Machine tool, power consumption estimation method, and computer program

Abstract

Provided are a machine tool, a power consumption estimation method, and a computer program with which it is possible to determine the power consumption of electric devices without using a power meter.　A machine tool 100 according to the present disclosure is characterized by comprising electric devices (pumps 13, 14, 60) that receive alternating current, and an estimation unit (control unit of a control apparatus 72) that estimates the power consumption of the electric devices on the basis of the voltage and frequency of the alternating current received by the electric devices. The estimation unit estimates the power consumption of the electric devices on the basis of the voltage and frequency of the alternating current received by the electric devices, and the power consumption of the electric devices can therefore be determined without using a power meter.

Description

Machine tool, power consumption estimation method, and computer program

[0001] The present disclosure relates to a machine tool, a power consumption estimation method, and a computer program.

[0002] In the machine tool described in Patent Document 1, an integrating wattmeter integrates the amount of power received by the machine tool. The machine tool calculates the total amount of power used in a predetermined period based on the integration result of the integrating wattmeter.

[0003] Japanese Patent Application Laid-Open No. 2002-243776

[0004] Patent Document 1 mentions a case where an integrating wattmeter is replaced with an indicating wattmeter, but does not mention a case where a wattmeter for directly determining the amount of power is omitted.

[0005] An object of the present disclosure is to provide a machine tool, a power consumption estimation method, and a computer program that can determine the amount of power consumed by an electrical device without using a power meter.

[0006] The machine tool according to the present disclosure is characterized by including an electrical device that receives AC power and an estimation unit that estimates the amount of power consumed by the electrical device based on the voltage and frequency of the AC power received by the electrical device.

[0007] In the present disclosure, an electrical appliance receives AC power. An estimation unit estimates the amount of power consumed by the electrical appliance based on the voltage and frequency of the AC power received by the electrical appliance. Therefore, the amount of power consumed by the electrical appliance can be determined without using a wattmeter.

[0008] The machine tool according to the present disclosure is characterized in that it further includes a detection unit that detects the voltage and the frequency, and the estimation unit estimates the amount of power consumption based on the detection results of the detection unit.

[0009] In the present disclosure, a detection unit detects the voltage and frequency of the AC power received by the electrical equipment. An estimation unit estimates the power consumption of the electrical equipment based on the detection result of the detection unit. The user or manufacturer does not need to set the voltage and frequency values ​​used for estimation by the estimation unit in the machine tool according to the region where the machine tool is installed or the environment in which the machine tool is used, thereby improving convenience for users and manufacturers. Furthermore, errors in the estimation of power consumption due to forgetting to set or incorrectly setting the voltage and frequency can be prevented. Furthermore, even if the AC voltage or frequency fluctuates while the machine tool is in use, the accuracy of the estimation of the power consumption of the electrical equipment is improved.

[0010] The machine tool according to the present disclosure further includes a storage unit that stores the following equation (1) for calculating the power consumption W based on the voltage V and the frequency f, and constants a, b, and c, and the estimation unit estimates the power consumption amount based on the following equation (1) and the constants stored in the storage unit: W=aV+bf+c (1)

[0011] In the present disclosure, a storage unit stores formula (1) and constants a, b, and c. An estimation unit estimates the power consumption of an electrical device based on formula (1) and constants a, b, and c stored in the storage unit. By approximating the power consumption of the electrical device with a simple linear expression, calculations for estimating the power consumption can be easily performed. The constants a, b, and c can be determined experimentally, for example.

[0012] The machine tool according to the present disclosure further includes a timing unit that measures the operating time during which the electrical equipment is in operation, and the estimation unit estimates the amount of power consumption based on the voltage and frequency and the timing results by the timing unit.

[0013] In the present disclosure, a timer measures the operating time of an electrical appliance. An estimation unit estimates the amount of power consumed by the electrical appliance based on the voltage and frequency of the AC power received by the electrical appliance and the timekeeping results of the timer. When estimating the amount of power consumed by the electrical appliance, the amount of time the electrical appliance actually consumed power can be taken into account, thereby improving the accuracy of estimating the amount of power consumed by the electrical appliance.

[0014] The machine tool according to the present disclosure further includes a temperature measuring unit that detects the temperature at a predetermined position, and the estimation unit estimates the amount of power consumption based on the voltage and frequency and the temperature measurement results of the temperature measuring unit.

[0015] In the present disclosure, the temperature measuring unit detects the temperature at a predetermined position. The estimation unit estimates the power consumption of the electrical appliance based on the voltage and frequency of the AC power received by the electrical appliance and the temperature measurement result of the temperature measuring unit. The temperature of the environment surrounding the electrical appliance can affect the power consumption of the electrical appliance. Therefore, by taking the temperature measurement result of the temperature measuring unit into consideration when estimating the power consumption of the electrical appliance, the accuracy of estimating the power consumption of the electrical appliance is improved.

[0016] The machine tool according to the present disclosure is characterized in that it includes a plurality of the electric devices, and the estimation unit estimates the power consumption amount of each of the plurality of electric devices.

[0017] In the present disclosure, an estimation unit estimates the power consumption of each of a plurality of electrical devices. If the power consumption of each electrical device is known, measures can be taken for each electrical device to prevent unnecessary power consumption.

[0018] The machine tool according to the present disclosure is characterized by including a plurality of electrical devices that receive AC power, a detection unit that collectively detects the voltage and frequency of the AC power received by each of the electrical devices, and an estimation unit that estimates the amount of power consumption of each of the electrical devices based on the detection results of the detection unit.

[0019] In the present disclosure, the detection unit collectively detects the voltage and frequency of the AC power received by each electrical device. Therefore, the machine tool does not need to have a detection unit for each electrical device. The estimation unit estimates the power consumption of each electrical device based on the detection results of the detection unit. Therefore, the power consumption of each electrical device can be determined without using a wattmeter. If the power consumption of each electrical device is known, measures can be taken for each electrical device to avoid wasting power.

[0020] The user or manufacturer does not need to set the voltage and frequency values ​​used by the estimation unit for estimation in the machine tool according to the region where the machine tool is installed or the environment in which the machine tool is used, improving convenience for users and manufacturers. Also, errors in estimating the amount of power consumption caused by forgetting to set or incorrectly setting the voltage and frequency can be prevented. Furthermore, even if the AC voltage or frequency fluctuates while the machine tool is in use, the accuracy of estimating the amount of power consumption of each electrical device is improved.

[0021] The power consumption estimation method according to the present disclosure is characterized in that it estimates the power consumption of an electrical device that is provided in a machine tool and receives AC power, based on the voltage and frequency of the AC power received by the electrical device.

[0022] In the present disclosure, a machine tool includes an electric device. A computer estimates the amount of power consumed by the electric device based on the voltage and frequency of the AC power received by the electric device. Therefore, the amount of power consumed by the electric device can be determined without using a wattmeter.

[0023] The computer program according to the present disclosure is provided in a machine tool and is characterized in that it causes a computer to execute a process of estimating the amount of power consumed by an electrical device that receives AC power, based on the voltage and frequency of the AC power received by the electrical device.

[0024] In the present disclosure, the power consumption estimation method according to the present disclosure can be realized in software using hardware elements of a computer.

[0025] According to the machine tool, the power consumption estimation method, and the computer program of the present disclosure, the power consumption of an electrical device can be determined without using a power meter.

[0026] Fig. 1 is a partial perspective view of a machine tool. Fig. 2 is a block diagram showing the main parts of the machine tool. Fig. 3 is a block diagram showing the configuration of a control device. Fig. 4 is a flowchart showing the procedure of a power consumption amount estimation process executed by the machine tool. Fig. 5 is another block diagram showing the main parts of the machine tool. Fig. 6 is a block diagram showing the configuration of a control device. Fig. 7 is a schematic diagram showing an example of a screen displayed on a display unit.

[0027] In the following description, arrows indicating up and down, front and rear, and left and right are used in the drawings.

[0028] The machine tool 100 shown in Figure 1 comprises a control box 3 and a column 4 mounted on a base 2 supported on the floor. A user operates the machine tool 100 from the front. The column 4 is a support that stands vertically in the center of the left-right direction at the rear of the base 2. The machine tool 100 comprises a machining chamber 40 in front of the column 4. Inside the machining chamber 40 is a machining table (not shown) that can move back and forth and left and right. The machine tool 100 machines a workpiece (not shown) on the machining table.

[0029] The column 4 supports a spindle head (not shown) at its front. The spindle head moves up and down along the column 4. The column 4 supports a tool changer in front of the spindle head. The tool changer is equipped with a tool storage section and a tool change mechanism. The tool change mechanism automatically changes one of a plurality of tools held in the tool storage section for the tool attached to the spindle. The control box 3 is attached to the rear of the column 4.

[0030] Machine tool 100 includes a cleaning liquid unit 10. Cleaning liquid unit 10 includes a tank 11, a collection tank 12, a pump 13 (chip shower pump), a pump 14 (cyclone pumping pump), and a pump 60 (CTS pump). Tank 11 is a box-shaped container that stores cleaning liquid to be supplied into machining chamber 40. Collection tank 12, pump 13, pump 14, and pump 60 are installed on top of tank 11.

[0031] The cleaning liquid unit 10 is detachably attached to the rear side of the base 2. The collection tank 12 collects used cleaning liquid. The collection tank 12 is equipped with a primary filter that performs primary filtration of the collected cleaning liquid. The primary filter is plate-shaped and has countless fine holes. The tank 11 includes a contaminated tank and a semi-purified tank. The contaminated tank is located below the primary filter. The contaminated tank stores cleaning liquid that has been filtered by the primary filter. The contaminated tank and semi-purified tank are adjacent to each other. The cleaning liquid stored in the contaminated tank flows into the semi-purified tank after being filtered by a pair of filters. The pair of filters consists of two filters facing each other with a predetermined gap between them, and each filter is plate-shaped and has countless holes that are smaller than those of the primary filter described above.

[0032] Pumps 13, 14, and 60 suck up the cleaning liquid in tank 11 and send it out to machining chamber 40. Pump 13 is a pump for cleaning machining chamber 40. The machining chamber 40 is equipped with a cleaning liquid nozzle (not shown) on its inner wall, and the discharge side of pump 13 is connected to the cleaning liquid nozzle. Pump 13 sucks up the cleaning liquid in tank 11 (semi-purification tank) and sends it to the cleaning liquid nozzle, which then sprays the cleaning liquid into machining chamber 40. The cleaning liquid washes away chips in machining chamber 40 into tank 11 (contamination tank).

[0033] The pump 14 is a pump for cleaning tools. A tool cleaning nozzle (not shown) is provided inside the machining chamber 40, and the discharge side of the pump 14 is connected to the tool cleaning nozzle via a pipe. The pump 14 sucks up cleaning liquid from the tank 11 (semi-purification tank) and sends it to a cleaning filter 141 (cyclone filter) via a pipe. The cleaning filter 141 filters the cleaning liquid. The cleaning liquid that has passed through the filtering process in the cleaning filter 141 is sent to a storage tank 50 via a pipe. When cleaning tools, the cleaning liquid in the storage tank 50 is sent to the tool cleaning nozzle in the machining chamber 40 via a pipe. The tool cleaning nozzle in the machining chamber 40 sprays the cleaning liquid from the storage tank 50 onto a tool (not shown) being replaced. The cleaning liquid washes away chips adhering to the tool before it is attached to the spindle.

[0034] Pump 60 is a pump that is used for both cooling and cleaning the tool and workpiece. The tool has an internal flow path that extends from the base end to the tip of the tool, and the tip of the tool is open. The discharge side of pump 60 is connected to the base end of the tool via piping. Pump 60 draws up cleaning liquid from tank 11 (semi-septic tank) and sends it to the tool, and the tool sprays the cleaning liquid from its tip toward the surface of the workpiece being machined during machining. The cleaning liquid cools and cleans the tool and workpiece during machining. Machine tool 100 may also be equipped with a coolant pump. The coolant pump draws up cleaning liquid from tank 11 (semi-septic tank) and sends the cleaning liquid via piping to nozzles provided around the tool and workpiece being machined, and the nozzles spray the cleaning liquid toward the tool and workpiece being machined.

[0035] Figure 2 is a block diagram showing the main parts of machine tool 100. For simplicity, Figure 2 collectively shows pumps 13, 14, and 60. Pump 13 is an electrical device equipped with a pump motor that receives AC power from AC power supply 700 to operate. Similarly, pumps 14 and 60 are also electrical devices that receive AC power to operate. A main breaker 701 is interposed between pumps 13, 14, and 60 and AC power supply 700. Machine tool 100 includes a DC power supply device 71, a control device 72, a display unit 73, an operation unit 74, and a relay unit 75.

[0036] The DC power supply 71 receives AC power from the AC power supply 700 and converts it into DC. The control device 72, display unit 73, and operation unit 74 receive DC power from the DC power supply 71 through a relay unit 75. A main breaker 701 and a DC power supply protection breaker 711 are interposed between the DC power supply 71 and the AC power supply 700. The control box 3 shown in FIG. 1 houses, for example, the DC power supply 71, the control device 72, and the relay unit 75.

[0037] 3 is a block diagram showing the configuration of control device 72. Control device 72 includes a main memory unit 81, an auxiliary memory unit 82 (memory unit), a control unit 83, and a clock unit 84. The units of control device 72 are connected to each other via a bus. Main memory unit 81 is volatile and is, for example, a random access memory (RAM). Auxiliary memory unit 82 is nonvolatile and includes a read only memory (ROM), a flash memory, a hard disk, an SSD (solid state drive), etc. Auxiliary memory unit 82 pre-stores a computer program for controlling the operation of machine tool 100 and various data necessary for executing the computer program.

[0038] The control unit 83 includes one or more processors such as a CPU (Central Processing Unit), MPU (Micro-Processing Unit), or GPU (Graphics Processing Unit). The control unit 83 uses the main memory unit 81 as a work area and executes various arithmetic processing and control processing in accordance with computer programs stored in the auxiliary memory unit 82. For example, the control unit 83 performs control processing such as machining operations and automatic tool change in the machine tool 100. During control processing of machining operations, the control unit 83 turns on / off each of the pumps 13, 14, and 60 at predetermined timings in accordance with the computer program for the machining operations. The control unit 83 may include a logic circuit (e.g., FPGA). The clock unit 84 measures the current time t.

[0039] The display unit 73 shown in Figure 2 is, for example, a liquid crystal display. The operation unit 74 has operation keys. The display unit 73 and operation unit 74 form, for example, an operation panel located on the outer surface of the machining chamber 40. The display unit 73 and operation unit 74 may be located on a terminal device carried by the user of the machine tool 100. The operation keys of the operation unit 74 may be hardware keys or software keys superimposed on the display unit 73. In the case of these software keys, the display unit 73 is a touch panel. The operation keys include a power switch for the machine tool 100.

[0040] If the power consumption Wh of each pump 13, 14, 60 is known, measures can be taken for each pump 13, 14, 60 to avoid wasting power. However, providing a power meter for each pump 13, 14, 60 increases the cost of machine tool 100. Therefore, control unit 83 estimates the power consumption Wh of each pump 13, 14, 60, and displays the estimated results on display unit 73, distinguishing between each pump.

[0041] The auxiliary storage unit 82 pre-stores a computer program 85 for estimating the power consumption Wh, and various data required for executing the computer program 85. The computer program 85 enables the power consumption estimation method of this embodiment to be realized in software using the hardware elements of a computer, and includes the following equations (1) and (2): W = aV + bf + c (1) Wh = W × h (2)

[0042] Equation (1) is an equation for calculating the power consumption W of each pump 13, 14, 60 based on the voltage V and frequency f of the AC power received by each pump 13, 14, 60, and was experimentally obtained by the inventors. Approximating the power consumption W with a simple linear equation simplifies the calculation for estimating the power consumption Wh. The units of voltage V, frequency f, and power consumption W are, for example, [V (volts)], [Hz (hertz)], and [W (watts)]. The ranges of voltage V and frequency f to which equation (1) can be applied are, for example, 160≦V [V] ≦ 280 and 49 ≦ f [Hz] ≦ 61, and more preferably, 180 ≦ V [V] ≦ 253 and 50 ≦ f [Hz] ≦ 60. Experiments have shown that the error between the estimated value using equation (1) and the actual measured value for each pump 13, 14, 60 is approximately 4.4%, which is sufficiently practical.

[0043] Equation (2) is an equation for calculating the power consumption Wh of each pump 13, 14, 60 based on the power consumption W of each pump 13, 14, 60 and the operating time h of each pump 13, 14, 60. The units of the operating time h and the power consumption Wh are, for example, h (hours) and Wh (watt-hours).

[0044] Auxiliary storage unit 82 stores constants a, b, and c in association with each of pumps 13, 14, and 60. Constants a, b, and c can be determined experimentally for each of pumps 13, 14, and 60, for example, and are provided to machine tool 100 by the manufacturer when machine tool 100 is manufactured. Note that constants a, b, and c may also be provided to machine tool 100 by the manufacturer or user operating operation unit 74 after machine tool 100 has been shipped from the factory. Equation (1) or constants a, b, and c may be downloaded by control unit 83 from an external source (for example, a server).

[0045] As shown in FIG. 2 , the DC power supply device 71 includes a detection unit 712. The detection unit 712 detects the voltage and frequency of the AC power received from the AC power supply 700. The voltage value is, for example, an effective value. The detection unit 712 is not a wattmeter for directly determining the amount of power consumed by each pump 13, 14, 60 from the current and voltage. The voltage and frequency detected by the detection unit 712 are equal to the voltage V and frequency f of the AC power received by each pump 13, 14, 60. In other words, the detection unit 712 detects the voltage V and frequency f of each pump 13, 14, 60 collectively.

[0046] Generally, power is calculated from current and voltage. Even if the same voltage is applied to each pump 13, 14, 60, the current flowing through each pump 13, 14, 60 varies depending on conditions such as the capacity of each pump 13, 14, 60 and the operating environment. The operating environment includes factors such as the concentration of the cleaning liquid, the temperature in the room where the machine tool is used, and the diameter of the piping. Therefore, when calculating the power consumption of each pump 13, 14, 60 based on current and voltage, three wattmeters or one voltmeter and three ammeters are required for the three pumps 13, 14, 60. However, the voltage V and frequency f for each pump 13, 14, 60 are the same. Therefore, only one detector 712 is required to simultaneously detect the voltage V and frequency f of the AC power received by each pump 13, 14, 60. Note that the detector 712 may be a voltmeter and a frequency meter for each pump.

[0047] 4 is a flowchart showing the procedure of the power consumption estimation process executed by machine tool 100. Control unit 83 executes the power consumption estimation process in accordance with computer program 85. The following describes an example of the process for estimating the power consumption Wh of pump 13. Control unit 83 determines whether pump 13 has been turned on from an off state (S11), and if pump 13 remains off (NO in S11), returns the process to S11.

[0048] When the pump 13 is turned on (YES in S11), the control unit 83 starts measuring the elapsed time hb (S12). In S12, the control unit 83 measures the elapsed time hb, for example, by counting up the number of clocks received by the control unit 83 or by turning on a timer provided in the control device 72.

[0049] The control unit 83 determines whether or not it is now time to estimate the power consumption Wh of the pump 13 (S13). The time to estimate the power consumption Wh is, for example, when the elapsed time hb reaches or exceeds a predetermined time hc (e.g., 0.1 msec). If it is now time to estimate the power consumption Wh of the pump 13 (YES in S13), the control unit 83 acquires the detection result of the detection unit 712 (i.e., the voltage V and frequency f of the AC power received by the pump 13) (S14).

[0050] After the process of S14 is completed, the control unit 83 estimates the power consumption W of the pump 13 (S15). In S15, the control unit 83 calculates the power consumption W by substituting the constants a, b, and c stored in the auxiliary storage unit 82 and the AC voltage V and frequency f acquired in S14 into equation (1) stored in the auxiliary storage unit 82.

[0051] After the process of S15 is completed, the control unit 83 estimates the power consumption Wh of the pump 13 (S16). In S16, the control unit 83 calculates the power consumption Wh by substituting the operation time h and the power consumption W calculated in S15 into equation (2) stored in the auxiliary storage unit 82. Here, the operation time h to be substituted into equation (2) is the elapsed time h converted into [h] (when the elapsed time h is 0.1 [msec], the operation time h is approximately 2.8 × 10 [h]).

[0052] The control unit 83 writes information about the power consumption Wh calculated in S16 to the auxiliary storage unit 82 (S17). The information written by the control unit 83 to the auxiliary storage unit 82 in S17 is, for example, the power consumption Wh, the cumulative operating time ha (ha = ha + hb), and the cumulative power consumption Wha (Wha = Wha + Whb). Here, Whb is the power consumption Wh for the elapsed time hb estimated in S16. The control unit 83 writes the power consumption Wh, the cumulative operating time ha, and the cumulative power consumption Wha to the auxiliary storage unit 82, for example, in association with information identifying the pump 13 and the time t measured by the clock unit 84. The control unit 83 may also write the power consumption W and the operating time h to the auxiliary storage unit 82. The control unit 83 resets the measurement result of the elapsed time hb (S18) and continues measuring the elapsed time hb.

[0053] The control unit 83 displays information about the power consumption Wh calculated in S16 on the display unit 73 (S19). In S19, the control unit 83 displays the power consumption Wh on the display unit 73, for example, as a bar graph or a line graph with time t on the horizontal axis and the power consumption Wh on the vertical axis. After the process of S19 is completed, or if it is not now the timing to estimate the power consumption Wh of the pump 13 (NO in S13), the control unit 83 determines whether the pump 13 has been turned off (S20).

[0054] If pump 13 remains on (NO in S20), control unit 83 returns the process to S13. If pump 13 is turned off (YES in S20), control unit 83 ends counting elapsed time hb (S21) and ends the power consumption estimation process. While machine tool 100 is operating, control unit 83 repeatedly executes the power consumption estimation process.

[0055] By displaying the power consumption Wh of the pump 13 in a graph, a user can intuitively grasp the amount of power consumption Wh by viewing the display unit 73. Furthermore, by plotting time t on the horizontal axis, the user can intuitively grasp the change in the power consumption Wh over time.

[0056] The control unit 83 is not limited to a configuration in which the power consumption amount Wh is displayed as a graph, and may instead display the power consumption amount Wh numerically, for example. The control unit 83 may also calculate an integrated value of the power consumption amount Wh for each predetermined time period (for example, every hour from the start of work to the end of work) and display this on the display unit 73. The control unit 83 may also calculate an integrated value of the power consumption amount Wh from a predetermined time point to the present time and display this on the display unit 73. The control unit 83 is not limited to a configuration in which the power consumption amount Wh is displayed each time the power consumption amount Wh is estimated, and may instead display the power consumption amount Wh when, for example, the user performs a predetermined operation on the operation unit 74.

[0057] 4 for each of the pumps 14, 60. For the power consumption Wh of each of the pumps 13, 14, 60, the control unit 83 displays, on the display unit 73, for example, a stacked bar graph or a grouped bar graph with the time t on the horizontal axis and the power consumption Wh on the vertical axis.

[0058] Note that control unit 83 may display on display unit 73 the total value of the power consumption Wh of each of pumps 13, 14, 60. The display is not limited to one in which the power consumption Wh of each of pumps 13, 14, 60 can be distinguished from one another, and may be, for example, a display in which the total value of the power consumption Wh of two of pumps 13, 14, 60 can be distinguished from the power consumption Wh of the other pumps. The graph is not limited to a bar graph or a line graph, and may be, for example, a pie chart showing the ratio of the power consumption Wh of each pump 13, 14, 60 to the power consumption of machine tool 100 as a whole.

[0059] According to the machine tool 100 described above, the power consumption Wh of each pump 13, 14, 60 can be calculated without using a wattmeter. The control unit 83 functions as the estimation unit in the embodiment in S15 and S16 of the power consumption estimation process. From the start of counting the operating time h in S12 to the end of counting the operating time h in S21, the control unit 83 functions as the timer in the embodiment.

[0060] The electrical equipment for which Wh should be estimated is not limited to pumps 13, 14, and 60, and may also be a spindle motor, a lighting fixture, etc. Furthermore, pumps other than pumps 13, 14, and 60 may also be estimated. Constants a, b, and c may be common to multiple pumps 13, 14, and 60. Machine tool 100 may be provided with multiple detection units instead of detection unit 712. For example, three detection units detect the voltages V and frequencies f related to the three pumps 13, 14, and 60 in one-to-one correspondence. However, the configuration of machine tool 100 is simpler if detection unit 712 detects the voltages V and frequencies f related to pumps 13, 14, and 60 collectively.

[0061] The voltage V and frequency f of the AC power received by each pump 13, 14, 60 may be set in machine tool 100 by the manufacturer, user, etc. The voltage V and frequency f set by the manufacturer, user, etc. are stored in auxiliary memory unit 82, for example. In this case, detection unit 712 can be omitted. However, if detection unit 712 is present, the user, manufacturer, etc. does not need to set the respective values ​​of voltage V and frequency f in machine tool 100 according to the region where machine tool 100 is installed, the operating environment of machine tool 100, etc., thereby improving convenience for users and manufacturers, etc. Furthermore, estimation errors in power consumption Wh due to forgetting to set or incorrectly setting voltage V or frequency f can be prevented. Furthermore, even if voltage V or frequency f fluctuates while machine tool 100 is in use, the estimation accuracy of power consumption Wh is improved.

[0062] The control unit 83 executes multiple processes, such as an estimation process for estimating the power consumption Wh and a display process for displaying the estimation result. The multiple processes may be executed by a single processor included in the control unit 83, or may be executed in a distributed manner by multiple processors included in the control unit 83. A processor for executing the estimation process and a processor for executing the display process may be separate. The control unit 83 may substitute a constant operating time h into equation (2) without measuring the operating time h. However, using the measured operating time h allows the length of time each pump 13, 14, 60 actually consumed power to be taken into account, thereby improving the accuracy of estimating the power consumption Wh of each pump 13, 14, 60. The equations for estimating the power consumption Wh are not limited to equations (1) and (2).

[0063] The power consumption estimation method of this embodiment is not limited to a configuration realized by a computer (control device 72) provided in machine tool 100. A computer external to machine tool 100 (for example, a server having computer program 85 and constants a, b, and c) may receive voltage V, frequency f, and operating time h from machine tool 100 and estimate power consumption Wh.

[0064] 5 is a block diagram showing the main parts of a machine tool 100A according to embodiment 2. Machine tool 100A is substantially similar to machine tool 100 according to embodiment 1, except that machine tool 100A includes a control device 72A instead of control device 72. Differences from embodiment 1 will be described below, and other components that are the same as those in embodiment 1 will be assigned the same reference numerals and descriptions thereof will be omitted.

[0065] The control device 72A is substantially the same as the control device 72 of the first embodiment, except that it includes a temperature measuring unit 741. The temperature measuring unit 741 detects the temperature at a predetermined position. It is desirable that the temperature measurement result of the temperature measuring unit 741 can substitute for the temperature of the surrounding environment of the pumps 13, 14, and 60. The temperature measuring unit 741 of this embodiment is mounted on a printed circuit board provided in the operation unit 74, and detects the temperature near the operation unit 74.

[0066] 6 is a block diagram showing the configuration of control device 72A. Computer program 85 includes the following equation (3) instead of equation (1) in embodiment 1: W = aV + bf + c + dT ... (3) Equation (3) was obtained experimentally by the inventors and is equal to equation (1) plus a fourth term, "dT." The fourth term, "dT," is the temperature T at a predetermined position multiplied by a constant d. Auxiliary storage unit 82 stores constants a, b, and c as well as constant d in association with each pump 13, 14, and 60. Constant d, like constants a, b, and c, can be obtained experimentally and is provided to machine tool 100A by the manufacturer when machine tool 100A is manufactured.

[0067] The control unit 83 of this embodiment also executes the power consumption estimation process shown in Fig. 4. However, in S14, the control unit 83 acquires the detection result of the detection unit 712 (i.e., the voltage V and frequency f of the AC power received by each of the pumps 13, 14, and 60) and the temperature measurement result of the temperature measurement unit 741 (i.e., the temperature T at a predetermined position). In S15, the control unit 83 calculates the power consumption W by substituting the constants a, b, c, and d stored in the auxiliary storage unit 82 and the AC voltage V, frequency f, and temperature T acquired in S14 into equation (3) stored in the auxiliary storage unit 82.

[0068] The temperature of the environment surrounding pumps 13, 14, and 60 can affect the amount of power consumption Wh of each pump 13, 14, and 60. Therefore, by taking into account the temperature measurement results of temperature measurement unit 741 when estimating the amount of power consumption Wh, the accuracy of estimating the amount of power consumption Wh of each pump 13, 14, and 60 is improved. Note that machine tool 100A may be provided with multiple temperature measurement units instead of temperature measurement unit 741. For example, three temperature measurement units detect the temperatures of the environments surrounding three pumps 13, 14, and 60 in one-to-one correspondence. However, the configuration of machine tool 100A is simpler if temperature measurement unit 741 detects temperature T at a predetermined position.

[0069] FIG. 7 is a schematic diagram showing an example of a screen displayed on the display unit 73. The control unit 83 displays a stacked bar graph on the display unit 73. The horizontal axis represents hourly time slots from midnight to 23:59 of the current day. The vertical axis represents the integrated value of the estimated power consumption Wh of each pump 13, 14, 60 during each time slot. Bars hatched downward to the right represent the pump 13, open bars represent the pump 14, and bars hatched upward to the right represent the pump 60. If the power consumption Wh of the spindle motor, lighting fixtures, etc. is also estimated in addition to the power consumption Wh of each pump 13, 14, 60, the control unit 83 may display bar graphs representing the spindle motor, lighting fixtures, etc. on the display unit 73 by adding them to the stacked bar graph shown in FIG. 7.

[0070] The embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is intended to encompass not only the above-described meaning but also the meaning equivalent to the claims and all modifications within the scope of the claims. The constituent elements (technical features) disclosed in each embodiment can be combined with each other to form new technical features. Furthermore, independent and dependent claims described in the claims can be combined with each other in any combination, regardless of the reference format. Furthermore, although the claims use a format in which a claim references two or more other claims (multiple claim format), this is not limiting. A multiple claim (multi-multi claim) that references at least one other multiple claim may also be used.

[0071] 100, 100A Machine tool 13, 14, 60 Pump (electrical equipment) 712 Detection unit 741 Temperature measurement unit 82 Auxiliary memory unit (memory unit) 83 Control unit (estimation unit, timing unit) 85 Computer program

Claims

1. A machine tool comprising: an electrical device that receives alternating current; and an estimation unit that estimates the amount of power consumed by the electrical device based on the voltage and frequency of the alternating current received by the electrical device.

2. The machine tool according to claim 1, further comprising a detection unit that detects the voltage and the frequency, and the estimation unit estimates the amount of power consumption based on the detection results of the detection unit.

3. The machine tool according to claim 1 or 2, further comprising a storage unit that stores the following formula (1) and constants a, b, and c for determining the power consumption W based on the voltage V and the frequency f, and the estimation unit estimates the power consumption based on the following formula (1) and the constants stored in the storage unit. W=aV+bf+c ... (1) 4. A machine tool as described in claim 1 or 2, further comprising a timing unit which measures the operating time during which the electrical equipment is in operation, and the estimation unit estimates the amount of power consumption based on the voltage and frequency and the timing result by the timing unit.

5. A machine tool as described in claim 1 or 2, further comprising a temperature measuring unit that detects the temperature at a predetermined position, and the estimation unit estimates the amount of power consumption based on the voltage and frequency and the temperature measurement result of the temperature measuring unit.

6. The machine tool according to claim 1 or 2, characterized in that it is provided with a plurality of the electrical devices, and the estimation unit estimates the amount of power consumption of each of the plurality of the electrical devices.

7. A machine tool comprising: a plurality of electrical devices that receive alternating current; a detection unit that collectively detects the voltage and frequency of the alternating current received by each of the electrical devices; and an estimation unit that estimates the amount of power consumption of each of the electrical devices based on the detection results of the detection unit.

8. A method for estimating power consumption, comprising the steps of: estimating the power consumption of an electrical device provided in a machine tool and receiving AC power, based on the voltage and frequency of the AC power received by the electrical device.

9. A computer program provided in a machine tool, which causes a computer to execute a process for estimating the amount of power consumed by an electrical device that receives AC power, based on the voltage and frequency of the AC power received by the electrical device.

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