Method for controlling internal combustion engine valve operating mechanism

Abstract

The reciprocating valve actuation and control system includes a poppet valve moveable between a first and second position; a source of pressurized hydraulic fluid; a hydraulic actuator including an actuator piston coupled to the poppet valve and reciprocating between a first and second position responsive to flow of the pressurized hydraulic fluid to the hydraulic actuator; an electrically operated valve controlling flow of the pressurized hydraulic fluid to the actuator; and an engine computer that generates electrical pulses to control the electrically operated valve. The electrically operated valve preferably comprises a three path rotary latched magnetic motor actuating a rotary valve portion having a housing, a rotor, and a stator receiving and supplying hydraulic fluid pressure to the rotor, which alternately directs the hydraulic fluid pressure to the valve cylinder for opening of the valve, or to return to the engine oil sump, for closing the valve. In a presently preferred embodiment, the hydraulic actuator comprises a self-contained cartridge assembly including an actuator piston with dampers for damping motion of the actuator piston, limiting the actuator stroke to assure soft seating of the actuator, and to avoid overshoot during the engine valve opening stroke and the engine valve return stroke. The electro-hydraulic valves are electrically controlled by the engine computer, which generates electrical signals carried to the electro-hydraulic valves. The engine computer typically senses conventional engine variables, and optimizes performance of the valve actuation and control system according to preestablished guidelines, with information being supplied to the engine computer by sensors. The engine computer controls all aspects of engine performance, interfaces with all of the peripheral sensors, and calculates fuel parameters, ignition timing and engine valve timing based upon prior mapping of the engine. In this manner the engine can be controlled so as to provide maximum fuel economy, minimum emissions, maximum engine torque, or a compromise between these parameters.

What is claimed is:  
     
         1 . A reciprocating valve actuation and control system for the cylinders of an internal combustion engine, comprising: 
 a poppet valve moveable between a first and second position;    a source of pressurized hydraulic fluid;    a hydraulic actuator including an actuator piston coupled to the poppet valve and reciprocating between a first and second position responsive to flow of the pressurized hydraulic fluid to the hydraulic actuator;    an electrically operated valve controlling flow of the pressurized hydraulic fluid to the actuator; and    control means generating electrical pulses to control the electrically operated valve.    
     
     
         2 . The reciprocating valve actuation and control system of    claim 1   , wherein the electrically operated valve controlling flow of the pressurized hydraulic fluid to the actuator supplies pressurized hydraulic fluid to the hydraulic actuator when electrically pulsed to a first position, and dumps pressurized hydraulic fluid to a system return when electrically pulsed to a second position.  
     
     
         3 . The reciprocating valve actuation and control system of    claim 2   , wherein the electrically operated valve comprises a three path rotary latched magnetic motor.  
     
     
         4 . The reciprocating valve actuation and control system of    claim 1   , wherein the electrically operated valve comprises: 
 a rotary valve having a housing;    a stator having an inlet pressure port receiving pressurized hydraulic fluid, an inner bore in fluid communication with the inlet pressure port through a plurality of radially oriented apertures;    a cylinder port groove in fluid communication with the hydraulic actuator;    a plurality of axial slots formed in the stator allowing fluid communication between the cylinder port groove and the inner bore of the stator;    a generally cylindrically shaped rotor disposed within the stator, the rotor having a pressure supply groove at one end for receiving pressurized hydraulic fluid from the inlet pressure port of the stator;    a plurality of axial pressure grooves in fluid communication with the pressure supply groove of the rotor for supplying pressurized hydraulic fluid to the actuator; and    a plurality of return groove formed in the rotor in fluid communication with a pressurized hydraulic fluid return, for receiving hydraulic fluid from the hydraulic actuator.    
     
     
         5 . The reciprocating valve actuation and control system of    claim 3   , wherein the three path rotary latched magnetic motor comprises: 
 a first pole piece connected to a first electromagnetic coil energized by electrical pulses from said control means;    a second pole piece connected to a second electromagnetic coil energized by electrical pulses from said control means, said first and second pole pieces being connected at a magnetic junction;    a magnetic rotor disposed for rotation between a first position and a second position contacting said first and second pole pieces, respectively;    a third pole piece disposed adjacent to the magnetic rotor so as to define an air gap between the magnetic rotor and the third pole piece;    a permanent magnet connected to third pole piece;    a fourth pole piece connected between the permanent magnet and the magnetic junction; and    an output shaft mounted on the magnetic rotor operatively connected to rotary valve means for controlling flow of the pressurized hydraulic fluid to the hydraulic actuator.    
     
     
         6 . The reciprocating valve actuation and control system of    claim 1   , wherein said hydraulic actuator comprises a self-contained cartridge assembly including an actuator piston having means for damping a stroke of the actuator piston to assure soft seating of the actuator, and to avoid overshoot of the actuator piston.  
     
     
         7 . The reciprocating valve actuation and control system of    claim 6   , wherein said means for damping comprises first damping means to avoid overshoot during an opening stroke of the engine valve.  
     
     
         8 . The reciprocating valve actuation and control system of    claim 7   , wherein said means for damping comprises second damping means to decelerate the actuator piston to avoid high impact of the engine valve into the valve seat.  
     
     
         9 . The reciprocating valve actuation and control system of    claim 6   , wherein said means for damping comprises a stepped land on the actuator piston.  
     
     
         10 . The reciprocating valve actuation and control system of    claim 6   , wherein said self-contained cartridge assembly further comprises a main generally tubular sleeve having a bore, said bore having a surface defining a damper cavity, said actuator piston having a damper land member, and said damper cavity receiving said damper land member during an actuating stroke of said actuator piston, whereby hydraulic fluid is trapped in the damper cavity to damp motion of the actuator piston during a stroke of the actuator piston.  
     
     
         11 . The reciprocating valve actuation and control system of    claim 10   , further comprising a secondary generally tubular sleeve having a bore, said secondary sleeve bore having a surface defining a secondary damper cavity, and said actuator piston having a surface defining a damper orifice for fluid communication of said hydraulic fluid from one of said main sleeve damping cavity and said secondary sleeve damping cavity to the hydraulic fluid return.  
     
     
         12 . The reciprocating valve actuation and control system of    claim 10   , when said self-contained cartridge assembly further comprises an alignment tube within which said main sleeve is disposed, a generally tubular damping spacer disposed within said alignment tube adjacent to the main sleeve, a damping ring disposed within said alignment tube adjacent to said damping spacer, and said actuating piston having a surface defining a damping orifice for fluid communication of hydraulic fluid from said damper cavity to the hydraulic fluid return.  
     
     
         13 . The reciprocating valve actuation and control system of    claim 12   , wherein said damper land member comprises a split ring, said split ring having a surface defining a damper orifice through said split ring for communicating hydraulic fluid to the hydraulic fluid return.  
     
     
         14 . The reciprocating valve actuation and control system of    claim 12   , wherein said damper land member comprises a laminar sealing ring, said sealing ring having a surface defining an orifice in the sealing ring for communication of hydraulic fluid to the hydraulic fluid return.  
     
     
         15 . The reciprocating valve actuation and control system of    claim 1   , wherein said source of pressurized hydraulic fluid comprises an engine driven hydraulic positive displacement pump for supplying said hydraulic fluid pressure, said hydraulic fluid is engine oil, and an engine oil sump connected in fluid communication with said pump for supplying engine oil to the pump, and said engine oil sump being connected in fluid communication for receiving return engine oil from the valve actuation and control system.  
     
     
         16 . The reciprocating valve actuation and control system of    claim 15   , further comprising an unloader valve connected in fluid communication with the pump for limiting output pressure of the pump.  
     
     
         17 . The reciprocating valve actuation and control system of    claim 16   , further comprising a check valve to prevent backflow from the accumulator.  
     
     
         18 . The reciprocating valve actuation and control system of    claim 16   , further comprising an accumulator connected in fluid communication with the pump and the unloader valve for storing a volume of the hydraulic fluid.  
     
     
         19 . The reciprocating valve actuation and control system of    claim 16   , wherein said unloader valve comprises a pressure sensing valve for sensing pump output pressure, said unloader valve opening when the pump output pressure reaches a preset threshold value, said unloader valve returning flow of said hydraulic fluid to return.  
     
     
         20 . The reciprocating valve actuation and control system of    claim 1   , wherein said control means comprises a computer and a plurality of sensors disposed in the engine for sensing engine variables, and optimizing performance of the reciprocating valve actuation and control system.  
     
     
         21 . The reciprocating valve actuation and control system of    claim 1   , the internal combustion engine having a cylinder head and a combustion chamber, and wherein the engine cylinder head has a bridge dividing the combustion chamber.  
     
     
         22 . The reciprocating valve actuation and control system of    claim 1   , wherein said control means comprises a digital signal processor to take advantage of its high speed real time signal processing capability, whereby crankshaft dynamic related problems are diagnosed, and dealt with in real time.  
     
     
         23 . A method for controlling reciprocating valve actuation for the cylinders of an internal combustion engine in a reciprocating valve actuation and control system, the system including a poppet valve moveable between a first and second position; a source of pressurized hydraulic fluid; a hydraulic actuator including an actuator piston coupled to the poppet valve and reciprocating between a first and second position responsive to flow of the pressurized hydraulic fluid to the hydraulic actuator; an electrically operated valve controlling flow of the pressurized hydraulic fluid to the actuator; and an engine control unit gene rating electrical pulses to control the electrically operated valve, wherein the source of pressurized hydraulic fluid comprises an engine driven hydraulic positive displacement pump for supplying the hydraulic fluid pressure, an unloader valve connected in fluid communication with the pump for limiting output pressure of the pump, and an accumulator connected in fluid communication with the pump and the unloader valve for storing a volume of the hydraulic fluid, the method comprising the step of: 
 storing hydraulic energy in the accumulator.    
     
     
         24 . The method of    claim 23   , further comprising the step of: 
 controlling the accumulator in a way that commands the engine driven pump to “run free” or be disconnected during brief power bursts.    
     
     
         25 . The method of    claim 23   , further comprising the step of: 
 controlling the accumulator in a way that forces the accumulator to be charged during braking.    
     
     
         26 . The method of    claim 23   , further comprising the step of: 
 controlling the accumulator in a way that forces the accumulator to be charged during the time the vehicle needs to decelerate.    
     
     
         27 . A method for controlling reciprocating valve actuation for the cylinders of an internal combustion engine in a reciprocating valve actuation and control system, the system including a poppet valve moveable between a first and second position; a source of pressurized hydraulic fluid; a hydraulic actuator including an actuator piston coupled to the poppet valve and reciprocating between a first and second position responsive to flow of the pressurized hydraulic fluid to the hydraulic actuator; and an electrically operated valve controlling flow of the pressurized hydraulic fluid to the actuator; the method comprising the step of: 
 controlling the electrically operated valve with an engine control unit generating electrical pulses.    
     
     
         28 . The method of    claim 27   , wherein said step of controlling comprises: 
 controlling the engine control unit in a way that commands a delay to take place in the opening of multiple intake or exhaust valves in the cylinder.    
     
     
         29 . The method of    claim 27   , further comprising the step of: 
 the engine control unit controlling the valve timing to create a swirl effect in the combustion chamber.    
     
     
         30 . The method of    claim 27   , further comprising the step of: 
 mapping the engine control unit in a manner that optimizes the swirl effect.    
     
     
         31 . The method of    claim 27   , wherein said step of controlling comprises: 
 the engine control unit controlling the valve timing of the intake and exhaust valves of an engine having at least three valves per cylinder, such that the intake and exhaust valves will not open at the same time, and controlling the valve timing of the intake and exhaust valves of the engine to provide a delay to off load driver electronics and reduce peak current load, allowing smaller current traces and preventing ringing of power transistors.    
     
     
         32 . The method of    claim 27   , the engine having a multi-inlet valve cylinder having shaped and directed inlet ports, wherein said step of controlling comprises: 
 the engine control unit controlling the valve timing to provide a delay of the opening of intake valves, to cause a swirl effect to take place that is augmented by the shaped and directed inlet ports.    
     
     
         33 . The method of    claim 27   , the engine having a multi valve cylinder having first and second exhaust valves, and first and second hydraulic actuators, the second exhaust valve being larger than the first exhaust valve, the first exhaust valve to open being smaller in head diameter, resulting in lower actuation pressure, wherein said step of controlling comprises: 
 the engine control unit controlling the timing of the valves to create a delay between the opening point of exhaust valves in the multi valve cylinder to reduce the demand placed on the second actuator, to lower horsepower required to drive the larger exhaust second valve.    
     
     
         34 . The method of    claim 27   , the engine having four intake and exhaust valves, wherein said step of controlling comprises: 
 the engine control unit controlling the timing of the valves in the following sequence: 
 a. number 1 Intake valve opens (large valve)  
 b. number 4 Exhaust valve closes (after start up)  
 c. number 2 Intake valve opens (smaller valve)  
 d. number 2 Intake valve closes  
 e. number 1 Intake valve closes  
 f. compression and power stroke take place  
 g. number 4 Exhaust valve opens (smaller valve w/less surface area)  
 h. number 3 Exhaust valve opens (larger valve w/more volume)  
 i. number 3 Exhaust valve closes  
 j. number 1 Intake valve opens (overlap begins)  
 k. number 4 Exhaust valve closes (overlap ends).  
   
     
     
         35 . The method of    claim 27   , the engine control unit commanding a first set of exhaust valve opening and closing events, wherein said step of controlling comprises: 
 the engine control unit controlling the timing of the valves by commanding a second set of exhaust valve opening and closing events to take place.    
     
     
         36 . The method of    claim 27   , the engine having four intake and exhaust valves, wherein said step of controlling comprises: 
 the engine control unit controlling the timing of the valves in the following sequence: 
 a. number 1 Intake valve opens (largest valve)  
 b. number 2 Intake valve opens (smaller valve)  
 c. number 2 Intake valve closes  
 d. number 1 Intake valve closes  
 e. compression and power stroke take place  
 f. number 4 Exhaust valve opens (smaller valve w/less surface area)  
 g. number 3 Exhaust valve opens (larger valve w/more volume)  
 h. number 3 Exhaust valve closes  
 i. number 1 Intake valve opens (overlap begins)  
 j. number 4 Exhaust valve closes (overlap ends).  
   
     
     
         37 . The method of    claim 27   , wherein said step of controlling comprises: 
 the engine control unit controlling the valve timing by opening and closing the valves several times during the same stroke.    
     
     
         38 . The method of    claim 27   , wherein said step of controlling comprises: 
 the engine control unit controlling the valve timing by opening and closing the valves several times to control throttling and braking.    
     
     
         39 . The method of    claim 27   , wherein said step of controlling comprises: 
 the engine control unit controlling the valve timing.    
     
     
         40 . A method for controlling reciprocating valve actuation for the cylinders of an internal combustion engine in a reciprocating valve actuation and control system, the system including a poppet valve moveable between a first and second position; a source of pressurized hydraulic fluid; a hydraulic actuator including an actuator piston coupled to the poppet valve and reciprocating between a first and second position responsive to flow of the pressurized hydraulic fluid to the hydraulic actuator; an electrically operated valve controlling flow of the pressurized hydraulic fluid to the actuator; a crankshaft; and a control means controlling the electrically operated valve, the method comprising the step of: 
 determining the position and direction of rotation of the crank shaft from the electrical outputs of a sin/cosine crankshaft position sensor.    
     
     
         41 . The method of    claim 40   , the method further comprising the step of: 
 operating valve openings and closings that are correct for forward/reverse crankshaft rotation, based upon the crankshaft position and direction information, to eliminating possible mechanical interference for crankshaft reverse rotation.    
     
     
         42 . The method of    claim 40   , further comprising the step of: 
 reversing the direction indication by electronically inverting one signal to cause the engine to run backwards.    
     
     
         43 . The method of    claim 40   , the engine being a four cycle engine having a distributor and camshaft, the method further comprising the step of: 
 dividing the electrical position output of the electrical crankshaft position sensor by two electronically to eliminate costly mechanical components that drive the distributor and camshaft at half speed, and determining the initial timing during startup sequencing for valves, fuel and ignition.    
     
     
         44 . The method of    claim 40   , the method further comprising the step of: 
 inputting preset default valve, fuel and ignition operating values into registers of the control means upon application of power, to be utilized if the control means fails to operate, allowing operation in emergencies.    
     
     
         45 . The method of    claim 44   , further comprising the step of: 
 the control means closing any open valves upon application of power to eliminate mechanical interference until correct crankshaft location is determined by a startup sequence.    
     
     
         46 . The method of    claim 40   , further comprising the step of: 
 the control means inhibiting fuel injection but not ignition during a shut-off command by the operator.    
     
     
         47 . The method of    claim 46   , further comprising the step of: 
 sequentially commanding all intake and exhaust valves of the engine to close before power termination to the control system, to eliminate any possible mechanical interference after power removal, in order to provide smooth termination, a low pollution termination, or a rapid deceleration termination, depending on the actual valve closure and ignition sequencing.    
     
     
         48 . The method of    claim 40   , further comprising the step of: 
 comparing whether the electrical crankshaft position and direction outputs of the position sensor are greater than but not equal to desired values that open valves, to allow for commanded valve event value changes asynchronously to crankshaft position without missed events, such as a missed valve open event causing a misfire and greater vibrations, noise and emitted pollution problem.    
     
     
         49 . The method of    claim 40   , further comprising the step of: 
 comparing whether the electrical crankshaft position and direction outputs of the position sensor are greater than but not equal to desired values that open valves, to allow for commanded valve event value changes asynchronously to crankshaft position without missed events, such as a missed valve closure event causing a mechanical interference problem.    
     
     
         50 . The method of    claim 40   , further comprising the step of: 
 comparing whether the electrical crankshaft position and direction outputs of the position sensor are greater than but not equal to desired values that open valves, to allow for commanded valve event value changes asynchronously to crankshaft position without missed events, such as a missed fuel injection event causing a misfire and greater mechanical vibrations and noise.    
     
     
         51 . The method of    claim 40   , further comprising the step of: 
 comparing whether the electrical crankshaft position and direction outputs of the position sensor are greater than but not equal to desired values that open valves, to allow for commanded valve event value changes asynchronously to crankshaft position without missed events, such as a missed ignition event causing a misfire and greater emitted pollution.    
     
     
         52 . A method for controlling reciprocating valve actuation for the cylinders of an internal combustion engine in a reciprocating valve actuation and control system, the system including a poppet valve moveable between a first and second position; a source of pressurized hydraulic fluid; a hydraulic actuator including an actuator piston coupled to the poppet valve and reciprocating between a first and second position responsive to flow of the pressurized hydraulic fluid to the hydraulic actuator; an electrically operated valve controlling flow of the pressurized hydraulic fluid to the actuator; and a control means controlling the electrically operated valve, the method comprising the step of: 
 controlling the dynamic performance of the system by newly added dimensions of mapping strategy, consisting of existing mapping of sensory inputs such as gas pedal position, inlet and exhaust manifold and barometric pressures, exhaust gas composition, coolant and ambient air temperatures with ignition timing and fuel injection, along with new dimensions of inlet/exhaust valve timing.    
     
     
         53 . The method of    claim 52   , the engine having individual fuel injectors, the method further comprising the steps of: 
 controlling the valve actuation solenoids; and    controlling the individual fuel injectors, as well as individual spark events on each cylinder used on the system, based upon said sensory input, and based upon multidimensional mapping.    
     
     
         54 . The method of    claim 52   , further comprising the step of: 
 determining if any cylinders are operating unsatisfactorily, based upon use rotational rate measurements.    
     
     
         55 . The method of    claim 54   , further comprising the step of: 
 the control means disabling defective cylinders entirely, reducing pollution and potential further engine damage, while offering a limited “limp home” operation.