JPH06109098A - Power transmission device for vehicle - Google Patents

Abstract

PURPOSE:To simplify constitution and reduce dimension by omitting the selection function for the normal revolution and reverse revolution in a reduction gear device. CONSTITUTION:A driving system for transmitting the engine output to a driving wheel has the first and second power transmission passages which are selected according to the operation state. A torque converter 2 and a reduction gear 3 are arranged in the first power transmission passage, and a continuously variable transmission 4 is arranged in the second power transmission passage. The reduction gear is constituted of a double pinion type planetary gear device, and a sun gear 3a is connected in an integrally rotational manner with the stator 26 of the torque converter, and a carrier 3e is connected with the turbine 25 of the torque converter, and a ring gear 3b is connected with the output shaft 51 which is common for the first and second power transmission passages. Further, the brakes 34 and 35 for advance and retreat which selectively fix the stator and the turbine with a case 30 are installed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device for a vehicle, and more particularly to an improvement of a power transmission system for transmitting engine output to drive wheels, which has two power transmission paths that can be switched according to operating conditions. .

[0002]

2. Description of the Related Art Conventionally, as a power transmission device for a vehicle,
For example, as disclosed in Japanese Patent Laid-Open No. 63-176862, a first power transmission path for outputting an engine output to driving wheels through a torque converter and a reduction gear, and an engine output driven through a belt type continuously variable transmission. It is known that a second power transmission path for outputting to the wheels is provided, and one of the two power transmission paths is selected according to the driving state to perform power transmission. According to such a power transmission device, when the first power transmission path is selected, the torque amplification function of the torque converter can be utilized to increase, for example, start acceleration, and the second power transmission path can be used. When selected, under the continuously variable transmission,
It is possible to set an appropriate gear ratio according to the driving state without causing a gear shift shock.

On the other hand, in the above conventional power transmission device, since the belt type continuously variable transmission is used, there is a problem that the diameter of the device becomes large. The present applicant has previously proposed a new power transmission device using a toroidal type transmission instead of the belt type continuously variable transmission in order to solve this problem (Japanese Patent Application No. 3-267446). ).

That is, in the proposed power transmission device, for example, as shown in FIG. 4, the torque converter 2, the reduction gear 3, and the continuously variable transmission 4 are arranged in series on the output axis of the engine 1. The torque converter 2 includes a pump 24 to which an engine output is input via an input shaft 21, a turbine 25 provided to face the pump 24 and connected to an output shaft 22, the pump 24 and the turbine 25. And a stator 26 arranged between them. The speed reducer 3 has a forward planetary gear unit 31 and a reverse planetary gear unit 32, and the sun gears 31a and 32a of both planetary gear units 31 and 32 are both the torque converter 2 described above.
Is connected to the output shaft 22 of. Further, the ring gear 31b of the forward planetary gear device 31 is a one-way clutch 33.
The carrier 32e of the reverse planetary gear device 32 is connected to the case 31 through the forward brake 34, and the carrier 31e of the forward planetary gear device 31 is connected to the case 30 through the forward brake 34. The ring gear 32b of the reverse planetary gear device 32 is connected to the case 30 via the reverse brake 35, and the carrier 32e of the reverse planetary gear device 32 is the output shaft 5 of the drive system.
It is connected to 1.

Further, the continuously variable transmission 4 is composed of two toroidal type transmissions 41, 41, and each toroidal type transmission 41 is an input which is rotatably fitted to an output shaft 51 of a drive system. A disc 42, an output disc 43 fixed to the output shaft 51, and a slide roller 44 tiltably arranged between the discs 42 and 43 are provided. By changing it, the gear ratio is changed. Both the toroidal type transmissions 41,
41 are arranged with the input disk 42 on the inside and the output disk 43 on the outside, and between the input disks 42, 42 of the toroidal transmissions 41, 41, an intermediate disk 45 engaging with them is arranged. ing. The intermediate disk 45 is connected to the pump 24 of the torque converter 2 via the gear-type power transmission mechanism 52 and the path switching clutch 6 so that power can be transmitted.

When the path switching clutch 6 is engaged, the engine output is transmitted from the pump 24 of the torque converter 2 via the power transmission mechanism 52 to the continuously variable transmission 4.
Is transmitted to the drive wheels via the output shaft 51 after being transmitted to the continuously variable transmission 4 and changed to a proper gear ratio according to the operating state. On the other hand, when the path switching clutch 6 is released, the engine output is subjected to torque amplification by the torque converter 2 and then output to the drive wheels via the speed reducer 3 and the output shaft 51. When the forward brake 34 of the speed reducer 3 is engaged and the reverse brake 35 is released, the input from the tor converter 2 is decelerated by the forward planetary gear device 31 and the one-way clutch 33 and the reverse planetary gears are decelerated. Output shaft 5 via carrier 32e of device 32
It is output with 1 forward rotation. When the forward brake 34 is released and the reverse brake 35 is engaged, the input from the tor converter 2 is output from the carrier 32e to the output shaft 51 in the reverse rotation while being decelerated by the reverse planetary gear device 32. It

[0007]

By the way, in the case of a power transmission device having two power transmission paths that can be switched according to the operating state as described above, normally, the power transmission path passing through the torque converter is from the start of forward movement. It is used during low-speed running and when reversing. Therefore, the speed reducer provided on the above path needs to have a function of decelerating in forward rotation when moving forward and a function of decelerating in reverse rotation when moving backward, which complicates the configuration and increases the size. . This means that in the case of the power transmission device shown in FIG. 4, the reduction gear device 3 requires two planetary gear devices 31, 32, and the length dimension in the axial direction thereof becomes long.

The present invention has been made in view of the above points, and its object is to pay attention to the fact that the stator of the tor converter receives a torque in the opposite direction to the pump and the turbine. Is used as power at the time of retreating, the function of switching between forward rotation and reverse rotation in the reduction gear device is omitted, and a vehicle power transmission device capable of simplifying and downsizing the configuration is provided. .

[0009]

To achieve the above object, the invention according to claim 1 is a power transmission device for a vehicle, in which a drive system for transmitting engine output to drive wheels is switched according to a driving state. A first and a second power transmission paths are provided, a torque converter and a speed reducer are arranged on the first power transmission path, and a continuously variable transmission is arranged on the second power transmission path. It is assumed that. The speed reducer includes two input elements and one output element, one input element for the stator of the torque converter, another input element for the turbine of the torque converter, and an output element. Are rotatably connected to the output shaft common to the first and second power transmission paths. Moreover, it is configured to include first and second fixing means for selectively fixing the stator and the turbine to the case.

The invention according to claim 2 is dependent on the invention according to claim 1, and more specifically shows a speed reducer which is a component thereof. That is, the speed reducer is configured by one double pinion type planetary gear device, and its sun gear is connected to the stator of the torque converter, the carrier is connected to the turbine of the torque converter, and the ring gear is connected to the output shaft so as to rotate integrally. is there.

A third aspect of the invention is dependent on the first aspect of the invention, wherein the torque converter, the speed reducer and the continuously variable transmission are arranged in series on the same axis. The continuously variable transmission is a toroidal type transmission. The toroidal transmission includes an input disk rotatably fitted to an output shaft, an output disk fixed to the output shaft, and a sliding roller tiltably arranged between the two disks. The gear ratio is changed by changing the inclination angle of the sliding roller.

[0012]

With the above construction, according to the first aspect of the invention, when the first power transmission path is selected and the engine output is transmitted to the drive wheels via the torque converter and the speed reducer, the torque converter When the stator is fixed to the case by the first fixing means, the torque is amplified by the torque converter. This torque is for normal rotation, is input from the turbine to the speed reducer, is decelerated by the speed reducer, and is then output to the drive wheels via the output shaft. On the other hand, when the turbine of the torque converter is fixed to the case by the second fixing means, the stator receives torque in the opposite direction to the pump and rotates. This torque is input from the stator to the speed reducer as it is in reverse rotation, decelerated by the speed reducer, and then output to the drive wheels via the output shaft.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show a vehicle power transmission device according to an embodiment of the present invention. This vehicle is a so-called FR vehicle in which the engine 1 is vertically mounted on the front part of the vehicle body and its output is transmitted via the drive system A to the rear wheels which are the drive wheels.

The drive system A has a first power transmission path A1.
And a second power transmission path A2, the first power transmission path A1 is provided with the torque converter 2 and the speed reducer 3, and the second power transmission path A2 is provided with a continuously variable transmission. Four
Is provided. Both power transmission paths A1 and A2 are
The path switching clutch 6 can be switched according to the operating state.

The torque converter 2 has an input shaft 21 and an output shaft (turbine shaft) arranged on the same axis.
22 and its input shaft 21 is connected to the output shaft (crank shaft) of the engine 1. A pump cover 23 is rotatably integrated with the input shaft 21, and the space inside the pump cover 23 is filled with oil as a working fluid. A pump impeller (also simply referred to as a pump) 24, a turbine liner (also simply referred to as a turbine) 25, and a stator 26 are arranged inside the pump cover 23. The pump impeller 24 serves as the pump cover 2
3, a turbine liner 25 is disposed so as to rotate integrally with the pump impeller 24, and the turbine liner 25 is coupled to the front end of the turbine shaft 22 so as to rotate integrally therewith.

The stator 26 is arranged between the pump impeller 24 and the turbine liner 25 and is first with respect to the front end of the first hollow shaft 27 which is arranged concentrically with the turbine shaft 22. Are connected via a one-way clutch 28. The pump impeller 24 is connected to the front end of a second hollow shaft 29 that is arranged concentrically with the turbine shaft 22 and the hollow shaft 27, and an oil pump 61 is attached to the middle portion of the shaft 29.

The speed reducer 3 comprises a double pinion type planetary gear device arranged on the same axis as the turbine shaft 22, and as shown in FIG. 3, a sun gear 3a, a ring gear 3b and a sun gear 3a. It has two internal and external planetary gears 3c and 3d that mesh with one gear between both gears 3a and 3b, and a carrier 3e that supports these planetary gears 3c and 3d. The sun gear 3a is
The sun gear 3a and the stator 26 of the torque converter 2 are connected to the rear end of the first hollow shaft 27 so as to rotate together.
And a first one-way clutch 28. The carrier 3e is connected to the rear end of the turbine shaft 22 via a second one-way clutch 33. Therefore, the carrier 3e and the turbine liner 25 of the torque converter 2 are connected to the second one-way clutch 33 and They are connected via the turbine shaft 22. Further, the ring gear 3b is connected to the output shaft 51 common to the first and second power transmission paths A1 and A2, and the output shaft 51 is arranged on the same axis as the turbine shaft 22. Therefore, the speed reducer 3 includes two input elements, the sun gear 3a and the carrier 3e, and one output element, the ring gear 3b.

The first hollow shaft 27 is
It is connected to the case 30 via a forward-moving brake 34 as a first fixing means. Therefore, the hollow shaft 27 and the stator 26 and the sun gear 3a, which are integrally rotated, are selectively fixed to the case 30 by the brake 34. It is supposed to be done. In addition, the carrier 3e is provided with the case 3 via a backward movement brake 35 as a second fixing means.
Therefore, the carrier 3e and the turbine liner 25, which is integrally rotated with the carrier 3e, are connected to the brake 3
5, it is selectively fixed to the case 30.

On the other hand, the continuously variable transmission 4 is disposed adjacent to the rear of the speed reducer 3, so that the torun converter 2, the speed reducer 3, and the continuously variable transmission 4 are provided in the engine 1. They are arranged in series on the output axis. The continuously variable transmission 4 is composed of two toroidal transmissions 41, 41, and these two toroidal transmissions 41, 41
41 is arranged in series on the outer periphery of the output shaft 51 as an axis.

Each of the toroidal type transmissions 41 has an input disc 42 rotatably provided on the output shaft 51, and an input disc 42 arranged to face the input disc 42 and integrally rotatable with the output shaft 51. Output disc 43 provided in
And a sliding roller 44 that is disposed between the disks 42 and 43 and that rotates while in contact with the disks 42 and 43 and is tiltable. The inclination angle θ of the sliding roller 44 is changed by a drive mechanism (not shown), and the gear ratio of the toroidal transmission 41 is changed accordingly. That is, the rotation of the input disk 42 is transmitted to the output disk 43 via the sliding roller 44, and the gear ratio at this time is such that the sliding roller 44 slides on the output disk 43 with the radius Ri where the sliding roller 44 makes sliding contact with the input disk 42. Corresponding to the ratio with the radius Ro of the contact point, when the sliding roller 44 is tilted, the sliding contact point is changed to change the gear ratio.

The above two toroidal type transmissions 41, 41
Are arranged with the input disk 42 inside and the output disk 43 outside. An intermediate disc 45 rotatable relative to the input discs 42, 42 is disposed between the input discs 42, 42 of the toroidal transmissions 41, 41. Cams 46 are respectively interposed between the disks 42, and as the input torque input to the input disks 42 increases, the pressing force of the cams 46 on the input disks 42 increases. There is.

The driving force (rotational force) is input to the continuously variable transmission 4 via a gear type power transmission mechanism 52 which constitutes a part of the second power transmission path A2. The power transmission mechanism 52 includes a turbine shaft 22 and an output shaft 51.
Has a bypass shaft 53 arranged in parallel with the first shaft 54, and a first gear 54 is provided at the front end of the bypass shaft 53.
The second gear 56 is linked to the gear 56, and is connected to the second hollow shaft 29 via the path switching clutch 6. A third gear 57 is provided at the rear end of the bypass shaft 53, and the third gear 57 is meshed with a fourth gear 58 that is provided integrally with the intermediate disc 45 so as to rotate together.

Next, the relationship between the engagement / release of the path switching clutch 6, the forward brake 34 and the reverse brake 35 and the operating state will be described with reference to Table 1 below.

[0025]

[Table 1] If the shift lever is in the neutral shift position,
All clutches 6 and brakes 34, 35 are released.

When the shift lever is in the forward shift position and is operating at low speed after starting, the path switching clutch 6 is released,
The forward brake 34 is engaged and the reverse brake 35 is released. As a result, the first power transmission path A1 is selected, and the stator 26 of the torque converter 2 is selected.
Is fixed to the case 30, the engine output is torque-amplified by the torque converter 2, and thereafter, is input from the turbine shaft 22 to the carrier 3e of the speed reducer 3 by positive rotation. At this time, the sun gear 3a of the speed reducer 3
Is fixed, the torque input to the speed reducer 3 is output to the rear wheels via the output shaft 51 from the ring gear 3b while being decelerated by the speed reducer 3 while being rotated forward.

When shifting from the start or low speed operation to the medium or high speed operation, the forward brake 34 and the reverse brake 35 remain unchanged, and the path switching clutch 6 is switched from the released state to the engaged state. As a result, the second power transmission path A2 is selected, and the engine output is input to the continuously variable transmission 4 via the clutch 6 and the power transmission mechanism 52 while bypassing the torque converter 2. In the continuously variable transmission 4, the torque is changed to an appropriate gear ratio according to the driving state, and thereafter, the torque is output to the rear wheels through the output shaft 51 in the positive rotation. At this time, the first and second one-way clutches 28 and 33 are in a rotation-free state, and the turbine liner 25 and the stator 26 of the torque converter 2 both idle.

When the shift lever is in the reverse shift position, the path switching clutch 6 is released, the forward brake 34 is released, and the reverse brake 45 is engaged. As a result, the first power transmission path A1 is selected and the turbine liner 25 of the torque converter 2 is fixed to the case 30, so that the engine output is between the pump impeller 24 and the stator 26 of the torque converter 2. The direction of rotation is reversed, and then the first hollow shaft 27
Input to the sun gear 3a of the speed reducer 3. At this time, since the carrier 3e of the reduction gear transmission 3 is fixed,
The torque input to the speed reducer 3 is output from the ring gear 3b to the rear wheel via the output shaft 51 while being reversely rotated while being decelerated by the speed reducer 3.

Therefore, in the above embodiment, the first
When the power transmission path A1 is selected and the engine output is transmitted to the rear wheels via the torque converter 2 and the speed reducer 3, the torque converter 2 selectively decelerates the torque in the forward rotation direction and the torque in the reverse rotation direction. Since it is input to the device 3, the deceleration device 3 only needs to exhibit the deceleration function.
It is not necessary to have the function of switching the rotation direction. Therefore, the speed reducer 3 can be configured by using one planetary gear device, and the configuration can be simplified and downsized.

Further, the torque converter 2, the speed reducer 3, and the continuously variable transmission 4 are arranged in series on the output axis of the engine 1, and the continuously variable transmission 4 and the input disk 42 on the output shaft 51 are arranged. Since it is of a toroidal type in which the gear ratio is variable by changing the inclination angle θ of the sliding roller 44 with respect to the output disk 43, the overall diameter of the power transmission device can be shortened, and the reduction gear transmission can be made compact. Combined with this, the overall size of the power transmission device can be reduced.

[0031]

As described above, according to the power transmission device for a vehicle of the present invention, when the engine output is transmitted to the drive wheels through the torque converter and the speed reducer, the torque converter rotates in the forward rotation direction and reversely rotates. Since the torque in the direction can be selectively taken out, the speed reducer only needs to exhibit the speed reducing function, and the structure can be simplified and downsized.

In particular, according to the second aspect of the invention, the speed reducer is composed of a planetary gear device having a short axial length dimension, so that the size reduction can be further achieved.

According to the third aspect of the invention, since the continuously variable transmission is constructed by using the toroidal type transmission having a smaller diameter than the belt type transmission, the reduction gear transmission can be made compact. Combined with this, the overall size of the power transmission device can be reduced.

[Brief description of drawings]

FIG. 1 is a skeleton diagram of a vehicle power transmission device according to an embodiment of the present invention.

FIG. 2 is a block configuration diagram of the same.

FIG. 3 is a schematic view of a double pinion type planetary gear device.

FIG. 4 is a view corresponding to FIG. 1 showing an example of a prior application.

[Explanation of symbols]

 A drive system A1 first power transmission path A2 second power transmission path 1 engine 2 torque converter 3 speed reducer 3a sun gear (input element) 3b ring gear (output element) 3e carrier (input element) 4 continuously variable transmission 25 turbine Liner 26 Stator 30 Case 34 Forward brake (first fixing means) 35 Reverse brake (second fixing means) 41 Toroidal type transmission 42 Input disk 43 Output disk 44 Sliding roller 51 Output shaft

Claims (3)

[Claims] 1. A drive system for transmitting engine output to drive wheels has first and second power transmission paths that are switched according to operating conditions, and a torque converter and a speed reducer are provided on the first power transmission path. And a continuously variable transmission is arranged in the second power transmission path, the speed reducer has two input elements and one output element. One of the input elements is connected to the stator of the torque converter, the other input element is connected to the turbine of the torque converter, and the output element is connected integrally to the output shaft common to the first and second power transmission paths. And a first and second fixing means for selectively fixing the stator and the turbine to the case, respectively. 2. The speed reducer comprises one double pinion type planetary gear unit, the sun gear of which is connected to the stator of the torque converter, the carrier of which is connected to the turbine of the torque converter, and the ring gear of which is connected to the output shaft so as to rotate integrally. 2. The vehicle power transmission device according to claim 1. 3. The torque converter, the speed reducer and the continuously variable transmission are arranged in series on the same axis, and the continuously variable transmission is an input rotatably fitted to an output shaft. A disc and an output disc fixed to the output shaft,
2. A toroidal transmission having a sliding roller disposed so as to be tiltable between the both disks, and a gear ratio being changed by changing a tilt angle of the sliding roller. Vehicle power transmission device.