JP5924305B2 - Variable valve operating device for internal combustion engine - Google Patents

Description

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

  In the variable valve operating device of Patent Document 1, the movable cam is advanced and retracted from the camshaft by the action of hydraulic pressure. When the movable cam is locked at a position protruding from the camshaft and the camshaft rotates, the movable cam drives the valve.

JP 2001-329819 A

  As described above, when the position of the movable cam is switched using the hydraulic pressure, there is a possibility that the switching of the position of the movable cam may be difficult when the hydraulic pressure is low and the hand is used. For example, as a case where the oil pressure is likely to drop, it is immediately after starting the internal combustion engine or at a low speed.

  An object of the present invention is to provide a variable valve operating apparatus for an electric internal combustion engine.

  The object is to provide a cam base portion that rotates integrally with the cam shaft, and a cam lobe portion that is connected to the cam base portion so as to be swingable between a high position protruding from the outer periphery of the cam base portion and a low position lower than the high position. A biasing member that biases the cam lobe portion to the high position, a cam follower that biases the cam lobe portion to the low position, a control shaft that rotates with the cam shaft and penetrates the cam base portion, and the control shaft An actuator for moving the cam base part relative to the cam base part, and a lock mechanism for locking or unlocking the cam lobe part in the high position according to the relative movement of the control shaft. An interlocking member held by the cam base and interlocking with relative movement of the control shaft, and a lock member held by a holding hole of the cam lobe. The member is achieved by a variable valve operating device for an internal combustion engine that engages and disengages the cam base portion in conjunction with the interlocking member while being held in the holding hole when the cam lobe portion is in the high position. it can.

  The locking mechanism includes a first spring disposed between the locking member and the interlocking member when the cam lobe portion is locked, and the interlocking member and the locking member are interposed via the first spring. The structure which interlock | cooperates may be sufficient.

  The lock mechanism may include a pressing member disposed between the first spring and the interlocking member.

  The lock mechanism may include a second spring that is held by the cam base portion and urges the lock member to engage the cam base portion when the cam lobe portion is in the high position. .

  The interlocking member may be configured to move in a radial direction of the control shaft in accordance with relative movement of the control shaft.

  The control shaft may include a concave portion or a convex portion in which the interlocking member slides according to relative movement in the axial direction or the circumferential direction of the control shaft.

    While the camshaft is rotating in the unlocked state, the cam lobe portion swings between the low position and the high position according to the urging force of the urging member and the cam follower. Good.

  The structure which does not provide the mechanism which locks the said cam lobe part in the said low position may be sufficient.

  The cam lobe portion includes first and second cam lobe portions, the cam follower includes first and second cam followers for urging the first and second cam lobe portions, respectively, and the lock mechanism includes the first and second cam lobe portions. The first and second lock mechanisms each lock the second cam lobe part, and the first and second lock mechanisms lock both the first and second cam lobe parts according to the relative movement of the control shaft. Alternatively, the configuration may be such that either one of the locks is released.

  The first and second lock mechanisms may be configured to unlock both the first and second cam lobes according to relative movement of the control shaft.

  A variable valve operating device for an electric internal combustion engine can be provided.

FIG. 1 is an external view of the variable valve operating apparatus of the present embodiment. FIG. 2 is an external view of the variable valve operating apparatus of the present embodiment. 3A and 3B are sectional views of the cam unit as seen from the axial direction. 4A and 4B are cross-sectional views showing the internal structure of the cam unit. 5A to 5C are explanatory diagrams of locking and unlocking of the cam lobe portion. 6A and 6B are explanatory diagrams of locking and unlocking the cam lobe portion. FIG. 7 is an explanatory diagram of a variable valve operating apparatus according to a first modification. FIG. 8 is an explanatory diagram of locking and unlocking of the first modified example. FIG. 9 is an explanatory diagram of a second modification. FIG. 10 is an explanatory diagram of a third modification. 11 is a cross-sectional view taken along the line BB of FIG. 10 showing only the control shaft. FIG. 12 is an explanatory diagram of a fourth modification. 13 is a cross-sectional view taken along the line CC of FIG. 12 showing only the control shaft. FIG. 14 is an explanatory diagram of a fifth modification.

  1 and 2 are external views of an electric variable valve operating apparatus 1 according to this embodiment. The variable valve operating apparatus 1 is employed in an internal combustion engine mounted on a vehicle or the like. The variable valve operating apparatus 1 includes a camshaft S and a cam unit CU provided on the camshaft S. The camshaft S includes a portion SA connected to one end of the cam unit CU and a portion SB connected to the other end of the cam unit CU. The camshaft S is rotated by power from the internal combustion engine. When the cam unit CU rotates together with the camshaft S, the valve V is lifted via the rocker arm R. The valve V is an intake valve or an exhaust valve of the internal combustion engine.

  The cam unit CU includes a cam base portion 10 having a diameter larger than that of the cam shaft S and connected to the portions SA and SB of the cam shaft S, and two cam lobe portions 20 connected to the cam base portion 10. The cam base portion 10 has a substantially cylindrical shape, and has a substantially circular base circle portion 11 when viewed from the axial direction of the camshaft S (hereinafter simply referred to as the axial direction). The base circle portion 11 corresponds to the outer peripheral surface of the cam base portion 10. The two cam lobes 20 are arranged at a predetermined interval in the axial direction. The two cam lobes 20 push the two rocker arms R and lift the two valves V, respectively. The axial thickness of the cam base portion 10 is thicker than the axial thickness of the cam lobe portion 20.

  As shown in FIG. 2, the cam base portion 10 has a recess 10 </ b> H formed between two cam lobe portions 20. The recess 10 </ b> H is formed between portions where the two rocker arms R contact the cam base portion 10. The recess 10H does not contact the rocker arm R. The two support shafts 33 penetrate the two cam lobe parts 20 together with the cam base part 10 in the axial direction. The cam lobe portion 20 swings with respect to the cam base portion 10 with the support shaft 33 as a fulcrum. The cam lobe portion 20 can swing between a high position that protrudes from the base circle portion 11 of the cam base portion 10 to the maximum and a low position that does not protrude from the base circle portion 11. The end of the support shaft 33 is exposed in the recess 10H. Each of the two cam lobes 20 is provided with a stopper pin 34P.

  In the recess 10 </ b> H of the cam base 10, two springs 34 s are wound around the end of the support shaft 33. One end of the spring 34s pushes the inner surface of the recess 10H, and the other end of the spring 34s pushes the stopper pin 34P. That is, the spring 34s biases the stopper pin 34P so as to separate from the recess 10H. As a result, the cam lobe portion 20 is biased so as to protrude from the cam base portion 10. The spring 34s is an example of an urging member.

  1 and 2, the two cam lobes 20 are in a high position. In this embodiment, when the cam lobe 20 is locked at the high position, the cam lobe 20 drives the rocker arm R to lift the valve V. When the lock at the high position of the cam lobe 20 is released, the cam lobe 20 contacts the rocker arm R and receives the reaction force of the rocker arm R, and resists the urging force of the spring 34s to the low position side. Moving. Therefore, in this case, the valve V does not lift. When the cam lobe 20 is retracted from the rocker arm R in the unlocked state, the cam lobe 20 moves to the high position side according to the urging force of the spring 34s. When the cam lobe 20 is in the high position with the lock released, the cam lobe 20 receives the reaction force from the rocker arm R again by the rotation of the cam shaft S and moves to the low position. Thus, the cam lobe portion 20 swings between the high position and the low position as the camshaft S rotates in the unlocked state.

  3A and 3B are sectional views of the cam unit CU as seen from the axial direction. 3A shows the cam lobe 20 in the high position, and FIG. 3B shows the cam lobe 20 in the low position. The cam lobe portion 20 has a substantially U shape or a substantially L shape that avoids a control shaft 40 described later. A support shaft 33 passes through the base end side of the cam lobe portion 20. 3A and 3B, the camshaft S rotates in the clockwise direction. Along with this, the cam base 10 and the cam lobe 20 also rotate clockwise. A long hole 14 through which the stopper pin 34P passes is formed in the cam base portion 10. The long hole 14 regulates the movement range of the stopper pin 34 </ b> P that moves along with the rocking of the cam lobe 20, thereby restricting the rocking range of the cam lobe 20.

  4A and 4B are cross-sectional views showing the internal structure of the cam unit CU. 4A and 4B, the two cam lobes 20 are both in a lifted state. 4A and 4B correspond to the AA cross-sectional view of FIG. 3A. As shown in FIGS. 4A and 4B, the cam unit CU is formed symmetrically in the axial direction at the center of the cam unit CU in the axial direction. Therefore, in the following description, one of the two cam lobes 20 will be described. The cam base portion 10 is formed with a slit 12 that can accommodate the cam lobe portion 20. A control shaft 40 is arranged coaxially with the camshaft S in the camshaft S and the cam base portion 10. The control shaft 40 rotates together with the cam shaft S and the cam unit CU. The control shaft 40 is an example of a control shaft.

  The drive mechanism D converts the rotational motion of the actuator AC into a translational motion and reciprocates the control shaft 40 in the axial direction. The drive mechanism D is connected to the end of the control shaft 40 exposed from the camshaft S. The drive mechanism D is, for example, a differential roller gear, but is not limited thereto. The control shaft 40 moves relative to the camshaft S and the cam unit CU in the axial direction while rotating together with the camshaft S and the cam unit CU. When the actuator AC stops rotating, the control shaft 40 stops at a predetermined relative position with respect to the cam base portion 10. Actuator AC is controlled by ECU5. The ECU 5 includes a CPU, a ROM, a RAM, and the like, and controls the operation of the entire internal combustion engine. The ROM stores a program for executing control described later.

  The cam base portion 10 holds the pins 16P and 17P and the taper pin M so as to be movable by a predetermined range. Each of the two cam lobes 20 holds a pin 26P. The pin 26P is an example of a lock member. FIG. 4B is a diagram in which the pins 16P and the like are omitted. The cam lobe portion 20 has a free end portion away from the base end portion through which the support shaft 33 passes, and a hole 26 holding a pin 26P is formed on the free end portion side of the cam lobe portion 20. The hole 26 penetrates the cam lobe 20 in the axial direction. The hole 26 is an example of a holding hole.

  A hole 16 communicating with the slit 12 is formed in the cam base portion 10. The hole 16 is formed on the same side with respect to the slit 12. The hole 16 extends in the axial direction and has a bottom surface. In the hole 16, a pin 16P is accommodated. A spring 16S connected to the pin 16P is disposed between the bottom surface of the hole 16 and the pin 16P. The spring 16S biases the pin 16P toward the cam lobe portion 20. The spring 16S is an example of a second spring.

  A hole 17 is formed in the cam base portion 10 so as to face the hole 16 through the slit 12. In the hole 17, a pin 17P is accommodated. The hole 17 is located coaxially with the hole 16. The hole 17 extends in the axial direction. The pin 17P is in contact with the taper pin M. The pin 17P is an example of a pressing member. A spring 17S is fixed to the end of the pin 17P on the cam lobe 20 side. One end of the spring 17S is fixed to the pin 17P, but the other end is a free end. The spring 17S is an example of a first spring. The pin 26P, the first spring 17S, the second spring 16S, and the like are an example of a lock mechanism that locks the cam lobe 20 at a high position.

  Two opposing holes 17 on both sides communicate with the communication space 18. The communication space 18 is a space that is positioned substantially at the center of the length of the cam base portion 10 in the axial direction and extends in the radial direction of the camshaft S (hereinafter simply referred to as the radial direction). An opening 19 that communicates with the communication space 18 is also formed. The taper pin M is slidably fitted into the opening 19 to allow movement in the radial direction in the communication space 18 and to restrict movement in the axial direction and the circumferential direction. The taper pin M is an example of an interlocking member. The communication space 18 is open to the outer peripheral portion of the cam base portion 10. Thereby, for example, lubricating oil can be supplied from the outer periphery of the cam base portion 10 to the inside through the communication space 18.

  A concave portion 41 that supports the taper pin M is formed on the outer peripheral portion of the control shaft 40. The recess 41 includes a bottom surface 42 that is parallel to the axial direction, and an inclined surface 43 that extends from the bottom surface 42 to be continuous with the outer peripheral surface of the control shaft 40. The corner portion of the taper pin M is tapered so that it can easily slide on the inclined surface 43 in accordance with the relative movement of the control shaft 40 in the axial direction.

  When the cam lobe 20 is at a high position, the holes 16, 17, and 26 are aligned in the axial direction, and the pins 16P, 17P, and 26P are aligned in the axial direction. In other words, the swing range of the cam lobe portion 20 is defined by the long hole 14 engaged with the stopper pin 34P so that the cam lobe portion 20 is positioned at such a position at one end of the swing range. Due to the biasing force of the spring 16S, the pin 16P is inserted into the holes 16 and 26 in common, and the pin 26P is inserted into the holes 26 and 17 in common. Thereby, the cam lobe part 20 is locked to the cam base part 10 at a high position.

  Next, the locking and unlocking of the cam lobe 20 will be described in detail. 5A to 6B are explanatory diagrams of locking and unlocking of the cam lobe portion 20. Since the two cam lobes 20 are locked and unlocked in the same manner, FIGS. 5A to 6B show only one cam lobe 20 side. From the state shown in FIG. 4A, when the control shaft 40 is moved relative to the cam base portion 10 to the right in the axial direction by the actuator AC, the taper pin M moves on the inclined surface 43 as shown in FIG. 5A. It moves on the outer peripheral surface of the control shaft 40. As a result, the taper pin M moves radially outward. When the taper pin M moves in the radial direction, the pin 17P is pushed toward the cam lobe 20 side. Thereby, the spring 17S is compressed between the pins 17P and 26P.

  Next, as shown in FIG. 5B, the pin 26 </ b> P moves away from the taper pin M by the urging force of the spring 17 </ b> S, and the pin 26 </ b> P is detached from the hole 17. As the pin 26P moves, the pin 16P moves to the bottom surface side of the hole 16 and the spring 16S is compressed. That is, the pins 16P, P, and 26P are accommodated in the holes 16, 17, and 26, respectively. Thereby, the lock | rock of the cam lobe part 20 is cancelled | released in a high position.

  When the camshaft S rotates with the cam lobe 20 unlocked, the cam lobe 20 receives a reaction force from the rocker arm R. As a result, as shown in FIG. 5C, the cam lobe 20 moves to a low position against the urging force of the spring 34s. In other words, the urging force of the spring 34s is set to such an extent that the cam lobe 20 can be moved to a low position only by the reaction force from the rocker arm R in a state where the lock of the cam lobe 20 is released. In this way, the rocker arm R urges the cam lobe portion 20 that has been unlocked to the low position side. As the cam lobe 20 moves from the high position to the low position, the other end of the pin 16P and the spring 17S comes into sliding contact with the cam lobe 20. When the cam lobe 20 is in the low position, the cam lobe 20 is located between the spring 17S and the pin 16P. The rocker arm R is an example of a cam follower for driving a bubble. The cam follower may be a valve lifter that is directly driven by the cam.

  In the unlocked state, the cam lobe 20 is in the low position as shown in FIG. 5C while receiving the reaction force from the rocker arm R. While the cam lobe 20 is retracted from the rocker arm R as the camshaft S rotates, it moves to a higher position by the biasing force of the spring 34s. That is, in the unlocked state, the cam lobe 20 repeats the state shown in FIGS. 5B and 5C while the camshaft S is rotating. Even when the cam lobe 20 is moved from the low position to the high position after the lock is released, the force balance with the springs 16S and 17S is maintained when the taper pin M is positioned radially outward. Thus, the pin 26P does not engage with the hole 17.

  Next, a case where the lock is performed from the unlocked state will be described. For example, when the cam lobe 20 is in the low position and the control shaft 40 moves relative to the left in the axial direction, the taper pin M receives the urging force of the spring 17S via the pin 17P. The bottom surface 42 of the shaft 40 is slid and supported by the recess 41. That is, the taper pin M moves inward in the radial direction. Along with this, the pin 17P moves to the taper pin M side by the urging force of the spring 17S. Further, the spring 17S extends so as to approach the natural length by the movement of the pin 17P. Next, as shown in FIG. 6B, when the cam lobe portion 20 is moved to the high position by the urging force of the spring 34s, the spring 16S is extended and the spring 17S is contracted due to the balance of the urging forces with the springs 16S and 17S. Accordingly, the pin 26P is inserted into the holes 26 and 17 in common, and the pin 16P is inserted into the holes 16 and 26 in common. Thereby, it will be in the state of FIG. 4A again, and the cam lobe part 20 will be locked in a high position.

  Thus, in the apparatus of the present embodiment, the cam lobe portion 20 can be locked at a high position without using hydraulic pressure, and the valve V lift state can be switched. For this reason, the lift state of the valve can be switched regardless of the hydraulic pressure, and the disadvantages associated with using the hydraulic pressure can be eliminated. For example, in the apparatus of this embodiment, the lock can be switched without depending on the oil pressure when the oil pressure decreases. Further, an oil pump with a small capacity can be adopted, and in this case, fuel efficiency is improved.

  Next, the reason why the spring 17S is provided between the pins 17P and 26P, in other words, between the taper pin M and the pin 26P will be described. When the cam lobe portion 20 is locked at the high position, the cam lobe portion 20 periodically receives a reaction force from the rocker arm R. The reaction force received by the cam lobe portion 20 acts on the pins 16P and 26P. Here, the pin 16P is engaged with the holes 16 and 26, and the pin 26P is engaged with both the holes 16 and 17. For this reason, while the cam lobe 20 receives the reaction force from the rocker arm R, the pins 16P and 26P receive the force on the radially inner side and are difficult to move in the axial direction. Therefore, for example, when the pin 26P is moved directly by the pin 17P and the taper pin M without the spring 17S interposed, the pins 16P and 26P do not move in the axial direction, and the taper pin M cannot move. There is a possibility that the control shaft 40 cannot move in the axial direction. Thereby, an excessive load may be applied to the actuator AC.

  However, by providing the spring 17S between the pins 26P and 17P, even if the pins 16P and 26P are difficult to move, the spring 17S is compressed as shown in FIG. Movement of the control shaft 40 is allowed. In this state, when the cam lobe 20 is retracted from the rocker arm R and the reaction force from the rocker arm R is reduced, the pins 26P and 16P are detached from the holes 17 and 26 according to the urging force of the spring 17S, respectively, and the cam lobe 20 is locked. Is released. Thereby, the load on the actuator AC is suppressed.

  In this embodiment, no mechanism is provided for locking the cam lobe 20 at a low position. For this reason, the structure is simplified. Further, when a mechanism for locking the cam lobe portion 20 at a low position is provided, in order to shift the valve V from the lift stop state to the lift state, it is necessary to first unlock the cam lobe portion 20 at the low position. . For this reason, the responsiveness of the cam lobe 20 may be lowered. In this embodiment, the cam lobe portion 20 is not locked at the low position, and the cam lobe portion 20 reciprocates between the high position and the low position as the cam shaft S rotates as described above. Therefore, the cam lobe 20 can be locked at a high position at an early stage, and the responsiveness of the transition from the lift stop state to the lift state is improved.

  In this embodiment, the taper pin M is moved in the radial direction by utilizing the sliding of the taper pin M on the recess 41 of the control shaft 40. However, the present invention is not limited to such a configuration. For example, a convex portion may be provided on the outer peripheral surface of the control shaft 40, and the taper pin M may be moved in the radial direction using the convex portion.

  As shown in FIGS. 3A and 3B, the free end of the cam lobe portion 20 is separated from the base end side of the cam lobe portion 20 in the reverse direction from the rotation direction of the camshaft S. Here, the base end side of the cam lobe portion 20 serves as a fulcrum for swinging by the support shaft 33. For this reason, it becomes easy for the cam lobe portion 20 to swing in the direction opposite to the rotation direction of the camshaft S due to the reaction force of the rocker arm R. This facilitates the movement of the cam lobe portion 20 from the low position to the high position in the unlocked state. Moreover, the load by the reaction force from the rocker arm R which the cam lobe part 20 receives when moving to a low position is reduced, and the durability of the cam lobe part 20 is ensured.

  The cam base portion 10 supports two cam lobe portions 20. For this reason, since the cam base part 10 has secured the length of the axial direction, the intensity | strength is ensured. In addition, since the cam base portion 10 is shared by the two cam lobe portions 20, the number of parts is reduced.

  Further, as described above, since the recess 10H in which the spring 34s is disposed is provided in a portion that does not contact the rocker arm R, this portion is effectively used. Since the spring 34s is disposed at a position retracted from the portion of the cam base portion 10 that contacts the rocker arm R, the cross-sectional area in the axial direction of the portion of the cam base portion 10 that contacts the rocker arm R is also secured. Thereby, the strength of the cam base portion 10 is also ensured.

  Next, a plurality of modifications will be described. In addition, about the structure same or similar to the said Example, the overlapping description is abbreviate | omitted by attaching | subjecting the same or similar code | symbol. FIG. 7 is an explanatory diagram of a variable valve operating apparatus according to a first modification. Two tapered blocks M1 and M2 arranged adjacent to each other are provided. Each of the taper blocks M1 and M2 has a substantially plate shape and is formed by dividing the above-described taper pin M into two. The taper blocks M1 and M2 are both slidably fitted into the opening 19 described above, and are allowed to move in the radial direction and are restricted from moving in the axial direction and the circumferential direction. The taper blocks M1 and M2 are examples of interlocking members.

  The taper blocks M1 and M2 are in contact with the two pins 17P, respectively. The recess 41a of the control shaft 40a has a different depth. Specifically, the concave portion 41a includes a deepest bottom surface 42a, an inclined surface 43a continuous from the bottom surface 42a, and a bottom surface 44a continuous to the inclined surface 43a and shallower than the bottom surface 42a. The corner portions of the taper blocks M1 and M2 are tapered so that the control shaft 40a can easily slide on the inclined surface 43a in accordance with the relative movement in the axial direction.

  8A to 8C are explanatory diagrams of lock and unlock of the first modified example. As shown in FIGS. 7 and 8A, when both the tapered blocks M1 and M2 are supported by the bottom surface 42a, the two cam lobes 20 are locked at a high position. As shown in FIG. 8B, when the control shaft 40a is relatively moved in the axial direction and only the taper block M1 is supported on the bottom surface 44a, only the taper block M1 moves radially outward and the left cam lobe portion 20 lock is released. As shown in FIG. 8C, when the control shaft 40a is further moved relative to the axial direction, both the tapered blocks M1 and M2 are supported on the bottom surface 44a, and the two cam lobes 20 are unlocked.

  Thus, only one of the two cam lobes 20 can be unlocked. That is, the lift of only one of the two valves V driven by the two cam lobes 20 can be stopped. For example, the lift of one of the two intake valves can be stopped. Thereby, a swirl flow can be generated in the cylinder. Therefore, for example, a swirl control valve for generating a swirl flow in the cylinder can be eliminated.

  In addition, you may provide the convex part provided with two upper surfaces from which height differs instead of the recessed part 41a.

  FIG. 9 is an explanatory diagram of a second modification. In the recess 41b, bottom surfaces 44b and 46b having a shallower bottom than the bottom surface 42b are formed on both sides in the axial direction of the bottom surface 42b having the deepest bottom. Further, the inclined surface 43b is continuous between the bottom surfaces 42b and 44b, and similarly, the inclined surface 45b is continuous between the bottom surfaces 42b and 46b. Further, the corners of the tapered blocks M1b and M2b are tapered so that they can easily slide on the inclined surfaces 43b and 45b.

  Since bottom surfaces 44b and 46b are formed on both sides of the bottom surface 42b, the control shaft 40b is moved to the right in the axial direction from the state shown in FIG. 9, and only the taper block M1b is moved radially outward to provide two cam lobes. Only one of the portions 20 can be unlocked. Further, from the state shown in FIG. 9, the control shaft 40b can be moved to the left in the axial direction, and only the taper block M2b can be moved radially outward to unlock only the other of the two cam lobes 20. Thus, the lift of only one side of the two cam lobes 20 can be stopped, or the lift of only the other side can be stopped. Thereby, a different swirl flow can be generated in the cylinder according to the operating state.

  FIG. 10 is an explanatory diagram of a third modification. The actuator AC can rotate the control shaft 40c in synchronization with the camshaft S or relatively via the drive mechanism Dc. By rotating the control shaft 40c at the same rotational speed as the camshaft S, the control shaft 40c can be rotated in synchronization with the camshaft S. In addition, the control shaft 40c can be rotated relative to the camshaft S by rotating the control shaft 40c faster or slower than the camshaft S. Specifically, based on the output of the angle sensor that detects the respective rotation angles of the camshaft S and the actuator AC, the ECU 5c detects the rotation speed and phase of the control shaft 40c and the camshaft S, and detects this. The actuator AC is rotated based on the result. An eccentric portion 41c that supports the taper pin M is formed on the control shaft 40c.

  11 is a cross-sectional view taken along the line BB of FIG. 10 showing only the control shaft 40c. The rotation center 40cp of the control shaft 40c and the center 41cp of the eccentric part 41c are displaced from each other. When the control shaft 40c rotates relative to the cam base portion 10 or the like, the height from the rotation center 40cp of the portion on the outer peripheral surface of the eccentric portion 41c with which the taper pin M is in sliding contact changes. Thereby, the taper pin M moves to radial direction, and the lock | rock of the cam lobe part 20 can be cancelled | released. The taper pin M is in sliding contact with the outer peripheral surface of the eccentric portion 41c. The diameter of the eccentric part 41c is smaller than the diameter of the other part of the control shaft 40c, and the eccentric part 41c is concave as seen from the radial direction as shown in FIG. As shown in FIG. 10, the eccentric part 41c is an example of a recessed part.

  The control shaft 40c may reciprocate within a predetermined range or may always rotate in the same direction. In any case, since the taper pin M reciprocates in the radial direction, it can be locked and released.

  The configuration in which the taper pin M is moved in the radial direction according to the relative rotation of the control shaft 40c may not be the outer peripheral surface of the eccentric circle as shown in FIG. That is, a surface in which the height from the rotation center 40 cp is different in the circumferential position is formed only in a predetermined angular range on the outer peripheral surface of the control shaft 40 c, and the taper pin M is slid on this surface. You may let them. Further, this surface may be a curved surface intersecting the circumferential line segment or a flat surface. Moreover, you may provide the eccentric part with a larger diameter than the diameter of the base part of a control shaft instead of the eccentric part 41c. In this case, the eccentric portion is convex when viewed from the radial direction.

  FIG. 12 is an explanatory diagram of a fourth modification. The two taper pins M1d and M2d are respectively supported by eccentric portions 41d and 42d of the control shaft 40d. The control shaft 40d also rotates relative to the cam base portion 10 and the like by the actuator AC and the drive mechanism Dc described above.

  13 is a cross-sectional view taken along the line CC of FIG. 12 showing only the control shaft 40d. As shown in FIG. 13, the center 41dp of the eccentric part 41d and the center 42dp of the eccentric part 42d are deviated from the rotation center 40dp of the control shaft 40d. The centers 41dp and 42dp are also offset from each other. Specifically, the line connecting the centers 41dp and 42dp is positioned so as to be separated from the rotation center 40dp.

  As shown in FIG. 13, in the region R1, the outer peripheral surfaces of the eccentric portions 41d and 42d are located closest to the substantially overlapping rotation center 40dp. In the region R2 located on the opposite side via the region R1 and the rotation center 40dp, the outer peripheral surfaces of the eccentric portions 41d and 42d substantially overlap, and also substantially overlap the outer peripheral surface of the rotation center 40dp. That is, in the region R2, it is at a position farthest from the rotation center 40dp. In the region R3, the outer peripheral surfaces of the eccentric portions 41d and 42d do not overlap, the outer peripheral surface of the eccentric portion 41d is separated from the rotation center 40dp, and the outer peripheral surface of the eccentric portion 42d is close to the rotation center 40dp. In the region R4 located on the opposite side via the region R3 and the rotation center 40dp, the outer peripheral surfaces of the eccentric portions 41d and 42d do not overlap, and the outer peripheral surface of the eccentric portion 41d is close to the rotation center 40dp, and the outer peripheral surface of the eccentric portion 42d Is away from the center of rotation 40dp.

  When the taper pins M1d and M2d are supported in the region R1, the two cam lobe portions 20 are both locked at the radially inner side. When the taper pins M1d and M2d are supported in the region R2, both are located radially outward and the two cam lobes 20 are unlocked. When the taper pins M1d and M2d are supported in the region R3, only the taper pin M1d is positioned on the radially outer side, and only the lock of the left cam lobe portion 20 shown in FIG. 12 is released. When the taper pins M1d and M2d are supported in the region R4, only the taper pin M2d is positioned radially outward and only the lock of the right cam lobe portion 20 shown in FIG. 12 is released. As described above, even when the control shaft 40d rotates relative to the cam base 10 or the like, only one of the two cam lobes 20 can be unlocked, and only the other can be unlocked. Can also be released.

  Moreover, you may provide the eccentric part larger in diameter than the diameter of the base part of a control shaft instead of the eccentric parts 41d and 42d. In this case, the eccentric portion is convex when viewed from the radial direction.

  FIG. 14 is an explanatory diagram of a fifth modification. The control shaft 40 relatively moves in the axial direction. The control shaft 40 moves in the axial direction. Cam lobes 20e and 20 are slidably coupled to the cam base 10e. The pins 17P and 26P on the cam lobe 20e side, the hole 16e, and the like are further away from the control shaft 40 than the pins 17P and the like on the cam lobe 20 side. As described above, the position in the radial direction differs between the pin 26P on the cam lobe 20e side and the pin 26P on the cam lobe 20 side.

  When the control shaft 40 is moved in the axial direction from the state shown in FIG. 14, the taper pin M gradually moves radially outward. In the process in which the taper pin M is moving radially outward, the pin 17P on the cam lobe 20 side is first pushed in the axial direction, and the lock of the cam lobe 20 is released. Further, when the control shaft 40 moves in the axial direction and the taper pin M moves outward in the radial direction, the cam lobe portion 20e is unlocked. Thus, even with a single taper pin M, the lock of only the cam lobe 20 out of the two cam lobes 20e, 20 can be released. Thereby, the number of parts is reduced.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

  In the present embodiment, the case where the cam lobe portion 20 is in a position where it does not protrude from the cam base portion 10 is described as a low position. However, the present invention is not limited to this. For example, the cam lobe portion 20 has a high position that protrudes from the base circle portion 11 of the cam base portion 10 and a low position that protrudes from the base circle portion 11 although the protrusion amount is smaller than the first high position. You may rock | fluctuate between. In this case, when the lock is released, the valve is driven with a small lift amount.

  The cam base portion 10 may be molded integrally with the cam shaft, or may be joined after being molded separately as in this embodiment.

  The pin 16P may not be provided, and the pin 26P may be directly biased by the spring 16S.

1 Variable valve gear 5 ECU
S Camshaft R Rocker arm (Cam follower)
V valve (cam follower)
M Taper pin (interlocking member)
10 Cam base portion 11 Base circle portion 12 Slit 16S Spring (second spring)
17P pressing member 17S spring (first spring)
20 Cam lobe 26 hole (holding hole)
26P pin (locking member)
34s Spring (biasing member)
40 Control shaft (control shaft)
41, 41a, 41b Recessed part 41c, 41d, 42d Eccentric part (recessed part)

Claims (10)

A cam base that rotates integrally with the camshaft;
A cam lobe connected to the cam base so as to be swingable between a high position protruding from the outer periphery of the cam base and a low position lower than the high position;
A biasing member that biases the cam lobe portion to the high position;
A cam follower for urging the cam lobe portion to the low position;
A control shaft that rotates with the camshaft and penetrates the cam base;
An actuator for moving the control shaft relative to the cam base;
A lock mechanism for locking the cam lobe portion at the high position or releasing the lock according to relative movement of the control shaft,
The locking mechanism includes an interlocking member that is held by the cam base portion and interlocked with relative movement of the control shaft, and a locking member that is held by a holding hole of the cam lobe portion,
When the cam lobe portion is at the high position, the lock member engages and disengages the cam base portion in conjunction with the interlocking member while being held in the holding hole. . The locking mechanism includes a first spring disposed between the locking member and the interlocking member when the cam lobe portion is locked,
The variable valve operating apparatus for an internal combustion engine according to claim 1, wherein the interlocking member and the lock member are interlocked via the first spring.   The variable valve operating apparatus for an internal combustion engine according to claim 2, wherein the lock mechanism includes a pressing member disposed between the first spring and the interlocking member.   4. The internal combustion engine according to claim 3, wherein the lock mechanism includes a second spring that is held by the cam base portion and urges the lock member to engage the cam base portion when the cam lobe portion is in the high position. Variable valve gear.   The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 4, wherein the interlocking member moves in a radial direction of the control shaft in accordance with relative movement of the control shaft.   6. The variable valve operating apparatus for an internal combustion engine according to claim 1, wherein the control shaft includes a concave portion or a convex portion in which the interlocking member slides in response to relative movement in the axial direction or circumferential direction of the control shaft. .   The cam lobe portion swings between the low position and the high position by the urging force of the urging member and the cam follower while the cam shaft is rotated in the unlocked state. The variable valve operating apparatus for any of the internal combustion engines.   The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 7, wherein a mechanism for locking the cam lobe portion at the low position is not provided. The cam lobe portion includes first and second cam lobe portions,
The cam follower includes first and second cam followers for urging the first and second cam lobes, respectively.
The locking mechanism includes first and second locking mechanisms that lock the first and second cam lobes, respectively.
The said 1st and 2nd lock mechanism locks both the said 1st and 2nd cam lobe part according to the relative movement of the said control axis | shaft, or releases any one lock | rock. A variable valve operating device for an internal combustion engine.   10. The variable valve operating apparatus for an internal combustion engine according to claim 9, wherein the first and second locking mechanisms release both locks of the first and second cam lobes according to relative movement of the control shaft.

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