JP2016200053A - Variable valve gear for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress rapid movement of a cam lobe member to a cam base member.SOLUTION: A variable valve gear according to this invention includes a cam base member 210 which is provided on a cam shaft, a cam lobe member 212 which has a main cam part 214 and an extrusion part 216 and is movable between a first position and a second position, an energizing member 222 for energizing the cam lobe member toward the first position, a pressing member 230 which can work on the extrusion part of the cam lobe member, and a fixing mechanism 240 which can fix the cam lobe member to the cam base member when the cam lobe member is in the second position. The main cam part is shifted to an axial direction of the cam shaft with respect to the extrusion part. The extrusion part is protruded to the cam base member at the first position. The main cam part is protruded at the second position. The cam lobe member is moved toward the second position from the first position when the pressing member works on the extrusion part.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a variable valve operating apparatus for an internal combustion engine.

  2. Description of the Related Art Conventionally, a mechanism or device that makes an engine valve lift variable is known. Patent Document 1 discloses an example of a device that can vary the amount of cam protrusion on a camshaft. This apparatus includes a cam base member that is rotationally driven by a driving force from a crankshaft, and a cam lobe member that is swingably connected to the cam base member. The cam lobe member is selectively positioned at either a retracted position stored in the cam base member or a protruding position protruding radially outward from the cam base member in accordance with the operating state of the hydraulic system. Thereby, in the apparatus of Patent Document 1, the lift amount of the engine valve is variable.

International Publication No. 2014/030226

  Here, the movement of the cam lobe member 102 relative to the cam base member 104 in the apparatus of Patent Document 1 will be described with reference to FIG. FIG. 1A shows an example when the cam lobe member 102 is in the protruding position, and FIG. 1B shows an example when the cam lobe member 102 is in the retracted position. The cam lobe member 102 is always urged toward the protruding position by a spring (not shown). In order to restrict the amount of protrusion (that is, the swinging range) of the cam lobe member 102 due to the urging of the spring, the stopper pin 106 fixed to the cam lobe member 102 is inserted into the guide groove (long hole) 108 of the cam base member 104 in the longitudinal direction. It is arranged to be movable along the direction.

  Oil supply to the upstream path of the pin acting on the cam lobe member 102 is stopped and a predetermined hydraulic pressure is not applied to the pin, and the cam lobe member 102 is fixed to the cam base member 104 at the protruding position. The valve can be opened by pushing the rocker arm by the cam lobe member 102 (see the solid line in FIG. 2A). On the other hand, when oil is supplied to the upstream path of the pin acting on the cam lobe member 102 and a predetermined hydraulic pressure is applied to the pin, the cam lobe member 102 is fixed to the cam base member 104 at the retracted position. The valve is not particularly subjected to a force in the opening direction (see the dotted line in FIG. 2 (a)). This is because the outer surface of the cam base member 104 in FIG. 1 has a shape based on a reference circle. When changing the position of the cam lobe member from the protruding position to the retracted position, hydraulic pressure is applied. Conversely, when the position of the cam lobe member is changed from the retracted position to the protruding position, the hydraulic pressure is released.

  When the hydraulic pressure to the pin is released, the cam lobe member continues to swing relative to the cam base member unless the cam lobe member is in a fixed state. FIG. 2B conceptually shows the movement of the stopper pin 106 (that is, the movement of the cam lobe member) when the camshaft rotates with the cam lobe member not fixed. In the graph of FIG. 2B, the movement of the stopper pin is represented by the lost angle. The lost angle α corresponds to the rotation angle of the stopper pin 106 around the swing center of the cam lobe member 102 with respect to the cam base member 104 (center of the fulcrum member 110), as shown in FIG. Here, the lost angle α is defined to be zero when the cam lobe member 102 is in the protruding position, as shown in FIG. 1A, and to increase as the position of the cam lobe member 102 approaches the retracted position.

  As schematically shown in FIG. 2B, when the cam lobe member 102 is not fixed by the lock pin, it is desirable that the lost angle changes as indicated by a solid line. However, when the biasing force of the spring is insufficient, the steep movement of the cam lobe member 102 immediately before the cam lobe member 102 reaches the protruding position, that is, the latter half of the swinging may not be realized by the spring biasing force. In this case, the contact between the cam lobe member and the rocker arm is once released, and then the cam lobe member reaches the protruding position. As a result, the stopper pin 106 collides with the longitudinal end portion 108a of the guide groove 108 at a speed equal to or higher than the originally provided ramp speed (see the dotted line in FIG. 2B). Such a collision between members produces a collision sound when the internal combustion engine is operated at a low speed (for example, during idling), and improvement is desired.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a variable valve operating apparatus for an internal combustion engine that can suppress a rapid movement of a cam lobe member relative to a cam base member.

According to one aspect of the invention,
A variable valve operating apparatus for an internal combustion engine that makes the lift amount of an engine valve variable,
A cam base member provided on the cam shaft and rotating according to the rotation of the cam shaft;
A cam lobe member movably provided with respect to the cam base member, comprising: a main cam portion; and an extrusion portion positioned so as to be displaced in an axial direction of the cam shaft with respect to the main cam portion, The cam base member is movable with respect to the cam base member integrally with the main cam portion, and the cam lobe member is movable with respect to the cam base member between a first position and a second position, and the cam lobe member is in the first position. When the cam lobe member is at the second position, the push portion of the cam lobe member protrudes from the cam base member. When the cam lobe member is at the second position, the main cam portion protrudes from the cam base member. A cam lobe member;
A biasing member for biasing the cam lobe member toward the first position;
A pressing member that acts on the pushing portion of the cam lobe member and moves the cam lobe member from the first position side toward the second position side;
A fixing mechanism that enables the cam lobe member to be fixed to the cam base member when the cam lobe member is in the second position;
A variable valve operating apparatus for an internal combustion engine is provided.

  Preferably, the pressing member has a concave curved surface that can act on the pushing portion of the cam lobe member.

  Preferably, the variable valve operating apparatus for the internal combustion engine further includes a restriction mechanism for restricting a movement range of the cam lobe member with respect to the cam base member.

  Preferably, the main cam portion of the cam lobe member is formed in a substantially U shape so as to have a front end portion positioned forward in the rotational direction of the camshaft and a rear end portion positioned rearward in the rotational direction. The fulcrum member is movable with respect to the cam base member around the fulcrum member, and the fulcrum member is disposed at one of the front end portion and the rear end portion. Preferably, the main cam portion and the pushing portion are connected via the fulcrum member, and the pushing portion is formed of a first bending portion closer to the fulcrum member and a first bending portion on a circumferential outer surface. And a second bending portion separated from the fulcrum member, and the first bending portion has a shape different from that of the second bending portion.

  According to the one aspect of the present invention, the cam lobe member provided for the cam base member includes a main cam portion and an extruding portion positioned so as to be shifted in the axial direction of the cam shaft with respect to the main cam portion, It is urged | biased toward the 1st position by the urging | biasing member, and it can move toward the 2nd position side from a 1st position side because a press member acts on this extrusion part. Therefore, the cam lobe member can be moved to the second position by the pressing member acting on the pushing portion different from the main cam portion against the urging force of the urging member, and further, the first position can be moved by the urging force of the urging member. The cam lobe member can be returned. The pushing portion is positioned so as to be displaced in the axial direction of the camshaft with respect to the main cam portion, and the degree of freedom in design is high. Therefore, according to the said one aspect | mode of this invention, the outstanding effect that the rapid motion of the cam lobe member with respect to a cam base member can be suppressed by optimizing the shape of an extrusion part is exhibited.

It is the figure which showed the conventional variable valve apparatus, (a) shows the state in which a cam lobe member exists in a protrusion position, (b) shows the state in which a cam lobe member exists in a retracted position. (a) is a graph showing the lift curve of the conventional variable valve gear, (b) is a graph for demonstrating the motion of the conventional cam lobe member. It is a figure which shows the principal part of the variable valve apparatus of the internal combustion engine which concerns on 1st Embodiment of this invention. It is the figure which looked at the cam unit of the variable valve apparatus of FIG. 3 from the axial direction. It is a figure which shows two cam lobe members by arrangement | positioning in FIG. (A) And (b) shows the main cam part and pushing part of the cam lobe member of the variable valve apparatus of FIG. (A) And (b) shows the state in which a cam lobe member exists in a 2nd position, and the state in which a cam lobe member exists in a 1st position, respectively. It is the figure which represented the motion of the cam lobe member in the variable valve apparatus of FIG. 3 in the non-fixed state in steps. It is the figure which represented the motion of the cam lobe member in the variable valve apparatus of FIG. 3 in the fixed state in steps. FIG. 4 is a cross-sectional view taken along line XX in FIG. 3, and is a schematic diagram for explaining a fixing mechanism for fixing a cam lobe member in the variable valve apparatus in FIG. 3. FIG. 11 is a diagram showing a state when hydraulic pressure is applied to the pin of the fixing mechanism in the sectional view of FIG. 10. In the cross-sectional view of FIG. 10, it is a figure which shows the state which the cam lobe member moved toward the 1st position from the state of FIG. FIG. 4 is a flowchart for controlling a cam lobe member in the variable valve apparatus of FIG. 3. FIG. 5 is a graph showing a period during which the cam lobe member is in a second position in the variable valve operating apparatus for an internal combustion engine according to the first embodiment of the present invention. It is a figure for demonstrating the modification of the press member in the variable valve apparatus of the internal combustion engine which concerns on 1st Embodiment of this invention. It is a graph for demonstrating expansion of the period when a cam lobe member exists in a 2nd position by the press member as a deformation | transformation of FIG. It is a figure regarding the internal combustion engine to which the variable valve apparatus of the internal combustion engine which concerns on 2nd Embodiment of this invention is applied, (a) shows the lift curve of an intake / exhaust valve, (b) is related with the cam unit of an exhaust valve. (C) relates to the cam unit of the intake valve. It is a figure for demonstrating the structure of the cam unit for exhaust valves of 2nd Embodiment, (a) shows the state which has a cam lobe member in a 2nd position, (b) has a cam lobe member in a 1st position. Indicates the state. It is a figure for demonstrating the modification of the cam unit for exhaust valves of FIG. 18, (a) shows the state in which a cam lobe member exists in a 2nd position, (b) shows the state in which a cam lobe member exists in a 1st position. Indicates.

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

  FIG. 3 is an external view of the variable valve operating apparatus 201 for the internal combustion engine of the first embodiment. FIG. 4 shows the cam unit of FIG. 3 in the axial direction of the camshaft (hereinafter simply referred to as “axial direction”). FIG. The variable valve gear 1 is applied to an internal combustion engine mounted on a vehicle. Although this internal combustion engine is a four-cylinder engine, the present invention does not ask | require the number of cylinders, cylinder arrangement | sequence, combustion type, etc. of the internal combustion engine applied. Further, the internal combustion engine to which the present invention is applied may be used other than the vehicle.

  The variable valve apparatus 201 includes a camshaft S. The camshaft S is provided with a cam unit CU. The camshaft S is rotated by power from the internal combustion engine. More specifically, the camshaft S is rotationally driven by a driving force from the crankshaft. As the camshaft S rotates along with the rotation of the camshaft S, the engine valve V can be lifted via the rocker arm R. Here, the valve V is an intake valve of an internal combustion engine, but may be an exhaust valve. The cam unit CU is not limited to the rocker arm R, which is a follower member connected to the valve V, but may be another member, for example, the valve itself.

  The cam unit CU includes a cam base member 210 having five sub cam base members 210 s and two cam lobe members 212. The sub cam base members 210s are arranged in the axial direction of the cam shaft S and are connected to each other by the inner shaft portion 210a. The inner shaft portion 210a is provided along the axis of the camshaft S. The cam base member 210 has a larger diameter than the inner shaft portion 210a. The sub-cam base member 210s has a substantially columnar shape, and has a substantially circular base circle portion BC (a shape portion corresponding to a reference base circle) when viewed from the axial direction of the camshaft S. The base circle portion BC corresponds to the outer peripheral surface of the cam base member 210. In the present specification, a direction perpendicular to the axial direction around the axis of the camshaft S or a direction parallel thereto is referred to as a “radial direction”. Further, a direction around the axis of the camshaft S or a similar direction is referred to as a “circumferential direction”.

  The cam lobe member 212 includes a main cam portion 214 and an extruding portion 216. The main cam portion 214 is integrally fixed to the pushing portion 216. Therefore, the main cam portion 214 and the pushing portion 216 are integrally movable with respect to the cam base member 210. First, the main cam portion 214 will be described.

  The main cam portion 214 is disposed between the sub cam base members 210s adjacent in the axial direction so as to be sandwiched therebetween. The main cam portion 214 is configured to push the corresponding rocker arm R to lift the corresponding valve V (that is, move to open). Specifically, the main cam portion 214 is shaped to have a substantially U shape when viewed from the axial direction of the camshaft S (see FIG. 6A) and has a flat plate shape. The main cam portion 214 has two opposing surfaces (hereinafter referred to as end surfaces) arranged so as to face in the axial direction, and a surface (hereinafter referred to as a peripheral side surface) extending between these end surfaces. The peripheral side surface has an outer peripheral surface arranged facing the outer side in the radial direction and an inner peripheral surface arranged facing the inner side in the radial direction (that is, the axis line side of the camshaft S). The main cam portion 214 has, in the circumferential direction, a cam portion 214a having a cam profile on the outer circumferential surface and two end portions on both sides thereof. The outer peripheral surface 214o of the cam portion 214a has a cam profile corresponding to a lift curve as shown by a solid line in FIG. That is, as will be described later, when the cam lobe member 212 is fixed to the cam base member 210, the cam portion 214a of the main cam portion 214 protrudes from the base circle portion BC of the cam base member 210 in the radial direction. Here, of the two end portions of the main cam portion 214, the end portion 214b positioned forward (that is, on the advance side) in the rotation direction of the camshaft S is referred to as a front end portion, and rearward in the rotation direction of the camshaft S. That is, the end 214c positioned on the retard side is referred to as a rear end.

  The axial width (lateral width) of the main cam portion 214 is shorter than the axial width of the rocker arm R. As shown in FIG. 3, they are arranged so that the outer peripheral surfaces of the sub cam base members 210 s on both sides of the main cam portion 214 (the outer peripheral surface of the cam base member 210) can come into sliding contact with the rocker arm R. Therefore, when the cam lobe member 212 is not fixed to the cam base member 210 by a fixing mechanism which will be described later, the cam base member 210 continues to contact the rocker arm R as the cam shaft S rotates. However, this invention can have another embodiment provided with the structure that the axial direction width | variety of a main cam part is longer than the axial direction width | variety of a rocker arm.

  The extruding portion 216 is disposed between them so as to be sandwiched between the sub cam base members 210s adjacent in the axial direction. The pushing portion 216 is fixed to the main cam portion 214 that forms a pair, with one sub cam base member 210s interposed therebetween. In particular, in the present embodiment, the pushing portion 216 is fixedly connected to the main cam portion 214 by a support shaft (fulcrum member) 218 disposed so as to extend in the axial direction of the camshaft S. Therefore, the pushing portion 216 and the main cam portion 214 are positioned so as to be shifted in the axial direction of the camshaft S. FIG. 5 shows the cam lobe member 12 (the assembly (set) of the main cam portion 214 and the pushing portion 216) in FIG. 3 in the arrangement shown in FIG.

  The pushing portion 216 is shaped to have a substantially U shape when viewed from the axial direction of the camshaft S (see FIG. 6B). The extruding part 216 has two opposing surfaces (hereinafter referred to as end surfaces) arranged so as to face the axial direction, and a surface (hereinafter referred to as a peripheral side surface) extending between these end surfaces. The peripheral side surface has an outer peripheral surface arranged facing the outer side in the radial direction and an inner peripheral surface arranged facing the inner side in the radial direction (that is, the axis line side of the camshaft S). In the circumferential direction, the pushing portion 216 has a pressed portion 216a having a driving profile of the cam lobe member 12 on the outer circumferential surface 216o, and two end portions on both sides thereof. The pressed portion 216a is configured to come into contact with a pressing member, which will be described later, and to be pressed as a result by the pressing member. Here, of these two ends, the end 216b positioned forward (that is, on the advance side) in the rotation direction of the camshaft S is referred to as a front end, and rearward (that is, the delay in the rotation direction of the camshaft S). The end 216c located on the (corner side) is referred to as a rear end.

  The support shaft 218 is disposed so as to fixedly connect the rear end portion 214 c of the main cam portion 214 of the cam lobe member 212 and the front end portion 216 b of the pushing portion 216. The support shaft 218 is arranged so that its axis is parallel to the axis of the camshaft S. The support shaft 218 is inserted into a through-hole 210 b provided in the sub cam base member 210 s between the main cam portion 214 and the push portion 216, and is provided movably with respect to the cam base member 210. Therefore, the main cam portion 214 and the pushing portion 216 are movable with respect to the cam base member 210, and in particular, can move around the support shaft 218.

  Further, a stopper pin 220 protruding in the axial direction is fixed to the main cam portion 214. The stopper pin 220 is a rod-shaped member. Here, the stopper pin 220 protrudes from the vicinity of the rear end portion 214 c of the main cam portion 214 to a side different from the associated pushing portion 216. The stopper pin 220 is also provided in parallel to the axis of the camshaft S, like the support shaft 218. The stopper pin 220 is inserted through the guide hole (long hole) 210c of the sub cam base member 210s on the side different from the associated pushing portion 216, and protrudes in the axial direction. The guide hole 210c is designed to define a range (movable range) in which the main cam portion 214 and the pushing portion 216 are allowed to move with respect to the cam base member 210, and the stopper pin 220 extends along the longitudinal direction of the guide hole 210c. It can move from one end to the other. Since the movement of the main cam portion 214 and the pushing portion 216 is restricted within the movable range of the stopper pin 220 in the guide hole 210c, the guide hole 210c and the stopper pin 220 provide the movable range of the cam lobe member 212 with respect to the cam base member 210. A regulating mechanism for regulating is configured. Therefore, the main cam portion 214 and the pushing portion 216 can swing with respect to the cam base portion 210 within the movable range of the stopper pin 220 in the guide hole 210c with the support shaft 218 as the center.

  Spring (biasing member) 222, which is an elastic member, is disposed on the end surfaces on the axially outer side of the sub cam base members 210s at both ends of the five sub cam base members 210s. The spring 222 is arranged to urge the stopper pin 220 in a direction in which the cam portion 214a of the main cam portion 214 is stored radially inward from the outer peripheral surface of the cam base member 10 (that is, in a non-projecting direction). The spring 222 is provided with respect to a shaft portion 222 a provided so as to protrude from the cam base member 210, one end of which pushes the fixed shaft portion 222 b provided so as to protrude from the cam base member 210, and the other end is The stopper pin 220 is urged. Therefore, the cam 222 is biased by the spring 222 in a direction in which the cam portion 214 a does not protrude in the radial direction from the cam base member 210 and the push portion 216 protrudes in the radial direction from the cam base member 210.

  Further, a pressing member 230 is provided outside the pressing portion 216 in the radial direction. The pressing member 230 is provided on the cylinder head CH. However, the pressing member 230 is not limited to being provided on the cylinder head CH, and may be provided at another location. The pressing member 230 is provided so as to be contactable or abutable so that a pressing force can be applied to the pressing portion 216. The pressing member 230 has a width smaller than the axial width (lateral width) of the extruding portion 216, but may have substantially the same dimensions as that. Therefore, when the pushing portion 216 rotates with the rotation of the camshaft S and the pressed portion 216a of the pushing portion 216 starts to contact the pressing member 230, the pressed portion 216a receives a pressing force from the pressing member 230. When the pressed portion 216a of the pushing portion 216 starts to contact the pressing member 230 and further rotates, the pushing portion 216 is pushed from the protruding position where the pushed portion 216a protrudes radially outward of the cam base member 210. Is moved from the outer peripheral surface of the cam base member 210 to the retracted position (non-projecting position) retracted radially inward. And by further rotating, the to-be-pressed part 216a will remove | exclude a contact state with the press member 230, and the extrusion part 216 will return to a protrusion position. The present invention allows the pressing member 230 to have an axial width that is longer than the axial width of the extruding portion 216, and not only when the pressing member 230 does not contact the sub cam base member 210 s but also contacts. Do not exclude cases.

  The pushing portion 216 is shaped so that the cam lobe member 212 can smoothly swing around the support shaft 218. The extruding portion 216 includes a first curved portion 216f near the support shaft 218, a second curved portion 216g farther from the support shaft 218 than the first curved portion 216f, and a transition portion 216h extending therebetween. Have. The first bending portion 216f, the transition portion 216h, and the second bending portion 216g are arranged side by side along the circumferential direction of the peripheral side surface of the pushing portion 216 of the cam lobe member 212. Accordingly, the first bending portion 216f is separated from the second bending portion 216g in the circumferential direction of the pushing portion 216. The transition part 216h connects the first curved part 216f and the second curved part 216g, and has a shape suitable for the base circle part BC. In the example illustrated here, the first bending portion 216f is located on the front side in the rotation direction of the transition portion 216h, and the second bending portion 216g is located on the rear side in the rotation direction of the transition portion 216h. Therefore, when the pressing member 230 pushes the cam lobe member 212 along the first curved portion 216f of the pushing portion 216, the cam lobe member 212 moves so that the main cam portion 214 protrudes radially outward from the cam base member 210. On the other hand, as the pressing member 230 continues to push the cam lobe member 212 along the second curved portion 216g of the pushing portion 216, the cam lobe member 212 moves so that the main cam portion 214 is stored in the cam base member 210.

  As shown in FIG. 4, when viewed from the axial direction of the camshaft S, the pushing portion 216 and the main cam portion 214 of one cam lobe member 212 are arranged around the central axis of the camshaft S or the inner shaft portion 210a. It arrange | positions in a different position regarding the circumferential direction.

  The cam lobe member 212 can be releasably fixed to the cam base member 210 by a fixing mechanism described later. Here, when the main cam portion 214 of the cam lobe member 212 is in the retracted position, it is defined as the “first position” of the cam lobe member 212, and when the main cam portion 214 of the cam lobe member 212 is in the protruding position, “ “Second position”. When the cam lobe member 12 is in the first position (see FIG. 7B), the main cam portion 214 of the cam lobe member 212 is radially outward from the cam base member 210 along a virtual plane orthogonal to the axial direction of the cam shaft. Although not protruding, the pushing portion 216 protrudes radially outward from the cam base member 210. On the other hand, when the cam lobe member 212 is in the second position (see FIG. 7A), the main cam portion 214 protrudes radially outward from the cam base member 210, but the pushing portion 216 does not protrude from the cam base member 210. In this way, the main cam portion 214 of the cam lobe member is in a state of projecting radially outward with respect to the cam base member 10 when the cam lobe member is in the second position, and on the cam base member 10 when the cam lobe member is in the first position. On the other hand, it does not protrude radially outward, that is, it is in a non-projecting state. On the contrary, the pushing portion 216 of the cam lobe member is in a state of projecting radially outward with respect to the cam base member 210 when the cam lobe member is in the first position, and with respect to the cam base member 210 when the cam lobe member is in the second position. Thus, it does not protrude radially outward, that is, it is in a non-projecting state. In particular, since the cam lobe member is arranged between the sub cam base members 210s as described above, the main cam portion 214 is stored in the cam base member 210 when the main cam portion 214 of the cam lobe member is in a non-projecting state ( Or in a contained state). 7 relates to a cam lobe member different from the cam lobe member shown in FIG. 4, and FIG. 7 is a view seen from the opposite direction to FIG.

  The aforementioned restriction mechanism is provided so as to define a range in which the cam lobe member 212 can reciprocate (that is, swing) with respect to the cam base member 210 as a region between the first position and the second position. The cam lobe member 212 can be fixed to the second position with respect to the cam base member 210 by the fixing mechanism, and this fixed state can be referred to as a lift state. Note that the restriction mechanism is not necessarily provided as long as the movable range of the cam lobe member 212 is restricted to a predetermined range by another structure or shape.

  The reciprocating motion (swinging motion) of the cam lobe member 214 with respect to the described cam base member 210 within a predetermined range will be further described with reference to FIG. However, the movement of the main cam portion 214 relative to the cam base member 10 in the column (a) of FIG. 8 is the pushing portion (fixed to the main cam portion 214 in FIG. 8A) relative to the cam base member 210 in the column (b) of FIG. This is linked to the movement of H.216. In FIG. 8, the main cam portion 214 and the pushing portion 216 arranged in the vertical direction have the same cam angle (that is, the same crank angle CA (°)). That is, in FIG. 8, (a-1) and (b-1) are in the same period, and (a-2) to (a-6) and (b-2) to (b-6) The same applies to the corresponding combinations. In FIG. 8, the support shaft 218 or a corresponding portion is easily understood by hatching. Further, in FIG. 8, regarding the rocker arm R and the pressing member 230, only the portions that can contact the cam lobe member 212 are schematically shown.

  In FIG. 8, for example, in (a-1), the main cam portion 214 is in the retracted position, and in (b-1), the pushing portion 216 is in the protruding position, and these are those when the cam lobe member 212 is in the first position. is there. Further, in (a-4), the main cam portion 214 is in the protruding position, and in (b-4), the pushing portion 216 is in the retracted position, and these are those when the cam lobe member 212 is in the second position. 7A corresponds to the main cam portion 214 in the (a-4) state and the pushing portion 216 in the (b-4) state as viewed from the axial direction of the camshaft S. FIG. Similarly, FIG. 7B corresponds to the main cam portion 214 in the (a-1) state and the pushing portion 216 in the (b-1) state as viewed from the axial direction of the camshaft S.

  As is apparent from the drawing, the pushed portion 216a of the pushing portion 216 receives a force (pressing force) from the pushing member 230, so that the pushing portion 216 moves from the protruding position to the retracted position. Along with this, the main cam portion 214 interlocked with the pushing portion 216 moves from the retracted position to the protruding position. Note that the reciprocating motion (swinging motion) of the main cam portion 214 and the pushing portion 216 of the cam lobe member 212 with respect to the cam base member 210 shown in FIG. As long as the camshaft S is not fixed to the cam base member 210, the process is repeated as the camshaft S rotates.

  Further, a fixing device 240 for selectively fixing the cam lobe member 212 to the cam base member 210 is provided. By the fixing device 240, the cam lobe member 212 is in a state where the cam lobe member 212 is fixed to the cam base member 210 (fixed state) and a state where the cam lobe member 212 is not fixed to the cam base member 210 (non-fixed). State or free state). The movement of the main cam portion 214 and the movement of the pushing portion 216 when the cam lobe member 212 is in the non-fixed state are as already described with reference to FIG. On the other hand, the fixing device 240 is configured so that the cam lobe member 212 can be fixed at the protruding position (second position) where the main cam portion 214 protrudes.

  FIG. 9 shows the movement of the main cam portion 214 and the movement of the pushing portion 216 when the cam lobe member 212 is in a fixed state by the fixing device 240, according to FIG. When the cam lobe member 212 is in a fixed state, the main cam portion 214 of the cam lobe member 212 is in the protruding position and acts on the rocker arm R. As shown in the column (c) of FIG. 9, the main cam portion 214 of the cam lobe member 212 can push down the rocker arm R by the cam portion 214a (see the column (c-1)). Thereby, the valve V is opened as shown by a solid line in FIG. On the other hand, as shown in the column (d) of FIG. 9, the cam lobe member 212 is fixed at the second position and the pushing portion 216 is at the retracted position, so that it comes into sliding contact with the pressing member 230. However, in FIG. 9C-1, the pressed portion 216 a of the pushing portion 216 slightly protrudes radially outward from the outer peripheral surface of the cam base member 210. This indicates that since there is play between a lock pin and a pin hole of the fixing device 240 described later, when the main cam portion 214 pushes the rocker arm R, the position of the pushing portion 216 is changed by the amount of play. Of course, this does not exclude a configuration in which the pushing portion 216 does not protrude at all when the main cam portion 214 pushes the rocker arm R. This state is also included when the cam lobe member 212 is in the second position. It is. In FIG. 9, (c-1) and (d-1) are in the same period, and (c-2) to (c-6) and (d-2) to (d-6) The same applies to the corresponding combinations.

  Here, a fixing mechanism or fixing device 240 for fixing the cam lobe member 212 to the cam base member 210 will be described with reference to FIGS. FIG. 10 is a schematic cross-sectional view showing the internal structure of the cam unit CU along the line XX in FIG. In order to facilitate understanding, a part of the pressing member 230 is indicated by a virtual line in FIG. In FIG. 10, the two cam lobe members 12 are in a fixed state, but as can be understood from FIG. 3, it is not clear that the main cam portion 214 of the cam lobe member 212 actually protrudes in the radial direction in this cross section. However, for easy understanding, the cam lobe 212 is shown in FIG. 10 so that the main cam portion 214 protrudes.

  The inner shaft portion 10d extends in the axial direction, and an oil passage T1 is formed along the axis. The axial oil passage T1 is connected to a radial oil passage T2 extending radially outward from the axial direction. The radial oil passage T <b> 2 further extends in the axial direction and extends toward the main cam portion 214 of the cam lobe member 212.

  An oil control valve CV that can be controlled by an electronic control unit (ECU) as a control device is provided upstream of the oil passage T1. When the oil control valve CV is open, the oil supplied from the oil pan (not shown) by the oil pump P can flow to the supply oil passage T1. The oil pump P is a mechanical pump linked to the crankshaft of the internal combustion engine, but may be an electric pump.

  The ECU is substantially constituted by a computer including an arithmetic processing device (for example, CPU), a storage device (for example, ROM, RAM), an A / D converter, an input interface, an output interface, and the like. Various sensors are electrically connected to the input interface. Based on signals from these various sensors, the ECU electrically outputs an operation signal or a drive signal from the output interface so that the internal combustion engine can be smoothly operated or operated in accordance with a preset program or the like. Thus, in addition to the operation of a fuel injection valve (not shown), the ECU also controls the oil control valve CV. Here, some of the sensors will be specifically described. An engine rotation speed sensor 240R for detecting the engine rotation speed is provided. Further, an engine load sensor 240L for detecting the engine load is provided. As the engine load sensor 240L, a throttle opening sensor, an accelerator opening sensor, an air flow meter, an intake pressure sensor, or the like can be used.

  The fixing device 240 has a plurality of pins (locking pins) that act on the cam lobe member 212. Here, in order to fix one cam lobe member 212, three locking pins 240a, 240b, 240c are used. The three pins 240a, 240b, 240c are arranged in series, and are arranged in order from the side close to the oil passage T1 in the flow passage direction. The innermost pin 240c is urged toward the radial oil passage T2 by a spring 240s. Due to the urging force of the spring 240s, the pins 240b and 240c are positioned so as to receive a shearing force from the cam base member 210 and the cam lobe member 212 as shown in FIG.

  The fixing pin hole 212j of the cam lobe member 212 is provided at the tip end portion 214b of the main cam portion 214, and is designed to have a size such that the middle pin 240b of the three pins can be accommodated. The corresponding pin hole 210f of the sub-cam base member 210s on the push-out portion 216 side has an axial width longer than the axial width of the pin 240a. Further, the pin hole 210g of the sub cam base member 210s on the spring 222 side is formed in a size that can substantially fit the pin 240c when the spring 240s is compressed.

  As shown in FIG. 10, when the oil pressure is not applied to the oil passage more than a predetermined value, the pins 240a, 240b, 240c are displaced from the corresponding pin holes by the biasing force of the spring 240s. Accordingly, a shearing force is applied to the pins 240b and 240c, and the cam lobe member 212 is fixed. Therefore, the rocker arm R can be driven by the main cam portion 214 of the cam lobe member 212. Note that the fixing pin hole 212j of the cam lobe member 212 is designed such that the cam lobe member 212 is positioned at the second position corresponding to one end side of the swingable range when in the fixed state of FIG.

  On the other hand, when the drive of the rocker arm R by the cam lobe member 212 is stopped, the ECU controls to open the oil control valve CV. As a result, as shown by an arrow in FIG. 11, a hydraulic pressure equal to or greater than a predetermined value is applied to the pin 24a via the oil passages T1 and T2. As a result, the spring 24s is compressed, and the pins 24a, 24b, and 24c are received in the corresponding pin holes. Thus, when the state shown in FIG. 11 is reached, the cam lobe member 212 can be moved toward the retracted position by the biasing force of the spring 222 as shown in FIG. FIG. 12 schematically shows the cam lobe member 212 being separated from the second position toward the first position. While the hydraulic pressure is applied, the cam lobe member 212 continues to swing between the first position and the second position. In the cross-sectional view of FIG. 12, as a result of the cam lobe member 212 swinging, the pin hole 212j is separated from the other pin holes 210f and 210g away from the portion along the line XX of FIG. 240b does not appear. In FIG. 12, the cam lobe member 212 is schematically shown to show that the cam lobe member 12 is closer to the retracted position.

  Then, the hydraulic pressure is released (the supply of the hydraulic pressure of a predetermined value or more is stopped), the cam lobe member 212 reaches the second position, and the fixing pin hole 212j of the cam lobe member 212 is axially connected to the pin hole 210f and the pin hole. When the holes 210g are aligned, the pins 240a, 240b, and 240c are moved by the biasing force of the spring 240s. Thereby, the cam lobe member 212 is maintained in a fixed state at the second position (see FIG. 10).

  The switching control of the oil control valve CV will be described based on the flowchart of FIG. First, it is determined in step S1301 whether or not the vehicle is in a predetermined operating state. Here, the ECU searches for preset data or performs a predetermined calculation based on the engine rotation speed detected by the engine rotation speed sensor 240R and the engine load detected by the engine load sensor 240L. Thus, it is determined whether or not the current operation state is a predetermined operation state. The internal combustion engine in the present embodiment is a four-cylinder engine, and can perform a reduced-cylinder operation in which two cylinders are deactivated in a predetermined operation state where the engine load is low. In this internal combustion engine, the variable valve operating device is applied to a reduced cylinder operation cylinder. Therefore, the predetermined operation state is set as an operation state in which the reduced cylinder operation is performed. However, the present invention allows the predetermined operating state to be another operating state. As described above, the number of cylinders of the internal combustion engine to which the present invention is applied is not limited to this embodiment, and the reduced-cylinder operation in which two cylinders in the four-cylinder engine are deactivated is only an example.

  If the determination is affirmative in step S1301, the hydraulic pressure is turned on in step S1303. That is, the ECU controls the opening of the oil control valve CV to a first predetermined opening (for example, fully open). The first predetermined opening may be fixed or variable, and is set so as to supply a hydraulic pressure equal to or higher than the predetermined value. As a result, the fixing pins 240a, 240b, 240c of the cam unit CU are brought into the state shown in FIGS. 11 and 12, for example, and the valve opening is stopped.

  On the other hand, if a negative determination is made in step S1301, the hydraulic pressure is turned off in step 1305. That is, the ECU controls the oil control valve CV to the second predetermined opening (for example, fully closed). Note that the second predetermined opening may be fixed or variable, so that the cam lobe member can be returned to the state shown in FIG. 10 in particular so that the hydraulic pressure equal to or higher than the predetermined value is not supplied to the pin 240a. Set to As a result, the cam unit CU enters the state shown in FIG. 10, and the valve opening is started.

  Here, returning to FIG. 8, the movement of the pushing portion 216 when the cam lobe member 212 is not fixed to the cam base member 210 will be further described. When the camshaft S rotates in the direction indicated by the arrow in FIG. 8 and the support shaft 218 reaches the rocker arm R side, the pressing member 230 comes into contact with the pushing portion 216. Thereby, the 1st curved part 216f of the to-be-pressed part 216a of the extrusion part 216 begins to be pressed by the pressing member 230 (refer (b-2)). Therefore, the pushing portion 216 is pushed in the direction from the protruding position toward the retracted position and starts to rotate around the support shaft 218. And the contact location of the pressing member 230 with respect to the extrusion part 216 passes the 1st curved part 216f, reaches the transition part 216h, and the cam lobe member 212 comes to be located at the retracted position (see (b-4)). Further, when the camshaft S rotates, the contact portion of the pressing member 230 with respect to the pushing portion 216 moves along the second curved portion 216g (see (b-5)). At this time, the pushing portion 216 moves relative to the cam base member 10 gradually and smoothly toward the protruding position. Then, the pushing portion 216 reaches the protruding position, and the pushing portion 216 is released from the contact state with the pressing member 230. This movement of the pushing portion 216 corresponds to the movement of the main cam portion 214.

  Attention is now directed to FIG. In the state of (b-2) in the (b) column of FIG. 8, it will be understood that the tangent L1 of the contact portion of the pressing portion 216 with the pressing member 230 substantially doubles as the tangent of the base circle portion BC. Further, in the state of (b-6) in the column (b) of FIG. 8, it will be understood that the tangent line L2 of the contact portion of the pushing portion 216 with the pressing member 230 substantially doubles as the tangent line of the base circle portion BC. . On the other hand, the concave curved surface 230a that can act on the pushing portion 216 of the cam lobe member 212 in the pressing member 230 has a shape that matches the base circle portion BC, and a predetermined angle around the axis of the camshaft S. Extend to range. Therefore, when the cam lobe member 212 is not fixed to the cam base member 210, the contact of the pressing member 230 with the pushing portion 216 can be smoothly started as the cam shaft S rotates. As the camshaft S further rotates, the contact of the pressing member 230 with the pushing portion 216 can be smoothly finished.

  Furthermore, the concave shape of the first curved portion 216f is concave in the radial direction compared to the portions on the outer peripheral surfaces on both sides of the maximum lift location M of the main cam portion 214 of the cam lobe member 212 (see, for example, reference numeral M1 in FIG. 8). It is depressed. Accordingly, the first bending portion 216f can be firmly in contact with the pressing member 230 and continue to receive sufficient force from the pressing member 230. Further, the convex shape of the second curved portion 216g, in particular, the shape of the portion near the rear end portion 216c, compared with the portions M1 on the peripheral side surfaces on both sides of the maximum lift location M of the main cam portion 214 of the cam lobe member 212. It bulges in a convex shape in the radial direction. Therefore, the second bending portion 216g can firmly contact the pressing member 230 in the process from the state (b-5) to the state (b-6) and can continue to receive sufficient force from the pressing member 230. . As described above, since the pressed portion 216a of the pushing portion 216 is formed, the cam lobe member is prevented from suddenly moving (problem occurrence) as described with reference to FIGS. 1 and 2, and between the various members. A collision can be prevented.

  Furthermore, in the above-described embodiment, the main cam portion 214 and the push-out portion 216 for driving the main cam portion 214 to push it out are separate (although fixed to each other) and are separated in the axial direction. Are displaced from each other. Therefore, the shape of the main cam portion 214 and the shape of the pushing portion 216 can be designed with a higher degree of freedom. Therefore, the valve opening period of the valve V by the main cam portion 214 of the cam lobe member 212 can be very long.

  Moreover, in the said embodiment, the cross-sectional shape (shape in the cross section orthogonal to the axis line of the camshaft S) of the concave curved surface 230a in the front-end | tip part of the press member 230 was not circular, and was curving in the circumferential direction of the camshaft S. Has a shape. Therefore, when the cam lobe member 212 is in the non-fixed state, the period during which the main cam portion 214 of the cam lobe member 212 is maintained at the protruding position is longer than when the cross-sectional shape of the tip end portion of the pressing member 230 is circular (for example, It can be made longer (as compared to having a shape following the rocker arm R). Thereby, it is possible to sufficiently secure a period during which the cam lobe member 212 can be fixed (that is, a period during which the cam lobe member is in the second position). FIG. 14 schematically shows these relationships. 14 indicates a period in which the cam lobe member is in the second position when the cross-sectional shape of the tip portion of the pressing member 230 is circular. The solid line in FIG. 14 indicates that the pressing member 230 has the concave curved surface 230a. In the case of this embodiment, the period when the cam lobe member is in the second position is shown. Note that the vertical axis in FIG. 14 is the swing angle, which indicates the movement position of the cam lobe member 212 around the support shaft 218, which is 0 ° when the cam lobe member 212 is in the first position, and the cam lobe member is in the second position. Maximizes when in position.

  Further, not a valve spring for the valve V but a dedicated spring called a spring 222 is used for swinging the cam lobe member 212. Therefore, by selecting an elastic member having an appropriate elastic force as the spring 222, it is possible to improve the motion followability of the cam lobe member 212 when the engine speed is high. Moreover, in the said embodiment, although the two pressing members 230 were used with respect to the two cam lobe members 212, these pressing members may be comprised integrally and may be made into one member.

  The first embodiment has been described above, but various changes can be made. First, in the first embodiment, the support shaft 218 is related to the rear end portion 214 c of the main cam portion 214 of the cam lobe member 212. However, the support shaft 218 may be disposed at the distal end portion 214 b of the main cam portion 214. However, preferably, as in the first embodiment, the support shaft 218 is disposed at the rear end 216c of the cam lobe member. Due to the arrangement of the support shaft 218 at the rear end portion 216b, the movement relative to the cam base member 210 immediately before the cam lobe member 212 reaches the first position can be made more gradual than when the support shaft 218 is arranged at the front end portion 216b. Therefore, as described above, the collision of the stopper pin can be prevented more suitably.

  Further, in the above embodiment, the pin of the fixing device is made to act on the cam lobe member 212. However, since the main cam portion 214 and the pushing portion 216 are fixed to each other in the cam lobe member 212, the fixing device may be configured so that the pin of the fixing device acts on the pressing portion 216. The same applies to the spring 222. Further, in the fixing device 240, the cam lobe member 212 can swing when the hydraulic pressure is positively applied. However, the fixing device may be changed so that the cam lobe member 212 can swing when the hydraulic pressure is not actively applied. The number of pins for fixing one cam lobe member in the fixing device is not limited to three, and may be one, two, or four or more. Moreover, in the said embodiment, the spring 222 was attached to the position opened outside the axial direction edge part of the cam unit CU. However, the spring 222 may be disposed inside the cam unit CU or may be disposed at any other location. As the spring 222, various types of springs such as a torsion spring and a coil spring, which are elastic members (biasing members), may be used.

  Further, in the above embodiment, the concave curved surface 230 a of the pressing member 230 extends in a predetermined angle range of about 30 ° around the axis of the camshaft S. However, the region where the concave curved surface 230a extends is not limited to an angle of 30 °, may correspond to an angle range smaller than 30 °, and may be expanded to an angle range larger than 30 °. Good. FIG. 15 schematically shows a pressing member 230 ′ in which the region where the concave curved surface 230 a extends corresponds to an angle range of about 180 °. FIG. 15 shows where the cam lobe member 212 moves in the order of (e-1) to (e-5). In FIG. 15, the movement of the pushing portion 216 of the cam lobe member 212 relative to the pressing member 230 ′ is shown, and the main cam portion 214 integrated with the pushing portion 216 is also shown for easy understanding. From FIG. 15, it is clear that the concave curved surface 230a is far larger than the case where the cross-sectional shape of the tip portion of the pressing member 230 is a circle indicated by a broken line. The swing angle of the cam lobe member 212 in the pressing member 230 ′ is shown in FIG. Increasing the angle range of the concave curved surface of the pressing member can further extend the period during which the cam lobe member 212 can be fixed, as indicated by arrows in FIG.

  Moreover, although the pressing member 230 of the said embodiment was fixed on the cylinder head, it may be urged | biased by the camshaft side by the further biasing member (or elastic member). In this case, the further biasing member is configured to exert a biasing force larger than the biasing force by the spring 222 on the cam lobe member 212 via the pressing member 230.

  In the first embodiment, the five sub cam base members 210s are independent members and are connected to each other. However, some or all of the sub cam base members 210s may be integrally formed from the beginning.

  Next, a second embodiment of the present invention will be described. In the second embodiment, the variable valve operating apparatus of the present invention is applied to each of the intake valve and the exhaust valve. Only the characteristic configuration of the second embodiment will be described below. Constituent elements corresponding to the constituent elements already described are denoted by the same reference numerals, and redundant description thereof is omitted.

  In the first embodiment, the cam base member 210 has an outer peripheral surface in the shape of the base circle portion BC, and the lift amount of the valve by the cam base member 210 is zero. However, the cam base member may have an outer surface corresponding to a lift amount (first lift amount) that is smaller than the lift amount (second lift amount) by the cam lobe member 212 but is not zero. The cam base member 210 is configured to realize the above. FIG. 17A is a graph showing the lift curve EV of the exhaust valve and the lift curve IV of the intake valve on the same time axis. Note that the lift curve EV of the exhaust valve and the lift curve IV of the intake valve may partially overlap or may not overlap.

  FIG. 17A shows two lift curves EV1 and EV2 of the exhaust valve. A lift curve EV1 indicated by a solid line is a lift curve when the rocker arm is driven by the cam lobe member 212, and a lift curve EV2 indicated by a broken line is a lift curve when the rocker arm is driven by the outer surface of the cam base member 210. is there. FIG. 17B shows the relationship between the cam base member 210 and the cam lobe member 212 of the cam unit for the exhaust valve having a configuration adapted to these. In FIG. 17B, the reference base circle is indicated by a broken line, and the cam base member 210 has a shape corresponding to a relatively small lift curve EV2. The cam lobe member 212 is represented such that the main cam portion 214 protrudes from the cam base member 210.

  FIG. 17 (a) shows two lift curves IV1 and IV2 of the intake valve. A lift curve IV1 indicated by a solid line is a lift curve by the cam lobe member 212, and a lift curve IV2 indicated by a broken line is a lift curve by the outer surface of the cam base member 210. FIG. 17C shows the relationship between the cam base member and the cam lobe member of the cam unit for the intake valve having a configuration adapted to these. In FIG. 17C, the reference base circle is indicated by a broken line, and the cam base member 210 has a shape corresponding to a relatively small lift curve IV2. The cam lobe member 212 is arranged so that the main cam portion partially protrudes from the cam base member 210.

  As shown in FIG. 17A, the two lift curves EV1 and EV2 of the exhaust valve overlap (or match) on the closing side. Therefore, when the cam lobe member is in the protruding position, the closed side portion of the main cam portion 214 of the cam lobe member 212 coincides with the outer surface of the cam base member 210 when viewed from the axial direction of the cam shaft S. Similarly, as shown in FIG. 17A, the two lift curves IV1 and IV2 of the intake valve overlap (or match) on the opening side, and the opening side portion of the main cam portion 214 of the cam lobe member 212 at the protruding position. Corresponds to the outer surface of the cam base member 210 when viewed from the axial direction of the camshaft S (see FIG. 17C).

  Here, the relationship between the cam base member 210 and the cam lobe member 212 of the cam unit of the exhaust valve is shown in FIG. 18A shows a state in which the cam lobe member 212 is in the second position with respect to the cam base member 210, and FIG. 18B shows a state in which the cam lobe member 212 is in the first position with respect to the cam base member 210. Show. As shown in FIG. 18, the support shaft 218 is disposed at the tip end portion 214 b of the two end portions of the main cam portion 214 of the cam lobe member 212. In addition, the arrow in FIG. 18 shows the rotation direction of a cam shaft. As described above, with respect to the exhaust valve, the lift curve by the cam lobe member 212 and the lift curve by the cam base member 210 overlap on the closed side (see FIG. 17A), and the support shaft 218 is connected to the main cam portion 214 of the cam lobe member 212. It arrange | positions at the edge part (tip part) 214b by the side of opening (refer FIG. 18).

  Regarding the intake valve, since the lift curve by the cam lobe member 212 and the lift curve by the cam base member 210 overlap on the opening side, the support shaft 218 is not shown, but the end portion on the closing side of the main cam portion 214 of the cam lobe member 212 (that is, (Rear end portion) 214c.

  The installation position of the support shaft 16 is selected such that the swing angle (corresponding to the lost angle α) of the cam lobe member 212 around the support shaft 218 between the first position and the second position is relatively small. (Refer to angle β in FIG. 18A <angle γ in FIG. 19A). (Thus, the range of the reciprocating motion of the cam lobe member 212 relative to the cam base member 210 is relatively small). Therefore, it is possible to more suitably switch the lift amount for each valve even in an operation region where the engine speed is higher.

  However, as shown in FIG. 19 (FIGS. 19A and 19B correspond to FIGS. 18A and 18B, respectively), the camshaft unit of the exhaust valve has a camshaft member 212. The main cam portion 214 may be configured to be disposed at an end portion (that is, a rear end portion) 214c on the closing side. Further, the cam unit of the intake valve may be configured such that the support shaft is disposed at the tip of the cam lobe member.

  As mentioned above, although this invention was demonstrated based on two embodiment, this invention accepts another form. In the first and second embodiments, the cam lobe member is configured to move around the support shaft positioned at the front end portion or the rear end portion of the main cam portion. However, the variable valve mechanism according to the present invention may be configured such that the cam lobe member moves linearly between the first position and the second position in a direction perpendicular to the axis of the camshaft.

  The embodiment of the present invention is not limited to the above-described embodiment, and includes all modifications, applications, and equivalents included in the concept of the present invention defined by the claims. Therefore, the present invention should not be construed as being limited, and can be applied to any other technique belonging to the scope of the idea of the present invention.

210 Cam base member 212 Cam lobe member 214 Main cam portion 216 Extruding portion 218 Support shaft 222 Spring 230 Pressing member 240 Fixing device (fixing mechanism)

Claims (5)

A variable valve operating apparatus for an internal combustion engine that makes the lift amount of an engine valve variable,
A cam base member provided on the cam shaft and rotating according to the rotation of the cam shaft;
A cam lobe member movably provided with respect to the cam base member, comprising: a main cam portion; and an extrusion portion positioned so as to be displaced in an axial direction of the cam shaft with respect to the main cam portion, The cam base member is movable with respect to the cam base member integrally with the main cam portion, and the cam lobe member is movable with respect to the cam base member between a first position and a second position, and the cam lobe member is in the first position. When the cam lobe member is at the second position, the push portion of the cam lobe member protrudes from the cam base member. When the cam lobe member is at the second position, the main cam portion protrudes from the cam base member. A cam lobe member;
An urging member for urging the cam lobe member toward the first position;
A pressing member that acts on the pushing portion of the cam lobe member and moves the cam lobe member from the first position side toward the second position side;
A fixing mechanism that enables the cam lobe member to be fixed to the cam base member when the cam lobe member is in the second position;
A variable valve operating device for an internal combustion engine.   2. The variable valve operating apparatus for an internal combustion engine according to claim 1, wherein the pressing member has a concave curved surface capable of acting on the pushing portion of the cam lobe member.   The variable valve operating apparatus for an internal combustion engine according to claim 1, further comprising a restriction mechanism for restricting a movement range of the cam lobe member relative to the cam base member. The main cam portion of the cam lobe member is formed in a substantially U shape so as to have a front end portion located in front of the rotation direction of the camshaft and a rear end portion located rearward in the rotation direction, It is movable around the fulcrum member with respect to the cam base member, and the fulcrum member is disposed at one of the front end and the rear end.
The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 3. The main cam part and the pushing part are connected via the fulcrum member,
The extruding portion has a first bending portion closer to the fulcrum member on the outer circumferential surface, and a second bending portion that is further away from the fulcrum member than the first bending portion, and the first bending portion is The variable valve operating apparatus for an internal combustion engine according to claim 4, having a shape different from that of the second bending portion.

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