JPH02190242A - Process control system for machining - Google Patents

Abstract

PURPOSE:To make it possible to uniformly compute process time by computing process elements and an amount of processing by each processed portion of a work piece, and thereby obtaining both the optimum kind of a process machine and its process time as well as the semi-applicable kind of a process machine and its process time. CONSTITUTION:A system is divided into A, B and C levels so that A level shall include the plural kinds of machine tools, B level shall include each process unit of a work piece, and C level shall include process element distinctions. Drawing information and other information (material dimension, product dimension and material) are inputted into a computer C, and data for all levels is concurrently inputted into a single program C. A process management planner inputs each process element and measurement of every processed portion of the work piece, computing an amount of processing, and obtains the optimum kind of a process machine based on process order and process time including handling time so as to be operated so that they are thereby directed on a written request.

Description

[Detailed Description of the Invention] (a) Industrial Application Field The present invention relates to a machining process control system, and more specifically, it is applicable to machining process control systems for machining a variety of workpieces in small quantities using multiple types of machine tools. It relates to process control systems.

([1) Prior Art FIG. 4 shows a typical example of a conventional process control system used when a workpiece is cut using a plurality of types of machine tools. Conventional management systems calculate each element, calculate the unit machining time, add the unit total to get the net cutting time, and finally multiply by the margin rate to calculate the required machining time manually. Since machine tools were selected empirically, it was difficult to set maintenance times in advance.

It takes time to perform detailed manual calculations for each element (
(about 30 minutes to 2 hours per case).

There are large individual differences depending on the person doing the calculation (there is a drawback that standard time calculations cannot be performed.There are many factors that only a veteran with machining experience can judge), making it impossible for an inexperienced person to calculate.Furthermore, Even if the processing time for each element was calculated, the combination of processes was left to the on-site workers.

To solve this problem, the following systems have been proposed.

JP-A-62-19380 discloses a device for allocating work to machine tools, which transmits information such as the time required to process a workpiece and priority to multiple machine tools with similar capabilities. This disclosure discloses a process control device based on a method in which a process is assigned and a process is selected by a computer.

Japanese Patent Application Laid-Open No. 136161 discloses a low-volume, high-mix machining process planning method in which the allocation of each part is calculated in various ways based on information such as the machining process of each part, requested date, and factory process status. , discloses a method that assigns processing priority to processed products with the least processing margin. This method takes into consideration the combination of machining processes, etc., and performs optimal allocation based on computer simulation.

JP-A No. 61-81752 discloses a device that estimates the operating status of the combination of the number of processing machines in an automatic processing line assuming various processed products, and is an effective method when considering the installation of a new processing line. The device is disclosed.

In Japanese Patent Application Laid-Open No. 82-224581, information on processed products and processes are manually calculated, the process load is calculated, and necessary countermeasures and measures are taken.
It is a method for displaying process changes, etc., and discloses an auxiliary means for process management.

Even in the above proposals, there are many matters that are difficult to judge unless one has practical experience in machining, and the amount of work differs for each machine tool model, so it is impossible to expect an equal load on each machine. For this reason, machining was frequently transferred to a different model at the discretion of the foreman, and machining delays often occurred due to intentional errors in judgment.

Q9 Problems to be solved by the invention The problems to be solved by the present invention are to eliminate individual differences among those who perform process control, select the most suitable machine from a wide variety of machine tools, and uniformize machining time. The objective is to obtain a machining process control system that can perform calculations.

(→ Means for Solving the Problems The machining process control system of the present invention is a machining process control system in which a workpiece is cut (including grinding) using multiple types of machine tools. The machining elements and machining parts are calculated for each machining part of the workpiece from the dimensions and materials, and the optimal machining model and machining time including handling time are calculated from the machining order, and the semi-adaptive machining model and machining time are calculated. The above problem is solved by means of instructions on the request form.

In other words, when performing machining process management (planning), we mechanize (computerize) calculation of machining time, which requires the most calculations, perform calculations for multiple types of machining forms, make it easier to judge work combinations, and In order to improve process control accuracy,
This is to ensure efficient operation of machine tools.

In addition, parts that require many decisions at the processing site, such as the operating status of each machine tool and the status of workers, are assigned manually as before, but instead, semi-adaptive model information is added to the processing instructions to improve process control. The system allows for easy changes (sudden interruptions, changes in processing equipment, etc.).

(e) Embodiment An embodiment of the machining process control system of the present invention will be described with reference to FIG.

The system of the present invention is divided into levels A, B, and C.

At the A level, multiple types of machine tools are provided. At the B level, each processing unit of the workpiece is provided. At C level, separate machining elements are provided.

Next, input the drawings and other information (workpiece material dimensions, product dimensions, materials) into computer C manually, and at the same time input all the aforementioned data into one program into computer C. put.

The process control planner inputs machining elements and finished dimensions for each machining part of the workpiece through interactive input with a computer, calculates the machining amount, and determines the optimal machining machine type and machining time including handling time from the machining order. Then, the semi-adaptive machining model and machining time are calculated and indicated on the machining request form.

First, input to the computer is made by selecting the model by number on the first processing selection processing screen, and then expanding to the next input screen. The material, material size, etc. may be self-maintained as internal data, thereby saving the effort of inputting them during subsequent processing. Other data and coefficient relationships are programmed in advance, so when a corresponding item appears, the computer automatically searches and calculates it.

Internal data includes the setup time for setting the material on the machine tool. This is done by dividing the materials into smaller pieces according to their size and length, and programming in a list format.

Approximately 7 types of material coefficients are input. For overlay repair products, we divide them into automatic overlay by machines and manual overlay by humans, and calculate the difficulty of processing into coefficients.

The slenderness coefficient is the strain caused when cutting a long and slender object,
Considering deflection, etc., the degree of difficulty of processing is expressed as a coefficient.

The difficulty of thread machining also changes depending on the inner and outer diameter, so it is corrected with a coefficient.

Other coefficients are shown in the tables below.

All of these coefficients are programmed as internal data of the computer, and the computer operator can calculate them simply by answering the computer's instructions.

When you enter one piece of data (drawing dimensions) on the input screen,
The cursor moves to the next input frame, and settings are made so that even beginners can input and there will be no erroneous operation. The computer internally compares the calculation results for each model and outputs the model that can perform the process in the shortest time and the required time.

Furthermore, the semi-adapted model and machining time are also calculated, and these are used as a reference and output in the form of a work instruction sheet, etc.

The worker decides which model to work on based on the optimal model, semi-adaptive model information, and the amount of work for each machine, and prioritizes the work based on the relationship between machining time (instruction sheet) and delivery date. Perform tasks such as giving instructions.

The concept of the cutting theory of the present invention will be explained with reference to FIG. Each symbol in FIG. 2 is defined as follows.

D = Material diameter d: Finished diameter L: Cutting length a: Depth of cut per time n: Number of cuts Tb 2 unit machining time For each block, length is cut once with depth of cut ff1 (a) The cutting time is calculated using the Tb formula.

Ts: Element machining time (Ts) = ΣTb Multiply the sum of Tb for each blot block by the coefficient specified in the next item (■) to obtain by equation 18.

T: Machining time (T) = ΣTs This is the required time for each machine type, which is the total of each block plus the criteria described below, and is determined by the T formula.

AT: Cumulative time (AT) = ΣT For multiple processes, the processing time is the sum of the processing time for each model and part.

However, special processing that is impossible based on calculations will depend on past results and experience.

The basic calculation method is to find the cutting volume for each block, multiply it by each coefficient, and total it. That is, ((block 1
× each coefficient) × direct margin + (block 2 × each coefficient) × direct margin 10...) × indirect margin Each coefficient depends on the workpiece material, cutter, inner and outer diameter, slenderness ratio, holder, setup, preparation, etc. stipulate.

- An example of how to determine the other coefficients mentioned above is listed below.

Drill coefficient (H) Familiarity coefficient (Fc) for drill tip shape and spot facing by cutting tool For products with the same shape, the coefficient is determined according to the number of machining Stepping coefficient (δ) If the workpiece has stepped machining, per location Coefficient (9) Holder coefficient (Dc is the appropriate holder diameter) Hole drilling is as follows:
Determine the coefficient depending on the diameter and depth.

However, Lc = hole length plus 15, Da = finished hole diameter x 0.6Le/De values are rounded to the first decimal place (Note)
DC value limit of 12 shaku or less 4514 to 18 shaku 5020 shaku
...60 30 shaku ...130 (Note) Upper limit milling machine for DC value...42 Horizontal boring machine...63 However, Lc= Hole length plus 15, DC-hole finishing diameter x 0.6
, Lc/Dc values are rounded to the first decimal place.

The holder coefficient when machining large diameters with a horizontal boring machine is calculated using the following formula.

(10〉Deep groove coefficient For deep groove machining, add the following coefficients.

*Definition of groove: Depth/width ≧0.5.

(11) Keyway coefficient Determined by keyway type.

(2) Setup time (1) Preparation time (A) The time required for preparing tools and polishing blades is determined and added.

■ Additional setup time for special machines (A3) a) Special setup time (A2) If steady rest work, transfer work, or midway setup change is required, the following time will be given.

The basic time is 15 minutes (30 minutes only for the large slotter), and the time calculated using the following formula is added depending on the size and length of the workpiece.

b) Special changeover time (A5) (4) Measurement time (A4) Time for changeover with other workpieces of the same head A time for measuring and checking the dimensions of the workpiece is determined and added.

C) Special setup change time (A6) An example of cutting conditions determined based on the data obtained as described above is shown below.

(1) Speed and depth of cut Defined on the element processing side.

0 Cutting speed (V) Since cutting performance varies depending on the material of the cutting tool, a standard cutting speed is determined.

Carbide near 0m/min HSS: 20m/winO
Cutting feed rate (S) Determine for each finish 1-roughness, model, and cutting tool.

0 Preparation amount (a) Determined for each cutting tool and model.

(2) Number of cuts (n) This is the value obtained by dividing the cutting allowance by the depth of cut (a) determined by the model and blade.

■ Handling of n number in lathe machining ■ Handling of n number in special machining An example of the margin factor multiplied by the cutting conditions obtained in this way is shown below.

(1) Direct margin (E) Mechanical margin during cutting and margin for removing chips, etc.

(2) Indirect margin (X) Ancillary work and worker leeway for processing work.

An example of minimum machining time compensation (when machining a single item on a lathe) is shown below.

When calculating the cumulative time, if the time is less than the time shown in the table below, the time shown in the table will be taken as the minimum compensation time.

The setting conditions for the cumulative time (AT) are as follows.

(1) Machine capacity General-purpose machine without numerical control or copying device.

(2) Worker ability A person who has skills equivalent to level 2 of the National Skills Test.

(F) Effects According to the present invention, drawing dimensions are input directly through an interactive method with a computer, so even a person with no machining experience can input them, and the results can be obtained without individual differences. Also, since there is no manual calculation, it is 10% lower than before.
Calculation time per round is reduced from 30 to 120 minutes per round to 2~
It is 15 times more efficient at 5 minutes/time.

The field of application of the present invention is that by uniformly calculating the time required for machining using a machine tool, process control in a production factory can be carried out in detail.

We can respond at an appropriate level with regard to costs when requesting production, pricing of finished products, etc.

In particular, repair parts for steelmaking equipment are mainly manufactured and repaired individually, so by incorporating the standard required time into the maintenance process in advance, it is possible to significantly reduce maintenance loss time.

Figure 3 shows the results of calculating the required machining time for 400 to 500 machining jobs per month at a specific machining specialty factory and comparing the actual drop-in rate over a one-year period.

In this example, the number of machining technicians is limited (52 people), and the actual machining time is compared with the calculated value to show the difference. The fact that the graph in the figure gradually slopes upward to the right indicates that the work efficiency has increased because the worker is a limited skilled worker.

4. (Brief explanation of the drawing) FIG. 1 is an explanatory diagram of the machining process control system of the present invention.

FIG. 2 is an explanatory diagram of the cutting theory of the present invention. FIG. 3 is a detailed explanatory diagram of the present invention. FIG. 4 is an explanatory diagram of a conventional machining process control system.

Claims (1)

[Claims] In a machining process control system that cuts a workpiece using multiple machine tools, the machining elements and machining amount are calculated for each part of the workpiece based on the material dimensions, product dimensions, and material of the workpiece, and the processing order is optimized. A machining process management system characterized by calculating the machining time including the machining machine type and handling time, and the semi-adaptive machining machine type and machining time, and instructing them on the machining request form.