JP2012021592A5 - - Google Patents

Description

Power transmission device for vehicle

According to the present invention, there is provided a transmission for shifting the rotation of an input shaft connected to a crankshaft of a multi-cylinder engine and transmitting the rotation to an output shaft, wherein the amount of eccentricity from the axis of the input shaft is variable, together with the input shaft A rotating input side fulcrum, a one-way clutch connected to the output shaft, an output side fulcrum provided on an input member of the one-way clutch, and a reciprocating motion with both ends connected to the input side fulcrum and the output side fulcrum The present invention relates to a vehicle power transmission device including a connecting rod.

  Such a vehicle power transmission device is known from Patent Document 1 below.

  FIG. 9 shows the principle of a continuously variable transmission of a vehicle power transmission device disclosed in Patent Document 1. An eccentric disk in which an input shaft 01 and an output shaft 02 are arranged in parallel and the amount of eccentricity with respect to the input shaft 01 is variable. One end of the connecting rod 04 is supported on the outer periphery of 03, and the other end of the connecting rod 04 is supported on the outer periphery of the output shaft 02 via the one-way clutch 05.

  When the input shaft 01 rotates, one end of the connecting rod 04 supported by the input shaft 01 via the eccentric disk 03 rotates eccentrically, and the connecting rod 04 reciprocates with a stroke corresponding to the amount of eccentricity. As a result, when the connecting rod 04 moves in one direction, the one-way clutch 05 is engaged and the output shaft 02 rotates in one direction, and when the connecting rod 04 moves in the other direction, the one-way clutch 05 is disengaged. Then, when the output shaft 02 stops rotating, the output shaft 02 rotates intermittently in one direction.

  When the eccentric amount of the eccentric disk 03 is increased, the stroke of the connecting rod 04 is increased, the intermittent rotation angle of the output shaft 02 per one rotation of the input shaft 01 is increased, and the gear ratio of the continuously variable transmission is changed to the TOP side. To do. Conversely, when the eccentric amount of the eccentric disk 03 is decreased, the stroke of the connecting rod 04 is decreased, the intermittent rotation angle of the output shaft 02 per one rotation of the input shaft 01 is decreased, and the gear ratio of the continuously variable transmission is LOW. Change to the side.

JP-T-2005-502543

  By the way, when the gear ratio of the continuously variable transmission decreases and approaches the TOP side, the intermittent rotation angle of the output shaft 02, that is, the intermittent rotation angle of the one-way clutch 05 increases as shown in FIG. Thus, there is a problem that the power transmission efficiency of the continuously variable transmission is lowered.

  In order to set the maximum transmission ratio of the continuously variable transmission small, it is necessary to increase the reciprocating stroke of the connecting rod 04. For this purpose, the diameter of the eccentric disc 03 is increased, or the eccentric disc 03 with respect to the input shaft 01 is increased. If the amount of eccentricity is increased, there is a problem that the dimensions of the continuously variable transmission are increased and the weight is increased. In addition, if the maximum transmission ratio of the continuously variable transmission is set to be small, the friction of the one-way clutch 05 increases especially during high-speed operation, so that the power transmission efficiency is remarkably reduced in a region where the transmission ratio is small as shown in FIG. There is.

  As described above, if the maximum transmission ratio of the continuously variable transmission is set to be small, the power transmission efficiency is remarkably lowered in a region where the transmission ratio is small. However, it is necessary to set the maximum transmission ratio to be small for the following reasons.

  FIG. 12 shows the engine speed (input shaft speed of the continuously variable transmission) on the horizontal axis and the output torque of the engine on the vertical axis, and the darker the region, the better the fuel efficiency of the engine E. For example, when the vehicle is traveling at a vehicle speed of 80 km / h, the fuel efficiency improves as the gear ratio decreases. When the minimum speed ratio is 2.1, the fuel efficiency of the region C is the limit (see ○), but when the minimum speed ratio is further smaller than 2.1, the fuel efficiency is brought closer to the better region B from the region C. (See ●). From the above, it is desirable to reduce the maximum gear ratio while ensuring the power transmission efficiency of the continuously variable transmission.

  The present invention has been made in view of the above-described circumstances, and enables the maximum gear ratio to be set small while ensuring the power transmission efficiency of a vehicle power transmission device including a continuously variable transmission using a four-bar linkage mechanism. For the purpose.

In order to achieve the above object, according to the first aspect of the present invention, there is provided a transmission that shifts rotation of an input shaft connected to a crankshaft of a multi-cylinder engine and transmits the rotation to an output shaft. An input side fulcrum whose amount of eccentricity from the axis of the shaft is variable and rotates together with the input shaft, a one-way clutch connected to the output shaft, an output-side fulcrum provided on an input member of the one-way clutch, A vehicle power transmission device comprising an input side fulcrum and a connecting rod connected to both ends of the output side fulcrum and reciprocating, wherein the speed increasing mechanism transmits the rotation of the crankshaft to the input shaft. And the speed increasing mechanism is arranged near the center in the axial direction of the crankshaft .

According to the invention described in claim 2, in addition to the first aspect, wherein the crank shaft and the entering-output shaft disposed in parallel to each other, the crankshaft and the look direction perpendicular to the axis A vehicle power transmission device is proposed in which the input shafts overlap at least partially .

Incidentally, the continuously variable transmission T of the implementation in the form corresponds to the transmission of the present invention, corresponds to the input side fulcrum of the eccentric disk 18 according to the present invention of the embodiment, the pin 19c of the embodiment of the present invention corresponding to the output side fulcrum, the outer member 22 of the embodiment you corresponds to the input member of the present invention.

According to the configuration of claim 1, 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 a one-way clutch Since it includes an output side fulcrum provided on the input member and a connecting rod that is connected to both ends of the input side fulcrum and the output side fulcrum and reciprocates, the rotation of the input shaft can be shifted and output to the output shaft. . Since transmitted to the input shaft by accelerating the rotation of the engine crankshaft at a speed increasing mechanism, while avoiding the decrease in power transmission efficiency in a small area of the gear ratio by increasing the maximum speed ratio of the transmission alone, the engine In addition, it is possible to secure a small maximum gear ratio of the vehicle power transmission device including the transmission and to increase the energy consumption efficiency of the engine . Moreover, since the speed increasing mechanism is arranged near the center of the crankshaft of the multi-cylinder engine in the axial direction, it is possible to minimize torsional deformation of the crankshaft due to the reaction load received from the speed increasing mechanism. It is possible to reduce weight and reduce vibration and noise.

According to the second aspect of the present invention, the engine crankshaft and the input shaft of the transmission, which are arranged in parallel to each other, overlap each other at least partially when viewed in a direction perpendicular to the axis. The axial dimension of the power transmission device can be reduced .

The skeleton figure of the power transmission device for vehicles. (In the form of implementation) The longitudinal cross-sectional view of a continuously variable transmission. (In the form of implementation) FIG. 3 is a sectional view taken along line 3-3 in FIG. 2 (TOP state). (In the form of implementation) FIG. 3 is a sectional view taken along line 3-3 in FIG. 2 (LOW state). (In the form of implementation) The action explanatory view in the TOP state. (In the form of implementation) The action explanatory view in the LOW state. (In the form of implementation) The perspective view of the power transmission device for vehicles. (In the form of implementation) The skeleton figure of the power transmission device for vehicles. ( Reference example ) The figure which shows the structure of the conventional continuously variable transmission. The graph which shows the relationship of the rotation angle of an output shaft with respect to a gear ratio, and power transmission efficiency. The graph which shows the relationship between the gear ratio and power transmission efficiency according to the magnitude of the maximum gear ratio. The graph which shows the relationship between engine speed and output torque, and fuel consumption.

Hereinafter, describing the implementation of the embodiment of the present invention with reference to FIGS. 1 to 7.

  As shown in FIGS. 1 and 7, the vehicle power transmission device for driving the left and right drive wheels W of the vehicle includes an engine E, a speed increasing mechanism I, a continuously variable transmission T, a clutch C, A differential gear D and left and right drive shafts S, S are provided.

The engine E is, for example, an in-line four-cylinder engine, and a drive sprocket 33 fixed at an intermediate position in the axial direction of a crankshaft 32 connected to four pistons 31... And a steplessly arranged parallel to the crankshaft 32. An endless chain 35 is wound around a driven sprocket 34 fixed to the input shaft 11 of the transmission T. Therefore, when the engine E is driven, the rotation of the crankshaft 32 is transmitted to the input shaft 11 of the continuously variable transmission T via the drive sprocket 33, the endless chain 35, and the driven sprocket 34. At this time, since the diameter of the drive sprocket 33 is larger than the diameter of the driven sprocket 34, the rotational speed of the input shaft 11 of the continuously variable transmission T is increased with respect to the rotational speed of the crankshaft 32. Drive sprocket 33, driven sprocket 34 and the endless chain 35 constitute the speed increasing mechanism I in the form of implementation.

  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 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. In this way, the driving force of the engine E is shifted by the continuously variable transmission T and output to the output shaft 12.

  Now, according to the present embodiment, the rotation of the crankshaft 32 of the engine E is accelerated through the speed increasing mechanism I and transmitted to the input shaft 11 of the continuously variable transmission T. Therefore, the continuously variable transmission T Even if the gear ratio between the input shaft 11 and the output shaft 12 is set large, that is, even if the rotational speed of the input shaft 11 is sufficiently decelerated and transmitted to the output shaft 12, the distance between the crankshaft 32 and the output shaft 12 is reduced. The gear ratio can be secured sufficiently small. As a result, it is possible to ensure the necessary speed ratio width while eliminating the need to operate the continuously variable transmission T in a region where the gear ratio is small and the power transmission efficiency is low (the region on the right side in FIG. 10).

  In addition, since the crankshaft 32 of the engine E and the input shaft 11 of the continuously variable transmission T overlap each other at least partially when viewed in the direction orthogonal to the axis, the axial dimension of the vehicle power transmission device is reduced. Can be Moreover, since the drive sprocket 33 of the speed increasing mechanism I is disposed in the vicinity of the center in the axial direction of the crankshaft 32 of the engine E, that is, between the two pistons 31, 31 inside the four pistons 31. Thus, the torsional deformation of the crankshaft 32 due to the reaction load received from the crankshaft 32 can be suppressed to a minimum, which makes it possible to reduce the size and weight of the crankshaft 32 and reduce vibration and noise.

Next, a reference example of the present invention will be described with reference to FIG.

Although the implementation of the form axis of the input shaft 11 in the axial and the continuously variable transmission T of the crankshaft 32 of the engine E are arranged in parallel, of the crankshaft 32 and the continuously variable transmission T of the reference example in the engine E The input shaft 11 is connected coaxially and in series. A planetary gear mechanism 41 as a speed increasing mechanism I is disposed between the crankshaft 32 of the engine E and the input shaft 11 of the continuously variable transmission T.

  The planetary gear mechanism 41 includes a sun gear 42 fixed to the input shaft 11, a ring gear 43 fixed to the crankshaft 32, a carrier 45 fixed to the casing 44, and a sun gear 42 that is rotatably supported by the carrier 45. A plurality of pinions 46 meshing with the ring gear 43 are configured. Therefore, the rotation of the crankshaft 32 is accelerated and transmitted to the input shaft 11 via the ring gear 43, the pinions 46, and the sun gear 42.

According to this reference example , the dimensions of the vehicle power transmission device including the engine E and the continuously variable transmission T in the direction perpendicular to the axis (direction perpendicular to the axes of the crankshaft 32, the input shaft 11, and the output shaft 12) are reduced. can do.

  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 speed increasing mechanism I is not limited to the one using the endless chain 35 or the planetary gear mechanism 41, and other means such as a gear train can be adopted.

11 Input shaft 12 Output shaft 18 Eccentric disc (input side fulcrum)
19 Connecting rod 19c Pin (Output side fulcrum)
21 one-way clutch 22 the input member 32 crankshaft preparative E engine <br/> I speed increasing mechanism T CVT (transmission)

Claims (2)

A transmission (T) for shifting the rotation of the input shaft (11) connected to the crankshaft (32) of the multi-cylinder engine (E ) and transmitting the rotation to the output shaft (12),
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);
A speed increasing mechanism (I) for increasing the rotation of the crankshaft (32) and transmitting it to the input shaft (11) is provided , and the speed increasing mechanism (I) is near the center in the axial direction of the crankshaft (32). It is arrange | positioned in the vehicle power transmission device characterized by the above-mentioned. Wherein the crankshaft (32) and the entering force shaft (11) disposed in parallel to each other, the look direction perpendicular to the axis crankshaft (32) and said input shaft (11) mutually over at least a portion The vehicle power transmission device according to claim 1, wherein the vehicle power transmission device is wrapped .