JP2019078168A - Variable valve mechanism of internal combustion engine - Google Patents

Abstract

To avoid the displacement of a link arm to an axial length direction even if a force in the axial length direction is applied on the link arm by the vibration or the like of an internal combustion engine at timing at which neither a first arm nor a second arm of the link arm is engaged with a rail groove.SOLUTION: A variable valve mechanism 101 comprises a camshaft 1 in which a rail groove 15 is formed, and a link arm 3 having first and second arms 31, 32. The link arm 3 is displaced to a first position at one d1 side in an axial length direction when turning to one r1 of a turn direction, and also when the first arm 31 is engaged with the rail groove 15, and displaced to a second position p2 at the other d2 side in the axial length direction when turning to the other r2 of the turn direction, and also when the second arm 31 is engaged with the rail groove 15. The variable valve mechanism 101 comprises a first engagement mechanism e1 which is engaged with the link arm 3 when the link arm 3 is arranged in the first position p1, and a second engagement mechanism e2 which is engaged with the link arm 3 when arranged in the second position p2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a variable valve mechanism that drives a valve of an internal combustion engine and changes the driving state thereof according to the operating condition of the internal combustion engine.

  FIGS. 9 (a) and 9 (b) show the variable valve mechanism 90 of the applicant's earlier application (Patent Document 1). The variable valve mechanism 90 includes a cam shaft 91, a support shaft 92 extending in parallel to the cam shaft 91, a link arm 93 axially movably supported by the support shaft 92, and a link arm 93. It is configured to include a rotating device 94 that rotates and a transmission mechanism 95 that extends from the camshaft 91 to the valve.

  The camshaft 91 is formed with a first drive cam 91a, a second drive cam 91b having a different profile from that, and a rail groove 91r composed of a plurality of grooves extending in the circumferential direction. The link arm 93 includes a first arm 93a and a second arm 93b alternately engaged with the rail groove 91r, and the first arm 93a engages with the rail groove 91r when the link arm 93 is rotated in one rotation direction. It is relatively displaced to the first position p1 on one side in the axial length direction, and when it is pivoted to the other in the rotation direction, the second arm 93b engages with the rail groove 91r to thereby relatively move the second side on the other side in the axial length direction. It is displaced to position p2.

  The transmission mechanism 95 includes an input roller 95 a which is axially displaced along with the link arm 93. When the link arm 93 is displaced to the first position p1, the transmission mechanism 95 causes the input roller 95a to abut on the first drive cam 91a, thereby transmitting the force of the first drive cam 91a to the valve. When the link arm 93 is displaced to the second position p2, the input roller 95a comes in contact with the second drive cam 91b, thereby transmitting the force of the second drive cam 91b to the valve.

JP 2014-224496 A

  In the link arm 93, in a state in which either the first or second arm 93a, 93b is engaged with the rail groove 91r, the engagement in the axial direction of the link arm 93 is restricted by the engagement. At this time, even if a force in the axial direction is applied to the link arm 93 due to vibration or the like of the internal combustion engine, the link arm 93 is not displaced to an unintended position.

  However, at the time of switching, one arm is disengaged from the rail groove 91r and then the other arm is engaged with the rail groove 91r, so that neither arm 93a, 93b momentarily engages with the rail groove 91r. There is. At this time, if a force in the axial direction is applied to the link arm 93 due to the vibration of the internal combustion engine or the like, the link arm 93 is displaced to an unintended position deviated from the rail groove 91r. In addition, the position of the input roller 95a with respect to the drive cams 91a and 91b is also shifted. As a result, an abnormality such as a half-ride state of the cam occurs, which may cause wear and an excessive force.

  On the other hand, when the other arm is engaged with the rail groove 91r before the engagement between one arm and the rail groove 91r is released, the timing when both arms 93a, 93b engage with the rail groove 91r In this case, an excessive force is applied to the link arm 93 by applying a force from the rail groove 91r to both arms 93a and 93b.

  Therefore, even if a force in the axial direction is applied to the link arm due to the vibration of the internal combustion engine or the like at a timing at which neither the first arm nor the second arm engage the rail groove, the link arm is intended to deviate from the rail groove. It is an object of the present invention to prevent displacement to an unintended position.

In order to solve the above problems, the variable valve mechanism of an internal combustion engine according to the present invention is a shaft that rotates according to the rotation of the internal combustion engine, and a drive cam and a rail groove including a plurality of circumferentially extending grooves are formed. Cam shaft, a support shaft extending parallel to the cam shaft, and a movable body axially supported in the axial direction of the support shaft, the first arm selectively engaging with the rail groove And the second arm, and the first arm is engaged with the rail groove after the engagement between the second arm and the rail groove is released when it is pivoted in the axial circumferential direction to one side relative to the axial direction The first arm and the rail groove are released from engagement when the second arm is displaced to the first position, and then the second arm is engaged with the rail groove, whereby the other in the axial length direction is relatively moved. Link arm that is displaced to the second position on the side, and A rotating device for moving and a mechanism that extends from the camshaft to the valve, the input unit being axially displaced with the link arm, and the input unit being in a predetermined position when the link arm is displaced to the first position By coming into contact with the drive cam, the force of the drive cam is transmitted to the valve, and when the link arm is displaced to the second position, the input part does not come in contact with the predetermined drive cam. A variable valve mechanism of an internal combustion engine comprising: a transmission mechanism which does not transmit the force of the drive cam to the valve;
A mechanism that engages with the link arm when the link arm is disposed at the first position, and the engagement suppresses the displacement of the link arm in the axial direction, and the second arm engages with the rail groove. When the link arm is placed in the second position, and when the link arm is displaced from the first position to the second position, the engagement between the mechanism and the link arm is released by the displacement force. The link arm is engaged with the link arm, and the engagement suppresses the displacement of the link arm in the axial direction, and the first arm engages with the rail groove to allow the link arm to move from the second position to the first position. And a second engagement mechanism that disengages the mechanism from the link arm by the displacement force.

  According to the present invention, when displacing the link arm from the first position to the second position, the time period from when the engagement between the first arm and the rail groove is released until the second arm engages with the rail groove. Even if a force in the axial direction is applied to the link arm due to the vibration of the internal combustion engine or the like at the timing, the link arm is not displaced in the axial direction because the first engagement mechanism is provided. Further, at the time from the disengaging of the second arm and the rail groove to the engagement of the first arm with the rail groove, when the link arm is displaced from the second position to the first position, Even if a force in the axial direction is applied to the link arm due to vibration or the like of the internal combustion engine, the link arm is not displaced in the axial direction because there is a second engagement mechanism. Therefore, in either case, the link arm can be reliably switched without being displaced to an unintended position deviated from the rail groove. Also, when the first or second arm engages with the rail groove and the link arm is displaced from one of the first position and the second position to the other, the link arm is engaged by the displacement force. Since the engagement with the one or the second engagement mechanism is released, no excessive force is applied to the link arm.

Fig.1 (a) is the perspective view which looked at the variable valve mechanism of the Example from diagonally from the front, (b) is the perspective view seen from diagonally back. FIG. 2A is a bottom view showing the link arm in the first position in the variable valve mechanism, and FIG. 2B is a bottom view showing the link arm in the second position. Fig.3 (a) is a front view which shows the state which distribute | arranged the link arm to the 1st position in the same variable valve mechanism, (b) is a front view which shows the state distribute | arranged to the 2nd position. FIG. 4A is a rear view showing the link arm in the first position in the variable valve mechanism, and FIG. 4B is a rear view showing the link arm in the second position. FIG. 5 (a) is a partially enlarged perspective view showing a state where the link arm is disposed at the first position in the same variable valve mechanism, and FIG. 5 (b) is a partially enlarged perspective view showing the state disposed at the second position. FIG. 6 (a) is a side view showing a state in which the first arm of the link arm is engaged with the rail groove, and FIG. 6 (b) is a state in which both arms are out of the rail groove by rotating the link arm from that state. FIG. FIG. 7 (a) is a partially enlarged front view showing a state in which both arms are out of the rail groove, and FIG. 7 (b) is to further rotate the link arm from that state to engage the second arm in the rail groove. It is a side view showing a broken state. FIG. 8 (a) is a partial enlarged front view immediately after engagement of the second arm with the rail groove, and FIG. 8 (b) is a portion showing a state in which the camshaft rotates from that state and the link arm is displaced to the intermediate position. (C) is a partially enlarged front view showing a state in which the cam is further rotated and the link arm is displaced to the second position. FIG. 9 (a) is a perspective view showing a state where the link arm is disposed at the first position in the variable valve mechanism according to the prior art, and FIG. 9 (b) is a perspective view showing the state disposed at the second position.

Although the aspect of the first and second engagement mechanisms is not particularly limited, the first engagement mechanism is a first restricting portion that restricts the displaceable range in one axial direction of the link arm to the first position; And a first suppressing portion that suppresses displacement of the link arm in the other axial direction of the link arm when the link arm is disposed at the first position; The coupling mechanism is a second restricting portion that restricts the movable range in the other axial length direction of the link arm to the second position, and when the link arm is disposed at the second position in one axial length direction of the link arm And a second suppression portion that suppresses the displacement of the link arm, and the embodiment in which the link arm is engaged by the restriction and the restriction.
However, the present invention is not limited to this. For example, when the link arm is disposed at the first position, the first engagement mechanism contacts the link arm from both sides in the axial length direction to both sides in the axial direction of the link arm. The second engagement mechanism includes a U-shaped member for suppressing displacement, and the second engagement mechanism contacts the link arm from both sides in the axial direction when the link arm is disposed at the second position. It can implement in various aspects, such as an aspect provided with another U-shaped member which controls displacement.

Although the aspect of a 1st and 2nd suppression part is not specifically limited, The following aspect is illustrated.
[I] The first suppressing portion suppresses the displacement of the link arm in the other axial direction by urging the link arm in one axial direction with an elastic force when the link arm is disposed at the first position. The second suppressing portion suppresses the displacement of the link arm in one axial direction by urging the link arm toward the other in the axial direction by an elastic force when the link arm is disposed at the second position.
[Ii] The first suppressing portion suppresses displacement of the link arm in the other axial length direction by being disposed on the other side in the axial length direction of the link arm when the link arm is disposed at the first position. The second suppressing portion is disposed on one side in the axial direction of the link arm when the link arm is disposed at the second position, thereby suppressing displacement of the link arm in the axial direction.
In addition, it can also implement in the aspect which combined both of these two aspects.

Although the aspect of the first and second restricting portions is not particularly limited, the link arm has a relatively long axial length relative to the first portion relatively on the other side in the axial length direction in that only one restricting member is required. Between the first portion and the second portion, a regulating member protruding from the support shaft is disposed between the first portion and the second portion, and the end face on the other side in the axial direction of the regulating member is the first regulating portion When the link arm is to be displaced in one axial length direction more than the first position, the first portion is in contact with the first restricting portion, and the end surface on one side in the axial length direction of the restricting member is the second restricting portion. It is preferable that the second portion abuts on the second restricting portion when the link arm is to be displaced in the other axial length direction than the second position.
However, the present invention is not limited to this. For example, a mode in which a restricting member is provided in a cylinder head or the like, or two restricting members are provided, a first restricting portion is provided in one restricting member, and a second restricting member It can implement in various modes, such as a mode provided with a control part.

Although the aspect of the first and second suppressing portions is not particularly limited, one elastic member is attached to the regulating member in that the structure is simplified, and the first suppressing portion and the second suppressing portion are attached to the one elastic member. Preferably, a part is provided.
However, the present invention is not limited to this. For example, an aspect in which an elastic member is attached to a cylinder head or the like, or two elastic members, one elastic member is provided with a first suppressing portion, and the other elastic member is a second The present invention can be implemented in various modes, such as a mode in which the suppressing portion is provided or a mode in which the pad attached to the elastic member is provided with the first or second suppressing portion.

The number of the first and second suppressing portions is not particularly limited, but the first suppressing portion includes one first suppressing portion that acts on the first portion, in that the displacement of the link arm can be suppressed more firmly. There is another first suppressing portion acting on the second portion, and the second suppressing portion includes one second suppressing portion acting on the second portion and the other second suppressing portion acting on the first portion Is preferred.
However, the present invention is not limited to this, and can be implemented in various aspects, such as an aspect in which only one first or second suppression portion is provided.

Although the aspect of the transmission mechanism is not particularly limited, the transmission mechanism is axially supported by the support shaft so as not to be axially displaceable in that the mass of the portion (input portion etc.) displaced in the axial length direction decreases with the link arm. Preferably, the locker arm is provided, and the input portion is attached to the rocker arm so as to be relatively displaceable in the axial direction.
However, the present invention is not limited thereto. For example, the transmission mechanism includes a rocker arm axially supported on the support shaft so as to be axially displaceable, the rocker arm is formed with an input portion, and the rocker arm itself together with the link arm. It can implement in various modes, such as a mode displaced to an axial direction.

  Although the aspect of the input unit is not particularly limited, it is preferable that the input unit is an input roller that rotatably abuts on the drive cam in that the friction between the drive cam and the input unit can be reduced. However, the present invention is not limited to this. For example, the input unit can be implemented in various modes, such as a mode in which the pad is in sliding contact with the drive cam.

Although the aspect of the rocker arm is not particularly limited, one rocker arm drives two valves at a point where only one rocker arm is dispersed and a force is applied in the axial direction, and the one rocker arm includes two It is preferable that the input units be arranged in line in the axial direction and that the predetermined drive cam be provided on the camshaft for each input unit.
However, the present invention is not limited to this, and can be implemented in various modes, such as an aspect in which a rocker arm is provided for each valve, an aspect in which only one input unit is attached to one rocker arm driving two valves.

  Although the aspect of a rotation apparatus is not specifically limited, The aspect provided with one actuator which rotates a link arm to one axial length direction, and the other actuator which rotates to an other axial length direction is illustrated. However, the present invention is not limited to this, and can be implemented in various modes, such as a mode provided with a return spring that is rotated in the other axial direction. The actuator is not particularly limited, but is exemplified by one provided with an electromagnetic solenoid, a hydraulic mechanism, a motor mechanism and the like.

  The manner of engagement between the link arm and the input unit is not particularly limited, but the link arm is in sliding contact with the input unit from both sides in the axial direction in that the link arm is easily engaged even when the input unit is an input roller or the like. Is preferred. However, the present invention is not limited to this, and can be implemented in various modes, such as an aspect in which the input unit is in sliding contact with the link arm from both sides in the axial direction.

The operating state of the valve when the link arm is displaced to the second position is not particularly limited, but illustrates the following aspect.
[I] The cam shaft is provided with a second drive cam having a profile different from that of the predetermined drive cam, and when the link arm is displaced to the second position, the input portion abuts on the second drive cam, whereby the transmission mechanism Is an aspect in which the force of the second drive cam is transmitted to the valve.
[Ii] A mode in which the cam shaft is provided with a circular cam not having a nose, and when the link arm is displaced to the second position, the transmission mechanism does not transmit force to the valve because the input portion abuts on the circular cam.

  Next, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the examples, and can be appropriately modified and implemented without departing from the scope of the invention.

  1 (a) and 1 (b) are perspective views showing a variable valve mechanism 101 of the embodiment. The variable valve mechanism 101 periodically opens and closes the valve 109 in cooperation with the valve spring by periodically pressing the valve 109 to which the valve spring (not shown) is attached. The variable valve mechanism 101 includes a camshaft 1, a support shaft 2 extending parallel to the camshaft 1, a link arm 3 pivotally supported by the support shaft 2 in the axial direction, and a link arm 3. A rotating device 4 is provided to rotate in the circumferential direction, and a transmission mechanism 5 extending from the camshaft 1 to the valve 109.

  The camshaft 1 rotates once every two revolutions of the internal combustion engine. The camshaft 1 has two sets of a first drive cam 11 and a second drive cam 12 arranged in the axial length direction and a rail groove 15 formed of three grooves 16, 17, 18 for each cylinder. It is provided. Each of the first and second drive cams 11 and 12 includes a base circle having a circular cross-sectional shape and a nose protruding from the base circle, and the nose of the first drive cam 11 is the second drive cam 12 The operating angle is wider than the nose. The first drive cam 11 and the second drive cam 12 are alternately provided in the axial direction.

  The rail groove 15 is composed of three grooves of a first switching groove 16, a locking groove 17 and a second switching groove 18. The locking groove 17 is a groove for locking the link arm 3 in the axial length directions d1 and d2 in a non-displaceable manner, and extends annularly in the circumferential direction of the camshaft 1 without shifting in the axial direction.

  The first switching groove 16 is a groove for displacing the link arm 3 in the axial length direction d1 and is provided on the other axial length direction d2 side than the locking groove 17. The first switching groove 16 extends from the base end to a predetermined position in the direction opposite to the rotational direction of the camshaft 1 without shifting in the axial length directions d1 and d2. From the predetermined position, the first switching groove 16 The spiral extending in the axial length direction d1 side as it travels in the direction opposite to the rotation direction of 1 extends in a spiral shape and joins the locking groove 17.

  The second switching groove 18 is a groove for displacing the link arm 3 in the other axial direction d2, and is provided on the one axial side d1 side of the locking groove 17. The second switching groove 18 extends from the base end to a predetermined position in the direction opposite to the rotational direction of the camshaft 1 without shifting in the axial length directions d1 and d2. From the predetermined position, the second switching groove 18 The spiral extending in the direction of the other side d2 in the axial direction as it travels in the direction opposite to the rotational direction of 1 and merges with the locking groove 17.

  The link arm 3 connects the three members of the base 33, the first cylindrical portion 35, and the second cylindrical portion 38, which are externally fitted to the support shaft 2, and the upper portions of the three members 33, 35, 38. The upper bridge portion 34, the rear bridge portion 36 connecting the rear portions of the first tubular portion 35 and the second tubular portion 38, and the front portion of the first tubular portion 35 and the second tubular portion 38 And a front bridge portion 37 to be connected. The rear bridge portion 36 has a rectangular frame shape, and when the rear bridge portion 36 is pressed by the pivoting device 4, the link arm 3 pivots. The base 33 is provided with the first arm 31 so as to protrude, and the tip end of the first arm 31 is provided with the first engagement portion 31 a which can be engaged with the first switching groove 16 and the locking groove 17. . A second arm 32 is provided in a protruding manner in the upper bridge portion 34, and a second engaging portion 32a which can be engaged with the second switching groove 18 and the locking groove 17 is provided in a projecting portion of the second arm 32. ing.

  The helically extending portion of the first switching groove 16 is provided in a phase in sliding contact with the first engagement portion 31 a when the base circular action of the first and second drive cams 11 and 12 is performed. Thus, the link arm 3 is displaced along the first switching groove 16 in the axial length direction d1 during base circle operation. The helically extending portion of the second switching groove 18 is provided in a phase in sliding contact with the second engagement portion 32 a when the base circular action of the first and second drive cams 11 and 12 is performed. Thus, the link arm 3 is displaced along the second switching groove 18 in the other axial direction d2 during base circle operation.

  The rotation device 4 includes a first actuator 41 for rotating the link arm 3 in one axial direction r1 and a second actuator 42 for rotating the link arm 3 in the other axial direction r2. It is done. Each actuator 41, 42 is composed of a body (not shown) and rods 41a, 42a inserted into the body, and the rods 41a, 42a are extended and retracted by turning on and off an electromagnetic solenoid installed inside the body. Let

  The transmission mechanism 5 includes a rocker arm 53 externally fitted to the support shaft 2 and an input roller 51 attached to the rocker arm 53. The rocker arm 53 has two arm portions 55 pivotally supported by the support shaft 2 on both sides in the axial length directions d1 and d2 sandwiching the first and second cylindrical portions 35 and 38, and a lower portion of the arm portion 55. It is configured to include an arm bridge portion 54 that connects the two and a roller shaft 52 that connects the tip portions of the arm 55. The two input rollers 51 are externally fitted on the roller shaft 52 so as to be displaceable and rotatable in the axial direction d1 and d2. Stoppers 25 for making the rocker arm 53 undisplaceable in the axial length directions d1 and d2 are attached to both side portions of the support shaft 2 in the axial length directions d1 and d2 sandwiching the two arm portions 55 therebetween.

  FIGS. 2A and 2B are bottom views showing a state in which the link arm 3 is disposed at the first position p1 and the second position p2. The front bridge portion 37 of the link arm 3 has a shape that is in sliding contact with the two input rollers 51 from both sides in the axial direction d1 and d2. Therefore, the link arm 3 and the input roller 51 are displaced together in the axial direction d1 and d2. The hatching of the two-dot chain line shown in the figure indicates the link arm 3. Therefore, the cross section is not shown. The same applies to FIGS. 3 (a) and 3 (b) and FIGS. 4 (a) and 4 (b).

  FIGS. 3A and 3B are front views showing a state in which the link arm 3 is disposed at the first position p1 and the second position p2. When the link arm 3 is displaced to the first position p1, the input roller 51 comes in contact with the first drive cam 11. As a result, the transmission mechanism 5 transmits the force of the first drive cam 11 to the valve 109, and drives the valve 109 in accordance with the profile of the first drive cam 11. When the link arm 3 is displaced to the second position p2, the input roller 51 comes in contact with the second drive cam 12. As a result, the transmission mechanism 5 transmits the force of the second drive cam 12 to the valve 109 and drives the valve 109 in accordance with the profile of the second drive cam 12.

  FIGS. 4A and 4B are rear views showing a state in which the link arm 3 is disposed at the first position p1 and the second position p2. The first and second actuators 41 and 42 are not displaced in the axial length directions d1 and d2, and the link arm 3 is displaced with respect to the actuators 41 and 42 in the axial length directions d1 and d2.

  5 (a) and 5 (b) are enlarged perspective views showing a state in which the link arm 3 is disposed at the first position p1 and the second position p2. Between the first cylindrical portion 35 and the second cylindrical portion 38, a restriction member 6 (bush) which protrudes downward from the support shaft is installed. The elastic member 7 is attached to the lower end surface of the restriction member 6 by a bolt 77. The elastic member 7 protrudes from the restriction member 6 on both sides in the axial length direction d1 and d2, respectively, and each protruding portion is curved such that the intermediate portion protrudes upward (the support shaft 2 side).

  As shown in FIG. 5A, when the link arm 3 is about to be displaced in the axial direction d1 relative to the first position p1, the end face on the other side d2 in the axial direction of the regulating member 6 has a first cylindrical shape. The first regulation portion 61 with which the portion 35 abuts is configured, and the displacement is regulated by the abutment. And, in the axial length direction one d1 side portion of the portion of the elastic member 7 projecting to the other axial length direction d2 side, the axial length direction of the first tubular portion 35 when the link arm 3 is disposed at the first position p1. On the other hand, one first suppressing portion 71 which is disposed on the d2 side and biases the first tubular portion 35 in the axial length direction d1 side is configured. Further, the portion in the axial length direction one d1 side of the portion of the elastic member 7 projecting in the axial length direction one d1 side is the axial length direction of the second cylindrical portion 38 when the link arm 3 is disposed at the first position p1. On the other hand, the other first suppressing portion 71 which is disposed on the d2 side and biases the second cylindrical portion 38 in the axial length direction d1 side is configured. The first restricting portion 61 and the one and the other first suppressing portions 71 constitute a first engagement mechanism e1 engaged with the link arm 3 when the link arm 3 is disposed at the first position p1. ing.

  As shown in FIG. 5 (b), the end face of the restricting member 6 on the one side d1 in the axial length direction has a second cylindrical shape when the link arm 3 tries to be displaced to the other side d2 in the axial direction than the second position p2. The second regulation portion 62 with which the portion 38 abuts is configured, and the displacement is regulated by the abutment. Then, the portion in the axial length direction the other d2 side of the portion of the elastic member 7 projecting in the axial length direction one d1 side is the axial length direction of the second cylindrical portion 38 when the link arm 3 is disposed at the second position p2. On the other hand, one second suppressing portion 72 which is disposed on the d1 side and biases the second cylindrical portion 38 to the other side in the axial length direction d2 is configured. Further, the portion in the axial length direction other d2 side of the portion of the elastic member 7 that protrudes to the other axial length direction d2 side is the axial length direction of the first cylindrical portion 35 when the link arm 3 is disposed at the second position p2. On the other hand, the other second suppressing portion 72 which is disposed on the d1 side and biases the first cylindrical portion 35 to the other side in the axial length direction d2 is configured. The second restricting portion 62 and the one and the other second suppressing portions 72 constitute a second engagement mechanism e2 engaged with the link arm 3 when the link arm 3 is disposed at the second position p2. ing.

  Next, displacement of the link arm 3 from the first position p1 to the second position p2 will be described with reference to FIGS. As shown in FIG. 6A, in the state where the link arm 3 is disposed at the first position p1, the first engagement portion 31a is engaged with the rail groove 15 (the locking groove). Therefore, even if a force in the axial length direction d1 or d2 is applied to the link arm 3 due to vibration or the like of the internal combustion engine at this time, the link arm 3 is not displaced in the axial length directions d1 and d2. From this state, as shown in FIG. 6 (b), when the link arm 3 is rotated in the other rotation direction r2 by the rotation device 4, the second engagement portion 32a engages with the rail groove 15 (second switching groove). Before entering, the engagement between the first engagement portion 31a and the rail groove 15 (locking groove) is released. Therefore, the first and second engaging portions 31 a and 32 a are not engaged with the rail groove 15.

  However, as shown in FIG. 7A, the displacement of the link arm 3 in the axial length direction d1 is restricted by the contact of the first cylindrical portion 35 with the first restricting portion 61. The first suppressing portion 71 of the first cylindrical portion 35 is disposed on the other side d2 in the axial direction of the first cylindrical portion 35, and biases the first cylindrical portion 35 to the one side d1 in the axial length direction. The second cylindrical portion 38 is disposed on the other side in the axial direction d2 and biases the second cylindrical portion 38 in the axial direction d1. The link arm 3 is not displaced in the axial direction d1 or d2 even if a force in the axial direction d1 or d2 is applied. As shown in FIG. 7B from that state, when the link arm 3 is further rotated by the rotating device 4 in the other rotation direction r2, the second engagement portion 32a engages with the rail groove 15 (second switching groove). Turn on.

  At this moment, as shown in FIG. 8A, the link arm 3 is still disposed at the first position p1. Thereafter, when the second engaging portion reaches the spirally extending portion of the second switching groove by the rotation of the camshaft, the link arm 3 is displaced in the other axial direction d2 as shown in FIG. 8B. . At this time, the link arm 3 and the first engagement mechanism e1 are configured such that the first tubular portion 35 pushes down one of the first suppression portions 71 and the second tubular portion 38 pushes down the other first suppression portion 71. Engagement is released. Thereafter, when the camshaft further rotates and the second engaging portion passes through the spirally extending portion of the second switching groove and enters the locking groove, the first and second cylindrical portions 35 and 38 are elastic. After passing above the member 7, as shown in FIG. 8C, the link arm 3 is disposed at the second position p2, and both sides of the elastic member 7 which has been pushed down return upward by elastic force. . Therefore, one second suppressing portion 72 is disposed on one side d1 side in the axial length direction of the second cylindrical portion 38, and the other second suppressing portion 72 is on the one side d1 side in the axial length direction of the first cylindrical portion 35. Will be distributed. In addition, one second suppressing portion 72 biases the second cylindrical portion 38 in the axial length direction to the other d2, and the other second suppressing portion 72 attaches the first cylindrical portion 35 to the other in the axial length direction d2. I will come to power. Therefore, the second cylindrical portion 38 is pressed against the second restricting portion 62. As a result, the second engagement mechanism e2 engages with the link arm 3.

  In the meantime, the description for displacing the link arm 3 from the second position p2 to the first position p1 contrary to the above is different from the above description in each of the “first position p1” and the “second position p2”. In the same way, each of the "first engagement portion 31a" and the "second engagement portion 32a", each of the "rotational direction one r1" and the "rotational direction other r2" One of the first switching groove and the second switching groove, each of the first restricting portion 61 and the second restricting portion 62, the first cylindrical portion 35 and the second cylindrical portion 38 Each of “one axial direction d1” and “the other axial direction d2”, each “first suppression portion 71” and “second suppression portion 72”, “first engagement mechanism e1 And “the second engagement mechanism e2” are similar to each other, with the other being read as the other.

  According to the present embodiment, as described above, at a timing when neither the first nor the second engaging portion 31a, 32a is engaged with the rail groove 15, the link arm 3 is axially elongated in the axial direction by the vibration of the internal combustion engine or the like. Even if a force is applied to d1 and d2, the link arm 3 does not shift in the axial direction d1 and d2 because the first and second engagement mechanisms e1 and e2 are present. Therefore, switching can be performed reliably. Further, at the time of switching in which the link arm 3 is displaced in the axial direction d1 or d2 by the first or second engaging portion 31a or 32a engaging with the rail groove 15 (first or second switching groove 16 or 18) Since the link arm 3 is released from the engagement with the engaged first or second engagement mechanism e 1, e 2 by the displacement force, no excessive force is applied to the link arm 3.

Reference Signs List 1 cam shaft 2 support shaft 3 link arm 4 rotation device 5 transmission mechanism 6 restriction member 7 elastic member 11 first drive cam (predetermined drive cam)
15 rail groove 31 first arm 32 second arm 35 first cylindrical portion (first portion)
38 Second tubular part (second part)
51 input roller (input unit)
53 Rocker arm 61 First restricting portion 62 Second restricting portion 71 First suppressing portion 72 Second suppressing portion 101 Variable valve mechanism 109 Valve d1 Axial length direction one side d2 Axial length direction other e1 first engagement mechanism e2 second engagement Mechanism p1 first position p2 second position r1 rotation direction one r2 rotation direction other

Claims (9)

A camshaft (1), which is a shaft that rotates according to the rotation of an internal combustion engine, in which a drive cam (11) and a rail groove (15) formed of a plurality of circumferentially extending grooves are formed;
A support shaft (2) extending parallel to the camshaft (1);
A first arm (31) and a second arm (32), which are movable bodies pivotally supported on the support shaft (2) in the axial direction so as to be displaceable in the axial direction and selectively engage with the rail groove (15). , And the first arm (31) engages with the rail groove (15) after the engagement between the second arm (32) and the rail groove (15) is released when the first arm (32) is turned in the axial circumferential direction (r1) By moving to the first position (p1) on the one side (d1) in the axial length direction and turning to the other (r2) in the axial circumferential direction, the first arm (31) and the rail groove (15) Link arm (3) relatively displaced to the second position (p2) on the other side (d2) in the axial length direction by the engagement of the second arm (32) with the rail groove (15) after the engagement is released )When,
A rotating device (4) for rotating the link arm (3);
The link arm (3) is a mechanism extending from the camshaft (1) to the valve (109), the input section (51) being displaced in the axial length direction (d1, d2) together with the link arm (3) Is displaced to the first position (p1), the input portion (51) comes into contact with the predetermined drive cam (11), thereby transmitting the force of the drive cam (11) to the valve (109). When the link arm (3) is displaced to the second position, the input part (51) does not abut on the predetermined drive cam (11), the force of the drive cam (11) is reduced by the valve (109). In a variable valve mechanism of an internal combustion engine provided with a transmission mechanism (5) which is not transmitted to the
A mechanism that engages with the link arm (3) when the link arm (3) is disposed at the first position (p1), and the axial length direction (d1, d2) of the link arm (3) by the engagement Of the link arm (32) from the first position (p1) to the second position (p2) when the second arm (32) engages with the rail groove (15). A first engagement mechanism (e1) in which the engagement between the mechanism and the link arm (3) is released by the
A mechanism that engages with the link arm (3) when the link arm (3) is disposed at the second position (p2), and the axial length direction (d1, d2) of the link arm (3) by the engagement Of the link arm (3) from the second position (p2) to the first position (p1) while the first arm (31) engages with the rail groove (15). A variable valve mechanism of an internal combustion engine, comprising: a second engagement mechanism (e2) in which the engagement between the mechanism and the link arm (3) is released. The first engagement mechanism (e1) comprises a first restricting portion (61) for restricting a movable range in one axial length direction (d1) of the link arm (3) to a first position (p1), and the link arm And a first suppression portion (71) for suppressing the displacement of the link arm (3) in the other axial length direction (d2) when the (3) is disposed at the first position (p1). Engage the link arm (3) by
The second engagement mechanism (e2) comprises a second restricting portion (62) for restricting the movable range of the link arm (3) in the other axial length direction (d2) to the second position (p2), and the link arm And a second suppression portion (72) for suppressing the displacement of the link arm (3) in the axial length direction one (d1) when the (3) is disposed at the second position (p2), The variable valve mechanism of an internal combustion engine according to claim 1, wherein the link arm (3) is engaged with the restraint. When the link arm (3) is disposed at the first position (p1), the first suppressing portion (71) urges the link arm (3) in one axial direction (d1) by an elastic force. Restraining displacement of the arm (3) in the other axial direction (d2),
When the link arm (3) is disposed at the second position (p2), the second suppressing portion (72) urges the link arm (3) to the other axial length direction (d2) by an elastic force. The variable valve mechanism for an internal combustion engine according to claim 2, wherein the displacement of the arm (3) in one axial direction (d1) is suppressed. When the link arm (3) is disposed at the first position (p1), the first suppressing portion (71) is disposed on the other side (d2) in the axial length direction of the link arm (3). 3) suppressing the displacement to the other axial length direction (d2),
When the link arm (3) is disposed at the second position (p2), the second suppressing portion (72) is disposed on one side (d1) of the link arm (3) in the axial length direction. The variable valve mechanism of an internal combustion engine according to claim 2 or 3, which suppresses the displacement of 3) in one axial length direction (d1). The link arm (3) includes a first portion (35) relatively on the other side (d2) in the axial length direction and a second portion (38) relatively on the one side (d1) in the axial length direction. ,
Between the first portion (35) and the second portion (38), a regulating member (6) protruding from the support shaft (2) is installed,
The end face on the other axial direction (d2) side of the regulating member (6) is the first regulating portion (61), and the link arm (3) is displaced to one axial direction (d1) than the first position (p1) When trying to do so, the first part (35) abuts on the first restriction part (61),
The end face on one axial direction (d1) side of the regulation member (6) is the second regulation portion (62), and the link arm (3) is displaced to the other axial direction (d2) than the second position (p2) The variable valve mechanism of an internal combustion engine according to any one of claims 2 to 4, wherein the second portion (38) abuts on the second restricting portion (62) when the second portion (38) tries to move.   The elastic member (7) is attached to the restricting member (6), and the elastic member (7) is provided with the first suppressing portion (71) and the second suppressing portion (72). Variable valve mechanism of an internal combustion engine as described above. The first suppressing portion (71) includes one first suppressing portion (71) acting on the first portion (35) and the other first suppressing portion (71) acting on the second portion (38). Yes,
The second suppression portion (72) includes one second suppression portion (72) acting on the second portion (38) and the other second suppression portion (72) acting on the first portion (35). A variable valve mechanism for an internal combustion engine according to claim 5 or 6.   The transmission mechanism (5) includes a rocker arm (53) axially supported in the axial direction of the support shaft (2) so that the input portion (51) can be displaced relative to the rocker arm (53) in the axial direction. The variable valve mechanism of an internal combustion engine according to any one of claims 1 to 7, which is mounted. One rocker arm (53) drives two valves (109), and the one rocker arm (53) has two input parts (51) axially aligned and mounted,
9. A variable valve operating mechanism for an internal combustion engine according to claim 8, wherein said predetermined drive cam (11) is provided on the camshaft (1) for each input portion (51).

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