Control device and rotating device

Abstract

To provide a control apparatus capable of suppressing wear of a bearing part (component) even in a case where air or a foreign matter enters a pump chamber, and a rotation device.SOLUTION: The present invention relates to a control apparatus 100 for controlling a rotor. The control apparatus comprises an arithmetic processing device 210 and a storage device 220. A protection temperature Th for protecting a bearing part from friction heat, which is generated by friction with a shaft caused by rotation, is stored in the storage device. The arithmetic processing device includes: an acquisition section 230 for acquiring a temperature of the bearing part; a comparison and determination section 240 for acquiring the protection temperature from the storage device, comparing an acquired temperature acquired by the acquisition section with the protection temperature and determining which one of the protection temperature and the acquired temperature is higher; and a control section 250 for continuing the rotation of the rotor by reducing a rotation speed of the rotor or reducing torque of the rotor in a case where it is determined by the comparison and determination section that the acquired temperature is equal to or higher than the protection temperature.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The disclosure provided herein relates to control devices and rotating devices. [Background technology]

[0002] Patent Document 1 describes a control device that prevents components of a hydraulic pump in a pump chamber from wearing out due to idling. The control device controls the hydraulic pump by driving an electric motor. The control device determines whether the rotation speed of the electric motor is equal to or higher than a specified rotation speed, and if the rotation speed of the electric motor is equal to or higher than the specified rotation speed, determines that the hydraulic pump is idling and stops the electric motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-258033 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, if foreign matter gets into the pump chamber, the rotation speed of the electric motor is likely to fall below the specified rotation speed. In this case, the electric motor is not stopped even though the components of the hydraulic pump are prone to wear. If foreign matter gets into the pump chamber, it is difficult to suppress the wear of the components of the hydraulic pump.

[0005] Therefore, an object of the present disclosure is to provide a control device and a rotating device that are capable of suppressing wear of a bearing portion (constituent element) regardless of whether air or foreign matter has entered the pump chamber. [Means for solving the problem]

[0006] A control device according to one aspect of the present disclosure includes: A control device (100) for controlling a rotor in a rotating device (60) including a shaft (54) extending in one direction, a rotor (51) having an inner peripheral surface (55b) facing an outer peripheral surface (54a) of the shaft and rotating in a circumferential direction along the outer peripheral surface, a bearing portion (57) provided between the inner peripheral surface and the outer peripheral surface and rotating together with the rotor, and a pump chamber (61c) that houses the shaft, the rotor, and the bearing portion and through which cooling water (40) flows, A processor (210) and a memory device (220), A protection temperature (Th) for protecting the bearing from frictional heat generated by friction with the shaft due to rotation is stored in a storage device. The arithmetic processing device includes: An acquisition unit (230) that acquires a temperature of the bearing portion; a comparison and determination unit (240) that acquires a protection temperature from the storage device, compares the acquired temperature acquired by the acquisition unit with the protection temperature, and determines which of the protection temperature and the acquired temperature is higher; a control unit (250) that, when the comparison and determination unit determines that the acquired temperature is equal to or higher than the protection temperature, reduces the rotation speed of the rotor or reduces the torque of the rotor to continue rotation of the rotor, The drive temperature (T0), which is the temperature of the bearing when the rotor rotates at a speed capable of removing air or foreign matter entering the pump chamber, is further stored in the storage device, The comparison and determination unit further acquires a driving temperature from the storage device when the acquired temperature is lower than the protection temperature, compares the acquired temperature acquired by the acquisition unit with the driving temperature, and determines which of the driving temperature and the acquired temperature is lower; The control unit further increases the rotation speed of the rotating body or increases the torque of the rotating body to continue rotation of the rotating body when the comparison and determination unit determines that the acquired temperature is equal to or lower than the drive temperature. .

[0007] When air gets in, the bearing portion (57) rotates freely, and the temperature of the bearing portion (57) rises due to frictional heat generated between the bearing portion (57) and the shaft (54). When a foreign object gets in, the bearing portion (57) interferes, and the temperature of the bearing portion (57) rises due to frictional heat generated between the bearing portion (57) and the shaft (54). Therefore, when the acquired temperature is equal to or higher than the protection temperature (Th), it can be considered that air or a foreign object has got into the pump chamber (61c). Therefore, when it is determined that the acquired temperature is equal to or higher than the protection temperature (Th), the rotation speed or torque of the rotor (51) is reduced. This makes it possible to reduce friction between the bearing portion (57) and the shaft (54) regardless of whether air or foreign matter has entered the pump chamber (61c). It makes it possible to reduce wear of the bearing portion (57). It makes it possible to reduce thermal damage to the bearing portion (57).

[0008] A rotation device according to another aspect of the present disclosure includes: A rotating device (60) including: a shaft (54) extending in one direction; a rotor (51) having an inner peripheral surface (55b) facing an outer peripheral surface (54a) of the shaft and rotating in a circumferential direction along the outer peripheral surface; a bearing portion (57) provided between the inner peripheral surface and the outer peripheral surface and rotating together with the rotor; a pump chamber (61c) that houses the shaft, the rotor, and the bearing portion and through which cooling water (40) flows; and a control device (100) for controlling the rotor, A processor (210) and a memory device (220), A protection temperature (Th) for protecting the bearing from frictional heat generated by friction with the shaft due to rotation is stored in a storage device. The arithmetic processing device includes: An acquisition unit (230) that acquires a temperature of the bearing portion; a comparison and determination unit (240) that acquires a protection temperature from the storage device, compares the acquired temperature acquired by the acquisition unit with the protection temperature, and determines which of the protection temperature and the acquired temperature is higher; a control unit (250) that, when the comparison and determination unit determines that the acquired temperature is equal to or higher than the protection temperature, reduces the rotation speed of the rotor or reduces the torque of the rotor to continue rotation of the rotor, The drive temperature (T0), which is the temperature of the bearing when the rotor rotates at a speed capable of removing air or foreign matter entering the pump chamber, is further stored in the storage device, The comparison and determination unit further acquires a driving temperature from the storage device when the acquired temperature is lower than the protection temperature, compares the acquired temperature acquired by the acquisition unit with the driving temperature, and determines which of the driving temperature and the acquired temperature is lower; The control unit further increases the rotation speed of the rotating body or increases the torque of the rotating body to continue rotation of the rotating body when the comparison and determination unit determines that the acquired temperature is equal to or lower than the drive temperature. .

[0009] The rotating device (60) includes a control device (100). Whether air or foreign matter enters the pump chamber (61c), wear of the bearing portion (57) can be suppressed. Thermal damage to the bearing portion (57) can be suppressed.

[0010] It should be noted that the reference numbers in parentheses above merely indicate the corresponding relationship with the configurations described in the embodiments described below, and do not in any way limit the technical scope. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a schematic diagram illustrating a cooling system. [Diagram 2] FIG. 2 is a cross-sectional view illustrating a rotating device. [Diagram 3] FIG. 2 is a schematic diagram illustrating a control device and a rotation device. [Figure 4] 4 is a flowchart illustrating the control of the control device. [Diagram 5] 6 is a graph illustrating the relationship between the rotation speed of a rotor and the temperature change of a bearing when air or foreign matter has entered a pump chamber. [Figure 6] 11 is a flowchart illustrating a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, the same reference numerals may be used to designate parts corresponding to matters described in the preceding embodiment, and duplicated descriptions may be omitted. In each embodiment, when only a part of the configuration is described, the other embodiment described previously may be applied to the other parts of the configuration.

[0013] In addition to combinations of parts that are explicitly stated as possible in each embodiment, it is also possible to partially combine embodiments together, embodiments and variations, and variations together, even if not explicitly stated, provided that there are no particular problems with the combination.

[0014] (First embodiment) <Cooling system> A cooling system 1 shown in Fig. 1 can be mounted on a vehicle and used as a system for cooling a heat-generating component 10 of the vehicle. The cooling system 1 has a cooling device 21, a reserve tank 22, piping 30, and an electric water pump 60. In the drawings, the cooling device 21 is abbreviated as CS. The reserve tank 22 is abbreviated as RT. The electric water pump 60 corresponds to a rotating device. The heat-generating component 10 is cooled by circulating cooling water 40 through the piping 30.

[0015] Examples of the heat-generating parts 10 include a battery 11, a drive motor, an inverter, a power control unit, etc. In the drawings, the battery 11 is abbreviated as BATT, the drive motor as M1, the inverter as INV, and the power control unit as PCU.

[0016] In particular, when one of the heat-generating components 10 is a battery 11, deterioration of the battery 11 due to an increase in temperature can be reduced by cooling the battery 11 with the cooling system 1. By suppressing deterioration of the battery 11, the performance of the battery 11 can be stably exhibited for a long period of time.

[0017] The cooling device 21 is a device that exchanges heat between the cooling water 40 flowing inside the pipe 30 and a fluid such as air flowing over the surface of the cooling device 21. When the cooling system 1 is mounted on a vehicle, the cooling device 21 receives wind generated by the vehicle while it is traveling, thereby promoting heat exchange.

[0018] The reserve tank 22 is a device that also serves to remove air that is generated when the temperature of the cooling water 40 rises or that has unintentionally entered the piping 30. By removing the air, the pressure in the cooling system is stabilized. This suppresses the temperature rise of the cooling water 40 and improves the cooling efficiency of the cooling device 21.

[0019] <Mechanical configuration of electric water pump> An example of the mechanical configuration of electric water pump 60 will be described below with reference to Fig. 2. Electric water pump 60 is a device that functions as a power source for circulating coolant 40 inside pipe 30. Note that the configuration of electric water pump 60 is not limited to the configuration shown below. Hereinafter, three mutually perpendicular directions will be referred to as x-direction, y-direction, and z-direction. The extension direction of shaft 54, which will be described later, will be referred to as z-direction. The z-direction corresponds to one direction.

[0020] The electric water pump 60 includes a pump housing 61, a motor housing 62, a rotating body 51, an impeller 52, a fixed body 53, a shaft 54, a bearing portion 57, a cover 63, a thermistor 64, a heat conductive member 65, and a control device 100.

[0021] The pump housing 61 is a case that forms part of the outer shell of the pump chamber 61c. The pump housing 61 is formed with an inlet 61a through which the cooling water 40 flows from the pipe 30 into the pump chamber 61c, and a removal port 61b through which the cooling water 40 is removed from the pump chamber 61c to the pipe 30. The rotor 51, the impeller 52, a part of the shaft 54, and a bearing 57 are disposed inside the pump chamber 61c. The cooling water 40 inside the pump chamber 61c is pressure-fed to the pipe 30 by the rotation of the impeller 52. This allows the cooling water 40 to circulate between the pump chamber 61c and the pipe 30.

[0022] The motor housing 62 is a housing fixed to the outside of the pump housing 61. The motor housing 62 includes a rotating body accommodating portion 62a and a fixed body accommodating portion 62b. The rotating body accommodating portion 62a is disposed in the center of the motor housing 62. In a radial direction perpendicular to the z direction, the fixed body accommodating portion 62b is disposed in an annular shape on the outside of the rotating body accommodating portion 62a of the motor housing 62.

[0023] The rotor 51 is accommodated in the rotor accommodating portion 62a. The fixed body 53 is accommodated in the fixed body accommodating portion 62b. The rotor 51 and the fixed body 53 are disposed facing each other in the radial direction. The rotor 51 and the fixed body 53 constitute a motor 50. The motor 50 is abbreviated as M2 in the drawings.

[0024] Further, a shaft 54 ​​extending in the z direction is provided at the radial center of the rotor accommodating portion 62a. The shaft 54 ​​is a material having higher heat resistance and higher thermal conductivity than a bearing, such as a metal. The shaft 54 ​​extends so as to penetrate a bottom 62c of the rotor accommodating portion 62a. As an example, the shaft 54 ​​is fixed to the bottom 62c. A rotor 51 is provided between a wall portion 62d of the rotor accommodating portion 62a and the shaft 54. The rotor 51 is provided so as to be rotatable around the shaft 54 ​​in the circumferential direction around the z direction.

[0025] The rotor 51 includes a support portion 55 and a rotor magnet 56. The support portion 55 has a generally cylindrical shape recessed in the z direction. The rotor magnet 56 is provided on an outer support surface 55a of the support portion 55. A bearing portion 57 is provided on an inner support surface 55b of the support portion 55.

[0026] The bearing portion 57 is a member such as resin that has a lower heat resistance than the shaft. The bearing portion 57 has a cylindrical shape that penetrates in the z direction. The rotor 51 is provided around the shaft 54 ​​in such a manner that the bearing inner peripheral surface 57a faces the shaft outer peripheral surface 54a in the radial direction. The rotor 51 can rotate around the shaft 54 ​​together with the bearing portion 57 in the circumferential direction.

[0027] Further, the rotor 51 is integrally formed with the impeller 52 at an end 51a separated from the bottom 62c of the rotor accommodating portion 62a. As the rotor 51 rotates, the impeller 52 can rotate.

[0028] The pump chamber 61c indicates a space partitioned by the pump housing 61 and the motor housing 62. As described above, the pump chamber 61c accommodates the rotor 51, the impeller 52, a part of the shaft 54, and the bearing portion 57. When the rotor 51 rotates in the circumferential direction around the bearing portion 57 in the above-described manner, the cooling water 40 in the pump chamber 61c can be pumped to the pipe 30 via the impeller 52.

[0029] <Control device> 2 and 3, the control device 100 includes a control board 110, a microcomputer 200, and various circuits. The microcomputer 200 and the various circuits are provided on the control board 110. The microcomputer 200 and the various circuits are electrically connected via wiring (not shown).

[0030] The control board 110 is provided on the end side of the shaft 54 ​​that is separated from the impeller 52. The control board 110 is attached to, for example, the motor housing 62 via a fixing part (not shown). The control board 110 is covered by a cover 63, and is housed in a space partitioned from the pump chamber 61c. The cover 63 is attached to the motor housing 62. This prevents external dust and moisture from adhering to the control board 110.

[0031] The thermistor 64 is a temperature sensor that utilizes the fact that its own resistance value changes with a change in temperature. Thermistor 64 is provided on the lower surface of control board 110. Thermistor 64 is electrically connected to microcomputer 200 via wiring provided on control board 110.

[0032] The location of the thermistor 64 is not limited to the lower surface of the control board 110. The thermistor 64 may be provided on the upper surface of the control board 110. The thermistor 64 may be provided in a location other than the control board 110. The thermistor 64 may be provided in the bearing portion 57. Thermistor 64 may be provided in the shaft 54. Thermistor 64 may be provided anywhere as long as it is possible to measure the temperature of the bearing portion 57. Another temperature sensor may be provided instead of the thermistor 64.

[0033] The heat conductive member 65 is a member having a higher thermal conductivity than the bearing portion 57. The heat conductive member 65 contains a material such as silicone. The heat conductive member 65 is in a gel state. The heat conductive member 65 may contain metal or filler having a high thermal conductivity in silicone. The heat conductive member 65 may not be in a gel state, but may be in a sheet state. The heat conductive member 65 is provided between the thermistor 64 and the shaft 54. Frictional heat generated by friction between the shaft 54 ​​and the bearing portion 57 can be transferred to the thermistor 64 via the shaft 54 ​​and the heat conductive member 65. By providing the heat conductive member 65 between the thermistor 64 and the shaft 54, the loss of frictional heat can be suppressed and the heat can be efficiently transferred to the thermistor 64. The frictional heat generated by friction between the shaft 54 ​​and the bearing portion 57 can also be said to be frictional heat received by the bearing portion 57 due to friction with the shaft 54.

[0034] <Electrical configuration of the motor control device> 3, the control device 100 includes a microcomputer 200, a driver circuit 300, and a communication circuit 400. Power is supplied to the microcomputer 200 and various circuits from a battery 11. An ignition switch 12 that controls on / off of power supply to the microcomputer 200 is provided between the battery 11 and the microcomputer 200. In the drawings, the driver circuit 300 is abbreviated as DC, the communication circuit 400 as CC, and the ignition switch 12 as IG.

[0035] The driver circuit 300 is provided between the battery 11 and the motor 50. The driver circuit 300 converts a direct current supplied from the battery 11 into an alternating current for driving the motor 50. The driver circuit 300 is electrically connected to the battery 11, the motor 50, and also to the microcomputer 200. The driver circuit 300 controls the motor 50 according to instructions from the microcomputer 200.

[0036] The communication circuit 400 is provided between the host ECU 70 and the microcomputer 200. The communication circuit 400 is a circuit capable of transmitting information between the microcomputer 200 and the host ECU 70. The rotation state of the motor 50 can be transmitted to the host ECU 70 via the communication circuit 400.

[0037] The microcomputer 200 includes a processor 210 such as a CPU, a storage device 220 such as a ROM or RAM, an IO interface, etc. The ROM stores programs executed by the CPU and data.

[0038] The data stored include a protection temperature Th and a drive temperature T0. The protection temperature Th and the drive temperature T0 are temperatures that are used as a guide when the control device 100 drives the rotor 51. The protection temperature Th is a temperature for protecting the bearing portion 57 from frictional heat. The protection temperature Th is lower than the temperature at which the bearing portion 57 begins to be thermally damaged. The drive temperature T0 is the temperature of the bearing portion 57 when the rotor 51 rotates at a speed that can remove air or foreign matter that has entered the pump chamber 61c.

[0039] The RAM temporarily stores the results of calculations performed by the arithmetic processing unit 210 and signals acquired through the IO interface. The CPU executes programs stored in the ROM while utilizing the temporary storage function of the RAM, thereby enabling the microcomputer 200 to execute various functions.

[0040] In terms of functions, the arithmetic processing device 210 includes an acquisition unit 230, a comparison and determination unit 240, and a control unit 250. The functions are also referred to as functional blocks. It can also be said that the program includes the functions of the acquisition unit 230, the comparison and determination unit 240, and the control unit 250. Details of the acquisition unit 230, the comparison and determination unit 240, and the control unit 250 will be described later.

[0041] In the drawings, the acquisition unit 230 is abbreviated as ACU, the comparison and judgment unit 240 as CJU, and the control unit 250 as CU. The storage device 220 is abbreviated as MD.

[0042] The control device 100 may also be called an electronic control unit (ECU). The control device 100 or the control system is provided by an algorithm as a plurality of logics called an if-then-else format, or an algorithm as a trained model tuned by machine learning, for example, a neural network.

[0043] The control device 100 is provided by a control system including at least one computer. The control system may include multiple computers linked by data communication devices. The computer includes at least one processor that is hardware (hardware processor). The hardware processor can be provided by the following (i), (ii), or (iii):

[0044] (i) The hardware processor may be at least one processor core that executes a program stored in at least one memory. In this case, the computer is provided with at least one memory and at least one processor core. The processor core is called a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a RISC-CPU, etc. The memory is also called a storage medium. The memory is a non-transient and tangible storage medium that non-temporarily stores "programs and / or data" that can be read by the processor. The storage medium is provided by a semiconductor memory, a magnetic disk, an optical disk, or the like. The program may be distributed alone or as a storage medium on which the program is stored.

[0045] (ii) The hardware processor may be a hardware logic circuit. In this case, the computer is provided by a digital circuit including a large number of programmed logic units (gate circuits). The digital circuit is also called a logic circuit array, e.g., ASIC, FPGA, SoC, PGA, CPLD, etc. The digital circuit may include a memory that stores programs and / or data. The computer may be provided by an analog circuit. The computer may be provided by a combination of a digital circuit and an analog circuit.

[0046] (iii) The hardware processor may be a combination of (i) and (ii) above. (i) and (ii) may be located on different chips or on a common chip. In these cases, the (ii) part may also be called an accelerator.

[0047] The control device 100, the signal sources and the controlled objects provide various elements, at least some of which may be referred to as blocks, modules or sections. Furthermore, the elements included in the control system are referred to as functional means only if this is the case.

[0048] The microcomputer 200 and its techniques may be implemented by a special-purpose computer provided by configuring a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the microcomputer 200 and its techniques described in this disclosure may be implemented by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits.

[0049] The microcomputer 200 and the method thereof may be implemented by a special-purpose computer configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured by hardware logic circuits. Also, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by the computer.

[0050] <Rotational speed of the rotor and temperature of the bearing> Before describing the flow of the control device 100 in this embodiment, a description will be given of the correlation between the rotation speed of the rotor 51 and the temperature of the bearing portion 57. As an example, the correlation between the rotation speed of the rotor 51 and the temperature of the bearing portion 57 will be described in the case where air gets mixed into the pump chamber 61c when replacing or refilling the coolant 40 during vehicle maintenance or the like.

[0051] When air enters the pump chamber 61c, the air may accumulate in the pump chamber 61c. In particular, when air accumulates between the shaft 54 ​​and the bearing 57, the rotor 51 is likely to rotate idly. In this case, the rotation speed of the rotor 51 becomes faster compared to when no air accumulates inside the pump chamber 61c. Friction may easily occur between the bearing 57 and the shaft 54, or the frictional force may easily increase.

[0052] As described above, the frictional heat generated by friction between the shaft 54 ​​and the bearing portion 57 can also be said to be frictional heat received by the bearing portion 57 due to friction with the shaft 54. The temperature of the bearing inner surface 57a of the bearing portion 57 is likely to increase due to the frictional heat. As a result, the bearing inner surface 57a is likely to be thermally damaged. In the following, for ease of explanation, the temperature of the bearing inner surface 57a is simply referred to as the temperature of the bearing portion 57.

[0053] As another example, a correlation between the rotation speed of the rotor 51 and the temperature of the bearing portion 57 in a case where foreign matter enters the pump chamber 61c together with the cooling water 40 from the components constituting the cooling system 1 will be described.

[0054] If a foreign object gets into the pump chamber 61c, the foreign object may be caught by the impeller 52 or may come into contact with the rotor 51 and the shaft 54, causing the relative positions of the rotor 51 and the shaft 54 ​​to fluctuate, resulting in interference between them. In particular, if a foreign object gets between the shaft 54 ​​and the bearing 57, friction is likely to occur between the bearing 57 and the shaft 54 ​​when the rotor 51 is rotated. In that case, the rotation speed of the rotor 51 becomes slower than when no foreign object has gotten inside the pump chamber 61c. In addition, the temperature of the bearing 57 is likely to rise due to frictional heat. The bearing 57 is likely to wear out. The bearing 57 is likely to be thermally damaged.

[0055] Therefore, in this embodiment, the control device 100 monitors the temperature of the bearing portion 57, and when the temperature is equal to or higher than the protection temperature Th, the control device 100 controls the rotation speed of the rotor 51 to be reduced. As a result, regardless of whether air or foreign matter has entered the pump chamber 61c, friction between the shaft 54 ​​and the bearing portion 57 is reduced. Wear of the bearing portion 57 is reduced. Thermal damage to the bearing portion 57 is reduced. Accordingly, the temperature of the bearing portion 57 is reduced. Furthermore, when the temperature reaches the protection temperature Th, the control device 100 allows the rotor 51 to continue rotating while reducing the rotation speed without stopping the rotation. By continuously rotating the rotor 51, air and foreign matter can be actively removed from the pump chamber 61c.

[0056] However, if the rotation speed is reduced so that the temperature of the bearing 57 falls below the drive temperature T0, it becomes difficult to actively remove air and foreign matter from the pump chamber 61c. Therefore, when the temperature falls below the drive temperature T0, the control device 100 controls the rotation speed of the rotor 51 to increase so that the removal of air and foreign matter continues. This makes it possible to both prevent thermal damage to the bearing 57 and remove air or foreign matter.

[0057] <Bearing protection control> The flowchart in Fig. 4 shows the control of the control device 100 applied to the cooling system 1 in Fig. 1. In this explanation, in order to clarify which component included in the control device 100 performs a process, the subject of a sentence explaining the process will be written as the component of the motor control device that executes the process, instead of the control device 100, as necessary.

[0058] When the ignition switch 12 is turned on, a command speed V0 is transmitted from the host ECU 70 to the control unit 250. The rotating body 51 starts to rotate based on the command speed V0. At the same time, the control device 100 starts to execute the flowchart shown in FIG. 4. The flowchart is repeated at predetermined time intervals. The flowchart may be continuously repeated until the ignition switch 12 is turned off.

[0059] In step S510, the acquisition unit 230 acquires the temperature of the bearing portion 57. The heat of the bearing portion 57 is transferred to the thermistor 64 via the shaft 54 ​​and the thermal conductive member 65. The thermistor 64 has a property that its resistance value changes when heat is applied. The acquisition unit 230 acquires the temperature of the bearing portion 57 by converting the resistance value of the thermistor 64 into temperature.

[0060] In step S520, the comparison and determination unit 240 obtains the protection temperature Th from the storage device 220, and determines whether the temperature of the bearing portion 57 obtained in step S510 is equal to or higher than the protection temperature Th.

[0061] If it is determined in step S520 that the acquired temperature of the bearing portion 57 is equal to or higher than the protection temperature Th, then in step S530, the rotation speed of the rotor 51 is decreased by a preset amount N1 (rpm) from the command speed V0, and the process proceeds to END. Note that, from the second flow onwards, the rotation speed may be controlled to be decreased by N1 (rpm) from the actual rotation speed or the rotation speed set in step S530 of the previous flow. In the drawing, the actual rotation speed or the rotation speed set in step S530 of the previous flow is indicated as V. If the acquired temperature is equal to or higher than the protection temperature Th, it can be considered that air has entered the pump chamber 61c and the temperature is rising.

[0062] If it is determined in step S520 that the temperature of bearing portion 57 is less than protection temperature Th, then in step S540 comparison / determination unit 240 acquires driving temperature T0 from storage device 220. Then it is determined whether or not the acquired temperature of bearing portion 57 acquired in step S510 is equal to or lower than driving temperature T0. If it is determined in step S540 that the acquired temperature of bearing portion 57 is equal to or lower than driving temperature T0, then in step S550 control unit 250 increases the rotation speed of rotating body 51 by a preset amount N2 (rpm) from the actual rotation speed or the rotation speed set in the previous flow, and proceeds to END.

[0063] If the acquired temperature is equal to or lower than the driving temperature T0, it can be considered that the foreign matter has been removed, or that the foreign matter has not been removed but the temperature of the bearing portion 57 has dropped and there is a margin for heat resistance. In step S550, in order to remove the foreign matter, the rotation speed of the rotor 51 is increased to a degree that does not cause thermal damage to the bearing portion 57. Also, the value of N2 (rpm) may be the same as or different from the value of N1 (rpm). As described above, since the control unit 250 changes the rotation speed in increments of N1 (rpm) or N2 (rpm), it can also be said that the control unit 250 controls the rotation speed in increments of a predetermined speed.

[0064] However, in step S550, the rotation speed can be increased by N2 (rpm) only when the rotation speed of the rotating body 51 does not exceed the command speed V0. For example, in the flow immediately after the ignition switch 12 is turned on, since the command speed V0 is transmitted from the upper ECU 70, the rotation speed does not increase even if the acquired temperature is lower than the driving temperature T0 in step S540. As a result, in the flow immediately after the ignition switch 12 is turned on, the command speed V0 is maintained. Note that, specifically, "immediately after the ignition switch 12 is turned on" refers to a time before time t1 shown in FIG. 5 when the temperature is lower than the driving temperature T0. In addition, the rotation speed is prevented from becoming higher than the command speed V0 after time t4 shown in FIG. 5.

[0065] If it is determined in step S540 that the acquired temperature of the bearing portion 57 is higher than the driving temperature T0, the control portion 250 maintains the rotation speed of the rotating body 51 in step S560. Then, the process proceeds to the end. Note that even if the acquired temperature is higher than the driving temperature T0 before time t1, it is possible to proceed from step S540 to step S560 and maintain the command speed V0. From time t0 to time t1, if the acquired temperature is equal to or lower than the protection temperature Th, the command speed V0 is maintained regardless of whether the acquired temperature is higher or lower than the driving temperature T0.

[0066] 5 shows the relationship between the rotation speed of rotor 51 over time and the temperature of bearing 57. The rotation speed of rotor 51 is determined based on instructions from control unit 250. In the drawing, the rotation speed is indicated as "rotation speed," and the temperature of bearing 57 is indicated as "temperature."

[0067] When the rotor 51 rotates at a constant command speed V0, for example, if air or foreign matter enters the pump chamber 61c between time t0 and time t1, the temperature of the bearing 57 gradually increases. When the comparison and determination unit 240 determines at time t1 that the temperature of the bearing 57 has reached the protection temperature Th (step S520), the control unit 250 reduces the rotation speed by N1 (rpm) at a time (step S530).

[0068] When the rotation speed of the rotor 51 starts to decrease by the control unit 250, the temperature of the bearing 57 starts to decrease later than time t1. Specifically, the temperature of the bearing 57 reaches a maximum temperature higher than the protection temperature Th, and then starts to decrease later than time t1. The rotation speed is decreased by N1 (rpm) at a time until the temperature of the bearing 57 reaches the protection temperature Th again at time t2. As an example, the rotation speed of the rotor 51 when the temperature of the bearing 57 reaches the protection temperature Th again after the rotation speed is decreased by N1 (rpm) is hereinafter referred to as a first speed V1.

[0069] The maximum temperature is lower than the thermal damage temperature at which thermal damage begins to occur in the bearing portion 57. The protection temperature Th is preset so that the maximum temperature becomes lower than the thermal damage temperature when the rotation speed is decreased by N1 (rpm) from time t1. In terms of Fig. 5, it can be said that the rotation speed is decreased linearly from the command speed V0 to the first speed V1 by N1 (rpm) from time t1 to time t2.

[0070] When the temperature of bearing 57 reaches protection temperature Th at time t2, control unit 250 stops reducing the rotational speed of rotor 51. Rotor 51 rotates at first speed V1. However, the temperature of bearing 57 cannot keep up with the change in rotational speed and continues to decrease. When comparison / determination unit 240 determines at time t3 that the temperature of bearing 57 has reached drive temperature T0 (step S540), control unit 250 increases the rotational speed by N2 (rpm) at a time (step S550).

[0071] When the rotation speed starts to increase by the control unit 250, the temperature of the bearing 57 starts to rise after time t3. Specifically, the temperature of the bearing 57 reaches a minimum temperature lower than the driving temperature T0, and then starts to rise after time t3. As an example, the rotation speed is increased by N2 (rpm) at a time when the temperature of the bearing 57 again reaches the driving temperature T0, and the rotation speed of the rotor 51 is hereinafter referred to as a second speed V2.

[0072] The minimum temperature is higher than the non-removal temperature when the rotation speed is reduced to such an extent that air or foreign matter entering the pump chamber 61c cannot be removed. The drive temperature T0 is preset so that the minimum temperature becomes higher than the non-removal temperature when the rotation speed is increased by N2 (rpm) from time t3. Based on FIG. 5, it can be said that the rotation speed is increased linearly from the first speed V1 to the second speed V2 by N2 (rpm) from time t3 to time t4.

[0073] When the temperature of the bearing portion 57 reaches the driving temperature T0 at time t4 (step S540), the control unit 250 stops increasing the rotation speed of the rotor 51. The control unit 250 maintains the rotation speed of the rotor 51. (Step S560) The rotor 51 rotates at the second speed V2. The temperature of the bearing portion 57 cannot follow the change in the rotation speed and continues to rise. Although the temperature of the bearing portion 57 continues to rise, it becomes constant at a temperature between the driving temperature T0 and the protection temperature Th. It is assumed that when air and foreign matter are removed from the pump chamber 61c, the temperature of the bearing portion 57 decreases so as to approach the temperature of the bearing portion 57 during normal operation. In that case, the rotation speed of the rotor 51 increases by N2 (rpm) at step S550 until it reaches the command speed V0. In other words, the rotation speed of the rotor 51 is controlled not to exceed the command speed V0. When the air and foreign matter are removed from the pump chamber 61c, the rotor 51 rotates based on the command speed V0.

[0074] Hereinafter, the temperature of the bearing portion 57 when no air or foreign matter has entered the pump chamber 61c and the rotor 51 is operating normally as expected is defined as the normal temperature TN. The normal temperature TN is lower than the drive temperature T0 and the protection temperature Th. The temperatures are lowest in the order of protection temperature Th, drive temperature T0, and normal temperature TN. Protection temperature Th is higher than drive temperature T0, which is higher than the normal temperature TN. The temperature difference between the normal temperature TN and drive temperature T0 is greater than the temperature difference between drive temperature T0 and protection temperature Th.

[0075] <Show Results> The microcomputer 200 transmits the rotational state of the rotating body 51 to the host ECU 70 via the communication circuit 400. The rotational state of the rotating body 51 is transmitted from the host ECU 70 to an external device 80. The external device 80 includes a display and the like. The host ECU 70 controls the display on the display based on the determined rotational state. This allows a mechanic to recognize that an abnormality has occurred in the rotational state of the rotating body 51 from the display on the display.

[0076] The control device 100 transmits a "low rotation state" to the host ECU 70 at the point in time when the control is performed to reduce the rotation speed below the command speed V0. In this case, the host ECU 70 that receives the signal may determine that the water pump is abnormal and display "low rotation state" on the display. The control device 100 may also always transmit the actual rotation speed to the host ECU 70. In this case, when the actual rotation speed is less than the command speed V0, the host ECU 70 may determine that the water pump is abnormal and display "low rotation state" or "actual rotation speed" on the display.

[0077] Since the flowchart starts when the ignition switch 12 is turned on, the driver can recognize the rotation state of the rotating body 51 while driving via the display. Even if an abnormality occurs in the rotation state of the rotating body 51 while driving, the driver can stop by a dealer without a long time having passed since the occurrence of the abnormality.

[0078] <Action and effect> The control device 100 monitors the temperature of the bearing 57 provided around the shaft 54 ​​in the pump chamber 61c, and performs control to reduce the rotation speed of the rotor 51 when the temperature reaches a protection temperature Th. The acquisition unit 230 acquires the temperature of the bearing 57. The comparison and determination unit 240 acquires the protection temperature Th from the storage device 220, and determines whether the acquired temperature of the bearing 57 is equal to or higher than the protection temperature Th. When the comparison and determination unit 240 determines that the temperature of the bearing 57 is equal to or higher than the protection temperature, the control unit 250 reduces the rotation speed of the rotor 51 at a constant rate to a predetermined value.

[0079] When air gets in, bearing 57 spins freely, and the temperature of bearing 57 rises due to frictional heat generated between shaft 54. When foreign matter gets in, bearing 57 interferes, and the temperature of bearing 57 rises due to frictional heat generated between shaft 54. Therefore, when the acquired temperature is equal to or higher than protection temperature Th, it can be considered that air or foreign matter has got into pump chamber 61c.

[0080] In this embodiment, since the above-described control device 100 is provided, the rotation speed of the rotor 51 can be reduced when the temperature of the bearing 57 reaches the protection temperature Th, regardless of whether air or foreign matter has entered the pump chamber 61c. As the rotation speed of the rotor 51 decreases, friction between the shaft 54 ​​and the bearing 57 is reduced. Wear of the bearing 57 is suppressed. Thermal damage to the bearing 57 is suppressed. Since the bearing 57 is made of resin, it is particularly important to prevent it from melting due to heat.

[0081] Furthermore, when the temperature reaches the protection temperature Th, the control device 100 does not stop the rotation of the rotor 51, but continues the rotation while reducing the rotation speed. By continuously rotating the rotor 51, air and foreign matter can be actively removed from the pump chamber 61c. Moreover, air and foreign matter can be actively removed from the pump chamber 61c regardless of the layout.

[0082] However, if the rotation speed is reduced to the extent that the temperature of the bearing portion 57 falls below the drive temperature T0, it becomes difficult to actively remove air and foreign matter from the pump chamber 61c. Therefore, when the drive temperature T0 is reached, the control device 100 controls the rotation speed of the rotor 51 to be increased so that the removal of air and foreign matter can be continued.

[0083] Specifically, when it is determined that the temperature of bearing portion 57 is lower than protection temperature Th, comparison and determination unit 240 acquires driving temperature T0 from storage device 220 and determines whether the acquired temperature of bearing portion 57 is equal to or lower than driving temperature T0. When comparison and determination unit 240 determines that the acquired temperature of bearing portion 57 is equal to or lower than driving temperature T0, control unit 250 increases the rotation speed at a constant rate up to a predetermined value.

[0084] In this way, the control device 100 controls the rotation speed of the rotor 51 to increase so that the removal of air or foreign matter continues even when the temperature of the bearing portion 57 reaches the drive temperature T0. This makes it possible to both prevent thermal damage to the bearing portion 57 and remove the air or foreign matter.

[0085] If it is determined in step S540 that the acquired temperature is equal to or lower than the driving temperature T0, the control device 100 repeats the flow to increase the rotation speed of the rotating body 51 to the second speed V2. The second speed V2 is a speed that is set lower than the speed at which the temperature of the bearing portion 57 reaches the protection temperature Th. This prevents the bearing portion 57 from being thermally damaged as a result of the rotation speed of the rotating body 51 being increased too much in step S550.

[0086] Furthermore, the temperature difference between the normal temperature TN and the drive temperature T0 is greater than the temperature difference between the drive temperature T0 and the protection temperature Th. Air or foreign matter can be efficiently removed from the pump chamber 61c without the temperature of the bearing portion 57 reaching the protection temperature Th.

[0087] Second embodiment In the first embodiment, the rotation speed of the rotor 51 is controlled in steps S530 and S550. In the second embodiment, the torque of the rotor 51 may be controlled instead of the rotation speed of the rotor 51 in steps S630 and S650 as shown in Fig. 6. In the drawing, the torque is indicated as Tr.

[0088] In step S610, the temperature of bearing portion 57 is acquired, and if it is determined in step S620 that the acquired temperature of bearing portion 57 is equal to or higher than protection temperature Th, in step S630 control portion 250 performs control to decrease the torque of rotating body 51 by a preset N3 (N·m). If it is determined in step S640 that the acquired temperature of bearing portion 57 is equal to or lower than driving temperature T0, in step S650 control portion 250 performs control to increase the torque of rotating body 51 by a preset N4 (N·m).

[0089] If it is determined in step S640 that the acquired temperature of the bearing portion 57 is higher than the driving temperature T0, in step S660 the control portion 250 performs control to maintain the torque of the rotating body 51. Note that in step S650, control is performed to increase the torque by N4 (N·m) only if the command torque does not exceed Tr0. In other words, the torque of the rotating body 51 is controlled so as not to exceed the command torque Tr0. This provides the same effects as the first embodiment.

[0090] Third embodiment In the third embodiment, when controlling the rotor 51 in steps S530, S550, S630, and S650, in addition to the control in the first or second embodiment, the rotation direction of the rotor 51 may be reversed, thereby removing air or foreign matter that has entered the pump chamber 61c.

[0091] (Fourth embodiment) In the first embodiment, the control device 100 including the microcomputer 200 is powered on when the ignition switch 12 is turned on. In a fourth embodiment, the microcomputer 200 may be in a sleep state when the ignition switch 12 is turned off, and may be released from the sleep state and start operating when the ignition switch 12 is turned on.

[0092] (Other embodiments) Although the present disclosure has been described based on the embodiment, it is understood that the present disclosure is not limited to the embodiment or structure. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, although various combinations and forms are shown in the present disclosure, other combinations and forms including only one element, more than one, or less than one element are also within the scope and concept of the present disclosure. [Explanation of symbols]

[0093] 12... ignition switch, 40... cooling water, 51... rotating body, 54... shaft, 54a... shaft outer peripheral surface, 55b... support inner peripheral surface, 57... bearing portion, 60... electric water pump, 61c... pump chamber, 64... thermistor, 65... heat conductive member, 70... host ECU, 80... external device, 100... control device, 110... control board, 210... arithmetic processing device, 220... storage device, 230... acquisition unit, 240... comparison and judgment unit, 250... control unit, 400... communication circuit, Th... protection temperature, T0... driving temperature, TN... normal temperature, V0... command speed

Claims

1. A control device (100) for controlling the rotating body in a rotating device (60) including a shaft (54) extending in one direction, a rotating body (51) having an inner peripheral surface (55b) facing an outer peripheral surface (54a) of the shaft and rotating in a circumferential direction along the outer peripheral surface, a bearing portion (57) provided between the inner peripheral surface and the outer peripheral surface and rotating together with the rotating body, and a pump chamber (61c) that houses the shaft, the rotating body, and the bearing portion and through which cooling water (40) flows, The present invention includes a processor (210) and a memory device (220), a protection temperature (Th) for protecting the bearing portion from frictional heat generated by friction with the shaft due to rotation is stored in the storage device; The arithmetic processing device includes: An acquisition unit (230) that acquires the temperature of the bearing portion; a comparison and determination unit (240) that acquires the protection temperature from the storage device, compares the acquired temperature acquired by the acquisition unit with the protection temperature, and determines which of the protection temperature and the acquired temperature is higher; a control unit (250) that, when the comparison and determination unit determines that the acquired temperature is equal to or higher than the protection temperature, reduces a rotation speed of the rotating body or reduces a torque of the rotating body to continue rotation of the rotating body, a drive temperature (T0) which is the temperature of the bearing portion when the rotor rotates at a speed capable of removing air or foreign matter entering the pump chamber is further stored in the storage device; the comparison and determination unit further acquires the driving temperature from the storage device when the acquired temperature is lower than the protection temperature, compares the acquired temperature acquired by the acquisition unit with the driving temperature, and determines which of the driving temperature and the acquired temperature is lower; The control unit further includes a control device that, when the comparison and judgment unit determines that the acquired temperature is lower than the driving temperature, increases the rotation speed of the rotating body or increases the torque of the rotating body to continue rotation of the rotating body.

2. The control device according to claim 1, wherein the control unit is capable of increasing the rotational speed of the rotating body until it reaches a preset command speed (V0) when the comparison and judgment unit determines that the acquired temperature is equal to or lower than the drive temperature.

3. the protection temperature is higher than the driving temperature; 3. The control device according to claim 1, wherein the drive temperature is higher than a normal temperature (TN) which is a temperature of the bearing portion in a normal state in which the air or the foreign matter does not enter the pump chamber.

4. The control device according to claim 1 or 2, wherein the control unit controls the rotation speed of the rotating body in increments of a predetermined speed.

5. The control device according to claim 1 or 2, further comprising a communication circuit (400) that transmits a state of the rotating body after the rotation of the rotating body is controlled by the control unit to a host ECU (70) connected to an external device (80).

6. 3. The control device according to claim 1, wherein the control unit controls the rotating body only when an ignition switch (12) provided in a vehicle is on.

7. 3. The control device according to claim 1, wherein the control unit rotates the rotating body in a direction opposite to a normal direction.

8. A rotating device (60) comprising: a shaft (54) extending in one direction; a rotating body (51) having an inner peripheral surface (55b) facing an outer peripheral surface (54a) of the shaft and rotating in a circumferential direction along the outer peripheral surface; a bearing portion (57) provided between the inner peripheral surface and the outer peripheral surface and rotating together with the rotating body; a pump chamber (61c) that houses the shaft, the rotating body, and the bearing portion and through which cooling water (40) flows; and a control device (100) for controlling the rotating body, The present invention includes a processor (210) and a memory device (220), a protection temperature (Th) for protecting the bearing portion from frictional heat generated by friction with the shaft due to rotation is stored in the storage device; The arithmetic processing device includes: An acquisition unit (230) that acquires the temperature of the bearing portion; a comparison and determination unit (240) that acquires the protection temperature from the storage device, compares the acquired temperature acquired by the acquisition unit with the protection temperature, and determines which of the protection temperature and the acquired temperature is higher; a control unit (250) that, when the comparison and determination unit determines that the acquired temperature is equal to or higher than the protection temperature, reduces a rotation speed of the rotating body or reduces a torque of the rotating body to continue rotation of the rotating body, a drive temperature (T0) which is the temperature of the bearing portion when the rotor rotates at a speed capable of removing air or foreign matter entering the pump chamber is further stored in the storage device; the comparison and determination unit further acquires the driving temperature from the storage device when the acquired temperature is lower than the protection temperature, compares the acquired temperature acquired by the acquisition unit with the driving temperature, and determines which of the driving temperature and the acquired temperature is lower; The control unit further increases the rotation speed of the rotating body or increases the torque of the rotating body when the comparison and judgment unit determines that the acquired temperature is lower than or equal to the driving temperature, thereby causing the rotating body to continue rotating.

9. A control board (110) on which the control device is provided; A thermistor (64) provided on the control board; A heat conductive member (65) having a higher thermal conductivity than the bearing portion, 9. The rotating device according to claim 8, wherein the heat conductive member is provided between the thermistor and the shaft.

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