WO2019176773A1

WO2019176773A1 - Wear amount estimation system, correction system, fault detection system, service life detection system, machine tool and wear amount estimation method, machine tool and fault detection method, and machine tool and service life detection method

Info

Publication number: WO2019176773A1
Application number: PCT/JP2019/009337
Authority: WO
Inventors: 巧人三好; 山田　栄二
Original assignee: 日本電産株式会社
Priority date: 2018-03-13
Filing date: 2019-03-08
Publication date: 2019-09-19

Abstract

[Problem] To provide a wear amount estimation system, a correction system, a fault detection system, a service life detection system, and a machine tool and wear amount estimation method for improving the accuracy of the estimated wear amount of a tool. [Solution] This wear amount estimation system is a system for estimating the amount of wear of a tool in a machine tool whereby workpieces having the same specifications are repetitively machined using the tool under the same conditions, wherein said system comprises a calculation unit that calculates A and α in a relational expression expressed by, e.g., W = At^α, where W is the amount of wear of the tool from the start of machining with the tool, t is the elapsed time, and A and α (< 1) are constants, the calculation being made on the basis of a plurality of measured values of the amount of wear of the tool with respect to the time elapsed from the start of machining with the tool.

Description

Wear amount estimation system, correction system, abnormality detection system, life detection system, machine tool and wear amount estimation method, machine tool and abnormality detection method, machine tool and life detection method

The present invention relates to a wear amount estimation system, a correction system, an abnormality detection system, a life detection system, a machine tool and a wear amount estimation method, a machine tool and an abnormality detection method, a machine tool, and a life detection method.

There is known a machine tool that uses a tool to repeatedly process a workpiece having the same specification under the same conditions while correcting the amount of wear of the tool. Such a machine tool is disclosed, for example, in JP-A-8-132332 (Patent Document 1). A method for estimating the wear amount of a tool of such a machine tool is disclosed in, for example, International Publication No. 00/12260 (Patent Document 2). Further, the machine tool predicts the life by confirming the state of wear of the tool used. Such a technique is disclosed in, for example, International Publication No. 00/12260 (Patent Document 3). *

In Patent Document 1, the position where the working surface of the tool is detected is measured at least three times, the deviation amount between the reference position and the measurement position is stored together with the measurement time, and the time is determined based on the relationship between the deviation amount and the measurement time. Disclosed is a method for correcting misalignment in a machine tool in which a function of a curve indicating the relationship between the amount of misalignment and the amount of misalignment is obtained and then the misalignment is obtained based on the function of the curve and the current time to correct the command position of the tool. Has been. *

Patent Document 2 describes a process for creating a tool wear database that associates a tool cutting length and a tool wear amount, and a tool wear amount when the machining is performed before actual machining using the tool wear database. A tool wear amount estimation method comprising: an estimation step. Further, a tool usage determination method is provided that includes a step of comparing the estimated amount of tool wear and a tool life database and giving permission for actual machining.

JP-A-8-132332 International Publication No. 00/12260

Patent Document 1 describes that a curve function for estimating a deviation amount is obtained by smoothly connecting measured points. Since there are many curve functions, the obtained curve function may be inaccurate. If the obtained curve function is inaccurate, the accuracy of estimating the wear amount of the tool is deteriorated. In this case, the command position of the tool cannot be corrected accurately.

In the method of Patent Document 2, in order to estimate the wear amount, it is necessary to measure the wear amount at the same timing as the tool cutting length in the tool wear database. For this reason, the burden of a worker is large.

In view of the above problems, the present invention improves the accuracy of the estimated tool wear amount and easily estimates the tool wear amount, correction system, abnormality detection system, life detection system, machine tool And a wear amount estimation method.

In the machine tool of the above-mentioned patent document 1, it is not assumed that an abnormality occurs during machining. Even if the misalignment is corrected in a state where some abnormality has occurred in the machine tool, the workpiece becomes defective.

In view of the above-described problems, the present invention provides an abnormality detection system, a machine tool, and an abnormality detection method for reducing defective products.

The method of Patent Document 2 has a problem in that the accuracy of determining the life is poor when there is not enough data in the tool wear database and the tool life database. *

In view of the above problems, the present invention provides a life detection system, a machine tool, and a life detection method that improve the accuracy of determining the life.

A wear amount estimation system according to a first aspect of the present invention is a system for estimating the amount of wear of a tool in a machine tool that repeatedly processes a workpiece having the same specifications under the same conditions using a tool. When the amount of wear from the machining start time of the tool is W, the elapsed time is t, and the constants are A and α (<1) , W = At ^α , a calculation unit for calculating A and α of the relational expression represented by:

A wear amount estimation method according to a second aspect of the present invention is a method for estimating a wear amount of a tool in a machine tool that repeatedly processes a workpiece of the same specification under the same conditions using a tool, Based on a plurality of measured values of the wear amount with respect to the elapsed time from the machining start time, the relationship represented by W = At ^α where W is the wear amount from the machining start time of the tool and t is the elapsed time. Calculating A and α in the equation.

A wear amount estimation system according to a third aspect of the present invention is a system for estimating a wear amount of a tool in a machine tool that repeatedly processes a workpiece of the same specification under the same conditions using a tool, Based on a plurality of measured values of the wear amount with respect to the elapsed time from the machining start time, the wear amount from the machining start time of the tool is W, the elapsed time is t, and constants calculated from the measured values are A ₁ and A _2. , Α ₁ , α ₂ , W = A ₁ t ^α1 (t ≦ T ₀ ) (Equation 1), W = A ₂ t ^α2 (T ₀ <t) (Equation 2) A storage unit having data of a plurality of tools of the same specification represented by the above, a calculation unit that calculates Formula 1 for a tool being processed of the same specification, and A ₁ and α calculated by the calculation unit from the storage unit Read the data closest to ₁ and use the read data formula 2 as the machining tool formula 2 And an estimation unit for estimating.

A wear amount estimation method according to a fourth aspect of the present invention is a method for estimating a wear amount of a tool in a machine tool that repeatedly processes a workpiece having the same specifications under the same conditions using a tool, Based on a plurality of measured values of the wear amount with respect to the elapsed time from the machining start time, the wear amount from the machining start time of the tool is W, the elapsed time is t, and constants A ₁ , A ₂ calculated from the measured values, When α ₁ (<1) and α ₂ (<1), W = A ₁ t ^α1 (t ≦ T ₀ ) (Equation 1), W = A ₂ t ^α2 (T ₀ <t) ... a step of preparing a storage unit having data of a plurality of tools of the same specification represented by (Equation 2), a step of calculating Equation 1 for a tool being processed of the same specification, and a storage unit, reads the calculated closest data a ₁ and alpha ₁ was, during processing the a ₂ and alpha ₂ of the data And a step of estimating the formula 2 fixings, the.

An abnormality detection system according to a fifth aspect of the present invention is an abnormality detection system for a machine tool that uses a tool to repeatedly process a workpiece having the same specifications under the same conditions, and the process from the start of machining the tool. Calculates the amount of tool wear over time and calculates a relational expression between the machining time and the amount of wear, and the difference between the amount of wear estimated from the relational expression and the amount of wear measured after the calculation is predetermined. And a determination unit that determines that an abnormality has occurred in the machine tool when the value is exceeded. *

An abnormality detection method according to a sixth aspect of the present invention is an abnormality detection method for a machine tool in which a workpiece having the same specifications is repeatedly processed using the tool under the same conditions, and the process has started since the tool was started. The difference between the process of calculating the relationship between the machining time and the amount of wear by measuring the amount of wear of the tool with respect to time and the amount of wear estimated from the relationship and the amount of wear measured after the calculation is a predetermined value. And a step of determining that an abnormality has occurred in the machine tool. *

A life detection system according to a seventh aspect of the present invention is a system for detecting the life of a tool in a machine tool that repeatedly processes a workpiece of the same specification under the same conditions using a tool. If the relational expression changes due to the calculation unit that calculates the relationship between the machining time and the amount of wear by measuring the amount of wear relative to the elapsed time from the start time, and the calculated amount of wear, the tool life will be reduced. And a determination unit that determines that it has been reached. *

A life detection method according to an eighth aspect of the present invention is a method for detecting the life of a tool of a machine tool that uses a tool to repeatedly process a workpiece of the same specification under the same conditions, and starts machining the tool. The tool life is reached when the relational expression changes due to the process of calculating the relational expression between the machining time and the wear amount by measuring multiple wear amounts with respect to the elapsed time from the time point and the calculation of the wear amount after the calculation. And a step of determining.

As described above, the present invention improves the accuracy of the estimated tool wear amount and easily estimates the tool wear amount, correction system, abnormality detection system, life detection system, and machine tool. In addition, a wear amount estimation method can be provided. *

The present invention can provide an abnormality detection system, a machine tool, and an abnormality detection method for the purpose of reducing defective products. *

The present invention can provide a life detection system, a machine tool, and a life detection method that improve the accuracy of determining the life.

FIG. 1 is a schematic diagram of a machine tool in the embodiment. FIG. 2 is a diagram illustrating the wear amount with respect to the elapsed time of the tool in the embodiment. FIG. 3 is a block diagram illustrating a control configuration of the machine tool according to the first embodiment. FIG. 4 is a flowchart showing a wear amount estimation method according to the first embodiment. FIG. 5 is a flowchart illustrating a correction method according to the embodiment. FIG. 6 is a diagram illustrating a relational expression specified by the wear amount estimation system in the embodiment and measured values of the tool in operation. FIG. 7 is a diagram for explaining parameters of the error index in the embodiment. FIG. 8 is a diagram for explaining an error index in the embodiment. FIG. 9 is a diagram for explaining another error index in the embodiment. FIG. 10 is a diagram for explaining still another error index in the embodiment. FIG. 11 is a flowchart illustrating an abnormality detection method according to the embodiment. FIG. 12 is a flowchart illustrating a life detection method in the embodiment. FIG. 13 is a diagram showing the amount of wear of the tool in the example. FIG. 14 is a diagram in which normal data is extracted from FIG. FIG. 15 is a diagram illustrating the wear amount with respect to the elapsed time of the tool in the example. FIG. 16 is a block diagram illustrating a control configuration of the machine tool according to the second embodiment. FIG. 17 is a diagram for explaining a relational expression in the second embodiment. FIG. 18 shows data stored in the storage unit in the second embodiment. FIG. 19 is a flowchart illustrating a wear amount estimation method according to the second embodiment. FIG. 20 is a flowchart illustrating an abnormality detection method according to another embodiment. FIG. 21 is a diagram showing measured values of the tool and two relational expressions in the embodiment. FIG. 22 is a diagram illustrating the measured values of the tool and the values of A and α in the embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated. *

1 to 12 and 16 to 22, a wear amount estimation system, a correction system, an abnormality detection system, a life detection system, a machine tool, a wear amount estimation method, and a machine tool according to an embodiment of the present invention. A machine, an abnormality detection method, a machine tool, and a life detection method will be described. *

(Machine Tool) As shown in FIG. 1, the machine tool 1 uses a tool 2 to repeatedly process a workpiece 5 having the same specifications under the same conditions. Thereby, the workpiece can be processed into a workpiece having the same shape. *

“Workpieces with the same specifications” are workpieces with the same manufactured conditions. In addition, the material of a workpiece is not specifically limited, A metal may be sufficient and materials other than a metal may be sufficient. “Repeatedly processing under the same conditions” means that the plurality of workpieces are processed under the same conditions because they are processed into the same shape. *

The machine tool 1 includes a tool 2, a support portion 3, and a placement portion 4. The tool 2 processes the workpiece 5. The method of processing is not specifically limited, For example, it is a cutting process. The support part 3 supports the tool 2. The support portion 3 is movable in the left-right (x-axis) direction, the front-rear (y-axis) direction, and the up-down (z-axis) direction. The position of the tool 2 can be moved by moving the support part 3. The placement unit 4 places the workpiece 5 thereon. The support unit 3 moves relative to the workpiece 5 placed on the placement unit 4. For this reason, the mounting part 4 may be movable in the left-right direction, the front-back direction, and the up-down direction. *

The machine tool 1 is an NC (numerical control) machine tool, and further includes a numerical control device that controls the operation of the machine tool 1. The control device instructs a work process necessary for machining such as a path of the tool 2 with respect to the workpiece with corresponding numerical information. *

When the operation of the machine tool 1 is continued, the tool 2 is worn by the processing of the workpiece 5 by the tool 2. Further, during the operation of the machine tool 1, the tool 2 reaches the end of its life or is damaged. Thus, when it cannot process into the workpiece of the same shape, it exchanges for another tool 2 of the same specification. “Tools with the same specifications” are tools with the same manufactured conditions. *

(Wear Amount Estimation System: First Embodiment) <Configuration of Wear Amount Estimation System: First Embodiment> As shown in FIG. 3, the control device of the machine tool 1 includes a wear amount estimation system 10. The wear amount estimation system is a system for estimating the wear amount of the tool 2 in the machine tool shown in FIG. *

As shown in FIG. 3, the wear amount estimation system 10 includes a measurement unit 11, a calculation unit 12, an average calculation unit 13, and a storage unit 14. The control unit including the calculation unit 12 and the average calculation unit 13 is realized by an arithmetic processing device such as a CPU (Central Processing Unit). The storage unit 14 is realized by, for example, a nonvolatile storage device such as a flash memory. *

The measuring unit 11 measures the amount of wear in the elapsed time from the machining start time of the tool 2. The measuring unit 11 may measure the wear amount of the machined surface of the tool, or may obtain the wear amount of the tool by measuring the shape of the workpiece. The measurement part of this Embodiment calculates | requires the wear amount of the tool 2 by measuring the workpiece after the process with the tool 2 with an air micrometer, for example.

The calculation unit 12 calculates a relational expression between the machining time and the wear amount from a plurality of measured values of the wear amount of the tool 2 with respect to the elapsed time from the machining start time of the tool 2. Specifically, the calculation unit 12 calculates a relational expression between the machining time and the wear amount based on a plurality of measurement values measured by the measurement unit 11 for the tool 2 in operation. *

Based on a plurality of measured values of the wear amount with respect to the elapsed time from the machining start time of the tool 2, the calculation unit 12 sets the wear amount from the machining start time of the tool 2 to W, the elapsed time to t, the constants to A and α. (<1) and the on time, to calculate the W = at relation represented by ^alpha a and alpha. As a result, a relational expression representing the wear amount of the tool is determined.

In the present embodiment, the calculation unit 12 uses at least two measured values for one tool 2 in order to calculate A and α and determine a relational expression. The calculation unit 12 may use measurement values obtained by measuring all the workpieces from the machining start time point, or may use measurement values obtained by measuring a part of the workpieces from the machining start time point. You may use only the measured value which measured the workpiece of (refer FIG. 2). *

When the calculation unit 12 calculates A and α for one tool 2, one relational expression can be acquired. The calculation unit 12 may calculate A and α of the tool in operation, or may calculate A and α of a tool having the same specification as that of the tool being operated. The tool of the same specification may be a tool attached to one machine tool, or may be a tool attached to another machine tool of the same specification. “Machine tools with the same specifications” are machine tools that produce the same workpiece by the same operation. *

Here, the relational expression will be described with reference to FIG. The wear amount W with respect to the elapsed time t from the machining start time of the tool 2 can be expressed by the model shown in FIG. The wear time of the tool is an initial stage (0 <t ≦ t ₀ ) in which the wear amount is W ₁ or less with respect to the elapsed time from the start of machining, and a steady stage in which the wear amount exceeds W ₁ and is W ₂ or less ( t ₀ <t ≦ t ₁ ), and there is an end stage (t ₁ <t) where the amount of wear exceeds W ₂ . The initial stage is a state where the amount of wear changes greatly. The steady stage is a stable state in which the change in wear amount is small. The final stage is a state where the amount of wear rapidly increases and reaches the end of its life.

In an initial stage and a steady stage (0 <t ≦ t ₁ ) until the tool 2 reaches the end of its life, it is expressed by a relational expression of W = At ^α (0 <α <1). For this reason, if there are two or more measured values of the wear amount for different times, A and α can be calculated, so that the relational expression can be determined.

The elapsed time t is the time that has elapsed while the machining has been continued, with the time when machining is started after installing a new tool having the same specification as 0. This elapsed time t means that the time for processing one workpiece 5 is the same and is continuously processed at the same pace. The elapsed time t does not include time required for tool replacement. For this reason, the elapsed time t and the number of processes are proportional. In other words, the wear amount from the machining start point of the tool 2 W, the machining number x, a constant when the A 'and α'(<1), may be expressed by W = A'x α ^'. Thus, if the workpiece and the machining conditions are the same, the amount of wear of the tool depends on the elapsed time t, that is, the number of machining.

The storage unit 14 stores the relational expression estimated by the calculation unit 12. The storage unit 14 of the present embodiment stores the relational expression acquired by the calculation unit 12 for each of a plurality of tools 2 having the same specification. That is, the storage unit 14 stores a plurality of relational expressions for the tool 2 having the same specification. The plurality of tools 2 of the same specification may be a tool of one specific machine tool, or may be a tool attached to another machine tool of the same specification. Further, the storage unit 14 may classify and store a relational expression of a plurality of tools having the same specification of one specific machine tool and a relational expression of tools having the same specification of another machine tool having the same specification. . *

The inventor has specified that when α is 1 or more, it is noise. Although α may be calculated as 1 or more in the initial stage, the storage unit 14 does not include a relational expression where α is 1 or more. For this reason, it is possible to prevent the error expression from being stored in the storage unit 14. *

The average calculation unit 13 reads a plurality of relational expressions from the storage unit 14 and calculates an average of the plurality of relational expressions. Since the average calculation unit 13 can calculate the average of a plurality of relational expressions of tools having the same specification, the reliability of the relational expression for estimating the wear amount can be improved. *

Means for calculating the average is not particularly limited, but it is preferable that the average calculation unit 13 calculates a geometric mean of a plurality of relational expressions. The geometric mean is calculated by the following formula 1. In this case, the accuracy of the estimated wear amount can be further improved and the relational expression can be easily specified. Specifically, the average calculation unit deforms Equation 1 as Equation 2 below, and calculates a geometric average of a plurality of relational expressions. *

The method for calculating the average is not particularly limited. The average calculator 13 may calculate an arithmetic average (arithmetic average) represented by, for example, Equation 3 below. *

(Wear Amount Estimation System: Second Embodiment) <Configuration of Wear Amount Estimation System: Second Embodiment> As shown in FIG. 16, the control device of the machine tool 1 includes a wear amount estimation system 10. The wear amount estimation system 10 is a system for estimating the wear amount of the tool 2 in the machine tool shown in FIG. *

As shown in FIG. 16, the wear amount estimation system 10 includes a storage unit 14, a measurement unit 11, a calculation unit 12, and an estimation unit 15. The storage unit 14 is realized by, for example, a nonvolatile storage device such as a flash memory. The control unit including the calculation unit 12 and the estimation unit 15 is realized by an arithmetic processing device such as a CPU (Central Processing Unit), for example. *

The storage unit 14 is expressed by W = A ₁ t ^α1 (t ≦ T ₀ ) (Equation 1) and W = A ₂ t ^α2 (T ₀ <t) (Equation 2). It has data on multiple tools with the same specifications. The plurality of tools 2 of the same specification may be a tool of one specific machine tool, or may be a tool attached to another machine tool of the same specification. “Machine tools with the same specifications” are machine tools that produce the same workpiece by the same operation. Further, the storage unit 14 may classify and store a relational expression of a plurality of tools having the same specification of one specific machine tool and a relational expression of tools having the same specification of another machine tool having the same specification. .

The storage unit 14 uses Formula 1 and Formula 2 obtained by obtaining A and α from a plurality of measured values with T ₀ as a boundary in the relational expression W = At ^α shown in FIG. 2 for one tool. Remember. Equation 1 is calculated from a plurality of measured values obtained by measuring the wear amount with respect to time up to time T ₀ . Expression 2 is calculated from a plurality of measured values obtained by measuring the wear amount with respect to the time after the time T ₀ is exceeded. Expression 1 is a relational expression at an initial stage, and expression 2 is preferably a relational expression at a stationary stage. That is, T ₀ is preferably the time t ₀ (T ₀ = t ₀ ) at the boundary between the initial stage and the steady stage shown in FIG. Further, Equation 2 is preferably calculated by measurements up t ₁ in FIG.

Note that T ₀ can be set arbitrarily. T ₀ may be set based on the number of measurements in consideration of the accuracy of Equation 1 and Equation 2.

For example, as shown in FIG. 17, when the relational expressions related to the tools I to III having the same specifications are acquired, the storage unit 14 stores A ₁ and α in Expression 1 for each of the tools I to III as shown in FIG. _1, and _{a 2} and alpha ₂ of formula 2, storing. In addition, although the numerical value is not described in FIG. 18, the acquired numerical value is actually stored as data.

α ₁ and α ₂ are not particularly limited, but are preferably less than 1. The inventor has specified that when α is 1 or more, it is noise. Since α may be calculated as 1 or more in the initial stage, the storage unit 14 does not include a relational expression where α is 1 or more. For this reason, it is possible to prevent the error expression from being stored in the storage unit 14.

The storage unit 14 of the present embodiment has only data that satisfies α ₁ > α ₂ . The present inventor has found that α is large in the initial stage, and that α decreases as the stage shifts from the initial stage to the steady stage. For this reason, since the storage unit has only accurate data satisfying α ₁ > α ₂ , it is possible to improve the accuracy of estimating the wear amount.

The measuring unit 11 measures the amount of wear in the elapsed time from the start of machining of the tool 2 in operation. The measuring unit 11 may measure the amount of wear on the machined surface of the tool 2 or may obtain the amount of wear on the tool 2 by measuring the shape of the workpiece. The measurement part 11 of this Embodiment calculates | requires the abrasion loss of the tool 2 by measuring the workpiece after the process with the tool 2 with an air micrometer, for example. *

The calculation unit 12 calculates Formula 1 for the tool 2 during machining (operation) with the same specifications. That is, the calculation unit 12 calculates A ₁ and α ₁ of the relational expression represented by W = A ₁ t ^α1 based on a plurality of measurement values up to time T ₀ . Thereby, Formula 1 showing the amount of wear of a tool is determined.

The calculation unit 12 uses at least two or more measurement values for one tool 2 in order to calculate A ₁ and α ₁ and determine Equation 1. Calculator 12 may use a measurement value measured for all workpieces from the machining start point to the time T _0, using the measurements of the part of the workpiece was measured from the machining start point to the time T ₀ May be. It is preferable that the calculation unit 12 calculates A ₁ and α ₁ using only the initial measurement values.

The estimation unit 15 reads data closest to A ₁ and α ₁ calculated by the calculation unit 12 from the storage unit 14 and estimates Formula 2 of the read data as Formula 2 of the tool being processed. When the calculation unit 12 calculates the initial-stage equation 1, the estimation unit 15 can acquire the normal-stage equation 2. By obtaining the equation 2 at the estimator 15 can estimate the wear amount with respect to the elapsed time exceeds the time T _0.

The estimation unit 15 is not particularly limited to a method of selecting data closest to A ₁ and α ₁ calculated by the calculation unit 12 from the data in the storage unit 14. Data that minimizes the error index value represented is selected.

N points are measured until time T ₀ , where the i-th measurement time is s _i , the cumulative correction amount (wear amount) is w _i , and Equation 1 stored in the storage unit 14 is W = A ₁ t ^α1 . error index value E ₁ is expressed by equation 4 below.

Equation 4 is a mean square error with respect to the equation of the storage unit 14 at each measurement point. *

Further, when Equation 1 calculated from the data of the tool in operation is W = A ₁ 't ^α1' , the error index value E ₂ is expressed by Equation 5 below.

The above formula 5 is obtained by continuously capturing the formula 4 and considers the data being measured. *

The wear amount estimation system 10 includes a measurement unit 11 that measures the wear amount with respect to a time exceeding the time T ₀ of the tool being processed, a calculation unit 12 that calculates Formula 2 based on this measurement value, and a calculation unit 12. And a storage unit 14 that further stores Formula 1 and Formula 2 obtained by the above. In this case, since the data accumulated in the storage unit 14 increases, the accuracy can be improved in the wear amount estimation system 10 of the machine tool 1 having the same specification including the tool 2 having the same specification.

<Abrasion Amount Estimation Method: First Embodiment> Next, a wear amount estimation method in the first embodiment will be described with reference to FIG. In the wear amount estimation method of the present embodiment, a relational expression represented by W = At ^α is determined, and the wear amount of the tool is estimated from the relational expression.

First, the measurement unit 11 measures a plurality of wear amounts with respect to the elapsed time from the machining start time of the tool 2 (step S1). *

Next, the calculation unit 12 calculates A and α (<1) of the relational expression represented by W = At ^α based on the plurality of measurement values (step S2). Thereby, the relational expression W = At ^α for one tool can be acquired. The acquired relational expression is stored in the storage unit 14 (step S3).

Next, steps S1 to S3 are performed for another tool 2 having the same specification. Thereby, a relational expression can be memorize | stored in the memory | storage part 14 about each of the some tool 2 of the same specification. *

Next, a plurality of relational expressions are read from the storage unit 14, and the average of the plurality of relational expressions is calculated by the average calculation unit 13 (step S4). In this step (S4), it is preferable to calculate a geometric mean of a plurality of relational expressions. *

By performing the above steps S1 to S4, it is possible to determine a relational expression representing the wear amount with respect to the elapsed time from the machining start time for the tools having the same specifications. For this reason, the wear amount with respect to the elapsed time from the machining start time can be estimated for the tool 2 having the same specification in operation. *

Note that steps S3 and S4 may be omitted. In this case, by executing steps S1 and S2 for the tool 2 in operation, A and α are calculated to obtain a relational expression, and the wear amount is estimated from the relational expression. Further, by omitting step S4, the relational expression of one tool stored in the storage unit 14 may be read and the wear amount may be estimated from the relational expression. *

As described above, according to the wear amount estimation system and the wear amount estimation method of the present embodiment, it has been found that the basic formula of the relationship between the elapsed time t and the wear amount W is W = At ^α . . For this reason, by calculating A and α by the calculation unit 12, it is possible to specify an expression of the wear amount with respect to the elapsed time of the tool. Therefore, the wear amount estimation system and the wear amount estimation method of the present embodiment can improve the accuracy of the estimated tool wear amount.

<Abrasion Amount Estimation Method: Second Embodiment> Next, a wear amount estimation method according to the second embodiment will be described with reference to FIG. In the wear amount estimation method of the present embodiment, the wear amount of the tool is estimated from the relational expression represented by W = At ^α .

First, the memory | storage part 14 which has the data of the several tool of the same specification represented by Formula 1 and Formula 2 is prepared (step S41). *

Next, the measurement unit 11 measures a plurality of wear amounts with respect to the elapsed time from the machining start time of the operating tool 2 (step S42). In step S42, by measuring the wear amount by time T _0, obtaining a plurality of measurements up time T _0.

Next, the calculation unit 12 calculates A ₁ and α ₁ of W = A ₁ t ^α1 based on the plurality of measurement values (step S43). Thereby, Formula 1 about the tool 2 in operation | movement can be acquired. In addition, Formula 1 of the tool 2 in operation may be calculated based on the measured values in the first half of the initial stage.

Next, data closest to A ₁ and α ₁ calculated by the calculation unit 12 is read from the storage unit 14, and the data A ₂ and α ₂ are estimated as Formula 2 of the tool being processed (step S 44). . Thereby, Formula 2 about the tool in operation can be acquired.

By performing the above steps S41 to S44, it is possible to determine the relational expression 2 representing the amount of wear with respect to the elapsed time from the machining start time for the tool 2 in operation. For this reason, about the tool 2 in operation | movement, the wear amount with respect to the elapsed time from a process start time can be estimated. *

As described above, the wear amount estimation system and the wear amount estimation method according to the present embodiment reads data closest to A ₁ and α ₁ calculated by the calculation unit 12 from the storage unit 14, and estimates the estimation unit 15. Thus, it is estimated as Formula 2 of the tool being processed.

As a result of intensive studies, the present inventor has found that the relationship between the elapsed time t from the start of machining and the wear amount W of the tool 2 is expressed by

Equations

1 and 2. Thus, since the basic formula of the relationship between the elapsed time and the wear amount has been found, the formula 1 can be specified by measuring the wear amount of the tool 2 being processed at an arbitrary timing before T _{0 has} elapsed. The expression 2 can be estimated by comparing the expression 1 of the tool 2 being processed and the expression 1 of the storage unit 14 and reading the closest data. That is, in the past, it has been necessary to compare at each measurement point, but in the present embodiment, the comparison can be made by an equation, and thus does not depend on the measurement timing. Therefore, since the expression of the wear amount with respect to the elapsed time of the tool can be easily obtained, the wear amount of the tool can be easily estimated.

In the present embodiment, T ₀ is stored in the storage unit 14 as a relational expression consisting of Expression 1 and Expression 2 for one tool, in the vicinity of the boundary between the initial stage and the steady stage. The wear amount estimation system 10 and the wear amount estimation method of the present invention may include, for example, a storage unit 14 that stores a relational expression including three or more expressions. In the case where there are three equations, the storage unit W = A ₁ t ^α1 (t ≦ T ₀ ) (Equation 1), W = A ₂ t ^α2 (T ₀ <t ≦ T ₁ ). (Equation 2), W = A ₃ t ^α3 (T ₁ <t) (Equation 3). For example, time T ₁ is the boundary between the initial stage and the steady stage. The estimation unit 15 may estimate Formula 3 from Formula 1 or Formula 2, or may estimate Formula 2 and Formula 3 from Formula 1.

(Correction System) <Configuration of Correction System> The control device of the machine tool 1 includes a correction system 20 as shown in FIG. The correction system 20 is a system that corrects the position of the tool 2 in accordance with the amount of wear of the tool 2 in order to process the workpiece 5 into the same shape in the machine tool 1 shown in FIG. *

The correction system 20 includes the wear amount estimation system 10 and the correction unit 21 described above. The wear amount estimation system 10 is based on the relational expression of the tool 2 having the same specification in the first embodiment, and from the expression 2 acquired by the estimation unit 15 in the second embodiment, from the machining start time of the operating tool 2. Estimate the amount of wear with respect to elapsed time. *

The correction unit 21 corrects the position of the operating tool 2 based on the estimated wear amount. Specifically, the correction unit 21 calculates a correction amount of the position of the support unit 3 that supports the operating tool 2 based on the estimated wear amount, and sends a correction command to the support unit 3. The correction unit 21 can employ a known technique. *

<Correction Method> As shown in FIG. 5, the wear amount with respect to the elapsed time of the operating tool 2 is estimated from the relational expression acquired by the above-described wear amount estimation method (step S10). *

Next, the correction unit 21 calculates a correction amount of the position of the support unit 3 according to the estimated wear amount (step S11). Next, a correction command is sent to the positioning means of the support unit 3 so as to change the position of the support unit 3 based on the correction amount. Thereby, since the position of the support part 3 can be corrected, the position of the tool 2 can be corrected according to the amount of wear (step S12). *

As described above, according to the correction system 20 and the correction method of the present embodiment, since the wear amount estimation system 10 described above is provided, the accuracy of the estimated wear amount can be improved. Therefore, the accuracy of correcting the position of the tool 2 can be improved in the machine tool 1 that uses the tool 2 having the same specification. Further, the wear amount of the tool 2 can be easily estimated. Therefore, in the machine tool 1, the position of the tool 2 can be easily corrected. *

In addition, by identifying the relational expression with the wear amount estimation system, the wear amount can be estimated over the entire use period of the tool 2, so measurement at regular intervals can be omitted. Therefore, since the number of work steps for correction can be reduced, labor costs can also be reduced. *

(Abnormality Detection System) <Configuration of Abnormality Detection System> The control device of the machine tool 1 includes an abnormality detection system 30 as shown in FIG. The abnormality detection system 30 is a system that detects an abnormality of the machine tool 1 in the machine tool 1 shown in FIG. The abnormality of the machine tool 1 includes an abnormality of the tool 2 and a failure in supplying cooling water. *

The abnormality detection system 30 includes the above-described wear amount estimation system 10, a measurement unit, an abnormality determination unit 31, and an abnormality display unit 32. In the first embodiment, the wear amount estimation system 10 is obtained from the relational expression related to the tool of the same specification acquired in the first embodiment, and from the expression 2 acquired by the estimation unit 15 in the second embodiment, from the processing start time of the operating tool 2. The amount of wear with respect to the elapsed time is estimated. *

After estimating the wear amount, the measurement unit measures the wear amount. Specifically, a measurement part measures the shape of the workpiece after a process, and calculates the wear amount of the tool 2 in operation | movement. The measurement unit of the present embodiment is also used as the measurement unit 11 of the wear amount estimation system 10. Note that the measurement unit of the abnormality detection system may be provided separately from the measurement unit 11 of the wear amount estimation system. *

The abnormality determination unit 31 determines that an abnormality has occurred in the machine tool 1 when the difference between the wear amount estimated by the wear amount estimation system 10 and the wear amount measured for the tool 2 having the same specification exceeds a predetermined value. . In the present embodiment, the abnormality determination unit 31 calculates a difference between the measured value and the estimated value, and sends a command to display an abnormality on the abnormality display unit 32 when the difference exceeds a predetermined value. *

The difference between the measured value and the estimated value may be the difference between the wear amount estimated from the relational expression acquired by the wear amount estimation system 10 and the measured wear amount. The relational expression acquired by the wear amount estimation system 10; It may be a difference from the relational expression calculated by measurement. *

The predetermined value determined as abnormal can be set arbitrarily. For example, the predetermined value can be set small in consideration of the safety factor. There may be a plurality of predetermined values that are determined to be abnormal. *

As a specific example, FIG. 6 shows a relational expression acquired by the wear amount estimation system and a measured value of the wear amount of the operating tool. In FIG. 6, at the elapsed time 190, the difference between the estimated wear amount and the measured value is large. The abnormality determination unit 31 determines that the difference is greater than a predetermined value at the elapsed time 190. *

Here, the predetermined value determined as abnormal will be described. As shown in FIG. 7, the relational expression estimated by the wear amount estimation system 10 based on the measured values up to the elapsed time s is W (s _n | t). _If the error index at the measurement time s _n is E (s _n ), for example, it is expressed by the following three formulas 6 to 8. Note that, in Equation 7-8, the measurement time in the i-th measurement point _{s i,} the wear amount and _{W i.}

Equation 6 above is an error in t = s _n of the relational expression up to the measurement time s _n .

The above Equation 7, in which view the error between the relational expression between relation to the measurement time s _n to the measurement time s _n-1, a mean square error at each measurement point.

Equation 8 above captures the mean square error of Equation 7 continuously. *

An error index E (s _n−1 ) at the previous measurement time s _n−1 is obtained, and the rate of change R (s _n ) = E (s _n ) / E (s _n−1 ) is calculated. When R (s _n ) is 0.5 or more and 1.5 or less, it is within a predetermined value, and when R (s _n ) is less than 0.5 or exceeds 1.5, it exceeds the predetermined value.

R (s _n ) calculated from the error indexes E ₁ (s _n ) to E ₃ (s _n ) are shown in FIGS. The measured values of the top wear amount in FIGS. 8 to 10 are the same as those in FIG. As shown in FIGS. 8 to 10, R (s _n ) exceeds 1.5 at the elapsed time 190.

The abnormality determination unit 31 determines that an abnormality has occurred in the machine tool 1 at a timing when R (s _n ) exceeds 1.5. In addition, since R (s _n ) may not be accurately determined in the initial stage, the abnormality determination unit 31 may use the case where R (s _n ) exceeds 1.5 or less than 0.5 in the steady stage. In addition, it may be determined that the difference between the measured value and the estimated value exceeds a predetermined value.

The abnormality determination unit 31 may determine abnormality by means different from the error index. The present inventor has found that α in the relational expression is large in the initial stage, and that α decreases as the stage shifts from the initial stage to the steady stage. Using this knowledge, it is preferable that the abnormality determination unit 31 of the present embodiment determines that an abnormality has occurred in the machine tool 1 when α measured in the steady stage is larger than α in the initial stage. In this case, the accuracy of determining an abnormality can be further improved. When a plurality of α are calculated in the initial stage, α in the initial stage may be a maximum value less than 1 in the initial stage. *

In addition, the inventor has specified that when α is 1 or more, it is noise. For this reason, it is more preferable that the abnormality determination unit 31 determines that an abnormality has occurred in the machine tool 1 when α measured in the steady stage is larger than α less than 1 in the initial stage. *

Also, a predetermined value that is determined to be abnormal may be set based on data when an abnormality has occurred for tools of the same specification. In order to exchange a tool and accumulate a plurality of data, the abnormality detection system 30 may further include a storage unit 14 that stores a predetermined value determined to be abnormal. When there are a plurality of data, the predetermined value may be an average value or a minimum value. When the abnormality detection system 30 includes the storage unit 14, the abnormality determination unit 31 reads and determines a predetermined value from the storage unit 14. *

The abnormality display unit 32 displays that an abnormality has occurred in order to notify the user of the abnormality based on a command from the abnormality determination unit 31. In addition, the abnormality display part 32 may be visually recognized, and may be audibly recognized. The latter is, for example, a buzzer that issues an alarm. *

The control device of the machine tool 1 may further include a stop unit that stops the operation of the machine tool 1 when the abnormality determination unit 31 determines that an abnormality has occurred in the machine tool 1. For example, when the difference between the measured value and the estimated value exceeds a predetermined value, the abnormality determination unit 31 sends a command to stop the operation of the machine tool 1 to the stop unit. The stop unit stops the operation of the machine tool 1 based on a command from the abnormality determination unit 31. *

Further, the control device of the machine tool 1 may perform control so that the abnormality detection system performs an on operation and an off operation. For example, the control device turns off the abnormality detection system in the initial stage, and turns on the abnormality detection system after entering the steady stage. *

<Abnormality Detection Method> As shown in FIG. 11, the above-described wear amount estimation method estimates in the second embodiment from the relational expression specified for the tool having the same specifications as the operating tool 2 in the first embodiment. The wear amount with respect to the elapsed time of the operating tool 2 is estimated from the equation 2 acquired by the unit 15 (step S10). Next, the wear amount of the operating tool 2 is measured (step S21). *

Next, it is determined whether or not the difference between the wear amount estimated by the wear amount estimation system and the wear amount measured for the tool of the same specification is within a predetermined value (step S22). If it is determined in step S22 that the value is within the predetermined value, the process proceeds to step S23. In step S23, since there is no abnormality in the machine tool, the machining with the same tool 2 is continued. On the other hand, if it is determined in step S21 that the predetermined value is exceeded, the process proceeds to step S24. In step S24, it is determined that an abnormality has occurred in the machine tool 1.

(Abnormality Detection Method) Next, another embodiment of the abnormality detection method will be described mainly with reference to FIG. *

First, the measurement unit 11 measures a plurality of wear amounts with respect to the elapsed time from the machining start time of the tool 2 (step S51). *

Next, the calculation unit 12 calculates A and α (<1) of the relational expression represented by W = At ^α based on the plurality of measurement values (step S52). Thereby, the relational expression W = At ^α for the tool 2 in operation can be acquired. For this reason, about the tool 2 in operation | movement, the wear amount with respect to the elapsed time from a process start time can be estimated.

Next, the measurement unit 11 measures the wear amount of the operating tool 2 (step S53). *

Next, it is determined whether or not the difference between the wear amount estimated in step S52 and the wear amount measured in step S53 is within a predetermined value (step S54). If it is determined in step S54 that the value is within the predetermined value, the process proceeds to step S55. In step S55, since there is no abnormality in the machine tool 1, machining by the operating tool 2 is continued. On the other hand, if it is determined in step S54 that the predetermined value is exceeded, the process proceeds to step S56. In step S56, it is determined that an abnormality has occurred in the machine tool 1. *

If it is determined in step S56 that an abnormality has occurred in the machine tool 1, the abnormality display unit 32 displays that an abnormality has occurred. Accordingly, the user can know that an abnormality has occurred in the machine tool 1. Therefore, the user can examine the cause of the abnormality. *

Here, an example of an abnormality detection method is given. In step S51, the shape of the workpiece of 10 to 50 points is measured, and the amount of wear of the tool with respect to the elapsed time is obtained. Next, in step S52, A and α are calculated by the calculation unit 12 based on the measured values of 10 to 50 points, and a relational expression is acquired. Thereafter, in step S53, the shape of the two workpieces is measured to determine the amount of wear of the tool with respect to the elapsed time. Next, in step S54, the difference between the wear amount estimated from the abnormality determination unit 31 and the relational expression acquired in step S52 and the one wear amount measured in step S53 is the relationship acquired in step S52. It is determined whether or not the wear amount estimated from the equation is within twice the difference between the previous wear amount measured in step S53. The abnormality determination unit 13 determines that an abnormality has occurred in the machine tool 1 when the subsequent difference exceeds twice the previous difference. *

Another example of the abnormality detection method is given. In step S51, the shape of the workpiece of 10 to 50 points is measured, and the amount of wear of the tool with respect to the elapsed time is obtained. Next, in step S52, A and α are calculated by the calculation unit 12 based on the measured values of 10 to 50 points, and a relational expression is acquired. Thereafter, in step S53, the shape of the workpiece of 10 to 50 points is measured, and the amount of wear of the tool with respect to the elapsed time is obtained. Based on the measurement value obtained in step S53, the calculation unit 12 calculates A and α, and acquires a new relational expression. Next, in step S54, the abnormality determination unit 31 determines whether or not the difference between the relational expressions acquired in steps S52 and S53 is within a predetermined range.

As described above, the abnormality detection system and the abnormality detection method according to the present embodiment do not apply the acquired relational expression to another tool, but determine an abnormality of the machine tool 1 including the tool 2 for which the relational expression is calculated. Is. *

As described above, according to the abnormality detection system 30 and the abnormality detection method of the present embodiment, since the wear amount estimation system 10 described above is provided, the accuracy of the estimated wear amount can be improved and the wear amount can be easily increased. Can be estimated. Since the abnormality is determined based on the difference between the estimated wear amount and the measured wear amount, the accuracy of determining the abnormality can be improved in the machine tool 1 that uses the tool 2 of the same specification, and the abnormality of the machine tool 1 can be detected. Easy to judge. Moreover, since the abnormality which arose in the machine tool 1 can be detected at an early stage, defective products can be reduced.

In the present embodiment, the case where the relational expression calculated by the calculation unit 12 is W = At ^α has been described. As a result of intensive studies, the present inventors have found that the relationship between the elapsed time t from the start of machining and the amount of tool wear W can be expressed as W = At ^α . For this reason, it is preferable that the calculation part 12 calculates A and (alpha) of W = At ( ^alpha) based on a measured value. In this case, the accuracy of the estimated wear amount can be increased. Therefore, the abnormality detection system 30, the machine tool 1, and the abnormality detection method of the present embodiment can improve the accuracy of determining an abnormality.

In the present invention, the relational expression between the processing time and the amount of wear is not limited to W = At ^α .

(Life Detection System) <Configuration of Life Detection System> The control device of the machine tool 1 includes a life detection system 40 as shown in FIG. The life detection system 40 is a system that detects the life of the tool 2 in the machine tool 1 shown in FIG. Tools reach the end of their lives due to significant changes in dimensions due to wear, wrinkling on the machined surface, tool breakage, and the like. The life detection system 40 of this embodiment detects the change point from the steady stage to the end stage in FIG. 2 as the life of the tool 2 at an early stage. *

The life detection system 40 includes the above-described wear amount estimation system 10, a measurement unit, a life determination unit 41, a life display unit 42, and a notification unit 43. The wear amount estimation system 10 determines a relational expression between the elapsed time and the wear amount for tools having the same specification. *

After determining the relational expression, the measurement unit measures the wear amount. Specifically, a measurement part measures the shape of the workpiece after a process, and calculates the wear amount of the tool 2 in operation | movement. The measurement unit of the present embodiment is also used as the measurement unit 11 of the wear amount estimation system. Note that the measurement unit may be provided separately from the measurement unit 11 of the wear amount estimation system. *

The life determination unit 41 determines that the life of the tool 2 has been reached when the relational expression calculated by measuring the wear amount of the tool 2 having the same specification changes from the relational expression estimated by the wear amount estimation system 10. “The relational expression changes” means that the shape of the graph represented by the relational expression changes, and does not include those in which some coefficients change. Specifically, as shown in FIG. 2, the relational expression at the end stage is a shape that cannot be expressed by W = At ^α (α <1), and therefore the relational expression changes.

In the present embodiment, the calculation unit 12 of the wear amount estimation system 10 calculates a relational expression from a plurality of latest measured values of the tool 2 in operation, and whether the life determination unit 41 changes the shape of the relational expression. Judge whether or not. The number of the most recent measurement values can be arbitrarily selected, may be constant, or may vary with elapsed time or stage. The number of the latest measured values for calculating the relational expression is preferably 20 to 40 points. In this case, the accuracy of determining the life can be further improved. When it is determined that the relational expression has changed, the life determination unit 41 sends a command for displaying that the life has been reached to the life display unit 42. *

In addition, whenever the lifetime determination part 41 acquires a measured value by the measurement part 11, it is preferable to calculate a relational expression with the calculation part 12, and to determine whether a relational expression changes. In this case, the life of the tool 2 can be detected early. *

When the difference between the wear amount estimated from the relational expression specified by the wear amount estimation system 10 and the wear amount measured for the tool 2 in operation exceeds a predetermined value, the life determination unit 41 It may be determined that the lifetime is reached. The predetermined value determined as the life can be arbitrarily set. For example, the predetermined value can be set small in consideration of the safety factor. *

Further, the present inventor has found that α in the initial stage and the steady stage shown in FIG. 2 is less than 1, and α after reaching the lifetime exceeds 1. For this reason, when α exceeds 1, the life determination unit 41 of the present embodiment determines that the life of the tool has been reached. In this case, the accuracy of determining the life can be further improved. *

Here, as a specific example, FIG. 21 and FIG. 22 will be described. FIG. 21 shows measured values of the amount of wear of the tool with respect to time, relational expression 1 acquired by the calculation unit 12 at time 200, and relational expression 2 acquired by the calculation unit 12 at time 260.

Relational expressions

1 and 2 are calculated from the latest 30 measured values. Specifically, the calculation was performed using measurement points at times 171 to 200 in relational expression 1 and at times 231 to 260 in relational expression 2. In the relational expression 2, α exceeds 1. In FIG. 21, the shape of the relational expression 2 changes with respect to the relational expression 1. For this reason, the life determination unit determines that the tool life has been reached at time 260. *

FIG. 22 shows the calculated A and α for the same measurement values as in FIG. As shown in FIG. 22, the life determination unit 41 monitors the calculated α, and determines that the life of the tool 2 has been reached when α exceeds 1. *

The life display unit 42 displays that the life has been reached based on a command from the life determination unit 41. The life display unit 42 may be visually recognized or audibly recognized. Further, the life display unit 42 may be used as the abnormality display unit 32 or may be arranged separately. *

The inventor of the present invention paid attention to the fact that the life of the tool 2 is difficult to predict and reaches suddenly. Therefore, the life detection system 40 includes a notification unit 43 that notifies in advance that the life is near. When the notification unit 43 notifies that the life is near, measures such as increasing the measurement frequency can be taken, so that the use of a tool that has exceeded the life can be suppressed. The notification part of this Embodiment notifies that a lifetime is near from two viewpoints. *

The notification unit 43 from one viewpoint notifies that the lifetime is near when α calculated from the measurement value exceeds the maximum value of less than 1 in the initial stage. Specifically, the calculation unit 12 calculates α from a plurality of latest measured values, and the notification unit 43 determines whether the calculated α exceeds a maximum value less than 1 in the initial stage. When α exceeds the maximum value of less than 1 in the initial stage, a command is sent to the display unit to issue an alarm in order to inform that the tool 2 in operation is near the end of its life. *

The inventor has found that α in the initial stage is larger than α in the stationary stage. As described above, the present inventor has specified that noise is present when α is 1 or more in the initial stage. Furthermore, the present inventor has found that the lifetime is near when the maximum value of α less than 1 is measured in the initial stage in the absence of noise and then the value exceeding the maximum value is measured. For this reason, the notification unit 43 can predict the life by specifying the maximum value excluding noise in the initial stage and notifying that the life is near when the maximum value is exceeded in the steady stage. *

Further, the notifying unit according to another aspect reads out the life data from the storage unit 14 that stores the life data of the tool of the same specification, and notifies the life time of the tool of the same specification. In the present embodiment, the storage unit 14 of the wear amount estimation system 10 stores life data of a plurality of tools having the same specification. The notification unit 43 reads a plurality of lifetime data from the storage unit 14, selects the shortest lifetime, and notifies that the lifetime is near when the selected shortest time is reached. The notification unit performs control by reading the storage unit 14, but the function of the notification unit can arbitrarily select an on operation and an off operation.

The storage unit 14 preferably stores a plurality of life data. Further, the life data may be stored in the storage unit 14 every time the life of the tool in operation is reached. *

The tool life data may be the life data of the same specification tool of one specific machine tool, or the life data of the same specification tool attached to another machine tool of the same specification. The storage unit 14 may classify and store life data of a plurality of tools having the same specification of one specific machine tool and a relational expression of tools of the same specification of another machine tool having the same specification. “Machine tools with the same specifications” are machine tools that produce the same workpiece by the same operation. *

<Life detection method> As shown in FIG. 12, the relational expression about the tool of the same specification as the tool 2 in operation | movement is determined by the wear amount estimation method mentioned above (step S10). Next, a plurality of wear amounts of the operating tool 2 are measured (step S21). Thereafter, the calculation unit 12 calculates a relational expression between the machining time and the wear amount for the tool 2 in operation (step S31). *

Next, it is determined whether or not the relational expression of the tool 2 in operation has changed from the relational expression determined by the wear amount estimation method (step S32). If it is determined in step S32 that there is no change, the process proceeds to step S33. In step S33, since the tool 2 has not reached its end of life, machining with the same tool 2 is continued. On the other hand, if it is determined that the change has occurred in step S32, the process proceeds to step S34. In step S34, it is determined that the life of the tool 2 has been reached. *

If it is determined in step S34 that the operating tool 2 has reached the end of its life, the life display unit 42 displays that the tool has reached its end of life. Thereby, the user can know that the tool 2 in operation has reached the end of its life. Therefore, the user replaces the tool 2 with a new one having the same specification. *

As described above, the life detection system 40 and the life detection method of the present embodiment do not apply the acquired relational expression to another tool, but determine the life of the tool 2 for which the relational expression is calculated. *

As described above, according to the life detection system 40 and the life detection method of the present embodiment, since the wear amount estimation system 10 described above is provided, the life can be determined by changing the relational expression. Therefore, regardless of the amount of data in the storage unit 14, in the machine tool 1 that uses the tool 2 of the same specification, the accuracy of determining the life of the tool 2 can be improved, and the martyrdom of the tool 2 can be easily determined. Moreover, since the life of the tool 2 can be detected at an early stage, defective products can be reduced by replacing the tool 2 that has reached the end of its life. Moreover, since the tool 2 can be used until the end of its life, it is advantageous in terms of cost. *

In the present embodiment, the case where the relational expression calculated by the calculation unit 12 is W = At ^α has been described. As a result of intensive studies, the present inventors have found that the relationship between the elapsed time t from the start of machining and the amount of tool wear W can be expressed as W = At ^α . For this reason, it is preferable that the calculation part 12 calculates A and (alpha) of W = At ( ^alpha) based on a measured value. When this relational expression is used, the accuracy of the estimated wear amount can be increased. Therefore, the life detection system 40, the machine tool 1, and the life detection method of the present embodiment can further improve the accuracy of determining the life.

Here, the machine tool 1 according to the present embodiment includes a wear amount estimation system 10, a correction system 20, an abnormality detection system 30, and a life detection system 40, as shown in FIG. The machine tool of the present invention is not particularly limited as long as it includes a wear amount estimation system, and may include any one or two of a correction system, an abnormality detection system, and a life detection system.

In the present embodiment, a relational expression between the elapsed time t from the start of machining the tool and the wear amount W will be described. *

First, in one machine tool 1, the work piece 5 of the same specification was repeatedly processed under the same conditions using the tool 2, and the amount of wear was measured. FIG. 13 shows data measured for nine tools having the same specifications. In FIG. 13, in region A, an abnormality occurred in the tool 4. In region B, the machine tool 1 was stopped. *

FIG. 14 shows a result of extracting the measurement values that are operating normally, except for the measurement points where the abnormality occurred, as in regions A and B, from FIG. *

Next, in FIG. 14, the time at which each tool is changed is set to 0 as the machining start time, and the vertical axis is inverted, as shown in FIG. As a result of accumulating the data shown in FIG. 15 and earnestly researching, the present inventor found that the relationship between the elapsed time t and the wear amount W from the machining start time of the tool is W = At ^α (A and α (<1) Was found to be represented by a constant). Note that the relational expression shown in FIG. 15 is a geometric mean of nine relational expressions.

As described above, as a result of intensive research conducted by the present inventor in order to specify a formula that is the basis of the relationship between the elapsed time and the amount of wear, a relational formula of W = At ^α was found. Wear amount estimation system, correction system, abnormality detection system, life detection system, machine tool and wear amount estimation method, machine tool and abnormality detection method, machine tool and life detection method of the present invention, using the found relational expression, Since the wear amount of the tool 2 is estimated, the accuracy of the estimated wear amount of the tool can be improved. In the present invention, the relational expression between the processing time and the amount of wear is not limited to W = At ^α .

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above-described embodiment but by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1: Machine tool 2: Tool 3: Support unit 4: Placement unit 5: Placement unit 5: Workpiece 10: Wear amount estimation system 11: Measurement unit 12: Calculation unit 13: Average calculation unit 14: Storage unit 15: Estimation unit 20: Correction system 21: Correction unit 30: Abnormality detection system 31: Abnormality determination unit 32: Abnormality display unit 40: Lifetime detection system 41: Lifetime determination unit 42: Lifetime display unit 43: Notification unit

Claims

A system for estimating the amount of wear of a tool in a machine tool that repeatedly processes a workpiece of the same specification under the same conditions using a tool, the wear of the tool with respect to the elapsed time from the machining start time of the tool A wear amount estimation system including a calculation unit that measures a plurality of amounts and calculates a relational expression between a machining time and a wear amount.
In the calculation unit, when the wear amount from the machining start time of the tool is W, the elapsed time is t, and the constants are A and α (<1), A and α in the relational expression represented by W = Atα The wear amount estimation system according to claim 1, wherein the wear amount is calculated.
For each of the plurality of tools of the same specification, a storage unit that stores the relational expression specified by the calculation unit;
An average calculation unit that reads a plurality of the relational expressions from the storage unit and calculates an average of the plurality of relational expressions;
The wear amount estimation system according to claim 2, further comprising:
The wear amount estimation system according to claim 3, wherein the average calculation unit calculates a geometric average of a plurality of the relational expressions.
The wear amount estimation system according to any one of claims 2 to 4,
Based on the wear amount estimated by the wear amount estimation system, a correction unit for correcting the position of the tool of the same specification,
A correction system comprising:
The wear amount estimation system according to any one of claims 3 to 4,
A determination unit that determines that an abnormality has occurred in the machine tool when a difference between a wear amount estimated by the wear amount estimation system and a wear amount measured for the tool of the same specification exceeds a predetermined value;
An abnormality detection system comprising:
The wear amount estimation system according to any one of claims 3 to 4,
When the relational expression calculated by measuring the amount of wear of the tool of the same specification changes from the relational expression estimated by the wear amount estimation system, a determination unit that determines that the tool life has been reached,
A life detection system comprising:
The wear amount estimation system according to any one of claims 2 to 4,
The tool for processing the workpiece;
A placement section for placing the workpiece;
A machine tool.
In machine tools that repeatedly process workpieces with the same specifications under the same conditions using tools,
A method for estimating the amount of wear of the tool,
Based on a plurality of measured values of the wear amount with respect to the elapsed time from the machining start time of the tool, where W is the wear amount from the machining start time of the tool and t is the elapsed time, W = Atα. A wear amount estimation method comprising a step of calculating A and α (<1) of the relational expression.
When the constants calculated from the measured values are A1, A2, α1, and α2,
W = A1tα1 (t ≦ T0) (Formula 1)
W = A2tα2 (T0 <t) (Expression 2)
A storage unit having data of a plurality of the same specifications represented by
For the tool being machined with the same specification, a calculation unit for calculating Formula 1;
An estimation unit that reads out the data closest to A1 and α1 calculated by the calculation unit from the storage unit, and estimates the equation 2 of the read data as the equation 2 of the tool being processed;
The wear amount estimation system according to claim 2, further comprising:
The wear amount estimation system according to claim 10, wherein α1 and α2 are less than one.
The wear amount estimation system according to claim 10 or 11, wherein the storage unit has only the data satisfying α1> α2.
The wear amount estimation system according to any one of claims 10 to 12,
Based on the wear amount estimated by the wear amount estimation system, a correction unit for correcting the position of the tool being processed,
A correction system comprising:
The wear amount estimation system according to any one of claims 10 to 12,
A determination unit that determines that an abnormality has occurred in the machine tool when a difference between a wear amount estimated by the wear amount estimation system and a wear amount measured for the tool being processed exceeds a predetermined value;
An abnormality detection system comprising:
The wear amount estimation system according to any one of claims 10 to 12,
A determination unit that determines that the tool has reached the end of its life when Equation 2 calculated by measuring the amount of wear of the tool during machining changes from Equation 2 estimated by the wear amount estimation system;
A life detection system comprising:
In machine tools that repeatedly process workpieces with the same specifications under the same conditions using tools,
A method for estimating the amount of wear of the tool,
Based on a plurality of measured values of the wear amount with respect to the elapsed time from the machining start time of the tool, the wear amount from the machining start time of the tool is W, the elapsed time is t, and constants A1 and A2 calculated from the measured values , Α1 (<1), α2 (<1),
W = A1tα1 (t ≦ T0) (Formula 1)
W = A2tα2 (T0 <t) (Expression 2)
Preparing a storage unit having data of a plurality of the same specification tools represented by
Calculating the formula 1 for the tool being machined with the same specifications;
Reading the data closest to the calculated A1 and α1 from the storage unit, and estimating A2 and α2 of the data as Formula 2 of the tool being processed;
A wear amount estimation method comprising:
The wear amount estimation system according to claim 1;
A determination unit that determines that an abnormality has occurred in the machine tool when a difference between a wear amount estimated by the wear amount estimation system and a wear amount measured for the tool of the same specification exceeds a predetermined value;
An abnormality detection system comprising:
The relational expression is expressed as W = Atα, where W is a wear amount from the machining start time of the tool, t is an elapsed time, and A and α (<1) are constants.
The abnormality detection system according to claim 17, wherein the calculation unit calculates A and α of the equation based on measurement values.
The determination unit determines that an abnormality has occurred in the machine tool when α measured at a steady stage where the wear amount exceeds a predetermined value is larger than α at an initial stage where the wear amount is equal to or less than a predetermined value. 18. The abnormality detection system according to 18.
An abnormality detection system according to any one of claims 17 to 19,
The tool for processing the workpiece;
A placement section for placing the workpiece;
A machine tool.
A machine tool abnormality detection method for repeatedly processing a workpiece of the same specification under the same conditions using a tool,
Measuring a plurality of wear amounts of the tool with respect to the elapsed time from the processing start time of the tool, and calculating a relational expression between the processing time and the wear amount;
A step of determining that an abnormality has occurred in the machine tool when a difference between a wear amount estimated from the relational expression and a wear amount measured after the calculation exceeds a predetermined value;
An abnormality detection method comprising:
The wear amount estimation system according to claim 1;
When the relational expression calculated by measuring the amount of wear of the tool of the same specification changes from the relational expression estimated by the wear amount estimation system, a determination unit that determines that the tool life has been reached,
A life detection system comprising:
The relational expression is expressed as W = Atα, where W is the amount of wear from the machining start time of the tool, t is the elapsed time, and A and α (<1) are constants.
The lifetime detection system according to claim 22, wherein the calculation unit calculates A and α of the formula based on measurement values.
The life detection system according to claim 23, wherein the determination unit determines that the life of the tool has been reached when α exceeds 1.
The lifetime detection system according to claim 23 or 24, further comprising a notification unit that notifies that the lifetime is near when α exceeds a maximum value of less than 1 in the initial stage.
A storage unit for storing life data of the tool of the same specification;
Read the life data from the storage unit, a notification unit for notifying the life time of the tool of the same specification,
The life detection system according to any one of claims 22 to 25, further comprising:
A life detection system according to any one of claims 22 to 26;
The tool for processing the workpiece;
A placement section for placing the workpiece;
A machine tool.
A method of detecting the tool life of a machine tool that repeatedly processes a workpiece of the same specification under the same conditions using a tool,
Measuring a plurality of wear amounts with respect to the elapsed time from the machining start time of the tool, and calculating a relational expression between the machining time and the wear amount;
A step of determining that the life of the tool has been reached when the relational expression is changed by measuring the wear amount after calculation;
A life detection method comprising: