JP6127785B2 - Driving force transmission device - Google Patents

Description

  The present invention relates to a driving force transmission device that transmits a driving force of a vehicle in a variable amount of driving force transmission.

  Conventionally, in a four-wheel drive vehicle, a drive force transmission system that transmits a drive force of a drive source to a main drive wheel (for example, a front wheel) and an auxiliary drive wheel (for example, a rear wheel) is provided. A driving force transmission device that increases or decreases in accordance with a traveling state is known (see, for example, Patent Document 1).

  The driving force transmission device (a torque distribution control device for a four-wheel drive vehicle) described in Patent Document 1 adds a pre-torque calculated based on the throttle opening and a correction torque calculated based on the rotational difference between the front and rear wheels. By calculating the command torque and supplying a current according to the command torque to the electromagnetic coil of the electromagnetic clutch, the driving force according to the command torque is transmitted to the auxiliary drive wheel side.

  In addition, the driving force transmission device described in Patent Document 1 supplies a command torque below an upper limit value determined according to the engine torque so as not to supply an unnecessarily large current to the electromagnetic clutch to overheat the control unit (ECU). Restrict. In other words, for example, when the accelerator is depressed greatly, the pre-torque increases, and the command torque increases accordingly.However, when the engine torque is small, the torque transmission capacity in the electromagnetic clutch increases more than necessary. Current more than necessary is supplied, and the control device generates heat wastefully. Therefore, the control device suppresses heat generation by limiting the command torque based on the engine torque so as not to supply more current than necessary.

JP 2004-262321 A

  By the way, the driving force generated by the driving source is not necessarily proportional to the acceleration operation amount due to the depression of the accelerator, for example. In particular, when the drive source is an engine equipped with a turbocharger such as a turbocharger, a large amount of fuel is supplied into the combustion chamber of the engine by the turbocharger after the accelerator is depressed and the engine speed increases. Therefore, the engine torque increases rapidly after the acceleration operation. In this case, when the command torque is calculated based on the throttle opening as in the driving force transmission device described in Patent Document 1, when the engine torque is increased by the supercharger, the torque transmission capacity of the driving force transmission device is reduced. Since the engine torque becomes excessive and a large driving force is distributed to the front wheels, slip occurs on the front wheels, and sufficient acceleration performance cannot be obtained.

  Further, if the command torque is calculated based on the engine torque, the driving force distributed to the rear wheels is small at the initial stage of acceleration, and the driving force distributed to the front wheels is large. This increases the torsion of the driving force transmission system on the front wheel side, but does not transmit sufficient driving force to the rear wheel side, so that sufficient acceleration is achieved as in the case of the driving force transmission device described in Patent Document 1. Performance cannot be obtained.

  Furthermore, in anticipation of an increase in engine torque due to the turbocharger, if the command torque based on the throttle opening is increased to such an extent that slip does not occur on the front wheels, an unnecessarily large current is supplied to the coil of the electromagnetic clutch. Heats up.

  Therefore, an object of the present invention is to provide a driving force transmission device capable of obtaining sufficient acceleration performance without supplying an unnecessarily large current when a vehicle acceleration operation is performed.

In order to achieve the above object, the present invention is provided in a driving force transmission system that transmits a driving force of a driving source of a vehicle to main driving wheels and auxiliary driving wheels, and drives the driving force toward the auxiliary driving wheels. A driving force transmission device that variably transmits a force transmission amount, calculates a driving force transmission command value according to a driving force to be transmitted to the auxiliary driving wheel based on a vehicle state quantity, and calculates the driving force transmission command value. A control unit that outputs a current corresponding thereto, and a clutch that is operated by the current output from the control unit and transmits a driving force corresponding to the current to the auxiliary driving wheel side. A first driving force transmission amount is calculated based on an acceleration operation amount by a driver of the vehicle, and a second driving force transmission amount is calculated based on a driving force generated by the driving source. Of the two driving force transmission amounts, the larger driving force transmission amount Depending defining said driving force transmission command value, to provide a driving force transmission apparatus.
In order to achieve the above object, the present invention is provided in a driving force transmission system for transmitting a driving force of a driving source of a vehicle to a main driving wheel and an auxiliary driving wheel, and the driving force is transmitted to the auxiliary driving wheel side. A driving force transmission device that variably transmits a driving force transmission amount to the driving force transmission command value according to a driving force to be transmitted to the auxiliary driving wheel based on a vehicle state quantity, and the driving force transmission command A control unit that outputs a current according to a value; and a clutch that is operated by the current output from the control unit and transmits a driving force according to the current to the auxiliary driving wheel side, The first driving force transmission amount is calculated based on the acceleration operation amount by the driver of the vehicle, the second driving force transmission amount is calculated based on the driving force generated by the driving source, and the first driving force transmission amount is calculated. And the driving force transmission amount by adding the second driving force transmission amount Calculating a decree value, to provide a driving force transmission apparatus.

  According to the present invention, it is possible to obtain sufficient acceleration performance without supplying an unnecessarily large current when the vehicle is accelerated.

It is a mimetic diagram showing an example of composition of a four-wheel drive vehicle carrying a driving force transmission device concerning a 1st embodiment of the present invention. It is sectional drawing which shows the structural example of a torque coupling. It is a flowchart which shows the content of the process which a control part performs. (A) is a graph which shows an example of the change of the throttle opening and engine torque when a four-wheel drive vehicle accelerates from a stop state. (B) is a graph showing an example of changes in the first driving force transmission amount, the second driving force transmission amount, and the driving force transmission command value. It is a flowchart which shows the content of the process which the control part which concerns on the 2nd Embodiment of this invention performs. It is a graph which shows the example of the change of the 1st driving force transmission amount in the 2nd embodiment, the 2nd driving force transmission amount, and a driving force transmission command value.

[First Embodiment]
FIG. 1 is a schematic diagram showing a configuration example of a four-wheel drive vehicle equipped with a driving force transmission device according to a first embodiment of the present invention.

  The four-wheel drive vehicle 100 includes an engine 101 as a drive source, a transmission 102 that changes the output of the engine 101, and the driving force of the engine 101 that is changed by the transmission 102 to the left and right front wheels 104 (the left front wheel 104L and the right front wheel). 104R) and the left and right rear wheels 105 (left rear wheel 105L and right rear wheel 105R). The driving force transmission system 110 is provided with the driving force transmission system 1.

  The driving force transmission device 1 includes a torque coupling 2 having a clutch that operates according to a supplied current, and a control unit 3 that supplies a current to the torque coupling 2. The control unit 3 calculates a driving force transmission command value to be transmitted to the rear wheel 105 based on the vehicle state quantity of the four-wheel drive vehicle 100, and outputs a current corresponding to the driving force transmission command value. The torque coupling 2 transmits a driving force corresponding to the current output from the control unit 3 to the rear wheel 105 side. The vehicle state quantity is a concept that includes one or more state quantities that can affect the behavior of the vehicle.

  The control unit 3 includes a storage element 31 such as a ROM or a RAM, a CPU 32 that executes arithmetic processing based on a program stored in the storage element 31, and a current output circuit 33 that outputs a current to the torque coupling 2. ing. The current output circuit 33 supplies a current corresponding to the driving force transmission command value calculated by the CPU 32 to the torque coupling 2. The current output circuit 33 is an inverter circuit that adjusts and outputs a current supplied from a battery (not shown), for example, by PWM (Pulse Width Modulation) control. The contents of the arithmetic processing executed by the CPU 32 in the control unit 3 and the configuration of the torque coupling 2 will be described later.

  The engine 101 combusts fuel such as gasoline in a cylinder as a combustion chamber, and outputs an engine torque obtained by converting a thrust of a piston disposed in the cylinder into a rotational force of a crankshaft as a driving force. The turbo engine is equipped with a turbocharger 101b as a supercharger that operates by exhaust pressure from the cylinder and supplies more fuel into the cylinder.

  The transmission 102 is an automatic transmission as an example, and changes the rotation output of the engine 101 based on state quantities such as a vehicle speed, an engine torque, and a depression amount (acceleration operation amount) of the accelerator pedal 103.

(Configuration of driving force transmission system)
The driving force transmission system 110 includes a front differential device 112 that distributes torque to the left front wheel 104L and the right front wheel 104R, a first gear mechanism 111 that transmits the output of the transmission 102 to the differential case 112a of the front differential device 112, and a propeller shaft. 113, a second gear mechanism 114 for connecting the differential case 112a and the propeller shaft 113, a pinion gear shaft 115 to which the torque of the propeller shaft 113 is transmitted via the torque coupling 2, and a torque transmitted to the pinion gear shaft 115. And a rear differential device 116 that distributes the power to the left rear wheel 105L and the right rear wheel 105R.

  A ring gear 116b is provided on the outer peripheral portion of the differential case 116a of the rear differential device 116 so as not to be relatively rotatable. The ring gear 116b is engaged with the gear portion 115a of the pinion gear shaft 115, and transmits torque from the pinion gear shaft 115 to the differential case 116a.

  Further, the driving force transmission system 110 has drive shafts 112L and 112R respectively connected to a pair of side gears of the front differential device 112, and drive shafts 116L and 116R respectively connected to a pair of side gears of the rear differential device 116. ing. The drive shafts 112L and 112R transmit torque to the left front wheel 104L and the right front wheel 104R, and the drive shafts 116L and 116R transmit torque of the left rear wheel 105L and the right rear wheel 105R.

  With the above configuration, the driving force of the engine 101 changed by the transmission 102 is constantly transmitted to the front wheels 104. Further, the driving force of the engine 101 is transmitted to the rear wheels 105 through the driving force transmission device 1 according to the vehicle state quantity of the four-wheel drive vehicle 100 when necessary. That is, in the present embodiment, the front wheels 104 are main drive wheels, and the rear wheels 105 are auxiliary drive wheels.

  The control unit 3 includes information on the depression amount of the accelerator pedal 103, information on wheel speeds of the left front wheel 104L, right front wheel 104R, left rear wheel 105L, and right rear wheel 105R, and driving force generated by the engine 101. Information on torque and information on the gear ratio (transmission ratio) in the transmission 102 can be acquired. The control unit 3 acquires these pieces of information by communication through an in-vehicle network such as a CAN (Controller Area Network).

(Configuration of driving force transmission device)
FIG. 2 is a cross-sectional view showing a configuration example of the torque coupling 2. The torque coupling 2 includes a housing 21 connected to the propeller shaft 113, an inner shaft 22 supported so as to be rotatable relative to the housing 21, an inner peripheral surface of the housing 21, and an outer peripheral surface of the inner shaft 22. A main clutch 23 arranged in between, a pilot clutch 24 arranged in parallel in the axial direction of the main clutch 23, an electromagnetic coil 25 and an armature 26 for applying an axial pressing force to the pilot clutch 24, and a pilot clutch A cam mechanism 27 that converts the rotational force of the housing 21 transmitted by 24 into the pressing force of the main clutch 23 is roughly constituted.

  The housing 21 includes a bottomed cylindrical front housing 211 and an annular rear housing 212 coupled to the front housing 211 so as to rotate integrally by screwing or the like. A plurality of spline teeth 211 a provided along the rotation axis O are formed on the inner peripheral surface of the front housing 211. The rear housing 212 includes a first member 212a made of a magnetic material coupled to the front housing 211, a second member 212b made of a nonmagnetic material integrally joined to the inner peripheral side of the first member 212a, and a second member 212b. It consists of the 3rd member 212c which consists of a magnetic material couple | bonded with the inner peripheral side.

  The inner shaft 22 is supported on the inner peripheral side of the housing 21 by a ball bearing 281 and a needle roller bearing 282. A plurality of spline teeth 22 a provided along the rotation axis O are formed on the outer peripheral surface of the inner shaft 22. A plurality of spline teeth 22b are formed on the inner peripheral surface of the inner shaft 22 to connect one end of the pinion gear shaft 115 (see FIG. 1) so as not to be relatively rotatable.

  The main clutch 23 includes a multi-plate clutch having a plurality of outer clutch plates 231 and a plurality of inner clutch plates 232 that are alternately arranged along the rotation axis O. The outer clutch plate 231 has a plurality of protrusions 231 a that engage with the plurality of spline teeth 211 a of the front housing 211, and is not rotatable relative to the front housing 211 and is movable in the axial direction. The inner clutch plate 232 has a plurality of protrusions 232 a that engage with the plurality of spline teeth 22 a of the inner shaft 22, and is not rotatable relative to the inner shaft 22 and is movable in the axial direction.

  The pilot clutch 24 is composed of a wet multi-plate clutch having a plurality of outer clutch plates 241 and a plurality of inner clutch plates 242 arranged alternately along the rotation axis O. The outer clutch plate 241 has a plurality of protrusions 241 a that engage with the plurality of spline teeth 211 a of the front housing 211, and is not rotatable relative to the front housing 211 and is movable in the axial direction. The inner clutch plate 242 has a plurality of protrusions 242b fitted to a plurality of spline teeth 271a formed on an outer peripheral surface of a pilot cam 271 of the cam mechanism 27 described later, and is not rotatable relative to the pilot cam 271 and has a shaft. The direction is movable.

  The cam mechanism 27 includes a pilot cam 271, a main cam 273 that presses the main clutch 23 in the axial direction, and a plurality of spherical cam balls 272 disposed between the pilot cam 271 and the main cam 273. Yes. The main cam 273 has spline teeth 273 a formed on the inner peripheral surface thereof fitted into the plurality of spline teeth 22 a of the inner shaft 22, and relative rotation with the inner shaft 22 is restricted. A thrust needle roller bearing 284 is disposed between the pilot cam 271 and the third member 212 c of the rear housing 212.

  A plurality of cam grooves 271b and 273b whose axial depth varies along the circumferential direction are formed on the opposing surface of the pilot cam 271 and the main cam 273. The cam mechanism 27 generates axial thrust that presses the main cam 273 against the main clutch 23 by the cam balls 272 rolling in these cam grooves.

  The electromagnetic coil 25 is held by a yoke 251 supported by the third member 212 c by a ball bearing 283 and is disposed on the opposite side of the rear housing 212 from the pilot clutch 24. Excitation current is supplied to the electromagnetic coil 25 from the current output circuit 33 (see FIG. 1) of the control unit 3 via the electric wire 252.

  The armature 26 is made of an annular magnetic material and is disposed so as to be movable in the axial direction at a position where the pilot clutch 24 is sandwiched between the armature 26 and the rear housing 212. A plurality of spline teeth 26 a that engage with the plurality of spline teeth 211 a of the front housing 211 are provided on the outer peripheral surface of the armature 26.

  When the exciting current is supplied from the control unit 3 to the electromagnetic coil 25, the torque coupling 2 configured as described above has the yoke 251, the first member 212a and the third member 212c of the rear housing 212, the pilot clutch 24, In addition, a magnetic flux is generated in the magnetic path G passing through the armature 26, and the armature 26 is attracted to the rear housing 212 side by the magnetic force of the magnetic flux, and presses the pilot clutch 24.

  As a result, the outer clutch plate 241 and the inner clutch plate 242 of the pilot clutch 24 are frictionally slid, the rotational force of the housing 21 is transmitted to the pilot cam 271 of the cam mechanism 27 via the pilot clutch 24, and the pilot cam 271 is transmitted to the main cam 273. Rotates relative to. Due to the relative rotation of the pilot cam 271 and the main cam 273, the cam ball 272 rolls on the cam grooves 271b and 273b, and axial thrust in the direction in which the pilot cam 271 and the main cam 273 are separated is generated. The main clutch 23 is pressed by the main cam 273 by the thrust of the cam mechanism 27.

(Processing content executed by the control unit)
The control unit 3 calculates a driving force transmission command value corresponding to the driving force to be transmitted to the rear wheel 105 side according to the vehicle state quantity. The controller 3 refers to at least the acceleration operation amount by the driver of the four-wheel drive vehicle 100 and the engine torque generated by the engine 101 as the vehicle state amount, and increases the engine torque as the acceleration operation amount increases. Along with this, the driving force transmission command value is increased.

  The control unit 3 calculates the first driving force transmission amount based on the acceleration operation amount, calculates the second driving force transmission amount based on the engine torque, and these first and second driving force transmission amounts. The driving force transmission command value is determined based on the above. More specifically, the driving force transmission command value is determined according to the larger driving force transmission amount of the first driving force transmission amount and the second driving force transmission amount. Hereinafter, the contents of the process executed by the control unit 3 will be described in more detail with reference to FIG.

  FIG. 3 is a flowchart showing the contents of processing executed by the control unit 3 when the CPU 32 operates according to the program stored in the storage element 31. The control unit 3 repeatedly executes the process shown in this flowchart for each predetermined control cycle.

  First, the control unit 3 acquires information on the depression amount of the accelerator pedal 103 as the acceleration operation amount (step S10). As the acceleration operation amount, an index value other than the depression amount (accelerator opening) of the accelerator pedal 103 is used as long as it indicates the operation amount of the operation performed by the driver for accelerating the four-wheel drive vehicle 100. May be.

  Next, the control unit 3 calculates the first driving force transmission amount based on the information on the acceleration operation amount acquired in step S10 (step S11). The first driving force transmission amount may increase linearly in proportion to the acceleration operation amount, for example, or may increase in a quadratic function as the acceleration operation amount increases. Further, the first driving force transmission amount may be calculated so that the first driving force transmission amount decreases as the vehicle speed increases by referring to the vehicle speed in addition to the acceleration operation amount. Furthermore, the first driving force transmission amount may be calculated using a map that three-dimensionally defines the relationship between the acceleration operation amount and the vehicle speed and the first driving force transmission amount.

  Next, the control unit 3 acquires information on the engine torque and information on the gear ratio in the transmission 2 (step S12). Here, the gear ratio is a value obtained by dividing the number of revolutions of the engine 101 by the number of revolutions of the output shaft of the transmission 102. Information on the gear ratio includes, for example, information indicating a transmission gear stage in the transmission 102, In the case of CVT (Continuously Variable Transmission), information indicating the rotation speeds of the primary pulley and the secondary pulley can be used. As the engine torque information, for example, a value obtained by detecting the torque of the crankshaft of the engine 101 by a torque sensor may be used, and a value calculated by calculation based on the amount of fuel supplied to the cylinder of the engine 101 or the like. May be used.

  Next, the control unit 3 calculates a second driving force transmission amount based on the information acquired in step S12 (step S13). The second driving force transmission amount can be obtained, for example, by further multiplying a value obtained by multiplying the engine torque by the gear ratio (output torque of the transmission 102) by a predetermined coefficient.

  Next, the control unit 3 compares the first driving force transmission amount calculated in step S11 with the second driving force transmission amount calculated in step S13, and determines which is larger (step S14). . As a result of this determination, when the first driving force transmission amount is larger than the second driving force transmission amount (S14: Yes), the first driving force transmission amount is set as the driving force transmission command value (step S15). When the first driving force transmission amount is equal to or less than the second driving force transmission amount (S14: No), the second driving force transmission amount is determined as a driving force transmission command value (step S16).

  Next, the control unit 3 acquires information on the rotational speeds of the left front wheel 104L, the right front wheel 104R, the left rear wheel 105L, and the right rear wheel 105R (step S17), and calculates the rotational speed difference between the front and rear wheels. (Step S18). Specifically, the difference between the rotational speed of the front wheel 104 that averages the rotational speeds of the left front wheel 104L and the right front wheel 104R and the rotational speed of the rear wheel 105 that averages the rotational speeds of the left rear wheel 105L and the right rear wheel 105R. The absolute value is calculated as the rotational speed difference between the front and rear wheels.

  Next, the control unit 3 corrects the driving force transmission command value based on the difference in rotational speed between the front and rear wheels calculated in step S16 (step S19). Specifically, a value obtained by multiplying the rotational speed difference between the front and rear wheels by a predetermined coefficient is added to the driving force transmission command value determined in steps S15 and S16. Thereby, for example, when the left front wheel 104L or the right front wheel 104R slips, the driving force distributed to the rear wheel 105 side increases, and the driving force distributed to the rear wheel 105 side increases by the amount corresponding to the front wheel 104 side. Since the driving force distributed to the vehicle is reduced, the slip can be converged at an early stage and the running can be stabilized.

  Next, the control unit 3 gives a signal corresponding to the driving force transmission command value to the current output circuit 33, and outputs a current corresponding to the driving force transmission command value from the current output circuit 33 (step 20). As a result, a current corresponding to the driving force transmission command value calculated by the processes in steps S10 to S19 is supplied to the electromagnetic coil 25 of the torque coupling 2 as an excitation current.

(Operation and effect of the first embodiment)
Here, the operation and effect of the first embodiment will be described with reference to FIG.

  FIG. 4A is a graph showing an example of changes in the accelerator opening and the engine torque when the accelerator pedal 103 is depressed and accelerated from the stop state of the four-wheel drive vehicle 100. In this graph, the horizontal axis represents the time axis, and the vertical axis represents the accelerator opening and the engine torque. In the present embodiment, since engine 101 is a turbo engine, the engine torque increases rapidly with a time delay after accelerator pedal 103 is depressed.

  FIG. 4B shows the first driving force transmission amount, the second driving force transmission amount, and the driving force transmission command value when the accelerator opening and the engine torque change as shown in FIG. It is a graph which shows the example of change.

  In FIG. 4B, for clarity and ease of explanation, the transmission 102 in which the first driving force transmission amount is proportional to the acceleration operation amount and the second driving force transmission amount is obtained by multiplying the engine torque by the gear ratio. The case where there is no difference in rotational speed between the front and rear wheels is illustrated. In FIG. 4B, the first driving force transmission amount is indicated by a broken line, the second driving force transmission amount is indicated by a one-dot chain line, and the driving force transmission command value is indicated by a solid line. Only the solid line is shown in the part where the solid line and the broken line or the alternate long and short dash line overlap.

  As described with reference to FIG. 3, in the processing of steps S14 to S16, the larger driving force transmission amount of the first driving force transmission amount and the second driving force transmission amount is the driving force transmission command value. Therefore, as shown in FIG. 4B, the control unit 3 calculates the driving force transmission command value based on the acceleration operation amount as the supercharging pressure of the turbocharger 101b increases. The state shifts to a second control state in which a driving force transmission command value is calculated based on the engine torque of the engine 101.

  Here, if the driving force transmission command value is calculated based only on the acceleration operation amount, the engine torque becomes excessive with respect to the driving force transmission command value in the second control state in which the engine torque has increased. The driving force on the front wheel 104 side becomes excessive and slip occurs on the front wheel, so that sufficient acceleration performance cannot be obtained.

  Further, if the driving force transmission command value is calculated based only on the engine torque, the engine torque rises gently in the first control state, so that the driving force distributed to the rear wheel 105 in the initial stage of acceleration is It is very small and the driving force distributed to the front wheels 104 becomes large. For this reason, the torsion of the front wheel driving force transmission system that transmits the driving force to the front wheels 104 becomes large, and acceleration cannot be obtained.

  In the present embodiment, since the larger driving force transmission amount of the first driving force transmission amount and the second driving force transmission amount is used as the driving force transmission command value, when the engine torque increases rapidly, Further, it is possible to suppress a decrease in response of driving force transmission to the rear wheel 105 due to slipping of the main clutch 23 in the torque coupling 2.

  That is, since the driving force transmission command value increases as the acceleration operation amount increases, an appropriate driving force can be distributed to the rear wheels 105 even in the early stage of acceleration in the first control state, and the front wheel driving force transmission is achieved. System twist can be suppressed. Further, since the driving force transmission command value increases as the engine torque increases, the slip of the front wheels 104 in the second control state is suppressed. Thereby, in the four-wheel drive vehicle 100 provided with the engine 101 with a supercharger, sufficient acceleration performance can be obtained without supplying an unnecessarily large current.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the present embodiment, the content of the processing executed by the control unit 3 is different from that of the first embodiment, and the configuration of the four-wheel drive vehicle 100 is the same as that of the first embodiment. Will not be described again.

  FIG. 5 is a flowchart showing the contents of processing executed by the control unit 3 according to the present embodiment. Of the steps in this flowchart, the same steps as those described with reference to FIG. 3 in the first embodiment are denoted by the same step numbers and description thereof is omitted.

  The control unit 3 in the present embodiment adds the first driving force transmission amount and the second driving force transmission amount in the process of step S14A instead of the processes of steps S14 to S16 in the flowchart shown in FIG. The driving force transmission command value is used. Thereafter, the driving force transmission command value is corrected based on the difference in rotational speed between the front and rear wheels (step S19), and a current corresponding to the driving force transmission command value is output from the current output circuit 33 to the torque coupling 2 (step 20). ).

  FIG. 6 shows the first driving force transmission amount, the second driving force transmission amount when the accelerator opening and the engine torque change as shown in FIG. It is a graph which shows the example of the change of a driving force transmission command value. In the present embodiment, since the first driving force transmission amount and the second driving force transmission amount are added to obtain the driving force transmission command value, the first driving force transmission amount and the second driving force are added. It is desirable to reduce the magnitude of each force transmission amount as compared with the first embodiment.

  Also according to the present embodiment, the driving force transmission command value increases as the acceleration operation amount increases, and also increases as the engine torque increases. Therefore, the torque coupling 2 in the first and second control states. Slip is suppressed. Thereby, the fall of the responsiveness of the driving force transmission to the rear wheel 105 can be suppressed.

  As mentioned above, although the driving force transmission apparatus of this invention was demonstrated based on 1st and 2nd embodiment, this invention is not limited to these embodiment, In the range which does not deviate from the summary, it is various. It is possible to implement in the embodiment.

DESCRIPTION OF SYMBOLS 1 ... Driving force transmission device, 2 ... Torque coupling, 3 ... Control part, 21 ... Housing, 22 ... Inner shaft, 22a, 22b ... Spline teeth, 23 ... Main clutch, 24 ... Pilot clutch, 25 ... Electromagnetic coil, 26 ... Armature, 26a ... Spline teeth, 27 ... Cam mechanism, 31 ... Memory element, 33 ... Current output circuit, 100 ... Four-wheel drive vehicle, 101 ... Engine, 101a ... Internal combustion engine section, 101b ... Turbocharger, 102 ... Transmission, DESCRIPTION OF SYMBOLS 103 ... Accelerator pedal, 104 ... Front wheel, 104L ... Left front wheel, 104R ... Right front wheel, 105 ... Rear wheel, 105L ... Left rear wheel, 105R ... Right rear wheel, 110 ... Driving force transmission system, 111 ... Gear mechanism, 112 ... Front differential device, 112L, 112R ... drive shaft, 112a ... differential case, 1 DESCRIPTION OF SYMBOLS 3 ... Propeller shaft, 114 ... Gear mechanism, 115 ... Pinion gear shaft, 115a ... Gear part, 116 ... Rear differential device, 116L, 116R ... Drive shaft, 116a ... Differential case, 116b ... Ring gear, 211 ... Front housing, 211a ... Spline teeth , 212 ... rear housing, 212a ... first member, 212b ... second member, 212c ... third member, 231 ... outer clutch plate, 231a ... projection, 232 ... inner clutch plate, 232a ... projection, 241 ... outer clutch plate, 241a ... protrusions, 242 ... inner clutch plates, 242b ... protrusions, 251 ... yoke, 252 ... electric wires, 271 ... pilot cams, 271a ... spline teeth, 271b, 273b ... cam grooves, 272 ... cam balls, 273 Main cam, 273a ... spline teeth, 281, 283 ... ball bearing, 282 ... needle roller bearings, 284 ... thrust needle roller bearing, 300 ... accelerator opening sensor, G ... path, O ... Rotation axis

Claims (4)

A driving force transmission device is provided in a driving force transmission system that transmits a driving force of a driving source of a vehicle to a main driving wheel and an auxiliary driving wheel, and transmits the driving force to the auxiliary driving wheel in a variable amount of driving force transmission. And
A control unit that calculates a driving force transmission command value corresponding to the driving force to be transmitted to the auxiliary driving wheel based on a vehicle state quantity, and outputs a current corresponding to the driving force transmission command value;
A clutch that operates by the current output from the control unit and transmits a driving force according to the current to the auxiliary driving wheel side;
The controller calculates a first driving force transmission amount based on an acceleration operation amount by a driver of the vehicle and calculates a second driving force transmission amount based on a driving force generated by the driving source. The driving force transmission command value is determined according to the larger driving force transmission amount of the first and second driving force transmission amounts.
Driving force transmission device. The drive source is an engine equipped with a supercharger,
The control unit generates a driving force generated by the driving source from a first control state in which the driving force transmission command value is calculated based on the acceleration operation amount as the supercharging pressure of the supercharger increases. Transition to a second control state in which the driving force transmission command value is calculated based on
The driving force transmission device according to claim 1 .   A driving force transmission device is provided in a driving force transmission system that transmits a driving force of a driving source of a vehicle to a main driving wheel and an auxiliary driving wheel, and transmits the driving force to the auxiliary driving wheel in a variable amount of driving force transmission. And
  A control unit that calculates a driving force transmission command value corresponding to the driving force to be transmitted to the auxiliary driving wheel based on a vehicle state quantity, and outputs a current corresponding to the driving force transmission command value;
  A clutch that operates by the current output from the control unit and transmits a driving force according to the current to the auxiliary driving wheel side;
  The controller calculates a first driving force transmission amount based on an acceleration operation amount by a driver of the vehicle and calculates a second driving force transmission amount based on a driving force generated by the driving source. , Calculating the driving force transmission command value by adding the first and second driving force transmission amounts;
  Driving force transmission device.   The drive source is an engine equipped with a supercharger,
  The control unit generates a driving force generated by the driving source from a first control state in which the driving force transmission command value is calculated based on the acceleration operation amount as the supercharging pressure of the supercharger increases. Transition to a second control state in which the driving force transmission command value is calculated based on
  The driving force transmission device according to claim 3.

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