Pulse generator for controlling the valves of an internal combustion engine

Claim 2

A pulse generator for operating the electrohydraulic or electropneumatic control for the inlet and outlet valves of an internal combustion engine, comprising, in combination, means for generating at least one first and at least one second train of electric pulses in synchronism with engine rotation and having a keying ratio independent of engine speed, each pulse of said first pulse train being for operation of a respective control for an inlet valve, and each pulse of said second pulse train being for operation of a respective control for an outlet valve, and including means for shifting, in degrees of crankshaft rotation, the first and second pulse trains with respect to each other independent of engine speed, and comprising a first, a second and a third storage capacitor, resettable integrating means for applying to each of said storage capacitors a voltage inversely proportional to engine speed, and a first a second and a third discharge circuit each connected to a respective one of said storage capacitors and operative for discharging the respective storage capacitor and generating a pulse whose duration corresponds to the duration of the discharge of the respective storage capacitor.

Claim 3

In combination with an internal combustion engine having a crankshaft and at least one engine cylinder having an inlet valve and an outlet valve, a valve timing arrangement comprising inlet-valve control means having an input for receipt Of a valve-opening pulse; outlet-valve control means having an input for receipt of a valve-opening pulse; synchronizing means coupled with said crankshaft and operative for generating a crankshaft-position synchronizing signal when said crankshaft assumes a predetermined angular orientation; first electronic pulse generating means having an output connected to the input of said inlet-valve control means and having an input connected to said synchronizing means and operative in response to receipt of a crankshaft-position synchronizing signal for generating a first timing pulse and applying the same to the input of said inlet-valve control means, and including crankshaft-speed-responsive first pulse-duration varying means operative for varying the duration of said first pulse inversely to crankshaft speed; and second electronic pulse generating means having an output connected to the input of said outlet-valve control means and having an input connected to said synchronizing means and operative in response to receipt of a crankshaft-position synchronizing signal for generating a second timing pulse and applying the same to the input of said outlet-valve control means, and including crankshaft-speed-responsive second pulse-duration varying means operative for varying the duration of said second pulse inversely to crankshaft speed, and further including crankshaft-speed-responsive electronic delay means operative for delaying the leading edge of said second timing pulse relative to the leading edge of said first timing pulse by a time period which varies inversely to crankshaft speed.

Claim 4

In combination with an internal combustion engine having a crankshaft and at least one engine cylinder having an inlet valve and an outlet valve, a valve timing arrangement comprising inlet-valve control means having an input for receipt Of a valve-opening pulse; outlet-valve control means having an input for receipt of a valve-opening pulse; synchronizing means coupled with said crankshaft and operative for generating a crankshaft-position synchronizing signal when said crankshaft assumes a predetermined angular orientation; first electronic pulse generating means having an output connected to the input of said inlet-valve control means and having an input connected to said synchronizing means and operative in response to receipt of a crankshaft-position synchronizing signal for generating a first timing pulse and applying the same to the input of said inlet-valve control means, and including crankshaft-speed-responsive first pulse-duration varying means operative for varying the duration of said first pulse inversely to crankshaft speed; and second electronic pulse generating means having an output connected to the input of said outlet-valve control means and having an input connected to said synchronizing means and operative in response to receipt of a crankshaft-position synchronizing signal for generating a second timing pulse and applying the same to the input of said outlet-valve control means, and including crankshaft-speed-responsive second pulse-duration varying means operative for varying the duration of said second pulse inversely to crankshaft speed, and further including crankshaft-speed-responsive electronic delay means operative for delaying the leading edge of said second timing pulse relative to the leading edge of said first timing pulse by a time period which varies inversely to crankshaft speed.

Claim 5

An arrangement as defined in claim 2, wherein said first pulse-duration varying means consists of means operative for causing said first pulse to have a value inversely proportional to crankshaft speed, and wherein said second pulse-duration varying means consists of means operative for causing said second pulse to have a value inversely proportional to crankshaft speed, and wherein said crankshaft-speed-responsive electronic delay means consists of means operative for delaying the leading edge of said second timing pulse relative to the leading edge of said first timing pulse by a time period inversely proportional to crankshaft speed, whereby the duration of said first and second timing pulses and also the duration of the delay between the leading edges of said first and second timing pulses are each equal to the time required for said crankshaft to turn through respective predetermined fixed angles irrespective of the prevailing engine speed.

Claim 6

The arrangement defined in claim 2, wherein said first pulse has a trailing edge and wherein the leading edge of said second pulse precedes said trailing edge of said first pulse.

Claim 7

The arrangement defined in claim 4, wherein the duration of said first pulse is different from the duration of said second pulse.

Claim 8

The arrangement defined in claim 2, wherein the duration of said first pulse is different from the duration of said second pulse.

Claim 9

The arrangement defined in claim 2, wherein said first electronic pulse generating means and first varying means comprises a storage capacitor, integrating means operative for transmitting to said storage capacitor a voltage inversely proportional to engine speed, and discharge circuit means connected to said storage capacitor for discharging the latter and generating a pulse whose duration corresponds to the duration of the discharge of said storage capacitor.

Claim 10

The arrangement defined in claim 7, said integrating means being resettable, and wherein said synchronizing means comprises a monostable multivibrator triggered in synchronism with crankshaft rotation and operative upon transition to its unstable state for resetting said integrating means.

Claim 11

The arrangement defined in claim 7, wherein said second pulse generating and varying means and delay means includes first and second additional storage capacitors, integrating means operative for transmitting to each of said additionAl capacitors an amount of charge inversely proportional to engine speed, first additional discharge circuit means connected to said first additional capacitor and operative for discharging said first additional capacitor and generating a respective first additional pulse whose duration corresponds to the duration of the discharge of said first additional capacitor and equals the time period between the leading edges of said first and second timing pulses, second additional discharge circuit means connected to said second additional capacitor and operative for discharging said second additional capacitor and generating a respective second additional pulse constituting said second timing pulse, and means for delaying the start of said second additional pulse until the end of said first additional pulse.

Claim 12

The arrangement defined in claim 9, wherein said first pulse generating means and first varying means include an impedance transformer connected between said integrating means and said storage capacitor of said first pulse generating means, and wherein said second pulse generating means includes first and second additional impedance transformers respectively connected between said integrating means of said second pulse generating means and said first and second additional capacitors.

Claim 13

The arrangement defined in claim 10, wherein said impedance transformers are emitter-follower transistor stages.

Claim 14

The arrangement defined in claim 9, wherein said first and second electronic pulse generating means share the same integrating means, and wherein said integrating means comprises a Miller integrator.

Claim 15

The arrangement defined in claim 9, wherein each of said discharge circuit means comprises a constant current source connected to the respective storage capacitor for discharging the latter at constant current and also a monostable circuit connected to the respective storage capacitor and undergoing a first change of state when the voltage on the respective storage capacitor falls below a predetermined lower threshold value and undergoing a reverse change of state when the voltage on the respective storage capacitor exceeds a predetermined higher threshold value.

Claim 16

The arrangement defined in claim 13, wherein at least the constant current source of said second additional discharge circuit means has a blocking input for receipt of a blocking pulse for rendering the constant current source non-conductive, and wherein said means for delaying is connected between the output of said first additional discharge circuit means and said blocking input.

Claim 17

The arrangement defined in claim 14, wherein said means for delaying comprises an inverter having an input connected to the output of said first additional discharge circuit means and having an output connected to said blocking input, and also an AND-gate having one input connected to the output of said inverter and another input connected to the output of said second additional discharge circuit means.

Claim 18

The arrangement defined in claim 9; and further including third electronic pulse generating means having the same circuit configuration as said second electronic pulse generating means but operative for generating a third timing pulse having a duration corresponding to a predetermined fraction of a crankshaft rotation and having a leading edge delayed relative to the leading edge of said second pulse by a time period corresponding to a predetermined fraction of a crankshaft rotation.

Claim 19

The arrangement defined in claim 16; and further including fourth electronic pulse generating means having the same circuit configuration as said second electronic pulse generating means but operative for generating a third timing pulse having a duration corresponding to a predetermined fraction of a crankshaft rotation and having a leading edge delayed relative to the leading edge of said third pulse by a time period corresponding to a predetermined fraction of a crankshaft rotation.

Claim 20

The arrangement as defineD in claim 9, wherein at least one of said constant current sources has a blocking input for receipt of a blocking pulse for rendering the respective constant current source non-conductive, whereby to permit receipt of blocking pulses for delaying discharge of the respective storage capacitor.