JP3047306B2 - 4-wheel drive vehicle with center differential device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a four-wheel drive vehicle provided with a center differential device, and more particularly to lubrication of an automatic transmission, a center differential device, and a hydraulic multi-plate clutch device sequentially arranged in a drive train.

[0002]

2. Description of the Related Art In recent years, as a four-wheel drive vehicle equipped with a center differential device, a torque converter having a lock-up clutch in a drive system, an automatic transmission, and a center differential device are arranged. And the center differential device is configured as a composite planetary gear, and a plurality of hydraulic multi-plate clutches, and a hydraulic multi-plate clutch device with a brake are attached to provide a differential function and a torque dividing function to front and rear wheels, It has already been proposed by the present applicant that the driving performance, maneuverability, stability, braking performance, etc. are further improved by variably controlling the torque distribution to the front and rear wheels or by using it as a deceleration or speed increasing device. .
In such a drive system, it is conceivable that the lubrication of the center differential device and the hydraulic multi-plate clutch device is commonly performed by using the same AT oil as that of the automatic transmission. Therefore, it is required that the lubrication path be appropriately routed and that each part be properly lubricated with a compact structure.

Conventionally, lubrication of a four-wheel drive vehicle with a center differential device is disclosed in, for example,
There is prior art in 274161. Here, oil is supplied from a torque converter to a forward sun gear and a pinion shaft of an automatic transmission via an oil cooler, oil is supplied to each gear from a forward sun gear, and lubrication is performed by supplying oil to a center differential device from a pinion shaft. Have been.

[0004]

The prior art described above relates to a case where the number of gears of the automatic transmission, the gears of the center differential device, the hydraulic multi-plate clutch and the like are relatively small, and these are increased. If they do, they cannot adapt. In particular, in the case of a center differential device having multiple functions, the structure of itself and the hydraulic multi-plate clutch device attached thereto become as complicated as an automatic transmission. Is required.

The present invention has been made in view of this point, and has a drive system in which an automatic transmission is combined with a center differential device, a hydraulic multiple disk clutch and a hydraulic multiple disk clutch device having a multiple disk type brake. It is an object of the present invention to sufficiently lubricate them with a compact structure.

[0006]

In order to achieve the above object, the present invention provides a torque converter having a lock-up clutch, an automatic transmission, a center differential device, and a hydraulic system having a plurality of hydraulic multi-plate clutches and multi-plate brakes. In a drive system in which a multi-plate clutch device is coaxially arranged, a first lubrication path from a converter pressure regulating valve is communicated with a front portion of an automatic transmission, and a second lubrication path from a lock-up control valve is connected to an oil passage. A cooler is provided, which communicates with the rear part of the automatic transmission and an oil passage inside a central shaft. The oil passage is divided into two parts by an orifice member, one of which is connected to a planetary gear of the automatic transmission and the other is connected to the other part. It communicates with the center differential device and the hydraulic multi-plate clutch device so as to supply oil to each.

[0007]

According to the above construction, the oil of the first lubrication path is supplied to the automatic transmission, and the oil of the second lubrication path cooled by the oil cooler is also supplied via the torque converter, thereby forcing each part. Lubricated. The oil in the second lubrication passage is divided into two by an oil passage inside the center shaft and an orifice member, and is also supplied to a center differential device and a hydraulic multi-plate clutch device. Forcibly lubricate properly.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. Referring to FIG. 1, a description will be given of a drive system according to a first embodiment in which an engine and an automatic transmission are vertically arranged in a vehicle longitudinal direction as a four-wheel drive vehicle with a center differential device to which the present invention is applied. First, the transmission case 3 is joined to the rear of the torque converter case 1 and the differential case 2, the transfer case 4 and the extension case 6 are joined to the rear of the transmission case 3, and the oil pan 5 is attached to the lower part of the transmission case 3. .

Reference numeral 10 denotes an engine. A crankshaft 11 of the engine 10 is connected to a torque converter 13 having a lock-up clutch 12 inside the torque converter case 1, and an input shaft 14 from the torque converter 13.
Is input to the automatic transmission 30 inside the transmission case 3. The transmission output shaft 15 from the automatic transmission 30 outputs coaxially with the input shaft 14, and this transmission output shaft 15 is coaxially connected to a center differential device 50 inside the transfer case 4.

Inside the transmission case 3, a front drive shaft 16 is disposed parallel to the input and output shafts 14 and 15, and a rear end of the front drive shaft 16 is connected to a center differential device 50 by a pair of reduction gears 17 and 18. The front end of the front drive shaft 16 is transmitted to the front wheels via a front differential device 19 inside the differential case 2. On the other hand, a hydraulic multi-plate clutch device 60 is provided at the rear of the center differential device 50. The rear drive shaft 20 output from the hydraulic multi-plate clutch device 60 is rearwardly transmitted via a propeller shaft 21, a rear differential device 22, and the like. Driven by wheels.

The automatic transmission 30 has a structure in which four forward gears and one reverse gear are obtained by two sets of front planetary gears 31 and rear planetary gears 32. That is, the input shaft 14 is connected to the sun gear 32 a of the rear planetary gear 32, and the ring gear 31 b of the front planetary gear 31 and the carrier 32 c of the rear planetary gear 32 are connected to the transmission output shaft 15. And the carrier 3 of the front planetary gear 31
A first one-way clutch 34 and a forward clutch 35 are provided in series between a connecting element 33 integral with 1c and the ring gear 32b, and a first one-way clutch 34 and a forward clutch 35 are provided between the connecting element 33 and a case side as a fixing member. 2 one-way clutch 3
6. A low reverse brake 37 is provided in parallel.
An overrunning clutch 38 is provided between the coupling element 33 and the ring gear 32b in a bypass manner.

The connecting element 39 integral with the sun gear 31a is provided with a band brake 40, and the input shaft 14
A high clutch 43 is provided between the connecting element 41 integral with the connecting member 41 and the connecting element 42 integral with the carrier 31c. Further, a reverse clutch 44 is provided between the connecting elements 39 and 41.

With the structure of the automatic transmission 30, the forward clutch 35 is engaged at the first speed in the D range or the third range and the second range, and in the case of acceleration, the two-way clutches 34 and 36 act together with the coupling element 33 to operate. Ring gear 3
By locking 2b, the sun gear 32
a, power is transmitted to the transmission output shaft 15 via the carrier 32c. At this time, when coasting, the first one-way clutch 34 becomes free, and even if the overrunning clutch 38 is engaged to restrict the free rotation of the first one-way clutch 34, the second one-way clutch 36 becomes free. The engine brake does not work. At the first speed in one range, the ring gear 32b is always locked via the overrunning clutch 38 by the engagement of the low reverse clutch 37, so that the engine brake operates.

In the D range or the second speed of the third and second ranges, the forward clutch 35 and the band brake 4
0 engages, and the band gear 40 locks the sun gear 31a. Therefore, the carrier 31c and the ring gear 32b are connected to the connecting element 33, the forward clutch 3
5, rotating via the first one-way clutch 34,
The motive power output is increased by an amount corresponding to the rotation of the ring gear 32b as compared with the speed. At this time, at the time of deceleration, by maintaining the connecting element 33 and the ring gear 32b in the connected state by the engagement of the overrunning clutch 38, the reverse driving force is transmitted to the engine side and the engine brake acts.

In the third speed range of the D range or the third range, the forward clutch 35 and the high clutch 43 are engaged, and the input shaft 14 is connected by the high clutch 43 to the connecting element 41,
42, the carrier 31c, the connection element 33, the forward clutch 35, and the first one-way clutch 34 to connect to the ring gear 32b. For this reason, the rear planetary gear 32 is integrated, and the input shaft 14 and the transmission output shaft 15 are directly connected. At this time, at the time of deceleration, the overrunning clutch 38 is engaged to restrict the idling of the first one-way clutch 34, so that the engine brake operates as in the case of the second speed.

At the fourth speed in the D range, the sun gear 31a is locked by the engagement of the band brake 40 in addition to the above. Therefore, the high planetary gear 31
3, the ring gear 3 is driven by the power input to the carrier 31c.
1b, which is transmitted to the transmission output shaft 15. In this case, since the first and second one-way clutches 34 and 36 do not intervene, the engine brake always operates.

In the R range, the power of the input shaft 14 is input to the sun gear 31a by the engagement of the reverse clutch 44. Further, since the carrier 31c is locked together with the connecting element 33 by the engagement of the low reverse clutch 37, the front planetary gear 31 reversely rotates to the ring gear 31b to output power having a large gear ratio, and this reverse power is transmitted to the transmission output shaft 15. Transmit and go to reverse speed. Thus, the automatic transmission 30 has four forward speeds and one reverse speed.

On the other hand, an oil pump 45 is provided in front of the automatic transmission 30 and is always driven by a drive shaft 46 on the pump impeller side of the torque converter 13. A control valve body 47 is housed in the oil pan 5, and supplies and discharges oil to and from each of the above-mentioned clutches and brakes to be selectively engaged.

Referring to FIG. 2, the parts of the center differential device 50 and the hydraulic multiple disc clutch device 60 will be described. First, the first and second gears are provided behind the transmission output shaft 15.
The rear drive shaft 20 is arranged coaxially via the intermediate shafts 23 and 24 of the first embodiment. Further, a reduction gear 17 on the front wheel side is rotatably fitted to the transmission output shaft 15, and the transmission output shaft 15, the reduction gear 17, and the first and second reduction gears 17 are provided.
A center differential device 50 is coaxially arranged between the intermediate shafts 23 and 24.

The center differential device 50 is configured as a compound planetary gear, and includes a first sun gear 51 formed on the transmission output shaft 15 and a second sun gear 53 formed on the second intermediate shaft 24. Have. The carrier 55 is formed by integrating left and right flanges 55a and 55b by an arm 55c.
First and second pinions 52 and 54 formed integrally in the axial direction are rotatably mounted via a needle bearing 27 on a pinion shaft 56 mounted between 55b. The first sun gear 51 is provided with the first pinion 52
The second pinion 54 meshes with each of the sun gears 53, and outputs the torque-distributed power to the second intermediate shaft 24.

On the other hand, a first intermediate shaft 23 is further loosely fitted inside the second intermediate shaft 24, and a connecting member is provided at a front end of the first intermediate shaft 23 at a gap between the two sun gears 51 and 53. The connecting member 57 is integrally spline-coupled to the arm 55c of the carrier 55 to perform an operation such as a differential restriction. Further, the reduction gear 17 is coupled to one flange 55 a of the carrier 55 so as to output the power of the carrier 55. Here, the reduction gear 17 integral with the carrier 55 is supported by the ball bearing 26a on the wall 3a of the transmission case 3 at the front thereof, and the outer periphery of the boss 55d of the flange 55b is defined by the wall 4a of the transfer case 4 on the rear. The ball bearing 26b is supported by the ball bearing 26b, and the inner circumference of the ball bearing 26b is
c, and installed rotatably with both ends supported.

This center differential device 50
According to the configuration described above, the power input to the first sun gear 51 is
The torque is transmitted to the carrier 55 and the second sun gear 53 at a torque distribution ratio according to the gear specifications of the first and second sun gears 51 and 53 and the first and second pinions 52 and 54, so that they are unequal to the front and rear wheels. It has a function to distribute torque. In addition, it has a differential function of absorbing a rotational speed difference between the carrier 55 and the second sun gear 53 caused by a difference in turning radius during turning due to the planetary rotation of the first and second pinions 52 and 54.

The unequal torque distribution function of the center differential device 50 will now be described in detail with reference to the schematic diagram of FIG. The input torque of the first sun gear 51 is Ti, the mesh pitch radius thereof is rs1, the front side torque of the carrier 55 is TF, the mesh pitch radii of the first and second pinions 52 and 54 are rp1 and rp2, and the second is Sun gear 53
The rear side torque is TR and the mesh pitch radius is rs2
Then, Ti = TF + TR (1) rs1 + rp1 = rs2 + rp2 (2)

The tangential load P acting on the meshing point between the first sun gear 51 and the first pinion 52 includes the tangential load P1 acting on the carrier 55, the second sun gear 53 and the second pinion. Since it is equal to the sum of the tangential load P2 acting on the meshing point with 54, the following equation is established. P = Ti / rs1 P1 = TF / (rs1 + rp1) P2 = TR / rs2 Ti / rs1 = {(TF / (rs1 + rp1)} + TR / rs2 (3) Then, the equations (1) and (2) are converted into the equation (3). Substituting into the equation and rearranging it gives the following: TF = (1−rp1 · rs2 / rs1 · rp2) × Ti TR = (rp1 · rs2 / rs1 · rp2) × Ti

Therefore, the first and second sun gears 5
It can be seen that the reference torque distribution ratio of the front torque TF and the rear torque TR can be set freely by the engagement pitch radii of the first and second pinions 52 and 54 with the first and second pinions 52 and 54. Here, rs1, rp1, rp2, rs2
Can be replaced by the number of teeth Zs1, Zp1, Zp2, Zs2, Zp1 = Zp2 = 21, Zs1 = 33, Z
Assuming that s2 = 21, TF: TR = 36.4: 63.6. Therefore, the reference torque distribution ratio for the rear wheel bias can be set sufficiently.

Next, the center differential device 5
A case where 0 is used as a gearbox will be described. In the composite planetary gear type center differential device 50, a predetermined speed increasing gear ratio can be obtained by fixing the second intermediate shaft 24, and the speed increasing gear ratio alone or the predetermined gear position of the automatic transmission 30 can be obtained. 5th
It is designed to shift to high speed. Therefore, for example, a case where the second speed is used will be described. The fifth speed gear ratio i5 is as follows based on the second speed gear ratio i2 and the speed increasing gear ratio ip of the center differential device 50. i5 = i2 · ip Here, if the above-described gear specifications of the center differential device 50 are used, ip = (33-21) / 3
3 = 0.363. For example, if i2 = 1.545, i5 = 0.561, and the fifth speed having a smaller gear ratio than the fourth speed can be obtained at an appropriate gear ratio interval. On the other hand, at the fifth speed, the transmission torque is generated by controlling the hydraulic pressure of the hydraulic multiple disc clutch 62 according to the traveling state or the road surface condition, and the four-wheel drive in which the torque distribution of the front and rear wheels can be controlled.

In FIG. 3, a hydraulic multiple disc clutch device 60 is shown.
Will be described. First, a hydraulic multi-plate clutch 61 interposed between the second intermediate shaft 24 and the rear drive shaft 20 as a frictional engagement element for transmitting torque, and a first intermediate shaft 23
Multi-disc clutch 6 interposed between the clutch and the rear drive shaft 20 as a frictional engagement element for limiting the differential and moving the torque
2 and the second intermediate shaft 24 to prevent the differential function of the center differential device 50 from being carried out.
And a fifth speed brake 63 as a friction engagement element for increasing the rotational speed of the motor. The hydraulic multi-plate clutches 61 and 62 and the fifth speed brake 63 are connected to the first intermediate shaft 23 immediately after the center differential device 50.
Are superposed three-dimensionally in the radial direction around them and are arranged coaxially. That is, the hydraulic multi-plate clutches 61 and 62 are both connected to the rear drive shaft 20, and the hydraulic multi-plate clutch 61 and the fifth speed brake 63 are both connected to the second intermediate shaft 24. A fifth speed brake 63 is provided outside the hydraulic multi-plate clutch 61.
However, a hydraulic multi-plate clutch 62 is disposed inside.

Therefore, the drum member 6 is attached to the second intermediate shaft 24.
4 is spline-coupled, and a drum member 65 integrally formed with the front end of the rear drive shaft 20 is disposed inside the drum member 64, and a hydraulic multi-plate clutch 61 is provided between the drum members 64 and 65. The hydraulic multi-plate clutch 61 has a drive plate 6 between the drum members 64 and 65.
1a and the driven plate 61b are provided alternately, and a hydraulic chamber 61c, a piston 61d, and a return spring 61e are provided inside the drum member 64, and the second intermediate shaft 24 is provided.
Is connected to or disconnected from the rear drive shaft 20.

The fifth speed brake 63 includes a drum member 64
A drive plate 63a and a driven plate 63b are provided alternately between the transfer case 4 and the transfer case 4. A hydraulic chamber 63c, a piston 63d, and a return spring 63e are provided inside a wall 4a of the transfer case 4, and a second intermediate shaft is provided. 24 is configured to be fixed or free.

The hydraulic multi-plate clutch 62 includes a first intermediate shaft 2
3 and a hub member 66 and a drum member 65 which are spline-connected
, Drive plates 62a and driven plates 62b are provided alternately. Further, inside the boss portion 6a of the fixed-side extension case 6, a hydraulic chamber 62c,
The piston 62d and the return spring 62e are provided so as to generate a large pressing force and to accurately control the hydraulic pressure without being affected by the centrifugal hydraulic pressure. The piston 62d is connected to the plate via a ball bearing 62f and a pressing member 62g, and is configured to generate a variably controlled differential limiting torque and transmission torque. A bush 28 is interposed in the shaft fitting portion, and a thrust bearing 25 is interposed in the abutting portion between the shafts or the shaft and another member.

The hydraulic multi-plate clutches 61 and 62 and the fifth speed brake 63 are provided with a control valve body 4.
At 7, hydraulic control is performed together with shift control of the automatic transmission 30 and the like. That is, when the automatic transmission 30 shifts to four forward speeds and one reverse speed, the fifth speed brake 63 is released and the hydraulic multiple disc clutch 61 is engaged. A differential limiting torque is generated in the multiple disc clutch 62. On the other hand, when the vehicle speed rises above the set value at the fourth speed, the fifth speed brake 63 is engaged to release the hydraulic multiple disc clutch 61, and at this time, the hydraulic multiple disc clutch 62 is Generates transmission torque.

Table 1 summarizes the clutch and brake operations of the automatic transmission 30 and the center differential device 50 in each of the D range and R range gear stages.

[Table 1] In Table 1, ○ indicates the clutch-brake engagement operation, ● indicates the generation of the differential limiting torque by the hydraulic multi-plate clutch 62, and ◎ indicates the driving force distribution control to the front and rear wheels by the hydraulic multi-plate clutch 62. In this case, the transmission torque state is shown.

Table 2 summarizes the gear ratios, examples of the gear ratios, and the torque distribution ratios at each shift speed.

[Table 2] In Table 2, α1 is the front planetary gear 31
Α1 = Zs1 / Zr1, α2 is the ratio of the number of teeth Zs2 of the sun gear 32a of the rear planetary gear 32 to the number of teeth Zr2 of the ring gear 32b, and α2 = Zs2. / Zr
2 is shown.

The relationship between the rotation speeds of each element of the front planetary gear 31 is as follows. Nr1 + α1 · Ns1 = (1 + α1) · Nc1 where α1 = Zs1 / Zr1 The relationship of the rotation speed of each element of the rear planetary gear 32 is expressed by the following equation. Nr2 + α2 · Ns2 = (1 + α2) · Nc2 where α2 = Zs2 / Zr2 where the ring gear 31 of the front planetary gear 31
b, the rotation speed Ns1 of the sun gear 31a, the rotation speed Nc1 of the carrier 31c, the rotation speed Nr2 of the ring gear 32b of the rear planetary gear 32, the rotation speed Ns2 of the sun gear 32a, and the rotation speed Nc of the carrier 32c.
2.

Further, the lubrication system of the automatic transmission 30, the center differential device 50 and the hydraulic multi-plate clutch device 60 will be described with reference to FIG. First, the oil passage 71 from the oil pump 70 is connected to the control valve body 47.
A line pressure is generated by communicating with a line pressure adjusting valve 72 of the above, and this line pressure is guided to a converter pressure adjusting valve 74 by an oil passage 73, a predetermined converter pressure is generated using the line pressure as a source pressure, and the lubricating oil is output. It is supposed to. The converter pressure is guided to a lock-up control valve 76 by an oil passage 75, and is operated by a pilot pressure by a solenoid valve 77. That is, in the case of the converter region, the converter pressure is introduced to the release side of the lock-up clutch 12 via the oil passage 78, the lock-up clutch 12 is turned off to operate the torque converter 13, and in the case of the coupling region, The converter pressure is introduced to the apply side of the lock-up clutch 12 via the oil passage 79 to turn on the lock-up clutch 12. The lock-up control valve 76 always outputs a predetermined flow rate of lubricating oil to the oil passage 80 when the lock-up clutch 12 is turned on and off.

The oil passage 81 from the converter pressure regulating valve 74 communicates with an oil passage 82 on the front case side of the automatic transmission 30 to supply the reverse clutch 44 and the high clutch 43 with oil. The oil passage 80 of the oil from the lock-up control valve 76 communicates with the oil cooler 84 to be cooled, and the oil passage 85 at the rear of the automatic transmission 30 on the case side is provided.
To the low reverse brake 37, the overrunning clutch 38 and the like. The oil passage 80 communicates with an oil hole 83 to introduce oil into oil passages 86 and 87 provided in the rear half of the input shaft 14 and the output shaft 15. A plurality of oil holes 88 are provided in the input shaft 14 and the output shaft 15, and the oil holes 88 supply oil to front and rear planetary gears 31, 32 and the like. An orifice member 90 is provided on the output shaft 15 as shown in FIG. 2, and a predetermined flow of oil is supplied from the oil passage 87 to the oil passage 9 provided first inside the intermediate shaft 23.
1 is introduced. Further, as shown in FIGS. 2 and 3, an oil hole 92 is provided in the output shaft 15, the first and second intermediate shafts 23 and 24, and the oil is supplied to the gears 51 to 54, the bearing 26 and the like of the center differential device 50. ,
An oil hole 93 is provided in the first intermediate shaft 23 and the like so that oil is supplied to the inside of the drum members 64 and 65 of the hydraulic multiple disc clutch device 50.

Next, the operation of this embodiment will be described. First, the power of the engine 10 is the torque converter 1
3, input to the automatic transmission 30 via the input shaft 14, and two sets of front planetary gears 31 and rear planetary gears 3
2, the clutches 44, 43, 35, 38, 36, 3
Due to the selective engagement of the brake 4 and the brakes 40 and 37, when shifting to the D range, the speed is automatically changed to the first to fourth forward speeds, and when shifting to the R range, the reverse speed is achieved. Then, the shifting power is input from the transmission output shaft 15 to the first sun gear 51 of the center differential device 50, and the torque is distributed. In this case, the hydraulic multiple disk clutch 61 of the hydraulic multiple disk clutch device 60 is engaged, and the second sun gear 53 of the center differential device 50 is engaged.
Are connected to the rear drive shaft 20.

Here, the center differential device 5
For example, TF: TR = 36.4:
66.4% of shifting power because it is set to 63.6
Is distributed to the carrier 55 and 63.6% is distributed to the second sun gear 53 and output. The power of the carrier 55 is transmitted to the front wheels via the reduction drive gear 17, the reduction driven gear 18, the front drive shaft 16, and the front differential device 19. In addition, the power of the second sun gear 53 is transmitted to the second intermediate shaft 24, the hydraulic multi-plate clutch 61, and the rear wheel after the rear drive shaft 20, so that the rear wheel is biased to drive four wheels. The vehicle tends to be over-steered, and the turning property, the maneuverability, and the like are improved. At the time of this four-wheel drive running turn, the first and second pinions 5 of the center differential device 50 are turned on.
Due to the 2,54 planetary rotations, the difference in the rotational speeds of the front and rear wheels generated at the time of turning is absorbed, and the vehicle can freely turn.

Next, when the vehicle is running on a slippery road surface, the rear wheel normally slips first because the reference torque distribution is the rear wheel biased torque distribution. In this case, the differential limiting torque Tc of the hydraulic multi-plate clutch 62 is slipped. It is controlled according to. Then, between the carrier 55 of the center differential device 50 and the second sun gear 53, the carrier 55, the connecting member 57, the first intermediate shaft 23, and the hydraulic multiple disc clutch 6
2 is formed by bypassing the low-speed carrier 5 from the rear wheel side of the high-speed second sun gear 53.
5, a torque bypass is performed on the front wheel side according to the differential limiting torque Tc. Therefore, torque distribution control is performed toward the front wheels to prevent rear wheel slip, thereby improving running performance.

At this time, when the differential limiting torque Tc becomes maximum, the center differential device 50 is locked by a direct connection between the second sun gear 53 and the carrier 55 to be a direct connection type four-wheel drive. The corresponding torque distribution results. By controlling the differential limiting torque Tc in this way, the torque distribution is variably controlled between the rear wheel biased and the direct connection type.

On the other hand, when the speed becomes higher than the fourth speed running condition, the automatic transmission 30 enters the second speed state, and at the same time, the second sun gear of the center differential device 50 is engaged by the engagement of the fifth speed brake 63. 53 is fixed, and the carrier 55 rotates at an increased speed. For this reason, the power of the second speed of the automatic transmission 30 is supplied to the center differential device 50.
And greatly transmitted to the front wheels after the carrier 55,
The speed is shifted to the overdrive fifth speed having a smaller gear ratio than the fourth speed, and the vehicle can run at high speed. In this case, the vehicle tends to be understeered and the stability at high speed is improved. At this time, when a predetermined hydraulic pressure is supplied to the hydraulic multi-plate clutch 62 according to the running state, the state of the front wheel slip, and the like, the transmission torque TD is variably controlled in the same manner as described above, and the first intermediate shaft 23, torque is also transmitted to the rear wheels via the hydraulic multi-plate clutch 62. Therefore, four-wheel drive traveling is performed in which the front wheel slip is prevented and the torque distribution of the front and rear wheels can be similarly controlled.

During traveling with the four-wheel drive or the like, lubricating oil is always produced by the converter pressure regulating valve 74 using the line pressure by the line pressure regulating valve 72 as the original pressure, and this oil is supplied to the front of the automatic transmission 30. Supplied. Similarly, lubricating oil is also generated by the lock-up control valve 76,
This oil flows into the oil cooler 84 to cool the heat generated by the operation of the torque converter 13 and the like, and this cooling oil is supplied to the rear part of the automatic transmission 30. On the other hand, the cooled oil is also distributed by the orifice member 90 to the central input shaft 14, the output shaft 15, and the oil passages 86, 87, 91 inside the first intermediate shaft 23. And is supplied directly from the oil passage 86 to the planetary gears 31 and 32 via the oil hole 88. Further, the oil is directly supplied from the oil passages 87 and 91 to the respective parts of the center differential device 50 via the oil holes 92, and thus the oil is forcibly lubricated.

Further, the drum members 64, 6 of the hydraulic multi-plate clutch device 60 are moved from the oil passage 91 through the oil holes 93.
Oil is supplied to the inside of the piston 5 and the oil forcibly lubricates the piston sides of the two hydraulic multi-plate clutches 61 and 62. In particular, since the members 64 to 66 are rotating at high speed during traveling, the oil is automatically scattered outward by centrifugal force, and first the inner hydraulic multi-plate clutch 62, then the intermediate hydraulic multi-plate clutch 61, 5th speed brake 6 on the outside
The oil flows continuously and continuously to the plate portion 3 and the piston side of the third, so that good lubrication is achieved.

Although the embodiment of the present invention has been described above, the present invention is not limited to this.

[0045]

As described above, according to the present invention,
In a four-wheel drive vehicle with a center differential device, a torque converter having a lock-up clutch,
When the automatic transmission, the center differential device, and the hydraulic multi-plate clutch device are coaxially arranged, the automatic transmission, the center differential device, and the hydraulic pressure are divided into two by an oil passage provided inside a center shaft. Since it is configured to supply oil to the multi-plate clutch device, the center differential device and the hydraulic multi-plate clutch device can be sufficiently lubricated with a large amount of oil with a compact configuration. Accordingly, in a multi-function system in which the center differential device is configured as a composite planetary gear and the hydraulic multi-plate clutch device has a plurality of hydraulic multi-plate clutches and brakes, lubricity and durability are particularly improved.

The automatic transmission is lubricated by two lubrication paths to the front and rear parts, so that sufficient lubrication can be achieved even when there are many gears. Since the oil via the torque converter is configured to be supplied from the lock-up control valve via the oil cooler, a large amount of oil can always be appropriately cooled and supplied.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram showing an entire embodiment of a four-wheel drive vehicle with a center differential device according to the present invention, which is vertically arranged.

FIG. 2 is an enlarged sectional view of a portion of a center differential device and a hydraulic multiple disc clutch device.

FIG. 3 is an enlarged sectional view of a portion of the hydraulic multiple disc clutch device.

FIG. 4 is a schematic diagram illustrating a flow of a torque distribution state, a differential limitation, and a transmission torque for direct connection.

FIG. 5 is an explanatory diagram showing a lubrication path of the entire drive system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Lock-up clutch 13 Torque converter 14 Input shaft 15 Output shaft 23 First intermediate shaft 24 Second intermediate shaft 30 Automatic transmission 50 Center differential device 60 Hydraulic multi-plate clutch device 81, 83 Lubricating oil passage 84 Oil cooler 86 , 87, 91 Oil passage 90 Orifice member

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B60K 17/00-17/36 F16H 47/06 F16H 57/00-57/04

Claims (2)

(57) [Claims] 1. A drive system in which a torque converter having a lock-up clutch, an automatic transmission, a center differential device, and a hydraulic multi-plate clutch device having a plurality of hydraulic multi-plate clutches and brakes are coaxially arranged. A first lubrication path from the regulator valve communicates with the front of the automatic transmission and a second lubrication path from the lockup control valve.
The lubrication path is provided with an oil cooler and communicates with the rear part of the automatic transmission and an oil passage inside a central shaft. The oil passage is divided into two by an orifice member, and one of the oil passages is a planetary gear of the automatic transmission. A four-wheel drive vehicle with a center differential device, characterized in that the other is connected to the center differential device and the hydraulic multi-plate clutch device so as to refuel. 2. The shaft according to claim 1, wherein the shaft is a part of an input shaft of an automatic transmission arranged coaxially, an output shaft, and a first intermediate shaft between a center differential device and a hydraulic multiple disc clutch device. The four-wheel drive vehicle with a center differential device according to claim 1.