JP2023152486A - Control apparatus and rotation device - Google Patents

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

The disclosure described herein relates to a control device and a rotating device.

Patent Document 1 describes a control device that prevents components of a hydraulic pump in a pump chamber from being worn out due to idling. The control device controls the hydraulic pump by driving the electric motor. The control device determines whether the rotation speed of the electric motor is equal to or higher than the specified rotation speed, and if the rotation speed of the electric motor is equal to or higher than the specified rotation speed, the control device determines that the hydraulic pump is idling and stops the electric motor. make it stop.

Japanese Patent Application Publication No. 2006-258033

By the way, if a foreign object enters the pump chamber, the rotation speed of the electric motor is likely to become less than the specified rotation speed. In this case, the electric motor is not stopped, even though the components of the hydraulic pump are subject to wear. If foreign matter enters the pump chamber, it is difficult to suppress wear on the components of the hydraulic pump.

Therefore, an object of the present disclosure is to provide a control device and a rotating device that can suppress wear of a bearing (component) even when air or foreign matter enters a pump chamber.

A control device according to one aspect of the present disclosure includes:
A shaft (54) extending in one direction, a rotating body (51) having an inner circumferential surface (55b) facing the outer circumferential surface (54a) of the shaft and rotating in the circumferential direction along the outer circumferential surface, an inner circumferential surface and an outer circumferential surface A rotating device (60) equipped with a bearing section (57) that is provided between the shafts and rotates together with the rotating body, and a pump chamber (61c) that accommodates the shaft, the rotating body, and the bearing section, and through which the cooling water (40) flows. ), a control device (100) for controlling a rotating body,
Comprising an arithmetic processing device (210) and a storage 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 the storage device.
The processing unit is
an acquisition section (230) that acquires the temperature of the bearing section;
a comparison 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 or the acquired temperature is higher;
a control unit (250) that reduces the rotational speed of the rotating body or reduces the torque of the rotating body to continue rotating the rotating body when the comparison and determination unit determines that the acquired temperature is equal to or higher than the protection temperature; , is provided.

When air enters, the bearing (57) idles, and the temperature of the bearing (57) increases due to frictional heat generated between it and the shaft (54). When foreign matter enters, the bearing (57) interferes, and the temperature of the bearing (57) increases due to frictional heat generated between it and the shaft (54). Therefore, if the obtained temperature is high, that is, equal to or higher than the protection temperature (Th), it can be assumed that air or foreign matter has entered the pump chamber (61c).
Therefore, when it is determined that the obtained temperature is equal to or higher than the protection temperature (Th), the rotational speed of the rotating body (51) or the torque of the rotating body (51) is lowered. According to this, even if either air or foreign matter enters the pump chamber (61c), friction between the bearing portion (57) and the shaft (54) can be suppressed. Wear of the bearing portion (57) can be suppressed. Heat damage to the bearing portion (57) can be suppressed.

Further, a rotating device according to another aspect of the present disclosure includes:
A shaft (54) extending in one direction, a rotating body (51) having an inner circumferential surface (55b) facing the outer circumferential surface (54a) of the shaft and rotating in the circumferential direction along the outer circumferential surface, an inner circumferential surface and an outer circumferential surface a bearing section (57) provided between the pump chambers and rotating together with the rotating body; a pump chamber (61c) that accommodates the shaft, the rotating body, and the bearing section and through which the cooling water (40) flows; and a pump chamber (61c) for controlling the rotating body. A rotating device (60) comprising a control device (100) of
Comprising an arithmetic processing device (210) and a storage 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 the storage device.
The processing unit is
an acquisition section (230) that acquires the temperature of the bearing section;
a comparison 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 or the acquired temperature is higher;
a control unit (250) that reduces the rotational speed of the rotating body or reduces the torque of the rotating body to continue rotating the rotating body when the comparison and determination unit determines that the acquired temperature is equal to or higher than the protection temperature; , is provided.

The rotation device (60) is equipped with a control device (100). Wear of the bearing portion (57) can be suppressed regardless of whether air or foreign matter enters the pump chamber (61c). Heat damage to the bearing portion (57) can be suppressed.

Note that the reference numbers in parentheses above merely indicate correspondence with the configurations described in the embodiments described later, and do not limit the technical scope in any way.

It is a schematic diagram explaining a cooling system. It is a sectional view explaining a rotation device. It is a schematic diagram explaining a control device and a rotating device. It is a flow chart explaining control of a control device. It is a graph explaining the relationship between the rotational speed of the rotating body and the temperature change of the bearing when air or foreign matter enters the pump chamber. It is a flow chart explaining a 2nd embodiment.

Hereinafter, a plurality of embodiments for carrying out the present disclosure will be described with reference to the drawings. In each form, parts corresponding to matters explained in the preceding form may be given the same reference numerals and redundant explanation may be omitted. When only a part of the configuration is described in each form, the other forms previously described can be applied to other parts of the structure.

In addition, it is not only possible to combine parts that are explicitly shown to be combinable in each embodiment, but also to combine embodiments with each other even if it is not explicitly stated, or between embodiments and modified examples, as long as there is no particular problem with the combination. It is also possible to partially combine the modified examples.

(First embodiment)
<Cooling system>
The cooling system 1 shown in FIG. 1 can be mounted on a vehicle and used as a system for cooling heat generating components 10 of the vehicle. The cooling system 1 includes a cooling device 21, a reserve tank 22, piping 30, and an electric water pump 60. Note that 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 the cooling water 40 through the piping 30.

Examples of the heat generating components 10 include a battery 11, a drive motor, an inverter, and a power control unit. 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.

In particular, when one of the heat generating components 10 is the battery 11, by cooling the battery 11 with the cooling system 1, deterioration of the battery 11 due to a rise in temperature can be reduced. Deterioration of the battery 11 can be suppressed and the performance of the battery 11 can be stably exhibited over a long period of time.

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 on the surface of the cooling device 21 . When the cooling system 1 is mounted on a vehicle, heat exchange is promoted by the cooling device 21 receiving wind from the vehicle.

The reserve tank 22 is a device that also has the role of removing air generated as the temperature of the cooling water 40 rises and air that unintentionally enters the pipe 30. Removing the air stabilizes the pressure in the cooling system. According to this, the temperature rise of the cooling water 40 is suppressed and the cooling efficiency of the cooling device 21 is increased.

<Mechanical configuration of electric water pump>
An example of the mechanical configuration of the electric water pump 60 will be described below based on FIG. 2. The electric water pump 60 is a device that functions as a power source that circulates the cooling water 40 inside the piping 30. Note that the configuration of the electric water pump 60 is not limited to the configuration shown below. Hereinafter, three mutually orthogonal directions will be referred to as an x direction, a y direction, and a z direction. The direction in which the shaft 54 extends, which will be described later, is the z direction. The z direction corresponds to one direction.

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. .

The pump housing 61 is a casing 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 piping 30 into the pump chamber 61c, and a removal port 61b through which the cooling water 40 is removed from the pump chamber 61c into the piping 30. The rotating body 51, the impeller 52, a portion of the shaft 54, and the bearing portion 57 are arranged inside the pump chamber 61c. The rotation of the impeller 52 forces the cooling water 40 inside the pump chamber 61c to the pipe 30. This allows the cooling water 40 to circulate between the pump chamber 61c and the piping 30.

The motor housing 62 is a casing fixed to the outside of the pump housing 61. The motor housing 62 includes a rotating body housing part 62a and a fixed body housing part 62b. A rotating body accommodating portion 62a is arranged at the center of the motor housing 62. In the radial direction perpendicular to the z direction, a fixed body housing part 62b is arranged in an annular shape outside the rotating body housing part 62a of the motor housing 62.

The rotating body 51 is accommodated in the rotating body accommodating portion 62a. The fixed body 53 is housed in the fixed body housing portion 62b. The rotating body 51 and the fixed body 53 are arranged to face each other in the radial direction. A motor 50 is configured by a rotating body 51 and a fixed body 53. The motor 50 is abbreviated as M2 in the drawings.

Further, a shaft 54 extending in the z direction is provided at the radial center of the rotating body housing portion 62a. The shaft 54 is made of a member such as metal that has higher heat resistance and higher thermal conductivity than the bearing. The shaft 54 extends to pass through the bottom 62c of the rotating body accommodating portion 62a. For example, the shaft 54 is fixed to the bottom 62c. The rotating body 51 is provided between the wall portion 62d of the rotating body housing portion 62a and the shaft 54. A rotating body 51 is provided so as to be rotatable around the shaft 54 in the circumferential direction around the z-direction.

The rotating body 51 includes a support portion 55 and a rotating body magnet 56. The support portion 55 has a substantially cylindrical shape recessed in the z direction. A rotating body magnet 56 is provided on the support outer peripheral surface 55a of the support portion 55. A bearing portion 57 is provided on the support inner circumferential surface 55b of the support portion 55.

The bearing portion 57 is made of a material such as resin that has lower heat resistance than the shaft. The bearing portion 57 has a cylindrical shape penetrating in the z direction. The rotating body 51 is provided around the shaft 54 in such a manner that the bearing inner circumferential surface 57a faces the shaft outer circumferential surface 54a in the radial direction. The rotating body 51 is rotatable in the circumferential direction around the shaft 54 together with the bearing portion 57.

Further, the rotary body 51 is integrally formed with the impeller 52 at an end portion 51a spaced apart from the bottom portion 62c of the rotary body housing portion 62a. As the rotating body 51 rotates, the impeller 52 can rotate.

The pump chamber 61c indicates a space partitioned by the pump housing 61 and the motor housing 62. As described above, the rotating body 51, the impeller 52, a portion of the shaft 54, and the bearing portion 57 are housed in the pump chamber 61c. By rotating the rotating body 51 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 into the pipe 30 via the impeller 52.

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

The control board 110 is provided at an end of the shaft 54 that is spaced apart from the impeller 52 . The control board 110 is attached to, for example, the motor housing 62 via a fixing part (not shown). Further, the control board 110 is covered with a cover 63 and is housed in a space separated from the pump chamber 61c. A cover 63 is attached to the motor housing 62. This prevents external dust and moisture from adhering to the control board 110.

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

Note that the placement of the thermistor 64 is not limited to the bottom surface of the control board 110. The thermistor 64 may be provided on the upper surface of the control board 110. Further, the thermistor 64 may be provided at a location other than the control board 110. The thermistor 64 may be provided in the bearing portion 57. The thermistor 64 may be provided on the shaft 54. The thermistor 64 may be provided anywhere as long as it can measure the temperature of the bearing portion 57. Note that another temperature sensor may be provided instead of the thermistor 64.

The heat conductive member 65 is a member having higher thermal conductivity than the bearing portion 57. The heat conductive member 65 includes a member such as silicone. The heat conductive member 65 is gel-like. Note that the heat conductive member 65 may include silicone containing a metal having high thermal conductivity, a filler, or the like. The heat conductive member 65 does not need to be gel-like, and may be sheet-like. A 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, heat can be efficiently transferred to the thermistor 64 while suppressing loss of frictional heat. Note that the frictional heat generated by the friction between the shaft 54 and the bearing portion 57 can also be said to be the frictional heat that the bearing portion 57 receives due to the friction with the shaft 54.

<Electrical configuration of motor control device>
As shown in FIG. 3, the control device 100 includes a microcomputer 200, a driver circuit 300, and a communication circuit 400. Power is supplied from the battery 11 to the microcomputer 200 and various circuits. Further, an ignition switch 12 is provided between the battery 11 and the microcomputer 200 to control on/off of power supply to 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.

Driver circuit 300 is provided between battery 11 and motor 50. Driver circuit 300 converts direct current supplied from battery 11 into alternating current for driving motor 50. The driver circuit 300 is electrically connected to the microcomputer 200 in addition to the battery 11 and the motor 50. The driver circuit 300 controls the motor 50 according to instructions from the microcomputer 200.

Communication circuit 400 is provided between host ECU 70 and microcomputer 200. The communication circuit 400 is a circuit that can transmit information between the microcomputer 200 and the host ECU 70. The rotational state of the motor 50 can be transmitted to the host ECU 70 via the communication circuit 400.

The microcomputer 200 includes an arithmetic processing unit 210 such as a CPU, a storage device 220 such as a ROM or RAM, an IO interface, and the like. The ROM stores programs executed by the CPU and data.

As data, a protection temperature Th and a driving temperature T0 are stored. The protection temperature Th and the driving temperature T0 are temperatures that are used as a guide when the rotating body 51 is driven by the control device 100. 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 starts to be thermally damaged. The driving temperature T0 is the temperature of the bearing portion 57 when the rotating body 51 rotates at a speed sufficient to remove air or foreign matter entering the pump chamber 61c.

The RAM temporarily stores calculation results calculated by the calculation processing unit 210, signals acquired by the IO interface, and the like. The CPU executes programs stored in the ROM while utilizing the temporary storage function of the RAM. The microcomputer 200 thereby executes various functions.

As functions, the arithmetic processing device 210 includes an acquisition section 230, a comparison determination section 240, and a control section 250. Functions are also referred to as functional blocks. It can be said that the program includes the functions of the acquisition section 230, the comparison and determination section 240, and the control section 250. Details of the acquisition section 230, comparison and determination section 240, and control section 250 will be explained later.

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

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 if-then-else type, or a learned model tuned by machine learning, for example, an algorithm as a neural network.

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

(i) A 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 by 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, or the like. Memory is also called a storage medium. Memory is a non-transitory and tangible storage medium that non-temporarily stores "programs and/or data" readable by a processor. The storage medium is provided by a semiconductor memory, a magnetic disk, an optical disk, or the like. A program may be distributed alone or as a storage medium in which the program is stored.

(ii) The hardware processor may be a hardware logic circuit. In this case, the computer is provided by a digital circuit containing a large number of programmed logic units (gate circuits). Digital circuits are also referred to as logic circuit arrays, such as ASICs, FPGAs, SoCs, PGAs, CPLDs, and the like. Digital circuits may include memory that stores programs and/or data. Computers may be provided by analog circuits. Computers may be provided with a combination of digital and analog circuits.

(iii) The hardware processor may be a combination of (i) and (ii) above. (i) and (ii) are placed on different chips or on a common chip. In these cases, part (ii) is also called an accelerator.

The control device 100, the signal source, and the controlled object provide various elements. At least some of those elements can be called blocks, modules, or sections. Moreover, the elements included in the control system are called functional means only if they are intentional.

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 by a computer program. Alternatively, the microcomputer 200 and techniques described in this disclosure may be implemented by a dedicated computer provided by configuring the processor with one or more dedicated hardware logic circuits.

The microcomputer 200 and its method may be realized by a dedicated computer configured by a combination of a processor and memory configured to execute one or more functions and a processor configured by a hardware logic circuit. good. The computer program may also be stored as instructions executed by a computer on a computer-readable non-transitory tangible storage medium.

<Rotational speed of rotating body and temperature of bearing part>
Before explaining the flow of the control device 100 in this embodiment, the correlation between the rotational speed of the rotating body 51 and the temperature of the bearing portion 57 will be explained. As an example, the correlation between the rotational speed of the rotating body 51 and the temperature of the bearing portion 57 will be explained when air enters the pump chamber 61c when replacing or replenishing the cooling water 40 during vehicle maintenance or the like.

When air enters the pump chamber 61c, the air may remain in the pump chamber 61c as an air pocket. In particular, when air remains between the shaft 54 and the bearing portion 57, the rotating body 51 tends to idle. In that case, the rotational speed of the rotating body 51 becomes faster than when no air pocket is generated inside the pump chamber 61c. Friction tends to occur between the bearing portion 57 and the shaft 54, or the frictional force tends to increase.

As described above, the frictional heat generated by the friction between the shaft 54 and the bearing portion 57 can also be said to be the frictional heat that the bearing portion 57 receives due to the friction with the shaft 54. The temperature of the bearing inner circumferential surface 57a of the bearing portion 57 tends to rise due to frictional heat. As a result, the bearing inner circumferential surface 57a becomes susceptible to thermal damage. Below, in order to simplify the explanation, the temperature of the bearing inner circumferential surface 57a is simply shown as the temperature of the bearing portion 57.

As another example, a description will be given of the correlation between the rotational speed of the rotating body 51 and the temperature of the bearing portion 57 in the case where foreign matter enters the pump chamber 61c together with the cooling water 40 from the components constituting the cooling system 1. do.

When a foreign object enters the pump chamber 61c, the foreign object gets caught in the impeller 52 or comes into contact with the rotating body 51 and the shaft 54, and as a result, the relative position of the rotating body 51 and the shaft 54 changes, causing interference between the two. be. In particular, if foreign matter enters between the shaft 54 and the bearing portion 57, friction is likely to occur between the bearing portion 57 and the shaft 54 when the rotating body 51 is rotated. In that case, the rotational speed of the rotating body 51 becomes slower than when no foreign matter has entered the pump chamber 61c. Furthermore, the temperature of the bearing portion 57 tends to rise due to frictional heat. The bearing portion 57 is likely to wear out. The bearing portion 57 becomes susceptible to thermal damage.

Therefore, in this embodiment, the control device 100 monitors the temperature of the bearing portion 57, and controls the rotational speed of the rotating body 51 to be lowered when the temperature is equal to or higher than the protection temperature Th. According to this, friction between the shaft 54 and the bearing portion 57 is suppressed regardless of whether air or foreign matter enters the pump chamber 61c. Wear of the bearing portion 57 is suppressed. Heat damage to the bearing portion 57 is suppressed. Correspondingly, the temperature of the bearing portion 57 decreases. In addition, in the control device 100, when the temperature reaches the protection temperature Th, the rotation of the rotating body 51 is not stopped but continues to rotate while lowering the rotational speed. By continuously rotating the rotating body 51, air and foreign matter can be actively removed from the pump chamber 61c.

However, if the rotational speed is lowered to the extent that the temperature of the bearing portion 57 falls below the driving temperature T0, it becomes difficult to actively remove air and foreign matter from the pump chamber 61c. For this purpose, the control device 100 performs control to increase the rotational speed of the rotating body 51 so that air and foreign matter can be continuously removed when the driving temperature falls below T0. This makes it possible to simultaneously suppress thermal damage to the bearing portion 57 and remove air or foreign matter.

<Control of bearing protection>
The flowchart of FIG. 4 shows the control of the control device 100 applied to the cooling system 1 of FIG. 1. In this explanation, in order to clearly indicate which component included in the control device 100 performs the process, the subject of the sentence explaining the process will be used instead of the control device 100 as necessary. Describe the components of the motor control device to be executed.

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

In step S510, the acquisition section 230 acquires the temperature of the bearing section 57. The heat of the bearing portion 57 is transmitted to the thermistor 64 via the shaft 54 and the heat conduction member 65. The thermistor 64 has a property that its resistance value changes when heat is applied. The acquisition section 230 acquires the temperature of the bearing section 57 by converting the resistance value of the thermistor 64 into temperature.

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

If it is determined in step S520 that the obtained temperature of the bearing portion 57 is equal to or higher than the protection temperature Th, in step S530, the rotational speed of the rotating body 51 is lowered by a preset N1 (rpm) from the command speed V0, and the Proceed to. Note that from the second flow onwards, control may be performed to lower the rotation speed by N1 (rpm) from the actual rotation speed or from 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 shown as V. When 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 has increased.

If it is determined in step S520 that the temperature of the bearing portion 57 is lower than the protection temperature Th, the comparison determination unit 240 acquires the driving temperature T0 from the storage device 220 in step S540. Then, it is determined whether the acquired temperature of the bearing portion 57 acquired in step S510 is lower than or equal to the driving temperature T0. If it is determined in step S540 that the acquired temperature of the bearing part 57 is lower than the driving temperature T0, in step S550 the control unit 250 adjusts the rotational speed of the rotating body 51 from the actual rotational speed or the rotational speed set in the previous flow. Increase the speed by the set N2 (rpm) and proceed to the end.

When the acquired temperature is 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 decreased and there is a margin in heat resistance. In addition, in step S550, in order to remove foreign matter, the rotational speed of the rotating body 51 is increased to such an extent that the bearing portion 57 is not damaged by heat. Further, the value of N2 (rpm) may be the same as the value of N1 (rpm), or may be different. As described above, since the control unit 250 changes the rotation speed by N1 (rpm) or by N2 (rpm), the control unit 250 may control the rotation speed by a predetermined speed. I can say it.

However, in step S550, it is possible to increase the rotational speed by N2 (rpm) only when the rotational 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, the command speed V0 is transmitted from the host ECU 70, so even if the obtained temperature is lower than the drive temperature T0 in step S540, the rotation speed does not increase. . As a result, the command speed V0 is maintained in the flow immediately after the ignition switch 12 is turned on. Note that immediately after turning on the ignition switch 12 specifically refers to a time when the temperature is lower than the driving temperature T0 before time t1, as shown in FIG. In addition, the rotational speed is suppressed from becoming higher than the command speed V0 after time t4 shown in FIG. 5.

If it is determined in step S540 that the obtained temperature of the bearing portion 57 is higher than the driving temperature T0, the control unit 250 maintains the rotational speed of the rotating body 51 in step S560. Then proceed to the end. Note that even when the temperature is higher than the drive 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 obtained temperature is below the protection temperature Th, the command speed V0 is maintained whether it is higher or lower than the driving temperature T0.

FIG. 5 shows the relationship between the rotational speed of the rotating body 51 and the temperature of the bearing portion 57 over time. The rotational speed of the rotating body 51 is determined based on instructions from the control unit 250. Note that in the drawings, the rotation speed is shown as rotation speed, and the temperature of the bearing portion 57 is shown as temperature.

When the rotating body 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 portion 57 gradually increases. When the comparison and determination section 240 determines that the temperature of the bearing section 57 has reached the protection temperature Th at time t1 (step S520), the control section 250 lowers the rotation speed by N1 (rpm) (step S530).

When the rotational speed of the rotating body 51 begins to decrease by the control unit 250, the temperature of the bearing portion 57 begins to decrease with a delay from time t1. Specifically, after the temperature of the bearing portion 57 reaches a maximum temperature higher than the protection temperature Th, it starts to decrease after time t1. The rotational speed is decreased by N1 (rpm) until the temperature of the bearing portion 57 reaches the protection temperature Th again at time t2. Further, as an example, the rotational speed of the rotating body 51 when the rotational speed is decreased by N1 (rpm) and the temperature of the bearing portion 57 reaches the protection temperature Th again is hereinafter referred to as a first speed V1.

Note that 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 set in advance so that when the rotational speed is decreased by N1 (rpm) from time t1, the maximum temperature becomes lower than the heat damage temperature. Based on FIG. 5, it can be said that the rotational speed is linearly lowered by N1 (rpm) from the command speed V0 to the first speed V1 from time t1 to time t2.

When the temperature of the bearing section 57 reaches the protection temperature Th at time t2, the control section 250 stops reducing the rotational speed of the rotating body 51. The rotating body 51 rotates while maintaining the first speed V1. However, the temperature of the bearing portion 57 cannot follow the change in rotational speed and continues to decrease. When the comparison and determination section 240 determines that the temperature of the bearing section 57 has reached the drive temperature T0 at time t3 (step S540), the control section 250 increases the rotational speed by N2 (rpm) (step S550).

When the rotation speed starts to increase by the control section 250, the temperature of the bearing section 57 starts to increase after time t3. Specifically, after the temperature of the bearing portion 57 reaches the lowest temperature lower than the driving temperature T0, it starts to rise later than time t3. Further, as an example, the rotational speed of the rotating body 51 when the rotational speed is increased by N2 (rpm) and the temperature of the bearing portion 57 reaches the driving temperature T0 again is hereinafter referred to as a second speed V2.

Note that the lowest temperature is higher than the non-removal temperature when the rotational speed is so low that the air or foreign matter entering the pump chamber 61c cannot be removed. The driving temperature T0 is set in advance so that when the rotational speed is increased by N2 (rpm) from time t3, the lowest temperature becomes higher than the non-removal temperature. Based on FIG. 5, it can be said that the rotational speed is linearly increased by N2 (rpm) from the first speed V1 to the second speed V2 from time t3 to time t4.

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

Hereinafter, the temperature of the bearing portion 57 when no air or foreign matter enters the pump chamber 61c and the rotating body 51 is performing the expected normal operation will be referred to as the normal temperature TN. The normal temperature TN is lower than the drive temperature T0 and the protection temperature Th. The temperatures are lower in this order: protection temperature Th, drive temperature T0, and normal temperature TN. The protection temperature Th is higher than the drive temperature T0, and the drive temperature T0 is higher than the normal temperature TN. The temperature difference between the normal temperature TN and the drive temperature T0 is larger than the temperature difference between the drive temperature T0 and the protection temperature Th.

<Display of 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 the external device 80. The external device 80 includes a display and the like. Based on the determined rotational state, the host ECU 70 controls the display on the display. According to this, a mechanic can recognize from the display on the display that an abnormality has occurred in the rotational state of the rotating body 51.

The control device 100 transmits a "low rotation state" to the host ECU 70 when controlling the rotation speed to be lower than the command speed V0. In that case, the host ECU 70 that receives the information may determine that the water pump is abnormal and may display "low rotation state" on the display. Further, the control device 100 may always transmit the actual rotation speed to the host ECU 70. In that case, the host ECU 70 may determine that the water pump is abnormal when the actual rotation speed<command speed V0, and display "low rotation state" or "actual rotation speed" on the display.

Note that since the flowchart starts when the ignition switch 12 is turned on, the driver can recognize the rotational state of the rotating body 51 while driving through the display. Even if an abnormality occurs in the rotational state of the rotating body 51 while driving, the driver can stop by a dealer without a long period of time elapsed after the abnormality occurs.

<Effect>
The control device 100 monitors the temperature of the bearing portion 57 provided around the shaft 54 in the pump chamber 61c, and performs control to reduce the rotational speed of the rotating body 51 when the temperature reaches the protection temperature Th. The acquisition section 230 acquires the temperature of the bearing section 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 portion 57 is equal to or higher than the protection temperature Th. When the comparison and determination section 240 determines that the temperature of the bearing section 57 is equal to or higher than the protection temperature, the control section 250 reduces the rotational speed of the rotating body 51 to a predetermined value at a constant rate.

When air enters, the bearing portion 57 idles, and the temperature of the bearing portion 57 increases due to frictional heat generated between it and the shaft 54 at that time. When foreign matter enters, the bearing portion 57 interferes with the foreign matter, and the temperature of the bearing portion 57 increases due to frictional heat generated between it and the shaft 54 at that time. Therefore, if the acquired temperature is equal to or higher than the protection temperature Th, it can be assumed that air or foreign matter has entered the pump chamber 61c.

In this embodiment, since the above-mentioned control device 100 is provided, regardless of whether air or foreign matter enters the pump chamber 61c, when the temperature of the bearing portion 57 reaches the protection temperature Th, the rotating body 51 The rotation speed can be lowered. As the rotational speed of the rotating body 51 decreases, the friction between the shaft 54 and the bearing portion 57 is alleviated. Wear of the bearing portion 57 is suppressed. Heat damage to the bearing portion 57 is suppressed. Note that since the bearing portion 57 is made of resin, it is particularly important to prevent it from being melted and damaged by heat.

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

However, if the rotational speed is lowered to the extent that the temperature of the bearing portion 57 falls below the driving temperature T0, it becomes difficult to actively remove air and foreign matter from the pump chamber 61c. For this purpose, the control device 100 performs control to increase the rotational speed of the rotating body 51 so that air and foreign matter can be continuously removed when the driving temperature T0 is reached.

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

In this way, the control device 100 performs control to increase the rotational speed of the rotating body 51 so that air and foreign matter can be continuously removed even when the temperature of the bearing portion 57 reaches the driving temperature T0. There is. This makes it possible to simultaneously suppress thermal damage to the bearing portion 57 and remove air or foreign matter.

If it is determined in step S540 that the obtained temperature is equal to or lower than the drive temperature T0, the control device 100 increases the rotational speed of the rotating body 51 to the second speed V2 by repeating the flow. The second speed V2 is a speed set lower than the speed at which the temperature of the bearing portion 57 reaches the protection temperature Th. According to this, it is suppressed that the rotational speed of the rotating body 51 is increased too much in step S550, and as a result, the bearing portion 57 is prevented from being thermally damaged.

Further, the temperature difference between the normal temperature TN and the drive temperature T0 is larger 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.

(Second embodiment)
In the first embodiment, a mode has been described in which the rotational speed of the rotating body 51 is controlled in step S530 and step S550. In the second embodiment, as shown in FIG. 6, the torque of the rotating body 51 may be controlled instead of controlling the rotational speed of the rotating body 51 in steps S630 and S650. Note that in the drawings, torque is indicated as Tr.

If the temperature of the bearing part 57 is acquired in step S610, and it is determined in step S620 that the acquired temperature of the bearing part 57 is equal to or higher than the protection temperature Th, the control part 250 sets the torque of the rotating body 51 in advance in step S630. Control is performed to lower N3 (Nm). If it is determined in step S640 that the obtained temperature of the bearing portion 57 is equal to or lower than the driving temperature T0, the control unit 250 performs control to increase the torque of the rotating body 51 by a preset N4 (N·m) in step S650.

If it is determined in step S640 that the acquired temperature of the bearing portion 57 is higher than the drive temperature T0, the control unit 250 performs control to maintain the torque of the rotating body 51 in step S660. Note that in step S650, control is performed to increase the torque by N4 (N·m) only when the command torque Tr0 is not exceeded. In other words, the torque of the rotating body 51 is controlled so as not to exceed the command torque Tr0. According to this, the same effects as in the first embodiment can be achieved.

(Third embodiment)
In the third embodiment, when controlling the rotating body 51 in step S530, step S550, step S630, and step S650, in addition to the control in the first embodiment or the second embodiment, the rotation of the rotating body 51 is The direction may be reversed. This may remove air or foreign matter that has entered the pump chamber 61c.

(Fourth embodiment)
In the first embodiment, the control device 100 including the microcomputer 200 is powered on at the timing when the ignition switch 12 is turned on. As a fourth embodiment, the microcomputer 200 may be in a sleep state when the ignition switch 12 is off, and when the ignition switch 12 is turned on, the microcomputer 200 may release the sleep state and start operating.

(Other embodiments)
Although the present disclosure has been described in accordance with embodiments, it is understood that the present disclosure is not limited to such embodiments or structures. The present disclosure also includes various modifications and equivalent modifications. In addition, while various combinations and configurations are shown in this disclosure, other combinations and configurations involving only one, more, or fewer elements are also within the scope and spirit of this disclosure. It is something that can be entered.

DESCRIPTION OF SYMBOLS 12... Ignition switch, 40... Cooling water, 51... Rotating body, 54... Shaft, 54a... Shaft outer circumferential surface, 55b... Support inner circumferential surface, 57... Bearing part, 60... Electric water pump, 61c... Pump chamber, 64... Thermistor, 65... Thermal conduction member, 70... Upper ECU, 80... External device, 100... Control device, 110... Control board, 210... Arithmetic processing unit, 220... Storage device, 230... Acquisition unit, 240... Comparison determination unit, 250...Control unit, 400...Communication circuit, Th...Protection temperature, T0...Drive temperature, TN...Normal temperature, V0...Command speed

Claims (10)

A shaft (54) extending in one direction, a rotating body (51) having an inner circumferential surface (55b) opposite to the outer circumferential surface (54a) of the shaft and rotating in the circumferential direction along the outer circumferential surface, and the inner circumferential surface and a bearing section (57) provided between the outer peripheral surface and rotating together with the rotating body, and a pump chamber (61c) that accommodates the shaft, the rotating body, and the bearing section, and through which cooling water (40) flows. ) A control device (100) for controlling the rotating body in a rotating device (60) comprising:
Comprising an arithmetic processing device (210) and a storage 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 is
an acquisition section (230) that acquires the temperature of the bearing section;
a comparison 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 or the acquired temperature is higher;
If the comparison and determination section determines that the acquired temperature is equal to or higher than the protection temperature, the rotation speed of the rotating body is lowered or the torque of the rotating body is lowered to continue the rotation of the rotating body. A control device including a control section (250). A driving temperature (T0), which is the temperature of the bearing portion when the rotating body rotates at a speed sufficient to remove air or foreign matter entering the pump chamber, is further stored in the storage device,
The comparison 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 controls the driving temperature. Determine which is lower between the temperature and the obtained temperature,
The control unit may further increase the rotational speed of the rotary body or increase the torque of the rotary body when the comparison determination unit determines that the acquired temperature is equal to or lower than the drive temperature. The control device according to claim 1, which causes the rotating body to continue rotating. The control unit is configured to increase the rotational speed of the rotating body until it reaches a preset command speed (V0) when the comparison and determination unit determines that the acquired temperature is equal to or lower than the drive temperature. The control device according to claim 2, wherein the control device is capable of: the protection temperature is higher than the drive temperature;
The control device according to claim 2 or 3, wherein the driving temperature is higher than a normal temperature (TN) that is a temperature of the bearing section in a normal state when the air or the foreign matter does not enter the pump chamber. The control device according to any one of claims 1 to 4, wherein the control section controls the rotational speed of the rotating body in predetermined speed increments. Claim 1, further comprising a communication circuit (400) that transmits the state of the rotary body after the rotation of the rotary body is controlled by the control unit to a host ECU (70) connected to an external device (80). 5. The control device according to any one of items 5 to 5. The control device according to any one of claims 1 to 6, wherein the control unit controls the rotating body only when an ignition switch (12) provided in the vehicle is on. The control device according to any one of claims 1 to 7, wherein the control unit rotates the rotating body in a direction opposite to a normal rotation direction. A shaft (54) extending in one direction, a rotating body (51) having an inner circumferential surface (55b) opposite to the outer circumferential surface (54a) of the shaft and rotating in the circumferential direction along the outer circumferential surface, and the inner circumferential surface and a bearing part (57) provided between the outer circumferential surface and rotating together with the rotating body, a pump chamber (61c) that accommodates the shaft, the rotating body, and the bearing part, and through which cooling water (40) flows; and a rotating device (60) comprising a control device (100) for controlling the rotating body,
Comprising an arithmetic processing device (210) and a storage 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 is
an acquisition section (230) that acquires the temperature of the bearing section;
a comparison 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 or the acquired temperature is higher;
If the comparison and determination section determines that the acquired temperature is equal to or higher than the protection temperature, the rotation speed of the rotating body is lowered or the torque of the rotating body is lowered to continue the rotation of the rotating body. A rotating device including a control unit (250). a control board (110) on which the control device is provided;
a thermistor (64) provided on the control board;
further comprising a thermally conductive member (65) having higher thermal conductivity than the bearing portion,
The rotating device according to claim 9, wherein the heat conductive member is provided between the thermistor and the shaft.

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