DE4446109B4 - Method for selective application of the exhaust brake in conjunction with upshifts - Google Patents

Abstract

A method of automatic, computer-assisted mechanical stepper gearing in internal combustion engine driven automobiles in which, in conjunction with upshifting, an engine brake control engine brake motor can be energized to rapidly obtain a next speed synchronous engine speed the engine braking member is turned on when shifting up depending on whether a vehicle parameter is above a predetermined value, characterized in that the engine brake member is selectively turned on in response thereto,
Whether an engine braking program has been activated, which results in lift-up points raised above normal predetermined increase points, or
- Whether during the switching process, the retardation or the loss of speed of the vehicle are above a threshold depending on the operating case.

Description

The invention relates to a method specified in the preamble to claim 1 Art.

State of the art

Upshifting to higher gears, with smaller gear ratios, in automotive transmissions, reduces engine speed. In semi-automatic and fully automatic shifting systems, preferably in mechanical step gears, the control of the engine speed by controlling the injected fuel quantity, and if the speed must be reduced when upshifting, during the switching process, an exhaust brake (engine brake, back pressure brake) can be switched on at the moment to Lower the engine speed faster to a value that is in sync with the next gear speed.

In US 4 787 044 A a solution is described in which the exhaust brake is turned on during a downshift to lower the engine speed faster to the speed synchronous to the next gear. However, this solution relates to an automated clutch function arrangement which interrupts the power flow between the engine and the transmission, after which the fuel control and the engagement of the exhaust brake take place during the upshift to rapidly lower the engine speed to the speed synchronous to the next gear.

A problem here is that each time the exhaust brake to reduce the engine speed in conjunction with the upshift an annoying puffing noise is generated, which is perceived as a nuisance, especially in buses.

As another prior art is on the DE 39 37 302 A1 directed.

Purpose of the invention

An object of the invention is to use in an automated circuit in motor vehicles with mechanical step gears on the gas exchange of the engine engine braking devices to increase the engine braking power, preferably by using the exhaust brake, only upshift operations when fast upshifts are required. As a result, the application of the increased engine braking power, preferably by switching on the exhaust brake, as well as the noise generation when upshifting to the minority of the upshift operations can be limited, thereby reducing said noise nuisance of drivers, passengers and environment.

Another purpose of the invention is that when there is an actual need for increased engine braking power in conjunction with gearshifts, it is automatically available in response to predetermined vehicle parameters without the driver having to take further action.

Another purpose of the invention is that the wear on the engine and its parts, especially in turbocharger supercharged engines, can be reduced.

A further purpose of the invention is to reduce wear on the exhaust brake mechanism by reducing selective application of the exhaust brake during power-up operations to reduce power-up frequency to a fraction of the total number of power-ups as compared to regular use in power up operations.

• – ein Heraufschaltvorgang aufgrund zu starker Retardation des Fahrzeugs während des Schaltvorgangs verlorengehen kann, was vor allem bei starken Steigungen gilt, oder
• – ein vom Schaltvorgang verursachter Ausfall der Motorbremsung auf möglichst kurze Dauer begrenzt werden soll, was vor allem bei starken Gefällen gilt.

A further purpose of the invention is that a rapid upshift with the exhaust brake on is essentially only obtained in two operating cases when:

• - An upshift due to excessive retardation of the vehicle during the shift can be lost, which is especially true for steep gradients, or
• - A caused by the switching failure of the engine braking is to be limited to the shortest possible duration, which is especially true for steep slopes.

As a result, under normal truck truck operating conditions, in conjunction with upshifts, the exhaust brake on and noise generation may be limited to 5-10 percent of the total number of upshifts required.

These purposes, the invention complies with the method by the features specified in the characterizing part of claim 1.

A purpose of a still further developed embodiment of the invention is that in case of operation, when an upshift can be lost due to excessive retardation of the vehicle, different severity decision criteria can be applied for the automatic activation of the exhaust brake. Depending on the actions by the driver automatic switching on the exhaust brake in conjunction with an upshift is already obtained at lower Retardationsniveaus if the driver turned on a so-called. Uphill program or the Accelerator pedal has depressed maximum in the so-called kick-down position, while in normal operation without kick-down or uphill program automatic switching on the exhaust brake in conjunction with an upshift is only obtained at higher levels of retardation and pending upshift in a gear, which is lower than a given gear.

These objects are met by the invention method-related by the in the characteristics of claim 3 or 4 and with respect to the specific Retardationsgrenzen for each operating case by the features specified in the characterizing part of claim 5.

Further, the invention characterizing features will become apparent from the dependent claims and from the following description of an embodiment. The description makes reference to the following figures.

List of figures

1 shows the basic structure of a switching system for mechanical step transmission.

2 FIG. 12 shows, in the form of a flowchart, how the controller detects the vehicle parameters that result in selectively turning on the exhaust brake in conjunction with upshifts.

Description of an embodiment

1 shows a switching system for monitoring and controlling a computer-controlled circuit of mechanical transmissions in motor vehicles. To drive the vehicle is an internal combustion engine 40 , preferably a diesel engine whose drive power via a clutch to be operated by the driver 41 , a mechanical step transmission 42 and a propeller shaft 43 on the drive wheels 44 of the vehicle is transmitted. The gear 42 preferably has an integrated retarder 48 on, which can apply to the drive train with a controllable braking force, which serves the purpose of generating a high braking performance in the vehicle without using the normal service brake of the vehicle. The switching system provided in the embodiment includes a manually operated clutch servo for start and stop, but has no automatic clutch servo, but the invention can also be applied to systems with automated clutch. The switching system effects the switching operations by controlling the engine speed and the engine torque during the switching operation and operation of the servo device 37 , which interprets the engaged gear and inserts the next gear, without the clutch 41 disengage. This places high demands on the engine control (engine management) and on the speed information required by the system so that the engine control can enable torque-free gearshifting and thus only by the engine control quickly obtain a synchronous speed for the next gear, with the shortest possible torque interruption in the mechanical indexer should be inserted.

Mechanical step transmissions, preferably with or without conventional synchronizers in the transmission, are in many respects a decidedly more advantageous choice than conventional hydraulic and instantaneous shift automatic transmissions, or as mechanical transmissions with complex dual clutches intended to enable shift operations without torque interruption. This applies above all with regard to the business economics, the maintenance costs and the acquisition costs. In addition, when the step transmission is equipped with conventional synchronizers, increased operational safety is also obtained since manual shifting or semi-automatic shifting, i. H. servo-assisted deployment and engagement of gears may occur due to foot-actuated disengagement while maintaining high shifting comfort should the automated shifting function fail due to a system failure.

The switching system comprises a control unit 12 with microprocessor, which has different signal lines 36 with the control units 23 for the fuel system, 22 for the retarder system and 24 connected to the service brake system. The signal lines transmit various signals to the controller 12 according to the signals represented by arrows 1 - 11 . 13 - 19 . 21 and 59 in 1 ,

• – Signal 1 von Bremsprogrammschalter 27, der für Fußbetätigung durch den Fahrer angeordnet ist. Der Bremsprogrammschalter beeinflußt die Retarderfunktion über das Steuergerät und außerdem, bei seiner Betätigung, die Schaltpunkte des Schaltsystems.
• – Signal 2 vom Kupplungspedalschalter 30, der die Stellung des Kupplungspedals 28 erkennt.
• – Signal 3 vom Fußbremspedal 29 des Fahrzeugs als Information über die Stellung des Bremspedals 29.
• – Signal 4 vom Fahrtschreiber 39 des Fahrzeugs, mit Sekundärinformation über die Geschwindigkeit des Fahrzeugs oder die Drehzahl Crpm der Gelenkwelle.
• – Signal 5 vom Fahrpedal 31 des Fahrzeugs als Information über die momentane Stellung des Fahrpedals 31.
• – Signal 7 vom Abgasbremsschalter 45, der im Armaturenbrett 32 angeordnet ist.
• – Signal 8 vom Schalthebel 25 als Information über die vom Fahrer gewählte Betriebsart beim Schaltsystem, und zwar entweder Automatikbetrieb A, Neutralstellung N, manueller Betrieb M oder Rückwärtsfahrt R, sowie über etwaige vom Fahrer vorgenommene Korrekturen des automatisch gewählten Gangs bei Automatik-Betriebsart A oder neuen Gangwahlen in einer der manuellen Betriebsarten N, M, R.
• – Signal 9 vom Fahrprogramm-Wähler 26, mit dem der Fahrer z. B. das Ökonomieprogramm E (Economy) für wirtschaftlichsten Betrieb und sanfte Schaltvorgänge wählen kann oder das Bergfahrt-Programm H (Hill), dessen Schaltpunkte so festgelegt sind, daß die maximale Zugkraft erhalten wird und schnelle Schaltvorgänge den Vorrang vor Komfort und Geräuscherzeugung haben.
• – Signal 11 vom Diagnoseschalter 35, mit dem ein im Programm des Steuergeräts 12 integriertes Testprogramm für Wartungszwecke oder zur Fehlerortung mittels im Info-Feld 33 des Armaturenbretts 32 angezeigter Fehlermeldungen aktiviert werden kann.
• – Signal 21 vom Retarder-Steuergerät 22, das die Schaltpunkte für die Aktivierungsdauer des Signals modifiziert, um hierdurch eine gesteigerte Motorbremsleistung sowie einen erhöhten Kühlflüssigkeitsdurchsatz zu erhalten.
• – Signal 19 von einem ausgangsseitig am Getriebe 42 und vorzugsweise auf der Gelenkwelle 43 angeordneten Drehzahlgeber 46.
• – Signal 18 von Quittierschaltern im Getriebe 42 als Information über den eingelegten Gang.
• – Signal 16 von einem eingangsseitig am Getriebe 42 und vorzugsweise an der Kurbelwelle oder dem Schwungrad des Motors 40 angeordneten Drehzahlgeber 47.
• – Signal 59 vom Temperaturgeber 49 als Information über die Temperatur der Kühlflüssigkeit nach Verlassen des Retarders 48.

The control unit 12 receives the following input signals:

• - signal 1 of brake program switch 27 which is arranged for foot operation by the driver. The brake program switch affects the retarder function via the control unit and also, when actuated, the switching points of the switching system.
• - signal 2 from the clutch pedal switch 30 , the position of the clutch pedal 28 recognizes.
• - signal 3 from the foot brake pedal 29 of the vehicle as information about the position of the brake pedal 29 ,
• - signal 4 from the tachograph 39 of the vehicle, with secondary information about the speed of the vehicle or the speed Crpm of the PTO shaft.
• - signal 5 from the accelerator pedal 31 the vehicle as information about the current position of the accelerator pedal 31 ,
• - signal 7 from the exhaust brake switch 45 in the dashboard 32 is arranged.
• - signal 8th from the shifter 25 as information about the mode selected by the driver in the switching system, either automatic mode A, neutral position N, manual mode M or reverse R, as well as any corrections made by the driver of the automatically selected gear in automatic mode A or new gear options in one of the manual Operating modes N, M, R.
• - signal 9 from the driving program selector 26 , with the driver z. B. the economic program E (Economy) for most economical operation and smooth shifts can choose or the uphill program H (Hill), whose switching points are set so that the maximum traction is obtained and fast shifts have priority over comfort and noise generation.
• - signal 11 from the diagnostic switch 35 , with the one in the program of the control unit 12 Integrated test program for maintenance purposes or for fault location by means of the info field 33 of the dashboard 32 displayed error messages can be activated.
• - signal 21 from the retarder control unit 22 which modifies the switch points for the activation period of the signal to thereby provide increased engine braking performance and increased coolant flow.
• - signal 19 from one output side on the gearbox 42 and preferably on the propeller shaft 43 arranged tachometer 46 ,
• - signal 18 of acknowledgment switches in the transmission 42 as information about the engaged gear.
• - signal 16 from an input side on the gearbox 42 and preferably on the crankshaft or the flywheel of the engine 40 arranged tachometer 47 ,
• - signal 59 from the temperature sensor 49 as information about the temperature of the cooling liquid after leaving the retarder 48 ,

• – Signal 6 an Info-Feld 33 im Armaturenbrett 32 zur Anzeige von Betriebsart (A-N-M-R) beim Schaltsystem, gegenwärtigem Gang, nächstem Gang, Fahrprogramm (E-H) sowie etwaiger Fehlercodes, Warnungen und Mitteilungen an den Fahrer.
• – Signal 17 an verschiedene Magnetventile im Getriebe 42 zur Aktivierung von Servogeräten 37, so daß diese Schaltorgane zum Aus- bzw. Einlegen von Gängen betätigen.
• – Signal 15 an Abgasbremse 58, die im Abgassystem des Motors angeordnet ist, so daß die Abgasbremse, zusätzlich zu ihrer Funktion als Zusatzbremse, zum schnellen Absenken der Motordrehzahl auf eine Synchrondrehzahl vor allem beim Heraufschalten in einen Gang mit kleinerem Übersetzungsverhältnis aktiviert werden kann.

The control unit 12 controls various servo devices or displays in info fields in the dashboard 32 via the following output signals:

• - signal 6 at info box 33 in the dashboard 32 to indicate the operating mode (ANMR) of the shift system, current gear, next gear, driving program (EH) and any error codes, warnings and messages to the driver.
• - signal 17 to various solenoid valves in the gearbox 42 to activate servo devices 37 , so that these switching elements operate for the removal and insertion of gears.
• - signal 15 on exhaust brake 58 located in the exhaust system of the engine, so that the exhaust brake, in addition to its function as additional brake, can be activated to quickly lower the engine speed to a synchronous speed, especially when shifting up into a gear with a smaller ratio.

• – Kommunikationsleitung 10 an Diagnosebuchse 34, an die eine Diagnoseausrüstung angeschlossen werden kann, die eine Abfrage von Fehlercodes aus dem Steuergerät 12 sowie eine Funktionsprüfung des Steuergerät-Programms durchführen kann.
• – Kommunikationsleitung 13 an Steuergerät 24 für Antiblockiersystem (ABS) und Antriebsschlupfregelung (ASR) der Bremsanlage, wodurch das Steuergerät 24 u. a. Schaltvorgänge bei aktivierter ASR verhindern kann.
• – Kommunikationsleitung 14 an Steuergerät 23 des Kraftstoffsystems; dieses Steuergerät 23 regelt über Kommunikationsleitung 20 die Kraftstoffzufuhr zu den Einspritzventilen des Verbrennungsmotors.

The control unit 12 It also communicates in interactive mode, ie it sends out output signals and receives input signals from various ECUs via the following communication lines:

• - Communication line 10 at diagnostic socket 34 to which diagnostic equipment can be connected, requesting error codes from the control unit 12 and perform a functional test of the controller program.
• - Communication line 13 to control unit 24 for anti-lock braking system (ABS) and traction control (ASR) of the brake system, causing the control unit 24 Among other things, switching operations can be prevented when the ASR is activated.
• - Communication line 14 to control unit 23 the fuel system; this controller 23 regulates via communication line 20 the fuel supply to the injection valves of the internal combustion engine.

The system described above allows in the A-position of the shift lever, an automatic sequence of shifts depending on detected engine parameters such as speed of the vehicle, engine load and speed, the derivation of one of these or a combination of vehicle speed accelerator pedal position engine speed, optionally fully depressed accelerator pedal (so-called Kick-down position) and whether a braking operation takes place. The switching process is automatic so that the optimum fuel consumption and optimum performance are obtained.

The retarder control unit 22 includes a hand lever 61 , preferably in the dashboard 32 is arranged. The lever has six setting positions with the names 0 to V. 0 is the starting position, ie the retarder 48 is switched off. The positions I-II-III-IV-V correspond to a progressive increase in the retarder braking power with the following braking torques: Position I - 500 Nm, II - 1000 Nm, III - 1500 Nm, IV - 2000 Nm and V - maximum retarder braking power of approx nm. With position V for maximum retarder braking power is also expediently switching on the exhaust brake (EB) 58 connected to the vehicle, which additionally strengthens the braking power acting on the drive wheels of the vehicle. Positions 0-V are stable, so that the lever remains in the selected position after release. However, the retarder function is always switched off as soon as the driver releases the accelerator pedal 31 the vehicle is activated, but the braking power of the retarder is automatically switched on when the accelerator pedal is released and the lever is simultaneously in one of the positions IV. The retarder function may also, depending on the operation of the brake pedal or a slide switch 63 on the lever 61 to keep the speed constant (cruise control). The braking performance of the retarder is then automatically adjusted to seek to maintain vehicle speed by progressively increasing braking power as vehicle speed increases. With appropriate position of the button 62 This function can automatically take effect to keep the speed constant as soon as the brake pedal 29 is pressed, and then remain effective as long as the accelerator pedal is not operated thereafter.

The invention is advantageously suitable for automatic switching operations in mechanical step gears, in which the switching operations without disengaging the clutch 41 expire.

The invention will be explained in more detail with reference to 2 describing, in the form of a flowchart, a control routine for selectively switching on the exhaust brake in response to vehicle parameters indicating a need for rapid upshifts. This control routine is in the microprocessor of the controller 12 saved.

In the first question step 80 is checked whether an upshift is pending. As long as no upshift is pending, the program returns to the main program. The control routine may preferably be in a program loop sampled at a frequency of 100 Hz. The control of whether an upshift is pending, thus 100 times per second.

If an upshift is pending, the control routine goes to step 81 in which it is checked whether a first condition for obtaining fast upshifts by turning on the exhaust brake is met.

When the driver is above the driving program selector 26 a driving program (Sprg = Shift program = gearshift program) for uphill (Hill) has turned on or the accelerator pedal has depressed maximum up to the so-called kick-down position, the first part of the condition is met. This first part indicates that there is a need for rapid gear shifts, on mountain routes where an interruption of drive torque caused by the shift may result in the vehicle losing speed and an upshift is lost or in acute traffic situations when the driver is requires a quick response of the vehicle.

On these occasions, a second sub-condition applies to the engagement of the exhaust brake during the upshift, which consists of the retardation of the vehicle, also referred to as speed loss. For this purpose, a speed difference dV (dV = delta velocity) is defined, which is positive when the vehicle is accelerating, and negative when the vehicle is decelerated. If the vehicle parameter speed loss is above a predetermined value, the second sub-condition is considered satisfied. If, for example, the speed loss should be more than 5 revolutions per second of the cardan shaft, the following applies: dV <-5 1 / s.

If both subconditions of the first condition in step 81 are met, the control routine goes to step 84 and causes the exhaust brake EB to be _{turned on upshift} during the upshift.

The threshold value of the vehicle parameter dV is appropriately set strictly at a speed loss of the vehicle, i. H. dV <0, whereby the exhaust brake is automatically turned on when the vehicle loses speed during a downshift. Only when the vehicle loses no speed, which could occur on a slope accidentally still switched on uphill program or kick-down position of the accelerator pedal, there is no turn on the exhaust brake, and this is indeed not necessary if the lack of speed of the vehicle, if the speed of the vehicle is lowered below the upshift point and the upshift demand is no longer there.

If one or both of the first and second parts of the first condition in step 81 are not satisfied, the control routine goes to step 82 , where it is checked whether a second condition for obtaining fast upshifts by turning on the exhaust brake is met.

If the next gear NG (= next gear) to which the control unit is to switch is lower than a predetermined gear EB _gear , the first part of the condition is fulfilled. This first part indicates that an upshift to a smaller gear of the total number of gears should take place. Preferably, the next selected gear is a gear that is lower than a predetermined gear, preferably a current gear in the lower part of the range group of the transmission. In the lower part of the range group of the transmission are all smaller gears that are engaged when starting the vehicle and therefore are closely graded and thus have a small increase in the gear ratios. These smaller gears are usually only for very short Permanently engaged, and the upshift can be prevented or quickly followed by a downshift as the vehicle loses speed such that the speed of the vehicle drops below the downshift point or below the downshift point for the next higher gear in the range group of the transmission.

When shifts occur in the relatively narrow-stepped portion of the transmission, and preferably in the range group of the transmission, a second sub-condition for turning on the exhaust brake comes into effect during the upshift, and this second sub-condition consists of the retardation or loss of speed of the vehicle during the shift ,

If this vehicle parameter, v dV of the vehicle, is below a second predetermined value, the second partial condition is fulfilled. The control routine then goes to step 84 and causes the switching on of the exhaust brake EB _upshift during the upshift.

The threshold value of the vehicle parameter dV is expediently less stringent than the threshold for the second partial condition of the first condition in step 81 set. The second partial condition is only satisfied when the vehicle during the switching operation, a retardation or a speed loss of considerable size detected by the propeller shaft speed Crpm, corresponding dV <-5 1 / s takes place.

If both subconditions of the second condition in step 82 are met, the control routine goes to step 84 and causes the exhaust brake EB to be _{turned on upshift} during the upshift. As a result, the exhaust brake is automatically turned on during the upshift event when the vehicle substantially loses speed when shifting up to a smaller gear in the narrow stepped portion of the transmission and preferably in the range group during the upshift.

If one or both of the first and second parts of the second condition in step 82 are not satisfied, the control routine goes to step 83 , where it is checked whether a third condition for obtaining fast upshifts by turning on the exhaust brake is met.

When an engine braking program is turned on, for example, by the driver selecting the brake program switch 27 has been actuated, an automatic activation of the exhaust brake during the upshift is obtained. The engine braking program effects as long as the switch 27 is actuated, raising the upshift points and turning on the exhaust brake. After releasing the switch remain only the raised upshift points, and this only as long as the accelerator pedal 31 not released after releasing.

When the engine brake program EnB (Engine Brake) is turned on and detected based on the ramp-up points raised by the vehicle parameter, the control routine goes to step 84 and causes the exhaust brake EB to be _{turned on upshift} during the upshift. As a result, the exhaust brake is automatically turned on during the upshift, provided that the engine braking program is turned on. Turning on the engine braking program indicates that the driver is requesting extra braking power, and consequently all momentary interruptions caused by the upshift, which are associated with a loss of engine braking power, must be as short as possible.

If the condition in the third step 83 is not satisfied, the control routine goes to step 85 In which the switching of the exhaust brake EB _upshift off during the shift-up process (off) is.

Retardation or velocity loss are detected either as actual acceleration or as actual velocity loss. The retardation is expediently determined in a calculation routine which lies in the program loop which is sampled at a frequency of 100 Hz. For the determination of the acceleration, a short time base of 0.5 s is used. The acceleration is then updated 100 times per second, and the acceleration value is stored in the memory of the controller, where it is from step 81 and 82 in the determination of whether the retardation condition is met or not, is asked. However, the acceleration value tends to be greatly affected by vibrations in the driveline of the vehicle, whereby a restive signal of varying value in acceleration / deceleration is obtained even when the tendency is retardation. Optionally, the speed at the beginning of the power up process can be stored in the memory of the controller and in step 81 and 82 are compared with the current speed to determine if the speed loss is greater than the predetermined threshold.

The control routine 80 - 84 / 85 runs continuously during the upshift, and if, for example, the retardation of the vehicle in the initial phase of the upshift does not exceed the predetermined thresholds, a later overshoot may cause the power to be turned on Achieve exhaust brake during one and the same upshift. The switching on of the exhaust brake is expediently carried out as a hysteresis function, in which switching off the exhaust brake already engaged is not effected during the control of the switching on of the exhaust brake to obtain the synchronous rotational speed, before the threshold values are undershot by a predetermined offset value. Optionally, a time function may lock off the exhaust brake due to undershooting of the thresholds during the shift, which time function keeps the exhaust brake on for preferably 50 milliseconds and only thereafter enables shutdown depending on the thresholds being undershifted during the shift. Switching off the exhaust brake, because a synchronous speed is to be obtained by switching on the exhaust brake has, however, always takes precedence over the hysteresis function.

The preferred threshold values for the retardation condition are suitably adapted to the response of the switching system.

Shorter servo gear and gear engagement responses, exhaust brake application, and fuel injection control allow the thresholds to be set to higher retardations without the torque interruption caused by the shift continuing so long as to cause a downshift or engine braking performance is missing for too long.

There is also the ability to adjust the thresholds, in part by setting higher retardation conditions to further reduce the use of the exhaust brake on upshifts and, in part, by setting lower retardation conditions to more frequently achieve faster shifts. With the same intention, other logical conditions can be introduced.

The predetermined threshold values are stored in non-volatile memory 57 in the control unit 12 saved.

The invention can be modified within the scope of the claims, so that there are differences from the preferred embodiment. Unique in the invention, however, is a selective application of acting on the gas exchange of the engine to enhance the engine braking power engine brake, preferably a switchable exhaust brake, in upshifts in switching systems for mechanical transmission, this application is automatically dependent on exceeding predetermined vehicle parameters and this exceeding the vehicle parameters indicates that brief momentary interrupts and fast shifts are requested, either because of the risk of a downshift being lost or because of the need to reduce engine brake interruptions when the driver requests additional braking power.

• – ”Jake-Brake”, die durch kurzzeitiges Öffnen des Auslaßventils im oberen Totpunkt (OT) am Ende des Verdichtungshubes die Motorbremsleistung erhöht, indem der von der verdichteten Luft auf den Kolben bei dessen Abwärtshub aus dem OT ausgeübte Druck vermindert und dadurch ein Rückprall verhindert wird, sowie
• – Motorbremsorgane, die durch kurzzeitiges Öffnen des Auslaßventils im unteren Totpunkt (UT) zu Beginn des Verdichtungshubes ein Befüllen des Zylinders mit unter erhöhtem Druck stehenden Abgasen bewirken, wodurch sich eine erhöhte Verdichtungsarbeit und damit gesteigerte Motorbremswirkung ergibt, und
• – Kombinationen der vorgenannten zwei Motorbremsfunktionen, eventuell noch kombiniert mit einer Abgasbremse.

The term engine braking devices, which act on the gas exchange of the internal combustion engine, includes, in addition to the exhaust brake, also selectively switchable engine brake such as

• - "Jake-Brake", which increases the engine braking performance by briefly opening the exhaust valve at top dead center (TDC) at the end of the compression stroke, reducing the pressure exerted by the compressed air on the piston as it moves down the TDC, thereby preventing rebound will, as well
• - Engine braking devices that cause by briefly opening the exhaust valve at bottom dead center (UT) at the beginning of the compression stroke filling the cylinder with exhaust gases under elevated pressure, resulting in increased compression work and thus increased engine braking effect, and
• - Combinations of the aforementioned two engine braking functions, possibly combined with an exhaust brake.

For example, with a Jake Brake Brake, a pneumatic cylinder may depress the exhaust valves of some or all of the cylinders in the TDC during the neutral phase, when raised downshift points are present, or the vehicle's deceleration is excessive during the shift, down to the open position. In a corresponding manner, the discharge valves in the BDC for filling the cylinders can be opened at the beginning of the compression stroke during the neutral phase, when raised downshift points are present or the retardation of the vehicle during the shift is too strong.

LIST OF REFERENCE NUMBERS

1

Signal from brake program switch

2

Signal from clutch pedal switch

3

Signal from service brake pedal

4

Signal from tachograph

5

Signal from accelerator pedal

6

Signal on dashboard information panel

7

Signal from exhaust brake switch (EB)

8th

Signal from shifter

9

Signal from driving program selector

10

Communication with diagnostic socket

11

Signal from diagnostic switch

12

uP-controller

13

Communication with ABS / ASR

14

Communication with EDC

15

Signal to exhaust brake (EB)

16

Signal from engine speed sensor

17

Signal to gear solenoid valves

18

Signal from gearbox acknowledgment switches

19

Signal from PTO shaft encoder

20

Communication with EDC motor control

21

Signal from retarder

22

Retarder control unit

23

EDC control unit

24

ABS / ASR control unit

25

gear lever

26

Driving program selector

27

Brake program switch

28

clutch pedal

29

brake pedal

30

Clutch pedal switch

31

accelerator

32

dashboard

33

Dashboard information field

34

diagnostic socket

35

diagnostic switch

36

communication line

37

servomechanism

40

internal combustion engine

41

clutch

42

step gear

43

powertrain

44

drive wheels

45

Exhaust brake switch (EB)

46

Speed sensor, output shaft

47

Speed sensor, motor

48

retarder

49

Retarderkühlflüssigkeit temperature gauge

57

Non-volatile memory

58

Exhaust brake (EB)

59

Signal from retarder coolant temperature transmitter

61

Retarder lever

62

Retarder-automatic key

63

Speed control slide switch

80

question step

81

question step

82

question step

83

question step

84

control step

85

control step

Claims (5)

A method of automatic, computer-assisted mechanical stepper gearing in internal combustion engine driven automobiles in which, in conjunction with upshifting, an engine brake control engine brake motor can be energized to rapidly obtain a next speed synchronous engine speed the engine brake member is turned on when upshifted depending on whether a vehicle parameter is above a predetermined value, characterized in that the engine brake member is selectively turned on when upshifted depending on whether an engine braking program has been turned on, which is upshifting points raised from normal predetermined upshift points yields, or - whether during the switching process, the retardation or the loss of speed of the vehicle over a threshold depending on the operating case lie lie gene. A method according to claim 1, characterized in that an exhaust brake as an engine brake member for rapidly obtaining a synchronous speed for the next gear can be turned on, the exhaust brake is selectively turned on when switching up depending on whether a vehicle parameter is above a predetermined value. Method according to claim 2, characterized in that the exhaust brake is selectively turned on in the upshift depending on whether during the switching operation, the retardation or the loss of speed of the vehicle over a predetermined depending on the operating case first threshold and simultaneously - The driver has depressed the accelerator pedal to maximum in the kick-down position, or - The control element has been operated to turn on a hill climb program. A method according to claims 2 or 3, characterized in that the exhaust brake is selectively turned on in the upshift depending on whether during the switching operation, the retardation of the vehicle is above a predetermined second threshold and at the same time the next selected gear is lower than a predetermined gear. A method according to claim 4, characterized in that the predetermined second threshold for the vehicle retardation, determined on the basis of the propeller shaft speed (Crpm), corresponds to a speed loss of more than 5 revolutions per second, so that applies to the speed difference dV: dV <-5 1 / s.

Images