JP2008095672A - Valve system for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To open/close an intake valve and an exhaust valve directly or through a locker arm by doing away with a camshaft of an engine and providing a hydraulic piston in the intake valve and the exhaust valve of each cylinder. <P>SOLUTION: In this valve system for the engine, the hydraulic piston is provided in the intake valve and the exhaust valve of each the cylinder, hydraulic pressure is forcibly fed to the hydraulic piston by a lubricating oil pump or a newly provided pump, information about an engine speed, a crank angle, an acceleration opening, an accumulator hydraulic pressure, a cooling water temperature and a lubricating oil temperature or the like at that time is processed by an ECU, and a solenoid valve installed near the hydraulic piston is turned on/off to open/close the respective valves in optimum timing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a valve operating mechanism that opens and closes an intake valve and an exhaust valve of an engine.

  In conventional engine valve mechanisms, the intake and exhaust valves of each cylinder are designed appropriately by transmitting the rotation of the crankshaft to the camshaft by means of a timing chain or timing belt to drive and rotate the camshaft. It is a mechanism that opens and closes according to the order of ignition at the right time.

  As described above, the valve operating mechanism of the engine according to the prior art converts the rotational motion of the cam provided on the camshaft into the vertical motion via the rocker arm or tappet, and opens and closes the valve. However, this mechanism has a large drive loss because the rotary motion is converted into the vertical motion.

  Since the timing chain or timing belt, timing gear, etc. are provided at the tip of the engine to drive the camshaft to drive the camshaft, the overall length of the engine will be enlarged, and the camshaft will be processed with high accuracy. Because it is required, processing cost is required.

  The present invention has been made in view of the above points, and its purpose is to eliminate the camshaft and provide hydraulic pistons for the intake and exhaust valves of each cylinder, either directly or via a rocker arm. It is to be able to open and close these valves.

  In order to achieve the above object, the valve operating mechanism of the engine of the present invention is provided with a hydraulic piston directly or via a rocker arm at the intake valve end and the exhaust valve end of each cylinder, and the hydraulic piston or The hydraulic pressure is pumped by a newly installed pump, and information such as the engine speed, crank angle, accelerator opening, accumulator hydraulic pressure, coolant temperature, and lubricating oil temperature is processed by the ECU and installed near the hydraulic piston. It is characterized in that each valve can be opened and closed at an optimal time by turning on and off the electromagnetic valves.

  As described above, according to the present invention, since the rotational motion of the camshaft is not converted into the vertical motion of the valve as in the prior art, it is possible to reduce drive loss.

  With the abolition of the camshaft, the timing chain, timing belt, timing gear and the like attached thereto can be abolished, so that the total length of the engine can be reduced and the cost can be reduced.

  Since the valve operating mechanism of the engine of the present invention is provided with hydraulic pistons on the intake valve and the exhaust valve of each cylinder, the cylinder can be easily stopped by the control when the vehicle is operated in a light load state. it can.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  1 to 3 relate to a first embodiment of the present invention, FIG. 1 is a sectional view in which a hydraulic piston assembly of the present invention is mounted so as to be in direct contact with a valve stem end, and FIG. 2 is a hydraulic piston of the present invention. FIG. 3 is a sectional view of a hydraulic piston assembly, FIG. 4 is a system diagram for electronic control according to a second embodiment of the present invention, and FIG. It is a hydraulic circuit figure concerning a 3rd embodiment of the invention.

  As shown in FIG. 1, in the hydraulic piston assembly 1 of the present invention, the valve stem end 5 of the valve 8 of the cylinder head 2 and the piston stem end 4 incorporated in the hydraulic piston assembly 1 come into contact with each other, and preload is applied to the valve spring 10. It is press-fitted into the cylinder head 2 while being applied. Since this preload is a force for returning the piston 18 of the hydraulic piston assembly 1, the hydraulic piston assembly 1 does not require a return spring. Further, the hydraulic piston assembly 1 is stopped by a retaining ring 12 so as not to come off from the cylinder head 2. At the same position as the oil hole 3 of the hydraulic piston assembly 1, a semicircular oil passage 13 through which the hydraulic pressure is passed through the hydraulic piston assembly 1 is provided at the cylinder head 2 around the hydraulic piston assembly 1.

  FIG. 2 shows an embodiment in which a rocker arm 16 is provided between the hydraulic piston assembly 1 and the valve 8 of the present invention. The rocker arm 16 can swing left and right around the rocker shaft 17, one end of the rocker arm 16 contacts the piston stem 15 of the hydraulic piston assembly 1, and the other end contacts the valve stem end 5. is doing. The piston stem 15 of the hydraulic piston assembly 1 is press-fitted into the cylinder head 2 with a preload applied to the valve spring 10 of the valve 8 via the rocker arm 16. Since this preload serves as a force for returning the piston 18 of the hydraulic piston assembly 1, the hydraulic piston assembly 1 does not require a return spring. Further, the hydraulic piston assembly 1 is stopped by a retaining ring 12 so as not to come off from the cylinder head 2. At the same position as the oil hole 3 of the hydraulic piston assembly 1, a semicircular oil passage 13 through which the hydraulic pressure is passed through the hydraulic piston assembly 1 is provided at the cylinder head 2 around the hydraulic piston assembly 1.

  As shown in FIG. 3, the hydraulic piston assembly 1 of the present invention includes a cylinder 21, a piston 18, a piston O-ring 20, a retainer 22, and a retainer O-ring 19. The cylinder 21 is provided with an oil hole 3 so that the hydraulic pressure is fed to the piston 18.

  In the case of a conventional four-cycle gasoline engine, in the intake stroke, a negative pressure is generated in the cylinder by lowering the piston of the engine, and a mixed gas of fuel and air flows into the cylinder, and the intake valve is opened at that time. When the intake valve opens, the piston starts to open slightly before the top dead center in the exhaust stroke before the intake stroke, and closes the intake valve when the piston slightly passes the bottom dead center in the intake stroke. It is a mechanism. On the other hand, at the opening / closing timing of the exhaust valve in the exhaust stroke, the piston in the combustion (expansion) stroke before the exhaust stroke starts to open slightly before the bottom dead center, and the top dead center of the exhaust stroke has passed slightly. The mechanism is closed at the time. In the case of a 4-cycle diesel engine, the mechanism is basically the same as that of a 4-cycle gasoline engine. However, a 4-cycle gasoline engine takes in a mixed gas in the intake stroke, whereas a diesel engine takes in air in the intake stroke. Therefore, only the gasoline engine and the diesel engine can be used for implementing the present invention.

  In conventional intake and exhaust processes of the engine, the intake and exhaust valves are opened and closed with a camshaft connected to the crankshaft of the engine via a timing chain or timing belt. The required number of rice ball-shaped cams protruding only in the cylinder is provided for each cylinder, and these cams come into contact with the intake valves and exhaust valves via the rocker arm and tappet, and these cams are used at the time required for intake and exhaust strokes. The intake and exhaust strokes are achieved by pushing and returning the valve. The valve is pushed out when the tip of the rice ball shape rotates to the rocker arm or tappet, and the amount of the valve is maximized.The valve opens to the maximum, and after that, the valve moves to the intake port and exhaust port by the spring attached to the valve. close. This mechanism is not preferable because drive loss occurs because the rotational motion is converted into the vertical motion.

  Accordingly, an electronic control system such as that shown in FIG. 4 is used for the intake valve and the exhaust valve according to the second embodiment of the present invention at the appropriate time of engine rotation in the hydraulic piston assembly 1 directly or via the rocker arm. These valves can be opened and closed.

  When the vehicle or the like is operated in a light load state by the electronic control system of FIG. 4, the hydraulic pressure to the hydraulic piston assembly 1 of any cylinder is controlled so that the intake and exhaust valves are fully opened or fully closed. Since cylinder deactivation can be performed, fuel consumption can be reduced.

  FIG. 5 is a hydraulic circuit diagram for operating the hydraulic piston assembly 1 according to the third embodiment of the present invention. As shown in FIG. 5, the lubricating oil 23 stored in the oil pan 36 of the engine is replaced with an oil strainer. After being sucked up by the oil pump 25 through 24 and further pumped to the oil filter 26, the hydraulic pressure 28 is pumped to the accumulator 30 through the discharge amount control valve 27. A pressure control valve 31 and a pressure sensor 29 are attached to the accumulator 30 and are controlled so that the hydraulic pressure in the accumulator 30 is constant. The accumulator 30 is connected to a hydraulic piston assembly 1 provided in each valve, and an electromagnetic valve 33 is provided therebetween. By turning this electromagnetic valve 33 ON, the hydraulic pressure in the accumulator 30 is pumped from the oil passage 13 in FIG. 1 through the oil hole 3 provided in the cylinder 21 to the back surface of the piston 18, and the hydraulic pressure causes the piston 18 to move. When the valve 8 is pushed out directly or through the rocker arm 16, a gap is formed between the piston cylinder 37 and the valve seat 35, and mixed gas and exhaust gas are sucked and exhausted therefrom. Further, when a command to close the valve 8 is input based on information from each sensor in FIG. 4, the electromagnetic valve 33 is turned off, the hydraulic pressure 28 of the hydraulic piston assembly 1 is released from the drain 34, and the valve 8 is driven by the force of the valve spring 10. Pushed back. This operation can perform the same function as when using a conventional camshaft.

  The present invention can be used in the industrial field of manufacturing and selling engines and automobiles.

  FIG. 1 is a sectional view when the hydraulic piston assembly of the present invention is mounted so as to be in direct contact with a valve.   FIG. 2 is a cross-sectional view when the hydraulic piston assembly and the valve of the present invention are attached via a rocker arm.   FIG. 3 is a sectional view of the hydraulic piston assembly.   FIG. 4 is a system diagram for electronically controlling the present invention.   FIG. 5 is a hydraulic circuit diagram for operating the present invention.

Explanation of symbols

1: Hydraulic piston assembly 2: Cylinder head 3: Oil hole 4: Piston stem end 5: Valve stem end 6: Valve stem 7: Oil seal 8: Valve 9: Valve guide 10: Valve spring 11: Spring seat 12: Retaining ring 13: Oil passage 14: Port 15: Piston stem 16: Rocker arm 17: Rocker shaft 18: Piston 19: Retainer O-ring 20: Piston O-ring 21: Cylinder 22: Retainer 23: Lubricating oil 24: Oil strainer 25: Oil Pump 26: Oil filter 27: Discharge control valve 28: Hydraulic pressure 29: Pressure sensor 30: Accumulator 31: Pressure control valve 32: Engine 33: Electromagnetic valve 34: Drain 35: Valve seat 36: Oil pan 37: Piston cylinder

Claims (4)

  By eliminating the conventional camshaft system for intake / exhaust of the engine, intake / exhaust stroke, and exhaust valves, the total length of the engine can be reduced because the timing chain or timing belt and their pulleys can be eliminated. In addition, the valve operating mechanism is characterized in that the intake and exhaust valves are opened and closed by a hydraulic piston.   The hydraulic piston is configured to open and close the valve by directly contacting the intake and exhaust valves and the hydraulic piston, or to open and close the valve via a rocker arm between the hydraulic piston and the intake and exhaust valves. 1. The valve operating mechanism according to 1.   A valve operating mechanism characterized in that, by performing electronic control to open and close the valve by the hydraulic piston, the valve can be fully opened or fully closed in a light load operation state to perform cylinder deactivation.   A valve operating mechanism characterized in that an accumulator is provided so that a stable hydraulic pressure can be supplied to improve valve responsiveness by opening and closing the intake and exhaust valves with the hydraulic piston.

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