the automatic input mode is selected in the above warming-up program creation method selection step (S20), a warming-up program parameter setting step (S30) for automatically calculating or determining the spindle rotation speed, spindle rotation time, shaft system feed speed, shaft system feed distance, shaft system feed count, and shaft system feed priority as parameters for creating the warming-up program;

[0028] A warming program creation step (S50) that reads the parameters set in the warming program parameter setting step (S30) and creates a warming program in a processing program format that can be recognized by the spindle and shaft system;

[0029] It includes a warming program execution step (S70) in which a warming program command created in the warming program creation step (S50) is applied to a numerical control device of a machine tool to operate a spindle with a rotational speed and rotational time set in the program parameter setting step (S30), and an shaft system feed operation is performed with a shaft system feed priority, feed speed, feed distance, and number of feeds set in the program parameter setting step (S30).

[0030] In a preferred embodiment, the machine tool warm-up control method further includes a warm-up parameter accumulation step (S10) in which the spindle rotation speed, the feed distance of the shaft system, and the feed speed of the shaft system are calculated in the warm-up program parameter setting step (S30), and the shaft system warm-up execution priority is determined and stored.

[0031] The above warming-up program parameter setting step (S30) further includes a warming-up program data calculation step (S40) in which, when the automatic input mode is selected in the warming-up program creation method selection step (S20), the temperature detected from the spindle and shaft system temperature detection unit (40) is read, the spindle rotation time is calculated by reducing the spindle rotation time by the amount by which the temperature of the spindle temperature detection unit (40) rises due to the rotation of the spindle from the predetermined basic warming-up rotation time and the shaft system transfer count is calculated by reducing the shaft system transfer count by the amount by which the temperature of the shaft system temperature detection unit (40) rises due to the transfer of the shaft system from the predetermined basic warming-up transfer count.

[0032] When a manual input mode is selected in the warm-up program creation method selection step (S20) above, the method is characterized by checking whether there are existing warm-up program parameters and, if there are existing parameters, checking whether to use the existing parameters through the existing data utilization verification step (S31), and if it is decided to use the existing parameters, performing the warm-up program creation step (S50).

[0033] In a preferred embodiment of a machine tool warm-up control method, in the warm-up parameter accumulation step (S10)

[0034] The above spindle rotation speed is calculated and stored at two-thirds of the predetermined maximum allowable speed of the spindle, and

[0035] The travel distance of the above shaft system is calculated and stored as a distance corresponding to two-thirds of the allowable travel distance of the shaft system, and

[0036] The feed speed of the above shaft system records the average feed speed at which the shaft system moves to process an actual workpiece from the start of operation until the end of operation of the machine tool each time, and stores the value calculated by taking a moving average of the past average feed speeds of the shaft system over a predetermined number of times.

[0037] The above-mentioned priority for shaft system warm-up execution is characterized by setting the priority so that when multiple shaft systems are shaft systems that do not collide or interfere with each other during the transfer process for warm-up, the warm-up is executed simultaneously, and when shaft systems that may collide or interfere are shaft systems, the priority is set to a lower priority.

[0038] In a preferred embodiment of a machine tool warm-up control method, in the warm-up parameter accumulation step (S10)

[0039] The above spindle rotation speed is calculated and stored at two-thirds of the predetermined maximum allowable speed of the spindle, and

[0040] The travel distance of the above shaft system is calculated and stored as a distance corresponding to two-thirds of the allowable travel distance of the shaft system, and

[0041] The feed speed of the above shaft system is calculated and stored at two-thirds of the maximum allowable feed speed of the shaft system, and

[0042] The above-mentioned priority for shaft system warm-up execution is characterized by setting the priority so that when multiple shaft systems are shaft systems that do not collide or interfere with each other during the transfer process for warm-up, the warm-up is executed simultaneously, and when shaft systems that may collide or interfere are shaft systems, the priority is set to a lower priority.

[0043] In a preferred embodiment of the machine tool warm-up control method, the program creation method selection step (S20) is characterized by selecting a manual input mode or an automatic input mode on an operable display screen using a touchscreen method.

[0044] In a preferred embodiment, the machine tool warm-up control method further includes a warm-up program storage step (S60) for storing the warm-up program created in the warm-up program creation step (S50) in the program storage unit (60).

[0045] The above warm-up program execution step (S70) is characterized by executing the warm-up by calling the warm-up program stored in the above warm-up program storage step (S60). Effects of the invention

[0046] The present invention allows a warm-up program to be created by freely selecting either a manual or automatic mode, and when the automatic input mode is selected when creating the warm-up program, a warm-up program corresponding to the current temperature conditions of the machine tool spindle and shaft system can be automatically created.

[0047] In addition, by creating a warm-up program tailored to the characteristics of each shaft system for not only the spindle but also each shaft system, and executing the warm-up, it is possible to eliminate the decrease in machine tool precision or the waste of warm-up time caused by insufficient or excessive warm-up, perform optimal warm-up to improve machining precision, and furthermore, promote productivity improvement through the optimization of warm-up time. Brief explanation of the drawing

[0048] FIG. 1 is a conceptual diagram of a machine tool warm-up control device as an embodiment of the present invention. FIG. 2 is a screen configuration diagram of a warm-up program parameter setting unit as an embodiment of the present invention. FIG. 3 is a flowchart for the creation and execution of a warm-up program of a warm-up control device as an embodiment of the present invention. Specific details for implementing the invention

[0049] In this embodiment, a spindle refers to a rotating body that grips a workpiece or tool and rotates by a spindle motor, which is a type of servo motor, and may be equipped with at least one spindle depending on the machine tool. In this embodiment, a single spindle is used as an example, but the same applies to cases with multiple spindles.

[0050] In addition, in this embodiment, the term "shaft system" refers to a transfer body comprising a ball screw that rotates by a servo motor and a nut that is conveyed by the ball screw, and each of these shaft systems is structured to reciprocate in the X-axis, Y-axis, or Z-axis direction.

[0052] Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS. 1 to 3.

[0053] FIG. 1 is a conceptual diagram of a machine tool warm-up control device as an embodiment of the present invention. FIG. 2 is a screen configuration diagram of a warm-up program parameter setting unit (20) as an embodiment of the present invention. FIG. 3 is a flowchart of the warm-up program creation and execution of the warm-up control device as an embodiment of the present invention.

[0054] As illustrated in FIG. 1, the machine tool warm-up control device of the present embodiment comprises a selection unit (10) for creating a warm-up program, a parameter setting unit (20), a program creation unit (50), a program storage unit (60), and a program driving unit (70). Meanwhile, the machine tool warm-up control device of the present embodiment may additionally be equipped with a data acquisition unit (30) and a temperature detection unit (40) for the automatic creation of a warm-up program.

[0056] In the machine tool warm-up control device of the present embodiment, the selection unit (10) is equipped with a manual input mode and an automatic input mode for selecting whether to manually input parameters for creating a warm-up program or to input them automatically. The selection unit (10) is configured as a touchscreen method for selecting the manual input mode or the automatic input mode on an operable display screen. In some cases, the selection unit (10) may be configured as a selection switch for selecting the manual input mode or the automatic input mode.

[0058] In addition, in the machine tool warm-up control device of the present embodiment, the parameter setting unit (20) is configured to provide a warm-up parameter setting screen that allows parameters for creating a warm-up program to be entered on a touchscreen, as shown in FIG. 2. The warm-up parameters entered in the parameter setting unit (20) are information regarding the spindle rotation speed and rotation time, the feed speed of the shaft system, the feed distance, the number of reciprocating feeds, and the feed priority of the shaft system.

[0059] Here, the spindle rotation speed set as a warm-up parameter is set to about two-thirds of the maximum spindle rotation speed, and the rotation time is set to an arbitrary time that can be recognized as the warm-up being completed based on prior experiments or empirical rules, taking into account the ambient temperature.

[0060] In addition, the feed speed and feed distance of the shaft system set as warm-up parameters are set to approximately two-thirds of the maximum feed speed and maximum feed distance of the shaft system, respectively, and the number of feeds is set to an arbitrary number that can be recognized as completed warm-up based on prior experiments or empirical rules, taking into account the ambient temperature.

[0061] In addition, regarding the feed priority of the shaft system set as a warm-up parameter, since compound machine tools are equipped with multiple axes in the X, Y, and Z directions, moving the shaft system simultaneously for warm-up may cause collisions or interference between the shaft systems; therefore, the feed sequence of the shaft system for warm-up is set to prevent collisions or interference.

[0062] Meanwhile, the shaft system includes a table that holds the workpiece and moves it in the left-right or forward-backward direction, a spindle head that moves the spindle up and down, and a tool holder that moves the tool in the forward-backward direction.

[0064] In addition, in the machine tool warm-up control device of the present embodiment, the program creation unit (50) activates the machining program creation function provided by the numerical control device based on the warm-up program parameters input by the parameter setting unit (20) and creates a machining program that can be recognized by the spindle and shaft system.

[0065] That is, the warm-up program for the spindle is written as a processing program (S code) so that the spindle motor idles for a rotation time at the spindle rotation speed input in the parameter setting unit (20), and the warm-up program for the shaft system is written as a processing program (G code) so that a transfer body including a servo motor and a ball screw constituting the shaft system in the X-axis, Y-axis, or Z-axis direction is transferred according to the transfer priority, the transfer speed, transfer distance, and number of reciprocating transfers input in the parameter setting unit (20).

[0067] In addition, in the machine tool warm-up control device of the present embodiment, the program storage unit (60) stores the warm-up program created by the program creation unit (50) in the memory device.

[0069] In addition, in the machine tool warm-up control device of the present embodiment, the warm-up program driving unit (70) transmits an operation command to the spindle driver or shaft system servo motor driver through the warm-up program created by the program writing unit (50), thereby enabling the operation of the spindle or shaft system.

[0070] In another embodiment, the program driving unit (70) may transmit operation commands to a spindle driver or an shaft system servo motor driver by calling and activating a warm-up program stored in the program storage unit (60).

[0072] Meanwhile, the machine tool warm-up control device of the present embodiment additionally includes a data acquisition unit (30) and a temperature detection unit (40) for the automatic creation of a warm-up program. The data acquisition unit (30) and the temperature detection unit (40) are configured as follows.

[0074] The above data acquisition unit (30) calculates and stores the rotational speed of the spindle to be warmed up as two-thirds of the maximum allowable speed of the spindle, and also calculates and stores the travel distance of the shaft system as two-thirds of the allowable travel distance of the shaft system.

[0075] Meanwhile, the above data acquisition unit (30) records the average feed speed of the shaft system for processing the actual workpiece from the time the machine tool starts operating until it ends operating, and calculates and stores the feed speed value of the shaft system for warming up by moving the average of the past average feed speeds of the shaft system over a predetermined number of times.

[0076] Meanwhile, in another embodiment, the feed speed value of the shaft system for the warm-up may be set to a feed speed corresponding to two-thirds of the maximum allowable feed speed of the shaft system.

[0078] In addition, the machine tool warm-up control device of the present embodiment is equipped with a temperature detection unit (40) that detects the temperature of the machine tool body. The temperature detection unit (40) is installed in a part of the machine tool body where a temperature change due to warm-up can be easily detected. In the case of the present embodiment, the spindle temperature detection unit (40) is a temperature sensor installed in the machine tool body surrounding the spindle motor, and the shaft system temperature detection unit (40) is a temperature sensor installed on one side of each ball screw nut constituting the shaft system.

[0080] Meanwhile, the above warm-up program creation unit (50) creates a warm-up program as follows.

[0081] When the automatic input mode is selected in the selection unit (10), the warm-up program creates a machining program that can be recognized by the spindle and shaft system by activating the machining program creation function provided by the machine tool numerical control device based on the warm-up parameter information calculated by the data acquisition unit (30) and the temperature detected by the temperature detection unit (40).

[0082] More specifically, the spindle warming program applies the spindle rotation speed stored in the data acquisition unit (30), and the spindle rotation time is applied as follows.

[0083] That is, the spindle rotation time applied to the warm-up program is determined by setting the arbitrarily set basic warm-up rotation time, which can be considered as the warm-up completed by experience, to 1800 seconds (30 minutes), and assuming the temperature around the spindle expected when the warm-up is completed is a predetermined reference temperature, and reducing the spindle rotation time by the amount the temperature of the spindle temperature detection unit (40) rises due to the spindle rotation. At this time, as obtained through repeated experiments, the machine tool body frame surrounding the spindle rises by approximately 1 degree Celsius every time the spindle rotates for 300 seconds, so the spindle rotation time (T) for spindle warm-up is calculated using the following formula.

[0084] Formula 1) Spindle rotation time (T) = 300 seconds (Reference temperature - Detected temperature)

[0085] However, if the spindle rotation time (T) is 1800 seconds or more, the spindle rotation time (T) shall be 1800 seconds.

[0087] In addition, the warm-up program for the shaft system is created by applying the transfer speed and transfer distance stored in the data acquisition unit (30). At this time, the number of transfers of the shaft system applied to the creation of the warm-up program is determined by reducing the number of transfers of the shaft system by the amount by which the temperature of the shaft system temperature detection unit (40) rises due to the transfer of the shaft system from a predetermined reference temperature, assuming that the arbitrarily set basic warm-up transfer count, which can be seen as a state where warm-up is completed by experience, is 60 times. At this time, as obtained through repeated experiments, the temperature of the shaft system temperature detection unit (40) rises by 1 degree Celsius every time the shaft system is transferred back and forth 10 times, so the number of transfers (N) of the shaft system for warming up the shaft system is calculated using the following formula.

[0088] Formula 2) The number of shaft system transfers (N) = 10 times (Reference temperature - Detected temperature)

[0089] However, if the number of shaft system transfers (N) is 60 or more, the number of shaft system transfers (N) shall be 60.

[0091] Meanwhile, the warm-up program creation unit (50) creates the warm-up parameters of the spindle (spindle rotation speed, rotation time) and the warm-up parameters of the shaft system (shaft system feed speed, feed distance, number of feeds) in the form of a machining program (S code or G code) as described above.

[0092] In addition, the warming program for the shaft system in the warming program creation unit (50) is written in the form of a processing program so that, when there are multiple shaft systems to be warmed up, the warming is executed sequentially according to the warming priority of the shaft system entered in the parameter setting unit (20) in order to avoid collision or interference between the shaft systems during the process of transferring the shaft systems for warming up.

[0093] Meanwhile, the warm-up program for the shaft system described above involves creating the feed speed, feed distance, and number of feeds of the shaft system servo motors in the form of a machining program (G-code) so that they are moved in the X-axis, Y-axis, or Z-axis direction.

[0095] In addition, in the machine tool warm-up control device of the present embodiment, the warm-up program storage unit (60) stores the warm-up program created by the warm-up program creation unit (50) in a memory device so that it can be called and used later.

[0097] In addition, in the machine tool warm-up control device of the present embodiment, the warm-up program driving unit (70) transmits the command of the warm-up program created by the warm-up program writing unit (50) to the driving unit, which is the spindle motor driver and each axis system servo motor driver, through the numerical control device of the machine tool, so that the spindle motor operates for the rotational speed and rotational time commanded by the warm-up program, and the servo motor of each axis system performs a feed operation at the feed speed, feed distance, and number of feeds commanded by the warm-up program to complete the warm-up.

[0099] Hereinafter, with reference to FIG. 3, a control method for a machine tool warm-up control device configured as in the above embodiment will be described.

[0101] First, the warm-up parameter accumulation step (S10) is executed.

[0102] This step involves acquiring parameters for writing a warm-up program. The spindle rotation speed is calculated and stored as two-thirds of the predetermined maximum allowable speed of the spindle, and the feed distance of the shaft system is calculated and stored as two-thirds of the allowable feed distance of the corresponding shaft system. Additionally, if there are multiple shaft systems, priority is set so that shaft systems that do not collide or interfere with each other during the feed process for warming are executed simultaneously, while shaft systems where collision or interference may occur are assigned a lower priority for warm-up feed. This warm-up priority of the shaft systems is determined according to the function of the numerical control device of the machine tool.

[0103] In addition, the spindle rotation speed, shaft system travel distance, and shaft system travel priority for creating the above warm-up program are executed only once when the warm-up program is initially created.

[0104] In addition, the feed rate of the shaft system for creating the above warm-up program is calculated and stored as the feed rate of the shaft system for warm-up by recording the average feed rate of the shaft system moving to process the actual workpiece from the time the machine tool starts operating until the operation ends, through the data acquisition unit (30) whenever the machining operation of the machine tool is executed.

[0105] In another embodiment, the feed speed value of the shaft system for the warm-up is set to a feed speed corresponding to two-thirds of the maximum allowable feed speed of the shaft system.

[0107] Next, execute the step of selecting the method for creating the warm-up program (S20).

[0108] This step involves selecting whether to manually or automatically input parameters for creating a warm-up program, and the selection is made via a touchscreen method that allows selecting between manual and automatic input modes on an operable display screen. In another embodiment, the selection of the manual or automatic input mode may also be made by operating a selection switch.

[0110] Next, the warm-up program parameter setting step (S30) is executed.

[0111] In this step, if the automatic input mode is selected in the warm-up program creation method selection step (S20), the spindle rotation speed, shaft system feed distance, shaft system average feed speed, and priority that were calculated and stored for creating the warm-up program in the warm-up parameter accumulation step (S10) are read, and the temperature detected from the spindle and shaft system temperature detection unit (40) is also read.

[0112] Meanwhile, if the manual input mode is selected in the warm-up program creation method selection step (S20) at this stage, the existing data utilization confirmation step (S31) is performed to check whether there are existing warm-up program parameters and, if there are existing parameters, to check whether to utilize the existing parameters. If it is decided to utilize the existing parameters, the warm-up program creation step (S50) described later is performed. On the other hand, if there are no existing parameters or if it is decided not to utilize the existing parameters, the parameter setting unit (20) for setting warm-up program parameters is activated as shown in FIG. 2, and the number of rotations of the spindle, the rotation time, the feed distance, feed speed, number of feeds, and priority of the shaft system to be used as warm-up program parameters are input.

[0114] Meanwhile, if the automatic input mode is selected in the warm-up program creation method selection step (S20), the warm-up program parameter setting step (S30) executes the warm-up program data calculation step (S40).

[0115] The above warm-up program data calculation step (S40) calculates the spindle rotation time applied to the warm-up program by setting the arbitrarily set basic warm-up rotation time, which can be considered as completed by experience, to 1800 seconds (30 minutes), and by reducing the spindle rotation time by the amount that the temperature of the spindle temperature detection unit (40) rises due to the rotation of the spindle from a predetermined reference temperature. At this time, it was confirmed through repeated experiments that the machine tool body frame surrounding the spindle rises by approximately 1 degree Celsius every time the spindle rotates for 300 seconds, so the spindle rotation time (T) for spindle warm-up is calculated using the following formula.

[0116] Formula 1) Spindle rotation time (T) = 300 seconds (Reference temperature - Detected temperature)

[0117] However, if the spindle rotation time (T) is 1800 seconds or more, the spindle rotation time (T) shall be 1800 seconds.

[0118] In addition, the warm-up program data calculation step (S40) calculates the number of shaft transfers applied to the creation of the warm-up program by setting the arbitrarily set basic warm-up transfer count, which can be considered as completed by experience, to 60 times, and by reducing the number of shaft transfers by the amount by which the temperature of the shaft system temperature detection unit (40) rises due to the transfer of the shaft system from a predetermined reference temperature. At this time, it was confirmed through repeated experiments that the temperature of the shaft system temperature detection unit (40) rises by 1 degree Celsius every time the shaft system is transferred back and forth 10 times, so the number of shaft transfers (N) for shaft warm-up is calculated using the following formula.

[0119] Formula 2) The number of shaft system transfers (N) = 10 times (Reference temperature - Detected temperature)

[0120] However, if the number of shaft system transfers (N) is 60 or more, the number of shaft system transfers (N) shall be 60.

[0122] Next, execute the warm-up program creation step (S50).

[0123] In this step, the machining program creation function provided by the numerical control unit is activated to create a machining program in a format that the spindle and shaft system can recognize.

[0124] More specifically, in this step, if the automatic input mode is selected in the warming program creation method selection step (S20), the warming program is created by applying the spindle rotation speed, shaft system feed distance, average feed speed, and feed priority read in the warming program parameter setting step (S30), the spindle rotation time and shaft system feed count calculated in the warming program data calculation step (S40).

[0125] Meanwhile, if a manual input mode is selected in the warm-up program creation method selection step (S20) at this stage, the warm-up program is created by applying the spindle rotation speed and rotation time, shaft system feed speed and feed distance, number of feeds, and feed priority set in the warm-up program parameter setting step (S30).

[0126] Meanwhile, at this stage, if a manual input mode is selected in the warm-up program creation method selection step (S20) and it is decided to use existing parameters because an existing warm-up program exists in the existing data utilization verification step (S31), the warm-up program is created using the existing warm-up program parameters stored in the program storage unit (60).

[0128] Next, the warm-up program saving step (S60) is executed.

[0129] This step is a step of saving the warm-up program created in the warm-up program creation step (S50) to the program storage unit (60). The warm-up program saved in the program storage unit (60) in this step is subsequently reused for creating a warm-up program if manual input mode is selected in the warm-up program creation method selection step (S20) and it is decided to use existing data in the existing data utilization verification step (S31) of the warm-up program parameter setting step (S30).

[0131] Next, the warm-up program execution step (S70) is executed.

[0132] This step is a step of warming up the machine tool by executing the warming-up program created in the warming-up program creation step (S50). In this step, the warming-up program command created in the warming-up program creation unit (50) is applied to the numerical control device of the machine tool through the warming-up program drive unit (70) and transmitted to the drive unit, which is the spindle motor and the driver of each shaft system servo motor, so that the spindle operates for the rotational speed and rotational time commanded by the warming-up program, and each shaft system performs a feed operation with a feed speed, feed distance, and number of feeds according to the feed priority commanded by the warming-up program to complete the warming-up.

[0134] As described above, the present invention allows a warm-up program to be created by freely selecting either a manual mode or an automatic mode, and when the automatic input mode is selected when creating the warm-up program, a warm-up program corresponding to the current temperature conditions of the machine tool spindle and shaft system can be automatically created.

[0135] In addition, by creating a warm-up program tailored to the characteristics of each shaft system for not only the spindle but also each shaft system, and executing the warm-up, it is possible to eliminate the decrease in machine tool precision or the waste of warm-up time caused by insufficient or excessive warm-up, perform optimal warm-up to improve machining precision, and furthermore, promote productivity improvement through the optimization of warm-up time. Explanation of the symbols

[0136] 10: Selection section 20: Parameter Setting Section 30: Data Acquisition Department 40: Temperature detection unit 50: Program writing section 60: Program storage area 70: Program drive unit S10: Warm-up parameter accumulation stage S20: Selection Step for How to Create a Warm-up Program S30: Warm-up program parameter setting step S31: Step to check whether existing data is utilized S40: Warm-up program data processing stage S50: Warm-up Program Creation Steps S60: Warm-up program saving stage S70: Warm-up program execution phase

Claims

Claim 1 A machine tool warm-up control device comprising: a selection unit (10) having a manual input mode and an automatic input mode for selecting whether to manually input parameters for creating a warm-up program or to input them automatically; a parameter setting unit (20) for setting the spindle rotation speed and rotation time, shaft system feed speed, shaft system feed distance, shaft system reciprocating feed count, and shaft system feed priority for creating a warm-up program; a program creation unit (50) for creating a warm-up program in a processing program format that can be recognized by the spindle and the shaft system by activating the processing program creation function provided by the numerical control device based on the warm-up program parameters input by the parameter setting unit (20); a program storage unit (60) for storing the warm-up program created by the program creation unit (50) in a memory device; and a program driving unit (70) for performing operations of the spindle and the shaft system through the warm-up program created by the program creation unit (50). Claim 2 A machine tool warm-up control device according to claim 1, wherein the selection unit (10) is configured as a touchscreen type for selecting a manual input mode or an automatic input mode on an operable display screen. Claim 3 A machine tool warm-up control device according to claim 1, characterized in that the program driving unit (70) performs the operation of the spindle and the shaft system by calling and activating a warm-up program stored in the program storage unit (60). Claim 4 A machine tool warm-up control device according to claim 1, further comprising a data acquisition unit (30) that pre-determines and stores the rotational speed of the spindle to be warmed up and the feed speed and feed distance of the shaft system, and a temperature detection unit (40) that detects the temperature of the machine tool body, wherein the program creation unit (50) creates a warm-up program as a processing program that the spindle and shaft system can recognize based on the parameters stored in the data acquisition unit (30) and the temperature detected by the temperature detection unit (40) when an automatic input mode is selected in the selection unit (10). Claim 5 A machine tool warm-up control device according to claim 4, characterized in that the data acquisition unit (30) records the average feed speed of the shaft system for processing an actual workpiece from the time the machine tool starts operating until it ends operating, and calculates and stores the feed speed value of the shaft system for warming up by moving the average of the past average feed speeds of the shaft system over a predetermined number of times. Claim 6 A machine tool warm-up control device according to claim 4, characterized in that the feed speed of the shaft system in the data acquisition unit (30) is calculated and stored as a value corresponding to two-thirds of the maximum allowable feed speed of the shaft system. Claim 7 A machine tool warm-up control device according to claim 4, wherein the temperature detection unit (40) is a temperature sensor installed on the main body of the machine tool surrounding the spindle motor and a temperature sensor installed on one side of the ball screw nut constituting the shaft system. Claim 8 A step for selecting a method for writing a warm-up program (S20) for selecting whether to input parameters for writing a warm-up program in manual input mode or automatic input mode; A warming-up program parameter setting step (S30) in which, if a manual input mode is selected in the warming-up program creation method selection step (S20), spindle rotation speed, spindle rotation time, shaft system feed speed, shaft system feed distance, shaft system feed count, and shaft system feed priority are set as parameters for creating a warming-up program, and if an automatic input mode is selected in the warming-up program creation method selection step (S20), spindle rotation speed, spindle rotation time, shaft system feed speed, shaft system feed distance, shaft system feed count, and shaft system feed priority are automatically calculated or determined as parameters for creating a warming-up program; a warming-up program creation step (S50) in which the parameters set in the warming-up program parameter setting step (S30) are read and a warming-up program is created in a machining program format recognizable by the spindle and shaft system; and a warming-up program command created in the warming-up program creation step (S50) is applied to the numerical control device of the machine tool and the program parameter setting step (S30) A warm-up control method for a machine tool comprising a warm-up program execution step (S70) that operates a spindle with rotational speed and rotational time, and performs an axis feed operation with the axis feed priority, feed speed, feed distance, and number of feeds set in the program parameter setting step (S30). Claim 9 In claim 8, the method further includes a warming-up parameter accumulation step (S10) in which the spindle rotation speed, the shaft system travel distance, and the shaft system travel speed are calculated in the warming-up program parameter setting step (S30), and the shaft system warming-up execution priority is determined and stored; the warming-up program parameter setting step (S30) further includes a warming-up program data calculation step (S40) in which, when an automatic input mode is selected in the warming-up program creation method selection step (S20), the temperature detected by the spindle and shaft system temperature detection unit (40) is read; the spindle rotation time is calculated by reducing the spindle rotation time by the amount by which the temperature of the spindle temperature detection unit (40) rises due to the rotation of the spindle from a predetermined reference temperature to a predetermined basic warming-up rotation time; and the shaft system transfer count is calculated by reducing the shaft system transfer count by the amount by which the temperature of the shaft system temperature detection unit (40) rises due to the transfer of the shaft system from a predetermined reference temperature to a predetermined basic warming-up transfer count. A method for controlling the warm-up of a machine tool, characterized by performing a step for checking whether to use existing data (S31) when a manual input mode is selected in the step for selecting the method for creating a warm-up program (S20), checking whether existing warm-up program parameters exist, and if existing parameters exist, checking whether to use existing parameters, and if it is decided to use existing parameters, performing a step for creating a warm-up program (S50). Claim 10 A method for controlling the warm-up of a machine tool according to claim 9, wherein in the warm-up parameter accumulation step (S10), the spindle rotation speed is calculated and stored as two-thirds of the maximum allowable speed of the spindle, the feed distance of the shaft system is calculated and stored as a distance corresponding to two-thirds of the allowable feed distance of the shaft system, the feed speed of the shaft system is recorded as the average feed speed at which the shaft system moves to process an actual workpiece from the start of operation of the machine tool until the end of operation, and is stored as a value calculated by taking a moving average of the past average feed speeds of the shaft system over a predetermined number of times, and the priority for executing the shaft system warm-up is set such that if multiple shaft systems are shaft systems where no collision or interference occurs between shaft systems during the feed process for warm-up, the priority is set so that warm-up is executed simultaneously, and if collision or interference may occur between shaft systems, the priority is set so that a lower priority is given. Claim 11 A method for controlling the warm-up of a machine tool according to claim 9, wherein in the warm-up parameter accumulation step (S10), the spindle rotation speed is calculated and stored at two-thirds of the maximum allowable speed of the spindle, the feed distance of the shaft system is calculated and stored at a distance corresponding to two-thirds of the allowable feed distance of the shaft system, the feed speed of the shaft system is calculated and stored at two-thirds of the maximum allowable feed speed of the shaft system, and the priority for executing the shaft system warm-up is set such that if multiple shaft systems are shaft systems where no collision or interference occurs between shaft systems during the feed process for warm-up, the priority is set so that the warm-up is executed simultaneously, and if collision or interference may occur between shaft systems, the priority is set so that the warm-up is executed later. Claim 12 A method for controlling the warm-up of a machine tool according to claim 8, wherein the program creation method selection step (S20) is selected using a touchscreen method that allows selecting a manual input mode or an automatic input mode on an operable display screen. Claim 13 A method for controlling the warm-up of a machine tool according to claim 8, further comprising a warm-up program storage step (S60) for storing a warm-up program created in the warm-up program creation step (S50) in a program storage unit (60), and wherein the warm-up program execution step (S70) is characterized by calling the warm-up program stored in the warm-up program storage step (S60) to execute the warm-up.

Images