JPS60214008A - Correcting method of work machining precision of numerically controlled machine tool - Google Patents

Abstract

PURPOSE:To improve the machining work by reading a basic work program in advance, and comparing this with a data file which is inputted previously and correcting a tool constant, etc. CONSTITUTION:A work is machined at a proper position in a work machining line by arranging an automatic conveying carriage which conveys the work along front surfaces of plural numerically controlled machine tools in a free reciprocating state and also arranging a centralized tool chamber, etc., along the run path. Further, a control computer is provided for the arithmetic processing of a work program for the work. The equipment identification number of a specific numerically controlled machine tool and its characteristic constant are stored as a data file in the storage part of the computer. Then, the computer reads the basic work program of a work to be worked in advance and selects and compares said stored numberd with said characteristic constant. Consequently, the constant is corrected and the machining is carried out on the basis of it.

Description

[Detailed Description of the Invention] The present invention relates to a method for correcting workpiece machining accuracy in a numerically controlled machine tool, and more particularly, to a method for correcting workpiece machining accuracy in a flexible manufacturing ring system. It is.

B. Conventional technology A work machining system that connects multiple numerically controlled machine tools such as machining centers via a computer and has the flexibility to respond to changes in the load of the workpiece or numerically controlled machine tools, the so-called flexible manual. It is known to configure a facturing system (hereinafter referred to as FMS). In this type of FMS, in order to maintain the machining accuracy of the workpiece at a predetermined level and to improve the productivity of the machining line, the machine program of the workpiece stored in the computer is used to monitor changes in the state of the workpiece in progress. It is necessary to correct it over time depending on the situation. In particular, an automatic transport line (ATL) for workpieces and tool cassettes is installed between multiple numerically controlled machine tools and a centralized tool room (Tool Storage Center (TSC)). )
When machining a workpiece according to the cutting program input to the combiator, dimensional variations between multiple numerically controlled machine tools and between multiple tools belonging to the same group are avoided. Since this has a large effect on the machining accuracy of the workpiece, prior to supplying the workpiece or tool cassette to the numerically controlled machine tool by the ATL, the dimensional characteristics of the individual numerically controlled machine tool to which the workpiece is installed and the numerically controlled machine tool must be checked. It is necessary to correct the dimensional characteristics of a group of tools used in a machine in accordance with the cutting program of the unprocessed workpiece. However, in a known workpiece machining system using a numerically controlled machine tool, a basic machining program is input to each of a plurality of numerically controlled machine tools, and the basic machining program is input to the numerically controlled machine tool from a management system. The dimensional characteristics of the individual numerically controlled machine tools or tool groups, which were only sent directly without correction and are not actually identical, are input in corrected form into the workpiece machining program prior to the start of machining. No consideration was given to keeping it safe. In this way, conventional FMS has been recognized to have limitations that cannot be overlooked when it comes to improving the machining accuracy of workpieces and the productivity of machining lines.

OBJECTS OF THE INVENTION The main object of the present invention is to provide a method for correcting workpiece machining accuracy in a numerically controlled machine tool that can solve the above-mentioned problems observed in conventional FMS.

Another main object of the present invention is to correct the machine-specific constants and tool-specific constants of a basic additive program using the machine-specific constants and tool-specific constants of the data file section input to the combinator of the FMS. The object of the present invention is to provide a method for correcting machining accuracy.

C9 Structure of the Invention The present invention provides a workpiece machining system in which a workpiece is machined using two or more numerically controlled machine tools (M+), (M2), and - using the same machining program. A management computer (C) built into the system reads the basic Canadian program (P^) of the workpiece in advance, and the prefetched basic program program (P^) of the workpiece and the data previously input to the management computer (C) are read in advance. The first gist is a method for correcting workpiece machining accuracy in numerically controlled machine tools, which corrects the basic addition program (P^) of the workpiece by comparing machine-specific constants and tool-specific constants in the file section. .

The invention also provides two or more numerically controlled machine tools (M+),
(K2) In a workpiece machining system including -, a management computer (C
) to select a numerically controlled machine tool (Mn) to set the workpiece by looking ahead at the basic addition program (P^) of the workpiece, and at the same time select the basic addition program (P^) for the workpiece read in advance.
＾) and the machine-specific constants of the data file section inputted in advance to the management computer (C) to determine the machine-specific constants (K1), (K2), - of the basic additive program.
are the new mechanical constants (K1'), (K2')...
The second gist is a method of correcting workpiece machining accuracy in a numerically controlled machine tool by correcting the basic addition program itself.

The present invention further provides two or more numerically controlled machine tools (Ml),
(K2) In a workpiece adjustment system including -, a management computer (C) incorporated in the workpiece adjustment system.
The basic machining program (P^) of the workpiece is read in advance, the tool (Tn) to be actually used for machining is selected from the group of tools (Gn) for machining the workpiece, and at the same time the basic machining program (P^) of the workpiece is read in advance. (P^) and the tool-specific constants in the data file section that have been input in advance to the management computer (C) to convert the tool-specific constants (C+), (C2), - of the basic additive program into new tool-specific constants. (C1')(C2')・-
Alternatively, the third gist is a method for correcting workpiece machining accuracy in a numerically controlled machine tool that corrects the basic cutting program itself.

2. Embodiment FIG. 1 is a plan view of a workpiece processing line employing the method of the present invention, and FIG. 2 is a flowchart for explaining the method of the present invention. Further, FIGS. 3 and 4 are flowcharts illustrating the procedure for correcting machine-specific constants and tool-specific constants according to the present invention.

The workpiece machining line shown in Figure 1 consists of pallets loaded with workpieces (P) and tool cassettes (
An automatic transport trolley (ATL) that functions as a common transport means for a pallet (P) loaded with T C') is arranged so as to be able to reciprocate, and on one side along the travel route of the A'TL. There is a centralized tool room (TSC), an automatic tool changer (ATC), a standby station (SI) for tool cassettes (TC), a standby station (S2) for pallets (P), and a numerically controlled machine tool (Ml). , (K2)
・On the - side, there is a tool cassette (TC) changing device (T
CC), a second automatic tool changer (ATC) is provided which performs a tool (T) exchange operation between the tool cassette changer (TCC) and the numerically controlled machine tool (Mn). Further, a management computer (C) for arithmetic processing of the added program of the workpiece is disposed at an appropriate position on the workpiece processing line.

On the other hand, the tool cassette (TC) contains a plurality of tools (T1) and (T2) selected according to the cutting program of the workpiece.
)... from the centralized tool room (TSC), stores these tools in groups according to tool type, and selects a specific numerically controlled machine tool as instructed by the management computer (C); For example, the present invention is a means for supplying tools to a numerically controlled machine tool indicated by the reference symbol (M+). Management computer (
In C), the basic addition program (P^) of the work is read in advance, and the basic addition program (P^) is compared with the data file previously input to the management computer (C) to determine the basic addition of the work. Nibrogram (P^)
This is to correct. FIGS. 3 and 4 are flowcharts explaining in more detail the procedure for correcting the basic Canadian program (P^) described above.
The terms "machine-specific constants" and "tool-specific constants" refer to individual numerically controlled machine tools (Ml), (K2), ... and individual tools (T+), ( T2) -〇 Machine-specific constants that are constants that indicate dimensional characteristics include, for example, errors in the stroke of the bed of individual numerically controlled machine tools (M+), (Ml)-, or the torsion angle or curvature of the column. Examples of tool-specific constants include taper errors in the shank of the tool holder, errors in attachment to the tool holder, and the like. In other words, the present invention is applicable to individual numerically controlled machine tools, regardless of whether they are of a single model or multiple models, or when a plurality of tools forming a group are displayed with the same standard dimensions. Alternatively, by focusing on the fact that there are inherent dimensional errors between tools, the workpiece basic theory nibogram is corrected by taking into account the above-mentioned inherent dimensional errors, and the machining accuracy of the work is determined only by the basic addition program. This is intended to further improve the performance compared to the case where

FIG. 3 is a diagram illustrating the procedure for correcting machine-specific constants. In the initial state, the management computer (C)
The machine number of a specific numerically controlled machine tool (for example, Ml) and the machine-specific constants (K1), (K2), (K8) of the numerically controlled machine tool (M+) are stored as a data file in the storage section of
−・−・ is input. In this example, machine-specific constants include, for example, the error (K+) of the bed stroke of the numerically controlled machine tool (Ml), the curvature (K2) of the column of the numerically controlled machine tool (M+), and the numerically controlled machine tool (M1). When the basic machining program of the next work to be machined is read in advance by the management computer (C), in which the deflection angle (K8) of the spindle of Ml) is input, the machine table of the numerically controlled machine tool to which the work is to be machined is first read. A number, for example (Ml), is selected, and at the same time, in the storage section of the management computer (C), the basic theory program (P^) of the previously read work and the machine-specific constants in the data file that have already been input are selected. are compared.

As a result, the machine number of the numerically controlled machine tool to which a new work is to be set is changed from (Ml) to (Ml), and the machine specific constants (K1), (K2), and (K8) are changed to the basic additive program of the work (P The machine specific constant (Kro) corresponding to the machine number (Ml) input in ^), (K2
) (Kgo). Thus, the bed stroke error (K+') and the column curvature (K2') of the newly selected numerically controlled machine tool (Ml)
), the deflection angle (Kg”) of the spindle is input in a corrected form into the basic machining program (P^) of the workpiece, and the corrected workpiece machining is applied to the workpiece set on the numerically controlled machine tool (Ml). Highly accurate processing is performed based on Nibrogram (Pg).

On the other hand, FIG. 4 is a flowchart illustrating the procedure for correcting tool-specific constants, and in the initial state, the group number of the tool, for example, a group of drills with a diameter of 30, is stored in the storage section of the management computer (C) as a data file. A tool group number (Gs) indicating a certain condition and tool-specific constants (C1), (C2), (Cs) of a plurality of tools including spare tools belonging to the tool group are input. Tool specific constants include, for example, the Taber error (CI) of the shank portion of the individual drills that make up the croup (G+) of the drill with a diameter of 30 m, the installation error on the tool holder (C2), the eccentricity (Ca) -. etc. are input. In this embodiment, the management combinator (
The basic machine program (P) of the workpiece to be machined next in C)
^) is read in advance, the tool group number 11 to be used first (for example, tool group number (G2), which means a group of drills with a diameter of 36 mm) is selected, and at the same time, the management computer (C ) is the basic program of the prefetched work (P^
) is compared with the fixed number of tools in the data file that has already been input.

As a result, the tool group is the first tool group (G1)
to the second tool group (G2), and the tool specific constants (cl), (C2), (C8), etc. belong to the group of drills with a diameter of 36 cranes corresponding to the tool group (G2). Taper error (C
s'), attachment error to the tool holder (C2'), eccentricity (Cso), etc., respectively. In this way, the first machining is performed using the tool belonging to the newly selected tool group number (G2), and thereafter, the basic cutting program (P^) of the workpiece is read in advance according to the same procedure, and the third machining program is read in advance.
tool group (C8)% 4th tool group (G4)
・Subsequent machining using tools belonging to - proceeds sequentially.

In the above explanation, in order to make it easier to understand, the correction of machine-specific constants and tool-specific constants in the basic machine program (P^) are described as being performed separately, but in reality, The above-mentioned machine-specific constants and tool-specific constants are corrected at the same time by comparing the basic additive program (P^) of the workpiece with the machine-specific constants and tool-specific constants in the data file. Furthermore, in the above embodiment, it is assumed that the machine-specific constants and tool-specific constants of the data file are input into the management computer (C) as comparison target values in advance, but there is an alternative method. It is also possible to omit the input and directly input the machine-specific constants and tool-specific constants of the basic machine program (P^) of the workpiece as absolute values to the management computer (C). Furthermore, the contents of the machine-specific constants or tool-specific constants are not limited by the description of the above embodiments, and can be freely selected from characteristic values other than those described above that indicate dimensional differences between numerically controlled machine tools or tools.

EFFECTS AND EFFECTS OF THE INVENTION As is clear from the above description, the present invention reads in advance the basic additive program of a workpiece, and compares the basic additive program with a data file input in advance to generate the basic additive program of the workpiece. This method corrects machine-specific constants and tool-specific constants, and can greatly improve the machining accuracy of the workpiece compared to machining using only the basic additive program. Furthermore, according to the method of the present invention, the same basic additive program can be used in multiple numerically controlled machine tools with different machine-specific constants, so that the individual numerically controlled machine tools that make up the FMS can be used effectively. can be achieved. Therefore, the usefulness of the present invention can be highly evaluated as it brings about a remarkable improvement effect in improving workpiece machining accuracy in FMS.

[Brief explanation of drawings]

FIG. 1 is a plan view of a workpiece processing line employing the method of the present invention, and FIG. 2 is a flowchart for explaining the method of the present invention. Further, FIGS. 3 and 4 are flowcharts illustrating the procedure for correcting machine-specific constants and tool-specific constants according to the present invention. (Mn) - Numerical control machine tool, (C) - Computer, (P^) - Basic addition program, (Pe) -
Workpiece programmable program, (Kn)--Machine specific constants, (Cn)--Tool specific constants, (Tn)--
Tools actually used for processing. Figure 2 Figure 8a Figure 4

Claims (1)

[Claims] (11) In a workpiece machining system in which a workpiece is machined by two or more numerically controlled machine tools using the same machine program, a management computer built into the workpiece machining system is used to machine the workpiece. Read the basic theory program in advance,
The pre-read basic theory Niprogram of the work is compared with the data file previously input into the management computer, the basic theory Niprogram of the work is corrected, and the corrected Niprogram is used as the actual Machining Niprogram of the work for each numerical control operation. \, A method for correcting workpiece machining accuracy in a numerically controlled machine tool that is characterized by sending data to a machine. (2) In a workpiece machining system that includes two or more numerically controlled machine tools, a management computer built into the workpiece machining system reads in advance the basic theory program of the workpiece and selects the numerically controlled machine tool that will set the workpiece. At the same time, the basic theory Niprogram of the work read in advance is compared with the machine-specific constant data file implanted in the management computer in advance, and the machine-specific constant part of the basic theory Niprogram is compared with the machine-specific constant data file implanted in the management computer in advance. A method for correcting workpiece machining accuracy in a numerically controlled machine tool, which is characterized by correcting using a characteristic constant or correcting the fundamental nibogram itself. (3) In a workpiece machining system that includes two or more numerically controlled machine tools, a group of tools that read in advance the basic program of the workpiece using a management computer built into the workpiece machining system and machine the workpiece. The tool to be actually used for machining is selected from among them, and at the same time, the basic theory nib program of the workpiece read in advance is compared with the tool-specific constant data file inputted in advance to the management combiator, and the tool-specific constants of the basic theory nib program are compared. Correct the constant part using the tool-specific constant in the data file, or
Or a method for correcting workpiece machining accuracy in a numerically controlled machine tool, which is characterized by correcting the basic cutting program itself.