EP2913504A1

EP2913504A1 - Vehicular drive apparatus

Info

Publication number: EP2913504A1
Application number: EP13848773.1A
Authority: EP
Inventors: Daisuke Tamaru
Original assignee: Aisin Seiki Co Ltd
Current assignee: Aisin Corp
Priority date: 2012-10-25
Filing date: 2013-09-24
Publication date: 2015-09-02
Also published as: WO2014065061A1; CN104736822A; JP5849930B2; JP2014084815A; EP2913504A4; IN2015DN03779A; BR112015008537A2

Abstract

Provided is a vehicular drive apparatus such that the development of shock upon engagement of a manual clutch can be decreased in a manual clutch-equipped vehicle. The apparatus includes a clutch-synchronizing timing engine torque calculating unit that calculates a clutch-synchronizing timing engine torque on the basis of a clutch transmitting torque; and an engine control unit that executes torque balancing control by controlling an engine so as to achieve the clutch-synchronizing timing engine torque when the absolute value of a clutch difference rotation speed, which is a difference rotation speed between an output shaft and a transmission input shaft during clutch synchronization, is converged to or below a first prescribed differential rotation speed.

Description

[Technical Field]

This invention relates to a vehicular drive apparatus which controls a vehicle starting operation for a vehicle equipped with a manual clutch.

[Background Art]

In an automobile which is equipped with a manual transmission (hereinafter referred to as "MT") and a manual clutch, at the start of the vehicle, an operator of the vehicle depresses the clutch pedal to be in a clutch disconnected state to shift the MT to a first speed stage. Then the operator depresses the acceleration pedal to increase the engine rotation speed and at the same time releases the clutch pedal gradually to be in a clutch connected state thereby transmitting an engine torque to vehicle wheels. Thus, the operator of the vehicle coordinates the depression operation of the acceleration pedal, in other words, an engine outputting (engine rotation speed) and the releasing operation of the clutch pedal, in other words, clutch engagement (engine load) so that a smooth vehicle start can be achieved.
In a Patent Literature 1, a technology is disclosed in which a shock generated upon clutch engagement operation can be reduced by agreeing the engine rotation speed with the input shaft rotation speed of the MT when the clutch is disengaged in a vehicle having the MT and the clutch.

[Citation List]

[Patent Literature]

Patent Literature 1: JP58(1983) - 200052 A

[Summary of Invention]

[Technical Problems]

However, according to the technology disclosed in the Patent Literature 1, engine rotation speed is controlled to agree with the input shaft rotation speed. However, even the engine rotation speed and the input shaft rotation speed agree with each other, if the change amount of the engine rotation speed and the change amount of the input shaft rotation speed differ from each other, upon clutch complete engagement, the change amount of the engine rotation speed suddenly changes and the engine rotation inertial torque is acted on the vehicle to generate a shock on the vehicle.
Further, when the operator of the vehicle depresses the clutch pedal during the half clutch operation to thereby decreasing the clutch transmitting torque, the engine rotation speed increases due to the response delay which leads to an elongation of the half clutch operation time period. On the other hand, when the operator of the vehicle releases the clutch pedal thereby increasing the clutch transmitting torque, the change amount per unit time of the difference in speed between the engine rotation speed and the input shaft rotation speed increases accordingly. When this change amount per unit time of the difference rotation speed is large, although the torque transmitting amount to the input shaft during the half clutch operation becomes large, this torque becomes zero at a moment when the engine rotation speed agrees with the input shaft rotation speed. This performance characteristic is a cause of a shock generated before and after the half clutch operation.
The present invention was made in consideration with the above problems and the object of the invention is to provide a vehicular drive apparatus for a vehicle equipped with the manual clutch, which can minimize occurrence of shocks upon the engagement of the manual clutch.

[Solution to Problem(s)]

The vehicular drive apparatus associated with the invention of claim 1 includes an engine outputting an engine torque to an output shaft, an engine operating means operated for variably outputting the engine torque from the engine, an input shaft which rotates in association with a rotation of a drive wheel of a vehicle, a clutch provided between the output shaft and the input shaft for controlling a clutch transmitting torque therebetween to be variable, a clutch operating means for operating the clutch to control the clutch transmitting torque to be variable, a clutch transmitting torque obtaining means for obtaining the clutch transmitting torque which is generated by the clutch, a clutch synchronizing timing engine torque calculating means for calculating the clutch synchronizing timing engine torque based on the clutch transmitting torque obtained by the clutch transmitting torque obtaining means and an engine control means for executing a torque balancing control by controlling the engine so that the engine torque becomes the clutch synchronizing timing engine torque when an absolute value of the clutch difference rotation speed, which is a difference rotation speed between the output shaft and the input shaft during a clutch being under synchronization, converges to equal to or less than a first defined difference rotation speed.
The invention of claim 2 is characterized in that in claim 1, the vehicular drive apparatus further comprises an adjusting torque calculating means for calculating an adjusting torque of a minus value when the rotation speed of the output shaft is faster than the rotation speed of the input shaft and calculating an adjusting torque of a plus value when the rotation speed of the output shaft is slower than the rotation speed of the input shaft at the execution of the torque balancing control, wherein the clutch synchronizing timing engine torque calculating means calculates the clutch synchronizing timing engine torque by adding the adjusting torque.
The invention of claim 3 is characterized in that in claim 2, the adjusting torque calculating means calculates the adjusting torque in such a manner that the larger the absolute value of the clutch difference rotation speed is, the larger the absolute value of the adjusting torque becomes.
The invention of claim 4 is characterized in that in any one of claims 1 through 3, wherein the vehicular drive apparatus further includes a required engine torque calculating means for calculating a required engine torque which is a torque required from the engine based on an operating amount of the acceleration pedal and a return control timing engine torque calculating means for calculating a return control timing engine torque which gradually changes from the clutch synchronizing timing engine torque to the required engine torque when the absolute value of the clutch difference rotation speed during the clutch being engaged becomes equal to or less than a second defined difference rotation speed which is slower than a first defined difference rotation speed, wherein the engine control means executes a return control which controls the engine so that the engine torque becomes the return control timing engine torque when the absolute value of the clutch difference rotation speed during the clutch being engaged becomes equal to or less than the second defined difference rotation speed.
The invention of claim 5 is characterized in that in claim 4, the return control timing engine torque calculating means calculates a return ratio per unit time of a minus value when the deviation torque is plus and a return ratio per unit time of a plus value when the deviation torque is minus in such a manner that the smaller the absolute value of the deviation torque is, the larger the absolute value of the return ratio per unit time becomes, and further calculates the torque deviation ratio by subtracting a value obtained by multiplying the return ratio per unit time by an elapsed time from the calculation of a previous time torque deviation ratio from the previous time calculated torque deviation ratio.
The invention of claim 6 is characterized in that in claim 5, the return control timing engine torque calculating means calculates a return ratio per unit time of a minus value when the deviation torque is plus and a return ratio per unit time of a plus value when the deviation torque is minus in such a manner that the smaller the absolute value of the deviation torque is, the larger the absolute value of the return ratio per unit time becomes, and further calculates the torque deviation ratio by subtracting a value obtained by multiplying the return ratio per unit time by an elapsed time from the calculation of a previous time torque deviation ratio from the previous time calculated torque deviation ratio.
The invention of claim 7 is characterized in that in any one of claims 1 through 6, the clutch transmitting torque obtaining means includes a clutch operating amount detecting means for detecting an operating amount of the clutch operating means.
The invention of claim 8 is characterized in that in any one of claims 1 through 7, wherein the vehicular drive apparatus includes a vehicle speed detecting means for detecting a vehicle speed of the vehicle wherein the engine control means does not execute the torque balancing control when the vehicle speed detected by the vehicle speed detecting means is slower than a predetermined speed.
The invention of claim 9 is characterized in that in any one of claims 1 through 8, the vehicular drive apparatus further includes a braking force applying means for applying a braking force to the vehicle and a braking force operating means for controlling the braking force of the braking force applying means to be variable, and wherein the engine control means does not execute the torque balancing control when the braking force operating means is in operation.

[Advantageous effects of invention]

According to the invention associated with claim 1, the clutch synchronizing timing engine torque calculating means calculates the clutch synchronizing timing engine torque based on the clutch transmitting torque. The engine control means executes the torque balancing control by controlling the engine so that the engine torque becomes the clutch synchronizing timing engine torque when the absolute value of the clutch difference rotation speed converges to equal to or less than the first defined difference rotation speed.
Thus, when the torque balancing control is executed, the engine torque outputted from the engine approaches to the clutch transmitting torque. Therefore, the change of the difference rotation speed per unit time between the engine rotation speed and the input shaft rotation speed can be reduced. Thus, the engine inertia torque which acts on the vehicle upon complete engagement of the clutch can be reduced accordingly. The reduction of the generation of the shock as well as an unnecessary increase of the engine rotation speed can be prevented thereby to shorten the half clutch operation time.
Further, the clutch synchronizing timing engine torque is calculated based on the clutch transmitting torque. Accordingly, even when the clutch transmitting torque changes due to the operation of the clutch by the operator of the vehicle, the clutch synchronizing timing engine torque is increased or decreased depending on the change of the clutch transmitting torque. Therefore, regardless of the operation of the clutch by the operator, the difference between the change amount of the engine rotation speed and the change amount of the input shaft rotation speed can be reduced. Due to such reduction of the difference, the generation of shock upon complete clutch engagement can be reduced.
According to the invention associated with claim 2, the adjusting torque calculating means calculates an adjusting torque of a minus value when the rotation speed of the output shaft is faster than the rotation speed of the input shaft and calculates an adjusting torque of a plus value when the rotation speed of the output shaft is slower than the rotation speed of the input shaft. The clutch synchronizing timing engine torque calculating means calculates the clutch synchronizing timing engine torque by adding the adjusting torque. Thus, the clutch synchronization can be surely performed.
According to the invention associated with claim 3, the adjusting torque calculating means calculates the adjusting torque in such a manner that the larger the absolute value of the clutch difference rotation speed is, the larger the absolute value of the adjusting torque becomes. Thus, the rotation speed of the engine can promptly approximate to the rotation speed of the input shaft to shorten the clutch synchronizing time.
Further, the adjusting torque calculating means calculates the adjusting torque in such a manner that the smaller the absolute value of the clutch difference rotation speed is, the smaller the absolute value of the adjusting torque becomes. Therefore, the difference between the change amount of the engine rotation speed and the change amount of the input shaft rotation speed immediately before the clutch being synchronized can be reduced. Due to such reduction of the difference, the generation of shock upon complete clutch engagement can be reduced.
According to the invention associated with claim 4, the return control timing engine torque calculating means calculates the return control timing engine torque which gradually changes from the clutch synchronizing timing engine torque to the required engine torque when the absolute value of the clutch difference rotation speed becomes equal to or less than the second defined difference rotation speed. The engine control means executes the return control which controls the engine so that the engine torque becomes the return control timing engine torque.
Thus, when the return control is executed, the engine torque outputted by the engine can be gradually returned to the required engine torque. Thus, an abrupt change of the engine torque can be prevented to give the operator of the vehicle any unpleasant feeling.
According to the invention associated with claim 5, the return control timing engine torque calculating means calculates a torque deviation ratio whose value becomes gradually decreased as the elapsed time from the start of the execution of the return control becomes long and further calculates the return control timing engine torque by adding a value obtained by multiplying the deviation torque by the torque deviation ratio to the required engine torque.
Thus, the engine torque can be surely gradually changed from the clutch synchronizing timing engine torque to the required engine torque.
According to the invention associated with claim 6, the return control timing engine torque calculating means calculates a return ratio per unit time of a minus value when the deviation torque is plus and on the other hand, calculates a return ratio per unit time of a plus value when the deviation torque is minus. Further, the return control timing engine torque calculating means calculates the return ratio per unit time in such a manner that the smaller the absolute value of the deviation torque is, the larger the absolute value of the return ratio per unit time becomes. Still further, the return control timing engine torque calculating means calculates the torque deviation ratio by subtracting a value obtained by multiplying the return ratio per unit time by an elapsed time from the calculation of a previous time torque deviation ratio from the previous time calculated torque deviation ratio.
Thus, the return ratio per unit time is calculated in such a manner that the smaller the absolute value of the deviation torque is, the larger the absolute value of the return ratio per unit time becomes. Thus, the smaller the absolute value of the deviation torque is, the faster the engine torque returns to the required engine torque which reflects the intention of the operator of the vehicle. Therefore, the time executing the engine control where the intention of the operator of the vehicle is not reflected can be shortened and this can prevent the operator of the vehicle from any unpleasant feeling.
On the other hand, the larger the absolute value of the deviation torque is, the smaller the absolute value of the return ratio per unit time is calculated. Accordingly, when the deviation torque is large, the engine torque is slowly returned to the required engine torque giving no unpleasant feeling to the operator of the vehicle.
According to the invention associated with claim 7, the clutch transmitting torque obtaining means includes a clutch operating amount detecting means which detects the operating amount of the clutch operating means. Therefore, the operating amount of the clutch operating means can be obtained by using a simple structure.
According to the invention associated with claim 8, wherein the engine control means does not execute the torque balancing control when the vehicle speed detected by the vehicle speed detecting means is slower than the defined speed. The vehicle can smoothly start when the engine torque is large relative to the clutch transmitting torque. The torque balancing control is not executed when the vehicle starts and accordingly, the engine torque does not approximate to the clutch transmitting torque. Thus, the vehicle can smoothly start.
According to the invention associated with claim 9, the engine control means does not execute the torque balancing control when the braking force operating means is in operation.
Thus, when the vehicle has to be quickly stopped by an emergency braking operation, the control in which engine torque is forcibly approximated to the clutch transmitting torque. Therefore, the vehicle can be safely stopped.

[Brief Explanation of Attached Drawings]

[Fig. 1] Fig. 1 is a schematic structural view of a vehicular drive apparatus according to an embodiment of the invention;
[Fig. 2] Fig. 2 illustrates a clutch transmitting torque mapping data illustrating a relationship between the clutch stroke and the clutch transmitting torque;
[Fig. 3] Fig. 3 is a graph illustrating an outline of the embodiment, wherein the horizontal axis indicates elapsed time and the vertical axis indicates engine rotation speed, engine torque, clutch transmitting torque, torque deviation ratio and acceleration opening degree;
[Fig. 4] Fig. 4 is a flowchart of clutch/engine cooperative control;
[Fig. 5] Fig. 5 illustrates a flowchart of the torque balancing control which is a sub-routine of the clutch/engine cooperative control of Fig. 4;
[Fig. 6] Fig. 6 is an example of a table illustrating adjusting torque calculating data which is a mapping data representing the relationship between the clutch difference rotation speed Δc and the adjusting torque Ta;
[Fig. 7] Fig. 7 is a flowchart of return control which is a sub-routine of the clutch/engine cooperative control in Fig. 4; and
[Fig. 8] Fig. 8 illustrates an example of a table illustrating return ratio per unit time calculating data which is a mapping data representing the relationship between the deviation torque ΔT and the return ratio Rr per unit time.

[Embodiments for Implementing Invention]

(Explanation of vehicle)

The vehicular drive apparatus 1 according to the embodiment of the invention will be explained with reference to Fig. 1. Fig. 1 illustrates an overall structure of the vehicular drive apparatus 1 equipped with an engine 2. In Fig. 1, the bold lines indicate mechanical connection between the devices and arrows with broken lines indicate signal lines for controlling.
As shown in Fig. 1, the vehicle is equipped with the engine 2, a clutch 3, a manual transmission 4 and a differential device 17, in series in this order of arrangement. The differential device 17 is connected to drive wheels 18R and 18L of the vehicle. The drive wheels 18R and 18L indicate either front, rear or front/rear wheels of the vehicle.
The vehicle includes an acceleration pedal 51, a clutch pedal 53 and a brake pedal 56. The acceleration pedal 51 is operated to variably change the engine torque outputted from the engine 2. The acceleration pedal 51 is provided with an acceleration sensor 52 which detects the acceleration opening degree Ac which corresponds to an operating amount of the acceleration pedal 51.
The clutch pedal 53 operates the clutch 3 to be in a disconnected state and in a connected state and is operated to variably change a clutch transmitting torque, which will be explained later. The vehicle further includes a master cylinder 55 which generates a hydraulic pressure corresponding to the operating amount of the clutch pedal 53. The master cylinder 55 is provided with a clutch sensor 54 which detects a stroke of the master cylinder 55.
The brake pedal 56 is provided with a brake sensor 57 which detects an operating amount of the brake pedal 56. The vehicle includes a brake master cylinder (not shown) which generates a hydraulic pressure responding to the operating amount of the brake pedal 56 and a brake device 19 which applies the wheels of the vehicle with a braking force according to the master pressure generated by the brake master cylinder.
The engine 2 is such as a gasoline engine or a diesel engine using hydrocarbon system fuel, such as gasoline or light oil. The engine 2 includes an output shaft 21, a throttle valve 22, an engine rotation speed sensor 23 and a fuel injection device 28. The output shaft 21 is rotated unitary with a crank shaft which is rotatably driven by a piston. Thus, the engine 2 outputs the engine torque Te to the output shaft 21. It is noted that when the gasoline engine is used as the engine 2, an ignition device (not shown) is provided on a cylinder head of the engine 2 for igniting an air-fuel mixture gas in the cylinder.
The throttle valve 22 is provided in a pathway which supplies the cylinder of the engine 2 with the air. The throttle valve 22 is used for adjusting the supplied air amount in the cylinder of the engine 2. The fuel injection device 28 is provided at a pathway which supplies inside of the engine 2 with the air or at the cylinder head of the engine 2. The fuel injection device 28 is used for injecting the fuel such as gasoline or the light oil.
The engine rotation speed sensor 23 is provided in the vicinity of the output shaft 21. The engine rotation speed sensor 23 detects the engine rotation speed Ne which corresponds to the rotation speed of the output shaft 21 and outputs the detected signal to a control portion 10. It is noted here that in this embodiment, the output shaft 21 of the engine 2 is connected to a flywheel 31 which is an input member of the clutch 3 which will be explained later.
The cutch 3 is provided between the output shaft 21 of the engine 2 and a transmission input shaft 41 of the manual transmission 4 which will be explained later. The clutch 3 is a manually operated type clutch which connects or disconnects the output shaft 21 and the transmission input shaft 41 by the operation of the clutch pedal 53 by the operator of the vehicle and at the same time variably changes the clutch transmitting torque Tc (See Fig. 2) between the output shaft 21 and the transmission input shaft 41. The clutch 3 includes the flywheel 31, a clutch disc 32, a clutch cover 33, a diaphragm spring 34, a pressure plate 35, a clutch shaft 36, a release bearing 37 and a slave cylinder 38.
The flywheel 31 is of a disc plate shape and is connected to the output shaft 21. The clutch shaft 36 is connected to the transmission input shaft 41. The clutch disc 32 is of a disc plate shape and is provided with a friction material 32a at the outer peripheral surfaces of both sides of the clutch disc 32. The clutch disc 32 faces with the flywheel 31 and is in spline connection with the clutch shaft 36 at the tip end thereof allowing slidable movement in an axial direction but restricting rotation relative to the clutch shaft 36.
The clutch cover 33 is formed by a flattened cylindrical shaped cylindrical portion 33a and a plate portion 33b extending in a rotation center direction from one end of the cylindrical portion 33a. The other end of the cylindrical portion 33a is connected to the flywheel 31. Therefore, the clutch cover 33 is rotated together with the flywheel 31. The pressure plate 35 is of a disc shape having a hole at the center thereof. The pressure plate 35 is provided at the opposite side of the flywheel 31 and facing to the cutch disc 32 and is slidably movable in an axial direction. The clutch shaft 36 is inserted into the pressure plate 35 at the central portion thereof.
The diaphragm spring 34 is formed by a ring shaped ring portion 34a and a plurality of plate spring portions 34b which is extending toward inside from an inner peripheral brim of the ring portion 34a. The plate spring portions 34b are gradually inclined towards the inside so as to be positioned on the plate portion 33b side. The plate spring portions 34b are elastically deformable in an axis line direction. The diaphragm spring 34 is disposed between the pressure plate 35 and the plate portion 33b of the clutch cover 33 under being compressed state in an axial direction. The ring portion 34a is in contact with the pressure plate 35. The center portion of the plate spring portion 34b is connected to the inner peripheral brim of the plate portion 33b. The clutch shaft 36 is inserted into the central portion of the diaphragm spring 34.
The release bearing 37 is attached on a housing (not shown) of the clutch 3. The clutch shaft 36 is inserted into the central portion of the release bearing 37 and is slidably movable in an axial direction. The release bearing is provided with a first member 37a and a second member 37b which are oppositely provided and relatively rotatable. The first member 37a is in contact with the tip end of the plate portion 33b.
The slave cylinder 38 includes a push rod 38a which advances and retreats by the hydraulic pressure. The tip end of the push rod 38a is in contact with the second member 37b of the release bearing 37. The slave cylinder 38 and the master cylinder 55 are connected with each other by a hydraulic pressure conduit 58.
Under the clutch pedal 53 being not depressed, no hydraulic pressure is generated at the master cylinder 55 and the slave cylinder 38. Under this state, the clutch disc 32 is biased towards the flywheel 31 pushed thereto by the diaphragm spring 34 via the pressure plate 35. Accordingly, the flywheel 31, the clutch disc 32 and the pressure plate 35 are integrally rotated by the friction force generated between the friction material 32a and the flywheel 31 and the friction force generated between the friction material 32a and the pressure plate 35. Thus, the output shaft 21 and the transmission input shaft 41 are connected for unitary rotation.
On the other hand, when the clutch pedal 53 is depressed, hydraulic pressure is generated in the master cylinder 55 and then also generated in the slave cylinder 38. By this hydraulic pressure, the push rod 38a of the slave cylinder 38 pushes the release bearing 37 towards the diaphragm spring 34 side. Then the plate spring portion 34b is deformed at a connecting portion thereof with the inner peripheral brim of the plate portion 33b as a fulcrum point. Then the biasing force for biasing the clutch disc 32 to the flywheel 31 becomes weak and finally becomes zero.
As shown in Fig. 2, as the clutch stroke which corresponds to the stroke of the master cylinder 55 increases, the clutch transmitting torque Tc which is transmitted by the clutch 3 from the output shaft 21 to the transmission input shaft 41 becomes small and when the biasing force above becomes zero, the clutch transmitting torque Tc becomes zero and the clutch 3 becomes in fully (completely) disconnected state. Thus as explained, the clutch 3 according to the embodiment is a normally closed type clutch, in which the clutch 3 is in connected state when the clutch pedal 53 is not depressed.
The manual transmission 4 is a stepped stage transmission wherein a plurality of speed stages respectively having different gear ratios is selectively shifted over between the transmission input shaft 41 and a transmission output shaft 42. A plurality of idle gears (not shown) which is idly rotatable relative to the axis and a plurality of fixed gears (not shown) engaging with the idle gears, whose idle rotation relative to the axis is restricted, are attached to either one of the transmission input shaft 41 and the transmission output shaft 42.
Further, the manual transmission 4 is provided with a select mechanism wherein one of the pluralities of idle gears is selected and the selected gear is restricted relative rotation to the shaft on which the selected gear is fitted. By this structure, the transmission input shaft 41 is rotated in association with the drive wheels 18R and 18L. Further, the manual transmission 4 is provided with a shift operation mechanism (not shown) in which the operation of the shift lever 45 by the operator of the vehicle is converted into a force for operating the select mechanism.
A transmission input shaft rotation speed sensor 43 is provided in the vicinity of the transmission input shaft 41 for detecting the rotation speed of the transmission input shaft 41 (transmission input shaft rotation speed Ni). The transmission input shaft rotation speed Ni (clutch rotation speed Nc) detected by the transmission input shaft rotation speed sensor 43 is outputted to the control portion 10.
A transmission output shaft rotation speed sensor 46 is provided in the vicinity of the transmission output shaft 42 for detecting the rotation speed of the transmission output shaft 42 (transmission output shaft rotation speed No.). The transmission output shaft rotation speed No detected by the transmission output shaft rotation speed sensor 46 is outputted to the control portion 10.
The control portion 10 controls the vehicle as a whole and has a memory portion which is formed by a CPU, RAM, ROM and a memory portion formed by a nonvolatile device (these are not shown). The CPU executes the programs corresponding to the flowcharts indicated in Figs. 4, 5 and 7. The RAM memorizes temporarily the variables which are necessary for executing the programs. The memory portion memorizes the above programs, mapping data shown in Figs.2, 6 and 8.
The control portion 10 calculates the required engine torque Ter which corresponds to the engine torque required by an operator of the vehicle based on the acceleration opening degree Ac detected by the acceleration sensor 52 according to the operation of the acceleration pedal 51 by the operator of the vehicle. Then based on the required engine torque Ter, the control portion 10 adjusts the opening degree S of the throttle valve 22 to adjust the suction amount of the air and the fuel injection amount of the fuel injection device 28, and further controls the ignition device.
By this, the supply amount of the air-fuel mixture including the fuel is adjusted and the engine torque Te outputted from the engine 2 is adjusted to be the required engine torque Ter and at the same time the engine rotation speed Ne is adjusted. It is noted here that when the acceleration pedal 51 is not depressed (acceleration opening degree Ac = 0 (zero)), the engine rotation speed Ne is kept to be the idle rotation speed (for example 700 r.p.m.).
The control portion 10 calculates the clutch transmitting torque Tc that is the amount that the clutch can transmit to the transmission input shaft 41 from the output shaft 21 by referencing the clutch stroke Cl detected by the clutch sensor 54 to the clutch transmitting torque mapping data which represents the relationship between the clutch stroke Cl and the clutch transmitting torque Tc illustrated in Fig. 2.
The control portion 10 calculates the vehicle speed V based on the transmission output shaft rotation speed No detected by the transmission output shaft rotation speed sensor 46. The control portion 10 calculates the clutch difference rotation speed Δc which corresponds to the difference rotation speed of the clutch 3 by subtracting the transmission input shaft rotation speed Ni detected by the transmission input shaft rotation speed sensor 43 from the engine rotation speed Ne detected by the engine rotation speed sensor 23. In other words, the clutch difference rotation speed Δc is the difference rotation speed of the clutch 3, i.e., the difference rotation speed between the output shaft 21 and the transmission input shaft 41.
The vehicular drive apparatus 1 according to the embodiment includes the engine 2, clutch 3, manual transmission 4, control portion 10, clutch pedal 53, clutch sensor 54, master cylinder 55, acceleration pedal 51, acceleration sensor 52, brake pedal 56, brake sensor 57 and hydraulic pressure conduit 58.

(Outline of the embodiment)

The outline of the embodiment of the invention will be explained with reference to Fig. 3. Under the clutch being in half clutch state and being engaged, when the clutch difference rotation speed Δc becomes equal to or less than a first defined rotation speed A (for example, 400rpm), (T1 in Fig. 3), the torque balancing control is executed. More specifically, the control in which the engine torque Te which the engine 2 generates is approximated to the clutch transmitting torque Tc is executed (1 in Fig. 3).
Next, when the clutch 3 is substantially synchronized and the absolute value of the clutch difference rotation speed Δc becomes equal to or less than the second defined difference rotation speed B (for example, 25rpm), (T2 in Fig. 3), the return control is executed. More specifically, the control that returns the torque which the engine 2 generates to the required engine torque Ter is executed. (2 in Fig. 3).
When the torque balancing control described above is executed, the difference between the change amount of the engine rotation speed Ne and the amount of the transmission input shaft rotation speed Ni can be reduced. Then the inertia torque of the engine 2 acting on the vehicle when the clutch is completely engaged is reduced and the shocks that the vehicle receives can be reduced.
On the other hand when the torque balancing control is not executed as is shown in Fig. 3 with a dot chain line, the clutch 3 is synchronized to be completely engaged in the situation where there is a difference between the change amount of the engine rotation speed Ne and the change amount of the transmission input shaft rotation speed Ni. Then the inertia torque of the engine 2 acts on the vehicle when the clutch 3 is completely engaged and the shocks that the vehicle receives are generated. This will be explained in detail with reference to Fig. 4, using the flowchart shown therein.

(Clutch/Engine cooperative control)

The clutch/engine cooperative control is explained hereinafter using the flowchart in Fig. 4. When an ignition key of the vehicle is NO and the engine 2 is started, the clutch/engine cooperative control starts and the program goes to the step S11.
At the step S11, when the control portion 10 judges that the brake pedal 56 is not depressed and the brake device 19 does not generate the braking force (Brake: OFF) based on the detection signal from the brake sensor 57 (S11; YES), the control portion 10 advances the program to the step S12. On the other hand, when the control portion 10 judges that the brake pedal 56 is depressed and the brake device 19 generates the braking force (Brake: ON), (S11; NO), the control portion 10 advances the program to the step S20.
At the step S12, when the control portion 10 judges that the clutch transmitting torque Tc is not zero (clutch 3 is not completely disconnected) based on the detection signal from the clutch sensor 54 (S12; YES), the control portion 10 advances the program to the step S13. On the other hand, when the control portion 10 judges that the clutch transmitting torque Tc is zero (clutch 3 is completely disconnected) (S12; NO), the control portion 10 advances the program to the step S20.
At the step S13, when the control portion 10 judges that the vehicle speed V is equal to or more than a predetermined defined speed (for example, 10 km/h) (S13; YES), the control portion 10 advances the program to the step S14 and when the control portion 10 judges that the vehicle speed V is lower than the defined speed (S13; NO), the control portion 10 advances the program to the step S20.
At the step S14, when the control portion 10 judges that the absolute value of the clutch difference rotation speed Δc converges equal to or less than a first defined difference rotation speed A (for example, 400 r.p.m.) based on the detection signal outputted from the engine rotation speed sensor 23 and the transmission input shaft rotation speed sensor 43 (S14; YES), the control portion 10 advances the program to the step S15. Further, when the control portion 10 judges that the absolute value of the clutch difference rotation speed Δc is more than the first defined difference rotation speed A (S14; NO), the control portion 10 advances the program to the step S20.
At the step S15, when the control portion 10 judges that the absolute value of the clutch difference rotation speed Δc is less than a second defined difference rotation speed B (S15: YES), the control portion 10 advances the program to the step S16. Further, when the control portion 10 judges that the absolute value of the clutch difference rotation speed Δc is greater than the second defined rotation speed B (S15: NO), the control portion 10 advances the program to the step S17. It is noted here that the second defined difference rotation speed B is set to be smaller than the first defined difference rotation speed A, for example, 25rpm. In other words, when the clutch difference rotation speed Δc is equal to or less than the second defined difference rotation speed B, the output shaft 21 and the transmission input shaft 41 are rotated with substantially synchronized and thus the clutch 3 is also substantially synchronized.
At the step S16, when the control portion 10 judges that the situation where the absolute value of the clutch difference rotation speed Δc is equal to or less than the second defined difference rotation speed continues for a time period equal to or more than a predetermined time period (for example, 300ms), the program goes to the step S18. On the other hand, when the control portion 10 judges that the situation where the absolute value of the clutch difference rotation speed Δc is equal to or less than the second defined difference rotation speed does not continue for a period time equal to or more a predetermined time period, the program goes to the step S17.
At the step S17, the control portion 10 executes the torque balancing control. This torque balancing control will be explained with reference to the flowchart shown in Fig. 5. After the processing of the step S17, the program returns to the step S15.
At the step S18, the control portion 10 executes the return control. This return control will be explained with reference to the flowchart shown in Fig. 7. After the processing of the step S18, the program returns to the step S19.
At the step S19, when the control portion 10 judges that the return control is finished (S19: YES), the control portion 10 advances the program to the step S20 and when control portion 10 judges that the return control is not finished (S19: NO), the program goes to the step S18. It is noted that the control portion 10 judges that the return control is finished when the return control timing engine torque Tert, which will be explained later, is judged to have become equal to the required engine torque Ter.
At the step S20, the control portion 10 executes the normal engine control. In other words, the control portion 10 controls the engine 2 so that the engine torque Te becomes the required engine torque Ter calculated by the operation of the acceleration pedal 51 by the operator of the vehicle. After the processing of the step S20, the program returns to the step S11.

(Torque balancing control)

The torque balancing control will be explained hereinafter with reference to the flowchart in Fig. 5. When the torque balancing control starts, the program goes to the step S17. At the step S17-1, the control portion 10 calculates the clutch transmitting torque Tc according to the method described above, and the program goes to the step S17-2.
At the step S17-2, the control portion 10 calculates the adjusting torque Ta by referencing the clutch difference rotation speed Δc to the adjusting torque calculating data indicated in Fig. 6. It is noted that when the clutch difference rotation speed Δc is a plus value, i.e., when the engine rotation speed Ne (rotation speed of the output shaft 21) is faster than the transmission input shaft rotation speed Ni, the adjusting torque becomes a minus value. On the other hand, when the clutch difference rotation speed Δc is a minus value, i.e., when the engine rotation speed Ne is slower than the transmission input shaft rotation speed Ni, the adjusting torque becomes a plus value. The absolute value of the adjusting torque Ta is set such that the larger the absolute value of the clutch difference rotation speed Δc is, the larger the absolute value of the adjusting torque Ta becomes.
It is noted here that when the clutch difference rotation speed Δc is between the values of the clutch difference rotation speed defined in the adjusting torque calculating data indicated in Fig. 6, the adjusting torque Ta is calculated by performing a linear interpolation on the adjusting torques corresponding to the clutch difference rotation speeds neighboring to the current clutch difference rotation speed Δc at both sides thereof. After processing the step S17-2, the program goes to the step S17-3.
At the step S17-3, the control portion 10 calculates the clutch synchronizing timing engine torque Tes by adding the clutch transmitting torque Tc and the adjusting torque Ta based on the following formula (1). $Tes = Tc + Ta$

Tes : Clutch synchronizing timing engine torque:
Tc: Clutch transmitting torque:
Ta: Adjusting torque.

After processing the step S17-3, the program goes to the step S17-4.
At the step S17-4, the control portion 10 controls the engine so that the engine torque Te becomes the clutch engaging timing engine torque Tes. After processing the step S17-4, the program returns to the step S15 in Fig. 4.

(Return control)

The return control will be explained hereinafter with reference to the flowchart in Fig. 7. When the return control starts, the program goes to the step S18-1. At the step S18-1, the control portion 10 calculates the clutch synchronizing timing engine torque Tes by similar method as in the above-described steps S17-1 through S17-3 for the torque balancing control indicated in Fig. 5. After the step S18-1, the program goes to the step S18-2.
At the step S18-2, the control portion 10 calculates the deviation torque ΔT by subtracting the required engine torque Ter from the clutch synchronizing timing engine torque Tes based on the formula (2). $ΔT = Tes - Ter$

ΔT: Deviation torque:
Tes: Clutch synchronizing timing engine torque:
Ter: Require engine torque.

After processing the step S18-2, the program goes to the step S18-3.
At the step S18-3, the control portion 10 calculates the return ratio Rr per unit time by referencing the deviation torque ΔT to the return ratio per unit time calculating data indicated in Fig. 8. It is noted here that the return ratio per unit time means a quotient per unit time for decreasing the torque deviation ratio Rt, which will be explained later.
When the deviation torque ΔT is a plus value, i.e., when the current clutch synchronizing timing torque Tes is larger than the required engine torque Ter, the return ratio per unit time becomes a minus value and on the other hand, when the deviation torque ΔT is a minus value, i.e., when the current clutch synchronizing timing torque Tes is smaller than the required engine torque Ter, the return ratio per unit time becomes a plus value.
Further, the absolute value of the return ratio Rr per unit time is set to be smaller as the absolute value of the deviation torque ΔT becomes large. It is noted here that when the deviation torque ΔT is between the deviation torques defined by the return ratios per unit time calculating data indicated in Fig. 8, the return ratio Rr per unit time is calculated by performing a linear interpolation on the return ratios per unit time corresponding to the deviation torques neighboring to the current deviation torque ΔT at both sides thereof. After the processing of the step S18-3, the program goes to the step S18-4. After processing the step S18-3, the program goes to the step S18-4
At the step S18-4, the control portion 10 calculates the torque deviation ratio Rt (n) based on the formula (3) below. $Rt (n) = Rt (n - 1) - Rr \times et$

Rt (n): Torque deviation ratio:
Rt (n - 1): Previous time calculated torque deviation ratio:
Rr: Return ratio per unit time:
et: Elapsed time from the previous step S18-3.

It is noted that at the first time processing of the step 18-3 the value of Rt (n - 1) is 100. After processing the step s18-4, the program goes to the step S18-5.
At the step S18-5, the control portion 10 calculates the return control timing engine torque Tert based on the flowing formula (4). $Tert = Ter + ΔT \times Rt (n) / 100$

Tert: Return control timing engine torque:
Ter: Required engine torque:
ΔT: Deviation torque:
Rt (n): Torque deviation ratio.

After processing the step S18-5, the program goes to the step S18-6.
At the step S18-6, the control portion controls the engine so that the engine torque Te becomes the return control timing engine torque Tert. After processing the step S18-6, the program goes to the step S19 in Fig. 4.

(Effects of the embodiment)

As explained above, the control portion 10 (clutch synchronizing timing engine torque calculating means) calculates the clutch synchronizing timing engine torque Tes based on the formula (1) above and the clutch transmitting torque Tc at the step S17-4 in Fig. 5. Then when the absolute value of the clutch difference rotation speed Δc converges to equal to or less than the first defined difference rotation speed A (S14: YES, S15: NO), the control portion 10 (engine control means) controls the engine 2 so that the engine torque Te becomes the clutch synchronizing timing engine torque Tes at the step S17-4 in Fig. 5.
Thus, when the torque balancing control is executed, as shown in Fig. 3 at point 1, the engine torque Te outputted from the engine 2 approaches to the clutch transmitting torque Tc. Then, the difference between the change amount of the engine rotation speed Ne and the change amount of the transmission input shaft rotation speed Ni can be reduced. Thus, the inertia torque of the engine 2 acting on the vehicle at the complete engagement of the clutch 3 can be reduced, which leads to the reduction of occurrence of the shock.
Further, the clutch synchronizing timing engine torque Tes is calculated based on the formula (1) above and the clutch transmitting torque Tc. Therefore, even the clutch transmitting torque Tc changes due to the operation of the clutch pedal 53 by the operator of the vehicle, the clutch synchronizing timing engine torque Tes also changes in response to the change of the clutch transmitting torque Tc. Thus regardless of the operation of the clutch pedal 53 by the operator of the vehicle, the difference between the change amount of the engine rotation speed Ne and the change amount of the transmission input shaft rotation speed Ni can be reduced. Thus, the reduction of occurrence of the shock can be reduced at the complete engagement of the clutch 3.
Further, the control portion 10 (adjusting torque calculating means) calculates the adjusting torque Ta of minus value when the engine rotation speed Ne is faster than the transmission input shaft rotation speed Ni, by referencing the clutch difference rotation speed Δc to the adjusting torque calculating data shown in Fig. 6 at the step S17-2 in Fig. 5. Further the control portion 10 calculates the adjusting torque Ta of plus value when the transmission input shaft rotation speed Ni is faster than the engine rotation speed Ne. Still further, the control portion 10 calculates the clutch synchronizing timing engine torque Tes by adding the adjusting torque Ta based on the formula (1) above at the step S17-3 in Fig. 4. The advantageous effects therefrom will be explained hereinafter.
In the torque balancing control, the engine torque Te approaches to the clutch transmitting torque Tc. Then as the difference between the change amount of the engine rotation speed Ne and the change amount of the transmission input shaft rotation speed Ni is reduced, the engine rotation speed Ne and the transmission input shaft rotation speed Ni would not synchronize, how much time elapsed.
For example, when the engine rotation speed Ne is faster than the transmission input shaft rotation speed Ni, as indicated with the two-dot chain line 3 shown in Fig. 3, the engine rotation speed Ne may be in parallel with the transmission input shaft rotation speed Ni keeping somewhat higher speed compared thereto. On the other hand, when the engine rotation speed Ne is slower than the transmission input shaft rotation speed Ni, as indicated with the two-dot chain line 4 in Fig. 3, the engine rotation speed Ne may be in parallel with the transmission input shaft rotation speed Ni keeping somewhat slower speed compared thereto.
As explained above, when the engine rotation speed Ne is faster than the transmission input shaft rotation speed Ni, the adjusting torque Ta becomes a minus value and then the engine rotation speed Ne is reduced by the adjusting torque Ta to synchronize the engine rotation speed Ne with the transmission input shaft rotation speed Ni.
On the other hand, when the engine rotation speed Ne is slower than the transmission input shaft rotation speed Ni, the adjusting torque Ta becomes a plus value and then the engine rotation speed Ne is increased by the adjusting torque Ta to synchronize the engine rotation speed Ne with the transmission input shaft rotation speed Ni. Thus the clutch 3 can be surely synchronized.
Further, at the step S17-2 in Fig. 5, the control portion 10 calculates the adjusting torque Ta such that the larger the absolute value of the clutch difference rotation speed Δc is, the larger the absolute value of the adjusting torque Ta becomes by referencing the clutch difference rotation speed Δc to the adjusting torque calculating data in Fig. 6. Accordingly, the engine rotation speed Ne can promptly approximate the transmission input shaft rotation speed Ni thereby to shorten the synchronizing time of the clutch 3.
On the other hand, at the step S17-2 in Fig. 5, the adjusting torque Ta is calculated such that the smaller the absolute value of the clutch difference rotation speed Δc is, the smaller the absolute value of the adjusting torque Ta becomes. Thus, the difference between the change amount of the engine rotation speed Ne and the change amount of the transmission input shaft rotation speed Ni can be reduced and the occurrence of the shock can be reduced at the complete engagement of the clutch 3.
Further, the control portion 10 (return control timing engine torque calculating means) executes the return control when the condition that the absolute value of the clutch difference rotation speed Δc is equal to or less than the second defined difference rotation speed B continues for a time period equal to or more than a predetermined time (S16 in Fig. 4: YES). In more detail, at the step 18-5 in Fig. 7, the control portion 10 calculates the return control timing engine torque Tert which gradually changes from the clutch synchronizing timing engine torque Tes to the required engine torque Ter. Then at the step s18-6 in Fig. 5, the control portion 10 controls the engine 2 so that the engine torque Te becomes the return control timing engine torque Tert.
Thus when the return control is executed, as shown in Fig.3 with the line 2, the engine torque Te outputted from the engine 2 gradually returns to the required engine torque Ter. Thus an abrupt change of the engine torque Te can be prevented to give no different feeling to the operator of the vehicle.
Further, at the step S18-4 in Fig. 7, the control portion 10 calculates the torque deviation ratio Rt whose value gradually becomes small as the time elapsed from the start of the execution of the return control becomes long, based on the formula (3) above. Then the control portion 10 calculates the return control timing engine torque Tert by adding the value obtained by multiplying the required engine torque Ter by the torque deviation ratio Rt based on the formula (4) above at the step S18-5.
At the step S18-6 in Fig. 5, the control portion 10 controls the engine 2 so that the engine torque Te becomes the return control timing engine torque Tert. Accordingly, the engine torque Te can be surely gradually changed from the clutch synchronizing timing torque Tes to the required engine torque Ter.
At the step S18-3 in Fig. 7, the control portion 10 calculates the return ratio Rr per unit time of the minus value when the deviation torque ΔT is a plus value by referencing the deviation torque ΔT to the mapping data shown in Fig. 8. On the other hand, when the deviation torque ΔT is a minus value, the control portion 10 calculates the return ratio Rr per unit time of the plus value. Further, the control portion 10 calculates the return ratio Rr per unit time such that the smaller the absolute value of the deviation torque ΔT, the larger the absolute value of the return ratio Rr per unit time becomes.
Further, the control portion 10 calculates the torque deviation ratio Rt (n) by subtracting the value obtained by multiplying the return ratio Rr per unit time by the elapsed time "et" from the calculation of the previous time torque deviation ratio Rt (n - 1) from the previous time calculated torque deviation ratio Rt (n - 1).
Thus, the return ratio Rr per unit time is calculated such that the smaller the absolute value of the deviation torque ΔT is, the larger the absolute value of the return ratio Rr per unit time becomes. Therefore, the smaller the absolute value of the deviation torque ΔT is, the more quickly the engine torque Te returns to the required engine torque Te which reflects the intention of the operator of the vehicle. Thus, the execution time of engine control, when the intention of the operator of the vehicle is not reflected can be shortened thereby to prevent the operator of the vehicle from feeling uncomfortable. It is noted that when the absolute value of the deviation torque ΔT is small, even if the engine torque Te quickly returns to the required engine torque Ter, the operator of the vehicle does not feel uncomfortable.
On the other hand, the return ratio Rr (n) per unit time is calculated such that the larger the absolute value of the deviation torque ΔT is, the smaller the absolute value of the return ratio Rr per unit time becomes. Thus, when the deviation torque ΔT is large, the engine torque slowly returns to the required engine torque Ter. Accordingly, the change of the engine torque Te can be suppressed not to give the operator any uncomfortable feeling.
The clutch stroke Cl corresponding to the operating amount of the clutch pedal 53 is detected by the clutch sensor 54 (clutch transmitting torque obtaining means). The control portion 10 calculates the clutch transmitting torque Tc by referencing the clutch stroke Cl to the clutch torque transmitting torque mapping data shown in Fig. 2. Therefore, the clutch transmitting torque Tc can be obtained by using a simple structure and a simple method.
When the control portion 10 judged that the vehicle speed is slower than a predetermined speed (S13 in Fig. 4: NO), the control portion 10 does not execute the torque balancing control. The vehicle can smoothly start when the engine torque Te is large relative to the clutch transmitting torque Tc. Since the torque balancing control is not executed at the start of the vehicle, the engine torque Te does not approach to the clutch transmitting torque Tc and accordingly, the vehicle can smoothly start at the starting operation.
When the brake pedal 57 (braking force operating means) is operated, (S11 in Fig. 4: NO), the control portion 10 does not execute the torque balancing control.
Therefore, when the vehicle has to be quickly stopped by an emergency braking operation, the control in which engine torque Te is forcibly approximated to the clutch transmitting torque Tc. Therefore, the vehicle can be safely stopped.
Further, the control portion 10 executes the return control only when the time when the condition that the absolute value of the clutch difference rotation speed Δc is equal to or less than the second defined difference rotation speed B continues for a time period equal to or more than a predetermined time period (S16 in Fig. 4: YES). Accordingly, even if a noise is mixed in the detection signals from the various sensors, and the absolute value of the clutch difference rotation speed Δc is erroneously judged to be equal to or less than the second defined difference rotation speed B, the return control would not be erroneously executed.

(Other embodiments)

Embodiments other than the hitherto explained embodiment will be explained hereinafter. According to the embodiments of the invention explained above, at the start of the vehicle the clutch 3 is engaged. However, the technical idea of the invention can be adapted to a case where the clutch 3 is disconnected and engaged upon the up-shifting or down shifting operation of the manual transmission 4.
Further, the technical idea of the invention is applicable to the case where the clutch 3 is engaged under a very slow vehicle speed situation where an excess dropping of the engine rotation speed is prevented by using the half-clutch operation to appropriately slide the clutch when the vehicle is running in a heavy traffic jam or the vehicle is under garage parking.
According to the embodiment explained above, operating force of the clutch pedal 53 is transmitted to the release bearing through the master cylinder 55, hydraulic pressure conduit 58 and slave cylinder 38. However, the operation force of the clutch pedal 53 may be transmitted to the release bearing 37 through the mechanical elements such as wire, rod and gear.
According to the embodiment explained above, the clutch transmitting torque Tc is calculated by referencing the clutch stroke Cl detected by the clutch sensor 54 to the clutch transmitting torque mapping data which represents the relationship between the clutch stroke Cl and the clutch transmitting torque Tc as shown in Fig. 2. However, as disclosed in a JP patent publication No. 2008-157184 A , it is possible that the clutch transmitting torque Tc is presumed based on the change amount of the clutch stroke Cl per unit time and then the required engine torque Ter is presumed thereby.
According to the embodiment explained above, the clutch transmitting torque Tc is calculated based on the detection signal from the clutch sensor 54. However, the clutch transmitting torque Tc may be calculated based on the information such as, the engine inertia, the engine friction torque, the rotation speed of the transmission input shaft 41 at the time the engagement starts, the current rotation speed of the transmission input shaft 41 and a time elapsed from the start of the engagement.
According to the embodiment explained above, the clutch sensor 54 detects the stroke amount of the master cylinder 55. However, the clutch sensor 54 may be a sensor which detects the operating amount of the clutch pedal 53, master pressure of the master cylinder 55, the stroke or the hydraulic pressure of the slave cylinder 38 or the stroke amount of the release bearing 37.
According to the embodiment explained above, the control portion 10 calculates the vehicle speed V based on the transmission output shaft rotation speed No detected by the transmission output shaft rotation speed sensor 46. However, the control portion 10 may calculate the vehicle speed V based on the vehicle wheel rotation speed which is detected by the vehicle wheel speed sensor which detects the wheel rotation speed of the vehicle, or a sensor which detects the rotation speed of an axis rotating in association with the vehicle wheel.
According to the embodiment explained above, the clutch operating member for transmitting the operating force of the operator of the vehicle to the clutch 3 includes is the clutch pedal 53. However, the clutch operating member is not limited to the clutch pedal 53, but a clutch lever may be used as the clutch operating member. Similarly, instead of using the acceleration pedal 51 for adjusting the acceleration opening degree Ac, for example, acceleration grip for adjusting the acceleration opening degree Ac may be used. Further, the vehicular drive apparatus according to the embodiment can be apparently used for a motor cycle or other vehicles.
According to the embodiment explained above, a single unit control portion 10 controls the engine 2 and at the same time executes the clutch/engine cooperative control as shown in Fig. 4. However, as a different embodiment, an engine control portion controls the engine 2 and the control portion 10 connected to the engine control portion through a communication means such as CAN (Controller Area Network) executes the clutch/engine cooperative control.
According to the embodiment explained above, the vehicle includes a manual transmission 4. However, the technical idea of this invention can be applied to a vehicle which does not includes a manual transmission but includes an input shaft which is rotatable in association with the rotation of the drive wheels 18R and 18L and connected to the clutch disc 32.

[Reference Signs List]

In the drawings:

1: vehicular drive apparatus, 2: engine, 3: clutch, 10: control portion (required engine torque calculating means, clutch synchronizing timing engine torque calculating means, engine control means, clutch transmitting torque obtaining means, adjusting torque calculating means, return control timing engine torque calculating means), 19: brake device (braking force applying means), 21: output shaft, 41:transmission input shaft (input shaft), 46: transmission output shaft rotation speed sensor (vehicle speed detecting means), 51: acceleration pedal (engine operating means), 52: acceleration sensor (required engine torque calculating means), 53: clutch pedal (clutch operating member), 54: clutch sensor (clutch transmitting torque obtaining means, clutch operating amount detecting means), 56: brake pedal (brake operating means), 57: brake sensor (brake operating amount detecting means), "t": oil temperature, "V": vehicle speed, "A": first defined difference rotation speed, "B" second defined difference rotation speed, "Nc": clutch rotation speed, "Ne" engine rotation speed, "Ni": transmission input shaft rotation speed, "Δc": clutch difference rotation speed, "Te": engine torque, "Tc": clutch transmitting torque, "Tern": required engine torque, "Tes": clutch synchronizing timing engine torque, "Tert": return control timing engine torque, "Ta": adjusting torque, "Rr": return ratio per unit time, Rt (n): torque deviation ratio, Rt (n - 1): previous time calculated torque deviation ratio.

Claims

A vehicular drive apparatus comprising:
an engine outputting an engine torque to an output shaft;

an engine operating means operated for variably outputting the engine torque from the engine;

an input shaft which rotates in association with a rotation of a drive wheel of a vehicle;

a clutch provided between the output shaft and the input shaft for controlling a clutch transmitting torque therebetween to be variable;

a clutch operating means for operating the clutch to control the clutch transmitting torque to be variable;

a clutch transmitting torque obtaining means for obtaining the clutch transmitting torque which is generated by the clutch;

a clutch synchronizing timing engine torque calculating means for calculating a clutch synchronizing timing engine torque based on the clutch transmitting torque obtained by the clutch transmitting torque obtaining means; and

an engine control means for executing a torque balancing control by controlling the engine so that the engine torque becomes the clutch synchronizing timing engine torque when an absolute value of the clutch difference rotation speed, which is a difference rotation speed between the output shaft and the input shaft during a clutch being under synchronization converges to equal to or less than a first defined difference rotation speed.
The vehicular drive apparatus according to claim 1, further comprising an adjusting torque calculating means for calculating an adjusting torque of a minus value when the rotation speed of the output shaft is faster than the rotation speed of the input shaft and calculating an adjusting torque of a plus value when the rotation speed of the output shaft is slower than the rotation speed of the input shaft at the execution of the torque balancing control, wherein the clutch synchronizing timing engine torque calculating means calculates the clutch synchronizing timing engine torque by adding the adjusting torque.
The vehicular drive apparatus according to claim 2, wherein the adjusting torque calculating means calculates the adjusting torque in such a manner that the larger the absolute value of the clutch difference rotation speed is, the larger the absolute value of the adjusting torque becomes.
The vehicular drive apparatus according to any one of claims 1 through 3, further comprising:
a required engine torque calculating means for calculating a required engine torque which is a torque required from the engine based on an operating amount of the acceleration pedal and

a return control timing engine torque calculating means for calculating a return control timing engine torque which gradually changes from the clutch synchronizing timing engine torque to the required engine torque when the absolute value of the clutch difference rotation speed during the clutch being engaged becomes equal to or less than a second defined difference rotation speed which is slower than a first defined difference rotation speed, wherein

the engine control means executes a return control which controls the engine so that the engine torque becomes the return control timing engine torque when the absolute value of the clutch difference rotation speed during the clutch being engaged becomes equal to or less than the second defined difference rotation speed.
The vehicular drive apparatus according to claim 4, wherein the return control timing engine torque calculating means calculates a deviation torque by subtracting the required engine torque from the clutch synchronizing timing engine torque and calculates a torque deviation ratio which becomes gradually small as an elapsed time from starting of the execution of the return control becomes long, and further calculates the return control timing engine torque by adding a value obtained by multiplying the deviation torque by the torque deviation ratio to the required engine torque.
The vehicular drive apparatus according to claim 5, wherein the return control timing engine torque calculating means calculates a return ratio per unit time of a minus value when the deviation torque is plus and a return ratio per unit time of a plus value when the deviation torque is minus in such a manner that the smaller the absolute value of the deviation torque is, the larger the absolute value of the return ratio per unit time becomes, and further calculates the torque deviation ratio by subtracting a value obtained by multiplying the return ratio per unit time by an elapsed time from the calculation of a previous time torque deviation ratio from the previous time calculated torque deviation ratio.
The vehicular drive apparatus according to any one of claims 1 through 6, wherein the clutch transmitting torque obtaining means includes a clutch operating amount detecting means for detecting an operating amount of the clutch operating means.
The vehicular drive apparatus according to any one of claims 1 through 7, further comprising:
a vehicle speed detecting means for detecting a vehicle speed of the vehicle wherein the engine control means does not execute the torque balancing control when the vehicle speed detected by the vehicle speed detecting means is slower than a predetermined speed.
The vehicular drive apparatus according to any one of claims 1 through 8, further comprising:
a braking force applying means for applying a braking force to the vehicle and

a braking force operating means for controlling the braking force of the braking force applying means to be variable, and wherein the engine control means does not execute the torque balancing control when the braking force operating means is in operation.