JP4418166B2 - Power transmission device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power transmission device including a differential mechanism.
[0002]
[Prior art]
Patent Document 1 describes a differential device 701 as shown in FIG. The differential device 701 includes a differential case 703 that is rotationally driven by the driving force of the engine, a plurality of pinion shafts 705 coupled to the differential case 703, a pinion gear 707 supported on each pinion shaft 705, and each pinion gear 707. And a bevel gear type differential mechanism 713 including output side gears 709 and 711 connected to the axles, respectively, and a clutch ring 715 and a side gear 711 movably connected to the differential case 703. The meshing clutch 717, the turn spring 719 that biases the clutch ring 715 to the meshing release side of the meshing clutch 717, and the clutch ring 715 that slides against the biasing force of the return spring 719 And a pneumatic actuator 721 to match viewing.
[0003]
The rotation of the differential case 703 is distributed from the pinion shaft 705, the pinion gear 707, and the side gears 709 and 711 to the left and right wheels through the respective axles, and when a driving resistance difference occurs between the left and right wheels while traveling on a rough road. The driving force of the engine is differentially distributed to the left and right sides by the rotation of each pinion gear 707.
[0004]
When the actuator 721 slides the clutch ring 715 and the engagement clutch 717 is engaged, the differential rotation of the differential mechanism 713 is locked to prevent the wheels from slipping, improving the running performance and escape performance of the vehicle on rough roads and the like. However, the startability, acceleration and maneuverability are improved even on good roads. When the operation of the actuator 721 is stopped, the clutch ring 715 is retracted by the urging force of the return spring 719 and the meshing clutch 717 is disengaged, the differential lock function is released, and the differential mechanism 713 is differentially rotated. Becomes free.
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-96461
[0006]
[Problems to be solved by the invention]
As described above, in order to improve the running performance, escape performance, startability, acceleration, maneuverability, etc. of the vehicle, the differential device requires a mechanism for limiting the differential, and this differential limiting mechanism In addition to the differential lock mechanism such as the meshing clutch 717 of the differential device 701, an initial torque adding mechanism that presses the friction portion with a spring or the like to give a constant differential limiting torque (initial torque), and a differential by a friction clutch. There are a differential limiting mechanism that provides a limiting torque, a viscous fluid coupling that provides a differential limiting torque using a shearing resistance of a viscous fluid, and the like.
[0007]
The initial torque addition mechanism is conventionally arranged inside the differential case, but in the case of a differential device (conventional differential) without differential limiting force, a sufficient torque bias ratio (differential limiting when one wheel slips) The driving force sent to the other wheel by force) cannot be obtained, and the space for arranging the initial torque adding mechanism and the necessary frictional portion cannot be obtained.
[0008]
Further, it is difficult for the initial torque adding mechanism disposed inside the differential case to adjust the initial torque from the outside of the differential case.
[0009]
In addition, in the case of the differential lock mechanism, the differential limiting mechanism using the friction clutch, and the viscous fluid coupling, a certain amount of arrangement space is required, and a differential case with a large volume is required. The differential case cannot be shared.
[0010]
In addition, an actuator is required for the differential lock mechanism and the differential limiting mechanism using the friction clutch, and when a hydraulic actuator such as a hydraulic actuator or a pneumatic actuator is used as this actuator, the piping is routed or the pump is arranged. Therefore, a problem arises that it is difficult to secure an arrangement space when accommodated in a transmission case or a transfer case.
[0011]
In particular, it is difficult to accommodate a differential limiting device using a fluid pressure actuator in a transmission case of an FF vehicle (front engine / front drive vehicle).
[0012]
In addition, automatic transmissions (ATs) dislike contamination (especially contamination by metallic wear powder: contaminants) in mission oils. Therefore, when a differential device is housed in the transmission case of an automatic transmission, contamination is not possible. I don't want to create a friction part.
[0013]
Therefore, the present invention can adjust the initial torque from the outside of the differential case (differential mechanism housing member), and can share the differential case with the conventional differential. The purpose is to provide a power transmission device (a differential device with a differential limiting function) that does not cause a problem of contamination.
[0014]
[Means for Solving the Problems]
  The power transmission device according to claim 1 is:A power transmission device disposed in a power system of a four-wheel drive vehicle in which front wheels and rear wheels are driven via a front differential and a rear differential by a driving force of a prime mover, and is housed in a transmission case, and the front differential and the rear differential Composed of one ofA differential mechanism is accommodated in a differential mechanism accommodating member that is a differential rotating member on the input side of driving force for the differential mechanism, and a transfer case connected to the transmission case, and the differential mechanism accommodating member And connected at one endAnd distributes the driving force to the other side of the front differential and the rear differential via a gear provided on the outer periphery.A pair of drive shafts that pass through the hollow shaft, the differential mechanism housing member, and the hollow shaft and output a driving force from the differential mechanismOne drive shaftAnd the differential mechanism housing member sideSaid one drive shaftAn intermittent mechanism capable of controlling the transmission torque between the other end of the hollow shaft and the drive shaft on the opposite side of the differential mechanism housing member with the hollow shaft interposed therebetween. It is arrange | positioned between.
[0015]
Thus, in the power transmission device of the present invention, the intermittent mechanism (differential limiting device) capable of controlling the transmission torque is disposed outside the differential mechanism housing member (difference case).
[0016]
Therefore, it becomes easy to arrange the initial torque adding mechanism in the differential limiting device, and the initial torque can be adjusted from the outside of the differential mechanism housing member.
[0017]
In addition, even if the differential limiting mechanism is any of an initial torque adding mechanism, a differential lock mechanism, a differential limiting mechanism that applies a differential limiting torque by a friction clutch, and a viscous fluid coupling, these are differential mechanism housing members. Since the differential mechanism housing member does not need to be enlarged, the differential case can be shared with conventional differentials, and these differential limiting mechanisms can be used to sufficiently limit the differential. Torque can be obtained.
[0018]
In addition, since the differential limiting device is arranged outside the differential mechanism housing member, even if contamination (metal wear powder) occurs in the differential limiting device, the differential mechanism (for example, a gear meshing portion) Adverse effects (wear, heat generation, vibration, etc.) are avoided.
[0019]
Further, in the configuration of the present invention in which the differential limiting device is disposed outside the differential mechanism housing member, the differential limiting device can be disposed outside the transmission case or the transfer case. The problem of the arrangement space for the transmission case in the FF vehicle) and the transfer case and the problem of contamination for the transmission (particularly, the automatic transmission) are solved.
[0021]
  Since the hollow shaft is disposed between the differential mechanism housing member and the intermittent mechanism, the intermittent mechanism restricts differential rotation transmitted through the drive shaft between the hollow shaft and the drive shaft.
[0022]
  In this configuration, the differential mechanism housing member and the intermittent mechanismHollow shaftSince the degree of freedom in deciding where to place the interrupting mechanism is improved, the layout becomes easier.
[0025]
  Claim2The invention of claim1The power transmission device according to claim 1, wherein the intermittent mechanism is a friction clutch.1'sActions and effects equivalent to the configuration can be obtained.
[0026]
In addition, the friction clutch is intermittently operated by an actuator to adjust the fastening force (differential limiting force), and is not operated by transmission torque or differential torque. Therefore, a desired differential limiting force can be stably obtained.
[0027]
  Claim3The invention of claim2The power transmission device according to claim 1, wherein the friction clutch is fastened by a cam thrust force of a cam mechanism that operates by receiving torque.2The same operation and effect as the configuration of can be obtained.
[0028]
In addition, the friction clutch can obtain a sufficient differential limiting force by the boosting function of the cam mechanism that operates by receiving torque, and the differential limiting force can be easily controlled by adjusting the cam thrust force of the cam mechanism.
[0029]
  Claim4The invention of claim1The power transmission device according to claim 1, wherein the intermittent mechanism is a rotation-sensitive coupling.1'sActions and effects equivalent to the configuration can be obtained.
[0030]
In addition, the rotational difference-sensitive coupling is, for example, the above-described viscous fluid coupling, and no contamination occurs. Therefore, even if the power transmission device of the present invention is accommodated in the transmission case or the transfer case, the contamination is not affected. There is no problem.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
[First Embodiment]
The power transmission device 1 (first embodiment of the present invention) and the transfer 3 configured using the power transmission device 1 will be described with reference to FIGS. FIG. 1 shows a power transmission device 1 and a transfer 3, and FIG. 2 shows a four-wheel drive vehicle using the transfer 3. The left and right directions are the four-wheel drive vehicle and the left and right directions in FIG. 1, and the upper side in FIG. 1 corresponds to the front of the vehicle.
[0033]
[Configuration of Power Transmission Device 1]
The power transmission device 1 accommodates a bevel gear type differential mechanism 5, a differential case 7 (differential mechanism accommodation member) that is a differential rotation member on the input side of driving force for the differential mechanism 5, and the differential mechanism 5. Transmission torque can be controlled between a pair of drive shafts 9 and 11 (drive shafts) that output drive force, and a hollow shaft 13 (torque transmission mechanism) and drive shaft 11 (torque transmission mechanism) connected to the differential case 7 Multi-plate clutch 15 (intermittent mechanism: friction clutch), a disc spring 97 (initial torque adding mechanism: FIG. 2) that presses the multi-plate clutch 15 to give a constant initial torque, and a hydraulic actuator that presses the multi-plate clutch 15 And a controller for operating the hydraulic actuator. The multi-plate clutch 15 and the hydraulic actuator are connected to the differential case 7 and the transfer case. It is located outside of the over scan 75. The differential mechanism 5 is housed in a differential case 7 and constitutes a front differential 31.
[0034]
[Configuration of Transfer 3]
The transfer 3 includes a power transmission device 1, a direction changing gear set 21 including bevel gears 17 and 19, a drive pinion shaft 23 formed integrally with the bevel gear 19, and a flange 25 splined to the drive pinion shaft 23. It is composed of
[0035]
[Configuration of power system of four-wheel drive vehicle]
As shown in FIG. 2, the power system of the four-wheel drive vehicle described above includes a horizontally installed engine 27 (prime mover), a transmission 29, a transfer 3 (and a power transmission device 1), and a power transmission device arranged at the front of the vehicle. 1 includes a front differential 31 (a differential device that distributes the driving force of the engine to the left and right front wheels), drive shafts 9 and 11 (front axles), left and right front wheels 33 and 35, a rear wheel side propeller shaft 37, and direction change. The gear set 39, the rear differential 41 (a differential device that distributes the driving force of the engine to the left and right rear wheels), the rear axles 43 and 45, and the left and right rear wheels 47 and 49 are configured.
[0036]
The driving force of the engine 27 is transmitted from the ring gear 53 meshed with the output gear 51 of the transmission 29 to the differential case 7 of the front differential 31 and distributed from the differential mechanism 5 to the left and right front wheels 33 and 35 via the drive shafts 9 and 11. At the same time, it is transmitted from the differential case 7 to the rear differential 41 through the hollow shaft 13, the direction change gear set 21, the drive pinion shaft 23, the flange 25, and the propeller shaft 37 and the direction change gear set 39. , 45 to the left and right rear wheels 47, 49.
[0037]
[Description of each member constituting power transmission device 1 and transmission 3]
The differential mechanism 5 includes a plurality of pinion shafts 55, a plurality of pinion gears 57, and left and right output side gears 59 and 61. Each pinion shaft 55 is fixed at the end to the differential case 7 and is prevented from coming off by a spring pin 63, and each pinion gear 57 is supported on the pinion shaft 55. The side gears 59 and 61 mesh with the respective pinion gears 57 from the left and right, the side gear 59 is splined to the left drive pinion shaft 9, and the side gear 61 is splined to the right drive pinion shaft 11.
[0038]
The differential case 7 is accommodated in the transmission case 65 and supported by the transmission case 65 by ball bearings 67 and 69. The ring gear 53 is fixed to the differential case 7 by bolts 71 and 71. Transmission oil is sealed in the transmission case 65.
[0039]
The drive shaft 9 penetrates the differential case 7 and the transmission case 65 to the left and protrudes to the outside, and is connected to the left front wheel 33 side. Further, a seal 73 is disposed between the drive shaft 9 and the transmission case 65 to prevent oil leakage from the transmission case 65 and entry of foreign matters from the outside.
[0040]
The drive shaft 11 passes through the differential case 7, the transmission case 65, and the transfer case 75 to the right and protrudes to the outside, and is connected to the right front wheel 35 side. Transfer oil is sealed in the transfer case 75.
[0041]
The hollow shaft 13 is accommodated in the transfer case 75, penetrates into the transmission case 65, and is splined to the right end portion of the differential case 7. A cover 77 is fixed to the right end portion of the transfer case 75 with a bolt 79. The hollow shaft 13 is supported at the left end portion by the thrust bearing 81 on the transfer case 75, and the right end portion is supported at the cover 77 by the thrust bearing 83. Has been. The drive shaft 11 passes through the hollow shaft 13, and a speed gear pulse gear 85 is connected to the outer periphery of the hollow shaft 13. Seals 87 and 87 are disposed between the transmission case 65 and the transfer case 75 and the hollow shaft 13, and seals 89 and 89 are disposed between the drive shaft 11 and the hollow shaft 13. Each prevents mixing with oil.
[0042]
The multi-plate clutch 15 is arranged outside (on the right side) of the transfer case 75 as described above, and includes a clutch housing 91 splined to the hollow shaft 13 and a clutch hub 93 splined to the drive shaft 11. It is provided between.
[0043]
The hydraulic actuator of the multi-plate clutch 15 includes a cylinder and a piston 95, and the piston 95 is positioned on the clutch housing 91 by a snap ring 96. The disc spring 97 is disposed between the piston 95 and the multi-plate clutch 15, and presses the multi-plate clutch 15 to give an initial torque as described above. An O-ring 99 is provided between the transfer case 75 and the cover 77, a seal 101 is provided between the cover 77 and the clutch housing 91, and a seal 103 is provided between the piston 95 and the drive shaft 11. An O-ring 104 is disposed between the piston 95 and the clutch housing 91 to prevent oil leakage from the transfer case 75 and entry of foreign matter from the outside.
[0044]
The bevel gears 17 and 19 constitute the direction change gear set 21 as described above. The bevel gear 17 is fixed to the flange portion 105 provided on the intermediate shaft 13 with the bolt 107, and the bevel gear 19 is driven as described above. The pinion shaft 23 is integrally formed. The direction change gear set 21 is given a speed increasing function by making the input-side bevel gear 17 larger in diameter than the output-side bevel gear 19.
[0045]
The drive pinion shaft 23 is disposed in the longitudinal direction of the vehicle. A cylindrical member 109 is fixed to the rear portion of the transfer case 75 by a bolt 111, and the drive pinion shaft 23 is supported on the cylindrical member 109 by thrust bearings 113 and 115, and a cylindrical shape is interposed between the thrust bearings 113 and 115. A spring member 117 is disposed.
[0046]
The flange 25 is splined to the drive pinion shaft 23 as described above, and a nut 119 is screwed to the rear end portion of the drive pinion shaft 23, and the thrust bearing 115, the spring member 117, and the thrust are connected via the flange 25. The thrust bearings 115 and 113 are preloaded by pressing the bearing 113 and the drive pinion shaft 23 is centered. Seal members 123 and 125 constituting a non-contact type seal 121 for preventing intrusion of dust and the like between them are fixed to the flange 25 and the cylindrical member 109, respectively. Also, the cylindrical member 109, the flange 25, and the seal member 123 are fixed. (Contact type) seal 127 is disposed between the transfer case 75 and the cylindrical member 109, and an O-ring 129 is disposed between the transfer case 75 and the oil leakage from the transfer case 75. Each entry of foreign matter is prevented.
[0047]
The controller performs operation of the hydraulic actuator, control of the pressing force, stop operation, and the like with the hydraulic pump.
[0048]
[Operation of Power Transmission Device 1 and Transfer 3]
In the power transmission device 1 and the transfer 3, the driving force of the engine 27 transmitted to the differential case 7 of the front differential 31 as described above is transmitted from the differential case 7 to the direction change gear set 21 via the hollow shaft 13 and the bevel gear 17. Then, the direction changing gear set 21 changes the direction while increasing the transmitted driving force and transmits it to the bevel gear 19 (drive pinion shaft 23), and transmits it from the flange 25 to the rear differential 41 via the propeller shaft 37. To do.
[0049]
Further, when a driving resistance difference occurs between the front wheels 33 and 35 during driving on a rough road, starting, acceleration, etc., the pinion gear 57 of the front differential 31 rotates to drive the driving force of the engine 27 to the left and right front wheels 33, 35. Differential distribution to 35.
[0050]
In addition, when one of the front wheels 33 and 35 is idled and the driving force tends to escape during a rough road, acceleration, or starting, the initial torque (a certain difference) applied to the multi-plate clutch 15 by the disc spring 97 is avoided. Dynamic limiting force) restricts the differential rotation of the front differential 31 (differential mechanism 5), and as a result, the driving force is transmitted to the other of the front wheels 33, 35, and escape performance, acceleration, and start of the rough road. The fall of property etc. is prevented.
[0051]
Further, when the controller operates the hydraulic actuator, the multi-plate clutch 15 is pressed and fastened, the differential limiting force of the front differential 31 is strengthened, and the escape performance, acceleration performance, and startability of the rough road are improved.
[0052]
The controller adjusts the pressing force (differential limiting force) of the multi-plate clutch 15 by the hydraulic actuator to give the front differential 31 the optimum differential limiting function according to the vehicle running conditions, road surface conditions, etc. Can do.
[0053]
When the operation of the hydraulic actuator is stopped and the multi-plate clutch 15 is released, the front differential 31 returns to the state where the initial torque is applied by the disc spring 97.
[0054]
[Effects of power transmission device 1 and transfer 3]
Since the power transmission device 1 and the transfer 3 are configured as described above, the following effects can be obtained.
[0055]
Since the multi-plate clutch 15 as the differential limiting device and the disc spring 97 as the initial torque adding mechanism are arranged outside the differential case 7 and the transfer case 75, the initial torque is applied to the multi-plate clutch 15 using the disc spring 97. Since it is not necessary to disassemble the differential case 7 and the transfer case 75 when changing the initial torque by replacing the disc spring 97, the initial torque can be easily adjusted from the outside. .
[0056]
Further, since the multi-plate clutch 15 is arranged outside the differential case 7, it is not necessary to enlarge the differential case 7 to accommodate the multi-plate clutch 15, and the differential case 7 can be shared with the conventional differential. become.
[0057]
Even if contamination (metal wear powder) is generated in the multi-plate clutch 15, adverse effects on the meshing portions of the gears 57, 59, 61 of the differential mechanism 5 accommodated in the differential case 7 (wear, heat generation, No vibration).
[0058]
In the configuration of the present invention, the multi-plate clutch 15 and the hydraulic actuator can be disposed outside the transmission case 65 and the transfer case 75 as described above. The problem of contamination with respect to the transmission 29 and the transfer 3 is solved.
[0059]
Further, since the drive shaft 11 passes through the differential case 7 and the multi-plate clutch 15, the differential case 7 and the multi-plate clutch 15 are arranged coaxially, and the power transmission device 1 is laid out in a radially compact manner. The onboard property of the transfer 3 is improved.
[0060]
Further, since the multi-plate clutch 15 operated by the hydraulic actuator is not affected by the transmission torque or the differential torque, a desired differential limiting function can be stably obtained.
[0061]
Further, since the multi-plate clutch 15 is small and has a wide friction area, a large coupling force (differential limiting force) can be obtained.
[0062]
[Second Embodiment]
The power transmission device 201 (second embodiment of the present invention) and the transfer 3 configured using the power transmission device 201 will be described with reference to FIG. The power transmission device 201 is an example in which the cone clutch 203 is used instead of the multi-plate clutch 15 in the power transmission device 1 of the first embodiment, and hereinafter, the same reference numerals are given to members having the same functions as the power transmission device 1. It will be explained with reference.
[0063]
[Configuration of Power Transmission Device 201]
The power transmission device 201 includes a differential case 7 that houses the differential mechanism 5, drive shafts 9 and 11, and a cone clutch 203 that can control transmission torque between the hollow shaft 13 and the drive shaft 11 connected to the differential case 7. (Intermittent mechanism: friction clutch), a disc spring 97 that presses the cone clutch 203 and applies a constant initial torque, a hydraulic actuator that presses the cone clutch 203, and a controller that operates the hydraulic actuator. The clutch 203 and the hydraulic actuator are disposed outside the differential case 7 and the transfer case 75.
[0064]
[Description of each member constituting power transmission device 201]
The cone clutch 203 includes a conical surface 205 formed on the clutch housing 91 on the hollow shaft 13 side and a conical surface 209 formed on the clutch ring 207 on the drive shaft 11 side.
[0065]
The disc spring 97 is disposed between the clutch ring 207 and the piston 95 of the hydraulic actuator, and presses the cone clutch 203 as described above to give an initial torque.
[0066]
[Operation of Power Transmission Device 201 and Transfer 3]
The power transmission device 201 and the transfer 3 distribute the driving force of the engine 27 to the left and right front wheels 33 and 35 by the front differential 31, and also the differential case 7, the hollow shaft 13, the direction change gear set 21, the drive pinion shaft 23, and the flange 25. To the rear differential 41 through the propeller shaft 37.
[0067]
Further, when a driving resistance difference occurs between the front wheels 33 and 35 during traveling on a rough road, starting, acceleration, or the like, the pinion gear 57 of the front differential 31 rotates to drive the driving force of the engine 27 to the left and right front wheels 33. , 35 and when one of the front wheels 33, 35 is idling and the driving force is about to escape, the front differential 31 (differential) is generated by the initial torque applied to the cone clutch 203 by the disc spring 97. The differential rotation of the mechanism 5) is limited, the driving force is transmitted to the other of the front wheels 33, 35, and deterioration of rough road escape performance, acceleration performance, startability, and the like is prevented.
[0068]
Further, when the cone clutch 203 is engaged, the differential limiting force of the front differential 31 is strengthened, and rough road escape performance, acceleration performance, and startability can be improved.
[0069]
Further, by adjusting the pressing force (differential limiting force) of the cone clutch 203, an optimum differential limiting function can be given to the front differential 31 according to the running condition of the vehicle, the road surface condition, and the like. When the clutch 203 is released, the front differential 31 returns to the state where the initial torque is applied by the disc spring 97.
[0070]
[Effects of power transmission device 201 and transfer 3]
Since the power transmission device 201 and the transfer 3 are configured as described above, the following effects can be obtained.
[0071]
Since the cone clutch 203 and the disc spring 97 are arranged outside the differential case 7 and the transfer case 75, it is easy to apply initial torque to the cone clutch 203 using the disc spring 97, and the disc spring 97 is replaced. In changing the initial torque, it is not necessary to disassemble the differential case 7 or the transfer case 75, so that the initial torque can be easily adjusted from the outside.
[0072]
Further, since the cone clutch 203 is arranged outside the differential case 7, it is not necessary to enlarge the differential case 7 in order to accommodate the cone clutch 203, and the differential case 7 can be shared with the conventional differential. .
[0073]
Further, even if contamination (metal wear powder) is generated in the cone clutch 203, adverse effects (wear, heat generation, vibration) on the meshing portions of the gears 57, 59, 61 of the differential mechanism 5 accommodated in the differential case 7 are achieved. Etc.) does not occur.
[0074]
Further, since the cone clutch 203 and the hydraulic actuator can be arranged outside the transmission case 65 and the transfer case 75 as described above, the problem of the arrangement space with respect to the transmission case 65 and the transfer case 75, the transmission 29 and the transfer 3 with respect to Freed from contamination problems.
[0075]
Further, when the drive shaft 11 passes through the differential case 7 and the cone clutch 203, the differential case 7 and the cone clutch 203 are coaxially arranged, and the power transmission device 201 is laid out in a compact radial direction. In-vehicle performance is improved.
[0076]
Further, since the cone clutch 203 operated by the hydraulic actuator is not affected by the transmission torque or the differential torque, a desired differential limiting function can be stably obtained.
[0077]
Further, the cone clutch 203 has a small number of parts and a large coupling force (differential limiting force) due to the wedge effect of the conical surfaces 205 and 209.
[0078]
[Third Embodiment]
A power transmission device 301 (a third embodiment of the present invention) and the transfer 3 configured using the power transmission device 301 will be described with reference to FIGS. The power transmission device 301 is an example in which the multi-plate clutch 15 is operated by the electromagnet 303 and the armature 305 instead of the hydraulic actuator in the power transmission device 1 of the first embodiment. The members having the same functions as those in FIG.
[0079]
[Configuration of Power Transmission Device 301]
The power transmission device 301 includes a differential case 7 that houses the differential mechanism 5, drive shafts 9 and 11,
A multi-plate clutch 15 disposed outside the differential case 7 and the transfer case 75 and capable of controlling transmission torque between the hollow shaft 13 connected to the differential case 7 and the drive shaft 11, an electromagnet 303, and an electromagnet 303. The armature 305 that presses the multi-plate clutch 15 and a controller that operates the electromagnet 303 are provided. The multi-plate clutch 15 and the electromagnet 303 are disposed outside the differential case 7 and the transfer case 75.
[0080]
[Description of each member constituting power transmission device 301]
The multi-plate clutch 15 is arranged outside the transfer case 75 as described above, and is provided between the clutch housing 91 on the hollow shaft 13 side and the clutch hub 93 on the drive shaft 11 side.
[0081]
A rotor 307 made of a magnetic material and constituting a part of the magnetic flux circulation path of the electromagnet 303 is supported on the outer periphery of the drive shaft 11 so as to be relatively rotatable, and the protrusion 309 is notched 311 of the clutch housing 91. And is positioned in the axial direction by a snap ring 313 attached to the clutch housing 91.
[0082]
The rotor 307 is divided into a radially outer side and an inner side by a ring 315 made of austenitic stainless steel, which is a nonmagnetic material. The multi-plate clutch 15 has a plurality of openings at radial positions corresponding to the ring 315. Bridge portions connecting 317 and each opening 317 are provided at equal intervals in the circumferential direction, and the magnetic resistance of these ring 315 and opening 317 prevents short-circuiting of the magnetic flux on the above-described magnetic flux circulation path. Yes.
[0083]
An X-ring 319, which is an X-shaped seal, is disposed between the rotor 307 and the drive shaft 11, and an O-ring 321 is disposed between the clutch housing 91 and the rotor 307. Oil leakage from the case 75 and entry of foreign matter from the outside are prevented.
[0084]
A coil housing 323 of the electromagnet 303 is supported on the rotor 307 by a double-side sealed ball bearing 325 and is prevented from rotating to the vehicle body side via a connecting member 329 engaged with a notch 327 and provided on the rotor 307. The ring-shaped recess 331 is inserted through an air gap at a predetermined interval. Moreover, the lead wire 333 of the electromagnet 303 is connected to the vehicle-mounted battery via the controller.
[0085]
The magnetic flux circulation path of the electromagnet 303 includes the coil housing 323, the rotor 307, the air gap, the multi-plate clutch 15, and the armature 305.
[0086]
The controller performs excitation of the electromagnet 303, control of excitation current, stop of excitation, and the like.
[0087]
When the electromagnet 303 is excited, a magnetic flux loop 335 is generated in the magnetic flux circulation path and the armature 305 is attracted, and the multi-plate clutch 15 is pressed and fastened to generate a differential limiting force.
[0088]
[Operation of Power Transmission Device 301 and Transfer 3]
The power transmission device 301 and the transfer 3 distribute the driving force of the engine 27 to the left and right front wheels 33 and 35 by the front differential 31 and transmit it to the rear differential 41 side.
[0089]
When one of the front wheels 33 and 35 is idling and the driving force is about to escape, when the multi-plate clutch 15 is engaged, the differential rotation of the front differential 31 (differential mechanism 5) is restricted, and the front wheels 33 and 35 are driven. The driving force is transmitted to the other of the two, and the deterioration of the escape performance, acceleration performance, and startability of the rough road is prevented.
[0090]
Further, when the excitation current of the electromagnet 303 is adjusted by the controller and the differential limiting force of the front differential 31 by the multi-plate clutch 15 is adjusted, the optimal differential limiting for the front differential 31 is made according to the running condition of the vehicle, the road surface condition, etc. Functions can be given, and rough road escape, acceleration, startability, etc. are improved.
[0091]
When the excitation of the electromagnet 303 is stopped, the multi-plate clutch 15 is released and the front differential 31 returns to a state where the differential is free.
[0092]
[Effects of power transmission device 301 and transfer 3]
Since the power transmission device 301 and the transfer 3 are configured as described above, the following effects can be obtained.
[0093]
By arranging the multi-plate clutch 15 outside the differential case 7, it is not necessary to enlarge the differential case 7 in order to accommodate the multi-plate clutch 15, and the differential case 7 can be shared with the conventional differential. .
[0094]
Even if contamination (metal wear powder) is generated in the multi-plate clutch 15, adverse effects on the meshing portions of the gears 57, 59, 61 of the differential mechanism 5 accommodated in the differential case 7 (wear, heat generation, No vibration).
[0095]
In addition, since the multi-plate clutch 15 and the electromagnet 303 can be arranged outside the transmission case 65 and the transfer case 75, there is a problem of arrangement space for the transmission case 65 and the transfer case 75, and contamination of the transmission 29 and the transfer 3 is caused. The problem is solved.
[0096]
Further, since the drive shaft 11 passes through the differential case 7, the multi-plate clutch 15, and the electromagnet 303, the differential case 7, the multi-plate clutch 15, and the electromagnet 303 are coaxially arranged, and the power transmission device 301 is laid out in a compact radial direction. The in-vehicle performance of the power transmission device 301 and the transfer 3 is improved.
[0097]
Further, since the multi-plate clutch 15 operated by the electromagnet 303 is not affected by the transmission torque or the differential torque, a desired differential limiting function can be stably obtained.
[0098]
Similarly to the power transmission device 1 of the first embodiment, if the disc spring 97 is used, it is easy to add initial torque to the multi-plate clutch 15, and the disc spring 97 is replaced to obtain the initial torque. Since there is no need to disassemble the differential case 7 and the transfer case 75 when changing, the initial torque can be easily adjusted from the outside.
[0099]
  [Reference example]
  FIG. 6 shows a power transmission device 401 (of the present inventionReference example) And the transfer 3 configured using the same. FIG. 6 shows a four-wheel drive vehicle in which the power transmission device 401 and the transfer 3 are used. The left and right directions are the four-wheel drive vehicle and the left and right directions in FIG. Is not shown. The following description will be made with reference to the members having the same functions as those of the power transmission device 1 of the first embodiment with the same reference numerals.
[0100]
[Configuration of Power Transmission Device 401]
The power transmission device 401 includes a differential case 7, drive shafts 9 and 11,
A multi-plate clutch 403 (intermittent mechanism: friction clutch) which is disposed outside the differential case 7 and the transfer case 75 and can control transmission torque; and a torque transmission mechanism 405 disposed between the differential case 7 and the multi-plate clutch 403; , A disc spring 97 that applies initial torque to the multi-plate clutch 403, a hydraulic actuator that presses the multi-plate clutch 403, and a controller that operates the hydraulic actuator. The multi-plate clutch 403 and the hydraulic actuator are provided with a differential case 7 And the outside of the transfer case 75.
[0101]
[Configuration of Transfer 3]
The transfer 3 includes a power transmission device 401, a direction changing gear set 21 including bevel gears 17 and 19, a drive pinion shaft 23 formed integrally with the bevel gear 19, and a flange 25 splined to the drive pinion shaft 23. It is composed of
[0102]
[Description of each member constituting power transmission device 401 and transfer 3]
The multi-plate clutch 403 is provided between the clutch housing 407 and the counter shaft 409 (secondary shaft), and the counter shaft 409 is disposed in parallel with the drive shafts 9 and 11. The disc spring 97 is disposed between the snap ring 411 attached to the clutch housing 407 and the multi-plate clutch 403, and applies an initial torque to the multi-plate clutch 403 as described above.
[0103]
The torque transmission mechanism 405 includes a counter shaft 409 and two pairs of gear sets 413 and 415.
[0104]
The gear set 413 includes a ring gear 53 fixed to the differential case 7 and a gear 417 meshed with the ring gear 53, and the gear 417 is splined to the counter shaft 409.
[0105]
The gear set 415 includes gears 419 and 421 that mesh with each other. The gear 419 is connected to the drive shaft 11 by spline, and the gear 421 is connected to the clutch housing 407 of the multi-plate clutch 403.
[0106]
As described above, the torque transmission mechanism 405 is disposed between the differential case 7 and the multi-plate clutch 403, and the multi-plate clutch 403 is interposed between the differential case 7 and the multi-plate clutch 403 via the torque transmission mechanism 405. The differential of (differential mechanism 5) is limited.
[0107]
[Configuration of power system of four-wheel drive vehicle]
The power system of the four-wheel drive vehicle includes the engine 27, the transmission 29, the transfer 3 (and the power transmission device 401), the front differential 31 included in the power transmission device 401, the drive shafts 9 and 11, and the left and right front wheels 33 and 35. The rear wheel side propeller shaft 37, the direction change gear set 39, the rear differential 41, the rear axles 43 and 45, and the left and right rear wheels 47 and 49 are included.
[0108]
[Operation of Power Transmission Device 401 and Transfer 3]
In the power transmission device 401 and the transfer 3, the driving force of the engine 27 is transmitted from the gears 51 and 53 to the differential case 7 and distributed from the front differential 31 to the left and right front wheels 33 and 35 via the drive shafts 9 and 11. The differential case 7 is transmitted to the rear differential 41 through the gear set 413, the counter shaft 409, the direction change gear set 21, the drive pinion shaft 23, the flange 25, the propeller shaft 37, and the direction change gear set 39. , 49.
[0109]
Further, when one of the front wheels 33, 35 is idled during driving on a rough road, during acceleration, or when starting, the driving force tends to escape, the initial torque applied to the multi-plate clutch 403 by the disc spring 97, The differential rotation of the front differential 31 (differential mechanism 5) is restricted, and the driving force is transmitted to the other of the front wheels 33 and 35, thereby preventing the rough road escape performance, acceleration performance, and startability from being deteriorated.
[0110]
Further, when the hydraulic actuator is operated, the multi-plate clutch 403 is engaged, the differential limiting force of the front differential 31 is strengthened, and rough road escape performance, acceleration performance, and startability can be improved. The controller adjusts the pressing force (differential limiting force) of the multi-plate clutch 403 by the hydraulic actuator, thereby giving the front differential 31 an optimum differential limiting function according to the traveling condition of the vehicle, the road surface condition, and the like. When the multi-plate clutch 403 is released, the front differential 31 returns to the state where the initial torque is applied by the disc spring 97.
[0111]
[Effects of power transmission device 401 and transfer 3]
Since the power transmission device 401 and the transfer 3 are configured as described above, the following effects can be obtained.
[0112]
By arranging the multi-plate clutch 403 and the disc spring 97 outside the differential case 7 and the transfer case 75, it becomes easy to apply initial torque to the multi-plate clutch 403 using the disc spring 97, and the disc spring 97 is When changing the initial torque by exchanging, it is not necessary to disassemble the differential case 7 or the transfer case 75, so the initial torque can be easily adjusted from the outside.
[0113]
Further, since the multi-plate clutch 403 is disposed outside the differential case 7, it is not necessary to enlarge the differential case 7 in order to accommodate the multi-plate clutch 403, and the differential case 7 can be shared with the conventional differential. become.
[0114]
Even if contamination (metal wear powder) is generated in the multi-plate clutch 403, adverse effects on the meshing portions of the gears 57, 59, 61 of the differential mechanism 5 housed in the differential case 7 (wear, heat generation, No vibration).
[0115]
Further, since the multi-plate clutch 403 and the hydraulic actuator can be arranged outside the transmission case 65 and the transfer case 75 as described above, the problem of the arrangement space with respect to the transmission case 65 and the transfer case 75, the transmission 29 and the transfer 3 This eliminates the contamination problem.
[0116]
Further, since the multi-plate clutch 403 operated by the hydraulic actuator is not affected by the transmission torque or the differential torque, a desired differential limiting function can be stably obtained.
[0117]
In addition, since the torque transmission mechanism 405 is arranged between the differential case 7 and the multi-plate clutch 403, the degree of freedom in arrangement of the multi-plate clutch 403 is improved, and the layout becomes easier.
[0118]
Further, since the multi-plate clutch 403 is small and has a wide friction area, a large differential limiting force can be obtained.
[0119]
[Other Embodiments Included within the Scope of the Present Invention]
In the power transmission device of the present invention, the intermittent mechanism (differential limiting device) capable of controlling the transmission torque may be a friction clutch such as a multi-plate clutch, a cone clutch or a single-plate clutch used in the embodiment. Further, a meshing clutch (dog clutch), a band brake, a drum brake, or the like may be used.
[0120]
If the meshing clutch is used, a differential lock function can be obtained.
[0121]
Further, the actuator for operating these may be a hydraulic actuator such as a hydraulic actuator or a pneumatic actuator, an electromagnet, an electric motor, or the like, or may be configured to manually operate the intermittent mechanism.
[0122]
Further, the power transmission device of the present invention is not limited to the example (front differential) used in a part of the transfer, but can be applied to a rear differential if necessary.
[0123]
The differential mechanism is not limited to a bevel gear type differential mechanism, but a planetary gear type differential mechanism, or a differential mechanism in which a side gear on the output side is connected by a pinion gear rotatably accommodated in an accommodation hole of a differential case. Alternatively, a differential mechanism using a worm gear may be used.
[0124]
【The invention's effect】
In the power transmission device according to the first aspect, an intermittent mechanism (differential limiting device) capable of controlling transmission torque is disposed outside the differential mechanism housing member (difference case), so that the initial torque adding mechanism is provided to the differential limiting device. It becomes easy to dispose and the initial torque can be adjusted from the outside of the differential mechanism housing member.
[0125]
Further, since the differential limiting mechanism is disposed outside the differential mechanism housing member, it is not necessary to increase the size of the differential mechanism housing member, and the differential mechanism housing member can be shared with the conventional differential.
[0126]
In addition, since the differential limiting device is arranged outside the differential mechanism housing member, even if contamination (metal wear powder) occurs in the differential limiting device, the differential mechanism (for example, a gear meshing portion) Adverse effects (wear, heat generation, vibration, etc.) are avoided.
[0127]
In addition, according to the configuration of the present invention, the differential limiting device can be arranged outside the transmission case or the transfer case, so that the arrangement space for the transmission case (particularly, the transmission case in the FF vehicle) and the transfer case is provided. And the problem of contamination with transmissions (especially automatic transmissions) and transfers.
[0129]
In addition, since the torque transmission mechanism is disposed between the differential mechanism housing member and the interrupting mechanism, the degree of freedom of the location (layout) of the interrupting mechanism is improved.
[0132]
  Claim2The power transmission device of claim1'sAn effect equivalent to that of the configuration can be obtained.
[0133]
Further, by using the friction clutch, a desired differential limiting force can be stably obtained without being affected by the transmission torque and the differential torque.
[0134]
  Claim3The power transmission device of claim2An effect equivalent to that of the configuration can be obtained.
[0135]
Further, by using the cam mechanism, the friction clutch can obtain a sufficient differential limiting force, and the differential limiting force can be easily controlled by adjusting the cam thrust force of the cam mechanism.
[0136]
  Claim4The power transmission device of claim1'sAn effect equivalent to that of the configuration can be obtained.
[0137]
In addition, since the rotation difference sensitive type coupling does not generate contamination, even if the power transmission device of the present invention is accommodated in the transmission case or the transfer case, the contamination problem does not occur.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a first embodiment of the present invention.
FIG. 2 is a skeleton mechanism diagram of a four-wheel drive vehicle using the first embodiment.
FIG. 3 is a cross-sectional view of a main part showing a second embodiment of the present invention.
FIG. 4 is a cross-sectional view showing a third embodiment of the present invention.
FIG. 5 is an enlarged view of a main part of FIG. 4;
FIG. 6 of the present inventionReference exampleIt is a skeleton mechanism diagram of a four-wheel drive vehicle.
FIG. 7 is a cross-sectional view of a conventional example.
[Explanation of symbols]
    1 Power transmission device
    5 Bevel gear type differential mechanism
    7 Differential case (differential mechanism housing member)
    9 Drive shaft (drive shaft)
  11 Drive shaft (Drive shaft: Torque transmission mechanism)
  13 Hollow shaft (torque transmission mechanism)
  15 Multi-plate clutch with controllable transmission torque (intermittent mechanism: friction clutch)
  97 Disc spring (Initial torque addition mechanism)
201 Power transmission device
203 Cone clutch that can control transmission torque (intermittent mechanism: friction clutch)
301 Power transmission device
401 Power transmission device
403 Multi-plate clutch with controllable transmission torque (intermittent mechanism: friction clutch)
405 Torque transmission mechanism disposed between the differential case 7 and the multi-plate clutch 403
409 Countershaft (torque transmission mechanism)
413, 415 Gear set (torque transmission mechanism)

Claims (4)

A power transmission device disposed in a power system of a four-wheel drive vehicle in which front wheels and rear wheels are driven via a front differential and a rear differential by a driving force of a prime mover, and is housed in a transmission case, and the front differential and the rear differential A differential mechanism accommodating member that is a differential rotating member on the input side of a driving force for the differential mechanism,
Wherein is housed in the transfer case is connected to the transmission case, the coupled differential mechanism housing member and the one end Rutotomoni, the driving force to the other side of the through gear provided on an outer peripheral front differential and the rear differential gear A hollow shaft to distribute ,
One of the pair of drive shafts that pass through the differential mechanism housing member and the hollow shaft and output a drive force from the differential mechanism ; and
An intermittent mechanism capable of controlling the transmission torque between the differential mechanism housing member side and the one drive shaft ;
The intermittent mechanism is disposed between the other end of the hollow shaft and the drive shaft on the opposite side of the differential mechanism housing member with the hollow shaft interposed therebetween. . The power transmission device according to claim 1,
The power transmission device, wherein the intermittent mechanism is a friction clutch. A power transmission device according to claim 2,
The power transmission device, wherein the friction clutch is fastened by a cam thrust force of a cam mechanism that operates by receiving torque. The power transmission device according to claim 1,
The power transmission device, wherein the intermittent mechanism is a rotation-sensitive coupling.

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