JP6517879B2 - Numerical control device - Google Patents

Description

  The present invention relates to a numerical control device, and more particularly to a numerical control device that controls a feed rate based on processing conditions of a cutting tool.

  For cutting using a machine tool, one or more blades are attached to the side surface of the tool, such as a milling tool or end mill tool, such as grooving, free-form surface processing, side processing, inclined surface processing, etc. There is a processing method of cutting a main shaft on which a provided tool is attached in a direction different from the direction of the main shaft (eg, Patent Document 1). For example, in side surface grooving using the end mill tool 2, as shown in FIG. 4, the end mill tool 2 attached to the spindle and rotated is cut and fed in a direction substantially orthogonal to the direction of the spindle Or, as shown in FIG. 5, the groove is machined by cutting and feeding the end mill tool 2 attached to the spindle and rotating in parallel with the surface of the work while cutting into the work. Further, in ramping groove machining using the end mill tool 2, as shown in FIG. 6, the end mill tool 2 attached to the spindle and rotated is cut and fed so as to be inclined to the surface of the work. Form a groove.

  In free-form surface machining using the ball end mill tool 4, as shown in FIG. 7, the ball end mill tool 4 attached to the spindle and rotated is in a direction different from the direction of the spindle (for example, along the target free-form surface) Machining the curved surface by cutting feed in the Further, in side processing using the end mill tool 2, as shown in FIG. 8, the end mill tool 2 attached to the spindle and rotated is cut and fed parallel to the side surface in a state of being cut into the workpiece. Process the

  As described above, cutting tools such as milling tools and end mill tools are mostly provided with one or more blades on the side face of the tool, etc. In the machining method exemplified in the above, when the cutting operation is observed limited to one blade, the blade hits the work by the rotational movement of the spindle (rotational direction of the spindle) and the movement in a direction different from the direction of the spindle. In the case of a tool provided with a plurality of blades, in particular, in the case of a tool provided with a plurality of blades, the machining of the workpiece is carried out by the respective blades striking the workpiece in turn.

  Further, for better understanding, the milling shown in FIG. 9 will be described as an example. In the example of FIG. 9, the milling tool 5 is provided with six blades 6, and the blade 6 is rotated in the main shaft rotational direction M by the rotational movement of the main shaft. In addition, the milling tool 5 is moved in the moving direction Q different from the direction of the spindle by controlling the moving axis of the spindle. Then, when the blade 6 included in the milling tool 5 hits the workpiece 3, the blade 6 slips out of the workpiece 3 while cutting the workpiece 3 by the rotational movement of the spindle and the movement in the moving direction Q different from the direction of the spindle. Go. By continuously performing such an operation, milling of the work 3 using the six blades 6 provided in the milling tool 5 is realized. In such a processing method, the single-edged feed amount D indicating one processing amount per blade 6 provided in the milling tool 5 is the number of the blades 6 provided in the milling tool 5 and the unit time in the spindle rotational direction M Using the rotation speed per contact and the cutting feed rate in the moving direction Q, the following equation 1 can be calculated. In addition, the single blade feed amount can be calculated by the same method by each processing method described above.

  The tool single feed distance is provided with the recommended value set by the tool maker for each tool, and the operator is recommended the feed distance recommended value described in the tool maker's catalog etc., and the processing shape of the work, Set the processing conditions including the cutting feed speed and the spindle speed while considering all factors related to cutting, such as processing accuracy, machine used, rigidity of tooling, etc. Here, if the operator erroneously sets the processing conditions, and as a result, the single-edge feed amount exceeds the recommended value, the processing quality of the workpiece may be reduced, the tool life may be significantly reduced, and the tool may be damaged. There is a case.

JP, 2016-066201, A

  As described above, the operator needs to be aware of the recommended values of the cutting conditions of the tool when determining the feed speed, the spindle rotational speed, etc., but it is not appropriate when creating a new machining program (does not satisfy the recommended values of the cutting conditions) ) There is a possibility of setting processing conditions. In addition, when changing to a tool of the same shape (different coatings, manufacturers) with respect to the existing program, cutting is performed as a result of processing without changing the processing conditions without confirming the recommended value of the cutting conditions of the new tool There is a possibility that processing may not be performed which does not satisfy the recommended value of the condition. Furthermore, if the operator changes the spindle rotational speed before machining, or changes the spindle rotational speed by operating the override etc. during machining, the machining does not satisfy the recommended value of the cutting conditions of the tool. there is a possibility.

  Therefore, an object of the present invention is to provide a numerical control device capable of calculating an optimal feed rate in machining in which cutting is performed in a direction different from the direction of the main shaft.

  The present invention solves the above-mentioned problems by providing the numerical control apparatus with a function of automatically calculating the feed speed from the information on the spindle rotational speed, the single blade feed, and the number of blades.

Then, one aspect of the present invention controls a machine tool provided with a spindle based on a machining program, moves the spindle relative to the workpiece, and performs cutting in a direction different from the direction of the spindle A numerical data control unit for storing a tool data storage unit that stores tool data including at least a recommended value of one blade feed of the tool and a number of blades of the tool related to the tool attached to the spindle, and a command block from the processing program Command analysis unit for generating movement command data for moving the spindle relative to the workpiece, and spindle rotation command data for rotating the spindle, and a tool included in the tool data of the tool one recommended values for blade feed and using at least the number of blades of the tool to calculate the recommended cutting feed speed of the main spindle, the cutting feed speed of the main shaft included in the movement command data for There is greater than the recommended cutting feed rate, and cutting speed controller for clamping in the recommended cutting feed rate cutting feed speed of the main shaft, a numerical control apparatus comprising a.

  According to the present invention, the machining program can be executed at an appropriate cutting feed rate without calculating the cutting feed rate based on the recommended value of the cutting conditions of the tool, and it is assumed when creating the machining program It is possible to use the program without changing the cutting feed rate for tools other than tools (different types, manufacturers). Furthermore, even if the spindle rotational speed is changed, it is not necessary to change the feed speed command. Therefore, the labor and mistakes of the operator can be reduced.

FIG. 1 is a schematic hardware configuration diagram showing a numerical control device according to one embodiment and a main part of a processing machine driven and controlled by the numerical control device. FIG. 2 is a schematic functional block diagram of a numerical control device according to one embodiment. It is a rough flowchart which shows the flow of processing of cutting speed control. It is a figure explaining side groove processing. It is a figure explaining the side groove processing of the work in which the processing surface inclined. It is a figure explaining a ramping groove process. It is a figure explaining free-form surface processing. It is a figure explaining side processing. It is a figure explaining a milling process.

  An example of the configuration of a numerical control device for realizing the present invention will be shown below. However, the configuration of the numerical control device of the present invention is not limited to the following example, and any configuration may be adopted as long as the object of the present invention can be realized.

  FIG. 1 is a schematic hardware configuration diagram showing a numerical control device according to one embodiment and a main part of a processing machine which is driven and controlled by the numerical control device. The CPU 11 included in the numerical control device 1 according to the present embodiment is a processor that controls the numerical control device 1 as a whole. The CPU 11 reads a system program stored in the ROM 12 via the bus 20, and controls the entire numerical control device 1 according to the system program. The RAM 13 stores temporary calculation data and display data, and various data input by the operator via a display / MDI unit 70 described later.

  The non-volatile memory 14 is configured as a memory that retains its storage state even if the power of the numerical control device 1 is turned off, for example, by being backed up by a battery not shown. In addition to the processing program read through the interface 15 and the processing program input through the display / MDI unit 70 described later, the non-volatile memory 14 has recommended values of cutting conditions of tools used for processing. Tool data and the like are stored. The non-volatile memory 14 further stores a processing program operation processing program and the like used to operate the processing program. These programs are expanded on the RAM 13 at the time of execution. In addition, various system programs (including a system program for cutting feed speed calculation) for executing processing of edit mode required for creation and editing of machining program are written in ROM 12 in advance. It is done.

  The interface 15 is an interface for connecting the numerical control device 1 and an external device 72 such as an adapter. A machining program and various parameters are read from the external device 72 side. Also, the processing program edited in the numerical control device 1 can be stored in the external storage means via the external device 72. A PMC (programmable machine controller) 16 is a sequence program built in the numerical control device 1 and signals via I / O unit 17 to peripheral devices of the processing machine (for example, an actuator such as a robot hand for tool change) Output and control. In addition, after receiving signals from various switches of the operation panel disposed on the main body of the processing machine and performing necessary signal processing, the CPU 11 is handed over.

  The display / MDI unit 70 is a manual data input device having a display, a keyboard and the like, and the interface 18 receives commands and data from the keyboard of the display / MDI unit 70 and passes it to the CPU 11. The interface 19 is connected to a control panel 71 provided with a manual pulse generator and the like used when manually driving each axis.

  An axis control circuit 30 for controlling an axis provided in the processing machine receives an axis movement command amount from the CPU 11 and outputs an axis command to the servo amplifier 40. In response to this command, the servo amplifier 40 drives a servomotor 50 that moves an axis provided in the processing machine. The servomotor 50 of the axis incorporates a position / speed detector, and the position / speed feedback signal from this position / speed detector is fed back to the axis control circuit 30 to perform position / speed feedback control. Although only one axis control circuit 30, one servo amplifier 40 and one servo motor 50 are shown in the hardware configuration diagram of FIG. 1, in actuality, only the number of axes provided in the machine tool to be controlled is provided. Prepared.

The spindle control circuit 60 receives a spindle rotation command to the processing machine, and outputs a spindle speed signal to the spindle amplifier 61. The spindle amplifier 61 receives the spindle speed signal and rotates the spindle motor 62 of the processing machine at a commanded rotational speed to drive the tool.
A position coder 63 is coupled to the spindle motor 62, and the position coder 63 outputs a feedback pulse in synchronization with the rotation of the main shaft, and the feedback pulse is read by the CPU 11.

  FIG. 2 is a schematic functional block diagram of a numerical control device according to an embodiment of the present invention when a system program for realizing a cutting speed control function is implemented in the numerical control device 1 shown in FIG. is there. Each functional block shown in FIG. 2 is controlled by the CPU 11 of the numerical control device 1 shown in FIG. 1 executing a system program for cutting feed speed calculation and controlling the operation of each part of the numerical control device 1 To be realized. The numerical control device 1 of the present embodiment includes a command analysis unit 100, an interpolation unit 110, a servo control unit 120, and an override input unit 140, and a processing condition storage unit that stores processing conditions set in the numerical control device 1. A non-volatile memory 14 is provided with a tool data storage unit 210 that stores 210 and tool data relating to a tool used for processing.

  The command analysis unit 100 sequentially reads the command block included in the machining program 200 from the non-volatile memory 14, analyzes the read command block, and transfers the movement command data including the command value F of the feed speed of the spindle and the spindle rotational speed. The spindle rotation command data including the command value S is calculated. When the command block S in the processing program 200 does not include the command value S of the spindle rotational speed in the processing program 200, the command analysis section 100 uses the value of the spindle rotational speed preset in the processing condition storage section 210 or the like. When the override value for the feed speed of the spindle and the override value for the spindle rotation speed are input from the override input unit 140, the command analysis unit 100 calculates the command value F of the calculated feed speed of the spindle and the spindle rotation speed. Is multiplied by each override value.

The command analysis unit 100 includes a cutting speed control unit 102 that controls the feed speed of the spindle at the time of cutting feed. The cutting speed control unit 102 calculates the recommended cutting feed speed Vc of the spindle based on the referenced tool data with reference to the tool data of the tool currently used for processing stored in the tool data storage unit 220. Do. The recommended cutting feed speed Vc of the spindle calculated by the cutting speed control unit 102 is, for example, the spindle rotation number S calculated by the command analysis unit 100, the recommended value D _r for one-edge feed of the tool included in the tool data, the blade of the tool Based on the number N, it can be calculated by the following equation 2.

  When the cutting speed control unit 102 performs control based on the cutting feed command at the time of machining, if the command value F of the spindle feed speed calculated by the command analysis unit 100 exceeds the recommended cutting feed speed Vc, The feed speed command value F is clamped at the recommended cutting feed speed Vc.

Interpolation unit 110 calculates a point on a command route instructed by the movement command data based on command value F of the spindle feed rate calculated by command analysis unit 100 (and clamped by cutting speed control unit 102). Interpolated data calculated by interpolation at an interpolation cycle is generated.
The servo control unit 120 controls a servomotor 50 that drives each axis of the machine to be controlled based on the interpolation data generated by the interpolation unit 110.
The spindle control unit 130 also controls a spindle motor 62 that rotates the main shaft of the machine to be controlled based on the main spindle rotation command data.

  The override input unit 140 has an override value for a feed speed of a main shaft input to the numerical control device 1 from the control panel 71 or the like when the operator operates an override switch (not shown) provided on the control panel 71 or the like. The override value for the spindle rotational speed is accepted, and the accepted value override value is output to the command analysis unit 100.

FIG. 3 is a schematic flowchart of the process executed on the numerical control device 1 shown in FIG. The process flow shown in FIG. 3 shows the operation when cutting feed is instructed by the instruction block of the machining program, and the process of the operation based on other instructions (such as fast-forwarding) is omitted.
[Step SA01] The command analysis unit 100 analyzes the command block of the machining program 200 to calculate the command value S of the spindle rotational speed.
[Step SA02] When the override value for the spindle rotational speed is input from the override input unit 140, the command analysis unit 100 overrides the spindle rotational speed for the command value S of the spindle rotational speed calculated in step SA01. Multiply.

[Step SA03] The command analysis unit 100 analyzes the command block of the machining program 200 to calculate the command value F of the cutting feed speed of the spindle.
[Step SA04] When the override value for the feed rate of the spindle is input from the override input unit 140, the command analysis unit 100 feeds the spindle with respect to the command value F for the cutting feed rate of the spindle calculated in step SA03. Multiply the override value for speed.

[Step SA05] The cutting speed control unit 102 refers to the tool data of the tool used for the current processing stored in the tool data storage unit 220, and recommends cutting of the spindle based on the referenced tool data. The feed speed Vc is calculated.
[Step SA06] The cutting speed control unit 102 compares the command value F of the cutting feed speed of the spindle calculated by the command analysis unit 100 with the recommended cutting feed speed Vc of the spindle calculated in step SA05. If the command value F of the cutting feed speed of the spindle is larger than the recommended cutting feed speed Vc of the spindle, the process proceeds to step SA07. If not, the process proceeds to step SA08.

[Step SA07] The cutting speed control unit 102 clamps the command value F of the cutting feed speed of the spindle at the recommended cutting feed speed Vc of the spindle (the command value F of the cutting feed speed of the spindle is the recommended cutting feed speed Vc of the spindle And).
[Step SA08] The command analysis unit 100 generates and outputs movement command data including the command value F of the cutting feed speed of the spindle and spindle rotation command data including the command value S of the spindle rotational speed.

  With the above configuration, the machining program can be executed at an appropriate cutting feed rate without calculating the recommended value of the cutting feed rate based on the recommended value of the cutting conditions of the tool, and it is assumed when creating the machining program It is possible to use the program without changing the cutting feed rate even with tools (different types, manufacturers) other than the above tools. Furthermore, even if the machining program is rewritten before machining, or the spindle speed is changed by operating the override switch during machining, the cutting feed rate is a recommended cutting feed rate value calculated from the recommended value of the cutting conditions of the tool. The operator is not required to change the feed speed command because it is automatically clamped. The present invention is a tool provided with one or more blades, and each blade is alternated (in the case of one blade) by the rotation of the spindle and the movement of the spindle (with respect to the workpiece) by the moving axis. The present invention can be applied to the whole process of cutting a workpiece intermittently). There are various processing methods such as side groove processing, ramping groove processing, free-form surface processing, side processing, inclined surface processing, face milling processing, plain milling processing, helical processing, etc. Even with the processing method of the invention, it is possible to appropriately control the single-edge feed amount by applying the present invention.

  As a modification of the numerical control device of the present embodiment, the cutting speed control unit 102 automatically sets the cutting feed speed F to the recommended cutting feed speed Vc when the cutting feed speed is not instructed in the machining program. You may do it.

  According to the above modification, the cutting speed control unit 102 calculates the recommended cutting feed speed Vc calculated based on the tool data of the currently used tool, even if the operator does not command the cutting feed speed in the processing program. Since it sets as the command value F of the feed speed of a spindle, an operator's effort and error can be reduced.

  As another modified example of the numerical control device of the present embodiment, the cutting speed control unit 102 sets the command value F of the cutting feed speed of the spindle instructed (and overridden based on the operation of the override switch) in the machining program. Is clamped at the recommended cutting feed speed Vc calculated based on the tool data of the tool currently being used, the display of the display / MDI unit 70 and the lamp of the control panel 71 to the operator that the speed is clamped It may be notified by sound, etc.

  According to the above modification, the command value F of the cutting feed speed of the spindle commanded in the processing program (and overridden based on the operation of the override switch) is clamped, or the clamped speed (recommended cutting (recommended cutting) It becomes possible to check the feed speed Vc).

  As another modification of the numerical control device according to the present embodiment, the cutting speed control unit 102 is configured such that the command value F of the cutting feed speed instructed in the machining program is based on the tool data of the tool currently being used. When it is less than the calculated recommended cutting feed speed Vc, that effect may be notified to the operator by the display of the display / MDI unit 70, the lamp of the operation panel 71, the sound, or the like.

  According to the above modification, the command value F of the cutting feed speed of the spindle commanded in the machining program can be changed to a larger value, and the recommended upper limit of the cutting feed speed of the spindle (recommended cutting feed speed Vc) Will be able to confirm.

  As another modified example of the numerical control device of the present embodiment, the cutting speed control unit 102 is a recommendation in which the cutting feed speed instructed in the machining program is calculated based on the tool data of the tool currently being used. When it is less than the cutting feed speed Vc, the command value F of the cutting feed speed of the spindle may be automatically set to the recommended cutting feed speed Vc.

  According to the above modification, the machining cycle is automatically increased to the recommended upper limit speed when the command value F of the cutting feed speed of the spindle commanded in the machining program can be changed to a larger value. Time can be reduced.

  As mentioned above, although embodiment of this invention was described, this invention can be implemented in various aspects by adding an appropriate change, without being limited only to the example of embodiment mentioned above.

1 Numerical Control Unit 2 Cutting Tool 3 Workpiece 4 Workpiece 11 CPU
12 ROM
13 RAM
14 non-volatile memory 15, 18, 19 interface 16 PMC
17 I / O unit 20 bus 30 axis control circuit 40 servo amplifier 50 servo motor 60 spindle control circuit 61 spindle amplifier 62 spindle motor 63 position coder 70 display unit / MDI unit 71 control panel 72 external device 100 command analysis unit 102 cutting speed control Unit 110 Interpolation unit 120 Servo control unit 130 Spindle control unit 140 Override input unit 200 Machining program 210 Machining condition storage unit 220 Tool data storage unit

Claims (4)

In a numerical control device which controls a machine tool provided with a spindle based on a machining program to move the spindle relative to a workpiece to cut in a direction different from the direction of the spindle.
A tool data storage unit storing tool data including at least a recommended value of one-edge feed of the tool and a number of blades of the tool related to the tool attached to the spindle;
A command analysis unit that generates move command data for reading out and analyzing a command block from the machining program and moving the spindle relative to the workpiece, and spindle rotation command data for rotating the spindle;
The recommended cutting feed rate of the spindle is calculated using at least the recommended value of the one-edge feed of the tool included in the tool data of the tool and the number of tool blades, and the cutting feed rate of the spindle included in the movement command data is A cutting speed control unit that clamps the cutting feed rate of the main spindle at the recommended cutting feed rate when the feed rate is larger than the recommended cutting feed rate;
Numerical control device provided with The cutting speed control unit sets the cutting feed speed of the spindle as the recommended cutting feed speed when the cutting feed speed is not commanded by the command block of the processing program.
The numerical control device according to claim 1. The cutting speed control unit sets the cutting feed speed of the spindle as the recommended cutting feed speed, when the cutting feed speed instructed by the command block of the processing program is smaller than the recommended cutting feed speed.
The numerical control device according to claim 1. When the cutting speed control unit changes the cutting feed speed of the spindle, the operator is notified that the cutting feed speed of the spindle has been changed,
The numerical control device according to any one of claims 1 to 3.

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