JP2002036050A - Tool changer and machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tool changer that can efficiently change tools between a tool magazine storing a plurality of tools and a machine tool body, and a machine tool that is equipped with the tool changer. SOLUTION: The automatic tool changer (ATC) 14 is equipped to sequentially select tools necessary for machining in accordance with a machining program executed by a numerical control device 20 from among a plurality of tools stored in a tool magazine (MG) 15, and automatically attaches and detaches the tools to and from a main spindle of a machine tool body 11. The numerical control device 20 has a tool rearrangement processing part 36 for preparing a tool rearrangement table in dependence on a machining program to be executed. When a programmable machine controller (PMC) 25 drives the ATC 14 and the MG 15 in dependence on the prepared tool rearrangement table, the plurality of tools stored in the tool magazine 15 are rearranged in advance of to work machining.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool changer for selecting a plurality of types of tools stored in a tool magazine and attaching and detaching the tool to and from a main spindle of a machine tool, and a machine tool equipped with the tool changer.

[0002]

2. Description of the Related Art A numerical control type machine tool such as a machining center capable of performing a plurality of types of cutting at the same place is usually provided with a numerical control device from a plurality of tools housed in a tool magazine (MG). An automatic tool changer (ATC), which sequentially selects tools necessary for machining in accordance with the machining program to be executed and automatically attaches / detaches to / from the main spindle of the machine tool body, is mounted on a standardized tool holder. It is housed in the tool pot of the tool magazine in the attached state.

After a user of a machine tool stores a tool in a tool pot in a tool magazine, the C
By registering all tools stored in each tool pot according to the tool registration screen displayed on the RT, the numerical controller recognizes the tool arrangement stored in the tool magazine.

[0004]

When a user of a machine tool stores a tool in a tool magazine, the tool used in the previous machining is usually vacant in a state where the tool is present in the tool magazine. Since new tools are added to the tool pot, there is generally no relation between the machining sequence according to the machining program and the arrangement of the tools housed in the tool magazine.

Therefore, for example, when the machining time with one tool is extremely short, if the tool used in the next machining is located at a position away from the tool change position in the tool magazine,
It takes time to find the next tool at the tool change position. For this reason, there is a problem that the waiting time until the start of the next machining is increased, and the overall machining cycle time is increased, so that the workpiece cannot be efficiently machined.

In particular, when the number of tools used in a series of machining increases, the time required for tool exchange may be extremely long depending on the arrangement of tools contained in the tool magazine, and the machining efficiency accompanying the tool exchange may be increased. Is remarkably reduced.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a tool exchanging device capable of efficiently exchanging tools between a tool magazine accommodating a plurality of tools and a machine tool main body, and a machine tool equipped with the tool exchanging device. Is to provide.

[0008]

Means for Solving the Problems and Effects There is provided a tool magazine for accommodating a plurality of tools, and a tool magazine for accommodating a plurality of tools before starting machining of a workpiece. And a tool rearranging unit for rearranging the plurality of tools, wherein the tool rearranging unit rearranges the tools stored in the tool magazine based on a use order of each tool at the time of processing a workpiece. Along with
When the same tool is used a plurality of times at the time of machining a workpiece, the arrangement of each tool in the tool magazine is determined by comprehensively considering all use orders of the tool. A feature of the present invention is to provide a tool changing device.

As described above, in this tool changer, the tools in the tool magazine are rearranged on the basis of the use order of the tools at the time of processing before starting the processing of the work. And the tool to be used for the next machining are accommodated in almost close positions, and the next tool can be indexed to the tool change position in a short time, so that the tool can be changed efficiently.

Also, since the tools are rearranged before the start of machining, unlike the case where the tools are rearranged while machining, the time required for rearrangement and the number of tools to be rearranged are different. The tools can be rearranged without restriction.

In the case where the same tool is used a plurality of times at the time of machining a workpiece, all the use orders of the tools used a plurality of times are considered in a comprehensive manner, and each tool in the tool magazine is used. Since the arrangement is determined, the tools can be rearranged in a rational arrangement suitable for tool exchange.

According to another aspect of the present invention, there is provided a tool magazine for accommodating a plurality of tools, and a plurality of the tools accommodated in the tool magazine before machining of a workpiece is started. Tool rearranging means for rearranging, wherein the tool rearranging means rearranges the plurality of tools stored in the tool magazine based on the frequency of use of each tool at the time of machining a workpiece. A feature of the present invention is to provide a tool changing device.

As described above, this tool changer rearranges the tools in the tool magazine based on the frequency of use of the tools at the time of machining before starting the machining of the work, so that the tools with a high frequency of use can be used. Since the tool is housed in a close position and a frequently used tool can be located at the tool changing position in a short time, the tool can be changed efficiently.

[0014] In this tool changer as well, the tools are rearranged before the start of machining as in the case of the tool changer according to the first aspect. Therefore, the time required for rearrangement and the number of rearranged tools are changed. It is possible to reliably perform the rearrangement of the tools without being restricted by the above-described method.

[0015] In particular, as in the tool changer according to claim 3, the tool rearranging means alternately arranges the tools on both sides thereof in descending order of the frequency of use, centering on the tool with the highest frequency of use. By arranging the tools, frequently used tools and infrequently used tools will not be extremely separated from each other.Therefore, when changing from frequently used tools to less frequently used tools, conversely, Tool replacement time when replacing a tool with a low frequency to a tool with a high frequency of use can be kept relatively short.

According to another aspect of the present invention, there is provided a tool magazine for accommodating a plurality of tools, and a tool reordering means for reordering the plurality of tools contained in the tool magazine. Comprising, the tool rearranging means,
There is provided a tool changer wherein a plurality of the tools stored in the tool magazine are rearranged based on the frequency of use of each tool obtained by counting while actually performing machining. It is.

As described above, this tool changer rearranges the tools in the tool magazine based on the frequency of use of each tool obtained by counting while actually performing machining. If the frequency of use of each tool is determined by executing various types of machining programs and the tools are rearranged based on the frequency of use, the frequency of use of each tool can be determined in consideration of multiple types of machining programs. In the case where the machining program is changed among a plurality of types of machining programs executed for obtaining the frequency, there is an effect that it is not necessary to rearrange the tools.

Therefore, as in the invention according to claim 5,
In a machine tool equipped with any of the above-described tool changers, tool change can be performed efficiently and in a short time, so that there is almost no waiting time for tool change and the overall machining cycle time is shortened. This has the effect that the work can be processed efficiently.

[0019]

Embodiments will be described below with reference to the drawings. As shown in FIG. 1, the NC machine tool 1 includes a plurality of tools stored in a tool magazine (MG) 15 having a plurality of tool storage pots connected endlessly by a chain or the like. An automatic tool changer (ATC) 14 for sequentially selecting tools required for machining according to a machining program executed by the operator and automatically attaching / detaching to / from a main spindle of the machine tool main body 11 is mounted. A tool rearranging function for rearranging a plurality of tools housed in a tool housing pot in the tool magazine 15 based on a machining program to be executed is provided.

As shown in FIG.
A CPU 21 for overall control of the control device, a ROM 22 for storing system programs and the like, a RAM 23 for temporarily storing calculation data and display data, and a non-volatile memory for storing machining programs and various parameters The memory (CMOS) 24 performs operations such as supply / cutoff of cutting fluid, automatic exchange of tools, and attachment / detachment of pallets based on a sequence control program.
/ O) Programmable machine controlled via 26
The controller (PMC) 25 converts the digital data such as the position of each axis, an alarm, a parameter, and image data into an image signal and converts the digital signal into a CRT 3 of the CRT / MDI unit 29.
Graphic control circuit (CRTC) 27 for outputting to 0
And an interface (INT) 28 for transferring data input from the keyboard 31 of the CRT / MDI unit 29 to the CPU 21, and outputting an axis movement command from the CPU 21 to the servomotor 12 via the servo amplifier 33. Axis movement control unit 3 that controls the movement of the axis
2 and a spindle drive control unit 34 that controls the rotation of the spindle motor 13 by outputting a spindle speed signal to a spindle amplifier 35 in response to a spindle rotation command or a spindle orientation command from the CPU 21. A tool rearrangement processing unit 36 that rearranges a plurality of tools stored in the tool magazine 15 based on a machining program to be executed is connected via a bus 37, and the actual tool rearrangement processing is performed by a tool rearrangement processing. Based on the tool sorting table created by the unit 36, the PM
C25 is performed by driving the automatic tool changer 14 and the tool magazine 15.

In the NC machine tool 1, as shown in FIG. 2, first, a tool rearrangement table for rearranging tools is created by the above-described tool rearrangement processing section 36 (step S1), and the tool rearrangement table is prepared. After rearranging the tools housed in the tool magazine 15 based on the replacement table (step S2), the workpiece is processed (step S3). The process of creating a tool rearranging table and the process of rearranging tools are performed each time the machining program is changed.

First, the above-mentioned tool rearranging table is created as follows. First, as shown in FIG.
After loading the machining program stored in the non-volatile memory (CMOS) 24 into the work area (step S
11) Analyze the program part in the machining program. As shown in FIG. 4, the program section of the machining program is generally composed of a plurality of blocks, and each block includes a sequence number word indicating a block number, and a sequence number word following the sequence number word. Preparation function word to specify the mode of control operation, dimension word to indicate the movement position and angle, feed function word to specify the feed speed, spindle function word to specify the rotation speed of the spindle, tool function word to specify the tool or work It has at least one function word of an auxiliary function word for instructing on / off control or the like on the machine side.

First, the sequence number (N) is set to an initial value 1
(Step S12), and it is determined whether a tool function word exists in the N-th block (step S13). Here, if a tool function word exists in the block, a parameter serving as a predetermined sorting guideline for the tool specified by the tool function word is set in the tool sorting table (step S14). . on the other hand,
If no tool function word exists for that block,
Without setting parameters in the tool sorting table,
Move to step S15.

The parameters which are set in step S14 and serve as a tool rearrangement guideline include a priority number determined by the order of tool specification by a tool function word in the machining program, and a parameter designated by a tool function word in the machining program. The number of specified times (number of specified frequencies) of each tool to be performed can be considered.

For example, when a priority number determined by the order in which tools are specified is adopted as a parameter serving as a tool rearrangement guideline, as shown in FIG. 4, the tool function words appear in the order in which the tool function words appear. The priority number is set for each of the tools specified by the command such as “1, 2, 3,... N”. If the same tool is specified multiple times, the priority number is set each time it is specified, so if the priority number has already been set, the newly set priority number is By adding “1” to the set priority number and adding “1” to the specified number of tools, and dividing the priority number to which the new priority number is added by the specified number of tools, the actual priority number at that time is calculated. The actual priority number is calculated and set in the tool sorting table as a parameter (see FIG. 5).

On the other hand, when the designated number of times (designated frequency number) of each tool is adopted as a parameter serving as a tool rearrangement guideline, as shown in FIG. "1" is added, and the designated number of the tool at that time is set in the tool rearranging table (see FIG. 7).

As described above, when the parameters are set in the tool sorting table in step S14,
The process proceeds to step S15, where 1 is added to the sequence number (N). Then, it is determined whether or not a block having the sequence number (N) exists (step S1).
6) If there is no block with the sequence number (N), that is, if the program section has ended, the processing for creating a tool rearrangement table ends. On the other hand, if there is a block with the sequence number (N), the process returns to step S13, and a series of processing is repeated for all blocks.

A tool rearrangement process for actually rearranging a plurality of tools stored in the tool magazine 15 based on the tool rearrangement table created as described above will be described.
This will be described with reference to the flowcharts shown in FIGS. In addition, as a parameter that serves as a tool sorting guideline,
Since the tool rearrangement process is different between the case where the priority number determined according to the order in which the tools are specified is used and the case where the specified number of times (designated frequency number) of each tool is used, each case will be described separately.

First, when a priority number determined by the order in which tools are specified is adopted as a parameter serving as a tool rearrangement guideline, a tool with a smaller actual priority number set in the tool rearrangement table has a larger machining program. Since the tools are specified in the initial stage of the above, it is necessary to rearrange the tools so that the tools are stored in the tool magazine 15 in ascending order of the actual priority number.

As shown in FIG. 8, after the tool storage pot number (Np) provided in the tool magazine 15 is set to the initial value 1 (step S21), each of the tools set in the tool rearranging table is set. It is determined whether the actual priority numbers are all “0” (step S22). here,
If the actual priority numbers of the tools set in the tool sorting table are all “0”, the tool sorting process ends. On the other hand, if there is a tool having a real priority number other than "0" in the tool rearranging table, a tool having a minimum real priority number other than "0" is searched (step S2).
3).

Next, it is determined whether the retrieved tool is stored in the Np-th tool storage pot (step S24). Here, if the retrieved tool is not stored in the Np-numbered tool storage pot, the tool stored in the Np-numbered tool storage pot at that time is replaced with the searched tool (step S25). In accordance with the change operation, the "tool registration table" as shown in FIG. 10 in which which tools are stored in which tool storage pots is registered in advance (step S
26), and proceed to step S27.

On the other hand, if it is determined in step S24 that the searched tool is already stored in the Np-th tool storage pot, it is not necessary to rearrange the tools. Therefore, the tools are not replaced and the tool registration table is not changed. Step S
Move to 27.

In step S27, it is determined that the rearrangement processing of the searched tools has been completed, and the "actual priority number", "designated number" and "sum of priority numbers" of the searched tools in the tool rearrangement table are all set. Rewrite to "0". Then, after adding 1 to the tool storage pot number (Np) (step S28), the process returns to step S22, and a series of processing is repeated for the remaining tool storage pots.

As a result, for example, in the case of the machining program as shown in FIG. 4, the tool stored in the tool magazine 15 in the state as shown in FIG. 10A is shown in FIG. As described above, the tools are rearranged in order from the tool specified in the initial stage of the machining program.

In the NC machine tool 1 equipped with the automatic tool changer 14 having the tool reordering function as described above, before starting the machining of the workpiece, the NC machine tool 1 is set on the basis of the number of priorities determined by the use order of the tools at the time of machining. Therefore, the tools in the tool magazine 15 can be rearranged, so that at the time of starting the machining of the workpiece, the tool used in a certain machining and the tool used in the next machining are almost in close proximity to each other.
Since the next tool can be indexed to the tool changing position in a short time, the automatic tool changing by the automatic tool changing device 14 at the time of machining a workpiece can be efficiently performed.

On the other hand, when the designated number (designated frequency number) of each tool is adopted as a parameter serving as a tool rearrangement guideline, a tool with a larger designated number set in the tool rearranging table is used more frequently. Therefore, it is necessary to rearrange the tools in the tool magazine 15 so that the tools having the larger designated times are adjacent to each other as much as possible. The tool magazine 15 is provided with N tool storage pots.

As shown in FIG. 9, first, a counter n is set to an initial value of 1 (step S31). Next, it is determined whether or not the counter n is an odd number (step S32),
When the counter n is an odd number, the calculation formula is: Np = (n-1)
A tool storage pot number (Np) to be rearranged is set according to / 2 + 1 (step S33). If the counter n is an even number, a tool to rearrange according to a calculation formula: Np = N- (n / 2-1). The accommodation pot number (Np) is set (step S34).

Next, it is determined whether or not the designated times of each tool set in the tool sorting table are all "0" (step S35). Here, all the designated times of each tool set in the tool sorting table are “0”.
In the case of, the tool rearrangement process ends. On the other hand, if there is a tool having the specified number of times other than “0” in the tool sorting table, the tool having the maximum specified number of times at that time is searched (step S36).

Next, it is determined whether or not the retrieved tool is stored in the Np-th tool storage pot (step S37). Here, if the retrieved tool is not stored in the Np-th tool storage pot, the tool stored in the Np-th tool storage pot at that time is replaced with the searched tool (step S38). In accordance with the change operation, after a "tool registration table" as shown in FIG. 11 in which which tool storage pot contains which tool is registered in advance is also changed (step S
39), and proceed to step S40.

On the other hand, in step S37, if the retrieved tool is already stored in the Np-th tool storage pot, it is not necessary to rearrange the tools, and the tools are not replaced and the tool registration table is not changed. Step S
Move to 40.

In step S40, assuming that the rearrangement process of the searched tool has been completed, the "designated number" of the searched tool in the tool rearranging table is rewritten to "0".
Then, after adding “1” to the counter n (step S
41), returning to step S32, and repeating a series of processes for the remaining tool storage pots.

As a result, for example, in the case of the machining program as shown in FIG. 6, the tools stored in the tool magazine 15 in the state as shown in FIG. In this way, the tools with the larger designated times are rearranged so as to be adjacent to each other as much as possible.

In the NC machine tool 1 equipped with the automatic tool changer 14 having the above-described tool rearranging function, before starting the machining of the workpiece, the number of times of use of the tool at the time of machining (the frequency of use) is determined. Since the tools stored in the tool magazine 15 can be rearranged, the tools frequently used are stored in close positions, and the tools frequently used are determined in a short time at the tool changing position. Automatic tool changer 1 for machining workpieces
4 can efficiently perform automatic tool change.

In particular, in the automatic tool changer 14 having the tool rearranging function, as described above, the frequency of use is stored in the tool storage pots on both sides of the tool storage pot containing the most frequently used tools. Tools are arranged alternately in descending order, so that frequently used tools and infrequently used tools are not extremely separated from each other, and when replacing frequently used tools with less frequently used tools On the contrary, there is an effect that the tool replacement time when replacing a tool with a low frequency of use with a tool with a high frequency of use can be kept relatively short.

In the NC machine tool 1 equipped with the automatic tool changer 14 having the tool reordering function as described above, the reordering of the tools is performed before the start of the machining of the work. However, unlike the case of rearranging the tools, the rearrangement of the tools can be reliably performed without being restricted by the time for rearranging the number of tools to be rearranged and the like.

In the above-described embodiment, a tool reordering table is created by analyzing a machining program in advance before starting machining of a workpiece, and the tool magazine 15 is stored in the tool magazine 15 based on the tool reordering table. The tools stored in the tool are sorted, but the present invention is not limited to this.For example, the frequency of use of each tool is determined based on a machining program while actually performing machining of a workpiece for a certain period of time. Creating a tool rearrangement table as a parameter as a rearrangement guideline, rearranging the tools housed in the tool magazine 15 based on the tool rearrangement table, and thereafter processing the workpiece. Is also possible.

As described above, when the tool rearranging table is prepared while actually performing the processing, a plurality of types of processing programs are executed, and the tool rearrangement is performed in consideration of a plurality of processing patterns. Table can be created. If the tools stored in the tool magazine 15 are rearranged based on the tool rearrangement table thus created, even if the machining program is changed, In addition, there is an effect that it is not necessary to perform a tool rearrangement process.

As described above, the tool rearrangement process taking into account a plurality of machining programs cannot necessarily be performed unless the machining program is executed. In the analysis processing stage, it is also possible to analyze a plurality of machining programs simultaneously.

In the above-described embodiment, the tools housed in the tool magazine 15 are rearranged by driving the automatic tool changer 14.
However, the present invention is not limited to this. For example, a tool rearrangement mechanism can be attached to the automatic tool changer 14.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a control system of an NC machine tool according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a machining process in the NC machine tool.

FIG. 3 is a flowchart showing a process of creating a tool rearranging table in the NC machine tool.

FIG. 4 is a program list showing an example of a machining program used in the NC machine tool.

FIG. 5 is a tool rearranging table created based on the machining program of the above.

FIG. 6 is a program list showing another machining program used for the NC machine tool.

FIG. 7 is a tool rearranging table created based on the machining program of the above.

8 is a flowchart showing a tool rearrangement process based on the tool rearrangement table shown in FIG.

FIG. 9 is a flowchart showing a tool rearrangement process based on the tool rearrangement table shown in FIG. 7;

FIG. 10A is a tool registration table showing the accommodation state of tools in a tool magazine at an initial stage, and FIG.
7 is a tool registration table showing the accommodation state of the tools in the tool magazine after performing the tool rearrangement process according to the flowchart shown in FIG.

FIG. 11A is a tool registration table showing the accommodation state of tools in a tool magazine at an initial stage, and FIG.
7 is a tool registration table showing the accommodation state of tools in the tool magazine after the rearrangement process is performed according to the flowchart shown in FIG.

[Explanation of symbols]

Reference Signs List 1 NC machine tool 14 Automatic tool changer 15 Tool magazine 20 Numerical controller 21 CPU 22 ROM 23 RAM 24 Non-volatile memory (CMOS) 25 Programmable machine controller (PM)
C) 36 tool rearrangement processing section

Claims (5)

[Claims] A tool magazine for accommodating a plurality of tools;
Before machining of the work, the tool magazine includes a tool rearranging means for rearranging the plurality of tools stored in the tool magazine, the tool rearranging means, based on the use order of each tool at the time of machining the work, In addition to rearranging the tools contained in the tool magazine, when machining the work, if the same tool is used a plurality of times, comprehensively consider all the use order of the tool, the tool A tool changing device, wherein an arrangement of each tool in a magazine is determined. 2. A tool magazine for accommodating a plurality of tools,
Before the start of machining of the workpiece, the tool magazine includes a tool rearranging unit that rearranges the plurality of tools stored in the tool magazine, wherein the tool rearranging unit is based on a frequency of use of each tool during machining of the workpiece. A tool changing device, wherein the plurality of tools stored in the tool magazine are rearranged. 3. The tool rearranging means is arranged such that the tools are alternately arranged on both sides thereof in descending order of the frequency of use, centering on the tool with the highest frequency of use. A tool changer according to item 1. 4. A tool magazine for accommodating a plurality of tools,
Tool rearranging means for rearranging the plurality of tools stored in the tool magazine, the tool rearranging means, based on the frequency of use of each tool obtained by counting while actually performing the processing, A tool changing device, wherein the plurality of tools stored in the tool magazine are rearranged. 5. A machine tool equipped with the tool changer according to claim 1, 2, 3, or 4.