Control device for machine tool and control system for machine tool

Abstract

Provided is a machine tool control device with which it is possible to simply set control parameter ranges. This machine tool control device which controls a machine tool comprises: a control parameter-setting unit which sets control parameters; a shaft operation control unit which operates an operation shaft on the basis of the control parameters; and a trigger reception unit which receives a trigger during shaft operation by the shaft operation control unit. The control parameter-setting unit has a specifiable range-setting unit for setting specifiable ranges for the control parameters in response to the trigger reception unit having received the trigger, and sets the control parameters on the basis of the specifiable range.

Description

Technical Field

[0001] The present disclosure relates to a control device for a machine tool and a control system for a machine tool.

Background Art

[0002] Conventionally, a control device for a machine tool that controls the movement of an operating axis while vibrating the operating axis to machine a workpiece, such as vibration cutting or crank pin machining, is known. When the operating axis is vibrated in this way, excessive vibration may occur in the entire machine tool due to the vibration, resulting in damage to the machine tool and having an adverse effect on the machining accuracy.

[0003] Therefore, in order to prevent excessive vibration of the entire machine tool due to the vibration of the operating axis, a technique has been proposed in which upper limit values of control parameters such as the acceleration and jerk of the vibration are set, and vibration control is performed within the set upper limit values (see, for example, Patent Document 1). According to this technique, it is said that a good finish surface can be ensured.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the upper limit values of control parameters such as the acceleration and jerk of the vibration need to be set by the designer of the machine tool from various viewpoints such as the strength of the machine tool and the load due to vibration. Therefore, it is not easy to set the upper limit values of these control parameters, and it takes time and effort, requiring a long time.

[0006] For example, after an operator sets the upper limit value of a control parameter to a provisional value and conducts a trial operation (dry machining) of vibration control, a more appropriate upper limit value of the control parameter is set based on the results of the trial operation. However, conventionally, since the trial operation of the machine tool and the setting of the upper limit value of the control parameter have not been coordinated as a system, it is still time-consuming at present.

[0007] Therefore, a control device for a machine tool that can easily set the range of control parameters is desired.

Means for Solving the Problem

[0008] One aspect of the present disclosure is a control device for a machine tool that controls a machine tool, including a control parameter setting unit that sets control parameters, an axis movement control unit that operates an operation axis based on the control parameters, and a trigger reception unit that receives a trigger during the axis movement by the axis movement control unit. The control parameter setting unit has a specifiable range setting unit that sets a specifiable range of the control parameters in response to the trigger reception unit receiving the trigger, and sets the control parameters based on the specifiable range.

Advantages of the Invention

[0009] According to the present disclosure, a control device for a machine tool that can easily set the range of control parameters can be provided.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0012] FIG. 1 is a diagram showing a control device 1 of a machine tool according to the present embodiment. The control device 1 of the machine tool according to the present embodiment operates at least one main shaft that relatively rotates a cutting tool (hereinafter, referred to as a tool) and a work, and at least one feed shaft that relatively moves the tool with respect to the work, thereby machining the work with the tool. In FIG. 1, for the sake of convenience, only a motor 3 that drives one feed shaft is shown.

[0013] The control device 1 of the machine tool according to this embodiment executes vibration cutting (also referred to as rocking cutting) by operating, for example, the main shaft and the feed shaft. That is, the control device 1 of the machine tool executes cutting while relatively rotating the tool and the workpiece and relatively vibrating (also referred to as rocking) the tool and the workpiece. The tool path, which is the locus of the tool, is set so that the current path partially overlaps the previous path, and the portion processed by the previous path is included in the current path. Therefore, by generating an idle stroke (also referred to as air cut) in which the cutting edge of the tool leaves the surface of the workpiece, the chips continuously generated by the cutting process are surely shredded.

[0014] Note that this embodiment is applicable not only to a configuration in which the tool moves in the feed direction while vibrating with respect to a workpiece that rotates around a central axis, but also to a configuration in which the tool T rotates around the central axis of the workpiece and the workpiece moves in the feed direction with respect to the tool. Further, this embodiment is applicable to both outer diameter machining and inner diameter machining of the workpiece. Furthermore, this embodiment is applicable not only when a plurality of feed shafts (Z-axis and X-axis) are required because the workpiece has a tapered portion or an arc-shaped portion on the machining surface, but also when the workpiece is cylindrical or tubular and a single specific feed shaft (Z-axis) is sufficient.

[0015] The control device 1 of the machine tool is configured using, for example, a computer including a memory such as a ROM (read only memory) and a RAM (random access memory), a CPU (control processing unit), and a communication control unit, which are connected to each other via a bus. As shown in FIG. 1, the control device 1 of the machine tool includes a control parameter setting unit 11, a set value storage unit 12, a specifiable range setting unit 13, an operating state possible range setting unit 14, an axis movement control unit 15, an operating state acquisition unit 16, a control parameter setting history storage unit 17, and a trigger reception unit 18. The functions and operations of these units can be achieved by the cooperation of the CPU, memory, and control program stored in the memory mounted on the computer.

[0016] The control device 1 of the machine tool is connected to a numerical control device (Computer Numerical Controller, hereinafter also referred to as CNC), a PLC (Programmable Logic Controller), and a host computer (not shown) such as an external computer. From these host computers, a machining program and machining conditions of the workpiece such as the rotational speed and feed rate are input to the control device 1 of the machine tool.

[0017] The machining conditions of the workpiece include the relative rotational speed of the workpiece and the tool around the central axis of the workpiece, the relative feed rate of the tool and the workpiece, the acceleration / deceleration time constant, and the position command of the feed axis. In this embodiment, the CPU in the control device 1 of the machine tool may be configured to read the rotational speed and feed rate from the input machining program as machining conditions and output them to the axis motion control unit 15, or the position command creation unit etc. in the axis motion control unit 15 may be provided in the above host computer.

[0018] Also, as shown in FIG. 1, the detection signal of the sensor 4 is input to the control device 1 of the machine tool. The sensor 4 includes sensors such as an encoder that detects the rotational speed, rotational angle, rotational position, etc. of the motor 3, and an acceleration sensor etc. provided on the machine tool itself to detect the vibration of the entire machine tool. The detection signal of the sensor 4 is transmitted to the operation state acquisition unit 16 and the trigger reception unit 18 described later.

[0019] Also, an input device 2 is connected to the control device 1 of the machine tool. The input device 2 includes a trigger input unit 22 and a control parameter input unit 21. The input device 2 preferably includes a display unit composed of a display screen (not shown) and an operation unit such as a keyboard or a touch panel (also not shown). The operator operates the operation unit and inputs the control parameters while confirming the input values on the display screen.

[0020] The input device 2 may be provided in a numerical control device (not shown), or may also be provided in an external computer or the like (not shown). The control system 10 of the machine tool according to the present embodiment is composed of the control device 1 and the input device 2 of the machine tool. Conventionally, the trial operation (dry machining) of the machine tool and the setting of the upper limit value of the control parameters were not linked as a system. According to the present embodiment, however, the trial operation of the machine tool and the setting of the upper limit value of the control parameters are linked as a system, enabling efficient work.

[0021] Here, examples of the control parameters include the vibration frequency, vibration amplitude, etc. in the vibration control operation. As the vibration frequency, in addition to the vibration frequency itself, the vibration frequency magnification is also included. As the vibration amplitude, in addition to the vibration amplitude itself, the vibration amplitude magnification is also included.

[0022] The vibration frequency magnification is a vibration frequency parameter obtained by dividing the vibration frequency by the spindle speed. The vibration amplitude magnification is a vibration amplitude parameter obtained by dividing the vibration amplitude by 1 / 2 of the feed amount of the feed axis per one rotation of the spindle.

[0023] In addition, examples of the control parameters include the feed speed, acceleration / deceleration time constant, etc. in the positioning operation (also referred to as the rapid feed operation). The control parameter setting unit 11 sets various control parameters in these vibration control operations and positioning operations, and the set control parameters are temporarily stored in the setting value storage unit 12 described later. Also, all the set control parameters are transmitted to the axis motion control unit 15, operation state acquisition unit 16, and control parameter setting history storage unit 17 described later.

[0024] The control parameter setting unit 11 has a specifiable range setting unit 13 that sets the specifiable range of control parameters in response to the trigger reception unit 18, which will be described later, receiving a trigger. The specifiable range of control parameters is, for example, the lower limit value and the upper limit value such as the vibration frequency and the vibration amplitude. In this case, the specifiable range setting unit 13 sets, as the specifiable range of control parameters, at least one of the lower limit value and the upper limit value of the vibration frequency and the vibration amplitude of the operation axis. Then, the control parameter setting unit 11 sets the control parameters based on the specifiable range set by this specifiable range setting unit 13. Specifically, the control parameter setting unit 11 sets the control parameters so that they are within the specifiable range.

[0025] The specifiable range setting unit 13 may set the specifiable range of control parameters based on the control parameters set by the control parameter setting unit 11 when the trigger reception unit 18 receives a trigger. The trigger reception unit 18 receives a trigger when a defect due to vibration exceeds the allowable range during the axis operation such as during the trial operation of the machine tool. Therefore, the specifiable range setting unit 13 sets the specifiable range based on the control parameters set by the control parameter setting unit 11 and temporarily stored in the set value storage unit 12 when the trigger reception unit 18 receives a trigger. Thereby, an appropriate specifiable range of control parameters is easily set.

[0026] The specifiable range setting unit 13 may set the specifiable range of control parameters based on the control parameters stored in the control parameter setting history storage unit 17. The control parameter setting history storage unit 17 stores the history of the control parameters set by the control parameter setting unit 11 in the past. Therefore, the specifiable range setting unit 13 can easily set an appropriate specifiable range of control parameters based on the control parameters set during, for example, the previous or the penultimate trial operation.

[0027] Preferably, the specifiable range setting unit 13 includes an operable state range setting unit 14 that sets an operable state range that can be operated by the axis motion control unit 15 described later based on the state information of the axis motion acquired by the motion state acquisition unit 16 described later. The state information of the axis motion is, for example, vibration speed, vibration acceleration, or vibration jerk. In this case, the specifiable range setting unit 13 sets the specifiable range of the control parameter based on the operable state range set by the operable state range setting unit 14. Thereby, a more appropriate specifiable range of the control parameter is easily set.

[0028] The operable state range is, for example, the lower limit value and the upper limit value of vibration speed, vibration acceleration, or vibration jerk. These vibration speed, vibration acceleration, or vibration jerk are parameters caused by the vibration of the entire machine tool. Therefore, preferably, the operable state range setting unit 14 sets at least one of the vibration speed upper limit, vibration acceleration upper limit, and vibration jerk upper limit of the motion axis as the operable state range.

[0029] The control parameter setting unit 11 may set the control parameter by continuously changing it. For example, the control parameter setting unit 11 may set the vibration frequency, vibration amplitude, etc. to change continuously, gradually, or step by step. Thereby, for example, the axis motion such as the trial operation of the machine tool is automatically performed continuously while changing the control parameter, so that the setting of the range of the control parameter can be efficiently and easily performed.

[0030] The control parameter setting unit 11 may change the set control parameters in response to the trigger reception unit 18 described later receiving a trigger. The trigger reception unit 18 receives a trigger when a defect due to vibration exceeds the allowable range during axis movement such as during a trial operation of the machine tool. Therefore, the control parameter setting unit 11 changes the control parameters set at that time and stored in the set value storage unit 12 in the direction in which the defect due to vibration is eliminated in response to the trigger reception unit 18 receiving a trigger, and may set this as the range of the control parameters. For example, when it is determined that it corresponds to the upper limit of vibration, the control parameters such as the vibration frequency and vibration amplitude that were set at that time and temporarily stored in the set value storage unit 12 are simply set as the upper limit value of the control parameters after being changed to a slightly smaller value.

[0031] The set value storage unit 12 temporarily stores the control parameters set by the control parameter setting unit 11. The control parameters temporarily stored in the set value storage unit 12 are used not only when setting the specifiable range as described above, but also when changing the control parameters later.

[0032] The control parameter setting unit 11 may obtain control parameters from the control parameter input unit 21 of the input device 2 and set the control parameters. In this case, the control parameters input by the operator via the control parameter input unit 21 are set as control parameters by the control parameter setting unit 11.

[0033] The axis movement control unit 15 operates the movement axis based on the control parameters. Specifically, the axis movement control unit 15 vibrates and controls the movement axis and positions and controls the movement axis based on the control parameters. The axis movement control unit 15 includes various functional units such as a position command generation unit, a vibration command generation unit, a superposition command generation unit, a learning control unit, and a position speed control unit (not shown in the figure) in order to execute the vibration control operation and the positioning control operation of the movement axis.

[0034] The position command generation unit generates a position command as a movement command for the motor 3 based on the machining program and machining conditions input to the control device 1 of the machine tool. Specifically, the position command creation unit generates a position command (movement command) for each feed axis based on the relative rotational speeds of the workpiece and the tool around the central axis of the workpiece and the relative feed speed of the tool and the workpiece.

[0035] The vibration command generation unit generates a vibration command. The vibration command generation unit generates a vibration command based on the control parameters set by the control parameter setting unit 11.

[0036] The superimposition command generation unit calculates a position deviation, which is the difference between the position feedback based on the position detection by the sensor 4 such as the encoder of the motor 3 of the feed axis and the position command, and superimposes the vibration command generated by the vibration command generation unit on the calculated position deviation to generate a superimposition command. Alternatively, the vibration command may be superimposed on the position command instead of the position deviation.

[0037] The learning control unit calculates a correction amount for the superimposition command based on the superimposition command, and corrects the superimposition command by adding the calculated correction amount to the superimposition command. The learning control unit has a memory, associates the vibration phase and the correction amount within one cycle or a plurality of cycles of vibration and stores them in the memory, and reads out the superimposition command stored in the memory at a timing capable of compensating for the phase delay of the vibration operation according to the responsiveness of the motor 3 and outputs it as the correction amount. When the vibration phase for outputting the correction amount does not exist in the vibration phase stored in the memory, the correction amount may be calculated from the correction amount close to the vibration phase. Generally, since the position deviation with respect to the vibration command increases as the vibration frequency increases, by performing the correction by this learning control unit, it is possible to improve the followability with respect to the periodic vibration command.

[0038] The position speed control unit generates a torque command for the motor 3 that drives the feed axis based on the superimposition command after adding the correction amount, and controls the motor 3 with the generated torque command. Thereby, machining is performed while relatively vibrating the tool and the workpiece.

[0039] The axis motion control unit 15 may stop the axis motion in response to the trigger reception unit 18 receiving a trigger. The trigger reception unit 18 receives the trigger during axis motion such as during a trial operation of the machine tool when the malfunction due to vibration exceeds the allowable range. Therefore, in response to the trigger reception unit 18 receiving the trigger, the axis motion control unit 15 automatically stops the axis motion, thereby avoiding the occurrence of malfunctions due to vibration.

[0040] The trigger reception unit 18 receives the trigger during the axis motion by the axis motion control unit 15. During axis motion, in addition to during the trial operation of the machine tool, it also includes during the operation of the machining program. The trigger reception unit 18 receives the trigger when the malfunction due to vibration exceeds the allowable range during axis motion such as during a trial operation of the machine tool. For example, the trigger reception unit 18 receives the trigger input by the operator visually confirming that the vibration of the entire machine tool reaches the upper limit and the operator operating the trigger input unit 22 described later.

[0041] The trigger reception unit 18 may receive the trigger according to the detection signal of the sensor 4 such as an acceleration sensor provided on the machine tool. In this case, for example, when the vibration acceleration of the entire machine tool detected by the sensor 4 such as an acceleration sensor exceeds a preset threshold value such as the vibration acceleration, the trigger reception unit 18 automatically receives the trigger.

[0042] The operation state acquisition unit 16 acquires the state information of the axis motion. As described above, examples of the state information of the axis motion include the vibration speed, vibration acceleration, vibration jerk, etc. of the moving axis. The operation state acquisition unit 16 acquires the state information of the axis motion based on the detection signal of the sensor 4, for example.

[0043] The operation state acquisition unit 16 may also acquire the state information of the axis motion by performing a predetermined calculation from the control parameters set by the control parameter setting unit 11. For example, the vibration acceleration is calculated by the following mathematical formula (1) using the vibration amplitude and vibration frequency. [Equation 1] Vibration acceleration = α × (vibration amplitude) × (vibration frequency) 2 ···Equation (1)

[0044] The control parameter setting history storage unit 17 stores the setting history of the control parameters set by the control parameter setting unit 11. When the specifiable range setting unit 13 sets the specifiable range based on the past control parameters, the control parameters set by the control parameter setting unit 11 in the past are acquired from this control parameter setting history storage unit 17.

[0045] The control parameter input unit 21 of the input device 2 inputs the set value of the control parameter from the input device 2. Specifically, the control parameter input unit 21 inputs the control parameter according to the operation by the operator via input means such as a keyboard or a touch panel provided in the input device 2, and transmits the input control parameter to the above-mentioned control parameter setting unit 11.

[0046] The trigger input unit 22 of the input device 2 inputs a trigger from the input device 2. Specifically, the trigger input unit 22 inputs a trigger according to the operation of the above-mentioned input means by the operator, and transmits it to the above-mentioned trigger reception unit 18. For example, the trigger input unit 22 is composed of an upper limit setting button or an upper limit setting display unit on the touch panel screen, etc.

[0047] Next, the setting procedure of the range of the control parameters in the vibration control operation and the positioning control operation executed by the control device 1 of the machine tool will be described in detail with reference to FIGS. 2 to 8.

[0048] FIG. 2 is a diagram showing the display screen of the numerical control device 5 when setting the vibration acceleration upper limit value in the vibration control operation, and is a diagram showing the input of a plurality of vibration frequencies and vibration amplitudes. Further, FIG. 3 is a diagram showing the display screen of the numerical control device 5 when setting the vibration acceleration upper limit value in the vibration control operation, and is a diagram showing the calculation and setting of the vibration acceleration upper limit value based on the vibration frequency and the vibration amplitude.

[0049] As shown in FIG. 2, first, as a preliminary preparation for performing the vibration control operation, in order to set the upper limit value of the vibration acceleration generated in the entire machine tool, the operator inputs the vibration amplitude and the vibration frequency as control parameters. Specifically, the operator operates the control parameter input unit 21 of the input device 2 provided in the CNC 5 to input the vibration amplitude and the vibration frequency. Then, for example, the input values are displayed on the vibration upper limit value setting tool screen that constitutes the touch panel type display screen of the CNC 5, and the input vibration amplitude and vibration frequency are set as control parameter setting values by the control parameter setting unit 11.

[0050] Then, under the conditions of the set vibration amplitude and vibration frequency, a trial operation (dry machining) of the machine tool is executed. As the control parameters, a plurality of vibration amplitudes and vibration frequencies are input as shown in FIG. 2, and the trial operation is executed for each set value.

[0051] As a result of the trial operation, if the operator determines that the vibration of the entire machine tool reaches the upper limit and the malfunction due to the vibration exceeds the allowable range, as indicated by the arrow in FIG. 3, the operator touches the acceleration upper limit value setting displayed on the vibration upper limit value setting tool screen of the CNC 5 as the trigger input unit 22. Then, the trigger reception unit 18 receives the trigger from the trigger input unit 22, and the vibration acceleration is calculated from the vibration amplitude and the vibration frequency set at the time of the trial operation by the above-mentioned mathematical formula (1). At the same time, it is displayed as the acceleration upper limit on the vibration upper limit value setting tool screen of the CNC 5 and set as the vibration acceleration upper limit value. Thus, in this embodiment, since the trial operation of the machine tool and the setting of the range of the control parameters are linked as a system, for example, the setting of the vibration acceleration upper limit value is easy.

[0052] When the operator touches the acceleration upper limit value setting to set the range of the control parameters, the control parameters set at that time may be changed in a direction in which the malfunction due to the vibration is suppressed. Also, at that time, the axis movement control unit 15 may stop the axis movement of the trial operation.

[0053] FIG. 4 is a diagram showing the display screen of the numerical control device 5 when setting the vibration amplitude upper limit value in the vibration control operation. As shown in FIG. 4, first, in order to set the upper limit value of the vibration amplitude as a preparatory step for performing the vibration control operation, the operator sets a plurality of vibration amplitudes while fixing the vibration frequency as a control parameter (fixed at 15 Hz in the example shown in FIG. 4). The input and setting procedures for these control parameters are as described above.

[0054] Then, under the conditions of the set vibration frequency (fixed value) and vibration amplitude (variable value), the operator performs a trial operation (dry machining) of the machine tool for each set value. As a result of the trial operation, if the operator determines that the vibration of the entire machine tool reaches the upper limit and the problems caused by the vibration exceed the allowable range, as indicated by the arrow in FIG. 4, the operator touches the upper limit value setting displayed on the vibration upper limit value setting tool screen of the CNC 5 as the trigger input unit 22. Then, the trigger reception unit 18 receives the trigger from the trigger input unit 22, and the vibration amplitude set during the trial operation is set as the vibration amplitude upper limit value. In this way, in the present embodiment, since the trial operation of the machine tool and the setting of the control parameter range are linked as a system, for example, the setting of the vibration amplitude upper limit value is easy.

[0055] In addition, when setting the vibration frequency upper limit value instead of the vibration amplitude upper limit value, the same procedure is performed. In this case, the vibration amplitude is set as a fixed value. Alternatively, it can be similarly applied to the setting of the vibration speed upper limit value and the vibration jerk upper limit value. Also, it can be similarly applied not only to the setting of the upper limit value of these control parameters but also to the setting of the lower limit value. For example, when setting the lower limit value of the control parameter to avoid problems such as fretting wear caused by minute vibrations of the machine tool, the same procedure may be applied. The same applies to the positioning control operation described later. In this case, since it is not easy for the operator to visually determine whether the problems caused by the vibration exceed the allowable range, it is better to make a judgment based on the detection signal of the sensor 4.

[0056] FIG. 5 is a diagram showing a display screen of the external computer 6 when setting the upper limit value of the vibration acceleration in the vibration control operation. FIG. 5 shows the case where the input device 2 is provided in the external computer 6 instead of the numerical control device 5. Thus, even when the input device 2 is provided in the external computer 6, the range of the control parameters can be easily set by the same procedure as described above.

[0057] FIG. 6 is a diagram showing a display screen of the numerical control device 5 when setting the upper limit value of the vibration acceleration in the vibration control operation, and is a diagram showing the case of varying the vibration amplitude with respect to a predetermined vibration frequency. As shown in FIG. 6, it is also possible to set the vibration frequency as a fixed value and change the vibration amplitude stepwise, gradually, or continuously. In this case, since the trial operation of the machine tool is automatically performed continuously while changing the control parameters, the setting of the range of the control parameters is easier. Note that it is also possible to set the vibration amplitude as a fixed value and change the vibration frequency stepwise, gradually, or continuously.

[0058] FIG. 7 is a diagram showing a display screen of the numerical control device 5 when setting the upper limit value of the acceleration in the positioning control operation, and is a diagram showing the input of the feed rate and the acceleration / deceleration time constant. Further, FIG. 8 is a diagram showing a display screen of the numerical control device 5 when setting the upper limit value of the acceleration in the positioning control operation, and is a diagram showing the setting of the upper limit value of the acceleration based on the feed rate and the acceleration / deceleration time constant.

[0059] As shown in FIG. 7, first, as a preliminary preparation for performing the positioning control operation, in order to set the upper limit value of the acceleration, the operator inputs the feed rate and the acceleration / deceleration time constant as control parameters. The procedure for inputting and setting these control parameters is as described above.

[0060] Then, under the conditions of the set feed rate and acceleration / deceleration time constant, a trial operation (dry machining) of the machine tool is executed. A plurality of feed rates and acceleration / deceleration time constants are input as control parameters, and the trial operation is executed for each set value.

[0061] As a result of the trial operation, when the operator determines that the vibration of the entire machine tool reaches the upper limit and the malfunction due to vibration exceeds the allowable range, as shown in FIG. 8, the operator touches the acceleration upper limit value setting displayed on the positioning operation control parameter setting tool screen of the CNC 5 as the trigger input unit 22. Then, the trigger reception unit 18 receives the trigger from the trigger input unit 22, and the acceleration is calculated from the feed rate and the acceleration / deceleration time constant set during the trial operation. At the same time, it is displayed as the acceleration upper limit on the positioning operation control parameter setting tool screen of the CNC 5 and set as the vibration acceleration upper limit value.

[0062] In addition, when the operator determines that the malfunction due to vibration exceeds the allowable range, the upper limit value of the feed rate and the upper limit value of the acceleration / deceleration time constant may be set from the feed rate and the acceleration / deceleration time constant set at that time.

[0063] According to this embodiment, the following effects are achieved.

[0064] The control device 1 of the machine tool according to this embodiment includes a control parameter setting unit 11 that sets control parameters, an axis motion control unit 15 that operates an axis based on the control parameters, and a trigger reception unit 18 that receives a trigger during the axis motion by the axis motion control unit 15. Further, the control parameter setting unit 11 has a specifiable range setting unit 13 that sets the specifiable range of the control parameters in response to the trigger reception unit 18 receiving the trigger, and sets the control parameters based on the specifiable range.

[0065] Conventionally, since the trial operation of a machine tool and the setting of the range of control parameters were not coordinated as a system, when it was determined that the trial operation at a certain time corresponded to the upper or lower limit of vibration, after the trial operation ended, it was necessary to separately set the upper and lower limit values of the control parameters, which was very troublesome. On the other hand, according to this embodiment, the specifiable range of control parameters can be easily set in response to a trigger received during the trial operation of the machine tool or during the axis movement during the operation of the machining program. Therefore, based on the specifiable range, appropriate control parameters can be easily set while suppressing problems caused by the vibration of the machine tool, and the work burden on the operator can be reduced.

[0066] Further, the control device 1 of the machine tool according to this embodiment further includes an operation state acquisition unit 16 that acquires state information of the axis movement. The specifiable range setting unit 13 has an operation state specifiable range setting unit 14 that sets an operation state specifiable range that can be made operable by the axis movement control unit 15 based on the state information of the axis movement acquired by the operation state acquisition unit 16, and sets the specifiable range of the control parameters based on the operation state specifiable range. Thereby, based on the operation state specifiable range of the control parameters set based on the state information of the axis movement such as vibration acceleration, the specifiable range of the control parameters can be easily set. Therefore, based on the specifiable range, appropriate control parameters can be easily set while suppressing problems caused by the vibration of the machine tool.

[0067] Also, in this embodiment, the specifiable range setting unit 13 sets the specifiable range of at least one of the vibration frequency and vibration amplitude of the moving axis. Thereby, by setting the specifiable range of at least one of the vibration frequency and vibration amplitude, based on the specifiable range, appropriate control parameters such as the vibration frequency and vibration amplitude can be easily set while more reliably suppressing problems caused by the vibration of the machine tool.

[0068] Also, in the present embodiment, the operation state available range setting unit 14 sets at least one of the vibration speed upper limit, vibration acceleration upper limit, and vibration jerk upper limit of the operation axis as the operation state available range. By doing so, by setting at least one of the vibration speed upper limit, vibration acceleration upper limit, and vibration jerk upper limit of the operation axis as the operation state available range, it is possible to more reliably suppress problems caused by the vibration of the machine tool and easily set appropriate control parameters.

[0069] Also, in the present embodiment, the operation state acquisition unit 16 acquires the state information of the axis operation by performing a predetermined calculation from the control parameters set by the control parameter setting unit 11. Further, the operation state acquisition unit 16 acquires the state information of the axis operation from the detection signal of the sensor 4 provided in the machine tool.

[0070] Conventionally, for example, when an operator performs a trial operation of a machine tool, visually checks the vibration of the entire machine tool, and determines that a certain trial operation motion corresponds to the upper or lower limit of vibration, the vibration acceleration at that time is calculated from the vibration frequency and vibration amplitude, or obtained from a sensor such as an encoder, thereby setting the upper and lower limits of the vibration acceleration. Such work was very laborious. However, according to the present embodiment, since the operation state acquisition unit 16 can acquire the upper and lower limits of the vibration acceleration, etc., based on the acquired upper and lower limits of the vibration acceleration, etc., it is possible to easily set the available range and the specifiable range of the control parameters of the control parameters.

[0071] Also, in the present embodiment, the specifiable range setting unit 13 sets the specifiable range of the control parameters based on the control parameters set by the control parameter setting unit 11 when the trigger reception unit 18 receives a trigger. Further, the specifiable range setting unit 13 sets the specifiable range of the control parameters based on the control parameters stored in the control parameter setting history storage unit 17 that stores the control parameters set by the control parameter setting unit 11 in the past.

[0072] Conventionally, for example, when an operator performs a trial operation of a machine tool, visually checks the vibration of the entire machine tool, and determines that a certain trial operation motion corresponds to the upper limit or lower limit of vibration, etc., it is necessary to input and set the vibration acceleration, etc. at that time again as the upper limit or lower limit of the vibration acceleration, etc. Further, when it is determined that the previous or the operation of the trial operation before the previous time corresponds to the upper limit or lower limit of vibration, etc., the operator has to remember the vibration acceleration, etc. at the previous or the operation of the trial operation before the previous time, and input and set it again as the upper limit or lower limit of the vibration acceleration, etc. These operations were very time-consuming. However, according to the present embodiment, based on the control parameters set by the control parameter setting unit 11 when the trigger reception unit 18 receives a trigger, or the control parameters stored in the control parameter setting history storage unit 17, the specifiable range of the control parameters can be easily set.

[0073] Also, in the present embodiment, the control parameter setting unit 11 sets the control parameters by continuously changing them. Conventionally, when setting appropriate control parameters while suppressing defects caused by the vibration of the machine tool, it was necessary to reset and try several patterns of control parameters during the trial operation of the machine tool. Such operations were very time-consuming. However, according to the present embodiment, since the control parameters can be set by continuously changing them, the trial operation of the machine tool can be automatically performed continuously while changing the control parameters, so that the range of the control parameters can be easily set.

[0074] Also, in the present embodiment, the axis motion control unit 15 stops the axis motion in response to the trigger reception unit 18 receiving a trigger. Further, the control parameter setting unit 11 changes the set control parameters in response to the trigger reception unit 18 receiving a trigger.

[0075] Conventionally, for example, during the trial operation of a machine tool, if a defect due to vibration exceeds the allowable range, a stop operation or a control parameter change operation is performed. Although the operation at this time should be judged to correspond to the upper and lower limits of vibration, since the trial operation of the machine tool and the setting of the control parameter range were not linked as a system, it was necessary to separately set the control parameter range. Such work was very time-consuming. According to this embodiment, in response to the trigger reception unit 18 receiving a trigger, the axis movement can be automatically stopped. Further, according to this embodiment, in response to the trigger reception unit 18 receiving a trigger, it is possible to automatically change to a control parameter that can eliminate defects due to vibration more than the control parameter set at that time.

[0076] Also, in this embodiment, the trigger reception unit 18 receives a trigger in response to the detection signal of the sensor 4 provided in the machine tool. Thereby, compared with the conventional situation where the operator visually confirmed the vibration of the entire machine tool, the upper and lower limits of vibration can be grasped more accurately regardless of the skill level of the operator. In particular, it is not easy to detect the lower limit of vibration by visual inspection by the operator, but according to this embodiment, the lower limit of vibration can be accurately and easily detected by the sensor 4. Therefore, according to this embodiment, the control parameter range can be set more accurately and easily.

[0077] The control system 10 of the machine tool according to this embodiment includes a control device 1 of the machine tool, and an input device 2 having a control parameter input unit 21 for inputting a set value of a control parameter and a trigger input unit 22 for inputting a trigger. Thereby, in response to a trigger received from the trigger input unit 22 during the trial operation of the machine tool or during the axis movement during the processing program operation, the control parameter input by the operator to the control parameter input unit 21 can be easily set.

[0078] Note that the present disclosure is not limited to the above aspects, and modifications and improvements within the scope that can achieve the object of the present disclosure are included in the present disclosure.

[0079] For example, in the above embodiment, the present disclosure is applied to vibration cutting, but it is not limited thereto. It can also be applied to a control device of a machine tool that controls the processing of a workpiece by controlling the axial movement while vibrating the operating axis, such as crank pin processing, and the same effects as those of the above embodiment can be obtained.

Explanation of Reference Numerals

[0080] 1 Control device of machine tool 2 Input device 3 Motor 4 Sensor 5 Numerical control device 6 External computer 10 Control system of machine tool 11 Control parameter setting unit 12 Set value storage unit 13 Specifiable range setting unit 14 Operable range setting unit for operating state 15 Axis movement control unit 16 Operating state acquisition unit 17 Control parameter setting history storage unit 18 Trigger reception unit 21 Control parameter input unit 22 Trigger input unit

Claims

1. A control device for a machine tool that controls a machine tool, comprising: a control parameter setting unit that sets control parameters; an axis movement control unit that moves an axis based on the control parameters; a trigger reception unit that receives a trigger during axis movement by the axis movement control unit, wherein the control parameter setting unit has a specifiable range setting unit that sets a specifiable range of the control parameters based on the control parameters set by the control parameter setting unit before receiving the trigger in response to the trigger reception unit receiving the trigger, and sets the control parameters based on the specifiable range. A control device for a machine tool.

2. The control device for a machine tool according to claim 1, wherein the specifiable range setting unit sets a specifiable range of the control parameters based on the control parameters set by the control parameter setting unit when the trigger reception unit receives the trigger.

3. Further comprising a control parameter setting history storage unit that stores control parameters set by the control parameter setting unit in the past, The control device for a machine tool according to claim 1 or 2, wherein the specifiable range setting unit sets a specifiable range of the control parameters based on the control parameters stored in the control parameter setting history storage unit.

4. A control device for a machine tool that controls a machine tool, comprising: a control parameter setting unit that sets control parameters; an axis movement control unit that moves an axis based on the control parameters; a trigger reception unit that receives a trigger during axis movement by the axis movement control unit; an operation state acquisition unit that acquires state information of the axis movement, wherein the control parameter setting unit has a specifiable range setting unit that sets a specifiable range of the control parameters, and sets the control parameters based on the specifiable range; the specifiable range setting unit has an operation state specifiable range setting unit that sets an operation state specifiable range that can be operated by the axis movement control unit based on the state information of the axis movement acquired by the operation state acquisition unit in response to the trigger reception unit receiving the trigger, and sets the specifiable range of the control parameters based on the operation state specifiable range; The control device for a machine tool, wherein the trigger reception unit receives a trigger from state information of an axis movement different from the state information of the axis movement acquired by the operation state acquisition unit or from input information of an operator.

5. The operating state possible range setting unit sets, as the operating state possible range, at least one of the vibration speed upper limit, vibration acceleration upper limit, and vibration jerk upper limit of the operating axis, for the control device of a machine tool according to claim 4.

6. The operating state acquisition unit acquires state information of the axis movement by performing a predetermined calculation from the control parameters set by the control parameter setting unit, for the control device of a machine tool according to claim 4 or 5.

7. The operating state acquisition unit acquires state information of the axis movement by performing a predetermined calculation from the control parameters set by the control parameter setting unit when the trigger reception unit receives the trigger, for the control device of a machine tool according to claim 6.

8. It further includes a control parameter setting history storage unit that stores the control parameters set by the control parameter setting unit, The operating state acquisition unit acquires state information of the axis movement by performing a predetermined calculation from the control parameters stored in the control parameter setting history storage unit, for the control device of a machine tool according to claim 6.

9. The operating state acquisition unit acquires state information of the axis movement from the detection signal of a sensor provided on the machine tool, for the control device of a machine tool according to claim 4 or 5.

10. The specifiable range setting unit sets a specifiable range of at least one of the vibration frequency and vibration amplitude of the operating axis, for the control device of a machine tool according to any one of claims 1 to 9.

11. The control parameter setting unit sets the control parameters by continuously changing them, for the control device of a machine tool according to any one of claims 1 to 10.

12. The axis movement control unit stops the axis movement in response to the trigger reception unit receiving the trigger, for the control device of a machine tool according to any one of claims 1 to 11.

13. The control parameter setting unit changes the set control parameters in response to the trigger reception unit receiving the trigger, for the control device of a machine tool according to any one of claims 1 to 12.

14. The trigger reception unit receives the trigger in response to the detection signal of a sensor provided on the machine tool, for the control device of a machine tool according to any one of claims 1 to 13.

15. The control device of a machine tool according to any one of claims 1 to 14, and A control system for a machine tool, comprising: an input device having a control parameter input unit for inputting a set value of the control parameter and a trigger input unit for inputting the trigger.

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