Motor monitoring device

Abstract

A motor monitoring device according to one embodiment of the present disclosure, which can easily ascertain the state of a motor, is provided with: a rotational speed acquisition unit that acquires the rotational speed of a motor that operates in accordance with an operation program; an output value acquisition unit that acquires an output value of the motor; a state information acquisition unit that acquires state information indicating the state of the motor, the state information being different from the rotational speed and the output value; a history information storage unit that associates the rotational speed, the output value, and the state information acquired at a predetermined timing, and stores the associated information as history information to which an identifier is added; and a graph display unit that displays a graph in which a label indicating the identifier is added to a graph region in which one axis is the rotational speed and the other axis is the output value, and in which a mark indicating a combination of the rotational speed and the output value is drawn.

Description

Technical Field

[0001] The invention relates to a motor monitoring device. Background Art

[0002] For example, in a motor such as a spindle motor of a machine tool, whose load may vary greatly, if the state of heavy load continues, heat may be accumulated and overheated. In such a motor, various time ratings can be set so that it can operate without overheating under specific conditions. As time ratings, for example, JIS-C4034-1 stipulates a continuous rating that can operate continuously, a short-time rating that can operate for a certain time (load time) from room temperature, and a repeated rating that can operate for a certain time (load time rate) within a specified cycle time.

[0003] It has also been proposed to estimate the time until the motor overheats while maintaining the current operating state (see, for example, Patent Document 1). If the time until overheating is known, it can be determined whether the current processing can be continued to the end.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 5628994 Summary of the invention

[0007] Problems to be solved by the invention

[0008] It is not easy to understand the safety and margin of the motor's operation by simply estimating the time until overheating. Specifically, when adjusting the setting value of the motor speed, etc., in order to minimize the margin for overheating and maximize efficient processing, it is not easy to determine to what extent the setting value should be increased or decreased. Therefore, a technology that can easily understand the state of the motor is desired.

[0009] Means for solving problems

[0010] A motor monitoring device according to one embodiment of the present invention comprises: a rotational speed acquisition unit, which acquires the rotational speed of a motor that operates according to an action program; an output value acquisition unit, which acquires the output value of the motor; a state information acquisition unit, which acquires state information indicating the state of the motor that is different from the rotational speed and the output value; a history information storage unit, which associates the rotational speed, the output value and the state information acquired at a specified timing and stores them as history information to which an identifier is attached; and a chart display unit, which displays a chart in which a label indicating the identifier is attached in a chart area and a mark indicating a combination of the rotational speed and the output value is drawn, wherein one axis of the chart area is set to the rotational speed and the other axis is set to the output value.

[0011] Effects of the Invention

[0012] According to the present disclosure, the state of the motor can be easily grasped. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is a block diagram showing a configuration of a machine tool including a motor monitoring device according to a first embodiment of the present disclosure.

[0014] FIG. 2 is a diagram illustrating a display of the motor monitoring device of FIG. 1 . DETAILED DESCRIPTION

[0015] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Fig. 1 is a block diagram showing a configuration of a machine tool 1 having a motor monitoring device according to a first embodiment of the present disclosure.

[0016] The machine tool 1 includes: a numerical controller 10 as an embodiment of the motor monitoring device of the present invention, a spindle motor 20, a rotation speed detector 21 for detecting the rotation speed of the spindle motor 20, a current detector 22 for detecting the current of the spindle motor 20, a temperature detector 23 for detecting the winding temperature of the spindle motor 20, a display device 30 for displaying a screen according to the numerical controller 10, and an input device 40 for a user to input to the numerical controller 10.

[0017] The numerical control device 10 controls the operation of the spindle motor 20 and other structural elements according to the action program (referred to as a machining program in the numerical control device) so that the workpiece can be processed as required in the machine tool 1. The numerical control device 10 has a memory, a processor (CPU), an input / output interface, etc., and can be implemented by one or more computer devices that execute appropriate control programs. The structural elements of the numerical control device 10 described below are obtained by classifying the functions of the numerical control device 10, and may not be clearly distinguished in the physical structure and program structure.

[0018] The spindle motor 20 is typically a motor that drives a cutting tool or a workpiece to rotate. As described above, the spindle motor 20 operates according to the operation program, but the load may vary regardless of the rotation speed depending on the processing conditions. The rotation speed detector 21, the current detector 22, and the temperature detector 23 can be respectively composed of known sensors.

[0019] The display device 30 is a well-known display that displays according to the signal input from the numerical controller 10. The display device 30 may be configured integrally with the numerical controller 10. The input device 40 is a device for the user to input information to the numerical controller 10, and may be a well-known structure such as a keyboard or a mouse. The input device 40 may be configured integrally with the numerical controller 10. In addition, the input device 40 may be configured integrally with the display device 30. Specifically, the display device 30 and the input device 40 may be a single input / output device such as a touch panel.

[0020] In this embodiment, the numerical control device 10 includes: a program storage unit 11; a motor control unit 12 that controls the operation of a motor that drives a drive shaft of the machine tool 1 including a spindle motor 20; and a motor monitoring unit 13 that performs the function of the motor monitoring device of the present disclosure.

[0021] The program storage unit 11 stores an action program executed in the machine tool 1. The action program includes a plurality of program blocks that respectively specify unit actions of the machine tool 1. Each program block includes one or more characters composed of a combination of a plurality of characters (letters). Generally, each program block is initially assigned a serial number for identifying the program block.

[0022] The motor control unit 12 controls the spindle motor 20 and other drive axis motors of the machine tool 1 according to the operation program, thereby executing the machining process described in the operation program. The configuration of the motor control unit 12 is the same as that of a known numerical control device, so detailed description is omitted.

[0023] The motor monitoring unit 13 includes a program acquisition unit 131 , a rotation speed acquisition unit 132 , an output value acquisition unit 133 , a state information acquisition unit 134 , a history information storage unit 135 , a graph display unit 136 , a history information display unit 137 , and a program display unit 138 .

[0024] The program acquisition unit 131 acquires an operation program that specifies an operation to be monitored by the spindle motor 20 from the program storage unit 11. That is, the program acquisition unit 131 develops the target operation program in the work memory.

[0025] The rotation speed acquisition unit 132 acquires the rotation speed of the spindle motor 20 from the rotation speed detector 21. The rotation speed acquisition unit 132 may acquire the rotation speed of the spindle motor 20 via the motor control unit 12.

[0026] The output value acquisition unit 133 acquires output values ​​of the spindle motor 20, such as current value, power value, torque value, etc. In the present embodiment, the output value acquisition unit 133 attempts to acquire the current value of the spindle motor 20 from the current detector 22 and uses the power value calculated from the current value as the output value, but the output value acquisition unit 133 may be configured to directly use the detection value such as the current value as the output value. The output value acquisition unit 133 may also acquire the output value or the value required to calculate the output value from the motor control unit 12. In addition, the output value acquisition unit 133 may also acquire two or more output values.

[0027] The status information acquisition unit 134 acquires status information indicating the status of the spindle motor 20 that is different from the rotation speed and the output value. In the present embodiment, the status information acquisition unit 134 calculates the estimated time until the spindle motor 20 reaches the overheating temperature while maintaining the rotation speed and the output value at that time point, based on the winding temperature of the spindle motor 20 acquired from the temperature detector 23 and the current value or the output value acquired by the output value acquisition unit 133, and uses the estimated time as one of the status information. In addition, the status information acquisition unit 134 may also use other indicators indicating the status of the spindle motor 20 as alternative or additional status information, for example, the winding temperature of the spindle motor 20 may be directly used as status information. In addition, the status information may include program position information that determines the position in the action program, and modal information that specifies the action of the spindle motor 20. As program position information, a sequence number, a line number, and a program block number may be cited. Examples of modal information include commands extracted from the action program (not limited to commands that directly specify the action of the spindle motor 20, such as commands that specify tools and may affect the action of the spindle motor 20), and setting values ​​of the numerical control device 10.

[0028] The history information storage unit 135 associates the rotation speed, output value, and state information obtained at a predetermined timing and stores them as history information with an identifier. That is, the history information storage unit 135 stores the rotation speed, output value, and state information of the spindle motor 20 at the same timing as one record and stores each record with a unique identifier. As the identifier, a continuous number or a time can be used.

[0029] The timing for acquiring the rotation speed, output value, and state information stored as the history information by the history information storage unit 135 may include the timing indicated by the user, and may also include when the combination of the rotation speed and the output value reaches a prescribed load level, and when an abnormality is detected. By storing the history information at the timing indicated by the user, the state of the spindle motor 20 at the time point of interest to the user can be confirmed in detail. In addition, by storing the history information when the combination of the rotation speed and the output value reaches a prescribed load level, and when the numerical control device 10 detects an abnormality, the information that the user wants to confirm can be stored. As the load level for storing the history information, in the area set to divide the chart area where the combination of the rotation speed and the output value can be obtained into a plurality of areas, an area with a maximum load level that can be allowed to operate can be set, for example, an area that is set to be above a specific time rating and below an instantaneous rating. In addition, in FIG. 2, according to the continuous rating, time rating, and maximum output represented by dotted lines, the chart area is divided into four areas: a load area that can be operated continuously, a load area that can be operated intermittently, a load area that can be operated exceptionally if it is a short time, and an operation area where short-time operation is not recognized.

[0030] Furthermore, it is preferred that the history information storage unit 135 confirms the rotation speed, output value, and state information at a certain time interval, and stores a plurality of combinations of the rotation speed, output value, and state information within a predetermined time range (e.g., the time point closest to the specified timing and a certain number of times immediately before) based on the specified timing as one or individual history information. In this way, by storing a certain number of continuous information at a certain interval, the user can confirm the rate of change of the operating state, and thus can more appropriately grasp the state of the spindle motor 20.

[0031] The chart display unit 136 displays a chart in which a label representing an identifier is added to a chart area, and a label representing a combination of a rotation speed and an output value stored in the history information storage unit 135 is drawn, wherein one axis in the chart area is set as the rotation speed and the other axis is set as the output value. In the example shown in FIG. 2 , the label representing the identifier is added adjacent to the label, but the label can also be enlarged and displayed on the label, or can be displayed separately from the label using a lead line. By displaying such a chart, the load of the spindle motor 20 can be visualized, and the user can easily identify the corresponding history information, that is, information other than the rotation speed and the output value.

[0032] Preferably, the chart display unit 136 displays the chart in a manner that allows the user to select the displayed mark. The selection of the mark can also be performed indirectly by selecting the label. In FIG. 2 , the mark of the label to which the identifier "3" is attached is selected by the chart display unit 136, and the display content of the history information display unit 137 and the program display unit 138 is determined accordingly. The display content of the history information display unit 137 and the program display unit 138 can be selected by the mark displayed by the chart display unit 136, thereby making it easy to determine the part of the history information and the action program to be confirmed. Conversely, the chart display unit 136 can also display the mark corresponding to the history information displayed by the history information display unit 137 in a recognizable manner.

[0033] The history information display unit 137 displays at least a portion of the history information corresponding to the mark selected by the user in the graph display unit 136. In FIG2 , the content of the history information to which the identifier "3" is added is displayed in the history information display unit 137. In addition, buttons for forwarding and reversely transmitting the history information may be provided in the history information display unit 137 so that the history information can be selected. In this way, by making the display of the history information display unit 137 correspond to the graph display unit 136, the operability can be improved.

[0034] The program display unit 138 displays at least a portion of the action program. Preferably, the program display unit 138 provides a user interface such that the user can edit the displayed action program. That is, it can be configured so that the edited content of the action program determined in the program display unit 138 is reflected in the storage content of the program storage unit 11. Preferably, the program display unit 138 identifiably displays the portion determined by the program position information of the history information corresponding to the mark selected by the user in the chart display unit 136. In FIG. 2, the serial number "N0007" of the program number "O0001" determined by the history information of the identifier "3" of the mark selected in the chart display unit 136 and its front and back are displayed, and the portion corresponding to the identifier "3" of the selected mark is identifiably displayed. In this way, by making the display of the program display unit 138 correspond to the chart display unit 136, the operability can be improved.

[0035] The numerical controller 10 of this embodiment includes: a history information storage unit 135 that associates the rotation speed, output value, and state information obtained at a predetermined timing and stores them as history information with an identifier; and a graph display unit 136 that displays a graph in which a label indicating the identifier is added to a graph area and a mark indicating a combination of the rotation speed and the output value is drawn, wherein one axis is the rotation speed and the other axis is the output value. Therefore, the state information other than the rotation speed and the output value can be included to easily grasp the state of the spindle motor 20.

[0036] The embodiments of the present disclosure are described above, but the present invention is not limited to the embodiments described above. In addition, the effects described in the embodiments described above are merely examples of preferred effects produced by the present invention, and the effects of the present invention are not limited to the effects described in the embodiments described above.

[0037] The motor monitoring device of the present disclosure can be provided independently of the numerical control device controlling the machine tool, and can also confirm the status of motors other than the spindle motor of the machine tool, such as the motor of the kneading machine, etc. As an example, the motor monitoring device of the present disclosure can also be a device in which the functions of the motor monitoring unit of the above-mentioned embodiment are added to a management computer that manages one or more numerical control devices, such as a control device such as a kneading machine, or a management computer that manages such a control device.

[0038] In the motor monitoring device of the present disclosure, the history information display unit and the program display unit may be of arbitrary configurations, and may not be a configuration in which the display position can be selected by the mark of the graph display unit.

[0039] Description of Reference Numerals

[0040] 1 Machine Tools

[0041] 10 Numerical control device (motor monitoring device)

[0042] 11 Program storage unit

[0043] 12 Motor control unit

[0044] 13 Motor monitoring unit

[0045] 131 Program Acquisition Department

[0046] 132 Speed ​​acquisition unit

[0047] 133 Output value acquisition unit

[0048] 134 Status information acquisition unit

[0049] 135 History Information Storage Department

[0050] 136 Graphic display unit

[0051] 137 History information display unit

[0052] 138 Program display unit

[0053] 20 Spindle motor

[0054] 21 Speed ​​detector

[0055] 22 Current detector

[0056] 23. Temperature detector

[0057] 30 Display device

[0058] 40 Input device.

Claims

1. A motor monitoring device, characterized in that: have: a rotation speed acquisition unit that acquires the rotation speed of the electric motor that operates according to the operation program; an output value acquiring unit that acquires an output value of the motor; a state information acquisition unit that acquires state information indicating a state of the electric motor that is different from the rotation speed and the output value; a history information storage unit that associates the rotation speed, the output value, and the state information acquired at a predetermined timing and stores them as history information to which an identifier is added; A graph display unit displays a graph in which a label indicating the identifier is added to a graph region in which one axis is the rotation speed and the other axis is the output value and a mark indicating a combination of the rotation speed and the output value is drawn.

2. The motor monitoring device according to claim 1, characterized in that: The identifier is a time or a sequential number.

3. The motor monitoring device according to claim 1 or 2, characterized in that: The predetermined timing includes when a combination of the rotation speed and the output value reaches a predetermined load level and when an abnormality is detected.

4. The motor monitoring device according to any one of claims 1 to 3, characterized in that: The predetermined timing includes a timing instructed by a user.

5. The motor monitoring device according to any one of claims 1 to 4, characterized in that: The motor monitoring device further includes a history information display unit that displays at least a portion of the history information corresponding to the mark selected by the user in the graph display unit.

6. The motor monitoring device according to any one of claims 1 to 5, characterized in that: The motor monitoring device further comprises: a program display unit which displays at least a part of the operation program; The state information includes program position information that identifies a position in the action program, The program display unit displays a portion of the history information that corresponds to the mark selected by the user in the graph display unit and is identified by the program position information.

7. The motor monitoring device according to any one of claims 1 to 6, characterized in that: The history information storage unit checks the rotation speed, the output value, and the status information at regular time intervals, and stores a plurality of combinations of the rotation speed, the output value, and the status information within a preset time range based on the predetermined timing.

8. The motor monitoring device according to any one of claims 1 to 7, characterized in that: The state information includes modal information specifying an operation of the motor.

9. The motor monitoring device according to any one of claims 1 to 8, characterized in that: The state information acquisition unit calculates, as one of the state information, an estimated time until the electric motor reaches an overheating temperature when the rotation speed and the output value at that point in time are maintained.

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