JP2000152689A - Motor power failure-detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor power failure-detecting device for detecting the failure in an actuation part, based on the change rate of power that is supplied to a motor for cyclically driving the actuation part. SOLUTION: In a motor power failure-detecting device 1, when power that is cyclically supplied to a motor M for driving a tool (actuation part) K of a machine tool MC is measured by a motor power sensor 2, the measurement power data is stored at a data storage part 4. Therefore, the change rate between the measurement power data of a current drive cycle and that of the previous drive cycle is calculated by a data-processing part 3. When the change rate exceeds an upper-limit value, the failure detection part 5 detects the failure in the tool (actuation part) K, so that the abnormality is displayed on a display part 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, the measurement of electric power supplied to a motor that cyclically drives an operating portion such as a cutting tool of a machine tool or a transfer mechanism of a transfer device, to thereby determine whether the cutting tool is defective or has a defect. The present invention relates to a motor power abnormality detection device that detects a mechanism abnormality or the like.

[0002]

2. Description of the Related Art Conventionally, there is a motor power abnormality detecting device for detecting a defect abnormality of a cutting tool by measuring a supply power of a motor that cyclically drives an operating portion such as a cutting tool of a machine tool. In the case of the conventional motor power abnormality detection device, as shown in FIG. 9, after the starting power is supplied to the motor, the actually measured waveform RF of the power supplied to the motor in a state where the work is cut and processed is the upper limit determination waveform UF and the lower limit determination of the power. If it exceeds the range of the waveform LF, it is determined that the power supplied to the motor is abnormal, and that an abnormality such as a defect in the cutting tool of the machine tool has occurred, and an abnormal signal is output to the outside. . FIG. 10 is an actually measured waveform showing the transition of the power supplied to the motor of the machine tool. The power supplied to the motor is the power at start-up and the power at no load before the blade comes into contact with the workpiece. The power changes during processing when the blade is processing the workpiece, and the no-load power after processing ends.

[0003]

In the case of the above-mentioned conventional motor power abnormality detecting apparatus, in the above-mentioned machine tool, since the power supplied to the motor generally increases in proportion to the wear of the cutting tool, the upper limit determination waveform UF is The electric power is set to a large value on the assumption that the wear of the cutting tool has progressed. On the other hand, the lower limit determination waveform LF is set to a small power value corresponding to a new blade. Therefore, if the cutting tool is missing when it is relatively new, the electric power supplied to the motor may not exceed the upper limit determination waveform UF, so that there is a problem that it is not possible to detect an abnormality of the cutting tool.

[0004] In view of the above, it is an object of the present invention to provide a motor power abnormality detecting device for detecting an abnormality of an operating unit based on a rate of change in electric power supplied to a motor that drives the operating unit cyclically. Is what you do.

[0005]

According to a first aspect of the present invention, there is provided a motor power abnormality detecting apparatus for measuring an electric power supplied to a motor for cyclically driving an operating unit, and for each driving cycle of the operating unit. A data storage unit that stores the data of the power measured by the power measurement unit; and a rate of change between the measured power data of the current drive cycle and the measured power data of the previous drive cycle stored in the data storage unit. Abnormality detecting means for detecting an abnormality of the operating section.

According to a second aspect of the present invention, there is provided the motor power abnormality detecting apparatus according to the first aspect, wherein the measured power data stored in the data storage means is displayed and an abnormality of the operating section is detected. In that case, a display unit for displaying the display is provided.

According to a third aspect of the present invention, there is provided a motor power abnormality detecting apparatus according to the first or second aspect, further comprising an input / output means capable of transmitting the measured power data to an external information processing apparatus.

According to the motor power abnormality detecting device of the first and second aspects, for example, the electric power supplied to the motor that cyclically drives the blade (operating portion) of the machine tool changes as shown in FIG. Therefore, when the power measurement means measures the supply power of the motor, the measured power data is stored in the data storage means, so that the measured power data of the current drive cycle and the measured power data of the immediately preceding drive cycle, for example, The abnormality of the operating section is detected based on the rate of change.

According to the motor power abnormality detecting device of the third aspect, since the measured power data can be transmitted to an external information processing device, the multi-cycle measured power data can be stored in the external information processing device. In addition to the above, the abnormality analysis of the operating unit can be performed by an external information processing device.

[0010]

Next, an embodiment of the present invention will be described. FIG. 3 is a block diagram showing the overall configuration of the motor power abnormality detection device 1. As shown in FIG. 3, the motor power abnormality detection device 1 uses a motor power sensor 2 to measure power supplied to a motor M of a machine tool MC that cyclically cuts a workpiece (not shown). If it is abnormal, it detects that an abnormality such as a defect has occurred in the cutting tool K driven by the motor M. In the machine tool MC, electric power is supplied from the motor drive circuit D to the motor M based on control by the motor control circuit C. The motor power sensor 2 measures the power supplied to the motor M based on the product of the voltage and the current by detecting the voltage supplied from the motor drive circuit D to the motor M and the current supplied to the motor M. I do. Further, the motor power sensor 2 is connected to a data processing unit 3 having a microcomputer as a center. The data processing unit 3 is connected to a data storage unit 4 that stores the measured power data from the motor power sensor 2 and data for, for example, 32,000 cycles of the blade life cycle.

The abnormality detecting unit 5 connected to the data processing unit 3 sends a signal to the motor M based on the rate of change of the measured power data at the time of cutting in each cycle stored in the data storage unit 4 as described later. This is to detect an abnormality in the supplied power. When the abnormality detecting unit 5 detects an abnormality in the power supplied to the motor M, the display unit 6 displays the abnormality, for example, graphically, and displays the measured power data stored in the data storage unit 4.

The setting operation section 7 sets an upper limit value of the rate of change of measured power data during cutting, which serves as a criterion when the abnormality detection section 5 detects an abnormality in the power supplied to the motor M. The user performs an operation for displaying the measured power data stored in the storage unit 4 on the display 6. In the case where the machine tool MC is an NC machine tool having a plurality of cutting tools K, the upper limit of the rate of change can be set for each cutting tool K. The input / output unit 8
Is connected to an external personal computer PC and is provided for transmitting the measured power data for each cutting cycle to the personal computer PC. In general, since the data storage capacity of the personal computer PC is large, the data of a plurality of motor power abnormality detection devices 1 can be stored in the personal computer PC. Can also.

Next, the operation of the motor power abnormality detecting device 1 will be described. As shown in FIG. 4, the electric power supplied to the motor M of the machine tool MC includes the starting electric power P1 and the cutting tool K.
There is a transition such as a no-load power P2 before contacting the workpiece, a cutting power P3 when the cutting tool K is processing the workpiece, and a no-load power P4 after the processing is completed. FIG.
Is a graph showing the transition of the measured power data at the time of cutting in each cycle measured by the motor power sensor 2 and stored in the data storage unit 4. FIG. 6 is a graph showing the transition of the rate of change between the current cycle and the previous cycle of the measured power data during cutting in each cycle stored in the data storage unit 4. The change rate of the measured power data is calculated by the data processing unit 3. That is, the rate of change between the measured power data at the time of cutting in the current cycle and the measured power data at the time of cutting in the previous cycle is calculated by the data processing unit 3, and the rate of change is an upper limit, for example, as shown in FIG. 3
%, The abnormality detection unit 5 detects an abnormality in the power supplied to the motor M. When the abnormality detection unit 5 detects an abnormality in the power supplied to the motor M, the abnormality is displayed on the display unit 6. Therefore, the operator checks the blade K, confirms the abnormality of the blade K, and replaces it.

As described above, the data storage unit 4 stores the blade K
Since the measured power data for the life cycle of each cycle can be stored, the transition graph of the measured power data during cutting in each cycle and the transition graph of the rate of change of the measured power data during cutting in each cycle can be analyzed. For example, the change rate upper limit value for determining the abnormality of the cutting tool K can be accurately determined.

FIG. 7 shows an example of an abnormal display displayed on the display unit 6. In the case of the number 67, the number of cycles is 123.
When the value is 45, the cutting power is abnormally high, and the rate of change with respect to the cutting power in the previous cycle exceeds the upper limit value set by the setting operation unit 7, indicating that the cutting tool K has been damaged. This indicates that the date and time of occurrence of the abnormality is 9:50:32 on August 17, 1998. Similarly,
In the case of number 66, when the number of cycles is 9876,
Since the cutting power became abnormally high and the rate of change with respect to the cutting power in the previous cycle exceeded the upper limit value set in the setting operation unit 7, it indicates that the cutting tool K was lost or the like.
The date and time of occurrence of this abnormality was 15:23 on July 25, 1998.
Minutes and 45 seconds. Similarly, in the case of the number 65, when the number of cycles is 5432, the cutting power is abnormally reduced, that is, for example, the cutting tool K is broken to be in a no-load state, and the power supplied to the motor M is abnormally reduced. Indicates that the rate of change with respect to the cutting power exceeds the upper limit value set by the setting operation unit 7. The date and time when this abnormality occurred was 1998
11:23:45 on May 23, 2011. FIG. 8 shows that, in the case of the number 66, the cutting power became abnormally high due to the occurrence of a defect or the like of the cutting tool K in the cycle of 9876.

As described above, the motor power abnormality detecting device 1
According to the method, the cutting power supplied to the motor M of the machine tool MC can be measured, and the measured power data can be stored in the data storage unit 4. Therefore, the cutting power of the previous cycle and the cutting power of the current cycle can be measured. If the rate of change of the cutting tool exceeds the upper limit, it is possible to detect that a defect abnormality or the like has occurred in the cutting tool K.

In the above-described embodiment, an example of a motor of a machine tool has been described. However, even in a motor of a device other than a machine tool that cyclically drives an operating unit, an abnormality in the supplied power is detected and an abnormality in the operating unit is detected. Can be detected.

[0018]

According to the first to third aspects of the present invention, the abnormality of the operating section is detected based on the change rate of the electric power supplied to the motor that cyclically drives the operating section. It can be detected reliably.

[Brief description of the drawings]

FIG. 1 is a graph showing a transition of electric power supplied to a motor of a machine tool as an example for explaining the operation of the present invention.

FIG. 2 is a graph showing a change in a rate of change between a previous cycle and a current cycle of cutting power supplied to a motor of a machine tool as an example of the operation of the present invention.

FIG. 3 is a block diagram illustrating a configuration of a motor power abnormality detection device.

FIG. 4 is a graph showing transition of electric power supplied to a motor of a machine tool as an example of an operation of the embodiment.

FIG. 5 is a graph showing transition of electric power supplied to a motor of a machine tool as an example for explaining the operation of the embodiment.

FIG. 6 is a graph showing a change in the rate of change between the previous cycle and the current cycle of the cutting power supplied to the motor of the machine tool as an example of the operation of the embodiment.

FIG. 7 is a diagram illustrating an abnormality display according to the embodiment;

FIG. 8 is a graph showing that the cutting power supplied to the motor of the machine tool as an example for explaining the operation of the embodiment is abnormally high.

FIG. 9 is an explanatory diagram of abnormality determination of a conventional motor power abnormality detection device.

FIG. 10 is a graph showing a transition of electric power supplied to a motor of a machine tool for explaining a conventional technique.

[Explanation of symbols]

 Reference Signs List 1 motor power abnormality detection device 2 motor power sensor 3 data processing unit 4 data storage unit 5 abnormality detection unit 6 display unit 7 setting operation unit 8 input / output unit MC machine tool M motor K cutting tool PC personal computer

Continuation of the front page (72) Inventor Yamazaki Saki Takafumi 5-4-16 Noto, Minato-ku, Nagoya Aichi Machinery Co., Ltd. F term (reference) 5H570 AA06 AA23 BB09 JJ02 LL07 LL28 MM04 MM07

Claims (3)

[Claims] 1. An electric power measuring means for measuring electric power supplied to a motor for driving an operating part cyclically, and data for storing data of the electric power measured by the electric power measuring means for each driving cycle of the operating part. Storage means, and abnormality detection means for detecting an abnormality of the operating unit based on a rate of change between the measured power data of the current drive cycle and the measured power data of the previous drive cycle stored in the data storage means. Motor power abnormality detection device. 2. A display unit for displaying the measured power data stored in the data storage unit and displaying an abnormality of the operating unit when the abnormality is detected.
The motor power abnormality detection device according to any one of the above. 3. The motor power abnormality detection device according to claim 1, further comprising an input / output unit capable of transmitting the measured power data to an external information processing device.