DD207424A1 - DEVICE FOR MEASURING OPERATING PARAMETERS OF PETROL AND DIESEL ENGINES - Google Patents

Abstract

The invention relates to an apparatus for measuring operating parameters of gasoline and diesel engines, comprising an input amplifier adapted to the internal combustion engine, a circuit, a time distribution unit synchronized with the internal combustion engine and a signaling evaluation unit. Its essence is that the time distribution unit, as a digital synchronizer, is switched on between the switching circuit and the signal-evaluating unit. Thanks to its universal construction, the device according to the invention is suitable for highly precise measurement of operating parameters of the petrol and diesel engines which follows the operating conditions well and quickly

Description

Berlin, 18.06.1982

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Device for measuring operating parameters of gasoline and diesel engines

Field of application of the invention

The invention relates to a device for measuring operating parameters of gasoline and diesel engines, comprising an input amplifier which can be adapted to the internal combustion engine, a circuit, a time distribution unit synchronized with the internal combustion engine and a signaling evaluation unit. The device according to the invention is therefore suitable for reliable, accurate measurement of operating parameters - such as injection angle, opritzzeitdauer, pre-ignition, pressure values, etc. - the gasoline and diesel engines.

Characteristic of the known technical solutions

An important task in motor vehicle diagnostics is the measurement of the various parameters which are characteristic of the operating state of internal combustion engines. For this purpose, several devices are known, which can be divided into two groups according to the measurement principle. The first includes the auto-electrical measuring devices, which measure the electrical parameters and therefore allow testing. The second group includes those devices in which the measuring probes to be installed in the engine are used. Following the state of the probes, processing the results of measurements obtained by the feeding system of the cylinders, numerous operating parameters of the motor are measurable.

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To test the diesel engines, a device is known. This device secures the input signal with the pressure sensors to be installed in the pipelines supplying the fuel. The pressure sensor is generally placed on the carburetor because the effects developed by the pipe in front of the engine do not distort the results of the measurement. Palis a measurement of the beginning of the promotion is necessary, it is expedient to determine the place of the Dr-uckfühlers in the injection pump. The device signals the measurement results through an oscilloscope or other units. The uniform time distribution is therefore necessary so that the signals obtained from the individual cylinders can be signaled in the appropriate order of the cylinder on the oscilloscope. One possible type of time distribution is e.g. the adaptation of a disc to the synchronous motor axis, in which along a circular line with a certain radius one of the number of cylinders of the engine to be tested number of holes are provided. At the front of the disk is a light source, behind a photodiode in a corresponding radius circle of the holes removal. The illumination of the disc results in passing through the perforated part of the disc depending on a signal · These signals are the oscilloscope * as sync signals.

A disadvantage of the synchronous motor based synchronization is that the inertia of the motor is relatively high. It can not follow the speed variations of the motor to be tested fast enough. During operation, the speed of the diesel engine generally has a swing of 5 % . In the case of the given solution, this means so much that - as the speed of the motor fluctuates more or less always - the image obtained on the oscilloscope screen moves, that is to say in the case of the present invention. h · blurs; As a result, the reading is difficult.

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flat on a similar principle, the other diagnostic devices that are generally suitable for testing either diesel engines or gasoline engines, and are unable to perform the testing of the two engine types with the same equipment ·

Object of the invention

The aim of the invention is to avoid the above disadvantages.

Presentation of the ffesens of the invention

The invention has for its object to provide a device for measuring operating parameters of gasoline and diesel engines, which for the exact, the speed changes immediately following measurements of Betriebsparanieter as Ventilsteuerungswinkei, Before sprit ζ wink el, measuring the Spritszeitdauer, characteristics of the beginning of the conveyor etc. of the diesel engines and, if necessary, the gasoline engines is suitable ·

The invention is based on the finding that the synchronous motor can be effectively converted with an appropriately designed for performing the given task electronic circuit »This solution can also be advantageous from the point of view of digital data processing»

On the basis of the above finding, in order to achieve the goal, such an apparatus has been provided which has an input amplifier adaptable to the engine, a switching circuit, a time distribution unit synchronized with the engine and a signaling evaluation unit, and according to the invention the time distribution unit between the switching circuit and the signaling

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Evaluation unit is turned on digital synchronizer is formed.

In an advantageous embodiment of the device according to the invention, the time distribution unit includes a strooikre to the switching is connected control circuit and signal shaper, a row unit, which consists of a first counter, a memory and a comparator and is in two-way communication with the control circuit, with its output to the Signalformer is connected, an oscillator which is connected by a second counter mit.einst comparator or with a divider «, Furthermore, the device comprises a coupled to the control circuit, the signal shaper and the Ieiler cylinder number plate, wherein the control circuit is supplied to the second counter An advantageous solution is also the one in which the output, the time divider unit, is connected to a series circuit consisting of a delay unit, logic circuit and a signal processor. The output of the signal conditioner is fed to the input of the signaling evaluation unit.

The device can preferably be supplemented with a stroboscope and with a unit which ensures a correct-angle measurement "

Palis the input amplifier of the device according to the invention consists of various, connectable to the diesel engine and the gasoline engine amplifiers, it may be appropriate not the amplifier unit as part of the switching circuit - formed within the body of the device - but to arrange the engine.

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The retarder is connected to the time divider unit's signal conditioner, while the logic circuit is connected to the cylinder number adjuster through the control circuit «

An output of the circuit is supplied both to the signal conditioner and to the signaling evaluation unit. The circuit is further connected to a number-of-cylinders selection unit.

The first counter is provided with a lock output supplied to the control circuit, which in turn is connected to the last output of the counter chain of the first counter.

The signaling evaluation unit contains an oscilloscope and is provided with digital, data processing circuits and digital signals.

With the aid of the device according to the invention, the operating parameters of the internal combustion engines can be measured with high accuracy with reliable tracking of the rotational speed for any number of cylinders. The accuracy and reliability of the measurement results are better than in known devices.

Exemplary embodiment

Laughing the device according to the invention will be explained in more detail with reference to Äasführungsbeispielen with reference to the accompanying drawings. In the drawing shows

the pig. the circuit arrangement of the device according to the invention.

The main units of the device according to the invention (FIG. 1) are: input amplifier G, circuit 30;

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The input amplifier G is expediently divided into two parts, has a first amplifier 28 to be arranged on a diesel engine and a second amplifier 29 connected to a gasoline engine. The inputs of the first amplifier 28 are the pressure sensors which are inserted in the high pressure lines connecting the injection pump and the injector of the diesel engine. Depending on whether they are switched on at the injection nozzle or at the injection pump, the device is suitable for testing the entire delivery process or the Pörderanfangsprozesses «The second amplifier 29 is at the breaker of the gasoline engine, to the center of the high-voltage distributor and to the first cylinder conductive ignition line connected »

The time divider unit A is designed as a digital synchronizer, to the operation of which no moving element is necessary. With its input, it is adapted to the circuit 30 »one of its outputs is here, the other directed to the signaling evaluation unit B» The signals are supplied from the circuit 30 in the time divider unit A control circuit 3. »The control circuit 3 is connected to a first counter 7 and a signal conditioner 4 in double-sided connection. Each output is connected to a memory 8 and a second counter 10. In the unit, an oscillator generates 15 pulses of high stability. Further, a cylinder number plate 13 is provided, which is set depending on the number of cylinders of the engine to be tested (generally at a cylinder number of one to eight, but exists if necessary) the possibility of considering a higher number of cylinders) The further output of the first counter 7 is connected through a memory 8 to a comparator 9,

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which is also connected to the output of the second counter 10. The cylinder number plate 13 and the oscillator 15 are each guided with one of their outputs to a divider 14 whose output is connected to the first counter 7. The oscillator 15 is coupled to the second counter 10, the comparator 9 to the signal converter 4. The first counter 7 is expediently provided with such a blocking output, which is connected to the control circuit 3 and is connected within the first counter 7 to the last output of the counting chain. "

The signaling evaluation unit 3 of the apparatus may be designed according to a conventional oscilloscope, but if necessary there is a possibility according to which it may be suitable for evaluating the measured and produced signals with the aid of the known digital data processing circuits or display. Of course, other analogue display methods can be used in addition to the oscilloscope »

The device is suitable in the described training for easy evaluation and display of the signals taken from the engine. It can be provided with a subsequent to the circuit 30 Zylinderzahlauswahleinheit 31, which is adapted to the fact that arrive in the signaling evaluation unit B only belonging to a certain number of cylinders signals.

A better evaluation of the signals to be tested can be achieved if a series connection is used which consists of a delay 16 connected to the output of the signal shaper 4, of a logic circuit 17 and of a signal shaper 18. In the series circuit is the

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logic circuit 17 connected to the output of the control circuit. This unit is suitable for appropriate deceleration and thus ensures that the signal or series of signals associated with the given cylinder should be practically full length, even before the pressure or signal is formed. The output of the signal shaper 18 is the corresponding output of the circuit 30 together to the signal-evaluating unit B ·

To an output of the circuit 30, preferably, a serial link can be connected, which consists of a retarder 20, a stroboscope 21, from a also connected to the output of the circuit 30 vorseichenwählenden logic circuit 22 and a protractor 23. This also makes possible the correct-angle measurement of the angles associated with the various processes taking place in the engine. In general, the diesel engines, their more modern types in any case, are provided with top-dead-center TDCs. Their signals carry a matching stage 32 into and through the circuit 30 Serial element # This makes the automatic correct-angle measurement of the angle of the beginning of the diesel engine belonging to the angle and the projection angle possible. The device can also be equipped in the form of a replaceable accessory with a top dead center which is adapted to the first cylinder.

The device according to the invention works as follows

The corresponding elements of the input amplifier C are assigned to the corresponding points of the combustion

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adapted motors. As described, they are connected to the lines feeding the fuel into the engine, and to the gasoline engine, to the breaker hammer, to the first ignition line and to the middle of the high-voltage divider «. The active elements of the input amplifier C can be arranged next to the motor. or if desired they can be inserted into the housing of the device. The signals of the input amplifier C enter the switching circuit 30. At the same time, before the start of the measurement, the cylinder number plate 13 is set according to the desired cylinder numbers. In the conventional design, testing of at most 8 cylinders is necessary, but there is the possibility of such a design suitable for testing an engine which even operates on twelve or more cylinders. The circuit 30 selects a synchronizing signal from the signal received at the input amplifier C. The synchronizing signal is generally generated according to a specific value of the signal belonging to a selected cylinder. The selection of the synchronizing signal takes place during the supply in each cycle, thus in the case of a four-stroke engine after every two revolutions of the engine. When the synchronous signal appears, the control circuit 3 overwrites the content of the first counter 7 in the memory 8. Thereafter, the first and the second counter 7 and 10 are set to Hull · The divider 14 divides the signal of the oscillator 15 in accordance with the number set at the cylinder number plate 13 At the same time, the undivided signal of the oscillator enters the second counter 10, which accordingly takes up the value set on the cylinder number controller 13 more quickly η times. The comparator 9 compares the current content

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of the second counter 10 with the value stored in the memory 8, and if the two values are equal, it turns on the signal conditioner 4, which sets the second counter 10 to Hull by the control circuit 3. Thereafter, the counting of the second counter 10 starts again. On the same side with the sheath passes through the signal shaper 4, an output signal to the circuit 30, lach a synchronizing signal can only follow η output signals from the signal shaper 4 in the circuit 30. If z, B. because of the large variation in the speed of the motor, the output of several erase signals, then - this detects the signal shaper 4 - locks the control circuit after reaching the Impulszhai η the further signal output until the appearance of a new sync signal, This solution allows also under changeable conditions, d. h * when the time of the motor axis revolutions changes rapidly, the same number of cylinders corresponding to the time duration between the two synchronizing signals can always be distributed. At the same time, it is also ensured that the change of the time duration can already be considered in the cycle following the speed change,

If the duration of the pause between the sync signals becomes too large, eg, the engine is stopped, the first counter 7 is charged. Then forces the counter state registering last output of the counter chain of the first counter 7 »appropriately through the lockout output, the control circuit 3 for actuation, which causes the setting of the further count of the first counter 7 and the sync signal output of the signal conditioner 4.

By the circuit 30, the measuring signals taken from the engine with the synchronizing signals come together on the Signali-

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Sierungs-Äuswertungseinheit B. In the circuit 30, such a logic unit can be formed, which according to the status of Zylinderzahlauswählleinheit 31, the signaling evaluation unit B prohibits the transfer of the signals, except for the cylinder with a set running number associated signals, Of course it comes also here in a known manner for the formation of the sync signals ·

The circuit 30 is designed in such a way that the signals of the time divider unit A also enter the input amplifier C, whereby the effective control of the measuring units belonging to the individual cylinders of the pressure sensors can be ensured. This solution is therefore expedient because thus the corresponding measurement signals of the individual cylinders of the engine in time sequence of operation decreased γ / ground, without the signals interfere or falsify each other, for. B. superimpose each other. In other words, the first amplifier 28 operates in a time divider system. From the signal conditioner 4, the signals can enter the delay 16, which can cause a large maximum delay, which lasts until the next signal appears. The control circuit 3 controls the position of the cylinder count controller This is necessary, therefore, so that the delay before the synchronizing signal, ie after the signal of the last cylinder, can be carried out in the same way. The delay can cause the process being tested, for example, to be checked. B, signal associated with pressure change usually be checked in full length. The delayed synchronization is also useful because it allows the occurring phase errors of the individual signals can also be evaluated · The sync signals are very accurate

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divided; For example, the phase relationships z, B. at the osailloscope can be easily observed or evaluated digitally. "In the given circuit, however, the signal belonging to the first cylinder plays an important role. In order for the 'displacement test is enabled, the control circuit 3 must be designed so that it not only shuts off the output of the signal shaper 4, after he notes the achievement of the number of cylinders, but at the same time the logic circuit 17 turns off so that these the last cylinder performs appropriate contact. The succeeding first delayed signal is sampled by the logic circuit 17 as the offset sync signal associated with the first cylinder. Since this sync signal was formed out of the signal corresponding to the last cylinder, it overruns the start of measurement of the signal under test, e.g. The signal shaper 18 fulfills essentially exactly the same task as the shaper 4 of the time divider unit A. With this solution it can be achieved that a synchronizing signal arranged at a corresponding time interval can be inserted before each signal belonging to the cylinder. The sync signal is for display as well as digital as well as analog processing. Since the delay can not last longer than the time between successive signals, despite the series circuit including the retarder 16, there can be no error in the order. The series connection is suitable for the operation of the input amplifier C by the circuit 30 *

The puncture of the retarder 20 and of the stroboscope 21 are practically the same as in the other devices of the motor vehicle diagnostics, but the retarder 20 is with the sign-selecting logical

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Circuit 22 is connected, which determines the sign for angle measurement due to the signal obtained from the circuit 30. This is also a device of known construction · Due to the output signal of the sign-selecting logic circuit 22, the protractor 23 ensures a correct-sign angle measurement. This option is particularly advantageous if the engine is equipped with upper dead center.

Thanks to its universal construction, the device according to the invention is suitable for highly accurate, good and fast operating conditions measurement of operating parameters of gasoline and diesel engines.

Claims (10)

238 37 7 O -H- 13.06.1982 60 617/13 Right to a claim for a claim. A device for measuring operating parameters of internal combustion engines, comprising an input amplifier adaptable to the internal combustion engine, a switching circuit, a time distribution unit synchronized with the internal combustion engine and a signal evaluating unit, characterized in that the time distribution unit (A) is connected between the switching circuit (30) and the signal-evaluating unit (B) is formed switched digital synchronizer. 2. A device according to item 1, characterized in that the time distribution unit (A) has a control circuit (3) and signal shaper (4) _} connected to the circuit (30), a series unit consisting of a first counting device (7), a memory (8 ), a comparator (9) is connected to the control circuit (3) in 'two-way connection is connected with its output to the signal shaper (4), an oscillator (15) by the second counter (10) to the comparator (9) or the divider (14) is connected and arranged on the control circuit (3), signal shaper (4) and divider (14) cylinder number divider (13), wherein "the control circuit (3) with the second counter (10 ) » Device according to points 1 or 2, characterized in that the time distribution unit (A) is connected to one of its outputs with a delay (16) and with a logic circuit (17) which - connected in series - to the input of Signalformers (18) is passed and the output of the signal shaper (18) is fed to the input of the Signali ¬ tion evaluation unit (B) » 238 3 7 7 O - ¹⁵ "18.06.1982 60 617/13 4 · Device according to one of the items 2 or 3 _9, characterized in that the retarder (16) is connected to the signal former (4) of the time divider unit (A), whereas the logic circuit (17) is connected to the cylinder counter by the control circuit (3) is 5. Device according to one of the items 3 or 4, characterized in that an output of the circuit (30) is fed to the signal conditioner (18) and to the signaling evaluation unit (B) » 6. Device according to one of the items 1 to 5 ₉ characterized in that the output of the circuit (30) by a retarder (20) to a stroboscope (21) or to a sign-selecting logic circuit (22) and to a "protractor ( 23) is connected, where the sign-selecting logic circuit (22) is supplied to another output of the circuit (30). Device according to one of the items 1 to 6, characterized in that the circuit (30) is connected to a cylinder number selector (31) " 8. A device according to any one of items 1 to 7, characterized in that the first counter (7) is provided with a lock output supplied to the control circuit (3), the lock output being connected to the last output of the counter chain of the first counter (7) is " 9 · Device according to one of the points 1 bia 8, characterized in that the signaling evaluation unit (3) comprises an oscilloscope. - ¹⁶ - 18.06.1982 60 617/13 Device according to one of the points 1 to 8, characterized in that the signaling evaluation unit (B) is provided with digital data processing circuits and digital signals. For this 1 page drawings