JP2018044450A - Internal combustion engine variable valve mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a forced shearing force from being applied to an arm when the arm is apt to oscillate during its changeover operation.SOLUTION: A variable valve mechanism 1 comprises a changeover device 50 for use in connecting and releasing a second arm 20 to and from a first arm 10 driven by a cam 9. In addition, the variable valve mechanism is provided with a holder device 60 for use in holding the second arm 20 at a cam housing 5 by engaging an engaged part 62 at the second arm 20 side with an engaging part 66 of a cam housing 5 side when the connecting is released and for releasing the holding kept by the engaging when the connecting is carried out. The engaged part 62 and the engaging part 66 are formed with slant surfaces s1, s2 extending in slanted state in respect to oscillation directions (f) and (b) of the second arm 20. When the second arm 20 is apt to oscillate together with the first arm 10 during changeover operation in which both connection and engagement are being carried out to cause a shear force to be added to the engaged part 62 and the engaging part 66, the shear force is converted by the slant surfaces s1, s2 into an alienation force and the engagement is released by the alienation force.SELECTED DRAWING: Figure 7

Description

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

  A variable valve mechanism 90 of Conventional Example 1 (Patent Document 1) shown in FIG. 13 includes a first arm 91 that swings when driven by a cam 99, a second arm 92 that drives the valve 7 when swinging, There is provided a switching device 95 that switches to a driving state by connecting the arms 91 and 92 so as to swing together and switches to a resting state by releasing the connection.

  A variable valve mechanism 90 ′ of Conventional Example 2 (Patent Document 2: unpublished at the time of filing) shown in FIGS. 14 to 16 includes a third arm 93 that swings together with the second arm 92 in addition to the configuration of Conventional Example 1. The second arm 92 drives the valve 7 via the third arm 93. Furthermore, the variable device 94 which changes the lift amount of the valve | bulb 7 in a drive state by changing the relative angle of the 3rd arm 93 with respect to the 2nd arm 92 is provided.

JP 2009-91969 A Japanese Patent Application No. 2015-167879

  The variable valve mechanism 90 of Conventional Example 1 can switch between the driving state and the resting state, but cannot change the lift amount of the valve 7 in the driving state. However, in order to further improve the engine performance, it is preferable that not only the switching but also the change can be made.

  In that respect, the variable valve mechanism 90 'of Conventional Example 2 can be changed as well as switched, but has the following problems. That is, with only the basic structure described above, the rest position of the second arm 92 is changed by changing the relative angle with the third arm 93. Therefore, the rest position of the second arm 92 is not fixed, and depending on the rest position, the connection with the first arm 91 (switching to the drive state) may be impossible or difficult. For this reason, as shown in FIG. 15, a holding device 96 for holding the second arm 92 on the cam housing 5 in the resting state is provided. When the connection is released by the holding device 96, the holding position of the second arm 92 is fixed by performing the holding as shown in FIG. 15 (b).

  However, there are the following problems. That is, if the switching timing is poor, as shown in FIG. 16 (a), the base circle time ends and the nose enters during the switching in which both the connection and the locking are performed. Therefore, as shown in FIG. 16B, the second arm 92 starts to swing together with the first arm 91 in the state where the locking is performed, and the second arm 92 and the holding device 96 are moved. An unreasonable shearing force F is applied.

  Accordingly, it is an object of the present invention to prevent an excessive shearing force from being applied when the second arm tries to swing together with the first arm during switching.

  In order to achieve the above object, a variable valve mechanism for an internal combustion engine of the present invention is configured as follows. The variable valve mechanism drives a valve by connecting a first arm that is driven by a cam and swings, a second arm that drives the valve when swinging, and both arms so as to swing together. A switching device that switches to a driving state and switches the driving state to a resting state by releasing the connection. And it has the following features.

  That is, a holding device is provided for holding the second arm on a cam housing protruding from the cylinder head of the internal combustion engine. The holding device includes a locked portion provided on the second arm side and a locking portion provided on the cam housing side. The locking portion is provided so as to be relatively displaceable in the approaching direction and the separation direction with respect to the locked portion, and when the connection is released, the locking portion is relatively displaced in the approaching direction to lock the locked portion. The holding is performed, and when the connection is made, the holding is released by relative displacement in the separating direction to release the locking.

  An inclined surface extending obliquely with respect to the swinging direction of the second arm is formed on at least one of the abutting surfaces of the locked portion and the locking portion that are in contact with each other. When a shearing force is applied to the locked portion and the locking portion while the second arm is about to swing together with the first arm during the switching in which both the connection and the locking are performed, the shearing force is applied. The inclined surface converts to a separating force in the separating direction, and the locking portion is displaced relative to the locked portion in the separating direction by the separating force, so that the locking is released.

  According to the present invention, when a shearing force is applied to the locked portion and the locking portion while the second arm swings together with the first arm during switching, the locking is released by the inclined surface. Therefore, an excessive shear force is not applied.

It is a perspective view which shows the variable valve mechanism of Example 1. FIG. It is a perspective view which shows the arm etc. of the variable valve mechanism. It is a disassembled perspective view which shows the arm etc. of the variable valve mechanism. In the variable valve mechanism, (a) is a rear cross-sectional view showing when switched to a drive state, and (b) is a rear cross-sectional view showing when switched to a rest state. In the same variable valve mechanism, it is back sectional drawing which shows in order from (a)-(c) switching from a drive state to a dormant state. In the same variable valve mechanism, it is back sectional drawing which shows in order to (a)-(c) switching from a rest state to a drive state. In the variable valve mechanism, (a) is a rear sectional view showing the middle of switching, and (b) is a rear sectional view showing a time when the second arm starts to swing together with the first arm during the switching. In the drive state of the variable valve mechanism, (a) is a side sectional view showing the base circle (VIIIa-VIIIa sectional view shown in FIG. 4 (a)), and (b) is a side sectional view showing the nose. . When the variable valve mechanism is in a resting state, (a) is a side sectional view showing the base circle (IXa-IXa sectional view shown in FIG. 4 (b)), and (b) is a side sectional view showing the nose. . In the variable valve mechanism according to the second embodiment, (a) is a rear cross-sectional view showing the time when it is switched to a driving state, and (b) is a rear cross-sectional view showing the time when it is switched to a resting state. In the variable valve mechanism, (a) is a rear sectional view showing the middle of switching, and (b) is a rear sectional view showing a time when the second arm starts to swing together with the first arm during the switching. It is a disassembled perspective view which shows the arm etc. of the variable valve mechanism of Example 3. FIG. It is a perspective view which shows the variable valve mechanism of the prior art example 1. FIG. It is a perspective view which shows the arm etc. of the variable valve mechanism of the prior art example 2. In the variable valve mechanism, (a) is a rear sectional view showing a driving state, and (b) is a rear sectional view showing a state where the state is switched from the resting state. In the variable valve mechanism, (a) is a rear sectional view showing the middle of switching, and (b) is a rear sectional view showing a time when the second arm starts to swing together with the first arm during the switching.

  The coupling device and the locking device may be driven by separate actuators, but are driven by a common actuator (displacement device, etc.) in terms of compactness and easy synchronization control. It is preferable. Although the specific aspect is not specifically limited, The following aspect is illustrated.

  That is, the switching device includes a connection pin that performs the connection and the release thereof, and a displacement device that displaces the connection pin. The holding device includes a locked pin in which the locked portion is installed, a locking pin in which the locked portion is installed, and the displacement device. The displacing device displaces the connecting pin, the locked pin, and the locking pin in one of the intersecting directions intersecting the swinging direction of the second arm with a ball, thereby releasing the locking and By displacing in the other of the crossing directions, the connection is released and the locking is performed.

Although the aspect of a to-be-latched part and a latching | locking part is not specifically limited, The following aspect is illustrated.
[1] The locked portion cannot be displaced relative to the locked pin. The locking part can be displaced relative to the locking pin in the intersecting direction. Between the locking pin and the locking portion, a spring is provided that biases the locking portion by biasing the locking portion to the other in the crossing direction. When the shearing force is applied, the locking portion is displaced in one of the intersecting directions against the biasing force of the spring by the separation force, so that the locking portion is separated from the locked portion. Relative displacement in the direction.
[2] The locked portion cannot be displaced relative to the locked pin. The locking portion cannot be displaced relative to the locking pin. When the shearing force is applied, the locking portion is displaced relative to the locked pin in one of the intersecting directions by the separation force, so that the locking portion is separated from the locked portion. Relative displacement in the direction.

Although the shape of an inclined surface is not specifically limited, The following aspect is illustrated.
[1] The inclined surface is an inner surface of a concave portion that is recessed in a part of a sphere, or a surface of a sphere or a protrusion that protrudes in a part of a sphere.
[2] The inclined surface is an inner surface of a recess recessed in a taper shape, or a surface of a protrusion protruding in a taper shape.

  The variable valve mechanism may directly drive the valve with the second arm, but is preferably configured as follows in that the lift amount of the valve in the driving state can be changed. That is, the second arm drives the valve via a third arm that swings together with the second arm. The variable valve mechanism includes a variable device that changes the lift amount of the valve in the drive state by changing the relative angle of the third arm with respect to the second arm.

  Next, examples of the present invention will be described. However, the present invention is not limited to the embodiments, and the configuration and shape of each part can be arbitrarily changed without departing from the spirit of the invention.

  The variable valve mechanism 1 of the first embodiment shown in FIGS. 1 to 9 is provided for a pair of valves 7 and 7. The pair of valves 7 and 7 may be a pair of intake valves or a pair of exhaust valves. A valve spring 8 is attached to each valve 7 as shown in FIGS. The variable valve mechanism 1 includes a cam 9, a first arm 10, a second arm 20, third arms 30 and 30, a variable device 40, a switching device 50, a holding device 60, and a displacement device 70. In the following, in accordance with FIGS. 4 to 7, one of the camshafts 9x in the length direction is referred to as “left” and the other is referred to as “right”.

[Cam 9]
The cam 9 shown in FIG. 1 and the like is provided on the camshaft 9x, and includes a base circle 9a and a nose 9b protruding from the base circle 9a. As shown in FIGS. 8 and 9, the camshaft 9x is attached to a cam housing 5 protruding from the cylinder head. The camshaft 9x rotates once every two rotations of the internal combustion engine.

  The cam housing 5 shown in FIG. 4A and the like includes a cam support 5c protruding from the cylinder head, a cam cap 5a mounted on the cam support 5c, and a block 5b. The cam housing 5 rotatably supports the camshaft 9x with a cam support 5c and a cam cap 5a. The block 5 b is installed on the left side L of the rear part of the second arm 20. The block 5b is provided with a locking pin hole 6 opened to the right R.

  In addition, in the above-mentioned “Brief description of the drawings” and the following, when the base circle 9a of the cam is in contact with the roller 11 of the first arm, as shown in FIG. 8A, FIG. When the base nose 9b is in contact with the roller 11 of the first arm, as shown in FIGS. 8B, 9B, etc., it is called “nose time”.

[First arm 10]
The first arm 10 shown in FIG. 2 and the like is driven by the cam 9 to swing. The first arm 10 is swingably supported by the rocker shaft 10x by inserting a cylindrical front and rear intermediate portion through the rocker shaft 10x. The rocker shaft 10x is a pipe-shaped shaft extending in the left and right directions L and R. In the following description, the circumferential direction of the rocker shaft 10x is referred to as “swing direction f, b”, and the direction in which the valve 7 is opened in the swing directions f, b is referred to as “lift direction f”, and vice versa. The direction is referred to as “return direction b”.

  A roller 11 that is in contact with the cam 9 is rotatably attached to the tip of the first arm 10. As shown in FIG. 3 and the like, a cylindrical storage pin 13 extending in the left and right directions L and R is attached to the rear portion of the first arm 10 so as to protrude leftward from the left side surface of the first arm 10. Yes. The surface on the return direction b side (lower side) of the portion protruding to the left L of the storage pin 13 constitutes the pressing portion 14 for pressing the pressed portion 21 of the second arm 20 in the return direction b (downward). doing. The cylindrical hole of the storage pin 13 constitutes a bottomed first pin hole 15 opened to the left L. As shown in FIG. 8A and the like, the roller 11 is cammed by pressing the rear part of the first arm 10 toward the return direction b side (downward) toward the lift direction f side (upward) of the rear part of the first arm 10. A lost motion mechanism 19 for energizing 9 is provided. The lost motion mechanism 19 includes a body 19a, a lifter 19c, and a lost motion spring 19b.

[Second arm 20]
The second arm 20 shown in FIG. 2 and the like is an arm that drives the valves 7 and 7 via the third arms 30 and 30 when swinging. The second arm 20 is provided on the left side L of the first arm 10, and is supported by the rocker shaft 10 x so as to be swingable by fitting a cylindrical tip portion to the rocker shaft 10 x. As shown in FIG. 3 and the like, a sleeve 23 protruding rightward R is provided at the cylindrical tip of the second arm 20. The sleeve 23 is inserted between the inner peripheral surface of the cylindrical front and rear intermediate portion of the first arm 10 and the outer peripheral surface of the rocker shaft 10x. A second-side helical spline 24 that is twisted in one direction is provided on the inner peripheral surface of the sleeve 23. One-way twist refers to twist on the side that turns in the return direction b as it advances to the left L. A second pin hole 26 penetrating in the left and right directions L and R is provided at the rear portion of the second arm 20. As shown in FIG. 4A and the like, the right end portion of the second pin hole 26 is a large-diameter portion 27 having a larger diameter than other portions. As shown in FIG. 3 and the like, a pressed portion 21 that protrudes in the return direction b (downward) by the pressing portion 14 of the first arm 10 protrudes from the right side surface of the rear portion of the second arm 20.

[Third arm 30, 30]
The third arms 30 and 30 shown in FIG. 2 and the like are arms that swing with the second arm 20 to drive the valves 7 and 7. One third arm 30 is provided on each of the right side R of the first arm 10 and the left side L of the second arm 20. Each of the third arms 30 is supported by the rocker shaft 10x so as to be swingable by having a cylindrical rear portion fitted on the rocker shaft 10x. As shown in FIG. 8A and the like, a third-side helical spline 34 twisted in the other direction is provided on the inner peripheral surface of the cylindrical rear portion. The other direction twist refers to the twist on the side that turns in the lift direction f as it moves to the left L. As shown in FIG. 2 and the like, the tip of each third arm 30 constitutes an output nose 39. As shown in FIG. 8 and the like, each third arm 30 drives the valve 7 by pressing the valve 7 via the intervening arm 80 with the output nose 39 when swinging. The intervening arm 80 is swingably supported by a lash adjuster 85.

[Variable device 40]
The variable device 40 shown in FIG. 3 and the like is a device that changes the lift amount and the working angle of the valve 7 in the driving state by changing the relative angle of the swing directions f and b of the third arm 30 with respect to the second arm 20. It is. The variable device 40 includes a slider gear 41, a control shaft 45, and an actuator (not shown).

  The slider gear 41 is a cylindrical member, and is between the cylindrical front portion of the second arm 20 and the cylindrical rear surface of the third arms 30 and 30 and the outer peripheral surface of the rocker shaft 10x. Is intervened. The slider gear 41 has a one-side-twisted second helical spline 42 meshed with the second-side helical spline 24 on the outer peripheral surface, and a third-direction twisted third helical spline 43, 43 meshed with the third-side helical splines 34, 34. And.

  The control shaft 45 extends in the left and right directions L and R, and is inserted inside the rocker shaft 10x so as to be slidable in the left and right directions L and R. The control shaft 45 is engaged with the slider gear 41 via an engagement pin (not shown) so as to be displaced together in the left and right directions L and R and to allow relative displacement in the swing directions f and b. ing. The engagement pin (not shown) is engaged with the control shaft 45 and the slider gear 41 in a state where a long hole (not shown) extending in the left and right directions L and R penetrating the rocker shaft 10x is inserted. . When the variable valve mechanism 1 is assembled, the engagement pin (not shown) includes a notch 18 provided in the cylindrical front / rear intermediate portion of the first arm 10 and a through hole provided in the sleeve 23 of the second arm 20. From 28, it is attached to the control shaft 45.

  The actuator (not shown) displaces the slider gear 41 in the left and right directions L and R with respect to the second arm 30 and the third arms 30 and 30 by displacing the control shaft 45 in the left and right directions L and R. Thereby, the relative angle of the swing directions f and b of the third arms 30 and 30 with respect to the second arm 20 is changed by meshing of the helical splines.

[Switching device 50]
The switching device 50 shown in FIG. 3 and the like is switched to a driving state by connecting the two arms 10 and 20 so that the second arm 20 swings together with the first arm 10 and is in a resting state by releasing the connection. It is a device for switching to. As shown in FIG. 8, the driving state is a state in which the second arm 20 and the third arm 30 swing together with the first arm 10 to drive the valve 7. As shown in FIG. 9, the resting state is a state in which the first arm 10 is swung and the second arm 20 and the third arm 30 do not swing, so that the driving is rested. The switching device 50 includes a connecting pin 51 as shown in FIG. The displacement device 70 also constitutes a part of the switching device 50.

  The connecting pin 51 is provided so as to be displaceable at a connecting position P that straddles between the first arm 10 and the second arm 20 and a non-connecting position Q that does not straddle. As shown in FIG. 4A, the connecting position P is such that the connecting pin 51 protrudes left L from the first pin hole 15 and its tip 52 (left end) is the large diameter portion 27 of the second pin hole 26. It is the position of the left side relatively inserted. When the connecting pin 51 is arranged in the connecting position P, the second arm 20 is connected to the first arm 10 so as not to be able to swing relative to the first arm 10, and the driving state is switched. The unconnected position Q is a position on the relatively right side where the connecting pin 51 retracts into the first pin hole 15 as shown in FIG. When the connecting pin 51 is arranged in the non-connecting position Q, the connection is released and the state is switched to the resting state.

[Holding device 60]
A holding device 60 shown in FIG. 7 and the like is a device for holding the second arm 20 in the cam housing 5. The holding device 60 includes a locked pin 61 and a locking pin 65. The displacement device 70 also constitutes a part of the holding device 60.

  The locked pin 61 is attached to the second arm 20 so as to be relatively displaceable in the left and right directions L and R by being inserted into the second pin hole 26. On the left end surface of the pin to be locked 61, a locked portion 62 formed of a concave portion that is recessed to the right R in a tapered shape is provided. A portion on the return direction b side (lower side) of the inner surface of the locked portion 62 (concave portion) constitutes an inclined surface s1 that advances to the left L as it advances in the return direction b (downward).

  The locking pin 65 is attached to the cam housing 5 so as to be displaceable in the left and right directions L and R by inserting the left side portion of the locking pin 65 into the locking pin hole 6. A storage hole 65 a recessed in the left direction L is provided in the right end surface of the locking pin 65. By inserting a latching portion 66 made of a latch ball into the storage hole 65a, the latching portion 66 (latch ball) is attached to the latching pin 65 so as to be relatively displaceable in the left and right directions L and R. Yes. By urging the locking portion 66 to the right R between the bottom surface of the storage hole 65a and the locking portion 66 (latch ball), the locking portion 66 is biased to the locked portion 62 (concave portion). A spring 67 is installed.

  The locking portion 66 is disposed at the locking position P ′ by being relatively displaced in the approaching direction (right R) with respect to the locked portion 62, and is not moved by being relatively displaced in the separating direction (left L). It is arranged at the locking position Q ′. As shown in FIG. 7A, the locking position P ′ is a position where the locked portion 62 is locked by being engaged with the locked portion 62 (concave portion). When the locking portion 66 is disposed at the locking position P ′, the second arm 20 is held by the cam housing 5. As shown in FIG. 7B, the non-locking position Q ′ is a position where the locking is released by exiting from the locked portion 62 (concave portion). When the locking portion 66 is disposed at the non-locking position Q ', the holding is released. The surface of the part (lower part) on the return direction b side of the right part of the locking part 66 (latch ball) constitutes an inclined surface s2 that advances to the left L as it advances in the return direction b (downward).

[Displacement device 70]
A displacement device 70 shown in FIG. 4 or the like is a device that displaces the three pins 51, 61, 65 of the connecting pin 51, the locked pin 61, and the locking pin 65 in the left and right directions L and R. The displacement device 70 includes a spring 71 and a hydraulic chamber 72. The spring 71 is interposed between the bottom surface of the first pin hole 15 and the connecting pin 51 and biases the connecting pin 51 to the left L. The hydraulic chamber 72 is provided in the locking pin hole 6 and urges the locking pin 65 to the right R with hydraulic pressure supplied from an oil passage (not shown) provided in the cam housing 5. .

(Switch to hibernation)
When the displacement device 70 is switched from the driving state shown in FIG. 4A to the resting state shown in FIG. 4B, the hydraulic pressure of the hydraulic chamber 72 is increased, and the three pins 51 51 are driven by the ball by the hydraulic pressure. , 61, 65 are displaced to the right R. Thereby, the connection pin 51 is arranged at the non-connection position Q, and the locking portion 66 is arranged at the locking position P ′. Specifically, it is as follows.

  That is, when the hydraulic pressure in the hydraulic chamber 72 increases during the nose, the three pins 51, 61, 65 are displaced to the right R as shown in FIG. Thereby, the connecting pin 51 is arranged at the non-connecting position Q, and the locking pin 65 contacts the left side surface of the second arm 20. At this time, the locking portion 66 remains arranged at the non-locking position Q ′.

  In the latter half of the nose (when swinging in the return direction b), as shown in FIG. 5B, the pressing portion 14 of the first arm 10 moves the pressed portion 21 of the second arm 20 in the return direction. By pressing b (downward), the second arm 20 swings in the return direction b together with the first arm 10. And at the time of a base circle, the to-be-latched part 62 (recessed part) comes just beside the latching | locking part 66 (latch ball). For this reason, the locking portion 66 (latch ball) is displaced to the right R (approach direction) by the urging force of the spring 67 and is engaged with the locked portion 62 (recessed portion), thereby being arranged at the locking position P ′. Is done. Therefore, thereafter, the second arm 20 is held by the cam housing 5 as shown in FIG.

  On the other hand, when the hydraulic pressure in the hydraulic chamber 72 increases during the base circle, the driving state shown in FIG. 4A is switched to the resting state shown in FIG.

(Switching to driving state)
Further, when the displacement device 70 is switched from the resting state shown in FIG. 4B to the driving state shown in FIG. The three pins 51, 61, 65 are displaced to the left L. Thereby, the connecting pin 51 is arranged at the connecting position P, and the locking portion 66 is arranged at the non-locking position Q ′. Specifically, it is as follows.

  That is, when the hydraulic pressure in the hydraulic chamber 72 decreases at the time of the nose, the connecting pin 51 is urged to the left L by the spring 71 as shown in FIG. Will not be displaced to the left L. Therefore, the connecting pin 51 is disposed at the non-connecting position Q, and the locking portion 66 remains disposed at the locking position P ′. And the 1st arm 10 continues idling | swinging because the left end surface of the connection pin 51 slides with respect to the right side surface of the 2nd arm 20. FIG.

  Then, as shown in FIG. 6B, the first pin hole 15 (the connecting pin 51) is directly beside the second pin hole 26 during the base circle. Therefore, the three pins 51, 61, 65 are displaced to the left L by the urging force of the spring 71. Thereby, the connecting pin 51 is arranged in the connecting position P. At this time, the locking portion 66 may be disposed at the non-locking position Q ′ away from the locked portion 62 (recessed portion) due to the displacement to the left L, as shown in FIG. As shown, it may remain in the locking position P ′.

  When the locking portion 66 remains arranged at the locking position P ′, as shown in FIG. 6C, in the initial stage after the nose (the initial stage when swinging in the lift direction f (upward)). As the second arm 20 swings, the inclined surfaces s1 and s2 press the locking portion 66 to the left L, so that the locking portion 66 (latch ball) and the locking pin 65 are moved to the left L (said separation). Direction). As a result, the locking portion 66 moves out of the locked portion 62 (recessed portion), so that the locking portion 66 is disposed at the non-locking position Q ′.

  On the other hand, when the hydraulic pressure in the hydraulic chamber 72 decreases during the base circle, the operation is switched directly from the resting state shown in FIG. 4B to the driving state shown in FIG.

(Oscillates during switching)
Further, as shown in FIG. 7 (a), the base circle time ends in the middle of the switching in which the connecting pin 51 is arranged in the connecting position P and the engaging pin 65 is arranged in the engaging position P ′. When the second arm 20 starts to swing together with the first arm 10 at a time, a shearing force is applied to the locked portion 62 and the locking portion 66. However, the shear force is converted into the separation force in the separation direction by the inclined surfaces s1 and s2. 7B, the locking portion 66 (latch ball) is displaced to the left L (the above-mentioned separation direction) against the biasing force of the spring 67, and the non-locking position Q is obtained. The lock is released by being placed in the '. FIG. 7A shows a case where the driving state is being switched to the resting state. However, the locking is similarly released even when the switching is being performed from the resting state to the driving state. .

According to the present embodiment, the following effects can be obtained.
[A] Since the variable valve mechanism 1 changes the lift amount of the valve 7 in the driving state by the variable device 40 in addition to switching between the driving state and the resting state by the switching device 50, the engine performance is further improved. To do.
[B] Since the second arm 20 is held by the cam housing 5 during the resting state, the resting position of the second arm 20 is fixed. Therefore, the connection (switching to the drive state) can be reliably performed. Further, the second arm 20 and the third arm 30 do not flutter when in a resting state.
[C] When a shearing force is applied to the locked portion 62 and the locking portion 66 in an attempt to swing the second arm 20 together with the first arm 10 during switching, the locking is performed by the inclined surfaces s1 and s2. Because it is released, excessive shear force is not applied.

  The variable valve mechanism 2 of the second embodiment shown in FIGS. 10 and 11 is different from the first embodiment in the following points and is the same in other points. That is, the locking portion 66 shown in FIG. 11 and the like is a tapered protrusion provided on the right end surface of the locking pin 65. The surface of the part on the return direction b side (lower side) on the right side of the protrusion constitutes an inclined surface s2 that advances to the left L as it advances in the return direction b (downward). The locking pin 65 is not provided with a storage hole 65 a or a spring 67.

  As shown in FIG. 11 (a), the connecting pin 51 is arranged in the connecting position P and the locking part 66 is arranged in the locking position P ′. When the second arm 20 starts to swing together with the first arm 10, a shearing force is applied to the locked portion 62 and the locking portion 66. However, the shear force is converted into the separation force in the separation direction by the inclined surfaces s1 and s2. With the separation force, as shown in FIG. 11 (b), the locking pin 65 moves to the left L (the separation direction) against the hydraulic pressure of the hydraulic chamber 72, or the locked pin 61 and the connecting pin 51 move. The spring 71 is displaced to the right R (the separating direction) against the urging force of the spring 71. As a result, the locking portion 66 is relatively displaced in the separating direction (left L) with respect to the locked portion 62 and is disposed at the non-locking position Q ′.

  Specifically, when switching from the driving state to the resting state (when the three pins are displaced to the right R), the hydraulic pressure in the hydraulic chamber 72 is completely stronger than the urging force of the spring 71. Only the locked pin 61 and the connecting pin 51 are pushed back to the right R. Also, when the urging force of the spring 71 is completely stronger than the hydraulic pressure of the hydraulic chamber 72 when switching from the resting state to the driving state (when the three pins are displaced to the left L). Only the locking pin 65 is pushed back to the left L. In other cases, as shown in FIG. 11B, the locking pin 65 is pushed back to the left L, and the locked pin 61 and the connecting pin 51 are pushed back to the right R. . In any of the above three cases, the locking portion 66 is displaced relative to the locked portion 62 in the separation direction (left L), so that the locking portion 66 is in the non-locking position Q ′. The lock is released.

  Also in this embodiment, the effects [A] to [C] described above can be obtained.

  The variable valve mechanism 3 of the third embodiment shown in FIG. 12 is different from the variable valve mechanism 1 of the first embodiment in the following points and is the same in other points. That is, the third arm 30 is not provided, and the valve 7 is driven by the second arm 20. Also, the variable device 40 is not provided. Therefore, the variable valve mechanism 3 only switches between the resting state and the driving state, and does not change the lift amount of the valve 7 in the driving state. According to the present embodiment, the effects [B] and [C] described above can be obtained.

The first to third embodiments may be modified as follows.
[Modification 1] The locked portion 62 (tapered recess) may be changed to a partially spherical (eg hemispherical) recess.
[Modification 2] The locking portion 66 (latch ball) of Embodiment 1 may be changed to a tapered member.
[Modification 3] The locking portion 66 (tapered protrusion) of the second embodiment may be changed to a part of a sphere (for example, a hemisphere).

[Modification 4] When the locking can be sufficiently released only by the inclined surface s2 on the locking portion 66 side, the locked portion 62 is changed to a concave portion such as a rectangle to tilt the locking portion 62 side. The surface s1 may be eliminated.
[Modification 5] When the locking can be sufficiently released only by the inclined surface s1 on the locked portion 62 side, the locking portion 66 is changed to a rectangular shape or the like to change the inclined surface s2 on the locking portion 66 side. It may be eliminated.

[Modification 6] In the first embodiment, the modes of the locked portion 62 and the locking portion 66 may be reversed. That is, the spring 67 may be interposed between the locked portion 62 and the locked pin 61 with the locking portion 66 as a recess and the locked portion 62 as a latch ball.
[Modification 7] In the second embodiment, the modes of the locked portion 62 and the locking portion 66 may be reversed. That is, the locking portion 66 may be a recess and the locked portion 62 may be a protrusion.

1 Variable valve mechanism (Example 1)
2 Variable valve mechanism (Example 2)
3 Variable valve mechanism (Example 3)
5 Cam housing 7 Valve 10 First arm 20 Second arm 30 Third arm 40 Variable device 50 Switching device 51 Connecting pin 60 Holding device 61 Locked pin 62 Locked portion 65 Locking pin 66 Locking portion 67 Spring 70 Displacement device s1 Inclined surface on the locked portion side s2 Inclined surface on the locked portion side f Lift direction (oscillating direction)
b Return direction (oscillation direction)
L Left (one of the crossing directions)
R right (the other in the crossing direction)

Claims (7)

The first arm (10) that swings when driven by the cam (9), the second arm (20) that drives the valve (7) when swinging, and the both arms (10, 20) swing together. The internal combustion engine is provided with a switching device (50) that switches to a driving state in which the valve (7) is driven by being connected, and switches to a resting state in which the driving is stopped by releasing the connection. In the valve mechanism,
A holding device (60) is provided for holding the second arm (30) in a cam housing (5) projecting from a cylinder head of the internal combustion engine, and the holding device (60) is on the second arm (20) side. And a locking portion (66) provided on the cam housing (5) side. The locking portion (66) is connected to the locked portion (62). Are provided so as to be relatively displaceable in the approaching direction and the separating direction, and when the connection is released, the displacement is relatively displaced in the approaching direction to lock the locked portion (62), and the holding is performed. The holding is released by releasing the locking by relative displacement in the separating direction when being performed,
Inclined surfaces (s1, s2) extending obliquely with respect to the swinging direction of the second arm (30) on at least one of the contact surfaces of the locked portion (62) and the locking portion (66) that are in contact with each other Formed,
The second arm (20) is about to swing together with the first arm (10) in the middle of the switching in which both the connection and the locking are performed, and the locked portion (62) and the locking portion (66) are moved. When a shearing force is applied, the shearing force is converted into a separating force in the separating direction by the inclined surfaces (s1, s2), and the locking portion (66 with respect to the locked portion (62) by the separating force is used. ) Is released by relative displacement in the separating direction. The variable valve mechanism for an internal combustion engine is released. The switching device (50) includes a connection pin (51) that performs the connection and release thereof, and a displacement device (70) that displaces the connection pin (51).
The holding device (60) includes a locked pin (61) in which the locked portion (62) is installed, a locking pin (65) in which the locking portion (66) is installed, and the displacement device. (70)
The displacement device (70) has one of the crossing directions (L) intersecting the swinging direction of the second arm (20) with a ball hitting the connecting pin (51), the locked pin (61), and the locking pin (65). ) To disengage the connection and to release the connection and to disengage the connection and to perform the locking. Item 6. A variable valve mechanism for an internal combustion engine according to Item 1. The locked portion (62) cannot be displaced relative to the locked pin (61), and the locking portion (66) is in the intersecting direction (L, R) with respect to the locking pin (65). The latched portion (66) is urged to the other (R) in the intersecting direction between the latch pin (65) and the latch portion (66) to be locked. A spring (67) for urging (62) is installed;
When the shearing force is applied, the locking portion (66) is displaced in one of the intersecting directions (L) against the biasing force of the spring (67) by the separation force, so that the locked portion The variable valve mechanism for an internal combustion engine according to claim 2, wherein the locking portion (66) is relatively displaced in the separating direction with respect to (62). The locked portion (62) cannot be relatively displaced with respect to the locked pin (61), and the locked portion (66) cannot be relatively displaced with respect to the locked pin (65).
When the shearing force is applied, the locking pin (65) is displaced relative to the locking pin (61) relative to the locking pin (61) by one of the separation forces, so that the locked portion The variable valve mechanism for an internal combustion engine according to claim 2, wherein the locking portion (66) is relatively displaced in the separating direction with respect to (62).   The inclined surface (s1) is an inner surface of a concave portion that is recessed in a part of a sphere, or a surface of a sphere or a surface of a protrusion that protrudes in a part of a sphere. A variable valve mechanism for an internal combustion engine.   The variable valve mechanism for an internal combustion engine according to any one of claims 1 to 4, wherein the inclined surfaces (s1, s2) are inner surfaces of concave portions that are recessed in a tapered shape or surfaces of protrusions that protrude in a tapered shape. The second arm (20) drives the valve (7) via a third arm (30) that swings with the second arm (20).
The variable device (40) which changes the lift amount of the valve (7) in the drive state by changing the relative angle of the third arm (30) with respect to the second arm (20) is provided. A variable valve mechanism for an internal combustion engine according to claim 1.

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