FR2837145A1 - DOUBLE CLUTCH GEARBOX AND METHOD FOR REALIZING A SPEED CHANGE IN A DOUBLE CLUTCH GEARBOX - Google Patents

Abstract

There is provided a method of performing a gear shift in a double clutch gearbox, wherein a speed downshift depending on the type of the gear change and / or at least one preset parameter of the vehicle is performed . In addition is proposed a double clutch gearbox, particularly for carrying out the method.

Description

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 The present invention relates to a dual-clutch gearbox and a method of performing a gearshift in a dual-clutch gearbox.

 Double-clutch gearboxes are known in the automotive art, in particular parallel-change gearboxes. A parallel change gearbox preferably comprises two transmission input shafts, which are coupled to the motor shaft respectively via a dry clutch.

 In the parallel-change gearbox, for example, with self-locking electromotor actuators, it may happen that the control of the gearbox does not take place due to a defect, for example due to a failure. of a safety device or the like during a shear rate change and that both clutches transmit a torque on the transmission input shafts. When this occurs even in certain driving situations, for example on a smooth roadway, and the driver also removes the foot of the accelerator pedal, because he notices the failure, the wheels can for example skate and a deletion adhesion of tires may occur.

 The object of the invention is therefore to propose a double-clutch gearbox and a method of producing a gearshift in a double-clutch gearbox, with which safe gearshift operations are carried out and resulting in optimized consumption.

 This object can be solved according to the invention in particular by means of a method of making a gearshift in a gearbox to

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 dual clutch, wherein a speed downshift is performed depending on the type of the gear change and / or at least one predetermined parameter of the vehicle. By appropriate setting of gear changes in the parallel shift gearbox, vehicle behavior, such as in a manual gearbox or in an automatic gearbox, can be achieved.

 It can be provided as part of a further training of the invention that a retraction of traction speed is achieved with an interruption of the tensile force, when a high probability of wheel slip is present as a parameter of the invention. vehicle represents or when the downshift of the traction speed is performed in the parallel shift gearbox in the winter program. The identification of the respective vehicle parameter can be done through the control system of the engine and / or the gearbox or the like. In this way, dangerous driving situations, in particular in downshifts, can be avoided. It is also possible that other parameters of the vehicle are used, to achieve an interruption of traction force during the retraction of traction speed.

 In the context of a development of the invention, it is also possible that a wheel slip probability parameter or the like is defined as a function of the wheel slip actually present. This parameter indicates how likely a vehicle wheel will lose traction with the road surface. It is particularly advantageous that the interruption of tensile force is carried out during a retrogression of traction speed in

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 function of the wheel slip probability parameter.

 It may be thought that, in the detection of wheel slip, for example, the wheel slip probability parameter is high and then reduced again by means of an appropriate time function or the like, in particular the higher the wheel slip detection is long. Preferably, in a complementary formation, the interruption of traction force can be stopped when the wheel slip probability parameter is reduced. Then, a filling of the traction force can for example begin. Preferably, the higher the degree or the height of the filling of the traction force, the smaller the wheel slip probability parameter.

 According to the invention, it can be provided for example in a parallel-change gearbox or a double-clutch gearbox, that in particular in a downshift of the thrust speed, a meshing of the engine torque is realized, when a high probability of wheel slip is present as a parameter of the vehicle. Additional training of the invention may also provide that the meshing of the engine torque is achieved, when a winter program is activated as a parameter of the vehicle. It may be thought that still other parameters of the vehicle are used to achieve a meshing of the engine torque. In this way, a parameterization is carried out in a parallel change gearbox, in particular in the downshifts of thrust speed.

 Preferably, in the engagement of the engine torque, the engine torque is increased during a predefined period of time by means of a double clutch or

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 similar, so that, on the clutch of the new lower speed, during the suppression of slippage after the change of transmission, no over torque or only minimal overtorque is removed.

 As part of another development of the invention, a high probability of wheel spin may be present, when the winter program is activated by the actuation of a touch switch of the winter program or a other appropriate switch by the driver. In addition, a high probability of wheel spin may be present when the wheels have lost the adhesion already once or several times before. This can be detected for example in the case of slippage during acceleration by a meshing of the traction control system, by a meshing of the anti-lock system (ABS meshing) or the like.

 In addition, there is provided a double-clutch gearbox comprising a device for performing a speed downshift depending on the type of gear change and / or at least one predetermined parameter of the vehicle. The double clutch gearbox according to the invention can preferably be used by carrying out the proposed method. Preferably, a control system of the gearbox or the like may be provided for identifying at least one parameter of the vehicle.

Further advantages and advantageous developments are apparent from the subclaims and drawings described hereinafter. The drawings show that:
Figure 1 is a flowchart of a first embodiment of a method according to the invention; Figure 2 shows various diagrams showing engine and gearbox measurements

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 in a downshift of traction speed with an interruption of the traction force; Figure 3 shows various diagrams showing engine and gearbox measurements in a traction shear downshift with a tensile force fill; Figure 4 is a plot of the probability of wheel spin as a function of time; Figure 5 is a representation of the degree of filling of the traction force with respect to the probability of wheel slip; Figure 6 is a flowchart of a second embodiment of the method according to the invention; Figure 7 shows various diagrams showing the engine and gearbox measurement plots during a double-clutch thrust speed downshift; and Figure 8 shows various diagrams showing the engine and gearbox measurement plots during a thrust speed downshift without double declutching.

 In Figure 1 is illustrated in the form of a flow chart an example of possible embodiment of the method according to the invention for making a gear change in a double clutch gearbox.

 At the beginning of the process, it is checked whether a winter program is selected. If yes, a downshift of traction speed is achieved only with an interruption of the traction force. If no, we verify that a raised probability of wheel slip is present. If yes, a downshift of traction speed is achieved only with an interruption of the traction force. If no, the process is stopped.

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 In Figure 2 is schematically shown a retraction of traction speed in a parallel change gearbox with an interruption of the traction force based on engine and gearbox measurements. In a diagram at the top, the engine speed is represented by an unbroken line, the speed of the old transmission input shaft (initial speed) by a dashed line and the speed of the new transmission input shaft. (final speed) by a dashed line during the time. It is apparent that the engine speed is approaching the new transmission input shaft after the speed shift instructions have occurred.

 In a centrally located diagram, the engine torque is represented by an unbroken line, the torque on the old clutch by a dotted line and the torque on the new clutch by a dashed line for time. This results in the suppression of the torque of the old speed and the constitution of the torque of the new speed.

 In a diagram located at the bottom, the traction force on the drive is represented by a line in dotted lines and dotted over time. It is visible from the drawing, that after the instructions of change of speed, an interruption of the traction force is carried out after the stop of the suppression of the couple, until the constitution of the couple is made on the new speed. The illustrated tractive effort pattern, when shifting the traction speed of the parallel shift gearbox, corresponds to the tracing in an automatic gearbox.

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 Taking into account a converter PLC, which the parallel-change gearbox must replace in a completely valid way, a residual filling torque can for example be transmitted on the control branch via the gear clutch. in operation thanks to a filling of the traction force, while thanks to a meshing of the engine, the engine is accelerated to the targeted speed of the new speed. This advantageously results in the control arm remaining taut and no annoying play passage emerging.

This procedure is indicated diagrammatically in FIG. 3, whereby on the diagrams the engine and gearbox measurements are indicated during a traction shifting downshift in a parallel shift gearbox with filling of the tractive force. In FIG. 3, the measurement plots of the engine and the gearbox are indicated as in FIG. 2.

 In Figure 4 is shown the probability of wheel slip during time, whereby wheel slip incidents are indicated respectively by a rhombus. It appears from the plot that the longer the detection of wheel spin, the lower the probability of wheel spin and vice versa.

 In Figure 5 is shown the degree of filling of the traction force with respect to the probability of wheel slip. It appears from the plot that depending on the probability of wheel slip, a continuous reduction of the fill level is achieved, particularly during a pull-back downshift.

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 In Figure 6 is shown a second possible embodiment of the method according to the invention based on a flowchart.

 At the beginning of the process, it is checked whether a winter operation or a winter program is activated. If yes, a downshift with double clutch is performed. If no, a downshift of thrust speed without double clutching is performed. Then the process is stopped.

 FIG. 7 shows diagrams showing the engine and gearbox measurements during a downshift with double clutch in a parallel shift gearbox or in a double clutch gearbox.

 On a diagram at the top, the plot of the engine torque is represented by a dashed and dashed line, the drawing of the torque on the old clutch running by a dashed line and the drawing of the torque on the new clutch to come by a dotted line during the time. These routes are obtained when, for example in the control system of the gearbox of the double-clutch gearbox, a winter operation (winter program) is activated, which the driver can request for example by means of at a winter program button or at a winter program switch or that the gearbox control can automatically detect through an accumulation of ABS and / or ESP adjustment processes.

Thanks to the use of an engine meshing, in a downshift of the thrust speed, the clutch of the lower speed can constitute, in the case of the suppression of the slippage, after the change of transmission, no over torque or constitute only minimal overtorque. Advantageously, a

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 Increasing the thrust torque is thus avoided in the widest way in the contact between the wheel and the road.

 In Figure 8 are also shown plots of torque and speed in a downshift of thrust, however here without double clutch. In addition, the traces are indicated as in FIG. 7. If no winter program is activated, a downshift of the pushing speed can preferably be carried out without double declutching. Thus, the vehicle can operate in thrust operation, in particular by reducing fuel consumption. When removing slip, after a transmission change, the clutch may end with a higher transmissible torque than the engine's torque and thus the engine speed may increase until the clutch the new lower speed holds. This is apparent in particular from the clutch patterns of the running clutch, the upcoming clutch and the internal combustion engine and the engine speed plot.

 In a parallel shift gearbox, the greatest possible consumption advantage over other gearboxes must be achieved.

In downshifts, this means that if winter operation is not activated, double declutching is prohibited for raising the engine. In this way, a consumption advantage of greater than 1% can be achieved in defined duty cycles.

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LEGENDS
<tb> Figure <SEP> 1
<tb> Beginn <SEP> start
<tb> Winterprogramm <SEP> gewâhlt? <SEP> winter <SEP> program
<tb> selected <SEP>?
<tb> nein <SEP> no
<tb> ja <SEP> yes
<tb> Radschlupf- <SEP> probability <SEP> high <SEP> of
<tb> Warscheinlichkeit <SEP> hoch <SEP>? <SEP> of <SEP> wheels <SEP>? <September>
<tb> nein <SEP> no
<tb> ja <SEP> yes
<tb> Zug-Rückschaltungen <SEP> nur <SEP> mit <SEP> make <SEP> the
<tb> Zugkraftunterbrechung <SEP> downgrades <SEP> of <SEP> speed
<tb> duurchführen <SEP> of <SEP> traction <SEP> only <SEP> with
<tb> a <SEP> interrupt <SEP> of
<tb> effort <SEP> of <SEP> traction
<tb> Ende <SEP> end
<tb> Figure <SEP> 2
<tb> Drehzahl <SEP> scheme
<tb> Schaltebefehl <SEP> for <SEP> Zug- <SEP><SEP> instructions <SEP> change
<tb> Rückschaltung <SEP> of <SEP> speed <SEP> for <SEP> la
<tb> demotion <SEP> of <SEP> speed
<tb> of <SEP> traction
<tb> Zeit <SEP> time
<tb> Moment <SEP> couple
<tb> Momentenabbau <SEP> remove <SEP> Gang <SEP> delete <SEP> from <SEP> couple <SEP> from
<tb> the old <SEP> speed
<tb> Momentenaufbau <SEP> neuer <SEP> Gang <SEP> constitution <SEP> of <SEP> la
<Tb>

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<Tb>
<tb> new <SEP> speed
<tb> Zeit <SEP> time
<tb> Zugkraft <SEP> effort <SEP> of <SEP> traction
<tb> Zugkraftunterbrechung <SEP> interruption <SEP> of <SEP> effort
<tb> of <SEP> traction
<tb> Zeit <SEP> time
<tb> Figure <SEP> 3
<tb> Drehzahl <SEP> scheme
<tb> Schaltbefehl <SEP> for <SEP> Zug- <SEP><SEP> instructions from
<tb> Rückschaltung <SEP> change <SEP> of <SEP> speed
<tb> for <SEP> the <SEP> demotion <SEP> of
<tb> speed <SEP> of <SEP> traction
<tb> Zeit <SEP> time
<tb> Moment <SEP> couple
<tb> Zwischengas <SEP> zur <SEP> double <SEP> release <SEP> for
<tb> Drehzahlhebung <SEP> elevation <SEP> of <SEP> diet
<tb> Kupplungsüberschneidung <SEP> shear <SEP> of
<tb> the clutch
<tb> Momentenfüllung <SEP> change <SEP> Gang <SEP> fill <SEP> of the <SEP> couple <SEP> of
<tb> the old <SEP> speed
<tb> Zeit <SEP> time
<tb> Zugkraft <SEP> effort <SEP> of <SEP> traction
<tb> Zeit <SEP> time
<tb> Figure <SEP> 4
<tb> Radschlupf- <SEP> probability <SEP> of <SEP> skating
<tb> Wahrscheinlichkeit <SEP> of <SEP> wheels
<tb> hoch <SEP> high
<Tb>

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<Tb>
<tb> niedrig <SEP> bass
<tb> Radschlupf-Ereignis <SEP> incident <SEP> of <SEP> skating <SEP> of
<tb> wheels
<tb> Zeit <SEP> time
<tb> Figure <SEP> 5
<tb> Radschlupf- <SEP> probability <SEP> of <SEP> skating
<tb> Wahrscheinlichkeit <SEP> of <SEP> wheels
<tb> Auffüllgrad <SEP> degree <SEP> of <SEP> filling
<tb> Figure <SEP> 6
<tb> Beginn <SEP> start
<tb> Winterbetrieb <SEP> aktiviert? <SEP> winter <SEP> operation
<tb> enabled <SEP>? <September>
<tb> ja <SEP> yes <SEP>
<tb> Schubrückschaltungen <SEP> mit <SEP><SEP> downgrades of <SEP> speed
<tb> Zwischengas <SEP> of <SEP> thrust <SEP> with <SEP> double
<tb> declutching
<tb> nein <SEP> no
<tb> Schubrückschaltungen <SEP> ohne <SEP> downshifts <SEP> of <SEP> speed
<tb> Zwischengas <SEP> of <SEP> thrust <SEP> without <SEP> double
<tb> declutching
<tb> Ende <SEP> end
<tb> Figure <SEP> 7
<tb> Moment <SEP> couple <SEP>
<tb> Zeit <SEP> time <SEP>
<tb> gehende <SEP> Kupplung <SEP> clutch <SEP> in <SEP> works
<Tb>

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<Tb>
<tb> kommende <SEP> Kupplung <SEP> clutch <SEP> to <SEP> coming
<tb> Verbrennungsmotor <SEP> engine <SEP> to <SEP> combustion
<tb> internal
<tb> Drehzahl <SEP> scheme
<tb> Zeit <SEP> time
<tb> Verbrennungsmotor <SEP> engine <SEP> to <SEP> combustion
<tb> internal
<tb> Figure <SEP> 8
<tb> Moment <SEP> couple
<tb> Zeit <SEP> time
<tb> gehende <SEP> Kupplung <SEP> clutch <SEP> in <SEP> works
<tb> kommende <SEP> Kupplung <SEP> clutch <SEP> to <SEP> coming
<tb> Verbrennungsmotor <SEP> engine <SEP> to <SEP> combustion
<tb> internal
<tb> Drehzahl <SEP> scheme
<tb> Verbrennungsmotor <SEP> engine <SEP> to <SEP> combustion
<tb> internal
<tb> Zeit <SEP> time
<Tb>

Claims (14)

A method of performing a gear shift in a dual-clutch gearbox, characterized in that a speed downshift is performed in accordance with the type of gear change and / or a predetermined parameter of the vehicle.  2. Method according to claim 1, characterized in that a retrogression of traction speed is achieved with an interruption of the tensile force, when a high probability of wheel slip is present as a parameter of the vehicle.  3. Method according to claim 1 or 2, characterized in that a retraction of traction speed is performed with an interruption of the traction force, when a winter program is activated as a parameter of the vehicle.  4. Method according to claim 2, characterized in that a wheel slip probability parameter is defined according to wheel slip actually present.  5. Method according to claim 4, characterized in that the interruption of the traction force is performed according to the wheel slip probability parameter.  6. Method according to claim 5, characterized in that the interruption of the tensile force is stopped, when the wheel slip probability parameter is reduced, and in that begins then a filling of the traction force .  7. Method according to claim 6, characterized in that the greater the degree of filling of the tensile force, the lower the wheel slip probability parameter. <Desc / Clms Page number 15>  8. Method according to claim 1, characterized in that a downshift of the thrust speed is performed with a meshing of the engine torque, when a high probability of wheel slip is present as a parameter of the vehicle.  9. A method according to claim 1 or 7, characterized in that a downshift of the thrust speed is performed with a meshing of the engine torque, when a winter program is activated as a parameter of the vehicle.  The method according to claim 8 or 9, characterized in that the engine torque is increased by a double clutch in the engagement of the engine torque for a predefined period of time, so that no minimum overtorque or only minimal overtorque is removed on the clutch of the new lower speed, during the suppression of slippage, after the change of transmission.  11. A method according to any one of claims 2 to 10, characterized in that a high probability of wheel spin is present when a winter program is activated.  A method according to any one of claims 2 to 10, characterized in that a high probability of wheel slippage is present, when at least one traction control system meshes with acceleration and / or meshing with anti-lock system is realized.  13. Double clutch gearbox, in particular for carrying out a method according to any one of claims 1 to 12, characterized in that there is provided a device for performing a speed downshift depending on the type shifting and / or at least one predetermined parameter of the vehicle. <Desc / Clms Page number 16>  14. Double clutch gearbox according to claim 13, characterized in that a control system of the gearbox is provided for identifying at least one parameter of the vehicle.