Numerical Control Device

Abstract

This numerical control device comprises: a control unit that interprets a machining program including tool information for identifying a tool to control the shaft of a machine tool; a feedback information acquisition unit that acquires, from the machine tool, feedback information indicating the position of the shaft; a tool replacement information acquisition unit that acquires the tool information from the machining program and acquires, from the machine tool, replacement information indicating that the tool has been replaced; a synthesized information generation unit that generates synthesized information by synthesizing the feedback information acquired by the feedback information acquisition unit with the tool information and replacement information acquired by the tool replacement information acquisition unit; a shape information storage unit that stores shape information indicating the shape of the tool; a machining simulation unit that executes workpiece machining simulation on the basis of the synthesized information and the shape information; and an output unit that outputs machining shape information indicating the shape of machined workpiece generated by executing workpiece machining simulation.

Description

[Technical field]

[0001] The present disclosure relates to a numerical control device for a machine tool. [Background technology]

[0002] Conventionally, in a numerical control device, a machining simulation is performed using feedback information from a servo motor, taking into consideration the effect on the machined surface quality of vibrations of a machine tool caused by the acceleration and jerk of the drive axis (Patent Document 1). By using the feedback information, a machining simulation that reflects the actual axis movements of the machine tool can be performed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-71734 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the feedback information acquired from the servo motor does not include information regarding tool replacement, so if the feedback information is used, it is not possible to perform a machining simulation including a simulation of tool replacement.

[0005] On the other hand, it is possible to perform a simulation of a tool change based on a tool change command included in a machining program. However, there is a discrepancy between the timing at which a tool change command is issued and the timing at which the tool change is actually performed by the machine tool. Therefore, it is not possible to incorporate a simulation of a tool change into a simulation performed based on feedback information in a timely manner.

[0006] An object of the present disclosure is to provide a numerical control device capable of executing a machining simulation by incorporating a simulation of tool replacement in a timely manner into a simulation performed based on feedback information. [Means for solving the problem]

[0007] The numerical control device includes a control unit that interprets a machining program including tool information that identifies a tool and controls the axes of the machine tool, a feedback information acquisition unit that acquires feedback information indicating the positions of the axes from the machine tool, and a feedback information acquisition unit that acquires the tool information from the machining program and detects that the tool has been replaced. of the feedback information acquired by the feedback information acquisition unit and the tool information and exchange information acquired by the tool exchange information acquisition unit to generate synthetic information; a shape information storage unit to store shape information indicating the shape of the tool; a machining simulation unit to execute a machining simulation of the workpiece based on the synthetic information and the shape information; and an output unit to output machining shape information indicating the shape of the workpiece after machining, generated by executing the machining simulation. Effect of the Invention

[0008] An object of one aspect of the present disclosure is to provide a numerical control device capable of executing a machining simulation by incorporating a simulation of tool replacement in a timely manner into a simulation performed based on feedback information. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a block diagram showing an example of a hardware configuration of a machine tool. [Diagram 2] FIG. 2 is a diagram illustrating an example of a function of a numerical control device. [Diagram 3] FIG. 4 is a diagram showing an example of a machining program. [Figure 4]FIG. 11 is a diagram illustrating an example of composition information. [Diagram 5] FIG. 11 is a diagram illustrating an example of shape information. [Figure 6A] FIG. 13 is a diagram illustrating an example of a processing simulation. [Figure 6B] FIG. 13 is a diagram illustrating an example of a processing simulation. [Figure 6C] FIG. 13 is a diagram illustrating an example of a processing simulation. [Figure 7] FIG. 2 is a diagram illustrating an example of a flow of processing executed by a numerical control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that not all combinations of features described in the following embodiments are necessarily required to solve the problem. In addition, unnecessary detailed description may be omitted. In addition, the following description of the embodiments and the drawings are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the scope of the claims.

[0011] 1 is a block diagram showing an example of a hardware configuration of a machine tool equipped with a numerical control device. The machine tool 1 includes a lathe, a machining center, and a multi-tasking machine.

[0012] The machine tool 1 includes a numerical control device 2, an input / output device 3, a servo amplifier 4, a servo motor 5, a spindle amplifier 6, a spindle motor 7, and auxiliary equipment 8.

[0013] The numerical control device 2 is a device that controls the entire machine tool 1. The numerical control device 2 includes a hardware processor 201, a bus 202, a ROM (Read Only Memory) 203, a RAM (Random Access Memory) 204, and a non-volatile memory 205.

[0014] The hardware processor 201 is a processor that controls the entire numerical control device 2 in accordance with a system program. The hardware processor 201 reads out the system program stored in the ROM 203 via the bus 202, and performs various processes based on the system program. The hardware processor 201 controls the servo motor 5 and the spindle motor 7 based on the machining program. The hardware processor 201 is, for example, a CPU (Central Processing Unit) or an electronic circuit.

[0015] The hardware processor 201 performs, for example, analysis of a machining program and outputs control commands to the servo motor 5 and the spindle motor 7 for each control period.

[0016] The bus 202 is a communication path that connects each piece of hardware in the numerical control device 2 to each other. The pieces of hardware in the numerical control device 2 exchange data via the bus 202.

[0017] The ROM 203 is a storage device that stores a system program for controlling the entire numerical control device 2. The ROM 203 is a computer-readable storage medium.

[0018] The RAM 204 is a storage device that temporarily stores various data and functions as a working area for the hardware processor 201 to process various data.

[0019] The non-volatile memory 205 is a storage device that retains data even when the machine tool 1 is turned off and power is not being supplied to the numerical control device 2. The non-volatile memory 205 stores, for example, a machining program and various parameters. The non-volatile memory 205 is a computer-readable storage medium. The non-volatile memory 205 is configured, for example, by a memory backed up by a battery or an SSD (Solid State Drive).

[0020] The numerical control device 2 further includes an interface 206 , an axis control circuit 207 , a spindle control circuit 208 , a PLC (Programmable Logic Controller) 209 , and an I / O unit 210 .

[0021] The interface 206 connects the bus 202 and the input / output device 3. The interface 206 sends, for example, various data processed by the hardware processor 201 to the input / output device 3.

[0022] The input / output device 3 is a device that receives various data via the interface 206 and displays the various data. The input / output device 3 also receives input of various data and sends the various data to the hardware processor 201 via the interface 206. The input / output device 3 is, for example, a touch panel. When the input / output device 3 is a touch panel, the touch panel is, for example, a capacitive touch panel. Note that the touch panel is not limited to a capacitive touch panel and may be a touch panel of another type. The input / output device 3 is, for example, installed in an operation panel (not shown) in which the numerical control device 2 is housed.

[0023] The axis control circuit 207 is a circuit that controls the servo motor 5. The axis control circuit 207 receives a control command from the hardware processor 201 and outputs various commands for driving the servo motor 5 to the servo amplifier 4. The axis control circuit 207 sends, for example, a torque command for controlling the torque of the servo motor 5 to the servo amplifier 4.

[0024] The servo amplifier 4 receives a command from the axis control circuit 207 and supplies a current to the servo motor 5 .

[0025] The servo motor 5 is driven by receiving a current supply from the servo amplifier 4. The servo motor 5 is connected to, for example, a ball screw that drives a tool post. When the servo motor 5 is driven, the structure of the machine tool 1, such as the tool post, moves in each axial direction. The servo motor 5 has a built-in encoder (not shown) that detects the position and speed of the axis, and feedback information on the position and speed from this encoder is fed back to the axis control circuit 207 to perform feedback control of the position and speed.

[0026] The servo motors 5 are provided for each axis. That is, the servo motors 5 include a servo motor for the X-axis, a servo motor for the Y-axis, and a servo motor for the Z-axis. The servo motors 5 may further include a servo motor for the A-axis, a servo motor for the B-axis, and a servo motor for the C-axis. The axis control circuits 207 and the servo amplifiers 4 are provided for each axis.

[0027] The spindle control circuit 208 is a circuit for controlling the spindle motor 7. The spindle control circuit 208 receives a control command from the hardware processor 201 and outputs a command for driving the spindle motor 7 to the spindle amplifier 6. The spindle control circuit 208 sends, for example, a spindle speed command for controlling the rotation speed of the spindle motor 7 to the spindle amplifier 6.

[0028] The spindle amplifier 6 receives a command from a spindle control circuit 208 and supplies a current to the spindle motor 7 .

[0029] The spindle motor 7 is driven by receiving a current supply from the spindle amplifier 6. The spindle motor 7 is connected to a main shaft and rotates the main shaft.

[0030] The PLC 209 is a device that executes a ladder program to control the auxiliary device 8. The PLC 209 sends commands to the auxiliary device 8 via the I / O unit 210.

[0031] The I / O unit 210 is an interface that connects the PLC 209 and the auxiliary device 8. The I / O unit 210 transmits commands received from the PLC 209 to the auxiliary device 8.

[0032] The auxiliary device 8 is installed in the machine tool 1 and performs auxiliary operations in the machine tool 1. The auxiliary device 8 operates based on commands received from the I / O unit 210. The auxiliary device 8 may be a device installed in the periphery of the machine tool 1. The auxiliary device 8 is, for example, a tool changer, a cutting fluid ejection device, or an opening / closing door drive device.

[0033] Next, the function of the numerical control device 2 will be described. The numerical control device 2 moves each axis by controlling the servo motor 5. The numerical control device 2 also rotates the spindle motor 7. In this way, the numerical control device 2 performs machining of the workpiece. The numerical control device 2 also executes a machining simulation based on feedback information.

[0034] The feedback information is, for example, information acquired from the servo motor 5. The information acquired from the servo motor 5 is information indicating the position of the axis. For example, the feedback information acquired from the X-axis servo motor is information indicating the position of the X-axis. Moreover, the feedback information acquired from the Y-axis servo motor is information indicating the position of the Y-axis.

[0035] 2 is a block diagram showing an example of functions of the numerical control device 2. The numerical control device 2 includes a program storage unit 21, a control unit 22, a feedback information acquisition unit 23, a tool exchange information acquisition unit 24, a synthesis information generation unit 25, a shape information storage unit 26, a machining simulation unit 27, and an output unit 28.

[0036] The program storage unit 21 and the shape information storage unit 26 are realized by storing the machining program inputted from the input / output device 3 or the like and the shape information indicating the shape of the tool in the RAM 204 or the non-volatile memory 205.

[0037] The control unit 22, the feedback information acquisition unit 23, the tool exchange information acquisition unit 24, the synthesis information generation unit 25, the machining simulation unit 27, and the output unit 28 are realized, for example, by the hardware processor 201 performing arithmetic processing using a system program stored in the ROM 203 and various data stored in the non-volatile memory 205.

[0038] The program storage unit 21 stores machining programs. The machining programs include at least one of a turning program and a milling program. The machining programs include commands that specify a tool movement path. The commands that specify the tool movement path are, for example, a positioning command, a linear interpolation command, and a circular interpolation command. The machining programs also include tool information that specifies a tool used for machining. The tool information is, for example, information indicating a tool number included in a tool selection command.

[0039] FIG. 3 is a diagram showing an example of a machining program. The T code written in the block with sequence number N11 is a tool selection command. That is, command "T01" is a command to select the tool with tool number 1. Also, command "M06" is a command to execute tool change. Therefore, the block with sequence number N11 specifies that the tool should be changed to the tool with tool number 1.

[0040] The command "G00" written in the block with sequence number N12 is a positioning command. Also, "X100.Y100." is a command that specifies the position where the tool is to be positioned. Therefore, the block with sequence number N12 specifies that the tool is to be positioned at the position X100, Y100. Also, the block with sequence number N13 specifies that the tool is to be positioned at the position Z3.

[0041] The command "G01" written in the block with sequence number N14 is a linear interpolation command. Also, "Z-2.8" is a command that specifies the destination of the tool. Also, the F code is a command that specifies the feed speed of the tool. In other words, the block with sequence number N14 specifies that the tool is to be moved to the position of Z-2.8 at a feed speed of 500 [mm / min] by linear interpolation. The block with sequence number N15 specifies that the tool is to be moved to the position of X120, Y120 by linear interpolation.

[0042] In the block with sequence number N21, it is specified that the tool is changed to the tool with tool number 2.

[0043] The block with sequence number N22 specifies that the tool is to be positioned at the position X100, Y100. Also, the block with sequence number N23 specifies that the tool is to be positioned at the position Z3.

[0044] In the block of sequence number N24, it is specified that the tool is moved to the position Z-3 by linear interpolation at a feed rate of 250 [mm / min]. In the block of sequence number N25, it is specified that the tool is moved to the position X120, Y120 by linear interpolation. The machining program ends, for example, when an end-of-program command M30 is specified. Now, we return to the explanation of FIG. 2.

[0045] Control unit 22 interprets a machining program including tool information that identifies a tool, and controls the axes of machine tool 1. The axes of machine tool 1 include an X-axis, a Y-axis, and a Z-axis. Control unit 22 interprets, for example, a machining program shown in Fig. 3 and controls each axis. This causes the tool to move along a movement path specified in the machining program.

[0046] The feedback information acquisition unit 23 acquires feedback information indicating the positions of the axes from the machine tool 1. The feedback information is time-series data. In other words, the feedback information is data indicating the movement path of the tool.

[0047] When the feedback information acquisition unit 23 acquires the feedback information, the workpiece may not be processed. In other words, the feedback information may be acquired in a state where no workpiece is placed on the workpiece gripping unit. Alternatively, when the feedback information acquisition unit 23 acquires the feedback information, the workpiece may be processed. In other words, the feedback information may be acquired in a state where a workpiece is placed on the workpiece gripping unit.

[0048] The feedback information acquisition unit 23 acquires information indicating the position of each axis for each predetermined control period. For example, the feedback information acquisition unit 23 acquires feedback information indicating the positions of the X-axis, Y-axis, and Z-axis within one control period. One control period is, for example, several milliseconds.

[0049] Feedback information acquisition unit 23 acquires feedback information (feedback information includes information indicating at least one of the position, speed, and acceleration of the motor) from a servo motor that drives each axis of machine tool 1. Alternatively, feedback information may be acquired from, for example, a linear encoder installed along each linear axis of machine tool 1, or from a rotary encoder installed around each rotation axis.

[0050] The tool replacement information acquisition unit 24 acquires tool information from the machining program and detects that the tool has been replaced. of The tool exchange information acquiring unit 24 acquires, for example, tool information stored in a predetermined register (not shown) by the control unit 22 that has interpreted the machining program. As described above, the tool information is information indicating the tool number included in the tool selection command.

[0051] The change information is information indicating that the tool change is complete. Completion of the tool change means that the tool specified in the machining program is attached to the tool spindle, and the axis can be moved. The information indicating that the tool change is complete is, for example, a signal output from a proximity switch installed at a predetermined position.

[0052] The composite information generating unit 25 generates composite information by combining the feedback information acquired by the feedback information acquiring unit 23 and the tool information and replacement information acquired by the tool replacement information acquiring unit 24 .

[0053] The synthetic information generating unit 25 generates synthetic information by matching a time axis related to the acquisition of feedback information with a time axis related to the acquisition of replacement information. Matching the time axes means matching the timing. For example, the feedback information acquiring unit 23 and the tool replacement information acquiring unit 24 each acquire feedback information and replacement information within one control cycle. The synthetic information generating unit 25 matches the time axes by combining the feedback information and replacement information acquired within one control cycle. This allows the synthetic information generating unit 25 to generate information indicating the position of each axis when tool replacement is completed.

[0054] 4 is a diagram illustrating an example of the combined information, which is time-series data that combines feedback information, replacement information, and tool information.

[0055] The composite information No. 1 includes feedback information. The feedback information includes data "X1, Y1, Z1" indicating the positions of the X-axis, Y-axis, and Z-axis, respectively. Furthermore, the composite information No. 1 does not include replacement information or tool information. In this case, in the control cycle in which the feedback information acquisition unit 23 acquires the feedback information No. 1, the tool replacement information acquisition unit 24 does not acquire the replacement information.

[0056] The composite information No. 2 includes feedback information. The feedback information includes data "X2, Y2, Z2" indicating the positions of the X-axis, Y-axis, and Z-axis, respectively. The composite information No. 2 also includes replacement information "completed" and tool information "T01." In this case, in the control cycle in which the feedback information acquisition unit 23 acquires the feedback information No. 2, the tool replacement information acquisition unit 24 acquires the replacement information.

[0057] The composite information of No. 3 includes feedback information. The feedback information includes data "X3, Y3, Z3" that indicate the positions of the X-axis, Y-axis, and Z-axis, respectively. In addition, the composite information of No. 3 does not include replacement information or tool information.

[0058] The composite information of No. 4 includes feedback information. The feedback information includes data "X4, Y4, Z4" that indicate the positions of the X-axis, Y-axis, and Z-axis, respectively. In addition, the composite information of No. 4 does not include replacement information or tool information.

[0059] The composite information of No. n includes feedback information. The feedback information includes data "Xn, Yn, Zn" indicating the positions of the X-axis, Y-axis, and Z-axis, respectively. The composite information of No. n also includes replacement information "completed" and tool information "T02." In this case, in the control cycle in which the feedback information acquisition unit 23 acquires the feedback information of No. n, the tool replacement information acquisition unit 24 acquires the replacement information.

[0060] The composite information of No. n+1 includes feedback information. The feedback information includes data "Xn+1, Yn+1, Zn+1" indicating the positions of the X-axis, Y-axis, and Z-axis, respectively. In addition, the composite information of No. n+1 does not include replacement information or tool information. Here, we return to the explanation of FIG. 2.

[0061] The shape information storage unit 26 stores shape information indicating the shape of a tool. The shape information includes, for example, information indicating the tool type, cutting edge diameter, cutting edge length, shank diameter, and overall length.

[0062] 5 is a diagram showing an example of shape information. Tool number 1 stores shape information of a tool whose type is a flat end mill, whose cutting diameter is D6.0 [mm], whose cutting length is 12 [mm], whose shank diameter is 6 [mm], and whose overall length is 55 [mm].

[0063] Shape information of a tool with a ball end mill type, a cutting edge diameter of R1.0 [mm], a cutting edge length of 4 [mm], a shank diameter of 4 [mm], and a total length of 60 [mm] is stored for tool number 2. Furthermore, shape information of tools with tool numbers 3 and onward may also be stored.

[0064] The machining simulation unit 27 executes a machining simulation of the workpiece based on the synthesis information and the shape information. The machining simulation unit 27 may execute the machining simulation further using workpiece shape information indicating the shape of the workpiece. In this case, the shape information storage unit 26 may store the workpiece shape information indicating the shape of the workpiece. When the machining simulation unit 27 executes the simulation using the workpiece shape information, the machining simulation unit 27 draws, for example, the workpiece W before machining as shown in FIG. 6A.

[0065] The machining simulation unit 27 draws the position of the tool based on the data indicating the position of each axis included in the synthesis information. When the machining simulation unit 27 executes a machining simulation based on the synthesis information shown in Fig. 4, for example, the machining simulation unit 27 first draws the tool at the position (X1, Y1, Z1) indicated by the feedback information No. 1. The tool drawn at this time is, for example, the tool last used in the previous machining simulation.

[0066] Next, the machining simulation unit 27 draws a tool at the position (X2, Y2, Z2) indicated by the feedback information of No. 2. The machining simulation unit 27 also draws a tool change at this position. That is, the machining simulation unit 27 draws a tool change to the tool with tool number 1. When the shape information storage unit 26 stores, for example, the shape information shown in Fig. 5, the machining simulation unit 27 draws a tool change to a flat end mill.

[0067] Next, the machining simulation unit 27 draws the tool at the position (X3, Y3, Z3) indicated by the feedback information No. 3. Next, the machining simulation unit 27 draws the tool at the position (X4, Y4, Z4) indicated by the feedback information No. 4. The machining simulation unit 27 performs such processing sequentially based on the synthesis information and shape information to perform a machining simulation including a simulation of tool replacement. The machining simulation unit 27 draws the result of the machining simulation performed using the tool with tool number 1, for example, as shown in FIG. 6B.

[0068] Similarly, the machining simulation unit 27 draws a tool at the position (Xn, Yn, Zn) indicated by the feedback information of No. n. The machining simulation unit 27 also draws a tool change at this position. That is, the machining simulation unit 27 draws a tool change from the flat end mill with tool number 1 to the ball end mill with tool number 2.

[0069] Next, the machining simulation unit 27 draws the tool at the position (Xn+1, Yn+1, Zn+1) indicated by the feedback information of No. n+1. When the machining simulation using the tool with tool number 2 is completed, the machining simulation unit 27 draws the result of executing the machining simulation using the tool with tool number 2, for example, as shown in FIG. 6C.

[0070] The output unit 28 outputs machining shape information indicating the shape of the workpiece W after machining, which is generated by executing the machining simulation. The output unit 28 may output not only the shape of the workpiece W after machining, but also information indicating the shape of the workpiece during machining, which is drawn by the machining simulation unit 27, and the operation of the tool. The output unit 28 outputs the machining shape information to, for example, a display screen of the input / output device 3.

[0071] Next, the flow of processing executed by the numerical control device 2 will be described.

[0072] FIG. 7 is a diagram illustrating an example of the flow of processing executed by the numerical control device 2.

[0073] In the numerical control device 2, first, the control unit 22 interprets the machining program and controls the axes of the machine tool 1 (step S1).

[0074] Next, the feedback information acquisition unit 23 acquires feedback information indicating the position of each axis (step S2).

[0075] Next, the tool replacement information acquisition unit 24 acquires the tool information and replacement information (step S3).

[0076] Next, the synthesis information generating unit 25 synthesizes the feedback information, the tool information, and the replacement information to generate synthesis information (step S4).

[0077] Next, the machining simulation unit 27 executes a machining simulation based on the synthesis information and shape information indicating the shape of the tool (step S5).

[0078] Next, the output unit 28 outputs machined shape information indicating the shape of the workpiece W after machining (step S6), and the process ends.

[0079] As described above, the numerical control device 2 includes a control unit 22 that interprets a machining program including tool information that identifies a tool and controls the axes of the machine tool 1, a feedback information acquisition unit 23 that acquires feedback information indicating the positions of the axes from the machine tool 1, and a processing unit 24 that acquires the tool information from the machining program and detects when a tool has been replaced. of the feedback information acquired by the feedback information acquisition unit 23 and the tool information and exchange information acquired by the tool exchange information acquisition unit 24 to generate synthetic information; a shape information storage unit 26 to store shape information indicating the shape of the tool; a machining simulation unit 27 to execute a machining simulation of the workpiece W based on the synthetic information and the shape information; and an output unit 28 to output machining shape information indicating the shape of the workpiece W after machining, generated by executing the machining simulation.

[0080] Therefore, a machining simulation can be executed by incorporating a simulation of tool replacement in a timely manner into a simulation executed based on feedback information.

[0081] Moreover, the synthetic information generating unit 25 generates synthetic information by matching the time axis related to the acquisition of feedback information with the time axis related to the acquisition of replacement information. Therefore, the numerical control device 2 can plot the timing of tool replacement of the tool plotted by the machining simulation unit 27 in accordance with the time axis of the time series data indicating the axis positions.

[0082] Furthermore, the feedback information acquisition unit 23 and the tool replacement information acquisition unit 24 acquire feedback information and replacement information, respectively, from the machine tool 1 within one control cycle. The replacement information is a signal indicating that the tool replacement has been completed. Therefore, the numerical control device 2 can easily align the timing of the tool replacement depicted by the machining simulation unit 27 with the time axis of the time series data indicating the axis positions.

[0083] In the above-described embodiment, the tool exchange information acquisition unit 24 acquires the tool information from the machining program. However, the tool exchange information acquisition unit 24 may acquire the tool information from a device installed in the machine tool 1. For example, an ATC (Automatic Tool Changer) mounted on the machine tool 1 has information indicating a tool number. Therefore, the tool exchange information acquisition unit 24 may acquire the tool information from the ATC together with the exchange information.

[0084] In the above-described embodiment, the feedback information acquisition unit 23 and the tool replacement information acquisition unit 24 acquire feedback information and replacement information, respectively, within one control cycle. However, as long as the synthesis information generation unit 25 can match the time axis related to the acquisition of feedback information with the time axis related to the acquisition of replacement information, it is not necessary that the feedback information and the replacement information are acquired within one control cycle.

[0085] For example, the feedback information acquisition unit 23 acquires information about the time when the feedback information is acquired together with the feedback information. The information about the time when the feedback information is acquired is given by, for example, a timestamp. Furthermore, the tool replacement information acquisition unit 24 acquires information about the time when the replacement information is acquired together with the replacement information. In this case, the synthesis information generation unit 25 can match the time axes of both based on the time information indicated by the timestamp and synthesize the feedback information and the replacement information.

[0086] The numerical control device 2 may further include a path error calculation unit. The path error calculation unit calculates the difference between the tool movement path calculated based on the commands of the machining program and the tool movement path indicated by the feedback information.

[0087] The output unit 28 outputs the difference between the movement paths calculated by the path error calculation unit, thereby enabling the operator to easily confirm the difference between the tool movement path specified in the machining program and the tool movement path when each axis of the machine tool 1 is actually operated.

[0088] In addition, the present disclosure is not limited to the above-described embodiment, and can be appropriately modified without departing from the spirit and scope of the present disclosure. In the present disclosure, any of the components of the embodiment can be modified or omitted. [Explanation of symbols]

[0089] 1 Machine tools 2. Numerical control device 201 Hardware Processor 202 Bus 203 ROM 204 RAM 205 Non-volatile memory 206 Interface 207 Axis control circuit 208 Spindle control circuit 209 PLC 210 I / O Unit 21 Program memory section 22 Control section 23 Feedback information acquisition unit 24 Tool exchange information acquisition section 25 Synthesis information generation section 26 Shape information storage section 27 Machining Simulation Department 28 Output section 3 Input / Output Devices 4 Servo Amplifier 5. Servo motor 6 Spindle Amplifier 7 Spindle motor 8 Auxiliary equipment W work

Claims

1. a control unit that interprets a machining program including tool information that identifies a tool and controls an axis of the machine tool; a feedback information acquisition unit that acquires feedback information indicating a position of the axis from the machine tool; a tool replacement information acquisition unit that acquires the tool information from the machining program and acquires replacement information indicating that the tool has been replaced from the machine tool; a synthetic information generating unit that generates synthetic information by synthesizing the feedback information acquired by the feedback information acquiring unit and the tool information and the replacement information acquired by the tool replacement information acquiring unit; A shape information storage unit that stores shape information indicating a shape of the tool; a machining simulation unit that executes a machining simulation of a workpiece based on the synthesis information and the shape information; an output unit that outputs machining shape information indicating a shape of a workpiece after machining generated by executing the machining simulation; A numerical control device comprising:

2. The numerical control device according to claim 1 , wherein the synthetic information generating unit generates the synthetic information by matching a time axis related to acquisition of the feedback information with a time axis related to acquisition of the exchange information.

3. The numerical control device according to claim 2 , wherein the feedback information acquisition section and the tool exchange information acquisition section acquire the feedback information and the tool exchange information, respectively, from the machine tool within one control cycle.

4. 4. The numerical control device according to claim 1, wherein the replacement information is a signal indicating that the tool replacement has been completed.

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