JP3080761B2 - Power transmission device for four-wheel drive vehicle - Google Patents

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 four-wheel drive vehicle.

[0002]

2. Description of the Related Art In a four-wheel drive vehicle based on a front wheel drive vehicle in which an engine is mounted horizontally and a transmission is arranged in series via a clutch or a torque converter on one side in the vehicle width direction of the engine, For example, Shokai 62
As disclosed in JP-A-44730, a multi-plate friction clutch operated by an external hydraulic control is provided coaxially with the front axle on the outer periphery of the front axle to limit and prevent the differential of the center differential. An arranged four-wheel drive is known.

Further, in a four-wheel drive vehicle based on a front-wheel drive vehicle in which an engine is mounted horizontally, a friction clutch as described above is used to transmit the driving force of the engine to a rear-wheel drive system as needed. A power transmission device arranged coaxially with a front axle as a transfer clutch has also been proposed.

In the four-wheel drive disclosed in the above publication, an inner cylindrical shaft and an outer cylindrical shaft are independently rotatably and coaxially fitted on the outer periphery of the front axle.
A friction plate of a friction clutch is attached to each of these cylindrical shafts, the inner cylindrical shaft is connected to one side gear of a center differential so as to transmit rotation, and the outer cylindrical shaft is capable of transmitting rotation to a center differential case. Are linked. Further, a ring gear composed of a bevel gear or a hypoid gear for converting the rotation of the outer cylindrical shaft by 90 ° and transmitting the rotation to the rear wheel drive system is coaxially fixed to the outer cylindrical shaft. The ring gear is disposed on the center differential side (transmission side) of the friction clutch in the case of the friction clutch and close to the hydraulic clutch, and includes a pinion gear that meshes with the ring gear. The driving force of the engine is transmitted to the rear wheel drive system via the rear wheel drive system.

[0005]

By the way, the engine is mounted horizontally and the transmission is arranged in series via a clutch (in the case of a manual transmission) or a torque converter (in the case of an automatic transmission). In a vehicle, a housing of a clutch or a torque converter protrudes more rearward than an engine and a transmission case. Therefore, when the friction clutch of the hydraulic control is arranged coaxially with the front axle, the friction clutch avoids the protrusion of the clutch housing or the torque converter housing and is located closer to the engine (transmission side) than the protrusion. On the other side).

On the other hand, an exhaust pipe that emits high heat is led out from the engine to the rear, and a catalytic converter is arranged in the middle of the exhaust pipe. Therefore, when a ring gear for converting the driving force of the engine by 90 ° and transmitting the same to the rear wheel drive system is provided closer to the transmission than the friction clutch and close to the friction clutch, the ring gear is also mounted on the housing. Therefore, the friction clutch may further project toward the engine, and may be damaged by heat from the exhaust system.

Accordingly, the present invention reduces heat damage from the exhaust system to the friction clutch when the friction clutch is disposed coaxially with the front axle and closer to the engine than the clutch housing or the converter housing. It is an object of the present invention to provide a power transmission device for a four-wheel drive vehicle that can perform the following.

[0008]

A power transmission device for a four-wheel drive vehicle according to the present invention receives the output of a transmission,
A first ring gear for transmitting a driving force to a first axle (for example, a front axle);
A friction clutch arranged coaxially with the axle;
The first axle is disposed coaxially with the first axle between the ring gear and the friction clutch and on the transmission side with respect to the projection of the clutch housing or the torque converter housing. And a second ring gear for transmitting a driving force to the axle.

[0009]

In the power transmission device for a four-wheel drive vehicle according to the present invention, the second ring gear for converting the engine driving force in the direction of 90 ° and transmitting it to the second axle side is formed by a projecting portion of the clutch housing or the torque converter housing. Also arranged on the transmission side, it is possible to provide a sufficient distance between the friction type clutch and the exhaust system.Thus, it is possible to reduce the heat damage that the friction type clutch receives from the exhaust system, and to reduce the friction type clutch. It is possible to reduce the size of the unit that includes it.

Further, in the case where the transmission is an automatic transmission, if the friction clutch is constituted by a hydraulic clutch, the hydraulic control system of the hydraulic clutch and the hydraulic control system of the automatic transmission can be shared. In case,
Bringing the hydraulic clutch closer to the transmission also has the effect of improving control responsiveness.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the skeleton diagram of FIG. In FIG. 1, reference numeral 1 denotes an engine mounted horizontally on a front portion of a vehicle body, and is arranged so that a crankshaft 2 extends in a vehicle width direction and is led out to the side of the engine 1.

A clutch housing 4 for housing the clutch 3 and a transmission case 6 for housing a manual transmission 5 arranged in series with the engine 1 are connected to the left side of the engine 1. The transmission 5 includes a primary shaft (input shaft) 7 connected to the crankshaft 2 of the engine 1 via the clutch 3, a secondary shaft (output shaft) 8 arranged in parallel with the shaft 7, and both of these shafts. The speed change gear train 9 is provided between the gears 7 and 8 for the 1st to 5th speeds and the reverse. And clutch 3
The rotation of the crankshaft 2 of the engine 1 transmitted to the primary shut 7 via the gears is shifted to the secondary shaft 8 by selective engagement of each gear of the transmission gear train 9, and is transmitted to the secondary shaft 8. The drive signal is output from a drive gear 10 fixed to the end of the shaft 8 on the engine 1 side. The drive gear 10 meshes with a first ring gear 13 made of a spur gear fixed to a differential case 12 of a front wheel differential 11.

The front wheel differential device 11 includes pinion gears 15 and 16 rotatably supported on a pinion shaft 14 provided in a differential case 12 and a pair of side gears 17 and 18 meshing with the pinion gears 15 and 16. A relatively short left front axle 19 is spline-coupled to one side gear 17, and a relatively long right front axle 20 is spline-coupled to the other side gear 18. And left front axle
19, the left front wheel drive shaft 32 through the constant velocity joint 31
And a right front wheel drive shaft 34 is connected to the right front axle 20 via a constant velocity joint 33.

On the outer periphery of the right front axle 20, an inner cylindrical shaft 21 is disposed coaxially with the right front axle 20 so as to be rotatable relative to the right front axle 20, and a left end of the inner cylindrical shaft 21 is a differential for a front wheel. It is connected to a differential case 12 of the device 11. Furthermore, the inner cylindrical shaft 21
An outer cylindrical shaft 22 is disposed coaxially with the shafts 20 and 21 so as to be rotatable relative to the shafts 20 and 21 to form a triple shaft. The two cylindrical shafts 21 and 22 extend to the engine 1 side from the mounting surface 4a of the clutch casing 4 with respect to the engine 1, and a friction clutch 23 is mounted on this extended portion.

The friction clutch 23 includes a plurality of friction plates that mesh with spline teeth formed on the outer peripheral surface of the outer cylindrical shaft 22.
23a and a cup-shaped body coaxially fixed to the inner cylindrical shaft 21
A plurality of friction plates 23 meshing with spline teeth formed on the inner peripheral surface of 23b and arranged alternately with the friction plates 23a
c, and in the case of a hydraulic clutch, it is operated by an external hydraulic control to press the friction plates 23a and 23c to
And a casing 23d in which these elements are accommodated. When the hydraulic clutch 23 is engaged, the two cylindrical shafts 21 and 22 rotate integrally.

Engine 1 and transmission case 6
The right side front axle 20, which constitutes the triple shaft, and a projection 4b projecting toward the inner and outer cylindrical shafts 21, 22 are formed in the clutch housing 4 interposed therebetween. Are arranged in such a manner that a part of a casing 23d of the friction clutch 23 enters into a concave portion 24 formed on the engine 1 side by the projecting portion 4b.

A friction clutch is provided on the outer periphery of the outer cylindrical body 22.
A second bevel gear or a hypoid gear for converting the output of the transmission 5 transmitted to the outer cylindrical shaft 22 to a direction of 90 ° and transmitting the output to the rear wheel side in accordance with the engagement of the second gear 23.
The ring gear 25 is the first ring gear 13 and the friction clutch
It is fixed in the position between 23. Second ring gear 25
Is mounted coaxially to the outer tubular body 22 with its tooth surface facing the hydraulic clutch 23 toward the transmission 5 from the protrusion 4b of the clutch housing 4 and extends to the rear of the vehicle body with the second ring gear 25. A pinion gear 27 having a power transmission shaft 26 is engaged. The power transmission shaft 26 is connected to a rear wheel differential (not shown) via a universal joint 28 and a propeller shaft 29.
Therefore, when the friction clutch 23 is engaged, the output of the transmission 5 is also transmitted to the rear wheel side to be in a four-wheel drive state, and when the friction clutch 23 is released, power transmission to the rear wheel is cut off. To a two-wheel drive (front-wheel drive) state.

The engine 1 is provided with a friction clutch
An exhaust pipe 35 that passes through the side of the exhaust pipe 35 at a required distance from the clutch 23 is led out rearward, and a catalytic converter 36 provided in the middle of the exhaust pipe 35 is disposed rearward of the friction clutch 23. The clutch 23 is arranged at a required interval.

The above is the configuration of the embodiment of the power transmission device for a four-wheel drive vehicle according to the present invention. According to this embodiment, the second ring gear 25 for transmitting the driving force to the rear wheel side is provided in the clutch housing 4. Is disposed closer to the transmission 5 than the projecting portion 4b, the friction type clutch 23 can be moved toward the transmission 5 by the space occupied by the second ring gear 25, thereby reducing the size of the transfer unit. As a result, it is possible to reduce the heat damage to the friction clutch 23 from the exhaust system while ensuring the serviceability of the friction clutch 23 by providing the friction clutch 23 at the end of the cylindrical shafts 21 and 22. .

In the embodiment described above, the transmission 5 is a manual transmission, and the clutch 3 operated by a clutch pedal is interposed between the engine 1 and the transmission 5. Instead of this, the present invention can also be applied to a configuration in which a torque converter is interposed between the automatic transmission and the torque converter housing has a protrusion, in which case, the second ring gear 25 is provided at a position smaller than the protrusion of the torque converter housing. It may be arranged on the transmission side. In this case, if the friction clutch 23 is constituted by a hydraulic clutch operated by an external hydraulic control, the control system of the hydraulic clutch and the hydraulic control system of the automatic transmission can be shared, and the hydraulic pressure The controllability of the hydraulic clutch can be improved by the configuration in which the clutch is brought closer to the transmission side.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram showing a configuration of a power transmission device of a four-wheel drive vehicle according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 3 Clutch 4 Clutch housing 4b Clutch housing protrusion 5 Transmission 7 Primary shaft 8 Secondary shaft 9 Transmission gear assembly 11 Front wheel differential 12 Differential case 13 First ring gear 19 Left front axle 20 Right front axle 21 Inner cylindrical shaft 22 Outer cylindrical shaft 23 Friction clutch 25 Second ring gear

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-63-315327 (JP, A) JP-A-64-1628 (JP, A) JP-A-64-60436 (JP, A) 5245 (JP, A) Japanese Utility Model Showa 62-84527 (JP, U) Japanese Utility Model Showa 62-44730 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 17/28-17 / 36

Claims (2)

(57) [Claims] An engine is mounted horizontally, and a transmission is connected in series to one side in the vehicle width direction of the engine via a clutch or a torque converter.
In a wheel drive vehicle, a first ring gear that receives an output of the transmission and transmits a driving force to a first axle; and is disposed coaxially with the first axle on an engine side of a protrusion of a housing of the clutch or the torque converter. A friction type clutch, disposed between the first ring gear and the friction type clutch, and on the transmission side of a projection of the clutch housing or the torque converter housing on the transmission side, coaxially with the first axle, A power transmission device for a four-wheel drive vehicle, comprising: a second ring gear that transmits driving force to a second axle when the friction clutch is engaged. 2. The power transmission device for a four-wheel drive vehicle according to claim 1, wherein said friction clutch comprises a hydraulic clutch controlled by hydraulic pressure.