JPS6288544A - Method of determining and controlling circumferential speed in machine tool - Google Patents

Abstract

PURPOSE:To reduce the frequency of tool exchange to aim at enhancing the availability factor of a machine tool, by computing the associated circumferential speed in accordance with a cutting condition, an override value for a material to be cut when no indication concerning the life of a tool is made, but in accordance with a quality coefficient of the material and a standard life time in addition to the above factors when the indication is made. CONSTITUTION:When a circumferential speed determining program FCP asks a cutting condition table CCT stored in a table memory 12 as to a cutting condition, the condition is at once determined since standard circumferential speeds RV, FV for a rough fabrication process and a finish fabrication process corresponding to the standard life times of tools, the cut-in amounts of the tools, the amounts of feed and the like for individual fabricating modes are stored in the CCT. Then, if no tool life desired by the operator is inputted, a circumferential speed determining section computes a circumferential speed from a peripheral speed override value. Further, if the tool life is set, a standard life time corresponding to an override value in a quality table for materials to be cut is read out from a tool data file to compute a peripheral speed suitable for a set tool life. Accordingly, a predetermined fabrication process is carried out in accordance with the cutting condition in order to reduce the frequency of tool exchange.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention is directed to a machine tool such as a lathe that is capable of automatically determining circumferential speed during processing in consideration of tool life. This invention relates to a circumferential speed determination control method.

(b), Conventional Technology Conventionally, in numerically controlled machine tools such as lathes, machining circumferential speed is determined based on a cutting condition table showing the circumferential speed predetermined based on the machining mode, and a cutting condition table for each workpiece. It was calculated and determined from the overwrite value as a correction value for the circumferential speed, and the life of the tool was not taken into account at all.

(C) 0 Problems to be solved by the invention However, in this case, the tool always wears out within a certain life time.
Even at night, etc., the tools wear out and therefore the tools need to be replaced at the same intervals as during the day, creating the inconvenience that the same number of management personnel are required as during the day. In addition, at night (or under certain conditions), it is more important to maintain the operating rate of the machine tool than the machining efficiency of the tool, and if there are fewer tool changes, the operating rate of the machine will increase accordingly). In some cases, it is desirable to be able to control the circumferential speed, and it has been desired to develop a control method that determines the circumferential speed while taking the life of the tool into account.

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned drawbacks, it is an object of the present invention to provide a tool circumferential speed determination control method for a machine tool that is capable of determining the circumferential speed in consideration of tool life.

(d) Means for solving the zero problem, that is, the present invention has a tool life input means (6), and a cutting condition table (OC
A workpiece material table (12) that stores the workpiece material T) and shows the material coefficient (a) for each workpiece material and the override value (vo) corresponding to the standard life time (To) of the tool.
A second memory (11) that stores the tool's standard life time (Tol) and a third memory (10) that stores the tool's standard life time (Tol).
), and when determining the cutting conditions, if the tool life (T) is not instructed from the input means, the first
Based on the cutting conditions read from the cutting conditions table (OCT) in the memory of When the calculation is determined and the tool life is instructed from the input means, the cutting conditions read from the cutting condition table (OCT) in the first memory and the work material read from the second memory. override value (vo) and material coefficient (α), and standard life time (To) of the used tool read out from the third memory.
), the circumferential speed corresponding to the instructed tool life (T) is calculated and determined, and the machining operation is performed based on the determined circumferential speed.

Note that the numbers in parentheses are for convenience and indicate corresponding elements in the drawings, and therefore, this description is not limited to the descriptions on the drawings. The following r (el
The same applies to the column ``, action''.

(e) Operation With the above-described configuration, the present invention allows the standard life time (T) to be inputted when the tool life time (T) is instructed from the input means.
From the circumferential speed corresponding to To), the circumferential speed corresponding to the specified life time is calculated and determined, and the machining operation is performed based on the calculated circumferential speed. Acts to perform processing.

(f), Example Embodiments of the present invention will be described below based on the drawings.

Fig. 1 is a control block diagram showing an example of a machine tool to which the present invention is applied, Fig. 2 is a flowchart showing an example of a circumferential speed determination program, Fig. 3 is a diagram showing a cutting condition table, Fig. 4 is a diagram showing a workpiece material table, and FIG. 5 is a diagram showing a tool data file.

A machine tool 1 such as a lathe, as shown in FIG. , system program memory 9, tool data memory 10, workpiece material table memory 11, cutting condition table memory 12,
The machine control section 13 and the like are connected.

Since the machine tool 1 has the above configuration, when determining the circumferential speed during machining when creating a cutting program, the main control section 2 reads the circumferential speed determination program FCP from the system program memory 9, The circumferential speed during cutting is determined based on the circumferential speed determination program FCP. That is, the circumferential speed determination program FCP is as shown in FIG.
In step S1, the main control unit 2 is instructed to determine cutting conditions such as depth of cut and feed rate, which are cutting conditions other than circumferential speed, by referring to the cutting condition table OCT stored in the cutting condition table memory 12. request.

As shown in Fig. 3, the cutting condition table OCT includes the standard circumferential speed R during rough machining corresponding to the standard life time of the tool for each machining mode (in the case of Fig. 3, turning is shown).
V and standard circumferential speed FV during finishing machining, depth of cut CT,
Since the feed amount FT and the like are stored, the cutting conditions, except for the circumferential speed, are immediately determined according to the machining mode input by the operator.

Next, in step S2, it is determined whether or not the operator has inputted the desired tool life through input means such as the keyboard 6. If the tool life has not been input, the process proceeds to step S3, where the circumferential speed determination calculation unit 7 is caused to calculate the circumferential speed using a normal format. That is, the speed V is V= (RV or HaFv) XV0/100
--------(11RV...
...Standard circumferential speed during rough machining, FV...Standard circumferential speed v0 during finishing machining...Determined from the circumferential speed override value. Note that since equation (1) is a normal, well-known calculation equation for circumferential speed, a detailed explanation of its contents will be omitted. The circumferential speed override value V is obtained from the workpiece material table MTL stored in the workpiece material table memory 11. That is, as shown in FIG. 4, the workpiece material table MTL stores a material coefficient a1 circumferential speed override value V for each workpiece material, and a circumferential speed override value v0 corresponding to the workpiece material to be machined. will become clear immediately.

If the operator has set the tool life in step S2, the process proceeds to step S4 and causes the circumferential speed determination calculation unit 7 to calculate a circumferential speed suitable for the tool life set by the operator. That is, there is generally a relationship between the circumferential speed V and the life time T of the tool as shown in equation (2).

V T = Const.
−・(21) Therefore, by substituting equation (1) into equation (2), VT = (RV or FV) ・V710G
-To = Const, -(3)To...
... m corresponding to vo in the workpiece material table MTL So, when the operator specifies the desired tool life T, V = (RV or +!FV) ・V0/100 ・ (
T/T) = (4), and the circumferential speed determination calculation section 7 calculates and obtains the circumferential speed V suitable for the tool life T specified by the operator based on equation (4). Note that the standard life time T0 for each tool is stored in the tool data file TDF stored in the tool data memory 10, so the standard life time T0 for a certain tool can be determined by reading the tool data file TDF. It becomes clear immediately. The main control unit 2 controls the machine control unit 13 to perform a predetermined machining based on the obtained circumferential speed V and other cutting conditions determined in step S1. Since the obtained circumferential speed V corresponds to the tool life specified by the operator, the tool is machined with the tool life T specified by the operator, regardless of the standard life time T0 of the tool. .

(g) 6 Effects of the Invention As explained above, according to the present invention, the keyboard 6
A first memory such as a cutting condition table memory 12 that stores a cutting condition table CCT showing cutting conditions for each machining mode, and a material coefficient α and standard for each work material. A second memory such as the workpiece material table memory 11 that stores the workpiece material table MTL indicating the override value v0 corresponding to the life time T0, and a third memory such as the tool data memory 10 that stores the standard life time T0. If a memory is provided and the tool life T is not specified from the input means when determining the cutting conditions, the first
Based on the cutting conditions read from the cutting condition table OCT in the memory of and the override value v0 of the workpiece read from the second memory, the peripheral speed based on the standard life time T0 is calculated and determined, and the input means If the tool life is specified by , the cutting conditions read from the cutting condition table OCT in the first memory, the override value v0 and material coefficient a1 of the work material read from the second memory, and Based on the standard life time T of the used tool read from the third memory, the peripheral speed corresponding to the specified tool life T is calculated and determined, and the machining operation is performed based on the determined peripheral speed. With this configuration, the circumferential speed determined in advance based on the standard life time T0 is
It is possible to change the settings to match the desired tool life T9. During night work, etc., the tool life can be used for a longer time than the standard life time T0, reducing the number of tool changes. As a result, the number of management personnel can be reduced, making it possible to build a highly flexible Canada system.

[Brief explanation of drawings]

Fig. 1 is a control block diagram showing an example of a machine tool to which the present invention is applied, and Fig. 2 is a flowchart showing an example of a circumferential speed determination program.
Fig. 3 is a diagram showing a cutting condition table, Fig. 4 is a diagram showing a workpiece material table, and Fig. 5 is a diagram showing a tool data file. 1... Machine tool 6... Input means (keyboard) 10...
・Third memory (tool data memory) 11...
Second memory (workpiece material table memory) 12...First memory (cutting condition table memory) α...Material coefficient T...Standard life time T... ...Life time ■ ...Override value V ...Cirfer speed MTL ...Work material table OCT ...Cutting condition table Applicant Yamazaki Co., Ltd. Iron Works Agent Patent Attorney Phase 1) Shinji (and 1 other person) Figure 1 FCP 131 ゛°′″″′・

Claims (1)

[Claims] A first memory having a tool life input means and storing a cutting condition table showing cutting conditions for each machining mode, a material coefficient for each work material, and a standard life time of the tool. A second table containing a workpiece material table showing the corresponding override values.
and a third memory storing the standard life time of the tool, and when determining the cutting conditions, if the tool life is not specified from the input means, the cutting time in the first memory is provided. Based on the cutting conditions read from the condition table and the override value of the workpiece read from the second memory, a circumferential speed based on the standard life time is calculated and determined, and the tool life is instructed from the input means. in case of,
The cutting conditions read from the cutting condition table in the first memory, the override value and material coefficient of the workpiece read out from the second memory, and the standard life of the tool used read out from the third memory. A circumferential speed determination control method for a machine tool configured to calculate and determine a circumferential speed corresponding to a specified tool life based on time, and perform machining operations based on the determined circumferential speed.