JP5996882B2 - Variable valve mechanism and operating method of internal combustion engine - Google Patents

Description

  The present invention relates to a variable valve mechanism that changes a driving state of a valve in accordance with an operating state of the internal combustion engine, and an operating method of the internal combustion engine.

  Some internal combustion engines change the drive amount of the valve by the rocker arm by changing the oil pressure input to the rocker arm through an oil passage formed in the rocker shaft. In an internal combustion engine in which one rocker shaft supports rocker arms of a plurality of cylinders, when the plurality of cylinders are divided into two or more groups and the drive amount of the valve is changed for each group, etc. The internal combustion engine needs to have an oil passage for each group in the rocker shaft. Therefore, in such an internal combustion engine, as described in Patent Documents 1 and 2, one or two or more inner cylinders extending in the length direction of the rocker shaft are inserted into a cylindrical rocker shaft. A rocker shaft is used in which a plurality of oil passages are provided so as not to communicate with each other.

Japanese Patent Laid-Open No. 8-150412 JP 2005-180195 A

  However, such a plurality of oil passages divide the inner space of the rocker shaft in the radial direction, so that each oil passage is narrow. In addition, when the rocker shaft is screwed onto the cylinder head with a bolt, the oil passage becomes thinner because the bolt intersects the oil passage. For this reason, resistance during oil feeding increases, and there is a possibility that the timing for changing the drive amount of the valve by the rocker arm may be delayed.

  Therefore, the present invention provides a variable valve mechanism for an internal combustion engine that can change the drive amount of the valve with good response without delaying the timing, and can change the drive amount of the valve without delay in timing. An object of the present invention is to provide a method of operating an internal combustion engine that performs with good response.

In order to solve the above problems, a variable valve mechanism for an internal combustion engine according to the present invention includes:
Two oil passages that are not partitioned in the radial direction but in the length direction are formed in the rocker shaft,
The one-side rocker arm supported on one side in the length direction of the rocker shaft is separated from the one oil passage through a lubrication hole formed in the rocker shaft so as to communicate with one oil passage of the two oil passages. Oil is supplied,
The other side rocker arm supported on the other side in the length direction of the rocker shaft is separated from the other oil passage through a lubrication hole formed in the rocker shaft so as to communicate with the other oil passage of the two oil passages. Oil is supplied,
At least one of the one side rocker arm and the other side rocker arm is connected to the one oil passage or the one oil passage through the hydraulic hole formed in the rocker shaft so as to communicate with the one oil passage or the other oil passage supplied with oil through the lubrication hole. On the other hand, the drive amount of the valve is changed by the change of hydraulic pressure input from the oil passage .
A mounting bolt screwing the rocker shaft to the cylinder head of the internal combustion engine is inserted in the radial direction of the rocker shaft,
More than the part other than the part in the part located right next to the attachment bolt on the inner peripheral surface of the one oil passage and / or the other oil passage intersecting with the attachment bolt and continuing to the hydraulic hole An expansion recess for expanding the oil passage cross-sectional area is provided .

  Here, the mode of changing the drive amount of the valve is not particularly limited, but according to the mode of switching between the state of driving the valve according to the rotation of the drive cam and the state of completely stopping this drive, or the rotation of the drive cam. A mode in which the valve is switched between a relatively large driving state and a relatively small driving state can be exemplified. The state of driving the valve relatively large includes a state in which the valve is driven with a relatively large lift amount, and a state in which the valve is driven so that the period during which the valve is open is relatively long. The relatively small driving state includes a state in which the valve is driven with a relatively small lift amount and a state in which the valve is driven so that the period during which the valve is open is relatively short.

Preparative crosses the Chakuboruto, the portion located right beside the attachment bolt in the inner peripheral surface of one oil passage and / or the other oil passage are continuous hydraulic bore, the oil passage sectional area than the portion other than the portion more that it is recessed extended recess to extend the slender is whereas that part of the oil passage and / or the other oil path for crossing the attachment bolt (narrowing) is to cause the flow resistance of the oil is increased Can be prevented.

Further, the mounting bolt is not particularly limited, but the mounting bolt that intersects the one oil passage and the other oil passage connected to the hydraulic hole is contracted at the portion that intersects the one oil passage and / or the other oil passage connected to the hydraulic hole. It is preferable that it is diameter. By reducing the diameter of the part where the mounting bolt intersects, the one oil passage and / or that part of the other oil passage becomes narrow (narrow) because it intersects with the mounting bolt, and the flow resistance of the oil increases. Can be prevented.

In addition, the form of the extended recess is not particularly limited, but is inserted into one oil passage and / or the other oil passage connected to the hydraulic hole from a bolt through hole drilled in the rocker shaft in order to insert the mounting bolt in the radial direction. The aspect etc. which are formed by cutting the internal peripheral surface of this one oil path or the other oil path with the blade part of T slot cutter can be illustrated. The surface of the extended recess according to the same aspect is a cutting surface.

  In order to solve the above problems, a first internal combustion engine operating method of the present invention uses the variable valve mechanism of the internal combustion engine, and drives one of the one side rocker arm and the other side rocker arm according to the rotation of the drive cam. The state is switched between a state where the drive is stopped and a state where the drive is completely stopped, and the other is driven according to the rotation of the drive cam.

  The second internal combustion engine operating method of the present invention uses the variable valve mechanism of the internal combustion engine, and drives both the one side rocker arm and the other side rocker arm in accordance with the rotation of the drive cam and completely drives this drive. Switch between stopped states.

  A third internal combustion engine operating method according to the present invention uses the variable valve mechanism of the internal combustion engine, and is relatively different from a state in which both the one side rocker arm and the other side rocker arm are driven relatively large in accordance with the rotation of the drive cam. Switching to a state of driving small.

  According to the present invention, it is possible to provide a variable valve mechanism for an internal combustion engine that can change a valve drive amount by a rocker arm with good response without delaying the timing. Also, a change in valve drive amount can be delayed in timing. Therefore, it is possible to provide a method of operating an internal combustion engine that performs with good response.

It is a perspective view of the variable valve mechanism of Example 1. It is a perspective view of the rocker shaft of the variable valve mechanism. It is sectional drawing cut | disconnected along the top view and the length direction of the rocker shaft. It is the perspective view and internal top view of the variable rocker arm of the variable valve mechanism. It is sectional drawing cut | disconnected along the radial direction of the rocker shaft of the variable valve mechanism. It is explanatory drawing of how to make the expansion recessed part of the rocker shaft of the variable valve mechanism. It is the front view of the diameter reduction bolt of the variable valve mechanism, and sectional drawing of the diameter reduction bolt vicinity. It is a perspective view of the variable valve mechanism of Example 2. It is the top view of the rocker shaft of the variable valve mechanism, and sectional drawing cut | disconnected along the length direction. It is the perspective view of the variable rocker arm of the variable valve mechanism of Example 3, and an internal top view.

  A variable valve mechanism 10 according to a first embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the variable valve mechanism 10 includes an intake valve 13 for an internal combustion engine in which six cylinders 12 each having two intake valves 13 and two exhaust valves 14 are arranged in a line. Is a variable valve mechanism for driving the motor. The variable valve mechanism 10 may be used for driving the exhaust valve 14. Further, in this internal combustion engine, the explosion order of the six cylinders 12 arranged in a row is the first, fifth, third, sixth, second, fourth explosion order from the one end side. Yes.

  As shown in FIGS. 1 and 2, the variable valve mechanism 10 includes a camshaft 15 that extends in the direction in which the cylinders 12 are arranged and has 12 drive cams 16 provided at corresponding positions of the intake valves 13, One rocker shaft 20 extending in parallel with the shaft 15 and screwed to the cylinder head mounting portion 17 by seven mounting bolts 31 and 33, and from one end 22 in the length direction to the intermediate portion 21. 6 one-side rocker arms 36 that are supported by the rocker shaft 20 at a position on one side and swing when driven by the drive cam 16 to drive the intake valve 13, and an intermediate portion from the other end 23 in the length direction. 6 is provided with six rocker arms 32 which are supported by the rocker shaft 20 at positions on the other side up to 21 and swing to drive the intake valve 13 when pressed by the drive cam 16.

  As shown in FIG. 4, the one-side rocker arm 36 is supported on the rocker shaft 20 so as to be swingable, and has a central arm 37 whose tip is in contact with the intake valve 13 and positions on both sides of the central arm 37. The side arm 38 includes a side roller 38 that is supported by the rocker shaft 20 in the middle of the length direction so as to be swingable, and that has a contact roller 42 that contacts the drive cam 16 at the end on the camshaft 15 side. Further, the connection pin 40 is moved to the one side rocker arm 36 by the hydraulic pressure supplied from the outside through the internal oil passage 39 provided in the side arm 38, and as shown in b-2 of FIG. 40 is connected across the central arm 37 and the side arm 38, and the central arm 37 and the side arm 38 are connected to each other so that they cannot be displaced relative to each other (a state in which the intake valve 13 is driven to open and close according to the rotation of the drive cam 16). As shown in b-1 of FIG. 4, the connection pin 40 does not straddle the central arm 37 and the side arm 38 and the connection is released (the intake valve 13 is not driven to open and close). A switching mechanism 41 is provided. Therefore, the one-side rocker arm 36 switches the switching mechanism 41 between a state in which the intake valve 13 is opened / closed and a state in which the opening / closing drive is completely stopped according to the rotation of the drive cam 16, thereby driving the intake valve 13. It has become a variable rocker arm that changes.

  Next, the rocker shaft 20 will be described.

  The rocker shaft 20 includes seven bolts 31 and 33 for inserting the mounting bolts 31 and 33 in the radial direction of the rocker shaft 20 (one in the intermediate portion 21, three on the one end 22 side from the intermediate portion, and the other end from the intermediate portion). Three bolt through holes 26 on the 23 side are formed at substantially equal intervals in the length direction. Further, a first oil passage 24 extending from one end 22 to the front of the intermediate portion 21 and a second oil passage 25 extending from the other end 23 to the front of the intermediate portion 21 are formed. On the other hand, the oil passage 24 and the other oil passage 25 have substantially the same length, are separated by the intermediate portion 21, and are separated from each other.

  The rocker shaft 20 is provided with lubricating holes 27 and 30 for sending oil supplied through the oil passages 24 and 25 to the rocker arms 32 and 36 and lubricating the sliding portions of the rocker arms 32 and 36. , 25 are communicated with each other. The lubricating holes 27 and 30 have different positions, inner diameters, and the like depending on the parts to be lubricated.

  Six hydraulic holes 28 for supplying control hydraulic pressure to the switching mechanism 41 are connected to the one oil passage 24 at a position corresponding to the internal oil passage 39 on the one end 22 side from the intermediate portion 21 of the rocker shaft 20. It is drilled to do. The hydraulic hole 28 has an inner diameter larger than that of the lubricating hole 27 in order to make it easy to supply hydraulic pressure to the switching mechanism 41.

On the other hand, when the mounting bolt 33 is inserted into the bolt through hole 26 on the inner peripheral surface of the oil passage 24, all the parts (six places) located beside the mounting bolt 33 are more than parts other than the part. An expansion recess 29 for expanding the oil passage cross-sectional area is also provided . As shown in FIG. 6, the extended recess 29 is formed by cutting the inner peripheral surface of the one oil passage 24 with the blade portion of the T slot cutter 45 inserted from the bolt through hole 26 into the one oil passage 24. Has been. Therefore, the surface of the extended recess 29 is a cutting surface. The shape of the extended recess 29 is arcuate in a cross-sectional view cut orthogonally to the mounting bolt 33 along the length direction of the rocker shaft 20, and in a cross-sectional view cut along the radial direction of the rocker shaft 20. It is rectangular. Since the portion of the rocker shaft 20 where the extended recess 29 is provided is supported by the mounting portion 17 of the cylinder head, even if the extended recess 29 is provided, the strength of the rocker shaft 20 during use is affected. Does not occur.

  The three bolts 31 and 33 that are inserted through the bolt through holes 26 and screw the rocker shaft 20 into the mounting portion 17 and are inserted through the bolt through holes 26 that intersect with the oil passage 24 are shown in FIG. As shown in FIG. 7, a reduced diameter bolt 33 is used in which a shaft portion intersecting with the one oil passage 24 is reduced in diameter to form a reduced diameter portion 34.

  Next, the change of the drive amount of the intake valve 13 by the variable valve mechanism 10 will be described.

  The variable valve mechanism 10 changes the hydraulic pressure supplied to the switching mechanism 41 by controlling the hydraulic pressure of the one oil passage 24, and the one side rocker arm 36 opens and closes the intake valve 13 according to the rotation of the drive cam 16 ( In this state, the cylinder 12 in which the intake valve 13 is provided is in an operating state) and the intake valve 13 is not driven to open and close (in this state, the cylinder in which the intake valve 13 is provided). 12 is in a dormant state).

  Specifically, by increasing the hydraulic pressure of the one oil passage 24, the connecting pin 40 is positioned across the central arm 37 and the side arm 38 as shown in b-2 of FIG. Thus, the central arm 37 and the side arm 38 are connected to each other so as not to be relatively displaceable with each other, and the side arm 38 and the central arm 37 swing together by the pressing of the drive cam 16 so that the central arm 37 The abutting intake valve 13 is driven to open and close as the drive cam 16 rotates.

  On the other hand, by reducing the hydraulic pressure of the one oil passage 24, the connecting pin 40 is positioned so as not to straddle the central arm 37 and the side arm 38 as shown in b-1 of FIG. The central arm 37 and the side arm 38 are disengaged from each other so that the central arm 37 and the side arm 38 can be displaced relative to each other. The intake valve 13 with which 37 abuts is prevented from opening and closing as the drive cam 16 rotates.

According to the variable valve mechanism 10 of the present embodiment, the following effects (a) to (g) can be obtained.
(A) By controlling the oil pressure in the one oil passage 24, the one side rocker arm 36 is switched between a state in which the intake valve 13 is opened / closed according to the rotation of the drive cam 16 and a state in which the opening / closing drive is completely stopped. The three-cylinder cylinders (fourth, fifth and sixth cylinders from one end side) in which the intake valve 13 is opened and closed by the other side rocker arm 32 are in an operating state, and the intake valve 13 is produced by the one side rocker arm 36. The three cylinders that are opened and closed (the first, second, and third cylinders from one end side) can be switched between an operating state and a resting state.

(B) The oil passage of the rocker shaft 20 is separated by the intermediate portion 21 and separated into two oil passages, one oil passage 24 and the other oil passage 25, thereby eliminating a complicated partition and simplifying 2 The oil passages of the book can be separated, and the one oil passage 24 and the other oil passage 25 can be prevented from becoming thin.
(C) Since the oil passage 24 does not become thin, the resistance of oil does not increase, and the drive amount of the intake valve 13 by the one side rocker arm 36 is changed with good response (smoothly) without delay in timing. Can do.

(D) Since the one oil passage 24 is a short oil passage from the one end 22 to the front of the intermediate portion 21, the change in the drive amount of the intake valve 13 by the one side rocker arm 36 can be performed without delay in response. It can be carried out.

(E) Since the expansion recess 29 is provided on the inner peripheral surface of the one oil passage 24, the one oil passage 24 has a sufficient thickness (cross-sectional area) even if the reduced diameter bolt 33 is inserted into the bolt through hole 26. The oil resistance is not increased, and the drive amount of the intake valve 13 by the one-side rocker arm 36 can be changed with good response without delaying the timing.
(F) By inserting the reduced diameter bolt 33 into the bolt through hole 26 intersecting with the one oil passage 24, the one oil passage 24 can secure a sufficient thickness (cross-sectional area), and the resistance of the oil is large. Instead, the drive amount of the intake valve 13 by the one side rocker arm 36 can be changed with good response without delaying the timing.

(G) Since the extended recess 29 is formed by cutting the inner peripheral surface of the one oil passage 24 with the blade portion of the T slot cutter 45 inserted from the bolt through hole 26 into the one oil passage 24, it is easy. An extended recess 29 can be provided.

  According to the operation method of the internal combustion engine of the embodiment of the present invention using the variable valve mechanism 10, the three cylinders (fourth, fifth and fourth from the one end side) in which the intake valve 13 is opened and closed by the other side rocker arm 32. The six cylinders) are in the operating state, and the three cylinders (the first, second, and third cylinders from one end side) in which the intake valve 13 is opened and closed by the one side rocker arm 36 are in the operating state and the inactive state. And can be switched. Further, the timing of switching between the state in which the intake valve 13 is opened / closed by the one side rocker arm 36 while the intake valve 13 is opened / closed by the other side rocker arm 32 and the state in which the opening / closing drive is completely stopped is not delayed. It can be done with good response. Improved response improves fuel efficiency and durability.

  A variable valve mechanism 50 according to a second embodiment of the present invention will be described with reference to FIGS.

  In the variable valve mechanism 50, the other side rocker arm 52, like the one side rocker arm 36, switches between a state in which the intake valve 13 is opened and closed according to the rotation of the drive cam 16, and a state in which the opening and closing drive is completely stopped. The rocker shaft 51 has a variable rocker arm that changes the drive amount of the intake valve 13, and the six hydraulic holes 53 for supplying control hydraulic pressure to the other rocker arm 52 communicate with the other oil passage 54. When the mounting bolt 55 is inserted into the bolt through hole 26 at the point where it is drilled, the number of the lubrication holes 57 communicating with the other oil passage 54 is increased, and the inner peripheral surface of the other oil passage 54, The expansion recesses 56 for expanding the cross-sectional area of the other oil passage 54 are formed in all parts (six locations) located just beside the attachment bolt 55, and the diameter reduction bolt is provided on the attachment bolt 55. Unlike that have been used with variable valve mechanism 10 of the first embodiment, the other points are the same as the variable valve mechanism 10. 8 and 9, the same members and the like as those of the variable valve mechanism 10 are denoted by the same reference numerals as those of the variable valve mechanism 10.

  Next, the change of the drive amount of the intake valve 13 by the variable valve mechanism 50 will be described.

  The variable valve mechanism 50 changes the hydraulic pressure supplied to the switching mechanism 41 by controlling the hydraulic pressure of the one oil passage 24 and the other oil passage 54, and rotates the one side rocker arm 36 and the other side rocker arm 52. Thus, the intake valve 13 is opened / closed and the intake valve 13 is not opened / closed.

  Specifically, by increasing the oil pressure of the one oil passage 24 and the other oil passage 54, the connecting pin 40 is positioned so as to straddle the central arm 37 and the side arm 38 as shown in b-2 of FIG. By doing so, the central arm 37 and the side arm 38 are connected to each other so that they cannot be displaced relative to each other, and the side arm 38 and the central arm 37 swing together as a result of pressing of the drive cam 16. The intake valve 13 with which the central arm 37 abuts is driven to open and close as the drive cam 16 rotates.

  On the other hand, by reducing the oil pressure of the one oil passage 24 and the other oil passage 54, the connecting pin 40 is in a position where it does not straddle the central arm 37 and the side arm 38, as shown by b-1 in FIG. By doing so, the central arm 37 and the side arm 38 are brought into a disengaged state in which the central arm 37 and the side arm 38 can be displaced relative to each other. As a result, the intake valve 13 with which the central arm 37 abuts is prevented from opening and closing as the drive cam 16 rotates.

According to the variable valve mechanism 50 of the present embodiment, the following effects (h) and (i) can be obtained in addition to the effects (b) to (g) obtained by the variable valve mechanism 10.
(H) By controlling the oil pressure of the one oil passage 24 and the other oil passage 54, the one side rocker arm 36 and the other side rocker arm 52 are driven to open and close the intake valve 13 according to the rotation of the drive cam 16, and this opening and closing drive is completely performed. It is possible to switch between a state in which the cylinder is stopped and all (six) cylinders can be switched between an operating state and a resting state.
(I) The other oil passage 54 can be made the same as the one oil passage 24.

  According to the operation method of the internal combustion engine of the embodiment of the present invention using the variable valve mechanism 50, all (six) cylinders can be switched between the operation state and the inactive state. Further, switching between the state in which the intake valve 13 is opened / closed by the one side rocker arm 36 and the other side rocker arm 52 and the state in which the opening / closing drive is completely stopped can be performed with good response without delay in timing. Improved response improves fuel efficiency and durability.

  A variable valve mechanism 60 according to Embodiment 3 of the present invention will be described with reference to FIG.

  The variable valve mechanism 60 switches between a state in which the one side rocker arm and the other side rocker arm both drive the valve with a relatively large lift amount and a state in which the valve is driven with a relatively small lift amount according to the rotation of the drive cam. Thus, the variable valve mechanism is that the variable rocker arm 61 changes the drive amount of the intake valve 13 and that the two types of drive cams 68 and 69 with different lift amounts are provided on the camshaft 67. Unlike the variable valve 50, the other points are the same as those of the variable valve mechanism 50. In FIG. 10, the same members as those of the variable valve mechanism 10 or the variable valve mechanism 50 are denoted by the same reference numerals as those of the variable valve mechanism 10 or the variable valve mechanism 50.

  As shown in FIG. 10, the camshaft 67 is provided with a first drive cam 68 having a relatively large lift amount and a second drive cam 69 having a relatively small lift amount. The variable rocker arm 61 is swingably supported by the rocker shaft 51 in the middle of the length direction, and has a main arm 62 whose one end is in contact with the intake valve 13 and the other end is in contact with the second drive cam 69. The auxiliary arm 63 is located on the side of the arm 62 and is supported by the rocker shaft 51 in the middle of the length direction so as to be swingable. The end of the camshaft 67 is in contact with the first drive cam 68. Yes. Further, the connecting pin 65 is moved to the variable rocker arm 61 by the hydraulic pressure supplied from outside through the internal oil passage 64 provided in the sub arm 63 so that the connecting pin 65 straddles the main arm 62 and the sub arm 63. The main arm 62 and the sub arm 63 are connected to each other such that they cannot be displaced relative to each other (the main arm 62 is relatively large and opens and closes the intake valve 13 in accordance with the rotation of the first drive cam), and the connecting pin 40 A connection release state in which the main arm 62 and the sub arm 63 are not straddled is released (a state in which the main arm 62 is relatively small and opens and closes the intake valve 13 in accordance with the rotation of the second drive cam 69). A switching mechanism 66 is provided.

  Next, the change of the drive amount of the intake valve 13 by the variable valve mechanism 60 will be described.

  The variable valve mechanism 60 changes the oil pressure supplied to the switching mechanism 66 by controlling the oil pressure of the one oil passage 24 and the other oil passage 54, and the variable rocker arm 61, which is the one side rocker arm and the other side rocker arm, The intake valve 13 is opened and closed with a relatively large lift amount according to the rotation of the one drive cam 68, and the intake valve 13 is opened and closed with a relatively small lift amount according to the rotation of the second drive cam 69. .

  Specifically, by increasing the oil pressure of the one oil passage 24 and the other oil passage 54, the connection pin 65 is in a position straddling the main arm 62 and the sub arm 63 as shown in b-2 of FIG. By doing so, the main arm 62 and the sub arm 63 are connected to each other so that they cannot be displaced relative to each other, and the main arm 62 and the sub arm 63 swing together by the pressing of the first drive cam 68, The intake valve 13 with which the main arm 62 is in contact is opened and closed with a relatively large lift amount as the first drive cam 68 rotates.

  On the other hand, by lowering the oil pressure of the one oil passage 24 and the other oil passage 54, the connecting pin 65 seems to be in a position where it does not straddle the main arm 62 and the sub arm 63 as shown in b-1 of FIG. As a result, the main arm 62 and the sub arm 63 are brought into a disengaged state in which the main arm 62 and the sub arm 63 can be displaced relative to each other. When the second drive cam 69 is rotated, the intake valve 13 is opened and closed with a relatively small lift amount.

According to the variable valve mechanism 60 of the present embodiment, in addition to the effects (b) to (g) obtained with the variable valve mechanism 10 and the effect (i) obtained with the variable valve mechanism 50, The effect of (j) is obtained.
(J) By controlling the oil pressure of the one oil passage 24 and the other oil passage 54, a state in which all of the intake valves 13 are opened / closed with a relatively large lift amount and a state in which the intake valve 13 is opened / closed with a relatively small lift amount And can be switched.

  According to the operation method of the internal combustion engine of the embodiment of the present invention using the variable valve mechanism 60, the intake valves 13 of all (six) cylinders are relatively opened and closed with a relatively large lift amount. It is possible to switch between a state of opening and closing with a small lift amount. Further, this switching of the intake valve 13 can be performed with good response without delaying the timing. Improved response improves fuel efficiency and durability.

  In addition, this invention is not limited to the said Example, In the range which does not deviate from the meaning of invention, it can change suitably and can be actualized. For example, when the attachment bolt 31 is inserted into the bolt through hole 26 on the inner peripheral surface of the other oil passage 25 of the variable valve mechanism 10, an expansion recess is provided in a portion located beside the attachment bolt 31. To do. The reduced diameter bolt 33 is inserted into the bolt passage hole 26 of the other oil passage 25 of the variable valve mechanism 10.

10 Variable valve mechanism (Example 1)
13 Intake valve 16 Drive cam 17 Mounting portion 20 Rocker shaft (Example 1)
21 Intermediate part 22 One end 23 The other end 24 One oil passage 25 The other oil passage (Example 1)
26 Bolt through hole 27 Lubrication hole (one side)
28 Hydraulic hole 29 Expansion recess 30 Lubrication hole (Example 1 other side)
31 Mounting bolt 32 Rocker arm on the other side (Example 1)
33 Mounting bolt (reduced diameter bolt)
34 Reduced diameter part 36 One side rocker arm 45 T slot cutter 50 Variable valve mechanism (Example 2)
51 Rocker shaft (Example 2)
52 Rocker arm on the other side (Example 2)
53 Lubrication hole (the other side)
54 Other oil passage (Example 2)
55 Mounting bolt (reduced diameter bolt)
57 Lubrication hole (the other side of Example 2)
60 Variable valve mechanism (Example 3)
61 Variable rocker arm (Example 3)
68 First drive cam 69 Second drive cam

Claims (7)

Two oil passages (24, 25, 54) that are not partitioned in the radial direction but are partitioned in the length direction are formed in the rocker shaft (20, 51),
One rocker arm (36) supported on one side in the length direction of the rocker shaft (20, 51) is communicated with one oil passage (24) of the two oil passages (20). 51), oil is supplied from the one oil passage (24) through the lubrication hole (27) drilled in
The other side rocker arm (32, 52) supported on the other side in the length direction of the rocker shaft (20, 51) is communicated with the other oil path (25, 54) of the two oil paths. Oil is supplied from the other oil passage (25, 54) through the lubricating holes (30, 57) drilled in the rocker shaft (20, 51),
At least one of the one side rocker arm (36) and the other side rocker arm (32, 52) is supplied with oil through the lubrication hole (27, 30, 57), or the one oil passage (24) or the other oil passage (54). ) Through a hydraulic hole (28, 53) drilled in the rocker shaft (20, 51) so as to communicate with the valve () by changing the oil pressure input from the one oil passage (24) or the other oil passage (54). 13) The drive amount is changed ,
The mounting bolts (31, 33, 55) screwing the rocker shaft (20, 51) to the cylinder head (17) of the internal combustion engine are inserted in the radial direction of the rocker shaft (20, 51),
The attachment bolt on the inner peripheral surface of the one oil passage (24) and / or the other oil passage (54) intersecting with the attachment bolt (33, 55) and continuing to the hydraulic hole (28, 53). A variable valve mechanism for an internal combustion engine in which an expansion recess (29, 56) for expanding the oil passage cross-sectional area is formed in a portion located directly beside (33, 55) than the portion other than the portion . The mounting bolts (33, 55) intersecting with the one oil passage (24) and / or the other oil passage (54) connected to the hydraulic holes (28, 53) are reduced in diameter at the intersecting portion (34). The variable valve mechanism for an internal combustion engine according to claim 1. The shape of the extension recesses (29, 56) is an arc shape in a cross-sectional view cut along the length direction of the rocker shaft (20, 51) and perpendicular to the mounting bolts (33, 55). The variable valve mechanism for an internal combustion engine according to claim 1 or 2, wherein the valve mechanism is rectangular in a sectional view cut along a radial direction of the rocker shaft (20, 51) . The variable valve mechanism for an internal combustion engine according to claim 1, 2 or 3, wherein the surface of the expansion recess (29) is a cutting surface . Using the variable valve mechanism of the internal combustion engine according to any one of claims 1 to 4,
One of the one side rocker arm (36) and the other side rocker arm (32, 52) is switched between a state in which the valve (13) is driven according to the rotation of the drive cam (16) and a state in which the driving is completely stopped. And operating the internal combustion engine for driving the valve (13) according to the rotation of the drive cam (16). Using the variable valve mechanism of the internal combustion engine according to any one of claims 1 to 4,
An internal combustion engine that switches both the one side rocker arm (36) and the other side rocker arm (52) between a state in which the valve (13) is driven and a state in which the driving is completely stopped according to the rotation of the drive cam (16). Driving method. Using the variable valve mechanism of the internal combustion engine according to any one of claims 1 to 4,
An internal combustion engine in which both the one side rocker arm and the other side rocker arm are switched between a state in which the valve (13) is driven relatively large and a state in which the valve (13) is driven relatively small in accordance with the rotation of the drive cam (68, 69). how to drive.

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