JP2012158311A - Drive steering actuator for vehicle - Google Patents

Abstract

A drive steering actuator for a vehicle that can freely control a driving force and a steering force with one electric motor and consumes less power.
A wheel drive unit includes a first planetary gear mechanism that decelerates and transmits rotation of an electric motor to a wheel, and a steering mechanism is operated in accordance with steering to rotate the electric motor. A continuously variable transmission 15 for increasing and decreasing the speed, a first input unit to which the rotational power of the electric motor is directly input, a second input unit to which the rotational power of the electric motor is input via the continuously variable transmission, and a steering unit. And a second planetary gear mechanism 17 having an output portion connected to a steering member to be steered.
[Selection] Figure 1

Description

  The present invention relates to a vehicle drive steering actuator that can drive or steer a vehicle with one electric motor.

  As a vehicle driving actuator that can control steering by using the power of an electric motor for driving wheels, one described in Patent Document 1 is known. The one described in Patent Document 1 includes an electric motor, a wheel drive unit that transmits the rotation of the electric motor to the axle and rotationally drives the wheel, and a rudder angle control mechanism that performs steering control of the wheel. The planetary gear mechanism that can decelerate the rotation of the electric motor and transmit it to the axle and distribute the power is configured to operate the rudder angle control mechanism by the power distributed by the planetary gear mechanism.

JP 2010-23809 A

  In the vehicle drive actuator described in Patent Document 1, a planetary gear mechanism is used, and a bevel gear is used for speed reduction. Therefore, the driving force (drive rotational speed) and the steering force (steering angular velocity) are reduced. The ratio is always constant, and the driving force and the steering force cannot be freely controlled. Whether the steering mechanism is used for the front wheels or the rear wheels, it is difficult to appropriately control the steering speed and the steering force according to the vehicle state due to the limitation of the drive rotation speed, and the vehicle posture is changed. It can be unstable or give the driver a bad feeling. For this reason, in the thing of patent document 1, although the steering control at the time of vehicle travel is possible, free steering can be performed at the time of a vehicle stop.

  Moreover, since the configuration described in Patent Document 1 is configured to switch the right steering and the left steering with two clutches (44, 45) with respect to the rotation of the electric motor in one direction, the power consumption due to energization of the clutch. However, there is a problem that power consumption is further increased due to inefficiency of the reduction bevel gear.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a vehicle drive steering actuator that can freely control the driving force and the steering force with a single electric motor and that consumes less power. It is what.

  In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that an electric motor, a wheel drive unit that drives a wheel by rotation of the electric motor, and a steering mechanism that steers the wheel are provided. The wheel drive unit includes a first planetary gear mechanism that decelerates and transmits the rotation of the electric motor to the wheel, and the steering mechanism rotates the electric motor in response to steering. A continuously variable transmission that increases and decreases speed, a first input unit that receives rotational power of the electric motor via the continuously variable transmission, a second input unit that directly inputs rotational power of the electric motor, and wheels. And a second planetary gear mechanism having an output unit that is connected and steers the wheel.

  A feature of the invention according to claim 2 is that, in claim 1, the continuously variable transmission is constituted by a toroidal continuously variable transmission.

  According to a third aspect of the present invention, in the first aspect, the first planetary gear mechanism includes a first sun gear, a first carrier, and a first ring gear, and the first sun gear is coupled to the electric motor, The first carrier is connected to the wheel.

  According to a fourth aspect of the present invention, there is provided a clutch mechanism according to the third aspect, wherein the first ring gear is freely rotated or fixed, and the clutch mechanism is configured to freely rotate the first ring gear. The clutch control means for controlling is provided.

  According to a fifth aspect of the present invention, in the first aspect, the second planetary gear mechanism includes a second sun gear, a second carrier, and a second ring gear, and the second sun gear passes through the continuously variable transmission. The second carrier is connected to the electric motor, and the second ring gear is connected to the input side of the steering gear box.

  According to a sixth aspect of the present invention, in the second aspect, the variator of the toroidal continuously variable transmission is rotated by an electric drive means that is operated in accordance with an output of a steering sensor that detects rotation of the steering wheel. That is.

  According to the first aspect of the present invention, the wheel drive unit includes the first planetary gear mechanism that decelerates the rotation of the electric motor and transmits it to the wheel, and the steering mechanism increases or decreases the rotation of the electric motor according to the steering. A continuously variable transmission, a first input unit to which the rotational power of the electric motor is input via the continuously variable transmission, a second input unit to which the rotational power of the electric motor is directly input, and a wheel connected to the wheel. And a second planetary gear mechanism having an output portion for steering.

  With this configuration, the driving force for driving the vehicle by one electric motor and the steering force for steering the vehicle can be freely controlled, and the rotational power of the electric motor is controlled by the continuously variable transmission of the second planetary gear mechanism. Since it can be transmitted to the second input section at an increased or decreased speed, the wheels can be steered left and right regardless of the direction of rotation of the electric motor that rotates in the forward / reverse direction depending on the traveling state, and the vehicle drive A steering actuator can be realized at low cost, and wheel steering can be achieved with low power consumption.

  According to the invention of claim 2, since the continuously variable transmission is constituted by a toroidal continuously variable transmission, the second planetary gear mechanism has a simple configuration in which the variator is simply rotated by a lever or the like. The rotational power of the electric motor can be input to the second input unit at a continuously variable transmission ratio.

  According to the invention of claim 3, the first planetary gear mechanism includes the first sun gear, the first carrier, and the first ring gear, the first sun gear is connected to the electric motor, and the first carrier is connected to the wheel. Therefore, the rotation of the electric motor can be transmitted to the wheels at a high reduction ratio by the first planetary gear mechanism.

  According to the fourth aspect of the present invention, the clutch mechanism for making the rotation of the first ring gear free or fixed, and the clutch control means for controlling the clutch mechanism to freely rotate the first ring gear are provided. Therefore, it is possible to perform stationary steering by driving the electric motor while the wheels are stopped.

  According to the invention of claim 5, the second planetary gear mechanism includes the second sun gear, the second carrier, and the second ring gear, the second sun gear is connected to the electric motor via the continuously variable transmission, Since the two carriers are connected to the electric motor and the second ring gear is connected to the input side of the steering gear box, the speed difference between the second sun gear and the second carrier can be freely adjusted by continuously variable transmission by the continuously variable transmission. The second ring gear can be rotated in the forward and reverse directions by rotating the electric motor in one direction, and right steering or left steering can be obtained.

  According to the sixth aspect of the invention, the variator of the toroidal continuously variable transmission is rotated by the electric drive means that is operated according to the output of the steering sensor that detects the rotation of the steering wheel. A vehicle drive steering actuator adapted to the steering unit can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing an entire vehicle drive steering apparatus according to an embodiment of the present invention. FIG. 2 is a diagram in which a control block diagram is shown together with the vehicle drive steering apparatus shown in FIG. 1. 1 is a schematic diagram showing a toroidal continuously variable transmission according to an embodiment. It is a figure which shows the relationship between the lever position of a toroidal continuously variable transmission, input rotation speed, and output rotation speed. It is a figure which shows the relationship between the rotation speed of a toroidal continuously variable transmission and a 2nd planetary gear mechanism. It is a figure which shows the clutch control means which controls the clutch mechanism which concerns on embodiment. It is a figure which shows the modification of a clutch control means. It is a figure which shows a steer-by-wire system. It is a figure which shows the flowchart which drives and steers a vehicle. It is a figure which shows the relationship between the lever position of a toroidal continuously variable transmission, input torque, and output torque.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of a vehicle drive steering actuator according to the present embodiment. The vehicle drive steering actuator 10 is mainly driven by an electric motor 11 and an electric motor 11 to drive a drive wheel 12. The steering planetary gear mechanism 13 is driven by the first planetary gear mechanism 13 that is rotationally driven, the toroidal continuously variable transmission 15 whose reduction ratio is changed by the operation of the lever 14, and the electric motor 11 and the toroidal continuously variable transmission 15. The second planetary gear mechanism 17 to be steered and the clutch mechanism 18 that restricts or permits the rotation of the ring gear of the first planetary gear mechanism 13 are provided.

  The electric motor 11 is composed of an in-wheel motor incorporated in each of the left and right drive wheels 12, and includes a stator as a stator and a rotor as a rotor disposed on the inner periphery of the stator.

  The first planetary gear mechanism 13 includes a first sun gear 21, a first ring gear 22, and a first carrier 23 that are rotatably supported around the same axis, and a first planetary gear mechanism 13 that is rotatably supported by the first carrier 23. And one planetary gear 24. The first planetary gear 24 meshes with the first sun gear 21 and the first ring gear 22 at the same time, and can revolve and rotate around the first sun gear 21.

  The first sun gear 21 is connected to the output shaft 25 of the electric motor 11 and is driven to rotate integrally with the output shaft 25. The first carrier 23 is connected to the wheel drive shaft 26 of the drive wheel 12, and the drive wheel 12 is rotationally driven via the wheel drive shaft 26 by the rotation of the first carrier 23. The electric motor 11 is rotated forward or backward in accordance with the traveling state of the vehicle, whereby the drive wheel 12 is rotated forward and backward to move the vehicle forward and backward.

  As shown in FIG. 6, the clutch mechanism 18 includes a housing 27 and a multi-plate clutch 28 accommodated in the housing 27, and an inner clutch plate 28 a of the multi-plate clutch 28 is formed on the outer periphery of the first ring gear 22. The outer clutch plate 28 b is rotationally engaged with a spline formed on the inner periphery of the housing 27. The multi-plate clutch 28 is fastened or released by a clutch control means 30 having a configuration described later. Normally, the multi-plate clutch 28 is fastened and the first ring gear 22 is in a fixed state. Is retained.

  The second planetary gear mechanism 17 forms an output section, a second sun gear 31 that forms a first input section that is rotatably supported around the same axis, a second carrier 32 that forms a second input section, and the like. The second ring gear 33 and the second planetary gear 34 rotatably supported by the second carrier 32 are configured. The second planetary gear 34 meshes simultaneously with the second sun gear 31 and the second ring gear 33, and can revolve and rotate around the second sun gear 31. The second carrier 32 is connected to the output shaft 25 of the electric motor 11 and is driven to rotate integrally with the output shaft 25.

  The input shaft 35 of the toroidal continuously variable transmission 15 is connected to the output shaft 25 of the electric motor 11, and the output shaft 36 of the toroidal continuously variable transmission 15 is connected to the second sun gear 31 of the second planetary gear mechanism 17. ing. The toroidal continuously variable transmission 15 is well known, and as shown in FIG. 3, by controlling the rotation angle of the lever 14, the variator 37 integrally connected to the lever 14 is rotated. The rotation of the input shaft 35 is changed steplessly and transmitted to the output shaft 36.

  As described above, the rotational power of the electric motor 11 is directly distributed to the first sun gear 21 of the first planetary gear mechanism 13 and the second carrier 32 of the second planetary gear mechanism 17, and at the same time, the second planetary gear mechanism 17. The second sun gear 21 of the gear mechanism 17 is distributed via the toroidal continuously variable transmission 15.

  A variator angle sensor 38 that detects the angle of the variator 37 is provided at the center of rotation of the variator 37 of the toroidal continuously variable transmission 15. FIG. 4 shows the relationship between the rotational speed of the input shaft 35 and the output shaft 36 of the continuously variable transmission 15 with respect to the angular position of the lever 14. In FIG. 3, the position A indicates the neutral position of the lever 14. In the neutral position, the rotational speeds of the input shaft 35 and the output shaft 36 are the same, and when the lever 14 is operated from the position A to the position B, the input shaft 35. When the lever 14 is operated from the position A to the position C, the rotation of the input shaft 35 is accelerated and transmitted to the output shaft 36.

  As described above, the rotational power of the electric motor 11 is divided and distributed to the second sun gear 31 and the second carrier 32 of the second planetary gear mechanism 17, and the second carrier 32 directly to the second sun gear 31. When the rotation is transmitted via the toroidal continuously variable transmission 15, the second ring gear 33 of the second planetary gear mechanism 17 causes the rotation speed of the second sun gear 31 and the rotation speed of the second carrier 32. Based on the difference, it is rotated forward and backward.

  The second ring gear 33 is connected to the steering shaft 41 that forms the input shaft of the steering gear box 16 via the reduction and direction changing gear 40. As shown in FIG. 8, the steering unit 211 is a steer-by-wire type steering unit in which the steering wheel 42 and the steering wheel 43 are mechanically separated, and the rotation of the steering wheel 42 is transmitted to the steering wheel 43 via an electrical signal. It is constituted by. In the FF type vehicle, the steering wheel 43 and the drive wheel 12 are the same.

  Although not shown, the steering gear box 16 houses a rack and pinion mechanism connected to the steering shaft 41, and tie rods 44a and 44b are connected to both ends of the rack shaft of the rack and pinion mechanism. The left and right steering wheels 43 are connected to the tie rods 44a and 44b via unillustrated knuckle arms, respectively, and the steering wheel 43 is steered right or left by the axial movement of the rack shaft and the tie rods 44a and 44b. It is like that. As shown in FIG. 8, the steer-by-wire steering unit 211 detects a steering angle of the steering wheel 43 that is steered by the steering sensor 46 that detects the steering of the steering wheel 42 and the axial movement of the tie rods 44a and 44b. A steering angle sensor 47 (see FIG. 1) for rotating the lever 14 connected to the variator 37 of the toroidal continuously variable transmission 15 is provided.

  The electric motor 11 and the first planetary gear mechanism 13 constitute a wheel drive unit 200 that drives the drive wheels 12. The electric motor 11, the second planetary gear mechanism 17, and the toroidal continuously variable transmission 15 constitute a steering mechanism 210 that steers the steering wheel 43.

  As shown in FIG. 2, a voltage is applied to an unillustrated coil of the stator 15 of the electric motor 11 from an inverter 51 controlled by an ECU 50 for vehicle motion control. The ECU 50 is supplied with an ignition switch ON / OFF signal IG, a vehicle speed signal SPD, an accelerator opening signal ACC, and a battery charge state signal SOC. The inverter 51 is controlled according to various signals, The rotation of the motor 11 is controlled. In the figure, reference numeral 52 denotes a battery for driving the electric motor.

  Therefore, when steering of the steering wheel 42 is detected by the steering sensor 46, the electric actuator 48 is actuated by the ECU 50 according to the signal of the steering sensor 46, and the angular position of the lever 14 is changed from the position A (neutral position) in FIG. The motor is operated at a predetermined angle in the position B or position C direction, and the rotation of the electric motor 11 is accelerated or decelerated and transmitted to the second sun gear 31 of the second planetary gear mechanism 17. That is, for example, when the steering wheel 42 is operated in the right direction, the lever 14 is operated from the position A to the position B by the electric actuator 48, and conversely, when the steering wheel 42 is operated in the left direction, the lever 14 is operated by the electric actuator 48. Operates from position A to position C. When the lever 14 is operated to the position B or the position C, the rotation of the electric motor 11 is increased or decreased and transmitted to the second sun gear 31 of the second planetary gear mechanism 17, and the second sun gear 31 and the second carrier are transmitted. As a result, the direction change gear 40 is operated.

  FIG. 5 shows the relationship between the rotational speeds of the second planetary gear mechanism 17 and the toroidal continuously variable transmission 15. If the rotation input of the electric motor 11 to the second planetary gear mechanism 17 is, for example, the normal rotation direction, the rotation input in the normal rotation direction is also given to the input shaft 35 of the toroidal continuously variable transmission 15. The toroidal continuously variable transmission 15 has the second sun gear of the second planetary gear mechanism 17 in either the forward rotation direction or the reverse rotation direction at a continuously variable transmission ratio depending on the angular position of the lever 14 shown in FIG. 31. The rotation input of the electric motor 11 is directly input to the second carrier 32 of the second planetary gear mechanism 17. As a result, the second ring gear 33 of the second planetary gear mechanism 17 is rotated in the forward or reverse direction depending on the angular position of the lever 14 of the toroidal continuously variable transmission 15 regardless of the rotation of the electric motor 11 in one direction. Rotate to.

  In FIG. 5, the vertical axis in the center indicates the rotation speed of the electric motor 11, that is, the rotation speed of the second carrier 32 of the second planetary gear mechanism 17. The left vertical axis indicates the rotational speed of the output shaft 36 of the toroidal continuously variable transmission 15, that is, the rotational speed of the second sun gear 31 of the second planetary gear mechanism 17. Further, the vertical axis on the right side indicates the input rotation speed of the steering gear box 16, that is, the rotation speed of the second ring gear 33 of the second planetary gear mechanism 17.

  As apparent from FIG. 5, the electric motor 11 is rotated in the forward / reverse direction within a range of N2 depending on the traveling state, but the second carrier 32 (the output shaft 36 of the toroidal continuously variable transmission 15) is driven by the electric motor 11. Regardless of the input rotation direction, the forward rotation and the reverse rotation can be steplessly performed within the range of N1, and thereby the second ring gear 33 is rotated forward and reverse within the range of N3, and the right steering or the left steering is performed. Can be made possible.

  FIG. 6 shows an example of the clutch control means 30 for controlling the clutch mechanism 18, and the multi-plate clutch 28 is pressurized by a hydraulic piston using the hydraulic pressure of a hydraulic pump that cools the electric motor 11. The mechanism 18 can be turned on and off (fastened and released).

  That is, a hydraulic pump 54 for cooling the electric motor 11 is connected to the output shaft 25 of the electric motor 11. When the hydraulic pump 54 is driven by the rotation of the electric motor 11, the cooling oil is pumped up from the reservoir 55, and the cooling oil is supplied to the cooling system of the electric motor 11 through the cooling oil supply passage 57. A clutch control passage 58 is branched into the cooling oil supply passage 56, and the clutch control passage 58 is connected to a hydraulic operation chamber 60 formed between the multi-plate clutch 28 and the hydraulic piston 53 via a throttle passage 59. ing. The clutch control passage 58 is connected to a discharge passage 61 communicating with the reservoir 55 between the hydraulic working chamber 60 and the throttle passage 59, and the opening degree is controlled in the discharge passage 61 based on a signal from the ECU 50. A clutch control valve 62 composed of a linear solenoid valve is provided.

  The clutch control valve 62 is normally closed, whereby a hydraulic pressure of a predetermined pressure is introduced into the hydraulic pressure working chamber 60 of the clutch mechanism 18, and the multi-plate clutch 28 of the clutch mechanism 18 is engaged to form the first planet. The first ring gear 22 of the gear mechanism 13 is held in a fixed state. However, when the clutch control valve 62 is opened by the clutch control signal from the ECU 50, the hydraulic pressure introduced into the hydraulic operation chamber 60 of the clutch mechanism 18 is reduced, and the engagement of the multi-plate clutch 28 of the clutch mechanism 18 is released. Thus, the first ring gear 22 can rotate freely.

  In this way, by introducing a predetermined pressure hydraulic pressure into the hydraulic working chamber 60 of the clutch mechanism 18 by the clutch control valve 62, the multi-plate clutch 28 is fastened at a predetermined pressure, and the first planetary gear mechanism 13 The first ring gear 22 is held in a fixed state so that the multi-plate clutch 28 does not slip at the maximum driving force during normal traveling. However, when an unexpected rotational torque is input to the drive wheel 12 and a torque greater than the fastening force of the multi-plate clutch 28 is applied, the multi-plate clutch 28 slips. This prevents damage to the first planetary gear mechanism 13 and other internal components of the actuator.

  Note that the clutch control means 30 is not limited to the one that uses the hydraulic pressure of the hydraulic pump that cools the electric motor 11 described above, but is provided by a rotary motor 63 that is different from the electric motor 11 as shown in FIG. The multi-plate clutch 28 of the clutch mechanism 18 may be engaged and released.

  7, a screw portion 27a is formed on the inner periphery of the housing 27 of the clutch mechanism 18, and the outer periphery of a pressure member 64 that presses the multi-plate clutch 28 is screw-engaged with the screw portion 27a. A gear portion 64 a is formed on the inner periphery of the pressure member 64, and a gear 65 that meshes with the gear portion 64 a is provided on the output shaft of the rotary motor 63. As a result, the multi-plate clutch 28 is engaged or released when the pressure member 64 is moved in the axial direction simultaneously with the rotation by the screw action by the rotation of the rotary motor 63.

  In the above-described embodiment, when the electric motor 11 is driven forward or reversely, the rotation of the electric motor 11 is transmitted to the first sun gear 21 of the first planetary gear mechanism 13. At the same time, the rotation of the electric motor 11 is transmitted to the second sun gear 31 of the second planetary gear mechanism 17 via the toroidal continuously variable transmission 15 and directly to the second carrier 32.

  Normally, since the clutch mechanism 18 is engaged and the first ring gear 22 of the first planetary gear mechanism 13 is held in a fixed state, when the first sun gear 21 is rotationally driven by the electric motor 11, The first planetary gear 24 supported by the first carrier 23 revolves while meshing with the first ring gear 22, and the first carrier 23 is decelerated and rotated at a predetermined reduction ratio. Thereby, the drive wheel 12 is rotationally driven via the wheel drive shaft 26, and the vehicle travels forward or backward at a speed corresponding to the rotational speed of the electric motor 11.

  On the other hand, when the vehicle is traveling straight ahead, the lever 14 is set to give the second sun gear 31 an appropriate rotational speed calculated by the gear ratio of the second planetary gear mechanism 17 with respect to the rotational speed of the electric motor 11. By holding in an appropriate position, the second ring gear 33 is held stationary, the steering shaft 41 is not rotated, and the steering gear box 16 is held in a neutral state.

  In this state, when the steering wheel 42 is rotated, for example, clockwise, this is detected by the steering sensor 46. Based on the output signal of the steering sensor 46, the electric actuator 48 moves the lever 14 in the above-described straight traveling state. Operate from position to position B. By the operation of the lever 14 from the position A to the position B, the variator 37 of the toroidal continuously variable transmission 15 is rotated counterclockwise in FIG. 3, and the rotation of the input shaft 35 of the toroidal continuously variable transmission 15 is output. It is transmitted to the shaft 36 after being shifted (decelerated).

  As a result, the rotational speed of the second sun gear 31 of the second planetary gear mechanism 17 becomes lower than the rotational speed of the second carrier 32, so that the direction change gear 40 is caused by the rotational difference between the second sun gear 31 and the second carrier 32. Is rotated in one direction, and the steering wheel 43 is steered to the right via the tie rods 44a and 44b of the steering gear box 16.

  On the other hand, when the steering wheel 42 is rotated counterclockwise, the electric actuator 48 moves the lever 14 in the position C direction from the position during the straight traveling, on the contrary, based on the output signal of the steering sensor 46. To operate. By the operation of the lever 14 from the position A to the position C, the variator 37 of the toroidal continuously variable transmission 15 is rotated counterclockwise in FIG. 3, and the rotation of the input shaft 35 of the toroidal continuously variable transmission 15 is output. It is transmitted to the shaft 36 at an increased speed.

  As a result, the rotational speed of the second sun gear 31 of the second planetary gear mechanism 17 becomes higher than the rotational speed of the second carrier 32, so that the direction change gear 40 is caused by the rotational difference between the second sun gear 31 and the second carrier 32. Is rotated in the opposite direction, and the steering wheel 43 is steered to the left via the tie rods 44a and 44b of the steering gear box 16.

  However, in the above-described example, it is described that the lever 14 is steered in the right direction by the operation to the position B, and the lever 14 is steered in the left direction by the operation to the position C. Depending on the internal configuration of the steering gear box 16, the steering gear box 16 may be steered in the opposite direction.

  By the way, when the vehicle is in a stopped state, the first ring gear 22 of the first planetary gear mechanism 13 is controlled to rotate freely by releasing the engagement of the clutch mechanism 18. Therefore, even if the electric motor 11 is driven based on the operation of the steering wheel 42 and the first sun gear 21 of the first planetary gear mechanism 13 is driven to rotate, the first carrier 23 is rotated by the rotation of the first ring gear 22. The drive wheel 12 can be held stationary without rotating, and stationary steering is possible.

  Next, the driving and steering operations of the vehicle in the above-described embodiment will be described based on the flowchart of FIG. This flowchart is executed based on the ignition switch being turned on.

  First, in step 100, variables stored in the memory of the ECU 50 are initialized (initialized), and then in step 102, the vehicle speed SPD input to the ECU 50 is read. In step 104, it is determined whether or not the vehicle speed SPD is 0. If the vehicle speed SPD is 0 (YES), the routine proceeds to step 112 where control is performed so that the clutch mechanism 18 can rotate freely. That is, when the vehicle speed is 0, the opening of the clutch control valve 62 of the clutch control means 30 shown in FIG. 6 is controlled so that the first ring gear 22 can rotate freely. The fastening is released and the process proceeds to step 120 described later.

  If the determination result in step 104 is NO, in step 106, the accelerator opening degree ACC input to the ECU 50 is read. In the following step 108, it is determined whether or not the accelerator opening degree ACC is zero. If (YES), the routine proceeds to step 112 described above, and the engagement of the multi-plate clutch 28 of the clutch mechanism 18 is released so that the first ring gear 22 can rotate freely. If the determination result in step 108 is NO, the process proceeds to step 110 and the clutch mechanism 18 is engaged. That is, the clutch control valve 62 of the clutch control means 30 is controlled to close, the multi-plate clutch 28 is engaged, and the first ring gear 22 of the first planetary gear mechanism 13 is fixed in a stationary state.

  Next, at step 114, the target rotational speed of the electric motor 11 is calculated according to the accelerator opening ACC, and at step 116, the rotational speed of the electric motor 11 is controlled so as to approach the calculated target rotational speed. Subsequently, in step 118, it is determined whether or not the actual rotational speed of the electric motor 11 is equal to the target rotational speed calculated in step 112. If NO, the process returns to step 116 and the electric motor 11 is turned on. Rotation control continues. When the actual rotational speed of the electric motor 11 becomes equal to the target rotational speed, the determination result in step 118 is YES, and the process proceeds to step 120.

  As described above, when the electric motor 11 is rotationally controlled to the target rotational speed corresponding to the accelerator opening degree ACC, the driving wheel 12 in which the rotation of the electric motor 11 is decelerated and rotated by the first planetary gear mechanism 13 is also controlled by the accelerator. The vehicle is driven at a rotational speed (rotational speed) corresponding to the opening degree ACC, and the vehicle is driven at a speed corresponding to the accelerator opening degree. That is, when the first sun gear 21 is rotated by the electric motor 11, the planetary gear 24 supported by the first carrier 23 is revolved while meshing with the first ring gear 22, so that the first carrier 23 is decelerated and rotated at a predetermined reduction ratio, the drive wheel 12 is driven to rotate, and the vehicle travels at a speed corresponding to the rotational speed of the electric motor 11.

  By the way, when the steering wheel 42 is rotated while the vehicle is running, the operation amount (operation angle) of the steering wheel 42 is detected by the steering sensor 46, and the steering angle corresponding to the operation amount of the steering wheel 42 is detected in step 120. The target value is read. Next, at step 122, the rotational speed of the second sun gear 31 of the second planetary gear mechanism 17 necessary for controlling the steering angle to the target value is estimated. Subsequently, in step 124, the target angle of the lever 14 of the continuously variable transmission 15 necessary for obtaining the rotation speed of the second sun gear 31 estimated in step 122 is calculated. The lever 14 is controlled to the target angle by the actuator 48.

  As a result, the variator 37 of the continuously variable transmission 15 is rotated by the lever 14, and the rotation of the input shaft 35 is transmitted to the output shaft 36 at a predetermined speed increase ratio or speed reduction ratio according to the rotation of the variator 37. The rotation of the second sun gear 31 of the planetary gear mechanism 17 is controlled to the rotational speed estimated in step 122.

  Therefore, while the rotation of the electric motor 11 is directly transmitted to the second carrier 32, the second sun gear 31 is controlled to rotate at a rotational speed corresponding to the target steering angle, whereby the continuously variable transmission 15 is controlled. The first sun gear 31 and the second carrier 32 can rotate at different rotational speeds, and the second ring gear 33 of the second planetary gear mechanism 17 rotates in one direction (right direction) or in the opposite direction (left direction). Is done.

  In this way, when the second ring gear 33 of the second planetary gear mechanism 17 is rotated in one direction (the other direction) by the rotation operation of the steering wheel 42 in the right direction (left direction), the direction conversion gear 40 is rotated. , The steering gear box 16 is operated, the tie rods 44a, 44b are moved in one direction (the other direction), and the steering wheel 43 is steered in the right direction (left direction) via a knuckle arm (not shown).

  The actual steering angle of the steering wheel 43 is detected by the steering angle sensor 47. In step 128, it is determined whether or not the actual steering angle detected by the steering angle sensor 47 is equal to the target steering angle read in step 120. If the determination result is NO and the determination result is NO, the process of step 126 is continued. If YES, the process returns to step 102 to newly read the vehicle speed and repeat the above operation.

  Note that the rotational speed and torque of the electric motor 11 have a reciprocal relationship, and the relationship between the torque of the input shaft 35 and the output shaft 36 of the continuously variable transmission 15 with respect to the angular position of the lever 14 is as shown in FIG. That is, in FIG. 10, contrary to FIG. 4 described above, when the lever 14 is operated from the position A to the position B, the torque transmitted to the output shaft 36 increases, and the lever 14 is moved from the position A to the position C. When actuated in the direction, the torque transmitted to the output shaft 36 decreases.

  Therefore, in steps 114 to 118 described in FIG. 9, instead of calculating the target rotational speed of the electric motor 11, the target torque of the electric motor 11 is calculated, and the electric motor 11 is controlled to rotate until it matches the target torque. You may make it do.

  According to the above-described embodiment, the wheel drive unit 200 includes the first planetary gear mechanism 13 that decelerates the rotation of the electric motor 11 and transmits it to the drive wheel 12, and the steering mechanism 210 is electrically driven in accordance with the steering. The toroidal continuously variable transmission 15 that increases and decreases the rotation of the motor 11, the second sun gear 31 to which the rotational power of the electric motor 11 is input via the toroidal continuously variable transmission 15, and the rotational power of the electric motor 11 are directly input. And a second planetary gear mechanism 13 having a second ring gear 33 which is connected to the second carrier 32 and the steering wheel 43 and steers the steering wheel 43.

  With this configuration, the toroidal continuously variable transmission 15 can transmit the rotational power of the electric motor 11 to the second sun gear 31 of the second planetary gear mechanism 17 at an increased or decreased speed. The driving force for driving the driving wheel 12 and the steering force for steering the steering wheel 43 can be freely controlled. In addition, the continuously variable transmission 15 can transmit the rotational power of the electric motor 11 to the second sun gear 31 of the second planetary gear mechanism 17 at an increased or decreased speed. Regardless of the direction of rotation of the electric motor 11, the steering wheel 43 can be steered left and right, the vehicle drive steering actuator 10 can be realized at low cost, and the wheel can be steered with low power consumption. be able to.

  Furthermore, since the steering wheel 43 can be steered left and right with a simple configuration in which the variator 37 of the toroidal continuously variable transmission 15 is simply rotated by a lever or the like, the vehicle drive steering actuator 10 can be realized at low cost. In addition, the steering wheel 43 can be steered with low power consumption.

  Further, according to the above-described embodiment, the first ring gear 22 of the first planetary gear mechanism 13 can be freely rotated or fixed, and the first ring gear 22 can be freely rotated. Since the clutch control means 30 for controlling the clutch mechanism 14 is provided, the steering wheel 43 can be steered by driving the electric motor 11 while the drive wheel 12 is stopped.

  In the above-described embodiment, the example in which the toroidal continuously variable transmission is used as the continuously variable transmission 15 has been described. However, the present invention is not limited to the toroidal continuously variable transmission 15, and for example, the diameter is A continuously variable transmission such as a belt-type CVT in which a belt is passed through two changing pulleys may be used.

  In the above-described embodiment, the electric motor 11 is connected to the second sun gear 31 of the second planetary gear mechanism 17 via the continuously variable transmission 15, and the electric motor 11 is directly connected to the second carrier 32. The second ring gear 33 is connected to the steering gear box 16, but any two of the second sun gear 31, the second carrier 32, and the second ring gear 33 of the second planetary gear mechanism 17 are connected to the electric motor 11. An input unit to which rotational power is input may be used, and the remaining one may be an output unit for steering the steering wheel 43.

  Further, in the above-described embodiment, the example in which the vehicle drive steering actuator 10 of the present invention is used in the steer-by-wire type steering unit 211 has been described, but the present invention is limited to the steer-by-wire type steering unit 211. However, the present invention can be applied to a steering unit having a configuration in which the steering wheel 42 and the steering wheel 43 are mechanically coupled.

  Thus, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention described in the claims.

  The vehicle drive steering actuator according to the present invention is suitable for use in a vehicle including a wheel drive unit operated by an electric motor and a steering mechanism.

  DESCRIPTION OF SYMBOLS 10 ... Vehicle drive steering system, 11 ... Electric motor, 12 ... Drive wheel, 13 ... First planetary gear mechanism, 14 ... Control lever, 15 ... Toroidal continuously variable transmission, 16 ... Steering gear box, 17 ... Second Planet gear mechanism, 18 ... clutch mechanism, 21 ... first sun gear, 22 ... first ring gear, 23 ... first carrier, 24 ... first planetary gear, 25 ... output shaft, 26 ... wheel drive shaft, 31 ... second Sun gear 32 ... second carrier 33 ... second ring gear 34 ... second planetary gear 35 ... input shaft 36 ... output shaft 37 ... variator 41 ... steering shaft 42 ... steering wheel 43 ... steering wheel 46 ... steering sensor, 48 ... electric drive means (electric actuator), 200 ... wheel drive unit, 210 ... steering mechanism, 211 ... steering unit .

Claims (6)

A vehicle drive steering actuator comprising an electric motor, a wheel drive unit for driving a wheel by rotation of the electric motor, and a steering mechanism for steering the wheel,
The wheel drive unit includes a first planetary gear mechanism that decelerates and transmits the rotation of the electric motor to the wheel,
The steering mechanism includes a continuously variable transmission that increases / decreases rotation of the electric motor according to steering, a first input unit to which rotational power of the electric motor is input via the continuously variable transmission, and the electric motor And a second planetary gear mechanism having a second input unit to which the rotational power of the first input is directly input and an output unit coupled to the wheel and steering the wheel.
A drive steering actuator for a vehicle.   2. The vehicle drive steering actuator according to claim 1, wherein the continuously variable transmission is a toroidal continuously variable transmission.   2. The first planetary gear mechanism according to claim 1, comprising a first sun gear, a first carrier, and a first ring gear, wherein the first sun gear is connected to the electric motor, and the first carrier is connected to the wheel. A drive steering actuator for a vehicle.   The clutch mechanism for making the rotation of the first ring gear free or fixing, and the clutch control means for controlling the clutch mechanism to make the rotation of the first ring gear free. A drive steering actuator for a vehicle that is characterized.   2. The second planetary gear mechanism according to claim 1, wherein the second planetary gear mechanism includes a second sun gear, a second carrier, and a second ring gear, and the second sun gear is coupled to the electric motor via the continuously variable transmission. A vehicle drive steering actuator, wherein two carriers are connected to the electric motor, and the second ring gear is connected to an input side of a steering gear box.   3. The vehicle drive steering actuator according to claim 2, wherein the variator of the toroidal continuously variable transmission is rotated by an electric drive means that is operated in accordance with an output of a steering sensor that detects rotation of a steering wheel. .

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