Engine monitoring device

Abstract

According to one embodiment of the present disclosure, a motor monitoring device capable of easily determining the condition of a motor comprises a speed sensing unit that detects the speed of a motor operating according to an operating program, an output value sensing unit that detects an output value for the motor, and a chart display unit that graphically displays or plots a marker representing a combination of the speed and the output value in a chart area, wherein one axis is the speed and the other axis is the output value. The chart display unit includes a unit range setting unit that sets a plurality of unit ranges that subdivide the chart area into a grid, and a format modification unit that modifies the display format of the marker for each unit range according to a prescribed indicator.

Description

TECHNICAL FIELD

[0001] The present invention relates to an engine monitoring device. TECHNICAL BACKGROUND

[0002] For example, motors such as spindle motors used in machine tools, where the load can vary significantly, are at risk of overheating if a high-load condition persists and heat builds up. Different time ratings can be specified or set for such motors to ensure operation without overheating under specific conditions. For example, the time ratings specified in JIS-C4034-1 include continuous ratings that allow continuous operation, short-term ratings that allow operation for a certain period of time (load time) when operation starts at room temperature, and repetitive ratings that allow operation for a certain period of time (load time ratio) within a specified cycle time.

[0003] It has been proposed to estimate the time until a motor overheats while maintaining the current operating state (see, for example, Patent Document 1). Knowing the time until overheating can help determine whether the current machining operation can be completed. List of citationsPatent document

[0004] Patent Document 1: Japanese Patent No. 5628994 DISCLOSURE OF THE INVENTION Problems to be solved by the invention

[0005] However, simply estimating the time to overheating does not provide a straightforward understanding of the engine's operational reliability and margin. Specifically, when adjusting settings such as engine speed to maximize efficient processing while minimizing the overheating margin, it is not easy to determine how much the set values ​​should be increased or decreased. Therefore, a technique that allows for a straightforward understanding of the engine's condition is sought. Means to solve the problems

[0006] The engine monitoring device according to one aspect of the present disclosure includes: a rotation speed detection unit that detects a rotation speed of an engine operating according to an operation program; an output value detection unit that detects an output value of the engine; and a chart display unit that plots a mark indicating a combination of the rotation speed and the output value on a chart area, one axis representing the rotation speed and the other axis representing the output value, wherein the chart display unit includes: a unit area setting unit that sets a plurality of unit areas by dividing the chart area into a grid pattern; and a mode changing unit that changes a display mode of the mark for each of the unit areas according to a predetermined index. Effects of the invention

[0007] According to the present disclosure, the condition of the engine can be easily understood. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram illustrating the configuration of a machine tool incorporating a motor monitoring device according to the first embodiment of the present disclosure; Fig. 2 is a table illustrating the information stored by the information storage unit of the engine monitoring device of Fig. 1 stored information; and Fig. Figure 3 is a diagram illustrating a control signal generated by the engine monitoring device of Fig. 1 displayed screen. PREFERRED MODE OF OPERATION FOR IMPLEMENTING THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Fig. 1 is a block diagram illustrating the configuration of a machine tool 1 incorporating a motor monitoring device according to the first embodiment of the present disclosure.

[0009] The machine tool 1 includes a numerical control device 10 as an embodiment of the motor monitoring device according to the present invention, a spindle motor 20, a speed detector 21 that detects the speed of the spindle motor 20, a current detector 22 that detects the current of the spindle motor 20, a temperature detector 23 that detects the winding temperature of the spindle motor 20, a display device 30 that displays a screen according to the numerical control device 10, and an input device 40 that is used by the user for inputting to the numerical control device 10.

[0010] The numerical control device 10 controls the operation of the spindle motor 20 and other components according to an operation program (referred to as a machining program in numerical control devices) to enable the machine tool 1 to perform predetermined machining on the workpiece. The numerical control device 10 includes a memory, a processor (CPU), input / output interfaces, etc., and can be implemented by one or more computer devices executing appropriate control programs. Components of the numerical control device 10 described below are categorized based on the functions of the numerical control device 10 and may not be clearly distinguishable in terms of physical configuration and program configuration.

[0011] The spindle motor 20 is typically a motor that rotates a cutting tool or workpiece. The spindle motor 20 operates according to the operating program described above, but the load may fluctuate independently of the speed depending on the machining conditions. The speed detector 21, the current detector 22, and the temperature detector 23 may be composed of known sensors.

[0012] The display device 30 is a known display that displays according to signals input from the numerical control device 10. The display device 30 can be integrated with the numerical control device 10. The input device 40 is a device used by the user to input information into the numerical control device 10 and can be composed of known components such as a keyboard or mouse. The input device 40 can also be integrated with the numerical control device 10. The input device 40 can also be integrated with the display device 30. Specifically, the display device 30 and the input device 40 can be a single input / output device such as a touch panel.

[0013] In the present embodiment, the numerical control device 10 includes: a program storage unit 11; a motor control unit 12 that controls the operation of motors that drive the drive axes of the machine tool 1, including the spindle motor 20; and a motor monitoring unit 13 that performs the functions of the motor monitoring device according to the present disclosure.

[0014] The program storage unit 11 stores operating programs executed by the machine tool 1. Each operating program includes a plurality of blocks that specify the unit operations of the machine tool 1. Each block includes one or more words formed by combinations of a plurality of characters (letters). Typically, each block is preceded by a sequence number to identify the block.

[0015] The motor control unit 12 executes the machining operations described in the operation program by controlling the spindle motor 20 and the motors of other drive axes of the machine tool 1 according to the operation program. The configuration of the motor control unit 12 is the same as that of known numerical control devices, so a detailed description is omitted.

[0016] The engine monitoring unit 13 includes a program acquisition unit 131, a rotational speed acquisition unit 132, an output value acquisition unit 133, an estimated time calculation unit 134, an information storage unit 135, and a chart display unit 136.

[0017] The program acquisition unit 131 acquires an operating program from the program storage unit 11 that specifies the operation to be monitored for the spindle motor 20. In other words, the program acquisition unit 131 loads the target operating program into the working memory.

[0018] The speed detection unit 132 detects the speed of the spindle motor 20 from the speed detector 21. The speed detection unit 132 can also detect the speed of the spindle motor 20 via the motor control unit 12.

[0019] The output value acquisition unit 133 acquires the output values ​​of the spindle motor 20, such as a current value, a power value, and a torque value. In the present embodiment, the output value acquisition unit 133 is configured to acquire the current value of the spindle motor 20 from the current detector 22 and use the power value calculated from the current value as the output value. However, the output value acquisition unit 133 may be configured to directly use the detected value, such as the current value, as the output value. The output value acquisition unit 133 may also acquire the output value or the values ​​necessary for calculating the output value from the motor control unit 12. The output value acquisition unit 133 may acquire two or more types of output values.

[0020] The estimated time calculation unit 134 calculates the estimated time until the overheating temperature is reached in a case where the rotational speed and the output value at that time are maintained by the spindle motor 20, based on the winding temperature of the spindle motor 20 detected by the temperature detector 23 and the current value or output value detected by the output value detection unit 133.

[0021] The information storage unit 135 stores historical information about the operating state of the spindle motor 20 at regular time intervals. The operating state includes the rotational speed and the output value, and may include position information indicating the position of the corresponding command in the operating program and modal information specifying the operation of the spindle motor 20. The position information of the operating program includes sequence numbers, line numbers, block numbers, etc. The modal information includes commands extracted from the operating program (not limited to those that directly specify the operation of the spindle motor 20, but also includes commands that can affect the operation of the spindle motor 20, such as a tool-specifying command) and setting values ​​of the numerical control device 10, such as the acceleration upper limit.The information storage unit 135 may precalculate values ​​such as load levels to be used later in the chart display unit 136 and store them as one of the items of operation information.

[0022] The time interval for storing operation information may be a predetermined fixed time or may be the time obtained by dividing the estimated machining time derived from the operation program by the preset number of times the operation information is to be acquired. The information storage unit 135 may be configured to store operation information at time intervals specified by the user via the input device 40 or the like. Fig. Figure 2 illustrates an example of the details of the operational information stored by the information storage unit 135. As can be seen from the drawing, the information storage unit 135 can be configured to create a relational database using the acquisition time or serial number of the data as a unique key for the operational information. The "-" in the drawing indicates that the calculation is not possible or the corresponding information is not available.

[0023] As in Fig. As illustrated in Figure 3, the chart display unit 136 displays a chart in the chart area, graphically displaying markers indicating the combinations of rotational speed and output value, with one axis representing the rotational speed and the other axis representing the output value. The chart display unit 136 includes a unit range setting unit 1361, a load zone setting unit 1362, a mode change unit 1363, a margin setting unit 1364, and a suggestion display unit 1365.

[0024] The unit area setting unit 1361 sets a plurality of unit areas by dividing the diagram area into a grid pattern. Fig. 3, the boundaries of the unit ranges are indicated by dashed lines. The boundaries of the unit ranges serve the purpose of explaining the unit ranges and do not need to be present on the screen displayed by the display device 30. The unit range setting unit 1361 can determine the size of the unit ranges based on user input. This ensures that the mode changing unit 1363 can secure the necessary amount of information to change the display mode of the markers while setting a sufficient number of unit ranges. The unit range setting unit 1361 can be configured to allow the user to specify the length of the unit ranges on each axis or the number of unit ranges (divisions) on each axis.

[0025] The load zone setting unit 1362 divides the diagram area into a plurality of load zones with different load levels. The load zones are set based on the combinations of speed and output value at which the load on the spindle motor 20 is considered equal, such as a setting based on the limits of various ratings. Fig. 3, the diagram area is divided into four zones based on the continuous rating, the short-term rating, and the maximum output, which are indicated by the phantom lines: a continuous load zone that allows continuous operation, a short-term load zone that allows intermittent operation, a maximum load zone that allows temporary operation in exceptional cases, and a non-operation zone in which no operation is permitted even for a short time. These load zone boundary lines do not need to be present on the screen displayed by the display device 30.

[0026] The mode changing unit 1363 changes the display mode of the markers for each unit according to the predetermined index. This makes it possible to display additional information on a two-dimensional diagram, making it easier for the user to understand the state of the spindle motor 20. Changes to the mode of the markers by the mode changing unit 1363 may include, for example, changing colors according to the value of the index (e.g., blue, yellow, red), changing the density or brightness according to the value of the index, and changing the length or size of the markers according to the value of the index. In other words, the mode changing unit 1363 preferably changes the display mode of the markers based on a predetermined rule to make the size of the index values ​​identifiable.

[0027] The indices for determining the mode of the markers may include the frequency of occurrence of the combinations of rotational speed and output value in each unit range, such as the load level determined by the load zone setting unit 1362, the estimated time until reaching the superheat temperature calculated by the estimated time calculation unit 134, etc. The mode changing unit 1363 may change a plurality of display modes of the markers according to a plurality of indices.

[0028] When changing the mode of the markers according to the frequency of occurrence of the combinations of rotation speed and output value in each unit range, the mode changing unit 1363 can change the display mode of the markers according to the ratio of the number of operation information items belonging to the unit range to the total number of operation information items within a predetermined period of time or the number of operation information items with a non-zero output value (excluding those with a zero output value). In this way, relative values ​​are used for the frequency rather than absolute numbers, and the changes in the mode of the markers can be made more noticeable, making it easier for the user to understand the state of the spindle motor 20.The period for counting the frequency of occurrence may be set with reference to the acceleration or deceleration completion time of the spindle motor 20, or may be the entire period from the start to the end of the operation of the spindle motor 20.

[0029] The margin setting unit 1364 sets the margin amount, which is the allowable range of distance from the boundary of the load zones for the combination of speed and output value. Fig. 3, the boundary of the allowable range is indicated by a dashed line. In the illustrated example, the boundary lines are rectangular because the allowable range is set for each axis. However, the allowable range can be set as a two-dimensional distance taking both axes into account, so that the boundary is circular. The boundary lines of the allowable range do not need to be present on the screen displayed by the display device 30.

[0030] The suggestion display unit 1365 adds a suggestion display to the markers based on the load level to suggest changes to the operating conditions of the spindle motor 20. In Fig.3, a downward-left arrow suggesting a load reduction is added as a suggestion indicator to the mark with a load level exceeding the rated time, and an upward-right arrow suggesting an increase in the load is added as a suggestion indicator to the mark with a load level below the rated time. The output value of the spindle motor 20 itself is not adjusted, but increases mainly with the increase in the rotational speed of the spindle motor 20. Consequently, the combination of the rotational speed and the output value moves in the direction of the suggestion indicator arrow. The suggestion display unit 1365 can display the suggestion indicators so that they are selectable by the user and can display an editor that allows the corresponding section of the operation program to be edited when a suggestion indicator is selected.

[0031] The suggestion display unit 1365 may be configured to add a suggestion display when the distance from the load zone boundary for the combination of speed and output value is equal to or greater than the margin amount. If the combination of speed and output value is close to the load zone boundary, suggesting an increase in output may cause the new combination of speed and output value to exceed the load zone boundary. Therefore, a change in the operating conditions of the spindle motor 20 is preferably only suggested when there is a sufficient distance to the load zone boundary. When suggesting a decrease in output, taking the margin into account is unnecessary from a safety perspective, but there is a potential disadvantage in increased machining time due to the reduced output.Thus, if the distance is close to the limit of the load zone, it may be preferable not to actively suggest a reduction in output.

[0032] The numerical control device 10 according to the present embodiment includes the chart display unit 136, which includes the unit area setting unit 1361 that sets a plurality of unit areas by dividing the chart area into a grid pattern, and the mode changing unit 1363 that changes the display mode of the markers for each unit area according to the predetermined index, thereby enabling the user to understand the state of the spindle motor 20 from a plurality of perspectives.

[0033] Although the embodiments of the present disclosure have been described above, the present invention is not limited to the above-described embodiments. The effects described in the above embodiments are merely examples of the preferred effects obtained from the present invention, and the effects of the present invention are not limited to those described in the above embodiments.

[0034] The motor monitoring device according to the present disclosure can be provided independently of the numerical control device that controls the machine tool and can be used to monitor motors other than the spindle motor of the machine tool, such as the motor of a kneading machine. For example, the motor monitoring device according to the present disclosure can add the functions of the motor monitoring unit described in the above embodiments to a management computer that manages one or more numerical control devices, such as a control device for a kneading machine, or to a management computer that manages such a control device. In the motor monitoring device according to the present disclosure, the load zone setting unit, the margin setting unit, and the suggestion display unit are optional configurations. List of reference symbols 1 machine tool 10 numerical control or regulation device (engine monitoring device) 11 Program storage unit 12 Engine control or regulation unit 13 Engine monitoring unit 131 Program acquisition unit 132 Speed ​​detection unit 133 Output value acquisition unit 134 Estimation time calculation unit 135 Information storage unit 136 diagram display unit 1361 Unit range setting unit 1362 Load zone adjustment unit 1363 Mode change unit 1364 margin adjustment unit 1365 Suggestion display unit 20 spindle motor 21 Speed ​​detector 22 Current detector 23 Temperature detector 30 Display device 40 Input device QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 5628994

[0004]

Claims

[1] Engine monitoring device comprising: a speed detection unit that detects a speed of an engine operating according to an operating program; an output value detecting unit that detects an output value of the motor; and a graph display unit that graphically displays or plots a mark indicating a combination of the rotational speed and the output value on a graph area, one axis representing the rotational speed and the other axis representing the output value, wherein The diagram display unit includes: a unit area setting unit that sets a plurality of unit areas by dividing the diagram area into a grid pattern; and a mode changing unit that changes a display mode of the marker for each of the unit areas according to a predetermined index. [2] The engine monitoring device according to claim 1, further comprising: an information storage unit which stores the speed and the output value at a regular time interval, wherein the mode changing unit changes the display mode of the marker according to a frequency of occurrence of the combination of the rotational speed and the output value in each of the unit ranges. [3] The engine monitoring device according to claim 2, wherein the mode changing unit changes the display mode of the marker according to a frequency of occurrence of the combination of the rotational speed and the output value within a predetermined period of time with respect to an acceleration or deceleration completion time of the engine. [4] The engine monitoring device according to claim 2, wherein the mode changing unit changes the display mode of the marker according to a frequency of occurrence of the combination of the rotational speed and the output value within an entire period from the start to the end of an operation of the engine. [5] An engine monitoring device according to any one of claims 1 to 4, wherein the mode changing unit changes the display mode of the marker so as to enable identification of a load level of the unit ranges. [6] The engine monitoring device according to any one of claims 1 to 5, wherein the unit area setting unit determines a size of the unit areas based on a user input. [7] An engine monitoring device according to any one of claims 1 to 6, wherein the diagram display unit further includes: a load zone setting unit that divides the diagram area into a plurality of load zones with different load levels; and a suggestion display unit that adds a suggestion display to the marker based on the load levels to suggest a change in an operating condition of the engine. [8] The engine monitoring device according to claim 7, wherein the chart display unit further includes: a margin setting unit that sets a margin amount that is an allowable range of a distance from a boundary of the load zone to the combination of the rotational speed and the output value, and the suggestion display unit adds the suggestion display in a case where a distance from the boundary of the load zone to the combination of the rotational speed and the output value is equal to or greater than the margin amount. [9] An engine monitoring device according to claim 7 or 8, further comprising: an estimated time calculation unit that calculates an estimated time until reaching a superheat temperature in a case where the speed and the output value at that time are maintained by the motor, wherein the mode changing unit changes the display mode of the marker according to the estimation time.

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