Abstract
A valve arrangement for a cylinder of an internal combustion engine arrangement includes a check valve configured to be positioned at an intake side port of the cylinder for controlling gas flow into the cylinder, wherein the valve arrangement further includes an intake valve arrangement positioned upstream from the check valve, and an actuating arrangement configured to controllably position the intake valve arrangement for closing the intake side port.
Claims
1. A valve arrangement for a cylinder of an internal combustion engine arrangement, valve arrangement comprising a check valve configured to be positioned at an intake side pert of cylinder for controlling gas flow into the cylinder, an intake valve means positioned upstream from check valve, and a pulse controlled actuating means configured to controllably position the intake valve means for closing intake side port.
2. The valve arrangement according to claim 1, wherein the check valve is a reed valve.
3. The valve arrangement according to claim 1, further comprising retracting means configured to position the intake valve means for opening said intake side port when a pressure in the cylinder is above a predetermined pressure threshold limit.
4. The valve arrangement according to claim 1, wherein the intake valve means is a slide valve, wherein the actuating means is configured to sliding position the slide valve for closing intake side port.
5. The valve arrangement according to claim 1, wherein the intake valve means is a valve plate, wherein the actuating means is configured to tiltably position the valve plate for closing intake side port.
6. The valve arrangement according to claim 3, wherein the retracting means is a spring.
7. The valve arrangement according to claim 3, wherein the retracting means (804) is a torsion spring,
8. The valve arrangement according to claim 3, wherein the retracting means (310) is a coil spring.
9. The valve arrangement according to claim 1, wherein the actuating means is a pneumatic actuating means.
10. The valve arrangement according to claim 9, wherein the intake valve means is a poppet valve actuated by means of pneumatic actuating means.
11. The valve arrangement according to claim 1, wherein the actuating means is an electromagnetic actuating means.
12. The valve arrangement according to claim 1, wherein the cylinder comprises a cylinder relief through hole (305), which in conjunction with a recess arranged in the intake valve means provides fluid communication between an inside volume of the cylinder and a volume delimited by the intake valve means and the check valve when the intake valve means and the check valve are arranged for closing intake side port.
13. The valve arrangement according to claim 1, wherein the check valve comprises a check valve relief through hole for providing fluid communication between an inside volume of the cylinder and a volume delimited by the intake valve means and the check valve when the intake valve means and the check valve are arranged for closing intake side port.
14. A cylinder for an internal combustion engine arrangement, cylinder comprising a check valve arranged at an intake side port of the cylinder for controlling gas flow into the cylinder, wherein the cylinder further comprises an intake vale means positioned upstream from the check valve, and a pulse controlled actuating means configured to controllably position the intake valve means far closing intake side port.
15. The cylinder according to claim 14, further comprises a second check valve arranged at an outlet side port of the cylinder for controlling gas flow out from the cylinder.
16. The cylinder according to claim 14, wherein the cylinder is a compression cylinder provided in a split-cycle internal combustion engine.
17. An internal combustion engine arrangement comprising a cylinder according to claim 14.
18. A vehicle comprising a cylinder arrangement comprising a cylinder according to claim 14.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] The above, as well as additional 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:
[0046] FIG. 1 is a side view of a vehicle comprising an internal combustion engine provided with a valve arrangement according to an example embodiment of the present invention;
[0047] FIG. 2 is a schematic top view of an internal combustion engine arrangement having at least one cylinder provided with a valve arrangement according to an example embodiment of the present invention;
[0048] FIGS. 3-6 schematically illustrate the functionality of an example embodiment of the valve arrangement according to the present invention;
[0049] FIG. 7 illustrates a further example embodiment of an intake valve arrangement according to the present invention; and
[0050] FIG. 8 illustrates a still further example embodiment of an intake valve arrangement according to the present invention.
DETAILED DESCRIPTION
[0051] 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, the embodiments are provided for thoroughness and completeness. Like reference character refer to like elements throughout the description.
[0052] With particular reference to FIG. 1, there is provided a vehicle 1 with an internal combustion engine arrangement 100 provided with a valve arrangement 101, 201, 301 (see FIGS. 3-8) according to the present invention. The vehicle 1 depicted in FIG. 1 is a truck for which the inventive intern& combustion engine arrangement 100 and the valve arrangement 101, 201, 301, which will be described in detail below, is particularly suitable for.
[0053] Turning to FIG. 2, illustrating an internal combustion engine arrangement 100 provided with a valve arrangement 101, 201, 301 according to example embodiments of the present invention. The internal combustion engine arrangement 100 depicted in FIG. 2 is a split-cycle internal combustion engine comprising a compression cylinder 202, two combustion cylinders 204, 206, and an expansion cylinder 208. Other configurations of a split-cycle internal combustion engine are of course conceivable, such as e.g. a split-cycle internal combustion engine using two parallel compression cylinders which are each in fluid communication with a respective combustion cylinder. Also, two expansion cylinders which are arranged in fluid communication with a respective combustion cylinder, is also conceivable. Accordingly, the following description with one compression cylinder, two combustion cylinders, and one expansion cylinder is to be understood as an exemplary embodiment only. According to a further split-cycle concept which the invention is suitable for is an arrangement utilizing two-stage compression, which means that a first compression stage is provided where gas is compressed in a compression cylinder, where compressed gas is delivered to a second compression cylinder where the gas is compressed before delivered to a combustion cylinder.
[0054] Still further, the invention is also applicable for compression cylinders where a cylinder is acting both as a compression cylinder as well as an expansion cylinder. Such a cylinder may provide an expansion stage delimited by the upper end of the piston and the inside of the cylinder and a compression stage delimited by the lower end of the piston and the inside of the cylinder.
[0055] In particular, the following description will he directed solely to the compression cylinder 202 and its associated valve arrangement 101, 201, 301.
[0056] Firstly, in order to describe the invention in further detail a short description, with reference to FIG. 2 in conjunction with FIG. 3, is made to a compression cylinder in the sense of the present invention.
[0057] A compression cylinder 202 should in the following and throughout the entire description be interpreted as a cylinder housing a compression piston 302, where the cylinder is arranged to provide compressed intake gas to e.g. a combustion cylinder 204, 206. Accordingly, the compression piston 302 compresses gas inside the compression cylinder, which compressed gas thereafter is transferred to the intake of the combustion cylinders. The pressure level of the compressed gas is then above atmospheric pressure. The compression cylinder can work in a two-stroke fashion, which means that when the compression piston is in an upper end position of die cylinder, also known as a top dead centre of the cylinder, gas is provided into the cylinder during the downward motion of the compression piston until the compression piston has reached a desired position, which will be described further below. When the compression piston thereafter has reached the bottom dead centre of the compression cylinder and is in an upward motion towards the upper end position of the cylinder, the gas provided into the cylinder is compressed due to the volume reduction within the cylinder caused by the reciprocating motion of the compression piston. At a desired point in time, the compressed gas is directed out from the compression cylinder and to the intake of the combustion cylinder. The gas which is compressed by the compression cylinder may, for example, be ambient air.
[0058] Turning now to FIG, 3, an example embodiment of the valve arrangement 101 and its associated components will be described. The valve arrangement 101 comprises a check valve 304, in FIG. 3 depicted as a reed valve, and an intake valve means 306, depicted as a slide valve. The valve arrangement 101, i.e. the check valve 304 and the intake valve means 306, is positioned at an intake side port 308 of the compression cylinder 202. Hereby, gas is allowed to enter the compression cylinder 202 via the intake side port 308 when the valve arrangement 101 is arranged in the open position as illustrated in FIG. 3. Further, the valve arrangement 101 comprises an actuating means 303. The actuating means 303 is arranged to controllably position the intake valve means 306 in a closed position, such that the intake side port 308 is closed. Controllably positioning the intake valve means 306 for closing the intake side port 308 of the cylinder can be achieved by a short pulse or the like, either hydraulically, pneumatically, or by means of an electric motor, etc. The actuating means illustrated in FIG. 3 is an actuator in the form of a reciprocating cylinder. Furthermore, the valve arrangement 101 also comprises a retracting means 310, here in the form of a coil spring, which is arranged in an un-tensioned state when the intake valve means 306 is arranged in an open position. The retracting means 310 is configured to position the intake valve means in the open position when the spring force exceeds a clamping force exerted on the intake valve means from the pressure of the compression cylinder 202.
[0059] Moreover, the compression cylinder 202 depicted in FIG. 3 further comprises a second check valve 312 arranged at an outlet side port 314 of the cylinder. The second check valve 312, here in the form of a reed valve, is configured to be positioned in an open state when compressed gas is to be forced out from the compression cylinder 202 and into e.g. the combustion cylinders 204, 206 depicted in FIG. 2.
[0060] Now, reference is made to FIGS. 3-6 in order to describe the functionality of the valve arrangement 101 in combination with the compression cylinder 202. The description is made for a compression cylinder 202 working in a two-stroke compression cycle. However, the invention is equally applicable for a cylinder working in a four stroke compression cycle as well.
[0061] At a first stage of the compression cycle, illustrated in FIG. 3, the compression piston 302 is positioned at an upper end position within the compression cylinder 202. The compression piston 302 is in a downward motion towards a lower end position of the compression cylinder, i.e. the bottom dead centre of the compression cylinder 202. The intake valve means 306 is arranged in an open position by means of the retracting force from the retracting means 310. Also, the check valve 306 is in the open position due to suction forces arising from the pressure difference between the pressure inside the compression cylinder and the pressure outside from the compression cylinder during the downward motion of the compression piston.
[0062] Hereby, at the first stage of the compression cycle, gas is allowed to enter the compression cylinder since both the intake valve means 306 as well as the check valve 304 are arranged in the open position. Further, the second check valve 312 is arranged in a closed position.
[0063] At a second stage of the compression cycle, illustrated in FIG. 4, the compression piston 302 is still in a downward motion towards the bottom dead centre of the compression cylinder 302. The intake valve means 306 is now positioned in a closed state, thus preventing gas from entering the compression cylinder via the intake side port 308. The closing of the intake valve means 306 is executed by a short pulse from the actuating means 303. The actuating force from the short pulse is exceeding the spring force from the retracting means 310 such that the intake valve means 306 is closing the intake side port 308. Now, when the compression cylinder 302 continues its downward motion towards the bottom dead centre of the compression cylinder 202, the pressure within the compression cylinder 202 will be lower compared to the pressure outside the cylinder. This will generate a clamping force on the intake valve means 306, which clamping force will maintain the intake valve means 306 in its closed position. Accordingly, the actuating force in the form of a short pulse is thus no longer needed. Hence, the intake valve means 306 is in this stage not exposed to an actuating force from the actuating means 303. In the second stage of the compression cycle, the compression cylinder will not receive any further gas during the remaining downward motion of the compression piston 302 within the compression cylinder 202. Hereby, the compression cylinder has controllably received a desired amount of gas. Furthermore, a cylinder relief through hole 305 is arranged in the upper portion of the cylinder 202. When the intake valve means 306 is arranged in a closed position, the cylinder relief through hole 305 is aligned with a recess 307 arranged in the intake valve means 306. Hereby, gas can be provided through the cylinder relief through hole 305 and into the intake side port 308 via the recess 307 in the intake valve means 306.
[0064] At a third stage of the compression cycle, illustrated in FIG. 5, the compression piston 302 is in an upward motion toward the upper end position of the compression cylinder 202. In FIG. 5. the compression piston 302 is positioned approximately at the same position as depicted in FIG. 4 where the intake valve means 306 was controllably arranged in the closed position. When the compression piston 302 is positioned as depicted in FIG. 5, the pressure within the compression cylinder 202 will be approximately the same as the pressure outside the compression cylinder 202. Hereby, the retracting force from the retracting means will, shortly before the piston reaches the position in FIG. 5, or when it has reached the position in FIG. 5, exceed the above described clamping force and the intake valve means will, by means of the retracting force, be provided at its open position. At approximately the same time as the intake valve means 306 will be arranged in its open position, the check valve 304 will be positioned in its closed position, i.e. the check valve will be arranged in such a way that the intake side port is closed and thus not allowing gas to enter the compression cylinder 302. Although FIG. 5 depicts a small opening of the intake side port, it should be readily understood that when the intake valve means 306 is forced to its open stage, the check valve 304 will be in its closed state such that gas is prevented from being directed out from the compression cylinder via the intake side port 308.
[0065] At a fourth stage of the compression cycle, illustrated in FIG. 6, the compression piston 302 is still in an upward motion towards the upper end position of the compression cylinder 202. The intake valve means 306 is arranged in the open position and kept in this position by means of the retracting means 310, while the check valve 304 is arranged in its closed state. Hereby, and as described above in relation to the third stage of the compression cycle, gas is prevented from being directed out from the compression cylinder 202 via the intake side port 308. On the other hand, when the pressure in the compression cylinder has been sufficiently built up, the second check valve 312 will, at this fourth stage, be arranged in an open position such that compressed gas can be forced out from the compression cylinder 202 via the outlet side port 314 and into e.g. the combustion cylinders 204, 206 as depicted and described in relation to FIG. 2.
[0066] With the above described cylinder arrangement, the flow of gas into the compression cylinder is controlled such that only a desired amount of gas is provided therein. Hence, the compression cylinder 202 will not receive gas during the complete downward motion of the compression piston 202 within the compression cylinder 302, but instead only receive gas during a specific and desired amount of time of the downward motion of the compression piston 302.
[0067] Reference is now made to FIGS. 7 and 8, illustrating two further example embodiments of the valve arrangement according to the present invention. The functionality of opening and closing the various valves are similar to the above description of the four stages in FIGS. 3-6 unless indicated otherwise.
[0068] Turning first to FIG. 7, illustrating a valve arrangement 201 having an intake valve means in the form of a poppet valve 702, and a check valve in the form of a reed valve. The check valve 304 of the embodiment depicted in FIG. 7 has the same functionality as described above and will not be described further. The poppet valve 702 on the other hand is connected to the retracting means 310 on, the upper end thereof, which end is facing away from the intake side port 308 of the compression cylinder 202. The retracting means 310 is in the form of a coil spring and has similar functionality as the coil spring described above. Further, the poppet valve 702 is configured to be controllably positioned in a closed state where it prevents gas from entering the compression cylinder via the intake side port 308. More specifically, a piston 704 of the poppet valve is configured to close the intake side port 308 of the compression cylinder 202. The poppet valve 702 in its closed state, i.e. where it is closing the intake side port of the compression cylinder 202, is depicted in FIG. 7 with the piston 704 in dashed lines. Also, the retracting means 310 is configured to retract the piston 704 of the poppet valve 702 to an open state, which open state is illustrated with the piston 704 in solid lines. Furthermore, the poppet valve 702 in FIG. 7 is connected to an actuating means 303 in the form of a pneumatic actuating means 303 positioned at a rear end of the poppet valve in relation to the intake side port 308 and connected to the poppet valve by means of a hose 706 or the like. Hence, the piston 704 of the poppet valve is arranged between the pneumatic actuating means and the intake side port 308 of the compression cylinder 202. The pneumatic actuating means 303 is configured to provide the above described actuating force by means of providing a short pulse of pressurised air, which will force the piston 704 of the poppet valve 702 to be arranged in the closed position until the pressure difference between the pressure inside the compression cylinder 202 and the pressure outside the compression cylinder 202 is such that it will keep the piston 704 in the dosed position, as described above.
[0069] Finally, reference is made to FIG. 8, illustrating a still further example embodiment of the valve arrangement 301 according to the present invention. The difference between the valve arrangement 301 depicted in FIG. 8 and the valve arrangements depicted in FIGS. 3 and 7 is mainly relating to the intake valve means 802 and its associated retracting means 804.
[0070] The valve arrangement 301 depicted in FIG. 8 comprises an intake valve means 802, in the form of a valve plate, and a check valve in the form of a reed valve as described above. The intake valve means 802 is connected to a retracting means 804 in the form of a torsion spring. The intake valve means 802 is also, as for the embodiment depicted and described in relation to FIG. 3, connected to an actuating means 303 for controllably position the intake valve means for closing the intake side port 308. Hereby, the valve plate 802 is configured to be tiltably arranged in the open and closed position, respectively. The valve plate depicted and described in relation to FIG. 8 is tilting between the closed position (seen in dashed lines) and the open position (seen in solid lines) by an approximately 90 degrees tilting. The valve plate may of course be tilting between an open state and a closed state by e.g. 180 degrees instead of 90 degrees.
[0071] As illustrated in both FIG. 7 and FIG. 8, the check valve 304 comprises a check valve relief through hole 705 which allows gas to be guided from the inside of the cylinder 202 and into the volume which is delimited by the intake valve means and the check valve when these valves are arranged in a closed state.
[0072] 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. For example, the intake valve means may also be a slide plate which is connected to a retracting means in the form of a torsion spring such that the slide plate slides between an open position and a closed position by means of rotating the slide plate relative to the compression cylinder.
