Motor monitoring device

Abstract

A motor monitoring device according to one embodiment of the present disclosure is provided with: a rotational speed acquisition unit that acquires the rotational speed of one or more motors driven by a plurality of windings selected for use; an output value acquisition unit that acquires an output value of the motor; a winding identification unit that identifies the winding being used; a load characteristic acquisition unit that acquires, for the motor, load characteristic information of the winding identified by the winding identification unit; and a graph display unit that plots a mark indicating a combination of the rotational speed and the output value in a graph region in which one axis is the rotational speed and the other axis is the output value, the graph display unit including: a graph region setting unit that sets a graph region in which the rotational speed and the output value are supposed to be combined, the graph region setting unit setting a graph region in which the rotational speed and the output value are supposed to be combined, and the graph region setting unit setting a graph region in which the rotational speed and the output value are supposed to be combined; dividing the chart area into a plurality of load areas having different load levels on the basis of the load characteristic information, and displaying the plurality of load areas in a recognizable manner; and a plotting section that plots the mark in the chart area.

Description

Technical Field

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

[0002] In motors such as spindle motors for machine tools, where the load may vary greatly, there is a risk of heat accumulation and overheating if the heavy load continues. For such motors, various rated times can be set so that they can operate without overheating under specific conditions. As rated times, for example, JIS-C4034-1 specifies a continuous rating that allows continuous operation, a short-time rating that allows operation for a certain time (load time) from room temperature, and an intermittent rating (Japanese: repeated rating) that allows operation for a certain time (load time rate) within a specified cycle time.

[0003] For example, assume the following situation: in a machine tool, the actual operation state of the motor is grasped, and the setting value of the motor speed, etc. is adjusted to reduce the margin for overheating so that machining can be performed more efficiently. As a means for grasping the current operation state of the motor, a load meter is known that sets one axis as the rotation speed and the other axis as the output, and plots the current values ​​of the motor rotation speed and output on a graph showing lines representing the above-mentioned various ratings (for example, refer to Patent Document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 10-90011 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] There are known device structures including a plurality of motors selectively used to drive one shaft and a device structure including a plurality of winding systems selectively used to drive one motor. In such device structures, it is also desired to accurately grasp the state of the motor.

[0009] Solutions for solving problems

[0010] A motor monitoring device according to one embodiment of the present disclosure comprises: a rotational speed acquisition unit, which acquires the rotational speed of one or more motors driven by a plurality of windings that are selectively used; an output value acquisition unit, which acquires the output value of the motor; a winding determination unit, which determines the winding being used; a load characteristic acquisition unit, which acquires the load characteristic information of the winding determined by the winding determination unit for the motor; and a graph display unit, which plots marks representing the combination of the rotational speed and the output value in a graph area in which one axis is set to the rotational speed and the other axis is set to the output value, wherein the graph display unit comprises: a graph area setting unit, which divides the graph area into a plurality of load areas with different load levels based on the load characteristic information for an assumed combination of the rotational speed and the output value, and displays the plurality of load areas in an identifiable manner; and a plotting unit, which plots the marks in the graph area.

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

[0014] Figure 2 is exemplified by Figure 1 Figure 2 shows the display of the motor monitoring device. DETAILED DESCRIPTION

[0015] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Figure 1 1 is a block diagram showing the configuration of a machine tool 1 including 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 involved in the present invention, a spindle 20 controlled by the numerical controller 10, a display device 30 that displays 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 controller 10 has a memory, a processor (CPU), an input / output interface, etc., and can be implemented by one or more computer devices that execute an appropriate control program. The components of the numerical controller 10 described below are obtained by classifying the functions (processor operations) of the numerical controller 10, and may be components that cannot be clearly distinguished in physical structure and program structure.

[0018] The spindle 20 is driven by a plurality of motors (a first motor 21 and a second motor 22) that are used selectively. The first motor 21 has a plurality of windings (a first winding 211 and a second winding 212) that are used selectively. Similarly, the second motor 22 has a plurality of windings (a first winding 221 and a second winding 222) that are used selectively. In other words, the spindle 20 is driven by any one of the four windings 211, 212, 221, and 222 that are used selectively. The spindle 20 is typically configured as a drive shaft that drives a cutting tool or a workpiece to rotate, and the load of the spindle 20 can vary according to the processing conditions regardless of the rotation speed.

[0019] The machine tool 1 further includes: a switching unit 23 that selects any one of the windings 211, 212, 221, and 222; a rotation speed detector 24 that detects the rotation speed of the spindle 20; and a current detector 25 that detects the current supplied to the windings 211, 212, 221, and 222 for driving the spindle 20. The switching unit 23 can be composed of a plurality of relays controlled by the numerical control device 10. The rotation speed detector 24 and the current detector 25 can be respectively composed of known sensors. The current detector 25 can be configured to detect the current of the circuit on the upstream side of the switching unit 23.

[0020] 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 can be a well-known structure such as a keyboard and 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.

[0021] In the present embodiment, the numerical control device 10 includes: a program storage unit 11; a motor control unit 12, which controls the operation of a motor that drives a drive shaft of a machine tool 1 including a spindle 20; a winding selection unit 13, which selects windings 211, 212, 221, 222 by controlling a switching unit 23; and a motor monitoring unit 14, which performs the functions of the motor monitoring device involved in the present disclosure.

[0022] The program storage unit 11 stores a machining program executed in the machine tool 1. The machining program includes a plurality of blocks for respectively specifying unit actions of the machine tool 1. Each block includes one or more words each consisting of a combination of a plurality of characters. Generally, each block is initially assigned a serial number for identifying the block.

[0023] The motor control unit 12 controls the spindle 20 and other drive axes of the machine tool 1 according to the machining program, specifically, controls the winding current of each motor, thereby executing the machining process described in the machining program. The structure of the motor control unit 12 is the same as that of a known numerical control device, so detailed description is omitted.

[0024] The winding selection unit 13 controls the switching unit 23 to connect only one of the windings 211 , 212 , 221 , and 222 of the main shaft 20 to the motor control unit 12 .

[0025] The motor monitoring unit 14 includes a program acquiring unit 141 , a winding specifying unit 142 , a load characteristic acquiring unit 143 , a rotation speed acquiring unit 144 , an output value acquiring unit 145 , an operation information storing unit 146 , an external operation information acquiring unit 147 , a graph display unit 148 , and an operation information selecting unit 149 .

[0026] The program acquisition unit 141 acquires a machining program for specifying the operation of the motors 21 and 22 of the main spindle 20 to be monitored from the program storage unit 11 .

[0027] The winding wire identification unit 142 acquires information for identifying the selected winding wires 211 , 212 , 221 , and 222 from the winding wire selection unit 13 .

[0028] The load characteristic acquisition unit 143 acquires load characteristic information, which indicates the load characteristics of the selected windings 211, 212, 221, and 222 determined by the winding determination unit 142. The load characteristic information preferably includes a plurality of rated times. In addition, the load characteristic acquisition unit 143 may acquire the load characteristic information from a storage device inside the motor monitoring unit 14 or from an external server or the like.

[0029] The rotation speed acquisition unit 144 acquires the rotation speed of the selected motors 21 and 22, that is, the rotation speed of the spindle 20 from the rotation speed detector 24. The rotation speed acquisition unit 144 may acquire information from the motor control unit 12 and the winding selection unit 13 and calculate the rotation speed of the spindle 20 based on the information.

[0030] The output value acquisition unit 145 acquires output values ​​of the main shaft 20, such as the current value, power value, and torque value. In the present embodiment, the output value acquisition unit 145 acquires the current value of the main shaft 20 from the current detector 25, and uses the power value and torque value calculated based on the current value as the output value, but the output value acquisition unit 145 may be configured to directly use the detection value such as the current value as the output value. The output value acquisition unit 145 may also acquire the output value or the value required to calculate the output value from the motor control unit 12. In addition, the types of output values ​​acquired by the output value acquisition unit 145 may be one type or three or more types.

[0031] The operation information storage unit 146 stores the windings 211, 212, 221, 222 identified by the winding identification unit 142 and the load characteristic information acquired by the load characteristic acquisition unit in association with the rotation speed acquired by the rotation speed acquisition unit 144, the output value acquired by the output value acquisition unit 145, and information for identifying the corresponding block of the machining program acquired by the program acquisition unit 141, such as a sequence number and a line number. In other words, the operation information storage unit 146 stores the number of the windings 211, 212, 221, 222, the rotation of the spindle, and the output value in such a manner that the number, the rotation of the spindle, and the output value are values ​​when the block of the machining program is executed. The operation information stored in the operation information storage unit 146 may also include information indicating the state of the spindle 20, especially the state of the windings 211, 212, 221, 222, such as the temperature of the windings 211, 212, 221, 222.

[0032] Generally speaking, the rotation speed and output value are obtained in a short cycle, so it is possible to obtain a plurality of combinations of rotation speed and output value for one block. However, the operation information storage unit 146 can also save one data for one block in a manner that makes the serial number a unique key that does not repeat between data. In this case, representative values ​​of the rotation speed and output value corresponding to each block are saved. As the representative value of the rotation speed and output value, it is preferably set to a value representing a higher load among the values ​​corresponding to the block in order to ensure safety (in the case of the rotation speed and current value, it is set to the maximum value).

[0033] The external operation information acquisition unit 147 acquires the operation information acquired in other motor monitoring devices from other motor monitoring devices (numerical control devices), a management computer that manages multiple motor monitoring devices, an external database, etc. In other words, the external operation information acquisition unit 147 is a structure for sharing operation information between multiple motor monitoring devices.

[0034] The graph display unit 148 displays a graph in which marks representing combinations of rotation speeds and output values ​​are plotted in a graph area in which one axis is set as the rotation speed and the other axis is set as the output value on the display screen of the display device 30. The graph display unit 148 can display a graph of a single output value or a plurality of output value graphs arranged in a row.

[0035] In order to facilitate understanding of the relationship between the machining program, the rotation speed, and the output value, the graph display unit 148 is preferably as follows: Figure 2 As illustrated, the graph is displayed simultaneously with the display of the corresponding portion of the program.

[0036] The graph display unit 148 includes a graph region setting unit 1481 that divides the graph region into a plurality of load regions and displays the plurality of load regions in an identifiable manner, and a plotting unit 1482 that plots marks indicating combinations of actual rotation speeds and output values ​​in the graph region.

[0037] The chart area setting unit 1481 divides the chart area into a plurality of load areas with different load levels based on the load characteristic information related to the selected windings 211, 212, 221, 222 for the assumed combination of the rotation speed and the output value. Typically, the chart area setting unit 1481 can be configured to divide the chart area into three or more load areas as the boundaries of each of the plurality of rated times. The load area of ​​the chart area changes according to the windings 211, 212, 221, 222 used. Thus, the user can easily grasp the load state (dangerousness or safety) of the main shaft 20.

[0038] The graph area setting unit 1481 preferably displays the plurality of load areas in a manner that can be identified by color or pattern. By adding color or pattern, it is easy to understand which load area the combination of rotation speed and output value belongs to. In addition, by using a color or pattern that can easily intuitively understand the level of the load level of the load area, such as blue, yellow, and red, it is easy to understand the degree of danger of the operating state of the spindle 20.

[0039] If the combination of the rotation speed and output value of the spindle 20 is set to be less than the continuous rating, the operation state of the spindle 20 can be continued without limitation on the load of the spindle 20. Therefore, it is preferable to set the upper limit of the load range with the lowest load level to the curve representing the continuous rating.

[0040] Preferably, the graph area setting unit 1481 sets the boundary of any load area among the plurality of load areas, preferably the lower limit of the load area with the highest load level, to a line connecting the maximum values ​​of a plurality of rated times (e.g., short-time ratings and intermittent ratings with different load time rates) at the same speed. The combination of the speed and the output value plotted in the area crossing the boundary line means a dangerous output state that may cause a failure immediately. On the contrary, if the boundary line is not crossed, a problem may not occur in a short time.

[0041] The chart area setting unit 1481 may also be configured to select the boundary of at least one of the multiple load areas according to the user's input. Specifically, it may be configured to select the boundary of the load area from the above-mentioned continuous rating, the maximum value of multiple rated times, multiple short-time ratings with different load times, and multiple intermittent ratings with different load time rates. In this way, a load area that is considered appropriate can be set in consideration of the content of the processing to be performed in the machine tool 1, so that the degree of danger or safety of the spindle 20 can be more appropriately grasped.

[0042] The plotting unit 1482 plots the combination of the rotation speed and output value of the windings 211, 212, 221, and 222 being used by the spindle 20. The plotting unit 1482 may plot the combination of the rotation speed and the output value by showing the size of the state value indicating the state of the spindle 20, such as the winding temperature, by differences in the shape, size, color, pattern, etc. of the mark. Thus, the user can simultaneously grasp the state value that is affected by the operating state of the spindle 20 at its time point indicated by the rotation speed and the output value, and may also be affected by the previous operating state of the spindle 20. As an example, there is a case where even if the state value is a state value indicating that the temperature of the spindle 20 has increased, if the load level at this time point is low, it can be determined that there is no danger of further increase in the temperature of the spindle 20. Conversely, there is a case where even if the load level at this time point is not so high, if the operating state is continued, it can be determined that there will be a risk of overheating in the near future. The mark may also be set in a form having an outer edge portion that is easily distinguished from the color or pattern of the graph area and a filling portion indicating the state value. As described above, the plotting unit 1482 indicates the status value in the form of a mark, so that the user can understand the operating status of the main spindle 20 in various aspects.

[0043] The plotting unit 1482 may plot, in addition to the mark indicating the current combination of rotational speed and output value, a mark indicating the combination of rotational speed and output value when the same block of the same program as the currently executed block was executed in the past. It is preferable to display these marks in a manner that allows the marks indicating the current state to be distinguished from the marks indicating the actual state in the past. Figure 2 In the diagram, the current state is plotted with a circular mark, and the actual state in the past is represented with a triangular mark. Thus, the user can easily confirm the margin of the operating state of the spindle 20 relative to the specification of the spindle 20 and whether there is an abnormal increase in load.

[0044] The mark representing the actual past state plotted in the graph area may be, for example, in the form of a cross-shaped auxiliary line that crosses the graph area vertically and horizontally, so as to be easily distinguished from the mark representing the current state. In addition, the actual past state plotted may be an average value of all matching operation information, or a value or range calculated based on one or more operation information selected by the operation information selection unit 149.

[0045] The operation information selection unit 149 selects the operation information to be plotted by the plotting unit 1482 from the plurality of operation information when the same operation program as the current one is executed. The operation information selection unit 149 can be configured to determine one or more operation information of the spindle 20 that is considered normal according to a predetermined algorithm. As a specific example, the operation information to be plotted by the plotting unit 1482 can be selected by using a statistical method such as an average and a standard deviation. In addition, the operation information selection unit 149 can also be configured to provide a user with an interface for requesting selection of a plurality of operation information.

[0046] The numerical control device 10 according to the present embodiment obtains the load characteristic information of the winding being used, divides the graph area into load areas based on the load characteristic information, and plots the combination of the rotation speed and the output value. Therefore, the user can easily understand the safety level of the motor operation state based on the load area in which the combination of the rotation speed and the output value is plotted.

[0047] The following supplementary notes are further disclosed regarding the above-mentioned embodiment and modified examples.

[0048] (Note 1)

[0049] The motor monitoring device (10) comprises: a rotation speed acquisition unit (144) for acquiring the rotation speed of one or more motors (21, 22) driven by a plurality of windings (211, 212, 221, 222) selected for use; an output value acquisition unit (145) for acquiring the output value of the motor (21, 22); a winding determination unit (142) for determining the winding (211, 212, 221, 222) being used; and a load characteristic acquisition unit (143) for acquiring, for the motor (21, 22), the output value of the winding (211, 212, 221, 222) determined by the winding determination unit (142). 2, 221, 222); and a graph display unit (148) which plots marks representing combinations of rotational speeds and output values ​​in a graph area in which one axis is set to a rotational speed and another axis is set to an output value, wherein the graph display unit (148) comprises: a graph area setting unit (1481) which divides the graph area into a plurality of load areas having different load levels based on the load characteristic information for an assumed combination of rotational speed and output value, and displays the plurality of load areas in an identifiable manner; and a plotting unit (1482) which plots marks in the graph area.

[0050] (Note 2)

[0051] The motor monitoring device (10) of Note 1 may also be provided with: a program acquisition unit (141) which acquires an action program including a plurality of blocks for specifying the action of the motors (21, 22); and an operation information storage unit (146) which stores operation information obtained by associating load characteristic information, rotation speed and output value with blocks, and the plotting unit (1482) may also plot a mark indicating a combination of a current rotation speed and output value, and a mark indicating a combination of a rotation speed and output value when the same block as the current one was executed in the past.

[0052] (Note 3)

[0053] The motor monitoring device (10) of Appendix 2 may also include an operating information selection unit (149) that selects operating information to be plotted by the plotting unit (1482) from a plurality of operating information when executing the same action program as the current one.

[0054] (Note 4)

[0055] The motor monitoring device (10) of Supplementary Note 2 or 3 may further include an external operation information acquisition unit (147) for acquiring operation information from the outside.

[0056] The present disclosure is described in detail above, but the present disclosure is not limited to the above-mentioned embodiments. These embodiments can be variously added, replaced, changed, partially deleted, etc. without departing from the scope of the main purpose of the present disclosure or the scope of the purpose of the present disclosure derived from the contents recorded in the claims and their equivalents.

[0057] The motor monitoring device of the present disclosure can be set up independently of the numerical control device for controlling the machine tool, or can be used to confirm the status of a motor other than the spindle motor of the machine tool or a motor outside the machine tool. As an example, the motor monitoring device of the present disclosure can also be a device obtained by adding the function of the motor monitoring unit of the above-mentioned embodiment to a management computer for managing one or more numerical control devices.

[0058] In the motor monitoring device of the present disclosure, the information storage unit, the program acquisition unit, the operation information storage unit, the external operation information acquisition unit, and the operation information selection unit may be omitted. In other words, the motor monitoring device of the present disclosure may only have the function of displaying the current motor load state in real time.

[0059] Description of Reference Numerals

[0060] 1: machine tool; 10: numerical control device (motor monitoring device); 11: program storage unit; 12: motor control unit; 13: winding selection unit; 14: motor monitoring unit; 141: program acquisition unit; 142: winding determination unit; 143: load characteristic acquisition unit; 144: speed acquisition unit; 145: output value acquisition unit; 146: operation information storage unit; 147: external operation information acquisition unit; 148: chart display unit; 1481: chart area setting unit; 1482: plotting unit; 149: operation information selection unit; 20: spindle; 21, 22: motor; 211, 212, 221, 222: winding; 23: switching unit; 24: speed detector; 25: current detector; 30: display device; 40: input device.

Claims

1. A motor monitoring device, comprising: A rotation speed acquisition unit that acquires the rotation speed of one or more motors driven by the plurality of windings that are selectively used; an output value acquiring unit, which acquires an output value of the motor; a winding determination unit that determines the winding being used; a load characteristic acquisition unit that acquires, for the motor, load characteristic information of the winding determined by the winding determination unit; and a graph display section that plots a mark indicating a combination of the rotation speed and the output value in a graph region in which one axis is the rotation speed and the other axis is the output value, Wherein, the chart display unit has: a graph region setting unit that divides the graph region into a plurality of load regions having different load levels based on the load characteristic information for the assumed combinations of the rotation speed and the output value, and displays the plurality of load regions in an identifiable manner; as well as A plotting section plots the mark in the graph area.

2. The motor monitoring device according to claim 1, wherein: Also available: a program acquisition unit that acquires an operation program including a plurality of blocks for specifying an operation of the motor; and an operation information storage unit for storing operation information obtained by associating the load characteristic information, the rotation speed, and the output value with the block, The plotting unit plots the mark indicating a current combination of the rotation speed and the output value and the mark indicating a combination of the rotation speed and the output value when the same block as the current one was executed in the past.

3. The motor monitoring device according to claim 2, wherein: The device further includes an operation information selection unit configured to select the operation information to be plotted by the plotting unit from among a plurality of pieces of operation information when the same operation program as currently executed is executed.

4. The motor monitoring device according to claim 2 or 3, wherein: The system further includes an external operating information acquisition unit configured to acquire the operating information from the outside.

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