JP7626602B2 - Machine tool system and method for estimating workpiece size - Google Patents

Description

The present disclosure relates to a machine tool system and a method for estimating the size of a workpiece.

Conventionally, computer numerically controlled machine tools (hereinafter referred to as "machine tools") are known that machine workpieces into desired shapes according to NC (Numerical Control) programs.

For example, Patent Document 1 discloses a system that includes one or more machine tools and a control device that automatically collects tool information and processing conditions stored in each machine tool.

JP 2018-41387 A

However, the system described in Patent Document 1 cannot collect the size of the workpiece machined by the machine tool.

In addition, if three-dimensional information (3D model) of the workpiece cannot be obtained separately, the system described in Patent Document 1 cannot determine the size of the workpiece.

On the other hand, if the size of the workpiece can be known, machine tool systems can be used to help manage the production of workpieces in the future. Specifically, the size of the workpiece can be useful for (i) selecting a machine tool suitable for processing the workpiece, (ii) grouping workpieces of similar size together and allocating them to a specific machine tool, and (iii) optimizing the processing conditions of the machine tool.

This disclosure has been made in consideration of the above-mentioned circumstances, and aims to provide a machine tool system that can easily estimate the size of a workpiece, and a method for estimating the size of a workpiece.

A machine tool system according to one aspect of the present disclosure includes a machine tool, a collection unit, and an estimation unit. The machine tool has a tool. The collection unit collects a first machining range of the tool in a first axis direction based on a movement trajectory of the tool when machining a workpiece using the tool. The estimation unit estimates the size of the workpiece in the first axis direction based on the collected maximum and minimum values of the first machining range.

A method for estimating the size of a workpiece according to another aspect of the present disclosure includes collecting the machining range of a tool in a specific direction based on a movement trajectory of the tool when machining a workpiece using the tool, and estimating the size of the workpiece in the specific direction based on maximum and minimum values of the machining range.

The present disclosure provides a machine tool system that can easily estimate the size of a workpiece, and a method for estimating the size of a workpiece.

FIG. 1 is a block diagram showing a configuration of a machine tool system according to an embodiment; FIG. 4 is a schematic diagram showing a movement trajectory of a tool according to the embodiment. Flowchart of a workpiece size estimation method according to an embodiment

(Configuration of machine tool system 1)
The configuration of a machine tool system 1 according to this embodiment will be described with reference to the drawings.

The machine tool system 1 includes a plurality of machine tool devices 10 and a management device 20. The plurality of machine tool devices 10 include first to fourth machine tool devices 10a to 10d. In the following description, the first to fourth machine tool devices 10a to 10d are collectively referred to as "machine tool devices 10". There is no particular limit to the number of machine tool devices 10 included in the machine tool system 1, and it may be one or more.

[Machine tool device 10]
Each machine tool 10 has a machine tool 11 and a CNC (Computer Numerical Control) control unit 12. In this embodiment, the machine tool 11 is assumed to be a lathe, but it may be a grinding machine, a machining center, or the like.

The machine tool 11 processes a workpiece (a so-called workpiece) into a desired shape by performing cutting on the workpiece. The machine tool 11 has a table 13, a storage space 14, a cutting tool 15, and a spindle 16. In this embodiment, the workpiece is assumed to be metal, but the workpiece may also be non-metallic.

A workpiece is placed on the table 13. The table 13 is movable while holding the workpiece. In this embodiment, the table 13 is movable in each of the x-axis direction (an example of a first direction), the y-axis direction (an example of a second direction), and the z-axis direction (an example of a third direction). The x-axis direction is perpendicular to the y-axis direction. The x-axis direction and the y-axis direction are parallel to the horizontal direction. In FIG. 1, the x-axis direction is the left-right direction of the machine tool 11, and the y-axis direction is the depth direction of the machine tool 11. The x-axis direction and the y-axis direction define a horizontal plane. The z-axis direction is perpendicular to both the x-axis direction and the y-axis direction. In FIG. 1, the z-axis direction is the vertical direction.

The storage space 14 is a space provided above the table 13. The storage space 14 accommodates a workpiece placed on the table 13. The cutting tool 15 is attached to the spindle 16 and rotates. The cutting tool 15 is used to cut the workpiece. In this embodiment, the position of the spindle 16 is fixed. The cutting tool 15 moves relative to the workpiece, which moves together with the table 13.

The CNC control unit 12 controls the machine tool 11 according to an NC (Numerical Control) program. The NC program includes G codes for processing the movement of the table 13 in the machine tool 11 and the setting of the coordinate system. The G codes include target coordinate values (X, Y, Z) and the feed rate (F code) for moving the table 13 toward the target coordinate values (X, Y, Z). The NC program also includes an O code, which is a program number for program identification.

The CNC control unit 12 acquires the movement trajectory M of the cutting tool 15 when cutting the workpiece using the cutting tool 15. The movement trajectory M is a line connecting the three-dimensional relative position coordinates of the cutting edge of the cutting tool 15 that moves relative to the workpiece. The movement trajectory M is represented by a group of three-dimensional relative position coordinate data.

Figure 2 is a schematic diagram showing an example of a movement trajectory M. The machine tool assumed in the schematic diagram of Figure 2 is a machining center. The movement trajectory M includes a machining trajectory M1 (solid line range in Figure 2) indicating the range where the cutting edge of the cutting tool 15 is in contact with the workpiece, and a non-machining trajectory M2 (dashed line range in Figure 2) indicating the range where the cutting edge of the cutting tool 15 is away from the workpiece. In the machining trajectory M1, the workpiece is actually cut by the cutting tool 15. In the non-machining trajectory M2, the workpiece is not cut by the cutting tool 15. The non-machining trajectory M2 is the movement trajectory of the cutting tool 15 in an area where the cutting tool 15 is not used for machining.

In the following description, the feed speed of the cutting tool 15 in the machining trajectory M1 is referred to as the "cutting feed speed", and the feed speed of the cutting tool 15 in the non-machining trajectory M2 is referred to as the "rapid feed speed". In this embodiment, the cutting feed speed is slower than the rapid feed speed. The movement trajectory M is distinguished into a machining trajectory M1 and a non-machining trajectory M2 depending on the difference in feed speed. If the feed speed is equal to or greater than a predetermined threshold, the movement trajectory M is determined to be a non-machining trajectory M2, and if the feed speed is less than the predetermined threshold, it is determined to be a machining trajectory M1.

The CNC control unit 12 transmits control data including the movement trajectory M and the NC program to the management device 20 each time the workpiece is cut.

[Management device 20]
As shown in Fig. 1, the management device 20 has a collection unit 21, an estimation unit 22, a storage unit 23, and a communication unit 24. The functions of the management device 20 are achieved by a server. The server is managed by a machine tool system administrator. The server may be a cloud server. The cloud server is owned and managed by a specialized business operator, and is used as a server by machine tool system users.

The management device 20 can communicate wirelessly or wired with the multiple machine tool devices 10 and multiple terminal devices 30 via a network using the communication unit 24. Each terminal device 30 may be a smart device such as a smartphone, or an information processing device such as a personal computer. A user can use the management device 20 via the terminal device 30.

The collection unit 21 is connected to the CNC control unit 12 of each machine tool device 10 via a network such as a LAN (Local Area Network) or a WAN (Wide Area Network). The collection unit 21 receives control data including the movement trajectory M and the NC program from the CNC control unit 12 of each machine tool device 10.

When the collection unit 21 receives the control data, it determines whether the movement trajectory M included in the control data is known. Specifically, the collection unit 21 refers to the program number of the NC program included in the control data, and determines whether the program number is stored in the storage unit 23 described below.

If the program number is stored in the memory unit 23, the collection unit 21 determines that the movement trajectory for the same type of workpiece as the workpiece is known, and discards the control data including the movement trajectory M. The same type of workpiece means a workpiece that can be machined using the same NC program. If the program number is not stored in the memory unit 23, the collection unit 21 determines that the movement trajectory M is not known, and proceeds with the collection process for the machining range.

If the collection unit 21 determines that the movement trajectory M is unknown, it collects the first to third processing ranges based on the movement trajectory M as follows:

First, the collection unit 21 refers to the NC program to obtain the range over which the cutting tool 15 moves at the cutting feed rate.

Next, the collection unit 21 refers to the movement trajectory M to obtain the machining trajectory M1 (see the solid line in Figure 2) that corresponds to the range in which the cutting tool 15 moved at the cutting feed rate.

Next, the collection unit 21 collects the first to third processing ranges based on the processing trajectory M1.

The first machining range is the machining range of the cutting tool 15 in the x-axis direction. The first machining range is represented by the maximum and minimum values of the position coordinates of the cutting edge of the cutting tool 15 in the x-axis direction. The second machining range is the machining range of the cutting tool 15 in the y-axis direction. The second machining range is represented by the maximum and minimum values of the position coordinates of the cutting edge of the cutting tool 15 in the y-axis direction. The third machining range is the machining range of the cutting tool 15 in the z-axis direction. The third machining range is represented by the maximum and minimum values of the position coordinates of the cutting tool 15 in the z-axis direction.

Next, the collection unit 21 associates the maximum and minimum values of each of the first to third machining ranges with the movement trajectory M and the NC program, and stores them in the memory unit 23.

The estimation unit 22 estimates the size of the workpiece in each of the x-axis direction, y-axis direction, and z-axis direction based on the maximum and minimum values of the first to third processing ranges stored in the memory unit 23. Specifically, the estimation unit 22 estimates the difference between the maximum and minimum values of the first processing range as the size of the workpiece in the x-axis direction. The estimation unit 22 estimates the difference between the maximum and minimum values of the second processing range as the size of the workpiece in the y-axis direction. The estimation unit 22 estimates the difference between the maximum and minimum values of the third processing range as the size of the workpiece in the z-axis direction. However, when estimating the size of the workpiece from the difference between the maximum and minimum values, the difference value may be used as it is as the size of the workpiece, or, for example, the difference value truncated to the first digit may be used as the size of the workpiece.

In this embodiment, the estimation unit 22 estimates the size _Sb of the workpiece before machining. Therefore, the size of the workpiece according to this embodiment means the size of the workpiece itself before machining.

The estimation unit 22 stores the estimated sizes of the workpiece in the x-axis direction, the y-axis direction, and the z-axis direction in the memory unit 23 in association with the maximum and minimum values of the first to third machining ranges, the movement trajectory M, and the NC program.

When the communication unit 24 receives a request query (information acquisition instruction) for the estimated size of the workpiece from the terminal device 30, it acquires the estimated size of the workpiece from the storage unit 23 and transmits it to the terminal device 30. The user can acquire the estimated size of the workpiece from the terminal device 30 and use it for production management of the workpiece.

[Estimated flow]
FIG. 3 is a flowchart showing a workpiece size estimation method executed in the machine tool system 1.

In step S1, when the machining of the workpiece is completed in the machine tool 11, the CNC control unit 12 transmits control data including the movement trajectory M and the NC program to the collection unit 21 of the management device 20.

In step S2, when the collection unit 21 receives the control data, it determines whether the movement trajectory M included in the control data is known. If it is determined in step S2 that the movement trajectory M is known, in step S3, the collection unit 21 discards the control data including the movement trajectory M and the NC program.

If it is determined in step S2 that the movement trajectory M is unknown, the flow for estimating the size of the workpiece in steps S4 to S7 is started. In other words, the estimation flow described below is triggered when the movement trajectory M is unknown.

In step S4, the collection unit 21 collects the first to third processing ranges based on the processing trajectory M1 of the movement trajectory M.

In step S5, the collection unit 21 associates the maximum and minimum values of each of the first to third machining ranges with the movement trajectory M and the NC program, and stores them in the memory unit 23.

In step S6, the estimation unit 22 estimates the size of the workpiece in each of the x-axis direction, y-axis direction, and z-axis direction based on the maximum and minimum values of each of the first to third processing ranges stored in the memory unit 23.

In step S7, the estimation unit 22 stores the estimated sizes of the workpiece in the x-axis direction, the y-axis direction, and the z-axis direction in the memory unit 23 in association with the maximum and minimum values of the first to third machining ranges, the movement trajectory M, and the NC program, and then the process ends.

(Features)
(1) The machine tool system 1 includes a collection unit 21 and an estimation unit 22. The collection unit 21 collects first to third machining ranges of the cutting tool 15 in the x-axis direction, y-axis direction, and z-axis direction based on a movement trajectory M of the cutting tool 15 when machining a workpiece using the cutting tool 15. The estimation unit 22 estimates the size of the workpiece in each of the x-axis direction, y-axis direction, and z-axis direction based on the maximum and minimum values of the collected first to third machining ranges, respectively.

In this way, the size of the workpiece can be easily estimated, and the size of the workpiece can be used to manage the future production of the workpiece. Specifically, the estimated size of the workpiece can be effectively used to (i) select a machine tool suitable for processing the workpiece, (ii) group similarly sized workpieces together and assign them to a specific machine tool, and (iii) optimize the processing conditions of the machine tool.

(2) The collection unit 21 collects the first to third machining ranges based only on the machining trajectory M1 of the movement trajectory M. In this way, by using only the range of the movement trajectory M where the cutting edge of the cutting tool 15 is in contact with the workpiece, the size of the workpiece can be estimated more accurately.

(3) If a movement trajectory for a workpiece of the same type as the workpiece is known, the collection unit 21 discards the movement trajectory M. This makes it possible to avoid duplicate size estimations, thereby reducing the processing load on the machine tool system 1.

(Modification)
The present disclosure is not limited to the above-described embodiments, and various modifications and alterations are possible without departing from the scope of the present disclosure.

(Variation 1)
In the above embodiment, an NC lathe, which is one of the machine tools 11 that performs cutting on a workpiece, has been described as an example of a machine tool, but the present invention is not limited to this. As the machine tool, a welding machine that performs welding on a workpiece or the like can be used. When a welding machine is used as the machine tool, the movement trajectory M is indicated by a line that connects three-dimensional relative position coordinates of the tip of a welding torch (an example of a tool) that moves relative to the workpiece.

(Variation 2)
In the above embodiment, the size of the workpiece in each of the x-axis direction, y-axis direction, and z-axis direction is estimated based on the maximum and minimum values of each of the first to third machining ranges, but this is not limited to this.

For example, the size of the workpiece in one of the x-axis, y-axis, and z-axis directions may be estimated based on the maximum and minimum values of one of the first to third processing ranges. In this case, it is preferable to estimate the size of the workpiece in the direction in which the difference between the maximum and minimum values is the largest among the x-axis, y-axis, and z-axis directions.

(Variation 3)
In the above embodiment, the estimation flow is initiated when the movement trajectory M is unknown, but the estimation flow may be initiated even when the movement trajectory M is known. For example, when the movement trajectory M stored in the storage unit 23 has a defect (e.g., missing data caused by a communication problem), it is necessary to initiate the estimation flow according to the above embodiment.

Specifically, when the collection unit 21 receives control data including a movement trajectory M' relating to a workpiece of the same type as the workpiece relating to the movement trajectory M stored in the memory unit 23, the collection unit 21 determines whether or not there is a defect in the movement trajectory M stored in the memory unit 23. If there is a defect in the movement trajectory M, the collection unit 21 collects the first to third machining ranges of the cutting tool 15 based on the movement trajectory M' relating to the same type of workpiece. The collection unit 21 updates the first to third machining ranges stored in the memory unit 23 to the newly collected first to third machining ranges based on the movement trajectory M', and updates the movement trajectory M stored in the memory unit 23 to the movement trajectory M'.

The estimation unit 22 estimates the size of the same type of workpiece in each of the x-axis direction, y-axis direction, and z-axis direction based on the maximum and minimum values of each of the first to third processing ranges updated in the memory unit 23. The estimation unit 22 updates the size of the workpiece stored in the memory unit 23 to the newly estimated size of the same type of workpiece.

(Variation 4)
In the above embodiment, the collection unit 21 collects the first to third processing ranges based only on the processing trajectory M1 of the movement trajectory M, but the collection unit 21 may also collect the first to third processing ranges based on both the processing trajectory M1 and the non-processing trajectory M2 of the movement trajectory M.

(Variation 5)
In the above embodiment, the estimation unit 22 estimates the size of the workpiece before machining based on the maximum and minimum values of each of the first to third machining ranges, but the estimation unit 22 may estimate the size S _a of the workpiece after machining. In this case, the size of the workpiece means the size of the article after machining. The estimation unit 22 may estimate both the size S _b of the workpiece before machining and the size S _a of the workpiece after machining. As shown in FIG. 2, the size S _a of the workpiece after machining may be estimated by subtracting the diameter of the cutting tool 15 from the difference between the maximum and minimum values of each of the first to third machining ranges. The diameter of the cutting tool 15 can be obtained from the NC program.

1 Machine tool system 10a to 10c First to third machine tool devices 11 Machine tool 12 CNC control unit 13 Table 14 Storage space 15 Cutting tool 16 Spindle 20 Management device 21 Collection unit 22 Estimation unit 23 Memory unit 24 Communication unit 30 Terminal device M Movement trajectory M1 Machining trajectory M2 Non-machining trajectory S _a Size of workpiece after machining S _b Size of workpiece before machining

Claims (4)

A machine tool having a tool;
a collection unit that receives control data including a movement trajectory of the tool when a workpiece is machined using the tool in accordance with an NC program and the NC program, and collects a first machining range of the tool in a first axis direction based on the movement trajectory ;
an estimation unit that estimates a size of the workpiece in the first axis direction based on the collected maximum and minimum values of the first machining range;
Equipped with
When a program number of an NC program for a workpiece machined according to the same NC program as that for the workpiece is stored in a storage unit , the collection unit does not collect the first machining range and discards the received control data .
Machine tool systems. A machine tool having a tool;
a collection unit that collects a first machining range of the tool in a first axis direction based on a movement trajectory of the tool when machining a workpiece using the tool in accordance with an NC program;
an estimation unit that estimates a size of the workpiece in the first axis direction based on the collected maximum and minimum values of the first machining range;
a storage unit that stores the movement trajectory, the first processing range, and a size of the workpiece in association with each other;
Equipped with
the collection unit updates the first machining range stored in the storage unit when there is a missing piece of data of the moving trajectory stored therein and the collection unit collects the first machining range related to a workpiece machined according to the same NC program as the workpiece;
the estimation unit estimates a size of the workpiece machined in the first axis direction according to the same NC program as the workpiece based on the updated maximum and minimum values of the first machining range, and updates the size of the workpiece stored in the memory unit to the size of the workpiece machined in the same NC program as the workpiece .
Machine tool systems. Collecting a machining range of the tool in a specific direction based on a movement trajectory of the tool when machining a workpiece using the tool in accordance with an NC program;
estimating a size of the workpiece in the specific direction based on a maximum value and a minimum value of the processing range;
A method for estimating a size of a workpiece, comprising:
The method is executed when a program number of an NC program for a workpiece machined according to the same NC program as that for the workpiece is not stored in a storage unit .
Workpiece size estimation method. Collecting a machining range of the tool in a specific direction based on a movement trajectory of the tool when machining a workpiece using the tool in accordance with an NC program;
estimating a size of the workpiece in the specific direction based on a maximum value and a minimum value of the processing range;
storing the movement trajectory, the processing range, and the size of the workpiece in association with each other;
When there is a gap in the stored data of the movement trajectory, and the size of the workpiece machined according to the same NC program as the workpiece in the specific direction is estimated based on the maximum and minimum values of the machining range of the workpiece machined according to the same NC program as the workpiece , updating the stored machining range and size of the workpiece to the machining range and size of the workpiece machined according to the same NC program as the workpiece ;
A method for estimating a size of a workpiece, comprising:

Images