JP5920177B2 - 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.

  2. Description of the Related Art A variable valve operating apparatus for an internal combustion engine that can change the lift amount of a valve according to the action of hydraulic pressure is known. For example, in Patent Document 1, the position of the movable cam with respect to the camshaft is switched by the pressure of the oil flowing through the paths formed in the camshaft and the movable cam, thereby changing the lift amount of the valve.

JP 2001-329819 A

  For example, when the amount of oil leaking from the path is large due to the configuration of the apparatus, in order to perform such switching, the oil is supplied to the path with a large pressure in consideration of a decrease in hydraulic pressure due to oil leakage. There is a need. For this reason, for example, a large oil pump is required, which may affect fuel consumption.

  An object of the present invention is to provide a variable valve operating apparatus for an internal combustion engine that suppresses the amount of oil leakage.

The object is to provide a cam base portion that rotates together with a cam shaft, 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 toward the high position; a cam follower that biases the cam lobe portion toward the low position; and the cam lobe held by the cam lobe portion at the high and low positions. A locking member that locks to a portion, and a hydraulic pressure applied to the locking member so that the cam lobe portion is unlocked at one of the high position and the low position and locked at the other position. comprising a path for the action, the said path, the cam lobe portion retracted and the said locking member and the cam lobe portion when the cam lobe portion is in the high position An opening mechanism that closes the opening when the cam lobe is in the high position is provided on the cam base. This can be achieved by a variable valve operating device for an internal combustion engine. Since the opening / closing mechanism closes the opening when the cam lobe is retracted from the opening, the amount of oil leakage from the opening can be suppressed.

  The opening / closing mechanism may include an opening / closing member capable of closing the opening, and an opening / closing member urging member which is pushed by the cam lobe at the low position and is supported by the opening / closing member so as to be retractable from the opening. Good.

  The opening / closing member biasing member may bias the cam lobe portion toward the high position via the opening / closing member when the cam lobe portion is in the low position.

  The cam base portion includes a slit through which the cam lobe portion escapes swinging between the high position and the low position, the opening is formed on an inner wall surface of the slit, and the opening / closing mechanism is provided in the slit. It may be.

  The path includes a first path and a second path communicating with each other by applying hydraulic pressure to the lock member when the cam lobe is in the high position and the low position, and the cam lobe is formed in the cam base. A first lock hole with which the lock member can be engaged when in the high position, and a second lock hole with which the lock member can be engaged when the cam lobe is formed in the cam base portion with the low position. And a first spring that biases the lock member in a direction opposite to the hydraulic pressure acting via the first path when the cam lobe is in the high position, and the cam lobe is in the low position. And a second spring that biases the lock member in a direction opposite to the hydraulic pressure acting via the second path.

An object of the present invention is to provide a variable valve operating apparatus for an internal combustion engine that suppresses the amount of oil leakage.
Can provide.

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 the lock of the cam lobe portion. 6A and 6B are explanatory diagrams of the lock of the cam lobe portion. FIG. 7 is an enlarged view of the periphery of the valve body of FIG. 4A. FIG. 8 is an explanatory diagram of a modified example of the opening / closing mechanism.

  Hereinafter, embodiments will be described in detail with reference to the drawings.

  1 and 2 are external views of the variable valve operating apparatus 1 of the present 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 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 support shaft 33 penetrates the cam base 10 and the two cam lobes 20 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. A part 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 </ b> S are wound around 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 that it is separated 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 left cam lobe portion 20 is at a high position, and the right cam lobe portion 20 is at a low 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 cam lobe 20 is locked at the low position, the cam lobe 20 contacts or does not contact the rocker arm R and the valve V does not lift. In FIGS. 1 and 2, only one cam lobe portion 20 is at a high position for easy understanding, but actually, the two cam lobe portions 20 are both located at the same position as will be described later.

  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 the supply path T of the cam base portion 10. 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. The cam lobe portion 20 is housed in a slit 12 formed in the cam base portion 10. The slit 12 is formed so as to miss the swing of the cam lobe portion 20.

  Further, a recess 18, a valve body 18 </ b> V, and a spring 18 </ b> S are provided in the slit 12. One end of the spring 18S is fixed to the bottom surface of the recess 18, and the valve body 18V is fixed to the other end to support the valve body 18V. When the cam lobe portion 20 is at the high position, the valve body 18V is maintained at a position for closing an opening portion T51 of the path T5 described later by the spring 18S. The opening T51 is formed on the inner surface of the slit 12. When the cam lobe 20 moves to the low position, the valve body 18V is pushed against the urging force of the spring 18S, and the valve body 18V is retracted from the opening T51 and stored in the recess 18. The valve body 18V and the spring 18S are examples of an opening / closing mechanism. The valve body 18V is an example of an opening / closing member. The spring 18S is an example of an urging member for an opening / closing member. Details will be described later.

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 about the center position 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. In the cam base portion 10, a supply path T extending on the axis of the camshaft S and paths T5 and T6 extending radially outward from the supply path T are formed. The paths T5 and T6 each extend radially outward from the supply path T, and then extend in the axial direction to the two cam lobe portions. The route T6 is an example of a first route. The route T5 is an example of a second route. Paths T5 and T6 are paths formed in the cam base portion 10 to apply hydraulic pressure to the pin 26P so that the cam lobe portion 20 is unlocked at one of the high position and the low position and locked at the other position. is there. Details will be described later.

  The oil control valve OCV is an electromagnetically driven flow control valve and is controlled by the ECU 5. The ECU 5 is an example of a control unit. The oil stored in the oil pan is supplied into the supply path T by the oil pump P. The oil pump P is a mechanical type interlocked with the crankshaft of the internal combustion engine. The oil control valve OCV can linearly adjust the hydraulic pressure supplied into the supply path T by the oil pump P based on the current value applied to the oil control valve OCV. The oil control valve OCV is an example of a hydraulic control valve. The hydraulic control valve may be capable of adjusting the hydraulic pressure supplied into the supply path T in stages. 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 pins 15P, 16P, and 17P that act on the two cam lobe portions 20, respectively. 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 15P 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.

  Holes 15 and 16 communicating with the slit 12 are formed in the cam base portion 10. The holes 15 and 16 are formed on the same side with respect to the slit 12. The holes 15 and 16 extend in the axial direction and have a bottom surface. Pins 15P and 16P are accommodated in the holes 15 and 16, respectively. A spring 15S connected to the pin 15P is arranged between the bottom surface of the hole 15 and the pin 15P. 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 15S is set to such a length that the pin 15P does not detach from the hole 15. The spring 15S is an example of a second spring. The spring 16S is an example of a first 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 communicates with the path T6. The hole 17 is located coaxially with the hole 16. The hole 17 extends 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. In the lift state, the pin 16P is inserted into the holes 16 and 26 in common by the biasing force of the spring 16S, 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 in a lift state. The hole 17 is an example of a first lock hole.

  Next, the locking of the cam lobe 20 will be described in detail. 5A to 6B are explanatory views of the lock of the cam lobe portion 20. When oil is supplied into the paths T5 and T6 via the supply path T by the oil control valve OCV and the oil pump P, the pin 17P resists the urging force of the spring 16S as shown in FIG. Pushed to the side. Thereby, the pin 16P is detached from the hole 26, and the pin 26P is detached from the hole 17. That is, the pins 16P, 17P, 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. Accordingly, the spring 16S urges the pin 26P in the direction opposite to the hydraulic pressure acting via the path T6 when the cam lobe portion 20 is at the high position.

  When the cam lobe 20 is in the high position, the valve body 18V closes the opening T51 of the path T5. For this reason, even if it is a case where oil_pressure | hydraulic is supplied to the path | route T5, the quantity of the oil which leaks from the opening part T51 is suppressed.

  When the camshaft S rotates with the cam lobe 20 unlocked, the urging force is received from the rocker arm R. As a result, as shown in FIG. 5B, the cam lobe part 20 moves the valve body 18V into the recess 18 against the urging force of the springs 34S, 18S and moves to the low position. In other words, the urging forces of the springs 34S and 18S are set to such an extent that the cam lobe 20 can be moved to a low position only by the urging force from the rocker arm R in a state where the lock of the cam lob 20 is released. . When the cam lobe portion 20 is in the low position, the holes 15 and 26 are aligned on the same axis. 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 the other end of the swing range. Further, when the cam lobe portion 20 is in the low position, the pin 26P faces to close the opening T51 of the path T5. 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.

  The pin 26P is inserted in common into the holes 15 and 26 against the urging force of the spring 15S as shown in FIG. 5C due to the pressure of the oil from the path T5. Thereby, the cam lobe part 20 is locked in a lift stop state. In this way, the cam lobe portion 20 is locked at the low position while the oil is being supplied into the supply path T at a predetermined pressure or higher. The hole 15 is an example of a second lock hole. Accordingly, the spring 15S biases the pin 26P in the direction opposite to the hydraulic pressure acting via the path T5 when the cam lobe 20 is in the low position.

  Next, when the oil supply to the supply path T is stopped by the oil control valve OCV, the pin 26P is detached from the hole 15 and stored in the hole 26 by the biasing force of the spring 15S as shown in FIG. 6A. As a result, the cam lobe 20 is unlocked at the low position.

  Next, according to the urging force of the springs 34S and 18S, as shown in FIG. 6B, the cam lobe 20 moves from the low position to the high position. Actually, while the cam lobe 20 is not in contact with the rocker arm R, the cam lobe 20 moves to the high position according to the urging force of the springs 34S and 18S. In the state where the cam lobe 20 is at the high position, the pins 16P, 26P, and 17P are arranged in the axial direction as described above.

  In this state, as shown in FIG. 4A, the pin 16P is inserted into the holes 16 and 26 in common according to the urging force of the spring 16S, and similarly the pin 26P is inserted into the holes 26 and 17 in common. Thereby, the cam lobe part 20 is locked in a high position. As described above, the cam lobe 20 is locked at the high position and the low position. The hole 26, the pin 26P, the springs 15S and 16S, the holes 15 and 17 and the like are examples of a lock mechanism. Thus, since the cam lobe part 20 is locked even at a low position, the cam lobe part 20 can be held in a stable state, and reliability and durability are ensured.

  As shown in FIGS. 1, 2, 3 </ b> A, 3 </ b> B, 4 </ b> A, and 4 </ b> B, the cam base portion 10 is connected to the cam shaft S, and the cam shaft S does not penetrate the cam base portion 10. For this reason, the axial cross-sectional area of the cam base part 10 can be ensured, and the strength of the cam base part 10 can be ensured. Since the camshaft S does not penetrate the cam base portion 10, it is not necessary to reduce the diameter of the camshaft S. For this reason, the strength of the camshaft S is also ensured. The holes 15, 16, and 17 formed in the cam base portion 10, the holes 26 formed in the cam lobe portion 20, and the like all extend in the axial direction. For this reason, for example, compared with the case where a hole extending in a direction crossing the axial direction is provided and a pin sliding in the hole is arranged, the cross-sectional area in the axial direction of the cam base portion 10 can be secured. . Thereby, the strength of the cam unit CU is ensured.

  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, since the support shaft 33 penetrates the two cam lobes 20 in common, the number of parts is also reduced.

  As shown in FIGS. 1 and 2, the springs 15 </ b> S, 16 </ b> S, and 34 </ b> S are disposed in the axial direction with respect to the cam lobe portion 20. For example, compared with the case where such a spring 34S etc. is arrange | positioned in the position which overlaps with the cam lobe part 20 in a radial direction, the cross-sectional area in the axial direction of the cam lobe part 20 is securable. Thereby, the strength of the cam lobe portion 20 can be ensured.

  Further, as described above, the recess 10H in which the spring S34 is disposed is provided in a portion that does not contact the rocker arm R, and this portion is effectively used. Since the spring S34 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.

  As described above, in order to move the cam lobe 20 from the high position to the low position, it is necessary to supply oil in the paths T5 and T6 at a predetermined pressure or higher. While the cam lobe 20 is in the high position, the opening T51 of the path T5 is closed by the valve body 18V. Thereby, the amount of oil leakage from the opening T51 can be suppressed, and a decrease in hydraulic pressure in the paths T5 and T6 can be suppressed. Therefore, for example, even if the oil pump P is small in output and size, the cam lobe 20 can be unlocked at a high position and the cam lobe 20 can be moved to a low position. By adopting such an oil pump P, fuel efficiency is improved.

  Further, since the amount of oil leakage from the opening T51 is suppressed, oil having a predetermined pressure or more can be supplied into the paths T5 and T6 in a short period of time. Thereby, the cam lobe 20 can be unlocked at a high position in a short period, and the cam lobe 20 can be moved from a high position to a low position in a short period. Thus, the responsiveness of the cam lobe 20 is improved.

  As described above, when the cam lobe 20 moves from the low position to the high position, the spring 18S and the spring 18S urge the cam lobe 20 to the high position. Thereby, the cam lobe part 20 can be moved from a low position to a high position in a short period of time. Thereby, even if it is a case where the camshaft S is rotating at high speed, the cam lobe part 20 can be moved to the high position side in a short period of time. Thus, the responsiveness of the cam lobe portion 20 is improved.

  FIG. 7 is an enlarged view of the periphery of the valve body 18V of FIG. 4A. A buffer member 18C is affixed to the surface of the valve body 18V that contacts the cam lobe 20. The valve body 18V is made of metal in consideration of durability, but the buffer member 18C is, for example, an elastic body such as rubber or a foamed body such as sponge. Thereby, the hitting sound, impact, vibration and the like between the valve body 18V and the cam lobe portion 20 can be suppressed.

  FIG. 8 is an explanatory diagram of a modified example of the opening / closing mechanism. An electromagnetic valve 19V is provided in the path T5. The electromagnetic valve 19V is controlled by the ECU 5, and the opening T51 is opened and closed. For example, the ECU 5 closes the opening T51 with the electromagnetic valve 19V when the cam lobe 20 is in the high position, and opens the opening T51 with the electromagnetic valve 19V when the cam lobe 20 is in the low position. Thereby, the lock | rock of the cam lobe part 20 in a low position is securable, suppressing the amount of oil leaks from opening part T51. The ECU 5 can determine whether the cam lobe 20 is in the high position or the low position based on the intake air amount supplied into the cylinder based on the output from the air flow meter. In this case, it is not necessary to provide the recess 18 in the slit 12 ′ of the cam base portion 10 ′.

  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 the lift state, the oil pressure may be applied directly to the pin 26P without using the pin 17P. Further, the springs 15S and 16S may directly bias the pin 26P without using the pins 15P and 16P.

  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.

  In the above-described embodiment, the valve body 18V is provided with the buffer member 18C, but may not be provided. Further, for example, the valve body itself may be an elastic body such as rubber having a certain degree of rigidity. The rocker arm R is an example of a cam follower for driving a bubble, but the cam follower may be a valve lifter that is directly driven by a cam.

1 Variable valve gear 5 ECU
S Camshaft R Rocker arm V Valve (Cam follower)
OCV Oil control valve 10 Cam base part 11 Base circle part 15 Hole (second lock hole)
17 holes (first lock hole)
18 Recess 18V Valve body (opening / closing member, opening / closing mechanism)
18S spring (biasing member for opening / closing member, opening / closing mechanism)
20 Cam lobe 26P Pin (locking member)
34S Spring (Biasing member)
15S spring (second spring)
16S spring (first spring)
T6 route (first route)
T5 route (second route)
T51 opening

Claims (5)

A cam base that rotates 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 toward the high position;
A cam follower for urging the cam lobe portion toward the low position;
A lock member that is held by the cam lobe portion and locks the cam lobe portion to the cam base portion at the high position and the low position;
A path that is formed in the cam base portion and applies hydraulic pressure to the lock member so that the cam lobe portion is unlocked at one of the high position and the low position and locked at the other position,
The path includes an opening portion where the cam lobe portion and the lock member are retracted when the cam lobe portion is in the high position, and the lock member is opposed when the cam lobe portion is in the low position,
A variable valve operating apparatus for an internal combustion engine, wherein the cam base portion is provided with an opening / closing mechanism that closes the opening when the cam lobe portion is in the high position.   The opening / closing mechanism includes an opening / closing member capable of closing the opening, and an opening / closing member urging member which is pushed by the cam lobe portion at the low position and is supported by the opening / closing member so as to be retractable from the opening. The variable valve operating apparatus for an internal combustion engine according to claim 1.   The variable valve for an internal combustion engine according to claim 2, wherein the urging member for the opening / closing member urges the cam lobe to the high position side via the opening / closing member when the cam lobe is in the low position. apparatus. The cam base portion includes a slit through which the cam lobe portion misses swinging between the high position and the low position,
The opening is formed on the inner surface of the slit,
The variable valve operating apparatus for an internal combustion engine according to claim 1, wherein the opening / closing mechanism is provided in the slit. The path includes a first path and a second path communicating with each other by applying hydraulic pressure to the lock member when the cam lobe portion is at the high position and the low position, respectively.
A first lock hole formed in the cam base portion and engageable with the lock member when the cam lobe portion is in the high position;
A second lock hole formed in the cam base portion and engageable with the lock member when the cam lobe portion is in the low position;
A first spring that urges the lock member in a direction opposite to the hydraulic pressure acting via the first path when the cam lobe is in the high position;
5. A second spring for urging the lock member in a direction opposite to the hydraulic pressure acting via the second path when the cam lobe is in the low position. A variable valve operating device for an internal combustion engine.

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