JP2012001049A - Power transmission device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of vibration or noise by effectively absorbing a variation in torque of a reciprocating-type transmission for intermittently transmitting drive force.SOLUTION: An output shaft 12 of a reciprocating-type continuously variable transmission consists of an inner output shaft 12a and an outer output shaft 12b, one end of the outer output shaft 12b is connected to one end of the inner output shaft 12a, the other end of the inner output shaft 12a is connected to the differential case 33 of a differential gear D and sun gears 39, 39' of the differential gear D are connected each to one end of right and left drive shafts S, S respectively. With this configuration, the outer output shaft 12b and the inner output shaft 12a each functioning as a torsion spring, the differential gear D functioning as a mass body and the right and left drive shafts S, S each functioning as a torsion spring are connected in series to configure a damper. Thus, the torque vibration of the reciprocating-type transmission T is prevented from crossing over a resonance point within a range of the usual number of rotations of an engine, thereby effectively preventing vibration or noise.

Description

  The present invention includes a drive source, a transmission that shifts the rotation of the input shaft connected to the drive source and transmits the rotation to the output shaft, a differential gear to which the driving force of the output shaft is input, and the differential gear. The present invention relates to a vehicle power transmission device including left and right drive shafts extending in a left-right direction of a vehicle body.

  Continuously converting the rotation of the input shaft connected to the engine into a reciprocating motion of the plurality of connecting rods having mutually different phases, and converting the reciprocating motion of the plurality of connecting rods into a rotating motion of the output shaft by a plurality of one-way clutches. A transmission is known from US Pat.

  In addition, the driving force of the engine is transmitted to the drive wheels via a damper mechanism, a belt type continuously variable transmission and a differential gear, and a motor / generator is connected to the driving force transmission path between the belt type continuously variable transmission and the differential gear. A hybrid drive device is known from Patent Document 2 below.

  Also, the pinion shaft (power transmission shaft) of the automatic transmission has a double structure of the outer shaft and the inner shaft, and the driving force input to the outer shaft is transmitted to the drive wheels via the inner shaft, differential gear and drive shaft. In Japanese Patent Application Laid-Open No. 2004-228561, a gear noise is reduced by reducing the torsional rigidity of one of the outer shaft and the inner shaft to absorb the gear meshing vibration force.

JP-T-2005-502543 JP 2009-1126 A JP-A-5-272604

  However, the one described in Patent Document 1 includes a continuously variable transmission that converts the reciprocating motion of the connecting rod into the rotational motion of the output shaft via the one-way clutch, so that torque fluctuation of the output shaft is transmitted to the tire. There was a problem that caused car body vibration.

  In addition, in Patent Document 2, engine vibration that cannot be absorbed by a damper mechanism disposed between the engine and the belt-type continuously variable transmission is transmitted from the drive shaft to the tire and causes vehicle body vibration. There was a possibility.

  Further, the one described in Patent Document 3 can function as a torsion spring by lowering the torsional rigidity of the outer shaft and the inner shaft on the upstream side of the differential gear. Since the drive shaft on the side is short, its torsional rigidity becomes high and cannot function as a torsion spring, and there is a possibility that the gear meshing vibration force cannot be sufficiently absorbed.

  The present invention has been made in view of the above-described circumstances, and it is an object of the present invention to effectively absorb torque fluctuations of a reciprocating transmission that intermittently transmits driving force to suppress generation of vibration and noise. To do.

  In order to achieve the above object, according to the first aspect of the present invention, a drive source, a transmission that shifts rotation of an input shaft connected to the drive source and transmits the rotation to an output shaft, and the output A differential gear to which shaft driving force is input and left and right drive shafts extending in the left-right direction of the vehicle body from the differential gear, wherein the transmission has a variable amount of eccentricity from the axis of the input shaft and the input An input side fulcrum that rotates with the shaft, a one-way clutch connected to the output shaft, an output-side fulcrum provided on an input member of the one-way clutch, and both ends connected to the input-side fulcrum and the output-side fulcrum A power transmission device for a vehicle comprising a reciprocating connecting rod, wherein the output shaft is a tubular inner projecting fitting fitted to the outer periphery of one of the left and right drive shafts. A shaft and a tubular outer output shaft connected coaxially to the outer periphery of the inner output shaft and connected to the output member of the one-way clutch, and one end of the outer output shaft is connected to one end of the inner output shaft The vehicle power, wherein the other end of the inner output shaft is connected to the input member of the differential gear, and the left and right output members of the differential gear are connected to one end of the left and right drive shafts, respectively. A transmission device is proposed.

  According to the invention described in claim 2, in addition to the configuration of claim 1, the transmission includes the input side fulcrum, the output side fulcrum, the connecting rod, and the one-way clutch. A vehicular power transmission device is proposed, which is composed of a plurality of transmission units having different phases of reciprocal motion.

  The eccentric disk 18 of the embodiment corresponds to the input side fulcrum of the present invention, the pin 19c of the embodiment corresponds to the output side fulcrum of the present invention, and the outer member 22 of the embodiment corresponds to the one-way clutch of the present invention. The inner member 23 of the embodiment corresponds to the output member of the one-way clutch of the present invention, and the differential case 33 of the embodiment corresponds to the input member of the differential gear of the present invention. The first and second sun gears 39 and 39 'correspond to the output member of the differential gear of the present invention, the engine E of the embodiment corresponds to the drive source of the present invention, and the continuously variable transmission T of the embodiment It corresponds to the transmission of the invention.

  According to the configuration of the first aspect, the driving force of the driving source is transmitted to the left and right drive shafts via the transmission including the input shaft and the output shaft and the differential gear. The transmission includes an input side fulcrum that is variable in eccentricity from the axis of the input shaft and rotates together with the input shaft, a one-way clutch connected to the output shaft, and an output-side fulcrum provided on an input member of the one-way clutch. And a connecting rod that is connected to both ends of the input side fulcrum and the output side fulcrum and reciprocates. Therefore, by changing the eccentric amount of the input side fulcrum and changing the reciprocating stroke of the connecting rod, the output shaft can be rotated. You can increase or decrease the number.

  The output shaft of the transmission is a tubular inner output shaft that fits to the outer periphery of one of the left and right drive shafts, and a tubular outer output that is coaxially fitted to the outer periphery of the inner output shaft and connected to the output member of the one-way clutch And one end of the outer output shaft is connected to one end of the inner output shaft, the other end of the inner output shaft is connected to the input member of the differential gear, and the output member of the differential gear is connected to one end of the left and right drive shafts. Since they are connected to each other, the outer output shaft and inner output shaft that function as torsion springs, the differential gear that functions as a mass body, and the drive shaft that functions as a torsion spring are connected in series to form a damper. As a result, the torque fluctuation of the reciprocating transmission does not straddle the resonance point within the range of the normal operating rotational speed of the drive source, and vibration and noise are effective. It can be suppressed to.

  According to the second aspect of the present invention, the transmission includes a plurality of transmission units including an input side fulcrum, an output side fulcrum, a connecting rod, and a one-way clutch, and the phase of the reciprocating motion of the connecting rods of the plurality of transmission units is Since they are different from each other, the output shaft can be smoothly and continuously rotated.

The skeleton figure of the power unit for driving | running | working for vehicles. 2 is a detailed view of part 2 of FIG. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2 (TOP state). FIG. 3 is a sectional view taken along line 3-3 in FIG. 2 (LOW state). The action explanatory view in the TOP state. The action explanatory view in the LOW state. FIG. 7 is a detailed view of part 7 of FIG. 1. FIG. 8 is an enlarged view of part 8 in FIG. 7.

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

  As shown in FIG. 1, the vehicle power transmission device for driving the left and right drive wheels W of the vehicle includes an engine E, a continuously variable transmission T, a dog clutch C, a differential gear D, and left and right drive shafts. S and S are provided.

  Next, the structure of the continuously variable transmission T will be described with reference to FIGS.

  As shown in FIGS. 2 and 3, the continuously variable transmission T of the present embodiment is obtained by superimposing a plurality of (four in the embodiment) transmission units 10 having the same structure in the axial direction. These transmission units 10 are provided with a common input shaft 11 and a common output shaft 12 arranged in parallel, and the rotation of the input shaft 11 is decelerated or increased and transmitted to the output shaft 12.

  Hereinafter, the structure of one transmission unit 10 will be described as a representative. The input shaft 11 connected to the engine E and rotates passes through the hollow rotating shaft 14a of the speed change actuator 14 such as an electric motor so as to be relatively rotatable. The rotor 14b of the speed change actuator 14 is fixed to the rotating shaft 14a, and the stator 14c is fixed to the casing. The rotation shaft 14 a of the speed change actuator 14 can rotate at the same speed as the input shaft 11 and can rotate relative to the input shaft 11 at a different speed.

  A first pinion 15 is fixed to the input shaft 11 passing through the rotation shaft 14 a of the speed change actuator 14, and a crank-shaped carrier 16 is connected to the rotation shaft 14 a of the speed change actuator 14 so as to straddle the first pinion 15. The Two second pinions 17, 17 having the same diameter as the first pinion 15 are supported via pinion pins 16 a, 16 a at positions forming an equilateral triangle in cooperation with the first pinion 15, respectively. The first pinion 15 and the second pinions 17, 17 mesh with a ring gear 18 a formed eccentrically inside a disc-shaped eccentric disk 18. A ring portion 19 b provided at one end of the rod portion 19 a of the connecting rod 19 is fitted to the outer peripheral surface of the eccentric disk 18 via a ball bearing 20 so as to be relatively rotatable.

  A one-way clutch 21 provided on the outer periphery of the output shaft 12 is arranged inside the outer member 22 with a ring-shaped outer member 22 pivotally supported by a rod portion 19a of a connecting rod 19 via a pin 19c. 12, a roller disposed in a wedge-shaped space formed between an inner member 23 fixed to 12 and an arc surface on the inner periphery of the outer member 22 and a flat surface on the outer periphery of the inner member 23, and urged by springs 24. 25.

  As is apparent from FIG. 2, the four speed change units 10 share a crank-shaped carrier 16, but the phases of the eccentric disks 18 supported on the carrier 16 via the second pinions 17 and 17 are respectively different. The transmission unit 10 is different by 90 °. For example, in FIG. 2, the eccentric disk 18 of the leftmost transmission unit 10 is displaced upward in the figure with respect to the input shaft 11, and the eccentric disk 18 of the third transmission unit 10 from the left is illustrated with respect to the input shaft 11. The eccentric disks 18 and 18 of the second and fourth transmission units 10 and 10 from the left are positioned in the middle in the vertical direction.

  Next, the structure around the output shaft 12, the dog clutch C, the differential gear D, and the left drive shaft S will be described with reference to FIGS.

  The planetary gear type differential gear D includes a differential case 33 rotatably supported on a transmission case 31 by a pair of ball bearings 32 and 32. The differential case 33 is configured by integrally connecting a right case body 34 and a left case cover 35 with bolts 36. The differential case 33 constitutes a carrier of the planetary gear mechanism, and a plurality of first pinions 37 and a plurality of second pinions 37 'are rotatably supported thereon. The first pinions 37 are meshed with a first sun gear 39 splined to the right end of the left drive shaft S, and the second pinions 37 'are second sun gears 39 splined to the left end of the right drive shaft S. Mesh with ′.

  The output shaft 12 includes a tubular inner output shaft 12a that is coaxially fitted to the outer periphery of the left drive shaft S, and a tubular outer output shaft 12b that is coaxially fitted to the outer periphery of the inner output shaft 12a. The left end of the outer output shaft 12b, in which the inner members 23 of the four one-way clutches 21 are coupled to the outer periphery, is rotatably supported by the mission case 31 by a ball bearing 40. The clutch housing 41 is spline-coupled b to the left end of the outer output shaft 12b and the left end of the inner output shaft 12a, and spline-coupled to the right end of the inner output shaft 12a. The case body 34 of the differential case 33 is rotatably supported by the transmission case 31 via the right ball bearing 42.

  The clutch piston 44 is spline-coupled e so as to be axially slidable and non-rotatable in the piston guide 43 that is spline-coupled to the inside of the clutch housing 41. When the clutch piston 44 is moved to the right by the hydraulic pressure supplied to the oil chamber 45, the dog teeth 44a mesh with the dog teeth 33a of the differential case 33, and the output shaft 12 contacts the differential case 33 via the clutch housing 41 and the clutch piston 44. Combined.

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

  First, the operation of one transmission unit 10 of the continuously variable transmission T will be described. When the rotation shaft 14 a of the speed change actuator 14 is rotated relative to the input shaft 11, the carrier 16 rotates about the axis L <b> 1 of the input shaft 11. At this time, the center O of the carrier 16, that is, the center of the equilateral triangle formed by the first pinion 15 and the two second pinions 17, 17 rotates around the axis L 1 of the input shaft 11.

  3 and 5 show a state in which the center O of the carrier 16 is on the opposite side of the output shaft 12 with respect to the first pinion 15 (that is, the input shaft 11). The eccentricity is maximized and the ratio of the continuously variable transmission T is in the TOP state. 4 and 6 show a state in which the center O of the carrier 16 is on the same side as the output shaft 12 with respect to the first pinion 15 (that is, the input shaft 11). At this time, the eccentric disk 18 with respect to the input shaft 11 The amount of eccentricity is minimized and the ratio of the continuously variable transmission T is in the LOW state.

  In the TOP state shown in FIG. 5, when the input shaft 11 is rotated by the engine E and the rotation shaft 14 a of the speed change actuator 14 is rotated at the same speed as the input shaft 11, the input shaft 11, the rotation shaft 14 a, the carrier 16, With the one pinion 15, the two second pinions 17 and 17, and the eccentric disk 18 being integrated, the pinion 15 rotates eccentrically around the input shaft 11 (see arrow A). While rotating from FIG. 5A through FIG. 5B to the state of FIG. 5C, the ring portion 19b is supported on the outer periphery of the eccentric disk 18 via the ball bearing 20 so as to be relatively rotatable. The connecting rod 19 rotates the outer member 22 pivotally supported by a pin 19c at the tip of the rod portion 19a in the counterclockwise direction (see arrow B). 5A and 5C show both ends of rotation of the outer member 22 in the arrow B direction.

  When the outer member 22 rotates in the arrow B direction in this way, the rollers 25... Bite into the wedge-shaped space between the outer member 22 and the inner member 23 of the one-way clutch 21, and the rotation of the outer member 22 passes through the inner member 23. Therefore, the output shaft 12 rotates counterclockwise (see arrow C).

  When the input shaft 11 and the first pinion 15 further rotate, the eccentric disk 18 in which the ring gear 18a is engaged with the first pinion 15 and the second pinion 17, 17 rotates eccentrically in the counterclockwise direction (see arrow A). While rotating from the state shown in FIG. 5C to the state shown in FIG. 5A, the ring portion 19b is supported on the outer periphery of the eccentric disk 18 via the ball bearing 20 so as to be relatively rotatable. The connecting rod 19 rotates the outer member 22 pivotally supported by a pin 19c at the tip of the rod portion 19a in the clockwise direction (see arrow B ′). FIG. 5C and FIG. 5A show both ends of the rotation of the outer member 22 in the arrow B ′ direction.

  Thus, when the outer member 22 rotates in the direction of the arrow B ′, the rollers 25 are pushed out from the wedge-shaped space between the outer member 22 and the inner member 23 while compressing the springs 24. Slips with respect to the inner member 23 and the output shaft 12 does not rotate.

  As described above, when the outer member 22 reciprocates, the output shaft 12 rotates counterclockwise (see arrow C) only when the rotation direction of the outer member 22 is counterclockwise (see arrow B). The shaft 12 rotates intermittently.

  FIG. 6 shows the operation when the continuously variable transmission T is operated in the LOW state. At this time, since the position of the input shaft 11 coincides with the center of the eccentric disk 18, the eccentric amount of the eccentric disk 18 with respect to the input shaft 11 becomes zero. In this state, when the input shaft 11 is rotated by the engine E and the rotating shaft 14a of the speed change actuator 14 is rotated at the same speed as the input shaft 11, the input shaft 11, the rotating shaft 14a, the carrier 16, the first pinion 15, 2 In a state where the second pinions 17 and 17 and the eccentric disk 18 are integrated, the input pin 11 is rotated eccentrically in the counterclockwise direction (see arrow A). However, since the eccentric amount of the eccentric disk 18 is zero, the stroke of the reciprocating motion of the connecting rod 19 is also zero, and the output shaft 12 does not rotate.

  Therefore, if the speed change actuator 14 is driven and the position of the carrier 16 is set between the TOP state of FIG. 3 and the LOW state of FIG. 4, operation at an arbitrary ratio between the zero ratio and the predetermined ratio becomes possible.

  In the continuously variable transmission T, the phases of the eccentric disks 18 of the four transmission units 10 arranged in parallel are shifted from each other by 90 °, so that the four transmission units 10 alternately transmit the driving force. In other words, any one of the four one-way clutches 21 is always in an engaged state, so that the output shaft 12 can be continuously rotated.

  When the oil pressure is supplied to the oil chamber 45 of the dog clutch C, the clutch piston 44 moves rightward in the figure, and the dog teeth 44a engage with the dog teeth 33a of the differential case 33, so that the output shaft 12 rotates. It is transmitted to the differential case 33 of the differential gear D through the housing 41, the piston guide 43 and the clutch piston 44. The rotation of the differential case 33 is transmitted to the left drive shaft S via the first pinions 37 ... and the first sun gear 39, and to the right drive shaft S 'via the second pinions 37' ... and the second sun gear 39 '. As a result, the left and right drive wheels W are driven. The left drive shaft S is connected to the right drive shaft S via the first sun gear 39, the first pinion 37 ..., the differential case 33, the second pinion 37 '..., and the second sun gear 39'. The differential between the wheels W and W is allowed.

  By the way, the continuously variable transmission T converts the reciprocating motion in which the phases of the plurality of connecting rods 19 are different from each other into the rotational motion of the outer output shaft 12b via the plurality of one-way clutches 21. There is a possibility that high-frequency torque fluctuations according to the number of motors will occur, and vibration and noise will increase through the resonance point of the continuously variable transmission T at the normal rotational speed of the engine E.

  However, according to the present embodiment, the outer output shaft 12b, the inner output shaft 12a, the differential gear D, and the right and left are on the path through which the driving force of the engine E is transmitted from the continuously variable transmission T to the drive wheels W and W. Drive shafts S and S are interposed, and the outer output shaft 12b, the inner output shaft 12a, and the left and right drive shafts S and S function as torsion springs that can be twisted and deformed over their entire length. Between the torsion springs (outer output shaft 12b and inner output shaft 12a) on the upstream side in the transmission direction and the torsion springs (drive shafts S, S) on the downstream side in the driving force transmission direction. A damper connecting D) is constructed.

  With this damper, the resonance point of torque fluctuation peculiar to the continuously variable transmission T can be moved to the outside of the normal rotation speed of the engine E, and the occurrence of resonance can be suppressed to reduce vibration and noise. In particular, by disposing a mass body between two torsion springs, it is possible to obtain a better damping characteristic of torque fluctuation than a damper having a single torsion spring. Moreover, since the driving force is transmitted to the output shaft 12 through the one-way clutch 21 surrounding the outer periphery, only the torsional load is input to the output shaft 12 and no bending load is input. Therefore, the inner output shaft 12a and the outer output shaft 12b can be formed into thin-walled tubes, and the torsional rigidity can be lowered to further improve the damping characteristic of torque fluctuation.

  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 transmission of the present invention is not limited to the reciprocating continuously variable transmission T of the embodiment, and may be another type of continuously variable transmission such as a belt-type continuously variable transmission. A stepped transmission may be used.

DESCRIPTION OF SYMBOLS 10 Transmission unit 11 Input shaft 12 Output shaft 12a Inner output shaft 12b Outer output shaft 18 Eccentric disk (input side fulcrum)
19 Connecting rod 19c Pin (Output side fulcrum)
21 One-way clutch 22 Outer member (input member for one-way clutch)
23 Inner member (Output member of one-way clutch)
33 Differential case (differential gear input member)
39 1st sun gear (differential gear output member)
39 'Second sun gear (differential gear output member)
D Differential gear E Engine (drive source)
S drive shaft T continuously variable transmission (transmission)

Claims (2)

A drive source (E);
A transmission (T) for shifting the rotation of the input shaft (11) connected to the drive source (E) and transmitting the rotation to the output shaft (12);
A differential gear (D) to which the driving force of the output shaft (12) is input;
Left and right drive shafts (S) extending in the left-right direction of the vehicle body from the differential gear (D),
The transmission (T)
An input side fulcrum (18) that is variable in eccentricity from the axis of the input shaft (11) and rotates together with the input shaft (11);
A one-way clutch (21) connected to the output shaft (12);
An output fulcrum (19c) provided on an input member (22) of the one-way clutch (21);
A vehicular power transmission device comprising: a connecting rod (19) connected to both ends of the input side fulcrum (18) and the output side fulcrum (19c);
The output shaft (12) has a tubular inner output shaft (12a) fitted to the outer periphery of the left or right drive shaft (S), and is coaxially fitted to the outer periphery of the inner output shaft (12a). A tubular outer output shaft (12b) connected to the output member (23) of the one-way clutch (21),
One end of the outer output shaft (12b) is connected to one end of the inner output shaft (12a), and the other end of the inner output shaft (12a) is connected to an input member (33) of the differential gear (D), The vehicle power transmission device, wherein left and right output members (39, 39 ') of the differential gear (D) are respectively connected to one ends of the left and right drive shafts (S).   The transmission (T) includes the input side fulcrum (18), the output side fulcrum (19c), the connecting rod (19), and the one-way clutch (21), and the reciprocating motion of the connecting rod (19). 2. The vehicle power transmission device according to claim 1, wherein the power transmission device comprises a plurality of transmission units (10) having different phases.

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