JPH0215341B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for improving the operating efficiency of a numerically controlled machine tool in a workpiece machining system, and more specifically, to a method for improving the operating efficiency of a numerically controlled machine tool in a workpiece machining system.
The present invention relates to a method for improving the operating efficiency of a numerically controlled machine tool in a workpiece processing system comprised of a workpiece supply device, a transport device that supplies the workpieces, and a computer that centrally controls these devices.

[Conventional technology]

A workpiece machining system consisting of multiple computer-controlled numerically controlled machine tools, a workpiece supply device, and a transport device that supplies the workpieces is equipped with a system that responds to load fluctuations of the workpiece or the numerically controlled machine tool. Flexible manipulating systems (hereinafter referred to as FMS) have been provided for the purpose of providing flexibility or self-control capabilities. The FMS supplies a workpiece to a specific numerically controlled machine tool that constitutes the FMS according to a machining program for the workpiece that has been input into the main computer in advance, and performs machining using a tool selected to match the machining program. A numerically controlled machine tool and a workpiece supply device work together to achieve this goal.

[Problem to be solved by the invention]

In the conventional FMS mentioned above, after inputting the workpiece machining program into the main computer, the correspondence relationship established between each numerically controlled machine tool and the workpiece conveyance device is basically unchanged. The machining program is executed. Therefore, if a situation such as damage to a tool or partial modification of a machining program occurs, the machining progress of the workpiece on the numerically controlled machine tool and the waiting time of the workpiece on the workpiece supply device will lose correspondence, and the corresponding relationship will be affected. The operating efficiency of the numerically controlled machine tool and, by extension, the FMS will be significantly reduced.

The main object of the present invention is to provide a method for improving the operating efficiency of a numerically controlled machine tool in a workpiece machining system that can solve the above-mentioned problems found in conventional FMS.

A further main object of the present invention is to read in advance the machining program for subsequent workpieces waiting on each workpiece supply device when machining a workpiece in a numerically controlled machine tool, and calculate the theoretical machining time and the workpiece being machined. Provides a method for improving the operating efficiency of FMS that selects a numerically controlled machine tool so as to minimize the machining waiting time of the workpiece by supplying the next workpiece to the numerically controlled machine tool that minimizes the total machining time of the workpiece and the remaining machining time. It's about doing.

[Means to solve the problem]

The present invention includes a plurality of numerically controlled machine tools _MN ,
A workpiece processing system consisting of a workpiece supply device F _N installed corresponding to each numerically controlled machine tool, a transfer device H that transports the workpiece to each workpiece supply device, and a computer C that centrally controls these. In the FMS, the machining program P _N of the subsequent workpieces W _N ' that is in standby state on each workpiece supply device, which is input to the computer C, is read in advance and the theoretical machining time of these subsequent workpieces is calculated in advance. and corresponding numerically controlled machine tools.
The numerically controlled machine tool M _N that minimizes the total time T _N of the remaining machining time T _RN of the workpiece W N on M _N and the theoretical machining time T _MN of the subsequent workpiece W _N ′ read in advance above is selected as _the subsequent workpiece W _N ′ is selected as a numerically controlled machine tool to load the workpiece W N ′ prior to the introduction of the subsequent workpiece W _N ′, so as to minimize the waiting time of the workpiece W _N ′ on the workpiece supply device F _N and the machine stop time. The present invention provides a method for improving the operating efficiency of a numerically controlled machine tool in a workpiece machining system.

〔Example〕

FIG. 1 is a layout diagram of a plurality of machining centers and a work supply device and a conveyance device that supply workpieces to the machining centers, illustrating an embodiment of the present invention. Further, FIG. 2 is a flowchart explaining the method of the present invention.

In the FMS shown in FIG. 1, there are five machining centers M ₁ to M ₅ , and the machining center M ₁
Five workpiece supply devices F ₁ to F ₅ that supply subsequent works W ₁ ′ to W ₅ ′ to M ₅ and a transfer device H that supplies these works are connected via a management computer C to form a single workpiece. Forming a processing line.

The unprocessed workpiece _WN is sent to the workpiece supply device _FN by the transport device H via a setup station and storage (not shown) based on a processing schedule file input in advance into a scheduling computer (not shown).
By pre-reading the machining program P _N of the unprocessed work W _N by the management computer C, any one of the work supply devices F ₁ to F ₅ disposed opposite to each of the machining centers M ₁ to M ₅ ,
For example, when F ₅ becomes empty, the machining remaining time T _R1 to T _R5 of the workpieces W ₁ to W ₅ set in the machining centers M ₁ to M ₅ and being processed and the workpieces corresponding to the machining centers M ₁ to M ₅ Feeding device F ₁ to
The total time T ₁ to T ₅ of the theoretical machining times T _M1 to T _M5 of the unprocessed workpieces W′ ₁ to W′ ₄ placed at F ₅
is calculated in advance, and the total time (T _N = T _RN + T _MN )
The numerically controlled machine tool M _N with the smallest value is the successor machine W _N
As a numerically controlled machine tool that sets the subsequent work
Selected prior to the introduction of _WN . In this way, the subsequent unprocessed workpiece W _N is introduced into any one of the workpiece supply devices F ₁ to F ₅ in which the waiting time until processing starts is minimized. In this way, the unprocessed workpiece _WN is transferred to one of the workpiece supply devices _F1 to _F5 .
For example, the fifth workpiece feeding device F ₅ is introduced, and after finishing processing of the workpiece W ₅ , the workpiece feeding device F ₅
It is installed in the fifth machining center _M5 corresponding to , and is subjected to cutting according to the machining program P _N . FIG. 2 shows a specific example of the present invention as a flowchart. In Fig. 2, when one work supply device becomes empty, the remaining machining time T _RN of the workpieces W ₁ to W ₅ set in the machining centers M ₁ to M ₅ and being machined is (machining time - machining elapsed time) and the theoretical machining time T _MN of the unmachined workpieces W' ₁ to W' ₄ placed in the work supply devices F ₁ to F ₅ are determined from the waiting time from the machining program P _N. The unprocessed machine table for the unprocessed workpiece W _N with the minimum waiting time is selected based on the minimum value of T _N =T _RN +T _MN . (However, T _N = T _RN + T _MN , (N=
1, 2,...5)) When selecting the unprocessed workpiece W _N as described above, if there is no workpiece W′ _N on the workpiece supply device F _N , the theoretical machining time T _MN is set to “0”. .

When determining the minimum waiting time using the above discriminant,
Machining center M _N that sets unprocessed workpiece W _N
If the machine number matches the machine number of the machining center M _N specified in the machining schedule file, the unprocessed workpiece W _N is determined to have a specified number and is selected by the above discriminant. The machine number of the machining center M _N to which _the unprocessed work _{W N} is to be placed is specified in the machining schedule file. If it does not match, this determination result is fed back to the part determination step of the machining program P _N , and thereafter a machining center to which the unmachined workpiece W _N is to be placed is selected in the same procedure as described above.

〔Effect of the invention〕

As is clear from the above explanation, by employing the method of the present invention, processing waiting time in FMS can be significantly shortened. Therefore, the flexibility of the workpiece machining schedule is improved, and FMS
In addition, the operating efficiency of the numerically controlled machine tools that make up the system is greatly improved. Thus, the present invention
It is possible to achieve improvements that greatly exceed the level of conventional technology in terms of improving FMS productivity and reducing manufacturing costs.

[Brief explanation of drawings]

FIG. 1 is a layout diagram of a management computer, a plurality of machining centers, a workpiece supply device to the machining centers, and a conveyance device that supplies the workpieces to these machining centers, illustrating an embodiment of the present invention.
FIG. 2 is a flowchart illustrating the method of the present invention. M _N ... Numerical control machine tool, F _N ... Work supply device, C ... Computer, FMS ... Work processing system, W _N ... Subsequent unprocessed work, P _N ...
...Machining program, T _RN ...Remaining machining time of the workpiece being machined, W ₁ ...Workpiece being machined, T _MN ...Theoretical machining time of the subsequent workpiece waiting on the workpiece supply device, W _N ′... ...Subsequent workpiece waiting on the workpiece transfer device, H...Workpiece transfer device.

Claims (1)

[Claims] 1. A plurality of numerically controlled machine tools, a work supply device installed corresponding to each numerically controlled machine tool,
In a workpiece processing system composed of a conveyance device that supplies workpieces to these devices and a computer that centrally controls these devices, subsequent workpieces waiting on each workpiece feeding device are input to the computer. The theoretical machining time of these subsequent workpieces is calculated in advance by reading the machining program of By selecting the numerically controlled machine tool that takes the minimum total time as the numerically controlled machine tool for setting the subsequent workpiece before introducing the subsequent workpiece, the waiting time for the workpiece on the workpiece supply device and the machine stop time are minimized. A method for improving the operating efficiency of a numerically controlled machine tool in a workpiece machining system.