This invention relates to internal combustion engines and more particularly to engines having fuel saving operating modes of the type disclosed in U.S. Pat. No. 8,443,769, the entire disclosure of which is hereby incorporated herein by reference.
The fuel saving modes of the '769 patent involve a step forward in the evolution of “skipping” technology. A skipped piston and cylinder is one that does not receive an injection of fuel during the injection stroke in which fuel would normally be injected. For the first time, the piston of the skipped piston and cylinder assembly actually enters into the creation of power rather than simply being neutral or requiring power from the rest of the engine to be moved through repeated cycles without cycle events taking place. The skipped piston enters into the creation of power by means of a passage between the combustion chambers of two paired assemblies. The increased pressure conditions in the cylinder of its paired assembly resulting from the internally fired power drive stroke therein is communicated by the passage to the skipped piston, causing it to undergo a simultaneous shared power drive stroke. Since the skipped piston is directly connected to the crankshaft, its shared power drive stroke creates power in the engine.
The '769 patent discloses several different engine configurations embodying the skipping advance including an opposed piston eight cylinder engine.
In the opposed piston eight cylinder engine disclosed in the '769 patent, two banks of four inline piston and cylinder assemblies each moving like a four cylinder engine. The two banks are configured in opposed inline relation to one another rather than in the more convenient V configuration. In each bank of four inline piston and cylinder assemblies, the side-by-side middle two which move together have their combustion chambers close enough to provide the passage necessary to achieve the shared power advancement during skipping. Consequently, there are two pairs out of a possible four which can operate on the advanced skipping/shared power.
The present invention has for one non-limiting object to provide an eight cylinder engine configuration which is in a convenient V configuration and provides the maximum four pairs of side-by-side piston and cylinder assemblies that can operate in accordance with the skipping principles of the '769 patent.
In accordance with the principles of the present invention, this object is obtained by mounting the eight piston and cylinder assemblies in two banks of four inline assemblies in a V formation. However, the V formation is inverted in comparison with the conventional V-8. Instead of having one crankshaft driving the pistons of both banks as in a conventional V-8, the inverted V configuration provides two spaced drive interconnected crankshafts, one driving the pistons of each bank. The inverting of the V configuration brings the upper combustion chamber ends of each bank of cylinders into a side-by-side relation providing four pairs of simultaneously moved side-by-side assemblies that can and do have passages intercommunicating the side-by-side combustion chambers thereof, thereby enabling all four pairs to operate on the skipping principles of the '769 patent.
Another non-limiting object of the present invention is to provide a commercially acceptable inverted V-8 engine construction which is cost effective.
The invention is also concerned with an improved preferred embodiment of an inverted V-8 internal combustion (I-C) engine having a construction which is cost effective. The improved I-C engine comprises eight inline cylinders mounted in two banks of four cylinders converging angularly and upwardly in a block component of the frame assembly so that open upper ends of the cylinders are disposed within upwardly facing surfaces of the block component in four interrelated pairs. Each pair is spaced transversely with respect to one another, covering the open upper ends of the cylinders with valved portions of a head component of the frame assembly supported on the block component and having downwardly facing surfaces in sealing relation with respect to the upwardly facing surfaces of the block component. This forms four recesses in communicating relation with the surface means of one of the head and block components at positions between the four interrelated pairs of cylinder open ends, fixedly mounting an insert of heat-resistant material in each recess having a passage extending therethrough with spaced open ends thereof communicating with an associated pair of spaced cylinder open ends respectively.
The invention also includes a method of operating the engine to move a vehicle in which the engine is mounted in driving relation so that the speed of vehicle movement is responsive to the movement of accelerator pedal from an initial position to a maximum position. The method includes computer controlling the injectors of each of the four pairs of assemblies as the pedal moves through five progressively more powerful zones causing a progression of five steps to take place within the four pairs of assemblies, starting with all four pairs undergoing paired shared power drive strokes, and changing one pair to undergo a paired directly fired power drive stroke in each progressive step so that at the high zone all four pairs have paired directly fired power drive strokes. The method also includes computer controlling the injectors so as to vary the increase of the amount of fuel injected from the beginning of each zone to the end of the next zone so that the total amount of fuel injected at the end of each zone is equal to the total amount of fuel injected in the greater number of injections in the next zone.
Other objects, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims.
The end walls 24′ and parallel inner walls 26′ of the lower pan section 16′ have upwardly facing planar surfaces interrupted by longitudinally aligned spaced pairs of upwardly facing 180° arcuate bearing engaging surfaces 30′.
The main block section 14′ includes a lower portion defined by exteriorly flanged upwardly and inwardly sloping side walls 32′ vertically aligned with the side walls 22′, upright end walls 34′ vertically aligned with the end walls 24′ of the lower pan section 16′ and four interior walls 36′ vertically aligned with the four inner walls 26′ of the lower pan sections. The vertically aligned walls 32′, 34′ and 36′ of the block section 14′ have downwardly facing surfaces which engage the upwardly facing wall surface of pan section 16′. Suitable fasteners 38′ extending through the flanges of the exteriorly flanged upright walls 32′ of the lower portion of the block section 14′ and into the aligned side walls 24′ of the lower pan section 16′ serve to fixedly the block section 14′ on the lower pan section 16′.
The lower portion of the main block section 14′ does not have downwardly facing surfaces which engage the 180° arcuate surfaces 30′ of the lower pan section 16′; instead the lower portion of the block section 14′ has downwardly facing 180° arcuate bearing engaging surfaces 38′ in alignment with the arcuate surfaces 30′ of the lower pan section 16′.
The main block section 14′ also includes a main upper portion configured to receive therein two banks of piston and cylinder assemblies, generally indicated at 40′ which diverge downwardly from the top of the block section 14′. Each of the two banks include four cylinders 42′. The lower end of each cylinder 42′ seats in surfaces 44′ provided in the block section 14′ to engage the lower end surface and exterior marginal lower end surface of each cylinder 42′.
The upper extremities of the cylinders 42′ are fixedly engaged within openings formed in a sheet metal plate 46′. The plate 46′ is essentially rectangular in shape bent along its longitudinal center line to form two longitudinally elongated areas having upper surfaces forming a shallow angle therebetween.
As best shown in
Each crankshaft 58′ includes axially aligned cylindrical bearing sections 62′ at each end thereof and between adjacent crank sections 56′. The cylindrical bearing sections 62′ have exterior surfaces thereof engaged with the interior surfaces of special separable bearings 64′. The exterior surfaces of which are engaged by corresponding mating 180° arcuate surfaces 30′ and 38′. In this way, the two horizontally spaced crankshafts 58′ are mounted for rotational movement on the frame structure 12′ about parallel horizontally extending axes.
Referring now more particularly to
As best shown in
Fixed on the stub shaft 72′ in meshing relation between the two gears 68′ on the crankshaft 58′ is a third gear 76′ enabling the stub shaft 72′ to act as a main rotational output for the engine 10′ when the crankshafts 58′ are operated by the operation of the two banks of piston and cylinder assemblies 40′.
As best shown in
Referring now more particularly to
In accordance with the principles of the patented invention, an angulated gasket, generally indicated at 90′, is fixed by suitable fasteners between the upper angulated surface of the plate 46′ and the lower angulated surface of the slab 88′.
Referring now to
Again referring to
Extending over each outlet opening 98′ from the upper surface of the slab 88′ is a tubular structure 100′ along the upper surface of slab 88′ which leads inwardly to a central longitudinally extending tubular structure 102′ defining an exhaust manifold for the engine.
Similarly, each inlet opening 96′ has a tubular structure 104′ disposed thereover on the upper surface of the slab 88′. The tubular structures 104′ in one bank of cylinders extend away from the tubular structures 104′ in the other bank. The outward ends of each bank of tubular structures 104′ communicate with a manifold defining longitudinally extending tubular structure 106′.
As best shown in
Each inlet opening defines a downwardly facing frustoconical valve seat. An inlet valve 114′ is mounted for movement with respect to each seat between an open position spaced from the seat and a closed position engaging the seat. Each inlet valve 114′ includes a valve stem 116′ extending upwardly therefrom through the associated inlet tubular structure 100. Surrounding the outwardly extending end of each inlet valve stem 116′ between a washer fixed on the outward extremity of the valve stem 116′ and the exterior of the associated inlet tubular structure 100′ is a coil spring 118′ which serves to spring bias the associated inlet valve 114′ into its closed position.
In a similar manner, an outlet valve 120′ with valve stem 122′ and surrounding coil spring 124′ is spring bias into a closed position with respect to each outlet opening 98′.
The inlet valves 114′ and outlet valves 120′ are moved out of their spring biased closed positions into their open positions by the operation of the camshaft 78′.
As best shown in
The four inlet valves 114′ in each bank are moved into their open positions by a corresponding four inlet rocker arms 130′ pivotally mounted on an associated rocker shaft 128′ and the four outlet valves in each bank are moved into their open positions by four outlet rocker arms 132′ pivotally mounted on an associated rocker shaft 128′. To enable side by side rocker arms on each shaft to actuate longitudinally aligned valves of a valve engaging end of one of the adjacent rockers includes a longitudinally bent end.
The rocker arms 130′ and 132′ are mounted on their associated rocker shaft 128′ so that the pivotal axis of each extends through a central portion thereof so that opposite free ends thereof can be engaged with the camshaft 78′ and the washer fixed to the upper end of an associated valve 114′ or 120′.
Each inlet valve 114′ is moved into its open position at an appropriate time in the normal four stroke cycle occurring in the associated cylinder when the associated inlet rocker arm 130′ is engaged by an inlet cam lobe 134′ on the camshaft 78′ and each outlet valve 120′ is moved into its open position at an appropriate time in the normal four stroke cycle occurring when the associated outlet rocker arm 132′ is engaged by an outlet cam lobe 136′ on the camshaft 78′.
The head assembly 18′ including the air inlet system up to the elbow pipes 110′, the exhaust system up to the exhaust pipe 108′, the camshaft 78′ and mount 126′ up to the end on which timing gear 82′ is mounted and all of the rocker arms 130′ and 132′, the rocker shafts 128′, valve stents 116′ and 122′ and valve springs 118′ and 124′ are enclosed within a cover member 137′ having its lower open end provided with an exterior peripheral mounting flange through which the cover member 137′ is bolted to the upper periphery of the slab 88′.
Referring now more particularly to
The chart also includes for each piston and cylinder assembly 40′, illustrations of the configuration of the camshaft. The illustrations show the relative circumferential position on the camshaft of the exhaust cam lobes in cross section and the related inlet cam lobes in elevation to indicate the opening of the exhaust valves during the exhaust event and the opening of the inlet valves during the inlet event without regard to their exact beginning or end which is in accordance with accepted practice.
Each communicated (i.e., across the banks) pair of piston and cylinder assemblies 40′ is fired together for one 180° turn during each of four consecutive 180° turns of the crankshafts 58′ and the firings of a different pair take place in each of the four consecutive 180° turns. As shown, the order of firing is 1-3-4-2.
Referring now more particularly to
Injecting fuel into a swirl chamber 142′ in the piston 48′ is characteristic of diesel operation. Wherein the compression ratio of each piston and assembly 40′ is such that at the end of the compression event, the air in the combustion chamber is at a temperature and pressure to cause auto ignition when the fuel is injected therein.
While the engine 10′ is shown as being diesel operated with compression ignition, the engine could be made to operate on a conventional spark ignition basis with a lesser compression ratio and a positioning of the fuel injectors with mating air injectors to direct an appropriate air fuel mixture into the combustion chamber through the open inlet valve during the inlet stroke.
It will also be understood that while the engine is disclosed as inverted V-8, it could be made into an inverted V-6 by appropriate changing the crank portions of the crankshafts from the 180° shown to 120°. Other numbers of pistons/cylinders are possible.
Referring now back to
The opening and closing of the solenoid valves determines the amount of fuel injected by each of the injectors 138′. The solenoids are normal spring biased into a closed position and opened when the solenoid valves are electrically energized.
The further descriptions of the skipping control assume that the engine is installed as the motive power of a vehicle. The solenoid actuating electrical energy comes from the battery of the vehicle shown at 152′ in
In any event, preferably there are at least three input signals that achieve three different skipping patterns. A first skipping pattern is simply no skipping in which case the computer 154′ is programmed to activate all of the solenoid valves at the appropriate time. This constitutes a full power mode which is desirable when, for example, the vehicle is going up a hill. This full power mode can be input into the computer 154′ either by manually pushing button 158′ of the three button assembly 156′ or by the actuation of a level sensor 160′.
A second skipping pattern is one which can be referred to as a normal operating mode. The input to the computer is by manually pushing button 162′ of the three button assembly 156′ or by a sensor 164′ which senses the turning on of the engine. When the computer 156′ receives the normal mode input signal, the computer, 156′ is programmed to alternately skip during consecutive two full rotations of the crankshafts between the injectors 138′ of one bank of piston and cylinders 40′ and then the injectors 138′ of the piston and cylinder assemblies 40′ of the other bank. In short, normal mode operation involves the saving of one half of the fuel used in the full power mode. However, because of the double expansion which takes place because of the passages 94′ enabling the combustion comparison in one cylinder of a communicated pair to drive the piston in the other cylinder of the pair, more than one half power is maintained as discussed in the '769 patent. Alternatively, not all the injectors of one bank are skipped simultaneously. In some embodiments, some of the skipped (i.e., those not receiving a fuel injection) are in one bank, while some are in the other bank, this better balances out the combustion locations within the engine frame structure.
A third skipping pattern can be termed a coasting mode. The input for this mode can come from, for example, manually pushing button 166′ of the three button assembly 156′ or from the actuation of sensor 168′ sensing release of the accelerator pedal. When the computer receives this signal two of the four pairs of piston and cylinder assemblies (e.g. 1 and 2) are alternately skipped as in the normal mode while the other two (e.g. 3 and 4) are both skipped entirely, in this mode, there is a double fire every 360° of the crankshaft turning and a fuel saving of three quarters of the full power mode. Again, the power loss should be less than three quarters of full power.
The description above refers to alternating the one cylinder receiving the injection when two cylinders are operatively receiving an injection and a skipped injection. This alternating method of proceeding is preferred because it achieves more uniform heat balance and more even part wear between the two assemblies involved. The alternation preferably is programmed to take place every predetermined number of piston cycles. The predetermined number of cycles can be any number. A preferred range of number of cycles is 1-10 with five being a preferred number.
It will be understood that the engine may be provided with a conventional lubricating and cooling system.
Referring now to
Electrically operated solenoid valves 124 are mounted in opening and closing relation to the nozzle of each injector 48. The opening and closing of the solenoid valve 124 determines the amount of fuel injected by each of the injectors 48. The solenoid valves 124 are normal spring biased into a closed position and opened when the solenoid of the valves 124 is electrically energized.
As shown schematically in
Referring now more particularly to
The chart also includes for each piston and cylinder assembly 14, an illustration of the configuration of the inlet and outlet cam 88 and 90. The illustrations show the relative circumferential position on the camshaft 84 of the outlet cam 90 and the related inlet cam 88 to indicate the opening of the outlet valves 70 during the exhaust event and the opening of the inlet valves 56 during the inlet event without regard to their exact beginning or end which is in accordance with accepted practice.
Each communicated pair of piston and cylinder assemblies 14 is fired together for one 180° turn during each of four consecutive 180° turns of the crankshafts 32 and the firings of a different pair take place in each of the four consecutive 180° turns. As shown, the order of firing is 1-3-4-2.
While the engine 10 is shown as being diesel operated with compression ignition, the engine could be made to operate on a conventional spark ignition basis with a lesser compression ratio and a positioning of the fuel injectors with mating air injectors to direct an appropriate air fuel mixture into the combustion chamber through the open inlet valve during the inlet stroke.
It will be understood that while the engine is disclosed as an inverted V-8, it could be made into an inverted V-6 by appropriately changing the crank portions of the crankshafts from the 180° shown to 120°. Other numbers of piston/cylinders are possible.
It will also be understood that the engine may be provided with a conventional lubricating and cooling system.
Referring now more particularly to
The frame assembly 12 includes a lower pan component 16, a central block component 18 and an upper head component 20.
The eight piston and cylinder assemblies 14 include eight cylinders 22 mounted in the block component 18 in two banks of four inline cylinders 22. The cylinders 22 of the two banks have their longitudinally axes dispose in two common bank planes which are disposed on opposite sides of a bisecting vertical plane in upwardly converging angular relation with respect to one another (i.e., an inverted V configuration).
As best shown in
The block component 18 which carries the cylinders 22 has structure defining upwardly facing surface means in the form of first and second angularly related planar surfaces 24 disposed within the aforesaid two angularly related planes.
The head component 20 is detachably fixedly supported on the block component 18 and has two angularly related downwardly facing planar surfaces 26 which sealingly engage the two angularly related upwardly facing surfaces 24 of the block component 18. The two angularly related downwardly facing surfaces 26 include portions 28 which cover the open ends of the cylinders 22. The remainder of the surfaces 26 are sealingly engaged with coextensive portions of the upwardly facing surfaces 24 by means of two separate gaskets 30 one in each of the two angularly related surfaces 24 and 26.
The block component 18 is detachably fixedly supported on the pan component 16 which, in turn, is configured to rest on and be secured to a horizontal supporting surface. The block component 18 cooperates with the pan component 16 when fixedly supported thereon to rotatably support two parallel transversely spaced crankshafts 32.
To this end, the block component 18 includes spaced vertical wall structures 34 which extend transversely in a direction perpendicular to the axis of rotation of the crankshafts 32 and define downwardly facing lower surface means which includes two transversely spaced semi-cylindrical bearing engaging surfaces 35, shown in dotted lines in
As best shown in
The eight piston and cylinder assemblies 14 also include eight pistons 42 slidably sealingly mounted in the eight cylinders 22. The four pistons 42 associated with one bank of cylinders 22 are pivoted to one end of four piston rods 44 which, in turn, are rotatably connected at the other ends thereof to four crank arm portions 46 of one of the two crankshafts 32. The four pistons 42 associated with the other bank of cylinders 22 are pivoted to one end of four other piston rods 44 which, in turn, are rotatably connected at the other ends thereof to four crank arm portions 46 of the other one of the two crankshafts 32. The fact that the crankshafts 32 rotate in different directions does not prevent the pistons 42 of each cooperating pair of assemblies 14 from having simultaneous movements which they are geared together to do.
From the above, it can be seen that the eight crankshaft connected piston and cylinder assemblies 14 include two crankshafts 32, eight cylinders 22, eight pistons 42, and eight piston rods 44. The eight assemblies 14 also include eight fuel injectors 48, one associated with each cylinder 22.
The positioning of each injector 48 in its associated assembly 14 in relation to the cam shaft actuated valving which accomplishes the conventional four cyclical events in each assembly during two revolutions of the crankshafts 32 is best shown in
As best shown in
Mounted in opening and closing relation to each valve seat 52 is an inlet poppet valve 56 having a valve stem 58 which extends upwardly through the associated inlet opening 50. Each inlet valve stem 58 extends upwardly from the associated inlet opening 50 through a wall portion 60 formed in the head component 20. A coil spring 62 surrounds each inlet valve stem 58 and has in its power end in engagement with the associated wall portion 62 and its upper end engaged with a washer 64 fixed to the associated valve stem 58. In this way, each inlet poppet valve 56 has its valve portion normally spring biased into closed sealing relation to the associated inlet valve seat 52.
Each pair of inlet openings 50 is associated with a single, somewhat larger outlet opening 66. As best shown in
As before, each outlet poppet valve 70 is spring biased so that its valve portion engages the associated outlet valve seat 68 in sealed relation. Thus, a coil spring 76 surrounds each outlet valve stem 72 in engagement between the wall section 76 and a washer 78 fixed to the end of each outlet valve stem 72.
As best shown in
The two inlet poppet valves 56 and single outlet poppet valve 70 associated with each of the four assemblies 14 of each bank are moved in cyclically timed relation by a cam actuating means including a cam shaft 84 and a plurality of cam followers hereinafter to be more fully described.
As best shown in
Each cam shaft 84 includes a series of inlet and outlet cams or camlobe surfaces 88 and 90 formed thereon for moving the associated inlet and outlet valves 58 and 70 into open positions against the spring bias thereof in proper cyclically timed relation.
The cam followers, as shown, are in the form of levers. The two inlet valves 56 associated with each assembly 14 are moved by a U-shaped lever 92 having the free ends of the legs of the U-shape connected to the upper ends of the two associated inlet valve stems 58 (see
The central portion of each leg of each U-shaped lever 92 is bifurcated and has a shaft mounted roller 98 therein in a position to be engaged by inlet cams 88 of the associated cam shaft 84.
The U-shaped configuration of each lever 92 provides space between the legs thereof to mount the associated injector 48 vertically downwardly so that its lower discharge end can extend centrally into the open end of the associated cylinder 22, enabling the injected fuel to mix with air within a recess formed in the upper end of the associated piston 42 which is brought to an auto ignition pressure and temperature at the end of the compression stroke.
The U-shaped configuration also provides space between the legs of each U-shaped lever 92 within which to position an outlet cam follower in the form of an adjustable outlet valve moving lever 98. Each outlet lever 98 has an inner end connected to the upper end of the associated outlet valve stem 72, an opposite outer end pivoted on the upper end of a hydraulic adjusting unit 100 mounted in the head component 20 and a central bifurcated portion provided with a cam actuated outlet roller 102 disposed in longitudinal alignment with an associated outlet cam 90 of the associated cam shaft 84.
Referring now more particularly to
Each recess 108 is disposed in the portion of the head component 20 overlying the structure of the block component 18 between the open ends of an associated pair of cylinders 22. Each recess 108 is defined by inverted perpendicularly related U-shaped walls which open downwardly toward an interim shallow U-shaped wall surface 110 between the two planar surfaces 24 of the block component 18.
The passage 104 in each insert 106, as shown in
Preferably, each insert 106 is made of a heat resistant material, for example inconel and is cut into pieces horizontally along the axis of the central passage portion 114. This two-piece construction enables the surfaces which define the passage 104 to be polished. Each two-piece insert 106 fits snuggly in the associated recess 108 and is fixedly retained therein by engagement with the associated surface 110 when the head component 20 is fixed onto the block component 18 by a series of bolts (not shown).
It can thus be seen that there has been provided an internal combustion engine 10 having two banks of four piston and cylinder assemblies 14 arranged in an inverted V configuration so that there are four cooperating pairs of assemblies 14, each pair having (1) cylinders 22 with adjacent combustion chambers intercommunicated by a passage 104 extending therebetween, and (2) crankshaft-driven pistons 42 in the cylinders 22 movable toward and away from the combustion chambers thereof through successive cycles, each including a compression stroke followed immediately by a power drive stroke. A computer-controlled fuel injector 48 capable of being selectively controlled to operate either to inject fuel into (a) both cylinders 22 of the pair to establish therein a double fire single expansion mode (1) or (b) into only one cylinder of a pair to establish therein a single fire double expansion mode (2). The single fire double expansion mode may also be referred to as a shared power drive event because the power generated by combustion in one cylinder of the pair is shared with the other cylinder via passage 104.
Preferably, when operating in mode (2), the one cylinder receiving the injection is alternated between the pair every predetermined number of piston cycles. This number is predetermined in random fashion in accordance with the teaching of U.S. Pat. No. 4,172,434, the entire disclosure of which is hereby incorporated by reference into the present specification.
Referring now more particularly to
The vehicle 138 is shown schematically to include the engine 10 with its eight injectors 48 connected by lines 126 to the battery-powered computer 128. The engine 10 is shown schematically to be drivingly connected to a convention lever controlled transmission 140 which, in turn, is selectively connected and disconnected to the vehicle 138.
The assembly of the transmission 140 is shown as including a conventional gear shift lever 142 with an exemplary small truck PRNDL position option. The N position stands for neutral and is the “idle” position where the transmission 140 is disconnected from the vehicle so as not to be moved by the engine 10 while the engine 10 is in operation, the R, D and L positions are the drive positions [R for reverse, D for drive (normally) and low (for rare occasions when greater torque is required for the vehicle]. When the lever 142 is in a drive position, the transmission 140 is connected to drive the vehicle 138 for movement by the engine 10.
Still referring to
As best shown in
Preferably, because cruise control is set for a steady speed, a significant amount of torque is not required. Thus, the engine can be operated in a lower power mode usually. Consequently, when the cruise control system 144 is actuated and operative, a 50% fuel saving can normally be achieved with the power available being greater than 50% by virtue of the pair of shared power drive events occurring in four pairs of piston and cylinder assemblies (an estimated 70%). Of course, since many cruise control systems have the ability to temporarily suspend the set speed, and later resume it, increased power through the other higher power modes may be used to achieve the set speed as well.
When the cruise control system 144 is deactuated and not operating, the vehicle 138 is operated normally in the manner hereinafter described which includes the method of operating the engine 10 or 10′ in accordance with the principles of the present method invention. The method may be automatically performed as well when the cruise control system is increasing power to resume to a set speed.
The method is similar to the usual method in that it starts with the vehicle 138 at rest and the lever 142 in neutral with the engine 10 operating and movement of the vehicle 138 occurs by moving the accelerator pedal 136 away from its initial position toward its maximum position to progressively increase the power delivered by the engine and hence the speed of movement of the vehicle proportional to how far the pedal is moved away from the initial position.
The method differs from the usual because the engine has four different pairs of piston and cylinder assemblies capable of operating in five different power level steps based on four changes in the number of injections and the injection option of dual firing (mode 1) or single injection shared power (mode 2).
The method involves transmitting signals from the pedal position sensor 134 through lines 132 to the computer 128 which are indicative of the position the pedal is in. The computer processes the position signals and determines a zone of pedal positions the pedal is in including a low power zone of positions between the initial position and a first transition position, a first intermediate power zone of positions between the first transition position and a second transition position, a second intermediate power zone of positions between the second transition position and a third transition position, a third intermediate power zone of positions between the third transition position and a fourth transition position, and a high power zone of positions between the fourth transition position and the maximum position.
As a result of determining the power zone the pedal 136 is in, a zone signal indicative of the zone determined is transmitted to the injectors 48 of the four pairs of assemblies. The injectors 48 receive the zone signals as corresponding step signals so that the four pairs of assemblies operate in the desired power level step for the corresponding power zone determined. That is, a zone signal for a given power mode represents the collective signals sent to individual fuel injectors.
The major distinguishing characteristic as between the power level steps is that a different number of injections occur in each. The number is dependent on the injection option of either two injections per pair as in the dual firing mode (mode 1) or one injection per pair as in the single injection shared power mode (mode 2). Since (mode 2) involves the injection of the lesser amount of fuel, when all four pairs of assemblies are operating in (mode 2) there is the least amount of fuel injected. This step of operation is designated as a low power level step equivalent to the low power zone of the pedal positions. In the low power level step, one of each of the four pairs is skipped an injection and the drive event of each of the four pairs of assemblies is a pair of shared power drive events. Consequently, there is a ½ (50%) fuel savings but a greater than the expected 50% of power available due to the sharing (an estimated 70%).
The next step up is the first intermediate power level step equivalent to the first intermediate power zone of pedal positions. In this step, three pairs of assemblies are operating in (mode 2) and one pair in (mode 1) so that there is only three skipped injections and a total of 5 out of 8 injections which take place. Consequently, with this additional injection, the fuel saving goes from 4/8 to ⅜ (37.5%) and the power available rather than going from the expected 50% to 62.5% is at an estimated 77.5% because three pairs still have shared power drive events.
The next step up is the second intermediate power level step equivalent to the second intermediate zone of pedal positions. In this step, two pairs of assemblies operate in (mode 2) and two pairs operate in (mode 1) so that there are two skipped injections and a total of 6 out of 8 injections that take place. Consequently, with this additional injection, the fuel saving goes from ⅜ to 2/8 (25%) and the power available rather than going from an expected 62.5% to 75% is at an estimated 85%.
The next step up is third intermediate power level step equivalent to the third intermediate power zone of pedal positions in this zone. In this step, one pair of assemblies is in (mode 2) and three pairs are in (mode 1) so that there is one skipped injection and a total of 7 out of 8 injections that take place. Consequently, with this additional injection, the fuel saving goes from 2/8 to ⅛ (12.5%) and the power available rather than going from an expected 75% to 86.5% is an estimated 95⅞%.
The next and last step up is the high power level step equivalent to the high power zone of pedal positions. In this step, all four pairs are in (mode 1) with no skipped injections and 8 out of 8 injections taking place with no fuel savings and 100% of power available.
In order to smooth the transition between the power level steps, the position signals are also processed by the computer 128 to determine the amount of fuel injected per injection as between minimum and maximum so that the total amount of fuel injected progressively increases or decreases as the accelerator pedal is moved in corresponding opposite directions between the initial and maximum positions.
When the four pairs of assemblies are in the low power level step, the amount of fuel injected is at a minimum and increases progressively to the end of the step to a first maximum where the pedal is at the first transition position which also is the position for the start of the next step which has an added injection. In order to have a smooth transition between the two steps, the total amount of fuel injected at the end of the preceding step is made to be equal to the total amount of fuel at the beginning of the following step. At the end of the low power level step, all four pairs of assemblies are at the first maximum level so that at the start of the next step any pair of assemblies staying in (mode 2) remains at the first maximum and any pair changing to (mode 1) is reduced an amount equal to one injection at the first maximum amount. As the step progresses to its end, the amount of fuel injected increases until at the end with the pedal in the second transition position the amount is at a second maximum amount. The same procedure of starting with an equal total amount by reducing the pairs operating in (mode 1) and increasing to a maximum for that step is continued at the third and fourth transition positions with third and fourth maximums at the ends.
Preferably, there is provided a sensor (not shown) which is capable of sensing a condition determinative of the load being carried by the vehicle. For example, a load cell between a semi rig cab and trailer measuring pull force, a scale sensor for measuring added load, or an acceleration sensor for a determined condition. The signal indicative of the load carried when transmitted to the computer is processed by the computer to modify the transition positions and/or the maximum amounts of fuel injected at the end of each step.
For example, when a no load signal is received, the computer determines the first transition position to be moved to a new position away from the initial position and the others proportionally, and/or the first maximum amount of fuel injected is determined to be ⅛ of maximum and the other maximums stay at ⅛ of maximum so that the only change at each transition is to reduce the assembly changing from one injection to two injections to ½ of ⅛ of maximum for each of the two.
When a max load signal is received, the computer determines the fourth transition position to be moved to a new position away from the max position and the others proportionally and/or the first maximum amount of fuel injected is determined to be actual maximum and the other maximums stay at actual maximum so that the only change at each transition position is to reduce the assembly changing from one injection to two injections to ½ of actual maximum for each of the two.
There are apparent progressive changes between the two extremes commensurate with load signals indicative of loads between no load and max load.
The foregoing embodiments have been provided solely to illustrate the structural and functional principle of the present invention and are not intended to be limiting. To the contrary, the present invention encompasses all modifications, alternations, substitutions and equivalents within the spirit and scope of the following claims.
The present application is a continuation-in-part of International Patent Application No. PCT/US2013/070387 bearing an international filing date of Nov. 15, 2013 which was published on Sep. 18, 2014 as No. WO 2014/143211, the entirety of which is incorporated herein by reference.
Number | Date | Country | |
---|---|---|---|
Parent | PCT/US2013/070387 | Nov 2013 | US |
Child | 14579229 | US |