JP3966148B2 - Continuously variable valve operating device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a continuously variable valve operating apparatus for an internal combustion engine in which a valve lift amount of a reciprocating valve can be continuously changed using movement of a swing fulcrum of a swing lever.
[0002]
[Prior art]
The gasoline engine (internal combustion engine) is equipped with a continuously variable valve operating device, and the work of the throttle bubble (adjustment of the intake air amount) is substituted by the reciprocating valve on the intake side provided in the cylinder head, that is, the intake valve. Thus, there is a structure for reducing the pump loss caused by the throttle bubble.
[0003]
Conventionally, a structure using a swing lever that has a swing fulcrum at the upper end and a contact surface that contacts the intake valve at the lower end has been proposed for such a continuously variable valve device that substitutes for the throttle bubble. .
[0004]
For this purpose, a control camshaft is arranged on one side of the upper part sandwiching the rocking lever from the rocking direction, and a driving camshaft is arranged in the middle part on the opposite side, and the eccentric displacement of the control camshaft is used for rocking. The swinging fulcrum of the moving lever can be moved between the control camshaft and the driving camshaft, and the driving force required to open the valve is input from the input part formed in the middle of the swinging lever by the driving camshaft. A variable valve mechanism is used. In other words, when the swing fulcrum of the swing lever is swung by the eccentric displacement of the control camshaft, the region of the contact surface where the swing lever is tilted and contacts the intake valve moves. On the contact surface of the swing lever, a base circle section and a lift section that determines the valve lift amount of the intake valve are formed in series along the control camshaft and the drive camshaft. The valve lift amount of the intake valve is continuously varied by moving the region between the base circle section and the lift section in contact with the intake valve. Using the continuously variable valve lift amount, the work of adjusting the intake air amount performed by the throttle valve is substituted (see, for example, Patent Document 1).
[0005]
[Patent Document 1]
JP-A-7-63023 (FIGS. 6 to 8)
[0006]
[Problems to be solved by the invention]
However, even when the eccentric cam is fixed at a certain position, the swing fulcrum moves during the movement of the swing lever. Therefore, it is necessary to maintain the valve closed state by the movement of the swing lever and the roller contact surface shape.
[0007]
For this reason, each component has a difficulty in requiring high machining accuracy.
[0008]
Therefore, the control camshaft and the drive cam are centered on the position that defines the closed state of the intake valve using the swing lever as the swing fulcrum for each swing lever (for each cylinder) and holding lever. A structure that can swing freely along the shaft is conceivable, but if the swing fulcrum is simply held by the holding lever, it will be affected by variations in processing at the support portion that supports the holding lever. .
[0009]
For example, the upper end of the holding lever is rotatably supported by the swing fulcrum of the swing lever, and the lower end is supported rotatably at a position defining the state when the intake valve is closed above the cylinder head. In this case, it is conceivable that a holding portion having a support hole for rotatably supporting the end portion of the holding lever is integrally formed on the upper surface of the cylinder head. Using a long tool from the outside of the cylinder head, it is compulsory to drill holes in the holding portion formed on the upper surface of the cylinder head for each cylinder. For this reason, the accuracy of each support hole is likely to be lost due to variations caused by tool runout or the like, and control of the valve lift amount with high accuracy is hindered.
[0010]
Accordingly, the present invention is to provide a continuously variable valve operating apparatus for an internal combustion engine that realizes highly accurate positioning of a swing lever and ensures highly accurate control of a valve lift amount.
[0011]
[Means for Solving the Problems]
The invention according to claim 1 in order to achieve the above object, using the arranged holding lever so as to extend in the vertical direction to a point adjacent to the pivot lever, the swing fulcrum of the swing lever at its upper end The shaft portion formed at the lower end of the revolving valve is supported so as to be rotatable, and the state when the reciprocating valve is closed is defined among the holding walls disposed on the opposite side of the swing lever with the holding lever interposed therebetween. A cylinder head that is rotatably supported by a lever support hole formed at a point corresponding to the position, and that the holding wall is detachably attached to the upper surface of the cylinder head and passes through the lever support hole. The holding wall is formed so that the upper part extends to the control camshaft and the drive camshaft, and the control shaft and the drive shaft are formed on the upper part. Support To the support hole camshaft respectively formed, and was a line the top along the upper surface of the cylinder head through the support hole for the cam shafts and dividable configured as a dividing surface.
[0012]
With this configuration, during the swinging of the swinging lever, the swinging fulcrum of the swinging lever is always fixed on the locus of the arc centered on the position that defines the valve closing state by the holding lever. Even if a large valve lift amount is set, the swing lever is always adjusted for swing displacement based on when the valve is closed, and the variation in the opening and closing timing of the reciprocating valve is eliminated.
[0013]
At this time, since the holding wall that holds the holding lever is separate from the cylinder head, the processing of the support hole for the lever that supports the shaft portion of the holding lever is not limited by the cylinder head, Since it can be carried out as a single piece with the holding wall in a state where the divided portions are combined with the dividing surface at another place, a highly accurate lever support hole is secured. Moreover, since the holding wall can be divided from the support hole for the lever, the shaft of the holding lever can be assembled as long as the shaft is sandwiched between the semicircular parts and attached to the cylinder head. The part is assembled to the cylinder head. Therefore, the swing fulcrum of the swing lever is positioned with high accuracy by the holding lever, and the valve lift amount is controlled with high accuracy. Further, the control camshaft and the drive camshaft can be supported by using the holding wall for holding the holding lever.
[0014]
According to a second aspect of the present invention, in addition to the above object, the reciprocating valve has one end portion having a swing shaft and abutting with the abutting surface at the intermediate portion so that the retaining lever is held with high accuracy. The rocker arm type has a rocker arm that supports a rotatable roller and a valve body that is opened and closed by swinging the other end of the rocker arm. The support hole for the rocker that supports the lever and the support hole for the lever are formed in parallel at the position corresponding to the axial center position of the roller when the reciprocating valve is closed, and the holding wall is the support hole for the lever and the support for the rocker It was set as the structure divided | segmented as a division surface on the line which passes a hole.
[0016]
In addition to the above object, the invention described in claim 3 further reduces the size of the continuously variable valve operating device, and includes various parts such as a control camshaft, a driving camshaft, a rocker arm swinging shaft, and a holding lever shaft. The support hole for the lever and the support hole for the rocker are arranged in parallel along the upper surface of the cylinder, and the shaft support hole of the control cam shaft and the shaft support hole of the drive shaft are aligned along the upper surface of the cylinder head. The lower part of the holding wall can be divided along a line parallel to the upper surface of the cylinder head passing through the lever support hole and the rocker support hole, and the upper part of the holding wall is divided into the lever support hole and the rocker. The retaining wall can be divided into three parts, which can be divided on a line parallel to the upper surface of the cylinder head passing through the support hole.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on an embodiment shown in FIG. 1 and FIG.
[0018]
In FIG. 1, reference numeral 1 denotes a plane of a cylinder head of an internal combustion engine, for example, a reciprocating gasoline engine in which a plurality of cylinders are arranged in series. In the cylinder head 1, combustion chambers (not shown) are arranged in the longitudinal direction according to the arrangement of the cylinders. An intake port and an exhaust port (both not shown) are provided for each combustion chamber. A valve operating system is provided at the top of the cylinder head 1 for each intake port and each exhaust port, and a continuously variable valve operating device 2 acting as a throttle valve for the intake side valve operating system. Is assembled.
[0019]
2 shows the configuration of the continuously variable valve gear 2 taken along the line AA in FIG. 1, FIG. 3 shows a cross-sectional view taken along the line BB in FIG. 1, and FIG. FIG. 6 shows an exploded view of the continuously variable valve operating device 2.
[0020]
The continuously variable valve operating apparatus 2 will be described. Reference numeral 4 in FIGS. 2 and 6 denotes a pair of intake valves (only one set shown: reciprocating valve) assembled to the cylinder head 1 for each cylinder (for each combustion chamber). ).
[0021]
As the intake valve 4 constituting the valve operating system, a rocker arm type valve using a rocker arm 5 is used. Specifically, the rocker arm 5 is formed of a substantially plate-like member extending in a direction perpendicular to the direction in which the cylinders are arranged, for example. For example, as shown in FIG. 1, FIG. 2, and FIG. 4, a rocker shaft 6 that forms a rocking shaft is rotatably attached to an end portion of each rocker arm 5 disposed on the center side of the combustion chamber. . The end of the combustion chamber end on the opposite side is in contact with the end of a shaft portion 7a extending from a pair of umbrella-shaped valve bodies 7 that are reciprocally attached to the intake port. The valve body 7 is urged in a closing direction, here upward, by a valve spring (not shown) so as to always return to the closed state. A rocker arm roller 8 (corresponding to a roller) is rotatably mounted at the center of the intermediate portion of the rocker arm 5 with its axis parallel to the rocking axis of the rocker arm 5. Each end of the rocker shaft 6 is supported by a holding holder 11 assembled to the upper surface of the cylinder head 1 so as to be swingable. When the rocker arm roller 8 is pressed from the upper side, the rocker arm 5 swings and displaces. Thus, the valve body 7 is opened. That is, the intake valve 4 is configured such that the valve body 7 is reciprocated by swinging of the rocker arm 5 to open and close the intake port. The structure of the holding holder 11 will be described later.
[0022]
Reference numeral 10 denotes a variable valve mechanism that constitutes the continuously variable valve apparatus 2. As shown in FIGS. 1 to 4 and 6, the variable valve mechanism 10 is assembled immediately above the intake valve 4 for each cylinder. These variable valve mechanisms 10 all have the same structure. The structure of one of them will be explained. Reference numeral 12 denotes a control camshaft disposed above the rocking fulcrum of the rocker arm 5 and disposed along the cylinder row direction, for example, 13 is an abbreviation of the rocking end of the rocker arm 5, for example. This is a drive camshaft that is positioned above and disposed along the cylinder row direction. The control camshaft 12 and the drive camshaft 13 are arranged in parallel along the upper surface of the cylinder head 1. Among these, the control camshaft 12 is connected to a control drive source, for example, a control motor 14, and is rotated by a desired amount of displacement by the operation of the control motor 14 (clockwise, Both counterclockwise). The drive camshaft 13 is connected to a crankshaft (not shown) assembled to a cylinder block (parts to be combined with the cylinder head 1) via a timing gear, a timing chain, and a crank gear (not shown). The rotation is driven (clockwise) by the crank output.
[0023]
As shown in FIGS. 2 and 6, a swing lever 15 is disposed directly above the rocker arm roller 8 along the vertical direction. The rocking lever 15 has a lower portion extending in the lateral direction (rocking fulcrum to rocking end) along the rocker arm roller 8 as a short side and passes between the control camshaft 12 and the crankshaft 13 between them. An L-shaped plate-like component having an upper portion extending upward along the longitudinal side is used. The lower end surface on the short side is brought into contact with the outer peripheral surface of the rocker arm roller 8. The lower end surface on the short side is a contact surface 16 with respect to the rocker arm roller 8.
[0024]
The upper end of the swing lever 15 is adjacent to the control camshaft 12, and the intermediate portion is adjacent to the drive camshaft 13. A holding shaft 17 formed of, for example, a short shaft member is fixed to the upper end of the swing lever 15 so as to penetrate in the cylinder row direction. The holding shaft 17 forms a swing fulcrum A at the upper end of the swing lever 15. For example, a pair of holding levers 18 disposed at a position adjacent to the swing lever 15 and a pair of holding holders 11 (holding walls) provided on the opposite side of the swing lever 18 with the lever 18 interposed therebetween. Can be swung between the control camshaft 12 and the drive camshaft 13 at a radius centered at a position that defines the closed state of the intake valve 4 from both sides. (Holding means).
[0025]
That is, each of the pair of holding holders 11 arranged for each cylinder is constituted by a substantially rectangular wall as shown in FIGS. A lever support hole 9 a and a rocker support hole 9 b are formed in the lower portion of the holding holder 11. The rocker support hole 9b is formed at the position of the rocker shaft 6, and the lever support hole 9a is a position that defines the state when the intake valve 4 is closed. The rocker arm roller 8 is closed when the intake valve 4 is closed. It is formed at the center position. The support holes 9 a and 9 b are arranged in parallel along the upper surface of the cylinder head 1. The end of the rocker shaft 6 is fitted into the rocker support hole 9b, and the rocker arm 5 is supported in a swingable manner.
[0026]
Each of the holding levers 18 disposed between the swing lever 15 and the holding holder 11 is composed of an L-shaped lever member. As shown in FIGS. 2 and 6, the holding lever 18 has a through hole portion 19 in the upper portion and a shaft portion 20 that protrudes to the side in parallel with the axis of the through hole portion 19 in the lower portion. A lever member having a length from the swing fulcrum A to the center of the rocker arm roller 8 when the valve is closed is used from the center of the through-hole portion 19 to the center of the shaft portion 20 (FIG. 6 shows only one side). Not shown). And the through-hole part 19 of each holding lever 18 is each inserted in the end of each holding shaft 17 of the rocking lever 15 so that rotation is possible, as FIG. 3 and FIG. 4 shows. Each shaft portion 20 is rotatably fitted in the lever support hole 9a of each holding holder 11, and the swing fulcrum A of the swing lever 15 is centered on the roller axis of the rocker arm roller 8 when the valve is closed. It is possible to move around its axis.
[0027]
The upper part of each holding holder 11 extends to a point where the control camshaft 12 and the drive camshaft 13 are located. As shown in FIGS. 4 and 6, camshaft support holes 21a and 21b are formed in the upper portion. Both the camshaft support holes 21 a and 21 b are arranged in parallel along the upper surface of the cylinder head 1. Of these, the control camshaft 12 is rotatably inserted into the camshaft support hole 21a, and the drive camshaft 13 is rotatably inserted into the camshaft support hole 21b. The camshafts 12 and 13 are made rotatable.
[0028]
Each holding holder 11 has a structure in which the holding holder 11 is detachable with respect to the cylinder head 1 as shown in FIG. It is. That is, each holding holder 11 is formed of a member separate from the cylinder head 1. The lower side of the holding holder 11 is parallel to the line passing through the lever support hole 9a, specifically, the upper surface of the cylinder head 1 passing through the axis of the lever support hole 9a and the axis of the rocker support hole 9b. The line is divided into upper and lower parts as a dividing plane V1. Further, the upper side of the holding holder 11 is on a line passing through the camshaft support hole 21a for supporting the control camshaft 12 and the camshaft support hole 21b for supporting the drive camshaft 13, specifically, the camshaft support. A line parallel to the upper surface of the cylinder head 1 passing through the axis of the hole 21a and the axis of the camshaft support hole 21b is divided into upper and lower parts as a dividing surface V2. That is, the holding holder 11 has a structure that is divided into three parts, that is, the lower holder 11a, the center holder 11b, and the upper holder 11c, by the dividing surfaces V1 and V2. Then, after each holding holder 11 is fixed, for example, a lower holder 11a, a center holder 11b, and an upper holder 11c stacked as shown in FIG. 4 are arranged on the upper surface of the cylinder head 1, a fastening tool such as a long bolt member is provided. 11d to the screw hole 24b formed on the upper surface of the cylinder head from the upper side through the through holes 24a formed on both sides of the end of the upper holder 11c, both ends of the center holder 11b, and both ends of the lower holder 11a. The structure is fixed by screwing, and is detachably fixed to the upper part of the cylinder head 1 (structure that can be divided into three).
[0029]
On the other hand, the outer peripheral surface of the upper end portion of the swing lever 15 is formed in a flat circular shape, and a contact surface 22 is formed on the outer peripheral surface. A cam surface (outer peripheral surface) of an eccentric cam 12 a formed eccentric to the control cam shaft 12 is in contact with the contact surface 22 of the swing lever 15 from the lateral direction. Thus, when the eccentric cam 12a is eccentrically displaced, the swing fulcrum A of the swing lever 14 follows the movement of the eccentric cam 12a and moves around the axis of the rocker arm roller 8. In addition, a roller 23 is provided at an intermediate portion (swinging fulcrum A to contact surface 16) of the swinging lever 14 so that a part of the roller 23 protrudes from a side part adjacent to the driving camshaft 13. The cam surface (outer peripheral surface) of, for example, a substantially triangular drive cam 13a formed on the driving cam shaft 13 is brought into contact with the outer peripheral surface of the roller 23 from above, and the driving cam shaft 13 rotates. Then, the roller 23 is periodically pressed. As a result, the driving force necessary to open the intake valve 4 is input to the swing lever 14 from the drive cam 13a using the roller 23 as an input portion. That is, if the control camshaft 12 is eccentrically displaced while the swing lever 15 is swinging by the drive cam 13a and the swing support point A of the swing lever 15 is moved, the tilt angle of the swing lever 15 changes. The region of the contact surface 16 that contacts the rocker arm roller 8 moves.
[0030]
A base circle section corresponding to the base circle of the drive cam 13a is formed on the control camshaft 12 side of the contact surface 16 as shown in FIG. The base circle section is formed on an arc surface having a base circle radius with the value obtained by subtracting the roller radius from the distance between the swing fulcrum A and the center of the rocker arm roller centered on the swing fulcrum A. On the contact surface 16 on the side of the driving camshaft 13 which is the opposite side, a lift section formed by an arcuate surface in the opposite direction continuous with the base circle section is formed. This lift section is formed by a circular arc for determining the valve lift amount of the intake valve 4 set in advance, and when the tilt angle of the swing lever 15 changes, the base circle section and the lift section where the rocker arm roller 8 goes and goes Is changed so that the valve lift amount of the intake valve 4 can be continuously varied. The drive cam 13a and the roller 23 employ an arrangement in which the contact position of both moves above the plane parallel to the upper surface of the cylinder head 1 passing through the center of the roller 23 at least during the maximum lift control.
[0031]
The operation of the continuously variable valve operating apparatus 2 configured as described above will be explained. While the swing lever 15 is swung by the drive cam 13a, the control motor 14 moves the largest as shown in FIG. 5 (a). When the eccentric cam 13a is rotationally displaced so as to give an amount, the swing fulcrum A of the swing lever 15 is centered on the axis of the rocker arm roller 8 when the valve is closed and is the most distant from the control cam shaft 12. Moving. Then, the swing lever 15 is displaced in the direction that occurs with the point where the roller 23 serving as the input unit and the drive cam 13a come into contact with each other. As a result, the rocker arm roller 8 crosses the region defined by the swing fulcrum of the swing lever 15, that is, the narrowest base circle section and the longest lift section as shown in FIG. Thus, control for ensuring the maximum valve lift amount is performed.
[0032]
Further, when the eccentric cam 13a is rotationally displaced by the control motor 14 so as to have the smallest movement amount as shown in FIG. 5B while the swing lever 15 is swinging, the swing lever 15 swings. The moving fulcrum A moves around the axis of the rocker arm roller 8 when the valve is closed to the point closest to the control camshaft 12. Then, the swing lever 15 is displaced in a tilting direction with a point where the roller 23 serving as the input unit and the drive cam 13a abut on each other. Thereby, the rocker arm roller 8 comes and goes between the region defined by the swing fulcrum of the swing lever 15, that is, the longest base circle section and the shortest lift section as shown in FIG. Thus, control for ensuring the minimum valve lift amount is performed. That is, by the movement of the swing fulcrum A, the maximum valve lift amount is continuously controlled from the minimum valve lift amount.
[0033]
As described above, during the swing of the swing lever 15, the swing support point A of the swing lever 15 is always fixed on an arc locus centering on the position defining the valve closing state. The intake valve 4 can be reliably opened / closed at the intended opening / closing timing even when controlling the large lift amount as shown in the middle X or when controlling the small lift amount as shown in Y (elimination of variations). That is, the intake valve 4 can be controlled to open and close according to the set valve lift amount.
[0034]
Moreover, the holding holder 11 that holds the swing lever 15 has a fixing structure that can be attached to and detached from the cylinder head 1 and a structure that can be divided by the divided surfaces V1 and V2 including the support holes. As shown in FIGS. 7A and 7B, the holes 9a, 9b, 21a, and 21b are formed by dividing the upper holder 11a, the center holder 11b, and the lower holder 11c into a divided surface V1 at a place different from the cylinder head 1. , V2 can be used alone to perform hole machining with the tool K, and machining using a long tool becomes unnecessary. That is, variations can be suppressed. In addition, the shaft portion 20 of the holding lever 18 can be secured to the cylinder head 1 with high accuracy if each holder portion is sandwiched between the semicircular portions and fixed to the upper surface of the cylinder head 1. Can be assembled.
[0035]
Therefore, the oscillating fulcrum A of the oscillating lever is positioned with high accuracy by the oscillating lever 18 on the upper surface of the cylinder head 1, and high-accuracy valve lift control can be promised. In particular, the intake valve 4 employs a structure in which the rocking fulcrum of the rocker arm 5 is held by the holding holder 11 and the rocking fulcrum A of the rocking lever 15 is movable around the axis of the rocker arm roller 8. Since the holding holder 11 can be divided on a line passing through the lever support hole 9a and the rocker support hole 9b, the shaft portion 20 of the holding lever 18 can be further accurately set to a point that defines the state when the valve is closed. Can be retained.
[0036]
In addition, by adopting the holding holder 11 having a three-part structure, the holding cam 11 can be shared and the control camshaft 12 and the driving camshaft 13 can be supported. In addition, the entire variable valve mechanism 10 including the intake valve 4 can be assembled using the holding holder 11 before the cylinder head 1 is assembled, and the assembled state. Therefore, the assembly work of the continuously variable valve gear 2 can be made more efficient.
[0037]
In addition, a lever support hole 9a, a rocker support hole 9b, a shaft support hole 21a (control camshaft 12), and a shaft support hole 21b (drive camshaft 13) are arranged in parallel along the upper surface of the cylinder head 1. Since both sides can be divided on a line parallel to the upper surface of the cylinder head 1, the control camshaft 21 a, the drive camshaft 21 b, and the rocker arm shaft 6 can be saved with a small holding holder 11 while saving space. Further, each part such as the shaft part 20 of the holding lever 18 can be supported, and the continuously variable valve apparatus 2 can be downsized.
[0038]
Since the contact position between the drive cam 13a and the roller 23 moves above the line passing through the center of the roller 23, the load F1 applied from the drive cam 13a to the roller 23 during the maximum lift control is from the horizontal direction. As shown in FIG. 5A, most of the load F1 cancels with the valve spring reaction force F2, so that the load applied to the swing fulcrum A is kept low even under the most heavy load. be able to. Therefore, the oil film formed between the holding shaft 17 and the bearing surface that supports the holding shaft 17 can be prevented from being interrupted, and a good control of the valve lift amount by the swing lever 15 can always be promised. In FIG. 5A, F3 indicates the direction of the load applied from the swing fulcrum A.
[0039]
The present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the spirit of the present invention. For example, in one embodiment, a rocker arm type intake valve is used, but a structure using an intake valve directly driven by a swing lever may be used.
[0040]
【The invention's effect】
As described above, according to the first aspect of the present invention, the swing fulcrum of the swing lever is always held by the holding lever regardless of the magnitude of the valve lift amount. Displacement on the reference trajectory eliminates variation in the opening / closing timing of the reciprocating valve. In addition, the holding wall that holds the holding lever is separate from the cylinder head and can be divided on the line that passes through the lever support hole that supports the shaft of the holding lever. Thus, the hole can be drilled at a location different from the cylinder head while the divided portions are aligned with the dividing surface, and a highly accurate lever support hole can be secured. In addition, as long as the shaft portion is sandwiched between the semicircular portions and fixed to the cylinder head, the shaft portion of the holding lever can be assembled to the cylinder head while maintaining high accuracy.
[0041]
【The invention's effect】
Therefore, the swing fulcrum of the swing lever is positioned with high accuracy by the holding lever, and the valve lift amount can be controlled with high accuracy. In addition, the control camshaft and the drive camshaft can be supported by sharing the holding wall. In addition, the entire variable valve mechanism including the reciprocating valve can be assembled using the holding wall before assembly of the cylinder head, or can be transported in the assembled state. There is an effect that work efficiency can be improved.
[0042]
According to invention of Claim 2, in addition to the said effect, there exists an effect that the axial part of a holding lever can be hold | maintained to the point which prescribes | regulates the state at the time of valve closing with high precision.
[0044]
According to the invention of claim 3 , in addition to the above effects, a small holding wall can be used to support each part such as a control camshaft, a driving camshaft, a rocker arm swinging shaft, and a holding lever shaft. It is possible to reduce the size of the continuously variable valve operating device.
[Brief description of the drawings]
FIG. 1 is a plan view showing a continuously variable valve operating apparatus according to an embodiment of the present invention.
FIG. 2 is a side sectional view taken along line AA in FIG.
FIG. 3 is a front sectional view taken along line BB in FIG.
4 is a side view taken along line CC in FIG. 1. FIG.
FIG. 5A is a side view showing a state of a movable valve mechanism at the time of maximum lift control.
(B) is a side view showing the state of the movable valve mechanism during the minimum lift control.
FIG. 6 is an exploded perspective view showing the structure of a continuously variable valve gear.
FIG. 7 is a diagram showing control of a valve lift amount performed in the apparatus.
FIG. 8A is a cross-sectional view showing a state in which each support hole is processed in the holding wall.
(B) is sectional drawing of the holding wall which finished the process.
[Explanation of symbols]
1 ... Cylinder head 4 ... Intake valve (reciprocating valve)
5 ... Rocker arm 6 ... Rocker shaft (oscillating shaft)
7 ... Valve 8 ... Rocker arm roller (roller)
9a ... Lever support hole 9b ... Rocker support hole 10 ... Variable valve mechanism 11 ... Holding holder (holding wall)
DESCRIPTION OF SYMBOLS 12 ... Control camshaft 13 ... Drive camshaft 15 ... Swing lever 16 ... Contact surface 17 ... Holding shaft 18 ... Holding lever 21a, 21b ... Support hole 23 for camshaft ... Roller (input part)
V1, V2 ... division planes.

Claims (3)

The control camshaft and the drive camshaft are arranged in parallel on the upper part of the cylinder head having the reciprocating valve, and there is a swinging lever that can swing along the camshaft. The lever has a contact surface that contacts the reciprocating valve at a lower end, a swing fulcrum that moves between the shafts upon receiving the cam displacement of the control cam shaft at the upper end, and a swing lever An input portion for inputting a driving force for opening the reciprocating valve from the driving camshaft, and when the swing fulcrum is moved, the reciprocating motion is detected from a change in the tilt angle of the swing lever. A variable valve mechanism that continuously moves a valve lift amount of the reciprocating valve by moving a region of a contact surface that contacts the valve;
Holding means for holding the swinging fulcrum of the swinging lever so as to be swingable between the camshafts around a position that defines the closed state of the reciprocating valve;
The holding means is disposed at a point adjacent to the swing lever, and the upper end is rotatably supported by the swing support point of the swing lever, and the holding lever is formed with a shaft portion at the lower end. Provided on the upper part of the cylinder head on the opposite side of the swing lever with the holding lever in between, the shaft of the swing lever is freely rotatable at the lower part corresponding to the position that defines the closed state of the reciprocating valve. And a holding wall formed with a support hole for a lever to be supported on,
And the holding wall, with detachably attached to the upper surface of the cylinder head, Ri tare to dividable construction lines along the upper surface of the cylinder head through the lever support hole as a dividing plane,
Further, the holding wall is further formed so that an upper portion thereof extends to the control camshaft and the drive camshaft, and a camshaft support hole for supporting the control shaft and the drive shaft on the upper portion. Are formed, and the upper part is configured to be splittable with a line along the upper surface of the cylinder head passing through each camshaft support hole as a splitting surface . 2. The continuously variable valve operating apparatus for an internal combustion engine according to claim 1, wherein the reciprocating valve has a swinging shaft at one end and a rotatable roller that contacts the abutting surface at an intermediate portion. It is composed of a rocker arm type having a rocker arm and a valve body that is opened and closed by swinging the other end of the rocker arm.
A rocker support hole that rotatably supports the rocking shaft of the rocker arm and a point corresponding to the axial center position of the roller when the reciprocating valve is closed are located below the holding wall. The lever support hole is formed in parallel,
And front lower divided surfaces of Kiho Jikabe is continuously variable valve device for an internal combustion engine, characterized in that it is formed on a line through the lever support hole and the rocker supporting hole. 3. The continuously variable valve operating apparatus for an internal combustion engine according to claim 2 , wherein the holding wall is provided with the lever support hole and the rocker support hole in parallel along the upper surface of the cylinder and the control. A shaft support hole of the cam shaft for driving and a shaft support hole of the drive shaft are arranged in parallel along the upper surface of the cylinder head,
The lower dividing surface of the holding wall is formed on a line parallel to the upper surface of the cylinder head passing through the lever supporting hole and the rocker supporting hole, and the upper dividing surface of the holding wall is formed on the lever supporting hole. A continuously variable valve operating apparatus for an internal combustion engine, characterized in that the holding wall is formed on a line parallel to the upper surface of the cylinder head passing through a hole and the support hole for the rocker, and can be divided into three.

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