Motor controller

Abstract

To make it easier to move a rotor in which a rotor part with a permanent magnet and a rotor part without a permanent magnet are arranged in parallel in an axial direction, into an axial direction, and to allow a user to easily know that the rotor has been moved.SOLUTION: A motor controller includes: a switch operation unit for switching a first position, in which the outer peripheral surface of a first rotor and the inner peripheral surface of a stator face each other, to a second position, in which the outer peripheral surface of a second rotor part and the inner peripheral surface of the stator face each other, in association with a switching operation input from a user and for switching from the second position to the first position; a calculation unit for calculating a current request output of the motor; and a control unit for controlling an electromagnet of the stator so that the output is smaller than the request output calculated by the calculation unit prior to switch from the first position to the second position.SELECTED DRAWING: Figure 20

Description

[Technical field]

[0001] The present disclosure relates to a motor control device that can be mounted on, for example, an electric vehicle or the like. [Background technology]

[0002] For example, Patent Document 1 discloses a motor in which a rotor unit with a permanent magnet and a rotor unit without a permanent magnet are arranged side by side in the axial direction to form an integrated rotor, which is rotated by a single stator. In the motor of Patent Document 1, the relative positional relationship between the stator and the rotor in the axial direction is changed by hydraulic pressure according to the rotational speed of the rotor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-125235 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of the motor of Patent Document 1, when the axial position of the rotor is determined so that the outer peripheral surface of the rotor part equipped with permanent magnets faces the inner peripheral surface of the stator, a rotational force is obtained by the rotor part equipped with permanent magnets, whereas when the axial position of the rotor is determined so that the outer peripheral surface of the rotor part not equipped with permanent magnets faces the inner peripheral surface of the stator, a rotational force is obtained by the rotor part not equipped with permanent magnets, which has the advantage that the motor's characteristics including torque characteristics, rotation characteristics and power consumption can be changed depending on the axial position of the rotor.

[0005] However, for example, in a state where the axial position of the rotor is determined so that the outer peripheral surface of the rotor part equipped with the permanent magnet faces the inner peripheral surface of the stator, the magnetic force acting between the permanent magnet of the rotor part and the stator acts as an attractive force on each other, so that when trying to move the rotor in the axial direction, it is necessary to apply an axial force to the rotor to resist the attractive force. In this case, for example, in a high-output motor used in an electric vehicle, the attractive force between the permanent magnet of the rotor part and the stator is strong, so a large force is required to move the rotor in the axial direction. How to secure this large force becomes an issue, and a large-scale moving mechanism is required to generate a large force.

[0006] In addition, in Patent Document 1, the relative axial positional relationship between the stator and the rotor is changed by hydraulic pressure according to the rotation speed of the rotor, but no consideration is given to allowing the user to know when the rotor position has been changed, so the user cannot determine whether the rotor position has really been changed or not.

[0007] The present disclosure has been made in consideration of such points, and its purpose is to facilitate axial movement of a rotor in which a rotor section with permanent magnets and a rotor section without permanent magnets are arranged side by side in the axial direction, and to make it easy for a user to understand that the rotor has moved. [Means for solving the problem]

[0008] In order to achieve the above object, a first aspect of the present disclosure can be based on a motor control device that controls a motor having a rotor integrated by arranging a first rotor section having a permanent magnet and a second rotor section not having a permanent magnet side by side in the axial direction, and a stator arranged to surround the outer circumferential surface of the rotor, the rotor being configured to be movable axially relative to the stator.

[0009] The motor control device includes a switching operation unit that switches the rotor position from a first position, where the outer circumferential surface of the first rotor part faces the inner circumferential surface of the stator, to a second position, where the outer circumferential surface of the second rotor part faces the inner circumferential surface of the stator, and switches the rotor position from the second position to the first position in response to a switching operation input by a user, a calculation unit that calculates a current required output of the motor, and a control unit that controls an electromagnet of the stator so that the output is lower than the required output calculated by the calculation unit prior to switching from the first position to the second position.

[0010] According to this configuration, when the motor is operated with the outer circumferential surface of the first rotor part with permanent magnets facing the inner circumferential surface of the stator, high torque can be generated. In the case of the first rotor part with permanent magnets, when the induced voltage increases in proportion to the increase in the rotation speed of the motor and becomes dominant, the current that can be passed through the motor may be reduced. On the other hand, when the outer circumferential surface of the second rotor part without permanent magnets faces the inner circumferential surface of the stator, the second rotor part can rotate at a higher speed than the first rotor. In other words, it is possible to change the torque characteristics and rotation characteristics by moving the rotor.

[0011] When the motor is operated with the outer peripheral surface of the first rotor part, which is equipped with permanent magnets, facing the inner peripheral surface of the stator, the magnetic forces acting between the permanent magnets of the first rotor part and the stator act as an attractive force on each other, so that a large force is required to move the rotor in the axial direction in this state.

[0012] In contrast, in this configuration, the electromagnet of the stator is controlled to output less than the required output before the rotor is switched to a position where the outer circumferential surface of the second rotor portion faces the inner circumferential surface of the stator, so that the rotor can be easily moved in the axial direction. Also, if the output of the motor becomes lower than the required output during switching, the user will feel the decrease in output, for example, through shaking, sound, vibration, etc., making it easy to know that the rotor has been moved.

[0013] The control unit according to the second aspect of the present disclosure can control the electromagnets of the stator to achieve the required output after switching from the first position to the second position and then setting the output to be higher than the required output calculated by the calculation unit.

[0014] According to this configuration, the output that is reduced before switching from the first position to the second position can be compensated for after switching, so that a large drop in output does not occur.

[0015] The control unit according to the third aspect of the present disclosure can make substantially equal the difference between the reduced output and the required output prior to switching from the first position to the second position and the difference between the increased output and the required output after switching from the first position to the second position.

[0016] According to this configuration, the reduced output and the increased output that accompany switching from the first position to the second position are substantially the same, so the load on the control device is reduced.

[0017] The control unit according to a fourth aspect of the present disclosure can control the electromagnets of the stator so as to obtain an output lower than the required output calculated by the calculation unit prior to switching from the second position to the first position.

[0018] According to this configuration, the output of the motor becomes lower than the required output even during switching from the second position to the first position, making it easy to know that the rotor has moved. Effect of the Invention

[0019] As described above, when the motor is operated with the outer peripheral surface of the first rotor part equipped with a permanent magnet facing the inner peripheral surface of the stator, the motor output can be made lower than the required output before the rotor is moved axially, thereby facilitating axial movement of the rotor and making it easy for the user to understand that the rotor has moved. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a left side view of an electric vehicle according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of the electric vehicle according to the embodiment of the present invention. [Diagram 3] FIG. 3 is a plan view showing the interior of the electric vehicle with the roof, doors, interior materials, etc. omitted. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] FIG. 5 is a cross-sectional view corresponding to the line VV in FIG. [Figure 6] FIG. 6 is a perspective view showing only the battery unit mounted on the vehicle body. [Figure 7] FIG. 7 is a partial cross-sectional view showing the structure of the motor when the rotor is in the first position. [Figure 8] FIG. 8 is a cross-sectional view corresponding to line VIII-VIII in FIG. 7, and shows a schematic diagram of the magnetic pole arrangement of the first rotor portion and the stator during driving and when the rotor position is switched. [Figure 9] FIG. 9 is a block diagram of the motor control device. [Figure 10] FIG. 10 is a view corresponding to FIG. 7, illustrating a state in which the first pin has entered the second gap. [Figure 11] FIG. 11 is a view corresponding to FIG. 7, illustrating a state in which the first pin has entered the first gap. [Figure 12] FIG. 12 is a view corresponding to FIG. 7, illustrating a state in which the second pin has entered the second gap. [Figure 13] FIG. 13 is a view equivalent to FIG. 7, illustrating a state in which the rotor has moved in the axial direction. [Figure 14] FIG. 14 is a view corresponding to FIG. 7, illustrating a state in which the second pin has been removed from the first gap. [Figure 15] FIG. 15 is a view corresponding to FIG. 7, illustrating a state in which the first pin has entered the first gap. [Figure 16] FIG. 16 is a view corresponding to FIG. 7, illustrating a state in which the first pin has been removed from the first gap. [Figure 17] FIG. 17 is a flowchart showing an example of a control procedure performed by the motor control device. [Figure 18] FIG. 18 is a flowchart showing an example of a procedure of magnetic pole alignment control executed when the rotor is switched from the first position to the second position. [Figure 19] FIG. 19 is a flowchart showing an example of a procedure of output control executed when the rotor is switched from the first position to the second position. [Figure 20] FIG. 20 is a graph showing changes in motor output. [Figure 21] FIG. 21 is a view corresponding to FIG. 7 according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. Note that the following description of the preferred embodiments is merely illustrative in nature and is not intended to limit the present invention, its applications, or its uses.

[0022] 1 and 2 show the exterior of an electric vehicle 1 according to an embodiment of the present invention. In the description of this embodiment, the front side of the vehicle is simply referred to as "front", the rear side of the vehicle is simply referred to as "rear", the right side of the vehicle is simply referred to as "right", and the left side of the vehicle is simply referred to as "left". The left-right direction of the vehicle is the vehicle width direction. When the electric vehicle 1 is viewed from the left or right side, it is referred to as a side view. When the electric vehicle 1 is viewed from above, it is referred to as a top view or plan view.

[0023] The electric vehicle 1 is a passenger vehicle and may be, for example, a coupe type, a hatchback type, or a sedan type vehicle. A bonnet hood 2 is provided at the front of the electric vehicle 1. A front luggage storage space R1 (shown by a dashed line only in FIG. 1) capable of storing luggage is provided below the bonnet hood 2. By opening the bonnet hood 2, the front luggage storage space R1 is opened, making it possible to load and unload luggage.

[0024] A rear hood 3 is provided at the rear of the electric vehicle 1. A rear luggage storage space R2 (shown by a dashed line only in FIG. 1) capable of storing luggage is provided below the rear hood 3. By opening the rear hood 3, the rear luggage storage space R2 is opened, making it possible to load and unload luggage. Note that one or both of the front luggage storage space R1 and the rear luggage storage space R2 may be used as spaces in which auxiliary machinery is disposed.

[0025] A left door 4 and a right door 5 are provided on the left and right sides of the electric vehicle 1, respectively, so as to be able to be opened and closed. The roof 6 may be a fixed roof, a removable roof, or a folding roof. In the case of a removable roof or a folding roof, the electric vehicle becomes an open-top car with no roof above the occupants.

[0026] A body structure A of the electric vehicle 1 includes front wheels 7 and rear wheels 8 on the left and right, and a drive motor M for driving the rear wheels 8 (shown in FIGS. 4 and 5, hereinafter simply referred to as motor M).

[0027] In this embodiment, the rear wheels 8 are the drive wheels, but the front wheels 7 may be drive wheels, or both the front wheels 7 and the rear wheels 8 may be drive wheels. Which wheels are to be drive wheels can be selected by the arrangement of the motor M; when the motor M is mounted only on the rear side, only the rear wheels 8 are drive wheels, when the motor M is mounted only on the front side, only the front wheels 7 are drive wheels, and when the motor M is mounted both on the front and rear sides, only the front wheels 7 and the rear wheels 8 are drive wheels. In the following explanation, a case where the motor M is mounted only on the rear side will be described.

[0028] As shown in Fig. 1, a vehicle interior R3 serving as a space for passengers is provided between the front wheels 7 and the rear wheels 8. As shown in Fig. 4, a vehicle body structure A of an electric vehicle 1 includes a floor panel 10 that forms the floor surface of the vehicle interior R3, and a dash panel 20 that forms the front wall of the vehicle interior R3. The vehicle body structure A also includes an inclined panel 16 that extends upward from the rear end of the floor panel 10 and is inclined so as to be positioned further rearward as it goes upward, and a rear panel 17 that extends rearward from the upper end of the inclined panel 16.

[0029] A tunnel section 11 that bulges upward and extends in the front-rear direction is formed in the center of the floor panel 10 in the vehicle width direction. The interior surfaces of the tunnel section 11, floor panel 10, and dash panel 20 are covered with interior materials (not shown). As shown in Fig. 3, the vehicle body structure A also includes a right side sill 12 that extends in the front-rear direction along the right edge of the floor panel 10, and a left side sill 13 that extends in the front-rear direction along the left edge of the floor panel 10.

[0030] The front end of the tunnel portion 11 is located at the front end of the floor panel 10, and the rear end of the tunnel portion 11 is located at the rear end of the floor panel 10. Therefore, the tunnel portion 11 has a shape that extends continuously from the front end to the rear end of the floor panel 10.

[0031] This electric vehicle 1 is a right-hand drive vehicle. Therefore, the vehicle body structure A is provided with a passenger seat 30 as a left seat (seat) and a driver's seat 40 as a right seat (seat) on the left and right sides of the tunnel section 11 in the floor panel 10, respectively. Specifically, the passenger seat 30 is provided on the left side of the tunnel section 11 in the floor panel 10, and the passenger seat 30 is disposed between the tunnel section 11 and the left side side sill 13. The driver's seat 40 is provided on the right side of the tunnel section 11 in the floor panel 10, and the driver's seat 40 is disposed between the tunnel section 11 and the right side sill 12. Therefore, the passenger seat 30 and the driver's seat 40 are provided to be aligned in the vehicle width direction with the tunnel section 11 between them. The electric vehicle 1 may be a left-hand drive vehicle, in which case the driver's seat 40 may be provided on the left side and the passenger seat 30 on the right side. In addition, a rear seat may be provided.

[0032] The driver's seat 40 is provided with a cushion portion 41 that mainly supports the buttocks and thighs of the occupant, and a back portion 42 that extends upward from the rear end of the cushion portion 41 and mainly supports the waist, back, and shoulders of the occupant. A seat surface is formed by the cushion portion 41. The passenger seat 30 is similarly provided with a cushion portion 31 and a back portion 32.

[0033] The upper end of the tunnel portion 11 is positioned higher than the upper surfaces of the cushion portions 31 and 41. By making the tunnel portion 11 at such a height, when the center battery unit BY1 (described later) is accommodated in the tunnel portion 11, a wide accommodation space can be secured in the vertical direction.

[0034] As shown in FIG. 4 and FIG. 5, the bulging height of the tunnel portion 11 from the floor panel 10 (the bulging height from the portion where the passenger seat 30 and the driver's seat 40 are attached) increases toward the front. Therefore, the upper end of the tunnel portion 11 is gently inclined so as to be located lower toward the rear. The passenger seat 30 and the driver's seat 40 are located on the sides of the rear portion of the tunnel portion 11, and the rear portion of the tunnel portion 11 overlaps with the passenger seat 30 and the driver's seat 40 in a side view. Since the height of the portion of the tunnel portion 11 that overlaps with the passenger seat 30 and the driver's seat 40 in a side view is low, for example, a passenger (driver) seated in the driver's seat 40 can move over the tunnel portion 11 to the passenger seat 30 side, and a passenger seated in the passenger seat 30 can move over the tunnel portion 11 to the driver's seat 40 side.

[0035] 3, the width (dimension in the vehicle width direction) of the tunnel section 11 becomes wider toward the front. Specifically, the distance between the left and right walls of the tunnel section 11 becomes narrower toward the rear, and the width of the rear portion of the tunnel section 11 is narrower than the width of the front portion. Since the width of the portions of the tunnel section 11 that overlap with the passenger seat 30 and the driver's seat 40 in a side view is narrow, it is possible to ensure a wide width for the passenger seat 30 and the driver's seat 40 while suppressing an increase in the vehicle width.

[0036] Incidentally, since the front portion of the tunnel section 11 does not overlap with the passenger seat 30 and the driver's seat 40 in a side view, even if the width of the front portion is wide, it does not cause a problem in terms of ensuring the width of the passenger seat 30 and the driver's seat 40. Moreover, since only the feet of the driver and the passenger in the passenger seat 30 are positioned to the sides of the front portion of the tunnel section 11, even if the width of the front portion of the tunnel section 11 is wide, it has almost no effect on the livability of the passenger seat 30 and the driver's seat 40.

[0037] The dash panel 20 extends upward and in the vehicle width direction from the front end of the floor panel 10, and is a member that separates the vehicle interior R3 from the space in front of the vehicle interior R3. A bulging portion 20a that bulges toward the vehicle interior R3 is provided in the center of the dash panel 20 in the vehicle width direction. As shown in FIG. 5, a lower end of the bulging portion 20a is connected to the front end of the tunnel portion 11.

[0038] 3 to 6, the vehicle body structure A includes a center battery unit BY1, a passenger-side battery unit BY2, a rear right battery unit BY3, and a rear left battery unit BY4. In this embodiment, the battery units BY1 to BY4 are arranged in various parts of the vehicle body, which makes it possible to effectively use multiple spaces formed in various parts of the vehicle body to increase the amount of batteries that can be mounted.

[0039] The center battery unit BY1 is housed in a tunnel section 11. A center battery arrangement section (first battery arrangement section) 11A in which the center battery unit BY1 can be arranged is provided long in the front-rear direction in the tunnel section 11, and the center battery unit BY1 arranged in the center battery arrangement section 11A is fixed to a floor panel 10 or the like so as to be detachable (replaceable). When fixed to the floor panel 10 or the like, the front end of the center battery unit BY1 is positioned rearward of the dash panel 20. This eliminates the presence of the battery, which is a heavy object, in the front portion of the vehicle.

[0040] The center battery unit BY1 includes multiple batteries (center batteries) B1 arranged in a row in the front-to-rear direction, and these batteries B are intended to supply power to a motor M. The motor M receives power from the center battery unit BY1 to drive the rear wheels 8. Although not shown, the center battery unit BY1 may also include a battery case that houses the center battery B1, a sensor that detects the temperature of the center battery B1, a heat exchanger that adjusts the temperature of the center battery B1, etc.

[0041] Center battery B1 is composed of chargeable and dischargeable secondary batteries (battery cells) and the like. Center battery B1 may be, for example, a lithium ion battery, an all-solid-state battery, or another type of secondary battery. Center battery B1 may be a so-called battery cell, or a battery pack containing multiple battery cells. In the figure, center battery B1 is shown as a rectangular parallelepiped to approximate its shape, but the shape of center battery B1 is not limited to a rectangular parallelepiped. All center batteries B1 are the same.

[0042] Since the motor M drives the rear wheels 8, it is provided at the rear of the vehicle body, specifically behind the center battery unit BY1. The center battery unit BY1 is configured to become heavier as it moves away from the motor M, i.e., toward the front. For example, as shown in FIG. 3, the center battery unit BY1 is configured so that the width (dimension in the left-right direction) of the center battery unit BY1 increases as it moves away from the motor M in a top view of the vehicle. Specifically, five center batteries B1 constituting the center battery unit BY1 are lined up in the front-rear direction with the longitudinal direction being the front-rear direction. The foremost center batteries B1 are lined up in three in the vehicle width direction. The second-nearest center batteries B1 are lined up in two in the vehicle width direction. The third- and fourth-nearest center batteries B1 and the rearmost center batteries B1 are lined up in a single row in the front-rear direction, and therefore are not lined up in the vehicle width direction.

[0043] Furthermore, center battery unit BY1 is configured so that its vertical dimension increases with increasing distance from motor M. As shown in Fig. 5, the frontmost center battery B1 and the second-nearest center battery B1 are lined up in fours vertically. The third-nearest and third-nearest center batteries B1 are lined up in threes vertically. The rearmost center battery B1 is lined up in twos vertically. The number of center batteries B1 lined up in the vertical direction can also be referred to as the number of stages or the number of layers.

[0044] In other words, the center battery B1 is arranged so that the width of the center battery unit BY1 increases the further away from the motor M, and the vertical dimension of the center battery unit BY1 increases the further away from the motor M. For this reason, the front end of the center battery unit BY1 is the heaviest, and the rear end of the center battery unit BY1 is the lightest. The weight of the front-to-rear intermediate part of the center battery unit BY1 is halfway between the front and rear ends.

[0045] The passenger seat 30 and the driver's seat 40 are located to the sides of the center battery B1, which is located third, fourth, and rearmost from the front of the center battery unit BY1. Meanwhile, the center batteries B1, which are located foremost and second from the front of the center battery unit BY1, are disposed forward of the passenger seat 30 and the driver's seat 40. That is, the center batteries B1 are not lined up in the vehicle width direction in the portion of the center battery unit BY1 between the passenger seat 30 and the driver's seat 40, so the width is set narrower than the portion of the center battery unit BY1 forward of the passenger seat 30 and the driver's seat 40. The width of the center battery unit BY1 corresponds to the width of the tunnel section 11, and becomes narrower toward the rear.

[0046] In addition, the center batteries B1 located at the front and second furthest from the front of the center battery unit BY1 have the most number of tiers, the third and fourth furthest from the front have the next fewest number of tiers, and the rearmost center battery B1 has the fewest number of tiers. As a result, the height of the center battery unit BY1 increases toward the front in accordance with the bulging height of the tunnel section 11.

[0047] The number of center batteries B1 constituting the center battery unit BY1, the number of rows in the front-rear direction, and the number of rows are not limited to those described above, and can be set arbitrarily. That is, the row and number of rows of the center batteries B1 may be set so that the center battery unit BY1 becomes heavier the farther it is from the motor M. For example, the number of rows in the front-rear direction may be any number equal to or greater than two, and the number of rows may be any number equal to or greater than one.

[0048] The passenger seat side battery unit BY2 is disposed in front of the cushion portion 31 of the passenger seat 30 on the floor panel 10. As a portion for disposing the passenger seat side battery unit BY2, a passenger seat side battery disposing portion (third battery disposing portion) 11B in which the passenger seat side battery unit BY2 can be disposed is provided in front of the passenger seat 30. Specifically, the passenger seat side battery unit BY2 is disposed in a rear portion of the floor panel 10 on the passenger seat side, and a front portion of the floor panel 10 on the passenger seat side is made into a foot rest portion 10a on which the feet of an occupant seated in the passenger seat 30 can be placed. An occupant with a normal body type rarely takes a posture in which the feet are placed immediately in front of the cushion portion 31 of the passenger seat 30, and often stretches out the legs a little and places the legs away from the cushion portion 31 forward. In this embodiment, the passenger side battery unit BY2 is not located forward from the cushion portion 31, and a footrest portion 10a is provided, so that the comfort of the occupant seated in the passenger seat 30 can be increased while the battery B2 is mounted on the passenger seat 30 side.

[0049] The passenger-side battery unit BY2 includes a plurality of passenger-side batteries B2 similar to the center battery B1 constituting the center battery unit BY1. The passenger-side batteries B2 also serve to supply power to the motor M. The passenger-side battery unit BY2 may include a battery case, a sensor for detecting the temperature of the passenger-side batteries B2, a heat exchanger for adjusting the temperature of the passenger-side batteries B2, etc.

[0050] The upper end of the passenger seat side battery unit BY2 is positioned below the upper surface of the front end of the cushion part 31 of the passenger seat 30. The passenger seat side battery unit BY2 is configured to be lower as it goes forward. That is, the passenger seat side batteries B2 are arranged in three in the front-rear direction with the longitudinal direction being the vehicle width direction, and the passenger seat side battery B2 located at the frontmost position has one tier, while the passenger seat side battery B2 located at the second position from the front and the rearmost position has two tiers. Of the passenger seat side batteries B2 arranged in two tiers, the height of the upper end of the upper passenger seat side battery B2 is lower than the upper surface of the front end of the cushion part 31 of the passenger seat 30. This makes it difficult for the passenger seat side battery unit BY2 to come into contact with the back of the thighs of the passenger seat 30, and therefore improves the habitability of the passenger seat 30. The passenger seat side battery B2 is covered by a battery cover 50 (only shown in FIG. 4). The battery cover 50 may be made of a flexible material such as cloth or synthetic leather, or may be made of a hard resin material. The battery cover 50 may be a member that constitutes a part of the passenger-side battery unit BY2.

[0051] Of the passenger-side batteries B2, the one located furthest from the front is a front battery, and the one located furthest from the rear is a rear battery. The rearmost passenger-side battery B2 is two-tiered, while the frontmost passenger-side battery B2 is a single-tiered battery. When comparing the heights of the upper ends, the rearmost passenger-side battery B2 is higher than the frontmost passenger-side battery B2.

[0052] In addition, the shape of the legs of an occupant sitting in the passenger seat 30 increases from the buttocks to the knees. In order to accommodate this shape of the legs, the rear upper surface of the passenger-side battery B1 is made higher than the buttocks, thereby increasing the loading capacity of the passenger-side battery B1.

[0053] The number of passenger-side batteries B2 constituting the passenger-side battery unit BY2, the number of batteries arranged in the front-rear direction, and the number of stages are not limited to those described above, and can be set arbitrarily. That is, the arrangement and number of stages of the passenger-side batteries B2 may be set so that the passenger-side battery unit BY2 becomes lower as it moves forward, and for example, the number of batteries arranged in the front-rear direction may be any number equal to or greater than 2, and the number of stages may be any number equal to or greater than 1. The passenger-side battery B2 may have its longitudinal direction facing the vehicle width direction or the front-rear direction.

[0054] The passenger-side battery unit BY2 is detachably mounted on the vehicle body, i.e., the floor panel 10. Specifically, as shown in FIG. 4, an attachment / detachment mechanism 14 for attaching and detaching the passenger-side battery unit BY2 is provided on the passenger-side seat 30 side of the floor panel 10. The attachment / detachment mechanism 14 includes a main body 14a fixed to the passenger-side seat 30 side of the floor panel 10 and a locking portion 14b provided on the main body 14a and locking to the passenger-side battery unit BY2. The locking portion 14b is movable between a locking position where it is locked to the passenger-side battery unit BY2 and a non-locking position where it is released from the passenger-side battery unit BY2. When the passenger-side battery unit BY2 is mounted, the locking portion 14b is switched to the locking position, so that the passenger-side battery unit BY2 is fixed to the floor panel 10 so as not to move even due to vibrations during driving. On the other hand, when the passenger-seat side battery unit BY2 is to be removed, the locking portion 14b is switched from the locking position to the unlocking position.

[0055] The attachment / detachment mechanism 14 for the passenger-side battery unit BY2 may be provided as necessary. The structure of the attachment / detachment mechanism 14 is not limited to the above-mentioned structure, and may be a structure in which the passenger-side battery unit BY2 is attached to the floor panel 10 or a bracket (not shown) by fastening with a screw or a band, or an engagement structure using an engagement claw.

[0056] For example, when weight reduction is to be prioritized over the driving range of the electric vehicle 1, the electric vehicle 1 can be driven with the passenger-side battery unit BY2 removed. The passenger-side battery unit BY2 can also be removed to expand the living space of the passenger seat 30. The passenger-side battery unit BY2 may be removed to prioritize the front-rear and left-right weight balance over the driving range of the electric vehicle 1. In this case, the passenger-side battery unit BY2 can be used to adjust the weight balance of the electric vehicle 1, so that the passenger-side battery unit BY2 can be used as a part of the weight balance adjustment means. Only a part of the multiple passenger-side batteries B2 constituting the passenger-side battery unit BY2 may be made detachable. The multiple passenger-side batteries B2 constituting the passenger-side battery unit BY2 may be divided into multiple groups, and each group may be made detachable separately.

[0057] As shown in Figs. 3 and 5, the motor M is attached to a subframe 80 provided on the rear lower part of the vehicle body, and is disposed in the middle part in the vehicle width direction below the inclined panel 16 and the rear panel 17. The motor M is disposed so that its output shaft M1 is oriented in the front-rear direction. In this embodiment, the output shaft M1 of the motor M protrudes rearward. The front part of the motor M is disposed inside the tunnel section 11. Since the mounting position of the motor M is thus set as far forward as possible, the motor M is disposed so as to overlap at least a part of the back section 32 of the passenger seat 30 in the side view shown in Fig. 4. For example, the lower part of the back section 32 and the front part of the motor M can be disposed so as to overlap in the side view. This allows the motor M to be closer to the center of the vehicle.

[0058] The vehicle body structure A includes a left drive shaft 60 and a right drive shaft 61 that are provided behind the tunnel portion 11 of the floor panel 10 and transmit the rotational force of the motor M to the rear wheels 8, which are drive wheels. The left drive shaft 60 and the right drive shaft 61 extend in the vehicle width direction. The motor M is provided between the left drive shaft 60 and the right drive shaft 61 and the tunnel portion 11. Therefore, the motor M is disposed closer to the center of the vehicle in the longitudinal direction than the drive shafts 60 and 61. Although not shown, in the case where the motor is provided on the front side and drives the front wheels 7, the left drive shaft and the right drive shaft may be provided in front of the tunnel portion 11.

[0059] The vehicle body structure A also includes a transmission 62 and a differential gear box 63. The transmission 62 and the differential gear box 63 are attached to a subframe 80. The transmission 62 and the differential gear box 63 are disposed behind the motor M and on the driver's seat 40 side of the vehicle body. The rotational force of the output shaft M1 of the motor M is input to the transmission 62 via a gear 64. The rotational force of the output shaft M1 extending in the front-rear direction is converted into a rotational force around an axis extending in the vehicle width direction via the gear 64 and input to the transmission 62. The transmission 62 is a transmission or a reduction gear. When the transmission 62 is a transmission, it may be a stepped transmission or a continuously variable transmission. The transmission 62 and the differential gear box 63 may be integrated, and the gears constituting the transmission and the gears constituting the differential mechanism may be housed in one gear box. In addition, the motor M and the transmission 62 may be modularized. Although not shown, in the case where the motor M is provided on the front side of the vehicle body to drive the front wheels 7, the transmission 62 and the differential gear box 63 may be provided in front of the tunnel section 11.

[0060] The rotational force of the motor M output from the transmission 62 is transmitted to the left and right rear wheels 8 via a differential mechanism (not shown) built into a differential gear box 63 and drive shafts 60 and 61 .

[0061] As shown in Fig. 3, the rear right battery unit BY3 is provided behind the driver's seat 40. The inclined panel 16 is located behind the driver's seat 40, and a rear right battery arrangement section (first battery arrangement section) 11C in which the rear right battery unit BY3 can be arranged is provided behind the inclined panel 16 (outside the vehicle compartment R3). The rear right battery unit BY3 includes a plurality of rear right batteries B3 similar to the center battery B1 that constitutes the center battery unit BY1. The rear right battery B3 also serves to supply power to the motor M. The rear right battery unit BY3 may include a battery case, a sensor that detects the temperature of the rear right battery B3, a heat exchanger that adjusts the temperature of the rear right battery B3, and the like.

[0062] The rear left battery unit BY4 is provided behind the passenger seat 30. The inclined panel 16 is located behind the passenger seat 30, and a rear left battery arrangement section (first battery arrangement section) 11D in which the rear left battery unit BY4 can be arranged is provided behind the inclined panel 16 (outside the passenger compartment R3). The rear left battery unit BY4 includes a plurality of rear left batteries (rear batteries) B4 similar to the center battery B1 constituting the center battery unit BY1. The rear left battery B4 also serves to supply power to the motor M. The rear left battery unit BY4 may include a battery case, a sensor for detecting the temperature of the rear left battery B4, a heat exchanger for adjusting the temperature of the rear left battery B4, and the like.

[0063] The rear right battery mounting section 11C and the rear left battery mounting section 11D are provided in front of the transmission 62 when the transmission 62 is used as a reference. The rear right battery mounting section 11C and the rear left battery mounting section 11D are provided on both sides of the motor M in the vehicle width direction. In other words, the motor M is disposed between the rear right battery B3 and the rear left battery B4, and is disposed so that the rear right battery B3 and the rear left battery B4 at least partially overlap the motor M in a side view. The rear right battery B3 and the rear left battery B4 are provided on both sides of the motor M in the vehicle width direction, and therefore can also be called side batteries.

[0064] The number of rear right batteries B3 constituting the rear right battery unit BY3, the number of arrangements in the front-rear direction, and the number of stages can be set arbitrarily. In addition, the number of rear left batteries B4 constituting the rear left battery unit BY4, the number of arrangements in the front-rear direction, and the number of stages can also be set arbitrarily. The rear right battery B3 and the rear left battery B4 may have their longitudinal directions facing the vehicle width direction or the front-rear direction. In addition, the rear right battery unit BY3 and the rear left battery unit BY4 are detachable.

[0065] (Motor configuration) 7, the motor M includes, in addition to the output shaft M1, a stator 100, a rotor 110, and a motor case 120, and is configured so that the rotor 110 is movable in the axial direction relative to the stator 100. The axial direction is the direction in which the output shaft M1 extends, which is the front-rear direction in this embodiment.

[0066] The stator 100 is formed by arranging a first rotor section 111 having a permanent magnet 111b and a second rotor section 112 having no permanent magnet side by side in the axial direction, and integrating them together. As shown in Fig. 7, the second rotor section 112 is disposed closer to the center in the vehicle longitudinal direction than the first rotor section 111. Note that the first rotor section 111 may be disposed closer to the center in the vehicle longitudinal direction than the second rotor section 112.

[0067] The first rotor section 111 has a first insertion hole 111a in the center thereof through which the output shaft M1 is inserted. The second rotor section 112 has a second insertion hole 112a in the center thereof through which the output shaft M1 is inserted. The output shaft M1 is fixed to the first rotor section 111 and the second rotor section 112 in a state in which the output shaft M1 is inserted through the first insertion hole 111a and the second insertion hole 112a, so that the output shaft M1 cannot rotate relative to the first rotor section 111 and the second rotor section 112, and is fixed so that the output shaft M1 cannot move relative to the first rotor section 111 and the second rotor section 112 in the axial direction. Therefore, the radial centers of the first rotor section 111 and the second rotor section 112 are concentrically arranged with the axis of the output shaft M1. Since the first rotor section 111 and the second rotor section 112 are fixed to the same output shaft M1, the relative positional relationship between the first rotor section 111 and the second rotor section 112 does not change. The output shaft M1 is a member that serves as the shaft of the rotor 110.

[0068] The permanent magnets 111b provided in the first rotor portion 111 are not particularly limited, and may be, for example, rare earth magnets (e.g., neodymium magnets, samarium-cobalt magnets) manufactured using rare earth elements, or ferrite magnets made of ferrite magnetic material, etc. As a structural example of the first rotor portion 111, for example, it may be an embedded magnet type rotor portion in which a plurality of permanent magnets 111b are embedded in a rotor body made of electromagnetic steel plate so as to be aligned in the circumferential direction, or it may be a surface magnet type rotor portion in which a plurality of permanent magnets 111b are arranged and fixed to the outer circumferential surface of the rotor body so as to be aligned in the circumferential direction.

[0069] Fig. 8 is a schematic cross-sectional view of a motor M, in which the first rotor portion 111 is configured to have two N poles and two S poles alternately arranged in the circumferential direction. The number of poles is not limited to two, and may be any number. The first rotor portion 111 and the stator 100 form a permanent magnet synchronous motor.

[0070] The second rotor portion 112 is made of, for example, an electromagnetic steel plate. The second rotor portion 112 and the stator 100 form an induction motor, and an induced current is generated in the second rotor portion 112 by a rotating magnetic field formed by the stator 100, and a rotational torque corresponding to the slip is generated. The outer diameter of the second rotor portion 112 and the outer diameter of the first rotor portion 111 are set to be the same. Furthermore, the width (dimension in the axial direction) of the first rotor portion 111 and the width of the second rotor portion 112 are set to be approximately the same, but may be different.

[0071] The stator 100 is formed in a cylindrical shape surrounding the outer circumferential surface of the rotor 110, and is disposed so as to surround the outer circumferential surface of the rotor 110. Specifically, the inner diameter of the stator 100 is set to be slightly larger than the outer diameters of the first rotor portion 111 and the second rotor portion 112. The stator 100 includes a stator body 100a made of electromagnetic steel plate or the like, and a plurality of stator coils 100b arranged in a line in the circumferential direction of the stator body 100a, and is fixed to the inner surface of the motor case 120 in a state of being disposed concentrically with the output shaft M1. As shown in FIG. 8, in the stator 100, N-pole portions and S-pole portions are formed alternately in the circumferential direction by supplying a current to each stator coil 100b.

[0072] The width (axial dimension) of the stator 100 is set to be approximately the same as the width of the first rotor portion 111 or the width of the second rotor portion 112, and for example, when the rotor 110 is arranged so that the outer peripheral surface of the first rotor portion 111 faces the inner peripheral surface of the stator 100, the second rotor portion 112 is arranged to protrude to the outside from the stator 100. Similarly, when the rotor 110 is arranged so that the outer peripheral surface of the second rotor portion 112 faces the inner peripheral surface of the stator 100, the first rotor portion 111 is arranged to protrude to the outside from the stator 100.

[0073] The motor case 120 is large enough to accommodate the stator 100, the first rotor portion 111, and the second rotor portion 112, and is fixed to the vehicle body. Bearings 121 that rotatably support the output shaft M1 are provided at both axial ends of the motor case 120. An outer ring member 121a of the bearing 121 is fixed to the motor case 120. On the other hand, an inner ring member 121b of the bearing 121 is not fixed to the output shaft M1, and the outer peripheral surface of the output shaft M1 can slide on the inner peripheral surface of the inner ring member 121b in the axial direction. This allows the rotor 110 to move relative to the stator 100 in the axial direction.

[0074] As shown in Fig. 7, the position of the rotor 110 where the outer circumferential surface of the first rotor portion 111 faces the inner circumferential surface of the stator 100 is called a first position. When the rotor 110 is in the first position, the motor M operates as a permanent magnet synchronous motor. Also, as shown in Fig. 13, the position of the rotor 110 where the rotor 110 moves leftward and the outer circumferential surface of the second rotor portion 112 faces the inner circumferential surface of the stator 100 is called a second position. When the rotor 110 is in the second position, the motor M operates as an induction motor.

[0075] Whether the rotor 110 is in the first position or the second position is displayed on a monitor 201 shown in Fig. 9. The monitor 201 is disposed, for example, on an instrument panel (not shown) in the vehicle interior R3, and is configured with a liquid crystal display or the like controlled by a control unit 220. The control unit 220 is configured to be able to detect the current position of the rotor 110, and causes the monitor 201 to display the detected result. The display form is not particularly limited, and examples of the display form include a PM (Permanent Magnet) motor for the first position and an IM (Induction Motor) motor for the second position.

[0076] 9, the electric vehicle 1 according to this embodiment includes a motor control device 200 that controls a motor M. The motor control device 200 includes a switching operation unit 210 that executes switching from a first position to a second position and switching from the second position to the first position by moving a rotor 110 in the axial direction, a control unit 220, and an inverter 230. Batteries B1, B2, B3, B4 may or may not be included in the motor control device 200.

[0077] The control unit 220 is composed of, for example, a microcomputer having a processor, memory, etc., and operates according to a program previously stored in the memory. As will be described in detail later, when the control unit 220 outputs a control signal to the inverter 230, power from the batteries B1, B2, B3, and B4 is supplied to the stator 100 via the inverter 230. This allows the motor M to rotate at a desired rotation speed and torque. Such basic control of the motor M is common for both PM motors and IM motors, and has been well known in the art.

[0078] The switching operation unit 210 is configured to execute switching of the rotor 110 from the first position to the second position and from the second position to the first position in response to a switching operation input by a passenger (an example of a user). The switching of the position of the rotor 110 is performed in a short time, such as the time required for shifting in an automatic transmission.

[0079] Specifically, as shown in Fig. 7, the switching operation unit 210 includes a first cylindrical cam 211, a second cylindrical cam 212, a first pin 213, a second pin 214, a first solenoid 215, a second solenoid 216, and a stopper member 217. The first cylindrical cam 211 and the second cylindrical cam 212 are fixed so as not to move or rotate relative to a portion of the output shaft M1 protruding outside the motor case 120. The first cylindrical cam 211 and the second cylindrical cam 212 are concentrically arranged with the output shaft M1. The first pin 213 and the second pin 214 are engaging members that can engage with the first cylindrical cam 211 and the second cylindrical cam 212, respectively.

[0080] A first cam groove 211a is formed on the outer peripheral surface of the first cylindrical cam 211 so as to extend in the circumferential direction and also in the axial direction. The first cam groove 211a extends continuously from one axial end to the other axial end on the outer peripheral surface of the first cylindrical cam 211, and is open at both ends. In a side view of the first cylindrical cam 211, the first cam groove 211a is inclined with respect to the axis of the first cylindrical cam 211.

[0081] The second cylindrical cam 212 is disposed on a side farther from the rotor 110 than the first cylindrical cam 211. The first cylindrical cam 211 and the second cylindrical cam 212 are spaced apart in the axial direction, and a first gap S1 is formed between the first cylindrical cam 211 and the second cylindrical cam 212. Similarly to the first cylindrical cam 211, a second cam groove 212a is formed on the outer circumferential surface of the second cylindrical cam 212 so as to extend in the axial direction while also extending in the circumferential direction.

[0082] The stopper member 217 is disposed on a side farther from the rotor 110 than the second cylindrical cam 212. The stopper member 217 and the second cylindrical cam 212 are spaced apart in the axial direction, and a second gap S2 is formed between the stopper member 217 and the second cylindrical cam 212. The widths of the first cam groove 211a, the second cam groove 212a, the first gap S1, and the second gap S2 are approximately the same.

[0083] The first solenoid 215 and the second solenoid 216 are attached to a fixed member 218. The fixed member 218 is fixed to a vehicle body or the like, and therefore the first solenoid 215 and the second solenoid 216 are also fixed to the vehicle body or the like. As a result, the positional relationship between the first solenoid 215 and the second solenoid 216 and the stator 100 is fixed.

[0084] The first solenoid 215 and the second solenoid 216 are aligned in the axial direction, with the first solenoid 215 being disposed closer to the stator 100 than the second solenoid 216. The first pin 213 is attached to the advancing / retreating member 215a of the first solenoid 215, and has an outer diameter that allows it to be inserted into the first cam groove 211a, the second cam groove 212a, the first gap S1, and the second gap S2, etc.

[0085] When the coil 215b of the first solenoid 215 is energized, the advancing / retreating member 215a is brought into an advanced state, and the first pin 213 attached to the tip of the member 215a enters the first gap S1 or the like. A locking mechanism (not shown) is provided to mechanically lock the first pin 213 so that it does not retract when the advancing / retreating member 215a is in an advanced state. This allows the first pin 213 to be held in the advanced state without continuing to energize the coil 215b, thereby preventing the coil 215b from burning out or the like. When the locking mechanism is released and the coil 215b is not energized, the advancing / retreating member 215a retracts due to the biasing force of a biasing member (not shown), and the first pin 213 comes out of the first gap S1 or the like.

[0086] The second pin 214 is attached to the advancing / retreating member 216a of the second solenoid 216, and like the first pin 213, has an outer diameter that enables it to be inserted into the first cam groove 211a, the second cam groove 212a, the first gap S1, and the second gap S2, etc.

[0087] When the coil 216b of the second solenoid 216 is energized, the advancing / retreating member 216a is brought into an advanced state, and the second pin 214 attached to the tip of the member 216a enters the first gap S1 or the like. The second solenoid 216 has a locking mechanism (not shown) that mechanically locks the second pin 214 so that it does not retract when the advancing / retreating member 216a is advanced. When the locking mechanism is released and the coil 216b is not energized, the advancing / retreating member 216a retracts due to the biasing force of a biasing member (not shown), and the second pin 214 comes out of the first gap S1 or the like. The axial distance between the first pin 213 and the second pin 214 is set to be equal to the axial distance between the first gap S1 and the second gap S2.

[0088] 9, the first solenoid 215 and the second solenoid 216 are controlled by a control unit 220 included in the motor control device 200. For example, a control unit 221 of the control unit 220 generates control signals for the first solenoid 215 and the second solenoid 216 and outputs the control signals to the first solenoid 215 and the second solenoid 216, thereby making it possible to operate the first solenoid 215 and the second solenoid 216 individually.

[0089] A case where the switching operation unit 210 switches the rotor 110 from the first position to the second position will be described. When the stator 100 of the motor M is energized and started in the state shown in FIG. 7, an attractive force is generated between the permanent magnet 111b of the first rotor unit 111 and the stator 100, so that the rotor 110 continues to rotate in a stable position even if an external force in the axial direction is not applied to the rotor 110. The stable position is also called an initial position, and even if an external force in the axial direction is applied and the rotor 110 moves, the rotor 110 returns to the initial position when the external force is removed. This action is also called an autonomous action. The second gap S2 is positioned so as to face the first pin 213 when the rotor 110 is in the stable position.

[0090] When the rotor 110 in the first position is switched to the second position, the control unit 221 first energizes the coil 215b of the first solenoid 215. As a result, as shown in FIG. 10, the advancing and retracting member 215a of the first solenoid 215 advances, and the first pin 213 attached to the tip of the member enters the second gap S2. As shown in FIG. 11, when the output shaft M1 rotates in the direction of the arrow Y, the first pin 213 that has entered the second gap S2 enters the first cam groove 211a of the first cylindrical cam 211 and enters and engages with it (engaged state). Then, the first pin 213 engages with the rotating first cam groove 211a, thereby applying a moving force in the axial direction (leftward in the figure) to the first cylindrical cam 211. This moving force is greater than the attractive force generated between the permanent magnet 111b of the first rotor portion 111 and the stator 100, so the rotor 110 moves leftward in the figure, and the first pin 213 leaves the first cam groove 211a and enters the first gap S1. The state in which the first pin 213 leaves the first cam groove 211a is also called a non-engaged state. In other words, the first pin 213 is switched between an engaged state in which it is engaged with the first cam groove 211a and a non-engaged state in which it is disengaged from the first cam groove 211a. The position of the rotor 110 when the first pin 213 leaves the first cam groove 211a is an intermediate position between the first position and the second position.

[0091] The motor M can also generate a driving force when the rotor 110 is in an intermediate position between the first position and the second position. When the rotor 110 is in an intermediate position between the first position and the second position, the motor M has weaker characteristics when in the first position and weaker characteristics when in the second position. The intermediate position may be called a third position, and therefore, in this embodiment, the switching operation unit 210 can also switch the rotor 110 to the third position. Note that the motor M may be immediately switched to the second position without generating a driving force in the third position.

[0092] Thereafter, as shown in FIG. 12, the control unit 221 energizes the coil 216b of the second solenoid 216. As a result, as shown in FIG. 12, the advancing and retracting member 216a of the second solenoid 216 advances, and the second pin 214 attached to the tip of the member enters the second gap S2. The second pin 214 that has entered the second gap S2 enters and engages with the first cam groove 211a of the first cylindrical cam 211. The second pin 214 then engages with the rotating first cam groove 211a, thereby exerting a moving force in the axial direction (leftward in the figure) on the first cylindrical cam 211. Since this moving force is greater than the attractive force generated between the permanent magnet 111b of the first rotor portion 111 and the stator 100 as described above, the rotor 110 moves further leftward in the figure, and as shown in FIG. 13, the rotor 110 is switched to a second position in which the outer circumferential surface of the second rotor portion 112 faces the inner circumferential surface of the stator 100. The first pin 213 is disposed closer to the rotor 110 than the first cylindrical cam 211 is.

[0093] When switching the rotor 110 from the second position to the first position, the control unit 221 retracts the advancing / retreating member 216a of the second solenoid 216 without energizing the coil 216b of the second solenoid 216, and removes the second pin 214 from the second gap S2 (as shown in FIG. 14). Then, as shown in FIG. 15, the first pin 213 passes through the first cam groove 211a due to the attractive force generated between the permanent magnet 111b of the first rotor portion 111 and the stator 100, and the rotor 110 moves rightward in the figure.

[0094] Thereafter, the control unit 221 de-energizes the coil 215b of the first solenoid 215, causing the advancing / retreating member 215a of the first solenoid 215 to retract, and the first pin 213 to be removed from the first gap S1. Then, due to the attractive force generated between the permanent magnet 111b of the first rotor portion 111 and the stator 100, the rotor 110 moves to the right in the figure and switches to the first position (as shown in FIG. 7).

[0095] The rotor 110 of the motor M is a heavy object, and when the rotor 110 moves in the fore-aft direction, the front-aft weight distribution of the vehicle changes as a result. The change in the front-aft weight distribution of the vehicle caused by the fore-aft movement of the rotor 110 is a proactive change in the front-aft weight distribution, unlike the riding of passengers or the loading of luggage, and can be changed at any time. The proactive change in the front-aft weight distribution caused by the movement of the rotor 110 makes it possible to change the handling characteristics even when the vehicle is traveling, without the need for loading weights or the like. In addition, by moving the rotor 110, not only can the handling characteristics be changed, but also the torque characteristics and rotation characteristics of the motor M can be changed according to the traveling conditions.

[0096] Specific control by motor control device 200 will now be described with reference to the flowchart shown in Figure 17. This flowchart starts after an ON button (not shown) that puts electric vehicle 1 into a state in which it can run is operated. In step SA1 after the start, control unit 220 reads signals output from each sensor.

[0097] 9, the motor control device 200 includes, as sensors for detecting physical quantities related to the motor M, a torque sensor 241 for detecting the torque currently generated by the motor M, a temperature sensor (temperature detection unit) 242 for detecting the temperature state of the permanent magnet 111b of the first rotor portion 111 of the motor M, and a rotation angle sensor 243 for detecting the rotation angle of the motor M. The detection results of the torque sensor 241, the temperature sensor 242, and the rotation angle sensor 243 are each input to the control unit 220. The temperature sensor 242 may directly measure the temperature of the permanent magnet 111b, or may measure the temperature of a portion other than the permanent magnet 111b and estimate the temperature of the permanent magnet 111b using a predetermined algorithm. In either case, the temperature state of the permanent magnet 111b can be detected.

[0098] The motor control device 200 also includes an accelerator pedal sensor 251 that detects the operation state of an accelerator pedal (not shown) of the electric vehicle 1, a brake pedal sensor 252 that detects the operation state of a brake pedal (not shown) of the electric vehicle 1, a shift lever sensor 253 that detects the operation state of a shift lever (not shown) of the electric vehicle 1, a vehicle speed sensor 254 that detects the vehicle speed of the electric vehicle 1, and a driving mode changeover switch 255. The accelerator pedal sensor 251 can detect whether or not the accelerator pedal is depressed by the occupant, and the amount of depression of the accelerator pedal by the occupant. The brake pedal sensor 252 can detect whether or not the brake pedal is depressed by the occupant, and the amount of depression of the brake pedal by the occupant. The brake pedal sensor 252 is an example of a pedal operation detection unit that detects the operation state of the brake pedal. The shift lever sensor 253 can detect the operation state of the shift lever by the occupant, i.e., whether the shift lever is in the parking position, forward position, or reverse position.

[0099] The traveling mode changeover switch 255 is a reception unit for receiving from the occupant a selection of whether the rotor 110 is to be in the first position or the second position. The traveling mode changeover switch 255 may be a physical switch operated by the occupant, or may be a virtual button or the like displayed on the monitor 201.

[0100] When the rotor 110 is in the first position, the outer circumferential surface of the first rotor section 111 having the permanent magnets 111b faces the inner circumferential surface of the stator 100, and thus a high torque characteristic is obtained. On the other hand, when the rotor 110 is in the second position, the outer circumferential surface of the second rotor section 112 having no permanent magnets faces the inner circumferential surface of the stator 100, and thus a high rotational speed, low power consumption characteristic is obtained. In this way, since the characteristics of the motor M can be changed depending on the position of the rotor 110, if a high torque characteristic is desired, the occupant performs a selection operation to place the rotor 110 in the first position using the driving mode changeover switch 255, and if a high rotational speed characteristic is desired, the occupant performs a selection operation to place the rotor 110 in the second position using the driving mode changeover switch 255. In other words, the driving mode of the electric vehicle 1 can be changed depending on whether the rotor 110 is in the first position or the second position. Driving modes that can be selected by switching the position of rotor 110 include, for example, a high torque mode (corresponding to the first position), a high rotation mode (corresponding to the second position), a low power consumption mode (corresponding to the second position), and an eco mode (corresponding to the second position).

[0101] The selection type by the traveling mode changeover switch 255 is not particularly limited, and may be, for example, a type that selects one of a "permanent magnet synchronous motor (first position)" and an "induction motor (second position)", a type that selects one of a "high torque type (first position)" and a "high rotation type (second position)", a type that selects one of a "normal mode (first position)" and an "eco mode (second position)", or a type that selects one of a "power mode (first position)" and an "eco mode (second position)".

[0102] The motor control device 200 also includes a power storage amount detection unit 261 that detects the total amount of stored power in the batteries B1, B2, B3, and B4 that supply power to the motor M. The power storage amount detection unit 261 can detect the total amount of stored power in the batteries B1, B2, B3, and B4 by a conventionally known method, and detailed description thereof will be omitted. The power storage amount detection unit 261 can also detect the current amount of stored power based on the total remaining amount of the batteries B1, B2, B3, and B4.

[0103] 17, calculation section 222 provided in control unit 220 calculates the current required output of motor M based on the signal read in step SA1, etc. For example, the greater the amount of depression of the accelerator pedal detected by accelerator pedal sensor 251, the higher the current required output of motor M is calculated to be, and conversely, the smaller the amount of depression of the accelerator pedal, the lower the current required output of motor M is calculated to be.

[0104] When calculating the current required output of the motor M, the driving condition acquisition unit 223 provided in the control unit 220 shown in Fig. 9 acquires the driving condition of the electric vehicle 1. For example, when the accelerator pedal is depressed a lot but the vehicle speed is increasing slowly, the driving condition of the electric vehicle 1 can be estimated as uphill, and the driving condition acquisition unit 223 acquires the estimated result. Also, when the vehicle speed is high, such as when driving on a highway, the driving condition of the electric vehicle 1 can be estimated as high-speed driving, and the driving condition acquisition unit 223 acquires the estimated result. In addition, the driving condition acquisition unit 223 can estimate whether the vehicle is in low-load driving or high-load driving depending on the accelerator pedal depression amount, and acquire the estimated result.

[0105] In step SA3 in Fig. 17, the control unit 221 performs a temperature determination process. The temperature determination process is a process for determining whether or not the temperature state of the permanent magnet 111b detected by the temperature sensor 242 shown in Fig. 9 is equal to or higher than a predetermined temperature. The predetermined temperature is a temperature at which deterioration of the permanent magnet 111b progresses. In other words, by keeping the temperature of the permanent magnet 111b below the predetermined temperature, deterioration of the permanent magnet 111b is hardly an issue.

[0106] In step SA4, the control unit 221 performs a stored power amount determination process. The stored power amount determination process is a process for determining whether or not the total stored power amount of the batteries B1, B2, B3, and B4 detected by the stored power amount detection unit 261 is equal to or greater than a predetermined amount. The predetermined amount is an amount at which no further charging is performed in consideration of deterioration of the batteries B1, B2, B3, and B4. In other words, when the total stored power amount of the batteries B1, B2, B3, and B4 is equal to or greater than the predetermined amount, charging of the batteries B1, B2, B3, and B4 by regenerating the kinetic energy of the electric vehicle 1, i.e., regeneration control, is not performed even if the brake pedal is depressed.

[0107] In step SA5, it is determined whether or not the selection of the driving mode by the occupant has been accepted. This determination can be made by the control unit 221 acquiring the operation state by the occupant of the driving mode changeover switch 255. If the driving mode has not been selected, that is, if the occupant has not performed an operation to select whether the rotor 110 is to be in the first position or the second position, the process proceeds to step SA6.

[0108] Proceeding to step SA6 means that the selection of the position of the rotor 110 has not been received by the traveling mode changeover switch 255, and the control unit 221 executes the rotor position automatic changeover control. Specifically, the control unit 221 executes a control (first changeover control) to automatically change the position of the rotor 110 from the first position to the second position and from the second position to the first position by controlling the changeover operation unit 210 according to the traveling condition acquired by the traveling condition acquisition unit 223. When the traveling condition acquired by the traveling condition acquisition unit 223 is uphill, the position of the rotor 110 is set to the first position, whereas when the traveling condition is high-speed traveling, the position of the rotor 110 is set to the second position. After returning from the flowchart, when the traveling condition has shifted from high-speed traveling to uphill, the position of the rotor 110 is changed from the second position to the first position. Also, when the traveling condition has shifted from uphill to high-speed traveling, the position of the rotor 110 is changed from the first position to the second position.

[0109] The position control of the rotor 110 may be control according to the vehicle speed of the electric vehicle 1. For example, the control unit 221 sets the rotor 110 to a first position when the vehicle speed detected by the vehicle speed sensor 254 is less than a predetermined value, and sets the rotor 110 to a second position when the vehicle speed is equal to or greater than the predetermined value. By performing such control, high torque can be obtained by the first rotor portion 111 at low speeds, and high rotation can be efficiently achieved by the second rotor portion 112 at high speeds.

[0110] In this manner, the control unit 221 executes the automatic rotor position switching control. During the automatic rotor position switching control, the occupant may operate the traveling mode switching switch 255 to select the position of the rotor 110. When the selection of the rotor position is accepted by the traveling mode switching switch 255, the determination in step SA5 is YES and the process proceeds to step SA7. In other words, when the selection of the rotor 110 position is accepted by the traveling mode switching switch 255 during the automatic rotor position switching control, the control unit 221 executes the control of step SA7 (second switching control) in preference to the automatic rotor position switching control.

[0111] In step SA7, the control unit 221 controls the switching operation unit 210 to switch the position of the rotor 110 to the position accepted by the traveling mode switching switch 255 in step SA5. For example, when the first position is selected as the position of the rotor 110 by the occupant, the rotor 110 is switched to the first position even if the rotor 110 is set to the second position by the rotor position automatic switching control. Conversely, when the second position is selected as the position of the rotor 110 by the occupant, the rotor 110 is switched to the second position even if the rotor 110 is set to the first position by the rotor position automatic switching control.

[0112] Furthermore, when the brake pedal sensor 252 detects that the brake pedal has been depressed while the rotor 110 is in the second position, the control unit 221 switches the rotor 110 to the first position. This is for the purpose of performing regenerative control, and when the rotor 110 is in the second position, the outer peripheral surface of the second rotor portion 112, which does not have a permanent magnet, faces the inner peripheral surface of the stator 100, so that the kinetic energy of the electric vehicle 1 cannot be regenerated. However, by switching the rotor 110 to the first position, the outer peripheral surface of the first rotor portion 111, which has the permanent magnet 111b, faces the inner peripheral surface of the stator 100, so that the kinetic energy of the electric vehicle 1 can be sufficiently regenerated.

[0113] However, when the rotor 110 is in the second position, if the temperature state of the permanent magnet 111b of the first rotor portion 111 detected by the temperature sensor 242 is equal to or higher than a predetermined temperature, the control portion 221 controls the switching operation portion 210 to prohibit switching of the rotor 110 from the second position to the first position even if the position accepted by the traveling mode changeover switch 255 is the first position. As a result, when the permanent magnet 111b of the first rotor portion 111 is in a high temperature state, the outer peripheral surface of the first rotor portion 111 is no longer disposed to face the inner peripheral surface of the stator 100, so that a further increase in temperature of the permanent magnet 111b is suppressed, and deterioration of the permanent magnet 111b can be suppressed.

[0114] In addition, when the position of the rotor 110 is in the second position, if the total amount of stored power of the batteries B1, B2, B3, and B4 detected by the stored power detection unit 261 is equal to or greater than a predetermined amount, the control unit 221 controls the switching operation unit 210 to prohibit switching of the rotor 110 from the second position to the first position even if the position accepted by the driving mode changeover switch 255 is the first position.

[0115] That is, when the control unit 221 detects that the brake pedal is depressed while the electric vehicle 1 is running, for example, regenerative control is executed by the motor M. If the charge amount of the batteries B1, B2, B3, B4 is equal to or greater than a predetermined amount (for example, close to a fully charged state) when the regenerative control is executed, a current for charging the batteries B1, B2, B3, B4 is not supplied to the batteries B1, B2, B3, B4 in order to protect the batteries B1, B2, B3, B4. At this time, if the outer circumferential surface of the first rotor portion 111 faces the outer circumferential surface of the stator 100, the permanent magnet 111b of the first rotor portion 111 may be overheated by the current not supplied to the batteries B1, B2, B3, B4, which may cause deterioration of the permanent magnet 111b. In this embodiment, when the amount of stored electricity in the batteries B1, B2, B3, and B4 is equal to or greater than a predetermined amount and charging is suppressed or prohibited, switching of the rotor 110 from the second position to the first position is prohibited, thereby suppressing high-temperature deterioration of the permanent magnet 111b.

[0116] 18 is a flowchart showing an example of a procedure of magnetic pole alignment control executed when the rotor is switched from the first position to the second position. This flowchart is repeated at a predetermined timing when the electric vehicle 1 is in a state where it can run or while it is running. In step SB1 after the start, the control unit 221 determines whether or not to switch the position of the rotor 110 from the first position to the second position. If the determination is NO, the process proceeds to step SB4, where the motor M is controlled so as to obtain the required output calculated by the calculation unit 222 while keeping the rotor 110 in the first position.

[0117] On the other hand, when the result of the determination in step SB1 is YES and the position of the rotor 110 is switched from the first position to the second position, the process proceeds to step SB2 before the switching is performed, and the control unit 221 executes magnetic pole alignment control. Specifically, in a state in which the outer peripheral surface of the first rotor portion 111 and the inner peripheral surface of the stator 100 are opposed to each other and the motor M is operated, before the rotor 110 is switched to a position in which the outer peripheral surface of the second rotor portion 112 faces the inner peripheral surface of the stator 100, the control unit 221 controls the electromagnet (stator coil 100b) of the stator 100 so that the magnetic poles of the first rotor portion 111 and the magnetic poles of the stator 100 coincide with each other in the circumferential direction. In other words, the control unit 221 executes magnetic pole alignment control before the switching operation of the position of the rotor 110 by the switching operation unit 210.

[0118] The magnetic pole alignment control is shown in Fig. 8, and the left side of the figure shows a state in which the rotor 110 is in the first position and generating a driving force. When a driving force is being generated, the control unit 221 executes current control for the stator coil 100b so that the magnetic poles of the first rotor portion 111 and the magnetic poles of the stator 100 do not match in the circumferential direction.

[0119] 8 shows a time when magnetic pole alignment control is being performed, and the control unit 221 controls the current to the stator coil 100b so that the N and S poles of the first rotor portion 111 and the N and S poles of the stator 100 are aligned in the circumferential direction. When the magnetic poles of the first rotor portion 111 and the magnetic poles of the stator 100 are aligned in the circumferential direction, the attractive force between the permanent magnet 111b of the first rotor portion 111 and the stator 100 decreases. Therefore, a small force is required to move the rotor 110 to the second position.

[0120] While the magnetic pole alignment control is being executed, the process proceeds to step SB3, where the rotor 110 is moved to the second position. When the control unit 221 detects that the rotor 110 has moved to the second position, the control unit 221 ends the magnetic pole alignment control and proceeds to step SB4, where the control unit 221 controls the motor M to obtain the required output calculated by the calculation unit 222. Note that the magnetic pole alignment control may be executed when switching the rotor 110 from the second position to the first position.

[0121] Fig. 19 is a flowchart showing an example of the procedure of output control executed when the rotor 110 is switched from the first position to the second position. This flowchart is repeated at a predetermined timing when the electric vehicle 1 is in a state where it can run or is running. In step SC1 after the start, the control unit 221 determines whether or not to switch the position of the rotor 110 from the first position to the second position, similar to step SB1 in Fig. 18. If the determination is NO, the process proceeds to step SC5, where the motor M is controlled so as to obtain the required output calculated by the calculation unit 222 while keeping the rotor 110 in the first position.

[0122] On the other hand, if the determination in step SC1 is YES and the position of the rotor 110 is switched from the first position to the second position, the process proceeds to step SC2 before the switching is performed, and the control unit 221 executes the output reduction control. Specifically, before the rotor 110 is switched from the first position to the second position, the electromagnet (stator coil 100b) of the stator 100 is controlled so that the output is lower than the required output calculated by the calculation unit 222. In other words, the control unit 221 executes the output reduction control before the rotor 110 is switched from the first position to the second position.

[0123] FIG. 20 is a graph showing the change in the output of the motor M, with the vertical axis being the output (kw) and the horizontal axis being the time (seconds). When the rotor 110 is in the first position, the control unit 221 controls the stator coil 100b so that the output is the required output calculated by the calculation unit 222, but the output of the motor M is instantly reduced by executing the output reduction control just before the switching timing of switching the position of the rotor 110 to the second position. In this way, the stator coil 100b is controlled so that the output is lower than the required output before the rotor 110 is switched to a position where the outer circumferential surface of the second rotor portion 112 faces the inner circumferential surface of the stator 100, so that the rotor 110 can be easily moved to the second position. Also, if the output of the motor M becomes lower than the required output during the switching of the position of the rotor 110, the occupant feels the reduction in the output, for example, by shaking, sound, vibration, etc., and therefore it becomes easy to know that the rotor 110 has been moved.

[0124] After step SC2, while the output of the motor M is in a state lower than the required output, the process proceeds to step SC3, and the rotor 110 is moved to the second position. When the control unit 221 detects that the rotor 110 has moved to the second position, the process proceeds to step SC4, and the output increase control is executed. The output increase control controls the stator coil 100b so that the output is higher than the required output calculated by the calculation unit 222. As a result, as shown in FIG. 20, the output of the motor M is instantly increased. Then, the process proceeds to step SC5 in FIG. 19, and the motor M is controlled so that the required output calculated by the calculation unit 222 is obtained. In short, the control unit 221 controls the stator coil 100b so that the output is higher than the required output calculated by the calculation unit 222 after the rotor 110 is switched from the first position to the second position, and then the required output is obtained. As a result, the output that has decreased before the switching from the first position to the second position can be compensated for after the switching, and therefore a large drop in output does not occur. The output increase control may be executed as necessary, and may be omitted. Moreover, when the rotor 110 in the second position is switched to the first position, the output reduction control and the output increase control may be executed.

[0125] The control unit 221 makes the difference between the output power that has been reduced before the rotor 110 is switched from the first position to the second position and the required output power substantially equal to the difference between the output power that has been increased after the rotor 110 is switched from the first position to the second position and the required output power. That is, in FIG. 20, the area of ​​the shaded area C is calculated by the time integration of the difference between the output power that has been reduced before the rotor 110 is switched from the first position to the second position and the required output power. The area of ​​the shaded area D is calculated by the time integration of the difference between the output power that has been increased after the rotor 110 is switched from the first position to the second position and the required output power. The control unit 221 calculates the amount of reduction in the output power, the time during which the output power is reduced, the amount of increase in the output power, and the time during which the output power is increased so that the area of ​​the shaded area C and the area of ​​the shaded area D are the same, and controls the stator coil 100b as calculated. By executing such control, the load on the motor control device 200 is reduced. The above two differences may be different.

[0126] (Modification of the switching operation unit) In the above embodiment, the switching operation unit 210 is configured using the cylindrical cams 211, 212 and the pins 213, 214, but is not limited thereto. Although not shown, the switching operation unit 210 may be configured, for example, by a linear actuator or a fluid pressure cylinder device operated by fluid pressure such as hydraulic pressure or air pressure. In the case of a linear actuator, it may be one that uses electromagnetic force or one that uses a feed screw mechanism. By connecting the linear actuator to the output shaft M1, it is possible to move the rotor 110 in the axial direction. Also, by connecting a fluid pressure cylinder device to the output shaft M1, it is possible to move the rotor 110 in the axial direction.

[0127] As shown in FIG. 21, the switching operation unit 210 may include an operation lever 270 and an operated member 280. The operated member 280 is cylindrical and fixed so as not to move or rotate relative to a portion of the output shaft M1 protruding outside the motor case 120. An annular groove 281 extending in the circumferential direction is formed on the outer circumferential surface of the operated member 280. An abutment portion 271 that enters the annular groove 281 of the operated member 280 and abuts against the inner surface of the annular groove 281 is provided at the tip of the operation lever 270. The operation lever 270 is supported at its middle portion via a support shaft 272 that extends in a direction perpendicular to the output shaft M1, and is freely swingable around the support shaft 272. The positional relationship between the support shaft 272 and the stator 100 is designed not to change. When an operating force is applied to the base end portion of operating lever 270 in the direction of arrow C (to the right in the figure), contact portion 271 tries to move to the left in the figure, exerting a force on operated member 280. This force can move rotor 110 from the first position to the second position. To move rotor 110 from the second position to the first position, operating lever 270 can be operated in the opposite direction.

[0128] The operation lever 270 may be operated by an electric actuator or the like, or may be operated by the occupant. When operated by the occupant, a base end portion of the operation lever 270 may be disposed inside the vehicle interior R3 and the occupant may directly operate this portion, or a rod or wire may be connected to the base end portion of the operation lever 270 and the occupant may indirectly operate it via the rod or wire. When the occupant operates the rotor 110 via the operation lever 270, it becomes a manual rotor moving mechanism, and the rotor 110 can be moved in the axial direction in accordance with the switching operation input by the occupant.

[0129] (Effects of the embodiment) As described above, when the motor M is operated with the outer peripheral surface of the first rotor portion 111 equipped with the permanent magnet 111b facing the inner peripheral surface of the stator 100, the magnetic poles of the first rotor portion 111 and the magnetic poles of the stator 100 are aligned in the circumferential direction prior to moving the rotor 110 in the axial direction. This requires less force to move the rotor 110 in the axial direction, and makes it possible to miniaturize moving mechanisms such as the switching operation portion 210.

[0130] In addition, by lowering the output of motor M below the required output prior to moving rotor 110 axially, it is possible to facilitate axial movement of rotor 110 and also make it easier for the user to understand that rotor 110 has been moved.

[0131] Furthermore, since the position of the rotor 110 can be automatically switched according to the driving conditions of the electric vehicle 1, the various characteristics of the motor M can be adapted to the driving conditions without the occupant being aware of it. When the occupant selects a position for the rotor 110, the position of the rotor 110 is switched to that position, so that the motor M can exhibit the various characteristics desired by the occupant when desired. In this way, the occupant can actively change the various characteristics of the motor M by switching the position of the rotor 110 at the desired timing.

[0132] In this embodiment, the rotor 110 of the motor M is movable in the fore-and-aft direction. Therefore, while a layout that is advantageous for the yaw moment of inertia is used as a base, it is possible to change the front-to-rear weight distribution while driving, for example, to change the yaw moment of inertia, thereby changing the handling characteristics.

[0133] The above-described embodiment is merely illustrative in every respect and should not be interpreted as being restrictive. Furthermore, all modifications and changes within the scope of equivalence of the claims are within the scope of the present invention. The motor M may be provided on the left side or the right side of the vehicle body. The motor M may also be disposed so that its output shaft M1 faces the vehicle width direction. [Industrial Applicability]

[0134] As described above, a motor control device according to the present disclosure can be used in, for example, electric vehicles. [Explanation of symbols]

[0135] 100 Stator 110 Rotor 111 First rotor section 111b Permanent magnet 112 Second rotor section 200 Motor control device 210 Switching operation section 221 Control Unit 222 Calculation section 223 Driving Status Acquisition Unit 242 Temperature sensor (temperature detection part) 261 Charge amount detection unit

Claims

1. A motor control device controls a motor including a rotor in which a first rotor section having a permanent magnet and a second rotor section not having a permanent magnet are arranged side by side in an axial direction and integrated with each other, and a stator arranged to surround an outer circumferential surface of the rotor, the rotor being configured to be movable in the axial direction relative to the stator, a switching operation unit that switches the rotor position from a first position, where an outer circumferential surface of the first rotor portion faces an inner circumferential surface of the stator, to a second position, where an outer circumferential surface of the second rotor portion faces an inner circumferential surface of the stator, and switches the rotor position from the second position to the first position in response to a switching operation input by a user; A calculation unit that calculates a current required output of the motor; a control unit that controls an electromagnet of the stator so that the output is lower than the required output calculated by the calculation unit before the motor is switched from the first position to the second position.

2. 2. The motor control device according to claim 1, A motor control device, wherein the control unit, after switching from the first position to the second position, sets an output higher than the required output calculated by the calculation unit, and then controls an electromagnet of the stator so as to achieve the required output.

3. 3. The motor control device according to claim 2, The control unit makes substantially equal a difference between the reduced output and the required output prior to switching from the first position to the second position and a difference between the increased output and the required output after switching from the first position to the second position.

4. 2. The motor control device according to claim 1, The control unit controls an electromagnet of the stator so as to obtain an output lower than the required output calculated by the calculation unit prior to switching from the second position to the first position.

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