Motor monitoring device

Abstract

A motor monitoring device according to one embodiment of the present disclosure, which makes it possible to easily grasp 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; a history information storage unit that stores history information including the rotational speed at a constant time interval; and a graph display unit that draws a mark indicating the rotational speed in a graph region in which one axis is taken as a time and the other axis is taken as the rotational speed, the graph display unit changing the pattern of the mark in accordance with a predetermined index.

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 to enable operation without overheating under specific conditions. As time ratings, for example, JIS-C4034-1 stipulates a continuous rating that enables continuous operation, a short time rating that enables operation from room temperature for a certain time (load time), and a repeated rating that enables operation for a certain time (load time rate) within a predetermined cycle time.

[0003] It is also 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 is possible to determine 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 values ​​such as the motor speed so that the margin for overheating can be minimized and efficient processing can be maximized, 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; a historical information storage unit, which stores historical information including the rotational speed at constant time intervals; and a graph display unit, which draws a mark representing the rotational speed in a graph area with one axis being time and the other axis being the rotational speed, wherein the graph display unit changes the style of the mark according to a predetermined indicator.

[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 an example Figure 1 A table of information stored in a historical information storage unit of a motor monitoring device.

[0015] Figure 3 is an example Figure 1 Diagram of the display of the motor monitoring device. DETAILED DESCRIPTION

[0016] Below, while referring to the attached Figure 1 Embodiments of the present disclosure will be described. 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.

[0017] 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, which detects the rotation speed of the spindle motor 20; a current detector 22, which detects the current of the spindle motor 20; a temperature detector 23, which detects the winding temperature of the spindle motor 20; a display device 30, which displays a screen according to the numerical controller 10; and an input device 40, which is used by a user to input to the numerical controller 10.

[0018] 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 planned 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 structural elements that classify the functions of the numerical control device 10, and may not be structural elements that can be clearly distinguished in the physical structure and program structure.

[0019] 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 an operation program, but the load may vary regardless of the rotation speed depending on the machining conditions. The rotation speed detector 21, the current detector 22, and the temperature detector 23 may be respectively constituted by known sensors.

[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 integrally configured 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 integrally configured with the numerical controller 10. In addition, the input device 40 may be integrally configured 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 controller 10 includes a program storage unit 11 , a motor control unit 12 for controlling motors including a spindle motor 20 that drive drive axes of the machine tool 1 , and a motor monitoring unit 13 for executing the functions of the motor monitoring device of the present disclosure.

[0022] 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 words composed of a combination of a plurality of characters. Generally, each program block is initially assigned a serial number for identifying the program block.

[0023] 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 steps 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.

[0024] The motor monitoring unit 13 includes a program acquisition unit 131 , a rotation speed acquisition unit 132 , an output value acquisition unit 133 , an estimated time calculation 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 .

[0025] The program acquisition unit 131 acquires an operation program for designating 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.

[0026] 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.

[0027] 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 acquires 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.

[0028] The estimated time calculation unit 134 calculates the estimated time until the spindle motor 20 reaches the overheat temperature when maintaining the current rotation speed and output value based on the winding temperature of the spindle motor 20 obtained from the temperature detector 23 and the current value or output value obtained by the output value acquisition unit 133 .

[0029] The history information storage unit 135 stores history information related to the spindle motor 20 at a constant time interval. The history information includes the rotation speed of the spindle motor 20 as one of its elements, and other elements may include the output value of the spindle motor 20, the winding temperature, the load level, other state information such as the above-mentioned estimated time, the program position information indicating the position of the corresponding command of the action program, and the modal information specifying the action of the spindle motor 20. As the program position information, the sequence number, the line number, and the program block number are cited. As the modal information, the command extracted from the action program (not limited to the command directly specifying the action of the spindle motor 20, for example, the command including the command specifying the tool and the like that can affect the action of the spindle motor 20), the set value of the numerical control device 10 such as the upper limit value of the acceleration, etc. In addition, the load level can be determined by the relationship with various ratings represented on a graph with the rotation speed and the output value as two axes. Specifically, the charts of continuous rating, time rating, and maximum output can be used as boundary lines to set the following four load levels: a continuous operation level that allows continuous operation, a short-time operation level that allows intermittent operation within a certain period of time, a maximum load operation level that allows exceptional operation for an extremely short time, and a non-operation level that, in principle, is not recognized even for an extremely short time.

[0030] The time interval (unit time) for saving the history information may be a predetermined constant time, or may be set according to the user's instruction via the input device 40, etc. If the time interval is too short, the correspondence with the operation program cannot be confirmed, so the user can specify the time interval for saving the history information, thereby being able to properly confirm the relationship between the operating state of the spindle motor 20 and the operation program. Figure 2The content of the historical information stored in the historical information storage unit 135 is illustrated in FIG. As can be seen from the figure, the historical information storage unit 135 can be configured to create a relational database for the historical information using the acquisition time or serial number of the data as a unique key. In addition, the "-" in the figure indicates that the corresponding information cannot be calculated or does not exist.

[0031] like Figure 3 As shown on the left side of , the graph display unit 136 draws a mark indicating the rotation speed in a graph area with one axis (vertical axis) representing time and the other axis (horizontal axis) representing rotation speed. In addition, the graph display unit 136 changes the style of the mark according to a predetermined index. As an index for determining the style of the mark, the state information of the spindle motor 20 such as the load level and the estimated time until the overheating temperature is reached can be used. By changing the style of the mark according to the state information such as the load level, the user can more easily grasp the state of the spindle motor 20 at each time, such as the margin.

[0032] As examples of changes to the marking style by the graph display unit 136, there are, for example, changes to colors such as blue, yellow, and red corresponding to the values ​​of the indicators, changes to the concentration or brightness corresponding to the values ​​of the indicators, and changes to the length or size of the marking corresponding to the values ​​of the indicators. That is, it is preferred that the graph display unit 136 changes the display mode of the marking based on a predetermined rule so that the magnitude of the value of the indicator can be identified. In order to increase the amount of information that can be presented to the user, the graph display unit 136 may also independently change multiple display modes of the marking based on multiple indicators.

[0033] The graph display unit 136 may also be configured to set the time range of the graph area based on a time specified by the user, a completion time of acceleration or deceleration of the spindle motor 20, or a start and end time of an operation program. By appropriately setting the time range of the graph area, the user can easily understand the time change of the state of the spindle motor 20.

[0034] The graph display unit 136 may also allow the user to select a displayed mark so that the trigger of the program can be displayed as the program display unit 138. In addition, the graph display unit 136 may omit marks to facilitate viewing of the graph when the rotation speed is zero as shown in the figure, or when the load is considered to be extremely small based on some indicators, etc.

[0035] like Figure 3As shown on the left side of the diagram, the history information display unit 137 displays at least a portion of the history information as character information arranged by aligning the time axis with the chart display unit 136. In the example shown in the figure, the sequence number (Seq No) and the T-code (T-Code) only display the update information, and if there is no record, it means that there is no change from the previous time. The items displayed by the history information display unit 137 can also be configured so that the user can select from the history information.

[0036] The history information display unit 137 may select the history information to be displayed for each unit time so that the program display unit 138 can display the trigger of the program.

[0037] The program display unit 138 displays in an editable manner a portion of the action program corresponding to the mark selected by the user in the graph display unit 136 or the historical information selected by the user in the historical information display unit 137. That is, the program display unit 138 provides an interface for partially rewriting the action program stored in the program storage unit 11. The historical information display unit 137 may display the program on the same screen as the graph display unit 136 and the historical information display unit 137, or may display the program in a larger area by switching screens or by pop-up display.

[0038] The numerical control device 10 of this embodiment has a graph display unit 136, which draws a mark representing the rotational speed of the spindle motor 20 by changing the style according to a predetermined indicator in a graph area in which one axis is set to time and the other axis is set to the above-mentioned rotational speed. Therefore, the relationship between the change in the rotational speed of the spindle motor 20 and the change in other states of the spindle motor 20 can be easily grasped.

[0039] Although the embodiments of the present disclosure have been described above, the present invention is not limited to the above embodiments. In addition, the effects described in the above embodiments 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 above embodiments.

[0040] The motor monitoring device of the present disclosure can be provided independently of the numerical control device for controlling the machine tool, and can also confirm the state of motors other than the spindle motor of the machine tool, for example, confirming the state of 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 function of the motor monitoring unit of the above-mentioned embodiment is added to a management computer for managing one or more numerical control devices, such as a control device for a kneading machine, etc., or a management computer for managing such a control device.

[0041] In the motor monitoring device of the present disclosure, the history information display unit and the program display unit may be arbitrary structures, and may have a structure that displays history information or an operation program independently of the graph display unit.

[0042] Description of Reference Numerals

[0043] 1Machine Tools

[0044] 10 Numerical control device (motor monitoring device)

[0045] 11Program storage unit

[0046] 12 Motor control unit

[0047] 13 Motor monitoring unit

[0048] 131 Program Acquisition Department

[0049] 132 Speed ​​acquisition unit

[0050] 133 Output value acquisition unit

[0051] 134 Estimated time calculation unit

[0052] 135 Historical Information Preservation Department

[0053] 136 Graphic Display Unit

[0054] 137 Historical Information Display Unit

[0055] 138 Program display unit

[0056] 20 Spindle motor

[0057] 21 Speed ​​detector

[0058] 22 Current detector

[0059] 23 Temperature detector

[0060] 30 Display device

[0061] 40 Input devices.

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; a history information storage unit that stores the history information including the rotation speed at a constant time interval; and a graph display unit that draws a mark indicating the rotation speed in a graph area having time as one axis and the rotation speed as the other axis, The graph display unit changes the style of the mark according to a predetermined index.

2. The motor monitoring device according to claim 1, characterized in that: The history information storage unit sets the time interval according to an instruction from a user.

3. The motor monitoring device according to claim 1 or 2, characterized in that: The motor monitoring device further includes an output value acquisition unit that acquires an output value of the motor. The graph display unit changes the pattern of the mark in accordance with a load level determined based on the rotation speed and the output value.

4. The motor monitoring device according to any one of claims 1 to 3, characterized in that: The graph display unit sets a time range of the graph area based on a time specified by a user, a time when acceleration or deceleration of the motor is completed, or a start or end time of the operation program.

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 part of the history information as character information arranged so as to align a time axis with the graph display unit.

6. The motor monitoring device according to claim 5, characterized in that: The motor monitoring device further includes an estimated time calculation unit that calculates, as one element of the history information, an estimated time until the motor reaches an overheating temperature when the motor maintains an operating state at that point in time.

7. The motor monitoring device according to claim 5 or 6, characterized in that: The history information includes program location information for determining the location of the action program. The motor monitoring device further includes a program display unit that displays a portion of the operating program corresponding to the mark selected by a user in the graph display unit or the history information selected by a user in the history information display unit in an editable manner.

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