Patent Application
20200347757
The present invention relates to system for operating a valve of an internal combustion engine. In particular, the present invention relates to a pneumatic system for pneumatically operating a valve of an internal combustion engine. In addition, the present invention relates to an internal combustion engine system comprising such a system. The invention also relates to a corresponding method for operating a valve of an internal combustion engine of a vehicle.
The invention is applicable on various types of vehicles, in particularly low, medium and heavy duty vehicles commonly referred to as trucks, but also on buses, construction equipment, working machines e.g. wheel loaders, articulated haulers, dump trucks, excavators and backhoe loaders etc. Although the invention will mainly be described in relation to a truck, the invention is not restricted to this particular, but may also be used in other vehicles such as cars etc.
In the field of vehicle, in particularly low, medium and heavy duty vehicles commonly referred to as trucks, there is a continuous development with regards to fuel consumption and the control and configuration of the internal combustion engine system. In particular, the demands on internal combustion engine systems have been increasing and engines are continuously developed to meet the various demands from the market in terms of fuel consumption etc. Reduction of exhaust gases, increasing engine efficiency, i.e. reduced fuel consumption, and lower noise level from the engines are some of the criteria that becomes relevant aspects when selecting a vehicle engine system. One area of particular relevance for reducing fuel consumption is within the field of controlling the supply of fuel and other fluids such as compressed air and exhaust gases to and from the combustion cylinders.
Increased controllability of the supply of compressed air to and removal of exhaust gases from the combustion cylinders may be achieved by using a freely controllable valve system, such as a cam-less valve system. One example of an internal combustion engine system using a so called cam-less engine system is described in US 2016/237866 A1, which discloses an engine having engine valves that are driven by a closed pneumatic pressure fluid circuit. Furthermore, there is provided a compressor operable driven by the crankshaft of the internal combustion engine, and which is used to pressurize the fluid in the closed pneumatic pressure fluid circuit. WO 2011/162714 A1 discloses another example of an internal combustion engine comprising at least two cylinders, the at least two cylinders comprising a working cylinder and a compressor cylinder connected to a compressed-air tank.
Despite the activity in the field, it would be desirable to further improve the fuel consumption in vehicles. In particular, it would be desirable to further improve the fuel consumption in vehicles comprising internal combustion engines utilizing engine valves operated by a closed fluid circuit.
It is an object of the present invention to provide a system for operating a valve of an internal combustion engine, in which the system at least partly contributes to facilitating fuel consumption by reducing parasitic losses in an internal combustion engine system. This is achieved by a system according to claim 1.
According to a first aspect of the present invention, there is provided a system for operating a valve of an internal combustion engine. The system comprises a primary fluid circuit configured to define a fluid passageway for circulating a compressible fluid medium there through, and being operatively connectable to an actuator of an actuated flow control valve of the internal combustion engine, thereby capable of delivering a valve opening force.
Moreover, the system comprises a secondary fluid circuit configured to define a secondary fluid passageway for transporting a compressed fluid medium, and having an inlet passage connectable to a cylinder for receiving the compressed fluid medium.
Further, the system comprises an auxiliary pressurized system arranged to separate the secondary fluid circuit from the primary fluid circuit. The auxiliary pressurized system is configured to transfer energy from the secondary fluid circuit to the primary fluid circuit. Further, the auxiliary pressurized system comprises a chamber and at least one reciprocating member operable in the chamber. The auxiliary pressurized system is arranged in fluid communication with the secondary fluid circuit and in fluid communication with the primary fluid circuit such that the at least one reciprocating member pressurizes the primary fluid circuit when the compressed fluid medium of the secondary fluid circuit acts on the at least one reciprocating member.
In this manner, the auxiliary pressurized system is configured to transfer energy from the secondary fluid circuit to the primary fluid circuit. In other words, the fluid medium compressed in the cylinder is routed through the inlet passage to the auxiliary pressurized system to act on the reciprocating member, which in turn acts on the compressible fluid medium in the primary fluid circuit, thus raising the pressure in the primary fluid circuit. As such, the auxiliary pressurized system defines an interface between the primary fluid circuit and the secondary fluid circuit. The example embodiments of the invention are particularly useful when the secondary fluid circuit is connected to a cylinder of an internal combustion engine, in which contaminated and dirty compressed air from the engine cylinder is supplied to the auxiliary pressurized system via the secondary fluid circuit, and subsequently used to act on the reciprocating member of the auxiliary pressurized system so as to pressurize the compressible fluid in the primary fluid circuit. To this end, the auxiliary pressurized system is arranged to separate the secondary fluid circuit from the primary fluid circuit so that only energy in the form of pressure is transferred between the two fluid circuits. In this manner, it becomes possible to transfer energy from dirty compressed air in the secondary fluid circuit to the primary fluid circuit in order to operate one or more valves of the internal combustion engine, while ensuring that no dirt is transferred to the primary fluid circuit. Accordingly, only the pressure generated by the auxiliary pressurized system is utilized in the primary fluid circuit. In this context, the transfer of energy from the secondary fluid circuit to the primary fluid circuit is provided in the form of a pressure increase of the compressible fluid medium in the primary fluid circuit, which is subsequently used to deliver the desired opening valve force.
While the example embodiments of the invention can be used both in pneumatically pressurized primary fluid circuits and hydraulic pressurized primary fluid circuits, the following passages mainly refer to a system when the system is a pneumatic system for operating a valve of an internal combustion engine. In this type of pneumatic system, the compressible fluid medium in the primary fluid circuit is a gaseous fluid medium such as air, in particular compressed air. However, the exemplary advantages may likewise be applicable when the system is a hydraulic system. As such, the term “compressible fluid medium”, as used herein, typically refers to a gaseous medium such as air, while also including oil, water or any other liquid fluid medium.
Further, the example embodiments of the invention are particularly useful when the compressed fluid medium is any one of compressed air, burnt gases or a mixture thereof. Thus, the term “compressed fluid medium”, as used herein, typically refers to compressed air, compressed burnt gases or a mixture thereof.
By the example embodiments of the invention, it becomes possible to reduce the parasitic losses occurring when operating the actuator of the actuated flow control valve of the internal combustion engine by utilizing an additional pressurized system, i.e. the auxiliary pressurized system, for further pressurizing the fluid in the primary fluid circuit of the system based at least partly on energy (e.g. compressed air) generated from a braking force of a cylinder in the event of deceleration or braking of the vehicle. The term parasitic loss is often applied to devices that take energy from the engine in order to enhance the engine's ability to create more energy. In a conventional internal combustion engine system, a mechanically driven compressor may for instance cause parasitic loss. In other words, it becomes possible to reduce the parasitic losses occurring when operating e.g. a pneumatic actuator of a pneumatically actuated flow control valve of the internal combustion engine by minimizing the input of needed energy from a mechanically driven compressor to open the control valve by the exchange of energy generated in the auxiliary pressurized system (the sub-system) upon a deceleration or braking event of the vehicle. Thus, the system also contributes to reduce the engagement need of the mechanically driven compressor. As such, the example embodiments of the system provide a system for reducing the parasitic load of the internal combustion engine system.
The present invention is thus based on energy recovery, i.e. utilizing recuperation of energy, as will be further described below. The system is particularly useful in an internal combustion engine system including a so called cam-less system or cam-less engine configuration, which may use e.g. electro-hydraulic-pneumatic, electro-pneumatic, electro-hydraulic, pneumatic or hydraulic actuators arranged in connection to the flow control valve in order to replace a conventional camshaft. A cam-less system allows for optimizing the circulation of gases in the engines, typically both intake gases and exhaust gases. In particular, a cam-less system allows for optimizing the gas exchange process in an engine.
A cam-less system is typically configured to use a closed primary fluid circuit for delivering valve opening force and counter action spring force by pressure control, e.g. to open the valves against the cylinder pressure and a return spring for each valve. This type of operation or “work” is performed by the mechanically driven compressor (a closed loop pump), which is powered by the combustion engine. The work required for driving the compressor will thus add an additional parasitic load to the engine.
It has been realized that the additional parasitic load, as mentioned above, should be minimized as much as possible in order to further improve fuel consumption of an engine, such as cam-less engine configuration. In some prior art system, a magnitude of the parasitic losses can be reduced during the actuation of the control valve, but there is hitherto no system configured to reduce the parasitic losses by utilizing a recuperation of energy. Further, it has been observed that the pressure generated in the event of a deceleration or braking of the vehicle due to the braking force may be well suited for being delivered to a pressurized sub-system (the auxiliary pressurized system) for subsequent use thereof.
In particular, the example embodiments allows for reducing parasitic losses by arranging the auxiliary pressurized system in fluid relationship with the cylinder of the internal combustion engine, and further connecting the auxiliary pressurized system in communication with the primary fluid circuit. In this manner, a sub-pneumatic gas system, i.e. the auxiliary pressurized system, is adapted to pressurize the fluid in the primary fluid circuit, corresponding to a closed loop gas system.
As the auxiliary pressurized system typically operates by receiving compressed air generated from brake recovery recuperation, it becomes possible to reduce parasitic losses in an effective manner. That is, during vehicle deceleration and braking vehicle events a part of the braking force is generated by using one or more of the cylinder intake valves of the cylinder in a compressor mode, or more specifically, by using one or more of the engine cylinders in compression mode. Typically, the cylinder intake valve is opened as in a normal event for an intake stroke, and then, late in the compression stroke, a separate or external valve is opened on the intake side of the engine, which is intended to be operatively connected to the auxiliary pressurized system to deliver the compressed air to the auxiliary pressurized system for effecting an increase in pressure. When this operation is performed in the auxiliary pressurized system, the increased pressure obtained by means of the movement of the reciprocating member is provided via the secondary fluid circuit to the primary fluid circuit so as to reduce the required energy of the primary fluid circuit by reducing the engagement need of the compressor.
To this end, the air compressed in the cylinder is routed through the inlet passage to the auxiliary pressurized system and acts on the reciprocating member, which in turn acts on the air in the primary fluid circuit, thus raising the pressure in the primary system.
An advantage of the example embodiments of the invention is thus that the internal combustion engine system can be operated with less required compressed air work, i.e. it becomes possible to raise the general pressure level in the system so that the compressor can operate in a more efficient manner. Thereby, the system can reduce the parasitic losses of the cam-less system. The fuel consumption of the vehicle will hereby also be reduced as a consequence of a more efficient system.
Further, by having the primary fluid circuit and the secondary fluid circuit separated by the auxiliary pressurized system, it becomes possible to pressurize the primary fluid circuit in a more efficient manner, as mentioned above, while ensuring that no dirt or particles are supplied to the closed and clean primary fluid circuit, which would have been at risk if the relatively more dirty compressed fluid medium from the engine cylinder would have been directly supplied to the primary fluid circuit from the engine cylinder.
It should be noted that when the secondary fluid circuit is connected to the cylinder, the secondary fluid circuit is arranged in fluid communication with the cylinder via the inlet passage of the secondary fluid circuit.
While the auxiliary pressurized system can be arranged to separate the secondary fluid circuit from the primary fluid circuit in several different manners, the movable reciprocating member is typically designed so that no fluid medium can be transferred in-between the reciprocating member and the inner surfaces of the chamber arranged to cooperate with the reciprocating member. Hence, the reciprocating member is movably arranged in the chamber to provide a transfer of energy between the secondary fluid circuit and the primary fluid circuit, while ensuring that no exchange of fluid medium is possible between the secondary fluid circuit and the primary fluid circuit.
By way of example, the secondary fluid circuit is separated from the primary fluid circuit by the reciprocating member and the chamber forming a fluid-tight configuration between the primary fluid circuit and the secondary fluid circuit. In other words, the term “separate”, as used herein in connection to the auxiliary pressurized system, generally refers to an arrangement adapted to prevent a transfer of fluid medium from the secondary fluid circuit to the primary fluid circuit.
According to one example embodiment, the primary fluid circuit comprises a first controllable valve assembly for regulating the flow of the compressible fluid medium in the primary fluid circuit. By way of example, the first controllable valve assembly is arranged to regulate the flow of compressible fluid medium between the primary fluid circuit and the auxiliary pressurized system. That is, the first controllable valve assembly is typically configured to either permit a flow of the compressible fluid medium from the primary fluid circuit to the auxiliary pressurized system or permit a flow of compressed fluid medium from the auxiliary pressurized system to the primary fluid circuit. The first controllable valve assembly can be arranged in the primary fluid circuit at several different locations depending on the design of the primary fluid circuit. By way of example, the first controllable valve assembly is arranged in a low-pressure side of the primary fluid circuit. In this manner, the fluid communication between the auxiliary pressurized system and the low-pressure side of the primary fluid circuit is further improved. Hence, according to one example embodiment, the first controllable valve assembly is arranged to regulate the flow of compressible fluid medium between the low-pressure side of the primary fluid circuit and the auxiliary pressurized system.
Typically, although strictly not required, the primary fluid circuit comprises a return passage to the auxiliary pressurized system for transporting compressible fluid medium to a first part of the chamber arranged in fluid communication with the primary fluid circuit, and wherein the return passage is connected to the first controllable valve assembly. By way of example, the first controllable valve assembly is arranged to regulate the transfer of compressible fluid medium from the return passage to the first part of the chamber of the auxiliary pressurized system. In this manner, the primary fluid circuit is arranged to direct a flow of compressible fluid medium to the auxiliary pressurized system, thereby enabling the auxiliary pressurized system to pressurize the compressible fluid medium from the primary fluid circuit, as described above. The compressed fluid medium (transferred from the primary fluid circuit and compressed in the auxiliary pressurized system) is subsequently transferred from the auxiliary pressurized system to the primary fluid circuit.
The first controllable valve assembly may be any one of a flow control valve, as described further herein, or a combination of a number of check valves, non-return valves or the like. If the controllable valve assembly comprises a number of check valves, each valve is arranged to regulate the flow of compressible fluid medium in a given direction in the primary fluid circuit. These types of valves may for instance be provided as conventional poppet type valves. Other combinations of valves are also conceivable, such as a combination of a flow control valve and a non-return valve. The flow control valve is typically operable by a control unit, as further described herein. Thus, the controllable valve assembly may either be a passive valve assembly or an active valve assembly.
According to an example embodiment, the secondary fluid circuit comprises a first intake valve disposed in the inlet passage and upstream of the auxiliary pressurized system. The first intake valve is configured to prevent discharge of compressed fluid medium from the secondary fluid circuit when the cylinder is not operated as a compressor. Hence, the compressed fluid medium is only permitted to flow from the cylinder to the auxiliary pressurized system.
According to an example embodiment, the auxiliary pressurized system comprises an additional chamber and an additional reciprocating member operable in the additional chamber. The additional reciprocating member is capable of pressurizing the primary fluid circuit when the compressed fluid medium of the secondary fluid circuit acts on the additional reciprocating member, wherein the chamber and the additional chamber are arranged in parallel to each other. By way of example, the chamber and the additional chamber are arranged in parallel to each other so as to pressurize the primary fluid circuit in an alternated manner.
In this manner, it becomes possible to increase the efficiency of the secondary fluid circuit as the pressure to the primary fluid circuit can be provided with fewer interruptions.
According to an example embodiment, the system comprises a second valve disposed downstream of the auxiliary pressurized system, and configured to control the pressure from the auxiliary pressurized system. In addition, if the auxiliary pressurized system includes two reciprocating members, the second valve can be configured to control the pressure from the auxiliary pressurized system and between the chambers.
Typically, although not strictly required, the reciprocating member is any one of a diaphragm membrane or a reciprocating piston member. In other words, either one of the reciprocating member and the additional reciprocating member may be a diaphragm membrane or a reciprocating piston member. When the reciprocating member is a reciprocating piston member, the auxiliary pressurized system is a reciprocating system operated and driven by the compressed fluid medium supplied to the auxiliary pressurized system via the inlet passage.
When the reciprocating member is a diaphragm membrane, the auxiliary pressurized system is a diaphragm membrane system. In a diaphragm membrane system, the compression of gas, such as air occurs by means of a flexible membrane, instead of an intake element. The back and forth moving membrane can be driven by a rod and a crankshaft mechanism. Also, when the reciprocating member is a diaphragm membrane, the auxiliary pressurized system is a diaphragm membrane system operated and driven by the compressed fluid medium supplied to the auxiliary pressurized system via the inlet passage.
According to one example embodiment, the secondary fluid circuit comprises a second controllable valve assembly for regulating the transfer of compressed fluid medium from the secondary fluid circuit to the auxiliary pressurized system. Typically, the second controllable valve assembly is arranged to regulate the transfer of compressed fluid medium from the inlet passage of the secondary fluid circuit to the auxiliary pressurized system. In addition, or alternatively, the second controllable valve assembly is arranged to regulate the transfer of compressed fluid medium from the auxiliary pressurized system to an outlet passage of the secondary fluid circuit. In other words, the second controllable valve assembly is configured to regulate the direction of the flow of the compressed fluid medium between the secondary fluid circuit and the auxiliary pressurized system. In this manner, the second controllable valve assembly is operable to either direct compressed fluid medium from the secondary fluid circuit to the auxiliary pressurized system, enabling the auxiliary pressurized system to pressurize the compressible fluid medium in the primary fluid circuit, or operable to permit a discharge of the compressed fluid medium from the auxiliary pressurized system via the secondary fluid circuit (which will typically occur when new compressible fluid medium is transferred from the primary fluid circuit to the auxiliary pressurized system). That is, the second controllable valve assembly is typically configured to either permit a flow of the compressed fluid medium from the secondary fluid circuit to the auxiliary pressurized system or permit a discharge of compressed fluid medium from the auxiliary pressurized system via the secondary fluid circuit.
According to one example embodiment, the secondary fluid circuit comprises a discharge fluid medium passage in fluid communication with a second part of the chamber of the auxiliary pressurized system. In this example, the second controllable valve assembly is arranged to regulate the flow of compressed fluid medium in the discharge fluid medium passage. In this manner, the second controllable valve assembly is arranged to permit the compressed fluid medium to discharge from the auxiliary pressurized system via the discharge fluid medium passage. Typically, although strictly not required, the discharge fluid medium passage may comprise the second controllable valve assembly arranged to permit the compressed fluid medium to discharge from the auxiliary pressurized system. In this context, the compressed fluid medium refers to the compressed fluid medium contained in the secondary fluid circuit. As mentioned above in relation to the first controllable valve assembly, also the second controllable valve assembly may be any one of a flow control valve or a combination of a number of check valves, non-return valves or the like. These types of valves may for instance be provided as conventional poppet type valves. Other combinations of valves are also conceivable, such as a combination of a flow control valve and a non-return valve. The flow control valve is typically operable by a control unit, as further described herein. Thus, the second controllable valve assembly may either be a passive valve assembly or an active valve assembly.
According to one example embodiment, the secondary fluid circuit further comprises a fluid medium storage device disposed between the inlet passage and the auxiliary pressurized system. Typically, the fluid medium storage device is arranged to accommodate a portion of the compressed fluid medium. By the provision of having a fluid medium storage device, compressed air generated in the cylinder during a braking vehicle event can be transferred to the secondary fluid circuit and stored in the fluid medium storage device for the purposes of pressurizing the compressible fluid medium in the primary fluid circuit at a later stage.
According to one example embodiment, when the secondary fluid circuit comprises the second controllable valve assembly, the second controllable valve assembly may be further arranged to regulate a transfer of compressed fluid medium from the fluid medium storage device to the auxiliary pressurized system. By way of example, the second controllable valve assembly is arranged in-between the fluid medium storage device and the auxiliary pressurized system.
Further, it is to be noted that the second controllable valve assembly may comprise a number of valves, i.e. sub-valves, arranged at different locations in the secondary fluid circuit. According to one example embodiment, the second controllable valve assembly is arranged to both regulate discharge of the compressed fluid medium from the auxiliary pressurized system and arranged to regulate transfer of compressed fluid medium from the fluid medium storage device to the auxiliary pressurized system.
In an example embodiment when the system comprises both the first controllable valve assembly in the primary fluid circuit and the second controllable valve assembly in the secondary fluid circuit, the system may be operable to deliver the opening force to the valve in an even more controlled manner.
According to an example embodiment, the system comprises a control unit configured to operate the auxiliary pressurized system upon a braking vehicle event or a vehicle deceleration event. In addition, or alternatively, the control unit is configured to operate the auxiliary pressurized system during the braking vehicle event or the vehicle deceleration event.
The control unit may also control the internal combustion engine to be operated by means of the auxiliary pressurized system upon the braking vehicle event or the vehicle deceleration event.
The control unit may also be arranged to control the first controllable valve assembly in the primary fluid circuit and the second controllable valve assembly in the secondary fluid circuit.
Typically, the control unit is configured to receive a signal indicative of a braking operation for the vehicle; and control the internal combustion engine system to be operated by means of the auxiliary pressurized system upon the braking vehicle event or the vehicle deceleration event.
As described above, the braking operation typically relates to an engine braking of the vehicle. Hereby, surplus energy from this operation can be used for delivering valve opening force by using the surplus energy and delivering compressed air from one of the engine cylinders to the auxiliary pressurized system in order to effect a movement of the reciprocating member to increase the pressure on the other side of the secondary fluid circuit, i.e. downstream of the reciprocating member, which in turn acts on the air in the primary fluid circuit, thus raising the pressure in the primary fluid circuit, as mentioned above. An advantage is thus that an improved utilization of energy is provided.
According to one example embodiment, when the system comprises the control unit, the fluid medium storage device and the second flow controllable valve assembly, as described above, the control unit may be arranged to operate the system to pressurize the primary fluid circuit in an intermittently manner. That is, the control unit is arranged to control the second controllable valve to supply compressed fluid medium to the auxiliary pressurized system from the fluid medium storage device. By way of example, the control unit is arranged to control the second controllable valve to supply compressed fluid medium to the auxiliary pressurized system from the fluid medium storage device upon receiving a signal indicating that the actuator is required to deliver the valve opening force, as described above.
The control unit may include a microprocessor, microcontroller, programmable digital signal processor or another programmable device. The control unit may also, or instead, include an application specific integrated circuit, a programmable gate array or programmable array logic, a programmable logic device, or a digital signal processor. Where the control unit includes a programmable device such as the microprocessor, microcontroller or programmable digital signal processor mentioned above, the processor may further include computer executable code that controls operation of the programmable device. According to one example embodiment, the control unit is an electronic control unit.
According to one example embodiment, the primary fluid circuit has a low-pressure side and a high-pressure side. In this example, the high-pressure side is operatively connectable to the actuator of the actuated flow control valve of the internal combustion engine. Moreover, in this example, the reciprocating member is capable of pressurizing at least one of the low-pressure side and the high-pressure side of the primary fluid circuit when the compressed fluid medium of the secondary fluid circuit acts on the at least one reciprocating member. Typically, although strictly not required, the low-pressure side and the high-pressure side of the primary fluid circuit are separated by an arrangement of a compressor in the primary fluid circuit.
According to one example embodiment, the system further comprises a compressor arranged in-between a low-pressure side and a high-pressure side of the primary fluid circuit. The compressor is configured to deliver a fluid medium pressure to the high-pressure side of the primary fluid circuit. By way of example, the compressor is a mechanically driven compressor. Alternatively, the compressor is an electrically driven compressor. In addition, or alternatively, the fluid medium pressure to the high-pressure side of the primary fluid circuit compressor can be delivered by an exhaust turbine, or any other type of compressor configuration.
The mechanically driven compressor may typically be operated in a two stroke fashion, but can be operated in several different manners, including e.g. the two stroke fashion, a four stroke fashion, a six stroke fashion etc. The compressor is typically, although not strictly necessary, driven by a crankshaft of the engine system. Typically, although not strictly required, the mechanically driven compressor may comprise a reciprocating member. The reciprocating member can be any one of a diaphragm membrane or a reciprocating piston member. In a compressor when the mechanically driven compressor comprises a reciprocating piston member, the compressor equals a reciprocating compressor. The details and configuration of a reciprocating compressor is a well-known type of compressor.
In another example embodiment, the example embodiments of the system can be activated by a so called cylinder deactivation. That is, the combustion in one of the cylinders of the engine, which is operatively connected to the secondary fluid circuit, is deactivated and instead the corresponding cylinder is operated as a compressor. In an example, when several cylinders are operatively connected to the secondary fluid circuit, the combustion in the corresponding several cylinders can be deactivated and instead operated as compressors. The several cylinders may either operate as compressors simultaneously, or operate as compressors in an alternated manner.
Typically, the actuated flow control valve may be any one of a pneumatic flow control valve, an electro-pneumatic flow control valve, a hydraulic flow control valve, an electro-hydraulic flow control valve, a pneumatic-hydraulic flow control valve, an electro-pneumatic-hydraulic flow control valve or the like.
The actuated flow control valve can be controlled in various manners. Typically, although not strictly necessary, the actuated flow control valve has a corresponding actuator operatively connected to a valve member, wherein the actuator is configured to operate the valve member by means of pneumatic pressure. Hence, in some example embodiments, the actuated flow control valve is a pneumatically actuated flow control valve. As such, each valve member has its own actuator controlling the valve position and timing. However, in other example embodiments, a number of valve members may be controlled by common actuator. The actuator is typically configured to control the opening and closure of the valve at a given point in time. By way of example, the actuator is typically configured to control the opening and closure of the valve at a given point in time by receiving a signal from the control unit or the like.
It is to be noted that the term “pneumatic flow control valve” or “pneumatically actuated flow control valve”, as used herein, typically refers to a pneumatically controlled flow control valve operated by a pneumatic actuator. The pneumatic flow control valve can also be provided in the form an electro-pneumatic flow control valve, an electro-pneumatic-hydraulic flow control valve or the like. Generally, the pneumatic flow control valve is configured to regulate the flow of a fluid medium passing through the valve, such as regulating the flow of compressed air passing through the valve. The pneumatic flow control valve typically comprises the pneumatic actuator, which is configured to operate the valve by means of pneumatic pressure. The operation and configuration of the pneumatically actuated flow control valve can vary depending on type of valve, and there are several different types of valves available for providing the operation described above in connection with the example embodiments of the system.
In another example embodiment, the actuated flow control valve is a hydraulically actuated flow control valve with a hydraulic actuator.
According to one example embodiment, the system is a pneumatic system comprising any one of the example embodiments as mentioned above. Thus, there is provided a pneumatic system for operating a pneumatic valve of an internal combustion engine. The system comprises a primary fluid circuit configured to define a fluid passageway for circulating a compressible fluid medium there through and being operatively connectable to a pneumatic actuator of a pneumatically actuated flow control valve of the internal combustion engine, thereby capable of delivering a valve opening force. Moreover, the system comprises a secondary fluid circuit configured to define a secondary fluid passageway for transporting a compressed fluid medium and in fluid communication with at least one cylinder via an inlet passage to receive the compressed fluid medium from the at least one cylinder. Further, the pneumatic system comprises an auxiliary pressurized system comprising a chamber and at least one reciprocating member operable in the chamber. The auxiliary pressurized system is arranged in fluid communication with the secondary fluid circuit and operatively connected to the primary fluid circuit such that the at least one reciprocating member is capable of pressurizing the primary fluid circuit when the compressed fluid medium of the secondary fluid circuit acts on the at least one reciprocating member.
According to a second aspect, there is provided an internal combustion engine system comprising the system according to any one of the preceding example embodiments of the system according to the first aspect of the invention. Typically, the primary fluid circuit of the system is connected to the actuator of the actuated flow control valve of the internal combustion engine. Moreover, the internal combustion engine system comprises at least one cylinder operatively connected to the inlet passage of the secondary fluid circuit of the system.
Further effects and features of the second aspect are largely analogous to those described above in relation to the first aspect. In detail, features described above in relation to the first aspect can equally well be combined with features of the second aspect.
It should be readily appreciated that the internal combustion engine thus typically comprises at least one flow control valve and a corresponding actuator for the flow control valve. However, the internal combustion engine may typically comprise a number of flow control valves having corresponding actuators.
In one example embodiment, when the system is a pneumatic system comprising any one of the preceding example embodiments of the system according to the first aspect of the invention, there is provided an internal combustion engine system comprising the pneumatic system, and at least one cylinder operatively connected to the inlet passage of the secondary fluid circuit of the system.
Typically, there is provided an internal combustion engine system, wherein the at least one cylinder is a cylinder of the internal combustion engine. In addition, the cylinder is used as an air compressor during a braking vehicle event or a vehicle deceleration event. In other words, in this example embodiment, the compressed fluid medium is transferred from one or more cylinders of the internal combustion engine comprising the one or more flow control valves, as mentioned above.
Alternatively, there is provided an internal combustion engine system, wherein the at least one cylinder is a separate braking compressor cylinder operatively connected to the inlet air passage.
According to a third aspect, there is provided a vehicle comprising a system according to any one of the example embodiments and/or features relating to the first aspect of the invention and/or an internal combustion engine system according to any one of the example embodiments and/or features relating to the second aspect of the invention.
Further effects and features of the third aspect are largely analogous to those described above in relation to the first aspect and/or the second aspect. Features described above in relation to the first aspect and/or the second aspect can equally well also be combined with features of the third aspect.
In one example embodiment, when the system is a pneumatic system comprising any one of the preceding example embodiments of the system according to the first aspect of the invention, there is provided a vehicle comprising the pneumatic system.
According to a fourth aspect, there is provided a provided a method for operating a valve of an internal combustion engine by means of a system according any one of the example embodiments described above. In addition, the method comprises the steps of:
An advantage is thus, as described above, that the system can be operated to supply compressed air to the internal combustion engine in order to reduce the parasitic losses as described above in relation to the first aspect of the invention. Also, the method is suitable for combining with an operation of a pneumatic valve, electro-pneumatic valve, or electro-pneumatic-hydraulic valve in a cam-less engine system. That is, the method is particularly useful for providing a pressure to an actuator of an engine inlet valve or an engine outlet valve (being a pneumatic valve, an electro-pneumatic valve or an electro-pneumatic-hydraulic valve) in a cam-less engine system. The method may also be used for providing a pressure to an actuator of a hydraulic or electro-hydraulic valve.
According to one exemplary embodiment, the fluid communication between the auxiliary pressurized system and the primary fluid circuit is at least partly provided by means of an outlet passage.
Further effects and features of the fourth aspect are largely analogous to those described above in relation to any one of the first aspect, second aspect and third aspect. As for the other aspects, features described above in relation to the other aspects can equally well be combined with features of the fourth aspect.
By way of example, the step of pressurizing the primary fluid circuit via the outlet passage comprises the step of pressurizing at least one of a low-pressure side and a high-pressure side of the primary fluid circuit via the outlet passage.
According to a fifth aspect, there is provided a computer program comprising program code means for performing the steps of the fourth aspect when the program is run on a computer.
According to a sixth aspect, there is provided a computer readable medium carrying a computer program comprising program means for performing the steps of the fourth aspect when the program means is run on a computer.
Effects and features of the fifth and sixth aspects are largely analogous to those described above in relation to the first aspect.
It is to be noted that although the example embodiments of the present invention sometimes refer to a method for operating a valve of an internal combustion engine, the method is typically intended for operating a plurality of valves of an internal combustion engine. Thus, in the context of the example embodiments of the present invention, it is to be noted that singular words such as “a” and “an” generally mean “one or more”.
Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following description. The skilled person realize that different features of the present invention may be combined to create embodiments other than those described in the following, without departing from the scope of the present invention.
The above, as well as additional objects, features and advantages of the present invention, will be better understood through the following illustrative and non-limiting detailed description of exemplary embodiments of the present invention, wherein:
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness. Like reference character refer to like elements throughout the description.
With particular reference to
The pneumatic system 100 is adapted to be operated according to a method of an example embodiment of the present invention, as described in more detail with respect to
With reference to
The combustion cylinder 94 is typically operated in a four stroke fashion. However, the combustion cylinder 94 may be operated in several different manners, e.g. a two stroke fashion, four stroke fashion, six stroke fashion etc.
It should be appreciated that although the example embodiment depicted in the
Also, each one of the combustion cylinder 94 typically comprises a fuel injection system (not shown) for providing fuel into the combustion cylinder 94 for combustion therein.
In connection with the combustion cylinders, there is disposed a primary fluid circuit 60 configured to define a fluid passageway for circulating compressed air there through. It may be noted that the compressible fluid medium in the primary fluid circuit is herein generally denoted with reference 60d, as indicated in e.g.
In this example, the primary fluid circuit is operatively connected to one or more actuator(s) 92 of corresponding one or more inlet actuated flow control valve(s) 90 of the internal combustion engine, thereby capable of delivering a valve opening force to the one or more inlet valves 90. In this example, the primary fluid circuit is also operatively connected to one or more actuator(s) 92 of corresponding one or more outlet actuated flow control valve(s) 95 of the internal combustion engine, thereby capable of delivering a valve opening force to the one or more outlet valves 95.
If the primary fluid circuit is operatively connected to one or more actuator(s) 92 of corresponding one or more inlet actuated flow control valve(s) 90 and to one or more actuator(s) 92 of corresponding one or more outlet actuated flow control valve(s) 95, the compressed fluid medium is typically directed to the various inlet valves 90 and the outlet valves 95 by one or more valves.
As illustrated in
In this example embodiment, the compressible fluid medium is compressed air. The compressed air may have different types of characteristics, i.e. temperature and pressure, depending on the type of system, engine and vehicle. Also, the temperature of the compressed air typically varies in relation to prevailing driving conditions of the vehicle. By way of example, the compressed air has an ambient temperature. It is to be noted that the primary fluid circuit typically includes the compressed air itself. Hence, the compressed air in this example is contained in the primary fluid circuit 60, i.e. the fluid passageway contains the compressed air. Accordingly, in the primary fluid circuit 60 there is a portion of compressed air being transportable, typically with the aid of the compressor 70.
It should be readily appreciated that the flow of compressed air is in a direction from the compressor 70 to the flow control valve(s) 90, 95 and then in a direction from the flow control valve(s) 90, 95 to the compressor 70, as indicated by the arrows in e.g.
The primary fluid circuit 60 can be designed in several different ways depending on type of engine and type of vehicle etc. In the example described in relation to
In addition, the return fluid passage 66 connects the fluid intermediate passage(s) 63 with the compressor 70. As described in more detail below in relation to
Accordingly, the primary fluid circuit is a closed loop circuit. It is to be noted that the components above, i.e. the fluid inlet passage 65, the fluid compartment 62, the number of fluid intermediate passages 63, the inter-connecting fluid passage 64 and the return fluid passage 66 provides one example of a primary fluid circuit having a fluid passageway for circulating compressed air there through, and which is operatively connectable to the pneumatic actuator of the pneumatically actuated flow control valve.
As mentioned above, the primary fluid circuit 60 is operatively connected to the pneumatic actuator 92 of the pneumatically actuated flow control valves 90, 95 of the internal combustion engine. In the example embodiment illustrated in
As illustrated in
In the example embodiment described in relation to
Moreover, the pneumatic system 100 comprises a secondary fluid circuit 80 configured to define a secondary fluid passageway for transporting a compressed fluid medium. The compressed fluid medium in the secondary fluid circuit is generally denoted with reference 80d, as indicated in
As mentioned above, the auxiliary pressurized system 81 is operatively connected to the primary fluid circuit, typically via an outlet passage 89. In the system depicted in
The auxiliary pressurized system 81 comprises a chamber 83 and at least one reciprocating member 82 operable in the chamber 83. Further, the auxiliary pressurized system is arranged in fluid communication with the secondary fluid circuit 80 and operatively connected to the primary fluid circuit such that the at least one reciprocating member 82 is capable of pressurizing the primary fluid circuit when the compressed fluid medium of the secondary fluid circuit acts on the at least one reciprocating member 82. By way of example, the reciprocating member 82 is capable of pressurizing at least one of the low-pressure side 60b and the high-pressure side 60a of the primary fluid circuit, as further described below.
As depicted in e.g.
As such, the increased pressure obtained by means of the movement of the reciprocating member in the chamber is provided via the secondary fluid circuit to the primary fluid circuit. In this manner, it becomes possible to reduce the required energy of the primary fluid circuit by reducing the engagement need of the compressor.
The auxiliary pressurized system 81 receives compressed air from the secondary fluid circuit 80, which is in fluid communication with at least one cylinder 94 via the inlet passage 87 to receive compressed air from the at least one cylinder. In this example embodiment, and as schematically illustrated in
The inlet passage 87 is thus in fluid communication with the cylinder 94. In addition the inlet 87 defines a passage for transporting compressed air from the cylinder 94 to the auxiliary pressurized system 81. That is, the inlet passage 87 defines a passage for transporting compressed air from the cylinder 94 to the auxiliary pressurized system 81 when the corresponding outlet valve 95 is open. In this manner, compressed air generated from the braking force during a braking event or deceleration event is permitted to be transported to the secondary fluid circuit 80. It is also to be noted that the inlet passage 87 can be operatively connected to a separate valve (not shown) of the cylinder 94. Hence, the inlet passage 87 may likewise define a passage for transporting compressed air from the cylinder 94 to the auxiliary pressurized system 81 when a cylinder valve operatively connected to the inlet passage is open.
As will be readily appreciated from the above configuration of the secondary fluid circuit, the secondary fluid circuit 80 also defines a fluid passage for transporting the compressed medium, i.e. compressed air or compressed gas, between the inlet passage 87 and the auxiliary pressurized system 81. The inlet passage 87 should thus be a fluid passage configured to transport a high pressure fluid medium.
Referring again to the auxiliary pressurized system 81 and
As such, compressed air generated in the cylinder 94 during engine braking can be delivered to the auxiliary pressurized system 81, such that the compressed air causes the reciprocating member 82 to move in the chamber 83 until the pressure is sufficiently increased to support the primary fluid circuit in delivering the valve opening force to the pneumatic actuator of the pneumatically actuated flow control valve 90, 95. Hereby, during engine braking, high pressure air is provided to the primary fluid circuit 60 via the auxiliary pressurized system 81 and the secondary fluid circuit 80.
In other words, by delivering compressed air from one of the engine cylinders 94 to the auxiliary pressurized system 81, it becomes possible to effect a movement of the reciprocating member so as to pressurize the air in the primary fluid circuit, thus raising the pressure in the primary fluid circuit. To this end, the energy obtained by means of the auxiliary pressurized system is transmitted from the secondary fluid circuit to the primary fluid circuit. An advantage is thus that an improved utilization of energy is provided.
The reciprocating member 82 of the auxiliary pressurized system 81 can be provided in several different designs and configurations. In the example described in relation to
Optionally, the secondary fluid circuit 80 comprises an air cooler 50 configured to lower the temperature of the compressed air received from the cylinder 94 prior to entering the auxiliary pressurized system 81. A system including the air cooler is described in relation to the
Moreover, the secondary fluid circuit is typically connected to an air inlet 78 for receiving external fresh air. The air inlet 78 is typically operatively connected to the secondary fluid circuit 80 at a position between the cylinder 94 and the auxiliary pressurized system 81. If the system 100 includes the air cooler 50, the air inlet 78 is typically operatively connected to the secondary fluid circuit 80 at a position between the cylinder 94 and the air cooler 50.
The cylinder being operatively connected to the secondary fluid circuit, as mentioned above, may not necessarily be one of the cylinders of the internal combustion engine. Rather, in another configuration example (not shown), the at least one cylinder is a separate braking compressor cylinder operatively connected to the air inlet 78. For example, the cylinder can be the vehicle compressor utilized for the braking system.
Typically, although not strictly required, the system comprises a control unit 96, illustrated in
Regarding the pneumatic actuator 92 and the pneumatically actuated flow control valves 90, 95 of the engine or the engine system, it should be noted that these components can be provided in several different configurations depending on installation and type of engine or engine system. Typically, the flow control valves 90, 95 are adapted to regulate the flow of the fluid medium passing through the flow control valve. The fluid medium may be air, compressed air, burnt gases, exhaust gases etc. depending whether the flow control valve is an inlet flow control valve or an outlet flow control valve. As mentioned above, the flow control valve 90, 95 comprises the actuator 92, which is typically operatively connected to a valve member of the flow control valve. The valve member can be 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
Accordingly,
As mentioned above, the primary fluid circuit may have one or more valves, or a valve assembly, in order to regulate the transfer of the compressible fluid medium in the primary fluid circuit. By way of example, the primary fluid circuit may comprise a first controllable valve assembly arranged in the low-pressure side 60b of the primary fluid circuit and configured to regulate the flow of compressible fluid medium between the low-pressure side 60b and the auxiliary pressurized system 81. By means of arrangement of the first controllable valve assembly, the direction of the flow of the compressible fluid medium in the primary fluid direction can be controlled between a first state, in which compressible fluid medium is transferred from the primary fluid circuit to the auxiliary pressurized system and a second state, in which compressed fluid medium is transferred from the auxiliary pressurized system to the primary fluid circuit. It should be noted that the transfer of compressible fluid medium from the primary fluid circuit to the auxiliary pressurized system and the transfer of compressed fluid medium from the auxiliary pressurized system to the primary fluid circuit can occur intermittently in one and the same passage of the primary fluid circuit or in two separate passages. One example of the transferring fluid medium in two separate passages between the primary fluid circuit and the auxiliary pressurized system is further described below in relation to
Analogously, the secondary fluid circuit may have a corresponding valve, or valve assembly, for regulating the transfer of the compressed fluid medium in the secondary fluid circuit. The arrangement of the valves, or valve assemblies, in the primary fluid circuit and the secondary fluid circuit are now further described in relation to the example embodiment illustrated in
In the example embodiment in
Also, as illustrated in
Turning now to the auxiliary pressurized system 81, while still referring to
Further, as illustrated in e.g.
Turning now to the secondary fluid circuit 81, it is also possible to arrange a valve assembly for regulating the flow of the compressed fluid medium 80d. As illustrated in FIG. 2c, the secondary fluid circuit here 80 comprises a second controllable valve assembly 44 arranged to regulate the transfer of compressed fluid medium 80d in-between the auxiliary pressurized system 81 and the secondary fluid circuit 80. As depicted in
Besides this differences, any one of the other features, configurations, components, effects, functions and/or advantages of the example embodiment of the system 100 described in relation to
Thus, in another example embodiment, although not illustrated, there is provided a pneumatic system 100, in which the auxiliary pressurized system 81 is operatively connected to the primary fluid circuit 60 and the compressor 70 via the outlet passage 89. In this configuration of the system, the auxiliary pressurized system is configured to pressurize the primary fluid circuit and the compressor via the outlet passage 89. Also, this example may incorporate any one of the other features, configurations, components, effects, functions and/or advantages of the example embodiment of the system 100 described in relation to
The additional reciprocating member 82b is capable of pressurizing the primary fluid circuit when the compressed air acts on the additional reciprocating member 82b. Accordingly, the additional reciprocating member 82b should be capable of pressurizing at least one of the low-pressure side 60b and the high-pressure side 60a of the primary fluid circuit when the compressed air acts on the additional reciprocating member 82b.
As depicted in
Further, the system 100 comprises a second valve 88 disposed downstream of the auxiliary pressurized system 81 and configured to control the pressure from the auxiliary pressurized system 81 and optionally between the chambers 83, 83b. The second valve 88 is in this example disposed in the outlet passage 89.
It is to be noted that the example embodiment described in relation to
By providing the auxiliary pressurized system with the additional reciprocating member 82b being operable in the additional chamber 83b, it becomes possible to increase the efficiency of the auxiliary pressurized system as the pressure can be provided with less interruption.
In addition, in the example embodiment in
Optionally, although strictly not required, the secondary fluid circuit 80 in the example embodiment in
In the example when the secondary fluid circuit is connected to the air inlet 78 for receiving external fresh air, the inlet passage may comprise an air inlet valve 79 configured to prevent discharge of compressed air through the air inlet 78, which is illustrated in
Besides this differences, any one of the other features, configurations, components, effects, functions and/or advantages of the example embodiment of the system 100 described in relation to
The difference between the embodiment depicted in
Moreover, the example embodiment in
In addition, the example embodiment in
Further, as depicted in
As illustrated in
Analogously, as depicted in
In a similar vein, the second valve 88 disposed downstream of the auxiliary pressurized system 81, i.e. in the primary fluid circuit, as described e.g. in relation to
Optionally, the high-pressure side 60a of the primary fluid circuit comprises a sub-valve 34b arranged upstream of the fluid compartment 62. The sub-valve 34b is here a part of the first controllable valve assembly 34. Hence, the first controllable valve assembly 34 here comprises a valve assembly with a sub-valve 34a and the sub-valve 34b. The sub-valve 34b is arranged to permit a regulation of the transfer of compressed fluid medium 60d between the fluid compartment 62 and the compressor 70. In this manner, it becomes possible to pre-fill the fluid compartment 62 and the compressor 70 with compressed fluid medium 60d. The sub-valve 34a has the same function as the valve assembly 34 described above in relation to
It may also be noted that the embodiment depicted in 5 is provided without the optional air cooler 50. However, the air cooler may likewise also be arranged in the embodiment described in relation to
Besides the above differences between the embodiment in
Also, it should be noted that any one of the features, configurations, components, effects, functions and/or advantages described in relation to the example embodiment in
Reference is now made to
The steps of the method described above are typically executed by a computer program comprising program code means for performing the method when the program is run on a computer. In addition, there is provided a computer readable medium carrying a computer program comprising program means for performing the steps of method as described above in relation to
The method described above in relation to
As mentioned above, there is thus also provided the internal combustion engine system 10 comprising the pneumatic system 100 according to any one of the example embodiments above, and which are described in relation to
Also, the example embodiments of the invention includes the vehicle 1 having a pneumatic system 100 according to any one of the example embodiments above, and which are described in relation to
It is to be understood that the present invention is not limited to the embodiments 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 appended claims. As an example, although the above example embodiments of the invention have been described in relation to one type of internal combustion engine system, it should be readily understood that other compression-combustion arrangements are conceivable. For example, two compression cylinders and another number of combustion cylinders may also equally as well be used. Furthermore, although the above example embodiments of the invention have been described in relation to pneumatic system for pressurizing compressed air in the primary fluid circuit, it should be readily understood that the primary fluid circuit also can be a hydraulic primary fluid circuit containing a liquid fluid such as oil. Thus the invention also relates to system for pressurizing a fluid medium such as a liquid in the primary fluid circuit.
| Number | Date | Country | Kind |
|---|---|---|---|
| PCT/EP2018/051180 | Jan 2018 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2019/051206 | 1/18/2019 | WO | 00 |
