JP5071234B2 - Variable valve operating device for internal combustion engine - Google Patents

Description

  The present invention relates to a variable valve operating apparatus for an internal combustion engine that changes a compression ratio by controlling a closing timing of an engine valve.

  In recent years, demand for reducing harmful components in exhaust gas from diesel engines has increased, and research on uniform premixed combustion capable of simultaneously reducing NOx and smoke in exhaust gas has been conducted.

  Uniform premixed combustion means that fuel is injected into the cylinder at a timing earlier than usual (a timing earlier than the piston top dead center by a predetermined time or more), and a uniform mixture is generated in the cylinder at the same time. It causes combustion. In order to realize this uniform premixed combustion, it is important to control the ignition timing, and a variable compression ratio system capable of significantly lowering the compression ratio than in the case of normal combustion is required. That is, in uniform premixed combustion, the uniform premixed gas in the cylinder is gradually compressed as the piston rises. At this time, if the compression ratio is the same as in normal combustion, the piston is at top dead center. Spontaneous ignition occurs before it reaches, and negative work is done on the crankshaft. In order to avoid this, it is necessary to lower the compression ratio so that the mixture does not ignite before the piston reaches top dead center.

  Conventionally, technologies that make the compression ratio variable include variable intake camshaft phase (variable phase method) and variable engine valve (intake and exhaust valve) lift by switching the cam used ( (Cam switching system) is known, but it is difficult to change the compression ratio significantly and arbitrarily. As a variable compression ratio system that can change the compression ratio significantly and arbitrarily, press the rocker arm with the hydraulic piston, hold the engine valve open, and relieve the hydraulic pressure in the hydraulic chamber that applies pressing force to the hydraulic piston There is known a variable valve operating system (valve holding system using hydraulic pressure) that closes the engine valve (see Patent Documents 1 to 3).

  An example of this type of variable valve operating apparatus is shown in FIG. This variable valve operating device presses the rocker arm 6 by the hydraulic pressure of the hydraulic chamber 12 above the rocker arm 6 that opens the engine valve (intake valve) 2 against the valve spring 5 by the rotation of the camshaft 3. A hydraulic piston 13 that holds the intake valve 2 in an open state, an introduction passage 16a that introduces hydraulic oil (engine lubricating oil) into the hydraulic chamber 12 via a check valve (not shown), and electromagnetic waves from the hydraulic chamber 12 A block 7 having a discharge passage 16b for discharging hydraulic oil through a valve 15 is arranged, and the valve closing timing of the intake valve 2 is controlled by holding or releasing the pressure of the hydraulic chamber 12 by the electromagnetic valve 15. is there.

  In this device, the opening of the intake valve 2 is the same as in a normal valve system, and the rocker arm 6 pushed by the cam crest 3a of the rotating camshaft 3 resists the urging force of the valve spring 5. 4 inclines clockwise and the intake valve 2 is pushed down to open. At this time, since the lubricating oil of the engine is supplied to the hydraulic chamber 12 through the introduction passage 16a at a normal hydraulic pressure, the hydraulic piston 13 descends following the lowering (valve lift) of the intake valve 2, The hydraulic oil flows into the hydraulic chamber 12 from the introduction passage 16a. At this time, the electromagnetic valve 15 is closed.

  When the solenoid valve 15 is opened when the intake valve 2 is lowered, that is, when the valve lift is maximum (the intake valve is fully open), the hydraulic chamber 12 is communicated with the discharge passage 16b and receives the urging force of the valve spring 5. The hydraulic fluid inside is relieved to the discharge passage 16b, and the hydraulic piston 13 is allowed to rise. As a result, the rocker arm 6 is tilted counterclockwise in FIG. 4 by the urging force of the valve spring 5 according to the cam crest 3a of the rotating camshaft 3, and the intake valve 2 is raised and closed.

  If the opening timing of the solenoid valve 15 is delayed for an arbitrary time from the time when the intake valve 2 reaches the maximum valve lift, the solenoid valve 15 is opened until the solenoid valve 15 is opened (while it is closed). 4 is maintained and the hydraulic piston 13 is prevented from rising, so that the tilting posture of the rocker arm 6 remains in the right-down state in FIG. 4, and the intake valve 2 is held open. Thereafter, when the electromagnetic valve 15 is opened, the hydraulic oil in the hydraulic chamber 12 is relieved to the discharge passage 16b, and the intake valve 2 is raised by the urging force of the valve spring 5 to be closed.

  Therefore, by appropriately controlling the valve opening timing of the solenoid valve 15, the valve closing timing of the intake valve 2 can be easily delayed from the valve closing timing determined by the cam crest 3a of the camshaft 3, and the compression ratio is normally set. Can be changed significantly and arbitrarily lower. Therefore, the variable valve operating device of the valve pressing type by hydraulic pressure is suitable for use in the variable compression ratio system of uniform premixed combustion.

Japanese Patent Laid-Open No. 7-233718 JP 2006-152943 A Japanese Utility Model Publication No. 6-67805

  By the way, in the variable valve operating system based on the above-described valve pressing method using hydraulic pressure, the hydraulic piston 13 moves up and down in accordance with the opening and closing of the intake valve 2 except during a period in which the intake valve 2 is held open. As the hydraulic piston 13 is moved up and down, a volume of lubricating oil obtained by multiplying the lift amount of the intake valve 2 by the diameter of the hydraulic piston 13 is sucked into the hydraulic chamber 12 from the introduction passage 16 a and is applied by the biasing force of the valve spring 5. It is discharged into the discharge passage 16b while being compressed. Therefore, the lubricating oil of the engine is consumed correspondingly, and lost work is generated.

  Accordingly, an object of the present invention is to provide a variable valve operating apparatus for an internal combustion engine that can recover the hydraulic pressure generated by the lifting and lowering of the hydraulic piston as engine drive energy.

  To achieve the above object, the present invention opens the engine valve by pressing the rocker arm by the hydraulic pressure in the hydraulic chamber above the rocker arm that opens the engine valve against the valve spring by rotation of the camshaft. A block having a hydraulic piston to be held in a valve state and an oil passage for introducing hydraulic oil into the hydraulic chamber via a check valve and discharging hydraulic oil from the hydraulic chamber via a solenoid valve; In a variable valve operating apparatus for an internal combustion engine that controls the closing timing of the engine valve by holding or releasing the pressure in the hydraulic chamber by the electromagnetic valve, the camshaft is provided with a hydraulic turbine, and hydraulic oil is supplied to the hydraulic turbine. In order to supply, the hydraulic turbine and the discharge port of the oil passage formed in the block are connected by an oil introduction passage, and an oil discharge passage for discharging the working oil therein is connected to the hydraulic turbine.

  The hydraulic turbine has a plurality of turbine blades circumferentially spaced on the outer peripheral surface of the camshaft other than the cam crest and the bearing portion, and the camshaft is surrounded by the turbine blades so as to surround the turbine blades. A turbine housing formed along a direction, and the oil introduction path and the oil discharge path may be connected to the turbine housing, respectively.

  You may provide the connection member with which the member attached to the upper part of the said engine valve, and raising / lowering integrally with the said engine valve, and the said hydraulic piston are connected.

  According to the present invention, in a variable valve operating apparatus for an internal combustion engine having a hydraulic piston that holds the rocker arm so that the engine valve is in an open state, the hydraulic pressure generated by the raising and lowering of the hydraulic piston can be recovered as engine drive energy. .

  Preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a side sectional view of the variable valve operating apparatus according to the present embodiment.

  This variable valve operating device 1 is applied to an engine valve (for example, an intake valve 2) of a diesel engine that switches between a normal combustion (diffusion combustion) mode and a premixed combustion mode, and is opened by a cam crest 3a of the camshaft 3. By making the valve closing timing of the intake valve 2 an arbitrary time later than the valve closing timing determined by the cam crest 3a, a part of the air-fuel mixture in the cylinder of the engine flows backward to the intake port 4 and the substantial compression ratio is increased. Change to the lower side. Thereby, the ignition timing in the premixed combustion mode can be controlled.

  As shown in FIG. 1, the variable valve gear (variable compression ratio device) 1 includes a camshaft 3 that is rotated in synchronization with the rotation of a crankshaft of a diesel engine, and an intake valve 2 that is driven by the camshaft 3. The rocker arm 6 that opens against the valve spring 5 and the rocker arm 6 are pressed to hold the intake valve 2 in the open state, and the pushing force is de-energized to control the closing timing of the intake valve 2. And a block 7 constituting an actuator.

  The camshaft 3 is pivotally supported by a cylinder head or the like (not shown), and the rotation of the crankshaft of the diesel engine is transmitted through a rotational force transmitting member such as a chain, belt or gear. The camshaft 3 is formed with a cam crest 3a formed in a predetermined shape for opening and closing the intake valve 2.

  The rocker arm 6 is slidably inserted into a rocker shaft 6a attached to a cylinder head or the like, and abuts against the cam crest 3a at an input end extending to the left in FIG. 1 from the rocker shaft 6a. An adjusting member 9 that contacts the bridge 10 mounted on the top of the intake valve 2 is attached to the output end of the roller 8 that extends rightward from the rocker shaft 6a. The adjustment member 9 is screwed into the screw hole formed in the rocker arm 6 from above and is fixed by the nut 9a. A slipper may be provided in place of the roller 8.

  The bridge 10 is mounted on the tops of the two intake valves 2 and is a member for operating these two intake valves 2 together. Each intake valve 2 is urged in a valve closing direction (upward in the figure) by a valve spring 5, a valve umbrella portion 2a protruding into the cylinder is seated on a valve seat 4a of the intake port 4, and the bridge 10 is By being pushed down against the spring 5, the valve head portion 2a is separated downward from the valve seat 4a and opened. A guide hole 10a for guiding the vertical movement of the bridge 10 is formed, and a guide rod 11 attached to a cylinder head or the like is inserted into the guide hole 10a.

  The block 7 is provided in a cylinder head or the like, and includes a hydraulic chamber 12, a hydraulic piston 13 for holding the intake valve 2 in an open state by pressing the rocker arm 6 by the hydraulic pressure of the hydraulic chamber 12, and a hydraulic pressure An oil passage 16 for introducing hydraulic oil (engine lubricating oil) into the chamber 12 through the check valve 14 and discharging hydraulic oil from the hydraulic chamber 12 through the electromagnetic valve 15 is provided. Specifically, the block 7 is formed with a hydraulic cylinder 17 into which a cylindrical hydraulic piston 13 is slidably inserted in the up-down direction, and is opened downward. The hydraulic piston 13 at the upper part in the hydraulic cylinder 17 is formed. A region partitioned by the upper surface of the hydraulic chamber 12 is a hydraulic chamber 12. The lower end of the hydraulic piston 13 protrudes from the lower surface of the block 7 and is in contact with the upper part of the output end of the rocker arm 6, specifically, the upper end part of the adjusting member 9.

  The oil passage 16 includes an introduction passage 16 a for introducing hydraulic oil from an introduction port 18 formed in the block 7 to the hydraulic chamber 12 via the check valve 14, and lubricating oil in the hydraulic chamber 12 via the electromagnetic valve 15. And a discharge passage 16b for discharging from a discharge port 19 formed in the block 7. The leading end of the introduction passage 16 a is connected to the upper side surface of the hydraulic cylinder 17. The discharge passage 16b is formed in an annular shape connected to the valve chamber 15a around the valve seat of the first communication passage 16b1 communicating with the top of the hydraulic cylinder 17 and the lower portion of the valve chamber 15a of the electromagnetic valve 15 and the valve seat of the electromagnetic valve 15. The first oil chamber 16b2, the second oil chamber 16b4 formed in an annular shape along the outer periphery of the solenoid valve 15 to cool the solenoid valve 15, and the first oil chamber 16b2 and the second oil chamber 16b4 communicate with each other. The second communication passage 16b3 and the third communication passage 16b5 that communicates the second oil chamber 16b4 and the discharge port 19 are provided.

  Further, a portion of the introduction passage 16a on the upstream side of the check valve 14 and the second communication passage 16b3 of the discharge passage 16b are communicated with each other by a bypass passage 16c. The bypass passage 16c is provided to cool the solenoid 15d of the solenoid valve 15 by guiding the hydraulic oil introduced from the introduction port 18 to the introduction passage 16a to the second oil chamber 16b4 by bypassing the hydraulic chamber 12. However, when the bypass passage 16c is provided, a part of the hydraulic oil toward the hydraulic chamber 12 is bypassed, so that the hydraulic pressure of the hydraulic oil that acts to push down the hydraulic piston 13 in the hydraulic chamber 12 is reduced, and the hydraulic pressure condition Depending on the operating conditions of the oil pump of the engine, oil temperature, etc., the hydraulic piston 13 may not descend following the tilt of the rocker arm 6, so the bypass passage 16c may be omitted or the bypass passage 16c may be omitted. An aperture may be provided.

  The solenoid valve 15 for releasing the hydraulic pressure in the hydraulic chamber 12 is an on-off type two-way solenoid valve that opens and closes depending on whether or not power is supplied. The electromagnetic valve 15 includes a hollow cylindrical valve chamber 15a that is long in the vertical direction, a columnar valve body 15b that is slidably inserted in the lower side of the valve chamber 15a, and a valve body 15b. It is mainly composed of a spring 15c that is always urged in the direction (downward in FIG. 1) and a solenoid 15d that moves the valve body 15b in the opening direction (upward) against the spring 15c when energized. The solenoid 15d is connected to a control unit 25 for controlling the energization / non-energization of the solenoid 15d to control the opening / closing of the solenoid valve 15.

  The hydraulic fluid discharged from the hydraulic chamber 12 through the first communication passage 16b1 to the first oil chamber 16b2 by the opening of the electromagnetic valve 15 flows into the second oil chamber 16b4 through the second communication passage 16b3, and the solenoid. After cooling 15b, it is discharged from the discharge port 19 through the third communication passage 16b5. The hydraulic oil discharged from the discharge port 19 is supplied to the hydraulic turbine 20 provided on the camshaft 3 via the oil introduction path 21 and is connected to the hydraulic turbine 20 after acting to rotate the camshaft 3. The oil is discharged from the oil discharge path 22 into the engine head cover.

  The hydraulic turbine 20 includes a plurality of turbine blades 20a provided on the outer peripheral surface of the camshaft 3 other than the cam crest 3a and the bearing portion at intervals in the circumferential direction, and the camshaft so as to surround the turbine blades 20a. 3 and a turbine housing 20b formed along the circumferential direction. An annular seal (not shown) is provided in a gap between the turbine housing 20b and the outer peripheral surface of the camshaft 3, so that hydraulic oil in the turbine housing 20b does not leak from the gap.

  The turbine housing 20b is connected to an oil introduction path 21 connected to the discharge port 19 of the block 7 in order to supply hydraulic oil to the turbine blade 20a, and discharges the hydraulic oil in the turbine housing 20b. An oil discharge path 22 is connected. The outlet 22a of the oil discharge path 22 is directed downward in FIG. 1 and discharges hydraulic oil into the engine head cover, but is directed to the rocker shaft 6a or the roller 8 of the rocker arm 6, You may make it supply hydraulic oil to them.

  The operation of the variable valve operating apparatus 1 according to this embodiment will be described.

  When the roller 8 at the input end of the rocker arm 6 rides on the upslope of the cam crest 3a of the camshaft 3 as the camshaft 3 shown in FIG. 1 rotates, the rocker arm 6 resists the force of the valve spring 5. The adjustment member 9 at the output end of the rocker arm 6 presses the bridge 10 downward, and the intake valve 2 is pushed down against the force of the valve spring 5 to open. Thereafter, when the roller 8 of the rocker arm 6 reaches the top of the cam crest 3a, the intake valve 2 enters the maximum lifted state (fully opened), and the camshaft 3 further rotates so that the roller 8 exceeds the top of the cam crest 3a. When the down slope is reached, each intake valve 2 is lifted by the force of the valve spring 5, and finally the valve umbrella portion 2a of each intake valve 2 is seated on the valve seat 4a and closed (fully closed). The

  During normal operation of the engine (diffusion combustion), operation is performed at a normal compression ratio. In the normal compression ratio operation, as shown in FIG. 2A, the electromagnetic valve 15 that has been closed is opened at the crank angle at which the intake valve 2 is in the maximum lift state. As a result, the hydraulic chamber 12 communicates with the first oil chamber 16b2 via the first communication passage 16b1, and the hydraulic piston 13 is allowed to rise. Therefore, the rocker arm 6 is allowed to swing, and the intake valve 2 is closed by the valve spring 5 according to the shape of the down slope of the cam crest 3a. If the intake valve 2 is closed, the electromagnetic valve 15 is closed. As a result, in FIG. 1, the outlet side of the hydraulic chamber 12 is closed, so that the hydraulic oil flowing into the introduction passage 16 a from the introduction port 18 passes through the bypass passage 16 c without going to the hydraulic chamber 12. The second oil chamber 16b4 is reached and the solenoid 15d is cooled.

  During homogeneous premix combustion of the engine, operation at a low compression ratio is performed. In the low compression ratio operation, as shown in FIG. 2B, the opening timing of the electromagnetic valve 15 is set to a predetermined period A longer than the crank angle at which the intake valve 2 is in the maximum lift state according to the desired low compression ratio. Just delay. As a result, the hydraulic pressure in the hydraulic chamber 12 is maintained in FIG. 1 to prevent the hydraulic piston 13 from rising, the rocker arm 6 is held in a downwardly inclined posture, and the intake valve 2 is pushed down to a substantially maximum lift position. Is kept in the state where Thereafter, by opening the electromagnetic valve 15, the hydraulic piston 13 is allowed to rise, the rocker arm 6 is allowed to swing, and the intake valve 2 is closed to the valve spring 5 by the biasing force. Therefore, by appropriately controlling the valve opening timing of the electromagnetic valve 15, the valve closing timing of the intake valve 2 can be arbitrarily and easily set as compared with the valve closing timing determined by the cam crest 3a of the camshaft 3, as shown in FIG. The compression ratio can be delayed and the compression ratio can be changed significantly and arbitrarily lower than usual.

  Next, the flow of hydraulic oil will be described.

  Before the intake valve 2 is lifted, the hydraulic oil flowing from the introduction port 18 shown in FIG. 1 passes through the introduction passage 16a, the bypass passage 16c, and the second communication passage 16b3, reaches the second oil chamber 16b4, and enters the solenoid 15d. Cooled and discharged from the discharge port 19. At this time, the solenoid valve 15 is closed, and the hydraulic oil chamber 12, the first communication passage 16b1, and the first oil chamber 16b2 are filled with hydraulic oil.

  During the lift of the intake valve 2, the hydraulic oil in the introduction port 18 passes through the introduction passage 16 a, the bypass passage 16 c, and the second communication passage 16 b 3, reaches the second oil chamber 16 b 4, and is discharged from the discharge port 19. Further, as the hydraulic piston 13 is lowered, the hydraulic oil that has passed through the check valve 14 flows into the hydraulic chamber 12. At this time, the electromagnetic valve 15 is closed, and the first oil chamber 16b2 is in a state filled with hydraulic oil.

  When the intake valve 2 is held in the lifted state, the hydraulic oil in the introduction port 18 passes through the introduction passage 16a, the bypass passage 16c, and the second communication passage 16b3, reaches the second oil chamber 16b4, and is discharged from the discharge port 19. Is done. The solenoid valve 15 is closed, the hydraulic chamber 12 and the first communication passage 16b1 are filled with hydraulic oil, and the hydraulic piston 13 is held in a state of protruding downward. The first oil chamber 16b2 is also filled with hydraulic oil.

  When the intake valve 2 is closed, the electromagnetic valve 15 is opened. Then, the hydraulic oil in the hydraulic chamber 12 moves to the first oil chamber 16b2 through the first communication passage 16b1, reaches the second oil chamber 16b4 through the second communication passage 16b3, and is discharged from the discharge port 19. . At the same time, the hydraulic oil flowing from the introduction port 18 passes through the introduction passage 16a, the bypass passage 16c, and the second communication passage 16b3, reaches the second oil chamber 16b4, and is discharged from the discharge port 19.

  The hydraulic oil discharged from the discharge port 19 is supplied into the turbine housing 20b of the hydraulic turbine 20 through the oil introduction path 21 shown in FIG. 1 and flows into the turbine blade 20a to give the camshaft 3 rotational force. Thereafter, the oil is discharged from the turbine housing 20 b through the oil discharge path 22. Since the camshaft 3 is connected to the crankshaft via a rotational force transmission member such as a chain, belt, gear, etc., the hydraulic pressure generated by the lifting and lowering of the hydraulic piston 12 is recovered as engine drive energy.

  That is, as the hydraulic piston 13 moves up and down, a volume of lubricating oil obtained by multiplying the lift amount of the intake valve 2 by the diameter of the hydraulic piston 13 is sucked into the hydraulic chamber 12 from the introduction passage 16 a and is compressed by the urging force of the valve spring 5. When discharged to the discharge passage 16b, the hydraulic oil pressurized by the urging force (spring load) of the valve spring 5 is effectively used as energy for rotating the hydraulic turbine 20 provided in the camshaft 3, and the engine It will be recovered as drive energy.

  Here, the hydraulic piston 13 is raised and lowered according to the opening and closing of the intake valve 2 to continuously generate hydraulic pressure, except during a period in which the intake valve 2 is held in the lifted state. The variable valve operating apparatus 1 utilizes the hydraulic pressure generated substantially continuously as described above to rotate the hydraulic turbine 20 provided on the camshaft 3 and collect it as engine drive energy. This ultimately leads to improved fuel economy.

  Further, the hydraulic oil in the hydraulic chamber 12 guided from the introduction port 18 through the introduction passage 16a is caused by the rising of the hydraulic piston 13, so that the first communication passage 16b1, the first oil chamber 16b2, the second communication passage 16b3, 2 is discharged to the discharge port 19 through the oil chamber 16b4. As a result, the hydraulic oil in the hydraulic chamber 12 is replaced without stagnation by one reciprocation of the hydraulic piston 13, and the temperature rise is suppressed. Therefore, it is possible to avoid variations in the closing timing of the intake valve 2 due to volume expansion due to the temperature rise of the hydraulic oil, and malfunctions of the hydraulic piston 13 and the intake valve 2 due to the vapor of the hydraulic oil.

  In the multi-cylinder engine, the variable valve operating device 1 is provided for each cylinder. The oil introduction passages 21 connected to the discharge ports 19 of the variable valve operating devices 1 are combined to form one hydraulic turbine. You may be made to guide to 20. As a result, the hydraulic oil is sequentially discharged from the discharge port 19 of the variable valve gear 1 of each cylinder in accordance with the lift order of the intake valve 2 of each cylinder, and is sequentially guided to the hydraulic turbine 20. The hydraulic oil is supplied without interruption, and the energy recovery efficiency increases. Further, the cost is low because only one hydraulic turbine 20 is required.

  By the way, depending on the hydraulic conditions of the hydraulic oil introduced into the introduction port 18 (engine pump operating conditions, oil temperature, etc.), there is a possibility that the hydraulic piston 13 does not descend following the tilt of the rocker arm 6. . In this case, even when the intake valve 2 is fully lifted, a gap is generated between the hydraulic piston 13 and the adjustment member 9 of the rocker arm 6, and when the rocker arm 6 returns with the rotation of the camshaft 3, Colliding with the hydraulic piston 13 at the lift position, the intake valve 2 is maintained at the intermediate lift position. Therefore, the problem that a desired compression ratio cannot be obtained may arise.

  As a countermeasure, a connecting member 26 that connects the hydraulic piston 13 and the bridge 10 attached to the top of the intake valve 2 may be provided as indicated by a virtual line in FIG. The connecting member 26 forcibly raises and lowers the hydraulic piston 13 in conjunction with the raising and lowering of the intake valve 2. Therefore, the above-described problem does not occur. In addition, the raising / lowering direction of the bridge 10 and the raising / lowering direction of the hydraulic piston 13 are parallel.

  The present invention is not limited to the above embodiment.

  For example, although the variable valve operating apparatus 1 has been described as being applied to the intake valve 2, it may be applied to an exhaust valve. Moreover, although the said variable valve operating apparatus 1 described the example applied to the diesel engine which switches a normal driving | operation and a uniform premixing driving | operation, you may apply to the diesel engine of only a normal driving | operation or only a uniform premixing driving | operation, Moreover, you may apply to a gasoline engine.

It is a sectional side view of the variable valve operating apparatus of the internal combustion engine which concerns on one Embodiment of this invention. It is explanatory drawing which shows the operating state of the solenoid valve at the time of normal compression ratio, and low compression ratio. FIG. 3 is an opening / closing stroke diagram of an engine valve. It is explanatory drawing which shows an example of the conventional variable valve apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Variable valve operating apparatus 2 Intake valve as engine valve 3 Camshaft 3a Cam crest 5 Valve spring 6 Rocker arm 7 Block 10 Bridge as member which moves up and down integrally with engine valve 12 Hydraulic chamber 13 Hydraulic piston 14 Check valve 15 Solenoid valve 16 Oil passage 19 Discharge port 20 Hydraulic turbine 20a Turbine blade 20b Turbine housing 21 Oil introduction passage 22 Oil discharge passage 26 Connecting member

Claims (3)

A hydraulic piston that holds the engine valve in an open state by pressing the rocker arm by the hydraulic pressure in the hydraulic chamber above the rocker arm that opens the engine valve against the valve spring by rotation of the camshaft, and the hydraulic pressure A block having an oil passage for introducing hydraulic oil into the chamber through the check valve and discharging hydraulic oil from the hydraulic chamber through the electromagnetic valve is disposed, and the pressure in the hydraulic chamber is maintained by the electromagnetic valve. Alternatively, in a variable valve operating apparatus for an internal combustion engine that releases and controls the closing timing of the engine valve,
A hydraulic turbine is provided on the camshaft, and the hydraulic turbine is connected to a discharge port of the oil passage formed in the block through an oil introduction passage so as to supply hydraulic oil to the hydraulic turbine, and the hydraulic turbine is internally connected to the hydraulic turbine. A variable valve operating apparatus for an internal combustion engine, wherein an oil discharge passage for discharging the hydraulic oil is connected.   The hydraulic turbine has a plurality of turbine blades circumferentially spaced on the outer peripheral surface of the camshaft other than the cam crest and the bearing portion, and the camshaft is surrounded by the turbine blades so as to surround the turbine blades. The variable valve operating apparatus for an internal combustion engine according to claim 1, further comprising a turbine housing formed along a direction, wherein the oil introduction path and the oil discharge path are connected to the turbine housing.   3. The variable valve operating apparatus for an internal combustion engine according to claim 1, further comprising a connecting member that is attached to an upper portion of the engine valve and connects the hydraulic piston to a member that moves up and down integrally with the engine valve.

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