JPH07243506A - Power transmission of car - Google Patents

Abstract

PURPOSE:To hinder generation of shift shocks in a continuously variable transmission while it is constructed in a small size. CONSTITUTION:A power transmission device of car has the first transmission line, through which the torque of an engine 1 is transmitted via the turbine 12 of a torque converter 2, and the second transmission line with which torque transmitting is made via a continuously variable transmission 3 while bypassing the turbine 12. The output rotations of the two lines are put together by a planetary gearing mechanism 4 and passed to the output shaft 5 leading to the driving wheels. The turbine shaft 16 is coupled with the sun gear 41 of the planetary gearing mechanism 4, and the output disc 22 of the transmission 3 is coupled with the ring gear 42, while the output shaft 5 is coupled with the carrier 44.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle power transmission device.

[0002]

2. Description of the Related Art Among power transmission devices for vehicles, there has been proposed a power transmission device including a torque converter and a continuously variable transmission. In Japanese Patent Laid-Open No. 163562/1990, a torque converter and a toroidal type continuously variable transmission are connected in series to input the engine torque amplified by the torque converter to the continuously variable transmission. It is disclosed. JP-A-5-263326 discloses a torque converter in which a torque converter and a continuously variable transmission are arranged in parallel with each other, and the continuously variable transmission is bypassed at the time of starting or accelerating when the transmission torque becomes large. Power transmission is carried out on the system path via
It is disclosed that power is transmitted through a system path that bypasses the torque converter and passes through the continuously variable transmission during steady running.

Japanese Unexamined Patent Publication No. 1-172679 discloses a first power transmission path that passes through a torque converter and a continuously variable transmission, and a second power transmission that bypasses the torque converter and the continuously variable transmission. Then, the rotation of each power transmission path is
It is disclosed that the compounding means is composed of a planetary gear mechanism and the resultant is transmitted to an output shaft connected to a drive wheel.

[0004]

By the way, as shown in the above-mentioned Japanese Patent Application Laid-Open Nos. 2-163562 and 1-172679, the engine torque after passing through a torque converter is input to a continuously variable transmission. In this case, since the input torque to this continuously variable transmission becomes large, the continuously variable transmission inevitably becomes large. In order to eliminate this point, a torque converter and a continuously variable transmission are arranged in parallel, as shown in Japanese Unexamined Patent Publication No. Hei 5-26326.
For those that select and switch one of them,
A shock at the time of this switching becomes a big problem.

The present invention has been made in consideration of the above circumstances, and it is premised that the torque converter and the continuously variable transmission are provided, while preventing the continuously variable transmission from increasing in size. An object of the present invention is to provide a power transmission device for a vehicle that does not generate shock or is small in size.

[0006]

In order to achieve the above object, the present invention has the following configuration. That is, in a power transmission device of a vehicle including a torque converter and a continuously variable transmission, a first power transmission path passing through a turbine of the torque converter and the turbine bypassing the turbine. From a planetary gear mechanism that is provided on the output side of each of the power transmission paths and that is provided on the output side of the second power transmission path via the continuously variable transmission and that combines the rotations of the power transmission paths and transmits the combined rotation to the output shaft And a synthesizing means including Preferred embodiments of the present invention based on the above configuration are as described in claims 2 and below in the claims.

[0007]

According to the present invention, since the engine torque is input to the continuously variable transmission without passing through the turbine of the torque converter, the continuously variable transmission can be downsized. Further, the rotation from the first power transmission system path passing through the turbine of the torque converter and the rotation from the second power transmission system path passing through the continuously variable transmission are combined by means of a planetary gear mechanism. Since they are combined and transmitted to the output shaft, that is, the drive wheels, a shock at the time of this selection switching is different from the one in which either one of the torque converter and the continuously variable transmission is selectively switched and used. Will not occur, which is also preferable in terms of shock prevention or shock reduction.

With the structure as described in claim 2, the planetary gear mechanism can be made as simple as possible including three rotating elements.

With the structure as described in claim 3, it is possible to obtain a gear shift that makes full use of the gear shift range of the continuously variable transmission when the lock-up clutch is engaged.

With the structure as described in claim 4, it is possible to sufficiently obtain the torque increasing action of the torque converter when the lockup clutch is released.

With the structure as described in claim 5, stalling can be prevented when the vehicle is stopped.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First Embodiment (FIGS. 1 to 3) In FIG. 1, reference numeral 1 denotes an engine, which is a torque converter 2 and a toroidal type continuously variable rotor in the direction of the crankshaft 1a of the engine 1 from the near side to the far side of the engine 1. A transmission 3, a planetary gear mechanism 4 as a rotation synthesizing means, and an output shaft 5 connected to driving wheels are arranged in series.

As is known, the torque converter 2 has a pump 11, a turbine 12, and a stator 13, and a stator.
The motor 13 is connected to the transmission case 2 a via a one-way clutch 14. And the torque converter 2
Is equipped with a lock-up clutch 15 for directly connecting the pump 11 and the turbine 12.

A turbine shaft 1 which rotates integrally with the turbine 12.
6 is arranged so as to extend on the same straight line as the crankshaft 1a and the output shaft 5, and is integrally connected to the sun gear 41 of the planetary gear mechanism 4. This planetary gear mechanism 4
As shown in FIG. 2, in addition to the sun gear 41, has a ring gear 42, a pinion gear 43 that meshes with both gears 41, 42, and a carrier 44 that rotatably holds the pinion gear 43. The carrier 44 is integrally connected to the output shaft 5, and the engine torque is input to the ring gear 42 via the continuously variable transmission 3 described later.

In the embodiment, the toroidal type continuously variable transmission 3 is provided with two toroids, a front toroidal 3A and a rear toroidal 3B, but each toroidal 3A, 3B has basically the same configuration. . Former toroidal 3A
It has an input disk 21, an output disk 22, and a roller 23 that comes into contact with both disks 21, 22. Then, by changing the tilt angle of the rotation axis Y of the roller 23, the rotation ratio of the output disk 22 with respect to the input disk 21, that is, the gear ratio is changed. With respect to the rear toroidal 3B, the same components as those of the front toroidal 3A are designated by the same reference numerals, and a duplicate description thereof will be omitted. The toroidals 3A and 3B always have the same gear ratio.

The toroidals 3A and 3B are arranged so that the input disks 21 thereof are close to each other. In other words, the output disk 22 of the front toroidal 3A is located near the torque converter 2, and the output disk 22 of the rear toroidal 3B is located near the planetary gear mechanism 4. Each disc 21,
22 are rotatably fitted to the outer periphery of the turbine shaft 16, and the output disks 22 are connected to each other via a hollow connecting shaft 24 so as to rotate integrally with each other. The assembly of the two output disks 22 and the connecting shaft 24, which rotate integrally, is the ring gear 2 of the planetary gear mechanism 4.
It is connected to 2 so as to rotate integrally.

An input cam 31 is provided between the input disks 21 of the two toroids 3A and 3B, and a cam roller 32 is provided between the input cams 31 and the input disks 21. ing. The input cam 31 is rotatably arranged on the outer circumference of the connecting shaft 24, and the gear 3 formed on the outer circumference of the input cam 31.
1a is interlocked with the pump 11 of the torque converter 2 via a switching clutch 33, an idle gear 34, a gear 35, an interlocking shaft 36, and a gear 37.

The front and rear toroidals 3A, 3B are regulated with respect to the turbine shaft 16 by a pair of front and rear thrust bearings 38 so as not to be separated from each other in the axial direction. Then, the cam roller 32 acts so as to increase the pressing force against the input disk 21 as the input torque input to the input cam 31 increases.

The lock-up clutch 15 is engaged, for example, during steady running except when accelerating and at a predetermined vehicle speed (for example, 40 km / h) or more, and is released at other times. The switching clutch 33 is stopped (when the vehicle speed is zero or at a low vehicle speed that can be regarded as zero).
The fastening is released at the beginning, and it is gradually fastened at the time of starting, and is completely fastened after the completion of starting.

In the configuration as described above, the engine 1
The torque from the crankshaft 1a is transmitted to the planetary gear mechanism 4 or the output shaft 5 by the following two power transmission paths. The first power transmission path is a path from the turbine shaft 16 to the sun gear 41 of the planetary gear mechanism 4 via the turbine 12 of the torque converter 2. The second power transmission path is from the pump 11 of the torque converter 2 to
It is a system path that bypasses the turbine 12, passes through the switching clutch 33, the interlocking gear mechanisms 34 to 37, further passes through the toroidal type continuously variable transmission 3, and then to the ring gear 42 of the planetary gear mechanism 4.

In the planetary gear mechanism 4, the rotations, that is, the torques from the first and second power transmission system paths are combined and transmitted to the output shaft 5. The composition of this rotation,
This is shown in the velocity diagram of FIG. In FIG. 3, the gear ratio shown on the vertical axis is for the engine speed,
The gear ratio λ on the horizontal axis is a value obtained by dividing the diameter (number of teeth) of the sun gear 41 by the diameter (number of teeth) of the ring gear 42, and 0 <
λ <1. In addition, the gear ratio of the sun gear 41 is α1,
The gear ratio of the ring gear 42 is indicated by α3, and the gear ratio of the carrier 44 exhibiting the combined rotation is indicated by α3.

On the α1, the torque converter 2
Let γ1 be the gear ratio when the gear is stolen, γ2 be the gear ratio when the lockup is made, and the gear ratio on the lowest side of the toroidal type continuously variable transmission 3 on the α3 is γ3. , The highest gear ratio is γ4. The straight line connecting γ1 and γ3 is shown as β1, and the straight line connecting γ2 and γ4 is shown as β2. Carrier 4 showing synthetic rotation
When the gear ratio λ is set to a certain predetermined value λ1, the rotation of 4 (gear ratio) is in the range of β1 and β2 on a straight line α2 extending in the up-down direction passing through this λ1. In other words, according to the configuration of the embodiment, the maximum shift width that the carrier 44 can take is smaller than the maximum shift width that the toroidal continuously variable transmission 3 can take. To increase this shift range,
It suffices to set the β2 line to the upper position in FIG. 3 as much as possible, and the maximum upper position of this β2 line is obtained by locking up the torque converter 2 (if not locking up, β
The two lines are more downward to the right than those shown in FIG. 3, and the shift range that the carrier 44 can take is smaller).

The relationship between the gear ratio λ, the number of revolutions NS of the sun gear 41, the number of revolutions NR of the ring gear 42, and the number of revolutions NC of the carrier 44 is expressed by the following equation (1). (1 + λ) NC = NR + λNS (1)

Second Embodiment (FIG. 4) FIG. 4 shows a second embodiment of the present invention, in which the same components as those in the above-mentioned embodiment are designated by the same reference numerals and the description thereof will be omitted. Is the same for the other examples below). In the present embodiment, the planetary gear mechanism 4 as the rotation speed synthesizing means is of the double pinion type. That is, as the pinion gear, the first pinion 43A that meshes only with the ring gear 42 and the second pinion 43B that meshes with the sun gear 41 and the first pinion 43A are provided. In this embodiment, the sun gear 41
Is connected to the turbine 12 and the ring gear 42 is connected to the output shaft 5
And the carrier 44 is connected to the output disk 22 of the toroidal-type continuously variable transmission 3. The relational expression of the rotational speed corresponding to the above equation (1) is as shown in the following equation (2). (1−λ) NC = NR−λNS (2)

Third Embodiment (FIG. 5) FIG. 5 shows a third embodiment of the present invention. In the present embodiment, claims 3 and 4 in the claims are provided.
Corresponding to the two first and second clutches 51,
52 is provided. That is, the first clutch 51 includes the ring gear 22 (the toroidal type continuously variable transmission 3
The second clutch 52 is provided so as to directly connect and disconnect the output shaft 5 and the second power transmission line passing through the carrier 24 (the first power transmission line passing through the turbine 12). It is provided so as to connect to and disconnect from the output shaft 5. The operation modes of both clutches 51 and 52 are set as follows.

When the lockup clutch 15 is engaged First clutch 51 = engaged, second clutch 52 = disengaged When the lockup clutch 15 is disengaged First clutch 51 = disengaged, second clutch 52 = engaged

According to this embodiment, when the lockup clutch 15 is disengaged, that is, when there is a request to transmit a relatively large torque, the torque converter 2 is brought into the same state as in FIG. Torque transmission that fully utilizes the torque increasing action of is obtained. Further, when the lock-up clutch 15 is engaged, that is, when there is no request to transmit an excessively large torque, it is possible to obtain a gear ratio that fully utilizes the shift width of the toroidal type continuously variable transmission 3.

Fourth Embodiment (FIG. 6) FIG. 6 shows a fourth embodiment of the present invention in which only one toroidal member is used and the length in the axial direction is shortened.

Fifth Embodiment (FIG. 7) FIG. 7 shows a fifth embodiment of the present invention, which has only one toroid as in the case of FIG. In addition to this, by forming the input disk 21 integrally with the pump of the torque converter 2, the length in the axial direction is further shortened and the interlocking gear mechanisms 34 to 37, 31a are unnecessary. An idle gear 61 is interposed between the ring gear 42 and the pinion gear 43 in the planetary gear mechanism 4 to match the rotation directions. The switching clutch 33 for releasing the connection between the ring gear 42 (toroidal type continuously variable transmission 3) and the output shaft 5 when the vehicle is stopped connects and disconnects the carrier 62 of the idle gear 61 and the transmission case 2a. When the vehicle is stopped, the switching clutch 33 is disengaged so that the idle gear 61 can freely revolve.

Although the embodiments have been described above, the present invention is not limited to this. For example, the continuously variable transmission may be a belt type in which a belt is wound between a pair of pulleys.

[Brief description of drawings]

FIG. 1 is an overall skeleton diagram showing an embodiment of the present invention.

FIG. 2 is a view of the planetary gear mechanism shown in FIG. 1 as viewed from the axial direction.

FIG. 3 is a diagram showing rotational composition of the planetary gear mechanism shown in FIG. 1.

FIG. 4 shows a second embodiment of the present invention and is a diagram corresponding to FIG.

FIG. 5 shows a third embodiment of the present invention, and is a main part view of a planetary gear mechanism portion.

FIG. 6 shows a fourth embodiment of the present invention and corresponds to FIG. 1.

FIG. 7 shows a fifth embodiment of the present invention and corresponds to FIG. 1.

[Explanation of sign]

 1: Engine 2: Torque converter 3: Continuously variable transmission 4: Planetary gear mechanism 5: Output shaft 12: Turbin 16: Turbin shaft 33: Switching clutch 41: Sun gear 42: Ring gear 43: Pinion gear 44 : Carrier 51: First clutch 52: Second clutch

Claims (5)

[Claims] 1. A vehicle power transmission device including a torque converter and a continuously variable transmission, wherein a first power transmission path passing through a turbine of the torque converter and the turbine are bypassed. And a second power transmission path that passes through the continuously variable transmission, and a planet that is provided on the output side of each power transmission path and that combines the rotations of each power transmission path and transmits it to the output shaft. A power transmission device for a vehicle, comprising: a synthesizing unit including a gear mechanism. 2. The planetary gear mechanism as the synthesizing means according to claim 1, wherein:
A first rotating element is connected to the first power transmission path, a second rotating element is connected to the second power transmission path, and a third rotating element is connected to the output shaft. What you have. 3. The first clutch according to claim 1, wherein the torque converter includes a lock-up clutch, and the first clutch that directly connects the second power transmission system path and the output shaft when the lock-up clutch is engaged. A second clutch that disconnects the first power transmission path and the output shaft from each other. 4. The operation state according to claim 3, wherein when the lockup clutch is disengaged, the operating states of the first clutch and the second clutch are opposite to the operating state when the lockup clutch is engaged, Two
The one in which the direct connection between the power transmission system and the output shaft is released. 5. The clutch according to claim 1, further comprising a clutch for releasing the connection between the output shaft and the engine via the second power transmission path when the vehicle is stopped.