US3823606A - Measuring internal combustion motor cylinder compression - Google Patents

Measuring internal combustion motor cylinder compression Download PDF

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Publication number
US3823606A
US3823606A US00332657A US33265773A US3823606A US 3823606 A US3823606 A US 3823606A US 00332657 A US00332657 A US 00332657A US 33265773 A US33265773 A US 33265773A US 3823606 A US3823606 A US 3823606A
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ignition
pulse
counter
coupled
stages
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A Maringer
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Siemens AG
Siemens Corp
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Siemens Corp
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L23/00—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid
    • G01L23/08—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid operated electrically
    • G01L23/085—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid operated electrically by measuring fluctuations of starter motor current or of battery voltage

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  • ABSTRACT To obtain an electrical measurement of the compression of an internal-combustion reciprocating-piston engine via the current taken by an electric starter, during a first cycle of electrical ignition sequences successive peak values of the starter current are stored in adjacent cells of an analog memory in the rhythm of the closing flanks of the distributor breaker point output pulses with the ignition coil short-circuited.
  • the first ignition pulse of a given cylinder is then fed into the first stage of a ring counter having a number of stages corresponding to the number of cylinders of the engine and assigned in reverse order to the cells of an analog memory, and is shifted along in the rhythm of the closing flanks to the end of a third cycle of ignition sequences.
  • the peak values of the starter current stored in the analog memory are called up serially via a relay selector by means of timing pulses of a timing generator which are fed to 1 the ring counter via a switching network which is programmed according to the ignition sequence applicable to the engine.
  • This invention involves the electrical measurement of the cylinder compressions of such an engine via the current taken by its electric starter.
  • the measured compression values are obtained in the firing sequence set for each motor type, but without fixation of a first cylinder for a measurement cycle.
  • the measuring described is based on the fact that during the starting process the starter must supply more work as the gas and/or vapor mixture in a cylinder is being compressed.
  • the increase in energy results in an increased instantaneous starter current, the magnitude of which is proportional to the compression of the respective cylinder in which the compression takes place.
  • the starter current consists therefore of a DC component which serves to overcome the friction in the uniformly moved parts, and an AC component which corresponds to the compression as it increases to a peak value and then decreases. This AC component can be filtered out from the starter current and be processed.
  • the peak values of the starter current stored in the analog memory are called up serially via the relay selector by means of timing pulses of a timing generator which are fed to the ring counter via a switching network which is programmed according to the firing sequence applicable to the engine.
  • the programmed switching network may be unnecessary and the ring counter can be advanced directly by the timing pulses of a timing generator.
  • the compression values which are storedin the cells of the analog memory according to the firing sequence, but with the starting cylinder undefined, can be taken in this manner from the memory cells in the order of the cylinder numbering and evaluated.
  • the compression value of a given cylinder can, for instance, be recorded in any memory cell, but in the subsequent callup it is nevertheless picked up in the desired order.
  • the switching network which is programmed according to the firing sequence applicable in each case,
  • An arrangement for carrying out the method contains advantageously n successive memory cells of an analog memory for voltages proportional to the compression, which via an access or hold input each are connected with outputs of a ring counter which has (n i, when n the number of cylinders) stages and is controlled by the interrupter, or ignition breaker points, in such a manner that the output of the first stage is connected to the access input of the first memory cell and the outputs of all following stages are connected to the respective hold inputs of the preceding and to the access inputs of the following cells.
  • FIGURE of the drawings illustrates schematically a preferred embodiment of the invention.
  • FIG. 1 DESCRIPTION OF THE PREFERRED EMBODIMENT
  • the leftbreaker points are fed to the circuit via an input pulse shaper ESl.
  • the circuit Via a pulse shaper B52 in the right-hand upper section of the FIGURE, the circuit is connected with an ignition pulse transmitter Z, which iscoupled to the ignition wire of a given cylinder, shown as being with the engine to be measured via three inputs.
  • Interrupter pulses from the cylinder 1 of a four cylinder engine.
  • An analog memory SP is finally connected via an input amplifier V with the ends of a ground strap MB, which connects one of the brushes of the starter motor M with ground.
  • the ground strap serves as a starter current measuring resistor.
  • E1 represents a signal input to which at the beginning of a storing operation a logical 1 signal is applied. It is connected with an input terminal of a bistable flipflop which is formed by two NAND gates G1 and G2. The other input terminal of this bistable flipflop is connected with the signal input E2 via an amplifier T1.
  • the input E1 is furthermore connected with one input terminal of a'NAND gate G3, its other input terminal being tied to the input E3. To this input is fed a starting pulse, which imparts a logical signal to the input E3.
  • the input E3 is further connected with an input terminal of a second bistable flipflop consisting of the NAND gates G7 and G8.
  • this bistable flipflop To the other input of this bistable flipflop is connected the input E4, to which for interrogating (calling up) the stored compression values a logical 1 potential must be applied.
  • the output of the NAND gate G3 is connected via an inverter ll with the resetting inputs of a counter Z1 and of two ring counters R21 and RZ2, respectively.
  • the pulse shaper B81 is connected on the input side with an interrupter, or breaker point, contact U of the ignition coil ZS of the engine. In shunt with the interrupter contact is a low resistance 1 in'series with or controlled by a relay contact r.
  • the relay contact r is actuated by a relay solenoid R which is energized via a NAND gate G4 from the input E1.
  • the inverting output of the pulse shaper B81 is connected with the clock input of a flipflop FFl, the D input and the resetting input of which are connected to the output of the bistable flipflop consisting of the NAND gates G1 and G2.
  • the output of the pulse shaper B51 is further connected via an inverter [3 with the clock inputs of the ring counter R21 and the counter Z1. Via a further inverter I4 in series with an inverter 16, the clock input of the ring counter RZ2 is also connected with the output of the inverter I3.
  • the ring counter RZl is a five-stage ring counter.
  • the output of the first stage of this ring counter is connected with an access input S of the first memory cell of the memory SP.
  • the outputs of all following stages of the ring counter RZl are connected to the respective hold inputs of the preceding and to access inputs S of the succeeding cells of the memory SP.
  • the fifth stage of the ring counter R21 is also connected via an inverter 17 to the second input of the NAND gate G4 which excites the relay solenoid R.
  • Outputs of the memory stages are connected via contacts a to d with a lines which leads to an elevator, not specifically shown, for the stored analog values, for instance, to a voltage-frequency converter.
  • the previously mentioned second bistable flipflop consisting of the NAND gates G7 and G8 connects the output belonging to the NAND stage G7 with the reset input of the counter Z2.
  • the clock input of this counter is, as will be remembered, connected with the output of the pulse shaper ESl via the inverters I3 and I4.
  • This input is furthermore connected via a NAND gate G9 with the Z output of a flipflop FF2, and via the second input of the NAND gate G9 with the output of a clock generator TG which is also connected to the clock input of the flipflop FF2.
  • the output, associated with the NAND gate G8, of the second bistable flipflop is connected with a D input and also with the resetting input of the flipflop FF2.
  • a NAND gate G10 With a total of .five inputs. Four of these inputs can be connected via programmable double-pole switches PSW alternatingly to mutually inverse outputs of the four stages of the counter Z2.
  • a fifth input. of the NAND gate G10 is connected to ground via a capacitor 4 and to a positive potential via a resistor S. This input of the NAND gate G10 is further connected, via an inverter 15, with the line leading to the clock input of the counter Z2.
  • the first bistable circuit consisting of the gates G1 and G2 is put in the ready position.
  • the NAND gates G3 and G4 are also put in the enabled or ready position.
  • a start pulse is transmitted from the input E3 to reset via the gate G3 and the inverter I1, the two ring counters RZl, RZ2 and the counter Z1.
  • the circuit is thereby placed in the starting position.
  • the relay R solenoid is energized via the inverter 17 and the NAND gate G4 by the signal at E1, so that the low resistance 1 is placed via the contacts r of the relay, in parallel with the interrupter contact U, or breaker points, of the ignition system of the engine.
  • the engine is thereby prevented from starting when the starter M is operated Subsequently, the starter M is operated and after a warmup time of about 3 seconds, a second start pulse is applied to the input E2.
  • This pulse sets the bistable flipflop formed by the NAND gates G1 and G2. It thereby enables the flipflop FF 1.
  • This flipflop synchronizes the circuit to the correct phase of the interrupter contact pulses normalized by means of the pulse shaper ESl.
  • the ring counters R21 and RZ2 are advanced by the closing flanks of the interrupter contact pulses.
  • the memory cells of the analog memory SP are peak-value storage devices and must therefore be released for access only prior to the occurrence of the voltage peaks to be stored, which arrive via the amplifier V. The release takes place via the access inputs S of the memory cells. If a voltage peak is stored, the hold input H of the memory cell just addressed is activated via the respective output of the ring counter RZl after the next closing flank of the interrupter contact.
  • the first synchronized closing flank of the interrupter contact pulse sets the first stage of the ring counter R21 and thereby activates the access input of the first memory cell.
  • This memory cell takes in the peak of the half-wave of the AC compo nents of the starter current that follows the closing flank.
  • the next closing flank sets the second stage of the ring counter R21 and thereby activates the hold input H of the first memory cell and the access input S of the second memory cell, which is thereby open for the next voltage peak.
  • the hold input of the fourth memory cell is activated. With that, the analog values of the compressionproportional voltage are stored.
  • the output signal of the fifth stage of the ring counter RZl deenergizes the solenoid R, via the inverter 17 and the NAND gate G4.
  • the contacts r open and the ignition can now function without impediment when the interrupter contact opening following its fifth closing takes place. In other words, the fifth circuit breaker actionfires the first cylinder compression measured.
  • the compression values for the cylinders l of the engine are stored in numerical order in the cells of the analog memory SP having the same numerical order, so the cylinder first compression measured must now be ignited with the first spark in the following or active ignition sequence cycle, the interrupter contact now no longer being shortcircuited.
  • the ignition pulse transmitter Z which taps the ignition wire for this chosen cylinder, provides a voltage pulse which sets the first stage of the ring counter RZ2 via the pulse shaper ES2. With the following sixth closing flank of the pulses from the pulse shaper ESl, this voltage pulse, stored initially in the first stage of the ring counter RZ2, is transferred to the second stage of the ring counter RZ2. Each further closing flank of the pulses from ESl shifts this information, identifying the chosen cylinder, by one stage. From the fourth stage the first stage is again setvia a feedback path.
  • the fourth stage in the ring counter RZ2 is loaded again. Simultaneously the counter Z1 has reached the count 12 and resets the first bistable circuit, which consists of the NAND gates G1 and G2, via the NAND gate G5. Thereby the flipflop FF 1 is also reset. Starting from the Q output of the latter, all interrupter or breaker point contact pulses transmitted by ESl through the inverter [3,are' blocked via the inverter I2. The correlation information stored in the ring counter RZ2 is therefore preserved, as also the NAND gate G6is blocked by the 0 output of the flipflop FF 1 and no longer receives pulses from the ignition line of the cylinder 1.
  • the pulse shaper ES2 transmits the ignition pulse of this cylinder only after the eighth closing flank.
  • the ignition pulse information is shifted via the second, third, fourth stage of the ring counter RZ2 to the latters first stage.
  • the first stage is associated, as will be seen, with the fourth memory cell, so that the correlation is correct.
  • the fourth stage of the ring counter RZ2 must be flipped.
  • the value stored for the cylinder 2 is to be read out as the next value, which is stored in the fourth memory cell of the analog memory SP.
  • the ring counter RZ2 must be shifted by one pulse.
  • first stage is loaded and the relay D isenergized.
  • the content of the fourth memory cell is fed to the bus via the contact d.
  • the shift pulses for the ring counter which cause the interrogation (call-up) of the analog values following the first one, are generated in the interrogation control section.
  • a step must be programmed in the programmed switching circuit PSW, which is set by the double-throw contacts at the inverted and noninverted outputs of the counter Z2.
  • the first switch at the left is positioned at the left-hand stop.
  • the input E4 furthermore, the program lnterrogate Memory, is selected.
  • the second bistable flipflop consisting of the NAND gates G7 and G8 is enabled.
  • this bistable circuit flips and releases theflipflop F F2, which synchronizes the interrogation control with the pulse sequenceof the timing (clock) pulse generator TG.
  • the NAND gate G9 has transmitted a clock pulse to the counter Z2 and to the ring counter RZ2
  • all inputs at the NAND gate G10 are at logical 1 potential. (This is delayed via the inverter I5).
  • the amplifier T2 thereupon resets the flipflop F F2 and the bistable flipflop consisting of the NAND gates G7 and G8.
  • the first stage in the ring counter RZ2 is tripped and the fourth storage cell with the analog value for cylinder 2, stored therein, is interrogated.
  • the value to be called up next is that for cylinder 3. According to the present example, this value is stored in the second memory cell. To select this memory cell, two shift pulses must be counted into the ring counter RZ2. To this end, the second contact from the left in the programmed switching circuit PSW is brought to the left-hand stop.
  • the interrogation control transmits two timing pulses after the start pulse.
  • the analog value stored for cylinder 4 is to be called up.
  • This value is stored in the third memory cell.
  • the second stage in the ring counter RZ2 must therefore be tripped. This, however, requires three shift pulses from the interrogation control unit, as the third stage was previously'tripped.
  • The-position of the programmed switching circuit PSW required therefor can be seen in the FIGURE.
  • all values can therefore be interrogated in any desired order, regardless of the memory cell in which the value for the given cylinder, which in the example is cylinder 1, is found.
  • Important for the interrogation is the firing sequence, which corresponds to the sequence of storing.
  • the method provides still further degrees of freedom.
  • the ignition pulse signal via the pulse shaper BS2 need not be derived from the ignition wire to the cylinder 1. It is completely optional concerning which of the cylinders is to be designated. All shifts that become necessary through the selection of a particular cylinder for furnishing the ignition pulse can be performed by means of the interrogation control unit.
  • An apparatus for measuring the cylinder compression of an internal combustion, reciprocating piston type engine including an electric starting motor, and an electric ignition system which is controlled by breaker points and is timed according to the firing order of the cylinders, the apparatus comprising:
  • a pulse counter coupled to said breaker points, having a series of stages, the number of which corresponds to the number of cylinders of the engine, and which are assigned in reverse serial order to said analog memory cells, including a feedback connection between a last and a first stage of said series of stages;
  • said pulse counter for generating a set pulse in response to a selected ignition voltage pulse generated during a second ignition cycle for firing a predetermined cylinder of the engine, said set pulse being transmitted to said pulse counter for setting the first stage of said counter and storing said set pulse therein, the ignition pulses generated by said breaker points, subsequent to the generation of said set pulse and through a third ignition cycle, shifting said set pulse stored in said first stage successively through said stages so that said set pulse is stored at the end of said third ignition cycle in a stage of said counter which is assigned to the memory cell in which the peak current value for said predetermined cylinder is stored;
  • said current value read out means includes a relay selector comprising .a plurality of relays, the coils of which are coupled to selected stages of said pulse counter and the contact switches of which are coupled to corresponding ones of said memory cells in said reverse serial order.
  • said current value read out means reads out said current values from said memory cells in successive order starting with the memory cell in which the peak current value for said predetermined cylinder is stored, and includes a timing pulse generator coupled to said pulse counter for shifting said set pulse to successive stages of said counter and thereby activating said relay contact switches in successive order.
  • said current value read out means includes a timing pulse generator coupled to said pulse counter for generating shift pulses for shifting said set pulse through said counter stages, and a programmable switching circuit, coupled to said timing pulse generator, for selectively transmit-' ting said shift pulses to said pulse counter and shifting said set pulse through said counter stages so as to activate said relay switches in said predetermined order.
  • said peak current value storing means includes n analog memory cells each having an access and hold input
  • said current measuring means comprises a pulse counter, having n 1 serial stages, coupled to said breaker points, the output of a first of said n 1 stages being coupled to the acess input of a corresponding first of said memory cells, and the output of each successive one of said n 1 stages up to and including the nthstage being coupled to the respective hold input of said memory cell preceding the memory cell corresponding thereto.
  • a method for the measurement of the cylinder compression of an internal combustion, reciprocating piston type engine including an electric starting motor and an electric ignition system which is controlled by breaker points and is timed according to the firing order of the cylinders, comprising the steps of:

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)
  • Ignition Installations For Internal Combustion Engines (AREA)
  • Measuring Fluid Pressure (AREA)
  • Testing Of Engines (AREA)
US00332657A 1972-02-18 1973-02-15 Measuring internal combustion motor cylinder compression Expired - Lifetime US3823606A (en)

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DE2207789A DE2207789C3 (de) 1972-02-18 1972-02-18 Schaltungsanordnung für die elektrische Messung der Kompression von Kolbenmotoren

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3938378A (en) * 1974-08-26 1976-02-17 The United States Of America As Represented By The Secretary Of The Army Engine compression testing
US3968425A (en) * 1975-06-30 1976-07-06 Rca Corporation Measuring ignition timing using starter current
US3984760A (en) * 1973-10-08 1976-10-05 Siemens Aktiengesellschaft Measurement of the synchronization of a combustion engine
US4050296A (en) * 1976-05-07 1977-09-27 United Technologies Corporation Relative compression of an internal combustion engine
US4144746A (en) * 1977-03-02 1979-03-20 Siemens Aktiengesellschaft Method for determining a measurement value proportional to the compression of an internal combustion engine
DE4337720A1 (de) * 1993-11-05 1995-05-18 Bayerische Motoren Werke Ag Vorrichtung zur Auswertung der Verdichtung eines mehrzylindrigen Verbrennungsmotors
US5945593A (en) * 1996-08-16 1999-08-31 Aft Atlas Fahrzeugtechnik Gmbh Method for selectively testing for leakage of combustion chambers of cylinders of internal combustion engines

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3105331C2 (de) * 1981-02-13 1986-10-23 Siemens AG, 1000 Berlin und 8000 München Verfahren zum Vergleich von an einer leer laufenden Dieselmaschine gemessenen Maschinenzykluszeiten
AT387463B (de) * 1986-11-25 1989-01-25 Avl Verbrennungskraft Messtech Diagnoseverfahren fuer mehrzylindrige brennkraftmaschinen und einrichtung zur durchfuehrung des verfahrens

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3100988A (en) * 1956-07-09 1963-08-20 Auto Test Inc Apparatus for measuring compression of internal combustion engines
US3186218A (en) * 1962-04-09 1965-06-01 Startron Corp Performance testing device and method for internal combustion engines
US3389599A (en) * 1964-06-01 1968-06-25 Beale Evelyn Stewart Lansdowne Engine-cylinder pressure indicators
US3421367A (en) * 1966-07-05 1969-01-14 Mobil Oil Corp Compression testing method and apparatus
US3543572A (en) * 1968-08-19 1970-12-01 Gen Motors Corp Ignition suppression system
US3625054A (en) * 1969-11-20 1971-12-07 Phillips Petroleum Co Engine analyzer to measure mean effective pressure of a four cycle internal combustion engine

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3100988A (en) * 1956-07-09 1963-08-20 Auto Test Inc Apparatus for measuring compression of internal combustion engines
US3186218A (en) * 1962-04-09 1965-06-01 Startron Corp Performance testing device and method for internal combustion engines
US3389599A (en) * 1964-06-01 1968-06-25 Beale Evelyn Stewart Lansdowne Engine-cylinder pressure indicators
US3421367A (en) * 1966-07-05 1969-01-14 Mobil Oil Corp Compression testing method and apparatus
US3543572A (en) * 1968-08-19 1970-12-01 Gen Motors Corp Ignition suppression system
US3625054A (en) * 1969-11-20 1971-12-07 Phillips Petroleum Co Engine analyzer to measure mean effective pressure of a four cycle internal combustion engine

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3984760A (en) * 1973-10-08 1976-10-05 Siemens Aktiengesellschaft Measurement of the synchronization of a combustion engine
US3938378A (en) * 1974-08-26 1976-02-17 The United States Of America As Represented By The Secretary Of The Army Engine compression testing
US3968425A (en) * 1975-06-30 1976-07-06 Rca Corporation Measuring ignition timing using starter current
US4050296A (en) * 1976-05-07 1977-09-27 United Technologies Corporation Relative compression of an internal combustion engine
US4144746A (en) * 1977-03-02 1979-03-20 Siemens Aktiengesellschaft Method for determining a measurement value proportional to the compression of an internal combustion engine
DE4337720A1 (de) * 1993-11-05 1995-05-18 Bayerische Motoren Werke Ag Vorrichtung zur Auswertung der Verdichtung eines mehrzylindrigen Verbrennungsmotors
US5945593A (en) * 1996-08-16 1999-08-31 Aft Atlas Fahrzeugtechnik Gmbh Method for selectively testing for leakage of combustion chambers of cylinders of internal combustion engines

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DE2207789A1 (de) 1972-08-30
DE2207789C3 (de) 1975-04-10
ZA73975B (en) 1973-11-28
JPS4890779A (enrdf_load_html_response) 1973-11-27
JPS5936225B2 (ja) 1984-09-03
DE2207789B2 (de) 1974-08-15

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