DE102022132180A1 - Cutting processing data analysis system - Google Patents

Abstract

[Problem] To provide a cutting processing data analysis system capable of identifying an air cut segment with high accuracy. [Solution] This cutting processing data analysis system 1 has an analysis unit 23 that analyzes time-series data of processing loads. The analysis unit 23 has a threshold value setting unit 24 and an air slice determination unit 25 . The threshold setting unit 24 demarcates a cutting machining step into a plurality of machining segments using, as a demarcation position, a start point of a cutting feed command that follows a rapid feed command or a starting point of a cutting feed command that is not continuous with an immediately preceding cutting feed command, and sets for each of the plurality of machining segments sets an air cut determination threshold based on a value of a machining load corresponding to each starting point among each of the plurality of machining segments in the time-series data. The air cut determination unit 25 determines a segment in which the machining load in the time-series data is less than the air cut determination threshold for each of the plurality of machining segments as an air cut segment.

Description

technical field

The present disclosure relates to a cutting processing data analysis system.

Technical background

Conventionally, there is known a cutting processing apparatus that forms an object to be processed into a desired shape according to a numerical control (NC) program. A rapid feed command and a cutting feed command are written in the NC program, and a cutting machining step of the object to be machined is divided into rapid feed segments according to the rapid feed command and machining segments according to the cutting feed command.

Air cut segments where the tool does not cut the object to be machined are included in the machining sections, and as the length of the air cut segments increases, more time is required to machine the object to be machined.

Patent Document No. 1 discloses a method in which the time when a cutting feed command is issued is set as the start point of an air-cut segment, and the time when a load applied to a tool has increased rapidly is set as the end time of the air-cut segment, thereby the air slice segment is identified.

Prior Art Document

reference

Patent Document #1: International Application WO 2015/029218

Summary of the Invention

Problem to be solved by the invention

However, in the method described in Patent Document No. 1, in order to set the time when a load applied to the tool has increased rapidly as the end time of an air cut segment, only the air cut segment included in the first machining segment can be identified when multiple machining segments are included in the cutting processing step.

The object of the present disclosure is to provide a cutting processing data analysis system that can easily and accurately identify an air cut segment.

means of solving the problem

A cutting processing data analysis system according to an embodiment of the present disclosure includes an acquisition unit and an analysis unit. The acquisition unit is configured to acquire time-series data of a machining load acting on a spindle when a cutting process step is performed on a workpiece with a tool attached to the spindle of a cutting machining apparatus according to a machining program in which a rapid feed command and a cutting feed command for the spindle are written . The analysis unit is configured to analyze the time series data. The analysis unit has a threshold setting unit and an air slice determination unit. The threshold value setting unit is configured to delimit a cutting machining step into a plurality of machining segments, using as a position for delimiting a starting point of the cutting feed command that follows the rapid feed command or a starting point of the cutting feed command that is not continuous with an immediately preceding cutting feed command, and for each of the plurality of machining segments sets an air cut determination threshold based on a value of a machining load corresponding to each start point of the plurality of machining segments in the time-series data. The air cut determination unit is configured to determine a segment in which the machining load in the time-series data is less than the air cut determination threshold for each of the plurality of machining segments as an air cut segment.

effect of the invention

According to the present disclosure, a cutting processing data analysis system capable of easily and accurately identifying an air cut segment can be provided.

character list

• 1 12 is a block diagram showing a function of the cutting processing data analysis system according to an embodiment.
• 2 14 is a schematic view showing an example of time-series data of machining loads and the content of a cutting machining step.
• 3 Fig. 12 is a flowchart showing a cutting processing data analysis method.

Description of the embodiments

(Configuration of cutting processing data analysis system 1)

The functions of a cutting processing data analysis system 1 according to the present embodiment will be explained with reference to the drawings. 1 12 is a block diagram showing the functions of the cutting processing data analysis system 1. FIG. 2 14 is a schematic view showing an example of time-series data of machining loads and the content of a cutting machining step.

The cutting processing data analysis system 1 has a cutting processing device 10 and a cutting processing data analysis device 20 . The number of the cutting processing devices 10 in the cutting processing data analysis system 1 is not particularly limited and may be one or more.

[Cutting Device 10]

The cutting processing device 10 has a machine body 11 and a computer numerical control (CNC) control unit 12 .

The machine body 11 performs cutting processing to cut a workpiece W into a desired shape. Cutting machining includes drilling, milling and turning.

The machine body 11 has a table 14, a tool 15 and a spindle 16. As shown in FIG.

The work W is placed on the table 14 . The tool 15 is used to cut the workpiece W. FIG. The tool 15 is rotated and driven while being attached to the spindle 16 . The spindle 16 is rotated and driven. The tool 15 moves relative to the workpiece W mounted on the table 14. The tool 15 moves relative to the workpiece W due to the movement of the table 14 or the movement of the spindle 16.

The type of the tool 15 (hereinafter abbreviated as “tool type”) is selected according to the machining content to be performed on the workpiece W. Accordingly, multiple types of tools 15 are typically used in the cutting processing apparatus 10 . While various types of tools are possible, such as a milling cutter, an end mill, a drill, a reamer, a tap, a boring tool or a milling cutter, the tool type is not limited to this.

The CNC control unit 12 performs a machining step on the workpiece W with the tool 15 by controlling the CNC control unit 12 according to a numerical control (NC) program. The NC program is an example of a machining program according to the present disclosure.

Rapid feed commands (q1, q2, q3, q4, ...) and cutting feed commands (p1, p2, p,3, p4, ...) are written in the NC program. The rapid feed commands are commands for moving the tool 15 toward and away from the workpiece W at a predetermined rapid feed speed. The cutting feed commands are commands for cutting the workpiece W with the tool 15 at a prescribed cutting feed speed.

The cutting machining step on the workpiece W is divided into rapid feed segments according to the rapid feed commands and machining segments according to the cutting feed commands, as shown in FIG 2 shown. Air cutting segments in which the tool 15 rotates freely without cutting the workpiece W are included in the machining sections.

The CNC control unit 12 generates machining data of the workpiece W when the machining of the workpiece W is completed. The machining data includes the NC program in which the rapid feed commands and the cutting feed commands are written, and time-series data of the machining loads acting on the spindle 16. The machining loads acting on the spindle 16 are detected, for example, by a torque sensor attached to the spindle 16 .

The CNC control unit 12 transmits the generated machining data to the cutting machining data analysis device 20.

[Cutting Processing Data Analysis Device 20]

The cutting processing data analysis device 20 can communicate with the cutting processing device 10 via a network. The functions of the cutting processing data analysis device 20 can be executed by a server. The server can be a cloud server.

The cutting processing data analysis device 20 has an acquisition unit 21, a storage unit 22 and an analysis unit 23.

The acquisition unit 21 acquires the machining data (NC program and time series data of the machining loads) from the cutting machining apparatus 10. The acquisition unit 21 stores the acquired machining data in the storage unit 22. The acquisition unit 21 stores the acquired machining data in the storage unit 22 every time the machining data is acquired.

The analysis unit 23 refers to the machining data in the storage unit 22 and analyzes the time-series data of the machining loads included in the machining data. The analysis unit 23 includes a threshold setting unit 24 , an air cut determination unit 25 , an evaluation value calculation unit 26 , a previous step evaluation unit 27 , and a workpiece evaluation unit 28 .

The threshold value setting unit 24 refers to the machining data in the storage unit 22 and demarcates the cutting machining step into machining segments and rapid-feed segments. In particular, the threshold setting unit delimits the cutting processing step into a plurality of processing segments by using, as positions for the delimitation, a starting point of a cutting feed command that follows a rapid feed command or a starting point of a cutting feed command that is not continuous with an immediately preceding cutting feed command. The cutting feed command that is not continuous with an immediately preceding cutting feed command means that the cutting feed speed and/or target coordinates are different from those of the immediately preceding cutting feed command.

in the in 2 In the example shown, the cutting processing step is divided into first through fourth processing segments. The first machining segment is a segment starting from a starting point S1 of a cutting feed command p1 following a rapid feed command q1. The second machining segment is a segment starting from a starting point S2 of the cutting feed command p2 following a rapid feed command q2. The third machining segment is a segment starting from a starting point S3 of a cutting feed command p3 (≠p2) that does not follow the immediately preceding cutting feed command p2. The fourth machining segment is a segment starting from a starting point S4 of the cutting feed command p4 following a rapid feed command q3. In 2 each machining segment ends at the end point of the cutting feed commands.

The threshold setting unit 24 sets a threshold for determining the air cutting rate for each machining segment based on the value of a machining load corresponding to each start point of the plural machining segments in the time-series data. in the in 2 In the illustrated example, a first threshold value TH1 is set for the first machining segment based on the value of the machining load corresponding to the start point S1 of the first machining segment, and similarly the second through fourth threshold values TH2 through TH4 are set for the second through fourth machining segments.

The air cut determination threshold values are set to values capable of determining whether the tool 15 rotates freely without cutting the workpiece W. For example, the air cut determination thresholds may be set to values slightly larger than the values of the machining loads corresponding to the starting points (e.g., a few percent of the maximum machining load in each machining segment). The machining load corresponding to a starting point is the machining load at the starting point or an average value of the machining load over a predetermined period of time (e.g. 2-3 seconds) from the starting point.

The air cut determination unit 25 determines a segment in which a machining load in the time-series data is smaller than the air cut determination threshold for each of the machining segments as an air cut segment. in the in 2 In the example shown, the air cut segments are at the beginning of the first machining segment, at the beginning of the third machining segment, and at the beginning and middle of the fourth machining segment.

As stated above, the air cut determination threshold values are set for each of the machining segments using as positions for demarcation the starting point of a cutting feed command that follows a rapid feed command and a starting point of a cutting feed command that does not follow the immediately preceding cutting feed command. Accordingly, all the air cut segments can be easily and accurately identified even when multiple machining segments are included in the cutting machining step.

The evaluation value calculation unit 26 calculates an air cut evaluation value indicating the quantity (amount) of the air cut segments included in the cutting processing step. At least one of the following can be used as an air cut score value: the duration of each air cut segment in a cut processing step, the total duration of the air cutting segments in the cutting processing step, a ratio of the duration of each air cutting segment to the total duration of the cutting processing step, or a ratio of the total duration of the air cutting segments to the total duration of the cutting processing step.

The evaluation value calculation unit 26 stores the calculated air cut evaluation value in the storage unit 22.

The previous step evaluation unit 27 evaluates the machining accuracy of the workpiece W in the previous step of the cutting processing step based on the air cut evaluation value. The previous step is the step performed before the cutting working step, and is a step for shaping (e.g. forging) the workpiece W.

For example, when the ratio of the total time of the air cut segments with respect to the total time of the cutting processing step is used as the air cut evaluation value, the previous step evaluation unit 27 evaluates the previous step as "good" when the air cut evaluation value is below a prescribed value (e.g. 10%), and judges the previous step as “Bad” when the air cut judgment value is equal to or greater than the prescribed value. Thereby, the need for improvements in machining accuracy in the previous step can be easily judged.

In addition, the preceding-step evaluating unit 27 calculates an index (e.g., a standard deviation) indicating the deviation between plural air-cut evaluating values when plural air-cut evaluating values are stored in the NC program storing unit 22 . The need for improvements in machining accuracy in the previous step can be easily judged based on the index showing the deviation.

The workpiece evaluation unit 28 evaluates the dimensional accuracy of the workpiece W based on the air cut evaluation value. For example, if the ratio of the total time of the air cut segments with respect to the total time of the cutting processing step is used as the air cut evaluation value, the workpiece evaluation unit 28 evaluates the previous step as "good" if the air cut evaluation value is less than a prescribed value (e.g. 10%). , and evaluates the previous step as "bad" if the air cut evaluation value is equal to or greater than the prescribed value. This makes it easy to assess the need for dimensional accuracy improvements in the previous step.

In addition, the workpiece evaluation unit 28 calculates an index (e.g., a standard deviation) indicating the deviation between a plurality of air-cut evaluation values when a plurality of air-cut evaluation values are stored in the NC program storage unit 22 . The need for dimensional improvements in the previous step can be easily judged based on the index indicating the deviation.

(cutting data analysis method)

A cutting data analysis method of the cutting data analysis system 1 will be explained with reference to the drawings. 3 FIG. 12 is a flow chart illustrating a cutting processing data analysis method.

In step S1, the acquisition unit 21 acquires the processing data from the cutting processing device 10.

In step S2, the threshold value setting unit 24 refers to the machining data (NC program and time-series data of machining loads) and delimits the cutting machining step into a plurality of machining segments. At this time, the threshold setting unit 24 sets the start point of a cut feed command subsequent to a rapid feed command or the start point of a cut feed command not continuous with an immediately preceding cut feed command as a position for the boundary.

In step S3, the threshold value setting unit 24 sets a threshold value for determining the air intersection for each machining segment based on the value of the machining load corresponding to each start point of the plural machining segments in the time-series data.

In step S4, the air cut determination unit 25 determines segments in which the machining load in the time-series data is smaller than the air cut determination threshold for each of the machining segments as air cut segments.

In step S5, the evaluation value calculation unit 26 calculates an air cut evaluation value indicating the amount of air cut segments included in the cutting processing step.

In step S6, the preceding-step judging unit 27 judges the machining accuracy and the dimensional accuracy of the workpiece W in the preceding step of the cutting machining step based on the air-cut evaluating value.

(Modified Examples of Embodiment)

The present disclosure is not limited to the above embodiment, and various changes and modifications can be made without departing from the spirit of the invention.

(Modified Example 1)

While the cutting processing apparatus 10 performs the cutting processing step on the workpiece W according to an NC program in the above embodiment, the cutting processing step can also be performed with a variety of types of NC programs.

In this case, the acquisition unit 21 acquires the machining data (including the time-series data of the machining loads) for each NC program from the cutting machining device 10 and stores the machining data in the storage unit 22. The analysis unit 23 identifies the air cut segments for each of the plural types of NC programs, by analyzing the time-series data of the machining loads in each NC program. The analysis unit 23 calculates the air cut evaluation values for each NC program.

The analysis unit 23 preferably includes a priority level setting unit for setting an improvement priority level for each NC program. The priority level setting unit sets the improvement priority level for each NC program based on the machining amount on the workpiece W and the air cut evaluation value over a predetermined evaluation period.

Specifically, the priority level setting unit sets a higher improvement priority level as the machining amount of the workpiece W increases and as the air cut evaluation values become higher. Consequently, the order of improvement can be easily decided when it is unclear which NC program should be improved among the plurality of types of NC programs.

While plural types of NC programs are used in one cutting processing device 10 in the above explanation, the same processing can be performed even when single NC programs are used in plural cutting processing devices 10 connected to the cutting processing data analysis device 20 .

(Modified Example 2)

While the functions of the cutting processing data analysis device 20 can be executed by a server in the above embodiment, the present invention is not limited in this respect. At least part of the functions of the cutting processing data analysis device 20 can be performed by a terminal. The terminal device may be attached to the cutting processing device 10 .

(Modified example 3)

In the above embodiment, while the cutting processing data analysis device 20 analyzes the processing data acquired from the cutting processing device 10 after the data is stored, the cutting processing data analysis device 20 may analyze the processing data while acquiring the processing data from the cutting processing device 10 . In this case, the series of analyzes including the identification of the starting points of the machining segments, the setting of the threshold values for the air cut determination and the identification of the air cut segments are performed in real time in parallel with the acquisition of the machining data.

Reference List

1

Cutting processing data analysis system

10

cutting processing device

11

machine body

12

CNC control unit

14

Table

15

Tool

16

spindle

20

Cutting processing data analysis device

21

registration unit

22

storage unit

23

analysis unit

24

Threshold setting unit

25

air cut determining unit

26

evaluation value calculation unit

27

Preceding step evaluation unit

28

Workpiece evaluation unit

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• WO 2015/029218 [0005]

Claims (6)

Cutting processing data analysis system comprising: an acquisition unit configured to acquire time-series data of a machining load acting on a spindle of a cutting machining device when a cutting machining step is performed on a workpiece with a tool attached to the spindle according to a machining program in which a rapid feed command and a cutting feed command for the spindle are programmed are written; and an analysis unit configured to analyze the time series data, wherein the analysis unit comprises: a threshold setting unit configured to demarcate the cutting machining step into a plurality of machining segments using, as a demarcation position, a starting point of the cutting feed command that follows the rapid feed command or a starting point of the cutting feed command that is not continuous with an immediately preceding cutting feed command, and sets an air cut determination threshold for each of the plurality of machining segments based on a value of a machining load corresponding to each start point of the plurality of machining segments in the time-series data; and an air cut determination unit configured to determine a segment in which the machining load in the time-series data is less than the air cut determination threshold value for each of the plurality of machining segments as an air cut segment. cutting processing data analysis system claim 1 , wherein the analysis unit comprises an evaluation value calculation unit configured to calculate, as an air cut evaluation value, a duration for each of the air cut segments included in the cutting processing step and/or a total duration of the air cut segments included in the cutting processing step, and/or or to calculate a ratio of a duration for each of the air cut segments with respect to a total duration of the cutting processing step and/or a ratio of a total duration of the air cut segments with respect to the total duration of the cutting processing step. cutting processing data analysis system claim 2 , wherein the analyzing unit includes a preceding-step evaluating unit configured to judge the machining accuracy on the workpiece in the preceding step of the cutting machining step based on the air-cut evaluating value. cutting processing data analysis system claim 2 , wherein the analysis unit includes a workpiece evaluation unit configured to evaluate the dimensional accuracy of the workpiece based on the air cut evaluation value. Cutting processing data analysis system according to any one of Claims 1 until 4 , wherein the acquiring unit is configured to acquire the time-series data when the cutting machining step is executed according to multiple types of the machining program, and the analyzing unit is configured to analyze multiple sets of the time-series data. cutting processing data analysis system claim 5 , wherein the analysis unit includes a priority level setting unit configured to set an improvement priority level for each of the plurality of machining program types based on the machining amount of the workpiece over a prescribed evaluation period and the air cut evaluation value.

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