JP2005113774A - Valve device for internal combustion engine, and initial setting device for variable valve mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve device for an internal combustion engine, and an initial setting device for a variable valve mechanism, in an internal combustion engine, in which the changeover action of the variable valve mechanism can be optimized, in which generation of abnormal sound in accordance with change over of actuation characteristics of an intake valve and an exhaust valve is restricted, and in which damaging and abrasion in the variable valve mechanism can be reduced. <P>SOLUTION: A first rocker arm is provided with a rocker cylinder having an opening part in a part of a slide surface and a rocker piston. A second rocker arm is provided with an abutment protrusion of which tip part is inserted into the rocker cylinder from the opening part when the rocker piston is at one slide end of the rocker cylinder as the first rocker arm oscillates, and abutted with a side surface of the rocker piston when it is at such a position as to close the opening part. A rocker piston actuation means includes a learning means S20 to learn actuation time of the rocker piston to prevent a prescribed actuation state (halfway of rising or halfway of falling) of the rocker piston when the second rocker arm starts oscillation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a valve operating device for an internal combustion engine and an initial setting device for a variable valve operating mechanism. More specifically, the present invention relates to a variable valve operating system for an internal combustion engine that can vary the operating characteristics of an intake valve and an exhaust valve according to the operating state of the engine. The present invention relates to a mechanism and a technology for initially setting a switching operation of the variable valve mechanism.

In recent years, it is possible to optimize the operating characteristics (opening / closing timing and valve opening period) of poppet-type intake valves and exhaust valves provided in internal combustion engines (hereinafter referred to as engines) according to engine load conditions and rotational speed conditions. A valve operating device having a variable valve operating mechanism has been developed and put into practical use.
For example, a low-speed cam having a cam profile suitable for low-speed rotation of the engine and a high-speed cam having a cam profile suitable for high-speed rotation of the engine may be used. A valve gear that can be selected according to the rotational speed state has been developed (see, for example, Patent Document 1).

Further, the applicant has proposed a valve operating apparatus as shown in FIGS. 8 and 9 in an SOHC type engine (see, for example, the specification and drawings attached to Japanese Patent Application No. 2002-151363).
FIG. 9 is a cross-sectional view taken along the line AA of FIG. 8. In the valve operating apparatus, as shown in FIGS. 8 and 9, the cylinder head 10 above each cylinder of the engine is provided for each cylinder. Two intake valves 11 and 12 and two exhaust valves 21 and 22 that are normally closed by return springs (not shown) are provided, and the intake valves 11 and 12 and the exhaust valves 21 and 22 are driven. For this purpose, a valve operating device 30 is provided.

  The valve gear 30 is divided into an intake valve drive system that drives the intake valves 11 and 12 and an exhaust valve drive system that drives the exhaust valves 21 and 22. The intake valve drive system includes a camshaft 31, cams 31 a to 31 c fixed to the camshaft 31, a rocker shaft 32, and is pivotally supported by the rocker shaft 32 and swings by the cams 31 a to 31 c. Rocker arms 33 to 35 are provided. On the other hand, the exhaust valve drive system includes a camshaft 31 shared with the intake system, cams 31d and 31e fixed to the camshaft 31, a rocker shaft 36, and a rocker shaft 36 that is pivotally supported by the rocker shaft 36. Rocker arms 37 and 38 that are swung by 31d and 31e are provided.

A variable valve mechanism 40 having a connection switching mechanism 41 is provided in the intake valve drive system of the valve gear 30. Details of the configuration of the variable valve mechanism 40 will be described below.
Among the rocker arms 33 to 35 for driving the intake valve, the medium and low speed rocker arms 33 and 34 have adjustment screws 33a and 34a at one end abutting against the stem ends of the intake valves 11 and 12, respectively. The intake valve 12 is configured to open and close in response to the swing of the medium / low speed rocker arm 34.

  Specifically, the medium / low speed rocker arm 33 is in contact with the medium / low speed cam 31a formed with a medium / low speed cam profile corresponding to the low speed rotation of the engine, and the roller 33b at the other end follows the medium / low speed cam 31a. By swinging, the intake valve 11 is configured to be opened with a low lift characteristic as indicated by a one-dot chain line in FIG. Further, the medium / low speed rocker arm 34 is in contact with a medium / low speed cam 31b having a medium / low speed cam profile corresponding to the roller 34b at the other end of the engine at a low speed rotation of the engine. By moving, the intake valve 12 is configured to be opened with a medium lift characteristic as indicated by a solid line in FIG. That is, the medium / low-speed rocker arm 33 and the medium / low-speed rocker arm 34 are configured to open and close the intake valves 11 and 12 with different valve lifts in accordance with the medium / low speed cams 31a and 31b, respectively, and to generate a swirl flow in the combustion chamber. Yes.

  On the other hand, the high-speed rocker arm 35 has a pair of abutting protrusions 35a and 35a formed at one end extending toward the middle and low-speed rocker arms 33 and 34, and a roller 35b provided at the other end corresponds to the high-speed rotation of the engine. The high-speed cam 31c is formed in contact with the high-speed cam 31c. That is, the high-speed rocker arm 35 swings following the high-speed cam 31c, whereby the front end surfaces 35d and 35d of the front end portions 35c and 35c of the contact protrusions 35a and 35a can come into contact with the middle and low-speed rocker arms 33 and 34. is there.

  The high speed rocker arm 35 is urged by an arm spring 43 so that the high speed rocker arm 35 is not separated from the cam 31c. As shown in FIG. 8, the arm spring 43 is composed of a spring body 43a and a casing 43b containing the spring body 43a. Specifically, the high-speed rocker arm 35 is pushed by the urging force of the spring body 43a via the casing 43b. The roller 35b is in contact with the cam 31c. The arm spring 43 is supported by a tip 44 a of a holder 44 attached around the rocker shaft 36, and a rear end 44 b of the holder 44 is in contact with an upper end of a rib 45 erected on the cylinder head 10. Thereby, the rotation of the holder 44 around the rocker shaft 36 is suppressed, and the urging force of the spring main body 43 a is transmitted to the high-speed rocker arm 35 satisfactorily.

Rocker cylinders 50 and 50 are formed at positions where the front end surface 35 d of the contact protrusion 35 a contacts the medium and low speed rocker arms 33 and 34, respectively. Inside the rocker cylinder 50, a sliding surface of the rocker cylinder 50 is formed. A rocker piston 51 is slidably provided.
Specifically, in the rocker cylinder 50, at the position where the tip surface 35d of the contact protrusion 35a contacts the medium / low speed rocker arms 33, 34, a part of the sliding surface is opened and an opening 53 is formed. The contact protrusion 35 a can be inserted into the rocker cylinder 50 through the opening 53.

  In the rocker cylinder 50, there is provided a spring 52 that urges the rocker piston 51 toward one sliding end side (lower side) of the rocker cylinder 50 so that the side surface 51a of the rocker piston 51 does not block the opening 53. Pressure oil (operating oil, here also used as lubricating oil, hereinafter also referred to as lubricating oil) is supplied from the rocker shaft 32 side through oil passages 32a and 32b. Thus, when the hydraulic pressure in the rocker cylinder 50 is increased, the rocker piston 51 receives the hydraulic pressure at one end and seals the opening 53 against the urging force of the spring 52 as shown in FIG. In this way, the rocker cylinder 50 slides toward the other sliding end side (upper side) of the rocker cylinder 50. On the other hand, when the hydraulic pressure in the rocker cylinder 50 is weakened, as shown in FIG. 10A, the rocker piston 51 prevents the side surface 51a of the rocker piston 51 from blocking the opening 53 by the biasing force of the spring 52. The rocker cylinder 50 is returned to the position on one sliding end side (lower side).

  Specifically, a hydraulic pressure adjustment device 42 that adjusts the hydraulic pressure of the lubricating oil supplied into the rocker cylinder 50 is provided on the upstream side of the oil passage 32a. The hydraulic pressure adjustment device 42 is operated in an engine, for example, engine rotation. When the hydraulic pressure is increased by switching according to the speed Ne, the rocker piston 51 slides toward the other sliding end side of the rocker cylinder 50 against the urging force of the spring 52 to seal the opening 53, and the hydraulic pressure adjusting device When 42 is switched according to the operating state of the engine and the hydraulic pressure is weakened, the rocker piston 51 is returned to one sliding end side of the rocker cylinder 50 by the urging force of the spring 52.

  More specifically, as shown in FIG. 11, the hydraulic pressure adjusting device 42 supplies lubricating oil pumped up to the cylinder head 10 from an oil pan (not shown) in the lower part of the engine through the common oil passage 42a. An oil passage 42c for supplying oil to the oil passage 32a, an oil passage 42b for supplying oil to the oil passage in the rocker shaft 36, an oil control valve 42d interposed in the oil passage 42c, a filter 42e, and the oil control valve 42d. It is comprised from the controller (not shown) which controls an opening degree.

Thus, for example, when a command according to the engine rotational speed Ne is supplied from the controller to the oil control valve 42d, the opening degree of the oil control valve 42d is set to the opening degree corresponding to the command, and the oil passages 32a and 32b are used. Thus, the hydraulic pressure of the lubricating oil supplied into the rocker cylinder 50 is adjusted, and the rocker piston 51 slides in the rocker cylinder 50.
Specifically, for example, when the engine rotational speed Ne becomes a predetermined value or higher, a large-diameter passage (not shown) for supplying lubricating oil of the oil control valve 42d communicates and is supplied into the rocker cylinder 50. The rocker piston 51 slides so that the side surface 51 a blocks the opening 53. On the other hand, when the engine rotational speed Ne becomes lower than a predetermined value, the oil pressure of the lubricating oil supplied into the rocker cylinder 50 is lowered through the small diameter passage for supplying the lubricating oil of the oil control valve 42d as shown in FIG. The side surface 51a of the rocker piston 51 is returned so as not to block the opening 53.

A connection switching mechanism 41 for switching the connection state between the medium / low speed rocker arms 33 and 34 and the high speed rocker arm 35 is configured from the rocker piston 51 in the rocker cylinder 50 and the hydraulic pressure adjusting device 42. Hereinafter, the operation of the connection switching mechanism 41 will be described.
As shown in FIG. 11, when the small diameter passage for supplying the lubricating oil of the oil control valve 42 d communicates and the hydraulic pressure in the rocker cylinder 50 is lowered, the side surface 51 a of the rocker piston 51 opens the opening 53 by the biasing force of the spring 52. A space 50a is formed from the opening 53 toward the rocker cylinder 50 by being buried in the rocker cylinder 50 so as not to be blocked and positioned on one sliding end side of the rocker cylinder 50 (see FIG. 10A). ). When the space 50a is formed from the opening 53 into the rocker cylinder 50 in this way, when the high-speed rocker arm 35 swings, as shown by a two-dot chain line in FIG. The tip 35c of the abutment projection 35a does not come into contact with the medium / low speed rocker arms 33, 34 at all, but appears in the space 50a. In this case, the medium / low speed rocker arms 33, 34 respectively correspond to the corresponding medium / low speed cams. The intake valves 11 and 12 are opened and closed by swinging following 31a and 31b.

That is, when the engine rotational speed Ne is lower than the predetermined value, the medium / low speed cams 31a and 31b are selected by switching the connection switching mechanism 41, and the intake valves 11 and 12 are indicated by a solid line and a one-dot chain line in FIG. Open and close with a medium lift and a low lift.
On the other hand, when a large-diameter passage (not shown) for supplying the lubricating oil of the oil control valve 42d is communicated and the hydraulic pressure in the rocker cylinder 50 is increased by the hydraulic pressure adjusting device 42, the rocker piston 51 is biased by the spring 52. Against this, the side 51a operates to block the opening 53 and close the opening 53 (see FIG. 10B). When the rocker piston 51 is thus operated so as to close the opening 53, the tip surface 35d of the contact protrusion 35a of the high-speed rocker arm 35 contacts the side surface 51a of the rocker piston 51 when the high-speed rocker arm 35 swings. In this case, the rollers 33b and 34b of the medium and low speed rocker arms 33 and 34 are separated from the corresponding medium and low speed cams 31a and 31b, respectively, and the medium and low speed rocker arms 33 and 34 are connected to the high speed cam 31c via the high speed rocker arm 35. Following this, the intake valves 11 and 12 are both opened and closed by swinging integrally with the high-speed rocker arm 35.

That is, when the engine rotation speed Ne is equal to or higher than a predetermined value, the high speed cam 31c is selected by switching the connection switching mechanism 41, and both the intake valves 11 and 12 are simultaneously opened and closed with a high lift as shown by the solid line in FIG. To do.
JP-A-63-170513

  By the way, in the variable valve mechanism 40, the rocker piston 51 is hydraulically operated using lubricating oil, but when switching to the high speed cam 31c or the medium / low speed cams 31a, 31b, the rocker piston 51 is raised. When the high-speed rocker arm 35 swings in the middle or in the middle of lowering and the tip surface 35d of the projection 35a comes into contact with the side surface 51a of the rocker piston 51, the rocker cylinder 50 of the tip surface 35d of the contact projection 35a. Only a portion (lower end) on one sliding end side may be caught on the end of the rocker piston 51 in some cases. In such a case, since the pressing force of the contact protrusion 35a is higher than the hydraulic pressure, the rocker piston 51 is repelled after being pressed by the contact protrusion 35a to some extent and returned to one sliding end side of the rocker cylinder 50. Can occur.

  When the rocker piston 51 is pushed back to a certain extent, the tip 35c of the contact protrusion 35a is detached from the rocker piston 51 and inserted into the space 50a from the opening 53 at a stretch. The rollers 33b and 34b of the medium and low speed rocker arms 33 and 34 that have been separated from each other suddenly come into contact with the medium and low speed cams 31a and 31b by the urging force of the return springs of the intake valves 11 and 12. Further, the valve face of the intake valves 11 and 12 and the valve seat may suddenly contact each other.

  Thus, the rollers 33b, 34b of the medium / low speed rocker arms 33, 34 and the medium / low speed cams 31a, 31b abruptly contact each other, or the valve faces of the intake valves 11, 12 abruptly contact each other. Then, there is a problem that a large impact sound (abnormal noise) is generated. In addition, if such abrupt contact is repeated, it causes damage and wear of each part of the valve mechanism, which is not preferable.

  In particular, in the variable valve mechanism 40 of the multi-cylinder engine, as described above, the lubricating oil is supplied to the rocker cylinders 50 and 50 of the medium and low speed rocker arms 33 and 34 in each cylinder via the oil passage 32a in the rocker shaft 32. Therefore, when the rocker piston 51 is rebounded in one of the medium and low speed rocker arms 33 and 34 of one cylinder, the oil pressure fluctuates greatly and pulsation occurs in the oil passage 32a, and supply to the rocker cylinder 50 of the other cylinders. The hydraulic pressure is temporarily lowered and the rocker piston 51 is in a halfway state, so that the opening 53 is likely to be blocked.

In this case, the operation timing of the rocker piston 51 may be set so that the rocker piston 51 does not rise or fall when the high-speed rocker arm 35 starts swinging. However, the operation timing of the rocker piston 51, that is, switching of the variable valve mechanism is changed. The problem is how to set the operation optimally.
The present invention has been made to solve such problems, and an object of the present invention is to optimize the switching operation of the variable valve mechanism in an internal combustion engine having a variable valve mechanism. To provide a valve operating device for an internal combustion engine and an initial setting device for the variable valve operating mechanism capable of suppressing the occurrence of noise due to switching of the operating characteristics of the valve and the exhaust valve and reducing the damage and wear of the variable valve operating mechanism. is there.

  In order to achieve the above object, in the valve operating apparatus for an internal combustion engine according to claim 1, the intake valve and the exhaust valve are opened and closed by swinging following the first cam that rotates as the camshaft rotates. A first rocker arm to be actuated, a second rocker arm having a shape different from that of the first cam and oscillating following a second cam that rotates as the cam shaft rotates, the first rocker arm, A rocker cylinder that is formed on one of the second rocker arms and has an opening in a part of the sliding surface; and a rocker piston that is slidably mounted in the rocker cylinder along the sliding surface; Depending on the operating state of the internal combustion engine, the side surface of the rocker piston is not between the one sliding end of the rocker cylinder where the opening is blocked and the other sliding end of the rocker cylinder is blocking the opening. A rocker piston actuating means for actuating the rocker piston, and protruding from either one of the first rocker arm and the second rocker arm, and the rocker piston is moved to the rocker cylinder by swinging the second rocker arm. When at the one sliding end, the tip is inserted into the rocker cylinder from the opening, while the rocker piston is actuated by the rocker piston actuating means so that the side surface of the rocker piston blocks the opening. The rocker piston actuating means has a predetermined operation in which the rocker piston is moving up or down when the second rocker arm starts swinging. Including learning means for learning the operation timing of the rocker piston so as not to be in a state, To have.

  That is, the internal combustion engine has a variable valve mechanism. Normally, when the first and second rocker arms swing along the first and second cams, respectively, the first and second When the rocker piston in the rocker cylinder provided on one of the rocker arms is at one sliding end of the rocker cylinder, the tip of the contact protrusion is inserted into the rocker cylinder from the opening of the rocker cylinder, and the intake valve or The exhaust valve operates following the first cam via the first rocker arm, while the tip of the rocker piston is actuated by the rocker piston actuating means and the side surface of the rocker piston seals the opening of the rocker cylinder. The second rocker arm pushes the first rocker arm away from the first cam, and the intake valve or the exhaust valve is in contact with the side surface. It operates following the second cam via a first rocker arm.

  However, at this time, when the second rocker arm starts to swing while the rocker piston is being raised or lowered, a portion on the one sliding end side of the rocker cylinder among the tip portions of the abutting protrusions. Only the (lower end) may be caught by the end of the rocker piston. In this case, after the abutting projection pushes the end of the rocker piston to some extent, the rocker piston is bounced by the abutting projection and one of the rocker cylinders The first rocker arm, which has been returned to the sliding end side of the first cam and is spaced apart from the first cam, suddenly comes into contact with the first cam, or the valve face of the intake valve or exhaust valve and the valve seat suddenly contact each other. Contact may generate impact sound.

Thus, in the valve operating apparatus according to the present invention, when the second rocker arm starts swinging in the variable valve mechanism, the rocker piston is prevented from being in a predetermined operating state during the ascent or descent. It learns the operation time of the.
Further, in the valve operating apparatus for an internal combustion engine according to claim 2, the internal combustion engine is a multi-cylinder internal combustion engine, and includes the first rocker arm and the second rocker arm for each cylinder. The operation time of the rocker piston is learned so that the rocker piston is not in a predetermined operating state when the second rocker arm starts swinging.

That is, in the case of a multi-cylinder internal combustion engine, the second rocker arm of each cylinder operates sequentially, but when the second rocker arm of any cylinder starts swinging, the rocker piston is in a predetermined operating state. The operation timing of the rocker piston is learned so as not to become.
For example, when the first rocker arm and the second rocker arm actuate the intake valve and the internal combustion engine is a one-side bank (three-cylinder row) of a four-cycle four-cylinder engine or a V-type six-cylinder engine, Since all the second rocker arms do not start to operate simultaneously, learning is performed so that all the rocker pistons of all the cylinders are operated in a period in which the second rocker arm of any cylinder does not start to operate.

  In the valve operating apparatus for an internal combustion engine according to claim 3, the rocker piston actuating means actuates the rocker piston by operating oil supplied from an oil pressure source through the oil passage, A hydraulic pressure adjusting means, and the learning means has a hydraulic pressure detecting means for detecting a hydraulic pressure in the oil passage so that the rocker piston does not enter a predetermined operating state when the second rocker arm starts swinging. Based on the change of the hydraulic pressure detected by the hydraulic pressure detecting means, the hydraulic pressure increase / decrease start timing by the hydraulic pressure adjusting means is learned.

That is, when the rocker piston is operated by hydraulic oil, if the rocker piston is bounced by the contact protrusion and is suddenly returned to one sliding end side of the rocker cylinder, the oil pressure in the oil passage changes. Then, by monitoring the change in the oil pressure detected by the oil pressure detecting means, the oil pressure adjusting means learns the increase / decrease start time of the oil pressure.
According to a fourth aspect of the present invention, there is provided a valve operating apparatus for an internal combustion engine according to the third aspect, wherein the learning means detects the change in oil pressure of a predetermined amount or more when the oil pressure detecting means is detected during the operation of the rocker piston. It is characterized in that the hydraulic pressure increase / decrease start time is learned by the hydraulic pressure adjusting means so that a change in hydraulic pressure exceeding a predetermined amount is not detected.

  In other words, when the rocker piston is operated by hydraulic oil, if the rocker piston is bounced by the contact protrusion and is suddenly returned to one sliding end side of the rocker cylinder, the oil pressure in the oil passage is increased. When the rocker piston is lifted, the oil pressure in the oil passage fluctuates greatly, and the oil pressure detecting means detects a change in the oil pressure exceeding a predetermined amount. Learns when to start increasing or decreasing oil pressure by the adjusting means.

The valve operating apparatus for an internal combustion engine according to claim 5 further includes engine rotational speed detecting means for detecting the rotational speed of the internal combustion engine, wherein the learning means is a rotational speed detected by the engine rotational speed detecting means or The operation timing of the rocker piston is learned for each rotation speed range.
That is, if the rotational speed of the internal combustion engine changes, the operating period of the second rocker arm changes accordingly, and the operating timing of the rocker piston relative to the start of the operation of the second rocker arm also changes. The operation timing of the rocker piston is learned for each rotational speed detected by the means.

  Further, in the initial setting device for the variable valve mechanism of the internal combustion engine according to the sixth aspect, the intake valve and the exhaust valve are opened and closed by swinging following the first cam that rotates as the camshaft rotates. A first rocker arm, a second rocker arm having a shape different from that of the first cam and oscillating following a second cam that rotates as the camshaft rotates, the first rocker arm, and the first rocker arm A rocker cylinder formed on one of the two rocker arms and having an opening in a part of the sliding surface; a rocker piston slidably mounted along the sliding surface in the rocker cylinder; and an internal combustion engine According to the operation state of the rocker piston, the side surface of the rocker piston does not block the opening, and the other sliding end of the rocker cylinder and the other rocker cylinder that blocks the opening are closed at a predetermined operation time. Rocker piston actuating means for actuating the rocker piston with the moving end, and protruding from either the first rocker arm or the second rocker arm, and by rocking the second rocker arm, the rocker piston When the piston is at the one sliding end of the rocker cylinder, the tip end portion is inserted into the rocker cylinder from the opening, while the rocker piston is moved to the side surface of the rocker piston by the operation of the rocker piston operating means. Is an initial setting device for a variable valve mechanism of an internal combustion engine having a contact protrusion whose tip is in contact with the side surface when the opening is in a position for blocking the opening, and starts swinging of the second rocker arm Sometimes, the operation timing of the rocker piston is learned so that the rocker piston does not enter a predetermined operating state during the ascending or descending. And learning means, it is characterized in that the learning value learned and a initial setting means for setting an initial value of the predetermined operating period by the learning means.

That is, with respect to the variable valve mechanism of the internal combustion engine, the initial setting device is configured to prevent the rocker piston from being in a predetermined operating state during the ascent or descent when the second rocker arm starts to swing. The operation time is learned, and the learning value is set as an initial value of a predetermined operation time by the initial setting means.
For example, the initial setting device is a bench tester for an internal combustion engine, which learns the operation timing of the rocker piston by the bench tester and stores the learned value, and stores the learned value for the controller of the internal combustion engine before shipment. It is set as the initial value for a predetermined operating time.

  In the initial setting device for a variable valve mechanism of an internal combustion engine according to claim 7, the internal combustion engine is a multi-cylinder internal combustion engine, and the learning means includes the first rocker arm and the second rocker arm for each cylinder. Is characterized in that the operation timing of the rocker piston is learned so that the rocker piston is not in a predetermined operating state when the second rocker arm of each cylinder starts to swing.

That is, in the case of a multi-cylinder internal combustion engine as in the second aspect, the second rocker arm of each cylinder sequentially operates, but when the second rocker arm of any cylinder starts swinging. The operation timing of the rocker piston is learned so that the rocker piston is not in a predetermined operation state.
Further, in the initial setting device for a variable valve mechanism for an internal combustion engine according to claim 8, the rocker piston actuating means actuates the rocker piston by operating oil supplied from an oil pressure source through an oil passage. The oil passage has a hydraulic pressure adjusting means, and the learning means has a hydraulic pressure detecting means for detecting a hydraulic pressure in the oil path, and the rocker piston is operated in a predetermined manner when the second rocker arm starts swinging. In order not to be in a state, the increase / decrease start timing of the oil pressure by the oil pressure adjusting means is learned based on the change of the oil pressure detected by the oil pressure detecting means.

That is, when the rocker piston is actuated by the hydraulic oil as in the third aspect, if the rocker piston is bounced by the contact protrusion and is suddenly returned to one sliding end side of the rocker cylinder, Since the oil pressure in the road fluctuates, the change in oil pressure detected by the oil pressure detecting means is monitored to learn the start time of the oil pressure increase / decrease by the oil pressure adjusting means.
Further, in the initial setting device for a variable valve mechanism of an internal combustion engine according to claim 9, the learning means according to claim 8, wherein the oil pressure detection means detects a change in oil pressure of a predetermined amount or more during the operation of the rocker piston. Then, the hydraulic pressure increase / decrease start time is learned by the hydraulic pressure adjusting means so that the change of the hydraulic pressure exceeding the predetermined amount is not detected.

  That is, when the rocker piston is actuated by hydraulic oil as in the case of claim 4 above, especially when the rocker piston is bounced by the contact protrusion and is suddenly returned to one sliding end side of the rocker cylinder. When the oil pressure in the oil passage is increased to raise the rocker piston, the oil pressure in the oil passage fluctuates greatly, and a change in oil pressure of a predetermined amount or more is detected by the oil pressure detecting means. The hydraulic pressure increase / decrease start time is learned by the hydraulic pressure adjusting means so that the change of the hydraulic pressure is not detected.

The initial setting device for a variable valve mechanism of an internal combustion engine according to claim 10 further comprises engine rotational speed detecting means for detecting the rotational speed of the internal combustion engine, wherein the learning means is detected by the engine rotational speed detecting means. The operation timing of the rocker piston is learned for each rotation speed or rotation speed range.
That is, as in the fifth aspect, when the rotational speed of the internal combustion engine changes, the operation period of the second rocker arm changes accordingly, and the operation timing of the rocker piston relative to the start of operation of the second rocker arm also changes. Therefore, the operation timing of the rocker piston is learned for each rotation speed or rotation speed range detected by the engine rotation speed detection means.

  According to the valve operating apparatus for an internal combustion engine of the first aspect of the present invention, the operation timing of the rocker piston is learned so that the rocker piston is not in a predetermined operation state when the second rocker arm starts to swing. Therefore, when the rocker piston is in a predetermined operating state while being raised or lowered, the second rocker arm starts to swing, and the tip of the contact protrusion does not contact the side surface of the rocker piston. Thus, the operation timing of the rocker piston can be maintained, the operation timing of the rocker piston can be optimized, and the rocker piston can be prevented from being rebound after the contact protrusion pushes the end of the rocker piston.

As a result, the rapid contact between the first rocker arm and the first cam and the rapid contact between the valve face of the intake valve or the exhaust valve and the valve seat can be suppressed, and the generation of impact noise can be prevented. . Furthermore, damage and wear of the variable valve mechanism can be prevented.
According to the valve operating apparatus for an internal combustion engine according to claim 2, in the case of a multi-cylinder internal combustion engine, the rocker piston is not in a predetermined operating state while the second rocker arm of any cylinder is swinging. Thus, the operation timing of the rocker piston is learned, so that in all cylinders, when the rocker piston is in a predetermined operating state during the ascending or descending, the second rocker arm swings and the tip of the contact protrusion The operation timing of the rocker piston can be maintained so as not to contact the side surface of the rocker piston, and the operation timing of the rocker piston can be optimized.

  According to the valve operating apparatus for an internal combustion engine of claim 3, when the rocker piston is operated by the hydraulic oil, the rocker piston is repelled by the abutting protrusion and suddenly moves toward one sliding end of the rocker cylinder. The oil pressure in the oil passage fluctuates when it is returned to, but the change in the oil pressure detected by the oil pressure detecting means is monitored and the start of increase / decrease of the oil pressure by the oil pressure adjusting means is learned. The second rocker arm swings when the rocker piston is in a predetermined operating state while being raised or lowered, and the tip of the abutting protrusion is positioned on the rocker piston. The operation timing of the rocker piston can be maintained so as not to contact the side surface, and the operation timing of the rocker piston can be optimized.

  Further, according to the valve operating apparatus for an internal combustion engine of claim 4, when the rocker piston is repelled by the abutting protrusion and is suddenly returned to one sliding end side of the rocker cylinder in claim 3, the oil passage particularly When the rocker piston is lifted by increasing the oil pressure in the oil pressure, the oil pressure in the oil passage fluctuates greatly and the oil pressure detecting means detects a change in the oil pressure greater than a predetermined amount. The hydraulic pressure increase / decrease start time by the hydraulic pressure adjusting means is learned so that the change of the hydraulic pressure is not detected, so that the second rocker arm swings and the tip of the contact protrusion when the rocker piston is in a predetermined operating state while being raised Therefore, the operation timing of the rocker piston can be maintained so as not to contact the side surface of the rocker piston, and the operation timing of the rocker piston can be optimized.

  According to the valve operating apparatus for an internal combustion engine according to claim 5, when the rotational speed of the internal combustion engine changes, the operation period of the second rocker arm also changes accordingly, and the operation time of the second rocker arm starts. The operation timing of the rocker piston also changes. However, since the operation timing of the rocker piston is learned for each rotation speed or rotation speed range of the internal combustion engine, the operation timing of the rocker piston is optimized regardless of the rotation speed of the internal combustion engine. Can be achieved.

  According to the initial setting device for the variable valve mechanism of the internal combustion engine according to the sixth aspect, the initial setting device is different from the variable valve mechanism of the internal combustion engine when the second rocker arm starts swinging. The operation timing of the rocker piston is learned so as not to be in a predetermined operating state, and the learning value is set as the initial value of the predetermined operation timing by the initial setting means. The operation timing of the rocker piston can be optimally initialized so that the second rocker arm does not swing and the tip of the contact protrusion does not contact the side surface of the rocker piston when in the operating state. The switching operation of the mechanism can be optimized, and the operation timing of the rocker piston can be made appropriate immediately after the shipment of the internal combustion engine.

As a result, it is possible to suppress the sudden contact between the first rocker arm and the first cam and the rapid contact between the valve face of the intake valve or the exhaust valve and the valve seat, thereby preventing the generation of an impact sound. Can do. Furthermore, damage and wear of the variable valve mechanism can be prevented.
According to the initial setting device for the variable valve mechanism of the internal combustion engine according to claim 7, in the case of a multi-cylinder internal combustion engine, the rocker piston is predetermined while the second rocker arm of any cylinder is swinging. Since the operation timing of the rocker piston is learned so that the operation state of the rocker piston is not obtained, the second rocker arm swings and abuts when the rocker piston is in a predetermined operation state in the middle of ascending or descending in all cylinders. The operation timing of the rocker piston can be optimally initialized so that the tip of the protrusion does not contact the side surface of the rocker piston.

  Further, according to the initial setting device for the variable valve mechanism of the internal combustion engine according to the eighth aspect, when the rocker piston is actuated by the hydraulic oil, the rocker piston is bounced by the abutting projection, and one slide of the rocker cylinder is made. The oil pressure in the oil passage fluctuates when it is suddenly returned to the moving end, but the change in the oil pressure detected by the oil pressure detecting means is monitored and the increase / decrease start time of the oil pressure by the oil pressure adjusting means is learned. The second rocker arm swings when the rocker piston is in a predetermined operating state during the ascent or descent while the lubrication of each part of the valve mechanism is performed satisfactorily, and the tip of the contact protrusion The operation timing of the rocker piston can be optimally initialized so that the portion does not contact the side surface of the rocker piston.

  According to the initial setting device for the variable valve mechanism of the internal combustion engine according to claim 9, when the rocker piston is repelled by the abutting protrusion and is suddenly returned to one sliding end side of the rocker cylinder, the oil passage in particular. When the rocker piston is lifted by increasing the oil pressure in the oil pressure, the oil pressure in the oil passage fluctuates greatly and the oil pressure detecting means detects a change in the oil pressure greater than a predetermined amount. The hydraulic pressure increase / decrease start time by the hydraulic pressure adjusting means is learned so that the change of the hydraulic pressure is not detected, so that the second rocker arm swings and the tip of the contact protrusion when the rocker piston is in a predetermined operating state while being raised The operation timing of the rocker piston can be optimally initialized so that does not contact the side surface of the rocker piston.

  Further, according to the initial setting device for the variable valve mechanism of the internal combustion engine according to claim 10, when the rotational speed of the internal combustion engine changes, the operating period of the second rocker arm changes accordingly, and the second rocker arm changes accordingly. The operation timing of the rocker piston with respect to the start of the operation of the engine also changes, but since the operation timing of the rocker piston is learned for each rotation speed or rotation speed range of the internal combustion engine, the rocker piston operation time does not matter regardless of the rotation speed of the internal combustion engine. The operation time can be optimally initialized.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
First, a valve operating apparatus for an internal combustion engine according to the present invention will be described.
The valve operating apparatus according to the present invention is an improvement of the valve operating apparatus shown in FIGS. 8 to 12, and the basic configuration of the valve operating apparatus is the same as described above. The parts according to the present invention will be described in detail with reference to FIG.

Here, the case where the engine is a V-type 6-cylinder engine will be described as an example, and the valve operating apparatus shown in FIGS. 8 to 12 is a one-side bank (right banks # 1, # 3) of the V-type 6-cylinder engine. , # 5 cylinder side or left bank # 2, # 4, # 6 cylinder side).
FIG. 1 shows details of a hydraulic circuit including the hydraulic pressure adjusting device (rocker piston operating means) 42 shown in FIG.

  As shown in the figure, one oil control valve (hydraulic pressure adjusting means, hereinafter abbreviated as OCV) 42d of the hydraulic pressure adjusting device 42 is provided in each of the right bank oil path 42c and the left bank oil path 42c. An oil passage 42 a and a hydraulic pump 46 are connected to an oil pan 47. In this case, since the lubricating oil is also used as the working oil, the hydraulic pump 46 and the oil pan 47 are applied as they are for supplying the engine lubricating oil.

The OCV 42d is an electromagnetic switching type ON / OFF valve, and the solenoid of the OCV 42d is electrically connected to an ECU (electronic control unit) 60.
Further, the engine is provided with a crank angle sensor 62, a cam angle sensor 64, an oil temperature sensor 66, and the like, and a hydraulic pressure sensor (hydraulic pressure detecting means) 68 is provided on the downstream side of the OCV 42d of each oil passage 42c. The ECU 60 is configured to receive information from these sensors. That is, the crank angle information is input from the crank angle sensor 62, the rotation angle information of the camshaft is input from the cam angle sensor 64, and the temperature information Toil of the hydraulic oil is input from the oil temperature sensor 66 to the ECU 60. The hydraulic information Poil is input from 68. Then, the ECU 60 calculates the engine rotation speed Ne based on the crank angle information, and transmits a TDC signal (piston top dead center signal) based on the rotation angle information of the camshaft.

The ECU 60 further transmits an ON signal or an OFF signal based on the engine rotational speed Ne, the TDC signal, and the temperature information Toil, and the OCV 42d is switched according to the ON signal or the OFF signal.
For example, when an OFF signal is supplied from the ECU 60 to the OCV 42d, the OCV 42d is switched to the state shown in the figure, and the oil passage 42c is narrowed by the orifice provided in the OCV 42d to form a small-diameter passage, and at the same time, the oil on the downstream side of the OCV 42d. The path 42c and the drain circuit 42f communicate with each other. As a result, the amount of oil supplied to the rocker cylinder 50 is limited, and the hydraulic oil in the rocker cylinder 50 is returned to the oil pan 47 through the drain circuit 42f, the hydraulic pressure in the rocker cylinder 50 is lowered, and the rocker piston 51 Is returned to one sliding end side (lower side) of the rocker cylinder 50 by the urging force of the spring 52. That is, when the signal from the ECU 60 is switched from ON to OFF, the side surface 51a of the rocker piston 51 does not close the opening 53 (or does not intersect the swinging locus of the contact protrusion 35a). When the high-speed rocker arm (second rocker arm) 35 is swung, the tip 35c of the abutting projection 35a of the high-speed rocker arm 35 is not in contact with the medium / low-speed rocker arms (first rocker arms) 33, 34. It appears in the space 50a without touching it. That is, the connection switching mechanism 41 is switched to the non-connected state, and the medium and low speed cams (first cams) 31a and 31b are selected.

Even in this case, since the hydraulic oil is supplied to the oil passage 32a in the rocker shaft 32 to some extent through the orifice, the operating portions of the medium / low speed rocker arms 33 and 34 and the high speed rocker arm 35 are well lubricated. .
On the other hand, when the ON signal is supplied from the ECU 60 to the OCV 42d, the OCV 42d is switched to a state (not shown), that is, a state where the large diameter passage is communicated. As a result, a sufficient amount of hydraulic oil is supplied to the rocker cylinder 50 to increase the hydraulic pressure in the rocker cylinder 50, and the rocker piston 51 resists the urging force of the spring 52 to the other sliding end side of the rocker cylinder 50. Move to (upper). That is, when the signal from the ECU 60 is switched from OFF to ON, the inside of the rocker cylinder 50 is set so that the side surface 51a of the rocker piston 51 blocks the opening 53 (or crosses the swinging locus of the contact protrusion 35a). When the high-speed rocker arm 35 swings, the tip surface 35 d of the contact protrusion 35 a of the high-speed rocker arm 35 contacts the side surface 51 a of the rocker piston 51. That is, the connection switching mechanism 41 is switched to the connected state, and the high speed cam (second cam) 31c is selected.

Hereinafter, the control content of the present invention of the valve gear thus configured, that is, the switching control content of the connection switching mechanism 41 according to the present invention will be described.
Referring to FIG. 2, a control routine of hydraulic pressure increase / decrease start control according to the present invention in the switching control is shown in a flowchart, and will be described along the flowchart.
First, in step S10, it is determined whether or not the connection switching mechanism 41 may be switched, that is, whether or not switching is possible. Here, based on the engine rotational speed Ne (the operating state of the internal combustion engine), when switching from the medium / low speed cams 31a, 31b to the high speed cam 31c, the engine rotational speed Ne is equal to or higher than a predetermined rotational speed N1 (eg, 3000 rpm). On the contrary, when switching from the high speed cam 31c to the medium / low speed cams 31a, 31b, hysteresis is provided, and whether the engine rotational speed Ne has become a predetermined rotational speed N2 (for example, 2800 rpm) or less. Is determined.

Here, the switching is performed based on the engine rotational speed Ne, but in addition, it is determined whether or not the engine load Le (the operating state of the internal combustion engine, the accelerator opening, etc.) has reached a predetermined load state. Switching may be performed based on this. Further, switching may be performed based on both the engine speed Ne and the engine load Le.
If the determination result in step S10 is false (No), it is determined that switching is impossible, and the routine is exited. On the other hand, if the determination result is true (Yes), the process proceeds to step S12.

In step S12, the oil pressure increase / decrease start timing S, that is, the supply timing of the ON signal or OFF signal to the OCV 42d is set.
As described above, when switching to the high speed cam 31c or the medium / low speed cams 31a and 31b, if the high speed rocker arm 35 swings while the rocker piston 51 is moving up or down, the tip surface of the contact projection 35a Only the part (lower end) on one sliding end side of the rocker cylinder 50 in 35 d is in a state of being caught by the end of the rocker piston 51, and the rocker piston 51 is bounced back to one sliding end side of the rocker cylinder 50. The rollers 33b and 34b of the medium and low speed rocker arms 33 and 34 and the medium and low speed cams 31a and 31b abruptly contact each other, or the valve faces of the intake valves 11 and 12 and the valve seat abruptly contact each other. (Abnormal noise) may occur.

Therefore, here, the hydraulic pressure increase / decrease start timing S is set so that the rocker piston 51 does not rise or fall (predetermined operating state) when the high-speed rocker arm 35 starts swinging.
Normally, even if an ON signal or an OFF signal is supplied from the ECU 60 to the OCV 42d, the operation delay or the hydraulic pressure of the OCV 42d including the filling time of the hydraulic oil into the oil passage 32a until the operation of the rocker piston 51 actually starts. A certain amount of time is required because there is a delay in the rise. Accordingly, in consideration of the operation delay time and the hydraulic pressure rise delay time, the hydraulic pressure increase / decrease start timing S, that is, the rocker piston 51 does not go up or down when the high-speed rocker arm 35 starts swinging. The supply timing of the ON signal or OFF signal to the OCV 42d is set.

  That is, referring to FIG. 3, for example, the operating state of the rocker piston 51 when an ON signal is supplied to the OCV 42d is shown in a time chart. As shown in FIG. 3, the rocker piston 51 is supplied to the OCV 42d. Since the signal does not rise immediately after switching from the OFF signal to the ON signal, the rocker piston 51 gradually rises with the hydraulic pressure rising delay time t2 after the operation delay time t1 of the OCV 42d has elapsed. The supply timing of the ON signal or the OFF signal to the OCV 42d is set so that the high-speed rocker arm 35 does not start to swing during the period gradually rising at t2.

  Here, referring to FIG. 4, the swing timing of the high-speed rocker arm 35 (ON indicates when swinging, OFF indicates when not swinging), hydraulic pressure increase / decrease start timing S setting range, operation of the rocker piston 51 The time chart regarding the state (at the time of rising and at the time of lowering) and the exhaust TDC signal of the cylinder # 1 (or # 2) is shown. A specific method for setting the hydraulic pressure increase / decrease start timing S will be described with reference to FIG. .

  In the V-type 6-cylinder engine, as shown in the figure, the high-speed rocker arm 35 is arranged in cylinder order (# 1 cylinder → # 3 cylinder → # 5 cylinder in the right bank, # 2 cylinder → # 4 cylinder → # 6 cylinder in the left bank). In this case, the rocker piston 51 is not in the middle of ascending or descending at the time when the high-speed rocker arm 35 of any cylinder starts to oscillate, that is, at the time indicated by the one-dot chain line. The hydraulic pressure increase / decrease start timing S is set. That is, also in the figure, t1 indicates the operation delay time of the OCV 42d, and t2 indicates the rise delay time or fall delay time of the hydraulic pressure, but the rocker piston 51 gradually rises or falls with the delay time t2. ON signal or OFF to the OCV 42d so that the high-speed rocker arm 35 of any cylinder does not start swinging during the period (predetermined operating state), that is, so that the period of the delay time t2 does not cross the alternate long and short dash line Set the signal supply timing.

  More specifically, in the figure, the operation time of the rocker piston 51 immediately before the period of the delay time t2 is dash-dotted, that is, just before the high-speed rocker arm 35 starts swinging and immediately after straddling the dash-dotted line ( Ascent and descent) are virtually shown for all cylinders, and correspondingly, the supply timing of the ON signal or OFF signal to the OCV 42d considering the operation delay time t1 and the delay time t2 is also a broken line for all cylinders. Although indicated by an arrow, the hydraulic pressure increase / decrease start timing S cannot be set within a period between all dashed arrows corresponding to a period from immediately before the delay time t2 is applied to the one-dot chain line to immediately after the one-dot chain line is straddled ( The period excluding the period between the broken-line arrows is a settable range (possible) of the hydraulic pressure increase / decrease start timing S. Then, the supply timing of the ON signal or OFF signal to the OCV 42d, that is, the hydraulic pressure increase / decrease start timing S is set within the settable range.

  Here, for convenience of explanation, the high-speed rocker arm 35 is prevented from starting to swing at all during the delay time t2, that is, during the operation of the rocker piston 51, but the tip of the contact protrusion 35a of the high-speed rocker arm 35. Only the part (lower end) on one sliding end side of the rocker cylinder 50 in the surface 35d is caught by the end of the rocker piston 51. The rocker piston 51 is in the middle of ascending or descending, and the rocker piston 51 is in the middle. Therefore, the high-speed rocker arm 35 is prevented from starting to swing only when the rocker piston 51 is in the intermediate operation state (predetermined operation state). You may do it.

  Incidentally, in order to set the hydraulic pressure increase / decrease start timing S, it is necessary to know the time when the high-speed rocker arm 35 starts swinging, but it is difficult to detect the time when the high-speed rocker arm 35 actually starts swinging. Therefore, as shown in the figure, the hydraulic pressure increase / decrease start timing S is set based on the exhaust TDC signal of the # 1 (# 2) cylinder. That is, the time from when the high-speed rocker arm 35 starts swinging to the exhaust TDC signal is always constant if the engine speed Ne is the same, and the transmission interval of the exhaust TDC signal for each cylinder is also constant. Here, for example, with reference to the exhaust TDC signal of the # 1 (# 2) cylinder, the hydraulic pressure increase / decrease start timing S is set based on the exhaust TDC signal of the # 1 (# 2) cylinder.

  Specifically, when the rocker piston 51 is raised, the connection switching mechanism 41 can be switched at an engine rotational speed Ne of a predetermined rotational speed N1 (for example, 3000 rpm). Therefore, an ON signal to the OCV 42d at the predetermined rotational speed N1 or When the OFF signal is supplied, the time t3 (for example, 1....) From the time when the high-speed rocker arm 35 of the # 1 (# 2) cylinder starts to swing to the exhaust TDC signal of the # 1 (# 2) cylinder. 3 ms), the OCV 42d operation delay time t1 (for example, 23 ms) and the hydraulic pressure rise delay time t2 (for example, 12 ms), and in the V-type six-cylinder engine, the timing at which the high-speed rocker arm 35 of each cylinder starts to swing. Is considered to be 240 [deg.] At one bank, i.e., every time t4 (for example, 11.4 ms), and before the exhaust TDC signal of the cylinder # 1 (# 2) {S1 = t1 + t The range of 3 + n · t4} to {S2 = t1 + t2 + t3 + n · t4} (n = 0, 1, 2) is a non-setting range of the hydraulic pressure increase / decrease start timing S.

  For example, focusing on the # 1 (# 2) cylinder, focusing on the # 5 (# 6) cylinder in the range of 24.3 to 36.3 ms before the exhaust TDC signal of the # 1 (# 2) cylinder (n = 0). Focusing on the # 3 (# 4) cylinder in the range of 35.7 to 47.7 ms before the exhaust TDC signal of the # 1 (# 2) cylinder and the # 3 (# 4) cylinder, the exhaust TDC signal of the # 1 (# 2) cylinder The previous 47.1 to 59.1 ms range (n = 2) is the setting range of the hydraulic pressure increase / decrease start timing S. The period excluding these periods is the settable range of the hydraulic pressure increase / decrease start timing S. Therefore, the hydraulic pressure increase / decrease start timing S is set within this settable range.

  Further, as described above, when the high-speed rocker arm 35 is not started to swing only when the rocker piston 51 is in the intermediate operation state, for example, the intermediate operation state is set to 3 ms to 3 ms after the rocker piston 51 starts to rise. If it is between 9 ms, the range of {S1 = t1 + 3 + t3 + n · t4} to {S2 = t1 + 9 + t3 + n · t4} (n = 0, 1, 2) before the exhaust TDC signal of the cylinder # 1 (# 2) is the hydraulic pressure increase / decrease start timing S The setting range is not possible.

  In this case, for example, focusing on the # 1 (# 2) cylinder, the range of 27.3 to 33.3 ms before the exhaust TDC signal of the # 1 (# 2) cylinder (n = 0), # 5 (# 6 ) Focusing on the cylinder, focusing on the # 1 (# 2) cylinder in the range of 38.7 to 44.7 ms (n = 1) before the exhaust TDC signal, and # 3 (# 4) cylinder # 1 (# 2) The range of 50.1 to 56.1 ms before the exhaust TDC signal of the cylinder (n = 2) is the non-setting range of the hydraulic pressure increase / decrease start timing S, and the period outside these periods is the settable range of the hydraulic pressure increase / decrease start timing S. It is.

Thus, if the high-speed rocker arm 35 does not start to swing only when the rocker piston 51 is in the intermediate operation state, the settable range of the hydraulic pressure increase / decrease start timing S is effectively increased.
When the rocker piston 51 is lowered, the connection switching mechanism 41 can be switched when the engine rotational speed Ne is a predetermined rotational speed N2 (for example, 2800 rpm). Therefore, the ON signal or OFF signal is supplied to the OCV 42d at the predetermined rotational speed N2. In the case where it is performed, the time t3 and the time t4 from the time when the high-speed rocker arm 35 of the # 1 (# 2) cylinder starts to swing to the exhaust TDC signal of the # 1 (# 2) cylinder according to the predetermined rotational speed N2. The hydraulic pressure increase / decrease start timing S can be set in the same manner as described above based on the operation delay time t1 of the OCV 42d and the hydraulic pressure rise delay time t2 that do not change regardless of the engine speed Ne. Ask for. Then, the hydraulic pressure increase / decrease start timing S is set within this settable range.

  By the way, when the ON signal or the OFF signal is supplied to the OCV 42d, the engine rotational speed Ne has already increased above the predetermined rotational speed N1 (for example, 3000 rpm) or decreased below the predetermined rotational speed N2 (for example, 2800 rpm). In this case, the operating period of the high-speed rocker arm 35 changes, and the time t3 and time t4 until the exhaust TDC signal of the cylinder # 1 (# 2) is greater than that at the predetermined rotational speed N1. Is also shorter or longer.

  Accordingly, in step S14, for example, the rate of change dNe / dt of the engine speed Ne when determining whether or not the connection switching mechanism 41 can be switched (step S10) is obtained, and the hydraulic pressure increase / decrease starts based on the rate of change dNe / dt. The time S is corrected. That is, as the rate of change dNe / dt is larger on the positive side, the time t3 and the time t4 are shorter, and as the rate of change dNe / dt is larger on the negative side, the time t3 and the time t4 are longer. The hydraulic pressure increase / decrease start timing S is corrected accordingly.

Further, the viscosity of the hydraulic oil changes according to the oil temperature Toil, and the viscosity increases as the oil temperature Toil becomes lower. Therefore, the hydraulic oil rise or fall delay time t2 changes according to the oil temperature oil temperature Toil. .
Therefore, in the next step S16, the hydraulic pressure increase / decrease start timing S is further corrected according to the oil temperature / oil temperature Toil. In other words, the lower the oil temperature and the oil temperature Toil, the longer the delay time t2, and the higher the oil temperature, the shorter the delay time t2, thereby changing the settable range of the hydraulic pressure increase / decrease start timing S and correcting the hydraulic pressure increase / decrease start timing S accordingly. .

Since the viscosity of the hydraulic oil has a correlation with the hydraulic pressure, and the change in the viscosity can be detected by the hydraulic pressure downstream of the OCV 42d, the hydraulic pressure increase / decrease start timing S is corrected according to the hydraulic pressure information Poil from the hydraulic sensor 68. It may be.
In step S18, the ON / OFF signal is supplied to the OCV 42d based on the hydraulic pressure increase / decrease start timing S set as described above. That is, the OCV 42d is switched at the hydraulic pressure increase / decrease start timing S.

  Theoretically, the operation timing of the rocker piston 51 can be optimized, and at the time of switching to the high speed cam 31c or the medium / low speed cams 31a and 31b, Only one sliding end side portion (lower end) of the rocker cylinder 50 will not be caught by the end of the rocker piston 51. Therefore, the rocker piston 51 is bounced and one sliding end side of the rocker cylinder 50 is removed. It will not be returned to.

  However, theoretically, as described above, the operation delay time t1 of the OCV 42d, the hydraulic pressure rise delay time t2, and the time point # 1 (# 2) from the time when the high-speed rocker arm 35 of the cylinder # 1 (# 2) starts swinging. The oil pressure increase / decrease start timing S can be set based on the time t3 and the time t4 until the exhaust TDC signal of the cylinder. Depending on the conditions, at the time of switching to the high speed cam 31c or the medium / low speed cams 31a and 31b, only the portion (lower end) on one sliding end side of the rocker cylinder 50 of the front end surface 35d of the contact projection 35a is the rocker piston. The rocker piston 51 may be bounced and returned to one sliding end side of the rocker cylinder 50 in some cases.

  In such a case, the rocker piston 51 tries to push back the hydraulic oil strongly, and the hydraulic pressure Poil in the oil passage 42c detected by the hydraulic pressure sensor 68 temporarily rises to generate a large hydraulic pulse. A phenomenon occurs. In particular, when switching to the high speed cam 31c, since the ON signal is supplied to the OCV 42d and the rocker cylinder 50 is filled with high-pressure hydraulic fluid, when the rocker piston 51 is pushed back, the cams 31a, 31b are driven to the medium / low speed. Compared with the switching of, an extremely high hydraulic pressure pulse is generated.

That is, referring to FIG. 5, when changing to the high speed cam 31c, the output change of the hydraulic sensor 68 when the rocker piston 51 is bounced back in the middle, that is, the change of the hydraulic pressure Poil is shown as an example. However, a high-pressure hydraulic pulse is suddenly generated in this way.
Therefore, in step S20, learning of the hydraulic pressure increase / decrease start timing S is performed based on such a change of the hydraulic pressure Poil, that is, a hydraulic pressure pulse (learning means).

  More specifically, as shown in FIG. 5, after the ON signal or OFF signal is supplied to the OCV 42d, the operation delay time t1 of the OCV 42d and the hydraulic pressure rise delay time t2 elapse (t1 + t2), that is, the rocker. When a large oil pressure pulse is generated while the piston 51 is rising or descending and the oil pressure Poil has increased by a predetermined amount or more, it is determined that the oil pressure increase / decrease start timing S is not appropriate, and the oil pressure pulse having the predetermined amount or more is generated. The hydraulic pressure increase / decrease start timing S is corrected so as not to occur, and the correction value is learned as the hydraulic pressure increase / decrease start timing S. That is, the hydraulic pressure increase / decrease start timing S is corrected so as to be advanced or delayed by the correction time Δt, and the correction value is stored in the ECU 60 as a learning value. Whether the correction time Δt is advanced or delayed is appropriately selected according to the set hydraulic pressure increase / decrease start timing S.

  Thus, the next time when switching to the high speed cam 31c or the medium / low speed cams 31a, 31b is performed, the rocker piston 51 is not bounced and returned to one sliding end side of the rocker cylinder 50. The generation of pulses is suppressed, and thereafter, the hydraulic pressure increase / decrease start timing S is set to an appropriate value, and when the rocker piston 51 is in the middle of ascending or descending, the high-speed rocker arm 35 starts to swing and contacts. The operation timing of the rocker piston 51 can be maintained so that the tip surface 35d of the protrusion 35a does not contact the side surface 51a of the rocker piston.

Note that when the oil pressure pulse is generated again or again after the next time, the oil pressure increase / decrease start timing S is learned again.
Therefore, the rollers 33b and 34b of the medium and low speed rocker arms 33 and 34 and the medium and low speed cams 31a and 31b do not suddenly contact each other, and the valve face of the intake valves 11 and 12 and the valve seat do not contact suddenly. Generation of loud impact noise (abnormal noise) is prevented. Further, damage and wear of the variable valve mechanism are prevented.

Since it is assumed that the engine speed Ne is different between the determination of whether the connection switching mechanism 41 can be switched and the actual hydraulic pressure increase / decrease start timing S (during sudden acceleration / deceleration, etc.), in addition to the predetermined rotation speeds N1, N2 Thus, a hydraulic pressure increase / decrease start timing S may be learned by providing a learning region in a plurality of rotational speed regions (for example, every 10 to 50 rpm) in the vicinity of the predetermined rotational speeds N1 and N2.
Next, an initial setting device for a variable valve mechanism for an internal combustion engine according to the present invention will be described.

The variable valve mechanism initial setting device according to the present invention applies the valve operating device shown in FIG. 1 and FIGS. 8 to 12 to the initial setting device, and the basic configuration of the valve operating device has been described above. Since it is as it is, description is abbreviate | omitted and the part of the initialization apparatus which concerns on this invention is demonstrated in detail.
Referring to FIG. 6, details of an initial setting device for a variable valve mechanism according to the present invention are shown.
As shown in the figure, the initial setting device mainly comprises a bench tester 70, and is configured by connecting two high-precision hydraulic sensors (hydraulic detection means) 72 to the controller of the bench tester 70. Further, the controller of the bench tester 70 is configured to be able to take in information from a crank angle sensor 62, a cam angle sensor 64, and an oil temperature sensor 66 provided in the engine.

Hereinafter, the initial setting contents according to the present invention of the initial setting device configured as described above, that is, the initial setting contents of the hydraulic pressure increase / decrease start will be described.
First, when the engine is set on the bench tester 70, various sensors such as a crank angle sensor 62, a cam angle sensor 64, and an oil temperature sensor 66 are electrically connected to the controller of the bench tester 70. It is controlled by the controller of the bench tester 70. Two oil pressure sensors 72 are attached to the oil passage 42c in the left bank and the oil passage 42c in the right bank, respectively, so as to detect the oil pressure Poil.

When the engine of the bench tester 70 is started, the hydraulic pressure increase / decrease start initial setting according to the present invention is started.
Referring to FIG. 7, a control routine for initial setting of the hydraulic pressure increase / decrease executed by the controller of the bench tester 70 is shown in a flowchart, and will be described along the flowchart.

First, in step S30, the hydraulic pressure increase / decrease start reference timing Sb at the predetermined rotational speed N1 (for example, 3000 rpm), that is, the reference supply timing of the ON signal to the OCV 42d at the time of switching to the high speed cam 31 is set.
Here, similarly to the hydraulic pressure increase / decrease start timing S described above, the OCV 42d operation delay time t1, the hydraulic pressure is controlled so that the rocker piston 51 does not rise (predetermined operating state) when the high-speed rocker arm 35 starts swinging. Rise time t2, hydraulic pressure increase / decrease start reference timing based on time t3 and time t4 from the time when the high-speed rocker arm 35 of the cylinder # 1 (# 2) starts swinging to the exhaust TDC signal of the cylinder # 1 (# 2) Set Sb. Note that the details of the setting method are the same as in the case of the hydraulic pressure increase / decrease start timing S described above, and thus the description thereof is omitted here.

When the engine rotational speed Ne becomes equal to or higher than the predetermined rotational speed N1 (eg, 3000 rpm), an ON signal to the OCV 42d at the hydraulic pressure increase / decrease start reference timing Sb is determined in step S32 based on the set hydraulic pressure increase / decrease start reference timing Sb. Supply. That is, the OCV 42d is switched at the hydraulic pressure increase / decrease start reference time Sb.
At this time, the hydraulic pressure increase / decrease start reference timing Sb may be an appropriate value. However, if the hydraulic pressure increase / decrease start reference timing Sb is not an appropriate value, as described above, the rocker piston 51 strongly pushes back the hydraulic oil, and the OCV 42d operates. Until the delay time t1 and the hydraulic pressure rise delay time t2 elapse (t1 + t2), the oil pressure Poil in the oil passage 42c detected by the oil pressure sensor 72 temporarily rises to generate a large oil pressure pulse (FIG. 5).

  Thus, in step S34, as described above, after the ON signal is supplied to the OCV 42d, the operation delay time t1 of the OCV 42d and the hydraulic pressure rise delay time t2 elapse (t1 + t2), that is, the rocker piston 51 is raised. When a large oil pressure pulse is generated while the oil pressure Poil is increased by a predetermined amount or more, the oil pressure increase / decrease start reference time Sb is learned and corrected so that the oil pressure pulse exceeding the predetermined amount is not generated (learning means). That is, as described above, the hydraulic pressure increase / decrease start reference timing Sb is corrected to be advanced or delayed by the correction time Δt.

  In step S36, it is determined whether or not a hydraulic pulse of a predetermined amount or more is not generated and learning is finished. If the determination result is false (No) and it is determined that learning has not ended, the engine rotational speed Ne is repeatedly increased and decreased, and steps S32 and S34 are repeated until no more than a predetermined amount of hydraulic pulses are generated. Repeat execution. If the determination result of step S36 is true (Yes) and it is determined that the learning is completed, the process proceeds to step S38.

In step S38, the learned value of the hydraulic pressure increase / decrease start reference time Sb obtained by learning is set as the initial value of the hydraulic pressure increase / decrease start timing S (predetermined operation timing) when switching to the high speed cam 31, that is, the hydraulic pressure increase / decrease start initial value S0. Set. Then, the hydraulic pressure increase / decrease start initial value S0 is stored in the controller of the bench tester 70 (initial setting means).
The initial setting of the hydraulic pressure increase / decrease start is performed for each engine rotational speed Ne. Further, in step S30, the hydraulic pressure increase / decrease start reference timing Sb at the predetermined rotational speed N2 (for example, 2800 rpm), that is, to the medium / low speed cams 31a and 31b. The reference supply timing of the OFF signal to the OCV 42d at the time of switching is set.

  Thereafter, similarly to the above, based on the oil pressure Poil in the oil passage 42c detected by the oil pressure sensor 72, the execution of steps S32 and S34 is repeated (learning means) until no more than a predetermined amount of oil pressure pulses are generated (step S38). , The learned value of the hydraulic pressure increase / decrease start reference time Sb obtained by learning is the initial value of the hydraulic pressure increase / decrease start timing S (predetermined operating time) when switching to the medium / low speed cams 31a, 31b, that is, the initial value S0 of hydraulic pressure increase / decrease. And stored in the controller of the bench tester 70 (initial setting means).

Although the case where the engine rotational speed Ne is a predetermined rotational speed N1 (for example, 3000 rpm) and the case where the engine rotational speed Ne is a predetermined rotational speed N2 (for example, 2800 rpm) has been described here, the hydraulic pressure increases and decreases at other engine rotational speeds Ne. It is preferable to learn the start reference time Sb and obtain the oil pressure increase / decrease start initial value S0 for each engine speed Ne.
The hydraulic pressure increase / decrease start initial value S0 thus stored in the controller of the bench tester 70 is output to the ECU 60 of the target engine, and the hydraulic pressure at the time of switching to the high speed cam 31 or the medium / low speed cams 31a, 31b. Used as the increase / decrease start time S.

  As a result, in each engine, when the rocker piston 51 is in a predetermined operating state in the middle of ascending or descending, the high speed rocker arm 35 swings and the tip surface 35d of the abutting protrusion 35a contacts the side surface 51a of the rocker piston. Therefore, the operation timing of the rocker piston 51 can be optimally initialized so that the switching operation of the variable valve mechanism 40 can be optimized.

  Accordingly, the operation timing of the rocker piston 51 can be made appropriate immediately after the shipment of the engine, and the rollers 33b and 34b of the medium and low speed rocker arms 33 and 34 and the medium and low speed cams 31a and 31b abruptly come into contact with each other. The valve face of the intake valves 11 and 12 and the valve seat do not suddenly come into contact with each other, and generation of a large impact sound (abnormal noise) is prevented. Further, damage and wear of the variable valve mechanism are prevented.

In addition, if the oil pressure increase / decrease start timing S is properly set in this way, it is possible to prevent the generation of impact noise without having to install a highly accurate and expensive oil temperature sensor in each engine, thus reducing costs. Can be achieved.
After the engine is shipped, the hydraulic pressure increase / decrease start initial value S0 may be corrected by the ECU 60 in accordance with the rate of change dNe / dt of the engine rotation speed Ne and the oil temperature / oil temperature Toil after each engine is shipped. As a result, the operation timing of the rocker piston 51 becomes more appropriate.

In the same manner as described above, it is assumed that the engine speed Ne is different between the determination of whether the connection switching mechanism 41 can be switched and the actual hydraulic pressure increase / decrease start timing S (such as during rapid acceleration / deceleration). In addition to N2, N2 may be provided in the vicinity of the predetermined rotational speeds N1 and N2 to learn a plurality of rotational speed regions (for example, every 10 to 50 rpm) to learn the hydraulic pressure increase / decrease start reference timing Sb.
Although the description of the embodiments of the valve operating device for an internal combustion engine and the initial setting device for the variable valve operating mechanism according to the present invention has been completed, the embodiments are not limited to the above-described embodiments.

For example, in the above-described embodiment, the variable valve mechanism 40 that switches the operating characteristics of the intake valves 11 and 12 is shown, but the operating characteristics of the exhaust valves 21 and 22 may be switched. The operation characteristics of both the exhaust valves 21 and 22 may be switched.
In the above-described embodiment, the variable valve mechanism 40 having the rocker cylinder 50 and the rocker piston 51 on the medium and low speed rocker arms 33 and 34 and the contact protrusion 35a on the high speed rocker arm 35 is shown. While the middle and low speed rocker arms 33 and 34 are provided with contact protrusions, the high speed rocker arm 35 may be a variable valve mechanism having a rocker cylinder and a rocker piston.

In the above embodiment, the example using the medium / low speed cams 31a, 31b and the medium / low speed rocker arms 33, 34 has been described. However, the medium / low speed cam may have the same shape or a single low speed cam. In addition, the intake valves 11 and 12 may be driven using a single bifurcated rocker arm.
In the above-described embodiment, the V-type 6-cylinder engine has been described as an example. However, the present invention is not limited to this, and the engine may be an in-line 4-cylinder engine. In this case, the hydraulic pressure adjusting device 42 is one OCV 42d. Consists of.

Further, in the above embodiment, the connection switching mechanism 41 includes the hydraulic pressure adjusting device 42 and is configured to operate the rocker piston 51 by the hydraulic pressure of the hydraulic oil because it is easy to configure and has a lubricating function. The operating means of the rocker piston 51 is not limited to hydraulic pressure.
However, in this case, since the hydraulic sensors 68 and 72 cannot be used, for example, a knock sensor is provided in the engine so that the rollers 33b and 34b of the medium and low speed rocker arms 33 and 34 and the medium and low speed cams 31a and 31b The vibration at the time of contact and the vibration at the time when the valve face of the intake valves 11 and 12 and the valve seat suddenly contact are detected, and based on the vibration, the oil pressure increase / decrease start timing S and the oil pressure increase / decrease start reference time Sb are detected. It is better to learn. Even if it does in this way, although a detection accuracy is a little inferior compared with the case where a hydraulic sensor is used, sufficient effect is acquired.

  In the above embodiment, the hydraulic pressure increase / decrease start timing S and the hydraulic pressure increase / decrease start reference time Sb are set first, and learning is performed based on them. However, the hydraulic pressure increase / decrease start timing S and the hydraulic pressure increase / decrease start reference timing Sb are set. Of course, it is possible to perform learning without setting.

It is a figure which shows the detail of the hydraulic circuit containing OCV among the valve operating apparatuses of the SOHC type engine containing the variable valve mechanism based on this invention. It is a flowchart which shows the control routine of the hydraulic pressure increase / decrease start control which concerns on this invention. It is a time chart which shows the operating state of a rocker piston when an ON signal is supplied to OCV. 4 is a time chart showing a swinging timing of a high-speed rocker arm, a setting range of hydraulic pressure increase / decrease start timing S, an operating state of a rocker piston, and an exhaust TDC signal of a # 1 (or # 2) cylinder. 5 is a time chart showing, as an example, a change in the output of the hydraulic sensor, that is, a change in the hydraulic pressure Poil when the rocker piston is rebounded in the middle of ascent when switching to the high speed cam. It is the schematic which shows the initial setting apparatus of the variable valve mechanism based on this invention. 4 is a flowchart showing a control routine for initial setting of hydraulic pressure increase / decrease according to the present invention. It is a figure which shows the structure of the valve operating apparatus of the SOHC type engine containing the variable valve mechanism proposed by the applicant, and is a figure which shows the basic composition of this invention. It is sectional drawing which follows the AA line of FIG. It is detail drawing which shows the part of a rocker cylinder and a rocker piston among the connection switching mechanisms of FIG. It is detail drawing which shows the part of the hydraulic control apparatus among the connection switching mechanisms of FIG. It is a figure which shows the operating characteristic (valve lift) at the medium low speed and the high speed of the intake valve of FIG.

Explanation of symbols

11, 12 Intake valve 21, 22 Exhaust valve 31a, 31b Medium / low speed cam (first cam)
31c High-speed cam (second cam)
32 Rocker shaft 33, 34 Rocker arm (first rocker arm)
40 Variable valve mechanism 41 Connection switching mechanism 42 Hydraulic pressure adjusting device (rocker piston operating means)
42a Common oil passage 42b, 42c Oil passage 42d Oil control valve (OCV, hydraulic pressure adjusting means)
50 Rocker cylinder 51 Rocker piston 51a Side surface 52 Spring 53 Opening 60 ECU
62 Crank angle sensor 64 Cam angle sensor 66 Oil temperature sensor 68 Hydraulic pressure sensor (hydraulic pressure detection means)
70 Bench tester 72 Hydraulic pressure sensor (hydraulic pressure detection means)

Claims (10)

A first rocker arm that swings following the first cam that rotates as the camshaft rotates to open or close either the intake valve or the exhaust valve;
A second rocker arm having a shape different from that of the first cam and swinging following a second cam that rotates as the cam shaft rotates;
A rocker cylinder formed on one of the first rocker arm and the second rocker arm and having an opening in a part of the sliding surface;
A rocker piston slidably mounted along the sliding surface in the rocker cylinder;
Depending on the operating state of the internal combustion engine, the side surface of the rocker piston does not seal the opening between the one sliding end of the rocker cylinder and the other sliding end of the rocker cylinder that blocks the opening. A rocker piston actuating means for actuating the rocker piston;
When the rocker piston is located at the one sliding end of the rocker cylinder due to the swinging of the second rocker arm, the tip portion is protruded from the other of the first rocker arm and the second rocker arm. When the rocker piston is inserted into the rocker cylinder from the opening, and the rocker piston is in a position where the side surface of the rocker piston seals the opening due to the operation of the rocker piston actuating means, the tip portion contacts the side surface. Abutting protrusions that contact,
The rocker piston operating means includes learning means for learning the operation timing of the rocker piston so that the rocker piston does not enter a predetermined operating state during the ascending or descending when the second rocker arm starts swinging. A valve operating apparatus for an internal combustion engine characterized by the above. The internal combustion engine is a multi-cylinder internal combustion engine, and includes the first rocker arm and the second rocker arm for each cylinder,
2. The learning device according to claim 1, wherein the learning unit learns the operation timing of the rocker piston so that the rocker piston does not enter a predetermined operation state when the second rocker arm of each cylinder starts to swing. A valve operating device for an internal combustion engine. The rocker piston actuating means is for actuating the rocker piston with hydraulic oil supplied from an oil pressure source via an oil path, and has an oil pressure adjusting means in the oil path,
The learning means includes oil pressure detecting means for detecting oil pressure in the oil passage, and is detected by the oil pressure detecting means so that the rocker piston is not in a predetermined operating state when the second rocker arm starts to swing. The valve operating apparatus for an internal combustion engine according to claim 1 or 2, wherein the start time of increase / decrease of oil pressure by the oil pressure adjusting means is learned based on a change in oil pressure.   The learning means detects a change in hydraulic pressure by the hydraulic pressure adjusting means so that a change in hydraulic pressure greater than a predetermined amount is not detected when the hydraulic pressure detection means detects a change in hydraulic pressure greater than a predetermined amount during the operation of the rocker piston. 4. The valve operating apparatus for an internal combustion engine according to claim 3, wherein an increase / decrease start time is learned. Furthermore, an engine rotation speed detection means for detecting the rotation speed of the internal combustion engine is provided,
5. The internal combustion engine according to claim 1, wherein the learning unit learns an operation timing of the rocker piston for each rotation speed or rotation speed range detected by the engine rotation speed detection unit. Valve gear. A first rocker arm that swings following the first cam that rotates as the camshaft rotates to open or close either the intake valve or the exhaust valve;
A second rocker arm having a shape different from that of the first cam and swinging following a second cam that rotates as the cam shaft rotates;
A rocker cylinder formed on one of the first rocker arm and the second rocker arm and having an opening in a part of the sliding surface;
A rocker piston slidably mounted along the sliding surface in the rocker cylinder;
Depending on the operating state of the internal combustion engine, at a predetermined operation timing, one side of the rocker cylinder where the side surface of the rocker piston does not block the opening and the other sliding of the rocker cylinder that blocks the opening Rocker piston actuating means for actuating the rocker piston between the ends;
When the rocker piston is located at the one sliding end of the rocker cylinder due to the swinging of the second rocker arm, the tip portion is protruded from either the first rocker arm or the second rocker arm. When the rocker piston is inserted into the rocker cylinder from the opening, and the rocker piston is in a position where the side of the rocker piston seals the opening due to the operation of the rocker piston actuating means, the tip is in contact with the side. An initial setting device for a variable valve mechanism of an internal combustion engine having an abutting protrusion in contact with it,
Learning means for learning the operation timing of the rocker piston so that the rocker piston does not enter a predetermined operating state during the ascending or descending at the start of swinging of the second rocker arm;
Initial setting means for setting a learning value learned by the learning means as an initial value of the predetermined operating time;
An initial setting device for a variable valve mechanism of an internal combustion engine, comprising: The internal combustion engine is a multi-cylinder internal combustion engine, and includes the first rocker arm and the second rocker arm for each cylinder,
7. The learning means according to claim 6, wherein the learning means learns the operation timing of the rocker piston so that the rocker piston does not enter a predetermined operation state when the second rocker arm of each cylinder starts to swing. An initial setting device for a variable valve mechanism of an internal combustion engine. The rocker piston actuating means is for actuating the rocker piston with hydraulic oil supplied from an oil pressure source via an oil path, and has an oil pressure adjusting means in the oil path,
The learning means includes oil pressure detecting means for detecting oil pressure in the oil passage, and is detected by the oil pressure detecting means so that the rocker piston is not in a predetermined operating state when the second rocker arm starts to swing. 8. The initial setting device for a variable valve mechanism of an internal combustion engine according to claim 6 or 7, wherein an oil pressure increase / decrease start timing is learned based on a change in oil pressure.   The learning means detects a change in hydraulic pressure by the hydraulic pressure adjusting means so that a change in hydraulic pressure greater than a predetermined amount is not detected when the hydraulic pressure detection means detects a change in hydraulic pressure greater than a predetermined amount during the operation of the rocker piston. 9. The variable valve mechanism initial setting device for an internal combustion engine according to claim 8, wherein an increase / decrease start time is learned. Furthermore, an engine rotation speed detection means for detecting the rotation speed of the internal combustion engine is provided,
The internal combustion engine according to any one of claims 6 to 9, wherein the learning means learns the operation timing of the rocker piston for each rotational speed or rotational speed range detected by the engine rotational speed detection means. Initial setting device for the variable valve mechanism.

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