DE3446577A1 - METHOD FOR TROUBLESHOOTING IN AN ELECTRONICALLY CONTROLLED GEARBOX FOR A VEHICLE - Google Patents

Description

PATENT LAWYERS dr.ino. ; rane vuesthoff

WUESTHOFF-v. PECHMANN-BEHRENS-GOETZ ^{DR PHIt / FrtDA} ™ ^E5THO "(« w

DIPL.-1NG. GERHARD PULS (l9 $ 2-lg7l)

EUROPEAN PATENT TORNEYS. If. _Dm , _CHEM . _D , _{E. FRElHERR V0N PECHMANN}

Q / / C CT Π Π DR.-ING. DIETER BEHRENS

O H H D U / / DIPL.-ING .; DIPL.-VIRTSCH.-ING. RUPERT GOETZ

D-8000 MUNICH 90 Saab-Scania Schweigerstrasse 2

LA-58 958 phone: (089) 6620 ji

TELEGRAM: PROTECT PATENT

TELEX: J 24 070

TELEFAX: VIA (089) 2 71 60 63 (in)

Method for troubleshooting in an electronically controlled gearshift of a vehicle

The invention relates to a method for troubleshooting and fault display in an electronically controlled transmission clutch arrangement in a vehicle, in which a display device / a plurality of Switches and electromagnetic valves are provided which are connected to an electronic control unit.

Known devices for troubleshooting in electronically controlled Gear changing devices in vehicles use special equipment, which is attached to the ones built into the vehicle Control is connected. This is why the driver has only very limited options for faults occurring in the control system To determine. Therefore, even an insignificant error there can result in the vehicle being put out of operation must in order to wait for qualified personnel to carry out the troubleshooting. It will be understood that for larger trucks Such downtimes are associated with high costs and should therefore be kept as short as possible.

The invention is therefore based on the object of specifying a method for troubleshooting, with which without special equipment the driver of the vehicle can easily find and determine the most common faults.

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According to the invention, this object is achieved in the following steps: In a first step, a test program switch is set manually operated, which is permanently installed in the vehicle and a program stored in the control device starts, which carries out an automatic functional test of the display device, whereupon one or more further test steps be initiated by repeated actuation or actuations, with the test program for each individual of these further actuations carries out a function test of the switches and / or electromagnetic valves of the arrangement, see above that for a given possible error certain information contained in the test program on the display device is shown.

According to the invention, it is thus possible to use a single, simple fault search command to perform the function of a large number of Check switches and valves of the arrangement. A test program permanently stored in the computer is used for troubleshooting, this program is divided into several individual steps, each of which responds to manual actuation a special test program switch can be called up one after the other. After the error search procedure, actuates certain devices, which are permanently installed in the vehicle, to certain components and functions of the gearbox to consider. The errors that occur are displayed by a code and / or shown in a display device, which is also permanently installed in the vehicle. The code information is explained in the operating instructions, so that a determination of the nature of the fault and its location are possible.

The invention is preferably used in a vehicle whose transmission housing has an electronically controlled gear shift is provided. In this arrangement there is at least one manually operable device for changing the input signals provided in the control device of the arrangement.

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According to the invention, in a further step, preferably the second actuation, a function test of the switches that can be actuated by the actuation device is carried out, wherein the program for a specific actuation of the actuating device carries out a special troubleshooting, the result of which by means of pre-stored information in the display device is pictured.

By executing the error search program and the individual error display steps provided therein, the driver can easily ensure that the switches tested are working properly.

The invention is described in more detail below with reference to the drawing. It shows:

Fig. 1 schematically shows a drive, which with an electronic Controller is connected, and

Fig. 2 is a flow diagram of the fault finding method according to the invention.

The drive shown in Fig. 1 has a vehicle engine 1, with which a conventional, synchronized, mechanical Transmission 2 is connected. The drive force is transmitted from the engine 1 to the transmission 2 via a manually operated friction clutch 3 transfer. An auxiliary gear 4 is in turn connected to the gear 2, the output shaft 5 of the auxiliary gear Via a cardan shaft 6 in driving engagement with the (not shown) The drive wheels of the vehicle are at a standstill. Such a transmission is preferably provided for heavy commercial vehicles. To make it easier for the driver to change gears and also to ensure reliable gear selection is a electronic control system provided.

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The selection of the correct gear while driving is carried out in a conventional manner by an electronic control unit 7, which has a computer as an essential component. The gear selected by means of the control unit 7 is in a gear change sequence by means of the clutch 3 between the
Engine 1 and the transmission 2 inserted, which is operated manually by the driver. This allows the conventional mechanical transmission with the clutch 3 between the engine and transmission and
thus their high efficiency can also be maintained.

The gear change in the transmission housing 2 is carried out by means of two pneumatic cylinders 10, 11, one of which is shown in FIG
Transverse gear changes while the other performs longitudinal gear changes. Correspondingly, gear changes are made in the auxiliary gear housing by means of
of the pneumatic cylinder 12 carried out. From the
pneumatic supply 13 of the vehicle is over air pressure
a variety of electric valves 15-21 to the cylinders
10, 11, 12 out. The valves mentioned are accordingly
Output signals from the control unit 7 either in their
placed in the open or closed position. the
Position of the pistons in cylinders 10-12 is means of
Microswitches 23-29 displayed, the number of which corresponds to that of the
electrical valves.

For the valves 15-21 and switches shown in Fig. 1
23-29, the following relationships apply to the piston positions of the
Piston-cylinder arrangements 10-12:

Electromagnetic valve 15 cylinder 10 left switch 23

¹¹ 16 "right" 24

"17" forward "25

18 "neutral" 26

¹¹ 19 "backwards" 27

20 "high" 28

21 deep "29

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To understand the above table, the first relationship is explained in more detail below.

The power supply of the electromagnetic valve 15 causes compressed air to be supplied to the cylinder 10, the Piston is thereby brought into the left position, which is confirmed by switch 23.

A multiplicity of input signals are input to the control device 7. For example, switches 23-29 transmit Via the bundle of conductors 31 signals to the control unit 7, which indicate the gear engaged, via the line 32 a Signal input to the control unit 7, which indicates the speed of the vehicle wheels. This speed will measured with a tachometer 30 on the output shaft 5. Furthermore, signals are sent to the control unit 7 via the Conductor bundle 33 entered from a plurality of switches, which are arranged in the driver's cab of the vehicle and are delimited schematically in FIG. 1 by block 34. The engine is conventionally acted upon by an accelerator pedal 35, whose position is determined by a switch 36. The position of a conventional clutch pedal 37 is through a switch 38 is determined. An operating selector switch 39 can be actuated by the driver and can be brought into various positions which are determined by a switch 40. A first position of the operating mode switch 39 is denoted by MAN and means that the gears are selected by hand. A second position is labeled AUTO and indicates that the journey is carried out with an automatic gear selection. A third position is labeled N and shows the so-called Neutral or idle position in which no gear is inserted, while a fourth position is denoted by R and corresponds to the reverse gear. A gear change link in Form of a small lever 41 has a stable rest position in a middle position, and on both sides of it unstable position

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lungs, which are labeled UP and DOWN. These positions are determined by the switch 42. A pivoting of the lever 41 in the ÜP position (= up position) means that has changed one step upwards, while pivoting the lever 41 into the DOWN position (= down position) one means corresponding change downwards.

The control unit sends according to the input signals mentioned above and a gear change program stored in the computer 7 output signals via the conductor bundle 44 to the electromagnetic valves 15-21. Output signals are also a buzzer or alarm clock 46 via a line 45 for an acoustic display and via a bundle of lines 47 in the display device 48 is entered for visual display. The display device 48 has twelve light emitting diodes which display the following symbols in sequence when the power is supplied: R, N, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

The usual task of the control unit 7 is accordingly certain input signals to make a gear selection and after corresponding manual operation by the driver to act on the gear changing devices so that the selected gear is engaged. Furthermore, a permanent test function is provided in the gear change program, which the operation interrupts immediately in the event of certain errors. The driver is informed by the alarm clock 46 when such an error occurs alarmed.

There is also a special test program in the control device 7 provided, which by manual actuation of a test program switch 14 arranged on the control unit 7 in Gear is set.

Certain main sources of error are caused by the permanent check function supervised. If an error occurs, an alarm is triggered at the alarm clock 46 and the error code in the error

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Memory of the control unit 7 is stored. The code is shown on the display device 46 by means of the special, test program described below. Among the errors observed in this way are also the code plug 22, which is connected to an output of the control unit 7, occurring anomalies. The code plug 22 has a code, which corresponds to a given combination of engine and transmission and certain basic output data for the gear selection program the control unit 7 is determined. There are also short circuits in the electromagnetic valves 15-21, faults in the control unit 7 including its memory, errors in the speed measurement and impossible switch positions the switch 23-29 checked.

The special test program stored in a programmable read-only memory (PROM) of the control unit 7 is carried out by manual actuation of the switch 14 of the control unit 7 set in motion. The switch 14, which in Fig. 2 by TPSS 14 is indicated, can by a screwdriver or the like. be operated. From a manual, the driver performing the troubleshooting can find information on how to switch 14 in is operated in different steps. When the test program switch 14 is pressed for the first time, the first step of the test program is activated initiated, which is represented by the operational step 51 in the flow chart according to FIG. This is followed by a Actuation step 52, by means of which all the display devices of the display unit 48 are put into their luminous state to check their function. The function of the alarm clock is also in this step 52 by means of about three seconds long tone checked. The program then follows according to the connecting line 53 to a further step 54 in which a possible code which is stored in the error memory of the control unit 7 is entered into the display device 48. As examples of possible errors and associated error codes are mentioned:

3A46577

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Incorrect speed determination = R control unit not operational = N Anomalies in the code plug = RN

After step 54, the line 53 corresponding to the sequence of steps leads to a so-called interruption step 55, which is provided to determine that the switch 14 is pressed. As long as this is not the case, the signal will be accordingly the command line 56 is returned to step 55. If the switch 14 is pressed, the program follows to step 57 at which two short acoustic signals are emitted by the alarm clock 46. This indicates that the second step of the test program has begun and that the program proceeds to step 58. In this step, the display devices are in the lighting state offset to indicate the function of the switches 23-29, which can be acted upon directly by actuating devices 35-37, 39-41 are. Here this is done in a step 58 by manual actuation of the actuating elements listed below executed, the display devices at the same time placed in the light state to display a correct function will:

- Operation selector switch 39 in R position R

- Operating selector switch 39 in AUTO position N

- Operation selector switch 39 in MAN position 1

- Lever 41 in DOWN position 2

- Lever 41 in UP position 3

- Clutch pedal 37 depressed 4

- Accelerator pedal 35 partially depressed 5

- Accelerator pedal 35 fully depressed 6

If the motor 1 is running, the display is also in its illuminated state.

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Step 58 is followed by a second interruption step 59 to determine whether the switch 14 is operated. If this is not the case, the program follows the command line 61 to step 58. The step 58 can therefore run through without interruption until the switch 14 is actuated. If the actuation takes place, so the program follows the flow line 53 to a further interrupt step 62, in which the program determines whether the last registered speed value is equal to 0, i.e. whether the vehicle is stationary at the moment. If this is not the case, then will the test program is interrupted and the program sequence returns to the main program according to command line 63. Is that Vehicle, the program continues according to command line 53 to step 64, with three short beeps from Alarm clock 46 are issued as an indication that the third step of the test program has started.

The third program stage is initiated by an interruption step 65, in which the position of the clutch pedal 37 is checked. If the pedal 37 is not depressed, the program follows the command line 66 to an interrupt step 67 in order to check whether the test switch 14 is depressed. If this question is answered in the affirmative in the interruption step 65, an operation step 68 follows in which the Gear changing movements in the main gearbox 2 and the associated valves 15-21 and switches 23-29 on their reliable Function to be checked. This is done by manually actuating the operating mode selector switch 39 and the lever 41 according to the following plan:

- Operating mode selector switch in R position, valve 15, stroke in Cross direction, switch 23, display R.

- Operating mode selector switch in AUTO position, valve 18, idle, Switch 26, displays 4,5.

- Operating mode selector switch in MAN position, valve 16, stroke in Longitudinal right, switch 24, display 10.

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- Lever in UP position, valve 17, stroke in longitudinal direction forwards, Switch 25, display 7.

- Lever in DOWN position, valve 19, stroke in longitudinal direction backwards, Switch 27, display 2.

In order to understand the relationships listed in the previous plan, the first-mentioned relationship chain is explained below. If the operating mode selector switch is in the R position, then the electromagnetic valve 15 is energized to control the input of compressed air into the cylinder 10 so that a gear change movement is carried out in the transverse direction to the left, which is confirmed by the switch 23, and what at proper function, the display "R" on the display device 48 results.

In another embodiment of the invention, step 68 can be preceded by another step which can also replace step 68 can, in which the above gear change movements are automatically checked according to the following sequence:

(1) The electromagnetic valve 18 is energized so that the cylinder 11 assumes a neutral position; the Switch 26 indicates this within a predetermined period of time.

(2) The electromagnetic valve 15 is energized so that the piston-cylinder assembly 10 is lifted in the transverse direction to the left executes what the switch 23 confirms within a predetermined period of time.

(3) The electromagnetic valve 18 is energized so that the piston-cylinder assembly 10 is lifted in the transverse direction to the right does what the switch 24 confirms within a given period of time.

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(4) The electromagnetic valve 17 is energized, so that the piston-cylinder assembly 11 performs a longitudinal stroke forward, which the switch 25 within a given Time span confirmed.

(5) The electromagnetic valve 19 is energized so that the piston-cylinder assembly 11 is lifted in the longitudinal direction reverse executes what the switch 27 confirms within a given period of time.

If an error is discovered in any of the steps, this is indicated on the display device 48 by means of the error code.

After step 68 has been carried out, the program follows command line 53 to interrupt step 67 in which it is checked once whether the test switch 14 is pressed. If this is not the case, the program returns according to the Command line 69 returns to the input of interrupt step 65 prior to operational step 68. This sequence will be continuous maintained until the test switch 14 is pressed. is if this is the case, the program follows the command line 53 to an operating step 71, in which four short beeps from the Alarm clock 46 are given as an indication that the fourth program stage has begun.

Just like the third program stage of the test program, the fourth program stage is also interrupted 72 initiated, in which the position of the clutch pedal 37 is checked. If the pedal 37 is not pressed, it follows Program of the command line 73 directly to an interruption step 74, where it is checked again whether the test switch 14 is pressed. If the pedal 37 is depressed, the program follows the command line 53 from the interrupt step 72 to an operating step 75. Here it is checked whether the gear change movements in the auxiliary gear housing 4 and the associated electrical

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magnetic valves 20, 21 and the switches 28, 29 according to regulations function. For this purpose, the driver manually operates the lever 41 in the UP position or the DOWN position. In the UP position, the electromagnetic valve 20 is supplied with current, as a result of which the piston-cylinder arrangement 12 reaches the HIGH position, which is confirmed by switch 28. If the function is correct, the display "N" brought to light on the display device 48. In the DOWN position, the electromagnetic valve 21 is energized supplied, whereby the cylinder 12 is in the LOW position, what is indicated by the switch 29. If the function is correct, the display "9" on the display device 48 becomes brought shine.

After operating step 75, the program follows the command line 53 to an interruption step 74 in which the position of the test switch 14 is checked again. If the switch K is not pressed, the program returns according to the command line 7 (to the input of the interruption step 72, after which the previous part of the program runs again. This sequence is repeated until the switch 14 is pressed. If this is the case, then the program follows the command line 53 to an operating step 77 in which two longer tone signals are emitted by the alarm clock 76 to indicate that the test program has been completed.

Claims (6)

PATENT LAWYERS - dr.-ikc. F! .Anz vuesthoff WUESTHOFF-v. PECHMANN- BEHRENS -GOET2- "'-" ^ / "" "" thoff Ύ / "/' r · r ~ ri fr 'DtPL .- ;: <G. Gikhard puls EUROPEAN PATENTATTORNEYS 34 465 77 d.pl.-chem . dr.e.fre.herr von pech DR.-ING. DIETER BEHRENS D1PL.-ING .; DIPL.-TFIRTSCH.-ING. RUPERT D-8000 MUNICH 90 Saab-Scania Schweigerstrasse 2 LA-58 958 phone: (089 ) 662051 TELEGRAM: PROTECTPATENT TELEX: j 24 070 TELEFAX: VIA (089) 2 J \ 60 63 (ill) Patent claims: 1. A method for troubleshooting an electronically controlled gear changing device of a vehicle, with a display unit (48), a plurality of switches (23-29, 36, 38, 40, 42) and electromagnetic valves (15-21) for controlling the gear changing device by means of an electronic control unit (7),
characterized in that troubleshooting is carried out with components permanently installed in the vehicle in the following steps: - A first operating step (51) is initiated by manual actuation of a test program switch (14), which starts a program stored in the control unit (7) in order to automatically check the display unit (48) execute, and - One or more further operating steps (57, 64, 81) are initiated by the test program switch (14) again is operated manually, the test program determining for each of the subsequent operational steps how the operational test the switch (23-29, 36, 38, 40, 42) and / or the electromagnetic valves (15-21) is carried out, so that, for a given error, information provided in the test program is displayed on the display device (48) will. 2. The method of claim 1, wherein the electronically controlled gear changing device is further manually operable Has actuating devices (35, 37, 39, 41) for resetting the input signals of the control unit (7), characterized in that in one of the further operating steps, preferably in second operating step (52), the switches (36, 38, 40, 40, 42) are subjected to a functional test, the program when a certain actuating element is actuated causes predetermined information to appear on the display device (48). 3. The method of claim 1, wherein the electronically controlled gear changer is further manually operable Has actuating devices (35, 37, 39, 41) for resetting the input signals of the control unit (7), characterized in that in at least one further operating step (54) the electromagnetic valves (15-21) and the switches (23-29), which interact with the gear change movements, on their Function can be checked, with a predetermined one by the test program when a certain actuating element is actuated Information appears on the display device (48). 4. The method according to any one of claims 2 or 3, characterized in that that in at least one of the further operating steps an automatic function test with regard to the gear change movements cooperating electromagnetic valves (15-21) and the switch (23-29) is carried out, wherein a predetermined information is displayed on the display device according to the detected error. 5. The method according to any one of claims 1, 2 or 3, characterized in that that during further operating steps each actuating devices (39, 41) are operated by hand, whereby in a first further operating step (58) a functional test of the Switch (40, 42) and, during a further operating step (68), a functional test of the electromagnetic valves (15-19) is carried out. 6. The method according to any one of the preceding claims, characterized in, that in those operating steps which follow the functional test of the display device (48), automatically on the Display device (48) an error code is displayed, which was previously stored in the control device (7).