JP2010036801A - Vehicular driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To assemble an oil pump for supplying hydraulic pressure to a clutch of a torque distributing mechanism without interfering with a transfer device. <P>SOLUTION: A transfer device T in which a gear shaft 23 of a transfer drive gear 22 to which torque is transmitted from an input part of a front differential mechanism Df and a gear shaft 25 of a transfer driven gear 24 connected to rear wheels through a propeller shaft P cross each other is arranged in an extended part 23a of the gear shaft 23 of the transfer drive gear 22, hydraulic pressure used for operating clutches CL, CR of a torque distributing mechanism A is generated by an oil pump 75 driven by the extended part 23a, so that not only it is possible to avoid a state that an oil pump 75 is not driven and the clutches CL, CR cannot be operated, but also the deterioration of the degree of freedom in a layout caused by the interference of an added transfer device T with an existing oil pump or its driving system when the transfer device T is added to a front-wheel driving vehicle to perform four-wheel driving is avoided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle drive device that transmits torque of a drive source to left and right front wheels via a differential mechanism and a torque distribution mechanism, and transmits a part of the torque to rear wheels via a transfer device.

  According to Japanese Patent Application No. 2007-101942, the present applicant is a front-wheel driving force distribution device that distributes the torque of a driving source to the left and right front wheels via a differential mechanism and a torque distribution mechanism, and the outer periphery of the differential case 33 of the differential mechanism. A drive gear 76 is provided, and an oil pump 67 is provided on a gear shaft 71 of a driven gear 75 that meshes with the drive gear 76, and the oil pump 67 is driven by the gear shaft 71.

  For example, the front wheel driving force distribution device disclosed in Patent Literature 1 below drives the oil pump in conjunction with rotation of one of the pair of output shafts of the differential mechanism. If the engine slips on contact with a road surface having a small friction coefficient, the oil pump may not be driven and the function of the torque distribution mechanism may be lost.

On the other hand, the front wheel driving force distribution device proposed in Japanese Patent Application No. 2007-101942 causes the inconvenience as described above because the oil pump 67 is driven whenever the differential case 33 rotates. Absent.
JP 2007-315449 A

  By the way, a transfer device is added to the driving force distribution device for front wheels proposed in the above Japanese Patent Application No. 2007-101942, so that the driving torque divided from the input part of the differential mechanism such as a differential case can be transmitted to the rear wheels. When four-wheel drive is used, there arises a problem that the oil pump and the gear shaft or gear that drives the oil pump interfere with the newly added transfer device.

  The present invention has been made in view of the above circumstances, and an object thereof is to incorporate an oil pump for supplying hydraulic pressure to a clutch of a torque distribution mechanism so as not to interfere with the transfer device.

  In order to achieve the above object, according to the first aspect of the present invention, a driving force distribution device for front wheels that distributes the torque of the drive source to the left and right front wheels via the differential mechanism and the torque distribution mechanism, and a gear A transfer device having a transfer drive gear and a transfer driven gear with intersecting axes, wherein the transfer drive gear is transmitted with the torque from an input portion of the differential mechanism, and the transfer driven gear is connected to a rear wheel via a propeller shaft. And an oil pump that generates hydraulic pressure for operating the clutch of the torque distribution mechanism is provided on the extension portion on the crossing side of the gear shaft of the transfer drive gear, and is driven by the extension portion. A vehicle driving apparatus is proposed.

  The left clutch CL and the right clutch CR of the embodiment correspond to the clutch of the present invention, the front differential mechanism Df of the embodiment corresponds to the differential mechanism of the present invention, and the engine E of the embodiment Corresponding to the drive source of the present invention, the pump shaft portion 23a of the embodiment corresponds to the extension portion of the present invention.

  According to the configuration of the first aspect, the gear shaft of the transfer drive gear to which torque is transmitted from the input portion of the differential mechanism of the front wheel and the gear shaft of the transfer driven gear connected to the rear wheel through the propeller shaft are crossed. Since the transferred transfer device generates a hydraulic pressure that is provided on the extension portion on the crossing side of the gear shaft of the transfer drive gear and operates the clutch of the torque distribution mechanism with an oil pump driven by the extension portion. Even if one of the front wheels slips due to mud etc., not only can the oil pump not be driven and the clutch become inoperable, but also a transfer device can be added to the front wheel drive vehicle When the four-wheel drive is used, the added transfer device is connected to the existing oil pump and its drive system. And Wataru can be avoided that the degree of freedom of layout is impaired.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 8 show an embodiment of the present invention, FIG. 1 is a diagram showing the overall configuration of a four-wheel drive vehicle, FIG. 2 is a skeleton diagram showing the structure of a driving force distribution device and a transfer device, and FIG. Is a diagram showing a specific structure of the driving force distribution device and the transfer device, FIG. 4 is an enlarged view of 4 parts of FIG. 3, FIG. 5 is an enlarged view of 5 parts of FIG. 3, FIG. 6 is an enlarged view of 6 parts of FIG. FIG. 7 is a diagram showing the operation of the driving force distribution device when turning left in the middle and low vehicle speed range, and FIG. 8 is a diagram showing the operation of the driving force distribution device when turning right in the middle and low vehicle speed region.

  As shown in FIG. 1, the four-wheel drive vehicle includes left and right front wheels WFL, WFR and left and right rear wheels WRL, WRR. A transmission M is connected to the left end of an engine E mounted horizontally at the front of the vehicle body, and a front differential mechanism Df and a torque distribution mechanism A are disposed at the rear of the engine E and the transmission M. A transfer device T is disposed at the rear of the dynamic mechanism Df and the torque distribution mechanism A. The left front wheel WFL and the right front wheel WFR are connected to the left axle AFL and the right axle AFR that extend left and right from the left and right ends of the front differential mechanism Df and the torque distribution mechanism A, respectively. In addition, a viscous coupling C capable of interrupting transmission of driving force is provided at an intermediate portion of the propeller shaft P extending rearward from the transfer device T, and extends left and right from the rear differential mechanism Dr connected to the propeller shaft P at the rear end. A left rear wheel WRL and a right rear wheel WRR are connected to the left axle ARL and the right axle ARR, respectively.

  As shown in FIGS. 2 and 3, the front differential mechanism Df to which the driving force is transmitted from the external gear 3 meshing with the input gear 2 provided on the input shaft 1 extending from the transmission M is a double pinion type planetary gear mechanism. A ring gear 4 that rotates integrally with the external gear 3, a sun gear 5 coaxially disposed inside the ring gear 4, an outer planetary gear 6 that meshes with the ring gear 4, and an inner planetary gear 7 that meshes with the sun gear 5. And a planetary carrier 8 that supports them in mesh with each other. In the front differential mechanism Df, the ring gear 4 functions as an input element, and the sun gear 5 that functions as one output element is connected to the right front wheel WFR via the right output shaft 9R, the half shaft 10, and the right axle AFR. The planetary carrier 8 functioning as the other output element is connected to the left front wheel WFL via the left output shaft 9L and the left axle AFL.

  The torque distribution mechanism A that distributes the driving force between the left and right front wheels WFL, WFR is a planetary gear mechanism, and the carrier member 11 is rotatably supported on the outer periphery of the right output shaft 9R and is 90 ° circumferentially. A triple pinion member 16 integrally formed with a first pinion 13, a second pinion 14, and a third pinion 15 is rotatably supported on each of the four pinion shafts 12 arranged at intervals.

  The first sun gear 17 that is rotatably supported on the outer periphery of the half shaft 10 and meshes with the first pinion 13 is connected to the right carrier half portion 8R of the planetary carrier 8 of the front differential mechanism Df. The second sun gear 18 fixed to the outer periphery of the half shaft 10 meshes with the second pinion 14. Further, the third sun gear 19 rotatably supported on the outer periphery of the right output shaft 9R meshes with the third pinion 15.

  The number of teeth of the first pinion 13, the second pinion 14, the third pinion 15, the first sun gear 17, the second sun gear 18, and the third sun gear 19 in the embodiment is as follows.

Number of teeth of the first pinion 13 Zb = 16
Number of teeth of second pinion 14 Zd = 16
Number of teeth of the third pinion 15 Zf = 32
Number of teeth of the first sun gear 17 Za = 30
Number of teeth of second sun gear 18 Zc = 26
Number of teeth of the third sun gear 19 Ze = 28
The third sun gear 19 can be coupled to the housing 20 of the torque distribution mechanism A via the right clutch CR, and the rotation speed of the carrier member 11 is increased by the engagement of the right clutch CR. Further, the carrier member 11 can be coupled to the housing 20 via the left clutch CL, and the rotation speed of the carrier member 11 is reduced by the engagement of the left clutch CL.

  The transfer device T includes a transfer drive gear shaft 23 to which a transfer input gear 21 and a transfer drive gear 22 are fixed, and a transfer driven gear shaft 25 to which a transfer driven gear 24 that meshes with the transfer drive gear 22 is fixed. The transfer drive gear 22 and the transfer driven gear 24 are hypoid gears, the transfer drive gear shaft 23 is disposed in the vehicle width direction, and the transfer driven gear shaft 25 is disposed in the longitudinal direction of the vehicle body. The transfer input gear 21 of the transfer drive gear shaft 23 receives a driving force from an external gear 26 that rotates integrally with the external gear 3.

  The electronic control unit U calculates the engine torque Te, the engine speed Ne, the vehicle speed V, and the steering angle θ based on a predetermined program, and controls the operation of the left clutch CL and the right clutch CR.

  Next, the structures of the front differential mechanism Df and the torque transmission mechanism A will be further described with reference to FIGS.

  The differential case 33 constituting the outer portion of the front differential mechanism Df housed between the left transmission case 31 and the right transmission case 32 is formed by connecting the first case 34 and the second case 35 with bolts 36. The external gear 3 is integrally formed with the first case 34, and the ring gear 4 and the external gear 26 are integrally formed with the second case 35. The first case 34 is rotatably supported by the left transmission case 31 via a roller bearing 37, and the second case 35 is rotatably supported by the right transmission case 32 via a roller bearing 38. The output of the transmission M is transmitted from the input gear 2 through the external gear 3 to the differential case 33 of the front differential mechanism Df.

  The planetary carrier 8 is divided into a left carrier half 8L and a right carrier half 8R, and the left output shaft 9L penetrates the first case 34 so as to be relatively rotatable and is splined to the left carrier half 8L. The output shaft 9R passes through the second case 35 so as to be relatively rotatable, and is splined to the sun gear 5. The left and right carrier halves 8L and 8R are connected to each other by outer pinion pins 39 and inner pinion pins 40, and outer planetary gears 6 are rotatably supported by outer pinion pins 39 and inner to inner pinion pins 40. The planetary gears 7 are rotatably supported.

  The torque distribution mechanism A is configured by connecting a left driving force distribution mechanism case 41 and a right driving force distribution mechanism case 42 with bolts 43..., And the left end of the half shaft 10 supported therein via a ball bearing 44. Is splined to the right end of the left output shaft 9R. A sleeve 46 supported by a left driving force distribution mechanism case 41 via a ball bearing 45 is fitted to the outer periphery of the left portion of the second sun gear 18 formed integrally with the half shaft 10 so as to be relatively rotatable. The first sun gear 17 is splined to the right end thereof. The right end of the sleeve 47, which is fitted to the outer periphery of the right output shaft 9R so as to be relatively rotatable and whose left end is splined to the right carrier half 8R of the front differential mechanism Df, is splined to the left end of the sleeve 46. The Accordingly, the first sun gear 17 is connected to the right carrier half 8R via the sleeves 46 and 47.

  The left clutch CL disposed between the left end of the carrier member 11 and the left driving force distribution mechanism case 41 includes a clutch inner 48 provided on the carrier member 11 and a clutch outer 49 provided on the left driving force distribution mechanism case 41. .., A clutch piston 51 that hydraulically engages the friction engagement members 50, and a return spring 52 that biases the clutch piston 51 in the disengagement direction. Is done.

  A third sun gear 19 is supported on the outer circumference of the right half shaft 10 of the second sun gear 18 via a ball bearing 53 so as to be relatively rotatable. The right clutch CR includes a friction engagement member 56 disposed between a clutch inner 54 formed integrally with the third sun gear 19 and a clutch outer 55 provided in the right driving force distribution mechanism case 42, and friction. A clutch piston 57 that engages the engagement members 56 with hydraulic pressure, and a return spring 58 that biases the clutch piston 57 in the disengagement direction.

  The carrier member 11 of the torque distribution mechanism A is supported on the outer periphery of the sleeve 46 via a ball bearing 59 and supported on the outer periphery of the clutch inner 54 via a ball bearing 60.

  Next, the structure of the transfer device T will be further described with reference to FIGS.

  The transfer device T includes a right transfer case 61 coupled to the right driving force distribution mechanism case 42 and a left transfer case 62 coupled to the right transmission case 32, and the transfer drive gear shaft 23 is disposed coaxially. The first shaft 23A is divided into a second shaft 23B, and the first shaft 23A is supported by a ball bearing 63 provided in the left transmission case 31 and a ball bearing 64 provided in the right transmission case 32. A transfer input gear 21 is integrally formed with the first shaft 23A and a transfer drive gear 22 is splined. The transfer drive gear 22 is supported by a left transfer case 62 via a roller bearing 66. The transfer driven gear shaft 25 in which the transfer driven gear 24 is integrally formed is supported by the left and right transfer cases 61 and 62 via a pair of roller bearings 67 and 68.

  A separator 70 and a pump case 71 are superimposed on the inner surface of the right transfer case 61 facing the tip of the second shaft 23B of the transfer drive gear shaft 23 press-fitted into the transfer drive gear 22, and the right transfer is performed with a bolt (not shown). Fastened to the case 61. The second shaft 23 </ b> B of the transfer drive gear shaft 23 is supported by the pump case 71 via a roller bearing 65.

  An oil pump 75 composed of a trochoid pump in which an outer rotor 73 and an inner rotor 74 are engaged is housed inside the pump case 71. The outer rotor 73 is rotatably supported on the inner periphery of the pump case 71, and the inner rotor 74 is formed by extending the tip of the second shaft 23B of the transfer drive gear shaft 23 so as to exceed the intersection with the transfer driven gear shaft 25. Is fixed to the outer periphery of the pump shaft portion 23a.

  A joint member 78 is splined to the transfer driven gear shaft 25 protruding rearward from the left and right transfer cases 61, 62, and the tip of the propeller shaft P is coupled to the joint member 78 by bolts 79.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  With the torque distribution mechanism A having the above-described configuration, the carrier member 11 is attached to the housing by engaging the left clutch CL in response to a command from the electronic control unit U when the vehicle is turning left in the middle and low vehicle speed range as shown in FIG. 20 to stop rotation. At this time, the right output shaft 9R integral with the right front wheel WFR and the left output shaft 9L integral with the left front wheel WFL (that is, the planetary carrier 8 of the front differential mechanism Df) are the second sun gear 18 and the second pinion. 14, since the first pinion 13 and the first sun gear 17 are connected to each other, the rotational speed NR of the right front wheel WFR is increased with respect to the rotational speed NL of the left front wheel WFL according to the following equation.

NR / NL = (Zd / Zc) × (Za / Zb)
= 1.154 (1)
When the rotational speed NR of the right front wheel WFR is increased with respect to the rotational speed NL of the left front wheel WFL as described above, the left front wheel WFL which is the turning inner wheel as shown by the hatched arrow in FIG. Is transmitted to the right front wheel WFR, which is the outer turning wheel, and the left turning of the vehicle is assisted to improve the turning performance.

  Instead of stopping the carrier member 11 with the left clutch CL, if the rotational speed of the carrier member 11 is reduced by appropriately adjusting the engagement force of the left clutch CL, the rotational speed NR of the right front wheel WFR is reduced according to the deceleration. The speed is increased with respect to the rotation speed NL of the left front wheel WFL, and an arbitrary torque can be transmitted from the left front wheel WFL that is the turning inner wheel to the right front wheel WFR that is the turning outer wheel.

  On the other hand, as shown in FIG. 8, the third sun gear 19 is coupled to the housing 20 by engaging the right clutch CR in response to a command from the electronic control unit U when turning right in the middle and low vehicle speed range of the vehicle. Stop rotation. As a result, the third pinion 15 meshing with the third sun gear 19 revolves and rotates, the speed of the carrier member 11 is increased with respect to the speed of the right output shaft 9R, and the speed NL of the left front wheel WFL is The speed is increased in accordance with the following equation with respect to the rotational speed NR of the front wheel WFR.

NL / NR = {1- (Ze / Zf) × (Zb / Za)}
÷ {1- (Ze / Zf) × (Zd / Zc)}
= 1.156 (2)
When the rotational speed NL of the left front wheel WFL is increased with respect to the rotational speed NR of the right front wheel WFR as described above, the right front wheel WFR that is the turning inner wheel is indicated by the hatched arrow in FIG. A part of the torque can be transmitted to the left front wheel WFL which is a turning outer wheel. Also in this case, if the rotational speed of the carrier member 11 is increased by appropriately adjusting the engagement force of the right clutch CR, the rotational speed NL of the left front wheel WFL is changed to the rotational speed NR of the right front wheel WFR according to the increased speed. On the other hand, it is possible to increase the speed and transmit an arbitrary torque from the right front wheel WFR which is the inner turning wheel to the left front wheel WFL which is the outer turning wheel, thereby assisting the right turning of the vehicle and improving the turning performance.

  Also in this case, instead of stopping the third sun gear 19 by the right clutch CR, if the rotational force of the third sun gear 19 is reduced by appropriately adjusting the engagement force of the right clutch CR, the left front wheel WFL is correspondingly reduced. Is increased with respect to the rotational speed NR of the right front wheel WFR, and an arbitrary torque can be transmitted from the right front wheel WFR that is the turning inner wheel to the left front wheel WFL that is the turning outer wheel.

  As is clear from the comparison of the expressions (1) and (2), the number of teeth of the first pinion 13, the second pinion 14, the third pinion 15, the first sun gear 17, the second sun gear 18, and the third sun gear 19 is determined. By setting as described above, the acceleration rate from the left front wheel WFL to the right front wheel WFR (about 1.154) and the acceleration rate from the right front wheel WFR to the left front wheel WFL (about 1.156) are made substantially equal. Can do.

  Now, since the differential case 33 always rotates while the vehicle is running, the rotation of the external gear 26 provided in the differential case 33 is caused by the transfer input gear 21 of the transfer device T → the transfer drive gear shaft 23 → the transfer drive gear 22 → Transfer driven gear 24 → transfer driven gear shaft 25 → propeller shaft P → fastened viscous coupling C → propeller shaft P → rear differential mechanism Dr → right and left axles ARL and ARR are transmitted along the left and right rear wheels WRL and WRR. The four-wheel drive state is realized by driving. On the other hand, when the viscous coupling C is brought into the non-engaged state, the transmission of the driving force is interrupted there, and the rear wheels WRL and WRR are brought into the non-driven state, thereby realizing the front wheel drive state.

  Oil pressure for operating the left and right clutches CL and CR of the torque distribution mechanism A is generated by an oil pump 75, and the oil pump 75 is driven by the transfer drive gear shaft 23 of the transfer device T that always rotates during traveling of the vehicle. Therefore, even when one of the left and right front wheels WFL, WFR slips due to mud etc., it is possible to reliably avoid the situation where the oil pump 75 is not driven and the left and right clutches CL, CR become inoperable. it can.

  In addition, since the oil pump 75 is incorporated in the transfer device T, when the transfer device T is added to the front-wheel drive vehicle for four-wheel drive, the added transfer device T interferes with the existing oil pump and its drive system. As a result, it is possible to prevent the degree of freedom of layout from being lost.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the structure of the torque distribution mechanism A is not limited to the embodiment.

  The drive source of the vehicle is not limited to the engine E, and may be an electric motor.

Diagram showing the overall configuration of a four-wheel drive vehicle Skeleton diagram showing structure of driving force distribution device and transfer device The figure which shows the specific structure of a driving force distribution apparatus and a transfer apparatus 4 enlarged view of FIG. 5 enlarged view of FIG. 6 enlarged view of FIG. The figure which shows the action of the driving force distribution device at the time of the left turn in the middle and low vehicle speed range The figure which shows the operation of the driving force distribution device at the time of the right turn in the middle and low vehicle speed range

Explanation of symbols

A Torque distribution mechanism CL Left clutch (clutch)
CR Right clutch (clutch)
Df Front differential mechanism (differential mechanism)
E Engine (drive source)
P propeller shaft T transfer device WFL front wheel WFR front wheel WRL rear wheel WRR rear wheel 22 transfer drive gear 23a pump shaft (extension)
24 Transfer Driven Gear 75 Oil Pump

Claims (1)

A front wheel driving force distribution device that distributes the torque of the drive source (E) to the left and right front wheels (WFL, WFR) via the differential mechanism (D) and the torque distribution mechanism (A);
The transfer drive gear (22) and the transfer driven gear (24) that mesh with each other with the gear shaft intersecting, and the transfer drive gear (22) receives the torque from an input portion of the differential mechanism (D), and the transfer drive gear (22) The driven gear (24) is connected to a rear wheel (WRL, WRR) via a propeller shaft (P), and a transfer device (T).
With
An oil pump (75) that generates hydraulic pressure for operating the clutches (CL, Cr) of the torque distribution mechanism (A) is provided on the extension (23a) on the crossing side of the gear shaft of the transfer drive gear (22). And is driven by the extension part (23a).

Images