JP2009097694A - Left / right driving force distribution mechanism - Google Patents

Abstract

A left-right driving force distribution mechanism provided with a differential limiting mechanism is provided.
A left and right driving force distribution mechanism 10 includes a sun gear 42 and a sun gear 52, a pinion gear 43 and a pinion gear 53 having different numbers of teeth, a carrier 46 that integrally supports the pinion gear 43 and the pinion gear 53, and rotation of the carrier 46. A right torque amplifying clutch 61 and a left torque amplifying clutch 63 are provided for each of the right drive shaft 31 and the left drive shaft 33. The sun gear 42 is connected to the differential case 22, and the sun gear 52 is connected to the right drive shaft 31 and the left drive shaft 33. The left / right driving force distribution mechanism 10 further includes a control LSD clutch 66 that engages the carrier 46 and the right drive shaft 31.
[Selection] Figure 1

Description

  The present invention generally relates to a left / right driving force distribution mechanism, and more particularly to a left / right driving force distribution mechanism that distributes a driving force at an appropriate ratio to left and right driving wheels of a vehicle.

  Regarding a conventional left and right driving force distribution mechanism, for example, Japanese Patent Application Laid-Open No. 10-151951 discloses a differential device for generating a rotation difference of each output side rotating body with a simple configuration. (Patent Document 1).

  The differential device disclosed in Patent Document 1 includes a gear case to which driving force from an engine is input, and a pair of drive shafts arranged coaxially with the rotation shaft of the gear case, and the rotational difference of each drive shaft is determined. The torque of the gear case is transmitted to each drive shaft while allowing. At one end of the gear case, a first input sun gear that rotates integrally with the gear case, a first output sun gear that rotates integrally with one drive shaft, and a plurality of first planetary gears that mesh with each sun gear, A first carrier that supports each first planetary gear so as to be able to rotate and a first clutch that restricts rotation of the first carrier with an arbitrary regulating force are provided. On the other end side of the gear case, a structure similar to that on the one end side is provided.

  Japanese Patent Application Laid-Open No. 5-208620 discloses a vehicle left / right driving force distribution device that aims to prevent both the left and right torque transmission mechanisms from engaging at the same time and to lock neither the left or right torque transmission mechanism in the event of a failure. Is disclosed (Patent Document 2).

In Patent Document 2, the left and right driving force distribution device is provided with a differential mechanism and a driving force transmission control mechanism. Allocate to the required ratio. The driving force transmission control mechanism includes a speed change mechanism including a double planetary gear mechanism and a multi-plate clutch mechanism.
JP-A-10-151951 Japanese Patent Laid-Open No. 5-208620

  In Patent Document 1 described above, the revolution of each first planetary gear is restricted by connecting the first clutch. Thereby, one drive shaft rotates faster than the other drive shaft by setting the gear ratio between each sun gear and the first planetary gear. For example, when the automobile turns, the drive wheel outside the curve Can be rotated faster than the inner drive wheels to improve turning performance. On the other hand, the differential device requires a differential limiting mechanism that limits the operation of the differential device in order to prevent the wheels from slipping when one wheel falls into a muddy state. However, Patent Document 1 makes no mention of this differential limiting mechanism.

  Therefore, an object of the present invention is to provide a left / right driving force distribution mechanism provided with a differential limiting mechanism.

  A left and right driving force distribution mechanism according to the present invention includes a differential including a differential case to which power is input, and left and right drive shafts that are arranged on both sides of the differential and output power from the differential, and the left and right drive shafts This is a left / right driving force distribution mechanism that distributes driving force to The left and right driving force distribution mechanism includes a first sun gear and a second sun gear, a first pinion gear and a second pinion gear having different numbers of teeth, a carrier, and a first engagement device that restricts rotation of the carrier. Prepare for each of these. The first sun gear and the second sun gear are coupled to the differential case and the drive shaft, respectively. The first pinion gear and the second pinion gear mesh with the first sun gear and the second sun gear, respectively. The carrier integrally supports the first pinion gear and the second pinion gear. The left / right driving force distribution mechanism further includes a second engagement device that engages the carrier and the drive shaft.

  According to the left / right driving force distribution mechanism configured as described above, the revolution of the first pinion gear and the second pinion gear is limited by limiting the rotation of the carrier by the first engagement device. At this time, the first sun gear and the second sun gear try to rotate at a rotation speed corresponding to the number of teeth of the first pinion gear and the second pinion gear, and as a result, the driving force moves between the left and right drive shafts. For this reason, by appropriately operating the first engagement devices provided for the left and right drive shafts, it is possible to distribute the driving force to the left and right drive shafts at an arbitrary ratio. Further, by engaging the carrier and the drive shaft by the second engagement device, each sun gear, each pinion gear, and the carrier rotate integrally. In this case, there is no rotational difference between the differential case and the drive shaft, and the differential between the left and right drive shafts is limited.

  Preferably, the first engagement device and the second engagement device are arranged offset in the axial direction of the drive shaft. According to the left / right driving force distribution mechanism configured as described above, the apparatus can be reduced in size in the radial direction centered on the drive shaft.

  Preferably, the first engagement device and the second engagement device are disposed adjacent to each other in the axial direction of the drive shaft. According to the left / right driving force distribution mechanism configured as described above, the structure of the actuator that operates the first engagement device and the second engagement device can be simplified.

  As described above, according to the present invention, a left and right driving force distribution mechanism provided with a differential limiting mechanism can be provided.

  Embodiments of the present invention will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are denoted by the same reference numerals.

(Embodiment 1)
FIG. 1 is a plan view schematically showing a left / right driving force distribution mechanism according to Embodiment 1 of the present invention. Referring to FIG. 1, a left / right driving force distribution mechanism 10 is mounted on a four-wheel drive vehicle or an FR (front engine rear wheel drive) vehicle.

  The left / right driving force distribution mechanism 10 includes a differential 21, a right drive shaft 31 and a left drive shaft 33. The right drive shaft 31 is connected to a wheel 32 on the right side of the vehicle, and the left drive shaft 33 is connected to a wheel 34 on the left side of the vehicle. Power from an engine as a power source is input to the differential 21 through the propeller shaft 11. The differential 21 automatically gives a rotation difference to the right and left wheels 32 and 34 when the vehicle turns or when the road surface is uneven, and transmits the driving force to the right drive shaft 31 and the left drive shaft 33.

  FIG. 2 is a sectional view showing the structure of the differential in FIG. In the figure, a bevel gear type differential 21 is shown, but the type of the differential 21 is not limited to this.

  Referring to FIGS. 1 and 2, differential 21 includes a differential case 22. The differential case 22 is disposed coaxially with the rotation axes of the right drive shaft 31 and the left drive shaft 33, and is provided so as to be rotatable about the axes. The differential case 22 is provided with a ring gear 23. The ring gear 23 meshes with a drive pinion 12 provided on the propeller shaft 11. The rotation of the propeller shaft 11 is transmitted to the differential case 22 by the engagement of the ring gear 23 and the drive pinion 12.

  The differential case 22 is provided with a pinion gear 28 and a pinion gear 29. The pinion gear 28 and the pinion gear 29 are provided so as to be able to rotate around an axis orthogonal to the revolution axis while revolving integrally with the differential case 22. The right drive shaft 31 and the left drive shaft 33 are provided with a side gear 26 and a side gear 27, respectively. Side gear 26 and side gear 27 mesh with pinion gear 28 and pinion gear 29. The rotation of the differential case 22 is transmitted to the right drive shaft 31 and the left drive shaft 33 by the meshing of the side gear 26 and the side gear 27 with the pinion gear 28 and the pinion gear 29. At this time, if a difference in rotation occurs between the right and left wheels 32 and 34, the pinion gears 28 and 29 rotate to allow a difference in rotation between the right drive shaft 31 and the left drive shaft 33.

  Referring to FIG. 1, left / right driving force distribution mechanism 10 includes a planetary gear unit 41 and a planetary gear unit 51. A set of the planetary gear unit 41 and the planetary gear unit 51 is provided for the right drive shaft 31 and the left drive shaft 33, respectively.

  The planetary gear unit typically provided on the right drive shaft 31 will be described. The planetary gear unit 41 and the planetary gear unit 51 are arranged side by side on the axis of the right drive shaft 31. A planetary gear unit 41 is disposed between the differential 21 and the planetary gear unit 51.

  Planetary gear unit 41 includes a sun gear 42 and a plurality of pinion gears 43. The sun gear 42 is provided to be rotatable about the rotation axis of the right drive shaft 31. The sun gear 42 is connected to the differential case 22 and rotates integrally with the differential case 22. The plurality of pinion gears 43 are arranged on the outer periphery of the sun gear 42 in a state of being engaged with the sun gear 42.

  Planetary gear unit 51 includes a sun gear 52 and a plurality of pinion gears 53. The sun gear 52 is provided to be rotatable about the rotation axis of the right drive shaft 31. The sun gear 52 is connected to the right drive shaft 31 and rotates integrally with the right drive shaft 31. The sun gear 42 has a larger diameter than the sun gear 52, and the number of teeth formed on the sun gear 42 is larger than the number of teeth formed on the sun gear 52. The plurality of pinion gears 53 are arranged on the outer periphery of the sun gear 52 in a state of being engaged with the sun gear 52. Each pinion gear 43 and each pinion gear 53 are arranged coaxially and are provided integrally. The pinion gear 43 and the pinion gear 53 have different numbers of teeth. The pinion gear 53 has a larger diameter than the pinion gear 43, and the number of teeth formed on the pinion gear 53 is larger than the number of teeth formed on the pinion gear 43.

  Planetary gear units 41 and 51 include a carrier 46. The carrier 46 is provided to be rotatable about the rotation axis of the right drive shaft 31. The carrier 46 supports the pinion gear 43 and the pinion gear 53 integrally. The carrier 46 supports the pinion gear 43 and the pinion gear 53 such that they can rotate and revolve around the rotation axis of the right drive shaft 31.

  The left / right driving force distribution mechanism 10 includes a right torque amplifying clutch 61 and a left torque amplifying clutch 63. The right torque amplifying clutch 61 is provided for the right drive shaft 31, and the left torque amplifying clutch 63 is provided for the left drive shaft 33. The right torque amplifying clutch 61 and the left torque amplifying clutch 63 are fixed to the right case 64 and the left case 65, which are stationary structures, respectively. The right torque amplifying clutch 61 and the left torque amplifying clutch 63 engage with the carrier 46, and limit the rotation of the carrier 46 with an arbitrary regulating force.

  The left / right driving force distribution mechanism 10 includes a control LSD (Limited Slip Differential Gear) clutch 66. In the present embodiment, a control LSD clutch 66 is provided for the right drive shaft 31. The control LSD clutch 66 is connected to the right drive shaft 31 and rotates integrally with the right drive shaft 31. The control LSD clutch 66 engages the right drive shaft 31 and the carrier 46.

  The right torque amplifying clutch 61, the left torque amplifying clutch 63, and the control LSD clutch 66 are, for example, a multi-plate clutch mechanism that includes a plurality of alternately arranged friction plates and a hydraulic cylinder that presses the friction plates together. Consists of The right torque amplifying clutch 61 and the control LSD clutch 66 are disposed between the wheel 32 and the planetary gear unit 51. The right torque amplifying clutch 61 and the control LSD clutch 66 are arranged side by side in the radial direction around the rotation axis of the right drive shaft 31. The right torque amplifying clutch 61 is disposed on the outer periphery of the control LSD clutch 66. The left torque amplifying clutch 63 is disposed between the wheel 34 and the planetary gear unit 51.

  Next, the operation of the left / right driving force distribution mechanism 10 in FIG. 1 will be described. First, when the right torque amplifying clutch 61, the left torque amplifying clutch 63 and the control LSD clutch 66 are not operated, the driving force is evenly distributed to the right and left wheels 32 and 34 by the action of the differential 21. It is.

  At the time of left / right wheel torque difference control that distributes the driving force to the right and left wheels 32, 34 at an arbitrary ratio, for example, when it is desired to suppress understeer during left turn, the right torque amplification clutch 61 is operated. At this time, as the rotation of the carrier 46 is restricted, the revolving motion of the pinion gear 43 and the pinion gear 53 is restricted. Thereby, the sun gear 42 and the sun gear 52 try to rotate at the number of rotations corresponding to the number of teeth of the pinion gear 43 and the pinion gear 53, respectively. That is, in the present embodiment, the sun gear 52 tries to rotate faster than the sun gear 42. As a result, the driving force of the right drive shaft 31 connected to the sun gear 52 that attempts to rotate fast increases, and the driving force of the left drive shaft 33 decreases as the driving force moves to the right drive shaft 31. This gives the vehicle a yaw moment that assists the turning motion around the center of gravity of the vehicle.

  The amount of movement of the driving force from the left drive shaft 33 to the right drive shaft 31 is arbitrarily set according to the clutch engagement force by the right torque amplifying clutch 61. When the left torque amplifying clutch 63 is operated, the driving force of the left drive shaft 33 increases and the driving force of the right drive shaft 31 decreases due to the same action as when the right torque amplifying clutch 61 is operated. .

  The control LSD clutch 66 is operated at the time of differential restriction that restricts the difference in rotation generated between the right and left wheels 32 and 34 by the differential 21. As a result, the right drive shaft 31 and the planetary gear units 41 and 51 rotate together, and no rotational difference occurs between the differential case 22 and the right drive shaft 31. As a result, when a rotation difference is about to occur between the right and left wheels 32 and 34, the clutch engaging force by the control LSD clutch 66 becomes a differential limiting force, and the differential of the differential 21 is limited. The magnitude of the differential limiting force is arbitrarily set according to the clutch engagement force by the control LSD clutch 66.

  The left and right driving force distribution mechanism according to the first embodiment of the present invention includes a differential 21 including a differential case 22 to which power is input, and left and right drive shafts that are disposed on both sides of the differential 21 and output power from the differential 21. The right drive shaft 31 and the left drive shaft 33, and the right and left drive force distribution mechanism 10 distributes the drive force to the right drive shaft 31 and the left drive shaft 33. The left and right driving force distribution mechanism 10 includes a sun gear 42 as a first sun gear and a sun gear 52 as a second sun gear, a pinion gear 43 as a first pinion gear and a pinion gear 53 as a second pinion gear having different numbers of teeth, a carrier 46, A right torque amplifying clutch 61 and a left torque amplifying clutch 63 are provided for each of the right drive shaft 31 and the left drive shaft 33 as first engaging devices that limit the rotation of the carrier 46. The sun gear 42 is connected to the differential case 22, and the sun gear 52 is connected to the right drive shaft 31 and the left drive shaft 33. The pinion gear 43 and the pinion gear 53 mesh with the sun gear 42 and the sun gear 52, respectively. The carrier 46 integrally supports the pinion gear 43 and the pinion gear 53. The left / right driving force distribution mechanism 10 further includes a control LSD clutch 66 as a second engagement device that engages the carrier 46 and the right drive shaft 31.

  According to the left / right driving force distribution mechanism 10 according to Embodiment 1 of the present invention configured as described above, both the left / right wheel torque difference control and the differential limit control can be achieved. In this case, both types of control can be established regardless of the type of the differential 21. For example, the differential 21 is not limited to the bevel gear type, and may use a planetary gear, or the differential 21 may be a helical gear type LSD or A mechanical LSD may be incorporated. Further, since the left / right driving force distribution mechanism 10 has a structure that utilizes the movement of the driving force between the left and right drive shafts, the torque difference between the left and right wheels can be determined regardless of the magnitude of the driving force input to the differential case 22. It can be set arbitrarily.

  In the present embodiment, the case where the control LSD clutch 66 is provided for the right drive shaft 31 has been described. However, the control LSD clutch 66 may be provided for the left drive shaft 33, or the right drive shaft 31 may be A control LSD clutch 66 may be provided for both the drive shaft 31 and the left drive shaft 33. When the control LSD clutch 66 is provided for both the right drive shaft 31 and the left drive shaft 33, the capacity of each clutch can be reduced, and the degree of freedom of design when the clutch is mounted is increased.

(Embodiment 2)
In the present embodiment, various modifications of the left / right driving force distribution mechanism 10 in the first embodiment will be described. Hereinafter, description is not repeated about the overlapping structure.

  FIG. 3 is a plan view schematically showing a first modification of the left / right driving force distribution mechanism in FIG. 1. Referring to FIG. 3, in the present modification, right torque amplifying clutch 61 and control LSD clutch 66 are arranged offset in the rotational axis direction of right drive shaft 31. In the rotational axis direction of the right drive shaft 31, the right torque amplification clutch 61 is disposed between the planetary gear unit 51 and the control LSD clutch 66, and the control LSD clutch 66 is connected to the right torque amplification clutch 61. It is arranged between the wheels 32.

  According to such a configuration, interference between the right torque amplifying clutch 61 and the control LSD clutch 66 can be avoided in the radial direction centered on the rotation axis of the right drive shaft 31, and the left and right driving force distribution mechanism 10 can be avoided. Can be miniaturized.

  FIG. 4 is a plan view schematically showing a second modification of the left and right driving force distribution mechanism in FIG. Referring to FIG. 4, in this modification, a right torque amplification clutch 61 and a control LSD clutch 66 are arranged adjacent to each other in the direction of the rotation axis of right drive shaft 31. The right torque amplifying clutch 61 and the control LSD clutch 66 are arranged in series in the rotational axis direction of the right drive shaft 31. The left / right driving force distribution mechanism 10 includes a hydraulic cylinder 72 and a hydraulic cylinder 73 that operate the right torque amplification clutch 61 and the control LSD clutch 66, respectively, and an oil passage 71 that supplies hydraulic pressure to the hydraulic cylinders 72 and 73. On the path of the oil path 71, a valve (not shown) for controlling the path leading to the hydraulic cylinder 72 and the hydraulic cylinder 73 so as to be freely opened and closed is provided.

  In the present modification, the right torque amplifying clutch 61 and the control LSD clutch 66 are arranged adjacent to each other in the direction of the rotation axis of the right drive shaft 31, and therefore, a hydraulic cylinder 72 that is an actuator for operating each clutch. 73, the oil passage 71, and the valve can be integrated between the right torque amplifying clutch 61 and the control LSD clutch 66. As a result, the actuator can be shared, and the left / right driving force distribution mechanism 10 can have a simple configuration.

  FIG. 5 is a plan view schematically showing a third modification of the left / right driving force distribution mechanism in FIG. 1. Referring to FIG. 5, in this modification, sun gear 52 has a larger diameter than sun gear 42, and the number of teeth formed on sun gear 52 is greater than the number of teeth formed on sun gear 42. The pinion gear 43 has a larger diameter than the pinion gear 53, and the number of teeth formed on the pinion gear 43 is larger than the number of teeth formed on the pinion gear 53.

  In this case, when the right torque amplification clutch 61 is operated, the sun gear 52 tends to rotate more slowly than the sun gear 42. As a result, the driving force of the right drive shaft 31 connected to the sun gear 52 that attempts to rotate slowly decreases, and the driving force of the left drive shaft 33 increases as the driving force moves from the right drive shaft 31. On the other hand, when the left torque amplification clutch 63 is operated, the driving force of the left drive shaft 33 decreases and the driving force of the right drive shaft 31 increases.

  According to the left / right driving force distribution mechanism according to the second embodiment of the present invention configured as described above, the effects described in the first embodiment can be similarly obtained.

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

It is a top view which represents typically the right-and-left driving force distribution mechanism in Embodiment 1 of this invention. It is sectional drawing which shows the structure of the differential in FIG. It is a top view which represents typically the 1st modification of the left-right driving force distribution mechanism in FIG. FIG. 9 is a plan view schematically showing a second modification of the left / right driving force distribution mechanism in FIG. 1. FIG. 10 is a plan view schematically showing a third modification of the left / right driving force distribution mechanism in FIG. 1.

Explanation of symbols

  10 Left / right driving force distribution mechanism, 21 differential, 22 differential case, 31 right drive shaft, 33 left drive shaft, 42, 52 sun gear, 43, 53 pinion gear, 46 carrier, 61 right torque amplification clutch, 63 left torque amplification clutch 66 Control LSD clutch.

Claims (3)

Left and right driving force that distributes driving force to the left and right drive shafts, including a differential including a differential case to which power is input, and left and right drive shafts that are arranged on both sides of the differential and that output power from the differential A distribution mechanism,
A first sun gear and a second sun gear respectively coupled to the differential case and the drive shaft;
A first pinion gear and a second pinion gear that mesh with the first sun gear and the second sun gear, respectively, and have different numbers of teeth;
A carrier that integrally supports the first pinion gear and the second pinion gear;
A first engagement device for restricting rotation of the carrier, for each of the left and right drive shafts;
A left-right driving force distribution mechanism comprising a second engagement device that engages the carrier and the drive shaft.   The left and right driving force distribution mechanism according to claim 1, wherein the first engagement device and the second engagement device are arranged offset in the axial direction of the drive shaft.   The left-right driving force distribution mechanism according to claim 1, wherein the first engagement device and the second engagement device are disposed adjacent to each other in the axial direction of the drive shaft.

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