KR20200131586A - Machine tool and controlling method of machine tool - Google Patents

Abstract

The present invention relates to a machine tool and a control method of the machine tool, capable of cutting chips generated during processing of a workpiece by changing the processing transfer rate of a spindle or a tool rest. Specifically, the present invention relates to the machine tool and the control method of the machine tool, wherein when the processing transfer rate is changed, the processing transfer rate of the tool rest or the spindle is repeatedly changed to the maximum processing transfer rate and the minimum processing transfer rate along a processing path during processing of the workpiece without vibrations due to repetition of an advancing and reversing operation of the tool rest or the spindle on the processing path of the workpiece to prevent damage to a driving part, thereby increasing the lifespan and the lifespan of the tools, reducing a processing time and thus improving productivity, and controlling and correcting the change of the processing transfer rate in real-time and thus improving the reliability of the machine tool.

Description

Machine tool and controlling method of machine tool}

The present invention relates to a machine tool and a control method of a machine tool, and more particularly, a machine tool and a control method of a machine tool capable of cutting chips generated during processing of a workpiece through conversion of the machining feed rate of a main shaft or a tool rest. It is about.

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

Various types of machine tools, including turning centers, vertical/horizontal machining centers, gate type machining centers, Swiss turns, electric discharge machines, horizontal NC boring machines, and CNC lathes, are widely used in various industrial sites to suit the purpose of their work.

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

In addition, the machine tool is a table on which the workpiece is placed and transported for processing the workpiece, a pallet to prepare the workpiece before processing, a spindle that rotates by combining a tool or workpiece, a tailstock to support the workpiece, etc. Etc.

In general, in a machine tool, a table, a tool rest, a main shaft, a tailstock, a vibration isolator, etc. have a conveying unit that conveys along a conveying axis to perform various processing.

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

Such a machine tool uses a number of tools for various processing, and a tool magazine is used in the form of a tool storage area storing a number of tools.

In addition, in general, machine tools are equipped with an automatic tool changer (ATC) for withdrawing or receiving a specific tool from a tool magazine according to a command from a numerical control unit in order to improve the productivity of the machine tool.

In addition, in general, machine tools are equipped with an automatic pallet changer (APC) to minimize non-processing time. The automatic pallet changer (APC) automatically exchanges pallets between the workpiece processing area and the workpiece installation area. Workpieces can be mounted on pallets.

In machine tools, if chips generated during processing of the workpiece are not removed quickly, the workpiece is damaged and the quality of the workpiece is deteriorated, the maintenance cost is increased by damaging the tool, and the non-machining time is increased by increasing the load on the motor. There was a problem.

Accordingly, many studies are being conducted to solve the problem that chips generated during cutting of a workpiece are not removed while being curled in a machine tool such as a horizontal lathe or turning center.

In order to solve this problem, the conventional machine tool cuts the chips generated during the cutting process by repeatedly vibrating the tool rest by repeatedly moving forward and backward at a constant frequency and amplitude during processing of the workpiece.

However, conventional machine tools or control methods of machine tools increase the load applied to the tool post and the servomotor of the main axis and the tool as the tool post repeats the forward and backward motions along the machining path during the processing of the workpiece, and fatigue is accumulated. There is a problem that the maintenance time and cost of the servo motor and tool increase, and the life of the servo motor and tool is shortened.

In addition, in the conventional machine tool or control method of a machine tool, the surface roughness of the workpiece deteriorates as the tool mounted on the tool rest along the machining path repeats the forward and backward motions while cutting the workpiece. There was a problem that the processing quality was deteriorated.

Moreover, in the conventional machine tool or the control method of the machine tool, as the tool mounted on the tool rest repeats the forward and backward motion along the machining path during the machining of the workpiece, the machining path and machining time increase compared to general machining, thereby reducing productivity. There was a problem of increasing the processing cost.

Korean Patent Publication No. 10-2016-0130505 Korean Patent Publication No. 10-2018-0055838 Korean Patent Publication No. 10-2016-0130506

The present invention is to solve the above problems, and an object of the present invention is a chip generated during machining of a workpiece through periodic and repetitive conversion of the machining feed rate at the time of machining transfer of the tool rest or main axis along the machining path of the workpiece. It is to provide a machine tool and a control method of the machine tool that can improve the processing quality by cutting.

In addition, another object of the present invention is to maximize the machining feed rate of the tool rest along the machining path during machining of the workpiece without repetition due to the vibration of the forward and backward motions on the machining path of the work piece when the tool rest or the main axis changes the machining feed rate. By repeatedly converting to the machining feed rate and the lowest empty feed rate, it prevents damage to the driving part to increase the life, increase the tool life, reduce machining time to improve productivity, and control and compensate the machining feed rate conversion in real time. It is to provide a machine tool and a control method of the machine tool that can improve the reliability of the machine tool.

In order to achieve the object of the present invention, a machine tool according to the present invention includes a main shaft to which a work is clamped; A tool rest for processing the workpiece; A driving unit for driving the main shaft and the tool rest; And a control unit for controlling the processing feed rate of the main shaft or the tool rest during processing of the workpiece.

In addition, in another preferred embodiment of the machine tool according to the present invention, the machine tool is the workpiece by converting the machining feed rate of the tool rest or the spindle when the main shaft or the tool rest is transferred along the machining path of the workpiece. Chips generated during the processing of can be cut.

In addition, in another preferred embodiment of the machine tool according to the present invention, the conversion of the machining feed rate of the tool post to the machine tool includes the number of rotations of the main shaft, the reference speed of the tool post, the rate of change of the speed and the speed multiplication rate, and the transfer distance of the tool post. The maximum machining feed rate and the lowest ball feed rate determined by may be repeatedly performed during machining transfer along the machining path of the workpiece.

In addition, in another preferred embodiment of the machine tool according to the present invention, the control unit of the machine tool stores information for performing the conversion of the machining feed rate of the tool rest when the tool rest is transferred along the machining path of the workpiece. Storage; Calculating the acceleration/deceleration time constant of the tool rest, which is conveyed along the processing path of the workpiece during processing of the workpiece, the processing feed conversion speed, the processing travel distance, and the number of repetitions of speed conversion during processing through the information stored in the storage unit. Operation unit; And a command unit for driving the driving unit according to the result of the operation unit to convert the machining feed rate of the tool holder.

In addition, in another preferred embodiment of the machine tool according to the present invention, the storage unit of the control unit of the machine tool includes a basic data storage unit for storing tool type and work type data; A machining program storage unit for storing a machining program for machining a workpiece; A rotation speed storage unit for storing the rotation speed of the main shaft; A reference speed storage unit that stores a reference speed at the time of machining and transfer of the tool rest; A speed change rate storage unit for storing a speed change rate at the time of processing transfer of the tool rest; And a speed magnification storage unit for storing the speed magnification at the time of machining and transfer of the tool rest.

In addition, in another preferred embodiment of the machine tool according to the present invention, the operation unit of the machine tool control unit is configured by data of the basic data storage unit, the machining program storage unit, the rotational speed storage unit, and the speed change rate storage unit. An acceleration/deceleration time constant calculation unit for calculating the acceleration/deceleration time constant of the tool rest; A machining feed conversion speed that calculates the maximum machining feed rate and the lowest blank feed rate at the time of machining of the tool rest based on the data of the reference speed storage unit, the speed change rate storage unit, the speed ratio storage unit, and the acceleration/deceleration time constant calculation unit Calculation unit; According to the data of the basic data storage unit, the processing program storage unit, and the processing feed conversion speed calculation unit, when the tool rest is transferred at the maximum machining feed rate or the lowest blank feed rate, the maximum machining feed distance and the lowest ball feed rate of the tool rest A machining feed distance calculation unit that calculates the summed feed distance of the distances; And the number of repetitions of the machining feed conversion during machining transfer along the machining path of the workpiece according to the data of the basic data storage unit, the machining program storage unit, the machining feed conversion speed calculation unit, and the machining feed distance calculation unit. It may include; a speed conversion iteration count calculation unit that calculates.

In addition, in another preferred embodiment of the machine tool according to the present invention, the ratio of the maximum machining feed rate and the lowest ball feed rate in the machine tool may be formed as 3:1.

In addition, in another preferred embodiment of the machine tool according to the present invention, the operation unit of the machine tool control unit includes a check unit for determining whether or not information stored in the storage unit is abnormal; And a selection unit for selecting a processing mode of the work piece.

In addition, in another preferred embodiment of the machine tool according to the present invention, the control unit of the machine tool stores the data calculated from the storage unit and the operation unit in real time when converting the machining feed rate of the tool holder through the command unit, It may further include a correction unit for comparing the real-time data and data stored in the storage unit to correct a result value of the operation unit transmitted to the command unit.

In addition, in another preferred embodiment of the machine tool according to the present invention, the machine tool includes an input unit for inputting information to the storage unit; And a display unit that displays a result of the storage unit, the operation unit, the command unit, and the correction unit.

In order to achieve another object of the present invention, the control method of a machine tool according to the present invention is to store data for performing the conversion of the machining feed rate of the tool rest in a storage unit when the tool rest is transferred along the machining path of the workpiece. step; Calculating an acceleration/deceleration time constant of the tool rest based on data stored in the storage unit; Calculating a machining feed conversion speed that is a maximum machining feed rate and a lowest blank feed rate during machining transfer of the tool rest based on the result of calculating the acceleration/deceleration time constant and the data stored in the storage unit; Machining feed, which is the sum of the maximum machining feed distance and the lowest ball feed distance when the tool rest is transferred at the maximum machining feed rate or the lowest blank feed rate according to the machining feed conversion speed calculation result and data stored in the storage unit. Calculating the distance; Calculating the number of repetitions of speed conversion of the machining feed conversion during machining transfer by the tool rest along the machining path of the workpiece according to the machining feed distance calculation result and data stored in the storage unit; According to the calculation result of the acceleration/deceleration time constant, the machining feed conversion speed, the machining feed distance, and the number of repetitions of the speed conversion, the tool rest converts the machining feed rate of the tool rest at machining feed along the machining path of the workpiece. Transmitting a command to the driving unit to perform; And performing machining of the work piece while cutting chips generated during machining of the work piece by converting the machining feed rate of the tool rest along the machining path during machining of the work piece by a command transmitted to the driving unit. It may include.

In addition, in another preferred embodiment of the control method of the machine tool according to the present invention, the control method of the machine tool includes the steps of checking whether data stored in the storage unit is abnormal after the step of storing the data; And selecting a processing mode of the workpiece.

In addition, in another preferred embodiment of the control method of a machine tool according to the present invention, the control method of the machine tool includes the acceleration/deceleration time constant, the machining feed conversion speed, and the machining feed distance after the step of performing machining of the workpiece. , And the calculation data of the number of repetitions of the speed conversion is stored in real time, and the data stored in the storage unit is compared with the data stored in the storage unit, and the acceleration/deceleration time constant, the processing feed conversion speed, and the processing It may further include a step of correcting the calculation data of the transfer distance and the number of repetitions of the speed conversion.

The control method of a machine tool and a machine tool according to the present invention cuts chips generated during machining of a workpiece through periodic and repetitive conversion of the machining feed rate during machining transfer of the tool rest or main axis along the machining path of the workpiece to improve machining quality. There is an effect that can be improved.

In addition, the control method of the machine tool and the machine tool according to the present invention is to follow the machining path during the machining of the workpiece without repetitive motion according to the vibration of the forward motion and the reverse motion on the machining path of the workpiece when the tool rest or the main shaft changes the machining feed rate. By repeatedly converting the machining feedrate of the tool stand to the maximum machining feedrate and the lowest machining feedrate, the load applied to the driving part and the tool is reduced, fatigue is minimized, saving maintenance time and cost, and maximizing the life of the driving part and the tool. There is an effect.

Moreover, the control method of the machine tool and the machine tool according to the present invention has the effect of improving the surface roughness of the workpiece by cutting the chip by only changing the machining feed rate without vibration due to the forward motion and the reverse motion. have.

In addition, the machine tool and the control method of the machine tool according to the present invention reduce the machining time by moving the same path as the existing tool path, thereby improving the productivity of the machine tool, and optimizing the change in machining feed rate through real-time correction. According to the control, there is an effect that can maximize the reliability of the machine tool.

1 shows a conceptual diagram of a machine tool according to the present invention.
2 shows a configuration diagram of a control unit for a machine tool according to the present invention.
Figure 3 shows a conceptual diagram for explaining the machining feed rate conversion of the tool rest of the machine tool according to the present invention.
4 to 7 are graphs showing a process calculated by the operation unit of the control unit of the machine tool according to the present invention.
8 shows a procedure diagram of a method for controlling a machine tool according to the present invention.

Hereinafter, with reference to the drawings of a machine tool and a control method of the machine tool according to an embodiment of the present invention will be described in detail. The following embodiments are provided as examples in order to sufficiently convey the spirit of the present invention 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. In addition, in the drawings, the size and thickness of the device may be exaggerated for convenience. Throughout the specification, the same reference numbers indicate the same elements.

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 together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only the present embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have it, and the invention is only defined by the scope of the claims. The same reference numerals refer to the same elements throughout the specification. In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity of description.

The terms used in this specification are for describing exemplary embodiments, and therefore, are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless specifically stated in the phrase. As used in the specification, "comprise" and/or "comprising" refers to the presence of one or more other components, steps, actions and/or elements, and/or elements, steps, actions and/or elements mentioned. Or does not exclude additions.

1 shows a conceptual diagram of a machine tool according to the present invention, FIG. 2 shows a configuration diagram of a control unit of a machine tool according to the present invention, and FIG. 3 is a description of the conversion of the machining feed rate of the tool rest of the machine tool according to the present invention. It shows a conceptual diagram for 4 to 7 are graphs showing a process calculated by the operation unit of the control unit of the machine tool according to the present invention. 8 shows a procedure diagram of a method for controlling a machine tool according to the present invention.

A machine tool according to the present invention will be described with reference to FIGS. 1 to 7. The machine tool according to the present invention includes a main shaft 100, a tool rest 200, a driving unit 300, a control unit 400, an input unit 500, and a display unit 600.

The main shaft, the tool rest and the driving part can be installed on the bed. The machine tool according to the present invention may be a horizontal lathe or turning center. The first direction (Z direction) is the longitudinal direction of the bed, the second direction (X direction) is orthogonal to the first direction and is a direction for transferring the tool toward the work piece, and the third direction (Y direction) is the first direction and It may be a direction orthogonal to the second direction.

The workpiece 110 is clamped to the main shaft 100. Although not shown in the drawings, the main shaft may include a chuck for clamping one end of the kongja cave. The chuck may be installed adjacent to the main shaft of the spindle motor. The chuck rotates the work mounted on the chuck as the rotating main shaft rotates by the operation of the driving unit.

The tool 210 is detachably installed on the tool rest 200. This tool rest is formed as a turret so that a number of gongs can be installed.

The driving unit 300 drives the main shaft 100 and the tool rest 200 by receiving a signal from the command unit 430 of the control unit 400 to be described later. Specifically, the drive unit is formed by a servo motor and is operated by a signal from the command unit to move the tool post to the first axis, the second axis, and/or the third axis relative to the main axis through the transfer unit, or to the main axis relative to the tool post. Can be moved to the first axis, the second axis, and/or the third axis. In addition, when the main shaft or the tool rest moves, the rest of the tool rest or the main shaft may be rotated by the driving unit.

The control unit 400 controls the processing feed speed of the main shaft or the tool rest during the processing of the workpiece 110. That is, the control unit 400 does not move the tool rest or the main axis backward on the machining path during the machining of the workpiece, and periodically and repeatedly converts only the machining feed rate when transferring the main axis or the tool rest along the machining path of the workpiece.

In addition, the control unit includes a screen display program and a data input program according to the screen display selection, displays a software switch on the display screen according to the output of the screen display program, and turns on/off the software switch. Recognizes and issues input/output commands for machine motion.

In addition, although not necessarily limited thereto, the control unit is installed in a housing, a case, or one side of a machine tool and includes a monitor capable of displaying various function switches or buttons and various information.

Hereinafter, a form in which the main shaft rotates while clamping the work piece, and the tool is mounted on the tool post and transferred by the tool post will be described as an example. However, as described above, both the spindle and the tool rest may be relatively moved, and the workpiece mounted on the spindle and the tool mounted on the tool rest may rotate simultaneously. In addition, if necessary, the spindle may move while the spindle clamps the workpiece, and the tool may rotate while the tool rest is mounted with the tool.

Specifically, the conversion of the machining feed rate of the tool rest in the control unit is the maximum machining feed rate and the lowest ball feed rate determined by the rotational speed of the main axis, the reference speed of the tool rest, the rate of change in the speed of the tool rest, the speed multiplication of the tool rest, and the feed distance of the tool rest. It is repeatedly performed during machining transfer along the machining path of the workpiece while machining the furnace workpiece. That is, it is repeated as many times as the number of iterations calculated according to the processing path in the calculation unit to be described later, and as many as the number of iterations per rotation of the main shaft. Accordingly, the processing quality of the workpiece is improved as the chips generated during the processing of the workpiece are not curled and are sequentially segmented, and only the maximum processing speed is processed while moving forward along the processing path of the workpiece rather than repeating the forward and backward motions. As the feed rate and the lowest common feed rate are repeatedly converted, the surface roughness of the workpiece is improved, the load on the driving part and the tool is reduced, increasing the life of the driving part and the tool, minimizing damage, and making the total travel distance the same as for general machining. Thus, the processing time can be reduced.

The input unit is installed in the form of a switch or a touch button, such as an operation panel or a control unit, so that information can be input to the storage unit of the control unit. That is, the user stores information for performing the conversion of the machining feed rate of the tool rest in the storage unit through the input unit when the tool rest is transferred along the machining path of the workpiece. In addition, a selection switch may be provided so that the user can arbitrarily select the chip cutting that occurs during machining through the conversion of the machining feed rate of the tool rest when the tool rest is transferred along the machining path of the workpiece.

That is, the user can select the relevant data by the input unit and select the change of the machining feed rate at the time of machining transfer of the tool rest or main shaft along the machining path during cutting of the machine tool. When the input part does not select the function to change the machining feed rate during machining transfer of the tool post or spindle along the machining path during cutting of the machine tool, during the cutting process of the machine tool, during machining transfer of the tool post or spindle along the machining path. Since the machining feed rate change does not work, the chip may not be automatically cut.

The display unit displays data or information of the storage unit, the operation unit, the command unit, and the correction unit. Accordingly, the operator can visually check the real-time change of the tool path and the data stored in the memory unit during cycle machining.

In addition, the display unit displays the result of changing the machining feed rate during machining transfer of the tool rest or main axis along the machining path during cutting of the machine tool performed through the storage unit, the operation unit, the command unit, and the correction unit, or When there is a problem, an alarm is displayed to prevent malfunction of the machine tool, improve reliability and stability, and promote the convenience of the operator. At this time, 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, LED, PDP monitor, or the like.

As such, the machine tool according to the present invention can improve the machining quality by cutting chips generated during the processing of the workpiece through the conversion of the machining feed rate of the tool rest or the main axis when the spindle or the tool rest moves along the machining path of the workpiece. have.

As shown in Figure 2, the control unit 400 of the machine tool according to an embodiment of the present invention includes a storage unit 410, an operation unit 420, a command unit 430, and a correction unit 440. .

The storage unit 410 converts the machining feed rate of the tool rest 200 when the tool 210 mounted on the tool rest 200 is transferred along the machining path of the workpiece as shown in FIG. 3 (when the tool rest moves The processing feed rate becomes the same). The storage unit 410 provides a human-machine interface for inputting various data. The user may input various types of data to be described later in the storage unit using the storage unit 410.

The calculation unit 420 uses the information stored in the storage unit to transfer the acceleration/deceleration time constant (Tf) of the tool stand along the processing path of the workpiece during processing, the maximum processing feed rate (F1), which is the processing feed conversion speed, and the minimum processing feed. Calculate the speed (F2), the machining feed distance (D), and the number of repetitions of the speed conversion during machining feed (n). The control unit 200 includes numerical control (NC) or computerized numerical control (CNC), and various numerical control programs are embedded. That is, the numerical control unit 200 includes a driving program of a driving unit, a tool operation program, and the like, and the corresponding program is automatically loaded and operated according to the driving of the numerical control unit. The operation unit 420 communicates with the storage unit 410, the command unit 430, the correction unit 440, the input unit 500, the display unit 600, and the driving unit 300 by a predetermined protocol.

The command unit 430 drives the driving unit 300 according to the calculation result of the calculation unit 420 to convert the machining feed rate of the tool rest along the machining path of the work piece while machining the work piece. The command unit includes a PLC (Programmable Logic Controller). The PLC communicates with the storage unit 410, the calculation unit 420, the correction unit 440, the input unit 500, the display unit 600, and the driving unit 300 according to a predetermined protocol, and is controlled through such communication. It performs the function of executing commands. That is, the PLC operates by receiving a control command according to the control program of the operation unit. In addition, the PLC may measure the rotational speed and torque of the first driving unit driving the tool rest and the second driving unit driving the main shaft using the encoder of the driving unit. Accordingly, it is possible to maximize compatibility and minimize installation cost as the present invention is easily installed and operated even for inexpensive machine tools by PLC.

The correction unit 440 stores all the data calculated from the storage unit and the operation unit in real time when performing the conversion of the machining feed rate of the tool holder along the machining path of the work piece through the command unit 430, and thus It compares the real-time data stored in real time with the existing data stored in the storage unit and corrects the result value of the operation unit transmitted from the command unit.

That is, the correction unit constructs big data based on the data stored through the machine tool and the control method of the machine tool according to the present invention, and stores the data, previously input data, and various data of the machine tool operating in real time. Based on analysis and judgment, the optimal number of rotations of the main axis for each tool or work piece, the reference speed of the tool stand, the rate of change in the speed of the tool stand, the speed multiplication of the tool stand, and the travel distance of the tool stand are determined by correcting and corrected by big data. The maximum machining feedrate and the lowest machining feedrate, which are recalculated again, are corrected in real time to change the machining feedrate conversion in real time to maximize the reliability and stability of the machine tool, improve performance, and reduce damage to the tool and the driving part. Can prevent and increase longevity.

As shown in Figure 2, the storage unit 410 of the control unit 400 of the machine tool according to an embodiment of the present invention is a basic data storage unit 411, a processing program storage unit 412, a rotational speed storage unit 413, a reference speed storage unit 414, a speed change rate storage unit 415, a speed magnification storage unit 416, and a work size data storage unit 417.

The basic data storage unit 411 stores tool type and work piece type data. That is, the basic data storage unit stores basic data such as the type of tool to be processed and whether the work piece is aluminum or iron.

The machining program storage unit 412 stores a machining program for machining a workpiece. The machining feed path of the tool rest is determined during machining of the workpiece by the machining program. That is, for example, when machining of the workpiece as shown in Fig. 3 is required, the machining transfer path of the tool rest is determined as ①→②→③→④→⑤ during the machining of the work piece by the machining program, and the tool rest is processed through a total of 5 steps. The transfer path is completed, and the transfer distance of the tool stand is determined by the sum of the linear distances moving ①→②→③→④→⑤.

The rotational speed storage unit 413 stores the rotational speed S of the main shaft.

The reference speed storage unit 414 stores the reference speed (F) at the time of processing transfer of the tool holder during processing of the workpiece. That is, the graph range shown in FIG. 7 is a range in which chips are not curled in a general turning tool based on a constant spindle speed, and the reference speed F is set to the same value as within the arrow range in the graph area of the existing data shown in FIG. 7. Can be specified.

The speed change rate storage unit 415 stores the speed change rate Q at the time of machining transfer of the tool rest during machining of the workpiece. The speed change rate (Q) is defined as the number of speed changes per rotation of the main shaft. That is, for example, when the speed change rate (Q) is 1, it means that the machining feed rate of the tool holder is changed once from the maximum machining feed rate to the lowest machining feed rate during the machining of the workpiece per rotation of the main axis. If Q) is 2, it means that the machining feedrate of the tool rest is changed twice from the maximum feedrate to the lowest feedrate during the machining of the workpiece per rotation of the spindle.

The speed magnification storage unit 416 stores the speed magnification (P) at the time of processing transfer of the tool rest during processing of the workpiece. Speed magnification (P) means the maximum processing feedrate (F1) compared to the reference speed (F). (P = F1/F) That is, for example, the reference speed is 10mm/rer, and the maximum processing feedrate is 12mm/ In the case of rev, the speed multiplication (P) is 1.2, the reference speed is 15mm/rer, and when the maximum processing feed speed is 20mm/rev, the speed multiplication (P) is 1.33.

However, as described above, the speed magnification is determined, and the maximum processing feedrate and the minimum processing feedrate are calculated by the reference speed and the speed magnification.

The workpiece size data storage unit 417 stores the size of the workpiece. That is, for example, the workpiece size data storage unit 417 stores the height of the workpiece in the X-axis direction as shown in FIG. 3.

As shown in Figure 2, the operation unit 420 of the control unit 400 of the machine tool according to an embodiment of the present invention is a confirmation unit 421, a selection unit 422, an acceleration/deceleration time constant calculation unit 423 , A machining feed conversion speed calculation unit 424, a machining feed distance calculation unit 425, and a speed conversion repetition count calculation unit 426.

The verification unit 421 determines whether there is an error in information stored in the storage unit, and when there is an error, an alarm is generated through a display unit or the like. Accordingly, it is possible to primarily maintain the stability of the machine tool.

The selection unit 422 selects a processing mode of the work piece. That is, for example, through the selection unit, the user may select straight machining, curved machining, and screw machining of the workpiece, and accordingly, a calculation formula or program input to each calculation unit to be described later may be applied differently.

Acceleration/deceleration time constant calculation unit 423 is based on the data of the basic data storage unit 411, the machining program storage unit 412, the rotational speed storage unit 413, and the speed change rate storage unit Q. Calculate the time constant (Tf).

As shown in FIG. 4, the acceleration/deceleration time constant is the same as the time corresponding to acceleration/deceleration one acceleration/deceleration, and the cycle time is set to be the same as the original. Finally, in the acceleration/deceleration time constant calculation unit 423, the acceleration/deceleration time constant is calculated by Equation 1.

<Equation 1>

Tf = 1/2 × 1/Q ×60 × 1000/S

Tf: acceleration/deceleration time constant

Q: Rate change rate

S: rotation speed

The machining feed conversion speed calculation unit 424 processes the workpiece by data of the reference speed storage unit 414, the speed change rate storage unit 415, the speed magnification storage unit 416, and the acceleration/deceleration time constant calculation unit 423. In the process, the maximum machining feedrate (F1) and the lowest common feedrate (F2) at the machining feed of the tool rest are calculated.

That is, as described above, when the reference speed (F) and the speed multiplication (P) are determined, the maximum processing feed rate (F1) is calculated, and the minimum processing feed rate is calculated through the arithmetic average of the maximum processing feed rate and the reference speed. do. For example, if the speed multiplication (P) is 1.2 and the reference speed is 10 mm/rev, the maximum processing feed rate (F1) is 12 mm/rev, and the minimum processing feed rate (F2) is 4 mm by arithmetic mean. becomes /rev.

Finally, in the machining feed conversion speed calculation unit 424, the maximum machining feed rate F1 is calculated by Equation 2, and the minimum machining feed rate F2 is calculated by Equation 3.

<Equation 2>

F1 = P × F

F1: Maximum processing feed rate

P: speed magnification

F: Standard speed at tool rest machining transfer

<Equation 3>

F2 = K×F

F2: Minimum machining feedrate

K: integer according to arithmetic mean

As shown in Fig. 6, it is most effective that the ratio of the maximum processing feed rate and the lowest blank feed rate is 3:1. That is, it is preferable that the K value in Equation 3 is 1/3. Accordingly, it is possible to reduce the load acting on the driving part and the tool while maximizing the chip-segmentation effect by suppressing the occurrence of vibration, and to improve the surface roughness of the workpiece.

The machining feed distance calculation unit 425 is based on the data of the basic data storage unit 411, the machining program storage unit 412, and the machining feed conversion speed calculation unit 424 to determine the maximum machining feed rate and the maximum machining feed rate during the machining of the workpiece. When transferring while converting to the lowest common feed speed, calculate the feed distance, which is the sum of the maximum machining feed distance and the lowest ball feed distance of the tool stand. As shown in Fig. 5, each moving distance is calculated as a linear distance and determined as the sum of them. When moving from the first point to the second point on the graph of Fig. 5, the transfer distance (arrow, D), which is the sum of the maximum machining distance and the lowest distance, is calculated as a straight line distance in the form of the square root of the distance of each coordinate.

X-axis travel distance: Xs = (X-Xi)/2

Z-axis travel distance: Zs = Z-Zi

Finally, the feed distance (D) in the machining feed distance calculation unit 425 is calculated by Equation 4.

<Equation 4>

Distance(D): Transfer distance

The speed conversion repetition count calculation unit 426 uses the data of the basic data storage unit 411, the machining program storage unit 412, the machining feed conversion speed calculation unit 424, and the machining feed distance calculation unit 425_. Calculate the number of repetitions (n) of machining feed conversion during machining feed along the machining path of the master workpiece, that is, the maximum machining feed rate in relation to the standard speed and the rate of change of speed and speed multiplication according to the total feed distance during machining of the workpiece. The total number of repetitions of speed conversion of the lowest common feed rate is determined Finally, the total number of repetitions of speed conversion (n) in the speed conversion repetition count calculation unit 426 is calculated by Equation 5.

<Equation 5>

n = D/F × Q-P/2

n: Total number of iterations of speed conversion

D: Transfer distance

Q: Rate change rate

P: speed magnification

Therefore, in the machine tool according to the present invention, the tool rest or the main axis increases the machining feed rate of the tool rest along the machining path during the machining of the workpiece without repeated motion according to the vibration of the forward and backward motions on the machining path of the workpiece when the machining feed rate is changed. By repeatedly converting to the maximum machining feed rate and the lowest machining feed rate, the load applied to the driving part and the tool is reduced, and fatigue is minimized to reduce maintenance time and cost, and maximize the life of the drive part and tool.

In addition, the machine tool and the control method of the machine tool according to the present invention can improve the surface roughness of the work piece by cutting the chip and processing the work piece only by changing the machining feed rate without vibration due to the forward motion and the reverse motion. Machine tool productivity is improved by reducing machining time by moving the same path as the existing tool path without repetitive movements of and backward, and maximizing the reliability of the machine tool by optimizing and controlling the change in machining feed rate through real-time correction. can do.

A method of controlling a machine tool according to an embodiment of the present invention will be described with reference to FIG. 8. The specific calculation or data input method is the same as that of the above-described machine tool. Hereinafter, a method of controlling the machine tool of the present invention will be described, focusing on differences from the machine tool.

When the tool rest moves along the machining path of the workpiece, the data for converting the machining feed rate of the tool rest is stored in the storage. Specifically, in the storage unit, basic data such as the type of tool and the type of workpiece, workpiece processing program, rotational speed of the main axis, reference speed at the time of machining transfer of the tool post, the rate of change of speed at the time of machining transfer of the tool post, The data on the speed magnification and the size of the workpiece at the time of machining transfer of the tool rest are stored in the storage unit.

After the step of storing the data (S1), the confirmation unit checks whether the data stored in the storage unit is abnormal. If there is an error in the stored data as a result of the check, an alarm can be generated through the display to warn the operator. Accordingly, it is possible to prevent equipment damage due to malfunction of the machine tool, reduce maintenance cost and time, and maximize the stability of the machine tool.

After the confirming step (S2), it is possible to select the machining mode of the workpiece. That is, for example, a processing mode can be selected as in the first mode in the case of linear processing, the second mode in the case of curved processing, and the third mode in the case of thread processing, and the operation unit can drive the corresponding program to facilitate calculation.

The acceleration/deceleration time constant of the tool rest is calculated by the acceleration/deceleration time constant calculation unit from the data stored in the storage unit after the step of storing data (S1) or after the step of selecting a processing type (S3). These calculation principles and calculation methods are the same as those described above.

After the step of calculating the acceleration/deceleration time constant (S4), according to the result of calculating the acceleration/deceleration time constant and the data stored in the storage unit, the machining feed conversion speed that is the maximum machining feed rate and the lowest common feed rate during machining of the tool rest during machining of the workpiece Is calculated in the machining feed conversion speed calculation section.

After the step of calculating the machining feed conversion speed (S5), the maximum machining feed of the tool rest when the tool rest is moving at the maximum machining feed rate or the lowest machining feed rate by the machining feed conversion rate calculation result and data stored in the storage unit. Calculate the machining feed distance, which is the sum of the distance and the lowest ball feed distance.

After the step of calculating the machining feed distance (S6), the tool rest calculates the number of repetitions of the speed conversion of machining feed conversion during machining feed along the machining path of the workpiece according to the machining feed distance calculation result and data stored in the storage unit.

After the step (S7) of counting the total number of repetitions of speed conversion, the tool rest is moved along the machining path of the workpiece according to the calculation result of acceleration/deceleration time constant, machining feed conversion speed, machining feed distance, and speed conversion repetition number. It transmits a command to the driving unit to perform the conversion of the machining feed rate of the tool rest.

After the speed conversion command step (S8), the processing of the workpiece is performed while cutting the chips generated during the processing of the workpiece through the conversion of the machining feed rate of the tool rest along the machining path during the machining of the workpiece by the command transmitted to the driving unit. do.

After the step (S9) of performing the machining of the workpiece, the calculation data of the acceleration/deceleration time constant, machining feed conversion speed, machining feed distance, and speed conversion repetition number are stored in real time, and the real-time data stored in real time and the above storage By comparing the data stored in the unit, the data stored in the storage unit and the acceleration/deceleration time constant, the machining feed conversion speed, the machining feed distance, and the calculated data of the speed conversion repetition number are corrected.

Therefore, the control method of the machine tool according to the present invention is the machining of the tool rest along the machining path during the machining of the workpiece without repeated motions due to the vibration of the forward motion and the reverse motion on the machining path of the workpiece when the tool rest or the main shaft changes the machining feed rate. By repeatedly converting the feed rate to the maximum machining feed rate and the lowest machining feed rate, the load applied to the driving part and the tool is reduced, fatigue is minimized to save maintenance time and cost, maximize the life of the drive part and tool, and process the workpiece. Improving the roughness improves the processing quality, reduces the processing path to maximize productivity, and improves the stability and reliability of machine tools.

In the detailed description of the present invention described above, it has been described with reference to preferred embodiments of the present invention, but those skilled in the art or those of ordinary skill in the relevant technical field of the present invention described in the claims to be described later It will be understood that various modifications and changes can be made to the present invention without departing from the spirit and technical scope. Therefore, the technical scope of the present invention should not be limited to the content described in the detailed description of the specification, but should be determined by the claims.

100: spindle, 110: workpiece
200: tool rest, 210: tool
300: drive unit, 400: control unit,
410: storage unit, 420: operation unit,
430: command unit, 440: correction unit,
500: input unit, 600: display unit.

Claims (13)

A spindle on which the workpiece is clamped;
A tool rest for processing the workpiece;
A driving unit for driving the main shaft and the tool rest; And
And a control unit for controlling the processing feed rate of the main shaft or the tool rest during processing of the workpiece.
The method of claim 1,
The machine tool, characterized in that the main shaft or the tool rest cuts the chips generated during the machining of the workpiece by converting the machining feed rate of the tool rest or the main shaft when machining is transferred along the machining path of the workpiece.
The method of claim 1,
The conversion of the machining feed rate of the tool rest is performed by processing the workpiece at the maximum machining feed rate and the lowest ball feed rate determined by the rotational speed of the main shaft, the reference speed and the speed change rate and the rate of the tool rest, and the feed distance of the tool rest. Machine tool, characterized in that it is repeatedly performed at the time of processing transfer along the path. The method of claim 3,
The control unit,
A storage unit for storing information for converting the machining feed rate of the tool rest when the tool rest is transferred along a machining path of the workpiece;
Calculating the acceleration/deceleration time constant of the tool rest, which is conveyed along the processing path of the workpiece during processing of the workpiece, the processing feed conversion speed, the processing travel distance, and the number of repetitions of speed conversion during processing through the information stored in the storage unit. Operation unit; And
And a command unit for driving the driving unit according to the result of the calculation unit to convert the machining feed rate of the tool rest.
The method of claim 4,
The storage unit,
A basic data storage unit for storing tool type and work type data;
A machining program storage unit for storing a machining program for machining a workpiece;
A rotation speed storage unit for storing the rotation speed of the main shaft;
A reference speed storage unit that stores a reference speed at the time of machining and transfer of the tool rest;
A speed change rate storage unit for storing a speed change rate at the time of processing transfer of the tool rest; And
A machine tool comprising a; speed ratio storage unit for storing the speed ratio at the time of processing transfer of the tool rest.
The method of claim 4,
The calculation unit,
An acceleration/deceleration time constant calculation unit for calculating the acceleration/deceleration time constant of the tool rest based on data of the basic data storage unit, the processing program storage unit, the rotational speed storage unit, and the speed change rate storage unit;
A machining feed conversion speed that calculates the maximum machining feed rate and the lowest blank feed rate at the time of machining of the tool rest based on the data of the reference speed storage unit, the speed change rate storage unit, the speed ratio storage unit, and the acceleration/deceleration time constant calculation unit Calculation unit;
According to the data of the basic data storage unit, the processing program storage unit, and the processing feed conversion speed calculation unit, when the tool rest is transferred at the maximum machining feed rate or the lowest blank feed rate, the maximum machining feed distance and the lowest ball feed rate of the tool rest A machining feed distance calculation unit that calculates the summed feed distance of the distances; And
According to the data of the basic data storage unit, the machining program storage unit, the machining feed conversion speed calculation unit, and the machining feed distance calculation unit, the tool rest determines the number of repetitions of machining feed conversion during machining transfer along the machining path of the workpiece. Machine tool comprising a; speed conversion repetition count calculation unit to calculate.
The method of claim 6,
The machine tool, characterized in that the ratio of the maximum processing feed rate and the lowest hole feed rate is 3:1.
The method of claim 6,
The calculation unit,
A confirmation unit that determines whether or not information stored in the storage unit is abnormal; And
A machine tool comprising a; selection unit for selecting a processing mode of the work.
The method of claim 4,
The control unit,
The calculation unit that stores the data calculated from the storage unit and the calculation unit in real time when performing the conversion of the machining feed rate of the tool holder through the command unit, compares the real time data with the data stored in the storage unit, and is transmitted to the command unit Machine tool comprising a; correction unit for correcting the result value of.
The method of claim 9,
An input unit for inputting information to the storage unit; And
And a display unit for displaying the result of the storage unit, the operation unit, the command unit, and the correction unit.
Storing data for performing a machining feed rate conversion of the tool rest in a storage unit when the tool rest is transferred along a machining path of the workpiece;
Calculating an acceleration/deceleration time constant of the tool rest based on data stored in the storage unit;
Calculating a machining feed conversion speed that is a maximum machining feed rate and a lowest blank feed rate during machining transfer of the tool rest based on the result of calculating the acceleration/deceleration time constant and the data stored in the storage unit;
Machining feed, which is the sum of the maximum machining feed distance and the lowest ball feed distance when the tool rest is transferred at the maximum machining feed rate or the lowest blank feed rate according to the machining feed conversion speed calculation result and data stored in the storage unit. Calculating the distance;
Calculating the number of repetitions of speed conversion of the machining feed conversion during machining transfer by the tool rest along the machining path of the workpiece according to the machining feed distance calculation result and data stored in the storage unit;
According to the calculation result of the acceleration/deceleration time constant, the machining feed conversion speed, the machining feed distance, and the number of repetitions of the speed conversion, the tool rest converts the machining feed rate of the tool rest at machining feed along the machining path of the workpiece. Transmitting a command to the driving unit to perform; And
Processing the workpiece while cutting chips generated during the machining of the workpiece by converting the machining feed rate of the tool rest along the machining path during machining of the workpiece according to a command transmitted to the driving unit; Control method of a machine tool comprising a.
The method of claim 11,
After the step of storing the data,
Checking whether data stored in the storage unit is abnormal; And
And selecting a processing mode of the work piece.
The method of claim 11,
After the step of performing the machining of the workpiece,
The acceleration/deceleration time constant, the machining feed conversion speed, the machining feed distance, and the calculation data of the speed conversion repetition number are stored in real time, and the real time data is compared with the data stored in the storage unit and stored in the storage unit. And correcting data and calculation data of the acceleration/deceleration time constant, the machining feed conversion speed, the machining feed distance, and the number of repetitions of the speed conversion.

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