Analyzer for multi-cylinder internal combustion engine having means for identifying individual cylinders

Abstract

An analyzer for multicylinder internal combustion engines in which there is an electronic counter triggered by pulses from the ignition system and normally reset by the firing voltage applied to any of selected spark plugs in which the electronic counter has a plurality of stages corresponding to the number of cylinders in the engine and in which there is an electrical testing means adapted to be operated by the output signal of any one or more stages of the counter to produce an electrical effect for analyzing the performance of the engine.

I claim as my invention: 
     
       1. An analyzer for multicylinder internal combustion engines of the type having an electrical igniter for each cylinder, electrical ignition pulse generating means and a distributor for sequentially applying each generated ignition pulse to the igniter of a different cylinder in a predetermined sequence, said analyzer being usable with engines having different numbers of cylinders and comprising: a first coupling circuit for producing discrete pulses at its output coincident with the application thereto of discrete input signals,   a first connector for coupling the input of said first coupling circuit to the electrical ignition pulse generator to receive signals at the frequency of generation of said ignition pulses,   a second coupling circuit producing discrete pulses at its output coincident to the application thereto of discrete input signals,   a second connector for coupling the input of the second coupling circuit to the igniter of an individual cylinder to receive signals at the frequency of firing of said cylinder,   a pulse counter having a plurality of stages corresponding to the maximum number of cylinders of any engine to be tested, each stage having an output connection, said counter having a first input connection and means operative upon successive pulses being applied to said input connection to cause an output signal to appear successively at the output connection of successive stages, said counter having a second intput connection, and means operative when a signal is applied to said second input connection to reset said counter to cause the output signal to appear at the output connection of the first stage regardless of whether an output signal has yet appeared at the output connections of all of said stages,   means for connecting said first input connection to the output of said first coupling circuit to cause said output signal to advance at the frequency of generation of said ignition pulses from one stage to the next stage,   means for connecting said second input connection to the output of said second coupling circuit so that the counter is reset each time that an ignition pulse would normally be applied to the igniter of the individual cylinder to which the input of said second coupling circuit is connected,   electrical testing means adapted to be controlled by the output signal of said counter and effective when a signal is applied thereto to produce an electrical effect useful in the analysis of the performance of the engine,   and switching means for selectively connecting said electrical testing means to the output connection of any one selected stage of said counter so that said testing means is operative to produce such an electrical effect concurrently with the period during which the generated pulse would normally be applied to the igniter of any selected cylinder.   
     
     
       2. The analyzer of claim 1 in which the electrical testing means is effective to indicate the voltage existing across any selected igniter. 
     
     
       3. The analyzer of claim 1 in which the electrical testing means may selectively indicate either the voltage across any selected igniter or the average voltage across all of the igniters. 
     
     
       4. The analyzer of claim 1 for use with an engine in which the electrical ignition pulse generating means comprises an ignition switch which is opened and closed for periods of time in connection with the generation of an ignition pulse and in which analyzer the electrical testing means is effective to indicate the "dwell" or the length of time the switch is closed. 
     
     
       5. The analyzer of claim 4 in which the electrical testing means may selectively indicate either the "dwell" in connection with the igniter of any one cylinder or the average "dwell" during a complete cycle of the engine. 
     
     
       6. The analyzer of claim 1 in which said switching means is adapted to connect said electrical testing means simultaneously to a plurality of selected output connections of said cylinder identifying means so that said electrical effect is produced whenever the ignition pulse would normally be applied to the igniters of certain selected cylinders. 
     
     
       7. The analyzer of claim 1 in which the electrical testing means is effective to render any selected igniter ineffective and in which the analyzer includes means for observing the effect on engine operation of said igniter being rendered ineffective. 
     
     
       8. The analyzer of claim 1 in which the means for observing the effect on engine operation of said igniter being rendered ineffective comprises an engine speed indicator controlled by the pulse generating means. 
     
     
       9. The analyzer of claim 1 in which said pulse counter is an electronic ring counter in which each successive pulse applied to said first input connection renders one stage nonconductive and the next succeeding stage conductive. 
     
     
       10. The analyzer of claim 1 in which the electrical testing means is effective to render any selected igniter ineffective and in which, when said igniter coupled to the input of said second coupling circuit is being rendered ineffective for testing purposes, auxiliary reset means are provided for applying a reset pulse to said second input connection independently of the connection of said second coupling circuit to said igniter. 
     
     
       11. The analyzer of claim 10 in which the auxiliary reset means comprises means connected to said counter and effective to apply said reset pulse when the counter indicates that the number of cylinders which have operated corresponds to the total number of cylinders in the engine. 
     
     
       12. The analyzer of claim 1 for use with an engine in which the electrical ignition pulse generating means comprises an ignition switch which is closed and opened for periods of time in connection with the generation of an ignition pulse which is initiated upon the opening of said switch and in which the output signal successively applied to each output connection of said .[.cylinder identifying means.]. .Iadd.pulse counter .Iaddend.is initiated at the time that said switch is first closed and continuous until after said switch opens. 
     
     
       13. The analyzer of claim 12 in which the output signal successively applied to each output connection of said .[.cylinder identifying means.]. .Iadd.pulse counter .Iaddend.begins when said switch is first closed and continues until said switch recloses after being opened. 
     
     
       14. A compression and ignition test circuit for an automotive type engine; said engine including a plurality of cylinders and an ignition circuit connected to said cylinders including an igniter for each cylinder and a pair of distributor points, said compression and ignition test circuit including high speed switching means operable between an open and closed circuit condition, means for operatively connecting said switching means across the distributor points to cause the points to be short-circuited each time that said switching means is closed, operating means connected to said high speed switching means and energizable to cause said high speed switching means to assume a closed circuit condition for a predetermined interval less than the time interval between subsequent closings of said distributor points; energizing means having input and output terminals, means for operatively connecting the input terminals of said energizing means to the distributor points, said energizing means having its output terminals connected to said operating means and effective to cyclically energize said operating means in synchronism with a preselected number of operations of said distributor points whereby said energizing means eenergizes said operating means after a predetermined number of operations of said distributor points thereby to close said high speed switching means to short-circuit said distributor points in a predetermined repetitive pattern to continually disable the operation of at least one cylinder of said engine; means connected to said energizing means and responsive to the energization of one of said igniters for initiating each cycle of said energizing means so that the time of energization of said operating means is related to the time of firing of the igniter of a predetermined selected cylinder; and a cylinder selection switching means connected between said energizing means and said operating means for varying said predetermined repetitive pattern for the selection of a different selected cylinder for disabling other than said at least one selected cylinder. 
     
     
       15. The device as set forth in claim 14 wherein said cylinder selection switching means includes cylinder selecting switches for at least one-half of the cylinders in said engine. 
     
     
       16. A compression and ignition test circuit for an automotive type engine; said engine including a plurality of cylinders and an ignition circuit connected to said cylinders including an igniter for each cylinder and a pair of distributor points; said test circuit including: a controlled rectifier having an anode and cathode terminals connected across said distributor points and a gate terminal; a pulse generator having input terminals connected to said distributor points and an output circuit connected to said gate terminal of said controlled rectifier; said pulse generator cyclically generating one output pulse in synchronism with a predetermined number of opening operations of said distributor points; means connected to said pulse generator and responsive to the energization of one of said igniters for initiating each cycle of said pulse generator so that the timing of said output pulse is related to the time of firing of the igniter of a predetermined selected cylinder; and pulse advancing means for shifting the point in the pattern of distributor point operation at which said one output pulse is generated and hence the particular cylinder whose timing of firing is being sensed. 
     
     
       17. The device as set forth in claim 16 wherein said pulse generator comprises a ring counter having a pair of input terminals and a plurality of output terminals, there being at least one output terminal for each of said igniters; said pair of input terminals being connected across said distributor points; said pulse advancing means comprising switching means for selectively connecting one of said output terminals to said gate terminal of said controlled rectifier. 
     
     
       18. The device as set forth in claim 16 wherein said pulse generator comprises a ring counter having a pair of input terminals and a plurality of output terminals, there being at least one output terminal for each of said igniters; means connected across the distributor points and connected to said pair of input terminals for applying to said input terminals at the time that the distributor points first open a pulse which causes said ring counter to shift the portion of the cycle at which said output pulse occurs; and said pulse advancing means comprising switching means for selectively connecting one of said output terminals to said gate terminal of said controlled rectifier. .Iadd. 19. In an apparatus for analyzing the operation of a multiple cylinder internal combustion engine having an ignition time interval for each cylinder during which ignition normally occurs, the combination which comprises: means coupled to the engine for generating a first control pulse in response to the ignition time interval for each of the cylinders,   means responsive to each occurrence of the first control pulse for providing a second control pulse which occurs at a time following the initiation of the first control pulse by a time period which is directly proportional to the interval between the successive times of cylinder ignition,   means responsive to each occurrence of the second control pulse for generating anticipatory ignition suppression signals in advance of the ignition times in respective cylinders, and   means coupled to the engine and responsive to the ignition suppression signals for suppressing the ignition in a selected cylinder. .Iaddend. .Iadd. 20. The combination as defined in claim 19 wherein the means for generating the ignition suppression signals includes:   a multistage ring counter having a stage individually associated with each cylinder,   means coupled to the engine and responsive to the ignition of the first cylinder thereof for resetting the stages of the ring counter, and   means for advancing the count in the ring counter in response to the occurrence of each second control pulse. .Iaddend. .Iadd. 21. The combination as defined in claim 19 including means coupled to the number one cylinder of the engine and to the suppression signal generating means for generating a third control pulse which corresponds to the firing time of the first cylinder. .Iaddend..Iadd. 22. The combination as defined in claim 19 including means responsive to the first control pulse for providing an indication of engine r.p.m., whereby the power contribution of individual cylinders can be ascertained when the ignition in each of the cylinders is suppressed. .Iaddend. .Iadd. 23. Apparatus for analyzing the functioning of a multiple-cylinder internal combustion engine having an ignition coil, comprising:   means for picking up ignition pulses from said ignition coil;   pulse shaping means connected to said ignition pulse pickup means for producing a first control pulse therefrom upon each occurrence of an ignition pulse;   means responsive to each first control pulse for providing a second control pulse which occurs at a time following the initiation of the first control pulse by a time period which is directly proportional to the interval between successive ones of the ignition pulses;   means connected to the first cylinder of said multiple-cylinder engine for producing a third control pulse whenever the first cylinder fires;   a multi-stage ring pulse counter having stages equal in number to the number of cylinders in said engine;   reset means responsive to the third control pulse to place all of the stages of the pulse counter in a reset condition;   means for incrementally advancing the counter in the ring pulse counter with the occurrence of each of the second control pulses; and   utilization means connected to the output of the stages of the ring pulse counter and responsive to the pulse count therein. .Iaddend. .Iadd. 24. In a system for diagnosing an engine including a source of periodic cycles of ignition signals, improved apparatus for preventing one or more predetermined ignition signals in each cycle from energizing engine components which are normally energized by said predetermined ignition signals comprising in combination:   input means for receiving said periodic cycles of ignition signals from said source;   generating means for generating a clock pulse in response to the receipt of each ignition signal by the input means, said generating means comprising clock means for producing in response to each ignition signal a clock pulse having a predetermined amplitude and having a duration proportional to the duration of the ignition signal;   counting means for producing counting states representative of the number of pulses received from said generating means;   adjustable resetting means for resetting the counting means to a predetermined counting state after the counting means has counted through a predetermined number of counting states;   removable setting means for setting the counting means to an initial counting state in response to the operation of a predetermined one of the engine components by an ignition signal;   adjustable selecting means for producing a disabling pulse in response to a predetermined counting state of the counting means; and   disabling means responsive to the disabling pulse for preventing any simultaneously-occurring ignition signal from energizing the engine component normally energized by the simultaneously-occurring ignition   
     
     
        signal. .Iaddend..Iadd. 25.  In a system for diagnosing an engine including a source of periodic cycles of ignition signals, improved apparatus for preventing one or more predetermined ignition signals in each cycle from energizing engine components which are normally energized by said predetermined ignition signals comprising in combination: input means for receiving said periodic cycles of ignition signals from said source;   generating means operatively connected to the input means for generating a clock pulse in response to the receipt of each ignition signal by the input means;   counting means operatively connected to the generating means for producing counting states representative of the number of pulses received from said generating means, said counting means comprising first, second and third binary flip-flop circuits each having an input circuit and an output circuit and each capable of producing a single output pulse for each two pulses transmitted to its input circuit;   adjustable resetting means operatively connected to the counting means for resetting the counting means to a predetermined counting state after the counting means has counted through a predetermined number of counting states;   removable setting means operatively connected to the counting means for setting the counting means to an initial counting state in response to the operation of a predetermined one of the engine components by an ignition signal;   disabling means operatively connected to the selecting means and responsive to the disabling pulse for preventing any simultaneously-occurring ignition signal from energizing the engine component normally energized by the simultaneously-occurring ignition signal. .Iaddend.