WO1996038261A1 - Procede de detection de charge anormale - Google Patents

Procede de detection de charge anormale Download PDF

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Publication number
WO1996038261A1
WO1996038261A1 PCT/JP1996/001486 JP9601486W WO9638261A1 WO 1996038261 A1 WO1996038261 A1 WO 1996038261A1 JP 9601486 W JP9601486 W JP 9601486W WO 9638261 A1 WO9638261 A1 WO 9638261A1
Authority
WO
WIPO (PCT)
Prior art keywords
abnormal load
load detection
machine tool
abnormal
detection level
Prior art date
Application number
PCT/JP1996/001486
Other languages
English (en)
Japanese (ja)
Inventor
Ryuji Suzuki
Original Assignee
Fanuc Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fanuc Ltd filed Critical Fanuc Ltd
Publication of WO1996038261A1 publication Critical patent/WO1996038261A1/fr

Links

Classifications

    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B19/00—Programme-control systems
    • G05B19/02—Programme-control systems electric
    • G05B19/18—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form
    • G05B19/406—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form characterised by monitoring or safety
    • G05B19/4065—Monitoring tool breakage, life or condition
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q11/00—Accessories fitted to machine tools for keeping tools or parts of the machine in good working condition or for cooling work; Safety devices specially combined with or arranged in, or specially adapted for use in connection with, machine tools
    • B23Q11/04—Arrangements preventing overload of tools, e.g. restricting load
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q17/00—Arrangements for observing, indicating or measuring on machine tools
    • B23Q17/09—Arrangements for observing, indicating or measuring on machine tools for indicating or measuring cutting pressure or for determining cutting-tool condition, e.g. cutting ability, load on tool
    • B23Q17/0952—Arrangements for observing, indicating or measuring on machine tools for indicating or measuring cutting pressure or for determining cutting-tool condition, e.g. cutting ability, load on tool during machining
    • B23Q17/0966—Arrangements for observing, indicating or measuring on machine tools for indicating or measuring cutting pressure or for determining cutting-tool condition, e.g. cutting ability, load on tool during machining by measuring a force on parts of the machine other than a motor

Definitions

  • the present invention relates to a load detection method for a machine tool.
  • the feed shaft gives machining feed to the work to the tool, and the work or the tool is driven by the spindle to perform cutting or the like. Perform processing.
  • an abnormal load applied to a feed shaft or a spindle has been detected in order to detect a collision between a movable portion and an obstacle.
  • This abnormal load detection is performed by comparing the magnitude of the detected load with the abnormal load detection level.
  • the conventional method of detecting an abnormal load has a problem in that it is not possible to detect an abnormal load according to the operation state of the machine tool. That is, the abnormal load detection level in the conventional abnormal load detection method is fixed to a constant value irrespective of the operation state of the machine tool, and the abnormal load detection level is determined by comparing with the fixed abnormal load detection level. Is being detected. Normally, in machine tools, the load during cutting operation is the largest, and the load during rapid traverse operation or manual feed operation is much smaller than the maximum load during cutting operation. Therefore, the abnormal load detection level used in the conventional abnormal load detection method is set based on the maximum load during the cutting operation. Stipulated.
  • Fig. 7 schematically shows the relationship between the magnitude of the load during the rapid traverse operation, the cutting feed operation, and the manual operation in the conventional abnormal load detection method, and the abnormal load detection level.
  • the abnormal load detection level L0 is set to a value obtained by adding a margin to that value, based on the maximum load during cutting feed operation.
  • Fig. 8 shows the relationship between the change in load in each operating state of the machine tool and the abnormal load detection level L0 in the conventional abnormal load detection method. It has been done.
  • the abnormal load detection level L0 is based on the maximum load during cutting, so the abnormal load during cutting operation indicated by b in Fig. 8 is the abnormal load cutting detection level L0. Detected when exceeds. However, abnormal loads during fast-forward operation and manual operation indicated by a and c in Fig. 8 are not detected because they do not exceed the abnormal load cutting detection level L O. If a collision between the tool and the jig occurs during rapid traverse operation or manual feed operation, the load level at which the tool or jig is damaged is smaller than the maximum load level during cutting. Then, it is not possible to detect this street collision.
  • An object of the present invention is to provide an abnormal load detection method capable of detecting an abnormal load according to the operation state of a machine tool.
  • the abnormal load detection method according to the present invention includes a step of detecting a load applied to a drive shaft of the machine tool during operation of the machine tool and a step of switching an abnormal load detection level according to the operation state of the machine tool. And comparing the detected load with the switched abnormal load detection level to determine whether the detected load exceeds the abnormal load detection level, and determining whether the detected load exceeds the abnormal load detection level. And a step of issuing an abnormal load detection signal when it is determined that the load has been exceeded.
  • the method of the present invention further includes a step of setting a plurality of abnormal load detection levels for each operating state of the machine tool, and the step of switching the abnormal load detection levels includes a plurality of steps. Includes a step to select an abnormal load detection level from the abnormal load detection levels according to the machine tool operating status.
  • Machine tools are operated in various operating states, and the magnitude of the load applied to the drive shaft changes according to the operating state.
  • the operation state includes, for example, a manual operation mode and an automatic operation mode, and the automatic operation mode includes a fast-forward operation and a cutting-feed operation.
  • the load during the cutting feed operation is larger than the load during the rapid feed operation.
  • the abnormal load detection level is switched according to the manual operation and automatic operation of the machine tool.
  • the machine tool When the machine tool is automatically operated, it is further switched according to the rapid traverse operation and the cutting feed operation.
  • the machine tool operates based on the machining program, and the abnormal unloading detection level is switched by a command in the processing program. Rukoto can.
  • the abnormal load detection level is switched according to the operating state of the machine tool, thereby detecting the abnormal load according to the actual operating state. This makes it possible to detect an abnormal load in an operating state where the maximum load is small.
  • FIG. 1 is an explanatory diagram showing the configuration of a machine tool and its control system for implementing the abnormal load detection method of the present invention
  • FIG. 2 is a flowchart showing an abnormal load detection process according to the present invention.
  • FIG. 3 is a graph showing the relationship between the operating state of the machine tool and the abnormal load detection level in the present invention.
  • FIG. 4 is a graph showing abnormal load detection during rapid traverse operation according to the present invention.
  • FIG. 5 is a graph showing abnormal load detection during cutting feed operation according to the present invention.
  • FIG. 6 is a graph showing abnormal load detection during manual feeding operation according to the present invention.
  • Fig. 7 is a graph showing the relationship between the magnitude of the load and the abnormal load detection level in the conventional abnormal load detection method.
  • Figure 8 is a graph showing the relationship between the load change and the abnormal load detection level in each operating state of the machine tool in the conventional abnormal load detection method.
  • a drive motor 2 is connected to a drive shaft 1a of a machine tool 1 that operates in various operation states.
  • the control device 4 outputs a current command value I c of the drive motor 2 to the drive circuit 3 based on the added program and the feedback signal from the drive motor 2.
  • the drive circuit 3 drives the drive motor 2 based on the command value Ic.
  • the load detecting means 5 detects a load applied to the drive motor 2.
  • the load detecting means 3 monitors, for example, a drive current command value Ic output from the control device 4 to the drive circuit 3 or a drive current I actually supplied to the drive coil of the drive motor 2. Then, the load applied to the drive shaft 1a is obtained using the current command value Ic or the drive current I, the torque constant of the drive motor 2, and the motor acceleration.
  • various methods other than the above-described methods for example, a method of estimating the load applied to the drive motor 2 by a disturbance estimation observer are known. Is omitted.
  • the load detected by the load detecting means 5 is compared with the abnormal load detection level by the comparing means 6.
  • the comparing means 6 includes a comparing circuit for comparing the load value detected by the load detecting means 5 with the abnormal load detection level, and the comparing circuit includes an abnormal load detecting level as a threshold value for detecting an abnormal load. Is set, and the abnormal load detection level is switched according to the actual operation state of the machine tool 1.
  • step S1 it is determined whether the machine tool is operated in the automatic operation mode or the manual operation mode (step S1).
  • an abnormal load detection level for the manual feed is set as a comparison level in the comparison means (step S2), and the comparison level is set.
  • the load value detected by the load detecting means is compared with the threshold value.
  • step S1 If it is determined in step S1 that the machine tool is operated in the automatic operation mode, the process proceeds to step S3, in which the rapid traverse operation or the cutting feed operation is performed. Is determined.
  • an abnormal load detection level for the rapid traverse operation is selected as a comparison level for detecting an abnormal load (step S3).
  • the comparison level is set as a threshold value, and the load value detected by the load detection means is compared.
  • step S3 If it is determined in step S3 that the machine tool does not perform the cutting feed operation, the abnormal load detection level for the cutting feed operation is selected as the comparison level for detecting the abnormal load (step S3).
  • step S5 the comparison level is compared with a load value detected by the load detection means as a threshold value.
  • the abnormal load detection level For the abnormal load detection level, a plurality of different abnormal load detection levels for various operation states of the machine tool are set and stored in a storage means in advance, and the abnormal load detection level is determined according to the judgment result of each judgment processing. Then, the abnormal load detection level corresponding to the operation state of the machine tool 1 is read from the storage means and set as a threshold value of the comparison means. Alternatively, the value of the potentiometer for inputting the threshold value to the comparing means may be switched according to the determination result of each determination process. Further, a plurality of comparison means are prepared in which each abnormal load detection level is set as a threshold value, and the comparison means corresponding to the operation state is selected according to the judgment result of each judgment processing. It can be configured to switch.
  • the operation of the machine tool is continued. If it is determined that the load value detected by the load detection means exceeds the abnormal load detection level corresponding to the operation state of the machine tool, it is determined that an abnormal load has occurred and the abnormal load detection signal is output. Emit. In this case, an alarm is issued
  • the determination of the operating state of the machine tool performed in step S1 or step S3 includes a symbol indicating the operating state in a machining program for controlling the machine tool. Describe the level value of the abnormal load detection level for the operating state, and read it by reading the symbol and level value.
  • the abnormal load detection level corresponding to the symbol read from the load program is read, and the read level value is set in the comparison means.
  • the level value read from the program is set as the threshold value for detecting the abnormal load.
  • Fig. 3 shows the operation in the manual operation mode and the rapid feed and cutting feed operation in the automatic operation mode.
  • the abnormal load detection level L3 is set for manual feed operation
  • the abnormal load detection level L2 is set for rapid traverse operation
  • the abnormal load detection level L1 is set for cutting feed operation.
  • the load on the machine tool is indicated by the solid line.
  • Each abnormal load detection level is set in the order of 3 ⁇ L2 ⁇ L1.
  • the load applied to the drive shaft of the machine tool is less than the abnormal load detection level L2 during rapid traverse operation, and the abnormal load detection level L1 during cutting feed operation.
  • the following is the abnormal load detection level L3 at the time of manual operation, and the abnormal load is detected at each abnormal load detection level in each operation state.
  • Figure 4 shows abnormal load detection during rapid traverse operation.
  • the abnormal load detection level is set to L2 for fast-forward operation.
  • the comparison means changes the load level to the abnormal load detection level. Compare with L2 to determine whether the load level has exceeded the abnormal load detection level L2. If an abnormal load occurs as indicated by the one-point line a during fast-forward operation, an abnormal load detection signal is output.
  • Figure 5 shows abnormal load detection during cutting feed operation.
  • the abnormal load detection level is set to L1.
  • the comparing means compares the load level with the abnormal load detection level L1, and determines whether the load level has exceeded the abnormal load detection level L1. If an abnormal load occurs as indicated by the dashed line b during cutting feed, an abnormal load detection signal is output.
  • Figure 6 shows abnormal load detection during manual feed operation.
  • the abnormal load detection level is set to L3 for manual feed operation.
  • the comparing means compares the load level with the abnormal load detection level L3, and determines whether the load level has exceeded the abnormal load detection level L3. If an abnormal load occurs as shown by the one-dot chain line c during manual feed operation, an abnormal load detection signal is output.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Human Computer Interaction (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Machine Tool Sensing Apparatuses (AREA)
  • Testing And Monitoring For Control Systems (AREA)
  • Automatic Control Of Machine Tools (AREA)

Abstract

L'invention porte sur un procédé de détection de charge anormale correspondant à certaines conditions de fonctionnement d'une machine-outil. La charge s'exerçant sur un arbre moteur de machine-outil est détectée, puis elle est comparée à un niveau de détection de charge anormale sélectionné en fonction des conditions de fonctionnement de la machine-outil, par exemple en mode manuel ou automatique, ou avec une avance rapide ou une avance de coupe en mode automatique.
PCT/JP1996/001486 1995-05-31 1996-05-31 Procede de detection de charge anormale WO1996038261A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP15558095A JPH08323585A (ja) 1995-05-31 1995-05-31 異常負荷検出方式
JP7/155580 1995-05-31

Publications (1)

Publication Number Publication Date
WO1996038261A1 true WO1996038261A1 (fr) 1996-12-05

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ID=15609159

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP1996/001486 WO1996038261A1 (fr) 1995-05-31 1996-05-31 Procede de detection de charge anormale

Country Status (2)

Country Link
JP (1) JPH08323585A (fr)
WO (1) WO1996038261A1 (fr)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3829559B2 (ja) * 1999-11-29 2006-10-04 三菱電機株式会社 数値制御工作機械
JP3699458B2 (ja) 2003-05-08 2005-09-28 義昭 垣野 切削抵抗検出方法及び切削抵抗による加工制御方法並びに制御装置
DE102005015317B4 (de) * 2005-04-01 2007-02-01 Siemens Ag Verfahren und Steuereinrichtung zur gezielten Reaktion bei einem Kontakt zwischen einem Maschinenelement einer Maschine mit einem Gegenstand
WO2009128156A1 (fr) * 2008-04-17 2009-10-22 三菱電機株式会社 Détecteur de collision et procédé de détection de collision dans une machine de traitement
US9459610B2 (en) 2011-04-11 2016-10-04 Mitsubishi Electric Corporation Electric discharge machine with contact detector and position detector
JP5740475B2 (ja) * 2011-09-02 2015-06-24 株式会社日立製作所 加工異常検知方法および加工装置
JP6900564B1 (ja) * 2020-09-02 2021-07-07 Dmg森精機株式会社 工作機械および情報処理装置

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5541458Y2 (fr) * 1972-05-23 1980-09-29
JPS58102656A (ja) * 1981-12-11 1983-06-18 Toyota Motor Corp Ｎｃ工作機

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5541458Y2 (fr) * 1972-05-23 1980-09-29
JPS58102656A (ja) * 1981-12-11 1983-06-18 Toyota Motor Corp Ｎｃ工作機

Also Published As

Publication number Publication date
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