Untitled record

The innovation relates to a double clutch for a differential torque transmission in motor vehicles in two, four or more driving wheels on one, two or more split axle shaft (s).

In motor vehicles, the drive power is usually transmitted from the drive train via angle and differential gear on the drive wheels of an axle. The differential gear allows the wheels, for example, to βίΠβΓ Λ'ϋΓνβΓίυαιιΓί 'different "egS Zu ZuckZülSgSn." ΤθΠΐί the adhesion conditions of the two drive wheels of an axle are different in size, eg when cornering by loading the kiirvenäußeren wheel and relief of the inside wheel, the propulsive force of the axle is determined by the wheel load on the unloaded side, ie there is a drop in propulsive power.

The innovation is based on the object to provide a dual clutch for a differentialless torque transmission in motor vehicles, in which the torques can be transmitted independently of each other via the axle shaft parts on the drive wheels. In particular, a double clutch is to be created, by means of which the shaft part with the loaded drive wheel with a higher torque and the shaft part with the unloaded drive wheel can be subjected to a reduced torque. In addition to be made uniform by the present innovation, the difference in slip on the drive wheels of an axle when cornering, so that an optimal power transmission wheel / road is possible. Finally, in vehicles with four-wheel drive and anti-lock brakes, the risk of skidding during braking should be further reduced. Further advantages of the innovation will become apparent from the following description.

This object is achieved according to the innovation in the above-mentioned double clutch, characterized in that for each of the two clutches of the split axle shaft a tubular body is provided as Außenmitnehmer with axially displaceable outer disks carrying the projecting from the two sides into the tubular body axle carrier with inner axially movable slats and the Tubular body with a through

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Pinion gearbox driven by the drive train is connected. In this multi-plate clutch, the clutches are independently controllable. The transmission moments can therefore be electronically controlled by a computer so that overall, ie for the sum of all drive wheels under the current cornering conditions results in an optimum power transmission wheels / road. Due to the individual controllability of both clutches of one axle, it is impossible. Hi η nnf Hip Trpi hräripr 7:11 eather moments to adapt to the power transmission conditions prevailing at the respective drive wheel. Thus, when cornering, the torque transmitted to the outside (loaded) drive wheel can be increased and the torque to be transmitted to the inside (unloaded) drive wheel can be reduced. The optimal to be transmitted under the given adhesion and load conditions moments are determined by a computer on the basis of the conditions on the drive wheel factors such as steering angle ß, vehicle speed, relative speeds of the wheels to each other and vehicle-specific factors and given as a control command to the appropriate clutch. The relative speeds of the wheels to each other are available with existing ABS anyway and can be supplied to the computer in this case without much effort. A vehicle-specific factor that can be supplied to the computer, for example, is a torsion protection for the axle shaft: When driving straight ahead, relative speeds at dfcrh wheels can occur due to road differences or due to a Notlaufrades. If the clutches of both axle shaft parts are closed when driving straight ahead, the axle shaft would be twisted. While in vehicles with ABS the supplied rotational speeds of the wheels are suitable signals for the computer to initiate the anti-twist protection, in other cases strain gauges can be used to generate an electrical signal proportional to the slip occurring which opens a clutch via the computer, if a predetermined one Value of the slip is exceeded.

Due to the renewal modern double clutch eliminates the differential gear in the or the drive axles, resulting in a considerable

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Cost savings results. In addition, operational advantages result from lower fuel consumption because the TreibrMder have lower slip and the renewal of the dual clutch compared to the differential gear brings a weight saving. In particular, the driving stability and driving safety are substantially increased.

The dual clutch allows continuous torque transmission to the Achswellenteile and thus the desired stepless control of the torque distribution to the drive wheels or from the Cardanwelle on the drive wheels associated Achswellenteilen. The coupling may be, for example, a hydraulically or electromagnetically actuated multi-plate clutch. It is actuated by servomotors, which are controlled by the computer. Moreover, depending on the application or size of the moments to be transmitted different couplings apply, for example, dry clutches, Ölbadkupplungen. The couplings can open or close by the action of oil pressure or they can, for example, also open or close electromechanically.

In one embodiment of the dual clutch in a vehicle with four-wheel drive is provided according to the innovation that the drive train is free of an intermediate differential. For vehicles with two driven axle shafts, the intermediate differential is used for torque distribution to the axle shafts. Since the moments are transmitted directly to the Achswellenteile by renewal Doppelkupplung, a torque distribution on the two drive axles is no longer required, ie the maximum available torques at the front and rear axles can be the same.

The torque transmission by the renewal of the invention double clutch is further characterized in a vehicle with four-wheel drive and anti-lock braking system that when activating the anti-lock braking system during a braking all clutches are opened by a running from the anti-lock brake system via the computer signal. At the moment of braking involving the anti-lock braking system, all clutches are thus

solved so that the four drive wheels are braked by the ABS free. In this way, it is avoided that the rear wheels on the Antriel, i> etrangely braked too strong and thereby even with ABS-braked vehicles strolling occurs or considerable costs arise from the fact that this defect is technically resolved.

The innovation will be described below with reference to the drawing. Show Ea

Figure 1 is a schematic representation of the inventive torque transmission in a motor vehicle with two driven wheels;

FIG. 2 shows a section of the dual clutch according to the invention in a detailed representation;

Figure 3 is a schematic representation as Figure 1, but for fine motor vehicle with four-wheel drive.

Figure 4 is a representation as in Figure 3, but with anti-lock braking system. and

Figure 5 is a graph showing in principle the torque distribution to the drive wheels of an axle shaft in dependence on the steering angle when cornering.

According to Figure 1, the divided drive axle of a vehicle • us an axle shaft 5 with the drive wheel 8 and the axle shaft • with the drive wheel 9. The inner ends of the shaft parts 5 and 6 are output parts of a dual clutch 1, which will be described in more detail below. The Aii _,. Iebsteil the double clutch 1 carries a ring gear 10, which forms an angular gear together with the pinion 12 of the drive train 11, as it is usual in differentials. The two coupling units of the double clutch 1 are dependent on the steering angle ß de ··⁵- 'Handlebar 13 and the vehicle speed controlled. For this purpose, the handlebar 13 with a wink 1-

fiensor 3, which converts the angle signal to an i; ieug

accommodated computer 2 gives. The calculator 2 calculates from the Ifinkeleingabe, the speed and, if necessary. Other, eg dependent on the vehicle movement and the vehicle itself factors

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separate manipulated variables for the control of KupplungsseJnheiten the double clutch 1 and transmits these control commands to the actuators of the coupling units. When starting the vehicle from a standstill all coupling units are basically closed, and the control process takes place immediately after reaching a predetermined minimum speed.

Figure 2 shows an embodiment of the double clutch, in which only one half, namely the coupling part for the axle shaft 5 is shown in section. The following description refers only to the illustrated half of the double clutch. The other, not shown half of the double clutch is consistent with the illustrated half substantially, so that it was possible to dispense with the illustration and description.

The driven by the pinion 12 ring gear 10 is rotatably supported via a fixedly attached to it Rohrstiick 21, for example by a ball bearing 22 on the housing 20. The connection between the ring gear IC and the pipe section 21 is not shown in detail in FIG. The parts can be screwed or welded, for example. When the coupling within the pipe section 21 is a dry clutch, a shaft seal 23 is required for sealing against the oil filled gear room 24. The shaft seal 23 may other than shown and against the housing end wall 20th^a dense, so that the ball bearing 22 has oil connection with the gear chamber 24.

The axle shaft part 5 is intercepted by a SchrMglager 23 in the ring gear 10, so that axial forces of the shaft can be accommodated. In addition, the axle shaft part 5 by means Leger 26 is still on the housing end wall 20th^a rotatably mounted. On the ring gear 10 and / or the pipe section 21, a tubular body 27 is further firmly angebra cht, which acts as an external driver for in the pipe

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For this purpose, the outer disks 28 have a plurality of radial grooves distributed over the beginning, into which correspondingly formed longitudinal noses of the tubular body 27 engage. The outer plates 28 sit with clearance in the tubular body 27 so that they can be moved axially. On the axle shaft part 5, a tubular body 29 is fixedly mounted as an inner cam, on the inner disk 30 are axially displaceable. For this purpose, the inner plates carry a plurality of grooves, engage in the appropriately trained longitudinal cams of the tubular body 29 with Spielpassui%. In the tubular body 27, a support ring 32 is fixedly mounted near its outer end. Between the StUtzring 32 and the outermost outer fin 28, a plate spring is used with bias, which compresses the disk set 28,30 and thus keeps the clutch closed. On the outer end of the tubular body 29, an annular release bearing 33 is axially displaceable. In an inwardly directed axial pressure of the release bearing 33 on the plate spring 31 whose pressure is reduced to the disk set 28,30 and thereby opened this coupling part continuously. The axial displacement of the release bearing 33 can take place in various ways, for example by a lever which from the outside through an opening in the end wall 20th^a the housing 20 engages and with the AusrUcklager 33 is engaged. The operation of the release bearing 33 has not been shown in Figure 2, because it can be carried out in principle in various ways and is not essential to the essence of the invention. The adjustment of the release bearing can be achieved for example by oil pressure or electromagnetically or by an electric motor. Thus, on the housing cover 20th^a a coarse thread be attached, by which a rotary motion supplied by the servomotor is converted into the axial movement of the release bearing 33. The scope of the torque transmission system according to the invention is basically independent of the way in which the two coupling parts are actuated, ie how the AusrUcklager 33 are moved from the outside.

FIG. 3 shows the use of the dual clutch according to the invention in a vehicle with four-wheel drive. In this embodiment, the rear axle as well as the front axle shown in Figure 1 from the two Achswellenteilen 16 and 17 with the drive wheels 18 and 19. The shaft parts 16 and 17 are also formed as driven parts of a Doppelkupplnng 1, the drive part of Aatriebsstrang 11 on the Angular gear 14,15 is driven. In this case, the computer determines 2 separate specific variables for the clutches of Achswellenteile 16 and 17, which are different from those for the clutches of the shaft parts 5 and 6. In this way it is possible to optimally distribute the drive torques to the four wheels 8, 9, 18, 19 as a function of the instantaneous wheel load variables. So less slip and better power transmission from the wheel to the road and thus lower fuel consumption are achieved. In this embodiment, not only di2 differential gears in the axle shafts, but also the intermediate differential in the drive train 11 are eliminated.

Figure A shows substantially the same representation as Figure 3, However, the brake system is equipped with a AntiblotAiersyetee. This system also serves as a signal generator for the computer 2. When a positive signal from the system 7 to the computer 2, this is caused to give opening commands to all four actuators of the clutches, so that the drive wheels 8,9, 18,19 from the drive train 11th be separated. The drive motors are then independent of each other and freely braked by the drive train through the anti-lock braking system.

FIG. 5 shows, for the double coupler according to the invention, the external moment of the coupling 1 to the outside wheel in relation to the sum of the external moments of this coupling in X as a function of the steering angle .beta. For two different driving speeds, v₂ > v_J is. Out of the illustration is

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can be seen that a stepless torque control on the drive wheels and thus an optimal adaptation to the current frictional conditions of the wheels is possible.