WO2022230688A1

WO2022230688A1 - Machine tool

Info

Publication number: WO2022230688A1
Application number: PCT/JP2022/017886
Authority: WO
Inventors: Tetsushi Asada; Akihisa Aoyama
Original assignee: Dmg Mori Co., Ltd.
Priority date: 2021-04-26
Filing date: 2022-04-15
Publication date: 2022-11-03
Also published as: JP2022168358A; EP4268031A1; JP7019085B1

Abstract

A machine tool includes a turret capable of attaching a plurality of tools, a tool storage unit capable of storing a plurality of tools, a machining control unit, for machining a workpiece in accordance with a machining program, controlling a tool attached to the turret, a tool changing unit for changing the tool attached to the turret with a tool stored in the tool storage unit, and a tool pattern memory for memorizing a tool pattern that specifies one or more attached tools to the turret corresponding to a process defined in the machining program. If the process is selected to execute, the tool changing unit performs tool change in accordance with the tool pattern associated with the selected process.

Description

MACHINE TOOL

The present invention relates to a technology for tool change in machine tools.

Machine tools include devices for cutting a workpiece into a desired shape, and devices for depositing metal powder or the like to make a workpiece. Examples of machine tools for cutting include a turning center that machines a workpiece by applying a cutting tool to the workpiece that is being turned, a machining center that machines a workpiece by applying a turning tool to the workpiece, and a combined machine including these functions in combination.

In a machine tool including a tool rest, a plurality of tools may be attached to the tool rest. The machine tool machines a workpiece while moving the tool rest (turret base) three-dimensionally and selecting a tool to be applied to the workpiece from the tools attached to the tool rest in accordance with a machining program prepared in advance.

Some machine tools include an external tool storage unit that has a number of tools stored therein. When a necessary tool is not attached to the tool rest, the machine tool attaches a specified tool to the tool rest from the tool storage unit and continues machining of the workpiece. Hereinafter, a tool attached to the tool rest is referred to as a "work tool", and a tool stored in the tool storage unit is referred to as a "spare tool". Unless otherwise specified, they are simply referred to as a "tool". Further, attaching a spare tool to the tool rest as a work tool is referred to as "tool change" (see Patent Literatures 1 to 3).

JP 2008-225738 A JP 2000-218459 A JP S62-236642 A

An operator may want to repeat only a part of processes included in the machining program. In general, processes of machining a workpiece include rough machining for removing an excess thickness of the workpiece to leave a thickness that is easy to finish, and finish machining for cutting the workpiece to polish the workpiece. Depending on the machined state of the workpiece, the operator may want to repeat the finish machining only.

As described above, the machine tool machines a workpiece while changing a work tool and a spare tool as needed. Therefore, when the machining program is re-executed, there is a possibility that a combination (hereinafter, a "tool pattern") of work tools attached to the tool rest has changed from a tool pattern in previous execution of the machining program.

When the tool rest is three-dimensionally moved in a narrow machining chamber, it is necessary to execute control in such a manner that the work tool does not come into contact with the workpiece itself or external equipment such as a tailstock (tailstock device) for supporting the workpiece or an anti-vibration device. Since there are various shapes and sizes of tools, even in the same machining process, there are cases where contact does not occur for a certain tool pattern but occurs for another tool pattern.

A machine tool according to an embodiment of the present invention includes: a turret capable of attaching a plurality of tools; a tool storage unit capable of storing a plurality of tools; a machining control unit, for machining a workpiece in accordance with a machining program, controlling a tool attached to the turret; a tool changing unit for changing the tool attached to the turret with a tool stored in the tool storage unit; and a tool pattern memory for memorizing a tool pattern that specifies one or more attached tools to the turret corresponding to a process defined in the machining program.
If the process is selected to execute, the tool changing unit performs tool change in accordance with the tool pattern associated with the selected process.

A machine tool according to another embodiment of the present invention includes: a turret capable of attaching a plurality of tools; a tool storage unit capable of storing a plurality of tools therein; a machining control unit, for machining a workpiece in accordance with a machining program, controlling a tool attached to the turret; a tool changing unit for changing the tool attached to the turret with a tool stored in the tool storage unit; and a tool pattern memory for memorizing a tool pattern that specifies one or more tools to be attached to the turret corresponding to a workpiece being selectable as a machining target.
The tool changing unit performs tool change between the turret and the tool storage unit in accordance with a tool pattern associated with one of the workpieces which is selected as the machining target.

According to the present invention, it becomes possible to reproduce a safe tool pattern at the time of execution of a machining program.

FIG. 1 is a plan view illustrating a schematic configuration of a machine tool in an embodiment of the present invention. FIG. 2 is a perspective view of the machine tool. FIG. 3 is a perspective view of a tool storage unit and a tool changing unit. FIG. 4 is an enlarged perspective view of a portion A illustrated in FIG. 3. FIG. 5 is a schematic diagram for explaining tool change in a turret. FIG. 6 is a hardware configuration diagram of the machine tool. FIG. 7 is a functional block diagram of an information processing device. FIG. 8 is a data structure diagram of setting pattern information in a first embodiment. FIG. 9 is a schematic diagram of a machining program. FIG. 10 is a flowchart illustrating processing of reproducing a setting pattern. FIG. 11 is a data structure diagram of setting pattern information in a second embodiment. FIG. 12 is a data structure diagram of setting pattern information in a modification.

A machine tool in the present embodiment is a turning center or a combined machine. First, the structure of a machine tool is mainly described with reference to FIGS. 1 to 4. Details of control of tool change in the present embodiment are described with reference to FIG. 5 and subsequent drawings.
Hereinafter, in re-execution of a machining program, a combination of work tools attached to a turret is referred to as a “tool pattern”. A tool pattern, details of which are described later, is information specifying one or more tools attached to the turret for each process defined in a machining program.

FIG. 1 is a plan view illustrating a schematic configuration of a machine tool 100 in the present embodiment.
The machine tool 100 includes a controller 160, machining equipment 112, a tool changing unit 114, and a tool storage unit 106. The controller 160 corresponds to an information processing device 118 and a machining control unit 116 described later with reference to FIG. 6. A turret base 102 and a turret 164 are movable in the X, Y, and Z-axis directions. The turret base 102 and the turret 164 may be collectively referred to as a tool rest, and only the turret 164 may be referred to as a tool rest. FIG. 1 is a plan view in an X-Z plane. The turret 164 is disposed on the turret base 102 to be rotatable about the Z-axis. The tool storage unit 106 (a tool magazine) is provided on the positive side in the Z-axis direction of the turret base 102. The tool changing unit 114 transfers a tool T.

FIG. 2 is a perspective view of the machine tool 100.
The turret 164 in the shape of a prism has a plurality of holders 168 for holding tools T on its outer peripheral plane. The holders 168 are attached to a turret body to be detachable. The tool T attached to the holder 168 at a position PT is the target of attachment and detachment. By rotating the turret 164 in a direction of an arrow B-C (a direction of rotation about the Z-axis), each holder 168 can be indexed to the attachment/detachment position PT.

The tool storage unit 106 includes a holding plate 170 provided to be rotatable in a direction of an arrow D-E (a direction of rotation about the X-axis), holding pots 174 arranged at regular intervals on the peripheral edge of the holding plate 170, and a driving motor 176 (see FIG. 3) that rotates the holding plate 170. The holding pot 174 holds the tool T. The holding pot 174 protrudes to the negative side in the X-axis direction. The tool T in the holding pot 174 at a position PM is the target of attachment and detachment. The driving motor 176 rotates the holding plate 170, whereby each holding pot 174 can be indexed to the attachment/detachment position PM.

FIG. 3 is a perspective view of the tool storage unit 106 and the tool changing unit 114.
The tool changing unit 114 is provided on the negative side in the X-axis direction of the turret base 102 and the tool storage unit 106 (see FIG. 1). The tool changing unit 114 includes a feed mechanism 178 provided along the Z-axis, a movable base 180 that can be moved along the Z-axis by the feed mechanism 178, and a first hand 182 and a second hand 194 attached to the movable base 180, for example.

The feed mechanism 178 includes a rail holding base 184 arranged parallel to the Z-axis, two guide rails 186 attached to a lower surface of the rail holding base 184 to be parallel to the Z-axis, two sliders 188 provided for each guide rail 186 to engage with that guide rail 186, a ball screw 190 arranged along the rail holding base 184, a ball nut 192 screwed to the ball screw 190, and a servo motor 196 coupled to an end of the ball screw 190 to rotate the ball screw 190 about an axis line. The sliders 188 are fixed to an upper surface of the movable base 180.

On a lower surface of the moving base 180, a holding member 198 is arranged to be rotatable in a direction of an arrow F-G (a direction of rotation about the Y-axis) and movable in the X-axis direction. The holding member 198 is driven in the X-axis direction by a moving cylinder 200. The holding member 198 is driven by a driving cylinder 202 via a mechanism such as a rack and pinion mechanism, and turns in the direction of the arrow F-G within an angular range of 90 degrees. That is, the holding member 198 is configured to be movable on an X-Z plane and rotatable in the F-G direction. FIG. 3 illustrates a state in which the holding member 198 has been rotated in the F direction.

A rotating shaft 204 is attached to the holding member 198 to penetrate therethrough. The rotating shaft 204 is driven by a driving cylinder 206 via a mechanism such as a rack and pinion mechanism, and rotates in a direction of an arrow J-K within an angular range of 180 degrees.

FIG. 4 is an enlarged perspective view of a portion A illustrated in FIG. 3.
The first hand 182 and the second hand 194 are attached to an end of the rotating shaft 204 to be point-symmetric with respect to the axis center of the rotating shaft 204 and be parallel to each other in a vertical direction. The first hand 182 and the second hand 194 have the same configuration as each other. The first hand 182 has a pair of gripping claws 208 for gripping the tool T and can grip the tool T with the gripping claws 208. Similarly, the second hand 194 also has a pair of gripping claws 210 and can grip the tool T with the gripping claws 210.

When the holding member 198 is rotated to the direction of the arrow F (the rotation state illustrated in FIGS. 3 and 4), the gripping

claws

208 and 210 of the first and

second hands

182 and 194 each have such a posture that it is along the Z-axis direction (an orthogonal direction orthogonal to the axis line direction of the tool T gripped by the gripping claws 208 or the like). When the holding member 198 is rotated to the direction of the arrow G, the gripping

claws

208 and 210 of the first and

second hands

182 and 194 each have such a posture that it is along the X-axis direction.

When the holding member 198 is at an end of movement on the positive side in the X-axis direction (this position is referred to as a "first X position") and at an end of rotation in the F direction, the tool T held in the holding pot 174 indexed to the attachment/detachment position PM can be gripped by the first hand 182 or the second hand 194.

Further, when the first hand 182 grips the tool T on its upper side and no tool T is held in the holding pot 174 at the attachment/detachment position PM, the tool T gripped by the first hand 182 can be accommodated in the holding pot 174 (an empty holding pot) at the attachment/detachment position PM.

It is assumed that the movable base 180 is located at an intermediate position between the turret 164 and the tool storage unit 106. Here, the holding member 198 is moved to an end of movement on the negative side in the X-axis direction (this position is referred to as a "second X position") and rotated to the end of rotation in the direction of the arrow F. Next, the movable base 180 is moved to the positive side in the Z-axis direction, and the axis center (the X-axis direction) of the tool T gripped by the first hand 182 is made to coincide with the axis center of the holding pot 174 (the Z coordinate at this time is referred to as a "first Z position"). Subsequently, the holding member 198 is moved to the positive side in the X-axis direction to the "first X position", and the tool T in the first hand 182 is attached to the empty holding pot 174 at the attachment/detachment position PM. Thereafter, the movable base 180 is moved to the negative side in the Z-axis direction (this position is referred to as a "second Z position"), whereby gripping of the tool T by the first hand 182 is released.

Meanwhile, when the first hand 182 is located on the upper side, no tool T is gripped by the gripping claws 208 of the first hand 182, and the tool T is held at the attachment/detachment position PM, the tool T at the attachment/detachment position PM can be taken out by the first hand 182.

It is assumed that the movable base 180 is located at an intermediate position between the turret 164 and the tool storage unit 106. Here, after the holding member 198 is rotated to the end of rotation in the direction of the arrow F (the rotation state illustrated in FIGS. 3 and 4) and the movable base 180 is moved to the "second Z position", the movable base 180 is moved to the "first X position" and then moved to the aforementioned "first Z position". Accordingly, the tool T attached at the attachment/detachment position PM enters to an opening of the pair of gripping claws 208 and is gripped by the gripping claws 208. Next, the holding member 198 is moved to the "second X position". The tool T attached to the holding pot 174 is thus taken out from the holding pot 174 while being gripped by the pair of gripping claws 208.

As for the turret 164, in a case where the holder 168 indexed to the attachment/detachment position PT is of a type that holds the tool T along a radial direction, the tool T held in the holder 168 can be gripped by the first hand 182 or the second hand 194 positioned on the lower side when the holding member 198 of the tool changing unit 114 is at the "first X position" and at the end of rotation in the direction of the arrow F.

When the first hand 182 is positioned on the upper side, the second hand 194 is positioned on the lower side, the first hand 182 grips the tool T, the second hand 194 does not grip the tool T, and the tool T is held at the attachment/detachment position PT, it is possible to change the tool T gripped by the first hand 182 with the tool T held in the holder 168 at the attachment/detachment position PT.

It is assumed that the movable base 180 is located at an intermediate position between the turret 164 and the tool storage unit 106. Here, the holding member 198 is rotated to the end of rotation in the direction of the arrow F and is moved to the "second X position. In this state, the movable base 180 is moved to a predetermined position (this position is referred to as a "third Z position") set in the negative side in the Z-axis direction. The "third Z position" is located at such a position that, when the holding member 198 is moved to the "first X position", the second hand 194 positioned on the lower side is located on the positive side in the Z-axis direction of the tool T held in the holder 168, in other words, at a front position at which the second hand 194 does not interfere with the tool T.

After the holding member 198 is moved to the "first X position", the movable base 180 is moved to a predetermined position (this position is referred to as a "fourth Z position") set in the negative side in the Z-axis direction. Accordingly, the tool T at the attachment/detachment position PT enters an opening of the pair of gripping claws 210 and is gripped by the gripping claws 210. Next, when the holding member 198 is moved to the "second X position", the tool T attached to the holder 168 is taken out from the holder 168 by the pair of gripping claws 210.

Next, the driving cylinder 206 turns the first and

second hands

182 and 194 upside down to position the second hand 194 on the upper side and position the first hand 182 on the lower side, and moves the holding member 198 to the "first X position". Accordingly, the tool T gripped by the first hand 182 is disposed at the attachment/detachment position PT. Subsequently, when the movable base 180 is moved to the "third Z position", gripping of the tool T by the first hand 182 is released. By the first change operation described above, the tool T gripped by the first hand 182 and the tool T at the attachment/detachment position PT are changed with each other. The tool T gripped by the second hand 194 can be accommodated in the tool storage unit 106 by the accommodating operation described above.

In a case where the holder 168 indexed to the attachment/detachment position PT of the turret 164 is of a type that holds the tool T along the Z-axis, the tool T held in this holder 168 can be gripped by the first hand 182 or the second hand 194 positioned on the lower side, when the holding member 198 is at an end of rotation in the direction of the arrow G and at the "first X position".

When the first hand 182 is positioned on the upper side, the second hand 194 is positioned on the lower side, the second hand 182 grips the tool T, the second hand 194 does not grip the tool T, and the tool T is held at the attachment/detachment position PT, it is possible to change the tool T gripped by the first hand 182 with the tool T at the attachment/detachment position PT.

It is assumed that the movable base 180 is located at an intermediate position between the turret 164 and the tool storage unit 106. Here, the holding member 198 is rotated to the end of rotation in the direction of the arrow G and is moved to the "second X position", and the movable base 180 is moved to the "third Z position" set in the negative side in the Z-axis direction. At this time, the second hand 194 is located at such a position that it can grip the tool T held in the holder 168.

Next, the holding member 198 is moved to the "first X position". The tool T at the attachment/detachment position PT thus enters the opening of the pair of gripping claws 210 and is gripped by the gripping claws 210. Thereafter, when the holding member 198 is moved to the "fourth Z position" set on the negative side in the Z-axis direction, the tool T attached to the holder 168 is taken out from the holder 168 by the pair of gripping claws 210.

Next, the driving cylinder 206 turns the first and

second hands

182 and 194 upside down to position the second hand 194 on the upper side and position the first hand 182 on the lower side, and moves the movable base 180 to the "third Z position". Accordingly, the tool T gripped by the first hand 182 is attached at the attachment/detachment position PT. Subsequently, when the holding member 198 is moved to the "second X position", gripping of the tool T by the first hand 182 is released. By the second change operation described above, the tool T gripped by the second hand 182 and the tool T at the attachment/detachment position PT are changed with each other. The tool T gripped by the second hand 194 can be accommodated in the tool storage unit 106 by the accommodating operation described above.

Next, a method of reproducing a tool pattern is described.
Note that a “tool pattern” in the present embodiment is information specifying one or more tools attached to the turret for each process defined in a machining program.

FIG. 5 is a schematic diagram for explaining tool change in the turret 164.
As described above, the turret base 102 of the machine tool 100 includes the turret 164 that is rotatable. The turret 164 is rotatable about its center axis. The turret 164 includes 12 stations 104 (S1 to S12) at each of which the holder 168 can be set, as tool attachment positions. A work tool is attached at each station 104. Depending on the holder shape, two or more tools can be attached at one station 104.

The shape and the size of the tool may vary. The tool is attached to the holder 168, and the holder 168 is attached at the station 104. The machine tool 100 identifies each tool by a tool number. In FIG. 5, a work tool having a tool number T3 (hereinafter, a "work tool (T3)") is attached at a station 104 corresponding to a station number S1 (hereinafter, a "station 104 (S1)"). Similarly, a work tool (T24) is attached at a station 104 (S2), and a work tool (T20) is attached at a station 104 (S3).

The turret base 102 machines a workpiece with a work tool corresponding to a predetermined machining position 110. In FIG. 5, the workpiece is machined by the work tool (T3) located at the machining position 110 (the station 104 (S1)). The machine tool 100 moves the turret base 102 and the turret 164 and applies the work tool (T3) to a predetermined position of the workpiece at a predetermined angle, thereby machining the workpiece. When the workpiece is to be machined by another work tool (T24), the machine tool 100 rotates the turret 164 to set the work tool (T24) at the machining position 110.

A work tool corresponding to a change position 108 is the target of tool change. The machine tool 100 has the tool storage unit 106 that is also referred to as a tool magazine in general. The tool storage unit 106 has a number of spare tools stored therein. For example, when a spare tool (T4) is attached on the turret base 102, the machine tool 100 stores the work tool (T24) that is located at the change position 108 (the station (S2)) (corresponding to the "attachment/detachment position PT") in the tool storage unit 106 and attaches the spare tool (T4) at the station 104 (S2) corresponding to the change position 108.

As described above, the machine tool 100 machines a workpiece while moving the turret base 102 to change the relative distance and the relative angle between the workpiece and a work tool. Further, the machine tool 100 selects a work tool that is actually used for machining the workpiece from 12 work tools by rotating the turret 164. The work tool and a spare tool can be changed with each other at any time. If a large number of spare tools are stored in the tool storage unit 106 having a large capacity, various types of machining can be realized by one machine tool. On the other hand, if 12 types of tools that are relatively frequently used are attached to the turret 164, it is possible to reduce loss of time involved in tool change.

The machine tool 100 machines a workpiece while repeating tool change in accordance with a machining program. Therefore, a combination of work tools in the turret 164, that is, a tool pattern changes in a complicated manner. The tool pattern referred to here is information specifying the arrangement of one or more tools to be attached to the turret 164 having the plural holders 168. When the turret base 102 is moved in a machining space, it is necessary to create a machining program so as to prevent contact of the work tools attached to the turret 164 with a tailstock or the like. Hereinafter, an event in which a work tool unintentionally comes into contact with a workpiece or external equipment such as a tailstock is referred to as "interference". Due to a large variety of sizes and shapes of tools, it is very difficult to predict in advance under what circumstances interference will occur.

For example, it is assumed that no interference occurs when a finishing process A, which is a part of a machining process, is executed using a tool pattern Q1. However, interference may occur if the same finishing process A is executed again. This is because the tool pattern Q1 at the start of the first finishing process A is different from a tool pattern Q2 at the start of the second finishing process A. At the start of the second finishing process A, a large work tool (TX) is attached to the turret 164, and this work tool (TX) may interfere when the turret base 102 is moved. As described above, even if the turret base 102 is moved in exactly the same manner, interference may or may not occur depending on the tool pattern. In the future, in order to miniaturize the machine tool 100, it is necessary to operate the turret base 102 in a narrow machining chamber, which may increase the risk of occurrence of interference.

Therefore, in the present embodiment, a tool pattern for which interference does not occur is memorized, and this "safe tool pattern" is reproduced and then a machining process is resumed or re-executed, whereby the risk of interference is reduced.

As described above, a "work tool" means a tool attached to the turret 164, and a "spare tool" means a tool stored in the tool storage unit 106 and not to be used for the time being. Among the work tools, a tool located at the machining position 110, that is, a tool indexed to the machining position 110 and used for machining a workpiece is particularly referred to as an "in-service tool". Selecting an in-service tool from a group of work tools by rotating the turret 164 is referred to as "indexing".

FIG. 6 is a hardware configuration diagram of the machine tool 100.
The machine tool 100 includes the information processing device 118, the machining control unit 116, the machining equipment 112, the tool changing unit 114, and the tool storage unit 106. The machining control unit 116 functioning as a numerical controller transmits a control signal to the machining equipment 112 in accordance with a machining program. The machining equipment 112 moves the turret base 102 to machine a workpiece in accordance with an instruction from the machining control unit 116. Further, the machining control unit 116 acquires a tool pattern to be set in the turret base 102 from a tool information management unit 130 (described later).

The information processing device 118 controls the machining control unit 116. In the present embodiment, the information processing device 118 provides a user interface function to an operator and manages tool patterns. The tool storage unit 106 stores spare tools therein. The tool changing unit 114 corresponds to a so-called ATC (Automatic Tool Changer). The tool changing unit 114 takes out a spare tool from the tool storage unit 106 and changes a work tool located at the change position 108 of the turret base 102 with the spare tool in accordance with a change instruction from the machining control unit 116.

FIG. 7 is a functional block diagram of the information processing device 118.
The components of the information processing device 118 are implemented by hardware including computing units such as CPUs (Central Processing Unit) and various computer processors, storage devices such as memories and storages, and wired or wireless communication lines that connect these units and devices, and software that is stored in the storage devices and supplies processing instructions to the computing units. Computer programs may be constituted by device drivers, operating systems, various application programs on upper layers thereof, and a library that provides common functions to these programs. Blocks that are described below do not refer to configurations in units of hardware but to blocks in units of functions.

Note that the machining control unit 116 may also be implemented by hardware including computing units such as processors, storage devices such as memories and storages, and wired or wireless communication lines that connect these units and devices, and software and programs that are stored in the storage devices and supply processing instructions to the computing units, which are executed on operation systems separate from the information processing device 118.

The information processing device 118 includes a user interface processing unit 120, a data processing unit 122, and a data storage unit 124.
The user interface processing unit 120 receives an operation made by a user and performs user-interface-related processing such as displaying an image and outputting audio. The data processing unit 122 performs various type of processing on the basis of data acquired by the user interface processing unit 120 and data stored in the data storage unit 124. The data processing unit 122 also functions as an interface of the user interface processing unit 120 and the data storage unit 124. The data storage unit 124 stores various types of programs and setting data therein.

The user interface processing unit 120 includes an input unit 126 and an output unit 128.
The input unit 126 receives input made by the user via a touch panel or a hardware device such as a handle. The output unit 128 provides various types of information to the user by displaying an image or outputting audio.

The data processing unit 122 includes the tool information management unit 130. The tool information management unit 130 controls return of a tool pattern (described later).
The data storage unit 124 includes a tool pattern memory 132. The tool pattern memory 132 stores therein a tool pattern for each machining program.

Hereinafter, the first embodiment and the second embodiment will be separately described focusing on a processing process of the machine tool 100, in particular, the information processing device 118. Unless the first embodiment and the second embodiment are particularly distinguished from each other, they are referred to as a "present embodiment".

<First embodiment>
In the first embodiment, tools and a tool pattern are associated with each other. A process of machining a workpiece executed in accordance with a machining program is represented as a combination of a plurality of processes. The term "process" used herein is a unit of work defined in accordance with the content of machining, such as end face roughing, outer diameter roughing, inner diameter roughing, semi-finish machining, and grooving.

FIG. 8 is a data structure diagram of setting pattern information 300 in the first embodiment.
The setting pattern information 300 is stored in the tool pattern memory 132. Hereinafter, among tool patterns, a combination of work tools actually attached to the turret 164 is referred to as a "current pattern". Further, a tool pattern associated with a process, in other words, a tool pattern defined for each process is referred to as a "setting pattern". Unless the patterns are particularly distinguished from each other, they are simply referred to as a "tool pattern". The setting pattern information 300 defines a setting pattern for each process. The output unit 128 of the information processing device 118 can also display the setting pattern information 300 on its screen. Performing tool change to make the setting pattern and the current pattern match each other is referred to as "reproduction of a setting pattern" or simply "reproduction".

The machining program is identified by a program number. The tool information management unit 130 manages the setting pattern information 300 for each machining program. The machining control unit 116 instructs the tool changing unit 114 to perform tool change. When performing tool change or indexing, the machining control unit 116 notifies the information processing device 118 of the tool change or the indexing in an appropriate manner. By this control method, the tool information management unit 130 always manages the current pattern.

A sequence number (N number) is assigned to each process. The machining program illustrated in FIG. 8 includes 18 processes of processes N1 to N18. The setting pattern is identified by a pattern ID. A setting pattern of a pattern ID=V1 (hereinafter, a "setting pattern (V1)") is associated with the processes N1 to N12. In the setting pattern (V1), a work tool (T1) is set at the station 104 (S1), and a work tool (T12) is set at a station 104 (S12), for example. When the machining control unit 116 executes the process N1, the tool changing unit 114 performs tool change in such a manner that the current pattern matches the setting pattern (V1) (described later), before start of actual machining.

A setting pattern (V2) is associated with a process N13. In the setting pattern (V2), a work tool (T13) is set at the station 104 (S1), and the work tool (T12) is set at the station 104 (S12), for example. When the process N13 is executed, the tool changing unit 114 performs tool change in such a manner that the current pattern matches the setting pattern (V2) (described later). In other words, the setting pattern (V2) is reproduced, and then the process N13 is executed.

A tool to be used in the process N13 is the tool (T13). The machining control unit 116 indexes the in-service tool (T13) located at the station 104 (S1) to the machining position 110. An instruction for selecting an in-service tool is referred to as an "index code". The index code in the present embodiment is assumed as "GR". When detecting "GR T13" that is an "instruction to index the tool T13 as an in-service tool" during execution of a machining program, the machining control unit 116 rotates the turret 164 to set the tool T13 that is located at the station 104 (S1) to the machining position 110.

The setting pattern can be reproduced as the current pattern by a "return code". The return code is assumed as "GY". When detecting "GY V5" that is an "instruction to reproduce a setting pattern (V5) as the current pattern" during execution of the machining program, the machining control unit 116 notifies the information processing device 118 of the "current pattern" and "pattern ID=V5". When the current pattern and the setting pattern (V5) do not exactly match each other, the tool information management unit 130 of the information processing device 118 notifies the machining control unit 116 of the setting pattern (V5). The machining control unit 116 instructs the tool changing unit 114 to perform tool change in accordance with the setting pattern (V5), whereby the setting pattern (V5) is reproduced as the current pattern.

Meanwhile, when the current pattern and the setting pattern (V5) match each other, tool change is not required. Therefore, the tool information management unit 130 instructs the machining control unit 116 to continue work without performing tool change.

As described above, the machining control unit 116 notifies the information processing device 118 of change of the current pattern every time the current pattern is changed by tool change. The output unit 128 displays the current pattern on its screen in an appropriate manner.

There is a case where it is desired to execute the processes N1 to N18 in turn and re-execute only the process N14 after completion of the process N18. For example, in a case where the process N14 is semi-finish machining, the process N14 may be re-executed if the precision of the semi-finish machining is insufficient for a workpiece after execution of the process N18. At this time, an operator can instruct re-execution of the process N14 after specifying the sequence number N14, from the information processing device 118.
Specifically, the operator selects, on an operation screen, any one process from a plurality of processes in a machining program. At this time, the machine tool executes a program corresponding to the selected process. For execution of the process, tools on the turret are first changed in accordance with the tool pattern associated with the selected process, and actual machining of a workpiece is then started. When any one of the processes is received as a target of execution, the tool pattern associated with the process received as the target of execution is compared with the tools on the turret and the arrangement of the tools, and tool change is performed so that the tool arrangement corresponds to the tool pattern. The tool change can be tool change between the turret and the tool storage unit, tool change within the turret, or tool change in other manners.

The current pattern at the end of machining, that is, at the end of the process N18 is the same as a setting pattern (V7). An in-service tool (T14) in the process N14 remains at the station 104 (S2) for the setting pattern (V7). Therefore, the machining control unit 116 should be able to execute the process N14 by rotating the turret 164 as it is to index a work tool (T14) to the machining position 110.

Here, it is assumed that the work tool (T15) located at the station 104 (S3) has a special shape. When the turret 164 is rotated as it is after completion of the process N18, there is a possibility that the work tool (T15) having a special shape interferes with a workpiece or the like. For this reason, in this case, it is not preferable to re-execute the process N14 while the setting pattern (V7) for the process N18 is kept as the current pattern. Therefore, in the first embodiment, a setting pattern (V3) associated with the process N14 is reproduced, and then the process N14 is re-executed.

FIG. 9 is a schematic diagram of a machining program.
The machining program includes 18 types of program parts corresponding to the processes N1 to N18. Each program part is preceded by the return code GY and the index code GR. The return code GY and the index code GR are followed by an actual machining process, specifically, a method of moving an in-service tool, for example.

When executing a program part of the process N1, the machining control unit 116 first detects a return code "GY V1". The return code "GY V1" is a command for reproducing the setting pattern (V1) as a current pattern. After the setting pattern (V1) is reproduced, that is, after tool change is performed so as to reproduce the setting pattern (V1) in the turret 164, the machining control unit 116 detects an index code "GR T1". The index code "GR T1" is a command for moving the tool (T1) to the machining position 110 in order to set the tool (T1) as an in-service tool. After the tool (T1) is set as the in-service tool, the machining control unit 116 executes a body program of the process N1.

When executing the process N2, the machining control unit 116 detects the return code "GY V1" again. Since the current pattern at the end of the process N1 matches the setting pattern (V1), the machining control unit 116 skips the return code "GY V1" in this case. Subsequently, the machining control unit 116 sets a tool (T2) as an in-service tool in accordance with an index code "GR T2" and executes a body program of the process N2.

As described above, when the process N2 is executed after the process N1, the return code "GY V1" in the process N2 is not necessary. This is because the current pattern at the end of the process N1 is the same as the setting pattern (V1) for the process N2. Meanwhile, there may be a case where it is desired to re-execute only the process N2 after execution of the process N18. Since the setting pattern (V7) for the process N18 is different from the setting pattern (V1) for the process N2, it is necessary to reproduce the setting pattern (V1) in this case. As described above, the tool information management unit 130 determines whether to perform tool change based on a return code GY on the basis of the current pattern.

FIG. 10 is a flowchart illustrating processing of reproducing a setting pattern.
When re-executing a part of processes included in a machining program, the machining control unit 116 transmits a pattern ID of a setting pattern specified by a return code and a current pattern (a list of current work tools) to the information processing device 118. The tool information management unit 130 of the information processing device 118 refers to the setting pattern information 300 and determines whether the specified setting pattern and the current pattern match each other (S20). If they match each other (Y in S20), the tool information management unit 130 transmits an execution instruction to the machining control unit 116. When receiving the execution instruction, the machining control unit 116 sets an in-service tool in accordance with an index code (S24) and executes a machining process (S26).

If they do not match each other (N in S20), the tool information management unit 130 instructs tool change together with the content of the setting pattern (a list of work tools to be reproduced) (S22). After the setting pattern is reproduced, the machining control unit 116 sets the in-service tool (S24) and resumes machining of a workpiece (S26).

<Second embodiment>
In the second embodiment, a workpiece and a machining program are associated with each other, and the machining program and a tool pattern are associated with each other. In the second embodiment, it is assumed that a plurality of types of workpieces are sequentially or randomly conveyed to one machining area. When a workpiece is set in a machining area, a workpiece ID for identifying the workpiece is notified from an external controller to the information processing device 118.

FIG. 11 is a data structure diagram of the setting pattern information 300 in the second embodiment.
The setting pattern information 300 in the second embodiment is also stored in the tool pattern memory 132. The setting pattern information 300 defines a setting pattern for each workpiece, more strictly, a setting pattern for each machining program associated with the workpiece. The output unit 128 of the information processing device 118 can also display the setting pattern information 300 on its screen.

It is assumed here that three types of machining programs P1 to P3 are prepared in association with workpieces W1 to W3, respectively. The tool information management unit 130 manages the setting pattern information 300 for each workpiece, in other words, for each machining program.

The machining programs P1 to P3 each include 12 processes of the processes N1 to N12. A setting pattern (V10) is associated with the processes N1 to N12 of the machining program P1 (the workpiece W1). In the setting pattern (V10), the work tool (T1) is set at the station 104 (S1), and the work tool (T12) is set at the station 104 (S12), for example. When the workpiece W1 is machined, the tool changing unit 114 performs tool change in such a manner that a current pattern matches the setting pattern (V10).

Further, a setting pattern (V11) is associated with the processes N1 to N12 of the machining program P2 (the workpiece W2). In the setting pattern (V11), the work tool (T13) is set at the station 104 (S1), and the work tool (T24) is set at the station 104 (S12), for example. When the workpiece W2 is machined, the tool changing unit 114 performs tool change in such a manner that the current pattern matches the setting pattern (V11).

Also in the second embodiment, each machining program is preceded by the return code GY and the index code GR. For example, a return code "GY V10" and an index code "GR T1" are written in the machining program P1.

When the workpiece W1 reaches the machining area, the tool information management unit 130 is notified of a workpiece ID together with the current pattern. The tool information management unit 130 refers to the setting pattern information 300 and determines whether a setting pattern associated with the workpiece ID and the current pattern match each other. If they do not match, the tool information management unit 130 instructs the machining control unit 116 to reproduce the setting pattern in an identical manner to that in the first embodiment.

The tool changing unit 114 reproduces the setting pattern (V10) in accordance with the machining program P1 and then starts machining the workpiece W1. After completion of machining of the workpiece W1, when the workpiece W3 reaches the machining area, the tool changing unit 114 reproduces a setting pattern (V12) in accordance with the machining program P3 and then starts machining the workpiece W3.

Instead of associating a workpiece and a machining program with each other and associating the machining program and a setting pattern with each other, the workpiece and the setting pattern may be directly associated with each other.

<Summary>
The machine tool 100 has been described above on the basis of the embodiments.
According to the first embodiment, a setting pattern is reproduced as a current pattern at start of a process, whereby any process can be safely re-executed at a desired timing. Further, according to the second embodiment, a setting pattern is changed in accordance with a workpiece, whereby a safe current pattern can be reproduced for each workpiece even in a case of successively machining various workpieces.

The present invention is not limited to the embodiments described above and modifications thereof, and any component thereof can be modified and embodied without departing from the scope of the invention. Components described in the embodiments and modifications can be combined as appropriate to form various embodiments. Some components may be omitted from the components presented in the embodiments and modifications.

<Modification>
The first embodiment has been explained on the assumption that a setting pattern is reproduced by a return command and an in-service tool is selected by an index command. In a modification, when a sequence number is specified, the tool information management unit 130 may refer to the setting pattern information 300 to specify the setting pattern and the in-service tool, and instruct the machining control unit 116 to perform tool change and tool selection.

The first embodiment has been explained such that after the processes N1 to N18 are executed, an operator instructs re-execution of the process N14. In a modification, even in a case where a machining program is defined in advance in such a manner that the process N14 is re-executed after the processes N1 to N18 are executed, reproduction of the setting pattern and re-selection of the in-service tool may be performed when the process N14 is executed for the second time.

The setting pattern may be reproduced not only when a process is re-executed but also when work is abnormally stopped during a process. For example, it is assumed that the machining equipment 112 is abnormally stopped in the middle of the process N15 and thus re-execution from the process N14 is desired. In this case, it suffices that the machining control unit 116 reproduces a setting pattern for the process N14 and then resumes machining of a workpiece from the process N14.

The first embodiment has been explained such that a process and a setting pattern are associated with each other. Further, the second embodiment has been explained such that a workpiece (a machining program) and a setting pattern are associated with each other. In addition, both the process and the workpiece may be associated with the setting pattern.

For example, the setting pattern (V1) may be associated with the workpiece W1 and the process N1, the setting pattern (V2) may be associated with the workpiece W1 and the process N2, and the setting pattern (V3) may be associated with the workpiece W2 and the process N1.

The second embodiment has been explained such that a machining program is associated with each workpiece, and a setting pattern is associated with each machining program. In addition, a plurality of types of workpieces is machined by the same machining program in some cases. In these cases, the workpiece and the setting pattern may be directly associated with each other.

There is also a situation in which all or some of the 12 stations 104 of the turret 164 are not equipped with tools. For example, for maintenance or repair, all tools on the turret 164 may be temporarily removed or manually accommodated in the tool storage unit 106. Further, a tool whose life has expired due to wear or a tool that has been chipped and is not suitable for continuous use may be removed from the turret 164.

For example, it is assumed that, in a current pattern, although only the station 104 (S2) is "vacant", the other stations 104 are the same as those in the setting pattern (V2) illustrated in FIG. 8. It is also assumed that the process N13 is re-executed in this state. The tool information management unit 130 may instruct the machining control unit 116 to perform tool change because the setting pattern (V2) for the process N13 and the current pattern do not exactly match each other.

Further, it is assumed that, in a current pattern, the station 104 (S2) is "vacant", and the tool (T14) is attached at the stations 104 (S3), instead of the tool (T3). It is assumed that the stations 104 other than the station 104 (S2) and the station 104 (S3) are the same as those in the setting pattern (V2). In this state, also when the process N13 is re-executed, the tool information management unit 130 instructs the machining control unit 116 to perform tool change based on the setting pattern (V2).

The first embodiment has been explained such that a setting pattern is associated with each process defined in a machining program. However, instead of the machining program that defines a method of machining a workpiece, a process included in a measurement program or a grinding program and the setting pattern may be associated with each other.

The first embodiment has been explained such that when the process N14 is re-executed after the process N18 is executed by the setting pattern (V7), the tool changing unit 114 reproduces the setting pattern (V2) for the process N14. In a modification, the tool changing unit 114 may reproduce a part of the setting pattern (V2) instead of completely reproducing the setting pattern (V2). For example, it is assumed that the tool (T15) included in the setting pattern (V7) is a tool having a special shape. When the tool (T15) is present on the turret 164, an operator may manually instruct tool change for only the station 104 (S3) holding the tool (T15), from the input unit 126. At this time, the tool changing unit 114 changes the tool (T15) with the tool (T3) at the station 104 (S3). This control method can shorten the time required for tool change because an entire tool pattern is not changed. When the operator is confident that no interference will occur if only the tool (T15) is changed, it may be desirable to perform tool change for a part of the stations 104, as described above.

The tool information management unit 130 may store information that the tool (T15) is a tool having a special shape therein beforehand. When the operator instructs re-execution of the process N14 after execution of the process N18, the tool information management unit 130 confirms that the tool (T15) having a special shape is included in a current pattern. When the tool (T15) is included in the current pattern, the tool information management unit 130 may notify the operator with an alarm. At this time, the operator may manually instruct change of the tool (T15) included in the current pattern with the tool (T3) from the input unit 126. Alternatively, under a condition that the tool (T15) having a special shape is included in the current pattern, the tool information management unit 130 may instruct the tool changing unit 114 to perform tool change so as to reproduce the setting pattern (V2).

FIG. 12 is a data structure diagram of the setting pattern information 300 in the modification.
In the setting pattern information 300 illustrated in FIG. 12, there are a plurality of tools to be used in the process N14. There are four types of tools to be used in the process N14, including the tool (T14), the tool (T3), a tool (T10), and a tool (T11).

It is assumed that the process N14 is re-executed after the process N18 is executed by the setting pattern (V7). The setting pattern (V7) includes the tool (T14), the tool (T10), and the tool (T11) to be used in the process N14, but does not include the tool (T3). In this case, an operator may instruct change of the tool (T15) with the tool (T3) for the station 104 (S3) only. This control method can shorten the time required for tool change because an entire tool pattern is not changed.

The tool information management unit 130 may detect tools to be used in the process N14 and determine whether all the tools to be used are included in a current pattern, when execution of the process N14 is instructed. The tool information management unit 130 may not perform tool change when all the tools to be used in the process N14 are included in the current pattern, and may instruct tool change for only the corresponding station 104 when all the tools to be used in the process N14 are not included in the current pattern. In the above example, the tool information management unit 130 may instruct the tool changing unit 114 to perform tool change for the station 104 (S3) only.

The machine tool 100 may be provided with an MDI mode (Manual Data Input Mode) for creating a simple command or a program at a work site and instructing execution thereof. Hereinafter, the program created in the MDI mode is particularly referred to as an "MDI program". The MDI program is often a one-time simple program created by the user interface processing unit 120, and a program number is not set. In this MDI program, any setting pattern associated with an existing machining program may be reproduced. For example, a return code may be written in the format of "GY B1234 V5" in the MDI program. In this case, the tool information management unit 130 reads the setting pattern (V5) for a machining program (with a program number B1234) and notifies the machining control unit 116 of the read setting pattern. It suffices that the machining control unit 116 instructs the tool changing unit 114 to perform tool change in accordance with the notified setting pattern (V5).

The present embodiment has been explained such that one holder 168 is attached at one station 104, and one work tool is attached to one holder 168. Alternatively, one holder 168 may allow a plurality of work tools, for example, a set of four work tools to be attached thereto. In this case, instead of associating the station 104 and tool numbers with each other as a tool pattern, the station 104 and a set number of a tool set may be associated with each other.

The input unit 126 of the information processing device 118 may receive selection of one of a plurality of processes defined in a machining program, as a machining target. When any one of the processes is received as the target of execution, the tool changing unit 114 performs tool change between the turret 164 and the tool changing unit 114 in accordance with a tool pattern associated with the process received as the target of execution. After tool change by the tool changing unit 114, the machining control unit 116 controls a tool attached to the holder 168 of the turret 164 to machine a workpiece.
When any one of the processes is received as the target of execution, the tool changing unit 114 may perform tool change on the turret 164 in accordance with a tool pattern associated with the process received as the target of execution.

The tool changing unit 114 performs tool change in accordance with a first tool pattern in a first one of a plurality of processes defined in a first machining program. The machining control unit 116 machines a workpiece after tool change to the first tool pattern. The tool changing unit 114 performs tool change in accordance with a second tool pattern in a second one of the processes defined in the first machining program. The machining control unit 116 machines the workpiece after tool change to the second tool pattern.

The tool pattern memory 132 may store therein the setting pattern information 300 that defines a plurality of tool patterns for each machining program, and each tool pattern defined in the setting pattern information 300 may be associated with any one of a plurality of processes defined in the machining program.

Cross-reference to Related Application(s)

This application claims priority from Japanese Patent Application No. 2021-073735 filed on April 26, 2021, the entire contents of which are hereby incorporated by reference herein.

Claims

A machine tool comprising:
a turret capable of attaching a plurality of tools;
a tool storage unit capable of storing a plurality of tools;
a machining control unit, for machining a workpiece in accordance with a machining program, controlling a tool attached to the turret;
a tool changing unit for changing the tool attached to the turret with a tool stored in the tool storage unit; and
a tool pattern memory for memorizing a tool pattern that specifies one or more attached tools to the turret corresponding to a process defined in the machining program,
wherein if the process is selected to execute, the tool changing unit performs tool change in accordance with the tool pattern associated with the selected process.
The machine tool according to claim 1, wherein
when execution of any of the processes is instructed by an operator, the tool changing unit performs tool change between the turret and the tool changing unit in accordance with a tool pattern associated with the process for which execution is instructed, and
the machining control unit machines the workpiece in accordance with the process for which the execution is instructed, after completion of the tool change.
The machine tool according to claim 1, wherein
the machining program includes a return code that is a command to instruct reproduction of a tool pattern for each process, and
when the return code is detected, the tool changing unit performs tool change between the turret and the tool storage unit in accordance with a tool pattern specified by the return code.
The machine tool according to claim 3, wherein, when the return code is detected, the tool changing unit skips the tool change in a case where the tool pattern specified by the return code and a combination of one or more tools attached to the turret are the same as each other.
A machine tool comprising:
a turret capable of attaching a plurality of tools;
a tool storage unit capable of storing a plurality of tools therein;
a machining control unit, for machining a workpiece in accordance with a machining program, controlling a tool attached to the turret;
a tool changing unit for changing the tool attached to the turret with a tool stored in the tool storage unit; and
a tool pattern memory for memorizing a tool pattern that specifies one or more tools to be attached to the turret corresponding to a workpiece being selectable as a machining target,
wherein the tool changing unit performs tool change between the turret and the tool storage unit in accordance with a tool pattern associated with one of the workpieces which is selected as the machining target.
The machine tool according to claim 1, wherein the tool changing unit performs tool change between the turret and the tool storage unit.
The machine tool according to claim 1, wherein the tool changing unit performs tool change within the turret.