JP2007192092A - Electric supercharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrict vibration during high speed rotation, and suppress cost increase. <P>SOLUTION: In a supercharger ECU in the electric supercharger, a program is executed which includes a step S102 to detect differential magnetic force Mx, My when the electric charger is rotated in a non-energized state (S100: YES), a step S104 to determine energization quantity in X- and Y-directions, a step S106 to energize a stator, and a step S108 to judge whether or not assist by an electrical rotating machine is unnecessary. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electric supercharger, and more particularly to control for reducing shaft vibration during high rotation of an electric supercharger.

  2. Description of the Related Art Conventionally, in order to improve the output of an engine, a supercharger that supercharges air supplied to the engine by compressing the air by rotation of a compressor wheel is known. An electric supercharger that applies a rotational force to a compressor wheel by a rotating electric machine is known. In such a supercharger, when the rotation speed of the compressor wheel increases, vibration may occur due to resonance. The supercharging region of the supercharger is wide (that is, the rotation region of the compressor wheel is wide), and it cannot be avoided that the rotation speed of the compressor wheel enters the resonance rotation speed region.

  In view of such a problem, for example, Japanese Patent Laid-Open No. 5-98985 (Patent Document 1) discloses a turbocharger rotation control device that prevents adverse effects due to an increase in amplitude at the resonance rotational speed. This rotation control device energizes / reduces the rotating shaft by the operation control of the rotating electric machine when the rotating speed of the turbo charger reaches the vicinity of the resonance rotating speed when the rotating speed of the turbo charger reaches the vicinity of the resonance rotating speed. And a control mechanism for speeding up the passage of the resonance point.

According to the rotation control device disclosed in the above-mentioned publication, an increase in amplitude at the resonance point is suppressed, and the work for sufficient quality control and rigidity improvement to obtain the damping effect of the oil film as in the past are improved. The effect that the malfunction based on is eliminated. Further, there is an advantage that the increase in the amplitude at the resonance rotational speed is prevented at the time of the above-described inability of continuous operation at the low speed or at the time of deceleration as in the case of the speed increase.
Japanese Patent Laid-Open No. 5-98985

  However, as in the rotation control device disclosed in the above-mentioned publication, even if the rotation speed of the compressor wheel passes through the resonance rotation region, passage through the resonance rotation region is unavoidable, and therefore shaft vibration occurs. Further, the shaft vibration is not only caused by resonance, but is also greatly influenced by the self-excited vibration of the bearing portion. In particular, in an electric supercharger, since the mass of a rotating body is larger than that of a conventional supercharger, shaft vibration in a high-speed rotation range tends to increase. Since such self-excited vibration is generated in a rotational region higher than the rotational speed range to which the rotational force is applied by the rotating electrical machine, there is a case where it is not possible to accelerate the passage through the region where the shaft vibration increases due to the assistance of the rotating electrical machine. Yes, shaft vibration cannot be reliably suppressed. In addition, if a new component such as a vibration damping device is provided in order to suppress the shaft vibration, there arises a problem that the electric supercharger becomes large and costs increase.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an electric supercharger that suppresses vibration during high rotation. The objective of this invention is providing the electric supercharger which suppresses a raise of cost further.

  An electric supercharger according to a first aspect of the present invention is an electric supercharger that applies a rotational force to a rotating shaft of a supercharger by a rotating electric machine. The rotating electrical machine includes a rotor provided on a rotating shaft, a stator core provided opposite to the rotor, and a coil wound around teeth formed on the stator core. This electric supercharger includes a detecting means for detecting a physical quantity corresponding to a displacement amount in a direction orthogonal to the rotation axis, and an axial center of the rotation axis after displacement in a supercharger operating region where no rotational force is applied. Control means for controlling the electric power supplied to the coil so that a magnetic force corresponding to the detected physical quantity appears in the direction from the axis to the axis center of the rotating shaft before displacement.

  According to the first invention, the detection means detects a physical quantity (for example, an induced voltage of a displacement detection coil wound around the tip of the tooth) corresponding to a displacement amount in a direction orthogonal to the rotation axis. In the operation region of the turbocharger in which the rotational force by the rotating electrical machine is not applied to the rotating shaft, the control means converts the detected physical quantity in the direction from the axial center of the rotating shaft after displacement to the axial center of the rotating shaft before displacement. The electric power supplied to the coil is controlled so that the corresponding magnetic force is developed. Thereby, at the time of rotation of a rotating shaft, magnetic force can be expressed in the direction opposite to the direction where the displacement by the shaft vibration of a rotating shaft becomes large. Therefore, an increase in the amplitude of shaft vibration can be suppressed. Further, by generating a magnetic force according to a physical quantity corresponding to the displacement amount, it is possible to increase the magnetic force according to the displacement amount that increases during high rotation. Therefore, shaft vibration can be effectively suppressed. Therefore, it is possible to provide an electric supercharger that suppresses vibration during high rotation while suppressing an increase in cost.

  In the electric supercharger according to the second invention, in addition to the configuration of the first invention, a displacement detection coil provided separately from the coil is wound around the tip of the tooth. The detecting means compares the first voltage change induced by the displacement detection coil during rotation of the rotating shaft with the second voltage change induced when the rotating shaft rotates without displacement, Means for detecting a physical quantity corresponding to the displacement based on the comparison result is included.

  According to the second invention, the detecting means includes the first voltage change induced by the displacement detecting coil during rotation of the rotating shaft and the second voltage induced when the rotating shaft rotates without displacement. The change is compared, and a physical quantity corresponding to the displacement is detected based on the comparison result. The voltage induced when the rotating shaft rotates without being displaced becomes a vibration waveform having substantially the same shape as a sine wave. That is, in the second voltage change, the amplitude of the vibration waveform is in a substantially constant state. In the first voltage change, when the amplitude of the vibration waveform of the voltage is displaced closer to the side where the rotation axis (ie, the rotor) and the displacement detection coil are closer, the amplitude of the vibration waveform of the induced voltage is It tends to be larger than the case where it is not displaced. Further, if the distance between the rotating shaft and the displacement detection coil is displaced to the far side, the amplitude of the vibration waveform of the induced voltage tends to be small. That is, the voltage difference between the first voltage change and the second voltage change corresponds to the amount of displacement of the rotating shaft. Therefore, the shaft vibration is suppressed by controlling the power supplied to the coil according to the voltage difference between the case where the axis center of the rotating shaft is displaced and the case where it is not displaced corresponding to the displacement amount. Can do.

  In the electric supercharger according to the third invention, in addition to the configuration of the second invention, the detecting means includes means for detecting a voltage difference between the first voltage change and the second voltage change. .

  According to the third invention, in the second voltage change, the amplitude of the vibration waveform is substantially constant. In the first voltage change, when the amplitude of the vibration waveform of the voltage is displaced closer to the side where the rotation axis (ie, the rotor) and the displacement detection coil are closer, the amplitude of the vibration waveform of the induced voltage is It tends to be larger than the case where it is not displaced. Further, if the distance between the rotating shaft and the displacement detection coil is displaced to the far side, the amplitude of the vibration waveform of the induced voltage tends to be small. That is, the voltage difference between the first voltage change and the second voltage change corresponds to the amount of displacement of the rotating shaft. Therefore, the shaft vibration is suppressed by controlling the power supplied to the coil according to the voltage difference between the case where the axis center of the rotating shaft is displaced and the case where it is not displaced corresponding to the displacement amount. Can do.

  In the electric supercharger according to the fourth invention, in addition to the configuration of the first invention, the rotating electrical machine is provided with a hall sensor at a position facing the rotor. The detection means compares the first output change of the Hall sensor during rotation of the rotating shaft with the second output change when the rotating shaft rotates without displacement, and calculates the displacement based on the comparison result. Means for detecting the corresponding physical quantity.

  According to the fourth aspect of the invention, the detecting means rotates without the displacement of the rotation shaft and the first output change of the Hall sensor (for example, the rectangular Hall sensor or the linear Hall sensor) when the rotation shaft rotates. The second output change in the case is compared, and a physical quantity corresponding to the displacement is detected based on the comparison result. The hall sensor outputs a signal according to the strength of the magnetic field that changes as the rotor rotates. In the second output change, when the rotation shaft rotates without being displaced, the distance between the Hall sensor and the rotor is substantially constant. Therefore, the change at the rise (increase) of the signal output shows the same tendency in each cycle. When the axis center of the rotating shaft is displaced, the distance between the Hall sensor and the rotor varies depending on the amount of displacement. Therefore, the change in output at the time of rising of the signal output is different by comparing the output change with the case where the rotating shaft rotates without being displaced. As a result, for example, a difference occurs in the phase angle when the signal output of the Hall sensor becomes a predetermined output value or the amount of change in the signal output between the predetermined phase angles. That is, the difference in phase angle between the first output change and the second output change when the predetermined output value is obtained and the difference in the amount of change in the signal output between the predetermined phase angles are expressed as follows. It corresponds to the amount of displacement. Therefore, the shaft vibration can be suppressed by controlling the electric power supplied to the coil in accordance with the phase angle difference or the change amount corresponding to the displacement. In addition, if the Hall sensor that detects the position of the rotor of the rotating electrical machine is used to detect the above-described phase angle difference and change amount difference, the electric supercharger is increased in size or new parts are provided. There is nothing. Therefore, an electric supercharger that suppresses an increase in cost can be provided.

  In the electric supercharger according to the fifth aspect of the invention, in addition to the configuration of the fourth aspect of the invention, the detection means includes a phase angle when a predetermined output value is obtained in the first output change, Means for detecting a difference from the phase angle when the output value changes to a predetermined output value is included.

  According to the fifth invention, in the second output change, when the rotation shaft rotates without being displaced, the distance between the Hall sensor and the rotor is substantially constant. Therefore, the change at the rise (increase) of the signal output shows the same tendency in each cycle. When the axis center of the rotating shaft is displaced, the distance between the Hall sensor and the rotor varies depending on the amount of displacement. Therefore, the change at the rise of the signal output is different from the case where the rotating shaft rotates without being displaced. As a result, a difference occurs in the phase angle when the signal output of the Hall sensor becomes a predetermined output value. That is, the difference in phase angle when the output value is determined in advance corresponds to the amount of displacement of the rotating shaft. Therefore, the shaft vibration can be suppressed by controlling the electric power supplied to the coil in accordance with the phase angle difference corresponding to the displacement amount.

  In the electric supercharger according to the sixth aspect of the invention, in addition to the configuration of the fourth aspect of the invention, the detection means includes a change amount of the output between predetermined phase angles in the first output change, and a second output. Means for detecting a difference between the change amount of the output between the predetermined phase angles in the change is included.

  According to the sixth invention, in the second output change, when the rotation shaft rotates without being displaced, the distance between the Hall sensor and the rotor is substantially constant. Therefore, the change at the rise (increase) of the signal output shows the same tendency in each cycle. When the axis center of the rotating shaft is displaced, the distance between the Hall sensor and the rotor varies depending on the amount of displacement. Therefore, the change at the rise of the signal output is different from the case where the rotating shaft rotates without being displaced. As a result, a difference occurs in the change amount of the signal output of the Hall sensor between the predetermined phase angles. That is, the difference in the change amount of the Hall sensor signal output between the predetermined phase angles corresponds to the displacement amount of the rotating shaft. Therefore, the shaft vibration can be suppressed by controlling the electric power supplied to the coil in accordance with the difference in the change amount corresponding to the displacement amount.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<First Embodiment>
With reference to FIG. 1, an engine system equipped with the electric supercharger according to the present embodiment will be described. The engine system includes an engine 100, an electric supercharger 200, an intercooler 162, an engine ECU (Electronic Control Unit) 250, and a supercharger ECU 340. The engine system according to the present embodiment is mounted on a vehicle such as an automobile. Engine ECU 250 and supercharger ECU 340 may be integrated into one ECU. In the present embodiment, engine ECU 250 and supercharger ECU 340 are connected so that they can communicate in both directions.

  Air sucked from the suction port 150 is filtered by the air cleaner 152. The air filtered by the air cleaner 152 flows to the electric supercharger 200 through the intake passage 156. The air flowing through the electric supercharger 200 is compressed by the compressor 202, then flows through the intake passage 160, and is cooled by the intercooler 162. The air cooled by the intercooler 162 flows through the intake passage 102 and is taken into the engine 100.

  An air flow meter 154 that detects the amount of intake air is provided in the middle of the intake passage 156. Air flow meter 154 transmits a signal representing the detected intake air amount to engine ECU 250.

  The intercooler 162 cools the air that has been compressed by the compressor 202 and has risen in temperature. Since the volume of the cooled air is smaller than that before cooling, more air is sent into the engine 100.

  Further, a bypass passage 158 that bypasses the intake passage 156 and the intake passage 160 is provided, and an air bypass valve 164 that adjusts the flow rate of the air flowing through the bypass passage 158 is provided in the middle of the bypass passage 158. Air bypass valve 164 operates in accordance with a control signal received from engine ECU 250.

  A throttle valve 166 that adjusts the flow rate of air flowing through the intake passage 102 is provided in the middle of the intake passage 102. The throttle valve 166 is driven by a throttle motor 168. Throttle motor 168 is driven in accordance with a control signal received from engine ECU 250.

  An intake pipe pressure sensor 170 and an intake air temperature sensor 172 are provided in the intake passage 102. The intake pipe pressure sensor 170 detects the pressure of air in the intake passage 102. Intake pipe pressure sensor 170 transmits a signal representing the detected air pressure to engine ECU 250. The intake air temperature sensor 172 detects the temperature of air in the intake passage 102. Intake air temperature sensor 172 transmits a signal representing the detected air temperature to engine ECU 250.

  Engine 100 includes a cylinder head (not shown) and a cylinder block 112. The cylinder block 112 is provided with a plurality of cylinders in the vertical direction of the drawing in FIG. In each cylinder, a piston 114 is slidable in the vertical direction of the drawing. Piston 114 is connected to crankshaft 120 via connecting rod 116. A piston 114, connecting rod 116 and crankshaft 120 form a crank mechanism.

  A combustion chamber 108 is formed at the upper part of the piston 114. The combustion chamber 108 is provided with a spark plug 110 and a fuel injection injector 106 toward the combustion chamber 108. In the present embodiment, engine 100 is described as being a direct injection engine, but is not particularly limited to a direct injection engine. For example, engine 100 may be an internal combustion engine, and may be a port injection type engine or a diesel engine.

  In the cylinder head, an intake passage 102 and an exhaust passage 130 are provided so as to be connected to the combustion chamber 108, respectively. An intake valve 104 is provided between the intake passage 102 and the combustion chamber 108. An exhaust valve 128 is provided between the exhaust passage 130 and the combustion chamber 108. The intake valve 104 and the exhaust valve 128 are driven by a camshaft (not shown) that rotates in conjunction with the crankshaft 120.

  The air flowing through the intake passage 102 is sucked into the combustion chamber 108 by opening the intake valve 104 when the piston 114 descends. The air flowing into the combustion chamber 108 is mixed with the fuel injected from the fuel injection injector 106. When the intake valve 104 is closed and the piston 114 rises to near the top dead center, the air mixed with fuel is ignited and burned in the spark plug 110. Piston 114 is pushed down by the pressure by combustion. At this time, the vertical motion of the piston 114 is converted into the rotational motion of the crankshaft 120 via the crank mechanism. When the piston 114 is lowered to near the bottom dead center, the exhaust valve 128 is opened. When the piston 114 rises again, the air combusted in the combustion chamber 108, that is, the exhaust gas, flows through the exhaust passage 130. The air that has flowed through the exhaust passage 130 drives the turbine 204 of the electric supercharger 200 and then flows through the exhaust pipe 180 and is guided to the catalyst 182. The exhaust gas is purified by the catalyst 182 and then discharged outside the vehicle.

  A pulley (not shown) is provided at one end of the crankshaft 120. The pulley is connected to a pulley provided on the rotating shaft of the alternator 126 via a belt 124. The alternator 126 is operated by the rotation of the crankshaft 120 to generate power.

  The timing rotor 118 is provided on the crankshaft 120 and rotates together with the crankshaft 120. A plurality of protrusions are provided on the outer periphery of the timing rotor 118 at predetermined intervals. The crank position sensor 122 is provided to face the protrusion of the timing rotor 304. When the timing rotor 118 rotates, the air gap between the projection of the timing rotor 118 and the crank position sensor 122 changes, so that the magnetic flux passing through the coil portion of the crank position sensor 122 increases and decreases, and an electromotive force is generated in the coil portion. . Crank position sensor 122 transmits a signal representing the electromotive force to engine ECU 250. Engine ECU 250 detects the crank angle based on the signal transmitted from crank position sensor 122.

  Further, the vehicle is provided with a vehicle speed sensor (not shown) on the wheel, and detects the rotation speed (wheel speed) of the wheel. The vehicle speed sensor transmits a signal representing the detection result to engine ECU 250. Engine ECU 250 calculates the vehicle speed from the rotational speed of the wheel.

  Engine ECU 250 performs arithmetic processing based on signals transmitted from each sensor such as intake pressure, intake air temperature, intake air amount, wheel speed, maps and programs stored in memory, and engine 100 enters a desired operating state. So that the equipment is controlled.

  Electric supercharger 200 includes a compressor 202, a rotating electrical machine 216, a shaft 210, and a turbine 204.

  A compressor wheel (also referred to as a compressor rotor, a compressor blade, etc.) 206 is accommodated in the housing of the compressor 202. The compressor wheel 206 compresses (supercharges) the air filtered by the air cleaner 152.

  A turbine wheel (also referred to as a turbine rotor, a turbine blade, or the like) 208 is accommodated in the housing of the turbine 204. The turbine wheel 208 is rotated by exhaust gas.

  The compressor wheel 206 and the turbine wheel 208 are provided at both ends of the shaft 210, respectively. That is, when the turbine wheel 208 is rotated by the exhaust gas, the compressor wheel 206 is also rotated.

  A rotating electrical machine 216 having a shaft 210 as a rotation axis is provided between the compressor wheel 206 and the turbine wheel 208. The shaft 210 is rotatably supported by the housing of the rotating electrical machine 216.

  The rotating electrical machine 216 applies a rotational force to the shaft 210 by electric power supplied from a supercharger EDU (Electronic Drive Unit) 330 according to a control signal of the supercharger ECU 340. The supercharger EDU 330 uses the power supplied from the high voltage battery 320 to supply power to the rotating electrical machine 216 according to the control signal input from the supercharger ECU 340. Supercharger EDU330 is an inverter, for example.

  The rotating electrical machine 216 is provided with a rotor position sensor (not shown). The rotor position sensor detects the rotation position (rotation angle) and rotation speed of the rotor (rotor). The rotor position sensor transmits a signal representing the detection result to supercharger ECU 340. The rotor position sensor is, for example, a hall sensor.

  High voltage battery 320 is electrically connected to DC / DC converter 310. The DC / DC converter 310 is electrically connected to the alternator 126 described above. Therefore, the electric power generated in the alternator 126 is boosted to an appropriate voltage by the DC / DC converter 310 and then supplied to the high voltage battery 320. Thereby, the high voltage battery 320 is charged. In addition, the electric power generated by the alternator 126 is supplied to the low voltage battery 300. Thereby, the low voltage battery 300 is charged. The low voltage battery 300 supplies electric power to the engine ECU 250, the supercharger ECU 340, and the like.

  Supercharger ECU 340 performs arithmetic processing based on information transmitted from engine ECU 250, a signal transmitted from the rotor position sensor, and a map and program stored in memory, and electric supercharger 200 performs a desired process. The devices are controlled so as to be in an operating state.

  In the electric supercharger 200 having the above-described configuration, after the air mixed with fuel is burned in the engine 100, the exhaust gas is guided into the turbine 204 from the exhaust passage 130. The exhaust gas then rotates the turbine wheel 208 and the rotational force is transmitted to the shaft 210. Thereafter, the exhaust gas flows through the exhaust pipe 180 and is guided to the catalyst 182. The exhaust gas guided to the catalyst 182 is exhausted outside the vehicle in a purified state.

  On the other hand, the air taken from outside the vehicle to be supplied to the engine 100 is filtered by the air cleaner 152, then flows through the intake passage 156 and is guided into the compressor 202. The air is compressed (supercharged) by a compressor wheel 206 that rotates integrally with the shaft 210. The compressed air is guided to the intercooler 162 and is sucked into the combustion chamber 108 through the intake passage 102 of the engine 100 in a cooled state.

  Further, supercharger ECU 340, when the air compressed by compressor 202 does not reach a desired supercharging pressure in the low rotation range of engine 100 (for example, the rotation speed of engine 100 is equal to or lower than a predetermined rotation speed). In some cases, the supercharging pressure of the compressor 202 is controlled to be forcibly increased by driving the rotating electrical machine 216.

  As shown in FIG. 2, in the present embodiment, the rotating electrical machine 216 includes a rotor 214 provided in the middle of the shaft 210, a stator core 212 provided facing the rotor 214 from a direction orthogonal to the rotation axis of the shaft 210, And a housing 230 that houses the stator core 212. The stator core 212 is formed so as to surround the rotor 214 around the rotation axis. A plurality of teeth are formed on the stator core 212 so as to face the rotor 214. A coil 234 is wound around each of the plurality of teeth. In the present embodiment, rotating electric machine 216 is, for example, a two-phase rotating electric machine (in this embodiment, an X phase and a Y phase), and stator core 212 has four teeth. The The rotary electric machine 216 is not particularly limited to a two-phase rotary electric machine, and may be, for example, a three-phase or higher rotary electric machine. The rotor 214 is provided with a permanent magnet. In the present embodiment, for example, the number of poles of the rotor 214 is two, but the present invention is not particularly limited to this.

  The shaft 210 is rotatably supported by the casing 230 of the electric supercharger 200 by a bearing portion 222 provided on the turbine wheel 208 side, a bearing portion 224 provided on the compressor wheel 206 side, and a thrust bearing 228. A spacer 232 is provided between the compressor wheel 206 and the thrust bearing 228.

  When power is supplied to the coil 234, a magnetic field is generated in the coil 234. A flow of magnetic flux is formed based on the generated magnetic field, and the rotor 214 obtains a rotational force. In the rotating electrical machine 216 according to the present embodiment, a search coil 218 is further wound around the tip of the teeth formed on the stator core 212 on the rotor 214 side, in addition to the coil 234. The voltage induced in search coil 218 is output to supercharger ECU 340.

  As shown in FIG. 3, which is a 3-3 cross section of FIG. 2, in the present embodiment, four teeth 242, 244, 246, and 248 are provided on the stator core 212 every 90 degrees around the rotation axis of the shaft 210. It is formed to have a phase angle. Coils 234, 236, 238, and 240 are wound around the teeth 242, 244, 246, and 248, respectively. In the present embodiment, the coils 236 and 240 correspond to the X-phase coil, and the coils 234 and 238 correspond to the Y-phase coil. The coils 236 and 240 and the coils 234 and 238 are electrically connected to each other. Further, search coils 218 and 220 for detecting displacement of the shaft 210 are wound around the tips of the teeth 242 and 244 on the rotor 214 side, in addition to the coils 234 and 236. The search coils 218 and 220 may be provided in the teeth corresponding to each phase, and are not particularly limited to being provided in the teeth 242 and 244. For example, in the case of a three-phase rotating electric machine, the teeth corresponding to at least two phases of the three phases (for example, the teeth corresponding to any two phases of the U phase, the V phase, and the W phase). A search coil may be provided, or may be provided on adjacent teeth. Further, the number of search coils is not particularly limited to two.

  The search coils 218 and 220 are induced by the rotation of the rotor 214. At this time, the induced voltage changes according to the distance between the search coils 218 and 220 and the rotor 214 and the rotation angle (phase angle) of the rotor 214. In the present embodiment, the left-right direction in FIG. 3 is the X direction, and the teeth 244 and 248 around which the X-phase coils 236 and 240 are wound are also referred to as teeth X. Further, the teeth 242 and 246 around which the Y-phase coils 234 and 240 are wound are also referred to as teeth Y, with the vertical direction on the paper surface of FIG.

  In such an electric supercharger 200, the rotor 214 is provided on the shaft 210, so that the mass of the rotating body is increased compared to the shaft of the supercharger that does not have the rotating electrical machine. Therefore, as shown in FIG. 4, when the vibration mode (broken line) when the rotating electrical machine 216 is not provided and the vibration mode (solid line) when the rotating electrical machine 216 is provided are compared, the case where the rotating electrical machine 200 is provided is compared. However, the shaft vibration of the shaft 210 tends to increase. This is because the degree of unbalance of the rotating body increases as the mass of the rotating body increases. In particular, in the high-speed rotation range of the electric supercharger 200, the centrifugal force generated due to imbalance increases in proportion to the square of the rotation speed. For this reason, the shaft vibration tends to increase due to a large influence of high-frequency whip vibration caused by self-excited vibration in the bearing portions 222 and 224 and the thrust bearing 228.

  As shown in FIG. 5, in the vibration distribution diagram when the horizontal axis is the frequency and the vertical axis is the rotation speed, the whip vibration is compared with the rotation speed outside the range of the motor assist zone (shaded portion) by the rotating electric machine 200. It occurs in a high area. Whip vibration is high energy and can cause vibration and noise.

  Therefore, the present invention provides an operating region in which the supercharger ECU 340 detects a physical quantity corresponding to the displacement amount of the shaft 210 in a direction orthogonal to the rotation axis of the shaft 210 and the rotational force by the rotating electrical machine 216 is not applied to the shaft 210. , The X-phase coils 236 and 240 and the Y-phase coil are arranged so that a magnetic force corresponding to the detected physical quantity is generated in the direction from the axial center of the shaft 210 after displacement to the axial center of the shaft 210 before displacement. It is characterized in that the power supplied to 234 and 238 is controlled.

  Specifically, the supercharger ECU 340 uses the search coils 218 and 220 when the shaft 210 rotates without displacement, and when the shaft 210 rotates without displacement. The induced second voltage change is compared, and a physical quantity corresponding to the displacement is detected based on the comparison result.

  Changes in the rotation of the rotor 214 when the shaft center of the shaft 210, that is, the rotation center of the rotor 214 is displaced by shaft vibration during high-speed rotation of the electric supercharger 200 is shown in FIGS. 6 (A) to 6 (H) and FIGS. 7 (A) to 7 (H), the position where the N pole of the rotor 214 faces the teeth 242 is 45 degrees clockwise with the phase angle of 0 degree. Shows the change of the rotating rotor 214. FIGS. 6A to 6H show changes in the rotation of the rotor from a phase angle of 0 degrees to a phase angle of 315 degrees. FIGS. 7A to 7H show changes in the rotation of the rotor from a phase angle of 360 degrees to a phase angle of 675 degrees. Note that, at the phase angle of 720 degrees, the rotor 214 is at the same position as that at the phase angle of 0 degrees.

  6 and 7, the rotation center of the rotor 214 (solid line) is displaced from the rotation center of the rotor 214 (broken line) when no shaft vibration occurs (hereinafter referred to as no vibration) and rotates.

  As shown in FIG. 6A, at the phase angle of 0 degree, the rotation center of the rotor 214 during high-speed rotation is displaced to the side closest to the search coil 218. At this time, the rotation center of the rotor 214 (solid line) at the time of high-speed rotation is approximately equal to the rotation center of the rotor 214 (broken line) without vibration and the distance from the search coil 220.

  As shown in FIGS. 6B to 6D, when the rotor 214 is rotated, the rotation center of the rotor 214 (solid line) during high-speed rotation is displaced to the side far from the search coil 218. Then, it is displaced closer to the search coil 220.

  As shown in FIG. 6E, at the phase angle of 180 degrees, the rotation center of the rotor 214 at the time of high speed rotation is substantially equal in distance to the rotation center of the rotor 214 and the search coil 218 without vibration. Displace to the side closest to 220.

  As shown in FIG. 6 (F) to FIG. 6 (H), when the rotor 214 rotates after the phase angle of 180 degrees, the rotation center of the rotor 214 at the time of high speed rotation is the rotation center of the rotor 214 without vibration. It is displaced further away from the search coil 218 than the center of rotation, and further displaced further away from the search coil 220.

  As shown in FIG. 7A, at the phase angle of 360 degrees, the rotation center of the rotor 214 during high-speed rotation is displaced to the side farthest from the search coil 218. At this time, the rotation center of the rotor 214 at the time of high speed rotation is substantially equal to the rotation center of the rotor 214 at the time of no vibration and the distance from the search coil 220.

  As shown in FIGS. 7B to 7D, when the rotor 214 rotates, the rotation center of the rotor 214 at the time of high-speed rotation is displaced closer to the search coil 218, and the search coil. It is displaced to the side far from 220.

  As shown in FIG. 7E, at the phase angle of 540 degrees, the rotation center of the rotor 214 at the time of high speed rotation is substantially equal in distance from the rotation center of the rotor 214 at the time of no vibration and the search coil 218. Displace to the farthest side from 220.

  As shown in FIG. 7 (F) to FIG. 7 (H), when the rotor 214 is rotated after the phase angle of 540 degrees, the rotation center of the rotor 214 at the time of high speed rotation is the rotation center of the rotor 214 without vibration. It is displaced closer to the search coil 218 than the center of rotation and is displaced closer to the search coil 220. At the phase angle of 720 degrees, the rotation center of the rotor 214 is the same position as the rotation center when the phase angle is 0 degree shown in FIG.

  FIG. 8A shows a change in voltage induced by the search coil 218 while the rotor 214 rotates from the phase angle of 0 degree to 720 degrees. Further, FIG. 8B shows a change in voltage induced by the search coil 220. In FIGS. 8A and 8B, the solid line indicates the change in the induced voltage when there is no vibration. In FIGS. 8A and 8B, the points indicate changes in the induced voltage during high-speed rotation. Since the distance between the rotation center of the rotor 214 and the search coils 218 and 220 is substantially constant when there is no vibration, the amplitude of the induced voltage is also substantially constant. On the other hand, at the time of high-speed rotation, since it rotates with whip vibration, the rotation center of the rotor 214 is displaced. Therefore, the amplitude of the voltage induced by the search coil 218 changes according to the amount of displacement in the Y direction with respect to the search coil 218, and the amplitude of the voltage induced by the search coil 220 is the amount of displacement in the X direction with respect to the search coil 220. It changes according to. Therefore, the voltage difference induced by the search coils 218 and 220 during high-speed rotation and no vibration corresponds to the amount of displacement of the shaft 210.

  Therefore, as shown in FIG. 9, which is an enlarged view of the broken line frame in FIG. 8, the difference between the voltage induced by the search coil 220 without vibration and the voltage induced by the search coil 220 during high-speed rotation (hereinafter referred to as magnetic force). By detecting as Mx (also referred to as a difference), it is possible to detect a physical quantity corresponding to the displacement amount of the rotation center (axial center) of the rotor 214 (that is, the shaft 210) in the X direction. For example, if the phase angle of the rotor 214 is 90 degrees, the amplitude difference of the voltage oscillation is detected as the magnetic force difference Mx.

  Similarly, the rotation center of the rotor 214 in the Y direction is detected by detecting the difference between the voltage induced by the search coil 218 without vibration and the voltage induced by the search coil 218 at high speed rotation as the magnetic force difference My. It is possible to detect a physical quantity corresponding to the amount of displacement.

  Supercharger ECU 340 of electric supercharger 200 according to the present embodiment operates in an operating region where rotational force by rotating electrical machine 216 is not applied to shaft 210 (that is, high rotational speed outside the range of the motor assist zone shown in FIG. 5). A magnetic force corresponding to the detected physical quantity (voltage difference in the present embodiment) is developed in the direction from the axial center of the shaft 210 after displacement to the axial center of the shaft 210 before displacement. The power supplied to the X-phase coils 236 and 240 and the Y-phase coils 234 and 240 is controlled.

  In the present embodiment, the power supplied to the X-phase coils 236 and 240 and the Y-phase coils 234 and 238 is controlled based on the detected magnetic force differences Mx and My. The amount of displacement in the X direction and the Y direction is calculated based on the magnetic force differences Mx and My, and the electric power supplied to the X phase coils 236 and 240 and the Y phase coils 234 and 238 is calculated based on the calculated displacement amount. You may make it control.

  Hereinafter, a control structure of a program executed by supercharger ECU 340 of electric supercharger 200 according to the present embodiment will be described with reference to FIG.

  In step (hereinafter, step is referred to as S) 100, supercharger ECU 340 determines whether or not rotating electric machine 216 is rotating in a non-energized state. For example, the supercharger ECU 340 determines that the rotational speed of the shaft 210 of the electric supercharger 200 detected by the rotor position sensor is equal to or higher than a predetermined rotational speed that is outside the range of the motor assist zone. Is determined to be rotating in a non-energized state. Alternatively, supercharger ECU 340 determines that rotating electrical machine 216 is rotating in a non-energized state if the engine rotational speed is outside the rotational speed range that requires assistance from rotating electrical machine 200. If electric supercharger 200 is rotating in a non-energized state (YES in S100), the process proceeds to S102. If not (NO in S100), the process returns to S100.

  In S102, supercharger ECU 340 detects magnetic force differences Mx and My. Specifically, in the memory of the supercharger ECU 340, a waveform indicating a change in voltage induced by the search coils 218 and 220 when there is no vibration before displacement, which is set by an experiment or the like, is stored in advance. The supercharger ECU 340 outputs the voltage output from the search coils 218 and 220, that is, the voltage at the same phase angle between the voltage induced by the search coil 220 during high-speed rotation and the voltage induced in the memory without vibration. The difference is calculated, and the magnetic force differences Mx and My are detected.

  When the voltage induced at high speed rotation at the same phase angle is smaller than the voltage induced at no amplitude, the shaft center of the shaft 210 at the time of high speed rotation is higher than the axis of the shaft 210 at the time of no vibration. , 220 is displaced to the far side. Further, when the voltage induced at high speed rotation at the same phase angle is larger than the voltage induced at no amplitude, the shaft center of the shaft 210 at the time of high speed rotation is higher than the axis center of the shaft 210 at the time of no vibration. , 220 indicates a displacement closer to the side.

  In S104, supercharger ECU 340 determines energization amounts in the X direction and the Y direction. Specifically, the supercharger ECU 340 determines the X-phase coils 236 and 240 wound around the teeth X and the Y-phase coil 234 wound around the teeth Y based on the detected magnetic force differences Mx and My. , 238 is determined.

  At this time, the energization amount in the X direction and the Y direction is such that magnetic force is applied in the direction from the axial center of the shaft 210 after displacement (that is, at high speed rotation) to the axial center of the shaft 210 before displacement (that is, when there is no vibration). To be generated. Thereby, a magnetic force is developed in a direction opposite to the direction in which the displacement increases due to the shaft vibration of the shaft 210.

  A specific method for determining the energization amount is not particularly limited. For example, a map (1) and a map (2) indicating the relationship between the magnetic force differences Mx and My and the energization amount are displayed in the supercharger ECU 340. Preliminarily stored in the memory, the supercharger ECU 340 determines the energization amount in the X direction based on the magnetic difference Mx and the map (1), and based on the magnetic difference My and the map (2), Y The energization amount in the direction may be determined. The map (1) and the map (2) may be different maps or the same map. Further, the relationship between the magnetic force differences Mx, My and the energization amount in the maps (1) and (2) is set so that the shaft vibration is suppressed by an experiment or the like. Further, the supercharger ECU 340 may determine the energization amounts in the X direction and the Y direction based on a predetermined table or function formula and the magnetic difference Mx, My instead of the map.

  In S106, supercharger ECU 340 controls electric power so that the energization amount determined in S104 is supplied. Specifically, the supercharger ECU 340 outputs a control signal to the supercharger EDU 330 so that the energization amounts determined for the X-phase coils 236 and 240 and the Y-phase coils 234 and 238 of the stator core 212 are set. Supply the corresponding power.

  In S108, supercharger ECU 340 determines whether or not the electric supercharger 200 needs to be assisted by rotating electric machine 216. For example, when the rotational speed of electric supercharger 200 is smaller than a predetermined rotational speed that falls within the range of the motor assist zone, supercharger ECU 340 determines that assist by rotating electrical machine 216 is necessary. Alternatively, if the engine speed is within the rotation speed range that requires assist by the rotating electrical machine 200, it may be determined that the assist by the rotating electrical machine 216 is necessary. If the assist by rotating electric machine 216 is necessary (YES in S108), this process ends. If not (NO in S108), the process returns to S102.

  An operation of electric supercharger 200 according to the present embodiment based on the above-described structure and flowchart will be described with reference to FIG.

  When the engine 100 is operated, the turbine wheel 208 is rotated by the energy of the exhaust gas to drive the compressor wheel. When the rotational speed of the engine 100 is low enough to be within the motor assist zone, electric power is selectively supplied to one of the X-phase coils 236 and 240 and the Y-phase coils 234 and 238 of the rotating electrical machine 216. The At this time, rotational force is applied to shaft 210 (NO in S100), and the boost pressure is quickly raised.

  When the rotational speed of the engine 100 increases and the rotational speed of the shaft 210 falls outside the range of the motor assist zone, power supply to the X-phase coils 236 and 240 and the Y-phase coils 234 and 238 is stopped. Therefore, in electric supercharger 200, rotating electric machine 216 rotates in a non-energized state (YES in S100).

  At this time, the magnetic differences Mx and My are detected (S102), and the energization amounts in the X direction and the Y direction are determined according to the detected magnetic differences Mx and My (S104). Then, power is supplied to the X-phase coils 236 and 240 and the Y-phase coils 234 and 238 so that the determined energization amount is obtained (S106). When electric power is supplied to the X-phase coils 236 and 240 and the Y-phase coils 234 and 238, a magnetic field is generated, and a magnetic force acts on the rotor 214 based on the generated magnetic field.

  As shown in FIG. 11, the power corresponding to the energization amount determined according to the detected magnetic force difference Mx is supplied to the X-phase coils 236 and 240, whereby the X-direction force Fx is applied to the rotor 214. Works. Further, the electric power corresponding to the energization amount determined according to the detected magnetic force difference My is supplied to the Y-phase coils 234 and 238, whereby the Y-direction force Fy acts on the rotor 214. . At this time, the resultant force Fxy of Fx and Fy acts on the rotor 214 from the axis center a of the rotor 214 (solid line) toward the axis center b of the rotor 214 (dashed line) when no vibration occurs.

  If the operating range is such that the rotational force assist by rotating electric machine 216 is not required (NO in S108), magnetic force differences Mx and My are calculated for each predetermined calculation cycle as rotor 214 rotates. The energization amount is determined. The magnetic differences Mx and My may be calculated for each predetermined phase angle. Electric power corresponding to the determined energization amounts is supplied to the X-phase coils 236 and 240 and the Y-phase coils 234 and 238, respectively. Therefore, magnetic force acts on the rotor 214 in a direction perpendicular to the shaft 210 and from the axial center of the shaft 210 during high-speed rotation to the axial center of the shaft 210 when no vibration occurs. An increase in the amplitude of vibration is suppressed.

  Then, when it is in an operation region where assistance by the rotating electrical machine is required (YES in S108), power is selectively supplied to any of X-phase coils 236, 240 and Y-phase coils 234, 238. .

  As described above, according to the electric supercharger according to the present embodiment, a magnetic force can be developed in the direction opposite to the direction in which the amplitude of the shaft vibration increases when the shaft rotates. Therefore, an increase in the amplitude of shaft vibration can be suppressed. Further, by increasing the magnetic force according to the voltage difference of the search coil during high-speed rotation and no vibration, an increase in the amount of displacement that increases during high-speed rotation is suppressed. Therefore, shaft vibration can be effectively suppressed. In addition, it is only necessary to provide a search coil at the tip of the tooth, and it is not necessary to increase the size of the structure of the electric supercharger, so that an increase in cost can be suppressed. Therefore, it is possible to provide an electric supercharger that suppresses vibration during high rotation while suppressing an increase in cost.

  In the present embodiment, electric supercharger 200 is configured such that bearings 222 and 224 are provided on both sides of rotor 214 with respect to shaft 210 on which rotor 214 is provided. Is not to be done.

  For example, as shown in FIG. 12, the present invention may be applied to a so-called cantilever type electric supercharger in which the shaft 210 is rotatably supported by a bearing portion 322 provided on one end side of the rotor 214. Since the cantilever type electric supercharger has a structure in which vibration is likely to increase, by applying the present invention, shaft vibration during high-speed rotation can be effectively suppressed.

<Second Embodiment>
Hereinafter, an electric supercharger according to a second embodiment of the present invention will be described. The electric supercharger according to the present embodiment is different from the electric supercharger 200 according to the first embodiment described above in that Hall sensors 252 and 254 are included instead of the search coils 218 and 220. . The other configuration is the same as that of the electric supercharger 200 according to the first embodiment described above. They are given the same reference numerals. Their functions are the same. Therefore, detailed description thereof will not be repeated here.

  As shown in FIG. 13, in electric supercharger 200 according to the present embodiment, hall sensors 252 and 254 are provided to face rotor 214 from a direction orthogonal to the rotation axis of shaft 210. The number of hall sensors is not particularly limited to two. In the present embodiment, the Hall sensors 252 and 254 are rectangular Hall sensors, and signals are output according to the strength of the magnetic field. More specifically, the Hall sensors 252 and 254 have a magnetic field intensity (or magnetic flux density value) generated by the rotation of the rotor 214 greater than or equal to a predetermined value (1) (hereinafter also referred to as + threshold level). Then, a signal is output. When the intensity of the magnetic field becomes equal to or less than a predetermined value (2) (hereinafter also referred to as “−threshold level”) that is smaller than the “+ threshold level”, signal output is stopped. In the present embodiment, Hall sensors 252 and 254 output a signal when one of N pole and S pole of rotor 214 approaches, and stop signal output when the other approaches (when one moves away). To do. In the present embodiment, for example, the Hall sensors 252 and 254 output a signal when the intensity of the magnetic field exceeds the + threshold level when the N pole approaches, and the intensity of the magnetic field decreases when the N pole moves away. Signal output is stopped when the threshold level is exceeded. In the present embodiment, Hall sensors 252 and 254 are provided so as to have an angle of 90 degrees around the rotation axis of shaft 210. The supercharger ECU 340 detects the rotational position (rotational angle) and rotational speed of the rotor 214 based on the combination of turning off and on the hall sensors 252 and 254. In other words, the rotor position sensor is realized by the Hall sensors 252 and 254.

  Further, the supercharger ECU 340 of the electric supercharger 200 according to the present embodiment compares the output change of the Hall sensors 252 and 254 when the shaft 210 rotates at high speed and the output change when no vibration is detected. It is characterized in that a physical quantity corresponding to a displacement amount in a direction orthogonal to the rotation axis of the shaft 210 is detected based on the result. Further, the supercharger ECU 340 corresponds to the detected physical quantity in the direction from the axial center of the shaft 210 after displacement to the axial center of the shaft 210 before displacement in an operation region where the rotational force by the rotating electrical machine 216 is not applied. The electric power supplied to the coils 234, 236, 238, and 240 is controlled so as to develop a magnetic force.

  In the present embodiment, the phase angle difference at which the output values of the signals of the Hall sensors 252 and 254 when the shaft 210 rotates at high speed and when there is no vibration is a predetermined value is a physical quantity corresponding to the displacement.

  As shown in FIG. 14A, the rectangular output signal (solid line) of the Hall sensor 252 when there is no vibration corresponds to the change in magnetic field strength (broken line) caused by the rotation of the Hall sensor 252 and the rotor 214. To change. Specifically, in the Hall sensor 252, the phase angle when the intensity of the magnetic field is substantially zero is set as a reference (phase angle 0 degree). As the N pole approaches the Hall sensor 252 as the rotor 214 rotates, the strength of the magnetic field increases. The hall sensor 252 outputs a signal when the intensity of the magnetic field exceeds the + threshold level. When the N pole moves away from the Hall sensor 252 and the strength of the magnetic field falls below the −threshold level, signal output is stopped. Since the hall sensors 252 and 254 have a phase angle of 90 degrees, the waveform of the signal output from the hall sensor 254 is the waveform shown in FIG. The waveform is shifted. Therefore, detailed description will not be repeated. When the rotor 214 rotates, the distance between the rotor 214 and the hall sensors 252 and 254 is substantially constant.

  As shown in FIG. 14B, when the rotor 214 rotates at a high speed, the rotation center of the rotor 214 is displaced from the rotation center when no vibration occurs, so the distance between the rotor 214 and the hall sensors 252 and 254 varies. To do. When the distance between the rotor 214 and the hall sensor 252 is small, the amount of change in the signal output is large as shown by the alternate long and short dash line in FIG. Therefore, there is a difference in the phase angle when the signal output of the Hall sensor 252 exceeds the + threshold level during high-speed rotation and no vibration. This phase angle difference corresponds to the amount of displacement of the shaft 210.

  Therefore, as shown in FIG. 15 which is an enlarged view of the broken line frame in FIG. 14B, the vibration is detected by detecting the phase angle difference ta when the + threshold level is exceeded during high-speed rotation and no vibration. A physical quantity corresponding to the amount of displacement of the shaft 210 in the direction from the center of rotation of the rotor 214 to the hall sensor 252 can be detected. Similarly, the shaft in the direction from the rotation center of the rotor 214 without vibration to the hall sensor 254 is detected by detecting the phase angle difference tb when the + threshold level is exceeded during high-speed rotation and no vibration. A physical quantity corresponding to the displacement amount 210 can be detected.

  The supercharger ECU 340 of the electric supercharger 200 according to the present embodiment is configured so that the shaft 210 of the shaft 210 before the displacement from the center of the shaft 210 after the displacement in the operation region where the rotational force by the rotating electrical machine 216 is not applied to the shaft 210. The electric power supplied to the X-phase coils 236 and 240 and the Y-phase coils 234 and 238 is controlled so that a magnetic force corresponding to the detected phase angle differences ta and tb appears in the direction toward the center.

  In the present embodiment, supercharger ECU 340 controls electric power supplied to X-phase coils 236 and 240 and Y-phase coils 234 and 238 based on the detected phase angle differences ta and tb. However, based on the detected phase angle differences ta and tb, the X-direction and Y-direction displacement amounts are calculated, and the X-phase coils 236 and 240 and the Y-phase coils 234 and 234 are calculated based on the calculated displacement amounts. The power supplied to 238 may be controlled.

  In particular, the phase angle differences ta and tb correspond to the amount of displacement of the shaft 210 in the direction of the Hall sensor 252 and the direction of the Hall sensor 254 from the axial center of the shaft 210 when there is no vibration. Therefore, the amount of displacement of the shaft 210 in the X direction and the Y direction is calculated by performing coordinate conversion in the X direction and the Y direction, and the X phase coils 236 and 240 and the Y phase are calculated based on the calculated displacement amount. The power supplied to the coils 234 and 238 may be controlled.

  Hereinafter, a control structure of a program executed by supercharger ECU 340 of electric supercharger 200 according to the present embodiment will be described with reference to FIG.

  In the flowchart shown in FIG. 16, the same steps as those in the flowchart shown in FIG. 10 are given the same step numbers. The processing is the same for them. Therefore, detailed description thereof will not be repeated here.

  In S202, supercharger ECU 340 detects rising phase angle differences ta and tb of the signal output. Specifically, the memory of the supercharger ECU 340 stores in advance the phase angle when a signal is output from the hall sensors 252 and 254, which is set by experiment or the like when there is no vibration before displacement. Supercharger ECU 340 stores in memory the phase angle (that is, the phase angle during high-speed rotation) when the strength of magnetic field exceeds the + threshold level due to rotation of rotor 214 and signals are output from Hall sensors 252 and 254. The phase angle difference ta, tb with the corresponding phase angle (that is, the phase angle without vibration) is detected.

  If the phase angle when the signal is output during high-speed rotation is smaller than the phase angle when the signal is output when there is no vibration, the axis center of the shaft 210 during high-speed rotation is the axis of the shaft 210 when there is no vibration. This indicates that the center is displaced closer to the Hall sensors 252 and 254 than the center. Also, if the phase angle when the signal is output during high-speed rotation is larger than the phase angle when the signal is output when there is no vibration, the shaft center of the shaft 210 during high-speed rotation is the axis of the shaft 210 when there is no vibration. It shows that the center is displaced farther from the hall sensors 252 and 254 than the center of the axis.

  In S204, supercharger ECU 340 determines energization amounts in the X direction and the Y direction. Specifically, supercharger ECU 340 determines the amount of power supplied to X-phase coils 236 and 240 and Y-phase coils 234 and 238. Note that the coordinate system defined by the direction from the axial center of the shaft 210 to the hall sensor 252 and the direction from the axial center of the shaft 210 to the hall sensor 254 is relative to the coordinate system defined by the X direction and the Y direction. The rotation angle of the shaft 210 is a predetermined angle around the rotation axis. Therefore, the supercharger ECU 340 calculates the displacement corresponding to the phase angle differences ta and tb in the direction from the axial center of the shaft 210 to the hall sensor 252 and the direction from the axial center of the shaft 210 to the hall sensor 254. The amount of energization is determined in terms of the Y coordinate system.

  At this time, the energization amount in the X direction and the Y direction generates a magnetic force in the direction from the axial center of the shaft 210 after displacement (that is, at high speed rotation) to the axial center of the shaft 210 before displacement (that is, when there is no vibration). To be decided. Thereby, a magnetic force is developed in a direction opposite to the direction in which the displacement increases due to the shaft vibration of the shaft 210.

  A specific method for determining the energization amount is not particularly limited. For example, a map (1) and a map (2) indicating the relationship between the phase angle differences ta and tb and the energization amount are superchargers. Based on the phase angle difference ta and the map (1), the supercharger ECU 340 determines the amount of energization in the X direction based on the phase angle difference ta and the map (2). Based on this, the energization amount in the Y direction may be determined. Further, the relationship between the phase angle differences ta and tb and the energization amount in the maps (1) and (2) is set so that the shaft vibration is suppressed by an experiment or the like in consideration of the coordinate conversion described above. . Further, the supercharger ECU 340 may determine the energization amounts in the X direction and the Y direction based on a predetermined table or function expression instead of the map and the phase angle differences ta and tb.

  An operation of electric supercharger 200 according to the present embodiment based on the above-described structure and flowchart will be described.

  When the engine 100 is operated, the turbine wheel 208 is rotated by the energy of the exhaust gas to drive the compressor wheel. When the rotational speed of the engine 100 is low enough to be within the motor assist zone, electric power is selectively supplied to one of the X-phase coils 236 and 240 and the Y-phase coils 234 and 238 of the rotating electrical machine 216. The At this time, rotational force is applied to shaft 210 (NO in S100), and the boost pressure is quickly raised.

  When the rotational speed of the engine 100 increases and the rotational speed of the shaft 210 falls outside the range of the motor assist zone, power supply to the X-phase coils 236 and 240 and the Y-phase coils 234 and 238 is stopped. Therefore, in electric supercharger 200, rotating electric machine 216 rotates in a non-energized state (YES in S100).

  At this time, the phase angle differences ta and tb are detected (S202), and the energization amounts in the X direction and the Y direction are determined according to the detected phase angle differences ta and tb (S204). Then, power is supplied to the X-phase coils 236 and 240 and the Y-phase coils 234 and 238 so that the determined energization amount is obtained (S106). When electric power is supplied to the X-phase coils 236 and 240 and the Y-phase coils 234 and 238, a magnetic field is generated, and a magnetic force acts on the rotor 214 based on the generated magnetic field.

  The resultant force of the X direction force acting on the rotor 214 by energizing the X phase coils 236 and 240 and the Y direction force acting on the rotor 214 by energizing the Y phase coils 234 and 238 acts on the rotor 214. To do. At this time, the resultant force of the force in the X direction and the force in the Y direction acts on the rotor 214 from the axis center of the rotor 214 toward the axis center of the rotor 214 when no vibration occurs.

  If the operating range is such that the rotational force assist by rotating electric machine 216 is not required (NO in S108), phase angle differences ta and tb are calculated for each predetermined calculation cycle as rotor 214 rotates. To determine the energization amount. The phase angle differences ta and tb may be calculated every time a signal is output from the hall sensors 252 and 254. Electric power corresponding to the determined energization amounts is supplied to the X-phase coils 236 and 240 and the Y-phase coils 234 and 238, respectively. Therefore, magnetic force acts on the rotor 214 in a direction perpendicular to the shaft 210 and from the axial center of the shaft 210 during high-speed rotation to the axial center of the shaft 210 when no vibration occurs. An increase in the amplitude of vibration is suppressed.

  Then, when it is in an operation region where assistance by the rotating electrical machine is required (YES in S108), power is selectively supplied to any of X-phase coils 236, 240 and Y-phase coils 234, 238. .

  As described above, according to the electric supercharger according to the present embodiment, a magnetic force can be developed in the direction opposite to the direction in which the amplitude of the shaft vibration increases when the shaft rotates. Therefore, an increase in the amplitude of shaft vibration can be suppressed. In addition, the amount of displacement that increases at high rotation speed by generating a magnetic force according to the phase angle difference when the output value output from the Hall sensor at a high speed rotation and no vibration is a predetermined value. Increase is suppressed. Therefore, shaft vibration can be effectively suppressed. Further, when the Hall sensor used as the rotor position sensor is in a non-energized state of the rotating electrical machine, a physical quantity corresponding to the displacement amount of the shaft 210 can be detected. Therefore, it is not necessary to provide new parts, and an increase in cost can be suppressed.

  Preferably, the Hall sensor is provided at a location where the amplitude of axial vibration is large on the rotation axis of the shaft. By detecting a physical quantity corresponding to the amount of displacement at a location where the vibration amplitude is large, axial vibration can be more effectively suppressed.

<Third Embodiment>
Hereinafter, an electric supercharger according to a third embodiment of the present invention will be described. The electric supercharger according to the present embodiment is different from the electric supercharger 200 according to the second embodiment described above in that the Hall sensors 252 and 254 are rectangular Hall sensors, The difference is that the Hall sensors 252 and 254 are linear Hall sensors. The other configuration is the same as that of the electric supercharger 200 according to the second embodiment described above. They are given the same reference numerals. Their functions are the same. Therefore, detailed description thereof will not be repeated here.

  In the present embodiment, the Hall sensors 252 and 254 are linear Hall sensors, and a signal that changes so as to correspond to the strength of the magnetic field is output. The supercharger ECU 340 detects the rotational position (rotational angle) and rotational speed of the rotor 214 based on the output values of the hall sensors 252 and 254, respectively. The Hall sensors 252 and 254 output a + side signal when one of the N pole and the S pole of the rotor 214 approaches, and output a − side signal when the other approaches (when one moves away). . In the present embodiment, the Hall sensors 252 and 254 output a positive signal when the N pole approaches, and output a negative signal when the S pole approaches.

  Further, the supercharger ECU 340 of the electric supercharger 200 according to the present embodiment compares the output change of the Hall sensors 252 and 254 when the shaft 210 rotates at high speed and the output change when no vibration is detected. It is characterized in that a physical quantity corresponding to a displacement amount in a direction orthogonal to the rotation axis of the shaft 210 is detected based on the result. Further, the supercharger ECU 340 detects the physical quantity detected in the direction from the axial center of the shaft 210 after displacement to the axial center of the shaft 210 before displacement in an operation region where the rotational force by the rotating electrical machine 216 is not applied to the shaft 210. The electric power supplied to the coils 234, 236, 238, and 240 is controlled so that a magnetic force corresponding to the frequency is developed.

  In the present embodiment, when the shaft 210 rotates at high speed and when there is no vibration, the difference between the change amounts of the output values of the signals of the Hall sensors 252 and 254 between the predetermined phase angles is a physical quantity corresponding to the displacement amount.

  As shown in FIG. 17A, the output signal (solid line) of the Hall sensor 252 when there is no vibration changes so as to correspond to the change in the magnetic field strength caused by the rotation of the Hall sensor 252 and the rotor 214. Specifically, in the Hall sensor 252, the phase angle when the intensity of the magnetic field is zero is set as a reference (phase angle 0 degree). As the N pole approaches the Hall sensor 252 as the rotor 214 rotates, the strength of the magnetic field increases. The Hall sensor 252 increases the output value of the signal in response to an increase in the magnetic field strength. When the N pole moves away from the Hall sensor 252 and the S pole approaches, the strength of the magnetic field decreases (increases to the minus side). The Hall sensor 252 decreases the output value of the signal (increases to the minus side) in response to the decrease in the magnetic field strength. Since the Hall sensors 252 and 254 have a phase angle of 90 degrees, the waveform of the signal output from the Hall sensor 254 is 90 degrees in the right direction on the paper surface of the waveform shown in FIG. The waveform is shifted. Therefore, detailed description will not be repeated. When the rotor 214 rotates, the distance between the rotor 214 and the hall sensors 252 and 254 is substantially constant.

  As shown in FIG. 17B, when the rotor 214 rotates at a high speed, the rotation center of the rotor 214 is displaced from the rotation center when no vibration occurs, so the distance between the rotor 214 and the Hall sensors 252 and 254 varies. To do. When the distance between the rotor 214 and the hall sensor 252 becomes smaller, the amount of change in signal output becomes larger as shown by the solid line in FIG. There is a difference in the amount of change in the signal output of the Hall sensor 252 between high-speed rotation and no vibration. This difference in change amount corresponds to the displacement amount of the shaft 210.

  Accordingly, as shown in FIG. 18 which is an enlarged view of the broken-line frame in FIG. 17B, a predetermined phase angle interval (for example, between phase angle 0 degrees and phase angle A (0) in FIG. 18). The physical quantity corresponding to the amount of displacement of the shaft 210 in the direction from the center of rotation of the rotor 214 to the Hall sensor 252 when no vibration is detected by detecting the difference (hereinafter also referred to as magnetic force difference) Mha of the change in signal output at Can be detected. Similarly, the shaft in the direction from the rotation center of the rotor 214 without vibration to the hall sensor 254 is detected by detecting the magnetic force difference Mhb of the signal output between predetermined phase angles during high-speed rotation and no vibration. A physical quantity corresponding to the displacement amount 210 can be detected. The predetermined phase angle is not particularly limited to the phase angle from 0 degree to the phase angle A (0).

  The supercharger ECU 340 of the electric supercharger 200 according to the present embodiment is configured so that the shaft 210 of the shaft 210 before the displacement from the center of the shaft 210 after the displacement in the operation region where the rotational force by the rotating electrical machine 216 is not applied to the shaft 210. The power supplied to the X-phase coils 236 and 240 and the Y-phase coils 234 and 238 is controlled so that a magnetic force corresponding to the detected magnetic force difference Mha and Mhb is developed in the direction toward the center.

  In the present embodiment, supercharger ECU 340 controls the electric power supplied to X-phase coils 236 and 240 and Y-phase coils 234 and 238 based on the detected magnetic force differences Mha and Mhb. Based on the detected magnetic differences Mha and Mhb, displacement amounts in the X direction and the Y direction are calculated, and supplied to the X-phase coils 236 and 240 and the Y-phase coils 234 and 238 based on the calculated displacement amounts. You may make it control the electric power to be performed.

  In particular, the magnetic force differences Mha and Mhb correspond to the amount of displacement of the shaft 210 in the direction of the Hall sensor 252 and the direction of the Hall sensor 254 from the axial center of the shaft 210 when there is no vibration. Therefore, the amount of displacement of the shaft 210 in the X direction and the Y direction is calculated by performing coordinate conversion in the X direction and the Y direction, and the X phase coils 236 and 240 and the Y phase are calculated based on the calculated displacement amount. The power supplied to the coils 234 and 238 may be controlled.

  Hereinafter, a control structure of a program executed by supercharger ECU 340 of electric supercharger 200 according to the present embodiment will be described with reference to FIG.

  In the flowchart shown in FIG. 19, the same steps as those in the flowchart shown in FIG. 10 are given the same step numbers. The processing is the same for them. Therefore, detailed description thereof will not be repeated here.

In S302, supercharger ECU 340 detects magnetic force difference Mha, Mhb. Specifically, in the memory of the supercharger ECU 340, the magnetic force differences Mha and Mhb of the signal output between the predetermined phase angles in the Hall sensors 252 and 254 when there is no vibration before the displacement set by experiment or the like are stored in advance. Remembered. The supercharger ECU 340 changes the amount of change in the signal output between the predetermined phase angles in the hall sensors 252 and 254 (that is, the amount of change during high-speed rotation) and the amount of change stored in the memory (that is, change without vibration). The difference Mha, Mhb from the amount) is detected.
If the amount of change in the output signal during high-speed rotation is smaller than the amount of change in the output signal during no vibration, the shaft center of the shaft 210 during high-speed rotation is higher than the axis center of the shaft 210 during no vibration. , 254 indicates a displacement to the far side. Further, when the change amount of the output signal at the time of high speed rotation is larger than the change amount of the output signal at the time of no vibration, the shaft center of the shaft 210 at the time of high speed rotation is higher than the axis center of the shaft 210 at the time of no vibration. , 254.

  In S304, supercharger ECU 340 determines energization amounts in the X direction and the Y direction. Specifically, supercharger ECU 340 determines the amount of power supplied to X-phase coils 236 and 240 and Y-phase coils 234 and 238. Note that the coordinate system defined by the direction from the axial center of the shaft 210 to the hall sensor 252 and the direction from the axial center of the shaft 210 to the hall sensor 254 is relative to the coordinate system defined by the X direction and the Y direction. The rotation angle of the shaft 210 is a predetermined angle around the rotation axis. Therefore, the supercharger ECU 340 determines the displacement corresponding to the magnetic force differences Mha and Mhb in the direction from the axial center of the shaft 210 to the hall sensor 252 and the direction from the axial center of the shaft 210 to the hall sensor 254. The amount of energization is determined in terms of the coordinate system.

  At this time, the energization amount in the X direction and the Y direction generates a magnetic force in the direction from the axial center of the shaft 210 after displacement (that is, at high speed rotation) to the axial center of the shaft 210 before displacement (that is, when there is no vibration). To be decided. Thereby, a magnetic force is developed in a direction opposite to the direction in which the displacement increases due to the shaft vibration of the shaft 210.

  A specific method for determining the energization amount is not particularly limited. For example, a map (1) and a map (2) indicating the relationship between the magnetic force differences Mha and Mhb and the energization amount are stored in the supercharger ECU 340 memory. The supercharger ECU 340 determines the energization amount in the X direction based on the magnetic difference Mha and the map (1), and determines the Y direction based on the magnetic difference Mhb and the map (2). The energization amount may be determined. Further, the relationship between the magnetic force differences Mha and Mhb and the energization amounts in the maps (1) and (2) is set so that the shaft vibration is suppressed by an experiment or the like in consideration of the coordinate conversion described above. Further, the supercharger ECU 340 may determine the energization amounts in the X direction and the Y direction based on a predetermined table or function formula instead of the map and the magnetic force differences Mha and Mhb.

  An operation of electric supercharger 200 according to the present embodiment based on the above-described structure and flowchart will be described.

  When the engine 100 is operated, the turbine wheel 208 is rotated by the energy of the exhaust gas to drive the compressor wheel. When the rotational speed of the engine 100 is low enough to be within the motor assist zone, electric power is selectively supplied to one of the X-phase coils 236 and 240 and the Y-phase coils 234 and 238 of the rotating electrical machine 216. The At this time, rotational force is applied to shaft 210 (NO in S100), and the boost pressure is quickly raised.

  When the rotational speed of the engine 100 increases and the rotational speed of the shaft 210 falls outside the range of the motor assist zone, power supply to the X-phase coils 236 and 240 and the Y-phase coils 234 and 238 is stopped. Therefore, in electric supercharger 200, rotating electric machine 216 rotates in a non-energized state (YES in S100).

  At this time, magnetic differences Mha and Mhb are detected (S302), and the energization amounts in the X direction and Y direction are determined according to the detected magnetic differences Mha and Mhb (S304). Then, power is supplied to the X-phase coils 236 and 240 and the Y-phase coils 234 and 238 so that the determined energization amount is obtained (S106). When electric power is supplied to the X-phase coils 236 and 240 and the Y-phase coils 234 and 238, a magnetic field is generated, and a magnetic force acts on the rotor 214 based on the generated magnetic field.

  The resultant force of the X direction force acting on the rotor 214 by energizing the X phase coils 236 and 240 and the Y direction force acting on the rotor 214 by energizing the Y phase coils 234 and 238 acts on the rotor 214. To do. At this time, the resultant force of the force in the X direction and the force in the Y direction acts on the rotor 214 from the axis center of the rotor 214 toward the axis center of the rotor 214 when no vibration occurs.

  If the operating range is such that the rotational force assist by the rotating electrical machine 216 is not required (NO in S108), when the rotor 214 rotates, the magnetic differences Mha and Mhb are calculated for each predetermined calculation cycle. The energization amount is determined. Electric power corresponding to the determined energization amounts is supplied to the X-phase coils 236 and 240 and the Y-phase coils 234 and 238, respectively. Therefore, magnetic force acts on the rotor 214 in a direction perpendicular to the shaft 210 and from the axial center of the shaft 210 during high-speed rotation to the axial center of the shaft 210 when no vibration occurs. An increase in the amplitude of vibration is suppressed.

  Then, when it is in an operation region where assistance by the rotating electrical machine is required (YES in S108), power is selectively supplied to any of X-phase coils 236, 240 and Y-phase coils 234, 238. .

  As described above, according to the electric supercharger according to the present embodiment, a magnetic force can be developed in the direction opposite to the direction in which the amplitude of the shaft vibration increases when the shaft rotates. Therefore, an increase in the amplitude of shaft vibration can be suppressed. Further, by increasing the magnetic force in accordance with the difference in the change amount of the output value output from the Hall sensor during high-speed rotation and no vibration, an increase in the amount of displacement that increases during high-speed rotation is suppressed. Therefore, shaft vibration can be effectively suppressed. Further, when the Hall sensor used as the rotor position sensor is in a non-energized state of the rotating electrical machine, a physical quantity corresponding to the displacement amount of the shaft 210 can be detected. Therefore, it is not necessary to provide new parts, and an increase in cost can be suppressed.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure which shows the structure of the engine system by which the electric supercharger which concerns on 1st Embodiment is mounted. It is a figure which shows the structure of the electric supercharger which concerns on 1st Embodiment. It is a figure which shows the 3-3 cross section of FIG. It is a figure which shows the vibration mode of the shaft of a rotary electric machine. It is a figure which shows distribution of whip vibration. FIG. 6 is a diagram (No. 1) showing a rotational change of a rotor rotating with its axis center displaced by vibration. FIG. 6 is a diagram (part 2) illustrating a rotational change of a rotor rotating with its axis center displaced by vibration. It is a figure which shows the change of the voltage induced by a search coil. It is an enlarged view of the broken-line frame of FIG. It is a flowchart which shows the control structure of the program performed by supercharger ECU of the electric supercharger which concerns on 1st Embodiment. It is a figure which shows the magnetic force which acts on a rotor. It is a figure which shows the structure of a cantilever type electric supercharger. It is a figure which shows the structure of the electric supercharger which concerns on 2nd Embodiment. It is FIG. (1) which shows the change of the signal output of a Hall sensor. It is an enlarged view of the broken-line frame of FIG. It is a flowchart which shows the control structure of the program performed by supercharger ECU of the electric supercharger which concerns on 2nd Embodiment. It is a figure (the 2) which shows the change of the signal output of a Hall sensor. It is an enlarged view of the broken-line frame of FIG. It is a flowchart which shows the control structure of the program performed by supercharger ECU of the electric supercharger which concerns on 3rd Embodiment.

Explanation of symbols

  100 Engine, 102 Intake passage, 104 Intake valve, 106 Fuel injection injector, 108 Combustion chamber, 110 Spark plug, 112 Cylinder block, 114 Piston, 116 Connecting rod, 118 Timing rotor, 120 Crankshaft, 122 Crank position sensor, 124 Belt, 126 Alternator, 128 Exhaust valve, 130 Exhaust passage, 150 Inlet, 152 Air cleaner, 154 Air flow meter, 156, 160 Intake passage, 158 Bypass passage, 162 Intercooler, 164 Air bypass valve, 166 Throttle valve, 168 Throttle motor, 170 Intake pipe pressure sensor, 172 Intake temperature sensor, 180 Exhaust pipe, 182 Catalyst, 200 Electric supercharger, 202 Compressor, 04 turbine, 206 compressor wheel, 208 turbine wheel, 210 shaft, 212 stator core, 214 rotor, 216 rotating electrical machine, 218, 220 search coil, 222, 224, 322 bearing portion, 228 thrust bearing, 230 housing, 232 spacer, 234 236, 238, 240 Coil, 242, 244, 246, 248 Teeth, 250 Engine ECU, 252, 254 Hall sensor, 300 Low voltage battery, 310 DC / DC converter, 320 High voltage battery, 330 Supercharger EDU, 340 Supercharge Machine ECU.

Claims (6)

An electric supercharger that applies a rotational force to a rotating shaft of a supercharger by a rotating electric machine, wherein the rotating electric machine includes a rotor provided on the rotating shaft, a stator core provided opposite to the rotor, and the stator core And a coil wound around the teeth formed on the
Detecting means for detecting a physical quantity corresponding to a displacement amount in a direction perpendicular to the rotation axis;
In the operating region of the supercharger to which the rotational force is not applied, a magnetic force corresponding to the detected physical quantity is developed in the direction from the axial center of the rotating shaft after displacement to the axial center of the rotating shaft before displacement. And an electric supercharger including control means for controlling electric power supplied to the coil. At the tip of the teeth, a displacement detection coil provided separately from the coil is wound,
The detection means includes a first voltage change induced by the displacement detecting coil during rotation of the rotating shaft and a second voltage change induced when the rotating shaft rotates without displacement. The electric supercharger according to claim 1, further comprising means for comparing and detecting a physical quantity corresponding to the displacement based on a comparison result.   The electric supercharger according to claim 2, wherein the detection means includes means for detecting a voltage difference between the first voltage change and the second voltage change. The rotating electrical machine is provided with a hall sensor at a position facing the rotor,
The detection means compares the first output change of the Hall sensor during rotation of the rotating shaft with the second output change when the rotating shaft rotates without displacement, and based on the comparison result. The electric supercharger according to claim 1, further comprising means for detecting a physical quantity corresponding to the displacement amount.   The detecting means calculates a difference between a phase angle when a predetermined output value is obtained in the first output change and a phase angle when the predetermined output value is obtained in the second output change. The electric supercharger according to claim 4, comprising means for detecting.   The detection means detects a difference between an output change amount between predetermined phase angles in the first output change and an output change amount between the predetermined phase angles in the second output change. 5. The electric supercharger according to claim 4, comprising means for

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