System and method for managing piston temperature in a vehicle

Abstract

A vehicle including an engine; a turbocharger; an intake air flow path of the vehicle, the intake air flow path defined by air entering the vehicle, passing through the compressor, and flowing into an air inlet of the engine; a coolant reservoir assembly; a temperature sensor configured to determine a temperature in the intake air flow path; and a controller configured to selectively flow coolant from the coolant reservoir into the intake air flow path. A method for managing engine intake air temperature or piston temperature of a turbocharged vehicle, the method including sensing a fluid temperature within an intake air flow path; determining an estimated piston temperature; and in response to the estimated piston temperature and / or the fluid temperature being above a threshold temperature, flowing an amount of coolant from a coolant reservoir to the intake air flow path.

Description

Technical Field

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 061,501, filed August 5, 2020, entitled “Air Intake System for a Vehicle,” the entire contents of which are incorporated herein by reference.

[0002] This technology relates to managing piston temperature in an engine. Background Technology

[0003] For internal combustion engines, such as those used in snowmobiles, the efficiency of the combustion process can be improved by compressing the air entering the engine. This can be achieved using a turbocharger connected to the intake and exhaust systems of the snowmobile. The compression of air by the turbocharger can be particularly important when the internal combustion engine is operating in environments with low atmospheric pressure or when the air becomes thinner.

[0004] While using a turbocharger to increase air pressure can help improve engine efficiency, the compression process also heats the air. This heating in the turbocharger can come from both pressure-related temperature increases due to the pressure-temperature relationship and heat transfer from the exhaust gases that spin the turbine through the turbocharger to the compressor. When the compressed air from the turbocharger is too hot, engine efficiency and performance can be affected by engine knock. Also known as "detonation," engine knock reduces engine efficiency by consuming a portion of the air-gas mixture during an incorrect part of the engine's stroke cycle.

[0005] In response to engine knock, compression through the turbocharger is typically reduced or shut off completely. This reduces the heating of the air entering the engine (reducing or eliminating knock), but any benefits from the turbocharger are also lost. In some cases, reducing engine load (RPMs) can address the knock problem, but this also results in a loss of engine efficiency or power.

[0006] One proposed solution to this problem is to include an intercooler to cool compressed air before it enters the engine. However, intercoolers can be space-consuming and must be located near the engine and arranged to be cooled by oncoming air or thrown snow (for snowmobiles). This can take up valuable space and complicate the design of compact engine layouts. In some cases, intercoolers may also be less effective at higher altitudes and under lower pressure conditions due to the generally lower atmospheric pressure.

[0007] Therefore, there is a need for an intake system for internal combustion engines that can benefit from the addition of a turbocharger while overcoming some of the previously known drawbacks of incorporating a turbocharger. Summary of the Invention

[0008] The purpose of this technology is to mitigate at least some of the inconveniences present in the prior art.

[0009] According to one aspect of the present technology, a vehicle is provided comprising an intake system having a turbocharger and a coolant container fluidly connected to an intake flow path along which air flows before entering the engine. By supplying coolant from the coolant container to the intake flow path, at least some of the heating of the intake air can be reduced. When coolant is added to the airflow upstream of the compressor, some of the heat generated by the compressor's compression is absorbed by the coolant in the compressor through evaporation and reheating. In some cases, coolant can be added downstream of the compressor, such that the air previously heated by the compressor causes some of the coolant to reheat and / or evaporate, thereby reducing the amount of air entering the engine.

[0010] While continuously supplying coolant to the airflow would ensure air cooling when the intake air becomes overheated, the coolant tank required to supply sufficient coolant for normal vehicle operation would be large and add considerable weight to the vehicle. With this technology, coolant is selectively delivered to the intake airflow path when engine power or efficiency may be affected. Specifically, this occurs when the intake air temperature and / or estimated piston temperature exceeds a threshold, i.e., when the intake air and / or piston 226 is heated to a temperature that poses a risk of detonation. The vehicle also includes a temperature sensor in the intake airflow path for measuring the intake air temperature. The controller for this system determines the estimated piston temperature based on the sensed intake air temperature. The estimated piston temperature is retrieved from a piston temperature model based on the intake air temperature. In some cases, the piston temperature model is also based on one or more engine operating values, including but not limited to: throttle position, engine speed (RPM), engine load, engine running time, ambient air temperature, ambient air pressure, engine coolant temperature, exhaust oxygen concentration (lambda), exhaust valve position, previously supplied coolant, and boost pressure.

[0011] This technology also provides a method for managing engine intake air temperature by using coolant to cool the intake air, thereby helping to reduce engine knock. The method involves determining one or more engine operating values, namely the intake air temperature and / or the engine operating values, and then estimating the piston temperature by retrieving the piston temperature from a model based on the air temperature and / or the engine operating values. In response to the intake air temperature and / or the estimated piston temperature exceeding a threshold (the threshold is calculated based on operating values ​​for snow-covered vehicles or a predetermined value), coolant is delivered to the intake air flow path. Therefore, this helps to reduce the intake air temperature, thereby avoiding or reducing engine knock without reducing boost pressure from the turbocharger and / or reducing engine speed. The intake threshold temperature and threshold piston temperature typically correspond to the temperatures above which the engine begins to face the risk of engine knock, but different thresholds can be selected.

[0012] To selectively deliver coolant to the intake airflow path, the controller opens a valve connected to the coolant reservoir to allow coolant flow into the intake airflow path. In this implementation, the vehicle may include an air pipe from the compressor to the coolant reservoir to pressurize it. In this way, there is no additional weight or space occupied by a pump used for the coolant reservoir—the pressure from the compressed air entering the coolant reservoir forces coolant through the coolant pipe when the valve is selectively opened. However, in some cases, a pump may be provided, and in this case, the controller will activate the pump connected to the coolant reservoir to pump coolant into the intake airflow path.

[0013] According to one aspect of the present technology, a vehicle is provided, the vehicle comprising: a frame; an engine supported by the frame, the engine having an engine air inlet; a turbocharger fluidly connected to the engine, the turbocharger including a compressor fluidly connected to the engine air inlet, the compressor having a compressor inlet and a compressor outlet, the intake air flow path of the vehicle being defined by air entering the vehicle, entering the compressor through the compressor inlet, leaving the compressor through the compressor outlet and flowing into the engine air inlet; a coolant container assembly supported by the frame, the coolant container assembly including a coolant container for containing coolant, the coolant container assembly being fluidly connected to the intake air flow path at a connection point; a controller communicatively connected to the coolant container assembly; and a temperature sensor communicatively connected to the controller, the temperature sensor being configured to determine the fluid temperature in the intake air flow path, the controller being configured to selectively allow a certain amount of coolant from the coolant container to flow into the intake air flow path via the connection point, at least based on the fluid temperature determined by the temperature sensor.

[0014] In some implementations, the controller is also configured to determine an estimated piston temperature based at least on the fluid temperature determined by a temperature sensor; and the controller is also configured to selectively allow a certain amount of coolant to flow based on the estimated piston temperature.

[0015] In some implementations, the controller is in communicative connection with the engine; and the controller is also configured to determine the estimated piston temperature based at least in part on at least one engine operating value received from the engine.

[0016] In some implementations, the vehicle also includes a first duct that is fluidly connected to the compressor inlet at a first end, receives air from the air surrounding the vehicle at a second end, and has a connection point on the first duct.

[0017] In some implementations, the vehicle also includes a second conduit, which is fluidly connected at a first end to a compressor outlet and at a second end to an engine air inlet, with the connection point located on the second conduit.

[0018] In some implementations, the connection point is located at the compressor inlet.

[0019] In some implementations, the vehicle also includes a coolant pipe for delivering cooling fluid to the intake air flow path, the coolant pipe being fluidly connected between the coolant container and the connection point.

[0020] In some implementations, the vehicle also includes a fuel reservoir supported by a frame; and a coolant container is located behind the fuel reservoir.

[0021] In some implementations, the coolant pipe passes under the fuel reservoir.

[0022] In some implementations, the coolant container assembly also includes a pump fluidly connected to the coolant container for pumping cooling fluid through the coolant pipes.

[0023] In some implementations, the coolant container assembly also includes a valve for controlling the flow rate of the coolant, which is located between the coolant container and the coolant pipe and is communicatively connected to a controller.

[0024] In some implementations, the valve is a solenoid valve.

[0025] In some implementations, the compressor is fluidly connected to the coolant container; and when the vehicle is in use, air flows from the compressor to the coolant container to pressurize it.

[0026] In some implementations, the first end of the coolant pipe is fluidly connected to a coolant container; and the vehicle also includes an injection nozzle connected to the second end of the coolant pipe.

[0027] In some implementations, the vehicle also includes at least one sliding element connected to the frame; and the vehicle is a snowmobile.

[0028] In some implementations, the temperature sensor is configured to sense the temperature of the fluid in the intake flow path before it passes through the compressor.

[0029] In some implementations, the temperature sensor is configured to sense the temperature of the fluid that has passed through the compressor.

[0030] According to another aspect of the present technology, a vehicle is provided, the vehicle comprising: a frame; an engine supported by the frame, the engine having an engine air inlet; a turbocharger fluidly connected to the engine, the turbocharger including a compressor fluidly connected to the engine air inlet, the compressor having a compressor inlet and a compressor outlet; a first duct fluidly connected to the compressor inlet at a first end, the second end of the first duct receiving air entering the vehicle; a second duct fluidly connected to the compressor outlet at a first end, the second end of the second duct fluidly connected to the engine air inlet, an intake air flow path defined by air entering the vehicle, entering the compressor inlet through the first duct, passing through the compressor, exiting the compressor outlet, passing through the second duct and entering the engine air inlet; a coolant container assembly supported by the frame, the coolant container assembly including a coolant container for containing coolant, the coolant container assembly being fluidly connected to the intake air flow path at a connection point; and a controller communicatively connected to the coolant container assembly, the controller being configured to selectively allow a certain amount of coolant from the coolant container to flow into the intake air flow path via the connection point based on an estimated piston temperature determined by the controller.

[0031] In some implementations, the vehicle also includes a main air box and a secondary air box, the main air box being fluidly connected between the second end of a second duct and the engine air inlet, and the secondary air box being fluidly connected to the second end of a first duct, the secondary air box being configured to introduce ambient air into the vehicle.

[0032] In some implementations, the vehicle also includes a fuel reservoir supported by a frame; and a coolant container is located behind the fuel reservoir.

[0033] In some implementations, the vehicle also includes a coolant pipe for delivering cooling fluid to the intake air flow path, the coolant pipe being fluidly connected between the coolant container and the connection point.

[0034] In some implementations, the coolant pipe passes under the fuel reservoir.

[0035] In some implementations, the coolant container assembly also includes a pump fluidly connected to the coolant container for pumping cooling fluid through the coolant pipes.

[0036] In some implementations, the coolant container assembly also includes a valve for controlling the flow rate of the coolant, which is located between the coolant container and the coolant pipe and is communicatively connected to a controller.

[0037] In some implementations, the valve is a solenoid valve.

[0038] In some implementations, the vehicle also includes a compressor fluidly connected to a coolant container; and when the vehicle is in use, air flows from the compressor to the coolant container to pressurize the coolant container.

[0039] In some implementations, the first end of the coolant pipe is in fluid connection with a coolant container; and the vehicle also includes an injection nozzle connected to the second end of the coolant pipe.

[0040] In some implementations, the connection point is located on the engine crankcase.

[0041] In some implementations, the vehicle also includes at least one sliding element connected to the frame; and the vehicle is a snowmobile.

[0042] According to another aspect of the present invention, a method for managing the intake air temperature of an engine in a turbocharged vehicle is provided. The method includes: sensing a fluid temperature within an intake air flow path by a temperature sensor, the intake air flow path being defined by air entering the vehicle, passing through a turbocharger, and entering the engine; determining an estimated piston temperature of the engine piston by a controller, based at least on the fluid temperature; and, in response to at least one of the estimated piston temperature being higher than a threshold piston temperature and the fluid temperature being higher than a threshold fluid temperature, causing a quantity of coolant to flow from a coolant container into the intake air flow path by the controller.

[0043] In some implementations, the estimated piston temperature is also determined based on at least one engine operating value received by the controller from the engine.

[0044] In some implementations, the method further includes determining at least one engine operating value by the controller, the at least one engine operating value being selected from the following: throttle position, engine speed, engine load, engine running time, ambient air temperature, ambient air pressure, oxygen concentration in exhaust gas, engine coolant temperature, exhaust valve position, previously delivered coolant volume, and boost pressure; and also determining an estimated piston temperature based on the at least one engine operating value.

[0045] In some implementations, determining the estimated piston temperature involves the controller retrieving the estimated piston temperature from a piston temperature model.

[0046] In some implementations, delivering a certain amount of coolant includes a solenoid valve operated by a controller on the coolant container assembly to allow coolant to flow out of the coolant container.

[0047] In some implementations, delivering a certain amount of coolant includes a pump operated by a controller from a coolant container assembly to pump coolant from the coolant container through coolant pipes.

[0048] According to another aspect of the present invention, a method for managing the intake air temperature of an engine in a turbocharged vehicle is provided. The method includes: determining at least one engine operating value by a controller; retrieving an estimated piston temperature of the engine's piston from a piston temperature model based on the at least one engine operating value by the controller; and, in response to the estimated piston temperature being higher than a threshold piston temperature, causing the controller to deliver a quantity of coolant from a coolant reservoir to an intake air flow path defined by air entering the vehicle, passing through the turbocharger, and entering the engine.

[0049] In some implementations, at least one engine operating value is selected from the following: air temperature in the intake flow path, throttle position, engine speed, engine load, engine running time, ambient air temperature, ambient air pressure, oxygen concentration in the exhaust, engine coolant temperature, exhaust valve position, previously supplied coolant volume, and boost pressure.

[0050] According to another aspect of the present invention, a vehicle is provided, comprising: a frame; an engine supported by the frame, the engine having an engine air inlet; a turbocharger fluidly connected to the engine, the turbocharger including a compressor fluidly connected to the engine air inlet, the compressor having a compressor inlet and a compressor outlet, the intake air flow path of the vehicle being defined by air entering the vehicle, entering the compressor through the compressor inlet, exiting the compressor through the compressor outlet, and flowing into the engine air inlet; a coolant container assembly fluidly connected to the intake air flow path at a connection point, the coolant container assembly being supported by the frame and including a coolant container for containing coolant, the compressor being fluidly connected to the coolant container, wherein, when the vehicle is in use, air flows from the compressor to the coolant container to pressurize the coolant container; a coolant pipe fluidly connecting the coolant container to the connection point; a valve for controlling the flow rate of coolant, the valve being disposed between the coolant container and the coolant pipe; and a controller communicatively connected to the valve of the coolant container assembly, the controller being configured to selectively allow a certain amount of coolant to flow from the coolant container into the intake air flow path via the connection point.

[0051] According to another aspect of the present technology, a vehicle is provided, the vehicle comprising: a frame; an engine supported by the frame, the engine having an engine air inlet and a crankcase; a turbocharger fluidly connected to the engine, the turbocharger including a compressor fluidly connected to the engine air inlet; a coolant container assembly supported by the frame, the coolant container assembly including a coolant container for containing coolant, the coolant container assembly being fluidly connected to the engine at a connection point; and a controller communicatively connected to the coolant container assembly and also communicatively connected to the engine, the controller being configured to selectively allow a quantity of coolant to flow from the coolant container to the engine via the connection point based on at least one engine operating value.

[0052] According to another aspect of the present invention, a method for managing piston temperature of a vehicle engine is provided. The method includes: determining a throttle position of the engine's throttle valve by a throttle position sensor connected to a controller; determining an engine speed (RPM) by an engine speed sensor connected to the controller; and determining an estimated piston temperature by the controller based at least on the throttle position and engine speed.

[0053] In some implementations, the method further includes: determining, by the controller, the difference between the desired piston temperature and the estimated piston temperature; and modifying, by the controller, at least one engine operating value of the engine, the modification being at least in part based on the difference between the desired piston temperature and the estimated piston temperature.

[0054] In some implementations, the controller may also modify at least one engine operating value of the engine in response to the controller determining that the estimated piston temperature is higher than a threshold piston temperature.

[0055] In some implementations, at least one engine operating value is at least one of the following: engine ignition timing; fuel pressure; exhaust valve position; fuel injection timing; fuel injection quantity; and boost pressure from the vehicle's turbocharger.

[0056] In some embodiments, the method further includes: determining a temperature gradient resulting from modifying at least one engine operating value; determining a modification time for at least one engine operating value based at least on the temperature gradient and the difference between a desired piston temperature and an estimated piston temperature; and modifying at least one engine operating value for the modification time.

[0057] In some implementations, the method further includes: determining the engine coolant temperature via an engine coolant temperature sensor connected to the controller; determining the intake air temperature via an air temperature sensor connected to the controller; and determining a corrected piston temperature by the controller based at least on the estimated piston temperature, engine coolant temperature, and intake air temperature.

[0058] In some implementations, the method further includes determining at least one of the following: engine coolant temperature, which is determined by an engine coolant temperature sensor connected to the controller; and intake air temperature, which is determined by a temperature sensor connected to the controller; and a corrected piston temperature is determined by the controller based on an estimated piston temperature and at least one of the engine coolant temperature and the intake air temperature.

[0059] In some implementations, the method further includes detecting a change in at least one engine operating value of the engine by the controller; and in response to the detected change in at least one engine operating value, determining a corrected estimated piston temperature based at least on the estimated piston temperature and the change in at least one engine operating value.

[0060] In some implementations, the corrected estimated piston temperature is also determined based on the duration of a change in at least one engine operating value.

[0061] In some implementations, determining the estimated piston temperature based at least on the throttle position and engine speed includes retrieving the estimated piston temperature from a temperature dataset.

[0062] In some implementations, determining the estimated piston temperature includes: determining the steady-state temperature (TS) based at least on the throttle position and engine speed; determining the temperature gradient (dT / dt) based on the calibration equation stored in the controller; and calculating the estimated piston temperature (T) using the following temperature determination relationship based on the steady-state temperature TS, the temperature gradient dT / dt, and the duration (t):

[0063]

[0064] In some implementations, the estimated piston temperature is recalculated for the duration t of the repetition.

[0065] In some implementations, in response to an estimated piston temperature exceeding a threshold piston temperature, a controller directs a quantity of coolant from the coolant container to an intake flow path defined by air entering the vehicle and then the engine.

[0066] According to another aspect of the present invention, a vehicle is provided, comprising: a frame; an engine supported by the frame, the engine having at least one engine air inlet; a turbocharger fluidly connected to the engine, the turbocharger including a compressor fluidly connected to the at least one engine air inlet, the compressor having a compressor inlet and a compressor outlet, the intake air flow path of the vehicle being defined by air entering the vehicle, entering the compressor through the compressor inlet, exiting the compressor through the compressor outlet, and flowing into the at least one engine air inlet; a coolant container assembly supported by the frame, the coolant container assembly including a coolant container for containing coolant, the coolant container assembly being fluidly connected to the intake air flow path at at least one connection point; and a controller communicatively connected to the coolant container assembly, the controller being configured to selectively allow a quantity of coolant from the coolant container to flow into the intake air flow path via the connection point.

[0067] In some embodiments, the engine includes at least one reed valve and at least one throttle valve; and at least one connection point is disposed on the intake flow path between the at least one reed valve and the at least one throttle valve.

[0068] In some embodiments, the system further includes: at least one coolant injection collar, the at least one coolant injection collar being fluidly connected to at least one engine air inlet; at least one injection nozzle, the at least one injection nozzle being connected to and extending through the at least one coolant injection collar, the at least one injection nozzle being fluidly connected to a coolant container assembly; and wherein at least one connection point is defined by at least one nozzle.

[0069] In some embodiments, the at least one engine air inlet includes a first inlet for supplying air to a first cylinder of the engine and a second inlet for supplying air to a second cylinder of the engine; the at least one coolant injection ring includes a first coolant injection ring connected to the engine and aligned with the first inlet, and a second coolant injection ring connected to the engine and aligned with the second inlet; and the at least one injection nozzle includes a first nozzle and a second nozzle, the first nozzle being connected to and extending through the first coolant injection ring and fluidly connected to a coolant container assembly, and the second nozzle being connected to and extending through the second coolant injection ring and fluidly connected to the coolant container assembly.

[0070] In some implementations, the controller is communicatively connected to the engine; and the controller is configured to: determine an estimated piston temperature based at least in part on at least one engine operating value received from the engine, and selectively allow a certain amount of coolant to flow from the coolant container into the intake flow path via at least one nozzle, based at least on the estimated piston temperature.

[0071] For the purposes of this application, the term "fluid" means at least both gas and liquid, as well as combinations of gas and liquid.

[0072] For the purposes of this application, terms related to spatial orientation, such as forward, backward, up, down, left, and right, shall be understood as would be normally understood by a snowmobile driver sitting in a normal driving position in the snowmobile. In describing or referring to components or sub-assemblies of the snowmobile that are detached from the snowmobile, such as heat exchangers, unless otherwise stated in this application, terms related to spatial orientation shall be understood as would be understood when such components or sub-assemblies are installed in the snowmobile.

[0073] The implementations of this technology each have at least one of the purposes and / or aspects mentioned above, but not necessarily all of them. It should be understood that some aspects of this technology resulting from attempts to achieve the purposes mentioned above may not satisfy those purposes and / or may satisfy other purposes not specifically set forth herein. The explanations of the foregoing terms provided above take precedence over those explanations of terms that can be found in any of the references incorporated herein by reference.

[0074] Further and / or alternative features, aspects and advantages of the implementation of this technology will become apparent from the following description, the accompanying drawings and the appended claims. Attached Figure Description

[0075] To better understand this technology, as well as other aspects and additional features thereof, reference is made to the following description used in conjunction with the accompanying drawings, in which:

[0076] Figure 1 This is a front view of the left side of a motor vehicle on snow.

[0077] Figure 2 yes Figure 1 A top-down, rear right-side perspective view of the engine, intake system, and exhaust system of a snowmobile.

[0078] Figure 3 yes Figure 2 Front view of the engine, intake system, and exhaust system;

[0079] Figure 4 yes Figure 2 A cross-sectional view of the engine, as well as some parts of the intake and exhaust systems;

[0080] Figure 5 yes Figure 2 A top plan view of the intake and exhaust systems.

[0081] Figure 6 yes Figure 1 A schematic diagram of the lubrication system for a snowmobile;

[0082] Figure 7 yes Figure 6 A schematic diagram of the lubricating oil flow in the lubrication system;

[0083] Figure 8 yes Figure 2 A schematic diagram of the exhaust system;

[0084] Figure 9 yes Figure 5 Close-up images of the intake and exhaust systems.

[0085] Figure 10 yes Figure 2 A right-side front view of the intake and exhaust systems.

[0086] Figure 11 yes Figure 10 Close-up images of the intake and exhaust systems.

[0087] Figure 12 yes Figure 2 Front view of the exhaust system's turbocharger, bypass duct, and exhaust collector;

[0088] Figure 13 It is shown separately. Figure 12 A three-dimensional diagram of the bypass conduit;

[0089] Figure 14 It is along Figure 13 The line 14-14 was cut Figure 12 A cross-sectional view of the bypass conduit, in which the valve is in the closed position;

[0090] Figure 15 yes Figure 14 A cross-sectional view showing the valve in the open position;

[0091] Figure 16 yes Figure 14 A cross-sectional view, in which the valve is in the middle position;

[0092] Figure 17 yes Figure 12 A perspective view of the turbocharger and bypass duct, in which part of the top of the bypass duct and valve has been removed;

[0093] Figure 18 yes Figure 12 Top plan view of the turbocharger and bypass duct;

[0094] Figure 19 It is along Figure 18The line 19-19 was cut off Figure 18 A cross-sectional view of a turbocharger;

[0095] Figure 20A It is shown separately. Figure 12 Left-side front view of the exhaust collector;

[0096] Figure 20B yes Figure 20A Top-view perspective of the exhaust gas collector on the right side;

[0097] Figure 20C yes Figure 20A A bottom view of the exhaust gas collector;

[0098] Figure 21 The illustration shows the process of passing through according to this technology. Figure 2 A flowchart of a method for controlling the exhaust flow of an exhaust system;

[0099] Figure 22 The illustration shows the process of passing through according to this technology. Figure 2 A flowchart of another method for controlling the exhaust flow of an exhaust system;

[0100] Figure 23 The illustration shows the process of passing through according to this technology. Figure 2 A flowchart of another method for controlling the exhaust flow of an exhaust system;

[0101] Figure 24 The diagram illustrates the direction according to this technology. Figure 2 A flowchart of a method for providing a fuel-air mixture to an engine;

[0102] Figure 25 It is along Figure 13 The line was cut at 25-25. Figure 12 A cross-sectional view of the bypass conduit, in which the valve is in the open position;

[0103] Figure 26 yes Figure 14 A front view of the upstream side of the valve;

[0104] Figure 27 yes Figure 26 A front view of the downstream side of the valve;

[0105] Figure 28 It is along Figure 27 The line 28-28 was cut off Figure 26 A cross-sectional view of the valve;

[0106] Figure 29 It is along Figure 27 The line 29-29 was cut off Figure 26 A cross-sectional view of the valve;

[0107] Figure 30 It is a graph representing the percentage of mass flow through the opening as a function of the valve's position;

[0108] Figure 31 It represents the passage Figure 2 A flowchart illustrating a scenario for controlling the exhaust flow of an exhaust system;

[0109] Figure 32 The diagram illustrates the use of Figure 31 Example datasets in illustrative scenarios;

[0110] Figure 33 The diagram illustrates the use of Figure 31 Additional example datasets in illustrative scenarios;

[0111] Figure 34 The diagram illustrates the use of Figure 24 Example dataset in the method;

[0112] Figure 35 yes Figure 2 A partial cross-sectional view of the air chamber of the intake system, in which a portion of the left side of the air chamber has been removed;

[0113] Figure 36 yes Figure 35 A partial cross-sectional view of the air chamber, in which a portion of the rear side of the air chamber has been removed;

[0114] Figure 37 yes Figure 1 A top-view plan view of the vehicle's engine, intake system, fuel tank, and coolant system.

[0115] Figure 38 yes Figure 37 The left-side front view of the vehicle section;

[0116] Figure 39 yes Figure 37 The right-side front view of the vehicle section;

[0117] Figure 40 yes Figure 37 Top plan view of the intake system and coolant system;

[0118] Figure 41 yes Figure 40 Top-view front left perspective view of the intake system and coolant system section;

[0119] Figure 42 yes Figure 40 Top-view exploded perspective view of the front left side of the intake system and coolant system section;

[0120] Figure 43 The illustration shows the operation according to this technology. Figure 37 A flowchart of the methods for the intake system and coolant system;

[0121] Figure 44 It is an engine, Figure 40 A schematic diagram of the intake system and the coolant system of another embodiment;

[0122] Figure 45 yes Figure 1 A three-dimensional view of the engine portion of a vehicle, in which a coolant injection ring is attached to the engine;

[0123] Figure 46 It is along Figure 45 The line 46-46 was cut off Figure 45 Cross-sectional view of the engine and coolant injection ring;

[0124] Figure 47 yes Figure 45 A three-dimensional view of a coolant injection collar, wherein the coolant injection collar is connected to a coolant pipe;

[0125] Figure 48 yes Figure 45 An exploded perspective view of the coolant injection nozzle of the coolant injection collar;

[0126] Figure 49 The illustration shows a method for management based on this technology. Figure 1 A flowchart of a method for determining the piston temperature of a vehicle's engine; and

[0127] Figure 50 The diagram illustrates the use of Figure 49 Example dataset in the method.

[0128] It should be noted that, unless otherwise stated, the accompanying drawings may not be drawn to scale.

[0129] Specific implementation method

[0130] This invention describes the technology in relation to a snowmobile 10 having an internal combustion engine and two skids. However, it is conceivable that some aspects of the technology can be applied to other types of vehicles, such as, but not limited to: snowmobiles with a single skid; road vehicles with two, three, or four wheels; off-road vehicles, all-terrain vehicles, side-by-side vehicles, and personal boats.

[0131] Reference Figure 1 and Figure 2The snowmobile 10 according to the present technology will be described. The snowmobile 10 includes a front end 12 and a rear end 14. The snowmobile 10 includes a body in the form of a frame or chassis 16, the frame or chassis 16 including a channel 18, an engine bracket portion 20, a front suspension module 22 and a superstructure 24.

[0132] An internal combustion engine 26 is housed in an engine compartment partially defined by an engine bracket portion 20 of the frame 16. A fuel tank 28, supported above a channel 18, supplies fuel to the engine 26 for its operation. The engine 26 receives air from an intake system 100. The engine 26 and the intake system 100 will be described in more detail below.

[0133] A ring-shaped drive track 30 is positioned at the rear end 14 of the snowmobile 10. The drive track 30 is generally positioned below the channel 18 and is operatively connected to the engine 26 via a belt drive system and a reduction gear. The ring-shaped drive track 30 is driven to travel around a rear suspension assembly 32 operatively connected to the channel 18 to propel the snowmobile 10. The ring-shaped drive track 30 has a plurality of lugs 31 extending from its outer surface to provide traction to the track 30.

[0134] The rear suspension assembly 32 includes a drive sprocket 34, an idler pulley 36, and a pair of rails 38 that slide in contact with the annular drive track 30. The drive sprocket 34 is mounted on a shaft 35 and defines a sprocket axis 34a. The shaft 35 is operatively connected to the crankshaft 126 of the engine 26 (see [link]). Figure 3 The slide rail 38 is attached to the channel 18 via the front suspension arm 40, the rear suspension arm 40, and the shock absorber 42. It is conceivable that the snowmobile 10 may be configured to have a different implementation of the rear suspension assembly 32 than that shown herein.

[0135] A straddle-style seat 60 is positioned above the fuel tank 28. A fuel tank filling opening, covered by a cap 92, is located on the upper surface of the fuel tank 28, in front of the seat 60. It is conceivable that the fuel tank filling opening could be located at other locations on the fuel tank 28. The seat 60 is adapted to accommodate the driver of the snowmobile 10. The seat 60 can also be configured to accommodate a passenger. Footrests 64 are positioned on each side beneath the seat 60 of the snowmobile 10 to accommodate the driver's feet.

[0136] At the front end 12 of the snowmobile 10, a fairing 66 encloses the engine 26 and belt drive system, providing not only protection for the engine 26 and drive system but also a more aesthetically pleasing shell for the snowmobile 10. The fairing 66 includes a hood 68 and one or more side panels that can be opened to allow access to the engine 26. A windshield 69, attached to the fairing 66, functions as a wind deflector to reduce the air pressure exerted on the rider as the snowmobile 10 moves.

[0137] Two skid members 70, positioned at the front end 12 of the snowmobile 10, are attached to the front suspension module 22 of the frame 16 via a front suspension assembly 72. The front suspension module 22 is connected to the front end of the engine mount portion 20. The front suspension assembly 72 includes skid member legs 74, support arms 76, and ball joints (not shown) for operatively connecting to the respective skid member legs 74, support arms 76, and (schematically shown) steering column 82.

[0138] A steering assembly 80, including a steering column 82 and a handlebar 84, is positioned approximately in front of the seat 60. The steering column 82 is rotatably connected to the frame 16. The lower end of the steering column 82 is connected to the coaster leg 74 via a steering rod (not shown). The handlebar 84 is attached to the upper end of the steering column 82. The handlebar 84 is positioned in front of the seat 60. The handlebar 84 is used to rotate the steering column 82, and thereby rotate the coaster 70 to steer the snowmobile 10. A throttle operator 86 in the form of a thumb-operated throttle lever is mounted to the right side of the handlebar 84. Other types of throttle operators, such as finger-operated throttle levers and rotary handles, are also conceivable. A brake actuator in the form of a handbrake lever is provided on the left side of the handlebar 84 for braking the snowmobile 10 in a known manner. It is conceivable that the windshield 69 can be directly connected to the handlebar 84.

[0139] At the rear end of the snowmobile 10, a snow deflector 94 extends downward from the rear end of the channel 18. The snow deflector 94 prevents dirt and snow that may be sprayed upward from the drive track 30 when the snowmobile 10 is propelled by the moving drive track 30. It is conceivable that the snow deflector 94 could be omitted.

[0140] The snowmobile 10 includes other components, such as a display cluster. Since it is believed that those skilled in the art will readily identify these components, further explanation and description of them will not be provided herein.

[0141] Additional reference Figures 2 to 6The engine 26 and intake system 100 will be described in more detail below. Airflow from the atmosphere surrounding the snowmobile 10 passes through side openings 113 defined in the upper portion 25 of the superstructure 24 of the chassis 16. The air then flows into the auxiliary air box 110. The auxiliary air box 110 is located above the front suspension module 22. A generally Y-shaped duct 118 (… Figure 2 The auxiliary air box 110 is fluidly connected to the air compressor 310 located on the right side of the engine 26 via the duct section 117. Figure 5 The compressor inlet 312 is connected to the main air box 120 via conduit 118. The main air box 120 includes a bypass valve 123 (see...). Figure 35 and Figure 36 The bypass valve 123 controls the airflow entering the main air chamber 120 through inlet 119. It is conceivable that the auxiliary air chamber 110 can be omitted, and air from the atmosphere can enter directly into inlet 312 and / or inlet 119 of the main air chamber 120 without passing through the auxiliary air chamber 110.

[0142] As in Figure 42 As further illustrated schematically, ambient air generally follows an intake flow path 444 into the snowmobile 10, passes through the air compressor 310, and flows into the engine 26. Atmospheric air enters the air compressor 310 via the auxiliary air box 110 and through duct 118 and inlet 312, where it is compressed. The compressed air then flows out of the air compressor 310 through outlet 314, enters duct 316, and enters the main air box 120. The main air box 120 is connected via two air outlets 122 (see also...). Figure 10 The fluid is connected to engine 26.

[0143] The bypass valve 123 of the main air box 120 is spring-loaded to the closed position, allowing air to be received from the air compressor 310, preferably via conduit 316. When the air pressure within the main air box 120 drops below a threshold, for example when the engine 26 is rotating at a speed requiring more air than is available in the main air box 120, the valve 123 opens to allow air from the atmosphere to enter the main air box 120 directly via the auxiliary air box 110. In some cases, this can help achieve optimal operation of the engine 26, especially when the turbocharger 300 is operating and the necessary airflow is not being supplied to the main air box 120 for the air required by the engine 26. Figure 35As shown, valve 123 includes spring 125. The spring constant of spring 125 is selected such that valve 123 will open and close at a predetermined pressure within the main airbox 120. Therefore, once open, bypass valve 123 will automatically close when airflow from turbocharger 300 increases the pressure within main airbox 120 to the predetermined pressure, and automatically open when the pressure within main airbox 120 drops to the predetermined pressure. The diameter of valve 123 is sized to allow high flow capacity between auxiliary airbox 110 and main airbox 120. This helps ensure optimal pressure within main airbox 120 and thus contributes to optimal engine performance under normal conditions, even when turbocharger 300 is not activated. Conduit portion 117 and bypass valve 123 also reduce the airflow advance distance between auxiliary airbox 110 and main airbox 120 compared to the airflow advance distance through conduit portion 121, turbocharger 300, and conduit 316. Thus, depending on the air pressure within the main air chamber 120, the airflow between the auxiliary air chamber 110 and the main air chamber 120 has either a short or long airflow path. A bypass valve 123 included in the main air chamber 120 further allows the engine 26 to operate in either turbocharged or naturally aspirated mode. The operation of the engine 26 and the corresponding operation of the turbocharger 300 for operation in both modes will be described in further detail below.

[0144] Engine 26 is an inline two-cylinder two-stroke internal combustion engine. The two cylinders of engine 26 are oriented relative to their vertically arranged cylindrical shafts, wherein each cylinder contains a piston 226, and one piston 226... Figure 4 As shown in the diagram. It is conceivable that engine 26 can be constructed differently. For example, engine 26 may have more or fewer than two cylinders, and the cylinders may be arranged in a V-shape rather than in an inline configuration. It is conceivable that, in some implementations, engine 26 may be a four-stroke internal combustion engine, a carburetor engine, or any other suitable engine capable of propelling the snowmobile 10. Engine 26 includes an engine coolant system 23 to aid in cooling engine 26. Engine coolant system 23 includes an engine coolant temperature sensor 127 for monitoring the temperature of the engine coolant circulating in engine coolant system 23.

[0145] like Figure 1 , Figure 2 and Figure 4 As shown, engine 26 receives air from intake system 100, particularly from outlet 122 of main airbox 120, via engine air inlet 27 defined in the rear portion of each cylinder of engine 26. Engine 26 includes reed valve 227 located in each air inlet 27 (see also...). Figure 46Each air inlet 27 is connected to the throttle body 37 of the intake system 100. The throttle body 37 includes a throttle valve 39, which rotates to regulate the amount of air flowing into the corresponding cylinder of the engine 26 through the throttle body 37. A throttle valve actuator (not shown) is operatively connected to the throttle valve 39 to change the position of the throttle valve 39, and thus adjust the opening of the throttle valve 39 by means of the throttle lever 86 on the operating handle 84. In this implementation, the throttle valve actuator is a mechanical linkage, although this is only a non-limiting implementation. The position and movement of the throttle valve 39 are controlled by (in...) Figure 8 The throttle position sensor 588 (illustrated schematically) is monitored and is operatively connected to the throttle valve 39, which will be described in more detail below. It is also conceivable that the throttle valve actuator may be in the form of an electric motor. The electric motor can change the position of the throttle valve 39 based on input signals received from an electronic control module (not shown), which in turn receives input signals from a position sensor associated with the throttle lever 86 on the handle 84. Further details regarding this drive-by-wire throttle system can be found in U.S. Patent No. 10,029,567, published July 24, 2018, the entire contents of which are incorporated herein by reference.

[0146] Engine 26 is injected via a direct injection (DI) injector 41 and a multi-point fuel injection (MPFI) injector 45 (both at least in... Figure 4 (As shown in the diagram) Receives fuel from fuel tank 28, and the engine 26 has openings in its cylinders. The fuel-air mixture in each of the left and right cylinders of engine 26 is composed of (in...) Figure 2 The spark plug 43 (best shown in the diagram) ignites the ignition system. Engine output power, torque, and engine speed are determined in part by throttle opening, in part by ignition timing, and also by various characteristics of the fuel-air mixture, such as its composition, temperature, and pressure. The following will refer to... Figure 24 A more detailed description is given of methods for controlling fuel-air mixtures according to some implementations of this technology.

[0147] The exhaust gas generated by the combustion event of the combustion process is delivered via exhaust system 600 ( Figure 5 Exhausted from engine 26. (For example...) Figure 4 As shown, an exhaust outlet 29 is defined in the front portion of each cylinder of the engine 26. Each exhaust outlet 29 has an exhaust valve 129. The exhaust outlet 29 is fluidly connected to an exhaust manifold 33. The exhaust system 600 includes an exhaust pipe 202 that is connected to and extends forward from the exhaust manifold 33 to guide exhaust gas away from the engine 26.

[0148] In this implementation, the exhaust pipe 202 is a tuning pipe with a geometry suitable for improving the efficiency of the engine 26.

[0149] Turbocharger 300 is operatively connected to engine 26. Turbocharger 300 compresses air and supplies it to engine 26. Figure 6 and Figure 12 As shown, the turbocharger 300 has a housing 302 that defines the air compressor 310 and the exhaust turbine 350. See also... Figure 19 The exhaust turbine 350 includes a turbine inlet 355 having an area 354, which in a turbocharger is typically defined as the cross-sectional area of ​​the volute 352 of the exhaust turbine 350 (measured at the tongue). The air compressor 310 includes a compressor impeller and is part of the intake system 100. As described above, the intake air flowing through the rotating compressor impeller is thereby compressed. The rotation of the compressor impeller is caused by the turbine impeller 351 of the exhaust turbine 350 (… Figure 19 , Figure 25 Powered by the exhaust turbine 350, which is part of the exhaust system 600, the turbine impeller 351 is driven by the exhaust gas discharged from the engine 26 and guided through the blades of the turbine impeller 351 around the turbine axis 353. Figure 19 Rotation. It is conceivable that in some implementations, the air compressor 310 could be a supercharger, where the compressor impeller would be directly powered by the engine 26. The exhaust system 600 will be described in more detail below.

[0150] Reference Figure 6 and Figure 7 The snowmobile 10 also includes a lubrication system for supplying lubricating oil to the engine 26 and turbocharger 300. The engine 26 is fluidly connected to an oil reservoir 52, which supplies oil to the crankshaft 126 and exhaust valve 129 of the engine 26. The oil reservoir 52 is also fluidly connected to the turbocharger 300 to supply lubricating oil to the turbocharger 300. As will be further described below, the turbocharger 300 is also fluidly connected to the engine 26.

[0151] The main oil pump 54 is fixed to and fluidly connected to the oil reservoir 52. It is conceivable that the pump 54 and the oil reservoir 52 may be connected together in different ways or may be separately located in the snow vehicle 10. The main oil pump 54 pumps oil from the oil reservoir 52 to the engine 26 and the turbocharger 300. The main oil pump 54 includes four outlet ports for pumping oil out of the oil reservoir 52. Two outlet ports 53 supply oil to the crankshaft 126. Another outlet port 55 supplies oil to one of the exhaust valves 129. A fourth outlet port 57 supplies oil to the turbocharger 300. Depending on the implementation, it is conceivable that the main oil pump 54 may include more or fewer outlet ports, depending on the specific details of the implementation.

[0152] Auxiliary oil pump 56 and oil / gas separator 59 are fluidly connected between turbocharger 300 and engine 26. Auxiliary oil pump 56 receives oil that has passed through turbocharger 300 and pumps the oil to another exhaust valve 129. Figure 7 The schematic diagram illustrates the flow direction of oil from pumps 54 and 56 and through turbocharger 300 to engine 26. It should also be noted that in this implementation, turbocharger 300 is a ball bearing-based turbocharger 300 sized for low-flow lubrication to provide efficient response. It is conceivable that different types of turbochargers could be used in different implementations.

[0153] With this configuration, only one oil reservoir 52 is used to lubricate both the turbocharger 300 and the engine 26. It is conceivable that the snowmobile 10 could also be arranged such that the auxiliary oil pump 56 could be omitted. It is also conceivable that the oil, after passing through the turbocharger 300, could circulate to the crankshaft 126 instead of the exhaust valve 129.

[0154] See also Figures 8 to 19 The exhaust system 600 will now be described in more detail. As described above, the exhaust flow from the engine 26 passes through the exhaust outlet 29, through the exhaust manifold 33, and enters the exhaust duct 202. As described above, the exhaust duct 202, being a tuning duct 202, is curved and has a varying diameter along its length. Other types of exhaust ducts 202 are conceivable. Figure 5As shown, the exhaust pipe 202 includes a pipe inlet 203 fluidly connected to the exhaust manifold 33 and a pipe outlet 206 located at the end of the exhaust pipe 202. The exhaust pipe 202 also has a widening portion 605 adjacent to the pipe inlet 203 and a narrowing portion 607 adjacent to the pipe outlet 206. The pipe outlet 206 is located downstream of the pipe inlet 203. It is well known in the field of two-stroke engines that the purpose of a narrowing-widening tuned pipe is to generate a returning rarefaction wave in the widening section and a returning pressure wave in the narrowing section, which pushes back any excess fresh air-fuel mixture flowing from the cylinder into the exhaust pipe into the cylinder. Pushing the fresh mixture back into the cylinder is desirable because this allows the returning pressure wave to “boost” the cylinder, providing more fresh mixture to the cylinder compared to when the cylinder is filled at ambient pressure. The term "tuned pipe" is used because the pipe's dimensions are specifically chosen so that boosting occurs within the pipe at a specific value or range of one or more parameters, such as at a specific temperature and / or pressure, consistent with the engine's desired operating RPM or desired operating RPM range. Once the physical dimensions of the tuned pipe are selected, the boosting effect on that pipe will be optimal at the specific parameter values ​​to which the pipe is tuned, and because conventional tuned pipes are fixed in size, these parameters are not adjustable during the use of the vehicle with the engine installed. When the tuned pipe does not operate at these specific tuning parameter values, the boosting effect will not be optimal, and therefore the engine operation will not be optimal at the desired operating RPM. Therefore, when the limits of the turbocharger or a variable valve such as Valve 630 are increased along the exhaust flow path, compensation must be made to prevent these changes from negatively impacting engine performance, or otherwise limit any negative impact on engine performance. The increase in the limits of the turbocharger or a variable valve such as Valve 630 along the exhaust flow path causes the temperature and / or pressure within the tuned pipe to change at any given operating time. Therefore, it should be understood that, due to this pressurization effect, two-stroke engines are very sensitive to changes within the tuning duct.

[0155] The exhaust system 600 also includes a bypass duct 620 for guiding exhaust flow around the turbocharger 300 or through the exhaust turbine 350 of the turbocharger 300 to operate the air compressor 310. A pipe outlet 206 located at the end of the exhaust pipe 202 is in fluid communication with the bypass duct 620. Specifically, the bypass duct 620 defines an exhaust inlet 622 that is fluidly connected to the pipe outlet 206. The exhaust inlet 622 and the pipe outlet 206 are arranged such that exhaust gas entering the exhaust inlet 622 from the pipe outlet 206 passes through the inlet 622 in a manner substantially perpendicular to the inlet 622. The central axis 629 of the exhaust inlet 622 (…) Figure 13 , Figure 14 The diagram illustrates the general direction of the exhaust flow into the bypass duct 620. In this implementation, the central axis 629 coincides with the center of the circular inlet 622, but this may not always be the case.

[0156] The bypass duct 620 is also fluidly connected to the housing 302 of the turbocharger 300. More specifically, in this implementation, the bypass duct 620 is mechanically connected to the turbocharger housing 302 via a clamp 303. It is conceivable that the bypass duct 620 may be a device independent of the turbocharger 300. It is also conceivable that the bypass duct 620 may be fastened to or otherwise mechanically connected to the turbocharger housing 302. It is also conceivable that the bypass duct 620 and the turbocharger housing 302 may be integrally formed.

[0157] The bypass duct 620 is approximately Y-shaped, wherein the inlet duct portion 690 extends from the exhaust inlet 622 and branches into two outlet duct portions 692 and 694. Figure 14 Similarly, and as described above, the bypass duct 620 is used to selectively guide exhaust gas entering the exhaust turbine 350 through the exhaust inlet 622 or bypassing the exhaust turbine 350. Figure 14 As shown, the turbine outlet portion 692 (one branch of the Y-shape) of the bypass duct 620 defines a passage terminating at outlet 615, which is in fluid communication with the turbine inlet 355. The bypass outlet portion 694 (the other branch of the Y-shape) allows exhaust gas to bypass the turbocharger 300, thus exiting the bypass duct 620 through bypass outlet 626. The bypass outlet portion 694 defines a passage 625 that allows fluid communication between the exhaust inlet 622 and the outlet 626. The outlet 626 and the passage 625 can... Figure 17 As seen in. (For example, in...) Figure 16 As best observed, the bypass duct 620 also includes a diverter 628 disposed between duct portions 692, 694. The diverter 628 helps to stably divide the exhaust flow through the bypass duct 620 in order to help avoid flow separation or eddy currents in the exhaust flow. For this purpose, the diverter 628 is typically shaped and arranged to avoid unsmooth edges.

[0158] A valve 630, disposed in the bypass duct 620, together with a system controller 500 controlling the valve 630, selectively controls the flow rate of exhaust gas through the passage 625. More specifically, the valve 630 is a valve for selectively diverting exhaust gas from the turbocharger 300. In this implementation, the valve 630 is disposed in the passage 625, and more specifically, at a valve seat 623 within the passage 625. Depending on the specific implementation of the valve 630, it is conceivable that the valve 630 could be disposed elsewhere in the bypass duct 620, for example, closer to the exhaust inlet 622 and directly upstream of the passage 625. It is also conceivable that in some implementations, the valve 630 could selectively open or close the turbine outlet portion 692, rather than the bypass passage 625.

[0159] Reference Figures 26 to 29 The valve 630 has a base portion 400 and a body portion 402 extending from the base portion 400. The base portion 400 is configured to pivotally mount the valve 630 within a bypass conduit 620 and thus defines a valve pivot axis 404 about which the valve 630 can pivot during use. More specifically, the base portion 400 is generally cylindrical and has a shaft 440 comprising two shaft portions 441 extending in opposite directions from a central portion of the base portion 400. While the shaft 440 is integrally formed with the valve 630 in this embodiment, it is contemplated that in other embodiments, the shaft 440 may be a separate component (e.g., two separate shaft portions capable of being connected to the base portion 400).

[0160] The body portion 402 is the portion of the valve 630 used to block the passage 625. The body portion 402 has an upstream side 406 and a downstream side 408 opposite to the upstream side 406. The upstream side 406 is exposed to fluid flow in the bypass conduit 620 during use. In other words, the upstream side 406 generally faces the inlet 622, while the downstream side 408 faces the bypass outlet 626. The body portion 402 of the valve 630 is shaped to facilitate control of the exhaust flow through the passage 625. Notably, the body portion 402 has a generally pointed shape, which defines a rounded tip 410 at the point furthest from the base portion 400 along the length direction of the valve 630 (generally perpendicular to the valve pivot axis 404). Thus, the body portion 402 of the valve 630 (i.e., the portion of the valve 630 used to block the passage 625) can be considered generally elongated.

[0161] The periphery 412 of the body portion 402 generally defines the shape of the body portion 402. The periphery 412 includes two opposing longitudinal edges 414 extending from the base portion 400 in a direction generally parallel to the length direction of the valve 630. The periphery 412 also includes a rounded edge 416 defined by a rounded tip 410, and two converging angled edges 418 extending between the respective ends of the two longitudinal edges 414 and the rounded edge 416 (i.e., the angled edges 418 connect the longitudinal edges 414 to the rounded edge 416). As the two angled edges 418 extend from the two longitudinal edges 414 to the ends of the rounded edge 416, the angled edges 418 converge toward each other. Therefore, each of the angled edges 418 is set at an angle θ relative to the length direction of the valve 630. The angle θ can be between 10° and 45° and includes extreme values. For example, in this implementation, the angle θ is approximately 30°.

[0162] like Figure 26 As shown, the body portion 402 of valve 630 is approximately symmetrical about a plane of symmetry PS that divides the rounded tip portion 410 equally. The plane of symmetry PS is perpendicular to the valve pivot axis 404. Each of the longitudinal edge 414 and the angled edge 418 is located on opposite sides of the plane of symmetry PS. Furthermore, in this implementation, the base portion 402 of valve 630 is also symmetrical about the plane of symmetry PS. However, it is conceivable that valve 630 may be asymmetrical about the plane PS.

[0163] The width of the body portion 402, measured along a direction parallel to the valve pivot axis 404, varies along the length of the valve 630. For example, the width of the body portion 402 is greatest near the base portion 400. More specifically, the maximum width W of the body portion 402 is measured between two opposite longitudinal edges 414. 最大 The width of the body portion 402 decreases at the angled edge 418 along the length of the valve 630 towards the rounded tip 410. Notably, the width of the body portion 402 is smallest at the rounded tip 410.

[0164] like Figure 27 As shown, the length L of valve 630 V The length L is measured from the base portion 400 along the length of the valve 630 to the rounded tip portion 410. In this implementation, the length L of the valve 630 is... V The maximum width W of the body portion 402 is greater than or equal to the maximum width of the body portion. 最大 It is worth noting that the length L V Greater than the maximum width W 最大 This makes the length L of valve 630 V The maximum width W of the body part 402 最大 The ratio L V / W 最大Greater than 1. For example, the ratio L V / W 最大 It can be between 1 and 2, including extreme values. It is worth noting that the ratio L... V / W 最大 Between 1.2 and 1.6. In one particular implementation, the ratio L V / W 最大 It is approximately 1.3.

[0165] In addition, the maximum width W of the body portion 402 最大 The tip radius R of the rounded tip 410 T The ratio W 最大 / R T Greater than 2. For example, the ratio W 最大 / R T It can exclusively lie between 2 and 6. In this implementation, the ratio W 最大 / R T Approximately 3.

[0166] like Figure 26 As shown, the body portion 402 of the valve 630 has a ridge 420 disposed on the upstream side portion 406. Notably, the ridge 420 protrudes from the generally flat surface 422 of the upstream side portion 406. In this implementation, the height of the ridge 420, measured from the surface 422, is constant. The ridge 420 is formed in a closed shape, which in this implementation is approximately pentagonal. As will be described in more detail below, the periphery 412 outlines a portion of the ridge 420.

[0167] In this implementation, the ridge 420 has five edges, including a base edge 424, two outwardly extending edges 426, and two inwardly extending edges 428. The base edge 424 extends generally parallel to the valve pivot axis 404 and is located near the base portion 400 of the valve 630. Each outwardly extending edge 426 extends outward from a corresponding end of the base edge 424 toward a corresponding longitudinal edge of the longitudinal edges 414 of the periphery 412 of the body portion 402. The inwardly extending edges 428 are generally parallel to a corresponding angled edge of the angled edges 418 of the periphery 412 of the body portion 402. Each inwardly extending edge 428 extends from the end of a corresponding outwardly extending edge of the outwardly extending edges 426.

[0168] The edges 424, 426, and 428 of the ridge 420 intersect at the corresponding rounded tops 4301-4305. Notably, the inwardly extending edges 428 converge at the distal rounded top 4305, with the top 4305 being the furthest from the base portion 400 among the tops 4301-4305. The distal rounded top 4305 is approximately concentric with the rounded edge 416 of the periphery 412 of the body portion 402. Notably, the rounded edge 416 of the periphery 412 outlines the contour of the rounded top 4305 of the ridge 420. Furthermore, the angled edge 418 and the longitudinal edge 414 outline the inwardly extending edge 428 and the outwardly extending edge 426, respectively.

[0169] like Figure 29 As shown, the cross-sectional profile of the ridge 420, for example, the cross-sectional profile that can be observed along a plane perpendicular to the length direction of the valve 630, is approximately trapezoidal.

[0170] Reference Figures 27 to 29 The body portion 402 of valve 630 also has a peripheral lip 432 protruding from the downstream side 408 of the body portion 402. The peripheral lip 432 extends from the periphery 412 of the body portion 402. Therefore, the peripheral lip 432 has a shape that is substantially the same as the shape defined by the periphery 412. The peripheral lip 432 has a variable height measured from the surface 434 of the downstream side 408 of the body portion 402. The height of the peripheral lip 432 adjacent to the base portion 400 is greater than the height of the ridge 420.

[0171] As described above, valve 630 is generally shaped to avoid unsmooth edges, which helps to prevent flow separation or eddy currents in the exhaust flow within bypass duct 620.

[0172] In this implementation, valve 630 is a single-piece component, wherein the base portion 400 and the body portion 402 are integrally formed. However, it is conceivable that in an alternative implementation, the base portion 400 and the body portion 402 can be made into separate components and connected to each other to form valve 630.

[0173] Reference Figure 12 The actuator 635 is operatively connected to the valve 630 so that the valve 630 revolves around the valve pivot axis 404 (e.g., Figure 26(As shown) Pivoting. In this implementation, actuator 635 is a servo motor. It is conceivable that any other suitable type of actuator could be used in other implementations. Actuator 635 is connected to valve 630 via linkage assembly 636. More specifically, in this implementation, linkage assembly 636 includes three arms 637, 638, and 639. Arm 637 is connected to actuator 635 and is thus rotatable. Arm 638 is connected to shaft 440 of base portion 400 of valve 630. Arm 639 is connected between arms 637 and 638. Rotation of arm 637 thus actuates the other two arms 638 and 639, and causes valve 630 to pivot between an open position, a closed position, and an intermediate position, as will be described below. It is conceivable that in some implementations, valve 630 can rotate, translate, or otherwise move to control the exhaust flow through passage 625.

[0174] Valve 630 is controlled to selectively block or open valve opening 627 defined by valve seat 623 of passage 625. Figure 15 The flow rate of exhaust gas through the turbocharger 300 is regulated by the valve seat 623. The valve opening 627, defined by the valve seat 623, is therefore shaped such that it corresponds to the shape of the body portion 402 of the valve 630 (i.e., a generally elongated shape with a rounded tip). The valve 630 is pivotally mounted on the valve seat 623 via the base portion 400 of the valve 630 and is selectively movable between: an open position, in which the exhaust flow through the valve opening 627 (and therefore the passage 625) is substantially unobstructed by the valve 630; a closed position, in which the valve 630 completely closes the valve opening 627, thereby blocking the exhaust flow through the valve opening 627; and any number of intermediate positions between the open and closed positions. In this implementation, such as Figure 15 As shown, valve 630 is at approximately 45° in its open position (measured from valve seat 623—that is, at 0° corresponding to the closed position of valve 630). Furthermore, in the open position, valve 630 contacts the wall of bypass conduit 620 on the side opposite to the diverter 628, but this is not the case in all implementations.

[0175] exist Figures 14 to 16 The diagram shows a cross-section of the bypass conduit 620 to illustrate different positions of the valve 630. Figure 14 The diagram shows the closing position; Figure 15 The diagram shows the opening location (also in...). Figure 25 (as shown in the image); and Figure 16The diagram illustrates one of many possible intermediate positions of valve 630. As can be observed, valve 630 is oriented in bypass conduit 620 such that the rounded tip 410 is downstream of the base portion 400. That is, in the open, closed, and intermediate positions, the rounded tip 410 of valve 630 is downstream of the base portion 400. The exhaust flow through bypass conduit 620 will be described in more detail below for each of the relative positions of valve 630. Figure 14 As can be observed, valve 630 is in contact with valve seat 623 in its closed position. More specifically, in the closed position, the ridge 420 of the body portion 402 of valve 630 sits against valve seat 623.

[0176] Compared to a circular valve, the generally elongated shape of valve 630, as described above, establishes a more linear relationship between the mass flow rate of exhaust gas through opening 627 and the angle at which valve 630 is open. In other words, the shape of valve 630 allows for better control of the mass flow rate of exhaust gas through opening 627. Therefore, compared to using a circular valve, the back pressure within exhaust system 600 caused by opening valve 630 can be controlled more precisely. This can be seen from... Figure 30 The graph, as shown, illustrates the percentage of mass flow through the opening as a function of the valve position (expressed as a percentage – 0% corresponds to the closed position; 100% corresponds to the fully open position) for both valve 630 and the circular valve of this technology. The mass flow percentage reaches 100% when the valve is in the open position (for valve 630, this corresponds to a 45° angle, but for the circular valve, it is approximately 90°). Notably, performance curve P1 represents the percentage of mass flow through opening 627 as a function of the position of valve 630 according to this technology. In contrast, performance curve PA represents the percentage of mass flow through the circular opening as a function of the position of the corresponding circular valve. As can be observed, according to this technology, the relationship between the percentage of mass flow through opening 627 and the position of valve 630 is significantly more linear than that of the circular valve, especially at smaller valve angles (e.g., below 45% – i.e., below 20° for valve 630).

[0177] In addition to the specific shape of valve 630, the different channels defined by bypass conduit 620 are also oriented in a specific manner. For example, refer to Figure 14In this embodiment, the bypass outlet 626 of the bypass outlet portion 694 and the outlet 615 of the turbine outlet portion 692 face directions that are not parallel to each other. Specifically, an angle ψ is formed between planes 657 and 659, with plane 657 extending through the outermost surface of the bypass outlet portion 694 defining the bypass outlet 626 and plane 659 extending through the outermost surface of the turbine outlet portion 692 defining the outlet 615. The measured angle ψ formed between planes 657 and 659 is between 40° and 80°, including the extreme values. More specifically, in this embodiment, the measured angle ψ is approximately 60°.

[0178] In addition, continue to refer to Figure 14 The angle β formed between the plane 661 extending through the periphery of the valve seat 623 defining the opening 627 and the central axis 629 of the exhaust inlet 622 is between 0° and 40°, including the extreme values. Specifically, in this embodiment, the measured angle β is approximately 20°. The angle α formed between the axis 655 perpendicular to the plane 661 and the central axis 629 of the exhaust inlet 622 is between 100° and 140°, including the extreme values. Specifically, in this embodiment, the measured angle α is approximately 115°. The angle γ formed between the central axis 629 of the exhaust inlet 622 and the axis 651 perpendicular to the plane 657 is between 0° and 40°, including the extreme values, wherein the plane 657 extends through the outermost surface of the bypass outlet portion 694 defining the bypass outlet 626. Specifically, in this embodiment, the measured angle γ is approximately 20°. Finally, the measured angle φ formed between plane 657 and axis 653 perpendicular to plane 659 is between 10° and 50°, including the extreme values, wherein plane 657 extends through the outermost surface of the bypass outlet portion 694 defining bypass outlet 626, and plane 659 extends through the outermost surface of the turbine outlet portion 692 defining outlet 615. Specifically, in this embodiment, the measured angle φ is approximately 30°. It should be understood that in this embodiment, axis 653 is parallel to the turbine axis 353 around which the turbine impeller 351 rotates. Specifically, axis 653 is coaxial with turbine axis 353.

[0179] The exhaust system 600 also includes a system controller 500, which is operatively connected to the engine control unit (or ECU) and / or electrical system (not shown) of the snowmobile 10. The engine control unit is in turn operatively connected to the engine 26. As will be described in more detail below, the system controller 500 is also operatively and communicatively connected to an atmospheric pressure sensor 504 for sensing the atmospheric or ambient air pressure of the intake air entering the intake system 100, the atmospheric pressure sensor 504 also referred to herein as the intake sensor 504. It should be noted that the atmospheric pressure sensor 504, also referred to herein as the intake pressure sensor 504, senses the air pressure in the main air chamber 120 and thereby measures the intake pressure of air entering from the ambient air surrounding the snowmobile 10 and / or from the turbocharger 300 into the main air chamber 120.

[0180] Similarly, the system controller 500 is also operatively and communicatively connected to the atmospheric temperature sensor 505 for sensing the temperature of the atmospheric or ambient air entering the intake system 100. This atmospheric temperature sensor 505 is also referred to as the intake air temperature sensor 505. It should be noted that the atmospheric temperature sensor 505 senses the air temperature in the main air chamber 120, and thereby measures the intake air temperature from the ambient air surrounding the snowmobile 10 and / or from the turbocharger 300 entering the main air chamber 120.

[0181] The actuator 635, used to selectively move valve 630, is communicatively connected to system controller 500, thus making the position of valve 630 controllable. It is conceivable that valve 630 can be controlled or moved in different ways depending on the implementation.

[0182] like Figure 8 As illustrated in the schematic diagram and as will be described in more detail below, the system controller 500 is also operatively connected to a throttle valve position sensor 588 for determining the position of the throttle valve 39, the opening rate of the throttle valve 39, or both the position of the throttle valve 39 and the opening rate of the throttle valve 39. In some operating modes of the exhaust system 600, the valve 630 moves selectively based on the throttle valve position determined by the throttle valve position sensor 588. In some operating modes of the exhaust system 600, the valve 630 moves selectively based on the rate of change of the throttle valve position or the opening rate of the throttle valve 39 determined by the throttle valve position sensor 588.

[0183] As in Figure 8As schematically shown and as will be described in more detail below, the system controller 500 is also connected to an exhaust pressure sensor 590 for sensing the pressure at a point near the exhaust outlet 29 along the exhaust path of the engine 26. The pressure sensed by the exhaust pressure sensor 590 is used to determine the back pressure of the engine 26. Back pressure is understood to be the resistance to the exhaust flow between the engine 26 and the muffler 650 outlet, caused at least in part by twists, bends, obstructions, rotations, and sharp edges present in the various components of the exhaust system 600. In this art, reducing back pressure can help optimize the performance of the engine 26, as high back pressure can negatively impact engine performance efficiency. Reducing the amount of back pressure in the exhaust system 600 can also have the effect of reducing so-called "turbo lag," which is the delay in response to a turbocharged engine after the throttle lever 86 has been moved to operate the throttle system.

[0184] Furthermore, to ensure proper purging within the cylinders of engine 26, in this embodiment, the ratio of exhaust pressure to intake pressure (as measured by sensors 590 and 504, respectively) is kept relatively constant. It is noteworthy that in this embodiment, the ratio of exhaust pressure to intake pressure is maintained at approximately 1.1, although this may vary in different embodiments.

[0185] Reference Figure 5In this implementation, the exhaust pressure sensor 590 is configured to sense pressure along the exhaust path of the engine 26. Specifically, the exhaust pressure sensor 590 has a sensing port (not shown) fluidly connected to the exhaust pipe 202. In this implementation, the exhaust pressure sensor 590 senses pressure within the expanding portion 605 of the exhaust pipe 202; however, it is conceivable that the exhaust pressure sensor 590 could be configured to sense pressure along other areas of the exhaust pipe 202. Since the exhaust pressure sensor 590 is not designed to withstand the high temperatures within the exhaust pipe 202, the sensing port of the exhaust pressure sensor 590 is connected to the exhaust pipe 202 via an intermediate tube member. Notably, a metal tube 593 is fluidly connected to the exhaust pipe 202, while a rubber tube 591 is fluidly connected between the metal tube 593 and the sensing port of the exhaust pressure sensor 590. The lengths and diameters of the tubes 591 and 593 are chosen such that pressure waves traveling through the exhaust pipe 202 do not exhibit significant distortion when they reach the sensing port of the exhaust pressure sensor 590, thereby ensuring higher accuracy of the pressure sensed by the exhaust pressure sensor 590. It is conceivable that the exhaust pressure sensor 590 may be arranged in different ways depending on the details of a particular implementation. In some implementations, the system 600 may also include a differential pressure sensor for determining the pressure difference between the intake pressure entering the engine 26 and the exhaust pressure leaving the engine 26. It is also conceivable that in some implementations, the differential pressure sensor may replace one or both of the intake pressure sensor 504 and the exhaust pressure sensor 590.

[0186] Also Figure 8 As shown, the system controller 500 is also connected to several sensors for monitoring various exhaust system components. The system controller 500 is communicatively connected to an exhaust pipe temperature sensor 512 to detect the temperature of the exhaust pipe 202. (As shown in...) Figure 5 As can be observed, the exhaust pipe temperature sensor 512 includes a temperature probe connected to the outer wall of the exhaust pipe 202 within the tapered section 607, but other locations along the exhaust pipe 202 are also possible. The temperature probe extends within the exhaust pipe 202 to measure the temperature of the exhaust gas circulating therein. The system controller 500 is also communicatively connected to the exhaust oxygen sensor 513 to detect the oxygen concentration in the exhaust gas passing through the exhaust pipe 202. Figure 5 As can be observed, the exhaust oxygen sensor 513 includes a probe that is connected to and extends through the outer wall of the exhaust duct 202 within the tapered section 607, but other locations along the exhaust duct 202 may also be considered.

[0187] Similarly, system controller 500 is communicatively connected to muffler temperature sensor 550 to detect the temperature of muffler 650. These sensors 512, 550 can be used to monitor for possible overheating or temperature imbalances, and to provide information to system controller 500 for use in control methods such as those described herein. To determine the engine speed of engine 26, system controller 500 is also communicatively connected to engine speed sensor 586, which is configured to communicate with engine 26.

[0188] The exhaust system 600 also includes an exhaust collector 640, which is fluidly connected to a bypass duct 620 and a turbocharger 300. Figures 20A to 20C The exhaust collector 640 shown separately includes an inlet 642 through which the exhaust collector 640 receives exhaust from both the bypass duct 620 and the exhaust turbine 350.

[0189] More specifically, inlet 642 receives exhaust gas that bypasses exhaust turbine 350 and exits through outlet 626 of bypass duct 620. Inlet 642 also receives exhaust gas that has passed through exhaust turbine 350 from outlet 315 of turbocharger housing 302. Inlet 642 comprises two parts: a lower part 643 and an upper part 645. The lower part 643 and the upper part 645 are integrally connected to define a peanut-shaped opening in inlet 642. It is conceivable that inlet 642 may have different shapes depending on the implementation.

[0190] The lower portion 643 is fluidly connected to the housing 302 to receive exhaust gas from the exhaust turbine 350 through outlet 315. The upper portion 645 is fluidly connected to a bypass duct outlet 626 to receive exhaust gas that has bypassed the exhaust turbine 350. The exhaust gas collector 640 also includes an outlet 646 through which exhaust gas entering the exhaust gas collector 640 exits. It is conceivable that the two inlet portions 643, 645 may be separate in some implementations, allowing the exhaust gas collector 640 to be, for example, generally Y-shaped.

[0191] The exhaust collector 640 is bolted to the housing 302 and the bypass duct 620 using a through-hole 641 defined in the periphery of the inlet 642. It is conceivable that the exhaust collector 640 can be connected to the turbocharger housing 302 and the bypass duct 640 in different ways in different implementations. It is also conceivable that the exhaust collector 640 can be integrally formed with the bypass duct 620 and / or the turbocharger housing 302.

[0192] Reference Figure 10The exhaust system 600 includes a muffler 650. The muffler 650 includes a muffler inlet 654 through which exhaust gas from the exhaust system 600 is received. The muffler 650 is fluidly connected to a collector outlet 646 of an exhaust gas collector 640. As can be observed in the accompanying drawings, the muffler inlet 654 and the collector outlet 646 are held in place by springs. It is conceivable that different methods can be used to connect the muffler 650 to the exhaust gas collector 640. As can be observed in the accompanying drawings, the muffler 650 includes only a single inlet 654 for receiving exhaust gas that bypasses and passes through the exhaust turbine 350.

[0193] The flow rate of exhaust gas through exhaust system 600, particularly the flow rate of exhaust gas between exhaust duct 202 and muffler 650, will now be described in detail. As briefly described above, valve 630 in bypass duct 620 selectively controls the flow rate of exhaust gas entering or bypassing exhaust turbine 350 by sending exhaust gas through duct outlet portions 692, 694.

[0194] In this technology, the bypass duct 620 is designed and arranged to balance two conflicting benefits: the first benefit is to allow efficient exhaust flow to enable engine 26 to operate as a naturally aspirated engine 26 when bypassing turbocharger 300, and the second benefit is to not impede the efficient operation of turbocharger 300 when needed. In conventional turbocharged engines, all exhaust is directed to turbocharger 300, where the associated bypass is only used when too much exhaust flow enters the turbocharger. In this technology, exhaust can be directed to bypass turbocharger 300 for naturally aspirated operation, or exhaust can be directed to turbocharger 300 for turbocharged operation. The inclusion of intake bypass valve 123 further facilitates allowing engine 26 to operate either naturally aspirated or turbocharged. As described above, since the turbocharger 300 is not operating or not running and therefore not supplying sufficient compressed air to the main airbox 120, the intake bypass valve 123 allows atmospheric or ambient airflow into the main airbox 120 when the pressure in the main airbox 120 drops below a threshold. Both intake and exhaust are managed to allow the engine 26 to operate naturally aspirated or turbocharged, by including both valve 630 and bypass valve 123—each of which operates independently.

[0195] As described above, the exhaust gas entering the bypass duct 620 flows approximately parallel to the central axis 629 of the inlet 622. For example, it is possible to... Figures 13 to 16As observed, the center axis 629, and therefore the center of the exhaust flow, points toward the turbine outlet portion 692 of the splitter 628. Since the splitter 628 is positioned toward the bypass side relative to the center axis 629, it should be understood that more than half of the exhaust flow is initially directed toward the turbine outlet portion 692.

[0196] On the bypass outlet portion 694 side of the central axis 629 (to the left of axis 629 in the attached figure), it can also be observed that some of the exhaust flow parallel to the central axis 629 is directed toward the opening 627. Since the duct inlet 622 and the opening 627 of the passage 625 are at least partially aligned along the direction of the central axis 629, at least a portion of the exhaust entering the duct inlet 622 parallel to the flow axis flows unimpeded into the bypass passage 625 when the valve 630 is in the open position. Since the engine 26 is designed for natural aspiration during standard operation, at least a portion of the exhaust flowing substantially directly through the bypass duct 620 and into the exhaust collector 640 with minimal bends and turns further helps to reduce back pressure, thereby again optimizing engine performance.

[0197] It should be noted that, as will be further described below, the percentage of exhaust flow directed toward each of the output conduits 692, 694 does not necessarily correspond to the percentage of exhaust flow passing through each of the output conduits 692, 694.

[0198] Now refer to Figure 8 The schematically illustrated flow paths 670 and 675 describe two different flow patterns of exhaust gas entering the bypass duct 620. Depending on the position of valve 630, the exhaust gas can flow along the bypass exhaust flow path 670, the turbine exhaust flow path 675, or a combination of both paths 670 and 675.

[0199] Exhaust flowing along the bypass exhaust flow path 670 passes through channel 625, which is not blocked by valve 630 when valve 630 is in the open position. The bypass exhaust flow path 670 is defined from exhaust inlet 622 of the bypass duct 620 to exhaust collector 640. Exhaust flowing along the bypass exhaust flow path 670 passes through exhaust inlet 622, then through bypass duct 620, and then into exhaust collector 640. Specifically, the exhaust flowing along the bypass exhaust flow path 670 is received in the upper portion 645 of inlet 642.

[0200] The turbine exhaust flow path 675 is similarly defined from the exhaust inlet 622 of the bypass duct 620 to the exhaust collector 640. Exhaust flowing along the second exhaust flow path passes through the exhaust inlet 622, then through the turbine outlet portion 692 of the bypass duct 620, then through the exhaust turbine 350, and then into the exhaust collector 640. Specifically, the exhaust flowing along the turbine exhaust flow path 675 is received in the lower portion 643 of the inlet 642.

[0201] For each flow path 670, 675, exhaust gas exits from collector outlet 646 and enters muffler inlet 654. A single muffler inlet 654 of muffler 650 receives exhaust gas from both bypass exhaust flow path 670 and turbine exhaust flow path 675.

[0202] Although most of the exhaust flow is directed toward turbine outlet 692, a significant portion of the exhaust entering exhaust inlet 622 flows through bypass outlet 694 along bypass exhaust flow path 670 when valve 630 is open. Flow path 675, through exhaust turbine 350 and designed to be diverted by the pressure of the exhaust flowing through exhaust turbine 350, is more restrictive and results in greater back pressure compared to flow path 670 through bypass passage 625. Therefore, although the initial flow direction is toward turbine outlet 692, more exhaust is directed through passage 625. It should be noted that a portion of the exhaust entering bypass duct 620 will continue to flow through exhaust turbine 350 even when valve 630 is fully open.

[0203] When valve 630 is in the closed position, most (approximately all) of the exhaust gas entering exhaust inlet 622 flows along turbine exhaust flow path 675. As schematically shown, the exhaust gas flowing along turbine exhaust flow path 675 is deflected by valve 630 when valve 630 is in the closed position and obstructs passage 625. When some of the exhaust gas entering through duct inlet 622 flows parallel to the central axis 629, at least a portion of valve 630 contacts the exhaust gas entering inlet 622 and deflects the exhaust gas entering inlet 622.

[0204] As mentioned above, valve 630 can also be positioned in the middle, for example... Figure 16 The intermediate position shown is merely a non-limiting example. With valve 630 in the intermediate position, a portion of the exhaust gas is allowed to bypass the exhaust turbine 350 through passage 625, and a portion of the exhaust gas is diverted toward the exhaust turbine 350 through turbine outlet portion 692. In the intermediate position, at least a portion of valve 630 is in contact with the exhaust gas that enters through duct inlet 622 and flows parallel to axis 629.

[0205] Therefore, when valve 630 is in an intermediate position, exhaust flows along both the bypass exhaust flow path 670 and the turbine exhaust flow path 675. The ratio of the portion of exhaust flowing along the bypass exhaust flow path 670 to the portion flowing along the turbine exhaust flow path 675 depends on various factors, including at least the angle at which valve 630 is positioned. Generally, the closer valve 630 is to the open position, the more exhaust will flow along the bypass exhaust flow path 670, and the further away valve 630 is from the open position, the less exhaust will flow along the bypass exhaust flow path 670.

[0206] As will be described in detail below, valve 630 is used to manage the exhaust flow through flow paths 670, 675. For example, in some cases, when engine 26 is operating below a threshold atmospheric pressure, valve 630 selectively moves to the closed position (or toward the closed position). In this case, when the snowmobile 10 climbs to an altitude where the air is thinner and therefore less oxygen enters engine 26 (which has an adverse effect on performance), turbocharger 300 can be used to help improve engine performance.

[0207] Regardless of the position of valve 630, in this implementation, there is no physical barrier obstructing airflow between exhaust inlet 622 and turbine inlet 355. As described above, even when valve 630 is in the open position, a portion of the exhaust gas entering through bypass inlet 622 also enters exhaust turbine 350 through turbine outlet portion 692 and turbine inlet 355. This relatively small portion of the exhaust gas entering exhaust turbine 350 helps create a pressure difference between the upstream and downstream locations of exhaust turbine 350. This pressure difference substantially improves the responsiveness of turbocharger 300, thereby causing exhaust turbine 350 to operate more quickly and contributing to reduced turbo lag.

[0208] Similarly, when exhaust flows along the bypass exhaust flow path 670, there is no physical barrier closing the turbine outlet 315. Thus, the flow of exhaust exiting from the bypass outlet 626 causes a decrease in air pressure at the turbine outlet 315. This low-pressure area also helps reduce turbine lag and increase operating speed. It should also be noted that when exhaust is directed to the turbine exhaust flow path 675 and flows out from the turbine outlet 315, there is also no barrier closing the bypass outlet 626.

[0209] According to this technology and as described above, the exhaust system 600 is generally designed to operate as a naturally aspirated engine system, wherein, except in specific cases where additional boost from the turbocharger 300 is required, the exhaust generally bypasses the exhaust turbine 350. This contrasts with some standard turbocharged engine arrangements in which the turbocharger is used for standard operation and turbocharger bypass is used to prevent compressor overload.

[0210] In the arrangement and configuration of the exhaust system 600 of this technology, compared to a conventional turbocharger arrangement, most of the exhaust gas flows through passage 625 (as described above) when valve 630 is in the open position. The exhaust flow is further managed by the comparative cross-sections of two flow paths 670, 675, specifically to allow gas to bypass the turbocharger 300 without generating excessive back pressure. Specifically, in this technology, the area of ​​the opening 627 of passage 625 (for bypassing flow path 670) and the intake area 354 of the exhaust turbine 350 (in turbine flow path 675) have similar dimensions.

[0211] The arrangement of the relative areas of the openings 627 and 355 in the two flow paths 670 and 675 allows exhaust gas to bypass the exhaust turbine 350 without generating excessive back pressure (excessive back pressure may be detrimental to the operation of engine 26), while still allowing good exhaust flow through turbine inlet 355 when turbine 300 is requested. According to this technology, the area of ​​opening 627 is approximately between 0.75 and 1.25 times the area 354 of turbocharger inlet 355. In this implementation, the area 354 of turbocharger inlet 355 is slightly larger than the area of ​​opening 627. However, it is conceivable that in some implementations, the area of ​​opening 627 may be larger than the area 354 of turbocharger inlet 355.

[0212] Compared to conventional turbocharger arrangements, the bypass outlet 626 is specifically arranged so that the deviation in exhaust flow required for the flow to travel from the bypass duct inlet 622 to the bypass outlet 626 is not excessive. In this implementation, the normal to the bypass outlet 626 forms an angle of approximately 20 degrees with the central axis 629 (although the exact angle can vary). With this arrangement, a portion of the exhaust entering the inlet 622—such as… Figure 15 As illustrated between lines 601 and 603, both parallel to the central axis 620, the bypass conduit 620, i.e., through channel 625 and opening 627, will discharge directly from the bypass outlet 626 without deviation. This is also true for the valve 630 in multiple positions between fully open and fully closed.

[0213] When the snowmobile 10 is not operating below the atmospheric pressure threshold, the exhaust system 600 will tend to deliver exhaust gas along a bypass exhaust flow path 670 that bypasses the exhaust turbine 350, and the engine 26 will operate as a naturally aspirated engine 26. When the snowmobile 10 is operating below such an intake pressure threshold, for example, at high altitude / low atmospheric pressure, valve 630 will move toward a (partially or completely) closed position to deliver some or all of the exhaust gas to the exhaust turbine 350, thereby providing boost to the engine 26. Further details regarding the operation of valve 630 relative to operating conditions will be provided below.

[0214] Example operation of exhaust system

[0215] Reference Figure 31 and Figure 32 A non-limiting illustrative description of the operation of the exhaust system 600 will now be provided. (Refer to...) Figures 21 to 23 The different implementations of the specific method are described in more detail below. It should be noted that this is merely a non-limiting example to provide a high-level understanding of the general operation of the exhaust system 600, and the different implementations and details will be elaborated below.

[0216] In summary, the system controller 500 retrieves the predetermined position of valve 630 from a data table (dataset) based on throttle position (TPS) and engine speed (RPM). Depending on the specific mode of operation (described further below), exhaust pressure, input pressure, or the difference between the two is simultaneously monitored by comparing it to a similar predetermined pressure dataset. Figure 31 The following flowchart 950 is shown: This flowchart 950 generally depicts the steps taken by the system controller 500 to control the valve 630 in this illustrative case.

[0217] First, the controller 500 determines whether the snowmobile 10 is operating near sea level or at a higher altitude. The relative altitude (high or low) is typically determined by the intake pressure sensor 504 by measuring the ambient air pressure entering the intake system; however, in some cases, the snowmobile 10 may include an altimeter communicatively connected to the system controller 500 for altitude determination. The system controller 500 can then retrieve a predetermined dataset of valve positions and pressures corresponding to the operation of the snowmobile 10 within the relevant altitude range. To avoid inaccurate altitude readings from the intake pressure sensor 504 due to additional pressure generated by the turbocharger 300, altitude-related pressure readings are acquired when the RPM and TPS outputs are below a predetermined level, corresponding to an operating state in which the turbocharger 300 should not generate boost pressure. It is also noted that datasets corresponding to different altitudes can be used in addition to low or high altitudes. Datasets corresponding to more than two altitudes are also conceivable.

[0218] After determining whether the snowmobile 10 is at a high or low altitude, the system controller 500 then determines whether valve 630 should be adjusted according to a "coarse" or "fine" adjustment mechanism. This determination is performed by comparing the actual boost pressure (the current intake pressure supplemented by the turbocharger 300) with a predetermined desired boost target pressure based on a dataset of TPS and RPM. The actual boost pressure generated by the turbocharger 300 is determined by the intake pressure sensor 504. The desired boost target pressure for the current TPS and RPM values ​​is determined by a predetermined dataset, an exemplary predetermined desired boost target pressure dataset 975 in... Figure 32 As shown in the diagram. A fine mechanism is used when the actual boost from the turbocharger 300 is within a predetermined range or threshold of the desired boost target (e.g., within 5, 10, or 15 millibars of the desired boost). Otherwise, a coarse mechanism is used. Depending on the specific implementation, the predetermined range can be modified based on factors such as ambient air temperature, altitude, etc. It should also be noted that in some cases, the predetermined range for switching from the coarse mechanism to the fine mechanism may differ from the predetermined range for switching from the fine mechanism to the coarse mechanism. This hysteresis is introduced into the coarse / fine determination method to help limit rapid switching between the two control mechanisms. For example, if the threshold difference used for switching between the coarse and fine control mechanisms is the same, the method could rapidly alternate between the coarse and fine control mechanisms whenever the pressure difference is slightly below or above the threshold. This can be unnecessarily inefficient, especially when the pressure difference oscillates around the threshold.

[0219] When operating under a coarse regulation mechanism, also known as a dynamic mechanism, back pressure is simultaneously monitored and controlled based on the pressure dataset to ensure that the movement of valve 630, intended to increase boost pressure, does not lead to an unfavorable increase in back pressure. Figure 33 The diagram shows sample pairs of valve position dataset 960 and pressure dataset 970 (these values ​​are merely illustrative and do not imply limitations). When pressure dataset 970 is used in a coarse-grained mechanism, the output value will represent the maximum difference between the exhaust pressure and the intake pressure, which will be described in more detail below.

[0220] During control of valve 630, if the back pressure rises above a certain amount for the current operating conditions (e.g., RPM and TPS), the performance of engine 26 may be negatively affected or at least suboptimal. To prevent this, the representation of the maximum back pressure determined by the current TPS and RPM values ​​in dataset 970 is compared with the actual back pressure, determined by subtracting the intake pressure from the exhaust pressure, which is obtained from exhaust pressure sensor 590 and intake pressure sensor 504, respectively. If the actual back pressure exceeds the value from dataset 970, system controller 500 corrects valve position dataset 960 to move valve 630 to a position that keeps the back pressure within an acceptable range, i.e., the actual pressure difference is lower than the pressure difference obtained from dataset 970. In some cases, a correction factor can be mathematically determined and applied to dataset 960. For example, the correction factor can be determined based on the difference between the value retrieved from dataset 970 and the actual back pressure determined by the pressures measured by exhaust pressure sensor 590 and intake pressure sensor 504. It is worth noting that the correction factor can be proportional to a difference between the value retrieved from dataset 970 and the actual back pressure determined by the pressures measured by exhaust pressure sensor 590 and intake pressure sensor 504. In some implementations, a different predetermined dataset 960 can be retrieved instead of determining the correction factor.

[0221] It should be understood that, in order to accurately calculate the actual back pressure, the amount of time elapsed between the measurements taken by the exhaust pressure sensor 590 and the intake pressure sensor 504 should be kept relatively short, such that the measurements are substantially simultaneous. It is worth noting that the pressure at the locations of sensors 590 and 504 can change rapidly, and therefore, if a large amount of time is allowed between the measurement taken by the exhaust pressure sensor 590 and the corresponding measurement taken by the intake pressure sensor 504, the correction of the position of valve 630 may not be very accurate in obtaining the desired back pressure. For example, the exhaust pressure sensor 590 and the intake pressure sensor 504 take corresponding measurements of each other within one revolution of the crankshaft 126. More specifically, in this embodiment, the exhaust pressure sensor 590 and the intake pressure sensor 504 take corresponding measurements of each other within one-tenth of a revolution of the crankshaft 126. The exhaust pressure sensor 590 and the intake pressure sensor 504 may take corresponding measurements of each other between one-tenth and one revolution of the crankshaft 126, but other frequencies are also conceivable.

[0222] In the fine-tuning mechanism, when there is a small difference between the actual boost pressure and the desired boost pressure as described above, a fine-tuning table, also known as a static dataset, is used. Fine-tuning is performed to approximate and maintain the optimal intake pressure (boost pressure) of engine 26, compared to the method used in coarse-tuning. Since minor adjustments to the position of valve 630 do not drastically affect back pressure, back pressure during the fine-tuning mechanism may not be monitored as continuously as it is under the coarse-tuning mechanism. Like the coarse mechanism, the fine-tuning mechanism uses a valve position dataset similar to the valve position dataset based on actual TPS and RPM values ​​in dataset 960, and a pressure dataset similar to the pressure dataset in 970, also based on actual TPS and RPM values. In the fine-tuning mechanism, pressure dataset 970 includes only values ​​representing intake pressure and will be compared to the actual intake pressure measured by intake pressure sensor 504. In the fine-tuning mechanism, the difference between the output from dataset 970 and the actual intake pressure will determine the correction factor to be applied to the valve position from dataset 970.

[0223] During operation, the system controller 500 continuously re-evaluates the altitude and coarse / fine measurements because the throttle position and RPM position will change when the snow vehicle 10 is running—which will also change the exhaust and intake pressures, since the valve 630 is controlled to improve the operation of the engine 26—and / or the altitude at which the snow vehicle 10 is running when it is driving on terrain will change.

[0224] Reference Figures 21 to 23Different methods for controlling the flow rate of exhaust gas from engine 26 will be described below. Each method will be described in more detail below. In short, methods 700, 750, and 800 aim to balance the optimized boost provided to engine 26 based on operating conditions (in the form of compressed air supplied by turbocharger 300) with the adverse increase in back pressure that may occur when turbocharger 300 is operating. This control is provided by valve 630. As briefly mentioned above, the operation of exhaust system 600 with valve 630 helps prevent back pressure from interfering with engine function when exhaust gas flows out through bypass duct 620. By closing valve 630, exhaust gas is introduced into exhaust turbine 350, allowing turbocharger 300 to supply additional air to engine 26; however, this exhaust flow path 675 also increases back pressure. In some implementations of these methods, the position of valve 630 can be adjusted to balance the demand for additional compressed air with the negative impact on engine operation due to increased back pressure.

[0225] Operation based on pressure readings

[0226] The operation of the exhaust system 600 according to different methods based on this technology will now be described in more detail. (Refer to...) Figure 21 A non-limiting implementation of controlling the operation in the exhaust system 600 is described in the form of a method 700 for controlling the flow rate of exhaust gas from the engine 26. According to this technology, method 700 is executed by a system controller 500. In some implementations, it is contemplated that additional or alternative computing systems may be implemented to execute method 700.

[0227] Method 700 begins at step 705, whereby at least one pressure of engine 26 is determined. Based on one or more pressures detected for engine 26, method 700 determines how to position valve 630 to optimize or improve the performance of engine 26. As will be described in more detail below, valve 630 may be positioned based on, but not limited to, exhaust pressure, intake pressure, and / or atmospheric pressure, as well as desired or actual boost pressure.

[0228] Then, method 700 continues to step 720, which moves valve 630 to a closed position, an open position, or an intermediate position based at least on the pressure determined in step 710. Depending on the determined pressure, valve 630 is moved to direct more or less exhaust gas into exhaust turbine 350. In some cases, the desired position of valve 630 will correspond to the current position of valve 630, and therefore valve 630 will not move.

[0229] In some implementations, determining the pressure at step 705 includes determining, at sub-step 710, the pressure difference between the actual boost pressure of the air flowing into engine 26 and the predetermined boost pressure of the air flowing into engine 26.

[0230] In some implementations, determining the pressure difference at sub-step 710 is performed in two sub-steps. First, the actual boost pressure is determined at sub-step 712. The actual boost pressure is determined based on readings from intake pressure sensor 504, which is used to determine the intake pressure from turbocharger 300. However, it is conceivable that different sensors and / or operating values ​​could be used to determine the actual boost pressure.

[0231] The predetermined boost pressure is determined at sub-step 714. The predetermined boost pressure is calculated or previously determined to substantially match the operating conditions of engine 26, thereby optimizing the operation of engine 26. The predetermined boost pressure is operatively connected from the system controller 500 (in... Figure 8 (Illustrated in the diagram) or retrieved from a computer-accessible storage medium 507 contained in the system controller 500. It is conceivable that additional sensors may be included in the exhaust system 600 and used in method 700.

[0232] In some implementations, determining the predetermined boost pressure at sub-step 714 includes at least one of the following: determining the engine speed of engine 26 via engine speed sensor 586; determining the throttle valve position of throttle valve 39 of engine 26 via throttle valve position sensor 588; determining the throttle valve stem position via throttle stem position sensor 86; and determining the throttle valve opening rate of throttle valve 39. In some implementations, instead of determining the throttle valve position, or in addition to determining the throttle valve position, the throttle valve opening rate may be determined. Then, based on the determined engine speed, throttle valve position, throttle stem position, and / or throttle valve opening rate, the predetermined boost pressure is retrieved from computer-based storage medium 507.

[0233] It is conceivable that, depending on the specific implementation and / or operational conditions, sub-steps 712 and 714 can be executed in any order or simultaneously. In some implementations, it is conceivable that the snowmobile 10 may include a differential pressure sensor for determining the pressure difference at sub-step 710 in a single measurement.

[0234] In some implementations or iterations, method 700 may also include determining that the difference between the predetermined boost pressure and the actual boost pressure, as determined in sub-step 710, is less than a difference threshold. The difference threshold typically indicates whether movement of valve 630 to more closely match the actual boost pressure with the predetermined boost pressure will require coarse adjustment (if the difference is above the threshold) or only fine adjustment (if the difference is below the threshold).

[0235] Based on the difference being less than a difference threshold, method 700 then proceeds to determine the desired valve position of valve 630 from the fine-tuning dataset. The fine-tuning dataset, based on at least one of the throttle position and engine speed determined above, pertains to fine-tuning or minor adjustments to the position of valve 630 required to provide the desired pressure in engine 26 by reducing the difference between the predetermined boost pressure and the actual boost pressure. After determining the desired valve position, method 700 then continues to move valve 630 toward the desired valve position.

[0236] Based on the difference being greater than a difference threshold, method 700 then similarly continues to determine the desired valve position of valve 630 from the coarse adjustment dataset. The coarse adjustment dataset based on at least one of the throttle position and engine speed determined above involves coarse or greater adjustments to the position of valve 630 required to provide the desired pressure in engine 26 by reducing the difference between the predetermined boost pressure and the actual boost pressure. After determining the desired valve position, method 700 then continues to move valve 630 toward the desired valve position.

[0237] In some implementations, method 700 can be iterative, such that when the difference between the predetermined boost pressure and the actual boost pressure is large, coarse adjustment is performed to reduce the difference. Once the difference between the predetermined boost pressure and the actual boost pressure is reduced to below a threshold, fine adjustment is used. The use of coarse and fine adjustments is merely a non-limiting example of adjusting the position of control valve 630. It is also conceivable that the adjustment can be divided into three or more datasets. For example, the adjustment can be divided into "large coarse adjustment," "small coarse adjustment," and "fine adjustment" using two thresholds. It is also conceivable that a single dataset can be used to determine the desired valve position.

[0238] In some implementations or iterations of method 700, determining the pressure difference at sub-step 710 includes determining the difference between the intake pressure of the air flowing into engine 26 and the exhaust pressure of the exhaust flowing out of engine 26, instead of determining the difference between a predetermined boost pressure and an actual boost pressure. In this implementation, method 700 then includes determining the intake pressure via intake pressure sensor 504 and the exhaust pressure via exhaust pressure sensor 590.

[0239] Method 700 will then further include determining a predetermined pressure difference between the exhaust pressure and the intake pressure. Similar to a predetermined boost pressure, the predetermined pressure difference corresponds to an optimal or preferred difference between the exhaust pressure and the intake pressure, which corresponds to better operation of the engine 26 under current operating conditions. For example, the predetermined pressure difference may be set based on engine parameters, such as engine speed, such that the engine 26 typically has the amount of air required for normal operation without generating excessive back pressure. In some implementations, the predetermined pressure difference may be determined based on, but not limited to, throttle position and engine speed.

[0240] In this implementation, method 700 then proceeds to determine that the difference between the pressure differential and the predetermined pressure differential is not zero. A non-zero difference only indicates that the actual pressure differential is not at the predetermined pressure differential, and therefore the engine 26 may not be operating optimally. Therefore, method 700 then continues to move valve 630 to an open position, a closed position, or an intermediate position based on the non-zero difference. In some implementations, the position to which valve 630 moves may depend on whether the actual pressure differential is greater than or less than the predetermined pressure differential.

[0241] In some implementations or iterations of method 700, method 700 includes determining that the intake pressure is below a threshold atmospheric pressure. Similar to the steps described above, determining the intake pressure involves measuring the pressure via intake pressure sensor 504. System controller 500 can then determine whether the measured air pressure of the air entering engine 26 is below a predetermined threshold. For example, the threshold can be set based on engine parameters to ensure that engine 26 typically has the amount of air required for normal operation. It is also conceivable that the threshold atmospheric pressure could be a predetermined range of atmospheric pressure. In a non-limiting example, when snowmobile 10 is climbing a hill and the altitude increases, the intake pressure may drop below the threshold.

[0242] Then, based at least on the intake pressure below the threshold atmospheric pressure, method 700 can continue to move valve 630 to the closed position or toward the closed position (if valve 630 is in the open or intermediate position). This will initiate or increase the operation of turbocharger 300. Thus, when engine 26 does not receive enough air for good or full operation, such as when snowmobile 10 is operating at high altitude, turbocharger 300 can be operated to supply compressed air to engine 26 (as described above).

[0243] In some implementations or iterations of method 700, method 700 may also include determining that the back pressure is too high and opening valve 630 to maintain a balance between increasing the intake pressure of engine 26 and allowing the back pressure to be relieved by opening valve 630.

[0244] After moving valve 630 to or toward the closed position, method 700 may further include determining that the exhaust pressure is higher than a threshold exhaust pressure. As described above, the exhaust pressure is measured by exhaust pressure sensor 590; system controller 500 then compares the measured value with the determined back pressure threshold.

[0245] Based on the exhaust pressure exceeding a threshold exhaust pressure, method 700 then continues to reposition valve 630 to the open or intermediate position, allowing exhaust to flow at least partially along the bypass exhaust flow path 670. By opening valve 630, the increased exhaust portion flows out through the bypass portion 620, thereby relieving back pressure. Depending on the iteration of method 700, valve 630 may move only a small degree, or in some cases, move all the way to the open position. In some implementations, the change in the position of valve 630 may be proportional to or directly related to the increase in exhaust pressure after moving valve 630 to the closed position.

[0246] In some implementations or iterations of method 700, once the snowmobile 10 operates at atmospheric pressure higher than the threshold mentioned above for initiating turbocharger 300, valve 630 can be moved back to the open position. In a non-limiting example, when the altitude of the snowmobile 10 decreases and the atmosphere around the snowmobile 10 becomes richer, valve 630 can be partially or fully opened back to the open position.

[0247] In this case, method 700 may further include (via intake pressure sensor 504 and system controller 500) determining that the intake pressure is higher than a threshold intake pressure, and then moving valve 630 to or toward the closed position. Then, based on the intake pressure being higher than the threshold intake pressure, method 700 may continue to move valve 630 such that most or more of the exhaust gas flows along bypass exhaust flow path 670.

[0248] It is conceivable that method 700 may include additional or different steps to perform additional functions and / or perform the steps described above. It is also conceivable that the steps described above may be performed in various different orders, based on, for example, user preferences, and are not limited to the order set forth in the above description.

[0249] Operation based on exhaust pressure

[0250] Reference Figure 22 The present invention describes a non-limiting implementation of the operation in the exhaust system 600 in the form of method 750. According to the present technology, method 750 is executed at least in part by system controller 500. In some implementations, it is contemplated that additional or alternative computing systems may be implemented to execute method 750.

[0251] Method 750 begins at step 760, which determines that the exhaust pressure of the air flowing out of engine 26 is higher than a threshold exhaust pressure, wherein valve 630 is in a closed position or an intermediate position, and wherein most of the exhaust gas flows along turbine exhaust flow path 675. As described above, in this implementation, the exhaust pressure is determined by exhaust pressure sensor 590 and system controller 500. In some implementations, valve 630 may have moved to the closed position based on the reduction in atmospheric pressure around snow vehicle 10, similar to the situation described above with respect to method 700. It is also conceivable that valve 630 may have moved to the closed position or moved toward the closed position for alternative reasons. For a non-limiting example, valve 630 may have moved to the closed position to supply more air to engine 26 via air compressor 310 due to insufficient performance of engine 26.

[0252] Then, method 750 continues to step 760, whereby valve 630 is moved to the open position or toward the open position to the intermediate position based on the exhaust pressure being higher than the threshold exhaust pressure.

[0253] It is conceivable that method 750 can be executed simultaneously or continuously with method 700, and the operation of the snowmobile 10 may include implementing both method 700 and method 750.

[0254] It is conceivable that method 750 may include additional or different steps to perform additional functions and / or perform the steps described above. It is also conceivable that the steps described above may be performed in various different orders, based on, for example, user preferences, and are not limited to the order set forth in the above description.

[0255] Operation based on engine speed and throttle position

[0256] Reference Figure 23 Another non-limiting implementation of the operation in the exhaust system 600 is illustrated in the form of a method 800 for controlling the exhaust flow of the engine 26. According to the present technology, method 800 is executed by a system controller 500. In some implementations, it is conceivable that an additional or alternative computing system may be implemented to execute method 800.

[0257] In addition to controlling the position of valve 630 to manage intake and exhaust pressure based on environmental conditions (i.e., atmospheric pressure), exhaust system 600 can also be operated to regulate exhaust flow to balance limiting back pressure while providing additional boost when the user of snowmobile 10 needs additional power from snowmobile 10.

[0258] In a non-limiting case, method 800 can be implemented in a situation where the throttle lever 86 is moved to request high power from the engine 26, for example, during acceleration of the snowmobile 10. As will be outlined in the following steps, valve 630 moves to the closed position in response to this movement of the throttle lever 86 to activate the turbocharger 300. With the turbocharger 300 in use, the engine 26 will therefore benefit from a more concentrated intake charge and will have increased power output compared to a similar naturally aspirated engine. As will be further described below, the need for excessive boost and the routing of all exhaust along the turbine exhaust flow path 675 may also cause back pressure to build up to a level exceeding the desired optimal level for engine operation. In this case, method 800 can further move valve 630 back towards the open position to allow some exhaust to bypass the exhaust turbine 350, thereby reducing back pressure.

[0259] Method 800 begins at step 810, whereby the engine speed of engine 26 is determined by engine speed sensor 586. Method 800 then continues at step 820, whereby the throttle valve position of throttle valve 39 of engine 26 is determined. As described above, the position of throttle valve 39 is sensed by throttle valve position sensor 588.

[0260] In some implementations, instead of determining the throttle valve position, or in addition to determining the throttle valve position, step 820 may include determining the throttle valve opening rate of the throttle valve 39. In some implementations, the throttle valve position sensor 588 may also be used alone or in conjunction with the system controller 500 to measure the throttle valve opening rate. Steps 810 and 820 may be performed in any order or simultaneously, depending on the specific implementation.

[0261] Then, method 800 continues at step 830, whereby method 830 moves valve 630 to an open position, a closed position, or any intermediate position based on the engine speed and throttle valve position determined in steps 810 and 820, and the initial position of valve 630. In method 800, the throttle valve position is taken into account to help control exhaust flow, thereby managing the operation of engine 26.

[0262] In some implementations or iterations, in addition to the engine speed and throttle valve position determined in steps 810 and 820, method 800 may also include moving valve 630 based on the temperature of exhaust pipe 202. The temperature of exhaust pipe 202 is received by system controller 500 from temperature sensor 512. In some implementations, moving valve 630 may additionally or alternatively be based on the exhaust temperature within exhaust pipe 202 sensed by temperature sensor 512.

[0263] In some implementations, method 800 may further include determining a pressure difference and, based on that pressure difference, further actuating valve 630. In some implementations, the pressure difference is determined by comparing a predetermined boost pressure of air flowing into engine 26 with an actual boost pressure of air flowing into engine 26. The predetermined boost pressure, described in more detail above, is determined at least based on one of the throttle position and engine speed as determined in steps 810, 820, and corresponds to the boost pressure that should flow into engine 26 based on the throttle position and / or engine speed. As described above, the actual boost pressure of air flowing into engine 26 is determined by measuring the intake pressure by intake pressure sensor 504 and system controller 500. In some implementations, the actual boost pressure may be determined differently.

[0264] In some implementations, method 800 may further include determining whether engine 26 is operating at low or high altitude (i.e., whether snowmobile 10 is operating at low or high altitude) before moving valve 630. In some implementations, determining whether engine 26 is operating at low or high altitude includes determining the atmospheric pressure of the air entering the snowmobile via intake pressure sensor 504. It is also conceivable that system controller 500 may include or be communicatively connected to an altimeter or similar altitude measuring device.

[0265] Upon determining that engine 26 is operating at low altitude, method 800 can then proceed to retrieve the desired valve position of valve 630 from the low-altitude dataset. Similarly, upon determining that engine 26 is operating at high altitude, method 800 can then proceed to retrieve the desired valve position of valve 630 from the high-altitude dataset. In some implementations, the low-altitude and high-altitude datasets can be stored in storage medium 507, which is communicatively connected to system controller 500 or a portion thereof.

[0266] The desired valve position retrieved from a low or high dataset typically corresponds to an optimal or predetermined valve position based on altitude and engine speed and / or throttle position, such that the airflow into engine 26 matches the operating conditions of engine 26. In this implementation, the desired position of valve 630 has been determined, and step 830 of moving valve 630 is performed by moving valve 630 to that desired position.

[0267] In some implementations or iterations, method 800 may further include determining a threshold pressure difference for engine 26 based at least on the throttle position and engine speed determined in steps 810 and 820. Method 800 then proceeds to determine the actual pressure difference for engine 26. In some implementations, determining the actual pressure difference includes determining the downstream exhaust pressure of engine 26 via exhaust pressure sensor 590, determining the upstream intake pressure of engine 26 via intake pressure sensor 504, and determining the difference between the exhaust pressure and the intake pressure.

[0268] Then, method 800 continues to determine that the actual pressure difference is greater than the threshold pressure difference, and if valve 630 is in the closed or intermediate position, moves valve 630 toward the open position. In this case, the actual pressure difference being greater than the threshold pressure difference may indicate that too much air pressure is entering engine 26. This may have an adverse effect on the operation of engine 26, and therefore method 800 can provide correction by further moving valve 630 toward the open position to allow more exhaust gas to bypass exhaust turbine 350.

[0269] In some implementations or iterations, method 800 may also include determining that the intake pressure, as determined by intake pressure sensor 504, is higher than an intake threshold, and determining that the throttle valve position exceeds a valve position threshold. For example, method 800 may determine that excessive air pressure is entering engine 26 when throttle valve 39 is already too open. This combination may have an adverse effect on the operation of engine 26, and method 800 may provide correction by further moving valve 630 toward the open position to allow more exhaust gas to bypass exhaust turbine 350.

[0270] Based on the intake pressure exceeding its respective threshold and the throttle valve position, valve 630 can therefore move from the closed or intermediate position toward the open position. This allows for a reduction in back pressure caused by excessive intake or too rapid demand for excessive throttle.

[0271] In some implementations or iterations, method 800 may also include moving valve 630 toward the closed position after moving it toward the open position, thereby increasing a portion of the exhaust gas flowing through the exhaust turbine 350 of the turbocharger 300. In this implementation, method 800 provides some regulation of the exhaust flow to balance the boost from the turbocharger 300 while limiting the adverse effects of increased back pressure, which helps to smooth the power increase of the engine 26.

[0272] In some implementations or iterations, method 800 may further include determining that the intake pressure is higher than an intake pressure threshold after moving the valve toward the closed position. Method 800 may then include moving valve 630 toward the open position based on the intake pressure being higher than the threshold.

[0273] In some implementations or iterations, method 800 may also include determining that the intake pressure is below an intake pressure threshold after moving the valve toward the closed position. Method 800 may then further include moving the valve 630 toward the closed position to allow further boost from the turbocharger 300.

[0274] In some implementations, determining the intake pressure may include determining the intake pressure downstream of the turbocharger 300 via a pressure sensor (not shown). Moving the valve may then include selectively moving the valve based on the downstream intake pressure of the turbocharger 300 determined by the pressure sensor.

[0275] In some implementations, method 800 may also include determining the downstream exhaust pressure of engine 26 by exhaust pressure sensor 590 and moving valve 630 toward an open position based on the exhaust pressure being higher than a predetermined exhaust pressure threshold.

[0276] In some implementations, when determining the throttle valve opening rate, method 800 may further include determining that the throttle valve opening rate is higher than a threshold rate; and moving valve 630 toward an open position at least based on the throttle valve opening rate being higher than the threshold rate. In this implementation, valve 630 is opened, for example, when too much throttle is needed too quickly, to prevent back pressure from adversely affecting engine operation (especially when the user attempts to increase the power of engine 26). In some implementations, method 800 may further include determining that the intake pressure is higher than a threshold intake pressure, and moving valve 630 based on the throttle valve opening rate being higher than the threshold rate and the intake pressure being higher than the threshold intake pressure.

[0277] It is conceivable that method 800 may include additional or different steps to perform additional functions and / or perform the steps described above. It is also conceivable that the steps described above may be performed in various different orders, based on, for example, user preferences, and are not limited to the order set forth in the above description.

[0278] As described above, various methods for controlling the operation of the turbocharger 300 include monitoring the back pressure affecting the engine 26. Given the availability of pressure information in this technology, the operation of the snowmobile 10 can be further optimized by adjusting the fuel-air mixture in the engine 26.

[0279] Changes in back pressure in engine 26 and exhaust system 600 will affect the fuel-air ratio present in engine 26. All other conditions being equal, engine 26 achieves maximum power while maintaining a target back pressure. If the effective back pressure in engine 26 deviates from this target, the fuel-air ratio is affected, which in turn reduces the performance of engine 26.

[0280] As back pressure increases, the total amount of air flowing through engine 26 decreases. In this situation, the constant amount of fuel injected will result in an increased fuel-air ratio in engine 26, and therefore engine 26 will be supplied with an excessively rich fuel-air mixture. Thus, engine 26 may not operate optimally.

[0281] All other things being equal, an excessive drop in back pressure at high engine speeds will also lead to an increase in the fuel-air ratio. When the back pressure is too low, the pressure wave generated by the exhaust pipe 202 (which helps create a trapping effect to retain air in a two-stroke engine) may be unsuitable, and the combustion chamber of engine 26 will exhaust more air than it would under optimal operating conditions. In this case, engine 26 will again end with a richer fuel-air mixture (receiving the same amount of fuel and less air). Again, engine 26 may not be operating optimally.

[0282] Supply fuel-air mixture

[0283] Reference Figure 24 and Figure 33 The method 900 for supplying a fuel-air mixture in the engine 26 of a snowmobile 10 will now be described.

[0284] Method 900 begins at step 910, which determines the pressure difference between the intake pressure of air flowing into engine 26 and the exhaust pressure of exhaust air flowing out of engine 26. As mentioned above regarding the dynamic mechanism, this pressure difference is typically related to the back pressure in engine 26. The pressure difference is determined by comparing measurements obtained by system controller 500 from intake pressure sensor 504 and exhaust pressure sensor 590. In some implementations, it is conceivable that snowmobile 10 may include a differential pressure sensor for determining the pressure difference in a single measurement.

[0285] In some implementations of method 900, the pressure difference is determined in two steps. Specifically, in sub-step 912, the intake pressure is determined by intake pressure sensor 504. Then, in sub-step 914, method 900 continues to determine the exhaust pressure by exhaust pressure sensor 590. Depending on the specific implementation, steps 912 and 914 can be performed in any order or simultaneously.

[0286] Method 900 continues at step 920, which determines the amount of fuel to be injected into engine 26 based at least on the pressure difference (as determined in step 910). System controller 500 calculates the amount of fuel to be injected based at least on the back pressure in engine 26, such that the fuel-air mixture is maintained at an appropriate value. It is conceivable that another calculation system, other than system controller 500, could be included to manage the determination of the amount of fuel to be injected. The base fuel injection amount is determined using a dataset associated with the amount of fuel to be injected corresponding to the current TPS and RPM. Figure 34 The example basic fuel injection dataset 982 is shown, where the basic fuel injection is represented as volume, which in this example is mm. 3 .

[0287] In some implementations, the base fuel injection quantity can be modified based on the back pressure as follows: The target back pressure (exhaust pressure minus intake pressure) is determined by a dataset of TPS and RPM, for example, in example dataset 984. The actual back pressure is obtained by subtracting the intake pressure from the exhaust pressure, where the exhaust pressure and intake pressure are obtained using exhaust pressure sensor 590 and intake pressure sensor 504, respectively.

[0288] Then, the fuel correction amount or percentage is obtained from the fuel correction dataset 986 of the RPM and the difference between the actual back pressure and the target back pressure (labeled ΔΔP). The fuel correction from this dataset 986 is then applied to the base fuel injection amount to determine the final injection amount modified according to the measured back pressure.

[0289] Method 900 then terminates at step 930, whereby a predetermined amount of fuel (as determined in step 920) is injected into engine 26. As described above, the fuel is injected by fuel injector 41.

[0290] It is conceivable that in some implementations, method 900 may restart after step 930. In some implementations, method 900 may continue to determine the changing pressure difference after step 930. Method 900 may then continue to determine the corrected amount of fuel based on the changing pressure difference. This implementation of method 900 may then terminate by injecting the corrected amount of fuel into engine 26.

[0291] In some implementations, method 900 may include determining that the pressure differential has increased, determining the amount of fuel to be injected to be reduced, and injecting the reduced amount of fuel into engine 26. In some implementations, method 900 may also include determining that the pressure differential has decreased, determining the amount of fuel to be injected to be reduced, and injecting the reduced amount of fuel into engine 26.

[0292] In some implementations, method 900 is repeated at predetermined time intervals after step 930 to readjust the fuel-air mixture to compensate for changes in back pressure. In some implementations, method 900 may be executed intermittently by system controller 500 during operation of the snowmobile 10. It is also conceivable that method 900 may be executed only once or only a few times during operation of the snowmobile. It is also conceivable that method 900 may be executed in response to a pressure difference and / or intake or exhaust pressure exceeding a predetermined threshold.

[0293] In some implementations, method 900 may further include determining an engine speed and, based on that engine speed, determining the amount of fuel to be injected. In some implementations, method 900 may further include determining a throttle position of throttle valve 39 and, further based on that throttle position, determining the amount of fuel to be injected.

[0294] It is also conceivable that, in determining or calculating the amount of fuel to be injected, other variables besides pressure differentials could be considered. These variables could include, but are not limited to: engine speed (rpm), throttle position, air temperature, ambient atmospheric pressure, closed-loop wideband lambda control, and exhaust temperature.

[0295] It is conceivable that method 900 may include additional or different steps to perform additional functions and / or perform the steps described above. It is also conceivable that these steps may be performed in various different orders depending on a particular implementation.

[0296] Temperature Management

[0297] Reference Figures 37 to 43 as well as Figure 4 Components and methods for managing the engine intake temperature of the air entering the engine 26 of the snow vehicle 10 will now be described.

[0298] The air compressed by the compressor 310 of the turbocharger 300 and supplied to the engine 26 typically follows an intake flow path 444, which has already been described above and Figure 42The diagram is schematically shown. In short, air from the atmosphere surrounding the snowmobile 10 flows through the side opening 113 of the chassis 16 and enters the auxiliary airbox 110. A duct portion 117 of the Y-shaped duct 118 is fluidly connected to the auxiliary airbox 110 at one end and to the compressor inlet 312 of the compressor 310 at the other end. The air entering the inlet 312 is then compressed by the compressor 310. The compressed air then flows out of the compressor outlet 314 and into the duct 316. Thus, air flows through one end of the duct 316 fluidly connected to the compressor outlet 314 and through the other end of the duct 316 into the main airbox 120. Air then flows from the main airbox 120 via the engine air inlet 27 (which is located in…) Figure 4 Depicted in and Figure 42 (Schematally shown) Two air outlets 122, which are fluidly connected, flow into the engine 26.

[0299] During the compression of air in compressor 310, the temperature of the air delivered to engine 26 may rise. To manage the intake air temperature, snow vehicle 10 includes a coolant container assembly 450 for selectively containing coolant and delivering it to the intake air flow path 444.

[0300] Coolant container assembly 520 includes a coolant container 452 supported by frame 16, specifically by channel 18 (the channel 18 in...) Figure 38 and Figure 39 (Shown schematically) A coolant container 452 is supported. The container 452 is located immediately behind the fuel tank 28 in the space formed by the fuel tank 28, although in some implementations the container 452 may be located elsewhere.

[0301] The coolant container 452 holds approximately 2 liters of water-ethanol mixture during use. Depending on the implementation, the coolant container 452 may have a larger or smaller volume. The size of the coolant container 452 for a given implementation is generally appropriate for the intended use of the particular vehicle 10. For example, an implementation of the snowmobile 10 intended for mountainous conditions may have a coolant container 452 of a different size than an implementation of the snowmobile 10 intended for standard routes. While continuously supplying coolant from the coolant container 452 to the intake air flow path 444 would also help manage the intake air temperature, this would require a larger coolant tank. In this art, instead, a smaller container 452 is provided to limit volume and weight, and coolant is selectively delivered only to the intake air flow path 444 (described in more detail below).

[0302] The specific coolant used may also depend on the different implementations of the snowmobile 10, or on a set of operating conditions for any particular vehicle. Various coolants can be used, including but not limited to: water, ethanol, isopropanol, ethylene glycol, methanol, and combinations thereof. In some implementations, the coolant container 452 may also include a level sensor for sensing the coolant level in the coolant container 452. In some cases, the level sensor may be connected to a coolant meter displayed to the user. In some cases, an alarm may be issued to the user that the coolant level in the coolant container 452 is below a certain threshold level.

[0303] Coolant pipe 462 is fluidly connected to coolant container 452 for delivering coolant from coolant container 452 to intake flow path 444. Specifically, coolant pipe 462 is fluidly connected between coolant container 452 and intake flow path 444 at connection point 464. In the illustrated implementation, connection point 464 is located on conduit 117 for delivering coolant to intake flow path 444 upstream of compressor 310. At connection point 464 on conduit 117, there is an injection nozzle 465, which is fluidly connected to coolant pipe 462 and guided into conduit 117 for delivering coolant in conduit 117. In this implementation, coolant pipe 462 passes below fuel tank 28. It is contemplated that coolant pipe 462 may be arranged differently within snowmobile 10 depending on the specific details of the given implementation.

[0304] Depending on the specific implementation, the connection point 464 and the injection nozzle 465 can be located at other positions. In some implementations, the connection point 464 can be located on the conduit 316, such as by... Figure 42 Alternative paths for the coolant pipe 471 are shown schematically. In other implementations, connection point 464 may be located in the compressor inlet 312, as indicated by... Figure 42 Alternative coolant pipe 473 is shown schematically. In other implementations, connection point 464 may be located in the crankcase of engine 26, through which intake air passes before entering the combustion chamber of engine 26. Figure 38 In this implementation (illustrated schematically in the alternative coolant pipe 465), it is also conceivable that some portions of the coolant, when injected into the crankcase, may also contact the piston 226 of the engine 26, thereby further contributing to reducing piston temperature. It is also conceivable that multiple connection points and / or multiple injection nozzles may be included. Other arrangements are also conceivable.

[0305] See also Figures 44 to 48The illustration shows another embodiment of the connection point and arrangement of the coolant container 452. In this non-limiting embodiment, the vehicle 10 includes two coolant injection collars 480 connected to the engine 26 for injecting coolant into the intake flow path 444 as described above.

[0306] Each coolant injection ring 480 is connected to the engine 26 upstream of the corresponding reed valve 227, between one of the throttle valves 39 in the throttle body 37 and one of the engine air inlets 27. An intake airflow path 444 passes through an orifice 485 defined by each ring 480. Each ring 480 is formed of rubber, although different materials, including, for example, elastic plastics, are conceivable. It is also conceivable that two rings 480 may be integrally formed or joined together.

[0307] For injecting coolant, each collar 480 includes a nozzle 490 in fluid communication with an orifice 485 for selectively supplying coolant to the intake flow path 444. Figure 48 As shown, each nozzle 490 is formed by a tube receiving portion 492 and a collar connecting portion 494. Portions 492 and 494 snap together, although the specific forms of portions 492 and 494 can vary. It is also conceivable that the nozzle 490 could be formed from a single integrally connected portion.

[0308] Each nozzle 490, particularly the pipe receiving portion 492, is connected to a pipe 488 for supplying coolant to the nozzle 490. Both pipes 488 are connected to a T-fitting 486, which in turn is connected to a pipe 462 connected to the coolant container 450 as described above.

[0309] return Figures 40 to 42 And continue to refer to Figure 44The coolant container assembly 450 also includes a solenoid valve 466, which is disposed and fluidly connected between the coolant container 452 and the coolant line 462. Although the solenoid valve 466 is schematically shown as being directly connected to the coolant container 452, it is contemplated that the valve 466 may be disposed away from the coolant container 452. For example, depending on design and space considerations, additional tubing may connect the valve 466 to the coolant container 452 in some cases. The solenoid valve 466 selectively controls the flow of coolant from the coolant container 452 to the line 462. Control of the solenoid valve 466 will be described in more detail below. It is contemplated that other types of valves may be used in different implementations. In some implementations, the solenoid valve 466 may be disposed adjacent to or integrated with the injection nozzle 465. It is conceivable that, in addition to or in place of valve 466, coolant container assembly 450 may include a pump fluidly connected to coolant container 452 for pumping cooling fluid through coolant line 462 to intake flow path 444.

[0310] The snowmobile 10 also includes a pressurization line 468 for pressurizing the coolant container 452 by fluidly connecting the compressor 310 to the coolant container 452. When the snowmobile 10 is in use, air flows from the compressor 310 through the pressurization line 468 to the coolant container 452 to maintain a certain pressure in the coolant container 452. The pressurization line 468 includes a pressure regulator 469 to prevent overpressure, but it is contemplated that other methods for controlling overpressure can be implemented. When the solenoid valve 466 is open, the pressure in the coolant container 452 forces coolant through the coolant line 462. In this way, coolant can be delivered from the coolant container 452 to the intake flow path 444 without the need for a pump system. As mentioned above, in some cases, the coolant container assembly 450 may include a pump for pumping cooling fluid through the coolant line 462 to the intake flow path 444. In such an implementation, the pressurization line 468 can be removed.

[0311] The coolant container assembly 450 is communicatively connected to the system controller 500. As described above, to limit the increased volume and weight due to the inclusion of the coolant container, coolant is selectively delivered to the intake flow path 444. The controller 500 is therefore configured to selectively allow a certain amount of coolant to flow when the estimated piston temperature of the piston in the engine 26 may be high enough to pose a risk of detonation. Specifically, the controller 500 is configured to selectively allow a certain amount of coolant from the coolant container 452 to flow into the intake flow path 444 via connection point 464 based on the fluid temperature in the intake flow path 444 and / or based on the estimated piston temperature. The determination of the estimated piston temperature and the control of the coolant flow rate will be described in more detail below. Specifically, the controller 500 is communicatively connected to a solenoid valve 466 for selectively opening the valve 466, thereby allowing coolant to flow out of the coolant container 452.

[0312] As described above, the system controller 500 is also operatively and communicatively connected to the engine control unit (or ECU) and / or electrical system (not shown) of the snowmobile 10, and receives various engine operating values ​​from the engine control unit and / or electrical system. Although the same system controller 500 described above with respect to the methods and systems of the snowmobile 10 is used in this implementation, it is contemplated that separate and / or additional controllers may be used, and that such separate and / or additional controllers may be communicatively connected to the system controller 500 and / or ECU.

[0313] The engine operating values ​​received or determined by the controller 500 may include, but are not limited to: previously supplied coolant, ambient air temperature, ambient air pressure, throttle position, engine speed (RPM), engine load, engine running time, exhaust oxygen concentration (lambda), engine coolant temperature, exhaust valve 129 position, and boost pressure. Boost pressure is sensed by intake pressure sensor 504, which is communicatively connected to the controller 500 (as described in more detail above). Also as described above, the system controller 500 is operatively and communicatively connected to the atmospheric pressure sensor 504 for sensing intake atmospheric pressure or ambient air pressure, the atmospheric temperature sensor 505 for sensing intake atmospheric temperature or ambient air temperature, the exhaust oxygen sensor 513 for sensing exhaust oxygen concentration, and the ECU for retrieving various operating parameters of the engine 26. The system controller 500 is also communicatively connected to the engine coolant temperature sensor 127. The controller 500 may be connected to various other instruments and / or sensors depending on the specific implementation.

[0314] To monitor the temperature of the fluid (air or a mixture of air and liquid) flowing through the intake flow path 444, the snowmobile 10 includes a temperature sensor 455 configured to determine the temperature of the fluid in the intake flow path 444. In this implementation, the temperature sensor 455 is disposed on a duct 316 to determine the temperature of the fluid entering the engine 26. A portion of the temperature sensor 455 extends into the interior of the duct 316 to sense the temperature of the fluid in the duct. It is contemplated that the temperature sensor 455 may be located elsewhere along the intake flow path 444, including but not limited to: located in or above the auxiliary airbox 110, duct 117, compressor 310, and main airbox 120. In an implementation that measures the temperature upstream of the compressor 310 (e.g., in the airbox 110, duct 117, etc.), the temperature determined will be the air temperature before additional heating from the compressor 310. In some implementations, the temperature sensor 455 may measure the ambient temperature of the air surrounding the snowmobile 10.

[0315] Specific reference Figure 43 The following will now describe a method 1100 for managing the engine intake air temperature of a turbocharged vehicle 10 using the components of the aforementioned snowmobile 10. Typically, method 1100 includes sensing the intake air temperature and determining an estimated piston temperature of the engine 26 by a controller 500. Based on the intake air temperature and / or engine operating values, the controller 500 retrieves the estimated piston temperature from a piston temperature model. In response to one or both of the fluid (typically intake air) temperature and the estimated piston temperature exceeding a threshold temperature, the controller 500 then delivers a quantity of coolant to the intake air flow path 444 to help reduce the intake air temperature (without necessarily reducing boost from the turbocharger 300 and / or reducing engine speed). The threshold temperature typically corresponds to a temperature above which the engine 26 would be at risk of detonation, but the threshold can be calibrated differently.

[0316] Method 1100 begins at step 1102, whereby temperature sensor 455 senses the fluid temperature in the intake flow path 444, and controller 500 receives the temperature sensed by sensor 455. The fluid in the intake flow path 444 is typically intake air, but may also include moisture and / or coolant in the intake flow path 444. Since temperature sensor 455 is located downstream of the injection nozzle 465 that delivers coolant, it senses the temperature of both the air in conduit 316 and the remaining coolant when coolant is introduced into the intake flow path 444. When there is no coolant in the intake flow path 444 and / or when temperature sensor 455 is located upstream of the injection nozzle 465, sensing the fluid in the intake flow path 444 typically means sensing the air temperature in the intake flow path 444.

[0317] Method 1100 continues to step 1104, whereby controller 500 determines an estimated piston temperature based at least on the fluid temperature in the intake flow path 444 sensed at step 1102. Determining the estimated piston temperature includes retrieving the estimated piston temperature from a piston temperature model by controller 500. In this implementation, the estimated piston temperature model is stored in and accessible via storage medium 507, which is communicatively connected to system controller 500. It is contemplated that, depending on the implementation, the model may be stored in another computer-readable medium communicatively connected to system controller 500. In some implementations, one or more tables or databases based on intake air temperature and / or engine operating values ​​may be used instead of the model.

[0318] In some implementations, method 1100 further includes determining at least one engine operating value by controller 500. As described above, the engine operating value determined or received by controller 500 may be selected from one or more of the following: throttle position, engine speed, engine running time, ambient air temperature, previously delivered coolant, and boost pressure. Depending on the implementation, the previously delivered coolant may include a specific amount of coolant previously delivered to intake flow path 444, the number of times coolant has been previously delivered to intake flow path 444, and / or the time elapsed since the most recent delivery of coolant to intake flow path 444. In some implementations, determining the estimated piston temperature at step 1104 is also based on retrieving the estimated piston temperature from a model according to one or more of these determined engine operating values. In implementations where temperature sensor 455 is located upstream of compressor 310, the estimated piston temperature may be further determined based on the expected temperature increase due to compression in compressor 310.

[0319] In some implementations or iterations, method 1100 may omit step 1102 and begin with step 1104, which determines the estimated piston temperature, based on one or more engine operating values.

[0320] Method 1100 continues to step 1106, in which step 1106, in response to at least one of the fluid temperature sensed at step 1102 being higher than a threshold fluid temperature or the estimated piston temperature determined at step 1104 being higher than a threshold piston temperature, a certain amount of coolant is discharged from coolant container 452 by controller 500.

[0321] The threshold piston temperature and threshold fluid temperature values ​​are predetermined values ​​stored in storage medium 507 and correspond to temperatures above which may affect engine efficiency, including, for example, due to engine knocking. In some implementations, the threshold temperature may depend on one or more engine operating values, such that controller 500 further determines one or both threshold temperatures before determining that the estimated piston temperature and / or fluid temperature is greater than the threshold temperature.

[0322] Specifically, delivering a quantity of coolant at step 1106 includes the controller 500 operating a solenoid valve 466 of the coolant container assembly 450 to allow coolant to flow out of the coolant container 452. In some implementations, delivering a quantity of coolant includes the controller 500 operating a pump of the coolant container assembly 450 to pump coolant from the coolant container 452 through the coolant line 462. In some such implementations, the pump may be further configured to provide pressure in the coolant line 462 to improve the delivery of coolant to the intake flow path 444.

[0323] The amount of coolant delivered to the intake flow path 444 is determined by the timing of when the controller 500 opens the solenoid valve 466. In this implementation, if the estimated piston temperature is higher than a threshold piston temperature, the controller 500 will be triggered to release a standard amount of coolant, regardless of the difference between the estimated piston temperature and the threshold piston temperature. In some implementations, the controller 500 may determine the amount of coolant to be delivered based on the temperature sensed by the sensor 455 and / or the estimated piston temperature.

[0324] Then, method 1100 typically repeats steps 1102 and / or 1104, where step 1102 re-sensing the fluid temperature in the intake air flow path 444 and step 1104 determining a revised estimated piston temperature. Depending on the implementation, method 1100 is typically repeated continuously during snowmobile operation, such that the controller 500 manages the intake air temperature throughout the entire use of the snowmobile. In some cases, method 1100 may be repeated at regular time intervals. In other cases, method 1100 may be triggered by different operating conditions, such as when engine speed or throttle position indicates that the engine 26 is operating under conditions that may increase piston temperature.

[0325] In some implementations, method 1100 may include sensing that coolant has been drained from coolant reservoir 452 and that no coolant is available for delivery to intake flow path 444. In some implementations, method 1100 may also include communicating to the operator of the snowmobile 10 that coolant reservoir 452 is empty. In some implementations, method 1100 may also include reducing engine load (RPMs) or decreasing compressor activity from turbocharger 300 when the fluid temperature and / or estimated piston temperature are greater than a threshold temperature and coolant reservoir 452 is empty.

[0326] It is conceivable that method 1100 may include additional or different steps to perform additional functions and / or perform the steps described above.

[0327] Specific reference Figure 49 A method 1200 for managing the piston temperature of the engine 26 of the snowmobile 10 using the components described above will now be described. Typically, method 1200 includes determining an estimated steady-state piston temperature of the piston 226 based on the throttle valve position and engine speed. The controller 500 retrieves the estimated piston temperature from a piston temperature model based on the throttle valve position and engine speed. Then, in the event of changes in engine operation, the estimated piston temperature is adjusted to utilize the gradient of temperature changes caused by these changes in engine operating parameters to determine the unsteady-state temperature.

[0328] Method 1200 begins at step 1210, whereby the throttle valve position of the throttle valve 39 of the engine 26 is determined via the throttle valve position sensor 588. Method 1200 continues to step 1220, whereby the engine speed (RPM) of the engine 26 is determined via the engine speed sensor 586. As described above, the throttle valve position sensor 588 and the engine speed sensor 586 are communicatively connected to the controller 500, although it is contemplated that different computer implementations may interact with the sensors 588 and 586. For example, in some embodiments, the ECU may collect information from the sensors 588 and 586.

[0329] Method 1200 then proceeds to step 1230, whereby controller 500 determines the estimated piston temperature based at least on throttle position and engine speed. In at least some embodiments, determining the estimated piston temperature based on throttle position and engine speed includes retrieving the estimated piston temperature from a temperature model, also referred to as a temperature dataset. The temperature model, for example... Figure 50 The non-limiting example model 1250 shown provides a steady-state temperature (T) for piston 226 based on engine speed and throttle position. S)1260. It should be noted that the values ​​shown in model 1250 are not intended to be limiting, and the actual value 1260 of model 1250 will depend on the specific implementation of vehicle 10 and / or engine 26.

[0330] In some cases, the temperature model can be a simulation model that predicts piston temperature based on operating conditions. It is also conceivable that the temperature model can be constructed from a dataset of piston temperatures measured under different operating conditions. In some cases, the temperature model can be a combination of the measured temperature and an extrapolated temperature based on that measured temperature.

[0331] In some implementations, method 1200 may then include determining the temperature gradient (dT / dt) based on a calibration equation stored in (or accessible by) controller 500. The calibration equation (not shown) is determined based on calibration tests of engine 26, wherein the steady-state temperature T is... S The piston temperature is compared with the actual measured piston temperature by the piston temperature sensor. The piston temperature sensor is not included in the vehicle 10, but is used in the calibration test for each specific implementation of the engine 26.

[0332] After determining the temperature gradient, the steady-state piston temperature is adjusted, and then the controller 500 applies a duration (t) to the gradient. Then, based on the steady-state temperature T... S The estimated piston temperature (T) is determined by the temperature gradient dT / dt and the repeated elapsed time t that causes the temperature gradient change. For example, at time = 0, the steady-state temperature is determined by the engine parameters as described above. Then, for a duration t = 100 ms, as a non-limiting example, the estimated temperature is adjusted by multiplying the gradient by the duration. In at least some embodiments, the estimated piston temperature (T) is calculated using the following temperature determination relationship:

[0333]

[0334] In at least some implementations, the relationship can be recursive, wherein the temperature T is readjusted by adding a gradient change over another duration to a previously determined temperature T.

[0335] In some embodiments, method 1200 may include determining an operating temperature gradient based on changes in one or more engine operating values. Depending on a specific embodiment of vehicle 10 or the implementation of method 1200, the engine operating values ​​used to correct the estimated piston temperature may include, but are not limited to, one or more of the following: engine ignition timing, fuel pressure, position of exhaust valve 129, position of throttle valve 39, fuel injection timing, fuel injection quantity, and boost pressure from turbocharger 300. In some cases, changes in piston temperature may be included in the adjustment of the determined piston temperature after coolant is injected into intake flow path 444 using the system described above. By changing one or more of these engine operating parameters, more or less heat may be generated in engine 26, thereby changing the temperature of piston 226 of engine 26.

[0336] In some cases, method 200 may include controller 500 detecting changes in one or more engine operating values. In this case, controller 500 may determine a corrected estimated piston temperature based on a previously determined estimated piston temperature and the detected changes in the engine operating values. In some cases, determining the corrected estimated piston temperature is also based on the duration of the changes in one or more engine operating values.

[0337] In some embodiments, method 1200 may further include determining the engine coolant temperature via engine coolant temperature sensor 127 and determining the intake air temperature via ambient air temperature sensor 505. In some such cases, method 1200 may then include determining a corrected piston temperature by controller 500 based at least on a steady-state piston temperature or a corrected estimated piston temperature T, engine coolant temperature, and intake air temperature. In some embodiments, adjusting the determined piston temperature to determine the corrected piston temperature may be based solely on either the engine coolant temperature or the intake air temperature.

[0338] In some non-limiting embodiments, method 1200 may also include determining the difference between the desired piston temperature and the estimated piston temperature by controller 500. In this case, method 1200 may then include modifying one or more engine operating values ​​of engine 26 by controller 500. In some embodiments, the magnitude of the modification to one or more engine operating values ​​may be at least partially based on the difference between the desired piston temperature and the estimated piston temperature.

[0339] For example, if the estimated piston temperature determined using model 1250 with steady-state temperature is higher than a predetermined threshold operating temperature, controller 500 may reduce the engine speed to help reduce the heat generated in engine 26, thereby helping to lower the piston temperature. In some embodiments, method 1200 may include determining a temperature gradient caused by modifying one or more engine operating values, and then determining a modification time for one or more engine operating values ​​based at least on the temperature gradient and the difference between the desired piston temperature and the estimated piston temperature. Controller 500 may then control engine 26 to modify one or more engine operating values ​​for the determined modification time.

[0340] In some non-limiting embodiments, method 1200 further includes: in response to an estimated piston temperature exceeding a threshold temperature, controller 500 directs a quantity of coolant to the intake flow path 444 to help reduce the intake air temperature (without reducing the boost pressure of turbocharger 300 and / or changing engine operating values). Reducing the intake air temperature can help reduce the piston temperature in at least the following situations. The threshold temperature typically corresponds to a temperature above which the engine 26 would have a risk of detonation, but the threshold can be calibrated differently. In some non-limiting embodiments, method 1200 may also include: in response to an estimated piston temperature exceeding a threshold temperature, controller 500 changing one or more engine operating parameters.

[0341] It is conceivable that method 1200 may include additional or different steps to perform additional functions and / or perform the steps described above.

[0342] Modifications and improvements to the above-described implementations of this technology will become apparent to those skilled in the art. The foregoing description is intended to be illustrative rather than restrictive. Therefore, the scope of this technology is intended to be defined only by the scope of the appended claims.

Claims

1. A method for managing piston temperature in a vehicle engine, the method comprising: The throttle position of the engine's throttle valve is determined by a throttle position sensor connected to the controller; The engine speed is determined by an engine speed sensor connected to the controller; The estimated piston temperature is determined by the controller based at least on the throttle position and the engine speed; as well as In response to the estimated piston temperature being higher than a threshold piston temperature, the controller causes a certain amount of coolant to flow from the coolant container to the intake flow path, which is defined by the air entering the vehicle and the engine.

2. The method according to claim 1, further comprising: The controller determines the difference between the desired piston temperature and the estimated piston temperature. as well as The controller modifies at least one engine operating value of the engine, based at least in part on the difference between the desired piston temperature and the estimated piston temperature.

3. The method according to claim 1, further comprising: In response to the controller determining that the estimated piston temperature is higher than the threshold piston temperature, the controller modifies at least one engine operating value of the engine.

4. The method according to claim 2 or 3, wherein, The at least one engine operating value is at least one of the following: The ignition timing of the engine; Fuel pressure; Location of the exhaust valve; Fuel injection timing; Fuel injection quantity; and The boost pressure from the turbocharger of the vehicle.

5. The method according to claim 2, further comprising: Determine the temperature gradient resulting from the modification of the operating values ​​of the at least one engine; The modification time for the at least one engine operating value is determined based at least on the temperature gradient and the difference between the desired piston temperature and the estimated piston temperature; as well as The operating value of the at least one engine is modified based on the modification time.

6. The method according to claim 1, further comprising: The engine coolant temperature is determined by an engine coolant temperature sensor connected to the controller; The intake air temperature is determined by an air temperature sensor connected to the controller; The controller determines the corrected piston temperature based at least on the estimated piston temperature, the engine coolant temperature, and the intake air temperature.

7. The method according to claim 1, further comprising: Determine at least one of the following: Engine coolant temperature, which is determined by an engine coolant temperature sensor connected to the controller; as well as Intake air temperature, which is determined by a temperature sensor connected to the controller; and The controller determines the corrected piston temperature based on the estimated piston temperature and at least one of the following: The engine coolant temperature; and The intake air temperature.

8. The method according to claim 1, further comprising: The controller detects changes in at least one engine operating value of the engine; as well as In response to detecting a change in the at least one engine operating value, a corrected estimated piston temperature is determined based at least on the estimated piston temperature and the change in the at least one engine operating value.

9. The method according to claim 8, wherein, The corrected estimated piston temperature is also determined based on the duration of the change in the at least one engine operating value.

10. The method according to claim 1, wherein, Determining the estimated piston temperature based at least on the throttle position and the engine speed includes retrieving the estimated piston temperature from a temperature dataset.

11. The method according to claim 1, wherein, Determining the estimated piston temperature includes: The steady-state temperature T is determined at least based on the throttle position and the engine speed. S ; The temperature gradient dT / dt is determined based on the calibration equation stored in the controller; and The following temperature-based relationship is determined using the steady-state temperature T. S The estimated piston temperature T is calculated using the temperature gradient dT / dt and the duration t.

12. The method according to claim 11, wherein, The estimated piston temperature is recalculated for the duration t of the repetition.

13. A vehicle comprising: frame; An engine, the engine being supported by the frame and having at least one engine air inlet; A turbocharger, fluidly connected to the engine and including a compressor fluidly connected to at least one engine air inlet, the compressor having a compressor inlet and a compressor outlet. The air intake flow path of the vehicle is defined by air entering the vehicle, entering the compressor through the compressor inlet, leaving the compressor through the compressor outlet, and flowing into the at least one engine air inlet; A coolant container assembly, supported by the frame and including a coolant container for containing coolant, the coolant container assembly being fluidly connected to the intake flow path at at least one connection point; A controller, which is communicatively connected to the coolant container assembly; At least one coolant injection ring, the at least one coolant injection ring being fluidly connected to the at least one engine air inlet; as well as At least one injection nozzle is connected to and extends through the at least one coolant injection collar, and the at least one injection nozzle is fluidly connected to the coolant container assembly. in: At least one of the connection points is defined by the at least one injection nozzle; The controller is communicatively connected to the engine; and The controller is configured such that: The estimated piston temperature is determined at least in part based on at least one engine operating value received from the engine, and Based at least on the estimated piston temperature, a certain amount of coolant is selectively allowed to flow from the coolant container into the intake flow path via the at least one injection nozzle.

14. The vehicle according to claim 13, wherein: The engine includes at least one reed valve and at least one throttle valve; and At least one of the connection points is located on the intake flow path between the at least one reed valve and the at least one throttle valve.

15. A vehicle comprising: frame; An engine, which is supported by the frame and has an engine air inlet; A turbocharger, fluidly connected to the engine and including a compressor fluidly connected to the engine air inlet, the compressor having a compressor inlet and a compressor outlet. The air intake flow path of the vehicle is defined by air entering the vehicle, entering the compressor through the compressor inlet, leaving the compressor through the compressor outlet, and flowing into the engine air inlet. A coolant container assembly, supported by the frame and including a coolant container for containing coolant, the coolant container assembly being fluidly connected to the intake flow path at a connection point; A controller, which is communicatively connected to the coolant container assembly; as well as A temperature sensor, which is communicatively connected to the controller and configured to determine the fluid temperature in the intake flow path; The controller is configured such that: The estimated piston temperature is determined at least based on the fluid temperature determined by the temperature sensor. as well as A certain amount of coolant is selectively allowed to flow from the coolant container into the intake flow path via the connection point, based at least on the fluid temperature determined by the temperature sensor and the estimated piston temperature.

16. The vehicle according to claim 15, wherein: The controller is communicatively connected to the engine; and The controller is also configured to determine the estimated piston temperature based at least in part on at least one engine operating value received from the engine, the at least one engine operating value being selected from the following: previously supplied coolant, ambient air temperature, ambient air pressure, throttle position, engine speed, engine load, engine running time, oxygen concentration in exhaust gas, engine coolant temperature, exhaust valve position, and boost pressure.

17. The vehicle according to claim 15, further comprising: A first conduit, which is fluidly connected to the compressor inlet at a first end, and receives air from the air surrounding the vehicle at a second end; and The connection point is located on the first conduit.

18. The vehicle according to claim 15, further comprising: A second conduit, which is fluidly connected at a first end to the compressor outlet and at a second end to the engine air inlet; and The connection point is located on the second conduit.

19. The vehicle according to claim 15, wherein, The connection point is located in the compressor inlet.

20. The vehicle of claim 15, further comprising a coolant pipe for delivering coolant to the intake flow path, the coolant pipe being fluidly connected between the coolant container and the connection point.

21. The vehicle of claim 20, further comprising a fuel reservoir supported by the frame; and in, The coolant container is located behind the fuel storage tank.

22. The vehicle according to claim 21, wherein, The coolant pipe passes beneath the fuel reservoir.

23. The vehicle according to claim 20, wherein, The coolant container assembly also includes a pump fluidly connected to the coolant container for pumping coolant through the coolant pipe.

24. The vehicle according to claim 20, wherein, The coolant container assembly also includes a valve for controlling the flow rate of the coolant, the valve being disposed between the coolant container and the coolant pipe, and the valve being communicatively connected to the controller.

25. The vehicle according to claim 24, wherein, The valve is a solenoid valve.

26. The vehicle according to claim 24, wherein: The compressor is fluidly connected to the coolant container; and When the vehicle is in use, air flows from the compressor to the coolant container to pressurize the coolant container.

27. The vehicle according to claim 20, wherein, The first end of the coolant pipe is fluidly connected to the coolant container; and The vehicle also includes an injection nozzle connected to the second end of the coolant pipe.

28. The vehicle of claim 15, further comprising at least one sliding member connected to the frame; and in, The vehicle in question is a snowmobile.

29. The vehicle according to claim 15, wherein, The temperature sensor is configured to sense the temperature of the fluid in the intake flow path before it passes through the compressor.

30. The vehicle according to claim 15, wherein, The temperature sensor is configured to sense the temperature of the fluid that has passed through the compressor.

31. The vehicle according to claim 15, wherein, The connection point is located on the crankcase of the engine.

32. A vehicle comprising: frame; An engine, which is supported by the frame and has an engine air inlet; A turbocharger, the turbocharger being fluidly connected to the engine and including a compressor being fluidly connected to an air inlet of the engine, the compressor having a compressor inlet and a compressor outlet; A first conduit, which is fluidly connected to the compressor inlet at a first end, and receives air entering the vehicle at a second end; A second conduit, which is fluidly connected at its first end to the compressor outlet and at its second end to the engine air inlet, is further fluidly connected to the engine air inlet. The intake airflow path is defined by air entering the vehicle, passing through the first duct into the compressor inlet, passing through the compressor, exiting the compressor outlet, passing through the second duct, and entering the engine air inlet; A coolant container assembly, supported by the frame and including a coolant container for containing coolant, the coolant container assembly being fluidly connected to the intake flow path at a connection point; as well as A controller, which is communicatively connected to the coolant container assembly and configured to selectively allow a certain amount of coolant to flow from the coolant container into the intake flow path via the connection point based on an estimated piston temperature determined by the controller.

33. The vehicle according to claim 32, further comprising: The main air box is fluidly connected between the second end of the second duct and the engine air inlet; as well as A secondary air chamber, which is fluidly connected to a second end of the first duct, is configured to introduce ambient air into the vehicle.

34. The vehicle of claim 32, further comprising a fuel reservoir supported by the frame; and in, The coolant container is located behind the fuel storage tank.

35. The vehicle of claim 34, further comprising a coolant pipe for delivering coolant to the intake flow path, the coolant pipe being fluidly connected between the coolant container and the connection point.

36. The vehicle according to claim 35, wherein, The coolant pipe passes beneath the fuel reservoir.

37. The vehicle according to claim 35, wherein, The coolant container assembly also includes a pump fluidly connected to the coolant container for pumping coolant through the coolant pipe.

38. The vehicle according to claim 35, wherein, The coolant container assembly also includes a valve for controlling the flow rate of the coolant, the valve being disposed between the coolant container and the coolant pipe, and the valve being communicatively connected to the controller.

39. The vehicle according to claim 38, wherein, The valve is a solenoid valve.

40. The vehicle according to claim 38, wherein: The compressor is fluidly connected to the coolant container; and When the vehicle is in use, air flows from the compressor to the coolant container to pressurize the coolant container.

41. The vehicle according to claim 35, wherein, The first end of the coolant pipe is fluidly connected to the coolant container; and The vehicle also includes an injection nozzle connected to the second end of the coolant pipe.

42. The vehicle of claim 32, further comprising at least one sliding member connected to the frame; and in, The vehicle in question is a snowmobile.

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