Engine monitoring device

Abstract

A motor monitoring device according to one aspect of the present disclosure comprises: a speed detection unit that detects the speed of a motor of a machine tool; a power value detection unit that detects the power value of the motor; a state value detection unit that detects a state value indicating the state of the motor; and a chart display unit that graphically represents a marker indicating a combination of the speed and the power value in a chart area in which one axis is the speed and the other axis is the power value.The chart display unit comprises: a chart area definition unit, which, with respect to the anticipated combinations of speed and power value, divides the chart area into a multitude of load zones with different load levels based on a multitude of engine time classifications and displays the multitude of load zones in an identifiable manner; and a graphic display unit, which changes and graphically displays the type of marking according to the state value.

Description

TECHNICAL FIELD

[0001] The present invention relates to an engine monitoring device. STATE OF THE ART

[0002] 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 for such motors to ensure operation without overheating under specific conditions. For example, the time ratings specified in JIS-C4034-1 include continuous ratings, which allow continuous operation; momentary ratings, which allow operation for a specified period of time (load time) in a case where operation begins at room temperature; and repetitive ratings, which allow operation for a specified 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. Literature listPatent document

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

[0005] However, estimating only the time to overheating does not allow for an easy understanding of the engine's operational reliability and operating margin. Especially when settings such as engine speed are adjusted to maximize efficient processing while minimizing the overheating margin, it is not easy to determine by how much the specified values ​​should be increased or decreased. Therefore, a technique that allows for an easy understanding of the engine's condition is desired. Means to solve the problems

[0006] One aspect of the present disclosure provides an engine monitoring device comprising: a rotational speed detection unit that detects a rotational speed of an engine; an output value detection unit that detects an output value of the engine; a state value detection unit that detects a state value indicating the state of the engine; and a graph display unit that graphically displays marks indicating a combination of the rotational speed and the output value in a graph area where one axis represents the rotational speed and the other axis represents the output value.The graph display unit includes: a graph area setting unit that divides the graph area into a plurality of load zones with different load levels based on a plurality of time ratings of the engine with respect to the expected combinations of the speed and the power value, and distinguishably displays the plurality of load zones; and a graphic display unit that graphically displays the markers by changing the appearance of the markers based on the condition value. Effects of the invention

[0007] According to the present disclosure, the condition of the engine is easily understood. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram illustrating the configuration of a machine tool including a motor monitoring device according to the first embodiment of the present disclosure; and Fig. Figure 2 is a diagram illustrating a screen displayed by the engine monitoring device of Fig. 1 is displayed. PREFERRED MODE FOR CARRYING OUT 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 including 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 to input into the numerical control device 10.

[0010] 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 suitable control programs. The components of the numerical control device 10 described below are categorized based on the functions of the numerical control device 10 and need not be distinguishably separable into a physical configuration and a program configuration.

[0011] The spindle motor 20 is typically a motor that rotates a cutting tool or workpiece, where the load can potentially fluctuate independently of the speed based on the machining conditions. The speed detector 21, the current detector 22, and the temperature detector 23 can each be composed of well-known sensors.

[0012] The display device 30 is a well-known display that displays according to signals input from the numerical control device 10. The display device 30 may 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 may be composed of well-known components, such as a keyboard or a mouse. The input device 40 may also be integrated with the numerical control device 10. The input device 40 may also be integrated with the display device 30. In particular, the display device 30 and the input device 40 may 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 machining programs executed by the machine tool 1. Each machining 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 machining program by controlling the spindle motor 20 and the motors of other drive axes of the machine tool 1 according to the machining program. The configuration of the motor control unit 12 is the same as that of well-known numerical control devices, so a detailed description is omitted.

[0016] The engine monitoring unit 13 includes a program acquisition unit 131, a speed acquisition unit 132, a power value acquisition unit 133, a state value acquisition unit 134, an information storage unit 135, a program display unit 136, and a graph display unit 137.

[0017] The program acquisition unit 131 acquires a machining 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 machining 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 power value acquisition unit 133 acquires the power values ​​of the spindle motor 20, such as a current value, a power value, and a torque value. In the present embodiment, the power value acquisition unit 133 is configured to acquire the current value of the spindle motor 20 using the current detector 22 and use the power value and the torque value calculated from the current value as the power value. However, the power value acquisition unit 133 may be configured to directly use the detected value, such as the current value, as the power value. The power value acquisition unit 133 may also acquire the power value or the values ​​required to calculate the power value by the motor control unit 12. The types of power values ​​acquired by the power value acquisition unit 133 may be one type or three or more types.

[0020] The state value acquisition unit 134 acquires state values ​​indicating the states of the spindle motor 20. In the present embodiment, the state value acquisition unit 134 calculates the estimated time until the spindle motor 20 reaches the overheating temperature in a case where the rotational speed and power values ​​of the spindle motor 20 are maintained at existing values ​​based on the winding temperature of the spindle motor 20 detected by the temperature detector 23 and the current value or power value detected by the power value acquisition unit 133, and uses this estimated time as the first state value. The state value acquisition unit 134 calculates the torque of the spindle motor 20 based on the current value detected by the power value acquisition unit 133 and uses this torque as the second state value.The state value acquisition unit 134 may use other indicators of the states of the spindle motor 20 as state values, such as directly using the winding temperature of the spindle motor 20 as the state value.

[0021] The information storage unit 135 stores the rotational speed detected by the rotational speed detection unit 132, the power value detected by the power value detection unit 133, and the state value detected by the state value detection unit 134, along with information identifying the corresponding block of the machining program detected by the program detection unit 131, such as sequence numbers or line numbers. In other words, the information storage unit 135 stores the rotational speed, the power value, and the state value to make it possible to determine which block of the machining program was being executed when such a value was obtained. For example, the information storage unit 135 may be configured to store table data with the data items including the rotational speed, the power value, the state value, and the sequence number.

[0022] Since the speed, power value, and state value are acquired in short cycles, typically a variety of combinations of the speed, power value, and state value can be acquired for a block. However, the information storage unit 135 may store one set of data per block as a unique key, ensuring that there are no duplicate sequence numbers between data. In this case, the representative values ​​of the speed, power value, and state value are stored corresponding to each block. The representative values ​​for the speed, power value, and state value should preferably indicate a higher load among the values ​​corresponding to that block (the maximum value for the speed, current value, and temperature, and the minimum value for the estimated time) to ensure safety.

[0023] The program display unit 136 displays the program part information, including a part of the machining program or information indicating a position (such as a line number) of the part, on the display screen of the display device 30. In other words, the program display unit 136 creates data of at least a part of the screen displayed on the display device 30. As shown in Fig. As illustrated in Figure 2, the program display unit 136 typically defines a program display area of ​​a specific size on the display screen of the display device 30 and displays the program part information including the machining program for lines as permitted in the program display area. The program display unit 136 may display the machining program including information such as sequence numbers as the program part information, may extract only the words that specify operations of the machine tool from the machining program and may display only those, may display only information indicating the position in the machining program, such as sequence numbers or line numbers, or may be configured to switch between these display modes.

[0024] The program display unit 136 preferably displays the position in the machining program for which the user desires detailed review, allowing it to be selected by units such as characters, words, or blocks, and may be configured to allow the user to select a plurality of blocks. The result of the user selecting the position in the machining program may be reflected in the details displayed by the diagram display unit 137, as described below.

[0025] The program display unit 136 is preferably configured to accept edits to the editing program. In other words, the program display unit 136 is preferably configured to allow the user to select and rewrite displayed words or text and to store the rewritten editing program in the program storage unit 11.

[0026] The program display unit 136 may display the program part information in a manner that allows distinguishing the magnitude of the rate of change of the rotational speed and / or the power value. As a specific example, the program display unit 136 may change the color or pattern of the characters, background, frame, etc. that display the information of the corresponding block based on the portion of the rate of change for which the limit value is set in advance or the portion for which the limit value is set as a ratio to the maximum rate of change. Typically, the program display unit 136 may be configured to classify the rate of change of the rotational speed and the power value into three portions, respectively, and display the characters or background of the blocks with a small rate of change in blue, those with a moderate rate of change in yellow, and those with a large rate of change in red.The color of the block is preferably determined by the higher rate of change between the speed section and the power value section. Thus, the program display unit 136 displays the program section information in a manner that allows differentiation of the magnitude of the rate of change of the speed and / or power value for each block, thereby allowing easy identification of the blocks that cause a significant change in the speed and / or power value. The rate of change can be the maximum rate of change within the block or can be the rate of change between the representative values ​​of the block.

[0027] The program display unit 136 can change the display mode for the program part information in a manner that allows distinguishing the load level determined based on the combination of the speed and the power value. For example, the program display unit 136 can indicate the load zone to which the combination of the speed and the power value associated with the displayed block belongs in the graph display unit 137 by a difference in the color or pattern of the characters, background, or frame that display the block information.

[0028] The program display unit 136 can change the display mode based on the state value, allowing the size of the state value to be differentiated either continuously or incrementally. The program display unit 136 can add characters indicating the section of the value or the size of the state value to each block and indicate the size of the state value by a difference in the color or pattern of the characters, background, or frame that display each block information. Typically, the possible range of the state value is divided into three or more sections, and the program display unit 136 can be configured to change the display mode of the block based on which section the state value belongs to. In this case, the program display unit 136 can be capable of setting the threshold value of the state value, which changes the display mode of the block according to user input.

[0029] As described below, the program display unit 136 can distinguishably display the block associated with the combination of the rotational speed and the power value whose difference, with respect to the coordinate position selected in the graph display unit 137, is less than or equal to a predetermined margin. Clearly displaying the block that provides a result the user will pay attention to in the graph display unit 137 allows the user to easily understand the problematic points in the machining program. By setting a margin for selecting a coordinate position, blocks including combinations of the approximate rotational speed and the approximate power value can be suggested as candidates, allowing for a rough selection.

[0030] The graph display unit 137 displays a graph on the display screen of the display device 30, with marks indicating combinations of the rotational speed and the power value graphically displayed in a graph area where one axis represents the rotational speed and the other axis represents the power value. The graph display unit 137 can display a graph for a single power value or display graphs for a plurality of power values ​​side by side. The graph display unit 137 preferably provides the aforementioned function of selecting a coordinate position.

[0031] In order to clarify the relationship between the machining program and the rotational speed and the power value, the program display unit 136 and the graph display unit 137 preferably display the program part information and the graph simultaneously on the same screen, as shown in Fig. 2. The program display unit 136 and the graph display unit 137 can display exclusively. In this case, when switching from the graph display unit 137 to the screen display, the rotational speed and power value corresponding to the block selected by the program display unit 136 can be graphically displayed. Conversely, when switching from the program display unit 136 to the screen display, the program part information corresponding to the rotational speed and power value near the coordinate value selected by the graph display unit 137 can be highlighted.

[0032] The graph display unit 137 includes: a graph area setting unit 1371 that divides the graph area into a plurality of stress zones and displays the stress zones distinguishably; and a graphic display unit 1372 that graphically displays the markers by changing the display mode based on the state value.

[0033] The graph area setting unit 1371 divides the graph area into a plurality of load zones with different load levels based on the plurality of time ratings of the spindle motor 20 with respect to the expected combinations of speed and power value. This allows the user to easily understand the danger level of the spindle motor 20.

[0034] The graphic area setting unit 1371 preferably displays the plurality of load zones distinguishably using colors or patterns. Using colors or patterns makes it easy to understand which load zone the combination of speed and power value belongs to. Using intuitive colors or patterns, such as blue, yellow, and red, to indicate the load level of the zones helps the user easily understand the danger level of the operating state of the spindle motor 20.

[0035] If the combination of the speed and power value of the spindle motor 20 remains within the continuous rating, the load on the spindle motor 20 can be maintained in this operating state indefinitely. Therefore, the upper limit of the lowest load zone is preferably represented by a curve indicating the continuous rating.

[0036] The graph range setting unit 1371 preferably forms a boundary of one of the plurality of load zones, preferably the lower boundary of the load zone with the highest load level, by connecting the maximum values ​​of the plurality of time ratings (such as short-term ratings and repetitive ratings with different load time ratios) with the same speed. The combination of speed and power value graphed in the range beyond this boundary line indicates a dangerous power condition that may immediately lead to failure. Conversely, remaining within this boundary may indicate that short-term operation will not cause problems.

[0037] The graph area setting unit 1371 may be configured to select the boundary of at least one of the plurality of stress zones according to user input. Specifically, the boundaries of the stress zones may be selected from the continuous rating, the maximum value of the plurality of time ratings, the plurality of short-term ratings with different stress times, and the plurality of repetitive ratings with different stress-time ratios. This allows the stress zones considered appropriate to be set based on the machining content of the machine tool 1, enabling a more appropriate understanding of the danger level of the spindle motor 20.

[0038] The graphic display unit 1372 graphically displays the combination of the speed and the power value, while indicating the magnitude of the state value by differences in the appearances of the mark such as the shape, size, color and pattern (as shown in Fig.2 with hatching within the circular outer edge). This allows the user to understand the operating state of the spindle motor 20 at that time, which is indicated by the speed and power value, as well as the state value that may be affected by the previous operating state of the spindle motor 20. For example, even if the state value indicates that the temperature of the spindle motor 20 is high, the user may be able to determine that there is no danger of a further increase in the temperature of the spindle motor 20 as long as the load level at that time is low. Conversely, even if the load level at that time is not very high, the user may be able to determine that overheating may soon occur if the operating state continues.The marker may include an outer border that differs slightly from the colors or patterns of the graph area, and a filled portion that indicates the state value. Thus, the graphic display unit 1372 indicates the state values ​​through the marker appearances, allowing the user to understand the operating state of the spindle motor 20 in a versatile manner.

[0039] The graphical display unit 1372 can continuously change the size, color, etc. of the marker based on the state value; however, the possible range of the state value is divided into three or more sections, and the appearance of the marker is preferably determined based on which section the state value belongs to. By gradually changing the appearance of the marker, the size of the state value can be presented more clearly. The sections of the state value can be predetermined or changed dynamically.For example, when the estimated time to reach the superheat temperature is used as the state value, the state value (estimated time) at the time when the combination of the rotational speed and power value exceeds the continuous rating is used as the maximum value within the possible range of the state value, and a predetermined ratio to this maximum value can be used as the limit value for the section of the state value. Typically, the graphical display unit 1372 can be configured to divide the possible range of the state value into three sections by setting the limit values ​​to trisect the maximum value.

[0040] The graphical display unit 1372 can be configured to set the threshold value of the state value that changes the marking appearances according to user input. The threshold value can be specified as an absolute value or as a ratio to the maximum value. The user can select the threshold value from a variety of predefined options. This allows the marking appearances to be changed at times deemed appropriate, taking into account the machining content of the machine tool 1, allowing the user to better understand the danger level of the spindle motor 20.

[0041] As previously described, when the position in the machining program is selected or edited in the program display unit 136, the graphic display unit 1372 is preferably configured to specifically graphically display the rotational speed and power value corresponding to the selected or edited position in the machining program. Specifically, when the user selects a plurality of blocks in the program display unit 136, the graphic display unit 1372 preferably simultaneously or continuously graphically displays and animates the rotational speed and power value corresponding to the plurality of selected blocks. This allows the user to easily check the rotational speed, power value, and state value of the spindle motor 20 in the blocks to be checked or edited in the machining program.

[0042] The numerical control device 10 according to the present embodiment includes the graph display unit 137, which includes: the graph area setting unit 1371, which divides the graph area into a plurality of load zones with different load levels based on the plurality of time ratings of the spindle motor 20 with respect to the expected combinations of the rotational speed and power value of the spindle motor 20, and distinguishably displays the plurality of load zones; and the graphic display unit 1372, which graphically displays the markers by changing the appearances of the markers based on the condition value. This allows the user to easily understand the safety of the load condition of the spindle motor 20.

[0043] 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-described embodiments are merely examples of the preferred effects resulting from the present invention, and the effects of the present invention are not limited to those described in the above-described embodiments.

[0044] 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 previous embodiments to a management computer that manages one or more numerical control devices, such as a control device for a kneading machine or a management computer that manages such a control device.

[0045] In the motor monitoring device according to the present disclosure, the information storage unit and the program display unit may be omitted. In other words, the motor monitoring device according to the present disclosure may be configured to display the load state of the spindle motor in real time. LIST OF REFERENCE SYMBOLS 1 machine tool 10 numerical control device (engine monitoring device) 11 Program storage unit 12 Engine control unit 13 Engine monitoring unit 131 Program acquisition unit 132 Speed ​​detection unit 133 Performance value recording unit 134 Condition value recording unit 135 Information storage unit 136 Program display unit 137 Graphic display unit 1371 Diagram area definition unit 1372 graphical representation 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] Cited non-patent literature

[0000] JIS-C4034-1

[0002]

Claims

[1] Engine monitoring device, comprising: a speed detection unit that detects a speed of an engine; a power value detection unit that detects a power value of the engine; a state value detecting unit that detects a state value indicating a state of the engine; and a graph display unit that graphically displays a mark indicating a combination of the rotational speed and the power value in a graph area in which one axis represents the rotational speed and another axis represents the power value; wherein the graph display unit comprises: a graph area setting unit that divides the graph area into a plurality of load zones having different load levels based on a plurality of time ratings of the engine with respect to an expected combination of the speed and the power value, and distinguishably displays the plurality of load zones; and a graphical representation unit that graphically represents the marker by changing an appearance of the marker based on the state value. [2] The engine monitoring device according to claim 1, wherein the graph area setting unit forms a boundary of one of the plurality of load zones by connecting maximum values of the plurality of time ratings having the same rotational speed. [3] The engine monitoring device according to claim 1 or 2, wherein the graph area setting unit selects a boundary of at least one of the plurality of load zones according to a user input. [4] The engine monitoring device according to any one of claims 1 to 3, wherein the graph area setting unit distinguishably displays the plurality of stress zones using colors or patterns. [5] The engine monitoring device according to any one of claims 1 to 4, wherein a possible range of the condition value is divided into three or more sections, and the graphic display unit determines an appearance of the mark based on which section the condition value belongs to. [6] An engine monitoring device according to any one of claims 1 to 5, wherein the graphical display unit is capable of setting a threshold value of the state value which changes the appearance of the marker according to a user input. [7] The engine monitoring device according to any one of claims 1 to 6, wherein the state value detecting unit calculates, as the state value, an estimated time until the engine reaches an overheat temperature in a case where the engine maintains the speed and the power value at existing values.

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