JP2736534B2 - Automatic transmission for four-wheel drive - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a four-wheel drive automatic transmission having four forward speeds.

[Conventional technology]

2 at the rear of the main transmission with starting and planetary gear
An automatic transmission in which an auxiliary transmission for switching between wheel drive and four-wheel drive is connected is disclosed in, for example, Japanese Patent Application Laid-Open No. 61-160664.

The automatic transmission disclosed in the above publication has a transmission having a forward fourth speed and a reverse first speed as a main transmission, and an auxiliary transmission device includes a reduction gear and a transfer device for switching between two-wheel drive or four-wheel drive. Have.

Accordingly, an automatic transmission having a high forward speed of four speeds and a reverse speed of one speed at the time of two-wheel drive, and an automatic transmission having the same high speed as at the time of two-wheel drive, at the time of four-wheel drive In addition, the speed reducer is activated to move forward at low speed 4 speeds
It can be used as an automatic transmission having a high speed.

[Problems to be solved by the invention]

However, since the automatic transmission has a support wall at the rear end of the main transmission that receives the reaction force of the friction engagement element, the output member of the main transmission is connected to the input of the auxiliary transmission device. In order to connect to the member, a connecting member radially extended between a ring gear which is an output member of the main transmission and a second intermediate transmission shaft 301 which is connected to a sun gear which is an input member of the auxiliary transmission. , And the size of the transmission in the axial direction increases accordingly.

Further, as disclosed in Japanese Patent Application Laid-Open No. 63-242731, there is a device in which a differential device 40 is provided as an auxiliary transmission device. In this technology, however, a ring gear and a main output shaft which are input members of the differential device are also provided. In order to connect with 34,
It requires a connecting portion 35E extending in the radial direction between the shaft 34 and the ring gear. Therefore, the axial dimension increases accordingly.

Therefore, the present invention provides a support wall disposed between the main transmission and the auxiliary transmission at the front end of the main transmission, and reduces the axial dimension between the main transmission and the auxiliary transmission. It is an object of the present invention to provide a compact full-time four-wheel drive automatic transmission with a center differential.

[Means for solving the problem]

In order to solve the above problems, the present invention relates to an automatic transmission in which a main transmission having a starting device and a planetary gear device and an auxiliary transmission device are connected in series, and a case (30) of the main transmission and a main transmission are provided. The case (360) of the transfer device fitted to the rear of the case (30) of the machine, the rear end of the input shaft (28) supported on the front of the case (30) of the main transmission, and the main transmission. An intermediate shaft (55) rotatably supported at the front end of a first output shaft (120) supported at the rear of the machine case (30);
A main transmission comprising a planetary gear set disposed on the outer periphery of the input shaft (28) and the intermediate shaft (55), and concentrically disposed on the outer periphery of the first output shaft (120). The second output shaft (1
85), wherein the main transmission is composed of a planetary gear device having a ring gear (96) as an output member that achieves a forward fourth speed and a reverse first speed. In the four-wheel drive automatic transmission, a carrier (161) of a planetary gear set integrally supported on a ring gear (96) of the planetary gear set, which is an output member of the main transmission, is used as an input member, and the second output shaft is provided. The planetary gear unit sun gear (170) connected to the first output shaft (120) and the planetary gear unit having the planetary gear unit ring gear (165) connected to the first output shaft (120) as an output member; A clutch (175) which is provided concentrically with the first output shaft (120), and which allows the first output shaft (120) and the second output shaft (185) to be freely disengaged from each other; The ring gear (165) of the planetary gear unit which is the output member of the transmission And a carrier (161) which is an input member of the auxiliary transmission device including a planetary gear device, is disposed on the outer peripheral side of the main transmission and the auxiliary transmission device, and is axially connected by a drum (95) type connection member; The first output shaft (120) is connected to one drive device of a front wheel or a rear wheel, and the second output shaft (185) is connected to the other drive device of a front wheel or a rear wheel. The present invention relates to an automatic transmission for wheel drive.

The reference numerals in parentheses above are for comparison with the drawings, but do not limit the configuration in any way.

〔Example〕

 An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a cross section of an automatic transmission according to the present invention. The automatic transmission generally designated by reference numeral 1 comprises a torque converter 2 as a starting device and a transmission 3. The transmission 3 includes a main transmission having a Ravigneaux type planetary gear set and an auxiliary transmission. The torque converter 2 is provided in a case 20, and includes a drum-shaped converter case 21 connected to a crankshaft of the engine at the forefront (hereinafter, the side closer to the engine is referred to as "front side"). Converter case 21
Connects and drives the engine crankshaft and the pump impeller 22, and the hydraulic oil pressurized by the pump impeller 22 drives the turbine runner 27 and returns to the pump impeller 22 through the stator 23. The turbine runner 27 drives a turbine shaft 28 directly connected thereto.

The stator 23 is supported by a fixed portion via a one-way clutch 24, and is provided with a turbine runner 27 and a drum-shaped converter case.
A lock-up piston 25 is disposed between the lock-up pistons 21 and, when necessary, a lock-up clutch 26 between the lock-up piston 25 and the converter case 21 is operated to operate a shaft 28 which is both a turbine output shaft and an input shaft of a transmission. And the converter case 21 are directly connected. Torque converter 2 case 20
And an oil pump cover 31, a partition plate 32, and an oil pump housing
Place 33.

The oil pump cover 31 includes a face plate-like portion having an oil passage and the like inside and a boss portion whose center portion projects rearward. Divider
An oil pump 32 supports the side surface of the rotating body of the oil pump 29 and defines an oil passage and the like. The oil pump 29 is formed in an oil pump housing 33.

A support cylinder 34 is provided on the inner periphery of the boss of the oil pump cover 31.
The support cylinder 34 supports the input shaft 28 of the transmission at the inner peripheral portions at the front and rear ends thereof. A first clutch drum 40 is integrally connected to the rear end of the input shaft 28. The clutch drum 40 is supported by a boss portion of the oil pump cover 31, and is provided with a first clutch 41 which is a forward clutch and a second clutch 52 which is a direct clutch inside the clutch drum 40.

The clutch hub 43 of the first clutch 41 also functions as the outer race of the first one-way clutch 45, and the inner race 47 is formed integrally with the large sun gear shaft 48. The hub 53 of the second clutch 52 is connected to the intermediate shaft 55.
The input shaft 28 is supported by a bearing on the inner periphery of the rear end.

A second clutch drum 60 is connected to the rear of the first clutch drum 40, and a fifth clutch 65, which is a coast clutch, is provided inside the second clutch drum 60.
The hub 67 of the fifth clutch 65 is connected to the inner race 47 of the first one-way clutch 45.

The rear of the second clutch drum 60 forms a clutch hub 74, between which a third clutch 73, which is a reverse clutch, is provided. The clutch drum 75 also functions as the brake drum of the first brake 71. The two clutch drums 60 and 75 have a central support member 35.
, And the drum 75 rotates integrally with the small sun gear shaft 77 via the hub 771.

The intermediate shaft 55 supports the large sun gear shaft 48, and the large sun gear shaft 48
Adopts a configuration for supporting the small sun gear shaft 77, so that this shaft portion has a triple shaft structure.

The rear side of the flange portion of the central support member 35 forms a cylinder, in which a piston for operating the third brake 93 is fitted. An iron sleeve 38 is press-fitted into the inner diameter portion of the central support member 35, and the rear end of the sleeve 38 is formed in a ring shape to form an inner race 92 of the second one-way clutch 90.
Press-fit. Outer race 91 of second one-way clutch 90
Serves also as a hub of the third brake 93, and a brake disk is spline-engaged with an outer peripheral portion thereof. The brake plate of the third brake 93 is fitted on the inner periphery of the case 30 with splines.

A ring member is fixed to the rear side of the outer race 91 of the second one-way clutch 90, and the pinion shaft 81 and the pinion shaft of the Ravigneaux type planetary gear train 80 are fixed between the ring member and the carrier 54 of the intermediate shaft 55. Supports 83. A plurality of these pinion shafts 81 and 83 are provided, and the pinion shaft 81 carries a long pinion 82, and the pinion shaft 83 serves as a short pinion 84.
I support. The short pinion 84 meshes with the small sun gear 78 and the ring gear 96, and the long pinion 82
Meshes with the large sun gear 49.

As described above, this automatic transmission mechanism has a Ravigneaux type planetary gear device using a ring gear as an output member, and four clutches, two brakes and two one-pieces as friction engagement elements for operating the same. A directional clutch is provided to achieve the fourth forward speed and the first reverse speed.

The friction engagement element is supported by a support member fixed to a case of the transmission, and the Ravigneaux type planetary gear device has an intermediate shaft,
It is supported by a large sun gear shaft and a small sun gear shaft supported by the intermediate shaft.

Next, a ring gear with a center differential is used as an input member with another ring gear integrated with the ring gear which is the output member of the transmission mechanism.
An auxiliary transmission for wheel drive is connected in series.

A groove for a parking brake is formed on the outer peripheral portion of a drum 95 formed with a ring gear 96 of the Ravigneaux type planetary gear device 80 at one end.
955, which together with the pawl 150 form a parking brake.

The other end of the drum 95 is connected to a carrier 161 of a center differential device 160 constituting an auxiliary transmission, and the carrier 161 supports a pinion 163 via a pinion shaft 162. Pinion
163 meshes with the ring gear 165 on the outer peripheral side.
165 is integrally fitted to the first output shaft 120. On the other hand, the inner peripheral side of the pinion 163 meshes with the sun gear 170, and the sun gear 170
Is connected to a stepped cylindrical sun gear shaft 171.

The sun gear shaft 171 has a large diameter inner peripheral portion supported by a support member 180.
It is supported rotatably. The support member 180 forms an oil passage or the like, and is inserted and fixed in a hole formed in the rear wall 305 of the transmission case 30.

A clutch drum 172 is provided on the outer periphery of the rear end of the sun gear shaft 171. A center deflector clutch 175 is provided between the inner periphery of the clutch drum 172 and a hub 166 formed at the rear of the support shaft 162 of the pinion 163. In the clutch drum 172, there are provided pistons 176, 177 for operating the center deflective clutch 175, and a sliding member 178 for transmitting the operation of these pistons to the clutch.

The inner peripheral portion of the sun gear shaft 171 is connected to a second output shaft 185 having a sprocket 186 formed at the rear. The front outer peripheral portion of the second output shaft 185 is supported via a bearing by a sleeve 181 pressed into the inner peripheral portion of the support member 180. The inner peripheral portion of the front end of the second output shaft 185 is connected to the first output shaft 120.
Support the front of the. An inner peripheral portion of the front end of the first output shaft 120 supports a rear end of the intermediate shaft 55.

A bracket 303 is fitted to the rear end of the transmission case 30. Since the bracket 303 is fixed to the case 30 via the in-row engaging portion 302, the concentric accuracy between the case 30 and the bracket 303 is high. This bracket 303 has a rear case 301
Is attached to the case 360 of the transfer device
To form The case 360 of the transfer device includes a wall 362 facing the bracket 303 and a rear case 301 extending rearward along the axis of the transmission. The space formed by the bracket 303 and the wall 362 of the case 360 of the transfer device is
It has an upper room 310 and a lower room 315, and an upper room 310
The rear end of the second output shaft 185 is supported by a bearing on the rear wall surface. The rear end of the first output shaft is supported by the rear end of the rear case 301 via a bearing.

A sprocket shaft 340 is supported at two fulcrums via bearings in a room 315 below the case 360 of the transfer device.

The first output shaft 120 is connected to an axle shaft of a rear wheel via a connecting member 135. Sprocket 186 of the second output shaft 185
Is connected to a sprocket shaft 340 supported in a lower chamber 315 by a chain (not shown), and the sprocket shaft 340 is connected to a driving device for a front wheel.

Since the automatic transmission is configured as described above, the driving force of the main transmission output to the drum 95 is input to the carrier 161 of the center differential device 160. Carrier 161 is shaft 162
The ring gear 165 and the sun gear 170 are driven by the orbit of the pinion 163 via the. At this time, if the center deflector clutch 165 is detached, the hub 166 attached to the carrier 161 and the drum 172 of the sun gear shaft 171 rotate freely with each other, so that the driving force of the carrier 161 is equal to the effective diameter of the ring gear 165 and the sun gear. The torque is output to the first output shaft 120 and the second output shaft 185 with a torque distribution according to the effective diameter of 170.

The distribution of the driving torque is usually performed by the first driving of the rear wheels.
70% to the output shaft 120, to the second output shaft 185 that drives the front wheels
Adopt a ratio of about 30%. Then, when one of the front and rear wheels is decelerated due to an increase in load or the like, the pinion 163 of the center differential device 160 revolves with the revolution and exhibits an operation function, thereby increasing the speed of the other drive wheel. With this function, smooth four-wheel drive can be achieved.

However, if the frictional engagement force between one of the front and rear wheels and the road surface suddenly increases or decreases, the driving force to the other wheel becomes excessive and slips, or the driving force becomes insufficient. Occurs. In such a situation, the center delock clutch 175 is operated to stop the relative rotation between the carrier 161 and the sun gear 170. As a result, the center differential device 160 is driven directly at the same speed of the front and rear wheels in a directly connected state.

〔The invention's effect〕

The four-wheel drive automatic transmission of the present invention employs a shaft support structure in which the input shaft and the output shaft are securely supported by the case of the transmission, and the intermediate shaft is supported by the input shaft and the output shaft. The input shaft, the intermediate shaft, and the output shaft which are arranged in series can be reliably supported. Then, the planetary gear device of the main transmission is disposed at the rear of the case of the transmission, and the frictional engagement elements such as the clutch to be employed are collectively disposed at the front of the planetary gear device. The rear side does not need a wall to receive the reaction force of the friction engagement element. According to the present invention, a carrier of a planetary gear unit integrally supported on a ring gear of a planetary gear unit, which is an output member of the main transmission, is input into a case of the main transmission by utilizing the above-described characteristics of the main transmission. The auxiliary transmission device comprises a planetary gear set having a sun gear of a planetary gear set connected to the second output shaft and a ring gear of the planetary gear set connected to the first output shaft as an output member. A center differential device is provided concentrically with the output shaft, and a clutch that enables the first output shaft and the second output shaft to freely engage with each other can be formed as a center differential clutch. Since the device is a planetary gear device in which a ring gear 165 concentric with the first output shaft 120 is used as an output gear, the device has good concentricity and operability, and is connected to the ring gear 96 of the planetary gear device, which is an output member of the main transmission. Output The driving force of the main transmission drives the planetary gear device as the auxiliary transmission. At this time, if the clutch 175 as the center deflective clutch is disengaged, the driving force becomes the effective diameter of the ring gear 165 and the sun gear 170. Are output to the first output shaft 120 and the second output shaft 185 with a torque distribution according to the effective diameter of
This drive torque distribution is normally 70% to the first output shaft 120 driving the rear wheels and 30% to the second output shaft 185 driving the front wheels.
Adopt ratio of degree. Then, when one of the front and rear wheels is decelerated due to an increase in load or the like, the pinion 163 of the planetary gear device rotates with the revolution and exhibits an operation function,
Increase the speed of the other drive wheel. With this function, smooth four-wheel drive can be achieved. However, if the frictional engagement force between one of the front and rear wheels and the road surface increases or decreases rapidly, the driving force to the other wheel becomes excessive, slipping occurs, and the driving force becomes insufficient. Occurs. In such a situation, when the clutch 175 is operated to stop the relative rotation between the first output shaft 120 and the second output shaft 185, the planetary gear unit is directly connected, and the front and rear wheels are connected. It can be driven at a constant speed. A ring gear 96 of a planetary gear unit, which is an output member of the main transmission, and a carrier 16 which is an input member of the auxiliary transmission device, which comprises a planetary gear unit.
1 is arranged on the outer peripheral side of the main transmission and the auxiliary transmission and is axially connected by a drum 95 type connecting member, so that when the main transmission and the auxiliary transmission are connected, they extend in the radial direction. The automatic transmission for the full-time four-wheel drive can be reduced as a whole without the need for the extended connecting member, thereby reducing the axial dimension between the main transmission and the auxiliary transmission. Therefore, the present invention is particularly suitable as an automatic transmission for a passenger car.

[Brief description of the drawings]

FIG. 1 is a sectional view of an automatic transmission for four-wheel drive with four forward speeds and one reverse speed. 2 ... Torque converter, 3 ... Transmission, 28 ... Input shaft, 30 ... Transmission case, 48 ... Large sun gear shaft, 55 ... Intermediate shaft, 77 ... Small sun gear shaft, 80 ... Ravigneaux type Planetary gear device, 95, drum, 120, output shaft, 135, connecting member, 160, center differential device, 175, center deflector clutch, 185, second output shaft, 186, sprocket, 301 …… Rear case, 302 …… In row engaging part, 303 …… Bracket, 305 …… Back wall, 310 …… Upper room, 315 …… Lower room, 340 …… Sprocket shaft, 360 …… Transfer device Case.

Continuation of the front page (72) Inventor Koji Noda 10 Takane, Fujii-machi, Anjo-shi, Aichi Prefecture Inside Aisin A. Daville Co., Ltd. (56) References JP-A-60-236841 (JP, A) JP-A-63- 242731 (JP, A)

Claims (2)

(57) [Claims] An automatic transmission in which a main transmission having a starting device and a planetary gear device and an auxiliary transmission device are connected in series, and a transfer device fitted to a case of the main transmission and a rear portion thereof. And a front end of a first output shaft supported by a rear end of an input shaft supported on a front portion of a case of the main transmission and a rear end of a case of the main transmission, respectively, and are rotatable. And a main transmission comprising a planetary gear set disposed on the outer periphery of the input shaft and the intermediate shaft, and a second transmission disposed concentrically on the outer periphery of the first output shaft. An auxiliary transmission device disposed on an outer peripheral portion of an output shaft, wherein the main transmission is a four-wheel drive automatic transmission including a planetary gear device having a ring gear of a planetary gear device as an output member for achieving a plurality of shift speeds. And a ring gear of a planetary gear unit, which is an output member of the main transmission. A planetary gear having a carrier of the connected planetary gear set as an input member, a sun gear of the planetary gear set connected to the second output shaft, and a ring gear of the planetary gear set connected to the first output shaft as an output member; The auxiliary transmission device comprising a device is provided concentrically with the first output shaft,
A clutch for making the first output shaft and the second output shaft freely engageable and disengageable, wherein the auxiliary transmission device includes a ring gear of a planetary gear device and a planetary gear device, which are output members of the main transmission. A carrier as an input member is arranged on the outer peripheral side of the main transmission and the auxiliary transmission device and is axially connected by a drum-type connecting member, and the first output shaft is connected to one of a front wheel or a rear wheel driving device. An automatic transmission for four-wheel drive, wherein the second output shaft is connected to the other drive device of the front wheel or the rear wheel. 2. The four-wheel drive automatic transmission according to claim 1, wherein said clutch is configured to be able to engage and disengage a carrier and a sun gear of said auxiliary transmission.