JPH0697062B2 - Car power transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a power transmission device for an automobile.

[Prior art]

In a general automobile, a transmission composed of a combination of a plurality of gear trains is used in order to match an engine characteristic with a power characteristic required for vehicle traveling. However, the above transmission requires a complicated selection mechanism for changing the combination of gears according to the vehicle speed. Therefore, there is one that employs a continuously variable transmission in order to omit the selection mechanism and obtain a desired power characteristic, but in this case, in order to compensate for the narrow operating speed range in the continuously variable transmission, it is combined with an auxiliary gear position. It is used.

By the way, in the structure in which the continuously variable transmission and the auxiliary transmission are combined as described above, the auxiliary transmission is operated stepwise in accordance with the change of the vehicle speed, so that the power characteristic also changes stepwise and the vehicle When observing the power characteristics over the entire traveling condition, there was an inevitable inconvenience that waves were generated there.

[Object of the Invention]

The present invention has been made in view of the above circumstances, and an object thereof is to provide a power transmission mechanism for a vehicle that can obtain smooth power characteristics over the entire traveling condition including the backward movement of the vehicle.

[Structure of Invention]

In the present invention, a main shaft that is connected to an output shaft of an engine and is rotatably arranged around an axis, a toroidal type continuously variable transmission that is configured on the main shaft, and is driven by rotation of the main shaft; A drive gear fixed to the main shaft, a sub shaft arranged in parallel with the main shaft in a manner parallel to the main shaft and rotatably arranged around the axis, and a sun gear fixed to the sub shaft. A planetary gear mechanism configured on the sub-shaft in a manner to be installed, a speed reduction means for transmitting an output from the toroidal type continuously variable transmission to a carrier of the planetary gear mechanism, and a mode for meshing with the drive gear. In a mode in which a driven gear rotatably arranged on the counter shaft and having a first clutch gear fixedly provided on one side thereof has the same shape as the first clutch gear and is arranged in parallel with the first clutch gear. A second clutch gear fixed to the counter shaft; A clutch gear and a second clutch gear are provided movably along the axial direction of the auxiliary shaft on the outer peripheral portions of the clutch gear, and a connecting position that meshes with both clutch gears and a disengagement position that meshes with only one clutch gear. And a clutch dog that is displaced between the two to form a power transmission device for an automobile so that power is taken out from the ring gear of the planetary gear mechanism.

〔Example〕

The present invention will be described below with reference to the embodiments shown in the drawings.

The drawings are skeleton diagrams of a power transmission device for an automobile according to the present invention.

This power transmission device is connected to an output shaft 27 of an engine (not shown) via a clutch 26 and is parallel to a main shaft 1 rotatably arranged around an axis. In this mode, the main shaft 1 is provided in parallel with the main shaft 1 and a sub shaft 2 is provided so as to be rotatable about its axis, and the main shaft 1 is provided with a toroidal type continuously variable transmission 3. There is.

The continuously variable transmission 3 has the input side traction disc 4, the output side traction disc 5, and the power rollers 6, 6 arranged between the both traction discs 4, 5.
The input side traction disc 4 is linked to the main shaft 1 via a torque cam 7, and the output side traction disc 5 has a drive sprocket 8. Further, a drive gear 9 is fixedly installed on the main shaft 1. On the other hand, in this power transmission device, the driven sprocket 13 is attached to the counter shaft 2.
And a planetary gear mechanism 10. The driven sprocket 13 is rotatably arranged at a portion of the counter shaft 2 corresponding to the position where the drive sprocket 8 is arranged. The drive sprocket 8 is provided via a chain 14 wound between the two. It is connected to the. The planetary gear mechanism 10 is formed on the sub shaft 2 in a manner in which the sun gear 11 is fixed to the sub shaft 2, and the driven sprocket 13 is connected to a carrier 12 of a planetary gear (not shown). In addition, the ring gear 15 in the planetary gear mechanism 10
A gear 16 is fixed to the shaft of the gear, and the gear 16 meshes with a gear 18 of a final reduction gear unit 17. Further, the power transmission device includes a driven gear 19 and a second clutch gear 22 on the auxiliary shaft 2, and a clutch dog gear 23 on an outer peripheral portion of the second clutch gear 22. The driven gear 19 is provided with a first clutch gear 21 on one side surface thereof, and is rotatably arranged on the sub shaft 2 in a manner to mesh with the drive gear 9 of the main shaft 1. Second clutch gear
Reference numeral 22 has the same shape as the first clutch gear 21 of the driven gear 19, and is fixed to the sub-shaft 2 in a manner of being arranged in parallel with the first clutch gear 21. Clutch dog gear
23 is the first clutch gear 21 and the second clutch gear
22 has inner teeth meshing with each of the 22 and is arranged so as to be movable along the axial direction of the sub shaft 2.
The driven gear 19 is connected to the countershaft 2 when the driven gear 19 is engaged with the clutch gear 21 and the second clutch gear 22 in meshing engagement with each other. When the driven gear 19 is engaged in the disengaged position where only the 2 clutch gear 22 meshes with the driven gear 19,
Clutch action to disconnect from. The operation of the clutch dog gear 23 described above in the above embodiment is performed by the operation of the piston 24 by the operation of the manual switching valve 25, for example.

In the power transmission device described above, the power of the engine is transmitted as follows.

A part of the engine power transmitted to the main shaft 1 via the clutch 26 and the like is transmitted to the input side traction disc 4 of the toroidal type continuously variable transmission 3 via the torque cam 7 and further via the power rollers 6 and 6. , To the output side traction disk 5. The power of the traction disc 5 on the output side is driven by the drive sprocket 8 and the chain 1.
4, input to the carrier 12 of the planetary gear mechanism 10 via the driven sprocket 13. The other part of the engine power transmitted to the main shaft 1 is transmitted to the sub shaft 2 via the drive gear 9, the driven gear 19, the first clutch gear 21, the clutch dog gear 23 and the second clutch gear 22. , Is input to the sun gear 11 of the planetary gear mechanism 10 via the sub shaft 2.
Then, each power input to the planetary gear mechanism 10 is taken out from the ring gear 15 and transmitted to the wheels via the gears 16 and 18 and the final reduction gear 17.

By the way, in the above embodiment, the transmission ratio i of the toroidal type continuously variable transmission 3 is such that when the radius of the input side traction disc 4 is R _i and the radius of the output side traction disc 5 is R _o , Becomes In the toroidal type continuously variable transmission 3, R _imax is R _{omin and} R _imin is R _omax due to the symmetry of the mechanism.
(However, i is the reciprocal of the speed reduction ratio in a normal transmission of an automobile.) Further, k is the speed reduction ratio between the drive sprocket 8 and the driven sprocket 13, and j is the speed reduction ratio between the drive gear 9 and the driven gear 19. Further, the angular velocity of the main shaft is ω _i , the angular velocity of the output side of the continuously variable transmission 3 is ω _o , the planetary gear mechanism 10
When the angular velocity omega _S of the sun gear 11, the angular velocity omega _R the angular velocity omega _c and a ring gear 15 of the carrier 12, the angular velocity omega _m of the synthesized output by the planetary gear mechanism _{10, ω o = -iω i,} ω s = jω i, ω The relationship of _c = kω _o , ω _m = ω _R is established, and in the planetary gear mechanism 10, the sun gear is
_Let Z _{s be} the number of teeth of 11 and Z _R be the number of teeth of the ring gear 15. Holds, and this equation (2) can be expressed as the following equation.

The total speed ratio m is And m = O, that is, Is within i _max to 1 / i _max , m takes a positive or negative value within this range, in other words, the vehicle can be moved forward or backward.

And when i = i _max , m = m _OD overdrive ratio,
When i = 1 / i _max m = m _R Reverse drive ratio and vice versa It is understood that i _max , m _OD , m _R , and P are approximately constant values in terms of vehicle design, performance, and space, and therefore k and j are within a certain range. Further or in the opposite direction to the same ratio of the overdrive (forward side) in the rotational direction of the input _{side, i max> 0i max -1 /} i max> 0 a is for k the sign of m _OD, the j The sign is inevitably set.

Therefore, | k | = 0.7 to 0.45 | j | = 1.3 to 0.9 (however, the combination is k (+), j (−) or k
(−) And j (+). ), The simplest continuously variable transmission for automobiles can be configured.

For example, if the above constants P, k, j are P = 1.82, k = 0.7, j = -1.3, then m = -1.997 to 0.280. Rewriting to a normal reduction ratio, from overdrive of 0.500 to retreat of 3.565. It is possible to shift continuously. Further, m = 0 is obtained at the time of i = 0.659 from the equation (5). At this time, even when the driven gear 19 is separated from the auxiliary shaft 2, the difference between the rotational speeds of the driven gear 19 and the first clutch gear 21 and the rotational speed of the second clutch gear 22 fixedly mounted on the auxiliary shaft 2. Becomes 0. In other words, no matter what the output speed is, if i is adjusted appropriately, the first clutch gear 21 and the second clutch gear 22 are rotated at the same speed, and they are always synchronized. It is possible to operate the clutch dog gear 23. Moreover, m = 0
In the case of, the reverse drive, that is, the drive from the wheel side becomes impossible, so that the parking function of the automatic transmission can be obtained without providing any special means.

〔The invention's effect〕

As described above, in the power transmission device for a vehicle according to the present invention, it becomes possible to obtain smooth power characteristics over all traveling conditions including the backward movement of the vehicle. Moreover, at any output speed, the first clutch gear and the second clutch gear
Since the clutch gear and the clutch gear can be rotated at the same speed, the clutch dog can always be operated smoothly. Further, by appropriately adjusting the gear ratio of the toroidal type continuously variable transmission, it is possible to disable the driving from the wheel side, so that the parking function of the automatic transmission can be obtained without providing any special means. .

[Brief description of drawings]

The drawings are skeleton diagrams showing a power transmission device for an automobile according to the present invention. 1 ... Main shaft, 2 ... Sub shaft, 3 ... Toroidal type continuously variable transmission, 8 ... Drive sprocket, 9 ... Drive gear, 10 ... Planetary gear mechanism, 11 ... Sun gear, 12 ... Carrier, 13 …… driven sprocket, 14 …… chain,
15 …… Ring gear, 19 …… Driven gear, 21 …… First clutch gear, 22 …… Second clutch gear, 23 …… Clutch dog gear, 27 …… Engine output shaft.

Claims (1)

[Claims] 1. A main shaft connected to an output shaft of an engine and rotatably arranged around an axis; a toroidal type continuously variable transmission configured on the main shaft and driven by rotation of the main shaft; A drive gear fixed to the main shaft, and arranged side by side on the main shaft in a manner to be parallel to the main shaft,
An auxiliary shaft rotatably arranged around an axis, a planetary gear mechanism formed on the auxiliary shaft in a manner in which a sun gear is fixed to the auxiliary shaft, and an output from the toroidal type continuously variable transmission. A speed reducer for transmitting to a carrier of the planetary gear mechanism; a driven gear rotatably disposed on the sub shaft in a manner meshing with the drive gear and having a first clutch gear fixedly mounted on one side thereof; A second clutch gear that has the same shape as the first clutch gear and is fixed to the sub shaft in a manner of being installed in parallel with the first clutch gear; and outer peripheries of the first clutch gear and the second clutch gear. And a clutch dog that is movably arranged along the axial direction of the sub shaft and that is displaced between a connection position that meshes with both clutch gears and a disengagement position that meshes with only one clutch gear. , The ring gear of the planetary gear mechanism A power transmission device of a motor vehicle, characterized in that retrieving the Luo power.