JP2008007113A - Transfer device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an influence on fuel economy, an influence on durability of a power transmission system, and noise and vibration, by separating a torque control mechanism in two-wheel driving. <P>SOLUTION: A dog clutch 15 is provided to change positions between a two-wheel driving position and a torque variable four-wheel driving position. In the two-wheel driving position, a driving force is transmitted to a power transmission system on a rear wheel side through a main shaft 7, a clutch hub 33, a clutch drum 95, and a multiple disc clutch 87, and a drive shaft 35 are separated from the main shaft 7. In the torque variable four-wheel driving position, the driving force is transmitted to the power transmission system on the rear wheel side through the main shaft 7, and the driving force is transmitted to a power transmission system on a front wheel side from the main shaft 7 through the clutch hub 33, clutch drum 95, multiple disc clutch 87, and drive shaft 35. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a transfer device for a four-wheel drive vehicle.

  Patent Document 1 discloses a transfer device 201 as shown in FIG.

  The transfer device 201 includes an input shaft 203 coupled to an output shaft of a transmission, a main shaft 205, a chain transmission mechanism 207 constituting a part of a front wheel side power transmission system, an HL switching mechanism (transmission torque switching mechanism) 209, A 2-4 switching mechanism 211 that is arranged at the subsequent stage and intermittently switches the power transmission system on the front wheel side to switch between a two-wheel drive state (and a torque variable four-wheel drive state described later) and a torque fixed four-wheel drive state, A 2-4 switching mechanism 211 is arranged in parallel, and includes a torque control mechanism 213 that controls the magnitude of the driving force transmitted to the front wheel side power transmission system.

  The input shaft 203 and the main shaft 205 are coaxially arranged, and the main shaft 205 is connected to the propeller shaft side of the rear wheel.

  The chain transmission mechanism 207 includes input-side and output-side sprockets 215, 217 and a chain 219 connecting them. The input-side sprocket 215 is rotatably disposed on the main shaft 205, and the output-side sprocket 217 is a front-wheel propeller. It is connected to the shaft side.

  The HL switching mechanism 209 includes a planetary gear mechanism 221 and a shift sleeve 223 for switching operation.

  The planetary gear mechanism 221 includes an internal gear 225, a planetary carrier 227 that supports the planetary gear, a sun gear 229, and the like. The internal gear 225 is connected to the transfer case 231 side, the planetary carrier 227 is disposed in a rotatable state, and the sun gear 229 is formed on the input shaft 203.

  When the shift sleeve 223 of the HL switching mechanism 209 is shifted to the H position, the driving force of the engine input from the transmission to the input shaft 207 bypasses the planetary gear mechanism 221 and passes through the shift sleeve 223 at a high speed (constant speed). ) To rotate the main shaft 205. When the shift sleeve 223 is shifted to the L position, the rotation of the input shaft 207 is decelerated via the sun gear 229, the planetary gear, and the planetary carrier 227, and is transmitted from the shift sleeve 223 to the main shaft 205 at a low speed. The rotation of the main shaft 205 is transmitted to the rear differential via the rear wheel side power transmission system and distributed to the left and right rear wheels.

  The shift sleeve 233 constituting the 2-4 switching mechanism 211 is movable between a two-wheel drive position (and a torque variable four-wheel drive position) and a torque fixed four-wheel drive position, and the shift sleeve 223 of the HL switching mechanism 209. It is comprised so that it may move integrally.

  When the shift sleeve 233 is shifted to the two-wheel drive position (and the variable torque four-wheel drive position), the connection between the main shaft 205 and the sprocket 215 is released, the shift sleeve 223 moves to the H position, and the vehicle is in the high speed mode. The two-wheel drive state (2H) is set.

  In this state, the torque control mechanism 213 can select the torque variable four-wheel drive state (4H automatic) in the high speed mode as described below.

  When the shift sleeve 233 is shifted to the fixed torque four-wheel drive position, the shift sleeve 223 moves to the L position, and the main shaft 205 and the input side sprocket 215 of the chain transmission mechanism 207 are directly connected via the shift sleeve 233. The driving force of the engine decelerated by the HL switching mechanism 209 is transmitted to the front wheel side by a fixed torque via the main shaft 205, the shift sleeve 233, and the chain transmission mechanism 207, and the vehicle is driven by a torque fixed four-wheel drive in the low speed mode. State (fixed to 4L).

  The torque control mechanism 213 includes a wet multi-plate clutch 235, a hydraulic actuator 237 that presses and fastens the multi-plate clutch 235, a main oil pump and sub oil pump 239 that drives the hydraulic actuator 237, and an electric motor that drives the sub oil pump 239. It consists of a motor 241 and the like.

  The multi-plate clutch 235 is disposed between a clutch drum 243 fixed to the sprocket 215 and a clutch hub 245 connected to the main shaft 205.

  The multi-plate clutch 235 is engaged by the main oil pump or the sub oil pump 239 when the shift sleeve 233 of the 2-4 switching mechanism 211 is in the two-wheel drive position.

  Further, the slip of the multi-plate clutch 235 is controlled by adjusting the hydraulic pressure of the hydraulic actuator 237 by each oil pump, and the two-wheel drive state in which the torque transmission ratio between the front wheels and the rear wheels is approximately 0: 100, and 50:50. Adjusted between four-wheel drive conditions.

  As described above, the conventional transfer device 201 has a two-wheel drive state (2H) and a variable torque four-wheel drive state (4H automatic) in the high speed mode by the HL switching mechanism 209 and the 2-4 switching mechanism 211. The fixed torque four-wheel drive state (4L fixed) in the low speed mode can be selected. In this 4H automatic mode, the driving force of the front wheels is driven by the torque adjustment function of the torque control mechanism 213 while driving the rear wheels. It can be adjusted between the state and the four-wheel drive state.

With such a switching function and a torque adjustment function, the transfer device 201 is capable of driving on rough roads, starting performance, acceleration performance, vehicle stability, engine fuel consumption according to changes in road surface conditions, engine output, steering conditions, and the like. , Improve turning performance.
NISSAN Terrano R50 series September 1995 Edited and published by Nissan Motor Co., Ltd.

  However, since the transfer device 201 creates the two-wheel drive state by releasing the multi-plate clutch 235 disposed between the power transmission system on the front wheel side and the main shaft 205, the drag torque is applied to the multi-plate clutch 235. When (the drag torque) is generated, there is a problem that the front wheel side power transmission system is connected to the main shaft 205 by the drag torque and cannot be completely separated.

  In such a state, the front wheel and its power transmission system are driven by the engine even when the two-wheel drive is running. These rotational resistances affect the fuel consumption of the engine and support the front wheel side power transmission system. There is a problem in that it has an effect on the durability and wear of the part and the sliding part and also generates noise and vibration in the front wheel side power transmission system.

  In addition, if the front wheels cannot be completely separated in this way, the turning performance cannot be sufficiently exhibited.

  Therefore, the present invention completely separates the torque control mechanism that adjusts the driving force transmitted to the one-side wheel when driving two wheels, thereby affecting the fuel efficiency of the engine, durability of the power transmission system, noise, vibration, An object of the present invention is to provide a transfer device that improves the turning performance of a vehicle.

  The transfer device according to claim 1 is a main shaft that transmits a driving force transmitted from an engine directly connected to a power transmission system on a rear wheel side, a drive shaft that transmits a driving force to a power transmission system on a front wheel side, and the main shaft. A multi-plate clutch provided between a clutch hub and a clutch drum disposed on the outer periphery of the front end side and transmitting torque to the front wheel side power transmission system in a variable manner by a fastening means, A two-wheel drive position for transmitting a driving force to the power transmission system on the rear wheel side via the main shaft and separating the clutch hub, the clutch drum, the multi-plate clutch and the drive shaft from the main shaft; Driving force to the rear wheel side power transmission system and from the main shaft to the clutch hub, the clutch drum, the multi-plate clutch, and the Via the live shaft, characterized in that a dog clutch switching between variable torque four-wheel drive position for transmitting a driving force to the power transmission system of the front wheel side.

  The transfer device according to claim 2 is the transfer device according to claim 1, wherein the meshing clutch connects the torque variable four-wheel drive position, the clutch hub side, and the clutch drum side, and the rear wheel. And a torque-fixed four-wheel drive position that fixes a transmission drive force of the front-wheel-side power transmission system.

  The transfer device according to claim 3 is the transfer device according to claim 1 or 2, wherein the meshing clutch is disposed between the main shaft and the clutch hub side, and the clutch drum is fixed to the input side sprocket. The drive shaft is provided with an output-side sprocket, which transmits a driving force from the main shaft to the power transmission system on the front wheel side.

  A transfer device according to a fourth aspect is the transfer device according to any one of the first to third aspects, wherein the meshing clutch is disposed on the input side in the axial direction of the main shaft with respect to the input side sprocket, and The plate clutch is arranged on the rear wheel output side in the axial direction of the main shaft with respect to the input side sprocket.

  Thus, in the transfer device of the present invention, the clutch hub, the clutch drum, and the multi-plate clutch can be separated from the main shaft by the meshing clutch during two-wheel drive, and the drag torque is generated in the multi-plate clutch by the rotation of the main shaft. Can be prevented.

  This prevents the energy loss from affecting the fuel efficiency of the engine and improves the turning performance because there is no rotational restraint force between the front and rear wheels in a complete two-wheel drive state.

  Further, by providing the meshing clutch, it is possible to select a dedicated position of 2WD instead of the combined position as in the conventional two-wheel drive / variable torque four-wheel drive.

  Thus, the transfer device of the present invention responds to changes in various conditions that occur during traveling, such as road surface conditions, engine output, and steering conditions, by the switching function of each position and the function of the multi-plate clutch. Road running ability, startability, acceleration, vehicle stability, and turning performance can be greatly improved.

  In the transfer device according to the second aspect, since the mesh clutch includes a sleeve capable of shifting the torque variable four-wheel drive position and the torque fixed four-wheel drive position, the torque fixed four-wheel drive position and the two-wheel drive position of the mesh clutch. And the torque variable four-wheel drive position can be continuously switched by the same shift mechanism, and the switching operability is greatly improved.

  In addition, the structure and layout are simple because it can be implemented by making very simple changes to the existing mechanism, and the shift mechanism can be shared. Can do.

  The transfer device according to the third aspect can obtain the same effect as that of the first or second aspect.

  The transfer device according to the fourth aspect can obtain the same effects as those of the first to third aspects.

  The transfer device 1 (one embodiment of the present invention) will be described with reference to FIGS.

  The left side of each figure corresponds to the front of a four-wheel drive vehicle using the transfer device 1.

  The power system of this four-wheel drive vehicle is the engine, clutch, transmission, transfer device 1, front wheel side power transmission system, front differential (differential device that distributes the driving force of the engine to the left and right front wheels), left and right front wheels, rear It consists of a wheel-side power transmission system, a rear differential (a differential device that distributes the driving force of the engine to the left and right rear wheels), left and right rear wheels, and the like.

  The engine, transmission, transfer device 1 and the like are arranged vertically, and hub clutches (separation mechanisms) that connect and disconnect the left and right front wheels and the respective axles are arranged.

  The driving force of the engine is transmitted from the clutch to the transfer device 1 via the transmission. As described below, the rear wheel side is directly connected via the transfer device 1, and the driving force is always transmitted to the rear differential via the rear wheel side power transmission system and distributed to the left and right rear wheels. Further, the driving force on the front wheel side is interrupted by the transfer device 1 and the transmission torque is controlled. The driving force output to the front wheel side via the transfer device 1 is transmitted to the front differential via the front wheel side power transmission system, and is distributed to the left and right front wheels via the hub clutch.

  The transfer device 1 is accommodated in a transfer case 3, and includes an input shaft 5, a main shaft 7, a chain transmission mechanism 9 constituting a part of a front wheel side power transmission system, and an HL switching mechanism (transmission torque switching) as a sub-transmission. (Mechanism) 11, a 2-4 switching mechanism 17 including a first meshing clutch 13 and a second meshing clutch 15, a torque control mechanism 19, a controller, and the like.

  The input shaft 5 is connected to the output shaft of the transmission, penetrates into the transfer case 3 from the front, and is supported on the transfer case 3 by ball bearings 20. A seal 21 is disposed between the input shaft 5 and the transfer case 3 to prevent mixing of transmission oil and transfer oil.

  The main shaft 7 is arranged coaxially with the input shaft 5 and is connected to a propeller shaft on the rear wheel side via a joint. The main shaft 7 is supported on the input shaft 5 by roller bearings 22 and 23 on the front end side, and supported on the transfer case 3 by a ball bearing 24 on the rear end side. A seal 26 is disposed between the main shaft 7 and the transfer case 3 to prevent oil leakage and prevent foreign matter from entering.

  The chain transmission mechanism 9 includes input-side and output-side sprockets 25 and 27 and a chain 29 that connects them.

  The input-side sprocket 25 is rotatably supported on the clutch hub 33 by needle bearings 31, 31, and the output-side sprocket 27 is formed on the drive shaft 35. The drive shaft 35 is supported on the transfer case 3 by ball bearings 37, 37, and a flange 39 is splined to the front end of the drive shaft 35 and fixed by a nut 41. The flange 39 is connected to the propeller shaft on the front wheel side via a mating flange 43, and a seal 45 is disposed between the flange 39 and the transfer case 3 to prevent oil leakage and intrusion of foreign matter. Has been.

  The HL switching mechanism 11 includes a planetary gear mechanism 47, a meshing clutch 49 for switching operation, an HL sleeve 51, and the like.

  The planetary gear mechanism 47 includes an internal gear 53, planetary carriers 57 and 59 that support a shaft 55 that supports the planetary gear from the front and rear, a sun gear 61, and the like.

  The internal gear 53 is connected to the transfer case 3, and the sun gear 61 is formed on the input shaft 5.

  The front planetary carrier 57 is rotatably supported on the input shaft 5 by a roller bearing 63. A thrust bearing 65 that absorbs relative rotation between the planetary carrier 57 and the ball bearing 20 (transfer case 3) is disposed between the planetary carrier 57 and the sun gear 61 (input shaft 5). A thrust bearing 66 that absorbs the relative rotation of each other is disposed therebetween.

  As shown in FIGS. 2 to 4, the meshing clutch 49 includes meshing teeth 69 formed on the inner periphery of the clutch drum 67, meshing teeth 71 and 73 formed on the outer periphery and inner periphery of the HL sleeve 51, respectively, It is composed of meshing teeth 75 and 77 formed on the outer circumferences of the shaft 5 and the main shaft 7. The clutch drum 67 is fixed to the rear planetary carrier 59.

  The HL sleeve 51 can be shifted to the H position and the L position. When the HL sleeve 51 is shifted to the H position, the meshing teeth 73, 75, and 77 mesh with each other, and the meshing teeth 69 and 71 mesh with each other. Is released, and the input shaft 5 and the main shaft 7 are connected via the HL sleeve 51.

  When the HL sleeve 51 is shifted to the L position, the meshing teeth 69 and 71 mesh with each other and the meshing teeth 73 and 75 are disengaged.

  When the HL sleeve 51 is shifted to the H position, the driving force of the engine that is input from the transmission to the input shaft 5 bypasses the planetary gear mechanism 47 and from the input shaft 5 through the HL sleeve 51 at a high speed (H : Spindle 7 is rotated at a constant speed).

  When the HL sleeve 51 is shifted to the L position, the rotation of the input shaft 5 is decelerated via the sun gear 61, the planetary gear, and the planetary carriers 57 and 59, and from the clutch drum 67 via the HL sleeve 51. The main shaft 7 is rotated at a low speed (L).

  The rotation of the main shaft 7 is transmitted to the rear differential via a rear wheel side power transmission system such as a propeller shaft and distributed to the left and right rear wheels.

  The first meshing clutch 13 includes a meshing tooth 81 formed on the inner periphery of the 2-4 sleeve 79, a meshing tooth 77 of the main shaft 7, meshing teeth 85 formed on the clutch hub 33 and the input side sprocket 25, respectively. Has been. Further, the 2-4 sleeve 79 is engaged with the meshing tooth 77 of the main shaft 7 by the meshing tooth 81 and can move back and forth.

  The second mesh clutch 15 includes a mesh tooth 81 of the 2-4 sleeve 79, a mesh tooth 77 of the main shaft 7, and a mesh tooth 83 of the clutch hub 33.

  That is, the 2-4 switching mechanism 17 includes the meshing teeth 81 of the 2-4 sleeve 79, the meshing teeth 77 of the main shaft 7, and the meshing teeth 83, 85 of the clutch hub 33.

  As described above, the 2-4 switching mechanism 17 is constituted by the first meshing clutch 13 and the second meshing clutch 15, and the second meshing clutch 15 is incorporated in the first meshing clutch 13. ing.

  The 2-4 sleeve 79 includes a two-wheel drive position (FIG. 2: 2WD), a variable torque four-wheel drive position (FIG. 3: 4WD (automatic)), and a fixed torque four-wheel drive position (FIG. 4: 4WD (fixed)). ).

  Further, such a shift operation of the 2-4 sleeve 79 is performed by the same shift mechanism via the shift fork 86.

  When the 2-4 sleeve 79 is shifted to the two-wheel drive position, the meshing between the meshing tooth 81 and the meshing teeth 83 and 85 is released. When the 2-4 sleeve 79 is shifted to the torque variable four-wheel drive position, the meshing teeth 81 and 83 are meshed, and the main shaft 7 and the clutch hub 33 are connected via the 2-4 sleeve 79. Further, when the 2-4 sleeve 79 is shifted to the torque fixed four-wheel drive position, the meshing teeth 81, 83, and 85 are engaged, and the main shaft 7, the clutch hub 33, and the sprocket 25 are connected via the 2-4 sleeve 79. The

  The torque control mechanism 19 includes a wet multi-plate clutch 87, a main oil pump, a sub oil pump 89, an electric motor 91 unitized with the sub oil pump 89, a hydraulic actuator 93 that presses and fastens the multi-plate clutch 87, and a controller. Etc.

  The multi-plate clutch 87 is disposed between the clutch drum 95 fixed to the sprocket 25 and the clutch hub 33, and the clutch hub 33 is supported on the outer periphery of the main shaft 7 by needle bearings 97.

  The multi-plate clutch 87 is arranged coaxially with the HL switching mechanism 11, and the first meshing clutches 13, 49, the second meshing clutch 15, and the 2-4 switching mechanism 17 are also coaxial with them. Has been placed.

  The main oil pump is rotationally driven by a gear 99 that rotates integrally with the main shaft 7 and sucks oil from an oil reservoir provided in the transfer case 3. As will be described below, this oil is used for lubrication and cooling of each part of the transfer device 1, and is also supplied to the cylinder 103 of the hydraulic actuator 93 via a valve controlled by the controller and the oil passage 101.

  When the main shaft 7 (main oil pump) is not rotating, the controller rotates the sub oil pump 89 by the electric motor 91 and supplies oil to the cylinder 103 via the valve and the oil passage 101.

  The cylinder 103 is formed in the transfer case 3, and a thrust bearing 107 and a pressure plate 109 are disposed between the piston 105 and the multi-plate clutch 87. The relative rotation between the stationary piston 105 and the rotating pressure plate 109 is absorbed by the thrust bearing 107.

  A return spring 111 that biases the pressure plate 109 toward the connection release side of the multi-plate clutch 87 is disposed between the clutch hub 33 and the pressure plate 109.

  When hydraulic pressure is applied to the cylinder 103, the hydraulic actuator 93 presses and fastens the multi-plate clutch 87 via the piston 105, the thrust bearing 107 and the pressure plate 109.

  At this time, the controller adjusts the opening of the valve as necessary, adjusts the slip of the multi-plate clutch 87 by changing the hydraulic pressure applied to the cylinder 103, and controls the magnitude of the driving force sent to the front wheel side.

  Further, when the oil supply to the cylinder 103 is stopped, the pressure plate 109 and the like are retracted by the return spring 111, and the connection of the multi-plate clutch 87 is released.

  When the 2-4 sleeve 79 of the first meshing clutch 13 is shifted to the two-wheel drive position, the meshing tooth 81, the meshing tooth 83 (clutch hub 33), and the meshing tooth 85 (sprocket 25: clutch drum 95) as described above. Is disengaged, and both the multi-plate clutch 87 and the sprocket 25, which are power transmission paths to the front wheels, are disconnected from the main shaft 7, so that the vehicle is in a two-wheel drive state by rear wheel drive.

  Further, since the multi-plate clutch 87 is disengaged in this way, the vehicle is in a complete two-wheel drive state, and unlike the conventional example, even if drag torque is generated in the multi-plate clutch 87, the front wheels and its power transmission by the engine are transmitted. The rotation of the system is prevented and the turning performance is improved.

  Furthermore, at this time, the controller separates the left and right front wheels from the axle by means of each hub clutch.

  When the left and right front wheels are disconnected, the rotation of the front wheel side power transmission system from the left and right front axles to the front differential, propeller shaft, chain transmission mechanism 9 and multi-plate clutch 87 stops, so the fuel consumption is reduced due to the rotational resistance. In addition to being prevented, vibrations, noises, and effects on the durability of the bearing part and the sliding part due to the rotation of the power transmission system are prevented.

  Further, for example, a switch (operating means that can be interlocked / interlocked) is provided in the driver's seat, and this switch shifts the 2-4 sleeve 79 to the two-wheel drive position to connect the second meshing clutch 15. A command to release and a command to release the connection of the hub clutch are sent to the controller.

  The controller interlocks and releases the second meshing clutch 15 and the hub clutch in accordance with the command of the switch, and connects the hub clutch when the 2-4 sleeve 79 is in a position other than the two-wheel drive position.

  Further, when the 2-4 sleeve 79 is shifted to the torque variable four-wheel drive position, the meshing teeth 81 and 83 mesh as described above, and the main shaft 7 and the multi-plate clutch 87 are connected.

  The controller operates the multi-plate clutch 87 only when the 2-4 sleeve 79 is in the torque variable four-wheel drive position as described above, and further, in response to changes in road surface conditions, engine output, steering conditions, etc. Thus, the slip of the multi-plate clutch 87 is adjusted, and the magnitude of the driving force transmitted to the front wheel side is controlled.

  This control consists of a two-wheel drive state where the driving force is not transmitted to the front wheels (a state where the torque transmission ratio between the front wheels and the rear wheels is approximately 0: 100) and a rigid four-wheel drive state (a torque transmission ratio between the front wheels and the rear wheels). Can be selected at any torque transmission ratio.

  When the 2-4 sleeve 79 is shifted to the torque fixed four-wheel drive position, the meshing teeth 81, 83, and 85 are meshed as described above, and the main shaft 7, the clutch hub 33, and the sprocket 25 are connected via the 2-4 sleeve 79. Since they are connected, the vehicle is in a rigid four-wheel drive state, and an equal driving force is sent to the front wheels and the rear wheels.

  Moreover, in the transfer apparatus 1, since the HL sleeve 51 of the HL switching mechanism 11 and the 2-4 sleeve 79 of the first meshing clutch 13 are separate bodies, if these are operated separately, the first A high speed (H) state and a low speed (L) state can be selected for each of the two-wheel drive position, the variable torque four-wheel drive position, and the fixed torque four-wheel drive position of the mesh clutch 13.

  With such a switching function and a torque control function at the time of variable torque four-wheel drive, the transfer device 1 can change four wheels according to changes in conditions such as road surface conditions, engine output, and steering conditions. In the driving state, it is possible to greatly improve rough road running performance, startability, acceleration, vehicle stability, and the like, and in the two-wheel driving state, fuel efficiency, turning performance, etc. can be greatly improved.

  Switching to the two-wheel drive position is performed by the driver's seat switch as described above, and other switching and control are performed by the controller by detecting changes in the above various conditions by various sensors. Is called.

  The main shaft 7 is formed with an axial oil passage and a number of radial oil passages communicating with the axial oil passage, and the input shaft 5 is formed with a radial oil passage facing the radial oil passage of the main shaft 7. .

  The oil of the main oil pump is ejected from these oil passages by its hydraulic pressure and the centrifugal force of the input shaft 5 and the main shaft 7, bearings 20, 22, 23, 31, 63, 65, 66, 97, 107, planetary gears. Mechanism 47, meshing clutch 49, HL sleeve 51 and sliding portion of its shift mechanism, first meshing clutch 13, second meshing clutch 15, 2-4 switching mechanism 17, 2-4 sleeve 79 and its shift The sliding portion of the mechanism, the chain transmission mechanism 9, the multi-plate clutch 87 and the like are sufficiently lubricated and cooled to greatly improve the durability.

  Thus, the transfer device 1 is configured.

  Since the multi-plate clutch 87 and the front-wheel-side power transmission system are disconnected by the second meshing clutch 15 when the two-wheel drive is used, the transfer device 1 is driven by the front wheel due to the drag torque of the multi-plate clutch 87 and the traveling resistance associated therewith. Is prevented and fuel consumption is improved.

  Further, since it is not affected by the drag torque, a complete two-wheel drive state is achieved, and the rotational restraint force between the front and rear wheels is eliminated, and the turning performance is improved.

  Further, the provision of the second meshing clutch 15 makes it possible to independently select the two-wheel drive position as described above, and furthermore, the variable torque and the fixed torque of the two-wheel drive position and the four-wheel drive can be selected. Since HL switching can be performed at each position, as many positions as possible can be selected, and it becomes easy to cope with a change in conditions during traveling, and the traveling performance of the vehicle can be greatly improved.

  Further, the first meshing clutch 13 incorporating the second meshing clutch 15 and the 2-4 switching mechanism 17 includes a two-wheel drive, a torque variable four-wheel drive, and a torque fixed four-wheel drive as shown in FIGS. However, such a configuration can be implemented only by extending the shift stroke of the 2-4 sleeve 79 by providing the meshing teeth 83 between the 2H / 4H position and the 4L position of the conventional example. become.

  In addition, since the two-wheel drive, torque-variable four-wheel drive, and torque-fixed four-wheel drive positions are arranged in a straight line, the same shift mechanism can be used for continuous switching operations, greatly improving operability. Yes.

  In addition, it can be implemented by making very simple changes to the existing mechanism in this way, and since the shift mechanism can be shared, the structure and layout are simple, and it is light and compact so that it can be mounted on the vehicle. At the same time, the cost becomes low.

  In the transfer device 1, the HL switching mechanism 11, the multi-plate clutch 87 of the torque control mechanism 19, the first meshing clutch 13, the second meshing clutch 15, and the 2-4 switching mechanism 17 are provided. Since it arrange | positions coaxially, compared with the structure which arrange | positions these in radial direction, it is compact in radial direction, and the vehicle-mounted property further improves.

  Further, when the multi-plate clutch 87 is disconnected, the front wheel and the axle are disconnected by the hub clutch, so that the power transmission system on the front wheel side is cut off from both the driving force of the engine and the rotation of the front wheel due to traveling. Therefore, fuel consumption is prevented from being reduced by the rotational resistance, and vibration, noise, wear of the power transmission system support and sliding parts, and durability are prevented from being reduced.

  Further, since the multi-plate clutch 87 can be disconnected by the second meshing clutch 15 and the front wheel can be disconnected by the hub clutch by a driver seat switch, the rotational stationary function of the front wheel side power transmission system as described above can be achieved. The driver's burden is prevented from increasing while enjoying the effect.

  It should be noted that the HL sleeve 51 of the HL switching mechanism 11 and the 2-4 sleeve 79 of the first meshing clutch 13 can be shifted by being interlocked by the same shift mechanism.

  If comprised in this way, a shift mechanism will become still more lightweight and compact, and the transfer apparatus 1 will become low-cost.

  In the transfer device of the present invention, the separation mechanism for intermittently connecting the separation-side wheel and its power transmission system is, for example, a differential device (FRD: free running differential) having a torque intermittent function, in addition to the hub clutch. A mechanism (ADD: axle disconnect) that interrupts driving force on the axle may be used.

  Further, the separation mechanism may be disposed not only on the axle, but also on the propeller shaft, for example, and even in such a case, the rotation of the propeller shaft having a large mass can be stopped. Noise, wear, durability and fuel consumption can be sufficiently prevented.

  The clutch used in the torque control mechanism is not limited to a multi-plate clutch, and may be a single-plate clutch or a cone clutch as long as it is a torque variable clutch, and these may be wet or dry.

  The clutch engagement means is not limited to a hydraulic actuator such as a hydraulic actuator, but may be an electromagnet, or an actuator composed of an electric motor and a conversion means that converts the rotation of the electric motor into an operating force while decelerating its rotation.

It is sectional drawing which shows one Embodiment of this invention. It is a principal part enlarged view of embodiment, and shows a two-wheel drive state. It is a principal part enlarged view of embodiment, and shows the four-wheel drive state of torque variable. It is a principal part enlarged view of embodiment, and shows the four-wheel drive state of torque fixation. It is sectional drawing of a prior art example.

Explanation of symbols

1 Transfer device 9 Chain transmission mechanism (front wheel power transmission system)
11 HL switching mechanism (transmission torque switching mechanism)
13 First meshing clutch 15 Second meshing clutch 19 Torque control mechanism 87 Multi-plate clutch (torque control mechanism)

Claims (4)

A main shaft that directly transmits the driving force transmitted from the engine to the power transmission system on the rear wheel side, a drive shaft that transmits the driving force to the power transmission system on the front wheel side, and a clutch hub disposed on the outer periphery of the main shaft And a multi-plate clutch that is provided between the clutch drum and transmits the driving force in a variable manner to the power transmission system on the front wheel side by a fastening means,
A two-wheel drive position for transmitting a driving force to the rear wheel side power transmission system via the main shaft and separating the clutch hub, the clutch drum, the multi-plate clutch and the drive shaft from the main shaft; Driving force is transmitted to the rear wheel side power transmission system via the main shaft and the driving force is transmitted from the main shaft to the front wheel side power transmission system via the clutch hub, the clutch drum, the multi-plate clutch and the drive shaft. A transfer device comprising a meshing clutch for switching between a variable torque four-wheel drive position to be transmitted. The transfer device according to claim 1,
The meshing clutch connects the torque variable four-wheel drive position, the clutch hub side and the clutch drum side, and fixes the transmission driving force of the rear wheel side power transmission system and the front wheel side power transmission system. A transfer device comprising a sleeve capable of shifting a torque fixed four-wheel drive position. The transfer device according to claim 1 or 2,
The meshing clutch is disposed between the main shaft and the clutch hub side, the clutch drum is fixed to the input side sprocket, the drive shaft is provided with an output side sprocket, and power transmission from the main shaft to the front wheel side is performed. A transfer device that transmits a driving force to a system. The transfer device according to any one of claims 1 to 3,
The meshing clutch is disposed on the axial input side of the main shaft with respect to the input-side sprocket, and the multi-plate clutch is disposed on the axial rear wheel output side of the main shaft with respect to the input-side sprocket. Transfer device.

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