JP2008267332A - Internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To impart a lift difference between a pair of intake valves in the same cylinder, without reducing performance. <P>SOLUTION: This internal combustion engine has two rocker arms 3a and 3b per one cylinder for opening-closing the intake valves 2a and 2b in the same two cylinders by a rocking cam of a variable valve train, two lash adjusters 4a and 4b supported by an internal combustion engine body and linking with the intake valves 2a and 2b via the rocker arms 3a and 3b, a pair of mutually independent hydraulic passages 31a and 31b supplying hydraulic pressure to the respective lash adjusters 4a and 4b, and a solenoid valve 33 interposed in the hydraulic passage 31a. The lash adjusted 4 is constituted so that a motion quantity transmitted to the intake valve 2 via the rocker arm 3 from the rocking cam becomes larger than when stopping the hydraulic pressure when supplying the hydraulic pressure, and is controlled so that the solenoid valve 33 is closed when controlling a lift quantity of the intake valve 2 in a predetermined small lift quantity or less. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an internal combustion engine provided with a hydraulic lash adjuster that automatically eliminates the valve clearance of an engine valve.

  Patent Document 1 has a first rocking cam and a second rocking cam that open and close two intake valves per cylinder, respectively, and the first rocking cam is integrally fixed to one end side of the camshaft. The second swing cam is swingably supported on the other end side, and the connection between the cam shaft and the second swing cam is established when the engine is started by a connection switching mechanism disposed on the outer peripheral side of the cam shaft. The one-cylinder stop state in which one of the two intake valves of the same cylinder is released to be closed and the camshaft and the second swing cam are connected to each other during steady operation or high load operation. There is disclosed a variable valve operating apparatus for an internal combustion engine in a double-valve drive state that opens and closes an intake valve.

  The connection switching mechanism in Patent Document 1 drives a connection piston with hydraulic oil supplied from the inside of the camshaft. When hydraulic oil is supplied, the connection piston causes the camshaft, the second swing cam, and so on. When the mechanical connection is released and the supply of hydraulic oil is stopped, the camshaft and the second swing cam are mechanically connected by the connecting piston. That is, the lift amount of the two intake valves of the same cylinder is changed by the supply of hydraulic pressure from the camshaft.

Further, in Patent Document 2, an intake valve for an internal combustion engine in which a tappet whose upper part is in contact with a cam is linked to a valve stem of a valve via a rocker arm and the rocker arm is swung to open and close the valve is disclosed. Two cams with different lift functions for valves or exhaust valves are provided as a pair, and tappets are respectively arranged in contact with these cams, and one rocker arm is arranged between the two tappets and the valve stem. A variable valve operating system for an internal combustion engine, in which a hydraulic passage is connected to the piston of the tappet, the height of the tappet is switched by the hydraulic pressure applied to the piston, and a valve pause mechanism is configured to control the amount of movement transmitted from the cam to the rocker arm Is disclosed.
JP 2000-213315 A JP-A-7-127410

  However, in Patent Document 1, the camshaft and the second swing cam are connected by fitting the connecting piston into the connecting hole, and the intake valve is moved from the one-valve stop state where the operating angle of the intake valve is small. When switching to the double valve drive state where the operating angle is large, the operating angle of the intake valve cannot be increased by the variable valve mechanism until the connecting piston is fitted into the connecting hole for each cylinder. Therefore, the responsiveness may be deteriorated.

  And in patent document 2, since the piston is provided in the tappet and the hydraulic passage is connected to this piston, the valve system inertial mass (the inertia of the variable valve operating device) is increased by the relative mass increase of the tappet. Mass) increases, so that the so-called crash speed of the valve train (variable valve gear) may be relatively decreased.

  Therefore, the internal combustion engine of the present invention includes a variable valve mechanism capable of changing the lift characteristics of a pair of engine valves of the same cylinder, and the above-mentioned engine by swinging on one end side based on rotation of a swing cam of the variable valve mechanism. Hydraulic pressure is applied to each of two rocker arms per cylinder for opening and closing the valve, two lash adjusters supported by the internal combustion engine body and supporting the other end of the rocker arm, and a pair of lash adjusters of the same cylinder. One of the pair of lash adjusters that is interposed only in one of the pair of hydraulic passages, one of the pair of hydraulic passages, and one of the pair of hydraulic passages. A hydraulic control valve that controls the supply of hydraulic pressure to the valve, a variable valve control unit that controls the variable valve mechanism, a hydraulic control valve control unit that controls opening and closing of the hydraulic control valve, The pair of lash adjusters is configured such that the amount of movement transmitted from the swing cam to the engine valve via the rocker arm is larger in a state where hydraulic pressure is supplied than in a state where hydraulic pressure is not supplied. When the hydraulic pressure is supplied from the hydraulic pressure supply means to the pair of hydraulic passages and the lift amount of the pair of engine valves is controlled to be equal to or less than a predetermined small lift amount, the hydraulic control valve is It is controlled to be closed by a hydraulic control valve control means.

  The height of the lash adjuster can be switched with high responsiveness according to the supply / stop of hydraulic pressure. Further, the lash adjuster is supported on the internal combustion engine body side and does not affect the inertial mass of the variable valve mechanism, so the so-called crash rotational speed of the variable valve mechanism due to the increase of the inertial mass of the variable valve mechanism. A decrease can be prevented. That is, a lift difference can be given to a pair of engine valves (intake valves) in the same cylinder without causing a decrease in the crash rotational speed of the variable valve mechanism.

  Of the pair of engine valves, the lift amount of the engine valve on the lash adjuster side where the supply of hydraulic pressure is stopped is relatively small. For this reason, there is a difference in the lift amount between the pair of engine valves, so that when the engine valve lift amount is controlled to be small, in other words, the in-cylinder swirl is strengthened when the operating state is idling or when the load is low. Can improve fuel efficiency.

  Depending on the setting, only one of the pair of engine valves can be opened and the other can be maintained in the closed state. In this case, the control accuracy of the intake air amount is improved, As a result, variation in the combustion pressure between cylinders can be suppressed, and vibration can be reduced.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  The internal combustion engine 1 according to the first embodiment of the present invention will be described with reference to FIGS. The internal combustion engine 1 is mounted on a vehicle such as an automobile. For convenience, the right side in FIG. 1 is the vehicle front side (Fr side) when the vehicle is mounted, and the left side in FIG. Side (Rr side).

  As shown in FIG. 1, the internal combustion engine 1 has a pair of intake valves 2a and 2b in the same cylinder. The intake valve 2a is located relatively on the front side (left side in FIG. 1) in the same cylinder, and the intake valve 2b is located relatively on the rear side (right side in FIG. 1) in the same cylinder. is there.

  As shown in FIGS. 1 to 3, a pair of intake valves 2a and 2b of each cylinder are linked to lash adjusters 4a and 4b via rocker arms 3a and 3b, respectively. In other words, the intake valve 2a is relatively forward of the pair of lash adjusters 4a and 4b of the same cylinder via the rocker arm 3a of the pair of rocker arms 3a and 3b of the same cylinder. It is linked to the lash adjuster 4a located. On the other hand, the intake valve 2b is relatively positioned on the rear side of the pair of lash adjusters 4a and 4b of the same cylinder via the rocker arm 3b positioned relatively on the rear side of the pair of rocker arms 3a and 3b of the same cylinder. It is linked to the lash adjuster 4b located. The lash adjuster 4a and the lash adjuster 4b have the same configuration, and the rocker arm 3a and the rocker arm 3b have the same shape.

  The rocker arm 3 is arranged so that one end contacts the valve stem 5 of the intake valve 2 and the other end contacts a plunger 42 (details will be described later) of the lash adjuster 4. Also, the rocker arm 3 rotatably supports a roller 6 that contacts a swing cam 17 of a variable valve mechanism 10 described later.

  More specifically, the rocker arm 3 is supported from one side (the lower side in FIGS. 2 and 3) by the valve stem 5 of the intake valve 2 and the plunger 42 of the lash adjuster 4, and the swing cam 17 of the variable valve mechanism 10 is The roller 6 is disposed so as to come into contact with the roller 6 from the other side (the upper side in FIGS. 2 and 3), and is substantially sandwiched between the intake valve 2 and the lash adjuster 4 and the variable valve mechanism 10.

  The variable valve mechanism 10 was previously proposed by the applicant of the present invention, but is known from, for example, Japanese Patent Application Laid-Open No. 11-107725, and only its outline will be described.

  The variable valve mechanism 10 includes a hollow drive shaft 12 rotatably supported by a cam bracket (not shown) above the cylinder head 11, an eccentric cam 13 fixed to the drive shaft 12 by press-fitting, and the like. A control shaft 14 rotatably supported by the same cam bracket at a position above the shaft 12 and arranged in parallel with the drive shaft 12, and a rocker arm member swingably supported by the eccentric cam portion 15 of the control shaft 14. 16 and a rocking cam 17 that contacts the rocker arm 3 disposed at the upper end of each intake valve 2. The eccentric cam 13 and the rocker arm member 16 are linked by a link arm 18, and the rocker arm member 16 and the swing cam 17 are linked by a link member 19.

  The drive shaft 12 is driven by a crankshaft of the engine via a timing chain or a timing belt.

  The eccentric cam 13 has a circular outer peripheral surface, the center of the outer peripheral surface is offset by a predetermined amount from the axis of the drive shaft 12, and the annular portion 18a of the link arm 18 is rotatable on the outer peripheral surface. It is mated.

  The rocker arm member 16 has a substantially central portion supported by an eccentric cam portion 15, and an extension portion 18 b of the link arm 18 is linked to one end portion thereof, and an upper end portion of the link member 19 is connected to the other end portion. It is linked. The eccentric cam portion 15 is eccentric from the axis of the control shaft 14, and accordingly, the rocking center of the rocker arm member 16 changes according to the angular position of the control shaft 14.

  The swing cam 17 is fitted to the outer periphery of the drive shaft 12 and is rotatably supported, and the lower end portion of the link member 19 is linked to the end portion 17a extending to the side. On the lower surface of the swing cam 17, there are a base circle surface 20a concentric with the drive shaft 12, and a cam surface 20b extending in a predetermined curve from the base circle surface 20a to the end portion 17a. The base circle surface 20 a and the cam surface 20 b are formed so as to come into contact with the roller 6 of the rocker arm 3 according to the swing position of the swing cam 17.

  That is, the base circle surface 20a is a section where the lift amount becomes 0 as a base circle section. When the swing cam 17 swings and the cam surface 20b contacts the roller 6 of the rocker arm 3, the base circle surface 20a gradually lifts. It will be. A slight ramp section is provided between the base circle section and the lift section.

  The control shaft 14 is configured to rotate within a predetermined rotation angle range by a control actuator (not shown) provided at one end. The control actuator is controlled based on a control signal from an engine control unit (not shown). That is, the variable valve mechanism 10 in the present embodiment is controlled by the engine control unit as variable valve control means.

  The operation of the variable valve mechanism 10 will be described. When the drive shaft 12 rotates, the link arm 18 moves up and down by the cam action of the eccentric cam 13, and the rocker arm member 16 swings accordingly. The rocking movement of the rocker arm member 16 is transmitted to the rocking cam 17 via the link member 19, and the rocking cam 17 rocks. The rocker arm 3 is pressed by the cam action of the swing cam 17, and the intake valves 2a and 2b of the respective cylinders are lifted.

  Here, when the angle of the control shaft 14 is changed via the control actuator, the initial position of the rocker arm member 16 is changed, and as a result, the initial swing position of the swing cam 17 is changed.

  For example, if the eccentric cam portion 15 is positioned upward (upward in FIGS. 2 and 3), the rocker arm member 16 is positioned upward (upward in FIGS. 2 and 3) as a whole, and the swing cam 17. The end portion 17a of this is pulled up relatively upward (upward in FIGS. 2 and 3). That is, the initial position of the swing cam 17 is inclined in a direction in which the cam surface 20 b is separated from the rocker arm 3. Therefore, when the swing cam 17 swings with the rotation of the drive shaft 12, the base circle surface 20a is kept in contact with the roller 6 of the rocker arm 3 for a long time, and the period during which the cam surface 20b is in contact with the roller 6 is short. Therefore, the lift amount is reduced as a whole, and the angle range from the opening timing to the closing timing, that is, the operating angle is also reduced.

  Conversely, if the eccentric cam portion 15 is positioned downward (downward in FIGS. 2 and 3), the rocker arm member 16 is positioned downward (downward in FIGS. 2 and 3) and swings. The end 17a of the cam 17 is in a state of being pushed downward relatively (downward in FIGS. 2 and 3). That is, the initial position of the swing cam 17 is inclined in a direction in which the cam surface 20 b approaches the roller 6 of the rocker arm 3. Therefore, when the swing cam 17 swings with the rotation of the drive shaft 12, the portion of the rocker arm 3 that contacts the roller 6 immediately shifts from the base circle surface 20a to the cam surface 20b. Therefore, the lift amount is increased as a whole, and the operating angle is increased.

  As described above, the variable valve mechanism 10 can continuously change the position of the eccentric cam portion 15, and accordingly, the valve lift characteristic continuously increases the lift and the operating angle at the same time. , Can be reduced. In particular, in this case, the opening timing and closing timing of the intake valve 2 change substantially symmetrically as the lift and operating angle change.

  Then, when the swing cam 17 rotates and pushes the roller 6 of the rocker arm 3, the rocker arm 3 swings around the portion supported by the lash adjuster 4, and this swing causes the valve stem 5 of the intake valve 2 to swing. Is pressed. The intake valve 2 opens and closes based on the force by which the rocker arm 3 pushes the valve stem 5 and the urging force of a valve spring (not shown) of the intake valve 2.

  Oil (hydraulic pressure) is supplied from an oil pump 32 (described later) to the pair of lash adjusters 4a and 4b of the same cylinder via the pair of hydraulic passages 31a and 31b. Here, an electromagnetic valve 33 serving as a hydraulic control valve is interposed in a hydraulic passage 31a for supplying oil (hydraulic pressure) to the lash adjuster 4a linked to the intake valve 2a, and even if the oil pump 32 is operated, the lash The supply of oil (hydraulic pressure) to the adjuster 4a can be stopped. On the other hand, no electromagnetic valve is interposed in the hydraulic passage 31b for supplying oil (hydraulic pressure) to the lash adjuster 4b linked to the intake valve 2b, and oil (hydraulic pressure) is always supplied during operation of the oil pump 32. It is the composition which becomes. The electromagnetic valve 33 is controlled based on a control signal from the engine control unit (not shown) described above.

  As shown in FIGS. 2 and 3, the lash adjuster 4 includes a bottomed cylindrical body 41 housed and held in a cylinder head 11 serving as an internal combustion engine body, and a plunger 42 slidably housed in the body 41. The first oil chamber 43 formed inside the plunger 42, the plunger bottom wall defined between the bottom wall 41 a of the body 41 and the bottom wall 42 a of the plunger 42 and penetrating into the bottom wall 42 a of the plunger 42. A second oil chamber 45 that communicates with the first oil chamber 43 via the communication passage 44, a bottom wall 41a of the body 41 and a bottom wall 42a of the plunger 42 that are disposed in the second oil chamber 45, A spring 46 that always urges the body 41 in the direction of protruding from the body 41 and the flow of oil from the first oil chamber 43 to the second oil chamber 45 are permitted, flow Has a first oil flow limiting means 47 for prohibiting the. The plunger 42 includes two parts, an upper plunger member 48a and a lower plunger member 48b.

  A through hole 49 is formed at the tip of the upper plunger member 48a that contacts the other end of the rocker arm 3. The oil in the first oil chamber 43 passes through the through hole 49, and the upper plunger member 48a, the rocker arm 3 and the like. It can flow out from the sliding surface with the end. The spring force of the spring 46 is set to be sufficiently weaker than the spring force of a valve spring (not shown) of the intake valve 2.

  Oil discharged from an oil pump 32 as hydraulic pressure supply means is supplied to the first oil chamber 43 through a body hole 50 formed in the body 41 and a plunger oil hole 51 formed in the plunger 42. Yes. The oil pump 32 is driven, for example, with the operation of the internal combustion engine 1.

  The first oil circulation restriction means 47 is disposed in the ball-shaped valve body 52 disposed in the second oil chamber 45 and the second oil chamber 45, and the plunger bottom wall communication path 44 extends from the second oil chamber 45 side. The valve body urging spring 53 that urges the valve body 52 so as to be closed and a cover member 54 that holds the valve body urging spring 53 are roughly configured.

  In such a lash adjuster 4, when oil (hydraulic pressure) is supplied from the oil pump 32 to the first oil chamber 43, as shown in FIG. 3, if the swing cam 17 tries to move away from the rocker arm 3, The spring 46 extends and the plunger 42 protrudes from the body 41, the overall length of the lash adjuster 4 becomes relatively long, and the rocker arm 3 is pressed against the swing cam 17 by the plunger 42. Thus, since the rocker arm 3 is displaced following the swing cam 17, it is possible to suppress the occurrence of a clearance between the roller 6 of the rocker arm 3 and the swing cam 17. When the lash adjuster 4 becomes longer, the pressure of the second oil chamber 45 decreases as the volume of the second oil chamber 45 increases, and the pressure difference between the second oil chamber 45 and the first oil chamber 43 increases. The differential pressure based on this acts on the valve body 52. When the valve body 52 opens the plunger bottom wall communication passage 44 against the biasing force of the valve body biasing spring 53 by this differential pressure, oil flows from the first oil chamber 43 to the second oil chamber 45. When the differential pressure becomes smaller than the urging force of the valve body urging spring 53, the plunger bottom wall communication path 44 is closed by the valve body 52.

  In the lash adjuster 4, when oil (hydraulic pressure) is supplied from the oil pump 32 to the first oil chamber 43, if the rocker arm 3 is pushed by the swing cam 17, the force at that time passes through the rocker arm 3. Is transmitted to the plunger 42, and the plunger 42 attempts to enter the body 41. At this time, since the plunger bottom wall communication path 44 is closed by the valve body 52, the flow of oil from the second oil chamber 45 to the first oil chamber 43 is restricted, and the oil in the second oil chamber 45 is Movement of the plunger 42 in the direction of reducing the volume of the second oil chamber 45, that is, entry of the plunger 42 into the body 41 is restricted. When the plunger 42 is about to enter the body 41, a little amount of oil in the second oil chamber 45 passes between the inner peripheral surface of the body 41 and the outer peripheral surface of the plunger 42 and leaks to the outside of the lash adjuster 4. Therefore, the plunger 42 slightly sinks into the body 41. However, the approach (sinking) of the plunger 42 into the body 41 is a state in which oil is supplied from the oil pump 32 to the first oil chamber 43. Thus, the swing cam 17 is recovered through the operation of the lash adjuster 4 when it is about to leave the rocker arm 3.

  On the other hand, in the lash adjuster 4, when the oil (hydraulic pressure) is not supplied from the oil pump 32 to the first oil chamber 43, the displacement of the rocker arm 3 is absorbed by the elastic deformation of the spring 46 in the second oil chamber 45. Here, since the spring force of the spring 46 is sufficiently smaller than the spring force of the valve spring of the intake valve 2 as described above, the displacement of the rocker arm 3 is first absorbed by the spring 46 and completely absorbed by the spring 46. The remaining amount is transmitted to the valve stem 5 of the intake valve 2 to push open the intake valve 2 (see FIG. 2). In the present embodiment, the control condition of the variable valve mechanism 10 is a small lift / small operating angle condition (the lift / operating angle of the intake valve 2 is a predetermined small lift / small operating angle or less), When the displacement of the rocker arm 3 such that the valve stem 5 extends slightly due to thermal expansion is small, all the displacement of the rocker arm 3 is absorbed by the retraction of the plunger 42 into the body 41 due to the compression deformation of the spring 46. The lash adjuster 4 is set so that the valve 2 does not open. In other words, the lash adjuster 4 is moved from the swing cam 17 through the rocker arm 3 in a state where oil (hydraulic pressure) is supplied to the first oil chamber 43, compared to a state where oil (hydraulic pressure) is not supplied to the first oil chamber 43. Thus, the amount of movement transmitted to the intake valve 2 is increased.

  In the present embodiment, when the lift / operating angle of the intake valve 2 is controlled to be equal to or smaller than a predetermined small lift / small operating angle (less than a predetermined small lift amount) by the variable valve mechanism 10, the hydraulic passage 31a. It is controlled to close the electromagnetic valve 33 interposed between the two.

  By closing the solenoid valve 33, oil (hydraulic pressure) is not supplied from the oil pump 32 to the lash adjuster 4a out of the two lash adjusters 4a, 4b of the same cylinder. Therefore, the intake valve 2a linked to the lash adjuster 4a does not open because the spring 46 of the lash adjuster 4a absorbs all the displacement of the rocker arm 3a. That is, in the present embodiment, when the lift / operating angle of the intake valve 2 is controlled to be equal to or smaller than a predetermined small lift / small operating angle, only the intake valve 2b is opened among the intake valves 2a, 2b, Maintaining the valve 2a in a closed state, that is, a so-called one-valve stop state, improves the control accuracy of the intake air amount, thereby suppressing variations in the inter-cylinder combustion pressure and reducing vibrations.

  The lash adjuster 4 can switch its length (height) with high responsiveness in response to supply / stop of oil (hydraulic pressure) from the oil pump 32.

  The lash adjuster 4 is supported on the main body side of the internal combustion engine and does not affect the inertial mass of the variable valve mechanism 10, so that the so-called variable valve mechanism 10 is increased by increasing the inertial mass of the variable valve mechanism 10. It is possible to prevent a decrease in the crash rotational speed. That is, it is possible to give a lift difference to the pair of intake valves (engine valves) 2a and 2b in the same cylinder without causing a decrease in the crash rotational speed of the variable valve mechanism 10.

  Further, since the hydraulic passage 31 is formed in the cylinder head 11 which is the internal combustion engine body, oil (hydraulic pressure) is supplied to the lash adjuster 4 on the variable valve mechanism 10 side such as the control shaft 14 of the variable valve mechanism 10. As compared with the case of forming a hydraulic passage for this purpose, it is possible to suppress an increase in the size of the variable valve mechanism.

  The lash adjuster 4 closes the solenoid valve 33 when the lift / operating angle of the intake valve 2 is controlled to be equal to or smaller than a predetermined small lift / small operating angle when no oil is supplied to the first oil chamber 43. When the valve is operated, the intake valve 2a can be set to open with a smaller lift / small operating angle (small lift) than the intake valve 2b. In this case, when the intake valve 2 is in an idle operation state or a low load operation state in which the intake valve 2 is controlled to a small lift and a small operating angle, a lift difference is generated between the pair of intake valves 2a and 2b of the same cylinder. The inner swirl can be strengthened, and fuel consumption can be improved.

  Further, when the intake valves 2a and 2b are controlled to a lift / operation angle larger than a predetermined small lift / small operation angle, the solenoid valve 33 is not closed. This is because, when the solenoid valve 33 is closed when the intake valves 2a and 2b are controlled to have a relatively large lift and a large operating angle, the seating speed of the intake valve 2a becomes excessive and the intake valve 2a is damaged. It is because there is a possibility of doing. In other words, the predetermined small lift / small operating angle can be obtained even when the electromagnetic valve 33 is closed when the intake valves 2a, 2b are controlled to a lift / operating angle equal to or smaller than the predetermined small lift / small operating angle. The seating speed of the intake valve 2a is not excessive, and is defined as a value that does not cause damage to the intake valve 2a.

  Hereinafter, although other embodiment of this invention is described, the code | symbol same about the part which becomes the same structure as 1st Embodiment mentioned above is attached | subjected, and the overlapping description is abbreviate | omitted.

  Next, a second embodiment of the present invention will be described. The internal combustion engine in the second embodiment has substantially the same configuration as the internal combustion engine 1 of the first embodiment described above, but the lash adjuster 60 in the second embodiment is as shown in FIGS. A body bottom wall communication passage 61 formed through the bottom wall 41a of the body 41, and a hydraulic second oil circulation capable of discharging the oil in the second oil chamber 45 to the outside through the body bottom wall communication passage 61. Limiting means 62.

  The second oil circulation restriction means 62 includes a third oil chamber 63 communicating with the second oil chamber 45 through the body bottom wall communication passage 61, a valve body 64 disposed in the third oil chamber 63, and one end hydraulic. The auxiliary hydraulic passage 65 is connected to either the passage 31 a or the hydraulic passage 31 b and the other end is connected to the third oil chamber 63, and the drain passage 66 is connected to the third oil chamber 63. ing.

  The third oil chamber 63 is defined by the cylinder head 11 in which the body 41 of the lash adjuster 60 a is accommodated and held, and the bottom wall 41 a of the body 41. The passage cross-sectional area of the body bottom wall communication passage 61 is set to be smaller than the area of the base end 64a of the valve body 64 on which the hydraulic pressure from the auxiliary hydraulic passage 65 acts.

  The valve body 64 is configured to move forward and backward in the third oil chamber 63 by oil (hydraulic pressure) supplied from the oil pump 32 via the auxiliary hydraulic passage 65. More specifically, when the oil (hydraulic pressure) is supplied to the third oil chamber 63 via the auxiliary hydraulic passage 65 and the hydraulic pressure is applied to the base end 64a, the valve body 64 has the tip 64b of the body 41 as shown in FIG. The body bottom wall communication path 61 is closed by abutting against the bottom wall 41a. In a state where oil (hydraulic pressure) is supplied to the third oil chamber 63, the oil pressure is also supplied to the second oil chamber 45 via the first oil chamber 43. Since the passage cross-sectional area of the passage 61 is smaller than the area of the base end 64 a of the valve body 64 to which the hydraulic pressure from the auxiliary hydraulic passage 65 acts, the distal end 64 b of the valve body 64 contacts the bottom wall 41 a of the body 41. Touch. Further, when the supply of oil (hydraulic pressure) to the third oil chamber 63 is stopped, the valve body 64 is separated from the bottom wall 41a of the body 41 as shown in FIG. The passage 61 and the drain passage 66 communicate with each other.

  In such a second embodiment, when oil (hydraulic pressure) is no longer supplied to the first oil chamber 43 of the lash adjuster 60, the valve body 64 in the third oil chamber 63 is quickly retracted, and the body bottom wall connection. Oil (hydraulic pressure) in the second oil chamber 45 can be released to the drain passage 66 via the passage 61, and when oil (hydraulic pressure) is supplied to the first oil chamber 43 of the lash adjuster 60, The valve body 64 in the oil chamber 63 can quickly advance to close the body bottom wall communication path 61.

  Of the two lash adjusters of the same cylinder, the lash adjuster 60 described above is applied only to the lash adjuster in which oil (hydraulic pressure) is supplied to the first oil chamber via the hydraulic passage 31a in which the solenoid valve 33 is interposed. The lash adjuster 4 of the first embodiment may be applied to a lash adjuster in which oil (hydraulic pressure) is supplied to the first oil chamber via the hydraulic passage 31b.

  Next, a third embodiment of the present invention will be described. The internal combustion engine 70 according to the third embodiment has substantially the same configuration as that of the first embodiment described above. However, as shown in FIG. 6, a variable valve is provided in a hydraulic passage 31a in which an electromagnetic valve 33 is interposed. A bypass passage 71 that bypasses the electromagnetic valve 33 is connected via the control shaft 14 of the mechanism 10.

  Here, as shown in FIGS. 7 and 8, the control shaft 14 of the variable valve mechanism 10 is a bearing 73 constituted by a cam bracket 11a of the cylinder head 11 and a cap member 72 fixed to the cam bracket 11a. It is supported rotatably by. In the control shaft 14, a groove 74 having a predetermined length along the circumferential direction of the control shaft 14 is formed on the outer peripheral surface at a position where the control shaft 14 is rotatably supported by the bearing 73.

  The bypass passage 71 is configured to open and close as the control shaft 14 rotates. As shown in FIGS. 7 and 8, the variable valve mechanism 10 allows the intake valve 2 to lift and operate at a predetermined small lift / operating angle. When the control valve is controlled to be larger than the small operating angle, it communicates. When the lift / operating angle of the intake valve 2 is controlled to be equal to or smaller than the predetermined small lift / small operating angle by the variable valve mechanism 10, the control is cut off. It is comprised so that. In other words, the bypass passage 71 is controlled so that the lift / operating angle of the intake valve 2 is larger than a predetermined small lift / small operating angle regardless of whether the electromagnetic valve 33 is open or closed. Oil (hydraulic pressure) can be supplied to the first oil chamber 43 of the lash adjuster 4 through the hydraulic passage 31a, and the variable valve mechanism 10 makes the lift / operating angle of the intake valve 2 a predetermined small lift / small operating angle. In the following control, oil (hydraulic pressure) from the oil pump 32 can be supplied to the first oil chamber 43 of the lash adjuster 4 via the hydraulic passage 31a only when the electromagnetic valve 33 is in the open state. It is configured.

  Specifically, the bypass passage 71 has one end connected to the hydraulic passage 31 a on the upstream side (oil pump 32 side) of the solenoid valve 33 and the other end connected to the inner peripheral surface of the bearing 73. One end of which is connected to the inner peripheral surface of the bearing 73 and the other end of which is connected to the hydraulic passage 31a on the downstream side (rush adjuster 4 side) of the solenoid valve 33, and the control shaft 14 described above. A bearing passage 77 defined by the groove 74 and the inner peripheral surface of the bearing 73 is generally configured.

  The upstream passage 75 is set so as to always communicate with the bearing passage 77 regardless of the rotational position of the control shaft 14. The downstream passage 76 does not communicate with the bearing passage 77 when the lift / operation angle of the intake valve 2 is controlled to be equal to or smaller than a predetermined small lift / small operation angle, and the lift / operation angle of the intake valve 2 is a predetermined small It is set to communicate with the bearing passage 77 when it is controlled to be larger than the lift / small operating angle.

  Further, as shown in FIG. 9, the lift / operating angle range (bypass passage open range) of the intake valve 2 in which the bypass passage 71 is in the communication state is the lift / operating angle range in which the electromagnetic valve 33 is controlled to be in the open state. The seating speed of the intake valve 2 is excessive when the oil supply to the lash adjuster 4 is stopped, and is set to be larger than the range of lift / operating angle where the intake valve 2 may be damaged.

  In such a third embodiment, when the lift / operating angle of the intake valve 2 is controlled to be a large lift / large operating angle, even if some trouble occurs and the electromagnetic valve 33 is not opened, the bypass passage Since the oil (hydraulic pressure) is forcibly supplied to the lash adjuster 4a via 71, it is possible to reliably prevent the intake valve 2 from being damaged due to the stop of the oil supply to the lash adjuster 4. .

  Next, a fourth embodiment of the present invention will be described with reference to FIGS. The internal combustion engine 81 in the fourth embodiment has substantially the same configuration as the internal combustion engine 1 in the first embodiment described above, but of the pair of lash adjusters 4a and 4b in the same cylinder, the rear lash adjuster 4b. A hydraulic support position changing mechanism 82 as a hydraulic support position changing means capable of changing the support position of the lash adjuster 4b is disposed between the main body and the internal combustion engine body. Also, oil (hydraulic pressure) is supplied from the oil pump 32 to the pair of lash adjusters 4a and 4b via the first hydraulic passage 83, and the hydraulic support position changing mechanism 82 is different from the first hydraulic passage 83. Oil (hydraulic pressure) is supplied from the oil pump 32 via the second hydraulic passage 84.

  The second hydraulic passage 84 is provided with an electromagnetic valve 85 as a hydraulic switching valve, and even when the oil pump 32 is operated, supply of oil (hydraulic pressure) to the hydraulic support position changing mechanism 82 can be stopped. It is configured as follows. The second hydraulic passage 84 has a control shaft passage 86 that is opened and closed as the control shaft 14 of the variable valve mechanism 10 rotates and is connected in series with the electromagnetic valve 85 on the downstream side of the electromagnetic valve 85. Yes.

  Here, as shown in FIG. 12, the control shaft 14 of the variable valve mechanism 10 is rotatable by a bearing 73 constituted by a cam bracket 11a of the cylinder head 11 and a cap member 72 fixed to the cam bracket 11a. It is supported by. In the control shaft 14, a groove 87 having a predetermined length along the circumferential direction of the control shaft 14 is formed on the outer peripheral surface at a position where the control shaft 14 is rotatably supported by the bearing 73. The control shaft passage 86 is defined by the groove portion 87 of the control shaft 14 and the inner peripheral surface of the bearing 73.

  The control shaft passage 86 is configured to be opened and closed as the control shaft 14 rotates, and the lift / operating angle of the intake valve 2 is controlled to be equal to or smaller than a predetermined small lift / small operating angle by the variable valve mechanism 10. The groove portion 87 is positioned and communicated as shown by a solid line in FIG. 12, and the lift / operating angle of the intake valve 2 is controlled by the variable valve mechanism 10 to be larger than a predetermined small lift / small operating angle. In this case, the groove 87 is positioned and blocked as shown by a broken line in FIG.

  The hydraulic support position changing mechanism 82 fixes the support position of the lash adjuster 4b with respect to the internal combustion engine body by engaging with the recess 89 on the internal combustion engine body side by the biasing force of the switching pin biasing spring 88 as the first elastic member. And a support member 92 that supports the lash adjuster 4b with respect to the internal combustion engine body so that the support position of the lash adjuster 4b can be changed using the elastic force of the support member biasing spring 91 as a second elastic member. Yes. The spring force of the support member biasing spring 91 is set to be sufficiently smaller than the spring force of the valve spring of the intake valve 2.

  In the hydraulic support position changing mechanism 82, when hydraulic pressure is supplied from the second hydraulic passage 84 to the recess 89, the switching pin 90 engaged with the recess 89 resists the biasing force of the switching pin biasing spring 88. As a result, the engagement between the recess 89 and the switching pin 90 is released, and the movement transmitted from the swing cam 17 to the intake valve 2b via the rocker arm 3b as compared with the state where the switching pin 90 and the recess 89 are engaged. The amount of becomes smaller.

  Note that reference numeral 93 in FIG. 10 denotes a rotation prevention groove formed in the body 41.

  In the fourth embodiment, the same operational effects as those of the first embodiment described above can be obtained.

  In the fourth embodiment, the variable valve mechanism 10 causes the engine valve 85 to open due to some trouble at the time of high engine rotation such that the lift / operating angle of the intake valve 2 becomes a large lift / large operating angle. Even if it becomes a state, since the oil (hydraulic pressure) can be stopped reliably in the control shaft passage 86, the intake valve 2 is damaged due to an incorrect oil supply to the hydraulic support position changing mechanism 82. Can be reliably prevented. In the fourth embodiment, the electromagnetic valve 85 can be arranged so as to be located on the downstream side of the control shaft passage 86.

  The technical idea of the present invention that can be grasped from the above embodiment will be listed together with the effects thereof.

  (1) The internal combustion engine has a variable valve mechanism capable of changing lift characteristics of a pair of engine valves of the same cylinder, and the engine valve is operated by swinging one end side based on rotation of a swing cam of the variable valve mechanism. Oil pressure is supplied to each of two rocker arms that open and close, two lash adjusters that are supported by the internal combustion engine body and support the other end of the rocker arm, and a pair of lash adjusters of the same cylinder. A pair of mutually independent hydraulic passages, a hydraulic pressure supply means for supplying hydraulic pressure to the pair of hydraulic passages, and only one of the pair of hydraulic passages, are connected to one of the pair of lash adjusters. A hydraulic control valve that controls supply of hydraulic pressure, variable valve control means that controls the variable valve mechanism, and hydraulic control valve control means that controls opening and closing of the hydraulic control valve, The pair of lash adjusters is configured so that the amount of movement transmitted from the swing cam to the engine valve via the rocker arm is larger in the state where the hydraulic pressure is supplied than in the state where the hydraulic pressure is not supplied. When the hydraulic pressure is supplied from the supply means to the pair of hydraulic passages and the lift amount of the pair of engine valves is controlled to be equal to or less than a predetermined small lift amount, the hydraulic control valve is a hydraulic control valve. Control is performed to close the valve by the control means. The height of the lash adjuster can be switched with high responsiveness according to the supply / stop of hydraulic pressure. Further, the lash adjuster is supported on the internal combustion engine body side and does not affect the inertial mass of the variable valve mechanism, so the so-called crash rotational speed of the variable valve mechanism due to the increase of the inertial mass of the variable valve mechanism. A decrease can be prevented. That is, a lift difference can be given to a pair of engine valves (intake valves) in the same cylinder without causing a decrease in the crash rotational speed of the variable valve mechanism. Thereby, the valve lift amount of the engine valve on the lash adjuster side in which the supply of hydraulic pressure is stopped among the pair of engine valves becomes relatively small. Therefore, because there is a difference in the valve lift amount of the pair of engine valves, when the engine valve is controlled to a small lift, in other words, the in-cylinder swirl when the operation state is idle or low load can be strengthened, Improved fuel economy can be realized. Further, depending on the setting, only one of the pair of engine valves can be opened and the other can be maintained in a closed state. In this case, the control accuracy of the intake air amount is improved, As a result, variation in the combustion pressure between cylinders can be suppressed, and vibration can be reduced.

  (2) In the internal combustion engine according to (1), specifically, the lash adjuster is slidably accommodated in the bottomed cylindrical body accommodated and held in the internal combustion engine body, and the body. A plunger, a first oil chamber formed inside the plunger and supplied with hydraulic pressure from the hydraulic passage, and defined between a bottom wall of the body and a bottom wall of the plunger, and communicates with the first oil chamber. A second oil chamber, a spring disposed in the second oil chamber and sandwiched between the bottom wall of the body and the bottom wall of the plunger, and the flow of oil from the first oil chamber to the second oil chamber And the first oil circulation restriction means for prohibiting the flow of oil from the second oil chamber to the first oil chamber, and the body bottom wall communication passage formed through the bottom wall of the body. Hydraulic pressure that can discharge the oil in the second oil chamber to the outside And when the hydraulic pressure is supplied from the hydraulic passage to the first oil chamber, the oil in the second oil chamber passes through the body bottom wall communication passage. When the hydraulic pressure is supplied from the hydraulic passage to the second oil circulation restriction means so as not to flow outside, and the supply of hydraulic pressure from the hydraulic passage to the first oil chamber is stopped, The supply of hydraulic pressure from the hydraulic passage to the second oil circulation restriction means is stopped so that oil can flow out to the outside through the body bottom wall communication passage. This makes it possible to quickly stop and restore the function of the lash adjuster.

  (3) In the internal combustion engine according to (1) or (2), the variable valve mechanism makes the lift characteristics of the engine valve variable as the control shaft rotates, A bypass passage that bypasses the hydraulic control valve via the control shaft is connected to a hydraulic passage in which the hydraulic control valve is interposed, and the bypass passage is opened and closed as the control shaft rotates. When the lift amount of the engine valve is controlled to be equal to or less than a predetermined small lift amount, the engine valve is shut off, and when the lift amount of the engine valve is controlled to be larger than the predetermined small lift amount. Communicate. This can reliably prevent the engine valve from being damaged due to the stop of the oil supply to the lash adjuster.

  (4) The internal combustion engine is linked to a variable valve mechanism capable of changing lift characteristics of a pair of engine valves of the same cylinder as the control shaft rotates, a swing cam of the variable valve mechanism, and an engine valve. Two hydraulic lash adjusters per cylinder supported by the internal combustion engine body, a pair of independent hydraulic passages for supplying hydraulic pressure to each of a pair of lash adjusters of the same cylinder, and the pair of hydraulic passages A hydraulic pressure supply means for supplying hydraulic pressure; a hydraulic control valve that is interposed only in one of the pair of hydraulic passages and controls the supply of hydraulic pressure to one of the pair of lash adjusters; and the variable valve Variable valve control means for controlling the mechanism, and hydraulic control valve control means for controlling the opening and closing of the hydraulic control valve, and the pair of lash adjusters are not supplied with hydraulic pressure in a state where hydraulic pressure is supplied. The amount of movement transmitted from the swing cam to the engine valve is larger than the state, and the hydraulic control valve is in a state where hydraulic pressure is supplied from the hydraulic supply means to the pair of hydraulic passages. When the lift amount of the pair of engine valves is controlled to be small, the hydraulic control valve is controlled to close by a hydraulic control valve control means, and the hydraulic passage in which the hydraulic control valve is interposed among the pair of hydraulic passages A bypass passage that bypasses the hydraulic control valve via the control shaft is connected to the bypass passage, and the bypass passage is configured to open and close as the control shaft rotates, and the lift amount of the engine valve is a predetermined small amount. It is shut off when it is controlled below the lift amount, and communicates when it is controlled so that the lift amount of the engine valve is larger than a predetermined small lift amount.

  (5) The internal combustion engine includes a variable valve mechanism capable of changing a lift characteristic of a pair of engine valves of the same cylinder, and a swing of one end based on rotation of a swing cam of the variable valve mechanism. Two rocker arms per cylinder that opens and closes, two lash adjusters supported by the internal combustion engine body and supporting the other end of the rocker arm, and a first hydraulic passage that supplies hydraulic pressure to a pair of lash adjusters of the same cylinder And a hydraulic support position changing means disposed between one lash adjuster of the pair of lash adjusters of the same cylinder and the internal combustion engine body, and capable of changing the support position of the one lash adjuster with respect to the internal combustion engine body. A second hydraulic passage for supplying hydraulic pressure to the hydraulic support position changing means, and a hydraulic supply for supplying hydraulic pressure to the first hydraulic passage and the second hydraulic passage. Means, a hydraulic switching valve that is interposed in the second hydraulic passage and controls the supply of hydraulic pressure to the hydraulic support position changing means, a variable valve control means that controls the variable valve mechanism, and the hydraulic pressure Hydraulic switching valve control means for controlling opening and closing of the switching valve, and the hydraulic support position changing means is engaged with the recess on the internal combustion engine body side by the biasing force of the first elastic member, thereby A switching pin that fixes the support position of the adjuster with respect to the internal combustion engine body, and an elastic force of the second elastic member when the engagement between the switching pin and the recess is released by hydraulic pressure that is supplied with hydraulic pressure and acts on the switching pin. And a support member that supports the lash adjuster so that the support position of the lash adjuster relative to the internal combustion engine body can be changed, and when the engagement between the switching pin and the recess is released, The first hydraulic passage and the second hydraulic passage are configured such that the amount of movement transmitted from the swing cam to the engine valve via the rocker arm is smaller than in a state where the replacement pin and the recess are engaged. The hydraulic switching valve is controlled to be opened by the hydraulic switching valve control means when the hydraulic pressure is supplied to the engine valve and the lift amount of the pair of engine valves is controlled to be equal to or smaller than a predetermined small lift amount. Is done.

  (6) In the internal combustion engine according to (5), the variable valve mechanism changes the lift characteristic of the engine valve as the control shaft rotates, and the second hydraulic passage includes A control shaft passage that is opened and closed with the rotation of the control shaft is connected in series with the hydraulic pressure switching valve, and the control shaft passage is configured to be opened and closed with the rotation of the control shaft, and the engine valve When the lift amount of the engine valve is controlled to be equal to or less than a predetermined small lift amount, the communication is performed. When the lift amount of the engine valve is controlled to be larger than the predetermined small lift amount, the lift amount is blocked. This can reliably prevent the engine valve from being damaged due to an incorrect oil supply to the hydraulic support position changing mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which showed typically schematic structure in 1st Embodiment of the internal combustion engine which concerns on this invention. Explanatory drawing which showed typically the correlation of the intake valve of the front side, rocker arm, and lash adjuster in the same cylinder in 1st Embodiment. Explanatory drawing which showed typically the correlation of the intake valve, rocker arm, and lash adjuster of the rear side in the same cylinder in 1st Embodiment. Explanatory drawing which showed typically the lash adjuster applied to 2nd Embodiment of the internal combustion engine which concerns on this invention. Explanatory drawing which showed typically the lash adjuster applied to 2nd Embodiment of the internal combustion engine which concerns on this invention. Explanatory drawing which showed typically schematic structure in 3rd Embodiment of the internal combustion engine which concerns on this invention. Explanatory drawing which showed the outline of the bypass channel typically. Explanatory drawing which showed the outline of the bypass channel typically. Explanatory drawing which compares and shows the lift and working angle range in which a bypass channel | path will be in a communication state, and the lift and working angle range in which a solenoid valve is controlled by the valve opening state. Explanatory drawing which showed typically the correlation of the intake valve, the rocker arm, and the lash adjuster of the rear side in the same cylinder in 4th Embodiment. Explanatory drawing which showed typically the schematic structure in 4th Embodiment of the internal combustion engine which concerns on this invention. Explanatory drawing which showed the outline of the control-shaft channel | path in 4th Embodiment typically.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 2a ... Intake valve 2b ... Intake valve 3a ... Rocker arm 3b ... Rocker arm 4a ... Rush adjuster 4b ... Rush adjuster 6 ... Roller 31a ... Hydraulic passage 31b ... Hydraulic passage 32 ... Oil pump 33 ... Solenoid valve

Claims (6)

A variable valve mechanism that can vary the lift characteristics of a pair of engine valves of the same cylinder;
Two rocker arms per cylinder that open and close the engine valve by swinging one end side based on the rotation of the swing cam of the variable valve mechanism;
Two lash adjusters per cylinder supported by the internal combustion engine body and supporting the other end of the rocker arm;
A pair of independent hydraulic passages for supplying hydraulic pressure to each of a pair of lash adjusters of the same cylinder;
Hydraulic supply means for supplying hydraulic pressure to the pair of hydraulic passages;
A hydraulic control valve that is interposed only in one of the pair of hydraulic passages and controls the supply of hydraulic pressure to one of the pair of lash adjusters;
Variable valve control means for controlling the variable valve mechanism;
Hydraulic control valve control means for controlling opening and closing of the hydraulic control valve,
The pair of lash adjusters is configured such that the amount of movement transmitted from the swing cam to the engine valve via the rocker arm is larger in a state where hydraulic pressure is supplied than in a state where hydraulic pressure is not supplied,
When the hydraulic pressure is supplied from the hydraulic pressure supply means to the pair of hydraulic passages and the lift amount of the pair of engine valves is controlled to be equal to or less than a predetermined small lift amount, the hydraulic control valve An internal combustion engine controlled to be closed by a control valve control means. The lash adjuster includes a bottomed cylindrical body that is housed and held in the internal combustion engine body, a plunger that is slidably housed in the body, a first body that is formed inside the plunger and is supplied with hydraulic pressure from the hydraulic passage. A first oil chamber, a second oil chamber defined between the bottom wall of the body and the bottom wall of the plunger and communicating with the first oil chamber; and a bottom of the body disposed in the second oil chamber. A spring sandwiched between the wall and the bottom wall of the plunger, and the flow of oil from the first oil chamber to the second oil chamber is permitted, and the oil from the second oil chamber to the first oil chamber is allowed to flow. Hydraulic second oil circulation that can discharge the oil in the second oil chamber to the outside through a first oil circulation restriction means that prohibits flow and a body bottom wall communication passage formed through the bottom wall of the body. Limiting means,
When the hydraulic pressure is supplied from the hydraulic passage to the first oil chamber, the second oil circulation restricting means prevents the oil in the second oil chamber from flowing out through the body bottom wall communication passage. Hydraulic pressure is supplied from the hydraulic passage,
When the supply of hydraulic pressure from the hydraulic passage to the first oil chamber is stopped, the hydraulic passage so that the oil in the second oil chamber can flow out to the outside through the body bottom wall communication passage. 2. The internal combustion engine according to claim 1, wherein the supply of hydraulic pressure to the second oil circulation restriction means is stopped. The variable valve mechanism makes the lift characteristic of the engine valve variable as the control shaft rotates,
A bypass passage that bypasses the hydraulic control valve via the control shaft is connected to a hydraulic passage in which the hydraulic control valve is interposed among the pair of hydraulic passages,
The bypass passage is configured to be opened and closed as the control shaft rotates, and is shut off when the lift amount of the engine valve is controlled to be equal to or less than a predetermined small lift amount. The internal combustion engine according to claim 1 or 2, wherein the internal combustion engine communicates when controlled to be larger than a predetermined small lift amount. A variable valve mechanism capable of changing the lift characteristics of a pair of engine valves of the same cylinder as the control shaft rotates;
Two hydraulic lash adjusters per cylinder linked to the swing cam and engine valve of the variable valve mechanism and supported by the internal combustion engine body;
A pair of independent hydraulic passages for supplying hydraulic pressure to each of a pair of lash adjusters of the same cylinder;
Hydraulic supply means for supplying hydraulic pressure to the pair of hydraulic passages;
A hydraulic control valve that is interposed only in one of the pair of hydraulic passages and controls the supply of hydraulic pressure to one of the pair of lash adjusters;
Variable valve control means for controlling the variable valve mechanism;
Hydraulic control valve control means for controlling opening and closing of the hydraulic control valve,
The pair of lash adjusters is configured such that the amount of movement transmitted from the swing cam to the engine valve is larger in a state where hydraulic pressure is supplied than in a state where hydraulic pressure is not supplied,
The hydraulic control valve controls the hydraulic control valve control means when the hydraulic pressure is supplied from the hydraulic supply means to the pair of hydraulic passages and when the lift amount of the pair of engine valves is controlled to be small. Controlled to close by
A bypass passage that bypasses the hydraulic control valve via the control shaft is connected to a hydraulic passage in which the hydraulic control valve is interposed among the pair of hydraulic passages,
The bypass passage is configured to be opened and closed as the control shaft rotates, and is shut off when the lift amount of the engine valve is controlled to be equal to or less than a predetermined small lift amount. An internal combustion engine that communicates when controlled to be larger than a predetermined small lift amount. A variable valve mechanism that can vary the lift characteristics of a pair of engine valves of the same cylinder;
Two rocker arms per cylinder that open and close the engine valve by swinging one end side based on the rotation of the swing cam of the variable valve mechanism;
Two lash adjusters per cylinder supported by the internal combustion engine body and supporting the other end of the rocker arm;
A first hydraulic passage for supplying hydraulic pressure to a pair of lash adjusters of the same cylinder;
A hydraulic support position changing means arranged between one lash adjuster of the pair of lash adjusters of the same cylinder and the internal combustion engine body, and capable of changing the support position of the one lash adjuster with respect to the internal combustion engine body;
A second hydraulic passage for supplying hydraulic pressure to the hydraulic support position changing means;
Hydraulic supply means for supplying hydraulic pressure to the first hydraulic passage and the second hydraulic passage;
A hydraulic switching valve that is interposed in the second hydraulic passage and controls the supply of hydraulic pressure to the hydraulic support position changing means;
Variable valve control means for controlling the variable valve mechanism;
Hydraulic switching valve control means for controlling opening and closing of the hydraulic switching valve,
The hydraulic support position changing means is supplied with hydraulic pressure and a switching pin that fixes the support position of the one lash adjuster with respect to the internal combustion engine body by engaging with the recess on the internal combustion engine body side by the biasing force of the first elastic member. When the engagement between the switching pin and the recess is released by the hydraulic pressure acting on the switching pin, the support position of the lash adjuster relative to the internal combustion engine body can be changed using the elastic force of the second elastic member. In the state where the engagement between the switching pin and the recess is released, the swinging cam is moved from the rocker arm through the rocker arm in a state where the engagement between the switching pin and the recess is released. Configured to reduce the amount of movement transmitted to the engine valve,
When the hydraulic pressure is supplied to the first hydraulic passage and the second hydraulic passage, and when the lift amount of the pair of engine valves is controlled to be equal to or less than a predetermined small lift amount, the hydraulic switching valve is An internal combustion engine controlled to open by a hydraulic switching valve control means. The variable valve mechanism makes the lift characteristic of the engine valve variable as the control shaft rotates,
A control shaft passage that opens and closes as the control shaft rotates is connected to the second hydraulic passage in series with the hydraulic switching valve.
The control shaft passage is configured to open and close as the control shaft rotates, and communicates when the lift amount of the engine valve is controlled to be equal to or less than a predetermined small lift amount. 6. The internal combustion engine according to claim 5, wherein when the engine is controlled to be larger than a predetermined small lift amount, the engine is shut off.

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