JP2010190284A - Vehicular power transmitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To generate the hydraulic pressure for operating hydraulic clutches of a torque distributing mechanism A with the minimum energy. <P>SOLUTION: A hydraulic pressure supplying device 61 for generating the hydraulic pressure for operating right and left hydraulic clutches CR and CL of a vehicular power transmitting device converts rotary motion of an electric motor 66 into linear motion of pistons 63L and 63R inside hydraulic cylinders 62L and 62R by using a driving direction converting mechanism 69, and generates the hydraulic pressure alternately in two oil chambers 64L and 64R in response to the moving direction of the pistons 63L and 63R. Since the right and the left hydraulic clutches CR and CL are not engaged at the same time, the torque distributing mechanism A can be operated without a trouble by supplying the hydraulic pressure, which is generated in one oil chamber 64R by moving the pistons 63L and 63R in one direction, through an oil passage P3R, and supplying the hydraulic pressure, which is generated in the other oil chamber 64L by moving the pistons 63L and 63R in the other direction, through an oil passage P3L. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle power transmission device provided with torque transmission means capable of transmitting torque between two rotating shafts.

  Between the left and right axles, a differential mechanism composed of a double pinion type planetary gear mechanism and a torque distribution mechanism composed of a planetary gear mechanism using a special triple pinion member are provided. One sun gear or carrier of the torque distribution mechanism A vehicle driving force transmission device that distributes torque between left and right wheels by selectively restraining a member with a pair of hydraulic clutches and forcibly regulating a rotation speed ratio between the left and right axles is disclosed in the following patent document: 1 is known.

JP 2008-256185 A

  By the way, in the above-mentioned conventional one, since the hydraulic pressure for operating the pair of hydraulic clutches is generated by the hydraulic pump driven by the rotation of the axle, the hydraulic pump is always driven and the fuel consumption of the engine increases. There was a problem.

  The present invention has been made in view of the above circumstances, and an object thereof is to generate a hydraulic pressure for operating a hydraulic clutch of a vehicle power transmission device with a minimum amount of energy.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a vehicle power transmission device provided with torque transmission means capable of transmitting torque between two rotary shafts. A carrier member rotatably supported about an axis, and a first pinion, a second pinion and a third pinion having mutually different pitch circles are rotatably supported by the carrier member so as not to be rotatable relative to each other. A plurality of triple pinion members, a first connecting means for connecting the first pinion to the other rotating shaft, a second connecting means for connecting the second pinion to the one rotating shaft, and the third pinion A first hydraulic clutch that applies a braking force to accelerate the other rotating shaft with respect to the one rotating shaft; and a braking force that is applied to the carrier member to cause the one rotating shaft to move to the other rotating shaft. Increase against And a hydraulic pressure supply device that supplies hydraulic pressure to the hydraulic oil chambers of the first hydraulic clutch and the second hydraulic clutch. The hydraulic pressure supply device includes: a hydraulic cylinder; A piston that linearly moves the two oil chambers between both ends of the hydraulic cylinder, a drive direction conversion mechanism that linearly moves the piston by converting the rotational motion of the electric motor into linear motion, An oil passage connecting the hydraulic oil chamber of the first hydraulic clutch to one oil chamber of the hydraulic cylinder, and an oil passage connecting the hydraulic oil chamber of the second hydraulic clutch to the other oil chamber of the hydraulic cylinder. Hydraulic pressure is generated in the one oil chamber or the other oil chamber by the linear motion of the piston by the rotational motion of the electric motor, and the first hydraulic clutch and the second hydraulic clutch Vehicle power transmission apparatus characterized by selectively actuating the switch is proposed.

  The planetary carrier 8 and the first sun gear 17 of the embodiment correspond to the first connecting means of the present invention, and the second sun gear 18 of the embodiment corresponds to the second connecting means of the present invention. The right output shaft 9R and the left output shaft 9L correspond to one and the other rotation shafts of the present invention, respectively, the ball screw mechanism 69 of the embodiment corresponds to the drive direction conversion mechanism of the present invention, and the torque distribution of the embodiment The mechanism A corresponds to the torque transmission means of the present invention, the right clutch CR of the embodiment corresponds to the first hydraulic clutch of the present invention, and the left clutch CL of the embodiment corresponds to the second hydraulic clutch of the present invention. The right third oil passage P3R and the left third oil passage P3L in the embodiment correspond to the oil passage of the present invention.

  According to the configuration of the first aspect, the hydraulic pressure supply device that generates the hydraulic pressure that operates the left and right hydraulic clutches of the vehicle power transmission device converts the rotary motion of the electric motor into the linear motion of the piston in the cylinder by the drive direction conversion mechanism. The oil pressure is alternately generated in the two oil chambers defined between the piston and both ends of the cylinder according to the moving direction of the piston. Since the first and second hydraulic clutches do not engage at the same time, the hydraulic pressure generated in one oil chamber by supplying the piston in one direction is supplied to the hydraulic oil chamber of the first hydraulic clutch via the oil passage. By moving the piston in the other direction and supplying the hydraulic pressure generated in the other oil chamber to the hydraulic oil chamber of the second hydraulic clutch via the oil passage, the vehicle power transmission device can be operated without hindrance. . Since the electric motor only needs to be driven when the vehicle power transmission device is operated, the energy required to generate the hydraulic pressure can be reduced compared to the case where the hydraulic power is generated by driving the hydraulic pump constantly with the vehicle power transmission device. Can do.

The figure which shows the whole structure of a front engine front drive vehicle. The skeleton figure which shows the structure of a driving force distribution apparatus. The figure which shows the specific structure of a driving force distribution apparatus. FIG. 4 is an enlarged view of part 4 of FIG. 3. Explanatory drawing of the hydraulic supply apparatus of the left and right clutch. The figure which shows the effect | action of the driving force distribution apparatus at the time of the left turn in a medium-low vehicle speed area. The figure which shows the effect | action of the driving force distribution apparatus at the time of the right turn in a medium-low vehicle speed range.

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

  As shown in FIG. 1, the front engine / front drive vehicle includes left and right front wheels WFL and WFR as drive wheels, and left and right rear wheels WRL and WRR as driven wheels. A transmission M is connected to the left end of an engine E mounted horizontally at the front of the vehicle body, and a differential mechanism D and a torque distribution mechanism A are disposed at the rear of the engine E and transmission M. A left front wheel WFL and a right front wheel WFR are connected to a left axle AFL and a right axle AFR that extend left and right from the left end and right end of the differential mechanism D and the torque distribution mechanism A, respectively.

  As shown in FIG. 2, a differential mechanism D for transmitting a driving force from an external gear 3 meshed with an input gear 2 provided on an input shaft 1 extending from a transmission M is a double pinion planetary gear mechanism, A ring gear 4 formed integrally with the tooth gear 3, a sun gear 5 coaxially disposed inside the ring gear 4, an outer pinion 6 that meshes with the ring gear 4, and an inner pinion 7 that meshes with the sun gear 5. It is composed of a planetary carrier 8 that is supported in a state of meshing with each other. In the differential mechanism D, 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. Planetary carrier 8 that functions as the other output element is connected to left front wheel WFL via left output shaft 9L and 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 8R of the planetary carrier 8 of the differential mechanism D. 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 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 differential mechanism D and the torque distribution mechanism A will be described in more detail with reference to FIGS.

  A differential case 33 constituting an outer shell of the differential mechanism D housed between the left transmission case 31 and the right transmission case 32 is formed by connecting a first case 34 and a second case 35 with bolts 36. The external gear 3 is fastened together at 36. 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 differential mechanism D.

  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 by outer pinion pins 39 and inner pinion pins 40, and outer pinions 6 are rotatably supported by outer pinion pins 39 and inner pins 34 are rotatably supported by inner pinion pins 40. The pinions 7 are rotatably supported.

  The torque distribution mechanism A is configured by connecting a left case 41 and a right case 42 with bolts 43..., And the left end of the half shaft 10 supported therein via a ball bearing 44 is the right end of the left output shaft 9R. Spline combined. A sleeve 46 supported by a left 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, and at the right end thereof. The first sun gear 17 is splined. 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 differential mechanism D, is splined to the left end of the sleeve 46. 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 case 41 is a friction disposed between a clutch inner 48 provided on the carrier member 11 and a clutch outer 49 provided on the left case 41. The engagement member 50 is configured by a clutch piston 51 that hydraulically engages the friction engagement member 50 and a return spring 52 that urges the clutch piston 51 in the disengagement direction.

  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 on the right case 42. Are hydraulically engaged, and a return spring 58 that urges 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.

  As shown in FIG. 5, the hydraulic pressure supply device 61 that operates the left and right clutches CL and CR is slidably fitted to the left and right hydraulic cylinders 62L and 62R and the left and right hydraulic cylinders 62L and 62R, respectively. The left and right pistons 63L, 63R, the left hydraulic chamber 64L defined between the left hydraulic cylinder 62L and the left piston 63L, the right hydraulic chamber 64R defined between the right hydraulic cylinder 62R and the right piston 63R, Between the piston rod 65 integrally connecting the pistons 63L and 63R, the electric motor 66, the drive gear 67 rotated by the electric motor 66, the driven gear 68 meshing with the drive gear 67, and between the driven gear 68 and the piston rod 65 And a ball screw mechanism 69 provided.

  The hydraulic oil tank 70 and the left oil chamber 64L are connected by a first oil passage P1 and a left second oil passage P2L, and the hydraulic oil flows from the hydraulic oil tank 70 into the left oil chamber 64L into the left second oil passage P2L. A check valve 71L that allows only the above is arranged. Further, the hydraulic oil tank 70 and the right oil chamber 64R are connected by a first oil passage P1 and a right second oil passage P2R, and the right second oil passage P2R receives hydraulic oil from the hydraulic oil tank 70 to the right oil chamber 64R. A check valve 71R that allows only inflow is arranged. The left oil chamber 64L and the hydraulic oil chamber 41a (see FIG. 4) of the left clutch CL are connected by the left third oil passage P3L, and the right oil chamber 64R and the hydraulic oil chamber 42a of the right clutch CR (see FIG. 4) are connected. Are connected by the right third oil passage P3R.

  Accordingly, in FIG. 5, when the electric motor 66 is driven in one direction by a command from the electronic control unit U, the piston rod 65 and the left and right pistons 63L and 63R are moved via the drive gear 67, the driven gear 68 and the ball screw mechanism 69. By moving to the left, the hydraulic pressure in the left oil chamber 64L is increased and the hydraulic pressure in the right oil chamber 64R is reduced, whereby the left clutch CL is engaged and the right clutch CR is disengaged. Conversely, when the electric motor 66 is driven in the other direction in response to a command from the electronic control unit U, the piston rod 65 and the left and right pistons 63L and 63R move to the right via the drive gear 67, the driven gear 68, and the ball screw mechanism 69. When the hydraulic pressure in the right oil chamber 64R is increased and the hydraulic pressure in the left oil chamber 64L is reduced, the right clutch CR is engaged and the left clutch CL is disengaged.

  The magnitude of the hydraulic pressure generated by the hydraulic pressure supply device 61 is controlled by the current value supplied to the electric motor 66. That is, the relationship between the current value supplied to the electric motor 66 and the hydraulic pressure generated in the left and right oil chambers 64L and 64R is stored in advance, and when the target hydraulic pressure to be supplied to the left and right clutches CL and CR is determined, Feed forward is performed to supply the current value to the electric motor 66. Alternatively, a hydraulic pressure sensor that detects the hydraulic pressure supplied to the left and right clutches CL and CR may be provided, and the current value supplied to the electric motor 66 may be feedback controlled so that the detected value of the hydraulic pressure sensor matches the target hydraulic pressure. .

  When hydraulic oil leaks from the O-ring of the hydraulic system of the left oil chamber 64L, the left third oil passage P3L, and the left clutch CL, the leaked hydraulic oil passes from the hydraulic oil tank 70 through the check valve 71L. When hydraulic oil leaks from the O-ring of the hydraulic system of the right oil chamber 64R, the right third oil passage P3R, and the right clutch CR, the hydraulic oil for the leak is a check valve from the hydraulic oil tank 70. It is replenished via 71R.

  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 engaged with 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 differential mechanism D) are the second sun gear 18, the second pinion 14, Since it is connected via the first pinion 13 and the first sun gear 17, 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 that is the turning inner wheel is indicated 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. 7, 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 rotation speed NL of the left front wheel WFL is increased with respect to the rotation 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, 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.

  As described above, the hydraulic pressure supply device 61 drives the left and right pistons 63L and 63R in the left and right hydraulic cylinders 62L and 62R with the driving force generated by the electric motor 66, and alternately hydraulically supplies the left and right oil chambers 64L and 64R. And the left and right clutches CL and CR of the torque distribution mechanism A can be operated by the hydraulic pressure. Although the hydraulic pressure supply device 61 cannot simultaneously generate hydraulic pressure in the left and right oil chambers 64L and 64R, the left and right clutches CL and CR of the torque distribution mechanism A are not engaged at the same time. Never do.

  Since the electric motor 66 of the hydraulic pressure supply device 61 only needs to be driven when the torque distribution mechanism A is operated, the hydraulic pressure generation is required as compared to the case where the hydraulic pump is constantly driven by the driving force of the engine E to generate the hydraulic pressure. Energy can be saved and fuel consumption of engine E can be reduced. Moreover, there is no need for a hydraulic pump, a pressure regulating valve that regulates the hydraulic pressure generated by the hydraulic pump, and a shift valve that selectively supplies the hydraulic pressure regulated by the pressure regulating valve to the left and right clutch CL, CR. It can reduce and contribute to cost reduction.

  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 hydraulic pressure supply device 61 according to the embodiment includes left and right cylinders 62L and 62R and left and right pistons 63L and 63R. One piston is arranged inside one cylinder, and both ends of the cylinder are arranged. The left and right oil chambers 64L and 64R can be formed between the portion and the piston.

  In the embodiment, the torque distribution mechanism A distributes the torque between the left and right front wheels WFL, WFR, but may distribute the torque between the left and right rear wheels WRL, WRR.

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

8 Planetary carrier (first connecting means)
9R Right output shaft (rotary shaft)
9L Left output shaft (rotary shaft)
11 Carrier member 13 First pinion 14 Second pinion 15 Third pinion 16 Triple pinion member 17 First sun gear (first connecting means)
18 Second sun gear (second connecting means)
41a Hydraulic oil chamber 42a Hydraulic oil chamber 61 Hydraulic supply device 62R Hydraulic cylinder 62L Hydraulic cylinder 63R Piston 63L Piston 64R Oil chamber 64L Oil chamber 66 Electric motor 69 Ball screw mechanism (drive direction conversion mechanism)
A Torque distribution mechanism (torque transmission means)
CR Right clutch (first hydraulic clutch)
CL Left clutch (second hydraulic clutch)
P3R right third oil passage (oil passage)
P3L Left third oil passage (oil passage)

Claims (1)

A vehicle power transmission device provided with torque transmission means (A) capable of mutually transmitting torque between two rotary shafts (9L, 9R),
A carrier member (11) rotatably supported around one rotating shaft (9R);
A plurality of first pinions (13), second pinions (14), and third pinions (15) having mutually different pitch circles are rotatably supported by the carrier member (11) so as not to rotate relative to each other. A triple pinion member (16),
First connecting means (17, 8) for connecting the first pinion (13) to the other rotating shaft (9L);
Second connecting means (18) for connecting the second pinion (14) to the one rotating shaft (9R);
A first hydraulic clutch (CR) that applies a braking force to the third pinion (15) to accelerate the other rotating shaft (9L) with respect to the one rotating shaft (9R);
A second hydraulic clutch (CL) that applies a braking force to the carrier member (11) to accelerate the one rotating shaft (9R) relative to the other rotating shaft (9L);
A hydraulic pressure supply device (61) for supplying hydraulic pressure to the hydraulic oil chambers (42a, 41a) of the first hydraulic clutch (CR) and the second hydraulic clutch (CL);
In what comprises
The hydraulic pressure supply device (61)
Two oil chambers (64R, 64L) are partitioned between the hydraulic cylinders (62R, 62L) and the hydraulic cylinders (62R, 62L) by linear movement within the hydraulic cylinders (62R, 62L). A piston (63R, 63L) and a drive direction conversion mechanism (69) for converting the rotational motion of the electric motor (66) into linear motion to linearly move the piston (63R, 63L), and the first hydraulic clutch (CR ) Hydraulic fluid chamber (42a) to one hydraulic chamber (64R) of the hydraulic cylinder (62R, 62L), and hydraulic fluid chamber (41a) of the second hydraulic clutch (CL). And an oil passage (P3L) connecting the other oil chamber (64L) of the hydraulic cylinder (62R, 62L),
Hydraulic pressure is generated in the one oil chamber (64R) or the other oil chamber (64L) by linear movement of the pistons (63R, 63L) due to the rotational movement of the electric motor (66), and the first hydraulic clutch ( CR) and the second hydraulic clutch (CL) are selectively operated.

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