Summary of the invention
The present invention proposes a kind of gear control method of wet-type dual-clutch, realize the steady switching of gear.
For achieving the above object, following technological scheme is embodiments provided:
A gear control method for wet-type dual-clutch, comprising:
Pre-hung step: first clutch hangs on a gear, and when needs are switched to target gear, second clutch carries out the pre-hung of target gear, obtains the switching point torque value that present engine passes to gearbox simultaneously;
Transition step: the oil pressure of first clutch reduces, the oil pressure of second clutch raises until reach the oil pressure value corresponding to switching point torque value, in the process, the moment of torsion sum that first clutch and second clutch transmit equals described switching point torque value all the time;
Switch step: the oil pressure keeping second clutch, engine speed is carried out synchronously.
Preferably, between pre-hung step and transition step, also comprise preacceleration inflation step: first clutch carries out sliding wear control, the oil pressure of second clutch rises and remains on preacceleration inflation value.
Preferably, in switch step: first clutch oil pressure value remains on preacceleration inflation value.
Preferably, after switch step, the oil pressure of first clutch discharges completely, and second clutch carries out sliding wear control.
The gear control method of wet-type dual-clutch of the present invention, when carrying out gear pre-hung, obtain the torque value that motor at that time passes to gearbox, and reduce at first clutch oil pressure, in the process that second clutch oil pressure raises, remain the torque value that the moment of torsion sum that two clutches transmit obtains when equaling pre-hung, expectation moment of torsion based on clutch in transient process controls, logic is simple, be easy to realize, and remain that transmitted moment of torsion sum is constant, ensure that the smoothness that two clutch pressures replace, improve the Security of shift quality and gearshift.
Embodiment
For enabling above-mentioned purpose, the feature and advantage of invention more become apparent, below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in detail.
Set forth a lot of detail in the following description so that fully understand the present invention, but the present invention can also adopt other to be different from alternate manner described here to implement, those skilled in the art can when without prejudice to doing similar popularization when intension of the present invention, therefore the present invention is by the restriction of following public specific embodiment.
Shown in figure 1, for the shift control method of wet-type dual-clutch of the present invention, comprise: pre-hung step: first clutch hangs on a gear, when needs are switched to target gear, second clutch carries out the pre-hung of target gear, obtains the switching point torque value that present engine passes to gearbox simultaneously; Transition step: the oil pressure of first clutch reduces, the oil pressure of second clutch raises until reach the oil pressure value corresponding to switching point torque value, in the process, the moment of torsion sum that first clutch and second clutch transmit equals described switching point torque value all the time; Switch step: second clutch oil pressure value keeps, and engine speed first reduces and then is transitioned into second clutch driven disc rotating speed.
When carrying out gear pre-hung, obtain the torque value that motor at that time passes to gearbox, and in the process of the reduction of first clutch oil pressure, the rising of second clutch oil pressure, remain the torque value that the moment of torsion sum that two clutches transmit obtains when equaling pre-hung, expectation moment of torsion based on clutch in transient process controls, logic is simple, be easy to realize, and remain that transmitted moment of torsion sum is constant, ensure that the smoothness that two clutch pressures replace, improve the Security of shift quality and gearshift.
Below in conjunction with preferred embodiment, technological scheme of the present invention is described in detail, in the present invention, be all with gear with first clutch, second clutch is that the target gear that will switch is described, but be understandable that, first, second clutch only refers to a clutch in double clutch.
As shown in Figures 2 and 3, first, S201, when normal vehicle operation, namely first clutch hangs on some gears, judges whether to need gear shift.
Normally, be input to the torque signal etc. of gearbox by detecting accelerator opening amount signal, vehicle speed signal and motor, and carry out comprehensive descision by car load processor, determine whether carry out transforming gear.
Then, S202, when target gear is arrived in needs gear shift, second clutch carries out the pre-hung of target gear, and that is, the gear synchronizer of second clutch combines in advance.
Meanwhile, the torque value that now motor passes to gearbox is obtained, i.e. switching point torque value.
Then, S203, carries out preacceleration inflation step, and particularly, be that the oil pressure of second clutch rises and remains on preacceleration inflation value (kisspoint), first clutch carries out sliding wear control.
Herein, carrying out preacceleration inflation is to ensure in shift process, and clutch can transmitting torque fast, reduces the time that two clutch moment of torque replace.Particularly, in the present embodiment, in advance to the certain oil pressure of second clutch preliminary filling, for eliminating the clutch pressure that self structure consumes before starting transmitting torque, as the resistance etc. of the oil pocket of the gap in clutch friction plate, clutch and the return spring of oil pocket, in the present invention, preacceleration inflation value (kisspoint) refers to that the gap between clutch friction plate is just eliminated, pressure corresponding when starting to contact, namely just started can transmitting torque time corresponding pressure.
In the present invention, sliding wear controls (sliding mode control) and refers in the process of clutch normal delivery moment of torsion, remain and keep certain speed discrepancy between the driving disc rotating speed (engine speed) of clutch and the driven disc rotating speed (corresponding input shaft rotating speed) of clutch, it is generally the speed discrepancy of 10rpm, this be in order to avoid vehicle under steam, injustice because of road surface produce jolt directly by reaction clutch on motor, thus ensure that engine running is stationarity.
Now first the oil pressure of second clutch is risen to preacceleration inflation value, to ensure, under special operation condition, can respond fast, meanwhile, another clutch normal delivery moment of torsion.
Then, S204, carry out transition step, the namely oil pressure checker of first clutch and second clutch, the oil pressure of first clutch reduces, the oil pressure of second clutch raises until reach the oil pressure value corresponding to switching point torque value, and in the process, the moment of torsion sum that first clutch and second clutch transmit equals described switching point torque value all the time.
Like this, by remaining that transmitted moment of torsion sum is constant, ensure that the smoothness that two clutch pressures replace, improving the Security of shift quality and gearshift.
Then, carry out switch step, keep the oil pressure of second clutch, engine speed is carried out synchronously.
That is, in this step, the oil pressure of second clutch remains on the oil pressure value corresponding to switching point torque value, the rotating speed of motor is transitioned into the rotating speed of the new second clutch driven disc combined, realizes being transitioned into second clutch by first clutch.Normally, first, S205, the new torque request of engine response gearbox, S206, and by first reducing the actual torque of present engine, make the rotating speed being transitioned into the new second clutch driven disc combined that the rotating speed of motor is level and smooth.More preferably, in this step, the oil pressure of first clutch remains at preacceleration inflation value, to ensure, under special operation condition, can respond fast.
Afterwards, S207, the oil pressure of first clutch discharges completely, second clutch carries out sliding wear control, S208, and the synchronous gear controller of first clutch is thrown off, transmit by second clutch the moment of torsion that motor is input to gearbox, Motor Vehicle normally travels under the gear of second clutch.
The above is only the preferred embodiment of the present invention; it should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.