JP2011133110A - Right and left wheel drive gear, front and rear wheel drive gear, and method for controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a differential in which each output element can be set to freely rotate, a front and rear drive gear using the differential, and a method of controlling the front and rear drive gear. <P>SOLUTION: The differential 1 causes a difference of rotation between two output elements. The differential 1 includes a planetary gear mechanism set 2 comprising two planetary gear mechanisms 20a, 20b combined. In the planetary gear mechanism set 2, a carrier 21 is connected between the planetary gear mechanisms 20a, 20b. A ring gear 22a of one the planetary gear mechanisms 20a is designed so that a brake mechanism 251 can stop its rotation. A ring gear 22b of the other 20b of the planetary gear mechanisms is connected to a motor shaft of a differential motor. Further, a sun gear 23 among component elements is connected to each of the output elements, either directly or indirectly. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a differential device that generates a rotational difference between two output elements, a front and rear wheel drive device for a four-wheeled vehicle using the differential device, and a control method for the front and rear wheel drive device.

  Conventionally, as a differential device that generates a rotational difference between two output elements, for example, there is one using a planetary gear mechanism. Then, there is an all-wheel drive type four-wheeled vehicle that uses such a differential device as a center differential and can always drive all wheels (see, for example, Patent Document 1).

  However, the conventional differential device has the following problems. That is, the above-described differential device has a problem that it is difficult to positively control the rotation difference between the output elements using, for example, an external control unit. Further, in order to freely set each output element, for example, a mechanism for restricting the relative rotation between the sun gear and the ring gear constituting the planetary gear mechanism is required. Here, the structure for restricting the relative rotation between the sun gear arranged at the innermost periphery and the ring gear arranged at the outermost periphery may be relatively complicated.

JP-A 64-45538

  The present invention has been made in view of the above-described conventional problems, and includes a differential device capable of freely setting each output element, a front and rear wheel drive device using the differential device, and the front and rear wheel drive device. The control method is intended to be provided.

1st invention is provided with the motor | power_engine which drives the driving wheel of a motor vehicle, and each drive shaft of the right-and-left wheel of the said driving wheel is each connected with each output shaft of the equal distribution differential which a differential gear has, respectively A device,
The differential device includes the equally distributed differential including one input shaft and two output shafts, and includes two output elements including the two output shafts. It is a three-gear element that generates a difference in rotation and includes a sun gear, a ring gear coaxially arranged on the outer peripheral side of the sun gear, and a carrier that holds a planetary gear that is gear-engaged with the ring gear and the sun gear. A planetary gear mechanism set in which two planetary gear mechanisms including a selected component are combined, a housing that accommodates the planetary gear mechanism set, and rotation of any one of the components in the one planetary gear mechanism. A brake mechanism configured to stop, and a differential motor that rotates any one of the components in the other planetary gear mechanism,
In the planetary gear mechanism set, the gear ratio that is the ratio of the number of teeth of the sun gear and the number of teeth of the ring gear is the same for each planetary gear mechanism, and
A first element of the selection components is interconnected between the planetary gear mechanisms;
Of the second elements of the selection components, one is configured to be able to stop rotation by the brake mechanism and the other is coupled to the motor shaft of the differential motor.
Of the selected elements, one of the third elements is directly connected to one of the input shaft of the equally distributed differential or the output shaft of the two axes, and the other is the output of the two axes. Directly connected to the other end of the shaft,
The motor shaft of the prime mover is connected to the input shaft of the equally distributed differential through a clutch mechanism (claim 1).
A second invention is a front and rear wheel drive device including a main prime mover for driving a front drive wheel or a rear drive main drive wheel of a four-wheel drive vehicle, and a sub prime mover for driving a sub drive wheel,
A left and right wheel drive device according to a first aspect of the invention is used as a drive device for the auxiliary drive wheel, and the prime mover in the left and right wheel drive device is used as the auxiliary prime mover. 9).

  The planetary gear mechanism set in the differential constituting the first invention has the first element as a common gear element. The rotation of the second element of one of the planetary gear mechanisms can be stopped by the brake mechanism. The second element of the other planetary gear mechanism is connected to the output shaft of the differential motor. Therefore, when the rotation of the motor shaft of the differential motor is input to the other second element in a state where the rotation of the one second element is stopped by the brake mechanism, the third planetary gear mechanism constituting each planetary gear mechanism is formed. A rotation difference can be generated between the elements according to the rotation input from the differential motor.

  Here, according to the planetary gear mechanism set obtained by combining two planetary gear mechanisms in which the gear ratio, which is the ratio of the number of teeth of the sun gear and the number of teeth of the ring gear, substantially matches, Regardless of the rotational speed, the rotational difference between the two third elements can be set according to the rotational speed input from the differential motor. That is, for example, if the rotation speed input from the differential motor is r rotation, the rotation difference can be always r rotation regardless of the rotation speed of the two third elements. Therefore, it is not necessary to change the rotational speed input from the differential motor in accordance with the rotational speed of each third element in order to realize a desired rotational difference between the two third elements. In general, the higher the rotational speed of each third element, the higher the rotational speed that should be input from the differential motor in order to obtain a desired rotational difference between the two third elements. Therefore, as described above, in the planetary gear mechanism set obtained by combining two planetary gear mechanisms in which the gear ratio, which is the ratio of the number of teeth of the sun gear and the number of teeth of the ring gear, substantially matches, The number of rotations to be input from the dynamic motor can be suppressed low.

  On the other hand, when the brake mechanism is opened to freely rotate one of the second elements, the rotation of each output element can be set freely. That is, in the above-described differential device, the function of causing the differential (rotational difference) between the output elements can be stopped. For example, in an automobile equipped with an anti-skid device that individually controls the rotation of each wheel, the output elements can be freely rotated when the anti-skid device is operated. Thereby, priority is given to the control by the anti-skid device, and the mutual interference between the control of each wheel by the anti-skid device and the control by the differential device can be prevented.

  In the front and rear wheel drive device according to the second aspect of the invention, the clutch mechanism is interposed between the motor shaft of the prime mover and the input shaft of the equally distributed differential. Therefore, in this front and rear wheel drive device, by switching the clutch mechanism, it is possible to appropriately switch whether or not the drive torque is transmitted from the sub prime mover to the sub drive wheels.

  Further, in the differential device in the front and rear wheel drive device, if the differential motor is rotationally driven in a state where the rotation of the one second element is stopped by the brake mechanism, the left and right of the differential motor are driven according to the rotation. A difference in rotation of the auxiliary drive wheels can be positively generated. If the rotation difference between the left and right auxiliary drive wheels can be controlled in this way, for example, an appropriate rotation difference can be given between the turning inner wheel and the turning outer wheel during turning. Therefore, according to the front and rear wheel drive device, it is possible to improve the running stability of the four-wheeled vehicle when turning.

  A third invention is a method for controlling a front and rear wheel drive device according to the second invention, wherein the clutch mechanism is engaged when the four-wheel drive vehicle mounted with the front and rear wheel drive device starts. The output shaft of the secondary prime mover is directly connected to the input shaft of the equally distributed differential, and the motor shaft of the secondary prime mover is rotationally driven in a state in which the brake mechanism is opened to freely rotate the second element. The present invention resides in a control method for a front and rear wheel drive device (claim 10).

  In the control method for the front and rear wheel drive device according to the third aspect of the invention, when the four-wheel drive vehicle starts, the motor shaft of the auxiliary prime mover is rotationally driven with the clutch mechanism engaged. Thereby, the rotational torque of the auxiliary prime mover can be transmitted as the driving force of the auxiliary driving wheels. Furthermore, in the control method for the front and rear wheel drive apparatus, the one second element is freely rotated by opening the brake mechanism. Therefore, the drive shaft connected to each third element of the planetary gear mechanism set via the equal distribution differential can rotate freely. Therefore, in a traveling situation where the four-wheel drive vehicle starts while turning, it is possible to appropriately absorb the rotation difference generated between the left and right auxiliary drive wheels.

  The start time of the four-wheel drive vehicle is a time interval from the stop state of the four-wheel drive vehicle until reaching a predetermined vehicle speed, and the vehicle speed increases with a certain acceleration or more. This is the driving situation. Here, the predetermined vehicle speed and the constant acceleration can be set in accordance with the magnitudes of the shaft outputs of the main prime mover and the sub prime mover, the balance of the shaft outputs of the both, and the like.

  A fourth invention is a control method for a front and rear wheel drive device according to the second invention, wherein the four wheel drive vehicle equipped with the front and rear wheel drive device is an anti-skid that individually controls the rotation of each wheel during braking. And when the anti-skid device is operated, the clutch mechanism is opened to disconnect the motor shaft of the auxiliary prime mover from the input shaft of the equally distributed differential, and the brake mechanism In the control method of the front and rear wheel drive device, wherein the first element is free to rotate.

  The control method for the front and rear wheel drive device of the fourth invention relates to a four-wheel drive vehicle equipped with an anti-skid device configured to individually control the rotation of each wheel during braking. The front and rear wheel drive device control method releases the clutch mechanism and disconnects the motor shaft of the auxiliary prime mover from the input shaft of the equally distributed differential when the anti-skid device operates. . Therefore, the drive torque transmitted from the sub prime mover to the sub drive wheel via the equal distribution differential can be made zero.

  Further, in the control method for the front and rear wheel drive device, when the anti-skid device is operated, the brake mechanism is opened to freely rotate the one second element. Accordingly, the output shafts of the equally distributed differential respectively connected to the drive shafts of the auxiliary driving wheels can freely rotate. Therefore, the anti-skid device can freely control each of the auxiliary driving wheels without causing interference with the control by the front and rear wheel driving device.

  A fifth aspect of the invention is a method for controlling a front and rear wheel drive device according to the second aspect of the invention, wherein when the four-wheel drive vehicle equipped with the front and rear wheel drive device turns, the clutch mechanism is opened to release the clutch mechanism. While disconnecting the connection between the motor shaft of the sub motor and the input shaft of the equally distributed differential, the motor shaft of the differential motor is engaged while engaging the brake mechanism and stopping the rotation of the one second element. Is a method for controlling a front and rear wheel drive device characterized in that the vehicle is rotationally driven.

  In the control method for the front and rear wheel drive device according to the fifth aspect of the invention, the clutch mechanism is released when the automobile turns. As a result, the torque transmitted from the sub motor to the sub drive wheel is made zero. Further, the brake mechanism is engaged to lock the rotation of the one second element and to drive the differential motor. Accordingly, by transmitting the rotation of the differential motor to the other second element, it is possible to positively generate a rotation difference between the left and right auxiliary drive wheels. Therefore, during the turning of the four-wheeled vehicle, a rotational difference between the inner and outer wheels can be positively generated to improve the turning performance.

  [0035]

[0106]
FIG. 2 is a block diagram showing a configuration of a front and rear wheel drive device in the first embodiment. The block diagram which shows the structure of the other front-and-rear wheel drive device in Example 1. FIG. The block diagram which shows the structure of the other front-and-rear wheel drive device in Example 1. FIG. FIG. 3 is a system diagram showing a control system of the front and rear wheel drive device in the first embodiment. Explanatory drawing explaining operation | movement of the front-and-rear wheel drive device at the time of start in Example 1. Explanatory drawing explaining the flow of the transmission torque in the front-and-rear wheel drive device at the time of start in Example 1. FIG. Explanatory drawing explaining operation | movement of the front-and-rear wheel drive device at the time of turning travel in Example 1. FIG. Explanatory drawing (A) explaining the flow of the transmission torque in the front-and-rear wheel drive device at the time of turning travel in Example 1. FIG. Explanatory drawing (B) explaining the flow of the transmission torque in the front-and-rear wheel drive device at the time of turning travel in Example 1. FIG. Explanatory drawing explaining the effect | action of the front-and-rear wheel drive device in Example 1. FIG. Explanatory drawing explaining operation | movement of the front-and-rear wheel drive device when the anti-skid device operates in the first embodiment. FIG. 3 is a block diagram illustrating a configuration of another differential device according to the first embodiment. FIG. 3 is a block diagram illustrating a configuration of another differential device according to the first embodiment. The block diagram which shows the structure of the other front-and-rear wheel drive device in Example 1. FIG. The block diagram which shows the structure of the other front-and-rear wheel drive device in Example 1. FIG. FIG. 3 is a configuration diagram illustrating a configuration of a planetary gear mechanism set according to the first embodiment. The block diagram which shows the 1st structure of the planetary gear mechanism group in Example 2. FIG. The block diagram which shows the 2nd structure of the planetary gear mechanism group in Example 2. FIG. The block diagram which shows the 3rd structure of the planetary gear mechanism in Example 2. FIG. The block diagram which shows the 4th structure of the planetary gear mechanism in Example 2. FIG. FIG. 9 is a block diagram illustrating a configuration of a differential device according to a third embodiment. The block diagram which shows the structure of the front-and-rear wheel drive device in Example 4. FIG. FIG. 10 is a block diagram illustrating a configuration of a front and rear wheel drive device according to a fifth embodiment. The operation | movement diagram in Example 5 explaining operation | movement of the front-and-rear wheel drive device (A: At the time of transmission, B: At the time of turning, C: At the time of anti-skid device operation). FIG. 10 is a block diagram showing a configuration of a front and rear wheel drive device in a sixth embodiment. FIG. 10 is a block diagram showing a configuration of another front and rear wheel drive device in a sixth embodiment.

  The differential device can be applied, for example, to realize a differential between the left and right wheels of a front wheel or a rear wheel of a four-wheeled vehicle.

The differential device has an equally distributed differential including a single input shaft and two output shafts as the two output elements.
The third element of one of the planetary gear mechanisms is directly connected to one of the input shaft or the two output shafts of the equally distributed differential and the third element of the other planetary gear mechanism. The element is directly connected to the other of the two output shafts.

In this case, if the clutch mechanism is engaged, the rotational torque transmitted from the differential motor to the input shaft of the equally distributed differential can be transmitted to the output shafts. Furthermore, if the clutch mechanism is released (disconnected), the rotational torque transmitted from the input shaft to the output shafts can be made zero. If the brake mechanism is opened, the rotation of each output shaft can be set freely.
This differential device can be applied to the drive wheel of a two-wheel drive four-wheeled vehicle or the main drive wheel or the sub-drive wheel of a four-wheel drive four-wheeled vehicle.

Moreover, it is preferable that each said planetary gear mechanism is a thing of the same specification (Claim 2).
In this case, the component parts can be shared by the planetary gear mechanisms constituting the planetary gear mechanism set. In addition, the said gear specification means specifications, such as the number of teeth of the said planetary gear mechanism, a diameter, and a tooth pitch.

Preferably, the second element is the ring gear, and the brake mechanism is fixedly supported by the housing.
When the ring gear as the second element arranged on the outer peripheral side of the planetary gear mechanism is configured to be braked by the brake mechanism fixedly supported by the housing, the outer periphery of the planetary gear mechanism set The brake mechanism can be efficiently arranged on the side.

The first element is preferably the carrier.
In each of the planetary gear mechanisms, the carrier holds a planetary gear that revolves around the sun gear. Therefore, when the carrier is configured as the first element, the carrier as a common element can be efficiently configured in a planetary gear mechanism set including a set of two planetary gear mechanisms.

The equal distribution differential is configured using a bevel gear, the one third element is connected to the input shaft of the equal distribution differential, and the other third element is the same. It is preferably connected to the output shaft of the distribution differential.
In this case, the differential device can be realized by combining the equally distributed differential configured using the bevel gear and the planetary gear mechanism set.

The equal distribution differential is configured by using a double pinion gear, and the one third element is connected to one of the two output shafts of the equal distribution differential or the input shaft, It is preferable that the other third element is connected to the other of the two output shafts of the equally distributed differential.
In this case, the differential device can be realized by combining the equally distributed differential configured using the double pinion gear and the planetary gear mechanism set.

Further, it is preferable that a speed reducer for reducing the rotation of the motor shaft of the prime mover is disposed between the prime mover and the clutch mechanism.
In this case, the controllability of the differential device can be improved by transmitting the rotation of the auxiliary prime mover to the input shaft of the equally distributed differential through the speed reducer.

Further, it is preferable that the equally distributed differential is of a differential limiting type.
In this case, the magnitude of the reverse input torque input from the main prime mover to the sub prime mover can be suppressed. Therefore, the allowable torque range of the sub prime mover with respect to the reverse input torque can be suppressed, and a small size can be adopted as the sub prime mover.

In the fifth aspect of the invention, the four-wheel drive vehicle has an anti-skid device that individually controls the rotation of each wheel during braking, and the clutch mechanism is installed when the four-wheel drive vehicle starts. The motor shaft of the secondary prime mover is directly connected to the input shaft of the equally distributed differential, and the brake mechanism is opened to freely rotate the second element of the secondary prime mover. The motor shaft is driven to rotate,
When the anti-skid device is operated, the clutch mechanism is released to disconnect the motor shaft of the auxiliary prime mover and the input shaft of the equally distributed differential, and the brake mechanism is opened to It is preferable to freely rotate the second element (claim 13).

In this case, when the four-wheel drive vehicle starts, the clutch mechanism is engaged to directly connect the motor shaft of the auxiliary prime mover and the input shaft of the equally distributed differential, and the brake mechanism is opened. By rotating the motor shaft of the auxiliary prime mover with the one second element free to rotate, the driving force is transmitted to the auxiliary driving wheel when the four-wheel drive vehicle starts. To assist in starting acceleration.
Further, when the anti-skid device is operated, the clutch mechanism is released to disconnect the motor shaft of the auxiliary prime mover from the input shaft of the equally distributed differential, and the brake mechanism is opened. By making the one second element freely rotatable, the left and right wheels of the auxiliary drive wheel can be freely set to rotate, and interference with the control by the anti-skid device can be avoided.

Example 1
This example is an example relating to the differential device 1 and the front and rear wheel drive device 10 for four-wheel drive using the differential device 1. The contents will be described with reference to FIGS.
As shown in FIG. 1, the differential device 1 generates a rotational difference between two output elements (in this example, the output shafts 32L and 32R of the equally distributed differential 30).
The differential 1 includes three parts: a sun gear 23, a ring gear 22 coaxially arranged on the outer peripheral side of the sun gear 23, and a carrier 21 that holds a planetary gear 24 that is gear-engaged with the ring gear 22 and the sun gear 23. In the planetary gear mechanism set 2 in which two (20a and 20b) planetary gear mechanisms 20 including a selection component that is a gear element are combined, a housing 25 that houses the planetary gear mechanism set 2, and one planetary gear mechanism 20b. A differential motor that rotates any one of the constituent elements of the ring gear 22, the sun gear 23, and the carrier 21 (in this example, also serves as the auxiliary prime mover 40), and each of the above-described components in the other planetary gear mechanism 20a. And a brake mechanism 251 configured to stop the rotation of any of the components.

In the planetary gear mechanism set 2, the gear ratio which is the ratio of the number of teeth of the sun gear 23 and the number of teeth of the ring gear 22 matches.
And the carrier 21 which is the 1st element of each said selection component is connected with the carriers 21a and 21b of each planetary gear mechanism 20a and 20b.
In addition, the ring gear 22 which is the second element among the selected components is configured such that the ring gear 22a of one planetary gear mechanism 20a can stop rotating by the brake mechanism 251 and the other planetary gear. The ring gear 22b of the mechanism 20b is connected to the motor shaft of the sub prime mover 40.
Further, in the sun gear 23 which is the third element among the selection components, the sun gears 23a and 23b of the planetary gear mechanisms 20a and 20b are directly or indirectly connected to the output shaft 32L or 32R, respectively. .
This content will be described in detail below.

  Further, as shown in FIG. 1, the differential device 1 of the present example includes a bevel gear type equally distributed differential 30 including a single-axis input shaft 31 and two-axis output shafts 32L and 32R as output elements. Become. One sun gear 23b is connected to the input shaft 31 of the equally distributed differential 30, and the other sun gear 23a is connected to the output shaft 32L. In the front and rear wheel drive device 10 of FIG. 1, the output shafts 32 </ b> L and 32 </ b> R of the equally distributed differential 30 are output elements of the differential device 1.

As shown in FIG. 1, the front and rear wheel drive device 10 using the differential device 1 includes a main prime mover 8 (hereinafter referred to as a vehicle engine as appropriate) that drives main drive wheels 80L and 80R of front wheels or rear wheels of a four-wheeled vehicle 100. 8) and a secondary prime mover 40 that drives the secondary drive wheels 50L and 50R.
The drive shafts 51L and 51R of the auxiliary drive wheels 50L and 50R are connected to the output shafts 32L and 32R of the equally distributed differential 30 in the differential device 1, respectively. The motor shaft of the secondary prime mover 40 is connected to the input shaft 31 of the equally distributed differential 30 via the clutch mechanism 41. The main drive wheels 80L and 80R are connected to the vehicle engine 8 via a power transmission unit 82.

  As shown in FIG. 1, the planetary gear mechanism set 2 of this example is configured by combining planetary gear mechanisms 20a and 20b having the same specifications (hereinafter abbreviated as appropriate). The housing 25 is integrally accommodated. Each planetary gear mechanism 20 includes a sun gear 23 disposed on the inner periphery, a plurality of planetary gears 24 that are rotatably supported by the carrier 21 and revolve around the sun gear 23, and an outer periphery thereof. It has an engagement structure with the ring gear 22 arranged on the side.

In the planetary gear mechanism set 2 of this example, as shown in the figure, the carrier 21 is configured as the first element. That is, each planetary gear 24 of each planetary gear mechanism 20 has a structure that is held by a common carrier 21.
In this example, the ring gear 22 is configured as the second element. That is, the ring gear 22a of one planetary gear mechanism 20a is configured to be stopped by the brake mechanism 251, and the ring gear 22b of the other planetary gear mechanism 20b is connected to the motor shaft of the differential motor. Has been. In this example, since the differential motor and the secondary prime mover 40 are shared, the motor shaft of the secondary prime mover 40 is connected to the ring gear 22b.

  Furthermore, in this example, as shown in FIG. 1, the sun gear 23 is configured as the third element. The sun gear 23b of one planetary gear mechanism 20b is connected to the input shaft 31 of the equally distributed differential 30, and the sun gear 23a of the other planetary gear mechanism 20a is connected to one output shaft 32L and one of the equally distributed differential 30. Is connected to the drive shaft 51L of the drive wheel 50L.

  Here, operation | movement of the planetary gear mechanism group 2 of this example is demonstrated easily using FIG. The number of teeth of each sun gear 23 is the same number of Zs, and the number of teeth of each ring gear 22 is the same number of Zr. When one ring gear 22a is stopped by the brake mechanism 251 and the rotational speed ωi input to the other ring gear 22b is set to zero, when one sun gear 23b is rotated at the rotational speed ω1, the carrier that is the first element The rotational speed of 21 is ωc = Zs / (Zs + Zr) × ω1. At this time, the other sun gear 23a rotates at the same ω1 as the one sun gear 23b.

  In order to rotate the other sun gear 23b at ω2 = ω1 + Δω with respect to the sun gear 23a having the rotational speed ω1 in a state where the one ring gear 22a is stopped by the brake mechanism 251, the carrier 21 which is the first element is used. Needs to be rotated at ωc = Zs / (Zs + Zr) × ω1. In order to obtain the rotation speed of the carrier 21, it is necessary to input the rotation of ωi = (− Zr) / Zs × Δω to the other ring gear 22b.

  The equally distributed differential 30 of this example is configured using a bevel gear as shown in FIG. The input shaft 31 of the equally distributed differential 30 is connected via a clutch mechanism 33 to a speed reducer 42 that is connected to the motor shaft of the sub prime mover 40. That is, the clutch mechanism 33 is intermittently connected so that the transmission of the rotational torque from the sub prime mover 40 to the equally distributed differential 30 can be interrupted. The right output shaft 32R of the equally distributed differential 30 is connected to a drive shaft 51R connected to the right sub drive wheel 50R. Further, as described above, the left output shaft 32L is coupled to the drive shaft 51L coupled to the left sub drive wheel 50L together with the sun gear 23a of one planetary gear mechanism 20a.

In addition, as shown in FIG.2 and FIG.3, what was comprised using the double pinion gear can also be applied instead of what was comprised using the bevel gear of this example as equal distribution differential 30. FIG. In particular, in the case of the equally distributed differential 30 using a double pinion, as shown in FIG. 3, sun gears 23a and 23b, which are the third elements of the planetary gear mechanisms 20a and 20b, are provided on the two output shafts 32L and 32R. Each can also be linked.
The clutch mechanism 33 may be a clutch having various structures such as a multi-plate clutch, a single-plate clutch, a hydraulic clutch, and an electromagnetic clutch.

Next, the front and rear wheel drive device 10 of this example is configured to be controlled by the control unit 6 as shown in FIG. In the figure, the vehicle engine 8 and the main drive wheels 80L and 80R (FIG. 1) are omitted. The control unit 6 is configured to capture operation signals of the vehicle speed sensor 61, the steering angle sensor 62, the yaw rate sensor 63, the acceleration sensor 64, and the anti-skid device 71. In addition, the signal of each sensor may be input directly to the control unit 6, or may be input indirectly via an engine ECU or the like for controlling the vehicle engine 8 (FIG. 1). The control unit 6 is configured to output a control signal toward the sub prime mover motor 40, the clutch mechanism 33, and the brake mechanism 251.
The anti-skid device 71 is configured to individually control the rotation of each wheel of a four-wheeled or two-wheeled vehicle in order to improve vehicle controllability under braking.

  The vehicle speed sensor 61 is configured to detect the traveling speed of the four-wheeled vehicle 100 and generate an output signal corresponding to the traveling speed. The steering rudder angle sensor 62 is configured to detect a steering rudder angle as an operation amount of the steering wheel by the driver and generate an output signal corresponding to the steering rudder angle. The yaw rate sensor 63 is configured to detect an angular velocity of a yaw angle (rotation angle around a vertical axis) generated in the four-wheeled vehicle 100 and generate an output signal corresponding to the angular velocity of the yaw angle. Further, the acceleration sensor 64 is configured to detect acceleration acting in the lateral direction of the vehicle and generate an output signal corresponding to the acceleration.

Next, a control method of the front and rear wheel drive device 10 of this example will be described. The front and rear wheel drive device 10 is controlled to perform a predetermined operation when the four-wheeled vehicle 100 starts, turns, and operates the anti-skid device 71.
First, the control of the front and rear wheel drive device 10 when the four-wheel vehicle 100 starts will be described. The control unit 6 (FIG. 4) determines whether or not the four-wheeled vehicle 100 is at the time of starting according to the vehicle speed value acquired from the vehicle speed sensor 61 and the acceleration obtained by time differentiation of the vehicle speed value. It is configured. In this example, when the vehicle speed value is within 20 km / h and the acceleration is 0.05 G (G is gravitational acceleration) or more, it is determined that the vehicle is starting.

  When it is determined that the four-wheel automobile 100 is at the start, as shown in FIG. 5, the brake mechanism 251 is released to freely rotate the ring gear 22a, and the clutch mechanism 33 is engaged to engage the auxiliary prime mover 40. To the equally distributed differential 30. Thereby, as indicated by the arrow lines a and b in FIG. 6, the rotational torque of the sub prime mover 40 is transmitted to the sub drive wheels 50L and 50R, and the sub drive wheels 50L and 50R are the same as the main drive wheels 80L and 80R. It becomes the state of four-wheel drive that rotates in the direction. In the figure, hatched arrows indicate the rotation directions of the sub drive wheels 50L and 50R with respect to the rotation direction of the motor shaft of the sub prime mover 40.

  Next, control of the front and rear wheel drive device 10 during turning traveling will be described. Note that the control unit 6 (FIG. 4) determines whether the four-wheeled vehicle 100 is in accordance with the vehicle speed value acquired from the vehicle speed sensor 61, the steering angle value acquired from the steering angle sensor 62, and the yaw rate acquired from the yaw rate sensor 63. It is configured to determine whether or not the vehicle is turning. In this example, when the vehicle speed value is 15 km / h or more, the steering angle is equal to or larger than a predetermined value, and the yaw rate is equal to or larger than a predetermined value, the vehicle is turning. It was judged. Note that the yaw rate sensor 63 may be omitted, and it may be determined whether the vehicle is turning by the combination of the vehicle speed value and the steering angle value.

  When it is determined that the four-wheel vehicle 100 is turning, the clutch mechanism 33 is released and the brake mechanism 251 is engaged as shown in FIG. If the ring gear 22b is rotated by the sub prime mover 40 in this state, a rotational difference can be positively generated between the sun gears 23a and 23b as the third element. In this example, the drive shaft 51L of the left auxiliary drive wheel 50L is directly connected to one sun gear 23a as described above. The other sun gear 23b is directly connected to the input shaft 31 of the equally distributed differential 30, and is connected to the drive shaft 51R of the right auxiliary drive wheel 50R via the equally distributed differential 30. Therefore, if the front and rear wheel drive device 1 is controlled as described above, the auxiliary drive wheels 50L and 50R are rotated in the reverse direction as shown by the arrow lines c and d in FIGS. 8A and 9B. Rotational torque can be transmitted. Then, the four-wheeled vehicle 100 can be easily turned by making a positive rotation difference between the auxiliary drive wheels 50L and 50R. 8A and 9B show the rotation directions of the sub drive wheels 50L and 50R relative to the rotation direction of the motor shaft of the sub prime mover 40 in the opposite direction.

  Here, as shown in FIG. 10 (an example of a front-wheel drive vehicle), as in the control during turning, the secondary motor 40 is released while releasing the clutch 33 and restricting the rotation of the ring gear 22a by the brake mechanism 251. If only the field current is applied to the four-wheeled vehicle 100, the straight running stability of the four-wheeled vehicle 100 can be improved. That is, according to the auxiliary prime mover 40 that is supplied with the field current and generates the braking torque, the differential between the auxiliary driving wheels 50L and 50R can be limited. And, for example, yaw (symbol “e” in the figure) that may occur in the four-wheeled vehicle 100 due to the influence of a crosswind or the like can be suppressed, and straight running stability can be improved. Further, for example, if the auxiliary prime mover 40 is actively controlled to rotate according to the yaw rate generated regardless of the operation of the steering wheel among the yaw rates measured by the yaw rate sensor 63, the straight-running stability of the four-wheeled vehicle 100 is further increased. It can also be improved.

  Next, control of the front and rear wheel drive device 10 when the anti-skid device 71 (FIG. 4) operates will be described. The control unit 6 is configured to be able to determine that the anti-skid device 71 is in operation based on an operation signal fetched from the anti-skid device 71. When the anti-skid device 71 is operating, the control of the auxiliary drive wheels 50L and 50R by the front and rear wheel drive device 10 is stopped so as to prevent mutual interference with the anti-skid device 71. Specifically, as shown in FIG. 11, the brake mechanism 251 is opened and the clutch mechanism 33 is opened. Thereby, the rotation of the output shafts 32L and 32R connected to the auxiliary drive wheels 50L and 50R in the front and rear wheel drive device 10 can be freely set.

  As described above, the front and rear wheel drive device 10 of this example transmits drive torque to the auxiliary drive wheels 50L and 50R when the four-wheel automobile 100 starts. Further, during turning, it is possible to assist the turning of the four-wheel vehicle 100 by actively giving a difference in rotation, that is, a differential between the auxiliary drive wheels 50L and 50R. Further, the rotation of the output shafts 32L and 32R is freely set when the anti-skid device 71 is operated so as to avoid interference with other devices that control the wheels of the four-wheeled vehicle 100 such as the anti-skid device 71. Therefore, the front and rear wheel drive device 10 of this example does not cause interference with control by other devices such as the anti-skid device 71.

As shown in FIG. 12, the reduction gear 42, the clutch mechanism 33, and the auxiliary prime mover 40 are omitted from the front and rear wheel drive device 10 (FIG. 1) of this example, and the differential motor 45 is added to configure the differential device 1. You can also According to the differential device 1, a rotational difference can be positively generated between the output shafts 32 </ b> L and 32 </ b> R according to the rotational speed input from the differential motor 45.
Furthermore, the differential distribution device 1 is configured to give a rotational difference to the driven wheels 57L and 57R of the two-wheel drive vehicle as shown in FIG. 13 by omitting the equally distributed differential from the front and rear wheel drive device 10 shown in FIG. You can also. The output elements of the differential 1 are shafts 571L and 571R connected to the driven wheels 57L and 57R. The sun gears 23a and 23b, which are third elements, are directly connected to the shafts 571L and 571R, respectively. According to the differential device 1, a rotational difference can be positively generated between the driven wheels 57 </ b> L and 57 </ b> R according to the rotation input from the differential motor 45.

  Further, as shown in FIG. 14, a differential motor 45 dedicated to the planetary gear mechanism set 2 can be provided separately from the auxiliary prime mover 40 for the front and rear wheel drive device 10 of this example. In this case, while the sub motors 40L and 50R are rotationally driven in the same direction by the sub motor 40, a rotation difference corresponding to the rotational speed input from the differential motor 45 is set between the sub driving wheels 50L and 50R. Can be granted. Therefore, the turning operation while starting can be actively assisted, and the controllability of the front and rear wheel drive device 10 can be further improved.

  Further, as shown in FIG. 15, the front and rear wheel drive device in which the clutch mechanism and the sub prime mover are omitted, and the propeller shaft 310 driven by the vehicle engine 8 and the input shaft 31 of the equally distributed differential 30 are connected via a hypoid gear or the like. 10 can also be configured. According to the front and rear wheel drive device 10, the drive torque transmitted from the vehicle engine 8 can be appropriately distributed to the auxiliary drive wheels 50L and 50R according to the rotation of the differential motor 45.

  Furthermore, the front and rear wheel drive device 10 shown in FIG. 15 may be applied to a vehicle including a traction control device configured to suppress idling of each wheel. In this case, the left and right auxiliary drive wheels 50L and 50R are unlikely to idle. That is, the magnitude of the reverse input torque that is input from the main prime mover 8 to the differential motor 45 can be suppressed. Therefore, in this case, it is possible to employ a small differential motor 45 having a small allowable torque range with respect to the reverse input torque. Similarly, if a limited slip differential having a differential limiting function is employed as the equally distributed differential 30, the same effect as described above can be obtained.

(Example 2)
In this example, the configuration of the planetary gear mechanism set 2 is changed based on the front and rear wheel drive device of the first embodiment. The contents will be described with reference to FIGS.
In the planetary gear mechanism set 2 (see FIG. 1) of the first embodiment, the carrier 21 is a first element, the ring gear 22 is a second element, and the sun gear 23 is a third element (configuration shown in FIG. 16). .) This configuration is characterized in that the structure is relatively simple and can be realized at low cost and in a compact manner. In particular, in this configuration, since the output is increased with respect to the input, this is particularly effective when the difference in the rotational speed between the left and right wheels is large, such as a vehicle having a small tire diameter.

  Instead of the configuration of the first embodiment, FIG. 17 shows a configuration in which the ring gear 22 is the first element, the carrier 21 is the second element, and the sun gear 23 is the third element. This configuration is advantageous in that it has a simple structure and can be realized at low cost and in a compact manner. In particular, in this configuration, it is possible to secure the largest speed increasing ratio, which is a rotation ratio of output to input.

FIG. 18 shows a configuration in which the sun gear 23 is a first element, the ring gear 22 is a second element, and the carrier 21 is a third element. This configuration can simplify the structure and can be realized at low cost. And this structure has the feature of a large torque type balance type that the output torque can be increased because the output is decelerated with respect to the input, and the load on the gear can be reduced, so that the planetary gear mechanism can be miniaturized. .

  FIG. 19 shows a configuration in which the ring gear 22 is a first element, the sun gear 23 is a second element, and the carrier 21 is a third element. In this configuration, the reduction ratio, which is the rotation ratio of output to input, can be increased, which is effective when a large torque is required for output.

FIG. 20 shows a configuration in which the sun gear 23 is a first element, the carrier 21 is a second element, and the ring gear 22 is a third element. This configuration has the advantage that the load on the gear can be reduced and the size can be reduced as compared with other combinations in which the sun gear 23 is the third element, although the structure is slightly complicated.
Other configurations and operational effects are the same as those in the first embodiment. In addition to the above, although the structure is complicated, the carrier can be the first element, the sun gear can be the second element, and the ring gear can be the third element.
(Example 3)
This example is another application example of the differential shown in FIG. 15 in the first embodiment. This will be described with reference to FIG.
The differential device 1 of this example is for giving a rotational difference to main drive wheels 60L and 60R of a two-wheel drive four-wheeled vehicle. In the differential device 1, the propeller shaft 310 driven by the vehicle engine 8 and the input shaft 31 of the equally distributed differential 30 are connected via a hypoid gear or the like. According to the differential device 1, a desired rotation difference can be given between the main drive wheels 60 </ b> L and 60 </ b> R according to the rotation speed input from the differential motor 45.
In addition, about another structure and an effect, it is the same as that of the differential apparatus shown in FIG. 15 of Example 1. FIG.
In addition to the above, the differential device 1 of this example can be used as a main drive wheel of a four-wheel drive four-wheeled vehicle or a differential device of a sub drive wheel. Furthermore, it can also be used as a differential device that provides a rotational difference between the front and rear wheels of a four-wheel drive four-wheeled vehicle.

Example 4
This example is an example in which a worm gear mechanism 253 is arranged between the differential motor 45 and the speed reducer 42 as shown in FIG. 22 based on the other front and rear wheel drive devices (see FIG. 15) of the first embodiment. It is.
That is, as shown in the figure, in the front and rear wheel drive device 10 of this example, the worm gear mechanism 253 is in the rotation transmission path from the differential motor 45 to the planetary gear mechanism set 2 and the equally distributed differential 30 via the speed reduction note 42. Is arranged.

  In the worm gear mechanism 253, a worm gear in which helical gear teeth are formed on the outer periphery of a substantially cylindrical member and a worm wheel in which oblique gear teeth are formed on an outer peripheral side surface of the substantially disk member are engaged with each other. The worm gear mechanism 253 has a characteristic that the torque transmission rate from the worm gear side toward the worm wheel is high and the torque transmission rate in the reverse direction is very low. Therefore, in this worm gear mechanism 253, the reverse transmission torque applied from the worm wheel side is not easily transmitted to the worm gear.

In the front and rear wheel drive device 10 of this example, the rotational torque of the differential motor 45 is input to the planetary gear mechanism set 2 or the equally distributed differential 30 via the worm gear mechanism 253. Therefore, in this front and rear wheel drive device 10, it is difficult for excessive torque of the main prime mover 8 to be transmitted as a reverse input to the differential motor 45 even when either of the left and right auxiliary drive wheels 50 </ b> L and 50 </ b> R idles. Therefore, the differential motor 45 can resist this reverse input with a relatively small torque. Therefore, in the front and rear wheel drive device 10 of this example, the torque range that the differential motor 45 should generate can be suppressed to be lower than the torque range that the main prime mover 8 generates. That is, in the front and rear wheel drive device 10 of this example, a small differential motor 45 can be adopted.
Other configurations and operational effects are the same as those in the first embodiment.

(Example 5)
In this example, the configuration of the differential device 1 is changed based on the front and rear wheel drive device of the first embodiment. The contents will be described with reference to FIGS.
In the differential device 1 of this example, as shown in FIG. 23, the rotation of the ring gear 22a of one planetary gear mechanism 20a is restricted. A differential clutch mechanism 252 for interrupting torque transmission is disposed between the ring gear 22b of the other planetary gear mechanism 20b and the speed reducer 42 that decelerates the rotation of the auxiliary prime mover 40. In the differential device 1 of this example, the rotation of the ring gear 22a is restricted by indirectly engaging the housing 25 and the ring gear 22a.

Next, a control method of the front and rear wheel drive device 10 of this example will be described. The front and rear wheel drive device 10 is controlled to perform a predetermined operation when the four-wheeled vehicle 100 starts, turns, and operates the anti-skid device 71.
When the four-wheel vehicle 100 is started, as shown in FIG. 24A, the differential clutch mechanism 252 is opened and the clutch mechanism 33 is engaged to transmit the drive torque from the sub prime mover 40 toward the equally distributed differential 30. Let Then, by transmitting the rotational torque of the auxiliary prime mover 40 to the auxiliary driving wheels 50L and 50R, the auxiliary driving wheels 50L and 50R rotate in the same direction as the main driving wheels 80L and 80R (FIG. 23). It becomes the state of. That is, the same torque transmission state as that of FIG. 6 described in the first embodiment is realized.

  When the four-wheel automobile 100 turns, as shown in FIG. 24B, the clutch mechanism 33 is released and the differential clutch mechanism 252 is engaged. If the ring gear 22b is rotated by the sub prime mover 40 in this state, a rotational difference can be positively generated between the sun gears 23a and 23b as the third element. In this example, the drive shaft 51L of the left auxiliary drive wheel 50L is directly connected to one sun gear 23a as described above. The other sun gear 23b is directly connected to the input shaft 31 of the equally distributed differential 30, and is connected to the drive shaft 51R of the right auxiliary drive wheel 50R via the equally distributed differential 30. Therefore, if the front and rear wheel drive device 1 is controlled as described above, the rotational torque can be transmitted so as to rotate the auxiliary drive wheels 50L and 50R in the reverse direction. Then, the four-wheeled vehicle 100 can be easily turned by making a positive rotation difference between the auxiliary drive wheels 50L and 50R. That is, the torque transmission state similar to that shown in FIGS. 8A and 9B described in the first embodiment is realized.

When the anti-skid device 71 (FIG. 4) operates, the control of the auxiliary drive wheels 50L and 50R by the front and rear wheel drive device 10 is stopped so as to prevent mutual interference with the control by the anti-skid device 71. Specifically, as shown in FIG. 24C, the differential clutch mechanism 252 is opened and the clutch mechanism 33 is opened. Thereby, in the front and rear wheel drive device 10, the output shafts 32L and 32R connected to the auxiliary drive wheels 50L and 50R can be freely rotated.
Other configurations and operational effects are the same as those in the first embodiment.

(Example 6)
This example is an example in which the configuration of the differential device is changed based on the other front and rear wheel drive devices (see FIG. 15) of the first embodiment. The contents will be described with reference to FIGS. 25 and 26. FIG.
In the differential device 1 of this example, as shown in FIG. 25, the rotation of the ring gear 22a of one planetary gear mechanism 20a is restricted. A differential clutch mechanism 252 is disposed between the ring gear 22b of the other planetary gear mechanism 20b and the speed reducer 42 that decelerates the rotation of the differential motor 45.

Other configurations and operational effects are the same as those in the first embodiment.
Furthermore, as shown in FIG. 26, a worm gear mechanism 253 can be disposed between the differential motor 45 and the differential clutch mechanism 252. According to the worm gear mechanism 253 having a very low torque transmission rate in the reverse direction, if either of the sub drive wheels 50L, 50R is idle, there is an excessive possibility that transmission from the main prime mover 8 toward the differential motor 45 may occur. Reverse input torque can be avoided in advance.

[0107]
DESCRIPTION OF SYMBOLS 1 Differential device 10 Front-and-rear wheel drive device 2 Planetary gear mechanism group 20a, 20b Planetary gear mechanism 21 Carrier 22 Ring gear 23 Sun gear 24 Planetary gear 25 Housing 251 Brake mechanism 30 Equal distribution differential 31 Input shaft 32L, 32R Output shaft 33 Clutch mechanism 40 secondary prime mover 42 reduction gear 45 differential motor 50L, 50R secondary drive wheel 51L, 51R drive shaft

Claims (13)

A left and right wheel drive device comprising a prime mover for driving a drive wheel of an automobile, wherein each drive shaft of the left and right wheels of the drive wheel is connected to each output shaft of an equally distributed differential included in the differential,
The differential device includes the equally distributed differential including one input shaft and two output shafts, and includes two output elements including the two output shafts. It is a three-gear element that generates a difference in rotation and includes a sun gear, a ring gear coaxially arranged on the outer peripheral side of the sun gear, and a carrier that holds a planetary gear that is gear-engaged with the ring gear and the sun gear. A planetary gear mechanism set in which two planetary gear mechanisms including a selected component are combined, a housing that accommodates the planetary gear mechanism set, and rotation of any one of the components in the one planetary gear mechanism. A brake mechanism configured to stop, and a differential motor that rotates any one of the components in the other planetary gear mechanism,
In the planetary gear mechanism set, the gear ratio that is the ratio of the number of teeth of the sun gear and the number of teeth of the ring gear is the same for each planetary gear mechanism, and
A first element of the selection components is interconnected between the planetary gear mechanisms;
Of the second elements of the selection components, one is configured to be able to stop rotation by the brake mechanism and the other is coupled to the motor shaft of the differential motor.
Of the selected elements, one of the third elements is directly connected to one of the input shaft of the equally distributed differential or the output shaft of the two axes, and the other is the output of the two axes. Directly connected to the other end of the shaft,
The motor shaft of the prime mover is connected to the input shaft of the equally distributed differential through a clutch mechanism.   2. The left and right wheel drive device according to claim 1, wherein each of the planetary gear mechanisms has the same gear specifications.   The left and right wheel drive device according to claim 1 or 2, wherein the second element is the ring gear, and the brake mechanism is fixedly supported by the housing.   The left and right wheel drive device according to any one of claims 1 to 3, wherein the first element is the carrier. In any one of Claims 1-4, the said equal distribution differential is comprised using a bevel gear,
In the differential device, the one third element is connected to the input shaft of the equally distributed differential, and the other third element is connected to the output shaft of the equally distributed differential. Left and right wheel drive device characterized by.   5. The equal distribution differential according to claim 1, wherein the equally distributed differential is configured by using a double pinion gear, and the one third element is one of the two output shafts of the equal distribution differential or A left and right wheel drive device, characterized in that it is connected to the input shaft, and the other third element is connected to the other of the two output shafts of the equally distributed differential.   The left and right wheel drive according to any one of claims 1 to 6, wherein a speed reducer for reducing rotation of a motor shaft of the prime mover is disposed between the prime mover and the clutch mechanism. apparatus.   8. The left and right wheel drive device according to claim 1, wherein the equally distributed differential is of a differential limiting type. A front and rear wheel drive device including a main prime mover for driving a front drive wheel or a rear drive main drive wheel of a four-wheel drive vehicle, and a sub prime mover for driving a sub drive wheel,
The left and right wheel drive device according to any one of claims 1 to 8 is used as the drive device for the auxiliary drive wheel, and the prime mover in the left and right wheel drive device is used as the auxiliary prime mover. Wheel drive device.   10. The control method for a front and rear wheel drive device according to claim 9, wherein when the four-wheel drive vehicle on which the front and rear wheel drive device is mounted starts, the clutch mechanism is engaged to output an output shaft of the auxiliary prime mover. And the input shaft of the equally distributed differential, and the motor shaft of the auxiliary prime mover is rotationally driven in a state where the brake mechanism is opened and the one second element is freely rotated. To control the front and rear wheel drive device.   10. The front and rear wheel drive device control method according to claim 9, wherein the four-wheel drive vehicle equipped with the front and rear wheel drive device includes an anti-skid device that individually controls the rotation of each wheel during braking. When the anti-skid device is operated, the clutch mechanism is opened to disconnect the motor shaft of the auxiliary prime mover and the input shaft of the equally distributed differential, and the brake mechanism is opened to A control method for a front and rear wheel drive device, characterized in that rotation of one second element is free.   10. The front and rear wheel drive device control method according to claim 9, wherein when the four-wheel drive vehicle on which the front and rear wheel drive device is mounted turns, the clutch mechanism is opened and the motor shaft of the auxiliary prime mover is opened. And disconnecting the equally distributed differential from the input shaft, and rotating the motor shaft of the differential motor while engaging the brake mechanism and stopping the rotation of the one second element. A control method for a front and rear wheel drive device. 13. The four-wheel drive vehicle according to claim 12, wherein the four-wheel drive vehicle includes an anti-skid device that individually controls rotation of each wheel during braking, and the clutch mechanism is engaged when the four-wheel drive vehicle starts. The motor shaft of the secondary prime mover is directly connected to the input shaft of the equally distributed differential, and the motor shaft of the secondary prime mover is set in a state in which the brake mechanism is opened to freely rotate the second second element. Rotation drive
When the anti-skid device is operated, the clutch mechanism is released to disconnect the motor shaft of the auxiliary prime mover and the input shaft of the equally distributed differential, and the brake mechanism is opened to A control method for a front and rear wheel drive device, wherein the second element is freely rotatable.

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