MXPA00004380A - Lost motion full authority valve actuation system - Google Patents

Abstract

A lost motion valve actuation system utilizing a single solenoid valve (105) or trigger valve (80) to vary the timing of the intake (26) and exhaust (56) valves for a cylinder of an internal combustion engine. The solenoid controls the oil supply (100) to the tappets (20, 50), which in turn, determine valve motion in response to a camshaft lobe. The system allows independent control of each valve and provides for advanced features such as enhanced intake air swirl, two-valve or four-valve operation and staggered valve opening. The invention provides for valve operation even in the event of a total loss of system hydraulic pressure. The invention provides the practical benefits of a fully-variable system while preserving the security and reliability of a mechanical, cam-driven valve train. The invention provides for filling the exhaust and intake tappets (20, 50) independently without connecting their respective hydraulic circuits.

Description

VALID AUTHORITY VALVE DRIVING SYSTEM OF LOST MOVI MENT REFERENCE RELATED TO RELATED PATENT APPLICATIONS This application claims priority over the Provisional Application Serial Number 60 / 066,376, entitled "Lost Motion System for Independent Control of Multiple Motor Valves", filed on November 21, 1997 and Provisional Application Serial Number 60 / 064,353, entitled "Valve Actuation System of Authority Total Motion Lost to Fault Tests "filed on November 4, 1997. FIELD OF THE I NVEN C ION The present invention relates to motor valve drive systems for internal combustion engines. In particular, the present invention relates to a lost motion valve drive system. BACKGROUND OF THE INVENTION Cylinder chamber valves are commonly disc-type valves with a rod. These rod-type motor valves are normally closed polarized by a valve spring. The valves open when enough force is applied to overcome the force of the spring. There are different methods to generate force to open the valve. Many valve drive systems use hydraulic pressure. The branch piston makes contact with the stem of the motor valve. The movement of the master piston generates an increase in the hydraulic pressure in the branch piston. In response to the increased hydraulic pressure, the diverted piston moves, forcing the motor valve to open. The master piston and the branch piston are hydraulically related. In these systems, a rotating cam commonly produces the displacement of the master piston. The movement of the master piston is transferred to the piston derived by the hydraulic articulation between the two pistons. The movement of the branch piston, relative to the profile of the cam, can be modified by draining and filling the hydraulic joint between the master piston and the branch piston. This process allows to transfer selected portions of the movement of the master piston, that is, the profile of the cam to the derived piston. A system capable of transferring only a portion of the movement is commonly referred to as a "lost motion" system. An example of this system is disclosed in U.S. Patent Serial Number 5,537,976, issued to the assignee of the present application and is incorporated herein by reference. Lost motion systems can be used to vary the timing of the motor valve. To achieve improved performance and fuel economy of the internal combustion engine, it may be necessary to vary the timing of the exhaust and inlet events of the engine. It may be desirable in engines having multiple inlet and / or exhaust valves per cylinder to make a stepped opening between the valves in a cylinder. It may also be desirable to operate a four-valve cylinder in a two-valve or four-valve mode. Addition- ally, it may be necessary to "turn off" the cylinder. Cylinder shutdown can be achieved by not operating all the exhaust, inlet and cylinder valves. A valve actuation system that is capable of varying the operation of the cylinder from the entire valve operation to the cylinder off is called a fully variable system. Fully variable valve drive systems are also known as "total authority" systems. As mentioned above, the common valve drive system uses a cam to impart movement to a master piston. However, recent efforts to achieve variable control over exhaust and inlet valve events have focused on non-cam engine designs. An example of a non-cam engine is described in the U.S. Patent of North America Serial No. 5, 619, 965, which is incorporated herein by reference. It has been found that non-cam engine designs are difficult and expensive to implement. A further disadvantage of many non-cam designs is the lack of any mechanical backup. Failure of electrical power or loss of hydraulic pressure can produce no valve movement. In fact, even some cam-driven designs can not produce valve movement in the event of hydraulic pressure loss.

These systems do not have a fail-safe mode of operation. There is a need for a variable lost-motion valve drive system that provides control of an exhaust valve and motor cylinder inlet using a common trigger valve. Current valve drive systems are commonly based on a single trigger valve for each motor valve. The few systems that use a single solenoid to control mule motor valves, do not have the ability to independently control the positions of the valves. There is also a need for a valve drive system that has the practical benefits of a fully variable system with the safety and reliability of a mechanical, cam-operated valve train, and with the advanced system features commonly available in designs of motor without cam. The present invention provides a means for controlling engine valves in an internal combustion engine cylinder having mule exhaust and / or inlet valves utilizing a novel electro-hydraulic valve actuating system. By matching an exhaust and inlet valve under the control of a single hydraulic solenoid valve, or tripping valve, independent control of each valve can be obtained, allowing for features such as improved intake air swirl, two valve operation over a range of determined speed, and staggered valve opening. This is possible because in most cases, the escape and entry events occur at different times in a four-cycle engine. Therefore, at any given time, only one of two valves in a series (either the exhaust or inlet) is active, with the other in base circle. Opening the trigger valve at this time would only affect the valve actuated by the projection of the cam outside the base circle at that instant. Events that significantly overlap, but need independent control, can be placed in different cams (ie, one of two exhaust cams in a dual cylinder cam system with discrete projections for each valve). OBJECTS OF THE I NVENC ION Therefore, an object of the present invention is to provide an innovative and economical variable timing valve drive design. A further object of the present invention is to provide a fail-safe mode of operation for a valve drive system. A further object of the present invention is to provide common control of the exhaust valve and inlet actuator circuits in a cylinder with a high velocity trip valve. A further object of the present invention is to provide improved reliability through a simple and innovative design of a variable timing motor valve drive system.

A further object of the present invention is to provide independent control of each pair of exhaust and inlet valves.

A further object of the present invention is to provide a valve drive system capable of cylinder cutting. A further object of the present invention is to provide selective valve operation for each cylinder. A further object of the present invention is to provide the stepped opening of exhaust or inlet valves. A further object of the present invention is to provide a total authority valve drive system for an internal combustion engine. Additional objects and advantages of the invention are set forth, in part, in the description presented below and in part, will be apparent to those skilled in the art from the description and / or practice of the invention. BR EVE D ESCR I I NN TION OF THE I NVENCTION In response to the above challenges, the Applicants have developed an innovative and economical method and apparatus for controlling the operation of the engine valve in an internal combustion engine. The present invention is directed to a valve drive system for a cylinder of an internal combustion engine having an exhaust and inlet valve comprising: a train of inlet valves; an exhaust valve train; a hydraulic inlet valve actuator that selectively responds to the movement of the inlet valve train and causes the inlet valve to open; a hydraulic exhaust valve actuator that selectively responds to the movement of the exhaust valve train and causes the exhaust valve to open; a control valve for controlling the supply of hydraulic fluid to the inlet valve actuator and the exhaust valve actuator to control the response of the actuators to the movement of the valve trains. The hydraulic actuators may include a master piston; a piston derived; and a variable volume fluid chamber formed between the master piston and the branch piston. The control valve may be a solenoid-operated valve or a spool valve. The actuators may be oriented such that the branch piston contacts the engine valve and the master piston contacts the valve train. However, the master piston can make contact with the motor valve and the branch piston can make contact with the valve train. The control valve controls the amount of fluid in the variable volume fluid chamber to selectively modify the exhaust valve openings in response to the exhaust valve train. The exhaust valve train may include an exhaust cam. The actuators may also comprise hydraulic impellers. The impellers may include master and derivative pistons, wherein the master piston includes a central bore and the branch piston is slidably positioned within the central bore. The system may also include a means for performing motor valve movement in the face of a loss of hydraulic pressure. The means for performing motor valve movement can comprise the mechanical joint created when the variable volume chamber completely collapses the master piston makes contact with the directly derived piston to transfer movement of the valve train to the valve. An alternative embodiment of the present invention is a valve drive system for a cylinder of an internal combustion engine having a plurality of engine valves comprising: a plurality of valve trains; wherein each valve train is moved to open one of the plurality of motor valves; a plurality of hydraulic actuators, wherein each hydraulic actuator selectively responds to the movement of one of the valve trains to open one of the motor valves; and a means for controlling the supply of fluid to each pair of hydraulic actuators. Each hydraulic actuator may comprise: a master piston; a piston derived; and a variable volume fluid chamber formed between the master piston and the branch piston. The means for controlling the fluid supply may comprise a solenoid operated valve. The means for controlling, controls the supply of fluid to a hydraulic actuator for an inlet valve and an exhaust valve. The system may also include a means for performing motor valve movement in the face of a loss of hydraulic pressure. The means for performing motor valve movement may comprise a mechanical joint created when the variable volume chamber collapses completely causing the master piston to make contact with the derived piston directly by transferring movement directly from the valve train to the motor valve.

A further embodiment of the present invention may be a valve drive system for an internal combustion engine having at least one motor valve operable to control flow in or out of a cylinder, the valve drive system comprising : an oscillating lever pivotally mounted adjacent to the engine valve to open the engine valve, wherein the oscillating lever includes a first and second ends, a fluid passage, and a bore in the first end of the oscillating lever, wherein the fluid passage connects the perforation to a source of fluid supply; an actuator piston slidably positioned in the bore; means for rotating the oscillating lever; and a means for controlling the pressure in the fluid passage. The means for controlling the pressure can be a control valve. The means for rotating may comprise a rotating cam. The first end of the oscillating lever can be moved by the means for rotating. The second end of the oscillating lever can displace the motor valve. The piston of the actuator can be forced out of the bore by the increased fluid pressure in the fl uid passage, and the amount of the stroke of the motor valve is proportional to the pressure in the fluid passage. The system states that in the event of a loss of pressure in the passage, the means for rotating causes the oscillating lever to rotate and an amount of the stroke of the motor valve will still occur. A further embodiment of the present invention may be a valve drive system for a cylinder of an internal combustion engine that includes two inlet valves and two exhaust valves comprising: a train of inlet valves; an exhaust valve train; a first inlet valve actuator that selectively responds to the movement of the inlet valve train and causes the first inlet valve to open; a second inlet valve actuator that selectively responds to the movement of the inlet valve train and causes the second inlet valve to open; a first exhaust valve actuator that selectively responds to movement of the exhaust valve train and causes the first exhaust valve to open, a second exhaust valve actuator that selectively responds to the movement of the exhaust valve train and makes that the second exhaust valve opens; a first control valve for controlling the operation of the first exhaust valve actuator and the first inlet valve actuator; and a second control valve for controlling the operation of the second inlet valve and exhaust valve actuators. The control valves can be solenoid valves. The valve actuators may be hydraulic impellers comprising: a piston derived; a master piston that includes a central bore; and wherein the branch piston is slidably positioned within the central bore forming a variable volume chamber between the master piston and the branch piston. It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention as claimed. The accompanying drawings, which are incorporated herein by reference, and which form a part of this specification, illustrate certain embodiments of. the invention and, together with the detailed description, serve to explain the principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS. Figure 1 is a schematic view of a valve drive system in which the exhaust valve and inlet valve actuators of a motor cylinder are controlled by a common solenoid valve; Figure 2 is a schematic view of a variable valve drive system in which the exhaust valve and inlet valve actuators of a motor cylinder are controlled by a common control valve; Figure 3 is a cross-sectional schematic side view of the variable valve drive system described in Figure 4; Figure 4 is a schematic top view of a variable valve drive system integrated in an exhaust cam with a single solenoid valve for two engine valves; Figure 5 is a schematic top view of one embodiment of the system shown in Figure 4, without an accumulator; Y Figure 6 is a schematic view of a variable valve drive system for a four-valve cylinder of an internal combustion engine. DETAILED DESCRIPTION OF THE PREFERRED MODALITIES Referring now to Figure 1, which describes a valve actuation system 10 in accordance with the present invention. The valve drive system 10 of the present invention comprises an inlet impeller 20, an exhaust impeller 50, and a trip valve 80. The system 10 may additionally comprise other elements such as: an oil supply 100 and an accumulator 90. The valve actuating system 10 of the present invention is a lost motion system for operating an inlet valve 26 and an exhaust valve 56 of a cylinder of an internal combustion engine. The input impeller 20 and the exhaust impeller 50 are hydraulic actuators which may be similar and which may comprise a master piston 30 and a branched piston 40. The master piston 30 comprises a hollow indic element cyl including an upper surface 36, the wall of inner end 33, and a hole 32. The branched piston 40 comprises the end wall 43 and the bottom surface 46. The branch piston 40 preferably comprises a cylindrical body of suitable dimension to be placed inside the master piston 30. Together, the piston branch 40 and master piston 30 define a chamber 45. The volume of chamber 45 may vary according to the position of the pistons relative to each other. A hole 32 is provided in the master piston 30 to allow the flow of oil in and out of the chamber 45. The impellers 20 and 50 can be driven by external valve trains that move to make contact with the impellers and drive the valves 26 and 56. The elements of the valve trains 24 and 54 make contact with the upper surface 36 of the master piston 30, while the lower surface 46 of the derived piston 40 controls with the appropriate motor valve. The elements of the valve trains 24 and 54 are located external to the system 10. The valve trains are preferably driven by a rotary cam (not shown). The valve trains may comprise, for example, an exhaust cam or a hydraulic joint. Valve trains can include a master piston and derivative piston configuration where the master piston is moved by a cam follower and the movement of the master piston is transferred hydraulically to a branch piston, which serves as train elements. Valves 24 and 54. The valve trains may also comprise a common rail system wherein the elements of the valve trains are displaced by fluid provided from a pressurized head. The impellers 20 and 40 function as a means for transferring movement of the elements of the valve trains 24 and 54 to the appropriate motor valves. The position of the valves 26, 56 can vary with respect to the impellers 20, 50. For example, the paper of the master piston and the bypass piston, described above, can be reversed so that the master piston 30 makes contact with the valve. motor and the branch piston 40 makes contact with the valve train. The present invention includes a trigger valve 80. The trigger valve 80 is commonly a hydraulic high-speed solenoid operated control valve. The trigger valve 80 comprises an inlet 84 and an outlet 86. The inlet 84 is hydraulically connected to the inlet impeller 20 via the passage 81, and to the exhaust impeller 50 via the passage 82. The outlet 86 is hydraulically connected to the impeller inlet 20 via passage 87, and exhaust impeller 50 via passage 88. Exit 86 is also hydraulically connected to accumulator 90 and oil supply check valve 102. Accumulator 90 comprises piston 92, the spring 94, and the variable volume chamber 93. The accumulator 90 is hydraulically connected directly to outlet 86 of the trigger valve 80, as well as the passages 87 and 88. The spring 94 comprises a biasing means for force the piston 92 in one direction to reduce the size of the chamber 93. The accumulator 90 provides an overpressure volume and a source of pressure and accumulation oil to the system 10. The check valve 94 is positioned in the passage 81 between the input impeller 20 and inlet 84, while check valve 96 is positioned in passage 87 between inlet impeller 20 and outlet 86. Likewise, check valve 95 is positioned in passage 82 between impeller 50 and the inlet 84, while the check valve 97 is positioned in the passage 88 between the exhaust impeller 50 and the outlet 86 to the release valve 80. The check valves 94 and 95 allow the the oil flows from the impellers 20, 50 to the release valve 80. The check valves 96 and 97 allow the supply oil to flow to the impellers 20, 50. The location of the above-mentioned check valves allows the impellers Fill and drain as necessary. The check valves also prevent the crossing between the impellers. The oil supply 100 preferably comprises a direct feed of the protrusion oil system of the internal combustion engine, but the oil supply 100 can also comprise any suitable source of hydraulic fluid, such as an independent presumed oil system. The check valve 102 serves to isolate the system 10 from the oil supply 100. The operation of the pump is written with additional reference to Figure 1. Focusing on the input impeller 20 , during normal operation the chamber 45 is filled with oil from the oil supply 100 through the passageway 87 and the orifice 32. The trip valve 80 closes and the oil in the chamber 45 maintains a constant volume since the valves retention 95 and 96, as well as trigger valve 80, prevent oil from leaking out of chamber 45. In this "solid" condition, all cam movement imparted to input valve train member 24 is not transferred to the Inlet valve 26, a control system (not shown) energizes trigger valve 80. Trip valve 80 is opened, and a hydraulic flow path from chamber 45 to accumulator 90 is established. camera 45 makes q The volume of the chamber shrinks, reducing the combined length of the input master piston 30 and the input-derived piston 40. A portion of the movement of the input valve train element 24 is absorbed before it reaches the inlet valve. 26. When lost motion is no longer desired, trigger valve 80 is de-energized allowing the accumulation of accumulator oil 90 and oil supply 100 to flow through passage 87 to chamber 45 to expand the chamber to its maximum volume . The input impeller 20 is now solid, and all movement of the inlet valve train is transferred to the inlet valve 26. The operation of the exhaust impeller 50 is similar to that described above for the inlet impeller 20. However , the events of escape and entry occur at different times in an internal combustion engine cycle. There is no significant period in which the cam of the inlet valve that imparts movement to the inlet valve train member 24 and the exhaust cam imparting movement to the exhaust valve train member 54 are both active. At any given time, one is active, while the other cam is in or near the base circle. As a result, when the trigger valve 80 is opened, only the valve actuated by the cam projection outside the base circle at that instant is affected. Thus, the design of the present invention allows independent control of the inlet valve 26 and the exhaust valve 56 using only a solenoid valve 80. As shown in Figure 6, two trip valves 80 and 81 can be provided to control four motor valves (two inlet valves and two exhaust valves) located in a cylinder. Figure 6 describes a system with two inlet valve actuators 20 and 21, two exhaust valve actuators 50 and 51, an accumulator 90, and several check valves 94-97 and 294-297 that operate as shown in FIG. Figure 1 and mentioned above.

Each trigger valve is connected to two impellers, one input and one exhaust. The configuration shown in Figure 6 allows each inlet valve and each exhaust valve to operate independently as mentioned above.

Trigger valves can be operated to allow one or more of the motor valves to shut off at any given time. The invention allows the total cutting of the cylinder. The configuration shown in Figure 6 allows to provide features such as improved intake air swirl, two valve operation over a certain speed range, and stepped valve opening. The operation of the trip valves 80 and 81 can be staggered to provide any combination of motor valve operation. For example, an exhaust valve and an inlet valve can be operated. Alternatively, one inlet valve and two exhaust valves can be operated. In another mode, an exhaust valve and two inlet valves can be operated together. The invention provides the operation of all or none of the motor valves or any combination thereof. In addition, trigger valves 80 and 81 can operate to provide motion lost in each actuator. Referring now to Figure 2, in an alternative embodiment of the invention, the trigger valve 80 is replaced by the solenoid-operated spool valve 105. E? In this embodiment of the invention, a separate input hydraulic circuit 106 and an exhaust hydraulic circuit 107 are provided. The circuits are independent of each other except for a common source of the oil supply 100. The check valves 102 and 103 isolate the circuits between them while allowing fluid to flow from the oil supply 100 to any circuit. The input circuit 120 is provided with an accumulator 98, while the exhaust circuit 150 is provided with the accumulator 97. The operation of the embodiment of the invention shown in FIG.

Figure 2 is similar to that of the modality shown in Figure 1 and as described above. When the spool valve 105 is in the open position, a flow path from the inlet impeller 20 to the accumulator 90, and from the exhaust impeller 50 to the accumulator 91 is established. When the spool valve 105 is in the open position, the Oil can flow out of the inlet impeller 20 and out of the exhaust impeller 50 to achieve the variable valve drive of the inlet valve 26 and the exhaust valve 56. When the spool valve 105 is in the closed position, the impeller inlet 20 and exhaust impeller 50 are "solid" so that the total cam-driven movement of the inlet valve 26 and the exhaust valve 56 occurs. As described above, accumulators 90 and 91 provide overpressure volumes and accumulation for the input circuit 120 and the exhaust circuit 150, respectively. Referring again to Figure 1, a further embodiment of the invention can be described which provides fail-safe valve operation in the event of power failure or hydraulic pressure. A mechanical joint is created between the valve train and the engine valve. The input master piston 30 and the inlet branch piston 40, and the input valve train element 24 and the inlet valve 26 are designed so that in the event of loss of system oil pressure for any reason, the end 33 of the inlet master piston 30 will contact the end wall 43 of the inlet-derived piston 40 to impart at least a portion of the movement of the inlet valve train member 24 to the inlet valve 26. Some movement will occur. valve entry even in the event of a total loss of system oil pressure. The exhaust impeller 50 can be constructed similarly. The system described in Figure 6, it can also provide fail-safe operation in the face of loss of hydraulic pressure. This embodiment of the invention provides variable timing benefits of the lost motion system with the reliability of a non-hydraulic cam operated valve drive system. Several internal configurations of the master piston and the branch piston can be used on an impeller while when the oil pressure is lost and the impeller collapses, the master piston and the branch piston contact in a manner that ensures the transfer of movement from the cam through the impeller to the respective motor valve. This embodiment of the invention may also employ a spool valve as shown in Figure 2. Figure 3 shows an alternative embodiment of a valve drive system in accordance with the present invention. The valve actuation system 100 shown in Figure 3 comprises an inlet valve swing lever 120, a solenoid operated trigger valve 180. The system 100 may further comprise a rotating pedestal 1 10 and an accumulator 140. Figure 3 , is a cross-sectional view of the inlet valve swing lever 120. An oscillating exhaust valve lever can be configured in the same way. As shown in Figure 3, the inlet valve swing lever 120 has a first end 121 and a second end 122. The swing lever additionally includes a fluid circuit 123 and an accumulator piston 124. The pressure in the circuit fluid 23 is controlled to selectively place the system in the valve actuation mode. The input valve swing lever 120 further includes an opening for the axis of the oscillating lever 125, in which the oscillating lever rotates in response to the cam projection stroke profile of the suitable motor valve. The pivoting of the rocker lever is initiated by lifting and dropping the thrust tube 126. The thrust tube 126 rises and falls in response to the cam shoulder movement, causing the rocker 120 to rotate in response to the movement of the cam . A bearing in the form of a cylindrical bushing 127 is disposed about shaft 125 and is rigidly connected to oscillating lever 120 to allow smooth pivotal rotation on shaft 125. Lubricating oil is provided to bearing 127 through passage 128 .

The operation of the valve actuation system 100 shown in Figure 3 will now be described. When the tripping valve 180 is open the fluid circuit 123 can be filled with fluid from the oil supply 100. The piston of the actuator 124 is located in slidable downwardly making contact with push tube 126. When valve operation is not desired, trigger valve 180 is kept open. When the thrust tube 126 is lifted in response to movement of the cam, the fluid above the piston of the actuator 124 moves through the fluid circuit 123 and the trigger valve 180 and into the accumulator 140. The exhaust cam 120 it does not move in response to the movement of the cam. When valve operation is desired, trip valve 180 is turned off. Actuator piston 124 may not move upward since fluid in circuit 123 may not escape. When the pusher tube 126 is displaced by the cam shoulder the inlet valve swing lever 120 rotates about the oscillating shaft 125 in response to the stroke profile of the inlet cam shoulder. As the first end 121 of the oscillating lever 120 is moved upwardly by the push tube 126, the oscillating lever 120 rotates by forcing the second end 122 downwards. A second end 122 moves downward and contacts the inlet valve 130 forcing it to open. When the valve operation is no longer desired, the trigger valve 180 opens allowing the accumulator 140 to absorb the movement of the push tube 126.

The system shown in Figure 3 can be connected to additional motor valves by means of the fluid supply head 160. Multiple motor valve drive systems can use the same fluid supply 100 and the accumulator 140. It is also within range of the present invention configure the valve drive system so that a thrust tube or cam follower makes contact with the oscillating lever directly and a piston of the actuator makes contact with the motor valve. Figure 4 shows an alternative view of the system shown in Figure 3, however the valve actuation system of Figure 4 allows the control of two engine valves with a single trigger valve. The system 100 described in Figure 4 comprises an inlet valve swing lever 120 and an exhaust valve swing lever 150. The levers are mounted on the rotating pedestal 110. The levers include actuator pistons 124 and 154 which function as shown in FIG. described earlier. The system of Figure 4 further includes a pair of check valves 115 located between the levers. The system 100 of Figure 4 may additionally include separate check valves 111 and 112 located between the fluid supply 100 and the valve actuators. When operation of the motor valve is desired, the trip valve 180 is closed creating a hydraulic link between the thrust tubes and the motor valves. While the trigger valve 180 is closed, the fluid can not escape from above the actuator and the movement of the thrust tube is transferred to the motor valve in the manner described above for the system described in Figure 3. When valve operation is desired, trigger valve 180 is opened allowing fluid pressure created by upward movement of the actuator piston to be absorbed by accumulator 140. FIG. 5 describes a system similar to that shown in FIG. Figure 4. The system described in Figure 5 does not include an accumulator. Instead, when the actuator pistons move upward the fluid is forced outwardly by the drain 109. The systems described in Figures 3, 4, and 5 may all include a method for providing valve operation in the case of a total pressure loss in circuit 123. With reference to Figure 3, for example, the system may be designed so that the total stroke up the thrust tube 126 exceeds the available stroke distance of the piston of the actuator 124 in the bore 129. If there is no pressure in the circuit 123, the piston of the actuator 124 will be forced upwardly into bore 129 by lifting push tube 126. Once the piston of actuator 124 has reached its mechanical stop, continuous upward movement of push tube 126 will cause first end 121 of the oscillating lever 120 is moved upwards by rotating the oscillating lever and causing the second end 122 to be moved downwards by opening the motor valve. Therefore, a fail-safe mechanical method can be provided to open the motor valves. It will be apparent to those skilled in the art that various modifications and variations may be made in the construction and configuration of the present invention without departing from the scope or spirit of the invention. Various modifications and variations may be made in the construction of the inlet impeller 20 and the exhaust impeller 50 without departing from the scope or spirit of the invention, for example, the master and derivative pistons may be of a variety of cross-sectional sizes and shapes while These elements are coupled to form a functioning impeller. The impellers can be concentric, axially mounted, etc. Any means capable of imparting mechanical movement to the impellers and still be within the scope of the invention can be employed. Additionally, it may be appropriate to make additional modifications, such as including different configurations of oscillating valve levers, thrust tubes, etc. , to form the drive train of the valve on either side of the impeller. Therefore, it is intended that the present invention cover the modifications and variations of the invention provided that are within the scope of the appended claims and their equivalents.

Claims (36)

1. CLAIMS 1. A valve drive system for a cylinder of an internal combustion engine having an inlet valve and an exhaust valve comprising: a train of inlet valves; an exhaust valve train; a hydraulic inlet valve actuator that selectively responds to the movement of said inlet valve train and causes said inlet valve to open; a hydraulic exhaust valve actuator responsively selectively responding to the movement of said exhaust valve train and causing said exhaust valve to open; a control valve for controlling the supply of hydraulic fluid to said inlet valve actuator and such an exhaust valve actuator for controlling the response of said actuators to the movement of such valve trains.
2. 2. The system according to claim 1, wherein the exhaust valve hydraulic actuator comprises: a master piston; a piston derived; and a variable volume fluid chamber formed between such master piston and branch piston.
3. 3. The system according to claim 1, wherein said control valve is a solenoid operated valve.
4. 4. The system according to claim 1, wherein said control valve is a spool valve.
5. The system according to claim 2, wherein said branch piston makes contact with the exhaust valve and said branch piston makes contact with the exhaust valve train.
6. The system according to claim 2, wherein said master piston makes contact with the exhaust valve and said branch piston makes contact with the exhaust valve train.
7. The system according to claim 2, wherein said control valve controls the amount of fluid in such variable volume fluid chamber to selectively modify the openings of such exhaust valve in response to such a valve train. escape.
8. The system according to claim 1, wherein said exhaust valve train comprises an exhaust cam.
9. The system according to claim 1, wherein the hydraulic inlet valve actuator comprises: a master piston; a piston derived; a fluid chamber of variable volume formed between said master piston and said branch piston.
10. The system according to claim 9, wherein said branch piston makes contact with the inlet valve and said branch piston makes contact with the inlet valve train. eleven .
11. The system according to claim 9, wherein said master piston makes contact with the inlet valve and said branch piston makes contact with the train of inlet valves.
12. The system according to claim 9, wherein said control valve controls the amount of fluid in such variable volume fluid chamber to selectively modify the openings of such exhaust valve in response to such a valve train. escape.
13. The system according to claim 1, wherein said input valve train comprises an exhaust cam.
14. The system according to claim 1, wherein each of said hydraulic actuators comprises a hydraulic impeller.
15. The system according to claim 14, wherein said hydraulic impeller comprises a master piston and a branch piston, wherein said master piston includes a central bore and said branch piston is slidably positioned within said central bore.
16. 16. The system according to claim 15, wherein said branch piston makes contact with one of said plurality of motor valves and such master piston makes contact with a valve train.
17. 17. The system according to claim 2, further comprising a means for performing motor valve movement in the face of loss of hydraulic pressure.
18. The system according to claim 17, wherein said means for performing motor valve movement comprises a mechanical joint in the hydraulic actuator created when the variable volume chamber collapses completely and the master piston makes contact with the branch piston. directly to transfer movement of the exhaust valve train to the exhaust valve.
19. 19. The system according to claim 9, further comprising means for performing motor valve movement in the face of loss of hydraulic pressure.
20. 20. The system according to claim 19, wherein said means for performing motor valve movement comprises a mechanical joint in the hydraulic actuator created when the variable volume chamber collapses completely and the master piston makes contact with the piston. directly derived to transfer movement of the exhaust valve train to the exhaust valve. twenty-one .
21. A valve actuation system for a cylinder of an internal combustion engine having a plurality of motor valves comprising: a plurality of valve valves; wherein each valve train is moved to open one of said plurality of motor valves; a plurality of hydraulic actuators, wherein each hydraulic actuator responds selectively to the movement of one of said valve trains to open one of said motor valves; and a means for controlling the supply of fluid to each pair of hydraulic actuators.
22. 22. The system according to claim 21, wherein each hydraulic actuator comprises: a master piston; a piston derived; a fluid chamber of variable volume formed between said master piston and said branch piston.
23. 23. A valve drive system according to claim 21, wherein said means for controlling the fluid supply comprises a solenoid operated valve.
24. 24. A valve drive system according to claim 21, wherein said means for controlling controls the supply of fluid to a hydraulic actu for an inlet valve and an exhaust valve.
25. 25. The system according to claim 22, further comprising means for performing motor valve movement in the face of a loss of hydraulic pressure.
26. 26. The system according to claim 25, said means for performing motor valve movement comprises a mechanical joint in the hydraulic actu created when the variable volume chamber collapses completely causing the master piston to make contact with the piston. directly derived to transfer movement of the valve train to the engine valve.
27. 27. A valve actuation system for an internal combustion engine having at least one motor valve operable to control the flow inside or outside of a cylinder, such valve actuation system comprising: an oscillating lever mounted in an adjacent pivotal manner to said motor valve for opening said motor valve, wherein said oscillating lever includes a first and second ends, a fluid passage, and a bore in said first end of said oscillating lever, wherein said fluid passage connects such perforation to a source of fluid supply; a pin of the actu slidably positioned in said bore; means for rotating said oscillating lever; and a means for controlling the pressure in said fluid passage.
28. 28. The system according to claim 27, wherein said means for controlling the pressure is a control valve.
29. 29. The compliance system with claim 27, wherein said means for making girder comprises a rotating cam.
30. 30. The co-form system with claim 27, wherein said first end of said oscillating lever is moved by said means to rotate.
31. 31. The system according to claim 27, wherein said second end of said oscillating lever displaces said motor valve.
32. 32. The system according to claim 27, wherein said piston of the actu is forced out of such drilling by fluid pressure in said fluid passage to contact said means for rotating and the amount of motor valve stroke. is proportional to the pressure in said fluid passage.
33. 33. The system according to claim 32, wherein said piston of the actu extends from such perforation an amount before a loss of pressure in such passage, said means for rotating makes contact with such piston of the actu and causes such lever oscillating turn and an engine valve stroke amount occurs.
34. 34. A valve drive system for a cylinder of an internal combustion engine that includes two inlet valves and two exhaust valves comprising: a train of inlet valves; an exhaust valve train; a first inlet valve actu that selectively responds to the movement of said inlet valve train and causes the first inlet valve to open; a second inlet valve actu responsively selectively moving said inlet valve train and causing the second inlet valve to open; a first exhaust valve actu that selectively responds to the movement of such an exhaust valve train and causes said first exhaust valve to open; a first exhaust valve actu that selectively responds to the movement of such an exhaust valve train and causes said first exhaust valve to open; a second exhaust valve actu that selectively responds to the movement of such exhaust valve train and causes said second exhaust valve to open; a first control valve for controlling the operation of said first inlet valve actuator and said first exhaust valve actuator; and a second control valve for controlling the operation of said second inlet valve actuator and said second exhaust valve actuator.
35. 35. The system of claim 34, wherein said first and second control valves are solenoid valves.
36. 36. The system of claim 34, wherein said valve actuators are hydraulic impellers comprising: a piston derived; a master piston that includes a central bore; and wherein said branch piston is slidably positioned in the central bore forming a chamber of variable volume between said master piston and said branch piston. RESU MEN A lost motion valve drive system that uses a single solenoid valve (105) or trigger valve (80) to vary the timing of the intake (26) and exhaust (56) valves for a cylinder of a Internal combustion engine. The solenoid controls the supply of oil (100) to the impellers (20, 50) which in turn determine the movement of the valve in response to a projection of the camshaft. The system allows for independent control of each valve, and provides advanced features, such as better intake air swirl, two-valve or four-valve operation, and stepped valve opening. The invention provides the operation of the valves, even in the case of a total loss of the hydraulic pressure of the system. The invention provides the practical benefits of an absolutely variable system, while maintaining the safety and reliability of a mechanical train of cam-driven valves. The invention provides the filling of the exhaust and inlet impellers (20, 50) in an independent manner, without connecting their respective hydraulic circuits.