JP2012152061A - Vehicle driving apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle driving apparatus in which a motor having an epoch-making structure where the motor is not bulky particularly in a radial direction is used, and a torque required for driving right and left drive wheels is generated while allowing the motor not to be bulky in the radial direction to secure a minimum ground clearance.SOLUTION: In the vehicle driving apparatus, a motor 8 driving right and left drive wheels 2l and 2r includes: right and left distributed magnetic path members 6l and 6r extending to right and left from a solenoid 3, respectively; rotors 4l and 4r in which a plurality of branched ends of the right and left distributed magnetic path members are arranged at an outer periphery to form a revolving field, thereby the drive wheels 2l and 2r are driven, respectively; and right and left magnetic flux adjusting means 5l and 5r magnetically adjusting between phases of the right and left distributed magnetic path members 6l and 6r, respectively. A stator is not arranged at inner peripheries and outer peripheries of the rotors 4l and 4r to form an epoch-making structure where the motor is not bulky in a radial direction, and a torque required for driving the right and left drive wheels 2l and 2r is generated while securing a minimum ground clearance.

Description

  The present invention relates to a vehicle drive device that drives left and right drive wheels with a motor, and more particularly, to improvement of difficulty in securing a minimum ground clearance due to bulkiness of the motor. In the present invention, the “vehicle” includes a motor including a four-wheel, three-wheel, etc. electric vehicle, an electric two-wheeled vehicle, an electric buggy, an electric wheelchair having two or more driving wheels such as two wheels and four wheels on the left and right. Various types of vehicles are included.

  2. Description of the Related Art Conventionally, some four-wheel electric vehicle drive devices drive left and right drive wheels by an induction motor such as a squirrel-cage induction motor (see, for example, Patent Documents 1 and 2).

  In addition, some of the motors such as the induction motors of Patent Documents 1 and 2 share one stator for the rotor that rotates the left and right drive wheels (see, for example, Patent Document 3).

JP 7-147704 A JP-A-6-46508 Japanese Patent Laid-Open No. 4-183204

  When the left and right drive wheels are driven by the induction motors or the like disclosed in Patent Documents 1 to 3, the motors are formed by concentrically winding coils on the salient poles of each phase on the rotor outer peripheral side or inner peripheral side. The Therefore, the stator needs to have a length in the radial direction more than a certain extent so that the coil can be wound sufficiently, and the stator becomes large. Therefore, in this type of drive device, the motor is bulky in the radial direction as a whole and is increased in size.

  By the way, in this kind of vehicle, it is necessary to ensure a prescribed minimum ground clearance.

  When a differential gear (hereinafter referred to as “differential gear”) or the like is used to divide the motor output into power for the left and right drive wheels, if the generated torque of the motor is increased sufficiently, the diameter of the motor as a whole will be reduced. Larger in size and larger in size. In other words, increasing the torque generated by the motor and ensuring the minimum ground clearance are in a trade-off relationship, and it is difficult to satisfy both. For example, it will be difficult to secure the specified minimum ground clearance.

  In radial type motors, if the rotor and stator are lengthened in the axial direction, it is possible to amplify the torque while suppressing the increase in the size of the motor in the radial direction, but the mass of the motor is extremely increased and practically used. Not right. In addition, in an axial type motor, if a large number of stators and rotors are alternately arranged in the axial direction, torque can be amplified while suppressing an increase in the size of the motor in the radial direction. Increased and reduced reliability, difficult to realize.

  Therefore, in the conventional drive control device for this type of vehicle, it is impossible to generate torque necessary for driving the left and right drive wheels while ensuring the minimum ground clearance so that the motor is not bulky in the radial direction.

  The present invention uses a motor with an epoch-making structure that is not bulky in the radial direction, and ensures the minimum ground clearance by preventing the motor from being bulky in the radial direction, while providing the torque necessary for driving the left and right drive wheels. The purpose is to occur.

  In order to achieve the above-described object, a vehicle drive device according to the present invention includes a motor for driving left and right drive wheels, left and right distribution magnetic path members extending left and right from magnetic flux generation means for generating magnetic flux, A plurality of branched ends of the distribution magnetic path member are arranged on the outer periphery to form a rotating field, and the left and right rotors that drive the left and right drive wheels respectively, and the phase between the left and right distribution magnetic path members It is the structure provided with the magnetic flux adjustment means on either side which adjusts magnetically (Claim 1).

  According to the first aspect of the present invention, in the motor for driving the left and right drive wheels, the magnetic flux generated by the magnetic flux generating means (for example, the solenoid coil) is distributed through the left and right distribution magnetic path members extending to the left and right respectively. A rotating field is formed by reaching each branched end, and the left and right rotors are rotated by this field.

  Further, the left and right magnetic flux adjusting means independently short-circuit and cut off the magnetic path in front of the rotor of each of the left and right drive wheels according to the vehicle going straight, turning left and right, etc., and exhibit functions equivalent to the differential gear.

  And it is not necessary to arrange | position the solenoid coil built in the stator like the conventional motor in the inner side of the rotor or the outer vicinity, and a motor does not become large in radial direction. In addition, since the magnetic field adjustment means that magnetically adjusts the field magnetic flux from the magnetic flux generation means to the left and right rotors, the rotational speed and torque of the left and right rotors can be increased and decreased independently. .

  Therefore, use a motor with an epoch-making structure that is not bulky in the radial direction, and generate the torque required to drive the left and right drive wheels while ensuring the minimum ground clearance by preventing the motor from being bulky in the radial direction. Can do. In addition, constant velocity joints and universal joints for securing the minimum ground clearance, as well as reduction gears and differential gears can be dispensed with, and costs can be reduced.

It is explanatory drawing of schematic structure of one Embodiment of the drive device of the vehicle of this invention. It is explanatory drawing of the solenoid part of FIG. It is the top view which showed the main components arrangement | positioning of the motor of FIG. FIG. 4 is a side view of FIG. 3. (A)-(d) is operation | movement explanatory drawing of the magnetic flux adjustment means of FIG. (A)-(c) is explanatory drawing of the other example of a magnetic flux adjustment means, respectively. It is explanatory drawing in case a magnetic flux adjustment means is a mechanical type.

  Next, in order to describe the present invention in more detail, an embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 1 shows an overall schematic configuration of a drive control apparatus for a vehicle 1 according to the present embodiment. The vehicle 1 is, for example, a four-wheel automobile, and left and right front wheels or rear wheels thereof are drive wheels 2l and 2r.

  There is a solenoid part 3 that forms the magnetic flux generating means of the present invention in the approximate center between the drive wheels 2l and 2r, and the solenoid part 3 has an n-phase AC power for driving left and right, for example, cylindrical cage rotors 4l and 4r. If there are three solenoids (coils and iron cores) of n, and the AC power is three-phase with n = 3, three-phase magnetic fields of U, V and W are supplied to the left and right rotors 4l and 4r, respectively. It consists of two sets of three-phase solenoids 31u, 31v, 31w (6 solenoids in total) that magnetize. FIG. 1 shows a set of three-phase solenoids 31u, 31v, 31w for convenience. Further, for example, in the case of four phases of n = 4, multiple solenoids of 4 are arranged in the solenoid unit 3 and in the case of five phases of n = 5, solenoids of multiples of 5 are arranged in the solenoid unit 3 to supply an alternating magnetic field of each number of phases.

  FIG. 2 shows an example of the configuration of a set of three-phase solenoids 31u, 31v, 31w. Each solenoid 31u, 31v, 31w is formed by winding a coil 33 around an iron core 32, for example.

  The solenoids 31u, 31v, 31w may be arranged (arranged) or the like, and the phases may be in contact or separated as long as they are magnetically insulated. For example, it may be a concentric circumferential shape, a stacking shape, a river-shaped arrangement, etc., but the leakage flux of the generated AC magnetic field is greatly increased so as to affect the running performance of the vehicle 1. It is preferable to arrange them so that there is no such problem.

  Both end surfaces of the iron core 32 of each of the left and right solenoids 31u, 31v, 31w are the magnetic flux output portions of each phase, and the present invention extends from the solenoid portion 3 to the left and right via the magnetic flux adjusting portions 5l and 5r of the present invention. Are connected to the left and right distribution magnetic path members 6l and 6r.

  The magnetic flux adjusting parts 5l and 5r are formed of a magnetic material (for example, an iron core member) having an electric or mechanical movable part, and magnetically short-circuit between the left and right solenoids 31u, 31v, and 31w according to steering or the like. Shut off and adjust the magnetic flux on the rotor 4l, 4r side.

  Distribution magnetic path members 6l and 6r form magnetic path branches (hereinafter referred to as magnetic flux manifolds) 61 corresponding to the number of stator magnetic poles, and the bases are connected to the end faces of the respective phases of magnetic flux adjusting parts 5l and 5r. The magnetic flux is divided into the number of poles of each phase so as to give amplified necessary torque to the left and right drive shafts 7l and 7r extending from 4l and 4r to the wheels 2l and 2r.

  The magnetic flux of each phase divided into the number of poles × number of phases by the magnetic flux manifolds 61 of the distribution magnetic path members 6l and 6r provides gaps on the outer circumferences of the rotors 2l and 2r and are arranged at predetermined intervals in the circumferential direction. The end face portion 62 of the magnetic flux manifold 61 forms a stator magnetic pole, and generates a rotating field with the number of poles distributed by the magnetic flux manifolds 6l and 6r to the rotors 2l and 2r. The rotors 21 and 2r are provided with the required number of rotating field radiation means. Each of the end face portions 62 of the magnetic flux manifold 61 is preferably formed in a taper gusset-shaped magnetic flux nozzle shape that bends the magnetic flux at right angles to the directions of the rotors 2l and 2r.

  3 shows the main part (solenoid part 3, magnetic flux adjustment) of the motor (motor of the present invention) 8 formed by the rotors 4l and 4r, the solenoid part 3, the magnetic flux adjustment parts 5l and 5r, the distribution magnetic path members 6l and 6r, and the like. FIG. 4 is a side view of a portion of the planar arrangement example of FIG. 3 as viewed from the front and the rear of the vehicle 1. FIG. 4 shows a planar arrangement example of the portions 5 l and 5 r and distribution magnetic path members 6 l and 6 r) and connection of the right rotor 2 r. FIG.

  In the solenoid unit 3, the magnetic flux adjusting units 5l and 5r, the distribution magnetic path members 6l and 6r, and the like, the members that form the magnetic path are thin strip stacks or wound iron cores such as electromagnetic steel plates, and magnetic powder compacts. The pipe is formed by a magnetic path pipe sealed with a magnetic powder or a colloidal solution of a magnetic fluid. If there is a possibility that magnetic foreign matter is attracted by the leakage magnetic field from the outside and enters the gaps between the phases and unintentional magnetic flux leakage may increase, cover each magnetic path with a non-magnetic living body cover. It is preferable to immerse and solidify the periphery of the magnetic path with a solid material of a non-magnetic body to prevent entry of these foreign substances.

  Cylindrical cage rotors 4l and 4r are, for example, cage rotors similar to general induction motors, and are installed using bearings or the like so as to maintain the air gap. This is applied to the left and right drive wheels 2l and 2r.

  Next, driving of the motor 8 configured as described above, magnetic flux control, and the like will be described.

  As shown in FIG. 1, a DC power source of a driving battery (main battery) 9 of a vehicle 1 is converted into three-phase AC power by, for example, an inverter unit 12 under the control of a power control unit 11 of a drive control unit 10 having a microcomputer configuration. The AC power is converted and supplied to the coils 33 of the left and right sets of solenoids 31u, 31v, 31w of the solenoid unit 3 to generate a three-phase magnetic flux. The three-phase magnetic flux generates the rotors 4l, 4r. Rotates to drive the motor 8.

  Further, the operation signal of the key switch 13 for starting the engine, the steering angle sensor 14 of the steering wheel, the shift position sensor 15, the accelerator sensor 16, the detection signal of the brake pressure sensor 17, the wheel speed sensors 18l and 18r of the drive wheels 2l and 2r. A detection signal or the like is input to the magnetic flux adjustment ECU 19 of the control unit 10.

  Then, the ECU 19 determines the difference in rotation between the left and right drive wheels 2l and 2r, which was conventionally performed by the differential gear when the vehicle 1 turns left and right, to the rotors 4l and 4r by the left and right magnetic flux adjustment units 5l and 5r. In order to achieve this by adjusting the magnetic flux, the adjustment amount of the magnetic flux is calculated mainly based on the detection signal of the steering angle sensor 14 on the steering shaft, and the magnetic path opening / closing of the magnetic flux adjusting units 5l and 5r is controlled based on the result. To do.

  FIGS. 5A to 5D show examples of magnetic flux adjustment by the magnetic flux adjusters 5l and 5r. The magnetic flux adjusters 5l and 5r have, for example, the lateral width of the magnetic path as a radius in the middle of the magnetic path of each phase. A state in which the movable member 51 of a hemispherical magnetic body is provided, and the ECU 19 rotates at least 90 degrees from the state of the angle 0 completely incorporated in the magnetic path of each phase and the half protrudes from the magnetic path. The position of the movable member 51 protruding from the magnetic path of each phase of the movable member 51 is slidably contacted with the connection portion 52 common to the respective phases of the magnetic material, and the movable member 51 is moved to 90. When the rotation is performed, the magnetic paths of the respective phases of the magnetic flux adjusting units 5l and 5r are almost completely cut off, and a short-circuit magnetic path of the magnetic path of each phase is formed via the connecting part 52 and the movable member 51 of the other phase. . That is, the rotation of the movable member 51 based on the turning of the vehicle 1 left and right, etc., magnetically shorts and blocks the phases of the distribution magnetic path members 6l and 6r, thereby adjusting the amount of magnetic flux on the rotors 4l and 4r side. .

  By this control, the magnetic flux on the rotor 4l, 4r side becomes as indicated by each arrow line in FIGS. 5 (a) to 5 (d), for example, in accordance with steering or the like, and the thickness of each arrow line indicates the amount of magnetic flux. . 5A to 5D, it is assumed that the left side (rotor 4l side) of the drawing is the inner ring side and the right side (rotor 4r side) of the drawing is the outer ring side when turning. FIG. 5A shows a case where the vehicle 1 is traveling straight. In this case, the movable member 51 of the magnetic flux adjusters 5l and 5r is in a state of an angle 0 that is completely incorporated in the magnetic path of each phase. The phase between the distribution magnetic path members 6l and 6r of each phase is magnetically cut off. FIG. 4B shows a case where the torque on the inner ring side is attenuated to prevent idling on a rough road with low frictional resistance μ. In this case, the movable member 51 of the magnetic flux adjusting unit 5l is rotated approximately 45 degrees. The phase of the magnetic distribution member 6l on the rotor 4l side is short-circuited magnetically incomplete (substantially half), and half of the magnetic flux on the rotor 4l side passes through the short circuit of the magnetic distribution member 6l, and the rotor The torque generated at 4l is approximately half of the torque generated at the rotor 4r. FIG. 6C shows a case where the torque on the inner ring side is set to 0 because the vehicle 1 turns with a small radius. In this case, the movable member 51 of the magnetic flux adjusting unit 5l is rotated by 90 degrees, and each phase The phases of the distribution magnetic path member 6l are magnetically completely short-circuited, and the magnetic flux on the rotor 4l side passes through the short-circuit path of the distribution magnetic path member 6l, and the generated torque of the rotor 4l becomes zero. FIG. 6D shows a special case when parking or towing. In this case, the movable member 51 of the magnetic flux adjusting portions 5l and 5r is rotated by 90 degrees in order to maintain the handle in a fixed state. In addition, the phases of the distribution magnetic path members 6l and 6r of each phase are both magnetically completely short-circuited, and the generated torques of the rotors 4l and 4r are both zero.

  Incidentally, in FIGS. 5A to 5D, the movable member 51 suitable for a case where each phase is a star-connected short circuit magnetic path (bypass magnetic path) is shown. However, each phase is a delta-connected short circuit magnet. In the case of a path (bypass magnetic path), a hemispherical movable member 53 shown in FIG. 6A may be used instead of the movable member 51, and FIG. 6A is the same as FIG. 5B. The magnetic path state in the case of attenuating the torque on the inner ring side in order to prevent idling on the rough road is shown.

  FIGS. 6B and 6C show still another example of movable members 54 and 55 in place of the movable member 51. FIG. 6B shows a short-circuit magnetic path (bypass magnetic path) in which each phase is a delta connection. In this case, even if the short-circuit magnetic path of the movable member 54 is formed, the magnetic flux of the rotors 4l and 4r passes through the movable member 54 and is not interrupted. It is suitable for protection during charging. FIG. 6C shows an example of the sliding movable member 55. In this case as well, even if a short-circuit magnetic path is formed across the movable member 55, the magnetic flux of the rotors 4l and 4r is the same as that of the movable member 54. Although passing through the movable member 55 and not being cut off, there is an advantage that the structure is simpler and cheaper than the movable members 51 and 53. In FIGS. 6B and 6C, it is assumed that the right side (rotor 4r side) of the drawing is the inner ring side and the left side (rotor 4l side) of the drawing is the outer ring side when turning. Moreover, the arrow line of FIG.6 (c) shows the movement of the movable member 55. FIG.

  In the case of the present embodiment described above, (1) in a conventional motor, a stator is disposed on the outer periphery or inner periphery of the rotors 4l and 4r, and the coil is concentratedly wound around the salient poles of the stator magnetic poles. Since it is necessary to adjust the energization amount to increase / decrease the field magnetic flux, the motor becomes bulky and large in the radial direction. In the motor 8 of this embodiment, a stator is disposed on the outer periphery or inner periphery of the rotors 4l, 4r. Without providing the solenoid unit 3 for generating the field magnetic flux in the middle of the rotors 4l and 4r, the magnetic flux adjusting units 5l and 5r are arranged on the left and right sides thereof, and the magnetic flux adjustment is performed by the magnetic flux manifold 61 of the distribution magnetic path members 6l and 6r. This is an unprecedented innovative structure that guides the magnetic flux adjusted by the parts 5l and 5r to the outer periphery of the rotors 4l and 4r. There is no conventional motor stator, and it is not bulky in the radial direction. Can be As a result, it is possible to generate the torque necessary for driving the left and right drive wheels 2l and 2r while easily ensuring the minimum ground clearance required for the vehicle 1, and a complicated mechanism (structure for ensuring the minimum ground clearance) ) Is not required, and the cost can be reduced. In addition, high transmission efficiency, high reliability, low noise, and space saving can be achieved.

  (2) Featuring magnetic flux adjusting parts 5l and 5r for short-circuiting and interrupting the magnetic path, a differential gearless structure is realized in terms of smoothness of state transitions due to the magnetic flux adjusting parts 5l and 5r and the slip characteristics of the induction motor. Low cost, high transmission efficiency, low noise and space saving. In addition, a limited slip differential function that can increase / decrease the differential limiting force as required can be added, and it is possible to demonstrate functions equivalent to conventional mechanical differential gear functions with rough road running performance and high speed stability. is there.

  (3) Since a reduction gear and a differential gear are not required, there is an advantage that maintenance such as temperature management and oil replacement is unnecessary because lubrication of these gears and oil for the cooling means are unnecessary.

  (4) It is possible to omit the stator yoke, which is the largest cause of the mass of this type of motor, and the motor 8 is reduced in weight.

  (5) Since there is no stator yoke and the solenoid part 3 is an open type, the heat generated in the motor 8 is easily released, and there is an advantage that no separate heat dissipating means or the like is required.

  (6) Since the solenoid unit 3 is provided with two sets of solenoids 31u, 31v, and 31w and branches the field magnetic flux for each magnetic pole, the minimum number of solenoids is required and power loss is small. There are also advantages in terms of light weight and low cost. Further, in the winding process of the coils 33 of the solenoids 31u, 31v, 31w to the iron core 32, the iron core 32 itself can be rotated, so that there is an advantage that an expensive winding machine is not required. In addition, it can easily cope with weight reduction with lightweight wires (aluminum wire, etc.) with low strain resistance and high density winding (edgewise winding) with flat wires, etc., making it lightweight, high heat dissipation, low floating static. There is also an advantage that electric capacity can be achieved.

  (7) Since components such as the solenoid unit 3, the magnetic flux adjusting units 5l and 5r, and the magnetic flux manifolds 6l and 6r of the motor 8 may be arranged in the drive shaft direction, there are few protrusions in the front-rear direction and the protrusions may protrude into the vehicle interior. There is also an advantage that it is possible to contribute to the expansion of the cabin volume of the vehicle 1. Further, as described above, the components of the motor 8 only have to be arranged in the direction of the drive shaft, so that the components can easily come into contact with the outside air, and the temperature can be controlled by inexpensive means such as natural air cooling or cooling by radiation. There are also advantages.

  (8) In the conventional motor, if the driving battery 9 is fully charged at the time of braking, the rotational energy from the driving wheel cannot be absorbed, and a braking means such as a brake is required separately. In addition, while the drive battery 9 is in a fully charged state and the motor is being driven, in order to maintain a high voltage in both the AC power line and the DC power line, components having a high withstand voltage must be used. As a result, the capacitance of the electric circuit connected to the coil 33 tends to increase and the switching loss and the like tend to increase. However, the motor 8 of this embodiment has a magnetic flux bypass function by the magnetic flux adjusting units 5l and 5r. Therefore, it is not necessary to absorb the rotational energy from the drive wheels 2l and 2r on the electric circuit side, and braking is performed with a structure with high heat dissipation of the rotors 4l and 4r, the magnetic flux adjusting parts 5l and 5r, and the magnetic flux manifolds 6l and 6r. Since energy can be absorbed, the electrostatic capacity of the component is small and switching loss and the like are reduced. Further, by combining the bypass function of the magnetic flux adjusting units 5l and 5r and the supply of the magnetic flux from the solenoid unit 3, it is possible to realize an ABS (Anti-Block Bracket System) function and a VSC (Vehicle Stability Control) function.

  If the signals of the rotational speed detecting means of the ABS and VSC, which have been standardized in recent years, are input to the ECU 19 as the speed signals of the left and right drive wheels 2l, 2r, the wheel speed sensors 18l, 18r for the motor 8 are obtained. It can be omitted.

  Next, in the above-described embodiment, the electric magnetic flux adjusting units 5l and 5r are provided. However, mechanical magnetic flux adjusting units 5l and 5r may be provided.

  FIG. 7 shows an example of mechanical magnetic flux adjusters 5l * and 5r * instead of the magnetic flux adjusters 5l and 5r. In this example, the magnetic flux adjusters 5l * and 5r * are linked mechanisms according to the steering operation of the steering wheel. When 20l and 20r are actuated, the movable member 56 in a portion surrounded by a broken line rotates to short-circuit / cut off the magnetic flux.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit thereof. For example, the rotors 4l and 4r are cylindrical cage types. Of course, the rotor structure of various induction motors may be used.

  Further, the number of phases, the number of stator magnetic poles formed by the end face portion 62 of each magnetic flux manifold 61, and the like may be any, and the magnetic flux generating means may be configured other than the solenoid.

  Further, the circuit configuration and control method of the drive control unit 10 may be whatever.

  The present invention can be applied to the case where the four wheels of the vehicle 1 are drive wheels, etc. Of course, four wheels, three wheels, two or more drive wheels such as two wheels and four wheels on the left and right,. The present invention can be applied to drive control devices for various motor-driven vehicles including electric vehicles, electric motorcycles, electric buggy vehicles, electric wheelchairs, and the like.

DESCRIPTION OF SYMBOLS 1 Vehicle 2l, 2r Drive wheel 3 Solenoid part 4l, 4r Rotor 5l, 5l *, 5r, 5r * Magnetic flux adjustment means 6l, 6r Distribution magnetic path member 8 Motor

Claims (1)

A vehicle drive device for driving left and right drive wheels by a motor,
The motor is
Left and right distribution magnetic path members extending left and right from magnetic flux generating means for generating magnetic flux, and
A plurality of branched end portions of the left and right distribution magnetic path members are arranged on the outer periphery to form a rotating field, and a rotor that drives each of the left and right drive wheels;
A vehicle drive apparatus comprising: left and right magnetic flux adjusting means for magnetically adjusting the phase between the left and right distribution magnetic path members.

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