WO2020018835A1

WO2020018835A1 - Fuel and turbocharger control systems and methods for piston aircraft engine

Info

Publication number: WO2020018835A1
Application number: PCT/US2019/042471
Authority: WO
Inventors: Jeffrey K. HUNT
Original assignee: Continental Motors, Inc.
Priority date: 2018-07-20
Filing date: 2019-07-18
Publication date: 2020-01-23

Abstract

An internal combustion engine for an aircraft includes a crankshaft configured to drive a driven element; a first camshaft coupled to the crankshaft; a second camshaft coupled to the crankshaft; a fuel flow control system including a fuel pump and a fuel control actuator communicating with the fuel pump and configured to restrict fuel flow downstream to a plurality of fuel injectors; and a turbocharger control system including a wastegate, a wastegate actuator configured to partially or completely open or close the wastegate, and an electronic controller; the electronic controller operatively connected to the wastegate actuator and configured to cause movement of the wastegate actuator in response to a turbocharger discharge pressure.

Description

FUEL AND TURBOCHARGER CONTROL SYSTEMS AND METHODS FOR PISTON

AIRCRAFT ENGINE

TECHNICAL FIELD

Field of Use

[0001] This disclosure relates to internal combustion engines with fuel injection systems and/or turbochargers. More specifically, this disclosure relates to spark ignition continuous flow fuel systems and electronic turbocharger control for such engines.

SUMMARY

[0002] It is to be understood that this summary is not an extensive overview of the

disclosure. This summary is exemplary and not restrictive, and it is intended to neither identify key or critical elements of the disclosure nor delineate the scope thereof. The sole purpose of this summary is to explain and exemplify certain concepts of the disclosure as an introduction to the following complete and extensive detailed

description.

[0003] In one aspect, disclosed is an internal combustion engine for an aircraft, the engine comprising: a crankshaft configured to drive a driven element; a first camshaft coupled to the crankshaft; a second camshaft coupled to the crankshaft; a fuel flow control system comprising a fuel pump and a fuel control actuator communicating with the fuel pump and configured to restrict fuel flow downstream to a plurality of fuel injectors; and a turbocharger control system comprising a wastegate, a wastegate actuator configured to partially or completely open or close the wastegate, and an electronic controller; the electronic controller operatively connected to the wastegate actuator and configured to cause movement of the wastegate actuator in response to a turbocharger discharge pressure.

[0004] In a further aspect, disclosed is a method of using an internal combustion engine for an aircraft, the method comprising: regulating fuel flow in a fuel flow control system of the engine with a fuel control actuator positioned between a fuel pump and a plurality of injectors of the engine, the fuel flow control system comprising the fuel pump and the fuel control actuator in fluid communication with the fuel pump; and operating a wastegate actuator of a turbocharger control system with an electronic controller in response to a turbocharger discharge pressure to move a wastegate of the turbocharger control system, the wastegate actuator configured to partially or completely open or close the wastegate, the turbocharger control system further comprising the electronic controller operatively connected to the wastegate actuator.

[0005] In yet another aspect, disclosed is an internal combustion engine for an aircraft, the engine comprising: a crankshaft configured to drive a driven element; a first camshaft coupled to the crankshaft; a second camshaft coupled to the crankshaft; a fuel flow control system; and a turbocharger control system.

[0006] In yet another aspect, disclosed is a fuel flow control system comprising a fuel pump and a fuel control actuator communicating with the fuel pump and configured to restrict fuel flow downstream to a plurality of fuel injectors.

[0007] In yet another aspect, disclosed is a turbocharger control system comprising a

wastegate, a wastegate actuator configured to partially or completely open or close the wastegate, and an electronic controller; the electronic controller operatively connected to the wastegate actuator and configured to cause movement of the wastegate actuator in response to a turbocharger discharge pressure.

[0008] Various implementations described in the present disclosure may comprise additional systems, methods, features, and advantages, which may not necessarily be expressly disclosed herein but will be apparent to one of ordinary skill in the art upon examination of the following detailed description and accompanying drawings. It is intended that all such systems, methods, features, and advantages be included within the present disclosure and protected by the accompanying claims. The features and advantages of such implementations may be realized and obtained by means of the systems, methods, features particularly pointed out in the appended claims. These and other features will become more fully apparent from the following description and appended claims, or may be learned by the practice of such exemplary implementations as set forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several aspects of the disclosure and together with the

description, serve to explain various principles of the disclosure. The drawings are not necessarily drawn to scale. Corresponding features and components throughout the figures may be designated by matching reference characters for the sake of consistency and clarity.

[0010] Figure 1 is a top rear perspective view of an internal combustion engine for a small aircraft comprising an ignition system, the ignition system comprising a pair of electronic engine controllers (EECs), all in accordance with one aspect of the current disclosure and with spark plug wires, and other mechanical and electrical components removed. [0011] Figure 2 is a top rear perspective view of a one of the pair of EECs of the engine of Figure 1.

[0012] Figure 3 is a side perspective view of the EEC of Figure 2.

[0013] Figure 4 is a top front perspective view of the engine of Figure 1 in accordance with another aspect of the current disclosure and with various mechanical and electrical components removed.

[0014] Figure 5 is a pair of EECs of the engine of Figure 4.

[0015] Figure 6A is an exemplary schematic illustration of a continuous flow fuel flow control system in accordance with an aspect of the current disclosure.

[0016] Figure 6B is an exemplary schematic illustration of a continuous flow fuel flow control system in accordance with another aspect of the current disclosure.

[0017] Figure 7 is a diagram illustrating components in a continuous flow fuel flow control system in accordance with an aspect of the current disclosure.

[0018] Figure 8 is an exemplary schematic illustration of a turbocharger control system in accordance with an aspect of the current disclosure.

[0019] Figure 9 is a diagram illustrating components in a turbocharger control system in accordance with an aspect of the current disclosure.

DETAILED DESCRIPTION

[0020] The present disclosure can be understood more readily by reference to the following detailed description, examples, drawings, and claims, and their previous and following description. However, before the present devices, systems, and/or methods are disclosed and described, it is to be understood that this disclosure is not limited to the specific devices, systems, and/or methods disclosed unless otherwise specified, as such can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting.

[0021] The following description is provided as an enabling teaching of the present devices, systems, and/or methods in their best, currently known aspect. To this end, those skilled in the relevant art will recognize and appreciate that many changes can be made to the various aspects described herein, while still obtaining the beneficial results of the present disclosure. It will also be apparent that some of the desired benefits of the present disclosure can be obtained by selecting some of the features of the present disclosure without utilizing other features. Accordingly, those who work in the art will recognize that many modifications and adaptations to the present disclosure are possible and can even be desirable in certain circumstances and are a part of the present disclosure. Thus, the following description is provided as illustrative of the principles of the present disclosure and not in limitation thereof. [0022] As used throughout, the singular forms“a,”“an” and“the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a quantity of one of a particular element can comprise two or more such elements unless the context indicates otherwise. In addition, any of the elements described herein can be a first such element, a second such element, and so forth (e.g., a first widget and a second widget, even if only a“widget” is referenced).

[0023] Ranges can be expressed herein as from“about” one particular value, and/or to

“about” another particular value. When such a range is expressed, another aspect comprises from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent“about” or “substantially,” it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0024] For purposes of the current disclosure, a material property or dimension measuring about X or substantially X on a particular measurement scale measures within a range between X plus an industry-standard upper tolerance for the specified measurement and X minus an industry-standard lower tolerance for the specified measurement. Because tolerances can vary between different materials, processes and between different models, the tolerance for a particular measurement of a particular component can fall within a range of tolerances.

[0025] As used herein, the terms“optional” or“optionally” mean that the subsequently

described event or circumstance may or may not occur, and that the description comprises instances where said event or circumstance occurs and instances where it does not.

[0026] The word“or” as used herein means any one member of a particular list and also comprises any combination of members of that list.

[0027] To simplify the description of various elements disclosed herein, the conventions of “left,”“right,”“front,”“rear,”“top,”“bottom,”“upper,”“lower,”“inside,”“outside,”“inboard,” “outboard,”“horizontal,” and/or“vertical” may be referenced. Unless stated otherwise, “front” describes that end of the vehicle, engine, system, or component thereof nearest to or facing a forwardmost end the vehicle;“rear” is that end of the vehicle, engine, system, or component that is opposite or distal the front;“left” is that which is to the left of or facing left from a person sitting in the vehicle and facing towards the front; and“right” is that which is to the right of or facing right from that same person while sitting in the vehicle and facing towards the front.“Horizontal” or“horizontal orientation” describes that which is in a plane extending from left to right and aligned with the horizon.“Vertical” or “vertical orientation” describes that which is in a plane that is angled at 90 degrees to the horizontal.

[0028] In one aspect, a fuel control system and a turbocharger control system for an engine and associated methods, systems, devices, and various apparatuses are disclosed herein. In one aspect, the fuel control system can comprise a fuel bypass actuator and the turbocharger control system can comprise a wastegate actuator.

[0029] As an initial matter, a vehicle such as an aircraft can comprise an internal combustion engine (ICE) 100. As shown in Figure 1 , the engine 100 can be, for example and without limitation, a 4-stroke piston-powered gasoline engine comprising a crankcase 110, which can also be considered an engine block, and a crankshaft (not shown). The engine 100 can further comprise an ignition system 120. The engine 100 and the crankshaft specifically can be configured to drive driven elements such as a propeller (not shown), which can be considered separate from the engine, and components that can be considered part of the engine such as, for example and without limitation, a flywheel 105 and ignition controllers 130.

[0030] In some aspects, the ignition controller 130 can comprise a magneto. In other

aspects, as shown in Figure 1 , the ignition controller 130 can be an electronic engine controller (EEC), which can comprise a permanent magnet generator (PMG) comprising a connection hub 180. The engine 100 can comprise a plurality of camshafts (not shown) to mechanically control fuel and air mixture delivery and exhaust removal into and from each of several combustion chambers (not shown) in the engine 100. Each of the camshafts can control such fuel and air delivery by opening and closing valves (not shown) providing access to the respective combustion chambers. As shown, the engine 100 can define a front end 102, which can be defined at least in part by the flywheel 105, and a rear end 103 disposed distally from the front end 102.

[0031] The electronic engine controller (EEC) is contemplated to include any one of a family of electrical or electronic engine control systems including, for example and without limitation, full authority digital engine controls (FADEC), supervisory controls, ignitions systems, and derivatives therof. FADEC is contemplated to include an EEC in which the primary functions are provided electronically and the EEC has full-range authority over the engine power or thrust. An ignition system is the system in an engine that provides electrical energy to each combustion chamber of an internal combustion engine at the appropriate time.

[0032] A permanent magnet generator is contemplated to include any device that converts mechanical energy to electrical energy by translating changes in a magnetic field produced by mechanical motion to the electrical energy. In some aspects, a permanent magnet generator can be a direct-current-producing device in which an“armature” in the form of wound wire rotates within or about a permanent magnet“stator.” Such a DC power permanent magnet generator is sometimes referred to as a“generator” but in a narrower sense than contemplated here. In other aspects, a permanent magnet generator can be an alternating-current-producing device in which a permanent magnet rotor typically rotates within or about a stationary stator— and armature— in the form of wound wire. Such an AC power permanent magnet generator is sometimes referred to as an alternator.

[0033] Each of the ignition controllers 130 of the ignition system 120 of the engine 100 can be coupled to a drive shaft (not shown) extending from the engine 100. A permanent magnet generator of a first ignition controller or EEC 130 of the pair of ignition controllers 130 can be driven by the first driveshaft, and a permanent magnet generator of a second ignition controller or EEC 130 of the pair of ignition controllers or EECs 130 can be driven by the second driveshaft. Each of the permanent magnet generator of the first EEC 130 and the permanent magnet generator of the second EEC 130 can be configured to generate AC power and then supply DC power to programmable controllers, each of which can be configured to direct energy to a plurality of fuel igniting devices 190. Each of the programmable controllers can be configured to apply a timing curve or timing map to the plurality of fuel igniting devices 190 and deliver an electrical spark to each combustion chamber in the order of compression and combustion of the fuel-air mixture in the combustion chambers.

[0034] The engine 100 can further comprise a fuel system (not shown) for delivery of the fuel— directly or indirectly— to the combustion chamber; an electrical system (shown only partially in the form of the ignition system 120); an air delivery system comprising an intake manifold; and a variety of other components such as, for example and without limitation, a fuel injector system or carburetor; and an exhaust system for removal of waste products from the engine 100. In some aspects, the engine 100 can be normally aspirated or ventilated. In other aspects, as described herein, the engine 100 can comprise a turbocharger. As familiar to one of ordinary skill in the art, an engine such as the engine 100 can come in a variety of sizes and configurations and is not limited to the examples described herein.

[0035] In some aspects, the aircraft can be a small aircraft comprising a single engine 100.

In other aspects, the aircraft can comprise more than one engine 100. In some aspects, the aircraft can be a fixed wing aircraft configured to generate lift through upward pressure on an airfoil shape that makes up each fixed wing of the aircraft as the airfoil shape— together with the rest of the aircraft— is propelled through the air through by the aforementioned propeller at a sufficient speed to create such lift. In other aspects, the aircraft can be a rotary aircraft (not shown) comprising a horizontal rotor (not shown) configured to create such lift. In some aspects, the engine 100 can comprise a full authority digital engine control (FADEC) system. In other aspects, the engine 100 need not comprise a FADEC system.

[0036] Each of the crankshaft and the camshafts can be housed within the crankcase 110.

As shown, the engine 100 can comprise a plurality of cylinders 140 and a plurality of cylinder heads 150, each of which can be dedicated to a single cylinder 140 or to more than one cylinder 140. In some aspects, as shown, the engine 100 can comprise four cylinders 140 and four cylinder heads 150. In other aspects, the engine 100 can comprise more than four cylinders or less than four cylinders. For example and without limitation, as shown in Figure 4, the engine 100 can comprise six cylinders 140 and as many cylinder heads 150.

[0037] As would be familiar to one of ordinary skill in the art, each cylinder head can

comprise a plurality of intake valves (not shown) and a plurality of exhaust valves (not shown) to allow, respectively, a fuel-air mixture to enter and an exhaust air mixture to exit the corresponding combustion chamber. Each of the valves can be moved in and out with a rod extending from the valve to the corresponding camshaft. Each set of valves can be covered with a valve cover 160. The fuel-air mixture can be brought into each combustion chamber via the aforementioned intake air manifold and can be brought out of the combustion chamber via an exhaust air manifold 170. Heat can be delivered to each combustion chamber via a spark produced by each of a plurality of fuel igniting devices 190. Each of the plurality of fuel igniting devices 190 can be, for example and without limitation, a spark plug.

[0038] Operation of the engine 100 with ignition controllers such as the EECs 130 can yield any one or more of several benefits over operation of the engine 100 without the EECs (e.g., with magnetos). With the EECs 130, timing can be varied to match loads encountered in each of the flight stages and sub-stages to improve efficiency, and other benefits can be achieved.

[0039] A wiring harness can connect each of the pair of ignition controllers 130 to other components of the ignition system 120 or the engine 100 such as through, for example and without limitation, the connection hub 180. More specifically, such a wiring harness can connect to various sensors and other inputs measuring, for example and without limitation, manifold air pressure or manifold air temperature from a portion of the intake air manifold.

[0040] As shown in Figures 2 and 3, the EEC 130 can comprise a body 210 and a drive shaft 220 defining a drive axis 221. The body 210 can define a mounting end or a first end 202 and a free end or a second end 203. The connection hub 180 can extend from a surface of the body 210. The drive shaft 220 can extend from and connect, directly or indirectly, to the crankshaft. In some aspects, the ignition controller 130, including when embodied as an EEC 130, can interface with the engine 100 as would the

aforementioned magneto.

[0041] As shown in Figure 4, each of the EECs 130 of the engine 100 can be oriented in an opposite direction of that shown in the engine 100 of Figure 1 and can be mounted to a gear train 410. Intake manifold portions 420a, b can receive sensors.

[0042] As shown in Figure 5, each of the EECs 130 can comprise the aforementioned body 210, which can be shaped and oriented such that the connection hub 180 and other components such as the connection points for the high-tension leads are easily accessible.

[0043] In some aspects, as shown in Figures 6A, 6B, and 7, an opportunity exists to improve continuous flow fuel injection fuel systems by incorporating a fuel control actuator in addition to or in place of the existing pilot controlled mixture valve. The bypass actuator can provide a mechanism to automatically lean the engine during operation without the need for individual injector control. Current methods for fuel leaning comprise manual mechanical air reference and individual cylinder fuel injector control. Manual mechanical air reference does not provide continuous adjustment during each of the different modes of operation, and injector control adds complexity and cost.

[0044] More specifically, an automatic mixture control device and method can control fuel flow in a spark ignition piston aircraft engine with a fuel control actuator and sensors. The fuel flow prescription can be derived from varying combinations of throttle position, manifold pressure, manifold air mass flow, and engine speed, among other parameters, depending on turbocharged or naturally aspirated engine configuration and constant speed or fixed pitch propeller configuration. In some aspects, to lean injection, the fluid control actuator, which can be a solenoid valve, can be connected to an unmetered fuel pressure line and can bypass the fuel going to the cylinders back to a fuel tank or pump inlet. The fuel delivered to the throttle and continuous flow injectors at each cylinder can be reduced by the amount bypassed, thereby leaning the fuel-to-air mixture. In other aspects, as will be described, the fuel bypass actuator can simply restrict flow of the fuel.

[0045] Figures 6A and 6B are exemplary schematic illustrations of a continuous flow fuel flow control system 600 in accordance with aspects of the current disclosure. The fuel flow control system 600 can be used in the engine 100.

[0046] As shown in Figure 6A, the fuel flow control system 600 can comprise, among other elements described herein, a fuel pump 602 in fluid communication with a fuel tank 604 and in operative communication with both a fuel metering unit 606 and a fuel control actuator 608, which as shown can be a fuel bypass actuator. In some implementations, the fuel pump 602 can be a positive displacement, vane type pump. The primary functions of the fuel pump 602, which can be a fuel injection pump, comprise supplying fuel under pressure to the rest of the fuel flow control system 600 and performing certain metering functions such as idle and altitude compensation if turbocharger-equipped. The fuel metering unit 606 can proportion fuel flow as engine requirements are changed at a fuel throttle 720 (shown in Figure 7). Traditional implementations of the fuel metering unit 606 comprise a pilot-controlled mixture adjustment valve. The fuel metering unit 606 is shown in dashed lines to indicate that, in some aspects, the fuel pump 602 can be positioned in operative communication with a fuel manifold 614. The fuel control actuator 608 can comprise a mechanism to automatically lean the engine 100 during operation without the need for individual injector control. A controller 610 can reference one or more sensors 612 and can command the fuel control actuator 608 to achieve a prescribed fuel flow. The fuel manifold 614 can equally distribute fuel flow to all of the engine cylinders by dividing the metered fuel flow between a plurality of injectors 616 in the fuel flow control system 600. The fuel manifold 114 can function as a positive idle cut-off valve whenever the engine 100 is shut down. Each of the fuel injectors 616 can be provided with a nozzle, which can be responsible for atomization and subsequent vaporization of raw metered fuel. The nozzle can spray fuel continuously into the intake chamber of the engine cylinder head. No timing adjustments need be made. Heat from the cylinder head can quickly accomplish vaporization of the atomized fuel. In some aspects, as shown, the fuel control actuator 608 as a fuel bypass actuator can cause the fuel to bypass the downstream portions of the fuel flow control system 600 and return to the fuel tank 604— or to the fuel pump 602 through the path 620 shown.

[0047] In other aspects, as shown in Figure 6B, the fuel control actuator 608 can be

positioned in the fuel flow control system 600 between the fuel pump 602 and the fuel metering unit 606, in which case each of the controller 610 and the sensor 612 can still provide input or control to the fuel control actuator. As also shown, however, instead of causing the fuel to bypass the downstream portions of the fuel flow control system 600 and return to the fuel tank 604 or the fuel pump 602, the fuel control actuator 608 can restrict flow to those downstream portions.

[0048] Figure 7 is a diagram illustrating the fuel flow control system 600. As shown, the fuel control actuator 608, which in some implementations can be a solenoid valve and is shown as a fuel bypass actuator but as noted above need not bypass and can instead simply restrict flow downstream, is fluidly connected to the fuel pump 602 via an unmetered fuel pressure line 718. The fuel control actuator 608 can operably

communicate with both the unmetered fuel pressure line 718 and with a metered fuel pressure line 722 to regulate the amount of fuel entering the metered fuel pressure line 722. The metered fuel pressure line 722 can feed into the fuel manifold 614, which can communicate with fluid output lines such as a gauge line 724 connected to a fuel pressure gauge 726, and such as injector lines 728 communicating with respective fuel injectors 616. As shown, the fuel control actuator 608 can thereby regulate the amount of fuel admitted into the metered fuel pressure line 722 from the bypass line (i.e. , the unmetered fuel pressure line 718).

[0049] In some aspects, the fuel flow control system 600 and specifically the fuel control actuator 608 can comprise a normally closed bypass solenoid. In such aspects, the controller 610 (shown in Figure 6A) can pass electrical current through the solenoid to proportionally bypass fuel from the fuel pump 602 back to either the fuel tank 604 or an inlet of the fuel pump 602. The solenoid bypass orifice can be sized appropriately to ensure that if the fuel control actuator 608 fails in an open position the amount of fuel bypass is limited.

[0050] In other aspects, the fuel control actuator 608 of the fuel flow control system 600 can comprise a normally open restriction solenoid placed after the fuel pump 602. In such aspects, the controller 610 can pass electrical current through the solenoid to

proportionally restrict fuel. The restriction solenoid can be designed with a bypass orifice to allow fuel flow if the solenoid fails in a closed position.

[0051] A controller such as the EEC 130 or another electronic controller such as the

controller 610 can measure fuel flow and can control or modulate the solenoid with a proportional-integral-derivative (PID) algorithm. The fuel flow setpoint can be determined from measured or estimated engine or aircraft parameters such as, for example and without limitation, engine speed, manifold mass air flow, and throttle position.

[0052] In other aspects, as shown in Figures 8 and 9, an opportunity exists to improve safe operation of turbochargers on spark ignition piston aircraft applications. Spark ignition piston aircraft engines have incorporated turbochargers from the early 1910s. The turbocharger is generally still the most widely used air charging source in current production aircraft engines. The turbocharger controller can be a simple pneumatic- mechanical-over-hydraulic device which contains parts such as an aneroid bellows, a spring, an adjustment screw, and an oil restrictor valve assembly. Current turbocharger control methods for piston aircraft engines can use air pressure reference to actuate an oil circuit, which in turn can operate the turbocharger’s wastegate. Conventional equipment aircraft spark ignition engine turbocharger systems can incorporate one of the following three types of controllers: absolute pressure controller, variable absolute pressure controller, and sloped controller. The absolute pressure controller regulates the wastegate actuator to prevent turbocharger compressor discharge pressure (measured between the turbocharger compressor and throttle plate) from exceeding a prescribed pressure as determined by the engine manufacturer. The variable absolute pressure controller uses a throttle-controlled cam to vary the prescribed turbocharger compressor discharge pressure limit. The sloped controller maintains a prescribed turbocharger compressor discharge pressure at wide-open throttle to reduce the prescribed pressure limit at lower manifold pressure settings. The controllers all use oil pressure to hydraulically open and close the turbocharger wastegate. Such conventional systems are complex and heavy.

[0053] In one aspect, a turbocharger control method for spark ignition piston aircraft engines can reference turbocharger discharge pressure, manifold air pressure, and optionally throttle position to control turbocharger discharge pressure with a wastegate actuator. The throttle position can be used in lieu of or in combination with manifold air pressure. The method uses a standard air pressure-actuated wastegate and a novel control method to provide increased performance with less complexity and weight. This method replaces the current oil-actuated wastegate with a different type of wastegate (such as a pneumatic-actuated wastegate) and replaces the slope controller (mechanical actuator) with an electronic controller, a sensor, and a pneumatic actuator. Through use of a wastegate actuator, the method limits turbocharger discharge pressure to a pressure prescribed by the engine manufacturer and also maintains a prescribed pressure differential (such as two inches of mercury) between the turbocharger discharge pressure and the engine manifold pressure.

[0054] In another aspect, a turbocharger control system can comprise a wastegate, a

wastegate actuator configured to partially or completely open or close the wastegate, an electronic controller operatively connected to the wastegate actuator, and at least one sensor in operative communication with to the electronic controller, the at least one sensor configured to read turbocharger discharge pressure, whereby the electronic controller is configured to cause movement of the wastegate actuator responsive to a turbocharger discharge pressure reading received from the at least one sensor.

[0055] In another aspect, the at least one sensor can be further configured to read manifold air pressure and/or to monitor a position of a throttle plate in a throttle, and the electronic controller can be further configured to cause movement of the wastegate actuator responsive to not only the turbocharger discharge pressure reading, but also responsive to the sensed position of the throttle plate and/or to the manifold air pressure reading.

[0056] Figure 8 is an exemplary schematic illustration of a turbocharger control system 800 in accordance with an aspect of the current disclosure. The turbocharger control system 800 can be used in the engine 100.

[0057] As shown in Figure 8, a turbocharger 16 can use exhaust air from exhaust cycles of the engine 100 to compress intake air in subsequent cycles. A controller 810 can receive readings from at least one sensor (not shown) regarding turbocharger discharge pressure, i.e., pressure at an intake side of a throttle 814, and at least one of manifold air pressure, i.e., pressure at a downstream side of the throttle 814, and a position of a throttle plate 917 (shown in Figure 9) in the throttle 814. The control method can actuate a wastegate 812 (which can be a pneumatic wastegate) to cause exhaust gas to bypass the turbocharger 816 and thereby control intake pressure. As shown, an intercooler 820 can be positioned to cool air between the turbocharger 816 and the throttle 814. The control method described herein is unique to aircraft piston engines and their altitude and performance requirements. Figure 8 shows that the controller 810 (which can be an electronic controller) can be operatively connected to both the wastegate 812 and the throttle 814.

[0058] Figure 9 is a diagram illustrating components of the turbocharger control system 800.

Compressed air flow from the turbocharger 816 can be routed to the engine cylinder via a conduit 918, and exhaust from the engine cylinder can be directed completely back to the turbocharger 816 via a conduit 920 if the wastegate 812 is closed. Otherwise, a portion of that exhaust can escape the turbocharger control system 800 via a discharge conduit 922. A pneumatic wastegate actuator 913 in the wastegate 812 can be configured to partially or completely open or close the wastegate 812. At least one sensor (not shown) can be operatively connected to the electronic controller 810 (shown in Figure 8), and the at least one sensor can be configured to read turbocharger discharge pressure (i.e., air pressure in the region of conduit 918 at an intake side 917A of the throttle plate 917). The at least one sensor can also be configured to read manifold air pressure (i.e., pressure in the region of conduit 918 at a downstream side 917B of the throttle plate 917, where compressed air flow arrow 915 is located). The electronic controller 810 (shown in Figure 1) can therefore be configured to cause movement of the pneumatic wastegate actuator 913 responsive to pressure readings received from the at least one sensor. The at least one sensor can be further configured to monitor a position of the throttle plate 917, and the electronic controller 810 can be further configured to cause movement of the pneumatic wastegate actuator 913 responsive to the sensed position of the throttle plate 917 as well as responsive to the pressure readings.

Alternatively, in other implementations, the electronic controller 810 can be configured to instead cause movement of the pneumatic wastegate actuator 913 responsive only to a turbocharger discharge pressure reading and the sensed position of the throttle plate 917.

[0059] In some aspects, the turbo control system can comprise a pneumatically controlled wastegate 812, where the wastegate 812 is opened when air pressure of a lower chamber is greater than a pressure in an upper chamber. The upper chamber and the lower chamber can be separated by a flexible diaphragm connected to a wastegate valve control arm. The upper chamber can have a spring to allow an offset in a pressure required to overcome the spring and move the diaphragm, thereby opening the wastegate control valve. The upper chamber can be connected to an upperdeck pressure just before the throttle plate 917, and the lower chamber can be connected to the manifold pressure just after the throttle plate 917. In such aspects, the wastegate can effectively maintain a differential pressure across the throttle equal to the spring force.

[0060] A controller such as the EEC 130 or another electronic controller can be connected between the upper chamber of the wastegate 812 and the manifold pressure. The wastegate actuator 913 can comprise a solenoid that directs either ambient (low pressure) air or manifold air to the upper chamber of the wastegate 812.

[0061] The controller can measure manifold air pressure and can control or modulate the solenoid control current with a PID algorithm. The manifold air pressure setpoint can be determined from measured or estimated engine or aircraft parameters such as, for example and without limitation, engine speed, manifold air mass flow, fuel flow, and throttle position.

[0062] In one exemplary aspect, an internal combustion engine for an aircraft can comprise a crankshaft configured to drive a driven element; a first camshaft coupled to the crankshaft; a second camshaft coupled to the crankshaft; a fuel flow control system comprising a fuel pump and a fuel control actuator communicating with the fuel pump and configured to restrict fuel flow downstream to a plurality of fuel injectors; and a turbocharger control system comprising a wastegate, a wastegate actuator configured to partially or completely open or close the wastegate, and an electronic controller; the electronic controller operatively connected to the wastegate actuator and configured to cause movement of the wastegate actuator in response to a turbocharger discharge pressure.

[0063] In a further exemplary aspect, the fuel flow control actuator can comprise a bypass solenoid configured to cause the fuel to bypass downstream components of the fuel flow control system. In a further exemplary aspect, the engine can further comprise a bypass line fluidly connecting the fuel pump to the fuel control actuator; and a metered fuel pressure line operably connected at one end to the fuel control actuator and

communicating at another end with a fuel manifold. In a further exemplary aspect, the fuel flow control actuator can comprise a restriction solenoid configured to restrict fuel flow to downstream components of the fuel flow control system without returning fuel to a fuel tank or the fuel pump of the fuel flow control system. In a further exemplary aspect, the fuel pump can be configured to vary output volume and pressure with one of engine speed and manifold air mass flow. In a further exemplary aspect, the engine can comprise at least one sensor in operative communication with the electronic controller, the at least one sensor configured to read the turbocharger discharge pressure, the electronic controller configured to cause movement of the wastegate actuator in response to a reading of the turbocharger discharge pressure received from the at least one sensor. In a further exemplary aspect, the at least one sensor can be further configured to read a manifold air pressure at a downstream side of a throttle; and the electronic controller can be further configured to cause movement of the wastegate actuator responsive to readings of both the turbocharger discharge pressure and the manifold air pressure. In a further exemplary aspect, the wastegate actuator can be pneumatic. In a further exemplary aspect, the at least one sensor can be further configured to sense a position of a throttle plate in the throttle; and the electronic controller can be further configured to cause movement of the wastegate actuator responsive to readings of the turbocharger discharge pressure and of a manifold air pressure, and responsive to the sensed position of the throttle plate. In a further exemplary aspect, the at least one sensor can be further configured to sense a position of a throttle plate in a throttle; and the electronic controller can be further configured to cause movement of the wastegate actuator in response to the turbocharger discharge pressure reading and in response to the sensed position of the throttle plate. In a further exemplary aspect, the engine can further comprise an electronic engine controller (EEC), at least one of the fuel flow control system and the turbocharger control system being controlled at least partially by the EEC. In a further exemplary aspect, the fuel flow control system can be controlled at least partially by the EEC. In a further exemplary aspect, the turbocharger control system can be controlled at least partially by the EEC.

In a further exemplary aspect, each of the fuel flow control system and the turbocharger control system can be controlled at least partially by the EEC. In a further exemplary aspect, the at least one of the fuel flow control system and the turbocharger control system can be fully controlled by the EEC. In a further exemplary aspect, the fuel flow control system can be fully controlled by the EEC. In a further exemplary aspect, the turbocharger control system can be fully controlled at least by the EEC. In a further exemplary aspect, each of the fuel flow control system and the turbocharger control system can be fully controlled by the EEC.

[0064] In another exemplary aspect, a method of using an internal combustion engine for an aircraft can comprise regulating fuel flow in a fuel flow control system of the engine with a fuel control actuator positioned between a fuel pump and a plurality of injectors of the engine, the fuel flow control system comprising the fuel pump and the fuel control actuator in fluid communication with the fuel pump; and operating a wastegate actuator of a turbocharger control system with an electronic controller in response to a

turbocharger discharge pressure to move a wastegate of the turbocharger control system, the wastegate actuator configured to partially or completely open or close the wastegate, the turbocharger control system further comprising the electronic controller operatively connected to the wastegate actuator.

[0065] In a further exemplary aspect, the fuel flow control actuator can comprise a bypass solenoid configured to cause the fuel to bypass downstream components of the fuel flow control system. In a further exemplary aspect, the engine further can comprise a bypass line fluidly connecting the fuel pump to the fuel control actuator; and a metered fuel pressure line operably connected at one end to the fuel control actuator and

communicating at another end with a fuel manifold; wherein regulating fuel flow in the fuel flow control system comprises regulating fuel flow into the metered fuel pressure line from the bypass line. In a further exemplary aspect, the fuel flow control actuator can comprise a restriction solenoid configured to restrict fuel flow to downstream components of the fuel flow control system without returning fuel to a fuel tank or the fuel pump of the fuel flow control system. In a further exemplary aspect, the method can comprise varying output volume and pressure with one of engine speed and manifold air mass flow using the fuel pump. In a further exemplary aspect, the engine can further comprise at least one sensor in operative communication with the electronic controller, the method further comprising: reading the turbocharger discharge pressure with the at least one sensor; and causing movement of the wastegate actuator in response to a reading of the turbocharger discharge pressure received from the at least one sensor. In a further exemplary aspect, the method can further comprise reading a manifold air pressure at a downstream side of a throttle; and causing movement of the wastegate actuator in response to readings of both the turbocharger discharge pressure and the manifold air pressure. In a further exemplary aspect, the wastegate actuator can be pneumatic. In a further exemplary aspect, the method can further comprise sensing a position of a throttle plate in the throttle; and causing movement of the wastegate actuator in response to readings of the turbocharger discharge pressure, a manifold air pressure, and a sensed position of the throttle plate. In a further exemplary aspect, the method can further comprise sensing a position of a throttle plate in a throttle; and causing movement of the wastegate actuator in response to the turbocharger discharge pressure reading and in response to the sensed position of the throttle plate. In a further exemplary aspect, the engine further can comprise an electronic engine controller (EEC), wherein the method comprises controlling at least one of the fuel flow control system and the turbocharger control system at least partially with the EEC. In a further exemplary aspect, the method can comprise controlling the fuel flow control system at least partially with the EEC. In a further exemplary aspect, the method can comprise controlling the turbocharger control system at least partially with the EEC. In a further exemplary aspect, the method can comprise controlling each of the fuel flow control system and the turbocharger control system at least partially with the EEC. In a further exemplary aspect, the method can comprise fully controlling the at least one of the fuel flow control system and the turbocharger control system with the EEC. In a further exemplary aspect, the method can comprise fulling controlling the fuel flow control system with the EEC. In a further exemplary aspect, the method can comprise fully controlling the turbocharger control system with the EEC. In a further exemplary aspect, the method can comprise fully controlling each of the fuel flow control system and the turbocharger control system with the EEC.

[0066] In another exemplary aspect, an internal combustion engine for an aircraft can

comprise a crankshaft configured to drive a driven element; a first camshaft coupled to the crankshaft; a second camshaft coupled to the crankshaft; a fuel flow control system; and a turbocharger control system.

[0067] In another exemplary aspect, a fuel flow control system can comprise a fuel pump and a fuel control actuator communicating with the fuel pump and configured to restrict fuel flow downstream to a plurality of fuel injectors.

[0068] In another exemplary aspect, a turbocharger control system can comprise a

[0069] One should note that conditional language, such as, among others,“can,”“could,” “might,” or“may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain aspects include, while other aspects do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more particular aspects or that one or more particular aspects necessarily comprise logic for deciding, with or without user input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular aspect.

[0070] It should be emphasized that the above-described aspects are merely possible

examples of implementations, merely set forth for a clear understanding of the principles of the present disclosure. Any process descriptions or blocks in flow diagrams should be understood as representing modules, segments, or portions of code which comprise one or more executable instructions for implementing specific logical functions or steps in the process, and alternate implementations are included in which functions may not be included or executed at all, may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present disclosure. Many variations and modifications may be made to the above-described aspect(s) without departing substantially from the spirit and principles of the present disclosure. Further, the scope of the present disclosure is intended to cover any and all combinations and sub-combinations of all elements, features, and aspects discussed above. All such modifications and variations are intended to be included herein within the scope of the present disclosure, and all possible claims to individual aspects or combinations of elements or steps are intended to be supported by the present disclosure.

Claims

CLAIMS That which is claimed is:

1. An internal combustion engine for an aircraft, the engine comprising:

a crankshaft configured to drive a driven element;

a first camshaft coupled to the crankshaft;

a second camshaft coupled to the crankshaft;

a fuel flow control system comprising a fuel pump and a fuel control actuator

communicating with the fuel pump and configured to restrict fuel flow downstream to a plurality of fuel injectors; and

a turbocharger control system comprising a wastegate, a wastegate actuator

configured to partially or completely open or close the wastegate, and an electronic controller; the electronic controller operatively connected to the wastegate actuator and configured to cause movement of the wastegate actuator in response to a turbocharger discharge pressure.

2. The engine of claim 1 , wherein the fuel flow control actuator comprises a bypass solenoid configured to cause the fuel to bypass downstream components of the fuel flow control system.

3. The engine of claim 2, further comprising:

a bypass line fluidly connecting the fuel pump to the fuel control actuator; and a metered fuel pressure line operably connected at one end to the fuel control

actuator and communicating at another end with a fuel manifold.

4. The engine of claim 1 , wherein the fuel flow control actuator comprises a restriction solenoid configured to restrict fuel flow to downstream components of the fuel flow control system without returning fuel to a fuel tank or the fuel pump of the fuel flow control system.

5. The engine of claim 1 , wherein the fuel pump is configured to vary output volume and pressure with one of engine speed and manifold air mass flow.

6. The engine of claim 1 , further comprising at least one sensor in operative

communication with the electronic controller, the at least one sensor configured to read the turbocharger discharge pressure, the electronic controller configured to cause movement of the wastegate actuator in response to a reading of the turbocharger discharge pressure received from the at least one sensor.

7. The engine of claim 6, wherein:

the at least one sensor is further configured to read a manifold air pressure at a

downstream side of a throttle; and

the electronic controller is further configured to cause movement of the wastegate actuator responsive to readings of both the turbocharger discharge pressure and the manifold air pressure.

8. The engine of claim 1 , wherein the wastegate actuator is pneumatic.

9. The engine of claim 6, wherein:

the at least one sensor is further configured to sense a position of a throttle plate in the throttle; and

the electronic controller is further configured to cause movement of the wastegate actuator responsive to readings of the turbocharger discharge pressure and of a manifold air pressure, and responsive to the sensed position of the throttle plate.

10. The engine of claim 6, wherein:

the at least one sensor is further configured to sense a position of a throttle plate in a throttle; and

the electronic controller is further configured to cause movement of the wastegate actuator in response to the turbocharger discharge pressure reading and in response to the sensed position of the throttle plate.

11. The engine of claim 1 , further comprising an electronic engine controller (EEC), wherein at least one of the fuel flow control system and the turbocharger control system is controlled at least partially by the EEC.

12. The engine of claim 11 , wherein the fuel flow control system is controlled at least partially by the EEC.

13. The engine of claim 11 , wherein the turbocharger control system is controlled at least partially by the EEC.

14. The engine of claim 11 , wherein each of the fuel flow control system and the

turbocharger control system is controlled at least partially by the EEC.

15. The engine of claim 11 , wherein the at least one of the fuel flow control system and the turbocharger control system is fully controlled by the EEC.

16. The engine of claim 15, wherein the fuel flow control system is fully controlled by the EEC.

17. The engine of claim 15, wherein the turbocharger control system is fully controlled at least by the EEC.

18. The engine of claim 15, wherein each of the fuel flow control system and the

turbocharger control system is fully controlled by the EEC.

19. A method of using an internal combustion engine for an aircraft, the method

comprising:

regulating fuel flow in a fuel flow control system of the engine with a fuel control actuator positioned between a fuel pump and a plurality of injectors of the engine, the fuel flow control system comprising the fuel pump and the fuel control actuator in fluid communication with the fuel pump; and operating a wastegate actuator of a turbocharger control system with an electronic controller in response to a turbocharger discharge pressure to move a wastegate of the turbocharger control system, the wastegate actuator configured to partially or completely open or close the wastegate, the turbocharger control system further comprising the electronic controller operatively connected to the wastegate actuator.

20. The method of claim 19, wherein the fuel flow control actuator comprises a bypass solenoid configured to cause the fuel to bypass downstream components of the fuel flow control system.

21. The method of claim 20, wherein the engine further comprises:

actuator and communicating at another end with a fuel manifold; wherein regulating fuel flow in the fuel flow control system comprises regulating fuel flow into the metered fuel pressure line from the bypass line.

22. The method of claim 19, wherein the fuel flow control actuator comprises a restriction solenoid configured to restrict fuel flow to downstream components of the fuel flow control system without returning fuel to a fuel tank or the fuel pump of the fuel flow control system.

23. The method of claim 19, further comprising varying output volume and pressure with one of engine speed and manifold air mass flow using the fuel pump.

24. The method of claim 19, wherein the engine further comprises at least one sensor in operative communication with the electronic controller, the method further comprising:

reading the turbocharger discharge pressure with the at least one sensor; and causing movement of the wastegate actuator in response to a reading of the

turbocharger discharge pressure received from the at least one sensor.

25. The method of claim 19, further comprising:

reading a manifold air pressure at a downstream side of a throttle; and

causing movement of the wastegate actuator in response to readings of both the turbocharger discharge pressure and the manifold air pressure.

26. The method of claim 19, wherein the wastegate actuator is pneumatic.

27. The method of claim 19, further comprising:

sensing a position of a throttle plate in the throttle; and

causing movement of the wastegate actuator in response to readings of the

turbocharger discharge pressure, a manifold air pressure, and a sensed position of the throttle plate.

28. The method of claim 19, further comprising:

sensing a position of a throttle plate in a throttle; and

causing movement of the wastegate actuator in response to the turbocharger

discharge pressure reading and in response to the sensed position of the throttle plate.

29. The method of claim 19, wherein the engine further comprises an electronic engine controller (EEC), wherein the method comprises controlling at least one of the fuel flow control system and the turbocharger control system at least partially with the EEC.

30. The method of claim 29, wherein the method comprises controlling the fuel flow control system at least partially with the EEC.

31. The method of claim 29, wherein the method comprises controlling the turbocharger control system at least partially with the EEC.

32. The method of claim 29, wherein the method comprises controlling each of the fuel flow control system and the turbocharger control system at least partially with the EEC.

33. The method of claim 29, wherein the method comprising fully controlling the at least one of the fuel flow control system and the turbocharger control system with the EEC.

34. The method of claim 33, wherein the method comprises fulling controlling the fuel flow control system with the EEC.

35. The method of claim 33, wherein the method comprises fulling controlling the

turbocharger control system with the EEC.

36. The method of claim 33, wherein the method comprises fulling controlling each of the fuel flow control system and the turbocharger control system with the EEC.

37. An internal combustion engine for an aircraft, the engine comprising:

a crankshaft configured to drive a driven element;

a first camshaft coupled to the crankshaft;

a second camshaft coupled to the crankshaft;

a fuel flow control system; and

a turbocharger control system.

38. A fuel flow control system comprising a fuel pump and a fuel control actuator

communicating with the fuel pump and configured to restrict fuel flow downstream to a plurality of fuel injectors.

39. A turbocharger control system comprising a wastegate, a wastegate actuator