METHOD AND SYSTEM FOR A VARIABLE COMPRESSION RATIO ENGINE

Abstract

Method for an engine (100), comprising: Vary, by means of an engine control (12), a compression ratio of a cylinder (206) by selectively removing combustion charge, which was generated by ignition of an air-fuel mixture in the cylinder (206), from the cylinder (206) through a drain valve on a cylinder head (202), Diverting the discharged combustion charge gas into a turbine generator (234) and Generating, by means of the discharged combustion charge, of usable electrical power by the turbine generator (234), wherein the turbine generator (234) is coupled downstream of the drain valve.

Description

AREA

[0001] The present description generally concerns methods and systems for a variable compression ratio engine. STATE OF THE ART / BRIEF OVERVIEW

[0002] An engine operating under varying load and speed conditions can be improved by varying its compression ratio. For example, the compression ratio can be increased at low loads to improve engine efficiency. At high loads, the compression ratio can be reduced to threshold levels that minimize engine knock caused by high temperatures and pressures in the combustion chambers. In this way, the engine can be tuned to produce a variable compression ratio based on engine load, speed, and other factors. By varying the compression ratio according to engine operating conditions, the overall performance and efficiency of the engine can be improved.

[0003] Numerous approaches to adjusting the compression ratio in an engine can include changing the combustion chamber geometry and modifying other engine components. One exemplary approach is described by Ma in US 5,101,776 A. There, the variable-compression engine incorporates a combustion chamber connected via a flow passage with a poppet valve to an auxiliary chamber. To achieve low engine compression ratios, the poppet valve can be opened to allow a flow of charge gas from the combustion chamber into the auxiliary chamber. Alternatively, high engine compression ratios can be achieved by closing the poppet valve to isolate the auxiliary chamber from the main combustion chamber.

[0004] DE 10 2015 119 160 A1 discloses a method comprising supplying exhaust gas from a first exhaust valve of a cylinder via a first exhaust manifold to an exhaust gas turbine, wherein the turbine drives a generator.

[0005] From EP 0 945 606 A2, a gas combustion engine is known that burns natural gas fuel, is equipped with a turbocharger and an engine generator, operates in the Miller cycle, and can control the actual compression ratios by regulating the timing of the opening and closing of the intake valves. The gas combustion engine has intake valve lift control devices to change the timing of the opening and closing of the intake valves at the intake ports in order to vary the actual compression ratios.

[0006] However, the inventors of the present invention have recognized potential problems associated with a system such as that described in US 5,101,776 A. For example, the energy contained in the charge gas, which is discharged from the main combustion chamber into the auxiliary chamber, may not be adequately recovered during engine operation. Furthermore, the aforementioned variable compression ratio engine configuration requires a significant modification of the combustion chamber geometry, which may entail additional manufacturing and assembly complexity.

[0007] The object of the present invention is to address at least some of the aforementioned potential problems. This object is achieved by the features of the independent claims. Advantageous embodiments of the invention are the subject of the dependent claims.

[0008] In one example, the problems described above can be solved by an engine system that may include: varying the compression ratio of a cylinder by selectively diverting combustion charge from that cylinder into a manifold via a bleed valve on a cylinder head; and converting the diverted combustion charge into usable electrical power at a turbine generator coupled downstream of the bleed valve. The manifold may be designed with an internal passage that diverts combustion charge gas from the cylinder into the turbine generator when both the bleed and check valves are set to open positions.

[0009] By adjusting the flow of the combustion charge gas from the cylinder to the distributor, the engine compression ratio can be varied based on engine operating conditions, while electrical energy is generated from the charge gas discharged from one or more cylinders. In this way, the engine compression ratio can be varied without altering the geometry of any of the cylinders, while promoting improved engine performance across a wide range of engine speeds and loads.

[0010] It is understood that the foregoing summary is provided to present, in simplified form, a selection of concepts that are described in greater detail in the detailed description. It is not intended to mention important or essential features of the claimed subject matter, the scope of which is defined solely in the claims following the detailed description. Furthermore, the claimed subject matter is not limited to implementations that eliminate the disadvantages mentioned above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 shows a schematic diagram of an exemplary engine system. Fig. Figure 2 shows a schematic representation of an engine system comprising a cylinder head mounted on a cylinder block. Fig. Figure 3 shows a schematic representation of a distribution system attached to a cylinder head to divert combustion charge gas from one or more cylinders to a turbine generator. Fig. Figure 4 shows a sectional view from the front of the distributor system, which is attached to the cylinder head to divert combustion charge gas from one or more combustion chambers to the turbine generator. Fig. Figure 5 shows a cross-sectional view of the distributor system attached to the cylinder head. Fig. Figure 6 shows a method for adjusting a compression ratio in the engine to generate a target engine torque. Fig. Figure 7 shows a graphical output of compression ratio and engine torque based on changes in control valve position, throttle position and ignition timing. Fig. Figures 3-5 are shown approximately to scale, although other relative dimensions can be used if required. DETAILED DESCRIPTION

[0011] The following description concerns systems and procedures for a variable compression ratio engine. Fig. Figure 1 shows an engine system with a control valve that can be adjusted to vary the compression ratio in the engine by diverting combustion charge gas from a combustion chamber to a distribution system coupled to a turbine generator. The control valve can be adjusted by an engine control unit based on engine operating conditions to vary the compression ratio in the engine. The cylinder can be mounted on a cylinder block coupled to a cylinder head, as shown in Figure 1. Fig. 2. be mounted. Air introduced into the combustion chamber can be mixed with injected fuel to form an air-fuel mixture that is burned to generate engine power. The distributor system coupled to the cylinder head may include a distributor designed with an internal passage that directs the combustion charge gas discharged from the combustion chamber to the turbine generator, as in Fig. Figures 3-5 show this. A fully functional check valve / particulate filter coupled to the manifold ensures system cleanliness and prevents backflow of charge gas or any upstream reversal. Furthermore, a gas sensor coupled to the manifold at a position downstream of the check valve is designed to detect the presence of unburned fuel in the combustion charge gas before it enters the turbine generator. If any unburned fuel is detected in the charge gas at the manifold, the engine control unit can set an igniter coupled to the manifold to combust the unburned fuel before the charge gas enters the turbine generator. Upon entering the turbine generator, the charge gas drives an impeller to generate electrical power, which can be distributed to power-demanding points in the engine.Any exhaust gas generated in the distribution system can be routed to an exhaust gas recirculation system, where the exhaust gas is directed to the air intake manifold.

[0012] An example procedure for adjusting the compression ratio in the engine, in which the control valve is coupled to the combustion chamber and the distributor is connected to the turbine generator, is described in Fig. Figure 6 shows that the compression ratio can be varied by adjusting the control valve timing, throttle position, and ignition timing. With the valves set to the open position, some of the charge air in the combustion chamber can be diverted into the distributor to reduce the engine's compression ratio. The diverted charge air in the distributor can then be directed to the turbine generator to produce electrical power. Alternatively, the compression ratio can be varied by adjusting the throttle position and / or the ignition timing, as shown in Figure 6. Fig. 6 reveals. The control valve timing, throttle position and / or ignition timing can be adjusted to produce an exemplary graphical output of the compression ratio and engine torque, as shown in Fig. Figure 7 shows that the engine compression ratio can be varied by adjusting one or more of the control valve timing, throttle position, and ignition timing to maintain engine torque close to a target value. The combustion charge gas, which is vented from the combustion chamber when the control valve and check valve are set to open positions, can be diverted to the turbine generator to produce electrical power for operating engine components and other vehicle systems. In this way, the engine compression ratio can be varied to improve engine performance while generating electrical power that can be distributed to points of power demand within the engine.

[0013] An inlet channel 42, further referring to Fig. 1. A throttle 62 can have a throttle valve 64. In this specific example, the position of the throttle valve 64 can be varied by the control unit 12 via a signal provided to an electric drive or actuator contained within the throttle 62, a design commonly referred to as electronic throttle control (ETC). In this way, the throttle 62 can be operated to vary the intake air supplied to the combustion chamber 30, along with other engine cylinders. The position of the throttle valve 64 can be provided to the control unit 12 by the throttle position signal TP. The intake port 42 can include a mass airflow sensor 120 and a manifold pressure sensor 122 to provide the corresponding MAF and MAP signals to the control unit 12.

[0014] The combustion chamber 30 can be supplied with fuel via a fuel injection device 66, which is supplied from a fuel system 115. The ignition system 88 can provide a spark to an air-fuel mixture in the combustion chamber 30 via the spark plug 92 in response to a pre-ignition signal SA from the control unit 12 under selected operating modes. Although spark ignition components are shown, the combustion chamber 30, or one or more other combustion chambers of the engine 100, can in some embodiments be operated in a compression ignition mode with or without a spark plug. Upon ignition, the air-fuel mixture in the combustion chamber 30 can combust to produce a charge gas that provides energy required for piston movement.

[0015] A manifold system 150 can be provided to vary the compression ratio in the engine 100. The manifold system 150 can include a control valve 152, a manifold 154, a check valve 156, a charge gas sensor 158, and an igniter 160. When the control valve 152 is set to an open position, the combustion charge gas in the combustion chamber 30 can be diverted into the manifold 154 to vary the compression ratio in the cylinder. The timing and duration of the opening and closing of the control valve 152 can be adjusted based on engine operating conditions such as engine speed and load. As metered combustion charge gas flows through a section of the manifold 154 past the check valve 156, the gas sensor 158 detects any unburned fuel in the charge gas before it enters a turbine generator 162.If unburned fuel is detected in the combustion charge gas, the igniter 160 can be activated by the control unit 12 to burn the unburned fuel before the charge gas flows to the turbine generator 162. The igniter 160 can be deactivated when all unburned fuel in the combustion charge gas has been forced downstream into the turbine generator 162, past the check valve 156 located upstream of the turbine generator, and it prevents any reversal or gas flow back upstream to the combustion chamber, so that all primary and secondary ignited combustion energy is directed to the impeller located inside the turbine generator 162.When it enters the turbine generator 162, the combustion charge gas drives the impeller to generate electrical energy, which is directed to points of power demand or to a battery storage system as needed, as indicated by arrow 164. The battery charge can be used to power the vehicle or to drive a compressor coupled to an engine in the vehicle. Any residual exhaust gas in the turbine generator 162 is routed to the EGR system via an exhaust duct 166. As shown in... Fig. 3-5, the control unit 12 can be used to adjust the valve positions of the control valve 152 and check valve 156 by sending signals 168 and 170, respectively, to each valve. The control unit 12 can also be used to control the igniter 160. For example, the control unit 12 can send a signal 174 so that the igniter is switched on upon receiving signal 172 from the gas sensor 158, which indicates unburned fuel in the combustion charge gas in the distributor 154. The performance of the turbine generator 162 can be monitored by the control unit 12 based on engine operating conditions. For example, the turbine generator 162 can receive a signal 176 from the control unit 12 when the amount of combustion charge gas delivered to the turbine generator changes due to changes in engine speed and load.

[0016] A pressure sensor 124 can be coupled to the exhaust port 48 downstream of the exhaust valve 54 and upstream of the emission control device 70. The pressure sensor 124 is preferably positioned close to the exhaust port 54 to measure the exhaust manifold pressure (EMP). In one embodiment, the pressure sensor can be a pressure transmitter. The engine control unit can derive cylinder torque imbalances based on the weighted output of the pressure sensor.

[0017] In the illustration, the emission control device 70 is arranged downstream of the pressure sensor 124 along the exhaust duct 48. The emission control device 70 can be a three-way catalyst (TWC) designed to reduce NOx and oxidize CO and unburned hydrocarbons. In some embodiments, the device 70 can be a NOx trap, various other emission control devices, or combinations thereof.

[0018] Furthermore, in the disclosed embodiments, an exhaust gas recirculation (EGR) system can direct a desired portion of the exhaust gas from the exhaust gas channel 48 to the intake channel 42 via the EGR channel 140. The amount of EGR provided at the intake channel 42 can be varied by the control unit 12 via the EGR valve 142. An EGR sensor 144 can also be arranged within the EGR channel and provide information on one or more parameters relating to the pressure, temperature, and concentration of the exhaust gas. Under certain conditions, the EGR system can be used to regulate the temperature of the air-fuel mixture within the combustion chamber.

[0019] Control 12 is in Fig. 1 is represented as a microcomputer which includes a microprocessor unit 102, input / output ports 104, an electronic storage medium for executable programs and calibration values, which in this specific example is represented as a read-only memory chip 106, a direct access memory 108, a keep-alive memory 110 and a data bus.In addition to the signals discussed above, the control unit 12 can receive various signals from sensors coupled to the engine 100, including the measurement of the mass air flow (MAF) from an air mass flow sensor 120; the exhaust manifold pressure (EMP) from the pressure sensor 124; the engine coolant temperature (ECT) from a temperature sensor 112 coupled to the cooling sleeve 114; a profile ignition pickup signal (PIP) from a Hall sensor 118 (or other type) coupled to the crankshaft 40; a cylinder torque from the crankshaft torque sensor coupled to the crankshaft 40; and the throttle position (TP) from a throttle position sensor. and a manifold absolute pressure (MAP) signal from a sensor 122.A motor speed signal (RPM) can be generated by controller 12 from the PIP signal. Controller 12 can also control the various actuators. Fig. 1. Use it to adjust the motor operation based on the received signals and instructions stored in a memory of the control unit.

[0020] Computer-readable data can be programmed onto the read-only memory 106 of a storage medium, representing instructions that can be executed by the processor 102 to carry out the procedures described below, as well as other variants that are anticipated but not explicitly listed.

[0021] As described above, shows Fig. 1 merely one cylinder of a multi-cylinder engine, and each cylinder can equally have its own set(s) of inlet / outlet valves, fuel injection device, spark plug, etc.

[0022] To Fig. Moving on to 2, a schematic diagram of a motor 200 (such as the one in Fig. Figure 1 shows the engine 200 (100), which is used to provide motive power to a vehicle. In the illustrated example, the engine 200 includes a cylinder head 202 coupled to a cylinder block 204, forming a combustion chamber 206. The engine 200 is designed to carry out combustion in the combustion chamber 206. An intake valve 208 is provided in the engine 200 to allow intake air to flow into the cylinder 206 at selected time intervals. Accordingly, an exhaust valve 210 is provided in the engine 200 to allow exhaust air to flow from the combustion chamber 206 into a downstream exhaust system at selected time intervals. Although the engine 200 is shown as having only a single cylinder, in other examples the engine 200 may include more than one cylinder.

[0023] Arrow 212 represents the flow of intake air from upstream intake system components such as intake pipes, an intake manifold 44, a throttle, a compressor, etc., to the intake valve 208. In contrast, arrow 214 represents the flow of exhaust gas to downstream components such as exhaust pipes, an exhaust manifold 48, emission control device(s), a turbine, etc., from the exhaust valve 210.

[0024] A fuel supply system 216 is also provided in the engine 200. The fuel supply system 216 is designed to supply fuel for combustion in the cylinder 206 at desired time intervals. The fuel supply system 216 includes a direct injection device 218, in the example shown, and upstream components 220. The upstream components 220, such as fuel pumps, valves, lines, etc., are designed to supply fuel to the fuel injection device 218. An injection device with one nozzle per intake port, designed to deliver fuel into a line upstream of the cylinder, may be additionally or alternatively included in the fuel supply system 216. The engine 200 is designed to implement a four-stroke combustion cycle.The combustion cycles include an intake stroke, a compression stroke, a combustion stroke, and an exhaust stroke, which are described in more detail below. An ignition device (not shown) may also be provided in the engine 200. The ignition device may be designed to provide sparks to cylinder 206 at selected time intervals. In other examples, however, the ignition device in the engine may be omitted, and the engine may be designed to operate by compression ignition or as a two-stroke engine.

[0025] A distribution system 222 (such as the one in Fig. The distributor system 150 shown can be provided to receive a combustion charge from one or more cylinders, thus allowing the compression ratio in the engine 200 to be varied. The distributor system 222 can include a control valve 224, a distributor 226, a check valve 228, a charge gas sensor 230, and an igniter 232. When the control valve 224 is set to an open position, combustion charge gas in the combustion chamber 206 can be diverted into the distributor 226 to adjust the engine compression ratio. The timing and duration of the opening and closing of the control valve 224 can be adjusted based on engine operating conditions such as engine speed and load.When the check valve 228 is set to an open position, the combustion charge gas flows through a section of the distributor 226 adjacent to the gas sensor 230, which detects any unburned fuel in the charge gas before it enters a turbine generator 234 located downstream of the gas sensor. If unburned fuel is detected in the combustion charge gas, the igniter 232 is activated to combust the unburned fuel before the charge gas flows into the turbine generator 234. The igniter 232 can be deactivated once all the unburned fuel in the combustion charge gas has been forced through the turbine generator 234; during this secondary combustion event, the check valve 228 remains closed to ensure that no unwanted reversal back upstream of the turbine generator occurs.When it enters the turbine generator 234, the combustion charge gas causes an impeller (not shown) to rotate in order to generate electrical energy, which is distributed to points of power demand, as indicated by arrow 236. Any residual exhaust gas in the turbine generator 234 is discharged via an exhaust duct 238 to a system.

[0026] With reference to Fig. Figure 3 shows a schematic view 300 of a distribution system 302, which is attached to a cylinder head 304 of an engine (such as the one in Fig. Figure 1 of the engine 100 shown discloses the distribution system 302, which is attached to the engine 100 to direct combustion charge gas from a plurality of cylinders 320 to an electric turbine generator 332. The distribution system 302 comprises a distributor 308, a control valve 316, a check valve / filter 326, a charge gas sensor 328, and an igniter 330. The check valve / filter 326 can be an operational combined system of a particulate filter and a valve that regulates the flow of charge gas from the distributor 308 into the turbine generator 332, while filtering the charge gas flowing through the distributor. The distribution system 302 can be mounted on an adjacent engine component, such as a cam carrier or cam cover, or attached to an outer surface 306 of the cylinder head 304. In this example, the distribution system 302 can be mounted on a distributor mounting projection 315.An inner surface 346 of the cylinder head 304 can be attached to a cylinder block (not shown) having a plurality of cylinders 320. The combustion charge gas from each combustion chamber 320 can be routed via the distributor 308 to the turbine generator 332. The turbine generator 332 can have an upper section 334, a middle section 336, and a lower section 338. The upper section 334 can have a projecting cap 335 attached to a conical housing. The middle section 336 can have a plurality of circular rings that transition into the lower section 338, which has a cylindrical tube. The lower section 338 can communicate with engine components that draw electrical power, as shown by arrow 340.Furthermore, the turbine generator 332 can be coupled to an exhaust gas channel 342, which leads to an exhaust gas recirculation (EGR) system located in a direction shown by arrow 344.

[0027] During engine operation, fuel can be injected into each combustion chamber 320 via a fuel injection device 322, which is mounted on a side section of the cylinder head. The injected fuel mixes with air supplied to the cylinder to create an air-fuel mixture, which is ignited by a spark plug 324. The ignited air-fuel mixture burns to produce charge gas, which generates energy to power the engine. Depending on the engine operating conditions, the charge gas in each combustion chamber 320 can be discharged into a flow line 318 to adjust the engine compression ratio. The charge gas enters the flow line 318 as shown by arrow 325. The control valve 316 can be selectively adjusted to regulate the amount of charge gas supplied to the distributor 308.In some examples, the control valve 316 can be described as a drain valve. In this case, the drain valve differs from an exhaust valve of the cylinder head assembly.

[0028] A multitude of flow lines 310 can be coupled to the distributor 308 via connecting pieces 312 to allow the flow of combustion charge gas from the combustion chamber 320 into the distributor when the control valve 316 is set to the open position. Each flow line 310 can be appropriately dimensioned with an internal flow passage 314, which supplies combustion charge gas from the combustion chamber 320 to the distributor 308. At low engine loads, for example, the control valve 316 can remain closed at relatively high engine loads and be set to a first position in which an initial quantity of combustion charge gas from the combustion chamber 320 is discharged into the distributor 308, and the compression of an air-fuel mixture in the cylinder produces an initial compression ratio.Under high engine loads, to give another example, the control valve 316 can be set to a second position in which a second quantity of charge gas from the combustion chamber 320 is discharged into the distributor 308, and the compression of an air-fuel mixture in the cylinder produces a second compression ratio that is lower than the first. Alternatively, the duration of the control valve's opening time can be adjusted to vary the engine compression ratio. In this way, the engine compression ratio can be set by varying the position of the control valve and / or the duration of its opening time. The check valve / filter 326 can remain open at all times, allowing positive downstream flow (towards the turbine generator) while counteracting or preventing any upstream reverse flow of charge gas into the combustion chamber.When the combustion charge gas flows downstream in distributor 308 towards the turbine generator 332, the gas sensor 328, which is mounted on the distributor downstream of the check valve / filter 326, can detect unburned fuel in the combustion charge gas. If any unburned fuel is detected in distributor 308, the engine control unit (such as the one in ) can Fig. The control unit 12 shown here switches on the igniter 330 so that the unburned fuel in the combustion charge gas is combusted before the charge gas flows into the turbine generator 332. The charge gas entering the turbine generator 332 drives an impeller to generate electrical power, which is transferred to points where the engine requires power, as indicated by the direction arrow 340. As one example, the electrical power generated by the turbine generator 332 can be supplied to electrically driven engine components or electrical vehicle systems. In another example, the electrical power generated by the turbine generator can be stored as usable electrical power in a battery connected to the turbine generator.Once the combustion charge gas has been converted into electrical power, any residual exhaust gas in the turbine generator 332 is directed to the exhaust duct 342, where the exhaust gas is directed to the EGR system, as shown by arrow 344.

[0029] With reference to Fig. Figure 4 discloses a front sectional view 400 of the distributor system 302, which is attached to the cylinder head 304 to direct combustion gas from each combustion chamber 320 to the turbine generator 332. The distributor system 302 can be mounted on the cylinder head 304 by means of the distributor mounting projection 315, which is attached to the outer surface 306 of the cylinder head. As an example, the distributor mounting projection 315 can be attached to the cylinder head using a clamp or any other mechanical assembly means.

[0030] As in Fig. As shown in Figure 4, the manifold mounting projection 315 can have a vertical column 402 that connects to a mounting surface 404 with a curved annular section 405. The mounting surface 404 can be a horizontally extending arm that is coupled, for example, to an outer section of the manifold 308. The manifold 308 can be fluidly coupled to the flow line 310 at a first end 406, which may be positioned above a curved transition 408 of the flow line. A second end 410 of the flow line 310 can have a sealing shell 412 that may be adequately sized to accommodate an O-ring seal 414 of the control valve 316. When the control valve 316 is set to an open position, combustion charge gas from the combustion chamber 320 can flow into the manifold 308.As an example, the degree of valve opening can be adjusted to allow a variable flow of combustion charge gas from the combustion chamber 320 into the distributor system 302, thereby enabling the engine compression ratio to vary based on engine operating conditions such as engine speed and load. Furthermore, the control valve 316 can be set to a closed position to stop the flow of combustion charge gas from the combustion chamber 320 into the distributor 308. By adjusting the flow of combustion charge gas from the combustion chamber 320 into the distributor system 302, the engine compression ratio can be adjusted based on engine load / speed and other engine parameters.

[0031] The check valve / filter 326 can be coupled to the distributor 308 to control the reverse flow of the combustion charge gas back or (upstream) into the combustion chamber. The check valve / filter 326 always allows a downstream flow of combustion gas into the turbine generator 332. In this case, the distributor 308 is fluidly coupled to the turbine generator 332, allowing the flow of combustion charge gas from the combustion chamber into the turbine generator 332. The combustion charge gas entering the turbine generator 332 drives a wheel 418, which is mounted within an internal compartment 416 of the turbine generator, to generate electrical power that is transmitted to locations where the engine requires power, as indicated by the direction arrow 340.As one example, the exhaust combustion charge gas is converted into usable electrical power, which can be stored as usable electrical power in a battery coupled to the turbine generator. In another example, the engine can be coupled in a hybrid vehicle that can be driven using engine torque derived from an electric motor, which in turn is driven by electrical power drawn from a battery. When the engine reaches, for example, a predetermined torque or limit speed, the control valve 316 can be set to a closed position. When the control valve 316 is set to a closed position, no combustion charge gas flows into the distributor 308 or into the turbine generator 332.

[0032] The turbine generator 332 can have a projecting section 422 with an internal slot which may be adequately dimensioned to accommodate a mounting rod for fastening the impeller 418 to the inner area 416 of the turbine generator, as described in reference to Fig. 5 more revealed.

[0033] The distributor system 302 can include the distributor 308, which is designed with an internal passage that directs combustion charge gas from the combustion chamber 320 into the turbine generator, even when the control valve 316 is set to the open position. By adjusting the flow of combustion charge gas from the combustion chamber 320 into the distributor system 302, the engine compression ratio can be varied, while electrical energy is generated from a portion of the combustion charge gas discharged from each combustion chamber 320.

[0034] With reference to Fig. Figure 5 reveals a cross-sectional view 500 of the distributor system 302, which is attached to the outer surface 306 of the cylinder head 304. As shown in Fig. Figure 5 shows a section of the distributor system 302: the distributor 308, the check valve / filter 326, the gas sensor 328, the igniter 330 and the turbine generator 332, which is coupled to the exhaust duct 342, which leads to the EGR system.

[0035] The distributor 308 can be mounted on the cylinder head 304 by means of the mounting surface 404, which is connected to the vertical column 402 of the distributor mounting projection 315. When mounted on the distributor mounting projection 315, the distributor 308 can be in surface-sharing contact with an annular section 405 of the mounting surface 404. The distributor 308 can be held firmly in position by the mounting surface 404, which allows a downstream end of the distributor system 302, including the turbine generator 332, to be supported by the distributor mounting projection 315. The distributor 308 can be an annular tube adequately dimensioned with an inner diameter 502, which allows a wide flow range of combustion charge gas from the cylinder to the turbine generator 332. As an example, the inner diameter 502 of the distributor 308 can be selected such that it ranges from 19 mm to 21 mm.In another example, the manifold 308 can have a wall thickness 504 with a first section of 1.8 mm to 2.5 mm for a first section of the manifold 308 from the combustion chamber 320 to the check valve / filter 326, and a second section of 2.8 mm to 3.2 mm for a second section of the manifold 308 from the check valve / filter 326 to the turbine generator 332. The manifold 308 can be made of a durable material such as ASTM A268 UNS S40900 or another suitable material that can withstand the high temperatures of the combustion charge gas discharged from one or more combustion chambers.

[0036] A portion of the combustion charge gas in each engine cylinder can be controlled via a control valve (such as the one in Fig. The charge gas from the combustion chamber can be diverted into the distributor system 302 via the control valve 316 (shown in Figures 3-4), which is set to an open position. For example, the control valve can be adjustable between a minimum and a maximum angle, with no flow or a small amount of charge gas flowing from the combustion chamber into the distributor when set to the minimum angle, and a large amount of charge gas flowing into the distributor when set to the maximum angle. The check valve / filter 326, coupled to the distributor 308, can be provided to regulate the flow of combustion charge gas from the distributor 308 into the turbine generator 332. The check valve / filter 326 can have an annular body 505 designed with an internal passage 506 and a sealing plate 508. For example, the check valve / filter 326 can be designed as a valve-and-filter combination.The inner passage 506 can be dimensioned with an inner diameter that adequately directs the flow of combustion charge gas from the distributor 308 into the turbine generator 332. The sealing plate 508 can be controlled by a controller (such as the one in ). Fig. The control unit 12 shown in Figure 1 can be set to an open-plate position to allow the flow of combustion charge gas from the distributor 308 into the turbine generator 332 during engine operation. For example, the sealing plate 508 can be set to a partially or fully open position, allowing a wide flow range of combustion charge gas from the distributor 308 into the turbine generator 332. In other examples, the control unit can set the sealing plate 508 to a closed position to stop the flow of combustion charge gas from the distributor 308 into the turbine generator 332.

[0037] The gas sensor 328, positioned downstream of the check valve / filter 326, can be designed to detect any unburned fuel in the combustion charge gas before it enters the turbine generator 332. For example, the gas sensor 328 can have an annular section 510 with an opening 512 dimensioned to accommodate a sensor element 514 with a probe tip 516. In one example, the probe element 514 can be positioned in the opening 512 such that part of the probe element extends outward from the annular section 510 and the probe tip 516 extends into an interior region of the distributor 308. The gas sensor 328 can detect unburned fuel in the combustion charge gas by, for example, measuring or estimating the hydrocarbon content of the charge gas.The measured or estimated hydrocarbon content of the combustion charge gas can be compared to a hydrocarbon threshold level to determine the amount of unburned fuel in the charge gas. If the measured or estimated hydrocarbon content in the combustion charge gas exceeds the hydrocarbon threshold level, then the charge gas is assumed to contain unburned fuel. Conversely, if the measured or estimated hydrocarbon content in the combustion charge gas is below the hydrocarbon threshold level, then the charge gas can be assumed to be free of unburned fuel. In alternative examples, the gas sensor 328 can detect the amount of unburned fuel in the combustion charge gas based on fuel properties other than hydrocarbon content.

[0038] If unburned fuel is detected in the combustion charge gas, the igniter 330 can be activated by the control unit to combust any unburned fuel flowing downstream of the check valve / filter 326 before the charge gas enters the turbine generator 332. The igniter 330 may have an annular section 518 with an opening 520 dimensioned to accommodate an ignition rod 522. As an example, the ignition rod 522 may have an ignition tip 524 extending into the interior of the distributor 308. When activated, the ignition tip 524 can be in contact with the combustion charge gas to provide an initial ignition to ignite the fuel in the charge gas. In this way, the unburned fuel in the combustion charge gas can be combusted before it enters the turbine generator 332.By burning any unburned fuel in the combustion charge gas, the efficiency of the turbine generator 332 can be improved while reducing fuel emissions.

[0039] The turbine generator 332 can have the impeller 418 mounted inside an inner opening 530 formed in the upper section 334. The impeller 418 can be mounted on the turbine generator 332 by means of a frame 532 having a shaft 534, a middle section 536, and a lower section 538. The shaft 534 of the frame 532 can be secured in an opening formed in the upper section 334 of the turbine generator 332. A lower section of the inner opening 530 can be closed off by a plate 540. As an example, the plate 540 can be a circular plate that encloses the lower section of the inner opening 530.A section of the distributor 308 can connect with a first section of the plate 540, forming a first contact surface 542, and a section of the exhaust duct 342 can connect with a second section of the plate 540, forming a second contact surface 544. A slot 546 formed in a central section of the plate 540 can be adequately dimensioned to accommodate a portion of the central section 536 of the frame 532, extending into the inner opening 530. When mounted on the upper section 334, the impeller 526 can form a gap 548 between a lower end of the impeller 418 and an inner surface 550 of the plate 540. As an example, the gap 548 can be adequately dimensioned to allow rotation of the impeller 418 about an axis 552 of the turbine generator 332.The combustion charge gas entering the turbine generator 332 drives the wheel 418 to generate electrical power, which is transferred to points of engine power demand or stored in a battery, as indicated by the directional arrow 340. The battery charge can be used to power the vehicle or to drive a compressor coupled to an engine in the vehicle. An outer surface 554 of the lower section 528 can be located below the plate 540 to form a gap 556 between the lower section 538 and the plate 540. Once the combustion charge gas has been converted into electrical power, any residual exhaust gas in the turbine generator 332 is routed to the exhaust duct 342, where the exhaust gas is discharged to the EGR system, as shown by the arrow 344.

[0040] The distributor 308 can be configured to direct combustion charge gas from the cylinder to the turbine generator 332 when the control valve is set to the open position. By adjusting the flow of combustion charge gas from the cylinder, compression ratios in the engine can be varied based on engine operating conditions, while generating electrical energy to power engine components and vehicle systems.

[0041] Procedure 600, with reference to Fig. Figure 6 illustrates an example method for controlling the compression ratio in an engine that has a control valve (e.g., the one in Fig. 3-4 control valve 316), which is coupled to a cylinder, and a distributor (e.g. the one in Fig. distributor 308 shown in Figures 3-5), which is connected to a turbine generator (e.g., the one shown in Figures 3-5). Fig. The method can enable the engine compression ratio to be set to threshold levels to minimize the occurrence of engine knocking while promoting better engine performance.

[0042] Instructions for executing procedure 600 and the other procedures included herein can be executed by a controller based on instructions stored in a memory of the controller and in conjunction with signals from sensors of the engine system, such as those mentioned above with reference to Fig. The sensors described in 1-2 will receive data. The controller can use motor actuators of the motor system to adjust the motor operation according to the procedures described below. The procedure according to Fig. 6 can be used in conjunction with the systems of Fig. 1-5 can be used.

[0043] In procedure 602, method 600 can involve determining the target engine torque based on engine operating conditions. Examples of engine operating conditions include: engine speed, engine load, accelerator pedal position, vehicle speed, engine temperature, tendency to knock, and the mass flow rate of the combustion charge.

[0044] Subsequently, at 604, the procedure can involve setting a control valve timing, ignition timing, throttle position, and boost pressure based on the engine operating conditions and the target torque. For example, the control valve timing, ignition timing, throttle position, and boost pressure can be set based on the engine load / speed and / or engine torque. In one example, the control valve coupled to each cylinder (e.g., control valve 316 coupled to combustion chamber 320, as in Fig. (as shown in Figure 4) can be set to a closed valve position under high engine load and high engine speed. This can allow the engine to operate at a higher compression ratio while generating adequate torque to match the high engine load. In other examples, the control valve can be set to an open valve position under low to moderate engine load / speed. In this case, some of the combustion charge gas in one or more cylinders can be vented into the distributor to vary the compression ratio. The charge gas in the distributor can further be directed into a turbine generator (e.g., the one shown in Figure 4). Fig. The flow is directed through the turbine generator 332 shown in Figures 3-5. In another example, the control valve can be partially opened, with the valve opening set to provide sufficient clearance to reduce the occurrence of knocking. For example, if the cylinders show an increasing tendency to knock, the control valve opening can be increased. In response to an indication of knocking, the control valve opening can be further adjusted (e.g., increased) to provide rapid correction of the knocking.

[0045] Similarly, ignition timing, throttle position, and boost pressure (based on engine load and speed) can be adjusted to vary the compression ratio. For example, at higher engine speeds and loads relative to the MBT (Maximum Throttle Rate), the ignition timing can be slightly retarded while an intake throttle is held more open, thus slightly reducing the compression ratio and providing some knock correction. In other examples, at high engine speed and load, a compression recirculation valve coupled to an intake compressor can be held partially open to provide some clearance from pumping. In response to the accelerator pedal being released, when pumping may occur, the compressor recirculation valve can be quickly moved to a fully open position to reduce boost pressure and move the engine away from pumping.

[0046] After determining the settings for the control valve timing, ignition timing, throttle position, and boost pressure, procedure 600 can proceed to 606. At 606, procedure 600 may include determining whether engine knock is present. Engine knock can occur when the temperature and pressure of the air-fuel mixture in an engine cylinder exceed a threshold level, causing the mixture to ignite spontaneously. This can generate a shock wave that causes a rapid increase in cylinder temperature and pressure, potentially leading to damage to engine components. The presence of engine knock can be determined using a knock sensor mounted on the engine to measure, for example, engine vibration.

[0047] If engine knock is detected, the procedure can proceed to 608. In 608, procedure 600 may involve adjusting the control valve timing or the ignition timing, or both, to control the compression ratio to reduce knocking. Adjusting the control valve timing or the ignition timing can decrease the compression ratio to reduce cylinder temperature and pressure.

[0048] Knocking can be reduced by retarding the ignition timing. However, using retarded ignition results in a loss of fuel. Knocking can also be reduced by decreasing the compression ratio of the knocking cylinder by narrowing the opening of the control valve. While this leads to a decrease in torque and engine power, at least some of the engine energy consumed by opening the control valve can be recovered through the operation of the turbine generator, which is coupled downstream of the control valve.In response to a knock indication, the control unit can compare the fuel loss associated with using retarded ignition timing with the loss of engine power associated with opening the boost control valve (taking into account the engine power recovered via the electric turbine) and select a knock-mitigating measure accordingly. For example, if the fuel loss associated with retarded ignition timing is less, the ignition timing can be retarded relative to the MBT (Motor-Based Throttle) to mitigate knocking. Conversely, if the loss of engine power associated with opening the boost control valve is less, the boost control valve can be moved (from its current position) to an open position while maintaining the ignition timing at the MBT.

[0049] In an example where the control valve setting is selected to mitigate knocking, the control valve can be moved from a partially open position to a more open (e.g., fully open) position in response to knocking, allowing the combustion charge in the cylinder to flow quickly into the distributor. The ignition timing can be maintained at or near the maximum blow-off temperature (MBT) while the control valve opening is increased. The duration and degree of control valve opening can be set based on engine operating conditions and a desired reduction in cylinder temperature and pressure, providing the necessary knock mitigation. Consequently, the engine compression ratio can be reduced to a threshold value, leading to a reduction in cylinder temperature and pressure to minimize the undesirable effects of engine knocking.The combustion charge in the distributor can flow downstream to the turbine generator, where the charge gas drives an impeller to generate electrical power, which is then distributed to points of power demand in the engine or vehicle. For example, the control valve can be opened further or held open longer until the indication of knocking, received from a knock sensor, subsides (and for a period thereafter). Subsequently, the control valve can be returned to the less open position, and the cylinder compression ratio can be returned to the higher value that provides greater engine efficiency.

[0050] Furthermore, boost pressure adjustments can be made simultaneously. For example, in response to the knock indicator, while the control valve is open to reduce cylinder temperature and pressure, a drop in boost pressure can be compensated for by increasing a throttle opening, reducing the opening of a compressor recirculation valve, and / or decreasing the opening of an exhaust bypass valve.

[0051] In an alternative embodiment, the ignition timing can be adjusted by delaying the spark ignition to reduce the compression ratio.

[0052] Reducing the compression ratio can lead to a reduction in cylinder temperature and pressure, minimizing the effects of engine knock on engine performance. After adjusting the control valve timing and / or ignition timing, the procedure can proceed from 600 to 610.

[0053] If, returning to 606, no engine knock is detected, the procedure may proceed to 610. At 610, procedure 600 may involve determining whether a torque jump is present. Torque jumps can include a sudden increase or a sudden decrease in torque. For example, a torque jump may occur when a vehicle is brought to a stop in response to the operator releasing an accelerator pedal or applying a brake pedal. Alternatively, a torque jump may occur when the vehicle accelerates after coming to a stop, for example, when starting the vehicle or in response to an accelerator pedal being applied. If a torque jump is present, procedure 600 proceeds to 612. Otherwise, if no torque jump is present, the procedure proceeds to 614 to resume rated engine operation.For example, if there is no torque surge, the ignition timing can be returned to the MBT (if it was previously retarded), and furthermore, the control valve can be returned to a nominal position based on the engine's tendency to knock. For example, the control valve can be returned to a partially open position.

[0054] In procedure 600, 612 can involve coordinating changes in the control valve timing, throttle position, and boost pressure for a limit duration in response to a torque surge. The engine control unit can make adjustments to the control valve timing, throttle position, and boost pressure for a duration that allows the actual engine torque to match the target engine torque. For example, in response to a temporary need for negative torque, such as when a driver applies the brake pedal or releases the accelerator pedal, the control unit can reduce the opening of the control valve (e.g., close the control valve) and adjust the throttle to a more closed position to reduce engine torque and thus allow the vehicle to stop.In an alternative example, if the driver depresses the accelerator pedal to initiate movement, the control unit can temporarily keep the control valve closed and set the throttle to an open position to increase engine torque, thereby allowing the vehicle to accelerate. Once the vehicle reaches a limiting speed, the control unit can set the control valve to a more open position to allow a combustion charge to flow from the engine cylinder to the distributor coupled to the turbine generator, thus modulating the engine compression ratio while maintaining the actual engine torque at values ​​close to the target engine torque.

[0055] Subsequently, at 614, the engine resumes rated operation, in which it continues to burn air and fuel to generate the torque necessary to propel the vehicle. The control valve in each cylinder of the engine can be periodically set to open and then closed during engine operation. When the control valve is set to the open position, combustion charge gas can flow from the cylinder into the distributor. A check valve (e.g., the one in the Fig. The check valve / filter 326 (shown in Figures 3-5) on the distributor stops the reverse flow of the combustion charge gas back into the combustion chamber. The check valve always allows the flow of combustion charge gas in the downstream direction into the turbine generator 332. A gas sensor (e.g., the one shown in Figures 3-5) Fig. The gas sensor 328 (shown in Figures 3-5), which is coupled to the distributor 308, can be provided to detect any unburned fuel in the combustion charge gas that is ignited before entering the turbine generator by means of an igniter (e.g., the one in Figure 3-5). Fig. The combustion gas can be burned in the igniter 330 shown in figures 3-5. Upon entering the turbine generator, the combustion charge gas drives an impeller (e.g., the one shown in the diagram). Fig. (4-5 shown impeller 418) to generate electrical power, which is distributed to points of power demand in the engine or vehicle. Any residual exhaust gas generated after the electrical power has been produced is routed to an EGR system, where the exhaust gas can be recirculated to an intake manifold.

[0056] In this way, the compression ratio in the engine can be varied by adjusting the control valve timing, throttle position, and ignition timing. The control valve can be set to the open position to reduce engine knock and mitigate the effects of high cylinder temperature and pressure that can occur at high compression ratios. When set to the open position, combustion charge gases from engine cylinders can be diverted to the distributor, allowing for a reduction in the compression ratio and a decrease in cylinder temperature and pressure. The charge gas in the distributor can then be diverted to the turbine generator to produce electrical power.In this way, the engine system provides a method for varying the engine compression ratio to promote better engine performance while generating electrical power to operate engine components.

[0057] With reference to Fig. Figure 7 shows an example graphic illustrating the adjustment of a control valve timing, throttle position, and ignition timing to vary the compression ratio and torque in an engine. The sequence of Fig. 7 can be done by executing instructions in the system of Fig. 1-5 according to the procedures of Fig. 6. The vertical markers at time points T0–T3 represent the relevant time during the sequence. In all subsequent graphs, the horizontal axis represents time, and time increases from the left side of each graph to the right side.

[0058] The first course from the top into Fig. Figure 7 depicts the compression ratio as a function of time. The vertical axis represents the compression ratio, and the compression ratio increases along the vertical axis. Curve 702 represents the compression ratio.

[0059] The second course from the top in Fig. Figure 7 depicts a control valve position as a function of time. The vertical axis represents the control valve position. The control valve is set to a closed position along the horizontal axis and to an open position along the vertical axis. The degree of valve opening of the control valve increases along the vertical axis. Curve 704 represents the control valve position. In alternative examples, the control valve can be referred to as a drain valve.

[0060] The third course from the top in Fig. Figure 7 depicts a throttle valve position as a function of time. The vertical axis represents the throttle valve position. The throttle valve is set to a closed position on the horizontal axis and to an open position along the vertical axis. The degree of throttle valve opening increases along the vertical axis. Curve 706 represents the throttle position.

[0061] The fourth course from the top in Fig. Figure 7 depicts the motor torque as a function of time. The vertical axis represents the motor torque, and the motor torque increases in the direction of the vertical axis. Curve 708 represents a target motor torque, and curve 710 represents an actual motor torque.

[0062] The fifth course from the top in Fig. Figure 7 depicts the ignition timing in relation to time. The vertical axis represents the ignition timing, and the ignition timing advances along the vertical axis. Curve 716 represents an actual ignition timing, and curve 718 represents an ignition timing for maximum braking torque (MBT).

[0063] During the time between T0 and T1, the engine can operate with a constant compression ratio (702) that is below a threshold level (703) for the compression ratio. For example, the compression ratio (702) can be set to a first level below the threshold level (703). The actual engine torque (710) can be at a constant level and can correspond to the target engine torque (708). The control valve position (704) can be maintained at a first open valve position that keeps the actual engine torque (710) at a constant level that corresponds to the target engine torque (708). For example, the control valve position (704) can be adjustable between an angle of 0 degrees and 60 degrees. When set to an angle of 0 degrees, the control valve is set to a closed valve position, and when set to an angle of 60 degrees, the control valve is set to a more open valve position.In other examples, the control valve position (704) can be adjustable between a minimum angle and a maximum angle, where the minimum angle represents no flow or a minimum flow rate of charge gas from a cylinder into a distributor (e.g., the one in . Fig. 3 distributors shown 308) enable and the maximum angle allows a maximum flow rate of charging gas from the cylinder into the distributor.

[0064] Furthermore, the throttle position (706) can be held in an open position, allowing a continuous flow of air into the intake manifold, with the air flowing downstream to a combustion chamber where the air mixes with fuel to form an air-fuel mixture that burns to generate engine torque (710). The ignition timing (716) can be set to the ignition timing for the MBT (718).

[0065] When the control valve is set to the open position, the combustion charge in the combustion chamber can flow from the chamber into the distributor (e.g., the one in the Fig. The combustion charge gas in the distributor can be diverted in the downstream direction to a turbine generator (e.g., the one shown in Figure 3, 308), while the compression ratio (702) is maintained at a constant level below the threshold level (703). Fig. 3-5 turbine generator 332) flow when a check valve (e.g. the one in Fig. The check valve / filter 326 (shown in Figures 3-5), which is coupled to the distributor, is set to an open position. Upon entering the turbine generator, the combustion charge gas drives an impeller (e.g., the one in Figure 3-5). Fig. 4-5 shown impeller 418) of the turbine generator for rotation to generate electrical power which can be distributed to points of power demand in the engine or vehicle.

[0066] At T1, the compression ratio (702) can be increased above the threshold level (703) to increase the actual engine torque (710) in the engine. For example, the compression ratio (702) can rise from the first level to a second level that is higher than the threshold level (703). In another example, the increase in the compression ratio (702) can occur when the flow rate of the combustion charge gas (flowing from the combustion chamber to the distributor) is reduced and the throttle position (706) is set to a more open valve position, allowing a greater flow of air into the combustion chamber via the intake manifold. The control valve position (704) can be set from the open position to a fully closed position to stop the flow of combustion charge gas from the combustion chamber to the distributor.

[0067] Between T1 and T2, the compression ratio (702) can be maintained at the second level above the threshold level (703). The control valve (704) can be held in the closed position, and the throttle position (706) can be maintained at a level greater than the initial throttle position before T1. Consequently, the actual engine torque (710) can initially rise rapidly before reaching a steady level above the initial torque observed between T0 and T1. The actual engine torque (710) may deviate slightly from the profile of the target engine torque (708). A first torque rise (712) can be attributed to the closing of the control valve, and a second torque rise (714) can be attributed to the adjustment of the throttle position. The first torque rise (712) may be greater than the second torque rise (714).Closing the control valve to stop the flow of combustion charge gas from the combustion chamber to the distributor can have the immediate effect of increasing the compression ratio (702), which can lead to a rapid increase in actual engine torque (710). In contrast, adjusting the throttle position (706) to allow a greater flow of air into the combustion chamber via the intake manifold can be done over a longer period of time, due to the increased transit time of air through the intake manifold before it reaches the combustion chamber. The increased mass of air flowing into the combustion chamber can mix with fuel to form an air-fuel mixture that is burned to produce a high level of engine torque (710).However, the increase in actual engine torque due to adjusting the throttle position may be less than the increase in actual engine torque due to closing the control valve. The ignition timing (716) can be gradually retarded to a level below the MBT level (718), while the actual engine torque (710) is maintained at a steady level close to the target engine torque (708).

[0068] At T2, the compression ratio (702) can decrease to a level below the threshold level (703) if the control valve is adjusted from the fully closed position to an open position. For example, the compression ratio (702) can decrease from the second level to the first level if the control valve is adjusted to a second open position with a smaller degree of valve opening compared to the first valve opening observed at T1. In other examples, the compression ratio can vary in response to a knock indication, where the knock indication includes both a detected knock and a predicted knock, and the variation involves decreasing the compression ratio in response to the knock indication by increasing the opening of the drain valve.In further examples, one or more of the drain valve opening degree and duration can be set based on the knock indication, whereby the drain valve is opened more fully or held open for a longer period until the knock indication falls below a threshold. The ignition timing (716) can be adjusted to match the MBT ignition level (718). As a result, the actual engine torque (710) can be maintained at values ​​close to the target engine torque (708).

[0069] After T2, the compression ratio (702) can be maintained at the first level by keeping the control valve position (704) at the second open valve position and gradually adjusting the throttle position (706) to a less open position to reduce the airflow into the combustion chamber (via the intake manifold). The rate of airflow into the combustion chamber may be lower compared to the airflow rate observed between T1 and T2, for example. Furthermore, the ignition timing (716) can be maintained at the MBT ignition level (718). Consequently, the compression ratio (702) is maintained at the second steady level, and the actual engine torque (710) can match the target engine torque (708).

[0070] In this way, the compression ratio in the engine can be varied by adjusting the control valve timing, throttle position, and ignition timing to keep the actual engine torque close to the target engine torque. The combustion charge gas, which is discharged from the combustion chamber when the control valve and check valve on the distributor are set to open positions, can flow into the turbine generator, where the charge gas causes the impeller to rotate to generate electrical power. Thus, the compression ratio in the engine can be varied to achieve better engine performance while generating electrical power that can be distributed to points of power demand within the engine.

[0071] In another description, a procedure for an engine involves: in response to a first knock indication in a cylinder - retarding the ignition timing while maintaining a compression ratio of the cylinder by closing a drain valve coupled to a cylinder head, which is different from an exhaust valve; and - in response to a second knock indication - maintaining the ignition timing while decreasing the compression ratio of the knocking cylinder by opening the drain valve.In a previous example, it is additionally or optionally assumed that the drain valve is coupled upstream of a turbine generator and that reducing the compression ratio by opening the drain valve involves removing at least part of the charge gas from the cylinder, allowing the removed charge gas to flow through the turbine generator, and generating usable electrical power at the turbine generator based on the flow.Additionally or optionally, any of the preceding examples may include: in response to both the first and second knock indications - estimating each of a first fuel loss associated with retarding the ignition timing while maintaining a compression ratio of the knocking cylinder by closing the coupled exhaust valve, and a second power loss associated with maintaining the ignition timing while reducing the cylinder's compression ratio by opening the exhaust valve and allowing discharged charge gas to flow through a downstream turbine generator.

[0072] Furthermore, in any one of the preceding examples, it is additionally or optionally stipulated that the second power loss is further estimated based on the electrical power generated by the flow of the discharged charge gas through the turbine generator. Any one of the preceding examples may additionally or optionally include that, at the first knock indication, the first fuel loss is less than the second power loss, and that, at the second knock indication, the second power loss is less than the first fuel loss. In any one of the preceding examples, it is additionally or optionally stipulated that the first and second knock indications include a general knock intensity. In any one of the preceding examples, it is additionally or optionally stipulated that the first knock indication includes a lower knock intensity and the second knock indication includes a higher knock intensity.Other examples may include: in response to the first knock indication - reducing the opening of an EGR valve to reduce the recirculation of exhaust gas from an exhaust manifold to an intake manifold; and - in response to the second knock indication - increasing the opening of the EGR valve to increase the recirculation of exhaust gas from the diverter manifold downstream of the turbine generator to the intake manifold.

[0073] In one example, an engine may comprise: varying the compression ratio of a cylinder by selectively diverting combustion charge gas from the cylinder through a vent valve on a cylinder head; and converting the diverted combustion charge gas into usable electrical power at a turbine generator coupled downstream of the vent valve. In the preceding example, the vent valve is additionally or optionally distinct from the cylinder's exhaust valve. In any or all of the preceding examples, the conversion involves igniting, by means of an igniter, unburned fuel in the diverted combustion charge upstream of the turbine generator, with an igniter output being set based on a detected amount of unburned fuel in the diverted combustion charge.

[0074] In other preceding examples, it is additionally or optionally included that the conversion of the discharged combustion charge into usable electrical power involves storing the usable electrical power in a battery coupled to the turbine generator. In any or all of the preceding examples, it is additionally or optionally included that the engine is coupled in a hybrid vehicle, the method further comprising driving the vehicle using engine torque derived from an electric motor, which in turn is driven by electrical power drawn from the battery.In any or all of the preceding examples, the compression ratio is additionally or optionally varied in response to a knock indication, wherein the knock indication includes a detected knock and a predicted knock, and the variation involves decreasing the compression ratio in response to the knock indication by increasing the opening of the drain valve. In any or all of the preceding examples, one or more of the drain valve opening degrees and durations are set based on the knock indication, with the drain valve being opened more fully or held open for a longer period until the knock indication falls below a threshold.

[0075] Any or all of the preceding examples may further, additionally or optionally, include: after conversion, recirculating the discharged combustion charge from downstream of the turbine generator to an intake port via an exhaust gas recirculation port. In any or all of the preceding examples, varying the compression ratio may additionally or optionally include: increasing the compression ratio by closing the exhaust valve to retain the combustion charge in the cylinder; and decreasing the compression ratio by opening the exhaust valve to discharge combustion charge from the cylinder.Any or all of the preceding examples may further, additionally or optionally, include: maintaining a distributor boost pressure while the compression ratio is varied, the maintenance comprising: in response to the opening of the bleed valve - one or more of increasing the intake throttle opening, reducing a compressor recirculation valve opening, and decreasing the opening of an exhaust bypass valve; and - in response to the closing of the bleed valve - one or more of decreasing the intake throttle opening, increasing the compressor recirculation valve opening, and increasing the opening of the exhaust bypass valve.In any or all of the preceding examples, the variation additionally or optionally includes the following: the variation occurs in response to a temporary change in the operator-induced torque requirement, wherein the temporary change includes a temporary increase in the operator-induced torque requirement to start a vehicle and a temporary decrease in the torque requirement to decelerate the vehicle, wherein the variation includes: in response to the temporary increase in the operator-induced torque requirement - closing the exhaust valve to decrease the compression ratio while enlarging an intake throttle opening; and - in response to the temporary decrease in the operator-induced torque requirement - opening the exhaust valve to increase the compression ratio while decreasing the intake throttle opening.

[0076] Another method may involve: in response to a knock indication - comparing a first fuel loss, associated with retarding the ignition timing while maintaining the compression ratio of a knocking cylinder by closing a bleed valve coupled to a cylinder head, with a second power loss, associated with maintaining the ignition timing while decreasing the cylinder's compression ratio by opening the bleed valve and allowing discharged charge gas to flow through a downstream turbine generator; and opening the bleed valve if the second power loss is less than the first fuel loss.In any or all of the preceding examples, the second power loss is additionally or optionally calculated as a function of a loss of cylinder pressure due to the discharge of charge gas through the open vent valve and an increase in battery charge status due to electrical power generated by the flow of the discharged charge gas through the turbine generator. In any or all of the preceding examples, the knock indication involves a knock sensor output exceeding a threshold value, and opening the vent valve involves setting a duration and degree of opening of the vent valve until the knock sensor output falls below the threshold value.Any or all of the preceding examples may further include, additionally or optionally, closing the drain valve and delaying the ignition timing if the first fuel loss is less than the second power loss.

[0077] In another example, an engine system may comprise: an engine cylinder having an intake valve that draws in air from an intake manifold and an exhaust valve that discharges a charge into an exhaust manifold; an EGR channel for recirculating exhaust gas from the exhaust manifold to the intake manifold; a cylinder head having a drain valve leading to a branch manifold, the branch manifold having an igniter coupled upstream of a turbine generator, the branch manifold being coupled to the EGR channel upstream of the turbine generator; a battery coupled to the turbine generator; a knock sensor coupled to the cylinder head; an oxygen sensor coupled to the branch manifold upstream of the igniter;and a control system with computer-readable instructions stored in non-volatile memory for the following: operating the cylinder at a high compression ratio by reducing the opening of the exhaust valve; operating the cylinder at a lower compression ratio by increasing the opening of the exhaust valve; and, while operating at the lower compression ratio, passing a charge discharged from the cylinder through the turbine generator; and charging the battery with electrical power generated by the current at the turbine generator.

[0078] Any or all of the preceding examples may further include, additionally or optionally: during operation at the lower compression ratio, recirculating the exhaust gas that has been discharged from the cylinder to the intake manifold via the EGR channel after it has passed through the turbine generator.

[0079] In other preceding examples, it is additionally or optionally the case that operation at the lower compression ratio occurs in response to a knock sensor output exceeding a threshold, with the vent valve opening being increased by a certain amount and held open until the knock sensor output falls below the threshold. Other preceding examples may further include, additionally or optionally: an accelerator pedal for receiving an operator-induced torque demand, wherein operation at the lower compression ratio occurs in response to a temporary decrease in the operator-induced torque demand, and wherein operation at the higher compression ratio occurs in response to a temporary increase in the operator-induced torque demand.

[0080] Fig.Figures 1-5 show exemplary layouts with a relative positioning of the various components. If such elements are shown in direct contact or are directly coupled, they can be described as directly contacting or directly coupled, respectively, in at least one example. Similarly, elements shown abutting or adjacent to each other can be described as abutting or adjacent, respectively, in at least one example. As one example, components that are in surface-dividing contact with each other can be described as being in surface-dividing contact. As another example, elements that are positioned separately from each other, with only a space between them and no other components, can be described as such, at least in one example.As another example, elements shown above / below each other, on opposite sides of each other, or to the left / right of each other can be described as such in relation to one another. Furthermore, as shown in the figures, a topmost element or the highest point of an element can be described as a "top" of the component in at least one example, and a bottommost element or the lowest point of the element can be described as a "bottom" of the component. In the sense used here, top / bottom, upper / lower, and above / below can refer to a vertical axis of the figures and be used to describe the positioning of elements of the figures in relation to one another. Accordingly, elements shown above other elements are, in one example, positioned vertically above the other elements.As another example, the shapes of the elements depicted in the figures can be described as having those shapes (e.g., circular, straight, planar, curved, rounded, beveled, angled, or the like). Furthermore, elements shown to intersect each other can be described, in at least one example, as intersecting elements or as intersecting each other. Additionally, an element shown inside or outside another element can be described as such in one example.

[0081] It should be noted that the exemplary control and estimation routines included herein can be used in connection with various engine and / or vehicle system designs. The control methods and routines disclosed herein can be stored as executable instructions in non-volatile memory and executed by the control system, which includes the control unit in combination with the various sensors, actuators, and other engine hardware. The specific routines described herein can represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multitasking, multithreading, and the like. Thus, various actions, operations, and / or functions shown can be performed in the sequence shown, in parallel, or, in some cases, omitted.Similarly, the processing sequence is not strictly necessary to achieve the features and advantages of the exemplary embodiments described here, but is provided to facilitate illustration and description. One or more of the illustrated actions, processes, and / or functions can be performed repeatedly, depending on the specific strategy employed. Furthermore, the described actions, processes, and / or functions can graphically represent code to be programmed into non-volatile memory of the computer-readable storage medium in the engine control system, with the described actions being executed by carrying out the instructions in a system that includes the various engine hardware components in combination with the electronic control unit.

[0082] It is understood that the interpretations and routines disclosed herein are exemplary in nature and that these specific embodiments are not to be interpreted in a limiting sense, as numerous variations are possible. For example, the aforementioned technology can be applied to V-6, I-4, I-6, V-12, 4-cylinder boxer, and other engine types. The subject matter of this disclosure includes all novel and non-obvious combinations and sub-combinations of the different systems and interpretations, and other features, functions, and / or properties disclosed herein.

[0083] The following claims, in particular, describe certain combinations and subcombinations that are considered novel and not obvious. These claims may refer to "one" element, "a first" element, or the equivalent thereof. Such claims are to be understood as including one or more such elements and neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by amending the present claims or by filing new claims in this or a related application. Such claims are also to be considered as included in the subject matter of the present disclosure, irrespective of whether their scope is broader, narrower, or the same as that of the original claims.

Claims

[1] Method for an engine (100), comprising: Vary, by means of an engine control (12), a compression ratio of a cylinder (206) by selectively removing combustion charge, which was generated by ignition of an air-fuel mixture in the cylinder (206), from the cylinder (206) through a drain valve on a cylinder head (202), Diverting the discharged combustion charge gas into a turbine generator (234) and Generating, by means of the discharged combustion charge, of usable electrical power by the turbine generator (234), wherein the turbine generator (234) is coupled downstream of the drain valve. [2] Method according to claim 1, wherein the drain valve differs from an exhaust valve (210) of the cylinder (206). [3] Method according to claim 1, wherein the generation includes igniting, by means of an igniter (232), unburned fuels in the discharged combustion charge upstream of the turbine generator (234), wherein an output of the igniter (232) is set based on a detected quantity of unburned fuels in the discharged combustion charge. [4] Method according to claim 1, wherein the generation includes storing the usable electrical power in a battery coupled to the turbine generator (234). [5] Method according to claim 4, wherein the motor (100) is coupled in a hybrid vehicle, the method further comprising driving the hybrid vehicle using motor torque derived from an electric motor which is driven by electrical power obtained from the battery. [6] Method according to claim 1, wherein the variation of the compression ratio is carried out in response to a knock indication, wherein the knock indication includes a detected knock and a predicted knock, and the variation includes a reduction of the compression ratio in response to the knock indication by enlarging an opening of the drain valve. [7] Method according to claim 6, wherein one or more of the opening degree of the drain valve and the opening duration of the drain valve are set based on the knock indication, wherein the drain valve is opened more or kept open for a longer period of time until the knock indication falls below a threshold value. [8] Method according to claim 1, further comprising that after generation the discharged combustion charge is returned from downstream of the turbine generator (234) to an inlet channel (42) via an EGR channel (140). [9] Method according to claim 1, wherein varying the compression ratio includes: Increasing the compression ratio by closing the exhaust valve to retain the combustion charge in cylinder (206); and Reducing the compression ratio by opening the drain valve to discharge combustion charge from the cylinder (206). [10] The method of claim 9, further comprising maintaining a distributor boost pressure while varying the compression ratio, wherein the maintenance includes: in response to the opening of the drain valve - one or more of which enlarge an intake throttle opening, reduce a compressor recirculation valve opening and decrease an exhaust bypass valve opening; and as a reaction to the closing of the drain valve - one or more of the following: reducing the intake throttle opening, increasing the compressor recirculation valve opening, and increasing the exhaust bypass valve opening. [11] Method according to claim 1, wherein the variation occurs in response to a temporary change in the torque requirement caused by the operator, wherein the temporary change includes a temporary increase in the torque requirement caused by the operator for starting a vehicle and a temporary decrease in the torque requirement caused by the operator for braking the vehicle, wherein the variation includes: in response to the temporary increase in operator-induced torque demand - closing the drain valve to reduce the compression ratio while an intake throttle opening is enlarged; and In response to the temporary decrease in operator-induced torque demand - opening the drain valve to increase the compression ratio while reducing the intake throttle opening. [12] Engine system, comprising: a cylinder (206) which has an inlet valve (208) which takes in air from an intake manifold (44) and an exhaust valve (210) which discharges a charge into an exhaust manifold (48); an EGR channel (140) for recirculating exhaust gas from the exhaust manifold (48) to the intake manifold (44); a cylinder head (202) which has a drain valve leading to a branch distributor (226), wherein the branch distributor (226) has an igniter (232) which is coupled upstream of a turbine generator (234), wherein the branch distributor (226) is coupled upstream of the turbine generator (234) to the EGR channel (140); a battery coupled to the turbine generator (234); a knock sensor coupled to the cylinder head (202); an oxygen sensor which is coupled to the branch distributor (226) upstream of the igniter (232); and a controller (12) with computer-readable instructions stored in non-volatile memory for the following: Operating the cylinder (206) at a higher compression ratio by reducing the opening of the drain valve; Operating the cylinder (206) at a lower compression ratio by increasing the opening of the exhaust valve; and, during operation at the lower compression ratio, flowing exhaust gas discharged from the cylinder (206) through the turbine generator (234); and charging the battery with electrical power generated by the flow at the turbine generator (234). [13] Engine system according to claim 12, further comprising: during operation at the lower compression ratio - detecting, by means of the oxygen sensor, an amount of unburned fuel in the exhaust gas discharged from the cylinder (206) and adjusting an output of the igniter (232) based on the detected amount of unburned fuel. [14] Engine system according to claim 12, further comprising: during operation at the lower compression ratio - recirculating the exhaust gas that has been discharged from the cylinder (206) to the intake manifold (44) via the EGR channel (140) after it has flowed through the turbine generator (234). [15] Engine system according to claim 12, wherein the operation at the lower compression ratio occurs in response to a knock sensor output exceeding a threshold value, wherein the opening of the drain valve is increased by a certain amount and it is kept open for a period of time until the knock sensor output falls below the threshold value.

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