Patent Application
20180371982
The present disclosure relates generally to motor vehicle powertrains. More specifically, aspects of this disclosure relate to coolant valve layouts and related control logic for active thermal management systems of internal combustion engine assemblies.
Current production motor vehicles, such as the modern-day automobile, are originally equipped with a powertrain that operates to propel the vehicle and power the onboard vehicle electronics. In automotive applications, for example, the powertrain is generally typified by a prime mover that delivers driving power through a multi-speed power transmission to the vehicle's final drive system (e.g., rear differential, axles, and road wheels). Automobiles have traditionally been powered by a reciprocating-piston type internal combustion engine assembly because of its ready availability and relatively inexpensive cost, light weight, and overall efficiency. Such engines include compression-ignited (CI) diesel engines, spark-ignited (SI) gasoline engines, flex-fuel models, two, four and six-stroke architectures, and rotary engines, as some non-limiting examples. Hybrid and full-electric vehicles, on the other hand, utilize alternative power sources, such as fuel-cell or battery powered electric motor-generators, to propel the vehicle and minimize/eliminate reliance on an engine for power.
During normal operation, internal combustion engine (ICE) assemblies and large traction motors (i.e., for hybrid and full-electric powertrains) generate a significant amount of heat that is radiated into the vehicle's engine compartment. To prolong the operational life of the prime mover(s) and the various components packaged within the engine compartment, most automobiles are equipped with passive and active features for managing heat in the engine bay. Passive measures for alleviating excessive heating within the engine compartment include, for example, thermal wrapping the exhaust runners, thermal coating of the headers and manifolds, and integrating thermally insulating packaging for heat sensitive electronics. Active means for cooling the engine compartment include high-performance radiators, high-output coolant pumps, and electric cooling fans. As another option, some vehicle hood assemblies are provided with active or passive air vents designed to expel hot air and amplify convective cooling within the engine bay.
Active thermal management systems for automotive powertrains normally employ an onboard vehicle controller or electronic control module to regulate operation of a cooling circuit that distributes liquid coolant, generally of oil, water, and/or antifreeze, through heat-producing powertrain components. A coolant pump propels the cooling fluid—colloquially known as “engine coolant”—through coolant passages in the engine block, coolant passages in the transmission case and sump, and hoses to a radiator or other heat exchanger. A heat exchanging radiator cools hot engine coolant by rapidly convecting heat to ambient air. Many modern thermal management systems use a split cooling system layout that features separate circuits and water jackets for the cylinder head and engine block such that the head can be cooled independently from the block. The cylinder head, which has a lower mass than the engine block and is exposed to very high temperatures, heats up much faster than the engine block and, thus, generally needs to be cooled first. Advantageously, during warm up, a split layout allows the system to first cool the cylinder head and, after a given time interval, then cool the engine block.
Disclosed herein are multi-valve, split-layout cooling systems and related control logic for thermal management of select vehicle powertrain components, methods for making and methods for operating such cooling systems, and vehicles equipped with an active thermal management (ATM) system for cooling the powertrain's engine assembly and other select components. By way of example, and not limitation, there is presented a novel “smart” cooling system with a two-valve coolant circuit layout that provides the same thermal management capabilities as three and four-valve systems. This coolant valve architecture integrates the functionalities of multiple coolant control valves—one valve for engine management and one valve for heatsink management—into a single control valve assembly. In a more specific example, a Main Rotary Valve (MRV) assembly is fabricated with coolant inlet ports for individually controlling coolant flow discharged from the engine block, cylinder head, and exhaust manifold, as well as coolant outlet ports for individually controlling coolant flow distributed to the transmission oil heater, engine oil heater, heater core, coolant pump, and radiator. This simplified system does not require modification to existing engine cooling jackets or existing radiator, turbocharger, and exhaust gas recirculation (EGR) hardware.
Attendant benefits for at least some of the disclosed concepts include simplified thermal management systems with fewer coolant system components, which results in lower system costs and reduced packaging space requirements. Disclosed two-valve ATM layouts may leverage available coolant system software and hardware with reduced circuit complexity, thus minimizing the impact on functional configurability and calibration of the ATM system. Aspects of the disclosed concepts also help to ensure optimal operating temperatures, better combustion conditions, faster warm up, and reduced specific consumption and emissions. Simplified two-valve, split-layout systems presented herein can be adapted for implementation into gasoline and diesel engines, as well as for manually operated and automatic transmission powertrains.
Aspects of the present disclosure are directed to active thermal management systems for regulating the operating temperatures of select powertrain components. Disclosed, for example, is a thermal management system for a vehicle powertrain with an engine assembly and one or more oil heaters. This thermal management system includes an electronic heat exchanger, such as a convective-cooling radiator, that actively transfers heat energy from a coolant fluid to an ambient fluid. A coolant pump, which may be driven by the engine crankshaft or a dedicated motor, circulates the coolant fluid emitted from the electronic heat exchanger. A first set of fluid conduits fluidly connects the coolant pump to the electronic heat exchanger. Additionally, a second set of fluid conduits include discrete lines for fluidly connecting the coolant pump to the engine block, cylinder head, and exhaust manifold. In the same vein, a third set of fluid conduits include discrete lines for fluidly connecting the engine block, cylinder head, and exhaust manifold to the electronic heat exchanger, coolant pump, and the oil heater(s). A first valve assembly, which may be in the nature of an electronic rotary valve, is interposed within the first set of fluid conduits and operable to regulate coolant fluid flow between the coolant pump and electronic heat exchanger. Likewise, a second valve assembly, which may also be rotary-type valve, is interposed within the third set of fluid conduits and operable to regulate coolant fluid flow, individually and jointly, between the engine block, cylinder head, exhaust manifold, electronic heat exchanger, coolant pump, and oil heater(s).
Other aspects of the present disclosure are directed to motor vehicles equipped with an active thermal management system for cooling a reciprocating-piston-type engine assembly and an epicyclic power transmission. A “motor vehicle,” as used herein, may include any relevant vehicle platform, such as passenger vehicles (ICE, hybrid electric, fuel cell hybrid, fully or partially autonomous, etc.), commercial vehicles, industrial vehicles, tracked vehicles, off-road and all-terrain vehicles (ATV), farm equipment, boats, airplanes, etc. A motor vehicle is presented that includes a vehicle body, and an ICE assembly mounted inside an engine compartment of the vehicle body. The ICE assembly includes a cylinder head mounted on an engine block, and an exhaust manifold attached to or integrally formed with the cylinder head. A multi-speed power transmission is operable to transmit torque output by the ICE assembly to one or more or all of the vehicle's drive wheels.
Continuing with the above example, the motor vehicle also includes a radiator that is selectively operable to transfer heat from coolant fluid to ambient air. A coolant pump circulates the coolant fluid cooled by and emitted from the radiator. The vehicle includes a first set of conduits that fluidly connect the coolant pump to the radiator, and a second set of conduits that fluidly connect the coolant pump to the engine block, cylinder head, and exhaust manifold. A third set of fluid conduits fluidly connect the engine block, cylinder head, and exhaust manifold to the radiator, coolant pump, a transmission oil heater, and an engine oil heater. A first valve assembly, which is interposed within the first set of fluid conduits, is selectively operable to regulate coolant fluid flow between the coolant pump and radiator. In addition, a second valve assembly, which is interposed within the third set of fluid conduits, is selectively operable to regulate coolant fluid flow, individually and jointly, between the engine block, cylinder head, exhaust manifold, radiator, coolant pump, and oil heaters.
Additional aspects of the present disclosure are directed to methods for making and methods for assembling any of the disclosed engine disconnect devices and corresponding latching assemblies. Aspects of the present disclosure are also directed to methods for operating disclosed engine disconnect devices and latching assemblies. Also presented herein are non-transitory, computer readable media storing instructions executable by at least one of one or more processors of one or more in-vehicle electronic control units, such as a programmable engine control unit (ECU) or powertrain control module, to govern operation of a disclosed engine disconnect device.
The above summary is not intended to represent every embodiment or every aspect of the present disclosure. Rather, the foregoing summary merely provides an exemplification of some of the novel aspects and features set forth herein. The above features and advantages, and other features and advantages of the present disclosure, will be readily apparent from the following detailed description of illustrative embodiments and representative modes for carrying out the present disclosure when taken in connection with the accompanying drawings and the appended claims. Moreover, this disclosure expressly includes any and all combinations and subcombinations of the elements and features presented above and below.
The present disclosure is amenable to various modifications and alternative forms, and some representative embodiments have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the novel aspects of this disclosure are not limited to the particular forms illustrated in the appended drawings. Rather, the disclosure is to cover all modifications, equivalents, combinations, subcombinations, permutations, groupings, and alternatives falling within the scope of this disclosure as defined by the appended claims.
This disclosure is susceptible of embodiment in many different forms. There are shown in the drawings and will herein be described in detail representative embodiments of the disclosure with the understanding that these illustrated examples are to be considered an exemplification of the disclosed principles and do not limit the broad aspects of the disclosure to the representative embodiments. To that extent, elements and limitations that are disclosed, for example, in the Abstract, Summary, and Detailed Description sections, but not explicitly set forth in the claims, should not be incorporated into the claims, singly or collectively, by implication, inference or otherwise. For purposes of the present detailed description, unless specifically disclaimed: the singular includes the plural and vice versa; the words “and” and “or” shall be both conjunctive and disjunctive; the word “all” means “any and all”; the word “any” means “any and all”; and the words “including” and “comprising” and “having” and synonyms thereof mean “including without limitation.” Moreover, words of approximation, such as “about,” “almost,” “substantially,” “approximately,” and the like, may be used herein in the sense of “at, near, or nearly at,” or “within 3-5% of,” or “within acceptable manufacturing tolerances,” or any logical combination thereof, for example.
Referring now to the drawings, wherein like reference numbers refer to like features throughout the several views, there is shown in
There is shown in
An air intake system transmits intake air to the cylinders 15 through an intake manifold 29, which directs and distributes air into the combustion chambers 17, e.g., via intake runners of the cylinder head 25. The engine's air intake system has airflow ductwork and various electronic devices for monitoring and controlling the flow of intake air. The air intake devices may include, as a non-limiting example, a mass airflow sensor 32 for monitoring mass airflow (MAF) 33 and intake air temperature (IAT) 35. A throttle valve 34 controls airflow to the ICE assembly 12 in response to a control signal (ETC) 120 from a programmable engine control unit (ECU) 5. A pressure sensor 36 operatively coupled to the intake manifold 29 monitors, for instance, manifold absolute pressure (MAP) 37 and, if desired, barometric pressure. An optional external flow passage recirculates metered quantities of exhaust gas from engine exhaust to the intake manifold 29, e.g., via a control valve in the nature of an exhaust gas recirculation (EGR) valve 38. The programmable ECU 5 controls mass flow of exhaust gas to the intake manifold 29 by regulating the opening and closing of the EGR valve 38 via EGR command 139. In
Airflow from the intake manifold 29 into each combustion chamber 17 is controlled by one or more dedicated engine intake valves 20. Evacuation of exhaust gases and other combustion byproducts from the combustion chamber 17 to an exhaust aftertreatment system 55 via an exhaust manifold 39 is controlled by one or more dedicated engine exhaust valves 18. In accord with at least some of the disclosed embodiments, exhaust aftertreatment system 55 includes an EGR system and/or a selective catalytic reduction (SCR) system. The engine valves 18, 20 are illustrated herein as spring-biased poppet valves; however, other known types of engine valves may be employed. The ICE assembly 12 valve train system is equipped to control and adjust the opening and closing of the intake and exhaust valves 20, 18. According to one example, the activation of the intake and exhaust valves 20, 18 may be respectively modulated by controlling intake and exhaust variable cam phasing/variable lift control (VCP/VLC) devices 22 and 24. These two VCP/VLC devices 22, 24 are configured to control and operate an intake camshaft 21 and an exhaust camshaft 23, respectively. Rotation of these intake and exhaust camshafts 21 and 23 are linked and/or indexed to rotation of the crankshaft 11, thus linking openings and closings of the intake and exhaust valves 20, 18 to positions of the crankshaft 11 and the pistons 16.
The intake VCP/VLC device 22 may be fabricated with a mechanism operative to switch and control valve lift of the intake valve(s) 20 in response to a valve lift control signal (iVLC) 125, and variably adjust and control phasing of the intake camshaft 21 for each cylinder 15 in response to a variable cam phasing control signal (iVCP) 126. In the same vein, the exhaust VCP/VLC device 24 may include a mechanism operative to variably switch and control valve lift of the exhaust valve(s) 18 in response to a valve lift control signal (eVLC) 123, and variably adjust and control phasing of the exhaust camshaft 23 for each cylinder 15 in response to a control signal (eVCP) 124. The VCP/VLC devices 22, 24 may be actuated using any one of electro-hydraulic, hydraulic, electro-mechanic, and electric control force, in response to respective control signals eVLC 123, eVCP 124, iVLC 125, and iVCP 126, for example.
With continuing reference to the representative configuration of
The ICE assembly 12 is equipped with various sensing devices for monitoring engine operation, including a crank sensor 42 having an output indicative of, e.g., crankshaft crank angle, torque and/or speed (RPM) signal 43. A temperature sensor 44 is operable to monitor, for example, one or more engine-related temperatures (e.g., coolant fluid temperature, fuel temperature, exhaust temperature, etc.), and output a signal 45 indicative thereof. An in-cylinder combustion sensor 30 monitors combustion-related variables, such as in-cylinder combustion pressure, charge temperature, fuel mass, air-to-fuel ratio, etc., and output a signal 31 indicative thereof. An exhaust gas sensor 40 is configured to monitor an exhaust-gas related variables, e.g., actual air/fuel ratio (AFR), burned gas fraction, exhaust temperature, etc., and output a signal 41 indicative thereof.
The combustion pressure and the crankshaft speed may be monitored by the ECU 5, for example, to determine combustion timing, i.e., timing of combustion pressure relative to the crank angle of the crankshaft 11 for each cylinder 15 for each working combustion cycle. It should be appreciated that combustion timing may be determined by other methods. Combustion pressure may be monitored by the ECU 5 to determine an indicated mean effective pressure (IMEP) for each cylinder 15 for each working combustion cycle. The ICE assembly 12 and ECU 5 cooperatively monitor and determine states of IMEP for each of the engine cylinders 15 during each cylinder firing event. Alternatively, other sensing devices, arrangements, and systems may be used to monitor states of other parameters within the scope of the disclosure, e.g., ion-sense ignition systems, EGR fractions, and non-intrusive cylinder pressure sensors.
Control module, module, controller, control unit, electronic control unit, processor, and any permutations thereof may be defined to mean any one or various combinations of one or more of logic circuits, Application Specific Integrated Circuit(s) (ASIC), electronic circuit(s), central processing unit(s) (e.g., microprocessor(s)), and associated memory and storage (e.g., read only, programmable read only, random access, hard drive, tangible, etc.), whether resident, remote or a combination of both, executing one or more software or firmware programs or routines, combinational logic circuit(s), input/output circuit(s) and devices, appropriate signal conditioning and buffer circuitry, and other components to provide the described functionality. Software, firmware, programs, instructions, routines, code, algorithms and similar terms may be defined to mean any controller executable instruction sets including calibrations and look-up tables. The ECU may be designed with a set of control routines executed to provide the desired functions. Control routines are executed, such as by a central processing unit, and are operable to monitor inputs from sensing devices and other networked control modules, and execute control and diagnostic routines to control operation of devices and actuators. Routines may be executed at in real-time, continuously, systematically, sporadically and/or at regular intervals, for example, each 100 microseconds, 3.125, 6.25, 12.5, 25 and 100 milliseconds, etc., during ongoing engine and vehicle operation. Alternatively, routines may be executed in response to occurrence of an event.
Turning next to
Similar to the cylinder head 25 of
ATM system 200 of
With continuing reference to
A second set of fluid conduits 260 fluidly connects the coolant pump 232 to constituent parts of the engine assembly 212, including individual segments for the engine block 220, cylinder head 222, exhaust manifold 224 and turbocharger 226. This set of conduits 260 includes a main line 265 and four discrete lines 261-264 whereby select portions of coolant fluid from the radiator 230 and pump 232 are transmitted to individual sections of the engine 212. Following
The ATM system 200 is also equipped with a third set of fluid conduits, designated generally as 270 in
A pair of coolant flow control valves 242, 244 are communicatively connected to the vehicle controller 205, and selectively positionable in response to control signals received from the controller 205 to direct coolant flow through the individual lines of the coolant flow loops. While it is envisioned that these valves can take on any relevant form of electronically controlled fluid valve apparatus, the representative ATM system 200 architecture portrayed in
Continuing with the above example, second coolant flow control valve 244 of
MRV assembly 242 of
Referring next to
Similar to ATM system 200, the ATM system 300 of
Aspects of the present disclosure have been described in detail with reference to the illustrated embodiments; those skilled in the art will recognize, however, that many modifications may be made thereto without departing from the scope of the present disclosure. The present disclosure is not limited to the precise construction and compositions disclosed herein; any and all modifications, changes, and variations apparent from the foregoing descriptions are within the scope of the disclosure as defined by the appended claims. Moreover, the present concepts expressly include any and all combinations and subcombinations of the preceding elements and features.
