Control device for controlling cooling device

Abstract

This control device comprises: a remaining time calculation unit that, by analyzing an operation program, calculates time remaining until a reference time; a temperature information reception unit that receives temperature information relating to a motor temperature detected by a sensor; an operating time calculation unit that calculates an operational time of the motor on the basis of at least the temperature information, the operation program, and a thermal model of the motor; and a cooling controller that controls a cooling device, which cools the motor, on the basis of the time remaining calculated by the remaining time calculation unit and the operational time calculated by the operating time calculation unit.

Description

Control device for controlling the cooling device

[0001] The present disclosure relates to a control device for controlling a cooling device.

[0002] To prevent motors used in industrial machinery and the like from overheating, the motors are cooled using cooling devices while they are running. For example, a cooling device is known that cools the motor by rotating a cooling fan at a constant speed to send air to the motor. Another cooling device is known that cools the motor by controlling the rotation speed of the cooling fan in accordance with the motor temperature measured in real time (see, for example, Patent Document 1).

[0003] Japanese Patent Application Publication No. 11-37097

[0004] When a cooling fan rotates at a constant speed and cools the motor with the air it blows in, it can cool the motor more than necessary, causing the cooling device to consume more energy than necessary.

[0005] On the other hand, if the rotation of the cooling fan is controlled based on the motor temperature measured in real time, the cooling capacity may not be able to keep up with fluctuations in the motor temperature. In this case, there is a risk that the motor may overheat. Therefore, there is a need for a cooling device control device that can prevent the cooling device from consuming more energy than necessary and prevent the motor from overheating.

[0006] The control device of the present disclosure includes a remaining time calculation unit that analyzes the operation program to calculate the remaining time until a reference time, a temperature information receiving unit that receives temperature information related to the temperature of the motor detected by a sensor, an operating time calculation unit that calculates the operable time of the motor based on at least the temperature information, the operation program, and a thermal model of the motor, and a cooling control unit that controls a cooling device that cools the motor based on the remaining time calculated by the remaining time calculation unit and the operable time calculated by the operation time calculation unit.

[0007] 1 is a block diagram showing an example of the hardware configuration of an industrial machine in which a control device is implemented; FIG. 2 is a block diagram showing an example of the functions of a control device of a first embodiment; FIG. 3 is an example of a graph showing the transition of the temperature of a motor, etc.; FIG. 4 is a flowchart showing an example of the flow of processing executed by the control device; FIG. 5 is a block diagram showing an example of the functions of a control device of a second embodiment; FIG. 6 is an example of a graph showing the transition of the temperature of a motor, etc.; FIG. 7 is a flowchart showing an example of the flow of processing executed by the control device; FIG. 8 is a block diagram showing an example of the functions of a control device of a third embodiment; FIG. 9 is a flowchart showing an example of the flow of processing executed by the control device;

[0008] Hereinafter, a control device according to an embodiment of the present disclosure will be described with reference to the drawings. In the following description, components having the same or similar functions will be denoted by the same reference numerals. Duplicate descriptions of those components may be omitted.

[0009] In this application, "based on XX" means "based on at least XX," and includes cases where it is based on other elements in addition to XX. Furthermore, "based on XX" is not limited to cases where XX is used directly, but also includes cases where it is based on XX that has been calculated or processed. "XX" is any element (for example, any information).

[0010] First Embodiment The control device is a device that controls a cooling device. The control device may further control an industrial machine. That is, the control device may be a device that controls the industrial machine. Furthermore, the control device may be a device separate from the device that controls the industrial machine. Below, an example in which the control device is a device that controls the industrial machine will be described.

[0011] Industrial machines are machines that operate in industrial sites, such as machine tools, injection molding machines, laser processing machines, three-dimensional printers, and robots.

[0012] 1 is a block diagram showing an example of the hardware configuration of an industrial machine in which a control device is implemented. The industrial machine 1 includes a control device 2, an input / output device 3, a servo amplifier 4, a servo motor 5, a spindle amplifier 6, a spindle motor 7, an auxiliary device 8, a sensor 9, and a cooling device 10.

[0013] The control device 2 is, for example, a numerical control device that controls the industrial machine 1. The control device 2 includes, for example, a hardware processor 201, a bus 202, a read-only memory (ROM) 203, a random access memory (RAM) 204, and a non-volatile memory 205.

[0014] The hardware processor 201 is a processor that controls the entire control device 2 in accordance with a system program. The hardware processor 201 reads the system program stored in the ROM 203 via the bus 202. The hardware processor 201 is, for example, a CPU (Central Processing Unit) or an electronic circuit.

[0015] The bus 202 is a communication path that connects the various pieces of hardware in the control device 2. The various pieces of hardware in the control device 2 exchange data via the bus 202.

[0016] The ROM 203 is a storage device that stores system programs, etc. The ROM 203 is a computer-readable storage medium.

[0017] The RAM 204 is a storage device that temporarily stores various data and functions as a work area for the hardware processor 201 to process various data.

[0018] The nonvolatile memory 205 is a storage device that retains data even when the power to the control device 2 is turned off. The nonvolatile memory 205 stores, for example, an operation program for the industrial machine 1. The nonvolatile memory 205 is a computer-readable storage medium. The nonvolatile memory 205 is, for example, a memory backed up by a battery or an SSD (Solid State Drive).

[0019] The control device 2 further includes a first interface 206, an axis control circuit 207, a spindle control circuit 208, a PLC (Programmable Logic Controller) 209, an I / O unit 210, a second interface 211, and a third interface 212.

[0020] The first interface 206 connects the bus 202 and the input / output device 3. The first interface 206 sends various data processed by the hardware processor 201 to the input / output device 3, for example.

[0021] The input / output device 3 receives and displays various data via the first interface 206. The input / output device 3 also accepts input of various data and sends the data to, for example, the hardware processor 201 via the first interface 206.

[0022] The input / output device 3 is, for example, a touch panel. When the input / output device 3 is a touch panel, the input / output device 3 is, for example, a capacitive touch panel. The touch panel is not limited to a capacitive touch panel and may be a touch panel of another type. The input / output device 3 is installed in an operation panel (not shown) in which the control device 2 is housed.

[0023] The axis control circuit 207 is a circuit for controlling the servo motor 5. The axis control circuit 207 receives control commands from the hardware processor 201 and sends various commands to the servo amplifier 4 for driving the servo motor 5. The axis control circuit 207 sends, for example, a torque command for controlling the torque of the servo motor 5 to the servo amplifier 4.

[0024] The servo amplifier 4 receives a command from the axis control circuit 207 and supplies a current to the servo motor 5 .

[0025] The servo motors 5 are driven by receiving a current supply from the servo amplifier 4. The servo motors 5 are provided for each control axis of the industrial machine 1. If the industrial machine 1 is a machine tool having five axes, the servo motors 5 include, for example, an X-axis servo motor, a Y-axis servo motor, a Z-axis servo motor, an A-axis servo motor, and a C-axis servo motor. In this case, an axis control circuit 207 and a servo amplifier 4 are provided for each servo motor 5.

[0026] The servo motor 5 is connected to, for example, a ball screw that drives a tool post. When the servo motor 5 is driven, a structure of the industrial machine 1, such as the tool post, moves along a predetermined control axis. The servo motor 5 has a built-in encoder (not shown) that detects the position and feed rate of the control axis. Position feedback information and speed feedback information indicating the position and feed rate of the control axis, respectively, detected by the encoder are fed back to the axis control circuit 207. In this way, the axis control circuit 207 performs feedback control of each control axis.

[0027] The spindle control circuit 208 is a circuit for controlling the spindle motor 7. The spindle control circuit 208 receives a control command from the hardware processor 201 and sends a command to the spindle amplifier 6 to drive the spindle motor 7. The spindle control circuit 208 sends, for example, a spindle speed command to the spindle amplifier 6 to control the rotation speed of the spindle motor 7.

[0028] The spindle amplifier 6 receives a command from the spindle control circuit 208 and supplies a current to the spindle motor 7 .

[0029] The spindle motor 7 is driven by receiving a current supplied from the spindle amplifier 6. The spindle motor 7 is connected to the main shaft and rotates the main shaft.

[0030] The PLC 209 is a device that executes a ladder program to control the auxiliary device 8. The PLC 209 sends commands to the auxiliary device 8 via an I / O unit 210.

[0031] The I / O unit 210 is an interface that connects the PLC 209 and the auxiliary device 8. The I / O unit 210 sends commands received from the PLC 209 to the auxiliary device 8.

[0032] The auxiliary device 8 is installed in the industrial machine 1 and performs auxiliary operations in the industrial machine 1. The auxiliary device 8 operates based on commands received from the I / O unit 210. The auxiliary device 8 may be a device installed in the periphery of the industrial machine 1. The auxiliary device 8 is, for example, a tool changer, a cutting fluid injection device, or an opening / closing door drive device.

[0033] The second interface 211 connects the bus 202 and the sensor 9. The second interface 211 sends, for example, information acquired by the sensor 9 to the hardware processor 201 via the bus 202.

[0034] The sensor 9 is a temperature sensor that detects the temperature of at least one of the servo motor 5 and the spindle motor 7. The sensor 9 sends temperature information regarding the detected temperatures of the servo motor 5 and the spindle motor 7 to, for example, the hardware processor 201 via the second interface 211. The sensor 9 is attached to, for example, the windings of the servo motor 5 and the spindle motor 7.

[0035] The third interface 212 connects the cooling device 10 to the bus 202. The third interface 212 sends, for example, a command from the hardware processor 201 to the cooling device 10.

[0036] The cooling device 10 is a device that cools the motor. The cooling device 10 has a pump that sends fluid to the motor. For example, if the cooling device 10 is an air-cooled type, the cooling device 10 includes a cooling fan that sends air to the motor. Alternatively, if the cooling device 10 is a water-cooled type, the cooling device 10 includes a gear pump that sends coolant to the motor.

[0037] 2 is a block diagram showing an example of the functions of the control device 2 according to the first embodiment. The control device 2 includes a storage unit 221, a remaining time calculation unit 222, a temperature information reception unit 223, an operation time calculation unit 224, and a cooling control unit 225.

[0038] The storage unit 221 is realized, for example, by storing various types of information in the RAM 204 or the nonvolatile memory 205. The remaining time calculation unit 222, the temperature information reception unit 223, the operation time calculation unit 224, and the cooling control unit 225 are realized, for example, by the hardware processor 201 performing arithmetic processing using the system program stored in the ROM 203 and various types of data stored in the nonvolatile memory 205.

[0039] The storage unit 221 stores, for example, an operation program, motor information, machine information, a thermal model, and an operable time calculation formula. The operation program is a program for operating the industrial machine 1. The operation program is, for example, a machining program for a machine tool. The machining program includes, for example, a command for specifying the rotation speed of the spindle, a command for specifying the feed rate of each axis, and a movement command for each axis using coordinate values.

[0040] The motor information is information about the motor. The motor information includes the motor's resistance value, the motor's heat capacity, the motor's iron loss heat coefficient, and information about the motor's specifications. The information about the motor's specifications may include information indicating the motor's rated current, starting torque, starting current, etc. The iron loss heat coefficient will be described later.

[0041] The machine information is information relating to the industrial machine 1. The machine information may include information relating to the specifications of the industrial machine 1. The machine information may include, for example, information indicating the weight of a structure of the industrial machine 1 that moves along each axis, such as a table of a machine tool. The machine information may also include information relating to frictional forces that occur when each structure of the industrial machine 1 moves along each axis.

[0042] The machine information may include, for example, information indicating the weight of a structure of the industrial machine 1 that rotates around each axis, such as a robot arm, etc. The machine information may include information regarding the frictional force that occurs when each structure of the industrial machine 1 rotates around each axis.

[0043] The thermal model is a mathematical expression that indicates the relationship between the operation of the motor and its heat generation capacity when the operating program is executed. The thermal model is expressed, for example, by the following mathematical expression 1.

[0044] However, H ｍ is the heat generation capacity of the motor, I is the root mean square current value of the motor, R is the resistance value of the motor, N is the root mean square rotation speed of the motor, and H is the iron loss heat generation coefficient.

[0045] The heat generation capacity of the motor is an estimate of the amount of heat generated by the motor from the time the heat generation capacity is calculated until a reference time, which may be, for example, the time when the currently running operating program ends or when an optional stop of the operating program is executed.

[0046] The root mean square current value of the motor is a value that indicates the average of the squares of the motor current values ​​at each time from the calculation time of the root mean square current value to a reference time. The root mean square current value is calculated based on the operation program, motor information, and machine information.

[0047] For example, the root mean square current value is calculated using the motor rotation speed, feed rate of each axis, and movement distance of each axis specified in the operation program. Alternatively, the root mean square current value may be calculated using a value calculated based on the operation program. The value calculated based on the operation program may be, for example, the acceleration of each axis.

[0048] The calculation of the root mean square current value of the motor may further use information about the specifications of the motor, such as the rated current of the motor and the starting torque of the motor.

[0049] The calculation of the motor's root mean square current value uses information about the machine tool's specifications, such as the weight of the table, and may also use information about the frictional force generated when a structure, such as a table, moves along each axis.

[0050] The motor resistance is a value that indicates the resistance of the motor windings. The motor resistance is a value that is measured in advance or a value that is indicated by the motor design information.

[0051] The root mean square (rms) speed of a motor is a value that indicates the average of the squares of the motor's rotation speed at each time from the calculation time of the root mean square speed to a reference time. The root mean square (rms) speed is calculated based on a command value specified in the operation program.

[0052] The iron loss heat generation coefficient is a value that indicates the ratio of the amount of heat generated by a motor to the root mean square rotation speed of the motor when the motor performs a predetermined rotation operation. The iron loss heat generation coefficient may be determined in advance by experiment. Alternatively, the iron loss heat generation coefficient may be a value indicated by the design information.

[0053] The operable time calculation formula is a formula for calculating the operable time of the motor, which is the time from the calculation of the operable time until the motor reaches the target temperature.

[0054] The operable time is calculated as the time until the motor reaches an overheated state, assuming that the cooling capacity of the cooling device 10 is maintained at the time of calculation of the operable time. The operable time calculation formula is expressed, for example, by the following formula 2.

[0055] However, t ｍ is the available driving time, T ｔ is the target temperature, T ｃ is the current temperature, H ｍ is the heat generation capacity of the motor, H ｒ is the cooling capacity of the motor, C ｍ is the heat capacity of the motor.

[0056] Target temperature T ｔ is the target temperature of the motor when the operation program is executed. ｔ is, for example, the temperature at which the motor reaches an overheated state. That is, the target temperature T ｔ is the upper limit of the motor temperature. ｔ is, for example, 100°C. The target temperature T ｔ may be stored in advance in the storage unit 221.

[0057] Current temperature T ｃ is the temperature of the motor when the operable time is calculated. That is, the current temperature T ｃis the temperature information about the motor temperature. ｃ is acquired by the sensor 9.

[0058] Motor cooling capacity H ｒ is a value indicating the motor cooling capacity. ｒ The cooling capacity H varies depending on whether the cooling system is natural cooling, air cooling, or water cooling. ｒ is expressed by Equation 3, Equation 4, and Equation 5 according to natural cooling, air cooling, and water cooling, respectively. ｒ is stored in advance in the storage unit 221.

[0059] However, J １ is the heat removal coefficient of the motor during natural cooling, T Ｅ is the temperature of the environment in which the motor is installed.

[0060] However, J ２ is the heat removal coefficient during air cooling, S ｆ is the rotation speed of the cooling fan of the cooling device 10.

[0061] However, J ３ is the heat removal coefficient when water-cooled, and Q is the flow rate of the coolant.

[0062] Motor heat capacity C ｍ is the amount of heat required to raise the temperature of the motor by 1°C. ｍ is measured in advance and stored in the storage unit 221.

[0063] The remaining time calculation unit 222 analyzes the operation program and calculates the remaining time until the reference time. In other words, the remaining time is the time from the calculation point of the remaining time until the reference time. The remaining time calculation unit 222 calculates the remaining time based on the movement commands for each axis in the operation program, commands specifying the feed rate, etc.

[0064] The remaining time calculation unit 222 calculates the time until the reference time when the operation program starts to be executed and during the execution of the operation program. For example, the remaining time calculation unit 222 calculates the remaining time every 10 seconds during the execution of the operation program.

[0065] The temperature information receiving unit 223 receives temperature information relating to the temperature of the motor detected by the sensor 9 from the sensor 9. The motor is, for example, the spindle motor 7 or the servo motor 5. The motor may also be a linear motor provided in the industrial machine 1. The temperature information receiving unit 223 receives the temperature information from the sensor 9, for example, for each control cycle of the control device 2.

[0066] The operation time calculation unit 224 calculates the available operation time of the motor based on at least the temperature information related to the temperature detected by the sensor 9, the operation program, and the thermal model of the motor. The operation time calculation unit 224 calculates the available operation time of the motor using, for example, the available operation time calculation formula described above. In this case, the operation time calculation unit 224 substitutes information stored in the memory unit 221 and the like into the available operation time calculation formula to calculate the available operation time.

[0067] The operation time calculation unit 224 calculates the operation time using, for example, the resistance value, iron loss heat coefficient, target temperature, and heat capacity of the motor. The operation time calculation unit 224 also calculates the operation time using the calculated heat generation capacity of the motor and temperature information related to the motor temperature.

[0068] The operation time calculation unit 224 is not limited to the above-described formula for calculating the available operation time, and may use other formulas. Furthermore, the formula for calculating the available operation time may include information such as the motor resistance, iron loss heat coefficient, target temperature, and motor heat capacity. In this case, the operation time calculation unit 224 does not need to read out this information from the storage unit 221 when calculating the available operation time.

[0069] The cooling control unit 225 controls the cooling device 10 that cools the motor based on the remaining time calculated by the remaining time calculation unit 222 and the operable time calculated by the operation time calculation unit 224. The cooling control unit 225 controls the start or stop of operation of the cooling device 10. In this case, the cooling capacity of the cooling device 10 may be a predetermined constant capacity.

[0070] The cooling control unit 225 first compares the remaining time with the operable time, and controls the cooling device 10 based on the comparison result.

[0071] When the cooling device 10 is in operation and the remaining time is shorter than the operable time, the cooling control unit 225 stops the operation of the cooling device 10. When the cooling device 10 is stopped and the remaining time is shorter than the operable time, the cooling control unit 225 keeps the cooling device 10 stopped.

[0072] When the cooling device 10 is in operation and the remaining time is the same as the operable time, the cooling control unit 225 continues the operation of the cooling device 10. When the cooling device 10 is stopped and the remaining time is the same as the operable time, the cooling control unit 225 maintains the stopped state of the cooling device 10.

[0073] When the cooling device 10 is stopped and the remaining time is longer than the operable time, the cooling control unit 225 starts the operation of the cooling device 10 .

[0074] FIG. 3 is an example of a graph showing the transition of the motor temperature, etc. L1 shows the transition of the motor temperature when the motor is cooled based on the conventional motor cooling method. L2 shows the transition of the cooling capacity of the cooling device 10 when the motor is cooled based on the conventional motor cooling method. L3 shows the transition of the motor temperature when the motor is cooled based on the cooling method of this embodiment. L4 shows the transition of the cooling capacity of the cooling device 10 when the motor is cooled based on the cooling method of this embodiment. L5 shows the transition of the motor target temperature T ｔ Shows.

[0075] As shown by L1 and L2, in the conventional cooling method, the motor is cooled to a temperature T １ When the reference time t is reached, the execution of the operating program ends. ｃ The motor temperature is T １ However, this temperature T １ is the target temperature T t This means that the motor is overcooled using conventional cooling methods.

[0076] On the other hand, as shown by L3 and L4, in the cooling method of this embodiment, the cooling control unit 225 １ The cooling control unit 225 stops the operation of the cooling device 10 at time t １ This is because the remaining time is compared with the operable time and it is determined that the remaining time is shorter than the operable time. As a result, the cooling method of this embodiment prevents the motor from being cooled excessively. As a result, the energy consumed by the cooling device 10 is saved.

[0077] 4 is a flowchart showing an example of the flow of processing executed by the control device 2. In the control device 2, first, the remaining time calculation unit 222 analyzes the operation program and calculates the remaining time until the reference time (step SA1). For example, when a predetermined time has elapsed since the start of execution of the operation program, the remaining time calculation unit 222 calculates the remaining time to be 600 [s].

[0078] Next, the temperature information receiving unit 223 receives temperature information regarding the temperature of the motor detected by the sensor 9 (step SA2). The temperature information receiving unit 223 receives temperature information indicating that the temperature of the motor is 20° C., for example.

[0079] Next, the operation time calculation unit 224 calculates the remaining operation time of the motor based on at least the temperature information, the operation program, and the thermal model (step SA3). Based on information indicating the motor's root mean square current and root mean square rotation speed, for example, for the remaining time of 600 seconds, the operation time calculation unit 224 calculates that the motor's temperature will rise at a rate of 0.2°C per second. If the target temperature is 100°C, the operation time calculation unit 224 calculates the remaining operation time to be, for example, 400 seconds.

[0080] Finally, the cooling control unit 225 controls the cooling device 10, which cools the motor, based on the remaining time calculated by the remaining time calculation unit 222 and the operable time calculated by the operation time calculation unit 224 (step SA4). For example, if the remaining time is 600 [s] and the operable time is 400 [s], the remaining time is longer than the operable time, and therefore the operation of the cooling device 10 cannot be stopped. In this case, the cooling control unit 225 continues the operation of the cooling device 10.

[0081] The processes from step SA1 to step SA4 are repeatedly executed at predetermined time intervals during the execution of the operation program, which may be, for example, 10 seconds, as described above.

[0082] For example, when the remaining time is 180 seconds, the temperature information receiving unit 223 receives temperature information indicating that the motor temperature is 66°C (step SA2). The operation time calculation unit 224 calculates that the motor temperature rises at a rate of 0.18°C per second (step SA3). In this case, it takes 188 seconds for the motor temperature to reach the target temperature of 100°C. In other words, the available operation time is 188 seconds. Since the remaining time of 180 seconds is shorter than the available operation time of 188 seconds, the cooling control unit 225 stops operation of the cooling device 10 (step SA4), and the process ends.

[0083] 5 is a block diagram showing an example of the functions of the control device 2 of the second embodiment. In addition to the functions of the control device 2 of the first embodiment, the control device 2 of the second embodiment further includes a cooling information receiving unit 226. The cooling information receiving unit 226 is realized, for example, by the hardware processor 201 performing arithmetic processing using a system program stored in the ROM 203 and various data stored in the non-volatile memory 205.

[0084] The cooling information receiving unit 226 receives cooling information indicating the cooling capacity of the cooling device 10. The cooling information indicating the cooling capacity includes, for example, information indicating whether the motor is cooled by air cooling or water cooling.

[0085] When the motor is cooled by air cooling, the cooling information indicating the cooling capacity is the heat removal coefficient J ２ , and the rotation speed S of the fan of the cooling device 10 ｆ That is, the cooling information is expressed by the above-mentioned formula 4.

[0086] When the motor is cooled by water cooling, the cooling information indicating the cooling capacity is the heat removal coefficient J of the motor when water cooled. ３ , and the flow rate Q of the cooling liquid. That is, the cooling information is expressed by the above-mentioned formula 5.

[0087] The operation time calculation unit 224 further calculates the available operation time based on the cooling information received by the cooling information reception unit 226. That is, the operation time calculation unit 224 calculates the available operation time based on at least the temperature information related to the temperature of the motor detected by the sensor 9, the operation program, the thermal model, and the cooling information.

[0088] The cooling control unit 225 first compares the remaining time calculated by the remaining time calculation unit 222 with the operable time calculated by the operation time calculation unit 224. The cooling control unit 225 controls the cooling device 10 based on the comparison result. In this case, the cooling control unit 225 performs control to increase or decrease the cooling capacity of the cooling device 10.

[0089] When the cooling device 10 is in operation and the remaining time is shorter than the available operation time, the cooling control unit 225 reduces the cooling capacity of the cooling device 10. That is, the cooling control unit 225 reduces the rotation speed of the cooling fan of the cooling device 10, reduces the flow rate of the coolant in the cooling device 10, or stops the operation of the cooling device 10.

[0090] When the cooling device 10 is in operation and the remaining time is longer than the available operation time, the cooling control unit 225 increases the cooling capacity of the cooling device 10. That is, the cooling control unit 225 increases the rotation speed of the cooling fan of the cooling device 10 and increases the flow rate of the coolant in the cooling device 10.

[0091] When the cooling device 10 is in operation and the remaining time is the same as the available operation time, the cooling control unit 225 continues the operation of the cooling device 10. In this case, the cooling control unit 225 maintains the cooling capacity of the cooling device 10. That is, the cooling control unit 225 maintains the rotation speed of the cooling fan of the cooling device 10 or the flow rate of the coolant of the cooling device 10.

[0092] When the operation of the cooling device 10 is stopped and the remaining time is the same as the available operation time, the cooling control unit 225 causes the cooling device 10 to maintain the stopped state.

[0093] When the operation of the cooling device 10 is stopped and the remaining time is longer than the operable time, the cooling control unit 225 increases the cooling capacity of the cooling device 10. That is, the cooling control unit 225 starts the operation of the cooling device 10.

[0094] When the operation of the cooling device 10 is stopped and the remaining time is shorter than the available operation time, the cooling control unit 225 causes the cooling device 10 to maintain the stopped state.

[0095] FIG. 6 is an example of a graph showing the transition of the motor temperature. L11 shows the transition of the motor temperature when the motor is cooled based on the conventional motor cooling method. L12 shows the transition of the cooling capacity of the cooling device 10 when the motor is cooled based on the conventional motor cooling method. L13 shows the transition of the cooling capacity of the cooling device 10 when the motor is cooled based on the conventional motor cooling method. Ｓ L14 indicates the target temperature T ｔ L15 shows the transition of the motor temperature when the motor is cooled based on the cooling method of this embodiment. L16 shows the transition of the cooling capacity of the cooling device 10 when the motor is cooled based on the cooling method of this embodiment.

[0096] As shown by L11, L12, and L13, in the conventional motor cooling method, the motor temperature is set to the set temperature T Ｓ The timing t １２ However, at the timing t １２There is a time lag between the time when the motor temperature reaches the set temperature T Ｓ Even if the operation of the cooling device 10 is started after the target temperature T ｔ It reaches the limit.

[0097] On the other hand, in the motor cooling method of this embodiment, the motor is cooled at a timing t １１ 6, the cooling control unit 225 increases the cooling capacity of the cooling device 10. In the example shown in FIG. 6, the cooling capacity of the cooling device 10 is increased to 10 [W]. Based on the cooling information received by the cooling information receiving unit 226, the cooling control unit 225 increases the cooling capacity so that the operable time becomes slightly longer than the remaining time. Therefore, in the cooling method of this embodiment, the reference time t ｃ By this time, the motor temperature has reached the target temperature T ｔ does not reach.

[0098] 7 is a flowchart showing an example of the flow of processing executed by the control device 2. In the control device 2, first, the remaining time calculation unit 222 analyzes the operation program and calculates the remaining time until the reference time (step SB1). For example, when a predetermined time has elapsed since the start of execution of the operation program, the remaining time calculation unit 222 calculates the remaining time to be 600 [s].

[0099] Next, the temperature information receiving unit 223 receives temperature information regarding the temperature of the motor detected by the sensor 9 (step SB2). The temperature information receiving unit 223 receives temperature information indicating that the temperature of the motor is 20° C., for example.

[0100] Next, the cooling information receiving unit 226 receives cooling information indicating the cooling capacity of the cooling device 10 (step SB3). ２ Then, information indicating that the rotation speed of the cooling fan is 600 [rpm] is received.

[0101] Next, the operation time calculation unit 224 calculates the remaining operation time of the motor based on at least the temperature information, the operation program, the thermal model, and the cooling information (step SB4). For example, the operation time calculation unit 224 calculates that the motor temperature will rise at a rate of 0.2°C per second based on information indicating the motor's root mean square current and root mean square rotation speed during the remaining time of 600 seconds. If the target temperature is 100°C, the operation time calculation unit 224 calculates the remaining operation time to be, for example, 400 seconds.

[0102] Finally, the cooling control unit 225 controls the cooling device 10, which cools the motor, based on the remaining time calculated by the remaining time calculation unit 222 and the operable time calculated by the operation time calculation unit 224 (step SB5). For example, if the remaining time is 600 [s] and the operable time is 400 [s], the remaining time is longer than the operable time, and therefore the cooling capacity of the cooling device 10 is insufficient. In this case, the cooling control unit 225 increases the cooling capacity of the cooling device 10.

[0103] The cooling control unit 225 calculates the cooling capacity of the cooling device 10 so that the operable time is, for example, 600 seconds or more (step SB4). The cooling control unit 225 calculates the cooling fan rotation speed to be, for example, 1000 rpm so that the operable time is 600 seconds or more. The cooling control unit 225 controls the cooling fan based on the calculated cooling fan rotation speed (step SB5).

[0104] The processes from step SB1 to step SB5 are repeatedly executed at predetermined time intervals during the execution of the program, which may be, for example, 10 seconds, as described above.

[0105] 8 is a block diagram showing an example of the functions of the control device 2 according to the third embodiment. In addition to the functions of the control device 2 according to the second embodiment, the control device 2 according to the third embodiment further includes an input receiving unit 227. The input receiving unit 227 is realized, for example, by the hardware processor 201 performing arithmetic processing using a system program stored in the ROM 203 and various data stored in the non-volatile memory 205.

[0106] The input receiving unit 227 receives input information input from outside the control device 2. For example, the input receiving unit 227 receives input information from the input / output device 3. The input information includes, for example, the target temperature T ｔ is.

[0107] The input receiving unit 227 receives, for example, the target temperature T ｔ When the input receiving unit 227 receives the temperature information, the operation time calculation unit 224 further calculates the operation possible time based on the input information received by the input receiving unit 227. That is, the operation time calculation unit 224 receives the temperature information, the operation program, the thermal model, the cooling information, and the target temperature T ｔ Calculate the available driving time based on this.

[0108] 9 shows an example of the flow of processing executed by the control device 2. In the control device 2, first, the remaining time calculation unit 222 analyzes the operation program and calculates the remaining time until the reference time (step SC1).

[0109] Next, the temperature information receiving unit 223 receives temperature information relating to the temperature of the motor detected by the sensor 9 (step SC2).

[0110] Next, the input receiving unit 227 receives input of input information (step SC3).

[0111] Next, the cooling information receiving unit 226 receives cooling information indicating the cooling capacity of the cooling device 10 (step SC4).

[0112] Next, the operation time calculation unit 224 calculates the operation time of the motor based on at least the temperature information, the operation program, the cooling information, and the input information (step SC5).

[0113] Finally, the cooling control unit 225 controls the cooling device 10 that cools the motor based on the remaining time calculated by the remaining time calculation unit 222 and the operable time calculated by the operation time calculation unit 224 (step SC6), and the process ends.

[0114] The processes from step SC1 to step SC6 are repeatedly executed at predetermined time intervals during the execution of the program, for example.

[0115] As described above, the cooling control unit 225 may perform control to stop the cooling device 10 or control to reduce the cooling capacity of the cooling device 10. In this case, the cooling control unit 225 may calculate the amount of energy saved compared to when the control to stop the cooling device 10 or the control to reduce the cooling capacity of the cooling device 10 is not performed.

[0116] 3, the cooling control unit 225 may calculate the difference between the energy consumed by the cooling device 10 in the conventional cooling method and the energy consumed by the cooling device 10 in the cooling method of the first embodiment. This difference is the saved energy. In this case, the control device 2 may, for example, cause the input / output device 3 to display information indicating the saved energy.

[0117] In the above-described embodiments, the motor cooling method was described for when one operating program is being executed. However, the cooling method of the present disclosure may also be applied when multiple operating programs are executed with machine stop periods in between. In this case, the operation time calculation unit 224 calculates the available operation time by taking into account not only the temperature information and the currently executing operating program, but also the machine stop periods during which no operating program is being executed.

[0118] Fig. 10 is an example of a graph showing the transition of the motor temperature, etc. In the example shown in Fig. 10, there is provided a first period during which a first operation program is executed, a second period following the first period during which a second operation program is executed, and a machine stop period during which no operation program is executed between the first period and the second period.

[0119] L21 shows the change in the motor temperature when the motor is cooled based on the conventional motor cooling method. L22 shows the change in the cooling capacity of the cooling device 10 when the motor is cooled based on the conventional motor cooling method. L23 shows the change in the target temperature T ｔ L24 shows the transition of the motor temperature when the motor is cooled based on the cooling method of this embodiment. L25 shows the transition of the motor cooling capacity when the motor is cooled based on the cooling method of this embodiment.

[0120] As shown by L21 and L22, in the conventional motor cooling method, the cooling capacity of the cooling device 10 is kept constant throughout the first period, the machine stop period, and the second period. In this case, the motor temperature rises during the first period, drops during the machine stop period, and rises during the second period to reach the target temperature.

[0121] On the other hand, in the cooling method of this embodiment, at the timing t ２１ The driving time calculation unit 224 calculates the driving time available at the timing t ２１ The operable time is calculated based on the cooling capacity of the cooling device 10 in the above.

[0122] Here, the operable time is the operable time when the control device 2 executes the first operation program, followed by a predetermined machine stop period, and then executes the second operation program.

[0123] The driving time calculation unit 224 first calculates the driving time at the timing t ２１In the above, the operation time calculation unit 224 calculates the motor temperature at the end of the first period, for example, using the above-mentioned Equation 2. Furthermore, the operation time calculation unit 224 calculates the motor temperature at the end of the machine stop period, for example, using the motor temperature at the end of the first period and the above-mentioned Equation 2. Furthermore, the operation time calculation unit 224 calculates the operable time in the second period based on the motor temperature at the end of the machine stop period, the second operation program, and the thermal model. The operation time calculation unit 224 adds up the operable time in the first period, the machine stop period, and the second period, thereby calculating the operable time in the case where the first operation program is executed, followed by a predetermined machine stop period, and then the second operation program is executed.

[0124] If the remaining time calculated by remaining time calculation unit 222 is longer than the operable time, cooling control unit 225 increases the cooling capacity of cooling device 10. Cooling control unit 225 increases the cooling capacity of cooling device 10 so that the temperature of the motor at the reference time, i.e., at the end of the second operation program, does not reach the target temperature.

[0125] As described above, the control device 2 includes a remaining time calculation unit 222 that analyzes the operation program and calculates the remaining time until the reference time, a temperature information receiving unit 223 that receives temperature information related to the temperature of the motor detected by the sensor 9, an operating time calculation unit 224 that calculates the operable time of the motor based on at least the temperature information, the operation program, and the thermal model, and a cooling control unit 225 that controls the cooling device 10 that cools the motor based on the remaining time calculated by the remaining time calculation unit 222 and the operable time calculated by the operating time calculation unit 224.

[0126] Therefore, the control device 2 can prevent the cooling device 10 from consuming more energy than necessary and the motor from overheating.

[0127] The control device 2 further includes a cooling information receiving unit 226 that receives cooling information indicating the cooling capacity of the cooling device 10, and the operation time calculation unit 224 further calculates the available operation time based on the cooling information received by the cooling information receiving unit 226. The cooling control unit 225 controls the start or stop of operation of the cooling device 10, or controls the increase or decrease of the cooling capacity of the cooling device 10.

[0128] Therefore, the control device 2 can appropriately control the cooling device 10 based on the current cooling capacity of the cooling device 10. As a result, the control device 2 can more effectively prevent the cooling device 10 from consuming more energy than necessary and the motor from overheating.

[0129] Furthermore, when the cooling control unit 225 performs control to stop the cooling device 10 or control to reduce the cooling capacity of the cooling device 10, it calculates the energy saved compared to when the control to stop the cooling device 10 or control to reduce the cooling capacity of the cooling device 10 is not performed. In this case, the control device 2 can, for example, display the saved energy on the input / output device 3.

[0130] The system further includes an input receiving unit 227 that receives input of the target temperature of the motor, and the operation time calculation unit 224 further calculates the available operation time based on the target temperature received by the input receiving unit 227. Therefore, the operator can input the target temperature of the motor according to the specifications of the motor. The operator can also easily change the target temperature.

[0131] The reference time is the end of the operation program, so the control device 2 can prevent the motor from overheating before the end of the operation program.

[0132] Furthermore, the operation time calculation unit 224 further calculates the available operation time based on information indicating machine stop periods during which no operation programs are being executed. Therefore, even when multiple operation programs are executed consecutively or with machine stop periods in between, the control device 2 can more effectively prevent the cooling device 10 from consuming more energy than necessary and the motor from overheating.

[0133] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible to these 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, these embodiments can also be implemented in combination.

[0134] The following are supplementary notes related to embodiments of the present disclosure. Supplementary Note [1] A control device comprising: a remaining time calculation unit that analyzes an operating program to calculate a remaining time until a reference time; a temperature information reception unit that receives temperature information related to the temperature of a motor detected by a sensor; an operation time calculation unit that calculates an operable time of the motor based on at least the temperature information, the operating program, and a thermal model; and a cooling control unit that controls a cooling device that cools the motor based on the remaining time calculated by the remaining time calculation unit and the operable time calculated by the operation time calculation unit. Supplementary Note [2] The control device according to Supplementary Note [1], further comprising a cooling information reception unit that receives cooling information indicating a cooling capacity of the cooling device, wherein the operation time calculation unit further calculates the operable time based on the cooling information received by the cooling information reception unit. Supplementary Note [3] The control device according to Supplementary Note [1] or [2], wherein the cooling control unit controls to start or stop operation of the cooling device, or control to increase or decrease the cooling capacity of the cooling device. Supplementary Note [4] The control device according to Supplementary Note [3], wherein, when performing control to stop the cooling device or control to reduce the cooling capacity of the cooling device, the cooling control unit calculates energy saved compared to when control to stop the cooling device or control to reduce the cooling capacity of the cooling device is not performed. Supplementary Note [5] The control device according to any of Supplements [1] to [4], further comprising an input receiving unit that receives an input of a target temperature of the motor, and the operation time calculation unit further calculates the operable time based on the target temperature received by the input receiving unit. Supplementary Note [6] The control device according to any of Supplements [1] to [5], wherein the reference time is the end of the operation program. Supplementary Note [7] The control device according to any of Supplements [1] to [6], wherein the operation time calculation unit further calculates the operable time based on information indicating a machine stop period during which the operation program is not being executed.

[0135] REFERENCE SIGNS LIST 1 Industrial machine 2 Control device 201 Hardware processor 202 Bus 203 ROM 204 RAM 205 Non-volatile memory 206 First interface 207 Axis control circuit 208 Spindle control circuit 209 PLC 210 I / O unit 211 Second interface 212 Third interface 221 Memory unit 222 Remaining time calculation unit 223 Temperature information reception unit 224 Operation time calculation unit 225 Cooling control unit 226 Cooling information reception unit 227 Input reception unit 3 Input / output device 4 Servo amplifier 5 Servo motor 6 Spindle amplifier 7 Spindle motor 8 Auxiliary equipment 9 Sensor 10 Cooling device

Claims

1. a remaining time calculation unit that analyzes the operation program and calculates the remaining time until a reference time; a temperature information receiving unit that receives temperature information regarding the temperature of the motor detected by the sensor; an operation time calculation unit that calculates an operable time of the motor based on the operation program, the temperature information, and a thermal model of the motor; a cooling control unit that controls a cooling device that cools the motor based on the remaining time calculated by the remaining time calculation unit and the operable time calculated by the operation time calculation unit; A control device comprising:

2. a cooling information receiving unit that receives cooling information indicating a cooling capacity of the cooling device; The control device according to claim 1 , wherein the operation time calculation unit further calculates the operable time based on the cooling information received by the cooling information reception unit.

3. The control device according to claim 1 or 2, wherein the cooling control unit controls the cooling device to start or stop operation, or controls the cooling device to increase or decrease cooling capacity.

4. The control device according to claim 3, wherein the cooling control unit calculates the energy saved when it controls to stop the cooling device or to reduce the cooling capacity of the cooling device compared to when it does not control to stop the cooling device or to reduce the cooling capacity of the cooling device.

5. an input receiving unit that receives an input of the target temperature of the motor; The control device according to claim 1 or 2, wherein the operation time calculation unit further calculates the available operation time based on the target temperature received by the input reception unit.

6. 3. The control device according to claim 1, wherein the reference time is the end time of the operation program.

7. The control device according to claim 1 or 2, wherein the operation time calculation unit further calculates the operable time based on information indicating a machine stop period during which the operation program is not being executed.