JP2007519847A - Rotary valve assembly - Google Patents

Abstract

  An axial flow rotary valve that is rotatable in a hole in a cylinder head (9) of an internal combustion engine has a port that extends from the outer peripheral opening (4) to an axial opening at one end of the valve. The outer peripheral opening (4), which periodically leads to the combustion chamber (30) via the hole window (8), has a first trailing edge (13). The window (8) has a second trailing edge (12). Each time the first trailing edge (13) passes the second trailing edge (12), the port closes from the combustion chamber (30). The edges (12, 13) are such that as the port closes, the instantaneous intersection (17) of the two edges (12, 13) gradually moves away from the axial opening over at least 50% of the total length of the window (8). Be placed.

Description

  The present invention relates to a method for improving the scavenging efficiency of an internal combustion engine having an axial flow rotary valve. It can be applied to all internal combustion engines incorporating a hollow cylindrical axial flow rotary valve, where the rotary valve houses one or more ports that terminate as an opening on the outer periphery of the valve.

  Most internal combustion engines use poppet valves to regulate the flow of intake air into and out of the cylinder through the combustion chamber. An alternative way of adjusting these flows is a rotary valve, in particular an axial flow rotary valve. Although many rotary valve devices have been tested and failed in the past, recent results have paved the way for commercial use of axial flow rotary valves that have many advantages over poppet valves.

  Axial-flow rotary valves are well known and examples are described in US Pat. No. 5,526,780 (by Wallis :) and US Pat. No. 4,852,532 (by Bishop :). The axial flow rotary valve rotates in a hole in the cylinder head of the engine and each port of the valve extends from an outer peripheral opening on the outer periphery of the valve to an axial opening at one end of the valve. The main part of each port is substantially parallel to the axis of rotation of the valve. There is usually one axial flow rotary valve in each cylinder of the engine, and each axial flow rotary valve incorporates both an intake port and an exhaust port terminating at the other end of the valve. While the axial flow rotary valve is rotating, the outer peripheral opening periodically passes through the cylinder head hole window to the combustion chamber and passes the fluid to and from the cylinder through the combustion chamber. The valve opening of the axial flow rotary valve is the opening through which the fluid passes as it passes between the port and the combustion chamber. At any rotational position of the valve, the opening of the valve is an overlapping area between the outer peripheral opening and the window.

  Usually, the intake flow path extends from the axial opening at the end of the intake port of the axial flow rotary valve. This flow path leads to atmospheric pressure or, in the case of a turbocharged engine or turbo engine, leads to a pressurized air source. The flow path can include a throttle valve. The combination of the intake flow path and the intake port forms an intake system. Similarly, the exhaust passage is usually in the shape of an exhaust pipe, and generally extends from the axial opening at the end of the exhaust port to the atmosphere, and the combination of the exhaust passage and the exhaust port defines the exhaust passage. Form.

  Similarly, the intake system of a poppet valve engine extends from the intake poppet valve opening to the atmosphere via an intake port and any connected flow path. The exhaust system of a poppet valve engine extends from the opening of the exhaust poppet valve to the atmosphere through an exhaust port and any connected flow path. The valve opening of the poppet valve is an annular opening between the valve seat and its mating surface on the poppet valve,

  The fluid occupying the internal combustion engine system receives periodic shocks from the cylinders, and this shock generates pressure pulses in the system. These pressure pulses travel the entire length of the system at the speed of sound at that location, which gives time to change the pressure wave in the system. All modern internal combustion engines utilize these pressure waves to improve fluid flow into and out of the cylinder. The sources of these pressure waves and how they are most utilized in poppet valve engines are well known techniques. In order to better explain the present invention, a short and simplified description of the pressure wave in the intake system is now provided.

  At the beginning of the intake stroke, the acceleration of the piston away from top dead center (TDC) causes a negative pressure pulse in the fluid in the intake system adjacent to the valve opening. This negative pressure pulse is transmitted toward the opening or the end of the intake system on the atmosphere side at the speed of sound at that location. At the open end of the system, the negative pressure pulse is reflected as a positive pressure pulse, and this positive pressure pulse returns towards the cylinder at the local speed of sound. When this positive pressure pulse reaches the valve opening, it again reflects as a negative pressure pulse returning toward the open end of the intake system. Depending on the overall length of the intake system and the engine speed, the pressure pulse can traverse the intake system several times before the intake port closes the combustion chamber. The overall length of the intake system is determined to ensure that the positive pressure pulse traffic to the valve opening coincides with the end of the intake stroke. The presence of this positive pulse increases the load density applied to the cylinder and serves to resolve any counter pressure gradient that exists between the cylinder and the intake system. Proper use of pressure waves increases engine scavenging efficiency.

  In high performance poppet valve engines, the intake port is located as close as possible to the poppet valve coaxial line. Thus, every pulse reflected from the open end of the system reaches all parts of the poppet valve opening simultaneously. However, in an axial flow rotary valve, many portions of the intake port are substantially perpendicular to the peripheral opening. Furthermore, the peripheral opening and the cylinder head hole window are each generally rectangular, the long side of which is parallel to the axis of the rotary valve. Hence, the reflected pressure pulse in the intake system does not reach all parts of the valve opening at the same time. Instead, the pressure pulse travels axially through the valve opening at the local speed of sound, so that at any instant a pressure gradient exists along the valve opening. This situation does not exist in poppet valve engines because the total length of the system can be adjusted so that the peak pressure occurs at the appropriate time on all poppet valve openings. For a typical axial rotary valve engine, adjust the overall length of the intake system so that the peak pressure occurs over a portion of the valve opening at the appropriate time, but not simultaneously over the full length. Can do.

  This particular problem is exacerbated by the fact that the overall length of the window is usually very long and therefore the overall length of the outer peripheral opening is also usually very long in order to maximize the ventilation performance of the axial rotary valve engine. Typically, the total length of the window can be greater than 60% of the size of the cylinder bore. This is comparable to a 4-valve poppet valve in each cylinder head, and the valve head diameter is typically less than 35% of the hole diameter. The problem is further exacerbated in a rotary valve engine designed for high travel speeds due to the relatively short overall length of the intake system that must operate at high travel speeds. In these engines, the overall length of the outer peripheral opening is the main part of the overall length of the system. The larger this main part, the steeper the pressure gradient along the valve opening, thus reducing the scavenging efficiency. The more the air is forced into the combustion chamber at one end of the valve opening, while the other end is forced from the combustion chamber to the port, the steeper the pressure gradient be able to.

  The peripheral opening and window of an axial flow rotary valve engine are usually approximately rectangular, maximizing the area of the valve opening. Each peripheral opening has a leading edge and a trailing edge on both sides of the opening. The window also has a leading edge and a trailing edge. As the valve rotates, when the leading edge of the outer peripheral opening of the port passes the leading edge of the window, the valve opens, allowing communication between the combustion chamber and its port. Similarly, the valve closes when the trailing edge of the peripheral opening passes the trailing edge of the window. The peripheral opening and the leading edge of the window are usually intentionally designed to be parallel to each other to maximize the opening ratio of the valve. Similarly, the peripheral opening and the trailing edge of the window are usually parallel to each other in order to maximize the valve closure rate.

  A variety of rotary valves with non-rectangular perimeter openings or windows have been proposed, but none of these devices mention the problem of pressure gradients along the valve openings of axial rotary valves. Or not trying to mention.

Several rotary valve devices with a substantially circular window have been proposed. Circular windows are usually dictated by the use of “shoe” type gas seals. These devices inevitably limit the rate of opening and closing of the valves, so a low air flow is a disadvantage. Even in these cases, the peripheral opening and the window are usually symmetric with respect to the respective axial center.

  In a few exceptional cases, asymmetric windows or peripheral openings have been proposed. These devices are generally classified into two types. The first is a device where the perimeter opening or window is asymmetric due to mounting or construction, and the second is a device introduced so that the timing of the valve changes due to asymmetry.

  A first type of example is shown in FIG. 2 of U.S. Pat. No. 4,022,178 (Cross et al.) And shows an asymmetric peripheral opening. The shape of the outer peripheral opening is similar to that shown in FIG. 8 of the present specification. Asymmetry arises in the outer peripheral opening of the valve from the invasion of the common wall between the intake and exhaust ports. In this case, the asymmetry is limited to a small axial portion of the outer peripheral opening. One way to determine the degree of asymmetry of the peripheral opening is to identify an axial full length portion that is symmetric about a plane perpendicular to the valve axis and passing through the axial center of the axial portion. From FIG. 2 of US Pat. No. 4,022,178, it can be seen that the axial portion of the outer peripheral opening that is 70% or more of the total length of the opening (ignoring the corner radius) is symmetric about its center.

  A second type of example is U.S. Pat. No. 4,163,438 (by Gunther et al.). In this case, the rotary valve is movable in the axial direction. This axial movement is controlled, resulting in a change in valve timing. However, in these devices, since the maximum window length and maximum width cannot be used, the air permeability is poor. It is important to note that unlike the present invention, the rotary valve described in US Pat. No. 4,163,438 is a radial rotary valve rather than an axial rotary valve. The geometry of a radial flow rotary valve, such as a poppet valve, is not detrimental to the problem of non-uniform pressure distribution along the valve opening. This is because the port of the radial flow rotary valve extends without any change in flow direction from one side of the outer surface of the valve to the other. Thus, like a poppet valve engine, all of the valve openings are substantially the same as the distance to the open end of the intake system.

  An object of the present invention is to improve the scavenging efficiency of an axial flow rotary valve engine.

  In a first aspect, the present invention comprises a rotary valve assembly for an internal combustion engine having a cylinder head and an axial flow rotary valve rotatable in a hole of the cylinder head, the valve being an outer periphery on an outer periphery of the valve. A port extending from the opening to the axial opening at one end of the valve; the outer opening periodically communicates with the combustion chamber through the hole window each time the valve rotates; The port has a first trailing edge, the window has a second trailing edge, and the port burns each time the valve rotates and the first trailing edge passes through the second trailing edge. In the rotary valve assembly that closes from the chamber, the first and second trailing edges are connected to the first and second trailing edges as the port closes from the combustion chamber. It is characterized in that the instantaneous intersection of the are arranged to gradually away from the axial opening over at least 50% of the total length of the window with.

  The port is preferably an intake port.

  The first and second trailing edges are such that as the port closes from the combustion chamber, the momentary intersection of the first and second trailing edges gradually leaves the axial opening substantially over the entire length of the window. It is preferable to arrange | position.

  The first trailing edge is preferably substantially straight and inclined with respect to the valve axis, and the second trailing edge is preferably substantially straight and parallel to the valve axis. Furthermore, the first trailing edge is preferably substantially straight and inclined with respect to the valve axis.

  The window is preferably substantially rectangular. The total length of the window is preferably at least 60% of the hole diameter of the cylinder adapted to the rotary valve assembly.

  In a second aspect, the present invention comprises a rotary valve assembly for an internal combustion engine having a cylinder head and an axial flow rotary valve rotatable about an axis in a hole of the cylinder head, the valve on the outer periphery of the valve A rotary valve having a port extending from an outer peripheral opening of the valve to an axial opening at one end of the valve, and the outer peripheral opening periodically communicates with the combustion chamber through a hole window each time the valve rotates. In the assembly, the peripheral opening or the axial part of the window, or both axial parts, which are longer than 50% of the total length of the window, are each asymmetric with respect to a plane perpendicular to the axis passing through the axial center of the axial part. It is characterized by a certain point.

  In a preferred embodiment, the perimeter opening has a first trailing edge, the window has a second trailing edge, the valve rotates, and the first trailing edge is the second trailing edge. Each time an edge is passed, the port closes from the combustion chamber, and the first and second trailing edges are windowed as the instantaneous intersection of the first and second trailing edges as the port closes from the combustion chamber. Is arranged to gradually move away from the axial opening over at least 50% of its total length.

  In another preferred embodiment, the perimeter opening has a first leading edge, the window has a second leading edge, the valve rotates, and the first leading edge has a second leading edge. Each pass, the port opens into the combustion chamber and the first and second leading edges are such that as the port closes from the combustion chamber, the instantaneous intersection of the first and second leading edges is at least the full length of the window. It is arranged to move gradually towards the axial opening over 50%.

  In a preferred embodiment, the outer peripheral opening is narrower at the end closer to the axial opening than at the end far from the axial opening. The width of the outer peripheral opening is preferably reduced from the maximum length at the end far from the axial opening to the minimum length at the end close to the axial opening. The trailing edge of the peripheral opening is preferably substantially parallel to the axis.

  In another preferred embodiment, the window is narrower at the end closer to the axial opening than at the end far from the axial opening. The width of the window preferably decreases from a maximum length at the end far from the axial opening to a minimum length at the end close to the axial opening. The trailing edge of the window is preferably substantially parallel to the axis.

  The window is preferably substantially rectangular. The port is preferably an intake port.

  1-4 show a first embodiment of an internal combustion engine having a rotary valve assembly of the present invention. Referring to FIG. 1, the rotary valve 1 is supported by a bearing 26 and rotates in the hole 11 of the cylinder head 9 with respect to the axis A. When the piston 20 reciprocates in the cylinder 10, the valve 1 rotates in relation to the piston 20 by means not shown. A small gap exists between the cylindrical portion 25 of the valve 1 and the hole 11. A small gap between the cylindrical portion 25 and the hole 11 is passed a row of floating seals (not shown) to prevent fluid loss. The valve 1 has an intake port 2 and an exhaust port 3. The intake port 2 extends from an intake outer peripheral opening 4 on the outer periphery of the valve 1 to an intake axial opening 6 at one end of the valve 1. The exhaust port 3 extends from the exhaust outer peripheral opening 5 to the exhaust axial opening 19 at the end of the valve 1 opposite to the intake axial opening 6. Each time the valve 1 rotates, the intake and exhaust peripheral openings 4 and 5 periodically communicate with the combustion chamber 30 through the window 8 in the hole 11 of the cylinder head 9. During the engine compression stroke and the explosion process, the cylindrical portion 25 covers the window 8 and prevents fluid leakage from the combustion chamber 30.

  The intake flow path 28 extends from the intake axial opening 6 to the opening end 29. The throttle valve 7 is installed in the intake passage 28. The combination of the intake port 2 and the intake flow path 28 forms an intake system. An exhaust pipe (not shown) extends from the exhaust axial opening 19 and the combination of the exhaust pipe and the exhaust port 3 forms an exhaust system.

  FIG. 2 shows a view of the cylinder head 9 and the valve 1 with the window 8 viewed from the surface of the cylinder head 9 facing the cylinder 10. The valve 1 rotates in the direction indicated by the arrow R, and this rotation causes the intake outer peripheral opening 4 (the broken line indicates a hidden portion) to move from the left to the right to open and close the window 8, thereby intake into the combustion chamber 30. Open and close port 2. In the illustrated position, the intake outer peripheral opening 4 closes the window 8 almost completely. The valve opening 16 remaining at this moment is an overlapping portion of the intake outer peripheral opening 4 and the window 8. The window 8 is rectangular in shape and its trailing edge 12 is substantially parallel to the axis A. In order to maximize engine airflow, the window 8 is longer in the direction of the axis A compared to the diameter of the cylinder 10. The trailing edge 13 of the intake outer peripheral opening 4 is inclined with respect to the axis A by a predetermined angular amount. As the valve 1 rotates and the intake peripheral opening 4 closes the window 8, the instantaneous intersection 17 between the trailing edge 13 of the intake peripheral opening and the trailing edge 12 of the window is the intake axial opening 6. Gradually away in the axial direction. That is, as the intake outer peripheral opening 4 closes, the intersection 17 gradually moves from the window end 14 closest to the intake axial opening 6 to the window end 15 far from the intake axial opening 6.

  At the start of the intake stroke, the piston 20 accelerates away from the top dead center, and a negative pressure pulse is generated in the fluid in the intake port 2 near the intake outer peripheral opening 4. This negative pressure pulse travels through the intake port 2 and the intake passage 28 at the local sound velocity, and then reaches the open end 29. Then, this negative pressure pulse is reflected to the combustion chamber 30 as a positive pressure pulse transmitted at the local sound velocity. As mentioned in the background, the pressure pulse can traverse the intake system several times. The angle of the intake perimeter opening with respect to the axis A of the trailing edge 13 is approximately the same as the momentary intersection 17 moves along the window 8 when the intake perimeter opening 4 is closed at a specific desired engine speed. At speed, a positive reflected pressure pulse is predetermined to traverse the entire length of the window 8. Further, the overall length of the intake system is determined such that when the positive reflected pressure pulse traverses the entire length of the window 8 at the same engine speed, the positive reflected pressure pulse passes near the instantaneous intersection 17. This means that at each position along the window 8, if a positive pressure pulse passes that position, that position is closed, preventing fluid from flowing out of the combustion chamber and becoming under low pressure under the positive pressure pulse. It means to do. Therefore, this relative configuration of the trailing edge 13 of the intake perimeter opening and the trailing edge 12 of the window is used to scavenge the axial rotary valve engine by utilizing positive reflected pressure pulses over the entire length of the window 8. Increase efficiency.

  3 and 4 show how the shape of the intake opening 4 is defined. The plane D is perpendicular to the axis A of the valve 1 and passes through the center point 31 of the intake outer peripheral opening 4. The center point 31 is in the middle of the axial direction between the end 32 and the end 33 of the intake outer peripheral opening 4, and the trailing edge 13 of the intake outer peripheral opening and the leading edge 18 of the intake outer peripheral opening and the plane D Between the point 34 and the point 35 defined by the intersection of The axis A and the center point 31 are located on the plane C. Plane B is perpendicular to both planes C and D and passes through intersections 34 and 35. In the present specification, all the descriptions regarding the shape of the intake outer peripheral opening 4 refer to the shape projected on the plane B as shown in FIG. Similarly, all other descriptions of the shape of the outer peripheral opening or window refer to the shape projected on the plane provided in the same way as plane B for that particular opening.

  FIG. 4 shows specific points for determining the angular orientation of the trailing edge 13 of the outer peripheral opening for intake with respect to the axis A. The axis A is located on both the plane E and the plane F, the plane E passes through the end point 21 of the trailing edge 13 of the intake outer peripheral opening, and the plane F corresponds to the trailing edge 13 of the intake outer peripheral opening. It passes through the end point 22. The taper angle α is an angle between the planes E and F.

The taper angle α for obtaining the advantages of the present invention is generally small. The maximum taper angle α for a 4-cycle engine can be calculated using the following formula:
Maximum α = (Full length L of window / Sound speed in the area) × (Number of engine revolutions × 3)
Here, it is assumed that the pressure pulse has a rectangular shape and is extremely narrow.
In practice, the pulses are neither rectangular nor narrow. Therefore, the desired taper angle α is generally smaller than the angle calculated by the above formula. The desired taper angle α increases with the overall length L of the window 8 and the engine speed.

  FIG. 5 shows a second embodiment of the internal combustion engine having the rotary valve assembly of the present invention viewed from the same viewpoint as FIG. The only difference between this rotary valve assembly and that of FIGS. 1 to 4 is that the trailing edge 12a of the window 8a is inclined with respect to the axis A at a predetermined angle, and the trailing edge of the intake outer peripheral opening 4a. 13a means that it is substantially parallel to the axis A. As the valve rotates and the intake outer opening 4a closes the window 8a, the momentary intersection 17 between the trailing edge 13a of the intake outer opening and the trailing edge 12a of the window gradually becomes the rotary shown in FIGS. Similar to the valve assembly, it is axially separated from the intake axial opening 6. Thus, this configuration also improves the scavenging efficiency of the axial rotary valve engine by utilizing positive reflected pressure pulses over the entire length of the window.

  The present invention is not limited to the shape and configuration of the outer peripheral opening or window shown in the above two embodiments. For example, in other embodiments not shown, the trailing edge of the intake perimeter opening and the trailing edge of the window may both be tilted relative to the axis of the valve and tilted relative to each other.

  The intersection of the trailing edge of the intake perimeter opening and the trailing edge of the window gradually leaves the intake axial opening over substantially the entire length of the window as the valve rotates, as in the two embodiments above. It is preferable. However, the scavenging efficiency of the axial rotary valve engine can also be improved with a configuration in which the intersection gradually moves away from the intake axial opening over at least 50% of the total length of the window. In such a rotary valve assembly, each axial portion of the outer peripheral opening for intake and / or the window, which is 50% or more of the total length of its own opening, is the center of each axial portion perpendicular to the axis of the valve. Has a geometric property of being asymmetric with respect to a plane passing through. For this verification, the corner radius of the opening must be ignored and the geometry of the opening is determined by projecting the leading edge, trailing edge and the edge of the opening. It must be considered to be the geometric shape where the intersection occurs.

  7 and 8 show two embodiments of the intake outer peripheral opening. An engine similar to the engine of FIGS. 1 to 4 is considered except for the intake outer peripheral opening 4b having the shape shown in FIG. 50% or more of the total length of the trailing edge 13b of the outer peripheral opening for intake is inclined with respect to the axis A, and the remaining part is parallel to the axis A. In this way, the momentary intersection 17 (see FIG. 2) gradually moves away from the intake axial opening 6 over at least 50% of the total length of the window 8. The above geometric verification is applied to the intake outer opening 4b, and H denotes an arbitrary axial portion of the intake outer opening 4b that is 50% or more of the length L. M is a plane passing through the center of the portion H perpendicular to the axis A. It is clear from FIG. 7 that the portion H is asymmetric with respect to the plane M regardless of whether the portion H is determined along the intake outer peripheral opening 4b.

  Next, an engine similar to the engine of FIGS. 1 to 4 is considered except for the intake outer peripheral opening 4c having the shape shown in FIG. The intake outer opening 4c is similar to the conventional intake outer opening in that only a small portion of the trailing edge 13c of the intake outer opening is inclined with respect to the axis A. H indicates an arbitrary axial direction portion of the intake outer peripheral opening 4c that is 50% or more of the length L. It is clear from FIG. 8 that the portion H shown is symmetric with respect to the plane M, so that the rotary valve assembly does not meet the above geometric verification. Therefore, such an engine cannot improve the scavenging efficiency over the prior art.

  The advantage in scavenging efficiency of the present invention is that as the intake port opens into the combustion chamber, the intersection of the intake outer opening and the trailing edge of the window gradually moves toward the intake axial opening. It can be further increased by arranging the leading edge. In the prior art where both the leading edge of the intake perimeter opening and the leading edge of the window are parallel to the valve axis, the downward movement of the piston when the intake port opens causes the fluid in the intake port to A uniform impact is given along the window. With this arrangement, the negative pressure pulses transmitted along the intake system can be considered as a combination of countless small pulses starting at different locations along the window, each arriving at the open end of the intake system at slightly different times. Thus, the pressure pulse as a whole is broadly defined rather than sharp. However, if the intersection of these trailing edges gradually moves towards the outer perimeter opening for intake, almost simultaneously with a sharper pressure pulse that can be used to improve scavenging efficiency when reflected as a positive pulse, Each small pulse along the window can be designed to arrive at the open end of the inspiration system. The shape and relative orientation of the leading edge for making an intersection that gradually moves toward the outer peripheral opening for intake is the same as the shape and relative orientation described on the trailing edge, except those reflected with respect to the valve axis. .

  The trailing edge of the outer peripheral opening for exhaust is the same as described for the opening of the intake port, and as the exhaust port opens, the instantaneous intersection of the outer peripheral opening for exhaust and the trailing edge of the window It can be designed to gradually move away from the exhaust axial opening. The overall length of the window is generally short compared to the total length of the exhaust system, but its advantages are low compared to applying the present invention to the intake port.

  Figures 6a-6l show various alternative shapes for the perimeter opening or window, where the instantaneous intersection of the perimeter opening and the trailing edge of the window as the valve rotates is the window's If it gradually moves away from the axial opening of the port over 50% of the total length, or if the momentary intersection of the peripheral opening and the leading edge of the window is 50% of the total length of the window if the valve rotates If it gradually moves towards the opening, it can be useful in the axial flow rotary valve assembly of the present invention. The examples presented herein are not complete. All of the shapes shown in FIGS. 6a-6l are asymmetrical with respect to a plane passing through the center of the axial portion perpendicular to the valve axis, with each axial portion more than half of the total length of each axial opening. Note that it has the geometric characteristics described above.

  It should be noted that the present invention also applies to engines having more than one axial flow rotary valve per cylinder or having an axial flow rotary valve where the intake and exhaust ports are separate axial flow rotary valves.

1 shows a cross-sectional view of a first embodiment of an internal combustion engine having a rotary valve assembly of the present invention. The figure of the cylinder head and valve | bulb of the internal combustion engine shown in FIG. 1 which looked at the window from the cylinder surface of the cylinder head is shown. The side view of the rotary valve of the internal combustion engine shown in FIG. 1 is shown. FIG. 4 is a projected view of the geometric shape of the outer peripheral opening for intake of the rotary valve shown in FIG. 3. FIG. 3 shows a cylinder head and valve view of a second embodiment of an internal combustion engine having a rotary valve assembly of the present invention as viewed from the cylinder surface of the cylinder head. Fig. 6 illustrates various alternative shapes for a peripheral opening or window that may be useful in the axial flow rotary valve assembly of the present invention. The figure of the outer peripheral opening part for suction | inhalation projected on the plane B of FIG. 3 of this invention is shown. The figure of the outer peripheral opening part for intake of the prior art is shown.

Claims (18)

A rotary valve assembly for an internal combustion engine having a cylinder head and an axial flow rotary valve rotatable in a hole of the cylinder head,
The valve has a port extending from an outer peripheral opening on an outer periphery of the valve to an axial opening at one end of the valve;
The outer peripheral opening periodically communicates with the combustion chamber through the hole window each time the valve rotates,
The outer peripheral opening has a first trailing edge, and the window has a second trailing edge, whereby the valve rotates and the first trailing edge becomes the second tray edge. In a rotary valve assembly, the port closes from the combustion chamber each time it passes through a ring edge,
As the port closes from the combustion chamber, the momentary intersection of the first and second trailing edges gradually leaves the axial opening over at least 50% of the total length of the window. The rotary valve assembly is characterized in that the first trailing edge and the second trailing edge are disposed.   The rotary valve assembly of claim 1, wherein the port is an intake port.   The first trailing edge and the second trailing edge are substantially equal to the instantaneous intersection of the first trailing edge and the second trailing edge as the port closes from the combustion chamber. The rotary valve assembly of claim 1, wherein the rotary valve assembly is arranged to gradually move away from the axial opening over the entire length of the window. At least 50% of the first trailing edge is substantially straight and inclined with respect to the axis of the valve;
The rotary valve assembly of claim 1, wherein the second trailing edge is substantially straight and parallel to the valve axis.   The rotary valve assembly of claim 4, wherein the first trailing edge is substantially straight and inclined with respect to the valve axis.   The rotary valve assembly of claim 1, wherein the window is substantially rectangular.   The rotary valve assembly of claim 1, wherein an overall length of the window is at least 60% of a bore diameter of a cylinder adapted to the rotary valve assembly. A rotary valve assembly for an internal combustion engine having a cylinder head and an axial flow rotary valve rotatable about an axis in a hole of the cylinder head,
The valve has a port extending from an outer peripheral opening on an outer periphery of the valve to an axial opening at one end of the valve;
In the rotary valve assembly, the outer peripheral opening periodically communicates with the combustion chamber through the hole window each time the valve rotates.
The axial portion of the outer peripheral opening, the axial portion of the window, or both axial portions thereof, which are longer than ½ of the total length of the window, are respectively the central points in the axial direction of the axial portion. A rotary valve assembly characterized in that it is asymmetric with respect to a plane passing through and perpendicular to said axis. The outer peripheral opening has a first trailing edge, and the window has a second trailing edge, whereby the valve rotates and the first trailing edge becomes the second tray edge. Each time it passes through the ring edge, the port closes from the combustion chamber,
As the port closes from the combustion chamber, the momentary intersection of the first and second trailing edges gradually leaves the axial opening over at least 50% of the total length of the window. The rotary valve assembly according to claim 8, wherein the first trailing edge and the second trailing edge are disposed. The outer peripheral opening has a first leading edge, and the window has a second leading edge, which causes the valve to rotate so that the first leading edge passes through the second leading edge. Each time the port opens to the combustion chamber,
The first leading edge and the second leading edge are such that the instantaneous intersection of the first leading edge and the second leading edge is the total length of the window as the port closes from the combustion chamber. The rotary valve assembly of claim 8, wherein the rotary valve assembly is arranged to gradually move toward the axial opening over at least 50%.   The rotary valve assembly according to claim 8, wherein the outer peripheral opening is narrower at an end near the axial opening than at an end far from the axial opening.   The rotary valve assembly of claim 11, wherein the width of the outer peripheral opening decreases from a maximum length at an end far from the axial opening to a minimum length at an end close to the axial opening.   The rotary valve assembly according to claim 11 or 12, wherein a trailing edge of the outer peripheral opening is substantially parallel to the axis.   The rotary valve assembly of claim 8, wherein the window is narrower at an end closer to the axial opening than at an end far from the axial opening.   The rotary valve assembly of claim 14, wherein the width of the window decreases from a maximum length at an end remote from the axial opening to a minimum length at an end close to the axial opening.   16. A rotary valve assembly according to claim 14 or 15, wherein the trailing edge of the window is substantially parallel to the axis.   The rotary valve assembly of claim 8, wherein the window is substantially rectangular.   The rotary valve assembly of claim 8, wherein the port is an intake port.

Images