JP3650472B2 - Vehicle drive device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle drive device used for a horizontally mounted engine.
[0002]
[Prior art]
Conventionally, there is a prior art disclosed in Japanese Patent Application Laid-Open No. 4-83948 regarding a driving device for a vehicle in which an engine is disposed horizontally. In this prior art, an engine, a torque converter, a forward / reverse switching device equipped with a double pinion planetary gear, and a belt type continuously variable transmission are provided coaxially in the vehicle body width direction, and output from the secondary shaft of the continuously variable transmission is provided. A transmission arrangement is shown for the differential device.
[0003]
[Problems to be solved by the invention]
However, in the above-mentioned prior art, a horizontally disposed engine is provided with a torque converter, a forward / reverse switching device, and a belt-type continuously variable transmission on the same axis as the engine. A differential device is provided below the secondary shaft of the step transmission, and a transmission case in which these are integrated is joined. Therefore, the overall length of the drive device is long in the vehicle width direction, and the engine room side wall and the drive device in the vehicle-mounted state If you try to secure a sufficient crash stroke at the time of a side collision, the degree of freedom in designing the vehicle body will be limited, and it will be difficult to obtain a working space in the engine room. May be disturbed.
[0004]
Further, in the drive device for a four-wheel drive vehicle based on this drive device, a center differential device is further provided on the secondary shaft side of the belt type continuously variable transmission, so that the structure and the control device for controlling them are complicated. There is a problem such as a cost increase.
[0005]
Also, it is desirable that the engine room structure having the same shape has in-vehicle compatibility with a belt-type continuously variable transmission, a manual transmission (manual transmission, MT), an automatic transmission (automatic transmission, AT), etc. If the overall length, the outer circumference of the transmission case, and the so-called waistline dimensions are made substantially the same as a manual transmission that can be designed relatively compactly, it becomes possible to share a support member and an exhaust system for in-vehicle use.
[0006]
Therefore, the object of the present invention is to reduce the width of the drive unit, particularly the transmission case, in the width direction of the vehicle, and can be mounted in a conventional engine room while ensuring a working space for freedom of vehicle body design, crash stroke, and transmission / removal. Moreover, it is an object of the present invention to provide a vehicle drive device that can be easily changed to a four-wheel drive vehicle drive device by sharing components.
[0007]
[Means for Solving the Problems]
  A vehicle drive device according to the present invention that achieves the above object includes an engine arranged horizontally,A primary shaft that extends in the vehicle body width direction on the same axis as the rotational axis of the crankshaft of the engine and that receives output from the engine, and a secondary that is arranged rearward of the vehicle body and parallel to the primary shaft at a high position A drive belt is wound between a primary pulley provided on the primary shaft and a secondary pulley provided on the secondary shaft, and the ratio of the winding diameter of the drive belt to the primary pulley and the secondary pulley. A belt type continuously variable transmission that changes speed, a front drive shaft that is arranged in parallel to the secondary shaft below the secondary shaft and transmits power to the front differential device, and is coaxial with the front drive shaft A double pinion planetary gear disposed on the carrier and a carrier of the double pinion planetary gear A first friction engagement element that selectively transmits power from the secondary shaft, an input member that transmits power from the secondary shaft to the sun gear of the double pinion planetary gear, and a double pinion planetary gear. An output transmission means for transmitting power from the carrier to the front drive shaft; and a second friction engagement element for selectively rotating and locking the ring gear of the double pinion planetary gear. The first friction engagement element is in a power transmission state, the second friction engagement element is in a ring gear rotation permissible state, and the reverse stage is the second friction engagement with the first friction engagement element in a released state. The coupling element is in a ring gear rotation locking state.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
In FIG. 1, a drive system of a drive device for a two-wheel drive vehicle with a belt type continuously variable transmission will be described as a vehicle drive device to which the present invention is applied.
[0011]
Reference numeral 10 denotes a horizontally mounted engine, a torque converter case 1 that is joined to the engine 10 and accommodates the torque converter 20, a belt-type continuously variable transmission 30 and a differential device that are located on the side of the torque converter case 1, for example, The transmission case 5 is formed by joining the differential and converter housing 2 and the side case 3 for accommodating the front differential device 40 and the end cover 4 for accommodating the transfer unit 50 in cooperation with the torque converter case 1. An oil pan (not shown) is provided at the lower part of the head.
[0012]
The crankshaft 11 of the horizontally mounted engine 10 is connected to the torque converter 20 inside the torque converter case 1, and the input shaft 21 from the torque converter 20 is connected to the primary shaft 31 of the belt type continuously variable transmission 30 inside the differential and converter housing 2. By connecting, the power from the crankshaft 11 is transmitted to the primary shaft 31 of the continuously variable transmission 30 via the torque converter 20.
[0013]
Then, the power continuously variable by the continuously variable transmission 30 is output to the secondary shaft 32 and input to the transfer unit 50 via the counter shaft 39 and the like, and is transmitted to the front wheels via the front differential device 40 by the transfer unit 50. The
[0014]
An oil pump 8 that is always driven by being connected to an oil pump drive shaft 24a provided in the torque converter 20 is provided in the transmission case 5, and the oil pump 8 always generates hydraulic pressure to supply the torque converter 20 and the like. The hydraulic control of the continuously variable transmission 30 is enabled, and the hydraulic control of the transfer unit 50 is enabled by the control of the hydraulic control circuit 9 based on signals from the vehicle speed sensor 9a, the throttle sensor 9b, the shift switch 9c, and the like. .
[0015]
Next, the torque converter 20, the belt type continuously variable transmission 30, the front differential device 40, and the transfer unit 50 will be sequentially described with reference to FIGS.
[0016]
As shown in FIG. 2, the torque converter 20 has an input shaft 21 that is rotatably supported coaxially with respect to the crankshaft 11 on the differential and converter housing 2 and the side cover 3 via a ball bearing 21a. have.
[0017]
The outer periphery of the input shaft 21 is substantially cylindrical, and a flange portion provided at the base end is rotatably surrounded by a stator shaft 22 bolted to the torque converter case 1 with an oil pump housing 8c interposed therebetween. The oil pump drive shaft 24a integrally coupled to the impeller 24 is rotatably fitted.
[0018]
The outer periphery of the impeller 24 is integrally coupled to the outer periphery of the front cover 25 and is coupled to the crankshaft 11 via the drive plate 26 so as to be rotated integrally with the crankshaft 11.
[0019]
A turbine 27 that is spline-fitted to the input shaft 21 is disposed facing the impeller 24, and a stator 28 that is supported on the stator shaft 22 via a one-way clutch 28a is interposed between the impeller 24 and the turbine 27. .
[0020]
Further, a lock-up clutch 29 is interposed between the turbine 27 and the front cover 25. An inner gear 8a that is rotationally driven by an oil pump drive shaft 24a at the base end of the stator shaft 22, an outer gear 8b that meshes with the inner gear 8a, and the aforementioned An oil pump 8 having an oil pump housing 8c is provided.
[0021]
When the crankshaft 11 of the engine 10 rotates, the impeller 24 is rotationally driven through the drive plate 26, the front cover 25, etc. coupled to the crankshaft 11.
[0022]
The rotation of the impeller 24 causes the oil in the impeller 24 to be discharged to the outside by centrifugal force. The oil flows from the outside of the turbine 27 and transmits torque in the same direction as the rotation of the impeller 24 to the turbine 27. The input shaft 21 for spline fitting is driven to rotate. Furthermore, the torque of the impeller 24 is increased by inverting the outflow direction of the oil flowing out of the turbine 27 by the stator 28 in a direction that promotes the rotational force of the impeller 24. Further, when the rotational speed of the turbine 27 is high, the flow of oil hits the back surface of the stator 28 and the stator 28 is idled by the one-way clutch 28a.
[0023]
On the other hand, when a certain vehicle speed or number of revolutions is reached, the lockup clutch 29 causes the impeller 24 and the turbine 27 to be directly connected via the front cover 25 to eliminate slippage of the so-called torque converter, thereby reducing the number of revolutions of the engine 10. This saves fuel consumption and improves quietness.
[0024]
  A belt type continuously variable transmission 30 includes a primary shaft 31 and a second shaft arranged in parallel to each other.DaBy having a primary pulley 33 and a secondary pulley 34 provided on the reshaft 32, and a drive belt 35 wound around these pulleys 33, 34, by changing the pulley groove width of each pulley 33, 34 The ratio of the effective winding diameter of the drive belt 35 to the pulleys 33 and 34 is changed to change the speed steplessly.
[0025]
Therefore, the primary pulley 33 provided on the primary shaft 31 formed integrally with the input shaft 21 moves in the axial direction with respect to the fixed sheave 33a formed integrally with the primary shaft 31 and the fixed sheave 33a. A movable sheave 33b is provided. The fixed sheave 33a and the movable sheave 33b transmit torque by holding the drive belt 35 with a predetermined clamping force in order to ensure a smooth continuously variable transmission of the transmission, and a pulley formed by the fixed sheave 33a and the movable sheave 33b. Since the groove width needs to be variably controlled, a plurality of ball grooves extending in the axial direction and facing each other are formed in the fitting portion between the primary shaft 31 and the movable sheave 33b. A means for transmitting torque via a ball 33c interposed between the two is employed.
[0026]
A substantially cylindrical piston 37a is fixed to the back surface of the movable sheave 33b opposite to the fixed sheave 33a. The piston 37a cooperates with a bottomed cylindrical cylinder 37b whose center is fixed to the primary shaft 31. Thus, a hydraulic actuator 37 including a spring 37c that forms the hydraulic chamber 37A and biases the movable sheave 33b in a direction of narrowing the pulley groove width is provided.
[0027]
An oil passage 31b communicating with the hydraulic chamber 37A is formed in the primary shaft 31, and the hydraulic actuator 37 is controlled via the oil passage 3a formed in the side cover 3 by being controlled by the hydraulic control circuit 9 based on the throttle opening degree and the like. The pulley groove width is variably controlled by moving the movable sheave 33b along the primary shaft 31 by the hydraulic pressure supplied to and discharged from the hydraulic chamber 37A.
[0028]
On the other hand, the secondary shaft 32 arranged in parallel with the primary shaft 31 is rotatably supported by the differential and converter housing 2 and the side cover 3 via roller bearings 32a and ball bearings 32b, and a secondary pulley 34 provided on the secondary shaft 32. Has a fixed sheave 34a formed integrally with the secondary shaft 32, and a movable sheave 34b that enables movement in the axial direction with respect to the fixed sheave 34a. The secondary shaft 32 and the movable sheave 34b are secondary shafts. 32 and the movable sheave 34b are configured to transmit torque via balls 34c that extend between the plurality of ball grooves that extend in the axial direction and are opposed to each other.
[0029]
A substantially cylindrical cylinder 36a is fixed to the back surface of the movable sheave 34b. The cylinder 36a cooperates with a cylindrical piston 36b whose center is fixed to the secondary shaft 32 to form a hydraulic chamber 36A. A hydraulic actuator 36 having a spring 36c that biases the movable sheave 34b in the direction of narrowing the pulley groove width is provided.
[0030]
An oil passage 32c communicating with the hydraulic chamber 36A is formed in the secondary shaft 32, and the hydraulic actuator 36 is controlled via the oil passage 3b formed in the side cover 3 by being controlled by the hydraulic control circuit 9 based on the throttle opening degree and the like. A drive gear 38 is provided at one end of the secondary shaft 32, and is configured to supply and discharge the hydraulic chamber 36 </ b> A.
[0031]
Here, since the pressure receiving area for receiving the hydraulic pressure of the movable sheave 33b of the primary pulley 33 is larger than that of the movable sheave 34b of the secondary pulley 34, the primary pulley 33 and the secondary pulley 34 are in accordance with the hydraulic pressure supplied to and discharged from the hydraulic chambers 37A and 36A. The pulley groove width is changed to the reverse relationship, and the ratio of the effective winding diameter of the drive belt 35 to each pulley 33, 34 is converted into a stepless manner, and the continuously variable power is output to the secondary shaft 32.
[0032]
The speed change output from the secondary shaft 32 is output from the drive gear 38, decelerated by the counter shaft 39, and transmitted to the transfer unit 50 via the driven gear 54 and the transmission shaft 53 that is bolted to the driven gear 54.
[0033]
The counter shaft 39 includes a shaft 39a whose both ends are fixed to the torque converter case 1 and the differential and converter housing 2, and a relatively large-diameter drive-side gear that is rotatably fitted to the shaft 39a and meshes with the drive gear 38. The inner side of the needle bearing 39e and the roller bearing 39f is formed integrally with the drive gear 39c and the driven gear 39d meshed with the driven gear 54, and both sides are supported by the torque converter case 1 and the differential and converter housing 2. And a gear 39b that is restricted from moving in the axial direction via the race.
[0034]
Next, the front differential device 40 and the transfer unit 50 will be described with reference to FIG. 2 and FIG.
[0035]
The front differential device 40 includes a driven gear 54 in which a cylindrical flange portion 54a is rotatably supported on the differential and converter housing 2 through a ball bearing 54b, and a torque converter case 1 through a ball bearing 53a. It is disposed in a differential housing 41 having an enlarged diameter at a joint with a substantially cylindrical transmission shaft 53 that is pivotally supported.
[0036]
The structure of the front differential device 40 is a hollow shape that is rotatably fitted in a large-diameter portion formed by the flange portion 54a of the substantially cylindrical driven gear 54 and the transmission shaft 53 that are integrally formed with the front drive shaft 51. A differential case 42 is provided. A pair of pinions 43b is provided in the differential case 42 by pinion shafts 43a supported at both ends of the differential case 42, and the differential gear 43 is configured by engaging the left and right side gears 43c and 43d with both pinions 43b. doing.
[0037]
The drive shaft 44 connected to one side gear 43c passes through the differential and converter housing 2 from the differential case 42 and transmits power to one front wheel via a constant velocity joint, an axle shaft, etc., and is connected to the other side gear 43d. 45 penetrates through the differential case 42 and the front drive shaft 51 integrally formed with the differential case 42, protrudes from the end cover 4, and transmits power to the other front wheel via a constant velocity joint, an axle shaft and the like.
[0038]
The transfer unit 50 has a front drive shaft 51 arranged in parallel with the crankshaft 11 of the engine 10, the input shaft 21, the primary shaft 31, the secondary shaft 32, and the like.
[0039]
The crankshaft 11, the primary shaft 31, the secondary shaft 32, the front drive shaft 51 and the like arranged in parallel with each other are arranged so that the rotation shaft of the crankshaft 11 as shown in FIG. 4 showing the arrangement from the direction of arrow A in FIG. The core 11a and the primary shaft 31 are coaxially positioned in the vehicle body width direction, the secondary shaft 32 is disposed parallel to the primary shaft 31 at a high position behind the vehicle body, and the secondary pulley 34 is disposed opposite to the primary pulley 33. The The front drive shaft 51 is arranged substantially in parallel below the secondary shaft 32, thereby reducing the size of the entire drive device in the longitudinal direction and reducing the size of the drive device. In order to improve the compatibility with the automatic transmission (AT) mounted car body.
[0040]
One end of the front drive shaft 51 configured integrally with the differential case 42 is interposed in the torque converter case 1 via a transmission shaft 53 and a ball bearing 53a that supports the transmission shaft 53, and the other end portion is connected through a needle bearing 51c. Each end cover 4 is rotatably supported.
[0041]
Further, a spline 51a to be fitted with a hub 52 described later is formed on the outer periphery of a substantially central portion of the front drive shaft 51, and a spline 51b to be fitted with a carrier 60 of a double pinion type planetary gear 55 described later is formed adjacent to the spline 51a. Has been.
[0042]
The front drive shaft 51 is surrounded by a substantially cylindrical fixed shaft 62 integrally formed with the torque converter case 1, and the oil chamber 62 </ b> A is formed by closing the end surface of the fixed shaft 62 and the front drive shaft 51 by the hub 52. In addition, an oil passage 62 a communicating with the oil chamber 62 A is formed in the fixed shaft 62, and an oil passage 62 b is formed on the outer periphery of the fixed shaft 62.
[0043]
A hub 52 serving as an input member is rotatably fitted to the front drive shaft 51. The hub 52 has a cylindrical portion 52a fitted to the front drive shaft 51 and a flange portion 52b formed at the proximal end of the cylindrical portion 52a. A sun gear 56 of a double pinion planetary gear 55 is fitted to the outer periphery of the cylindrical portion 52a. Splines 52c to be engaged with the splines 51a of the drive shaft 51 are formed on the inner periphery. The flange portion 52b is provided with a clutch drum 66 of the first multi-plate clutch 65 serving as a first friction engagement element. The hub 52 is spline-fitted to the tip of the transmission shaft 53 and is rotatably supported on the fixed shaft 62 via a thrust bearing 52d supported by the fixed shaft 62.
[0044]
The double pinion planetary gear 55 fitted and coupled to the spline 52c formed on the outer periphery of the hub 52 is engaged with the sun gear 56, the ring gear 57, the sun gear 56, and the ring gear 57 that are spline fitted to the spline 52c. The first and second pinions 58 and 59 meshing with each other, and the carrier 60 that rotatably supports the first and second pinions 58 and 59 via a needle bearing 60a. The carrier 60 has a function of decelerating and rotating in the reverse direction with respect to the sun gear 56 by the power input to the sun gear 56. The carrier 60 is a spline 51b formed on the output transmission means, for example, the drive shaft 51. Is fitted so that power can be transmitted. A first multi-plate clutch 65 is provided between the transmission shaft 53 and the double pinion planetary gear 55 as a first friction engagement element for selectively inputting the output from the transmission shaft 53 to the carrier 60. .
[0045]
The first multi-plate clutch 65 will be described. A clutch drum 66 is fitted to a hub 52 rotatably supported by a fixed shaft 62 so that power can be transmitted, and the clutch hub 67 is attached to a carrier 60 of a double pinion planetary gear 55. Join. Thus, the first multi-plate clutch 65 is interposed between the transmission shaft 53 and the carrier 60 so as to be able to transmit power. Then, the hydraulic pressure of the hydraulic chamber 68 presses the retaining plate 70c that contacts the snap ring 70d fixed in the clutch drum 66 via the piston 69 and the drive plate 70a between the driven plate 70b and the clutch hub 67 to transmit power. Configured to do. A retainer 72 is provided on the opposite side of the piston 69 from the hydraulic chamber 68, and the pressing force of the return spring 73 is urged on the piston 69.
[0046]
A second frictional engagement element is provided between the end cover 4 of the transmission case 5 and the ring gear 57 of the double pinion type planetary gear 55 as a second friction engagement element for selectively locking to the end cover 4 and fixing the ring gear 57. A multi-plate clutch 75 is provided.
[0047]
The second multi-plate clutch 75 is a clutch hub provided on the retaining plate 80 c and the driven rate 80 b that are in contact with the snap ring 80 d fixed in the end cover 4 via the piston 79 by the hydraulic pressure of the hydraulic chamber 78 and the ring gear 57. The ring gear 57 is locked and fixed to the end cover 4 by pressing the drive plate 80a between the piston 77 and the piston 79 is urged by the pressing force of the return spring 83.
[0048]
In the oil pan provided in the lower part of the transmission case 5, the oil pressure from the oil pump 8 is controlled by the oil pressure control circuit 9 based on signals from the vehicle speed sensor 9a, the throttle sensor 9b, the shift switch 9c, etc. A control valve for selectively switching and supplying the hydraulic chambers 68 and 78 of the second multi-plate clutch 65 and 75 and the continuously variable transmission 30 is provided.
[0049]
Next, the operation of the drive device for a two-wheel drive vehicle configured as described above will be described with reference to the schematic explanatory views shown in FIGS. The friction engagement element operation explanatory view showing the connected state will be described. In this frictional engagement element operation explanatory diagram, ◯ indicates that the corresponding multi-plate clutch is engaged or operated.
[0050]
First, the power of the engine 10 is input from the crankshaft 11 to the primary shaft 31 of the continuously variable transmission 30 via the torque converter 20. Then, the primary shaft 31, the primary pulley 33, the drive belt 35, and the secondary pulley 34 are continuously stepped and output to the secondary shaft 32. The speed change output from the secondary shaft 32 is decelerated by the drive gear 38, the counter shaft 39, the driven gear 54, the transmission shaft 53, the hub 52 serving as an input member, etc., and the first multi-plate clutch 65 and the double pinion planetary gear 55. Is input to the sun gear 56. Here, in the neutral (N) range and the parking (P) range, the first and second multi-plate clutches 65 and 75 are released and the power transmission is cut off, and power transmission thereafter is not performed.
[0051]
In the drive (D) range, which is the forward gear, the first multi-plate clutch 66 is engaged, and the power transmission state is indicated by a bold line in FIG. That is, hydraulic pressure is supplied from the control valve to the hydraulic chamber 68, and the retaining plate 70c, the driven plate 70b, and the drive plate 70a that are in contact with the snap ring 70d fixed in the clutch drum 66 through the piston 69 are pressed and engaged. The first multi-plate clutch 65 transmits the power from the driven gear 54 to the carrier 60 of the double pinion planetary gear 55 via the transmission shaft 53 and the hub 52, and the front drive shaft 51 that is spline-fitted with the carrier 60 has the same direction as the driven gear 54. To drive the power to the front differential device 40.
[0052]
Accordingly, in the double pinion planetary gear 55, the engagement of the ring gear 57 by the second multi-plate clutch 75 is released as shown in FIG. 6, and the carrier 60 and the front drive shaft 51 are integrally coupled by spline fitting. Thus, the whole rotates together with the front drive shaft 51.
[0053]
On the other hand, in the reverse (R) range, which is the reverse stage, the first multi-plate clutch 65 is disengaged, the second multi-plate clutch 75 is engaged, and the power transmission state is shown by a bold line in FIG. . That is, the hydraulic pressure from the control valve is supplied to the hydraulic chamber 78, and the retaining plate 80c, the driven plate 80b, and the drive plate 80a that contact the snap ring 80d fixed in the end cover 4 via the piston 79 are pressed to The input from the transmission shaft 53 is transmitted to the sun gear 56 of the double pinion planetary gear 55 via the hub 52 by rotating and locking the ring gear 57 to the transmission case 5 by the two multi-plate clutch 75.
[0054]
  Accordingly, as shown in FIG. 8, the double pinion planetary gear 55 rotates along the ring gear 57 while the first and second pinions 58 and 59 engaged with each other by the rotation of the input side sun gear 56 rotate in the opposite directions. To rotate the carrier 60 in the opposite direction to the sun gear 56.Front drive shaft 51Is rotated in the opposite direction with respect to the input side to transmit power to the front differential device 40.
[0055]
Here, the gear ratio by the double pinion planetary gear 55 will be described.
[0056]
  In this case, the gear ratio output to the carrier 60 with respect to the input to the sun gear 56, that is, to the input to the sun gear 56.Front drive shaft 51The gear ratio to be output is set by the following equation where the number of teeth of the sun gear 56 is ZS and the number of teeth of the ring gear 57 is ZR.
[0057]
Gear ratio = [ZS + (− ZR)] / ZS
This shows that the gear ratio can be set freely by appropriately setting the number of teeth ZS of the sun gear 56 and the number of teeth ZR of the ring gear 57.
[0058]
If ZS = 37 and ZR = 82,
Gear ratio = [37 + (− 82)] / 37 = −1.216
Thus, the reduction ratio in the reverse (R) range is appropriately secured.
[0059]
Therefore, a forward / reverse switching device having the double pinion planetary gear 55 and the first and second multi-plate clutches 65 and 75 as main parts is configured.
[0060]
  Therefore, the engine 10, the torque converter 20, and the belt type continuously variable transmission 30 are coaxially arranged in the vehicle body width direction, and function as a forward / reverse switching device, a double pinion type planetary gear 55, first and second multi-plate clutches 67, 75 etc. are arranged at a low position with respect to the crankshaft 11 of the engine 10.Front drive shaft 51The upper part of the drive unit can be shortened because it is placed above, and the drive unit can be made compact without increasing the height of the drive unit. The work space can be easily secured.
[0061]
In the above vehicle drive device, an input switching means is interposed between the transmission shaft 53 and the double pinion planetary gear 55, the hub and front drive shaft 51 are replaced with a hub and front drive shaft for a four-wheel drive vehicle, and By additionally providing a power transmission mechanism for transmitting power to the rear differential device, a four-wheel drive vehicle drive device sharing the main part of the vehicle drive device can be easily configured.
[0062]
10 to 19, a four-wheel drive vehicle drive device based on the vehicle drive device will be described. Here, for convenience, the same parts as those in FIGS. 1 to 8 are denoted by the same reference numerals.
[0063]
FIG. 10 is a diagram for explaining the outline of the drive system of the drive device for a four-wheel drive vehicle.
[0064]
A torque converter case 81 for a four-wheel drive vehicle is provided in place of the torque converter case 1 and the end cover 4 constituting the transmission case 5, and the torque converter case 81 accommodates a transfer unit 90 for a four-wheel drive vehicle. A case 82 and an end cover 83 are sequentially joined, and an extension case 84 that houses a power transmission mechanism that transmits the output from the transfer unit 90 to the rear wheels is joined to the rear of the torque converter case 81 to join a transmission for a four-wheel drive vehicle. A case 85 is formed, and an oil pan (not shown) is provided below the transmission case 85.
[0065]
The crankshaft 11 of the horizontally mounted engine 10 is connected to the torque converter 20 inside the torque converter case 81, and the input shaft 21 from the torque converter 20 is connected to the primary shaft 31 of the belt type continuously variable transmission 30 inside the differential and converter housing 2. By connecting, the power from the crankshaft 11 is transmitted to the primary shaft 31 of the continuously variable transmission 30 via the torque converter 20.
[0066]
The power continuously variable by the continuously variable transmission 30 is output to the secondary shaft 32 and input to the transfer unit 90 via the counter shaft 39 and the like, and the transfer unit 90 is configured to transmit to the front wheels via the front differential device 40. On the other hand, it is transmitted to the rear wheels via a propeller shaft 86, a rear differential device 87, and the like.
[0067]
  An oil pump 8 that is always driven by being connected to an oil pump drive shaft 24a provided in the transmission case 85 is provided.AndOil pressure is always generated by the oil pump 8 and supplied to the torque converter 20 and the like, enabling the oil pressure control of the continuously variable transmission 30, and the vehicle speed sensor 9a, throttle sensor 9b, shift switch 9c, front wheel speed sensor 9d, rear The hydraulic pressure control circuit 9 controls the hydraulic pressure of the transfer unit 90 based on the signals from the wheel rotational speed sensor 9e and the steering angle sensor 9f.
[0068]
Next, the front differential device 40 and the transfer unit 90 will be described with reference to FIG.
[0069]
The front differential device 40 includes a driven gear 54 in which a cylindrical flange portion 54a is rotatably supported on the differential and converter housing 2 through a ball bearing 54b, and a torque converter case 81 through a ball bearing 53a. It is disposed in a differential housing 41 having an enlarged diameter at a joint with a substantially cylindrical transmission shaft 53 that is pivotally supported.
[0070]
The structure of the front differential device 40 is formed integrally with a front drive shaft 91 serving as a first drive shaft, and is a substantially cylindrical hollow shape that is rotatably fitted in the flange portion 54a of the driven gear 54 and the transmission shaft 53. The differential case 42 is provided with a pair of pinions 43b by pinion shafts 43a supported at both ends of the differential case 42, and the left and right side gears 43c and 43d are engaged with both pinions 43b, thereby allowing the differential gear 43 to be engaged. It is composed.
[0071]
The drive shaft 44 connected to one side gear 43c passes through the differential and converter housing 2 from the differential case 42 and transmits power to one front wheel via a constant velocity joint, an axle shaft, etc., and is connected to the other side gear 43d. 45 penetrates through the differential case 42 and the front drive shaft 91 integrally formed with the differential case 42, protrudes from the end cover 83, and transmits power to the other front wheel via a constant velocity joint, an axle shaft and the like.
[0072]
The transfer unit 90 serves as a front drive shaft 91 and a second drive shaft serving as a first drive shaft arranged in parallel to the crankshaft 11, the input shaft 21, the primary shaft 31, the secondary shaft 32, and the like of the engine 10. A rear drive shaft 92 is provided.
[0073]
The crankshaft 11, the primary shaft 31, the secondary shaft 32, the front drive shaft 91, the rear drive shaft 92, and the like that are arranged in parallel with each other are arranged as shown in FIG. The rotating shaft core 11a of the shaft 11 and the primary shaft 31 are coaxially positioned in the vehicle body width direction, and the secondary shaft 32 is disposed opposite to the primary shaft 31 at a high position on the rear side of the vehicle body. 34 is arranged opposite to the high position behind the vehicle body. The front drive shaft 91 is disposed substantially in parallel with the lower side of the secondary shaft 32, and the rear drive shaft 92 is disposed in parallel with the rear side of the vehicle body of the front drive shaft 91. It is designed to improve compatibility with a vehicle body equipped with a manual transmission (MT) and an automatic transmission (AT) by improving the storage property in the room.
[0074]
One end of the front drive shaft 91 configured integrally with the differential case 42 is interposed in the torque converter case 81 via a transmission shaft 53 and a ball bearing 53a that pivotally supports the transmission shaft 53, and the other end is ended through a needle bearing 91c. The cover 83 is rotatably supported.
[0075]
Further, the outer periphery of the other end of the front drive shaft 91 has a clutch hub 107 of a fourth multi-plate clutch 105 serving as a fourth friction engagement element and a fifth multi-plate clutch 115 serving as a fifth friction engagement element. A spline 91b is formed in which the disk 104 supporting the clutch hub 117 is fitted.
[0076]
The front drive shaft 91 is surrounded by a substantially cylindrical fixed shaft 62 integrally formed with the torque converter case 81, and a hub 93 is rotatably fitted to the front drive shaft 91. The hub 93 has a cylindrical portion 93a fitted to the front drive shaft 91 and a flange portion 93b formed at the proximal end of the cylindrical portion 93a. A double pinion planetary gear 55 is provided on the outer periphery of the cylindrical portion 93a in the vicinity of the flange portion 93b. A spline 93c into which the sun gear 56 is fitted is formed at the tip thereof, and a spline 93d into which the clutch drum 116 of the fifth multi-plate clutch 115 serving as a fifth friction engagement element is fitted is formed on the flange portion 93b. A clutch hub 74 of one multi-plate clutch 65 is formed.
[0077]
The hub 93 includes a thrust bearing 92f supported by a fixed shaft 62, a thrust bearing 92g supported via a clutch drum support member 66a, and each clutch hub of the fourth multi-plate clutch 105 and the fifth multi-plate clutch 115. Axial movement is prevented by pinching with the thrust bearing 92h supported by the extension case 83 via the disk 104 supporting 107 and 117.
[0078]
The double pinion type planetary gear 55 fitted and coupled to the spline 93c formed on the outer periphery of the hub 93 is engaged with the sun gear 56, the ring gear 57, the sun gear 56, and the ring gear 57 that are spline-fitted to the spline 93c. The first and second pinions 58 and 59 that mesh with each other, and the carrier 60 that rotatably supports the first and second pinions 58 and 59 via a needle bearing 60 a, and the power that is input to the ring gear 57 Is transmitted to the sun gear 56 and the carrier 60 by torque distribution according to the gear specifications of the sun gear 56 and the ring gear 57, and the carrier 60 is moved to the sun gear 56 by the power input to the sun gear 56 by locking the ring gear 57 to the case 82. It has a function of decelerating and rotating in the reverse direction.
[0079]
On the other hand, a transfer driven gear 92a is attached to one end of a rear drive shaft 92 arranged in parallel with the front drive shaft 91, and a bevel gear 92b meshing with a bevel gear 120a provided at one end of an output shaft 120 described later is attached to the other end. A ball bearing 92c rotatably supports the torque converter case 81 and the end cover 83 of the transmission case 85.
[0080]
The first multi-plate clutch 65 and the third friction engagement element for selectively inputting the output from the transmission shaft 53 to the ring gear 57 or the sun gear 56 between the transmission shaft 53 and the double pinion planetary gear 55. Input switching means 94 having a third multi-plate clutch 95 is provided.
[0081]
The first multi-plate clutch 65 will be described. A clutch drum support member 66a rotatably supported on the fixed shaft 62 is fitted into a spline 53b formed at the tip of the transmission shaft 53, and this clutch drum support member 66a. And a clutch hub 74 is formed integrally with the hub 93 and is coupled to the sun gear 56 of the double pinion planetary gear 55. Thus, the first multi-plate clutch 65 is interposed between the transmission shaft 53 and the sun gear 56 so as to be able to transmit power. Then, the hydraulic pressure in the hydraulic chamber 68 presses the retaining plate 70c that contacts the snap ring 70d fixed in the clutch drum 66 via the piston 69 and the drive plate 70a between the driven plate 70b and the clutch hub 74 to transmit power. Configured to do. A retainer 72 is provided on the opposite side of the piston 69 from the hydraulic chamber 68, and the pressing force of the return spring 73 is urged on the piston 69.
[0082]
The third multi-plate clutch 95 will be described. The clutch drum 66 is shared with the first multi-plate clutch 65, and the clutch hub 77 is shared with the second multi-plate clutch 75. Thus, the third multi-plate clutch 95 is interposed between the transmission shaft 53 and the ring gear 57 so as to be able to transmit power. Then, the hydraulic pressure of the hydraulic chamber 98 presses the retaining plate 100c that contacts the snap ring 100d fixed to the clutch drum 66 via the piston 71 and the drive plate 100a between the driven plate 100b and the clutch hub 77 to transmit power. Configured as follows. The pressing force of the return spring 73 is urged to the piston 71 through the piston 69.
[0083]
On the side opposite to the input switching means 94 with respect to the double pinion planetary gear 55, a transfer drive gear 112 is rotatably supported by a case 82 of a transmission case 85 via a ball bearing 112a, and a hub via a needle bearing 112b. The transfer drive gear 112 is meshed with a transfer driven gear 92a of the rear drive shaft 92 so that power can be transmitted.
[0084]
The carrier 60 of the double pinion planetary gear 55 and the transfer drive gear 112 are spline-fitted so that power can be transmitted.
[0085]
In the fourth multi-plate clutch 105, the clutch drum 106 is coupled to the transfer drive gear 112 via the drum member 106a, and is supported on the end cover 83 so as to be rotatable coaxially with the front drive shaft 91. It is engaged with the spline 91 b of the front drive shaft 91 through 104. Thus, the fourth multi-plate clutch 105 is interposed between the transfer drive gear 112 and the front drive shaft 91 so as to be able to transmit power. Then, the hydraulic pressure of the hydraulic chamber 108 presses the retaining plate 110c contacting the snap ring 110d fixed in the clutch drum 106 via the piston 109 and the drive plate 110a between the driven plate 110b and the clutch hub 107 to transmit power. The piston 109 is biased by the pressing force of the return spring 111.
[0086]
Between the front drive shaft 91 and the end portion of the hub 93, a fifth multi-plate clutch 115 serving as a fifth friction engagement element for selectively transmitting power between the front drive shaft 91 and the hub 93 is disposed. The
[0087]
In the fifth multi-plate clutch 115, the clutch drum 116 is spline-coupled to the spline 93 d of the hub 93, and the clutch hub 117 is spline-fitted to the front drive shaft 91 via the disk 104, so that the front drive shaft 91 and the hub 93 are connected. It is interposed so that power can be transmitted between them. Then, the hydraulic pressure of the hydraulic chamber 118 presses the retaining plate 120c that contacts the snap ring 120d fixed in the clutch drum 116 via the piston 119 and the drive plate 120a between the driven plate 120b and the clutch hub 117 to transmit power. The piston 119 is urged by the pressing force of the return spring 121.
[0088]
Between the case 82 of the transmission case 85 and the ring gear 57 of the double pinion planetary gear 55, a second multi-plate clutch 75 for selectively locking to the case 82 and fixing the ring gear 57 is disposed.
[0089]
The second multi-plate clutch 75 includes a retaining plate 80 c that abuts on a snap ring 80 d fixed in the case 92 via a piston 79 by the hydraulic pressure of the hydraulic chamber 78, and a clutch hub 77 provided on the driven rate 80 b and the ring gear 57. The ring plate 57 is pressed and fixed to the case 82 by pressing the drive plate 81a therebetween, and the pressing force of the return spring 81 is biased to the piston 79.
[0090]
In an oil pan provided under the transmission case 85, the oil pressure from the oil pump 8 is supplied to the vehicle speed sensor 9a, throttle sensor 9b, shift switch 9c, front wheel speed sensor 9d, rear wheel speed sensor 9e, and steering angle sensor 9f. The hydraulic chambers 68 and 78 of the first, second, third, fourth and fifth multi-plate clutches 65, 75, 95, 105 and 115 are controlled by a hydraulic control circuit 9 based on signals from the above. 98, 108, 118 and a control valve for selectively supplying to the continuously variable transmission 30 is provided.
[0091]
In an extension case 84 provided at the rear end of the torque converter case 81, an output shaft 120 is supported by a pair of roller bearings 119 supported by the retainer 117 by a retainer 117 and spaced apart by a predetermined dimension via a spacer 118. Yes.
[0092]
A bevel gear 120a that meshes with a bevel gear 92b provided on the rear drive gear 92 is provided at the tip of the output shaft 120, and the other end is configured to transmit power to the rear differential device 87 via a universal joint, a propeller shaft 86, and the like. The
[0093]
Next, the operation of the thus configured four-wheel drive vehicle driving apparatus will be described with reference to the schematic explanatory views shown in FIGS. 14 to 18 and the first, second, third, fourth, and second driving ranges shown in FIG. The multi-plate clutch 65, 75, 95, 105, 115 will be described with reference to FIG. In this friction engagement element operation explanatory diagram, ◯ indicates that the corresponding multi-plate clutch is engaged or operated, and (◯) indicates that it is engaged or operated as required later. ing.
[0094]
First, the power of the engine 10 is input from the crankshaft 11 to the primary shaft 31 of the continuously variable transmission 30 via the torque converter 20. Then, the primary shaft 31, the primary pulley 33, the drive belt 35, and the secondary pulley 34 are continuously stepped and output to the secondary shaft 32. The speed change output from the secondary shaft 32 is decelerated by the drive gear 38, the counter shaft 39, and the driven gear 54, and is transmitted to the first multi-plate clutch 65 and the third multi-plate clutch 95 via the transmission shaft 53, the clutch drum 69, and the like. Entered. Here, in the neutral (N) range and the parking (P) range, the first and third multi-plate clutches 65 and 95 are released and the power transmission is cut off, and the subsequent power transmission is stopped.
[0095]
In the drive (D) range, which is the forward gear, the third multi-plate clutch 95 and the fifth multi-plate clutch 115 are engaged, and the power transmission state is indicated by a bold line in FIG. That is, hydraulic pressure is supplied from the control valve to the hydraulic chamber 98, and the retaining plate 100c, the driven plate 100b, and the drive plate 100a that are in contact with the snap ring 100d fixed in the clutch drum 66 via the piston 71 are pressed and engaged. Power is transmitted from the driven gear 54 via the transmission shaft 53 to the ring gear 57 of the double pinion planetary gear 55 by the third multi-plate clutch 95, and the fifth multi-plate is connected via the piston 119 by the hydraulic pressure supplied to the hydraulic chamber 118. The fifth multi-plate clutch 115 that presses and engages the retaining plate 120c, the driven plate 120b, and the drive plate 120a of the clutch 115 with the sun gear 56 and the front drive shaft 91 of the double pinion planetary gear 55 Through the hub 93 to the power transmission linked.
[0096]
Accordingly, in the double pinion type planetary gear 55, as shown in FIG. 15, the input side ring gear 57 meshes with the first pinion 58, and the second pinion 59 meshed with the first pinion 58 meshes with the sun gear 56 and the sun gear 56 and the carrier 60. Is rotated in the same direction as the ring gear 57 to transmit the torque to the sun gear 56 and the carrier 60 at a predetermined distribution ratio and rotate differentially, and a hub 93 spline-coupled to the sun gear 56, a fifth multi-plate The clutch 115, the front drive shaft 91 that is coupled to the front drive shaft 91 via a spline-fitted disk 104, and the transfer drive gear 112 that is spline-fitted to the carrier 60 are rotated in the same direction as the ring gear 57. Transfer meshing with 112 And it outputs the driven gear 92a for rotating the backwards ring gear 57 as an input side rear drive shaft 92. Then, it functions as a so-called center differential device that absorbs the rotational difference between the sun gear 56 and the carrier 60 by the rotation and revolution of the first and second pinions 58 and 59 during torque transmission.
[0097]
Here, the torque distribution of the double pinion planetary gear 55 will be described with reference to the schematic diagram of FIG.
[0098]
The input torque to the ring gear 57 is Ti, the front torque output to the front drive shaft 51 via the sun gear 56 and the hub 93, etc., TF, and the carrier 60 is output to the rear drive shaft 92 via the transfer drive gear 112. When the rear side torque is TR, the number of teeth of the sun gear 56 is ZS, and the number of teeth of the ring gear 57 is ZR,
Ti = TF + TR
TF: TR = ZS: (ZR-ZS)
Is established.
[0099]
From this, it is understood that the reference torque distribution of the front side torque TF and the rear side torque TR can be freely set by appropriately setting the number of teeth ZS of the sun gear 56 and the number of teeth ZR of the ring gear 57.
[0100]
If ZS = 37 and ZR = 82,
TF: TR = 37: (82-37)
become. Therefore, the front and rear wheel torque distribution ratio is
TF: TR≈45: 55
Thus, approximately 45% is allocated to the front wheels and approximately 55% is allocated to the rear wheels, and the reference torque distribution of the rear wheel deviation can be set sufficiently.
[0101]
On the other hand, the fourth multi-plate clutch 105 is configured to press the snap ring 110d, the retaining plate 110c, the driven plate 110b, and the drive plate 110a via the piston 109 with the hydraulic pressure of the hydraulic chamber 108 to generate the clutch torque Tc. The clutch torque Tc is variably controlled by the hydraulic pressure from the control valve controlled by the hydraulic pressure control circuit 9.
[0102]
Here, the front wheel rotational speed NF and the rear wheel rotational speed NR detected by the front wheel rotational speed sensor 9d and the rear wheel rotational speed sensor 9e are input to the hydraulic control circuit 9, but after TF <TR when traveling on a slippery road surface. Since the rear wheel always slips first with the reference torque distribution of wheel deviation, the slip ratio is calculated as S = NF / NR (S> O). The slip ratio S and the steering angle ψ input to the hydraulic control circuit 9 from the steering angle sensor 9 f are used to search the clutch pressure Pc from the map shown in FIG. 16 of the hydraulic control circuit 9. Here, when S ≧ 1 non-slip, the clutch pressure Pc is set to a low value, and in the slip state where S <1, the clutch pressure Pc increases as the slip ratio decreases, and the slip ratio S becomes the set value S.₁ P below_max Stipulated in The line pressure is adjusted to the clutch pressure Pc, and the clutch torque Tc of the fourth multi-plate clutch 105 is variably controlled.
[0103]
Accordingly, the fourth multi-plate clutch 105 causes the front drive shaft 91 to drive the front drive via the fourth multi-plate latch 105, the transfer drive gear 112, the carrier 60, the sun gear 56, the hub 93, and the fifth multi-plate clutch 115. A bypass system 125 leading to the shaft 91 is configured separately. In the bypass system 125, when the rear wheel slips, the differential function of the rear wheel rotational speed NR> the rotational speed of the ring gear 57> the front wheel rotational speed NF is established in the transfer unit 90, and the front drive shaft according to the clutch torque Tc. 91 is transmitted from the transfer drive gear 112 through the fourth multi-plate clutch 105 to the front drive shaft 91 with the torque increased by the clutch torque Tc, and further flows to the front wheel to the transfer driven gear 92a meshing with the transfer drive gear 112. Torque obtained by subtracting the clutch torque Tc is input and transmitted to the rear drive shaft 92. As a result, the front and rear wheel torques TF and TR are as follows.
[0104]
TF = 0.45Ti + Tc
TR = 0.55Ti-Tc
Accordingly, in the non-slip state, the clutch torque Tc is zero, so that the torque is distributed to the rear wheel with a bias of TF: TR = 45: 55. Is larger, the input torque Ti flows to the front wheel side via the bypass system 125, and TF: TR = TF as shown in FIG.₁ : TR₁ As a result, the front wheel torque is positively controlled to increase, and the rear wheel torque is reduced to prevent slipping and improve the running performance. When the slip S is equal to or less than the set value, the differential limiting torque is maximized together with the hydraulic pressure of the fourth multi-plate clutch 105, and the sun gear 56 and the carrier 60 are directly connected. For this reason, the transfer unit 90 is differentially locked, and becomes a direct-coupled four-wheel drive running with torque distribution corresponding to the axial load distribution of the front and rear wheels, and the running performance is maximized.
[0105]
On the other hand, when the front wheel slips, a differential function of rear wheel rotational speed NR <rotational speed of ring gear 57 <front rotational speed NF is established in transfer unit 90, and transfer drive gear 112 is transferred from front drive shaft 91 according to clutch torque Tc. Torque is transmitted to the front wheel from the front drive shaft 91 and the torque obtained by reducing the clutch torque Tc flowing to the rear wheel is transmitted. As a result, the front and rear wheel torques TF and TR are as follows.
[0106]
TF = 0.45Ti-Tc
TR = 0.55Ti + Tc
Therefore, in the non-slip state, the clutch torque Tc is zero, so that the torque is distributed to the rear wheel with a bias of TF: TR = 45: 55. When the clutch torque Tc is generated when the front wheel slips, the input torque Ti is The rear wheel torque is actively controlled to increase as it flows to the rear wheel side, and the front wheel torque is reduced to prevent slipping and improve running performance. When the slip ratio is lower than the set value, the differential limiting torque is maximized together with the hydraulic pressure of the fourth multi-plate clutch 105, and the sun gear 56 and the carrier 60 are directly connected. Therefore, torque distribution corresponding to the axial load distribution of the front and rear wheels. This is a direct-coupled four-wheel drive, and the running performance is fully demonstrated. In this way, the torque to the front and rear wheels is controlled widely to avoid the slip state.
[0107]
Further, when the vehicle turns in the torque distribution control accompanying the occurrence of the slip described above, the differential limiting torque of the fourth multi-plate clutch 105 is corrected to decrease by the steering angle ψ. For this reason, the differential limitation of the transfer unit 90 is reduced, and the difference in rotational speed can be sufficiently absorbed, tight corner braking phenomenon is avoided, and good maneuverability is ensured.
[0108]
In the reverse (R) range, which is the reverse gear, the third multi-plate clutch 95 and the fifth multi-plate clutch 115 are released, and the first multi-plate clutch 65, the fourth multi-plate clutch 105, and the second multi-plate clutch 115 are released. The plate clutch 75 is engaged and the power transmission state shown in FIG. That is, the hydraulic pressure is supplied to the hydraulic chamber 68 and the snap ring 70d, the retaining plate 70c, the driven plate 70b, and the drive plate 70a are pressed via the piston 69 to engage the first multi-plate clutch 65 and the transmission shaft 53. Power is transmitted to the sun gear 56 of the double pinion type planetary gear 55 from the hub 93, and the snap ring 80d, the retaining plate 80c, the drive plate 80a, and the driven plate 80b are connected via the piston 79 by the hydraulic pressure supplied to the hydraulic chamber 78. The ring gear 57 is locked and fixed to the case 82 by the second multi-plate clutch 75 that is pressed and engaged. Then, the hydraulic pressure is supplied to the hydraulic chamber 108, and the snap ring 110d, the retaining plate 110c, the driven plate 110b, and the drive plate 110a are pressed via the piston 109 to drive the front drive from the transfer drive gear 112 by the fourth multi-plate clutch 105. Power can be transmitted to the shaft 91.
[0109]
Accordingly, as shown in FIG. 18, the double pinion planetary gear 55 rotates along the ring gear 57 while the first and second pinions 58 and 59 meshing with each other by the rotation of the input-side sun gear 56 rotate in the opposite directions. The carrier 60 is rotated in the opposite direction to the sun gear 56 to rotate the transfer drive gear 112 in the opposite direction to the input side, and the transfer drive gear 112 is connected to the front drive shaft 91 via the fourth multi-plate clutch 105. Power is transmitted and the rear drive shaft 92 is rotationally driven in the direction opposite to the front drive shaft 91.
[0110]
Therefore, the input from the driven gear 54 is such that the ring gear 57 of the double pinion type planetary gear 55 is locked to the case 82 by the second multi-plate clutch 75 to reverse the front drive shaft 91 and the rear in the direction opposite to the drive (D) range state. The double pinion planetary gear 55 is output to the drive shaft 92 and has a forward / reverse switching function.
[0111]
In this case, the gear ratio output to the front drive shaft 91 and the rear drive shaft 92 with respect to the input of the sun gear 56 is set by the following equation.
[0112]
Gear ratio = [ZS + (− ZR)] / ZS
If ZS = 37 and ZR = 82 as in the above,
Gear ratio = [37 + (− 82)] / 37 = −1.216
Thus, the reduction ratio in the reverse (R) range is appropriately secured.
[0113]
On the other hand, the torque Ti input to the sun gear 56 is transmitted to the front drive shaft 91 according to the clutch torque Tc, and the torque obtained by subtracting the clutch torque Tc transmitted to the front wheels is input to the rear wheels. , TR is as follows.
[0114]
Ti = TF + TR
TR = Ti-Tc
TF = Tc
Therefore, by increasing the clutch torque Tc when the rear wheel slip occurs, the input torque Ti is caused to flow to the front wheel side, the front wheel torque is actively increased and controlled, the rear wheel torque is reduced to prevent slipping, and the running performance is improved. In addition, when the front wheel slips, the input torque Ti is caused to flow to the rear wheel side by reducing the clutch torque Tc, and the rear wheel torque is positively increased to reduce the front wheel torque so that slip does not occur and the running performance is improved. When the slip ratio is less than the set value, the clutch torque Tc is maximized together with the hydraulic pressure of the fourth multi-plate clutch 105, and the front drive shaft 91 and the transfer drive gear 112 are directly connected to each other, and the torque corresponding to the axial load distribution of the front and rear wheels. Running performance is maximized with the direct-coupled 4-wheel drive. In the case of further turning, the differential limiting torque of the fourth multi-plate clutch 105 is reduced by the steering angle ψ, and the difference in rotational speed can be sufficiently absorbed, and the tight corner braking phenomenon is avoided. , The maneuverability will be good.
[0115]
Therefore, in the present embodiment described above, the front drive shaft 91 and the rear drive shaft 92 that transmit power to the front differential device 40 or the rear differential device 87 that are configured to be transmitted to the output side of the belt-type continuously variable transmission 30 are laterally arranged. A third multi-plate clutch that is arranged in parallel to the crankshaft 11 of the stationary engine 10, is provided with a double pinion planetary gear 55 coaxially with the front drive shaft 91, and transmits the output from the continuously variable transmission 30 to the ring gear 57. 95, the first multi-plate clutch 65 that transmits to the sun gear 56 via the hub 93, the fourth multi-plate clutch 105 that connects the front drive shaft 91 and the transfer drive gear 112 so that power can be transmitted, the carrier 60 and the transfer drive. A fifth multi-plate that connects the gear 112 so that power can be transmitted. A second multi-plate clutch 75 that locks the latch 115 and the ring gear 57 is provided, and the first, second, third, fourth, and fifth multi-plate clutches 65, 75, 95, 105, and 115 are selected. Center differential which enables appropriate torque distribution and differential limitation to the front drive shaft 91 and the rear drive shaft 92 in the drive (D) range which is the forward stage and the reverse (R) range which is the reverse stage by controlling them in a controlled manner It functions as a device to obtain good running performance and functions as a forward / reverse switching device when switching to the drive (D) range or reverse (R) range.
[0116]
Therefore, a dedicated double-pinion planetary gear that functions independently for each of the center differential device and the forward / reverse switching device has been conventionally required. However, both functions are achieved by a single double-pinion planetary gear, and it is driven while maintaining high performance. Device configuration and control can be simplified and reduced in weight, reducing cost and downsizing, especially the overall length in the vehicle body width direction. It is possible to obtain a degree of freedom in designing the vehicle body while ensuring a crash stroke at the time of a side collision and a work space for assembling and maintenance.
[0117]
Further, instead of the torque converter 20, an electromagnetic clutch or a wet clutch can be used as a starting clutch. In this case, the belt-type continuously variable transmission 30 is connected to the primary shaft 31 in the neutral (N) range and the parking (P) range. The power transmission after the continuously variable transmission 30 with the input cut off is eliminated.
[0118]
According to the embodiment described above, the torque converter 20, the belt type continuously variable transmission 30, the front differential device 40, and these are accommodated between the drive device for a two-wheel drive vehicle and the drive device for a four-wheel drive vehicle. In addition to the differential and converter housing 2 and the side cover 3, the transfer units 40 and 90 can share many main parts such as the double pinion planetary gear 55, the first and second multi-plate clutches 65 and 75, and the two-wheel drive. A power transmission mechanism for transmitting power to the rear differential device such as the third, fourth and fifth multi-plate clutches 95, 105, 115 and the rear drive shaft 92, transfer drive gear 112, etc. based on the vehicle drive device is additionally provided. By disposing, the main part of the drive device for a four-wheel drive vehicle can be configured relatively easily. It is possible to reduce the significant production cost becomes possible.
[0119]
【The invention's effect】
According to the vehicle drive device of the present invention described above, the drive shaft is arranged in parallel to the crankshaft of the horizontal engine, the double pinion planetary gear is provided coaxially with the drive shaft, and the first and second frictional engagements are provided. Since the forward / reverse switching is performed by the selective operation of the joint element, the drive device can be made compact, and the freedom of the vehicle body design, the crash stroke, and the work space when the transmission is detached can be secured.
[0120]
Moreover, the input switching means is interposed between the transmission and the double pinion type planetary gear, and the power transmission mechanism is additionally provided, so that the main part of the drive device for a four-wheel drive vehicle can be configured relatively easily. There are many common parts, and the present invention has effects peculiar to the present invention such as a significant reduction in manufacturing cost.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of an embodiment of a vehicle drive device according to the present invention.
FIG. 2 is a cross-sectional view illustrating a vehicle drive device.
3 is an enlarged view of essential parts of the cross-sectional view shown in FIG.
4 is an explanatory view showing the arrangement of main parts as seen from the direction of arrow A in FIG. 2; FIG.
FIG. 5 is a schematic explanatory view showing the operation in the same manner.
FIG. 6 is a schematic explanatory view showing the operation in the same manner.
FIG. 7 is a schematic explanatory view showing the operation in the same manner.
FIG. 8 is a schematic explanatory view showing the operation in the same manner.
FIG. 9 is an operation explanatory view of the friction engagement element showing the action in the same manner.
FIG. 10 is also a diagram showing an outline of a vehicle drive device of the present invention.
FIG. 11 is a cross-sectional view illustrating the vehicle drive device.
12 is an enlarged view of essential parts of the cross-sectional view shown in FIG.
13 is an explanatory view showing the arrangement of main parts as seen from the direction of arrow B in FIG.
FIG. 14 is a schematic explanatory view showing the operation in the same manner.
FIG. 15 is a schematic explanatory view showing the operation in the same manner.
FIG. 16 is a schematic explanatory view showing the operation in the same manner.
FIG. 17 is a schematic explanatory view showing the operation in the same manner.
FIG. 18 is a schematic explanatory view showing the operation in the same manner.
FIG. 19 is an operation explanatory view of the friction engagement element showing the action in the same manner.
[Explanation of symbols]
10 engine
11 Crankshaft
20 Torque converter
30 belt type continuously variable transmission
31 Primary axis
32 Secondary shaft
33 Primary pulley
34 Secondary pulley
35 Drive belt
40 Front differential device
50 transfer units
51 drive shaft
52 hub
53 Transmission shaft
55 Double pinion type planetary gear
56 Sungear
57 Ring gear
58 First Pinion
59 Second Pinion
60 Carrier
65 First multi-plate clutch
75 Second multi-plate clutch
87 Rear differential device
90 Transfer unit
91 Front drive shaft
92 Rear drive shaft
93 Hub
94 Input switching means
95 Third multi-plate clutch
105 4th multi-plate clutch
112 Transfer drive gear
115 fifth multi-plate clutch

Claims (1)

With the engine placed horizontally,
A primary shaft that extends in the vehicle body width direction on the same axis as the rotation axis of the crankshaft of the engine and that receives output from the engine, and a secondary that is arranged rearward of the vehicle body and parallel to the primary shaft at a high position A drive belt is wound between a primary pulley provided on the primary shaft and a secondary pulley provided on the secondary shaft, and the ratio of the winding diameter of the drive belt to the primary pulley and the secondary pulley. A belt type continuously variable transmission that changes speed and
A front drive shaft transmits power to the front differential device is arranged parallel against the said secondary shaft below the said secondary shaft,
A double pinion planetary gear disposed coaxially with the front drive shaft;
A first friction engagement element that selectively transmits power from the secondary shaft to the carrier of the double pinion planetary gear;
An input member for transmitting power from a secondary shaft to the sun gear of the double pinion planetary gear;
Output transmission means for transmitting power from the carrier of the double pinion planetary gear to the front drive shaft;
A second friction engagement element that selectively rotates and locks the ring gear of the double pinion planetary gear;
In the forward stage, the first friction engagement element is in a power transmission state, the second friction engagement element is in a ring gear rotation allowable state, and in the reverse stage, the first friction engagement element is in a released state. The vehicle drive device characterized in that the second friction engagement element is in a ring gear rotation locking state.

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