WO2007028496A2

WO2007028496A2 - Method and device for reducing a traction force interruption in an automatic gear box drive train

Info

Publication number: WO2007028496A2
Application number: PCT/EP2006/008219
Authority: WO
Inventors: Karl-Fritz Heinzelmann
Original assignee: Zf Friedrichshafen Ag
Priority date: 2005-09-07
Filing date: 2006-08-21
Publication date: 2007-03-15
Also published as: DE102005042352A1; WO2007028496A3

Abstract

The invention relates to a device for reducing an interruption in motor vehicles provided with an automatic gear box (2), to a jerk caused by said interruption and to a corresponding method, wherein the compression, extension, distortion or another deformation of the motor vehicle geometry is avoidable by reducing a driving torque of wheels (8) driven by a main drive motor (1) and by simultaneously increasing the driving torque of wheels (8) driven by at least one auxiliary drive motor, and the auxiliary motor(s) operate the wheels (8) which can be also driven by the main drive motor (1). The method controls the torque output of the auxiliary motor based on the actual or the estimated drop in torque during an initiated gear shift and/or a gear shift which is to be initiated and to the temporal course thereof.

Description

Device and method for reducing a Zuqkraftunterbrechunq in drive trains with automated manual transmissions

The invention relates to a device for reducing a traction interruption in automated manual transmissions according to the preamble of patent claim 1 and a method for its application according to the preamble of patent claim 11.

Automated manual transmissions have been used for quite some time in different types of motor vehicles. In this case, a large number of different variants are known, which each have specific advantages and disadvantages.

A major disadvantage of many automated manual transmission is the interruption of traction during gear changes. Since a large part of the manual transmissions used, in particular in passenger cars, can not be switched under load, a gear change requires an interruption or at least substantial reduction of the drive power acting on the driven wheels. Depending on the design of the drive, this drive power reduction may be due to the fact that the drive clutch or another clutch between a main drive motor and the automated manual transmission must be opened to change the driving gear, and / or the automated gearbox for changing from a first drive to another First drive must disable the first drive before the other drive can be engaged and thus in the meantime switches to an idle, and / or that the drive power of the main drive motor is lowered in the course of the switching process to almost zero. This has the consequence that no or at least no significant drive torque of a main drive motor can be transmitted to the wheels of the vehicle for a certain time. As a result, a shift shock often felt by vehicle occupants to be annoying or even dangerous under some circumstances, such as downshifts in fast corners, is considered dangerous. This is particularly true in automatically triggered switching operations, since the shift shock here also occurs surprisingly for the driver, as well as generally in passenger cars, which are made by the occupants increased demands on ride comfort. In addition, the total acceleration capability of the vehicle is adversely affected by this interruption of traction.

To reduce the perceived by the occupant shift shock can be reduced in an early stage of the shift by engaging in the engine management of the main drive motor and increased after activation of the target gear output to the automated transmission power at a lower than the technically possible rate of increase. Although these measures can reduce the perceived as unpleasant or dangerous switching shock by a temporal extension, but this is paid for by a further extension of the interruption of traction and is therefore usually undesirable especially in passenger cars.

Alternatively, it has been proposed in DE 199 16 926 A1, the seat or the vehicle in the direction of the vehicle longitudinal axis form at least partially movable, and the seats or their backs at a traction interruption forward and after the interruption of traction back to the starting position back to move. However, this approach does not eliminate the actual shift shock of the vehicle, but only dampens its impact on the occupants. Insofar as they do not even perceive a displacement of their sitting position relative to the vehicle interior as being more unpleasant than the shift shock, this measure is certainly not suitable, fears relating to a possible negative influence on the driving stability counteract or improve the acceleration of a vehicle or equalize.

In contrast, DE 103 16 862 A1, which is considered as the closest prior art, describes a drive system for vehicles in which at least one first wheel is driven by an associated axle or Einzelelradantriebsmotor, and at least one second wheel is provided the drive train of which is provided between at least two speed transmission stages switchable transmission.

In a switching command, the motor driving the first wheel is more heavily loaded by a controller, the switching of the transmission is made, and the load of the motor driving the first wheel is reduced again. A circuit-related reduction in power on the second wheel is thus partially or completely compensated by a corresponding increase in tensile force on the first wheel. The motor (s) acting on the first wheel or its axle are electric motors or hydraulic motors.

Although DE 103 16 862 A1 initially formally generally refers to a drive system for vehicles, this document is consistently concerned with heavy special vehicles, such as agricultural or industrial tractors. In addition, the document mainly refers to vehicles in which all driven wheels are driven by Achsantriebsmotoren or by Einzelradantriebsmotoren, wherein one or more manual transmission can be arranged in the moment flow between these motors and the driven wheels. The teaching of DE 103 16 862 A1 is thus not geared to passenger cars and light commercial vehicles for road traffic or readily transferable to those skilled in such. Basically, according to DE 103 16 862 A1, a shift shock is always reduced or avoided by increasing an effective torque at a wheel other than the first wheel when the effective torque on a first wheel is reduced by a shifting operation. Thus, the compensation of a reduction of a drive torque to a first wheel by increasing the drive torque to another wheel inevitably causes a corresponding distortion of the vehicle. This applies both in an axle-related effect of the corresponding moments in which, for example, the drive torque is suddenly redistributed from the front axle to the rear axle, as well as z. B. in a diagonal distribution, which instead of an extension or compression has a rotation of the vehicle body result.

This may be tolerable in heavy tractors and in particular in a very stiff and thus usually heavy construction of the vehicle and at least at the usual, relatively low driving speeds here. For passenger cars and light commercial vehicles, which often reach speeds of 180 or more kilometers per hour, in which even at 100 kilometers per hour can still be done switching and which are also relatively easy to construct as a mass-produced vehicles, but this is hardly tolerable.

Against this background, the invention has for its object to present a device for reducing a traction interruption in drive trains with automated manual transmissions and a method for its use, which avoids the disadvantages of the prior art described. In particular, it should be achieved that compression, extension, twisting or other deformation of the vehicle geometry does not take place with a reduction in the interruption of traction during a switching operation. The solution of this problem arises from the features of the main claim, while advantageous embodiments and further developments of the invention are the dependent claims can be removed.

The invention is based on the finding that the shift shock can be reduced or avoided in the event of a change in a driving gear of an automated gearbox without distortion of the vehicle, if a reduction of the drive torque acting on a wheel of a main drive motor by at least one drive wheel acting on the same wheel an auxiliary drive motor is fully or partially compensated.

Accordingly, the invention is based on a device for reducing a traction interruption in vehicles with an automated manual transmission with a plurality of different ratios, wherein the vehicle has a gear change control device and a, preferably exactly one, main drive motor via the automated transmission on at least one driven wheel of the Vehicle can act. To reduce the interruption of traction, at least one auxiliary drive motor is provided.

The speed change control device is designed so that when changing the transmission ratio of the automated transmission, the power output of the at least one auxiliary drive motor can be influenced such that a change in the output from the main drive motor via the automated transmission to the at least one driven wheel of the vehicle drive torque at least partially, and preferably almost completely, can be compensated.

The change in the output from the main drive motor via the automated transmission to the at least one driven wheel of the vehicle torque can thereby both the reduction of a positive Be torque, for example, if there is an upshift during an acceleration phase, as well as the reduction of a negative torque, for example, when using an engine brake is switched back and the braking effect of the main drive motor during the switching operation can not be transmitted to the wheels of the vehicle.

Under an automated gearbox is understood not only a fully automatic gearbox, but also gear in which a gear change can be triggered additionally or exclusively by an operator, but which make the actual internal gear shift with the help of power-operated actuators and the operator only the information to change gears. In the broadest sense, this also refers to manual transmissions in which there is information about a planned or initiated gear change, at least also in the form of an electrical or other information signal, which can serve for influencing the engine control and which can serve as the input variable of the gear change control device used here. Thus, the invention is also applicable to purely manually connected transmissions, provided that a corresponding switching signal is available.

The invention preferably relates to vehicles with automated manual transmissions that can not be switched under load. However, since even under load switchable gearbox sometimes have considerable shift shocks and also in these transmissions, a circuit without load may be preferred, the invention can be beneficial used for these types of transmissions.

To achieve the object, it is now provided according to the invention that the at least one auxiliary drive motor is arranged so that it can act on at least one of the driven wheels, on which also the main drive motor can act. By this initiation of the drive torque of the auxiliary drive motor in at least one of the normally or immediately before the switching operation of the main drive motor driven wheels distortion of the vehicle with a reduction in the drive torque of the main drive motor and a simultaneous increase in the drive torque of the at least one auxiliary drive motor avoided or at least compared to the state the technology is greatly reduced.

It is particularly advantageous if the one or more auxiliary drive motors act on all wheels previously driven by the main drive motor. In order to keep the construction costs as low as possible, it may also be sufficient, for example, in vehicles with a plurality of driven axles if the auxiliary drive motors only act on one or some of the axles previously driven by the main drive motor.

The invention is basically applicable to vehicles with any main propulsion engines. However, in vehicles having multiple main propulsion engines, the shift shock is often controlled by skillful control of e.g. can be mitigated the individual achievements of electric machines, most of the known from this area solutions can not or only with difficulty transferred to conventional vehicles with a single internal combustion internal combustion piston engine. Therefore, the application of the invention to these vehicles is particularly beneficial.

The application of the invention offers particular advantages for certain vehicle categories:

Modern passenger cars are on the one hand to achieve good performance and to achieve the lowest possible fuel consumption easily constructed and also must be easily deformed in essential parts be able to reduce energy in the event of an accident by deformation work. Under these conditions, the rigidity of the vehicle is necessarily limited. In addition, the demands of the occupants of passenger cars on ride comfort are particularly high and a shift shock is perceived as particularly disturbing.

By the described device according to the invention, it is possible not only to minimize the shift shock with respect to the entire vehicle, but also to avoid twisting of the vehicle at least as far as possible. In addition to the increased ride comfort is due to the high speeds of these vehicles also highlight the safety gain by improving the road holding.

The same is true for light commercial vehicles, although due to the significantly higher vehicle weights and payloads compared to tractors still very high speeds, the advantages in terms of road holding are relatively higher than the advantages in terms of ride comfort.

In the case of heavy utility vehicles, which are preferably designed for road operation, the advantages in terms of ride comfort are in the foreground, since these vehicles are rarely driven in the physical boundary area due to the tendency to lower speeds and high payloads. By contrast, the shift jerks are often particularly high due to the large inert masses. They also tend to result in a heavier compression and extension of the vehicle than passenger cars and light commercial vehicles. The benefit of an increase in comfort is particularly evident in terms of the usual long driving times by professional drivers here. In buses or generally in vehicles to carry a larger number of people, the application of the invention is therefore particularly useful, because the number of beneficiaries is particularly large. In addition, at least for large buses without compensation of the shift shock due to the vehicle mass is relatively pronounced.

Certain types of drive of the auxiliary drive motor offer particular advantages, which will be discussed below:

If the auxiliary drive motor is an electric machine, the integration into an existing drive concept is particularly simple, since the supply lines can be laid easily and in compliance with only a few restrictions at any location of the vehicle. Electric machines are also low maintenance and at the same time offer a good ratio between deliverable power, in particular between the briefly deliverable power on the one hand, and costs and weight on the other. In addition, the electric machine can often be used as part of a functional integration for other purposes such as recuperation, electric braking or electric driving and maneuvering, or use an existing anyway for this purpose electric motor.

Particularly noteworthy is the fact that electric motors can deliver a significantly higher power than their nominal power for a short time. In this way, it is possible to operate the same engine, for example, to support the main drive motor while driving at full rated power, and in the case of a switching operation to double this power again briefly. Alternatively, electric motors can be made very small and lightweight for a given short-term nominal power. In contrast, the use of pneumatic or hydraulic motors as an auxiliary drive motor is particularly suitable for vehicles that already have a powerful pneumatic or hydraulic system.

If the auxiliary drive motor is a motor that is driven by mechanically stored energy, this can be particularly advantageous for heavy commercial vehicles, since it is less on small footprint and low weight, but all the more on longevity and value for money arrives. Thus, for example, a strong spring element can be provided as an energy store that is tensioned via a clamping mechanism, for example, during braking operations, and, if required, transmits torque to a vehicle wheel via any transmission means.

Although it is merely critical to the invention in its basic form that the torque of the auxiliary drive or drives acts on those wheels that were previously driven by the main drive, different mounting positions of the auxiliary drive motor or motors offer particular advantages, which are presented in detail below:

According to a first related embodiment, it is provided that the auxiliary drive motor is integrated in the automated manual transmission. In this way, it is particularly easy to offer different vehicle variants with and without means for reducing the interruption of traction in otherwise identical transmissions within an assembly process. In addition, it is possible to use certain data and power lines about the on-board network and the gear change control device twice.

Depending on the design of the transmission, however, it may be even more advantageous if the auxiliary drive motor is adapted to the automated manual transmission. In this way, the space conditions outside the gearbox optimal billing can be borne, and the auxiliary drive motor is for possible service work without disassembly of the gear housing easily accessible.

In both embodiments presented so far it is particularly advantageous in the case of long drive trains that the following elements of the drive train are largely uniformly loaded by the close-to-starting introduction of the torque of the auxiliary drive motor and unwanted effects, which can occur as a result of torsional vibration of the drive shaft due to changing loads, are largely avoided become.

In a further embodiment, the auxiliary drive motor acts directly on the cardan shaft strand. Here, for example, for a subsequent equipment of vehicles and in particular of commercial vehicles often better room conditions than directly on the gearbox.

If an additional transfer case is provided in the torque flow from the main drive motor to driven wheels, the auxiliary drive motor can also be arranged so that it can act on the additional transfer case. As a result, a single auxiliary drive motor, for example, in vehicles with switchable four-wheel drive, depending on the shift position of the transfer case optionally act on the wheels only one or both axes, without requiring a modification of manual or propeller shaft must be made. With regard to the advantages of integration in a transmission or the adaptation to a transmission is essentially that already stated above.

Alternatively, the auxiliary drive motor can also act directly on an axle to be driven, wherein, of course, an integration in an axle differential is possible. The term axle is to be understood here as meaning the front axle or rear axle and includes both shafts and axles, it being only necessary for a connection to be made from the vehicle frame to a wheel is made. In this case also provide drive shafts of individually suspended wheels in this sense an axis. By placing close to the driven wheels resulting in large torque changes only comparatively small torsions of the transmission links and thus a fast and accurate transmission of the introduced torque to the wheels.

Finally, the auxiliary drive motor can also be arranged so that it acts directly on a driven by the main drive motor wheel or is arranged directly in or on this. In particular, this variant offers the possibility of controlling the auxiliary drive motor not only in relation to the respective axle but separately for a single wheel. It goes without saying that although this variant does not necessarily require the equipment of at least one wheel on each side of the axle, it is usually required in practice. With such an equipment, it is also possible to use the auxiliary drive motors not only in the context of Schaltruckvermeidung, but also for targeted braking or acceleration of individual wheels, for example in the context of an ESP system (Electronic Stability Program) use.

After the device according to the invention has been explained above, a method for reducing traction interruption in vehicles with an automated transmission with a plurality of different ratios is presented below, in addition to a gear change control device and a main drive motor via the automated transmission to at least one driven wheel of the Vehicle may also have at least one auxiliary drive motor.

The gear change control device determines or estimates at an initiated and / or to be initiated gear change due to read Data and / or stored data and / or programs, the size of the actual or suspected torque reduction on the driven wheels and their timing. On the basis of these data and possibly with the inclusion of further data, it determines at least one setpoint torque curve which is suitable for compensating the actual or assumed torque drop at the driven wheel (s) in terms of size and chronological progression, or at least partially. It sends output signals to the at least one auxiliary drive motor which cause a corresponding torque output of the auxiliary drive motor or motors.

By this method, unwanted shift shocks can be completely avoided by a traction interruption or at least greatly attenuated, without causing a twisting of the vehicle by a torque change between the main drive motor and an auxiliary drive motor driven wheels of the vehicle.

The invention can be further explained with reference to an embodiment. For this purpose, three drawing figures are attached to the description.

In these shows

1 shows a drive train of an inventively equipped

Vehicle with a longitudinally installed main drive motor and an arranged on the propeller shaft additional transfer case,

2 shows a drive train of an invention equipped

Vehicle with a longitudinally installed main drive motor and a side of the transmission arranged additional transfer case and

Fig. 3 shows a drive train of an inventively equipped vehicle with a transversely mounted main drive motor.

Specifically, the powertrain shown in FIG. 1 includes a main drive motor 1, which is preferably an internal combustion type piston internal combustion engine. The drive torque of the main drive motor 1 is introduced into an automated transmission 2, from where it is transmitted via a propeller shaft 5 to an axle differential 6 of the rear axle 7 and finally brought to the road via the wheels 8 for driving the vehicle.

In this case, it is a vehicle with switchable four-wheel drive, which is why the propeller shaft 5 carries an additional transfer case 4, which divides the propeller shaft 5 into a front part 5a and a rear part 5b. Finally, leads from the additional transfer case 4, a front-wheel drive train 3 to the not shown and optionally driven front wheels.

According to the invention, one or more auxiliary drive motors, which in this example are intended to be electric motors and are each braced against a fixed vehicle part, are located at the sites of action or points M2 and / or M5a and / or M4 and / or M5b and / or M6 and / or M7 and / or M8 and / or M9 arranged, wherein the number in the respective reference numerals refers to the respective drive train element. In this case, in the case of an arrangement of the auxiliary drive motors at the point M8 (at the vehicle wheels 8) and preferably also at the point M7 (at the rear axles 7) in pairs symmetrically to the longitudinal axis of the vehicle at least two auxiliary drive motors not shown here should be arranged.

Not shown are possible other sites of action of auxiliary drive motors, such as the front wheel drive train 3, the front axle, not shown, or on the front wheels, not shown.

Regardless of the number and distribution of the auxiliary drive motors, a gear change control device 10 is always provided which is in communication with the one or more auxiliary drive motors, the transmission 2 and other sensors. For reasons of clarity, the data lines, sensor lines and control lines to various sensors, control devices and the auxiliary drive motors are indicated merely by arrows on the gear change control device 10.

When the speed change control device 10 recognizes an onset or imminent gear change, it uses read or estimated data to determine the actual, imminent or assumed amount and time course of the torque drop at a reference point. This reference point may be, for example, the transmission output shaft or even a wheel 8 of the vehicle, but preferably the location M2, M4, M5a, M5b, M6, M7, M8 or M9 at which the one or more auxiliary drive motors are located. On the basis of the ascertained data, this at least one auxiliary drive motor is controlled by the gear change control device 10 in such a way that it or these deliver a torque that is proportional to the amount and temporal The course of the change in torque caused by the switching process is completely or at least partially compensated.

Fig. 2 shows a drive train of a vehicle equipped according to the invention, wherein parts of the same function are provided with the same reference numerals. The front axle 9 is driven in this example via an integrated differential directly from the automated transmission, while the propeller shaft 5 to the rear axle (not shown) of an arranged in this case laterally next to the automated transmission 2, additional transfer case 4 goes off.

Finally, FIG. 3 shows an arrangement according to the invention for a drive train of a vehicle with a transversely mounted main drive motor 1. An automated manual transmission 2 is arranged on it, which carries an additional transfer case 4, which in this case only fulfills the function of an axle differential gear.

Of course, in place of the drive trains shown in FIGS. 1 to 3 with front main drive motor 1 and a respective structure with rear main drive motor 1 is also possible and is therefore encompassed by the invention.

Bezuαszeichen

1 main drive motor

2 automated manual transmission

3 front wheel drive train

4 additional transfer case

5 cardan shaft

5a front part of the propeller shaft

5b rear part of the propeller shaft

6 axle differential

7 rear axle

8 wheel

9 front axle

10 gear change control device

M2, M4, possible mounting or mounting locations or M5a, M5b, action locations of the auxiliary drive motor or motors M6, M7, M8. M9

Claims

claims

1. A device for reducing traction interruption in vehicles with an automated manual transmission (2) having a plurality of different transmission ratios, a Gangwechselsteuerungseinrich- device (10), a main drive motor (1) via the automated transmission (2) on at least one driven wheel ( 8) of the vehicle, and at least one auxiliary drive motor, wherein the Gangwechselsteuerungs- device (10) is designed such that when changing the transmission ratio of the automated transmission (2), the power output of the at least one auxiliary drive motor can be influenced such that a reduction of the main drive motor (1) via the automated manual transmission (2) on the at least one driven wheel (8) of the vehicle applied torque can be at least partially compensated, characterized in that the at least one auxiliary drive motor is arranged (positions M2, M4, M5a, M5b, M6, M7, M8, M9) that it can act on at least one of the driven wheels (8) on which also the main drive motor (1) can act.

2. Apparatus according to claim 1, characterized in that the main drive motor (1) is a combustion piston engine with internal combustion.

3. Device according to one of claims 1 or 2, characterized - characterizes that the vehicle is a passenger car, a light commercial vehicle, a heavy commercial vehicle or a bus.

4. The device according to at least one of claims 1 to 3, characterized in that the auxiliary drive motor is an electric machine, a pneumatic motor, a hydraulic motor or a motor which is driven by mechanically stored energy.

5. Device according to at least one of the preceding claims, characterized in that the auxiliary drive motor in the automated transmission (2) is integrated (impact location M2).

6. Device according to at least one of claims 1 to 4, characterized in that the auxiliary drive motor to the automated transmission (2) is adapted (site of action M2).

7. The device according to at least one of claims 1 to 4, characterized in that the auxiliary drive motor is arranged (M5, M5a, M5b), that it can act directly on the propeller shaft train (5, 5a, 5b).

8. The device according to at least one of claims 1 to 4, characterized in that an additional transfer case (4) in the torque flow from the main drive motor (1) to at least one driven wheel (8) is provided, and the auxiliary drive motor on or in the additional Transfer case (4) is arranged (M4).

9. Device according to at least one of claims 1 to 4, characterized in that the auxiliary drive motor is arranged (M7, M9), that it can act directly on a driven wheels bearing axle (7, 9) or shaft.

10. The device according to at least one of claims 1 to 4, characterized in that the auxiliary drive motor is arranged (M8), that it can act directly on a wheel (8) which can also be driven by the main drive motor (1).

11. A method for reducing traction interruption in vehicles with an automated manual transmission (2) having a plurality of different transmission ratios, a Gangwechselsteuerungseinrich- device (10), a main drive motor (1) via the automated transmission (2) on at least one driven wheel ( 8) of the vehicle, and at least one auxiliary drive motor, which can act on at least one wheel (8) which can be driven by the main drive motor (1), characterized in that the gear change control device (10) is engaged in a gear change initiated and / or to be initiated from read-in data and / or stored data and / or programs the size of the actual or suspected torque drop at the driven wheels (8) and determines its timing or estimated on the basis of these data and possibly including further data at least ei NEN desired torque curve determined which is suitable to compensate for the actual or suspected torque drop on the driven wheels (8) according to size and timing completely or at least partially and sends output signals to the at least one auxiliary drive motor, the corresponding torque output of or cause the auxiliary drive motors.