Abstract:
A poly valve system for an internal combustion engine having at least one cylinder having a bore, a piston capable of reciprocal travel within the bore, a cylinder head adjacent the bore, and a combustion chamber defined between the cylinder head and the piston, comprising a plurality of independently operated valves. Intake and exhaust manifolds are located adjacent to the cylinder head. Valve seats comprise openings in the cylinder head between one of the manifolds and the combustion chamber. Poppet valves are situated in the valve seats to selectively allow communication between one of the manifolds and the combustion chamber. The valves are electrically, pneumatically, or hydraulically operated so that each valve, including one of several intake valves per cylinder, may be operated independently of each other.

Description:
CROSS REFERENCES AND RELATED SUBJECT MATTER 
     This application is a continuation of patent application Ser. No. 09/312,032, filed in the United States Patent office on May 14, 1999, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates to a poly valve system for internal combustion engines. More particularly, the invention relates to a valve system which employs several independently operated intake valves and several independently operated exhaust valves per cylinder. 
     In an internal combustion engine, intake and exhaust valves serve a crucial function. They must each open at an appropriate time to allow combustible gases in or exhaust out, and remain tightly closed at all other times to maximize the power derived from combustion. 
     The performance of the engine is also closely linked to the valves. It is well known that the more an engine “breathes” the more power it will generate. It seems obvious that the more fuel and air that enters the combustion chamber, the greater the force of the explosion and the greater the power generated thereby. However, the ability of the engine to eliminate combustion by-products is also an important factor in performance. In fact the engine “redline”—the practical rev limit for an engine—is in large part determined by the speed at which the exhaust valves can no longer expel sufficient burned gases to allow efficient combustion to occur. 
     Traditionally, valve systems are fully mechanical systems. At least one cam shaft is used to precisely determine the times during the engine cycle when each valve is to be opened and closed. For each valve, a cam follower traces the movements of the cam shaft, and causes the valve “poppet” to open and close. One problem with this arrangement is the lack of flexibility. Once the cams are set, it is not possible to change the relative opening and closing times of the valves. In addition, the entire cam system itself comprises numerous moving parts which require maintenance and which to some extent detract power from the engine. 
     Over the last two decades, adding an extra intake and an extra exhaust valve per cylinder has become prevalent in automobile engines of all types. This change has thus lead to increased engine performance by simply increasing the inward and outward flow of the combustion chamber. In such engines, it has been the general practice to have both intake valves to open and close at the same time. 
     Experimentation with increasing the number of valves has revealed practical limitations. Having a large number of valves quickly increases the complexity of the cylinder head configuration, and causes porting problems. Some have sought to maximize the number of valves by conceiving variations of traditional cam operated valve technology. 
     U.S. Pat. No. 5,375,568 to Manolis et al. discloses a multi-valve internal combustion engine which has a cluster valve system, wherein four intake valves are mechanically ganged and all operate off a common cam follower. Four exhaust valves are also provided in a similar arrangement. 
     U.S. Pat. No. 5,111,791 to Onodera discloses a cylinder head and valve train arrangement for a multiple valve engine. Onodera discloses a six valve arrangement, wherein special attention has been given to solving the problem of positioning and synchronizing cam shafts to operate these valves. Care is taken to carefully synchronize the opening of all four intake valves even though two separate cam shafts are used for opening these valves. 
     U.S. Pat. Nos. 4,658,780 to Hosoi; U.S. Pat. No. 5,007,387 to Arao; U.S. Pat. No. 5,094,197 to Rosa; and U.S. Pat. No. 5,184,580 to Ascari all disclose multiple intake and exhaust valve systems. These patent references are all concerned with working out the mechanics of a multi-valve system using existing cam operated valves. They are generally concerned with synchronizing the valves where the use of multiple valves conflicts with the ordinary design constraints of standard single cam valve operation. 
     U.S. Pat. No. 4,587,936 to Matsuura et al. discloses a valve control system which employs traditional cam-based valve opening. Matsuura has provisions to mechanically deactivate one of the intake valves under certain engine conditions. However Matsuura is not able to provide any other flexibility or control over valve opening or timing, other than being able to simply disable one of the valves. 
     U.S. Pat. No. 5,669,341 to Ushirono et al. discloses a valve operating system which uses an electrically operated valve in addition to a mechanically operated valve. However, Ushirono et al. only employs the electrically operated valve during certain engine conditions. 
     While these units may be suitable for the particular purpose employed, or for general use, they would not be as suitable for the purposes of the present invention as disclosed hereafter. In particular, these multiple valve systems all seek to employ a modified mechanical cam-based opening system. They are generally concerned with ensuring that all intake valves open together. However, some study has revealed that carefully creating turbulence in the combustion chamber can increase engine performance. But, the prior art systems are unsuitable for experimentation to optimize such effects, because they do not allow independent operation or opening timing between the various intake valves. In addition, internal stresses generated by the cam system inertia in itself limits rev speeds that the engine can achieve. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to increase the performance of an internal combustion engine. Accordingly, the invention is a poly valve system which employs several intake and several exhaust valves per cylinder. 
     It is another object of the invention to provide multiple valves per cylinder without requiring a complex cylinder head configuration. Accordingly, the poly valve system eliminates the cam structure ordinarily required in four stroke engines. 
     It is yet another object of the invention to create turbulence within the cylinder during the intake cycle. Accordingly, fully independent valve operation and freedom of valve placement allow the effects of intake turbulence to be optimized. 
     It is a further object of the invention to greatly increase the revolution limit of the engine. Accordingly, the use of multiple valves, and the lack of reliance on a mechanical system to open and close the valves greatly increases the allowable rotary speed for the engine. In addition, the lower mass and complexity of the poly valve system allows greater speeds to be achieved. 
     It is a still further object of the invention that practically random valve operation is achievable. Accordingly, electric, hydraulic, or pneumatic valves may be employed so that fully random selection of opening and closing times can be determined and executed in accordance with achieving maximum efficiency. 
     It is yet a further object of the invention to reduce the overall size of the engine. Accordingly, by eliminating standard camming mechanisms, a significant space savings can be achieved. 
     It is a still further object of the invention to optimize the shape of the combustion chamber. Accordingly, by having the ability to place numerous, smaller valves at flexible locations in the cylinder head, the piston need not be altered to provide valve clearance and thus can have a smoother shape. 
     The invention is a poly valve system for an internal combustion engine having at least one cylinder having a bore, a piston capable of reciprocal travel within the bore, a cylinder head adjacent the bore, and a combustion chamber defined between the cylinder head and the piston, comprising a plurality of independently operated valves. Intake and exhaust manifolds are located adjacent to the cylinder head. Valve seats comprise openings in the cylinder head between one of the manifolds and the combustion chamber. Poppet valves are situated in the valve seats to selectively allow communication between one of the manifolds and the combustion chamber. The valves are electrically, pneumatically, or hydraulically operated so that each valve, including one of several intake valves per cylinder, may be operated independently of each other. 
     To the accomplishment of the above and related objects the invention may be embodied in the form illustrated in the accompanying drawings. Attention is called to the fact, however, that the drawings are illustrative only. Variations are contemplated as being part of the invention, limited only by the scope of the claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings, like elements are depicted by like reference numerals. The drawings are briefly described as follows. 
     FIG. 1 is a diagrammatic top plan view, illustrating a portion of a cylinder head associated with one cylinder, indicating an exemplative valve placement which may be used in accordance with the present invention. 
     FIG. 2 is a cross sectional view of a cylinder, showing a pair of independently operable valves, wherein the valves are constructed according to an electrically operated embodiment of the invention. 
     FIG. 3 is a cross sectional view of a cylinder, wherein similar to FIG. 2, except wherein the valves are of an electrically operated embodiment of the invention which uses a coil spring to restore the valve to the closed position. 
     FIG. 4 is a cross sectional view of a cylinder, wherein the valves are hydraulically or pneumatically operated. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 diagrammatically illustrates a cylinder head  10  having a plurality of valve openings  12  depicted therein. The valves comprise intake valves  12 A and exhaust valves  12 B. An intake manifold  15  is in communication with the intake valves  12 A, and an exhaust manifold  16  is in communication with the exhaust valves  12 B. 
     FIG. 2 is a cross sectional view, which illustrates a cylinder  20 . The cylinder  20  has a bore  21 , through which a piston (not shown) reciprocates. A cylinder head  22  is located on top of the bore  21  toward and away from which the piston reciprocates. Together the bore  21 , the cylinder head  22  and the piston define a combustion chamber. The cylinder head  22  includes an intake passageway  24  and an exhaust passageway  26 , which form part of the intake and exhaust manifolds shown in FIG.  1 . Both the intake passageway  24  and exhaust passage way  26  are in communication with the combustion chamber though a valve seat  30 . A poppet  32  is located at each valve seat  30  for selectively opening its respective passageway to the combustion chamber, or closing the same. 
     Illustrated in FIG. 2 are one of the intake valves  12 A and one of the exhaust valves  12 B, which are capable of operating their respective poppets  32  to selectively open and close the intake passageway  24  and exhaust passageway  26  to the combustion chamber. In FIG. 2, the poppet  32  for the intake valve  12 A is open, and the poppet  32  for the exhaust valve  12 B is closed. 
     With respect to the particular structure of the valves  12 , the most apparent feature is the absence of any cam structure. Each of the valves  12  is independently operable by electrical, hydraulic, or pneumatic means. In the embodiment illustrated in FIG. 2, the valves  12  are electrically operated. 
     FIG. 2 illustrates one example of an electrically operated valve suitable for the poly valve system of the present invention. The valve  12  includes a T-cap  40  attached to the poppet  32  by a poppet shaft  42 . The T-cap  40  has a flange  41  which is fully opposite the poppet  32  and a barrel  44  extending from the T-cap  40  toward the poppet  32  and coaxial with the poppet shaft  42 . At least a portion of the flange  41  is made of a ferrous metal. The valve includes a solenoid  50  located between the poppet  32  and the T-cap  40 . A limit sleeve  46  is mounted between the cylinder head  22  and the T-cap  40 , the poppet shaft  42  extending through the limit sleeve  46 , for limiting the downward travel of the poppet. The limit sleeve  46  stops downward travel of the poppet  32  when the barrel  44  of the T-cap  40  reaches the limit sleeve  46 . 
     The solenoid  50  comprises a solenoid coil  52  mounted on a spindle  54  coaxial with the poppet shaft  42 . When the solenoid coil  52  is energized, the flange  41  of the T-cap  40  is attracted toward the spindle  54 , moving the poppet shaft  42  and thus the poppet downward, opening the valve. 
     A spring means is provided between the cylinder head and T-cap  40  for biasing the T-cap away from the cylinder head, and thus for biasing the poppet in the closed position. The spring means acts to return the poppet to its valve seat and close the valve immediately after power is removed from the solenoid coil. 
     In FIG. 2, the spring means is an elastomeric housing  60  which also acts as an enclosure for the solenoid  50 . The elastomeric housing  60  is cylindrical, is coaxial with the poppet shaft  42 , and has two housing ends  62 . One of the housing ends  62  extends against the flange  41  of the T-cap  40 , and the outer housing end  62  extends against the cylinder head. The cylinder head has a valve recess  27  within which said housing end  62  is mounted and is stabilized thereby. 
     In FIG. 2, the intake valve  12 A is shown in the open position, while the exhaust valve  12 B is shown in the closed position. As illustrated, the elastomeric housing  60  has buckled as the intake valve  12 A opened. When the solenoid coil is de-energized, the elastomeric housing  60  “pops back”, closing the valve, as shown by the exhaust valve  12 B. 
     FIG. 3 illustrates another embodiment of the valve  12 , wherein the spring means is a coil spring  65  mounted between the T-cap  40  and the cylinder head  22 . The coil spring  65  and the solenoid are preferably contained within a rigid housing  67  which is mounted in the valve recess  27 . Once again, in FIG. 3, the intake valve  12 A is shown in the open position while the exhaust valve  12 B is shown in the closed position. As in the embodiment of FIG. 2, the valve  12  operates by attracting the T-cap flange  41  toward the solenoid coil  52  to open the valve, and then the valve is closed by de-energizing the solenoid coil  52  and allowing the coil spring  65  to return poppet  32  to the closed position. 
     FIG. 4 illustrates a further embodiment of the invention, in which the valves  12  are hydraulically or pneumatically operated using a fluid medium. “Fluid” as used herein, can refer to either a liquid or gas medium suitable for use in transfering mechanical energy. The valves  12  comprise a sealed housing  80  which is mounted within the valve recess  27  of the cylinder head. The sealed housing  80  has smooth inner walls  83 , an upper portion  81  and a lower portion  82 . The T-cap  40  is sized to fit tightly within the sealed housing  80  so that it can move upward and downward within the sealed housing  80 , toward and away from the cylinder head  22 , while maintaining a close fit with the inner walls  83 . The coil spring is mounted between the T-cap  40  and the lower portion  82  of the sealed housing  80  The upper portion is in fluid communication with a control line  86 . Fluid  84  is present in the upper portion  81  above the T-cap  40 . When the fluid  84  in the upper portion  81  is pressurized by means of the control line  86 , the T-cap  40  is pushed downward and thus the valve is opened, as shown by the intake valve  12 A. When pressure in the upper portion  81  is released by releasing pressure in the control line  86 , the coil spring  65  returns the poppet to its valve seat, closing the valve, as illustrated in FIG. 4 by the exhaust valve  12 B. 
     Regardless of the particular valve configuration used, all valves are operated under the control of a central control unit. Since the valves are each individually operable operation of the engine, valve timing and opening duration may be completely determined by said control unit. In the case of the electrically operated valves, a buffered or amplified signal from a microcontroller is all that is necessary to actuate the valves. When pneumatic or hydraulic valves are used, an intermediary system is necessary to pressurize and evacuate the control lines at appropriate times under the direction of the control unit. Nevertheless, whether pneumatic or hydraulic lines are used for the control line, or an electrical connection is made to the solenoid, such control connections communicate what may be referred to as a control signal. The term control signal is appropriate because it is the mere presence of the signal that causes the valve to operate, and not the position of any other engine components. In other words, the valve can even be made to operate at a completely inappropriate time, such as during the compression or combustion strokes, if so desired. 
     Because the valves are not mechanically linked to the rotation of the crankshaft, they are fully independently operable, the various intake valves for each cylinder may be operated independently. Thus, the staggered opening of the various intake valves may be used to create a turbulent “swirl” during the intake stroke. Empirical study can determine the most effective opening order, opening times, and opening duration for the valves, and can determine variations for different engine speeds. The control unit can then be programmed with this data, and operate the valves accordingly. With the flexible valves arrangement of the present invention, similar study could conceivably be used to determine if varying the exhaust valve opening order has an bearing on the ability of the engine to evacuate the combustion chamber of exhaust gases during the exhaust stroke. In addition, valve placement on the cylinder head has greater flexibility when compared to cam operated valve systems. Thus, the valve placement can be optimized through empirical experimentation to maximize the swirl effect, air flow, and thus engine performance. 
     In conclusion, herein is presented a poly valve system which improves engine performance by providing multiple, independently operable valves per cylinder. The engine configuration disclosed herein provides a platform for experimentation to determine valve order, opening timing, and opening duration to maximize engine performance.