JP5766094B2 - Variable valve mechanism - Google Patents

Description

  The present invention relates to a variable valve mechanism that includes a two-valve integrated rocker arm that swings to drive two valves when driven by a cam.

  Examples of the variable valve mechanism that includes the two-valve integrated rocker arm include the variable valve mechanism of Patent Document 1 previously filed by the present applicant and the variable valve mechanism of Patent Document 2 (unpublished). is there.

JP 2008-190393 A Japanese Patent Application No. 2010-212268

  In these variable valve mechanisms of Patent Documents 1 and 2, the connecting pin is driven to switch between a driving state in which both valves are driven and a resting state in which driving of both valves is paused. Although fuel efficiency can be realized, since the rocker arm is a two-valve integrated type, it is not possible to change only the driving amount of the other valve without changing the driving amount of one valve, and hence the high Output cannot be realized.

  Accordingly, in a variable valve mechanism including a two-valve integrated rocker arm, it is a first object to be able to change only the drive amount of the other valve without changing the drive amount of one valve. In addition, the second object is to allow the two valves to be stopped.

In order to achieve the above first object, the variable valve mechanism of the present invention includes a rocker arm that swings when driven by a cam and drives two valves. Is a rocker arm body that is driven by the cam and swings, and that has a one-side cam surface that drives one valve, and the rocker arm body cannot be relatively displaced in the swing direction and in the swing axis direction. The other side first cam surface and the second side second cam surface, which are engaged with each other so as to be capable of relative displacement and have different cam profiles to drive the other valve, are divided into slide arms arranged side by side in the swing axis direction. is formed, includes a displacement mechanism for displacing the slide arm pivot axis direction, the displacement mechanism, first change shifted to one of the swing axis direction in accordance with the process proceeds to the circumferential direction of the slide arm A groove, a second switching groove that shifts to the other in the swing axis direction as it advances in the circumferential direction, a first engaging portion and a second engaging portion, and the second engaging portion is engaged with the second switching groove. Then, the rocking force of the rocker arm is changed to a displacement force to one side of the rocking axis direction and transmitted to the slide arm, thereby displacing the slide arm to one side of the rocking axis direction, and the first switching groove Displace the slide arm to the other in the swing axis direction by engaging the first engaging portion and changing the rocking force of the rocker arm to the displacement force to the other in the swing axis direction. And the displacement mechanism displaces the slide arm in the direction of the swing axis so that the cam surface for driving the other valve is changed to the other side first cam surface and the other side second cam surface. Switch between And changes the driving amount of the square of the valve.

The configuration of the displacement mechanism is not particularly limited , and includes a V-shaped arm, and the V-shaped arm includes a cylindrical cylindrical portion that is rotatably fitted to a support shaft that extends in the swing axis direction. A first arm and a second arm that protrude from the cylindrical portion and sandwich the slide arm therebetween are provided in a V-shape, and the first engagement portion is formed inside the distal end portion of the first arm, and the second arm The second engaging portion is formed on the inner side of the distal end of the arm, and by rotating the V-shaped arm in one circumferential direction, the second engaging portion is engaged with the second switching groove. Exemplifies a configuration in which the first engagement portion is engaged with the first switching groove by rotating the first engagement groove in the circumferential direction .

  To achieve the second object, the rocker arm main body is divided into an input arm that is driven by the cam and swings, and an output arm that includes the one-side cam surface and is engaged with the slide arm. The variable valve mechanism is a switching mechanism that switches between a connected state in which the input arm and the output arm are connected in a swinging direction so as not to be relatively displaceable and a disconnected state in which the connection is released. It is preferable to switch between a driving state for driving the two valves and a resting state for stopping the driving by switching between a connected state and a non-connected state by the switching mechanism. . In addition to changing the drive amount of the other valve as needed with the displacement mechanism, it is possible to achieve both high output and low fuel consumption by stopping the drive of the two valves with the switching mechanism when not needed. is there.

The variable valve mechanism is not particularly limited, but is preferably any one of the following {1} {2} modes. This is because the number of shafts can be reduced and compact.
{1} The two valves are two intake valves, and the rocker arm that drives the two intake valves is pivotally supported by a camshaft of an exhaust cam that drives the exhaust valve.
{2} The two valves are two exhaust valves, and the rocker arm that drives the two exhaust valves is pivotally supported by a camshaft of an intake cam that drives the intake valve.

  According to the present invention, in a variable valve mechanism configured to include a two-valve integrated rocker arm that drives two valves, only the driving amount of the other valve can be changed without changing the driving amount of one valve. Can be.

It is a perspective view which shows the variable valve mechanism for intake / exhaust of Example 1. FIG. 1 is a perspective view illustrating a variable valve mechanism for intake air according to a first embodiment. It is the disassembled perspective view which looked at the rocker arm of the variable valve mechanism for intake of Example 1 from diagonally upward. It is the disassembled perspective view which looked at the rocker arm of the variable valve mechanism for intake of Example 1 from diagonally downward. (A) is sectional drawing which shows the non-connection state of the variable valve mechanism for intake of Example 1, (b) is sectional drawing which shows a connection state. (A) is a perspective view which shows the time of high speed rotation of the variable valve mechanism for intake of Example 1, (b) is a perspective view which shows the time of low speed rotation. (A) is a graph which shows the valve drive amount at the time of high speed rotation of the variable valve mechanism for intake / exhaust of Example 1, (b) is a graph which shows the valve drive amount at the time of low speed rotation. It is a perspective view which shows the variable valve mechanism for intake / exhaust of Example 2. FIG. (A) is a graph which shows the valve drive amount at the time of high speed rotation of the variable valve mechanism for intake / exhaust of Example 2, (b) is a graph which shows the valve drive amount at the time of low speed rotation.

  The variable valve mechanism 9 for intake and exhaust according to the first embodiment shown in FIGS. 1 to 7 includes a variable valve mechanism 9I for intake that drives two intake valves and an exhaust valve that drives two exhaust valves. And a variable valve mechanism 9E.

  Since the variable valve mechanism 9I for intake and the variable valve mechanism 9E for exhaust are substantially similar in structure, only the structure and function of the variable valve mechanism 9I for intake will be described below. The description of the structure and function of the variable valve mechanism 9E for use is as follows: description of the structure and function of the variable valve mechanism 9I for intake shown below (paragraphs 0014 to 0028), “intake” and “exhaust” The same applies to reading the opposite directions, reading “I” and “E” opposite each other, and reading “i” and “e” opposite each other.

  The intake variable valve mechanism 9I includes a cam 10, a link 20, a rocker arm 30, a switching mechanism 50, and a displacement mechanism 60 described below. In the following, for the sake of convenience, one of the rocker arm 30 in the swing axis direction is referred to as the left L and the other of the rocker axis direction is referred to as the right R for convenience.

[Cam 10]
The cam 10 (intake cam 10i) is a cam having a true circular cross section formed integrally with a camshaft 11 (intake camshaft 11i) provided in the left and right directions L and R provided immediately above the exhaust valve. The center is eccentric from the axis of the camshaft 11. The camshaft 11 rotates once every time the internal combustion engine rotates twice.

[Link 20]
The link 20 is a linear member extending in a straight line that changes the rotational force of the cam 10 to a rocking force and transmits it to the rocker arm 30. The rear end of the link 20 is externally fitted to the cam 10 so as to be relatively rotatable.

[Rocker arm 30]
The rocker arm 30 is slidably fitted on an exhaust camshaft 11e extending in the left and right directions L and R provided immediately above the intake valve. When the cam 10 (intake cam 10i) is driven via the link 20, it swings to drive the two intake valves via the two intervening arms 3 and 4. The rocker arm 30 is divided into a left rocker arm main body 31 and a right slide arm 41 as shown below.

  The rocker arm main body 31 is divided into a left input arm 31a and a right output arm 31b. The input arm 31a is an arm that swings when driven by the cam 10 via the link 20, and an intermediate portion in the longitudinal direction is externally fitted to the exhaust camshaft 11e so as to be swingable. The rear end portion is pivotally attached to the tip end portion of the link 20 via a connecting shaft 22 so as to be relatively rotatable, and a part of the switching mechanism 50 is provided at the tip end portion. The output arm 31b is an arm that is connected to the input arm 31a via the switching mechanism 50 so as not to swing relative to the input arm 31a, and has a cylindrical cylindrical portion 32 that is externally fitted to the exhaust camshaft 11e so as to swing. A rib 33 projecting rightward (from the slide arm 41 side) from the right end of the cylindrical portion 32 and a cam nose 35 projecting radially from the cylindrical portion 32 are configured. A plurality of groove-shaped outer peripheral straight splines 34 extending straight in the left and right directions L and R are provided on the outer peripheral surface of the rib 33. Further, a one-side cam surface 36 that drives one valve via one intervening arm 3 is formed at a portion extending from the lower surface of the cylindrical portion 32 to the lower surface of the cam nose 35.

  The slide arm 41 is an arm engaged with the output arm 31b by meshing the straight splines 34, 44, and has a cylindrical cylindrical portion 42 that is externally fitted to the exhaust camshaft 11e so as to be swingable, and the cylindrical portion 42. A storage portion 43 for storing the rib 33 of the rocker arm body 31 that is recessed on the inner peripheral side of the left portion (portion on the output arm 31b side), and a cam nose 45 that protrudes from the cylindrical portion 42 in the radial direction. It is configured. An inner peripheral straight spline 44 that meshes with the outer peripheral straight spline 34 of the output arm 31 b is provided on the inner peripheral surface of the storage portion 43. The slide arm 41 is engaged with the output arm 31b so as not to be relatively displaceable in the swing direction and to be relatively displaceable in the left and right directions L and R by meshing these straight splines 34 and 44. Further, at the portion extending from the lower surface of the cylindrical portion 42 to the lower surface of the cam nose 45, the other valve is driven via the other intervening arm 4 and the driving amount is relatively small (the driving amount of the one-side cam surface 36). The left side first cam surface 46 and the right side second cam surface 47 having a relatively large driving amount.

[Switching mechanism 50]
The switching mechanism 50 performs switching between a connection state in which the left input arm 31a and the right output arm 31b of the rocker arm body 31 are connected and a non-connection state in which the connection is released, thereby switching between two intake valves ( A mechanism for switching between a driving state in which the two intervening arms 3 and 4) are driven and a resting state in which the driving is suspended, and includes a connecting pin 51, a connecting spring 52, and a hydraulic mechanism 53, which will be described below. And is configured. The connecting pin 51 is attached to the distal end portion of the left input arm 31a so as to protrude rightward R, and the connecting position spans between the distal end portion of the left input arm 31a and the cam nose 35 of the right output arm 31b. And the unconnected position that does not straddle. The connection spring 52 is a spring for pressing the connection pin 51 to the right R (connection position side) with a restoring force, and is provided inside the distal end portion of the left input arm 31a. The hydraulic mechanism 53 is a mechanism for pressing the connecting pin 51 to the left L (non-connecting position side) with hydraulic pressure, and is provided inside the right output arm 31b. The hydraulic mechanism 53 includes a hydraulic chamber 54 that is recessed in the left side surface of the cam nose 35 of the right output arm 31 b, and is inserted into the hydraulic chamber 54 to close the hydraulic chamber 54 and has a left end surface that is connected to the connecting pin 51. A hydraulic pin 55 in contact with the right end surface and a hydraulic path 56 for supplying hydraulic pressure to the hydraulic chamber 54 are configured. The hydraulic path 56 is provided via the inside of the exhaust camshaft 11e and the inside of the output arm 31b. Then, by increasing the hydraulic pressure in the hydraulic chamber 54, the connecting pin 51 is displaced to the left unconnected position against the restoring force of the connecting spring 52 as shown in FIG. Further, by lowering the hydraulic pressure in the hydraulic chamber 54, the connecting pin 51 is displaced to the right R connecting position by the restoring force of the connecting spring 52, as shown in FIG.

[Displacement mechanism 60]
The displacement mechanism 60 changes the rocking force of the rocker arm 30 to the slide arm 41 by changing the rocking force of the rocker arm 30 to the left L, thereby displacing the slide arm 41 to the left L, and the rocking force of the rocker arm 30 to the right R It is a mechanism that displaces the slide arm 41 to the right R by transmitting it to the slide arm 41 instead of the displacement force. The displacement mechanism 60 includes a V-shaped arm 61 and an engaged portion 71 shown below.

  The V-shaped arm 61 includes a cylindrical cylindrical portion 62 that is rotatably fitted to a support shaft 68 that extends in the left and right directions L and R, and protrudes from the cylindrical portion 62 to sandwich the slide arm 41 therebetween. One arm 63 and second arm 65 are provided in a V shape. A first engaging portion 64 is formed on the inner side of the first arm 63 (on the slide arm 41 side), and a second engaging portion 66 is formed on the inner side of the second arm 65 (on the slide arm 41 side). Has been. Further, the first arm 63 is an actuator rod that rotates the V-arm 61 to both sides in the circumferential direction of the support shaft 68 by urging the first arm 63 toward the slide arm 41 and the opposite side. 69 is connected. The actuator may be a hydraulic actuator that moves under hydraulic control, or an electromagnetic actuator that moves under solenoid control.

  The engaged portion 71 is composed of a plurality of grooves recessed in the outer peripheral surface of the slide arm 41, a first switching groove 74 for displacing the slide arm 41 to the right R, and the slide arm 41 to the right R The first restraining groove 73 for restraining the left and right directions L and R to be undisplaceable at the position displaced to the left, the second switching groove 76 for displacing the slide arm 41 to the left L, and the slide arm 41 to the left And a second restraining groove 75 for restraining the left and right directions L and R to be undisplaceable at a position displaced in the direction L. The first switching groove 74 and the first restricting groove 73 are grooves for engaging the first engaging portion 64 of the V-shaped arm 61, and the first restricting groove 73 slides in the left and right directions L and R without shifting. The arm 41 extends in a straight arc shape in the circumferential direction. Further, the first switching groove 74 is provided on the right side R of the first restraining groove 73, and shifts to the left L as it advances in the circumferential direction of the slide arm 41 at a predetermined position to join the first restraining groove 73. doing. The second switching groove 76 and the second restricting groove 75 are grooves for engaging the second engaging portion 66 of the V-shaped arm 61, and the second restricting groove 75 slides without shifting in the left and right directions L and R. The arm 41 extends in a straight arc shape in the circumferential direction. Further, the second switching groove 76 is provided on the left side L of the second restraining groove 75, and is shifted to the right side R as it advances in the circumferential direction of the slide arm 41 at a predetermined position to join the second restraining groove 75. doing.

  The state when the two intake valves are driven through the two intervening arms 3 and 4 by the variable valve mechanism 9I for intake shown above is shown in [a] at the time of high speed rotation of the internal combustion engine and [b] of the internal combustion engine. This will be described below separately for low-speed rotation.

[A] During high-speed rotation of the internal combustion engine During high-speed rotation of the internal combustion engine, as shown in FIG. 6 (a), the V-arm 61 is rotated in one of the circumferential directions by the rod 69 of the actuator. The engaging portion 64 is retracted from the first restraining groove 73 and the second engaging portion 66 is engaged in the second switching groove 76. In this state, when the slide arm 41 swings together with the rocker arm body 31, the left inner surface of the second switching groove 76 is pressed to the left L by the left outer surface of the second engaging portion 66. As a result, the slide arm 41 is displaced to the left L, and the cam surface that drives the other intervening arm 4 is switched from the left-side first cam surface 46 to the right-side second cam surface 47. Therefore, one valve (intervening arm 3) is driven by the one side cam surface 36 of the rocker arm main body 31, and the other valve (intervening arm 4) is the other side second cam surface 47 of the slide arm 41 (driving amount: Large).

  At this time, the second switching groove 76 is shifted to the right R while the other intervening arm 4 is in contact with the cylindrical portion 42 (base circle), and before the other intervening arm 4 is in contact with the cam nose 45, Since it is designed to join the restraining groove 75, the slide arm 41 is moved to the left L when the base circle abuts at the minimum load, regardless of the timing when the V-shaped arm 61 is rotated in one of the circumferential directions. Driven by.

[B] When the internal combustion engine rotates at a low speed When the internal combustion engine rotates at a low speed, as shown in FIG. 6B, the V-arm 61 is rotated in the other circumferential direction by the rod 69 of the actuator. The engaging portion 64 is engaged with the first switching groove 74 and the second engaging portion 66 is retracted from the second restricting groove 75. In this state, the slide arm 41 swings together with the rocker arm body 31, whereby the right inner surface of the first switching groove 74 is pressed to the right R by the right outer surface of the first engagement portion 64. As a result, the slide arm 41 is displaced to the right R, and the cam surface that drives the other intervening arm 4 is switched from the right side second cam surface 47 to the left side first cam surface 46. Therefore, one valve (intervening arm 3) is driven by the one side cam surface 36 of the rocker arm body 31, and the other valve (intervening arm 4) is the other side first cam surface 46 of the slide arm 41 (driving amount: Small).

  At this time, the first switching groove 74 is shifted to the left L while the other intervening arm 4 is in contact with the cylindrical portion 42 (base circle), and before the other intervening arm 4 is in contact with the cam nose 45, Since it is designed to join the restraining groove 73, the slide arm 41 moves to the right R when the base circle comes into contact with the minimum load, regardless of the timing when the V-shaped arm 61 is rotated to the other circumferential direction. Driven by.

  According to the first embodiment, since the slide arm 41 and the displacement mechanism 60 are provided on both sides of the intake and exhaust, at the time of high speed rotation of the internal combustion engine, as shown in FIG. Thus, only the drive amount of the other valve can be increased while keeping the drive amount of one valve constant, and at the time of low speed rotation of the internal combustion engine, as shown in FIG. Only the drive amount of the other valve can be reduced while keeping the drive amount of one valve constant. In addition, since the switching mechanisms 50 are provided on both sides of the intake and exhaust, when the valves need not be driven, the drive of the two valves on both sides of the intake and exhaust may be stopped. it can. Therefore, it is possible to achieve both high output by changing the valve drive amount and low fuel consumption by stopping the valve drive.

  The rocker arm 30 of the intake variable valve mechanism 9I is pivotally supported by the exhaust camshaft 11e, and the rocker arm 30 of the exhaust variable valve mechanism 9E is pivotally supported by the intake camshaft 11i. The variable valve mechanism can be gathered compactly by reducing the number. Further, it is possible to change the driving amount of the other valve only by changing the structure of the rocker arm 30 or the like without changing the design of the housing or the like of the cylinder head from the state of Patent Document 2 previously filed by the present applicant. Therefore, the function of the variable valve mechanism can be improved at a low cost.

  The variable valve mechanism 9 for intake and exhaust of the second embodiment shown in FIGS. 8 and 9 is substantially the same as the variable valve mechanism 9 for intake and exhaust of the first embodiment, but the variable valve mechanism for exhaust is shown in FIG. The 9E rocker arm 30 is not divided into the rocker arm main body 31 and the slide arm 41, and the output arm 31b of the rocker arm main body 31 is integrally formed with a portion corresponding to the slide arm 41 of the first embodiment. 31b is different from the first embodiment in that 31b does not include the second cam surface 47 on the other side and only the first cam surface 46 on the other side, and that the variable valve mechanism 9E for exhaust does not include the displacement mechanism 60. The other points are the same as those in the first embodiment.

  According to the second embodiment, the variable valve mechanism 9 for intake / exhaust can be configured with a smaller number of parts than the first embodiment. However, at the time of high speed rotation of the internal combustion engine, as shown in FIG. 9 (a), the drive amount of the other valve can be increased only by the intake air among the intake air and the exhaust gas. However, as shown in FIG. 9B, it is disadvantageous compared to the first embodiment in that the drive amount of the other valve can be reduced only by intake air.

  In addition, this invention is not limited to the structure of the said Example 1, 2, It can also be changed and embodied in the range which does not deviate from the meaning of invention.

DESCRIPTION OF SYMBOLS 9 Variable valve mechanism for intake / exhaust 9I Variable valve mechanism for intake 9E Variable valve mechanism for exhaust 9E 10 Cam 10i Intake cam 10e Exhaust cam 11 Camshaft 11i Intake camshaft 11e Exhaust camshaft 30 Rocker arm 31 Rocker arm main body 31a Input arm 31b Output arm 36 One side cam surface 41 Slide arm 46 The other side first cam surface 47 The other side second cam surface 50 Switching mechanism 60 Displacement mechanism

Claims (5)

In a variable valve mechanism including a rocker arm (30) that swings when driven by a cam (10) to drive two valves,
The rocker arm (30) is driven by the cam (10) and swings, and a rocker arm body (31) having a one-side cam surface (36) for driving one valve, and the rocker arm body (31). The other first cam surface (46) that engages in such a manner that it cannot be relatively displaced in the swinging direction and is relatively displaceable in the swinging axis direction (L, R) and has a different cam profile for driving the other valve. ) And the second cam surface (47) on the other side are divided into a slide arm (41) provided side by side in the swing axis direction (L, R),
A displacement mechanism (60) for displacing the slide arm (41) in the swing axis direction (L, R) is provided, and the displacement mechanism (60) moves in the swing axis direction as it advances in the circumferential direction of the slide arm (41). A first switching groove (74) that shifts to one (L), a second switching groove (76) that shifts to the other (R) in the swing axis direction as it advances in the circumferential direction, a first engagement portion (64), and A second engaging portion (66), the second engaging portion (66) is engaged with the second switching groove (76), and the rocking force of the rocker arm (30) is increased in one of the rocking axis directions ( L) is transferred to the slide arm (41) instead of the displacement force to displace the slide arm (41) in one of the swing axis directions (L), and the first switching groove (74) has the The rocking force of the rocker arm (30) by engaging the first engaging portion (64) By telling the other of the swing axis direction the sliding arm in place of the displacement force to the (R) (41), a configuration which displaces the slide arm (41) on the other of the swing axis direction (R),
By displacing the slide arm (41) in the swing axis direction (L, R) by the displacement mechanism (60), the cam surface for driving the other valve is changed to the other first cam surface (46). And the other second cam surface (47) to change the driving amount of the other valve. The displacement mechanism (60) includes a V-shaped arm (61),
The V-shaped arm (61) includes a cylindrical cylindrical portion (62) that is rotatably fitted to a support shaft (68) extending in the swing axis direction (L, R). 62) and a first arm (63) and a second arm (65) sandwiching the slide arm (41) between the first arm (63) and the second arm (65). One engaging portion (64) is formed, and the second engaging portion (66) is formed inside the tip of the second arm (65),
By rotating the V-shaped arm (61) in one circumferential direction, the second engaging portion (66) is engaged with the second switching groove (76), and the V-shaped arm (61) is rotated. The variable valve mechanism according to claim 1 , wherein the first engaging portion (64) is engaged with the first switching groove (74) by being rotated in the other direction . The rocker arm main body (31) includes an input arm (31a) that is driven by the cam (10) and swings, and an output arm that is engaged with the slide arm (41) while having the one-side cam surface (36). (31b) and divided,
A switching mechanism (50) is provided for switching between a connected state in which the input arm (31a) and the output arm (31b) are connected in a swinging direction so as not to be relatively displaceable and a disconnected state in which the connection is released. The switching mechanism (50) switches between a connected state and a non-connected state, thereby switching between a driving state for driving the two valves and a resting state for stopping the driving. 3. The variable valve mechanism according to 1 or 2.   The two valves are two intake valves, and the rocker arm (30) that drives the two intake valves is pivotable to a camshaft (11e) of an exhaust cam (10e) that drives the exhaust valve. 4. The variable valve mechanism according to claim 1, 2, or 3.   The two valves are two exhaust valves, and the rocker arm (30) that drives the two exhaust valves is pivotable on a camshaft (11i) of an intake cam (10i) that drives the intake valve. 4. The variable valve mechanism according to claim 1, 2, or 3.

Images