Patent Application
20240141840
The inventive concept relates generally to exhaust valve arrangements for internal combustion engines. In particular aspects, the inventive concept relates to a method of controlling an exhaust valve arrangement of an internal combustion engine. The inventive concept can be applied in heavy-duty vehicles, such as trucks, buses, and construction equipment. Although the inventive concept may be described with respect to a particular vehicle, the inventive concept is not restricted to any particular vehicle.
The speed of heavy-duty vehicles can be controlled by service brakes as well as by operating an internal combustion engine to assume a compression release brake operation. During the compression release brake operation, the exhaust valves are opened at the top of the compression stroke. Hereby, the energy contained in the compressed air is released into the atmosphere instead of being returned to the crankshaft. The compressed air is thus released before the piston begins its downward travel.
However, the cylinder of the engine is exposed to various pressure levels during operation and compression release brake may not be as efficient as desirable during high cylinder pressures. It is therefore a desire to improve the compression release brake to be efficiently operable at a wider pressure range within the cylinder.
According to a first aspect of the inventive concept, there is provided a method of controlling an exhaust valve arrangement of an internal combustion engine, the exhaust valve arrangement is operable to direct combusted exhaust gas out from a combustion chamber of the internal combustion engine, wherein the exhaust valve arrangement comprises a first exhaust valve and a second exhaust valve, the method comprising determining a pressure level in the combustion chamber during compression release braking, comparing the pressure level with a predetermined threshold pressure; and controlling the exhaust valve arrangement to control either a single one, or both, of the first and second exhaust valves to be arranged in an open position during compression release braking in response to the pressure level being below or above the predetermined threshold pressure.
The first aspect of the inventive concept may seek to solve the problem of handling compression release braking operation at different pressure levels in the combustion chamber. The present inventive concept is based on the insight that compression release braking can be handled by releasing different levels of compressed air to the atmosphere based on the pressure level in the combustion chamber. A technical benefit may thus include that a more versatile compression release braking can be achieved, which is operable for high—as well as low pressure levels in the combustion chamber.
In some examples, the exhaust valve arrangement may be configured to control the first exhaust valve to be arranged in the open position and to arrange the second exhaust valve in a closed position when the pressure level in the combustion chamber is above the predetermined threshold pressure. A single exhaust valve may hereby be opened during compression release braking when the pressure level is relatively high. A technical benefit may include that the compression release braking operation is more responsive.
In some examples, the exhaust valve arrangement may be configured to control the first and second exhaust valves in the open position when the pressure level in the combustion chamber is below the predetermined threshold pressure. When the pressure level is lower, both exhaust valves may be arranged in the open position to increase the compression release and thus in turn increase the braking action of the vehicle. A technical benefit may include that the compression release braking operation can be run more efficiently at a longer duration.
In some examples, each of the first and second exhaust valves may be controllable to be arranged in the open position and the closed position independently of a crank angle degree a reciprocating piston arranged in a combustion cylinder of the internal combustion engine. A technical benefit may include that each of the exhaust valves may be controlled solely based on the pressure level in the combustion chamber to rapidly change from controlling a single exhaust valve to be open, to opening both exhaust valves when the pressure level falls below the predetermined threshold pressure.
In some examples, the exhaust valve arrangement may comprise a first actuator operable to arrange the first exhaust valve in the open position when exposed to a flow of pressurized fluid. Thus, compared to a conventional exhaust valve operably connected to a cam shaft following the rotational motion of crankshaft, the first exhaust valve may here be operable by flow of pressurized fluid, independently of the rotational motion of the crankshaft. A technical benefit may include that the pressurized fluid can be rapidly fed to the first actuator to open the first exhaust valve when desirable. Thus, and in some examples, the method may further comprise controlling a first valve of the first actuator to force the first exhaust valve to be arranged in the open position when the pressure in the combustion chamber is above the predetermined threshold pressure.
In some examples, the exhaust valve arrangement may comprise a second actuator operable to arrange the second exhaust valve in the open position when exposed to a flow of pressurized fluid. In a similar vein as described above, also the second exhaust valve may here be operable by flow of pressurized fluid, independently of the rotational motion of the crankshaft. A technical benefit may include that the pressurized fluid can be rapidly fed to the second actuator to open the second exhaust valve when desirable. Thus, and in some examples, the method may further comprise controlling a second valve of the second actuator to force the second exhaust valve to be arranged in the open position when the pressure in the combustion chamber is below the predetermined threshold pressure.
In some examples, each of the first and second exhaust valve may be a pneumatically operable valve. A technical benefit may include that pneumatics may be rapid in its control of the valves.
In some examples, the internal combustion engine may further comprise at least one intake valve controllable to direct air into the combustion chamber during an intake stroke. In some examples, the at least one intake valve may be controllable to be arranged in an open position and a closed position independently of a position of a reciprocating piston arranged in a combustion cylinder of the internal combustion engine. The at least one intake valve may preferably be operable by an intake actuator operable by a flow of pressurized fluid. Hence, when feeding pressurized fluid to the intake actuator, the at least one intake valve is opened. In a similar vein as for the first and second actuators, the intake actuator may be a pneumatically controlled actuator.
According to a second aspect of the inventive concept, there is provided an exhaust valve arrangement operable to direct combusted exhaust gas out from a combustion chamber of an internal combustion engine, the exhaust valve arrangement comprising a first exhaust valve, a second exhaust valve, and processor device operable to control the first and second exhaust valves to assume an open and closed position, respectively, the processor device being configured to determine a pressure level in the combustion chamber during compression release braking, compare the pressure level with a predetermined threshold pressure; and control the exhaust valve arrangement to arrange either a single one, or both, of the first and second exhaust valves in an open position during compression release braking in response to the pressure level being below or above the predetermined threshold pressure.
Effects and features of the second aspect are largely analogous to those described above in relation to the effects and features of the first aspect.
According to a third aspect of the inventive concept, there is provided a vehicle comprising an internal combustion engine, the internal combustion engine comprising an exhaust valve arrangement according to the above described second aspect.
According to a fourth aspect of the inventive concept, there is provided a computer program product comprising program code for performing, when executed by the processor device, the method of any of the examples described above in relation to the first aspect.
According to a fifth aspect of the inventive concept, there is provided a control system comprising one or more control units configured to perform the method according to any of the examples described above in relation to the first aspect.
According to a sixth aspect of the inventive concept, there is provided a non-transitory computer-readable storage medium comprising instructions, which when executed by the processor device, cause the processor device to perform the method of any of the examples described above in relation to the first aspect.
Effects and features of the third, fourth, fifth and sixth aspects are largely analogous to those described above in relation to the effects and features of the first aspect.
The above aspects, accompanying claims, and/or examples disclosed herein above and later below may be suitably combined with each other as would be apparent to anyone of ordinary skill in the art.
Additional features and advantages are disclosed in the following description, claims, and drawings, and in part will be readily apparent therefrom to those skilled in the art or recognized by practicing the disclosure as described herein. There are also disclosed herein control units, computer readable media, and computer program products associated with the above discussed technical benefits.
With reference to the appended drawings, below follows a more detailed description of aspects of the inventive concept cited as examples.
Aspects set forth below represent the necessary information to enable those skilled in the art to practice the inventive concept.
The inventive concept described in the following with reference to the drawings may seek to solve the problem of handling compression release braking operation at different pressure levels in the combustion chamber. An overall technical advantage of the below disclosure may thus be that a more versatile compression release braking can be achieved, which is operable for high—as well as low pressure levels in the combustion chamber.
With reference to
Reference is now made to
The intake valve arrangement 212 comprises at least one intake valve 214. In the example of
The exhaust valve arrangement 210 comprises a first exhaust valve 220 and a second exhaust valve 222. The exhaust valve arrangement 210 is operable to direct combusted exhaust gas out from the combustion chamber 218 during an exhaust stroke when the piston moves from the BDC towards the TDC.
The internal combustion engine 101 depicted in
The present inventive concept is however based on the realization that compression release braking can be handled in a different manner based on the pressure level in the combustion chamber to enable for a more versatile compression release braking. Reference is therefore made to
In the example depicted in
On the other hand, when the pressure level in the combustion chamber reduces and falls below the predetermined threshold pressure during the compression release brake operation, the exhaust valve arrangement controls both the first 220 and second 222 exhaust valves to be arranged in the open position. At this lower pressure level the compressed air in the combustion chamber 218 is released through both of the exhaust ports of at least one of the internal combustion engine's cylinder.
Hence, based on the above, and with reference to
Based on the above, each of the first 220 and second 222 exhaust valves is controllable to be arranged in the open position and the closed position independently of a crank angle degree the reciprocating piston 204. An example of such independently controllable exhaust valve will now be given below with reference to
In
In detail,
The first exhaust valve 220 thus comprises the flow controllable actuator 520 operatively connected to a valve member 92. The valve member is here a lift type valve member. By way of example, the lift type member can be a conventional poppet valve or the like, as shown in e.g.
The flow controllable valve may also have a hydraulic circuit comprising a hydraulic valve 84 and a chamber 82. Hydraulic fluid is provided to a chamber 83 in connection with the actuator piston 95. Hereby, when the piston moves to the second position, the hydraulic fluid in the chamber 83 dampen the motion of the actuator piston 95. The hydraulic fluid may also keep the valve stationary at a given position.
Accordingly, and with reference to the description of
Reference is now made to
The computer system 600 may comprise at least one computing device or electronic device capable of including firmware, hardware, and/or executing software instructions to implement the functionality described herein. The computer system 600 may include a processor device 602 (may also be referred to as a control unit), a memory 604, and a system bus 606. The computer system 600 may include at least one computing device having the processor device 602. The system bus 606 provides an interface for system components including, but not limited to, the memory 604 and the processor device 602. The processor device 602 may include any number of hardware components for conducting data or signal processing or for executing computer code stored in memory 604. The processor device 602 (e.g., control unit) may, for example, include a general-purpose processor, an application specific processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a circuit containing processing components, a group of distributed processing components, a group of distributed computers configured for processing, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processor device may further include computer executable code that controls operation of the programmable device.
The system bus 606 may be any of several types of bus structures that may further interconnect to a memory bus (with or without a memory controller), a peripheral bus, and/or a local bus using any of a variety of bus architectures. The memory 604 may be one or more devices for storing data and/or computer code for completing or facilitating methods described herein. The memory 604 may include database components, object code components, script components, or other types of information structure for supporting the various activities herein. Any distributed or local memory device may be utilized with the systems and methods of this description. The memory 604 may be communicably connected to the processor device 602 (e.g., via a circuit or any other wired, wireless, or network connection) and may include computer code for executing one or more processes described herein. The memory 604 may include non-volatile memory 608 (e.g., read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc.), and volatile memory 610 (e.g., random-access memory (RAM)), or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a computer or other machine with a processor device 602. A basic input/output system (BIOS) 612 may be stored in the non-volatile memory 608 and can include the basic routines that help to transfer information between elements within the computer system 600.
The computer system 600 may further include or be coupled to a non-transitory computer-readable storage medium such as the storage device 614, which may comprise, for example, an internal or external hard disk drive (HDD) (e.g., enhanced integrated drive electronics (EIDE) or serial advanced technology attachment (SATA)), HDD (e.g., EIDE or SATA) for storage, flash memory, or the like. The storage device 614 and other drives associated with computer-readable media and computer-usable media may provide non-volatile storage of data, data structures, computer-executable instructions, and the like.
A number of modules can be implemented as software and/or hard-coded in circuitry to implement the functionality described herein in whole or in part. The modules may be stored in the storage device 614 and/or in the volatile memory 610, which may include an operating system 616 and/or one or more program modules 618. All or a portion of the examples disclosed herein may be implemented as a computer program product 620 stored on a transitory or non-transitory computer-usable or computer-readable storage medium (e.g., single medium or multiple media), such as the storage device 614, which includes complex programming instructions (e.g., complex computer-readable program code) to cause the processor device 602 to carry out the steps described herein. Thus, the computer-readable program code can comprise software instructions for implementing the functionality of the examples described herein when executed by the processor device 602. The processor device 602 may serve as a controller or control system for the computer system 600 that is to implement the functionality described herein.
The computer system 600 also may include an input device interface 622 (e.g., input device interface and/or output device interface). The input device interface 622 may be configured to receive input and selections to be communicated to the computer system 600 when executing instructions, such as from a keyboard, mouse, touch-sensitive surface, etc. Such input devices may be connected to the processor device 602 through the input device interface 622 coupled to the system bus 606 but can be connected through other interfaces such as a parallel port, an Institute of Electrical and Electronic Engineers (IEEE) 1394 serial port, a Universal Serial Bus (USB) port, an IR interface, and the like. The computer system 600 may include an output device interface 624 configured to forward output, such as to a display, a video display unit (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)). The computer system 600 may also include a communications interface 626 suitable for communicating with a network as appropriate or desired.
The operational steps described in any of the exemplary aspects herein are described to provide examples and discussion. The steps may be performed by hardware components, may be embodied in machine-executable instructions to cause a processor to perform the steps, or may be performed by a combination of hardware and software. Although a specific order of method steps may be shown or described, the order of the steps may differ. In addition, two or more steps may be performed concurrently or with partial concurrence.
The terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including” when used herein specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It will be understood that, although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the scope of the present inventive concept.
Relative terms such as “below” or “above” or “upper” or “lower” or “horizontal” or “vertical” may be used herein to describe a relationship of one element to another element as illustrated in the Figures. It will be understood that these terms and those discussed above are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element, or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this inventive concept belongs. It will be further understood that terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
It is to be understood that the present inventive concept is not limited to the aspects described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the present inventive concept and appended claims. In the drawings and specification, there have been disclosed aspects for purposes of illustration only and not for purposes of limitation, the scope of the inventive concepts being set forth in the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 22204844.9 | Nov 2022 | EP | regional |
