Machine tool

Abstract

A machine tool according to one embodiment of the present disclosure that is capable of highly precisely ascertaining power consumption comprises: a plurality of power verification targets; a single power meter provided in an electrical circuit that supplies power to all of the power verification targets; and a control device that controls the plurality of power verification targets. The control device includes a measurement control unit that operates the power verification targets one at a time and acquires detected values from the power meter during operation of the power verification targets, thereby measuring a reference power consumption of each of the power verification targets.

Description

machine tools

[0001] The present invention relates to a machine tool.

[0002] In a system that supplies power to multiple electrical appliances from a distribution board, a technology has been proposed that receives current and voltage waveforms measured by the distribution board and estimates the power consumption of the electrical appliance (a power confirmation target) from the current waveform of the electrical appliance (see, for example, Patent Document 1). Patent Document 1 further proposes correcting the power based on the power consumption pattern of each electrical appliance.

[0003] Japanese Patent Application Laid-Open No. 2015-102526

[0004] In a machine tool having a plurality of power confirmation targets, including a plurality of drive axes and simple motion mechanisms, it may be necessary to estimate the power consumption of each of the power confirmation targets. However, with the method described in Patent Document 1, there is a risk that the power consumption cannot be determined with high accuracy due to deterioration of the power confirmation targets, etc.

[0005] A machine tool according to one aspect of the present disclosure comprises a plurality of power confirmation objects, a single power meter installed in an electrical circuit that supplies power to all of the power confirmation objects, and a control device that controls the plurality of power confirmation objects, wherein the control device has a measurement control unit that operates the power confirmation objects one by one and measures the reference power consumption of each of the power confirmation objects by acquiring the detection value of the power meter while the power confirmation objects are operating.

[0006] According to the present disclosure, power consumption can be determined with high accuracy.

[0007] FIG. 1 is a block diagram illustrating a configuration of a machine tool according to an embodiment of the present disclosure.

[0008] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] An embodiment of the present disclosure will now be described with reference to the accompanying drawings. Fig. 1 is a block diagram showing the configuration of a machine tool 1 according to an embodiment of the present disclosure. In the figure, solid arrows indicate electrical paths for supplying power, and dashed arrows indicate paths for transmitting information (which may be wireless).

[0009] Machine tool 1 includes a single power meter 10, a power supply circuit 20, a plurality of power confirmation targets 31-37, and a control device 40. Machine tool 1 performs machining by driving power confirmation targets 31-37 with power supplied from AC power supply S.

[0010] The power meter 10 is provided on an electric circuit that supplies power to all of the power confirmation targets 31 to 37. In this embodiment, the power meter 10 is provided on an electric circuit that supplies power from the AC power source S to the power supply circuit 20 that distributes power to all of the power confirmation targets 31 to 37. The power meter 10 is preferably provided on an electric circuit that does not supply power to devices that are not controlled by the control device 40, so that the power consumption of the power confirmation targets 31 to 37 can be accurately measured. The power meter 10 may be any device that detects power or a value from which power can be calculated. For example, the power meter 10 may be configured to detect a current value that can be used to calculate power by multiplying the voltage value of the AC power source S.

[0011] The power supply circuit 20 converts AC power supplied from the AC power supply S into DC power of a voltage required by the power confirmation targets 31 to 37 and the control device 40. The power supply circuit 20 may output a plurality of different voltages according to the specifications of the power confirmation targets 31 to 37 and the control device 40.

[0012] The power confirmation targets 31 to 37 are components that consume power and are controlled by the control device 40. The power confirmation targets 31 to 37 include servo mechanisms 31 to 35 that are feedback controlled, and simple operation mechanisms (cooling fan 36 and cutting fluid pump 37) that are not feedback controlled. Each of the servo mechanisms 31 to 35 has a motor M and an amplifier A that drives the motor M. Each of the servo mechanisms 31 to 35 is a drive mechanism for a drive axis (including a spindle) that moves the tool and workpiece relative to each other.

[0013] The control device 40 controls the operation of the power confirmation targets 31 to 37. Specifically, the control device 40 has a processing control unit 41, a measurement control unit 42, a calculation control unit 43, a power consumption storage unit 44, a notification unit 45, a threshold setting unit 46, and a lifespan estimation unit 47. The control device 40 can be realized by one or more computers that include a memory, a processor, an input / output interface, etc. and execute appropriate control programs. In this embodiment, the control device 40 is a so-called numerical control device. The above-mentioned components of the control device 40 categorize the functions of the control device 40 and do not necessarily have to be clearly distinguishable in terms of physical configuration and program configuration.

[0014] The machining control unit 41 controls the operations of the power confirmation targets 31 to 37 in accordance with a machining program written in, for example, G-code etc. The machining control unit 41 may be configured in the same manner as in a known numerical control device.

[0015] The measurement control unit 42 operates the power confirmation targets 31-37 one by one and acquires the detected values ​​of the power meter 10 while the power confirmation targets 31-37 are operating, thereby measuring the reference power consumption of each of the power confirmation targets 31-37. It is preferable that the measurement control unit 42 measures the reference power consumption of at least all of the servo mechanisms 31-35 among the power confirmation targets 31-37, one by one, in order. At this time, it is preferable that the measurement control unit 42 operate the servo mechanisms 31-35 under constant conditions to reduce measurement errors. Specifically, the measurement control unit 42 can be configured to operate each of the servo mechanisms 31-35 at a predetermined torque, such as a rated torque, set for each of them in order to measure the reference power consumption.

[0016] The measurement control unit 42 is preferably configured to operate the power confirmation targets 31-37 at a predetermined timing, such as when the machine tool 1 is started up. The timing for operating the power confirmation targets 31-37 to measure the reference power consumption can be, for example, when the machine tool 1 is started up or stopped after a predetermined time has elapsed since the previous measurement of the reference power consumption, in order to prevent a decrease in the availability of the machine tool 1 due to the measurement of the reference power consumption. The specific interval for measuring the reference power consumption can be, for example, one week or more and three months or less.

[0017] In this way, the measurement control unit 42 operates the power confirmation targets 31 to 37 one by one and measures the reference power consumption, which is the power consumption when the power confirmation targets 31 to 37 are operated under predetermined input conditions, thereby making it possible to grasp the reference power consumption that reflects changes in power consumption due to deterioration of the power confirmation targets 31 to 37. The control device 40 can estimate the power consumption of the power confirmation targets 31 to 37 based on the input values ​​for operating the power confirmation targets 31 to 37, but by correcting the estimated value of power consumption during processing in consideration of changes in the reference power consumption, the power consumption of the power confirmation targets 31 to 37 can be estimated with high accuracy.

[0018] The calculation control unit 43 calculates the current power consumption of the simple motion mechanisms 36, 37 by subtracting the power consumption of the power confirmation targets (servo mechanisms) 31-35 other than the simple motion mechanisms 36, 37 from the values ​​detected by the power meter 10 while the multiple power confirmation targets 31-37, including the simple motion mechanisms 36, 37, are operating. This allows for highly accurate estimation of the actual power consumption of the simple motion mechanisms 36, 37, even if the power consumption cannot be estimated from the input values. The calculation control unit 43 may be configured to calculate the power consumption of the simple motion mechanisms 36, 37 while the machining control unit 41 is performing the machining operation. Furthermore, to more accurately calculate the power consumption of the simple motion mechanisms 36, 37, the calculation control unit 43 may operate the servo mechanisms 31-35 under the same conditions as when the measurement control unit 42 measured the reference power consumption. Because the simple motion mechanisms 36, 37 are on / off controlled, their power consumption is considered to be constant, and therefore the power consumption of the simple motion mechanisms 36, 37 calculated by the calculation control unit 43 may be treated as the reference power consumption, which is the power consumption in a standard operating state.

[0019] The power consumption storage unit 44 stores the reference power consumption measured by the measurement control unit 42 and the power consumption calculated by the calculation control unit 43 for each of the power confirmation targets 31 to 37. This allows the user to easily check whether or not there has been a change in power consumption due to deterioration of the power confirmation targets 31 to 37.

[0020] The notification unit 45 notifies the outside when the reference power consumption exceeds the power threshold set for each power confirmation target. The reference power consumption of the power confirmation targets 31-37 can increase due to a malfunction or the end of their life, even if the load is constant. The power threshold is a value at which it is determined that there is a high possibility that the power confirmation target 31-37 has malfunctioned or reached the end of its life, if the reference power consumption of the power confirmation target 31-37 is greater than that value. In other words, when the reference power consumption of the power confirmation target 31-37 increases, the machine tool 1 requests the user to replace or maintain the power confirmation target 31-37. The power threshold may be configured to be input by the user, but is preferably configured to be automatically set or updated by the threshold setting unit 46.

[0021] The threshold setting unit 46 sets the power threshold used by the notification unit 45. Specifically, when a power check target 31-37 is replaced, the threshold setting unit 46 can be configured to set the power threshold for the replaced power check target 31-37 based on the reference power consumption immediately before the replacement. By setting the reference power consumption when the power check target 31-37 is replaced, that is, when the user determines that the power check target 31-37 needs to be replaced, as the power threshold, it is possible to prompt the user to replace the power check target 31-37 when it has deteriorated to the same extent as when it was replaced.

[0022] Furthermore, the threshold setting unit 46 may set the power threshold for each of the power confirmation targets 31 to 37 based on multiple reference power consumptions stored in the power consumption storage unit 44 immediately before multiple replacements of the power confirmation targets 31 to 37. In other words, a more appropriate power threshold can be set for each of the power confirmation targets 31 to 37 by using, for example, an average value of the reference power consumption immediately before multiple past replacements.

[0023] The lifespan estimation unit 47 estimates the lifespan of each of the power confirmation targets 31 to 37 based on multiple reference power consumptions stored in the power consumption storage unit 44 for that power confirmation target 31 to 37. Specifically, the lifespan estimation unit 47 calculates the time until the reference power consumption of each of the power confirmation targets 31 to 37 is predicted to reach a power threshold from the change over time in the reference power consumption of each of the power confirmation targets 31 to 37. By presenting the time until the reference power consumption is predicted to reach the power threshold to the user, replacement parts for the power confirmation targets 31 to 37 can be prepared at the appropriate time, thereby minimizing downtime.

[0024] As described above, the machine tool 1 according to this embodiment measures the reference power consumption of the power confirmation objects 31 to 37 using the measurement control unit 42, and therefore can relatively accurately determine when to replace the power confirmation objects 31 to 37, and can accurately estimate the actual power consumption of the power confirmation objects 31 to 37.

[0025] The following supplementary notes are further disclosed regarding the above-described embodiments and modifications: (Supplementary Note 1) A machine tool (1) includes a plurality of power confirmation targets (31 to 37), a single power meter (10) provided on an electric circuit that supplies power to all of the power confirmation targets (31 to 37), and a control device (40) that controls the plurality of power confirmation targets (31 to 37), and the control device (40) has a measurement control unit (42) that operates the power confirmation targets (31 to 37) one by one and measures the reference power consumption of each of the power confirmation targets (31 to 37) by acquiring the detection value of the power meter (10) while the power confirmation targets (31 to 37) are operating.

[0026] (Note 2) The measurement control unit (42) may operate the power confirmation targets (31 to 37) at a predetermined timing.

[0027] (Supplementary Note 3) The control device (40) may further include a notification unit (45) that notifies the outside when the reference power consumption exceeds a power threshold set for each of the power confirmation targets (31 to 37).

[0028] (Supplementary Note 4) The control device (40) may further include a threshold setting unit (46) that, when the power confirmation target (31 to 37) is replaced, sets a power threshold for the replaced power confirmation target (31 to 37) based on the reference power consumption immediately before the replacement.

[0029] (Supplementary Note 5) The control device (40) may further include a power consumption storage unit (44) that stores a reference power consumption for each power confirmation target (31 to 37), and a lifespan estimation unit (47) that estimates a lifespan of the power confirmation target (31 to 37) based on the plurality of reference power consumptions.

[0030] (Supplementary Note 6) The plurality of power confirmation targets (31 to 37) may include servo mechanisms (31 to 35) including a motor (M) and an amplifier (A).

[0031] (Supplementary Note 7) The plurality of power confirmation targets (31 to 37) may include simple operation mechanisms (36, 37) that are not feedback controlled, and the control device (40) may further include a calculation control unit (43) that calculates the current power consumption of the simple operation mechanisms (36, 37) by subtracting the power consumption of the power confirmation targets (31 to 35) other than the simple operation mechanisms (36, 37) from the detection value of the power meter (10) while the plurality of power confirmation targets (31 to 37) including the simple operation mechanisms (36, 37) are operating.

[0032] Although the present disclosure has been described in detail above, the present disclosure is not limited to the above-described embodiments. Various additions, substitutions, modifications, partial deletions, etc. are possible in the above-described embodiments without departing from the gist of the present disclosure or the gist of the present disclosure derived from the content of the claims and their equivalents. Furthermore, in the above-described embodiments, the order of each operation and the order of each process are shown as examples, and the present disclosure is not limited to these.

[0033] For example, a machine tool according to the present disclosure may not have a common power supply circuit, but may be configured to perform DC conversion or the like at each power confirmation target. Furthermore, a power meter may be provided downstream of the power supply circuit. A machine tool according to the present disclosure may include any number of power confirmation targets. Furthermore, the simple operation mechanism may be, for example, a belt conveyor, an air compressor, an electric heater, etc. In a machine tool according to the present disclosure, the control device may include a measurement control unit, and the calculation control unit, power consumption storage unit, threshold setting unit, and notification unit may be configured as desired. Furthermore, the control device may be a computer device capable of controlling the power confirmation targets via a numerical control device.

[0034] REFERENCE SIGNS LIST 1 Machine tool 10 Power meter 20 Power supply circuit 31 to 35 Servo mechanism (power check target) 36 Cooling fan (simple operation mechanism / power check target) 37 Cutting fluid pump (simple operation mechanism / power check target) 40 Control device 41 Machining control unit 42 Measurement control unit 43 Calculation control unit 44 Power consumption memory unit 45 Notification unit 46 Threshold setting unit 47 Life estimation unit A Amplifier M Motor S AC power supply

Claims

1. Multiple power check targets, A single power meter is provided on an electric line that supplies power to all of the power confirmation objects; A control device that controls the plurality of power confirmation targets; Equipped with The control device includes: a measurement control unit that operates the power confirmation objects one by one and measures the reference power consumption of each of the power confirmation objects by acquiring the detection value of the power meter while the power confirmation objects are operating.

2. The machine tool according to claim 1 , wherein the measurement control unit operates the power confirmation target at a predetermined timing.

3. 3. The machine tool according to claim 1, wherein the control device further comprises a notification unit that notifies an outside device when the reference power consumption exceeds a power threshold value set for each of the power confirmation targets.

4. The machine tool according to claim 3 , wherein the control device further has a threshold setting unit that, when the power confirmation target is replaced, sets the power threshold of the replaced power confirmation target based on the standard power consumption immediately before the replacement.

5. 3. The machine tool according to claim 1, wherein the control device further includes a power consumption memory unit that stores the standard power consumption for each of the power confirmation objects, and a lifespan estimation unit that estimates a lifespan of the power confirmation objects based on a plurality of the standard power consumptions.

6. 3. The machine tool according to claim 1, wherein the plurality of power confirmation targets include a servo mechanism having a motor and an amplifier.

7. the plurality of power confirmation targets include a simple motion mechanism that is not feedback controlled; 3. The machine tool according to claim 1 or 2, wherein the control device further has a calculation control unit that calculates a current power consumption of the simple motion mechanism by subtracting the power consumption of the power confirmation objects other than the simple motion mechanism from the detection value of the power meter during operation of the plurality of power confirmation objects including the simple motion mechanism.