CN100559016C - Variable valve mechanism - Google Patents
Variable valve mechanism Download PDFInfo
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- CN100559016C CN100559016C CNB2005100689462A CN200510068946A CN100559016C CN 100559016 C CN100559016 C CN 100559016C CN B2005100689462 A CNB2005100689462 A CN B2005100689462A CN 200510068946 A CN200510068946 A CN 200510068946A CN 100559016 C CN100559016 C CN 100559016C
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- 230000007246 mechanism Effects 0.000 title claims abstract description 94
- 230000001105 regulatory effect Effects 0.000 claims abstract description 9
- 230000001360 synchronised effect Effects 0.000 claims description 7
- 230000000694 effects Effects 0.000 claims description 5
- 230000008602 contraction Effects 0.000 claims description 4
- 230000008859 change Effects 0.000 description 31
- 238000002485 combustion reaction Methods 0.000 description 16
- 238000000034 method Methods 0.000 description 8
- 230000008901 benefit Effects 0.000 description 7
- 230000008569 process Effects 0.000 description 6
- 239000000446 fuel Substances 0.000 description 4
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 239000000498 cooling water Substances 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000002277 temperature effect Effects 0.000 description 1
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Abstract
The present invention includes rocking arm (16), the heart has arm roller (18) therein, slack adjuster (30), be used to support the fulcrum (P) of rocking arm (16), shaker arm (20), it has and the contacted vibration cam face of arm roller (18) (non-pushing portion (24) and pushing portion (26)), and regulating mechanism, and it is used for changing with respect to rocking arm (16), for the operation angle that changes valve disc (12) in predetermined adjustment range and lifting capacity the reference arm angle of rotation of shaker arm (20).Regulating mechanism comprises Control Shaft (22), running roller contact surface (32), control arm (34), and vibration running roller arm (38).Slack adjuster (30) is positioned so that its stretch/shrink direction is arranged essentially parallel to the straight dashed line that the rotating center (Q) of shaker arm (20) is connected to the rotating center (S) of arm roller (18).
Description
Technical field
The present invention relates to a kind of variable valve mechanism, particularly relate to a kind of variable valve mechanism of internal-combustion engine, it can change the operation angle and/or the lifting capacity of valve disc, and this valve disc is synchronous On/Off with the rotation of camshaft.
Background technique
Be disclosed in the variable valve mechanism among the open No.2003-239712 of Japanese Patent Laid for example, comprise a mechanism that is positioned between cam and the valve disc, to be used to change the operation angle and the lifting capacity of valve disc.This variable valve mechanism has a shaker arm, itself and cam-operated synchronous vibration and a rocking arm, its be provided with one with the contacted arm roller of shaker arm.One end of this rocking arm contacts with the end of valve rod, and its other end is supported by slack adjuster.This rocking arm is configured to like this, and promptly when using the end of rocking arm, it is operated with the vibration of shaker arm and matches and rotate, and this rocking arm end is supported by slack adjuster and as fulcrum.This variable valve mechanism also comprises regulating mechanism, and its change according to the Control Shaft rotational position changes the reference arm angle of rotation of shaker arm.
When the reference arm angle of rotation of shaker arm changes according to the change of Control Shaft rotational position, shaker arm in the above-mentioned conventional variable valve mechanism and the point of contact between the arm roller will change.When point of contact changed, rocking arm depresses the time of valve disc according to the operation of cam and the slippage of valve disc will change.Therefore, above-mentioned traditional variable valve mechanism can change the operation angle and the lifting capacity of valve disc continuously by the rotational position of control Control Shaft.
Except that comprising above-mentioned document, the claimant is also with the pertinent literature of following document as the application.
[patent documentation 1]: the open No.2003-239712 of Japanese Patent Laid
[patent documentation 2]: the open flat 7-293216 of No. of Japanese Patent Laid
[patent documentation 3]: the open flat 7-63023 of No. of Japanese Patent Laid
But when the slack adjuster stretch/shrink at the rocking arm fulcrum place that is positioned above-mentioned traditional mechanism, naming a person for a particular job of rocking arm moved along the direction of stretch/shrink.Therefore, the point of contact between shaker arm and the arm roller may change.If point of contact changes, as previous description, rocking arm depresses the time of valve disc according to the operation of cam and the slippage of valve disc will change.In other words, when the slack adjuster stretch/shrink so that zero tappet clearance to be provided, beyond thought change will take place in the operation angle of valve disc and lifting capacity.
Summary of the invention
The present invention is made addressing the above problem, and the invention provides a kind of variable valve mechanism, and it can be avoided when the slack adjuster stretch/shrink, and beyond thought change takes place for the operation angle of valve disc and/or lifting capacity.
Above-mentioned target realizes that by a kind of variable valve mechanism this mechanism comprises rocking arm, and the one end contacts with the horizontal end that does not have valve disc of valve rod, and the other end plays the effect of fulcrum, and the intermediate portion is provided with the arm roller.Slack adjuster, its stretch/shrink is to provide zero tappet clearance and to be positioned to support the fulcrum of described rocking arm.Shaker arm with vibration cam face, it is used for contact with the arm roller and with the rotation synchronous vibration of cam, thereby further provides the propagation of pressure with cam to arrive this rocking arm.Also provide regulating mechanism, to be used for changing the reference arm angle of rotation of shaker arm with respect to rocking arm, in order in predetermined adjustment range, to change valve disc operation angle and/or lifting capacity.The axis of slack adjuster is arranged essentially parallel to the straight dashed line that the rotating center of shaker arm is connected to the rotating center of arm roller.
When in conjunction with the accompanying drawings and read following detailed description, other purpose of the present invention and further feature will be very obvious.
Description of drawings
Fig. 1 shows the configuration according to the variable valve mechanism of first embodiment of the invention.
Fig. 2 A and 2B show the variable valve mechanism operation of Fig. 1 to offer the less lifting capacity of valve disc.
Fig. 3 A and 3B show the variable valve mechanism operation of Fig. 1 to offer the big lifting capacity of valve disc.
Fig. 4 shows a variable valve mechanism, its will as with the reference of comparing according to the configuration of first embodiment of the invention variable valve mechanism.
Fig. 5 A and 5B show the admissible angular range according to the slack adjuster in the variable valve mechanism of first embodiment of the invention.
Fig. 6 shows the configuration according to the variable valve mechanism of second embodiment of the invention.
Fig. 7 shows the admissible angular range according to the slack adjuster in the variable valve mechanism 50 of second embodiment of the invention.
Fig. 8 shows the example that an internal-combustion engine is arranged, it will be as a reference to be used to explain the advantage according to the configuration of second embodiment of the invention.
Realize optimal mode of the present invention
First embodiment
[configuration of variable valve mechanism]
Fig. 1 shows the configuration according to the variable valve mechanism 10 of first embodiment of the invention.The variable valve mechanism that is shown in Fig. 1 drives the valve disc of internal-combustion engine, and this valve disc has the function of intake valve or exhaust valve.
The configuration that is shown in Fig. 1 comprises valve disc 12, and it has the function of intake valve or exhaust valve.Valve rod 14 is fixed to valve disc 12.The horizontal end that does not have valve disc of valve rod 14 is covered by rod end cover 15.The end of valve rod 14 contacts with an end of rocking arm 16 by rod end cover 15.The core of rocking arm 16 is provided with arm roller 18.
Shaker arm 20 (vibration member) is positioned on the arm roller 18.Shaker arm 20 is kept by this way by Control Shaft 22, can allow the shaker arm rotation.The vibration cam face is as being formed on the shaker arm 20 with arm roller 18 contacted surfaces.The vibration cam face comprises non-pushing portion's (non-pushes against surface) 24 and pushing portion 26.Non-pushing portion (non-pushes against surface) 24 is formed, so that from the spacing of the Q of rotating shaft center of shaker arm 20, is constant from the spacing of the axial centre Q of Control Shaft 22 promptly also.Pushing portion 26 is formed, so as from the spacing of the axial centre of Control Shaft 22 along with the spacing in non-pushing portion 24 increases and increases.In other words, non-pushing portion 24 forms has fixing curvature, so the axial centre Q of Control Shaft 22 (the rotating center Q of shaker arm 20) is this centre of curvature Q.Point of contact between arm roller 18 and the shaker arm 20 refers to running roller point of contact 27 hereinafter.Boundary point between non-pushing portion 24 and the pushing portion 26 is called hereinafter and upgrades initial point 28.
The other end of rocking arm 16 is supported by slack adjuster 30.When using the end supported by slack adjuster 30 as fulcrum P, rocking arm 16 is rotatable.Slack adjuster 30 energy stretch/shrink are to provide zero tappet clearance.According to this embodiment's variable valve mechanism 10, the stretch/shrink direction (axis) of slack adjuster 30 is parallel to the rotating center Q with shaker arm 20, also is the straight dashed line (see figure 1) that the axial centre Q of Control Shaft 22 is connected to the rotating center S of arm roller 18.As indicated above, be such according to this embodiment's mechanism, so that the centre of curvature R of the rotating center Q of shaker arm 20 and non-pushes against surface 24 is identical.In other words, when from axially the seeing of Control Shaft 22, be connected to the straight dashed line of the rotating center S of arm roller 18 in centre of curvature R according to the parallel axes of this embodiment's slack adjuster 30 with non-pushes against surface 24.
And running roller contact surface 32 is kept by this way by Control Shaft 22, can allow the rotation of running roller contact surface.Running roller contact surface 32 is configured to can be with shaker arm 20 around Control Shaft 22 rotations.Control arm 34 is connected to Control Shaft 22.Control arm 34 is provided with through hole.Control Shaft 22 and control arm 34 are integrated into single component by using the fastener (not shown), and Control Shaft 22 is inserted in this through hole.Control arm 34 is provided with running shaft 36, and it is positioned at along the outstanding place of the diametric(al) of Control Shaft 22.Vibration running roller arm 38 is kept by this way by running shaft 36, can allow to vibrate the rotation of running roller arm.
Vibration running roller arm 38 has cam touch roll 44 and slide roller 46.Cam touch roll 44 contacts with the cam 42 that is fixed to camshaft 40.Slide roller 46 contacts with running roller contact surface 32.Cam touch roll 44 and slide roller 46 can rotate freely, when they are kept by vibration running roller arm 38.
As the fact was, when in the rotary course of cam 42, during cam nose extruding cam touch roll 44, the power that causes thus was passed to running roller contact surface 32 by slide roller 46.When slide roller 46 was rolled on running roller contact surface 32, slide roller can will be delivered to shaker arm 20 continuously by the power that cam 42 applies.As a result, shaker arm 20 rotates around Control Shaft 22, thereby pushes rocking arm 16 downwards and move valve disc 12 along the valve opening direction.As mentioned above, by cam touch roll 44 and slide roller 46 and the power of cam 42 is delivered to running roller contact surface 32, variable valve mechanism 10 operable valve dishes 12.
[operation of variable valve mechanism]
Referring now to accompanying drawing 2A, 2B, 3A and 3B describe the operation according to the variable valve mechanism 10 of first embodiment of the invention.Fig. 2 A and 2B show variable valve mechanism 10 operation to offer the less lifting of valve disc 12.This operates in hereinafter referred to as little lifting operation.More particularly, Fig. 2 A shows valve disc 12 and closes in little lifting operating process, and Fig. 2 B shows valve disc 12 and opens in little lifting operating process.
In the state shown in Fig. 2 A, be the state that cam 42 is not exerted pressure, running roller point of contact 27 is connected to Control Shaft 22 axial centre Q straight line and will upgrade initial point 28 and be connected to that formed angle is defined as reference arm angle of rotation Φ between the straight line of axis centre Q of Control Shaft 22.
In variable valve mechanism 10, the rotational position of shaker arm 20, promptly reference arm angle of rotation Φ is determined by the position of slide roller 46.The position of slide roller 46 is determined by the position of the running shaft 36 that is used to vibrate running roller arm 38 and the position of cam touch roll 44.When cam touch roll 44 and cam 42 kept contacting with each other, because the angle that is rotated counterclockwise of Control Shaft 22 increases among Fig. 2, slide roller 46 moved up.Therefore in variable valve mechanism 10, the amount of being rotated counterclockwise of Control Shaft 22 is big more, and reference arm angle of rotation Φ is big more.
In the state shown in Fig. 2 A, reference arm angle of rotation Φ has in fact reached maximum value.Variable valve mechanism 10 is configured to when reference arm angle of rotation Φ has in fact reached maximum value, and the approximate center of the non-pushing portion 24 of shaker arm 20 contacts with the arm roller 18 of rocking arm 16, thereby closes valve disc 12.
When cam 42 rotated with the state shown in Fig. 2 A, cam touch roll 44 moved to Control Shaft 22 by the cam nose extruding.The running shaft 36 of control arm 34 and the distance between the slide roller 46 remain unchanged.Therefore, when cam touch roll 44 when Control Shaft 22 moves, running roller contact surface 32 is pushed downwards by slide roller 46, this slide roller is rolled on running roller contact surface 32.Therefore, shaker arm 20 turns clockwise in Fig. 2, so that running roller point of contact 27 is shifted to pushing portion 26 from non-pushing portion 24.
As mentioned above, in little lifting capacity operation, Φ is bigger for the reference arm angle of rotation.Therefore, appear at the maximum angle of rotation of the shaker arm 20 in cam 42 rotary courses, less relatively in little lifting capacity operation.When the angle of rotation of shaker arm 20 was maximum, valve disc 12 suffered maximum lifting.Shown in Fig. 2 B, after variable valve mechanism 10 was configured to this angle of rotation of shaker arm 20 occur with box lunch, running roller point of contact 27 slightly entered pushing portion 26, thereby gave valve disc 12 with less lifting.Therefore, when the above-mentioned less lifting of execution was operated, variable valve mechanism 10 can give valve disc 12 with less lifting with the rotation of cam 42 synchronously.
In said circumstances, during the actual extruding downwards of the power of cam 42 valve disc 12, promptly cam 42 rotates with during the unlatching valve disc 12 (crankangle width), relatively short (being called operation angle during this period hereinafter).Therefore, when the little lifting of execution was operated, variable valve mechanism 10 can reduce the operation angle of valve disc 12.
Fig. 3 A and 3B show variable valve mechanism 10 operation to offer the bigger lifting of valve disc 12.This operates in hereinafter referred to as big lifting operation.More particularly, Fig. 3 A shows valve disc 12 and closes big the lifting in the operating process, and Fig. 3 B shows valve disc 12 and opens big the lifting in the operating process.
In the time will carrying out big lifting operation, as shown in Figure 3A, Control Shaft 22 is adjusted to a position, and this position turns clockwise from main position little lifting operating process.Therefore, when carrying out lifting operation greatly, reference arm angle of rotation Φ becomes enough little, and does not make slide roller 46 leave running roller contact surface 32.Variable valve mechanism 10 is configured to enough hour of convenient reference arm angle of rotation Φ, and running roller point of contact 27 is located in and upgrades near the initial point 28 and towards non-pushing portion 24.Therefore, valve disc 12 still keeps in the operating process closing big the lifting.
When cam 42 rotates with the state shown in Fig. 3 A, shown in Fig. 3 B, cam nose extruding cam touch roll 44, thus cause shaker arm 20 to turn clockwise.Therefore, running roller point of contact 27 is shifted to pushing portion 26 from non-pushing portion 24.When carrying out lifting operation greatly, as indicated above, reference arm angle of rotation Φ will diminish.Therefore, the maximum angle of rotation of the shaker arm 20 that occurs when cam 42 rotations is bigger.Shown in Fig. 3 B, variable valve mechanism 10 is configured to when the angle of rotation of shaker arm 20 occurring, and running roller point of contact 27 is enough to arrive pushing portion 26.As a result, when the above-mentioned big lifting of execution was operated, variable valve mechanism 10 provided valve disc 12 with bigger lifting and operation angle synchronously with the rotation of cam 42.
[according to the advantage of this embodiment's variable valve mechanism 10]
As mentioned above, can change the vibration operation (being reference arm angle of rotation Φ) of shaker arm 20 by the position that changes Control Shaft 22 according to this embodiment's variable valve mechanism 10, thereby change the lifting capacity and the operation angle of valve disc 12.As previous description, be configured according to this embodiment's variable valve mechanism 10, so that the stretch/shrink direction of slack adjuster 30 is parallel to the straight dashed line that the axial centre Q of Control Shaft 22 is connected to the rotating center S of arm roller 18.The advantage of this configuration of variable valve mechanism 10 4 is described with reference to the accompanying drawings.
Fig. 4 shows a variable valve mechanism, its will as with the reference of comparing according to the configuration of this embodiment's variable valve mechanism 10.Will with the variable valve mechanism A that makes comparisons according to this embodiment's variable valve mechanism 10, be the position of slack adjuster with difference according to this embodiment's variable valve mechanism 10.More particularly, be shown in the variable valve mechanism A of Fig. 4, its configuration do not stipulate, so that the stretch/shrink direction of slack adjuster becomes predetermined angle theta with the straight dashed line that axial centre Q with Control Shaft is connected to the rotating center S of arm roller.
As shown in Figure 4, when variable valve mechanism A is used, the thermal expansion owing between for example cylinder head and the valve rod clearance delta h will occur between valve rod end and rocking arm
1When clearance delta h occurring
1The time, slack adjuster expands with clearance delta h
1Be reduced to zero.If the swell increment of slack adjuster is Δ h
2, as shown in Figure 4, when slack adjuster expands, the rocking arm fulcrum P shifted by delta h that will make progress
2(P1 moves on to P2 from fulcrum).
As mentioned above, above mentioned angle θ offers the slack adjuster of variable valve mechanism A.Therefore, as the rocking arm fulcrum P shifted by delta h that makes progress
2The time, as shown in Figure 4, it is also with slipping Δ x.Therefore, running roller point of contact 27 changes, and promptly reference arm angle of rotation Φ is from Φ
1Become Φ
2Because value Δ x increases with the increase of above-mentioned angle θ, the value that is provided for the reference arm angle of rotation Φ of slack adjuster increases with the increase of above-mentioned angle θ.The change of reference arm angle of rotation Φ means for the lifting capacity of valve disc and the setting of operation angle and changes.In other words, variable valve mechanism A is configured to, and during with convenient slack adjuster stretch/shrink, the lifting capacity of valve disc and operation angle are different from by the determined predetermined value of the rotational position of Control Shaft.
On the other hand, be configured to according to this embodiment's variable valve mechanism 10, so that the stretch/shrink direction of slack adjuster 30 is parallel to the straight dashed line that the axial centre Q of Control Shaft 22 is connected to the rotating center S of arm roller 18, promptly above-mentioned angle θ is zero.Therefore, even when the stretch/shrink owing to slack adjuster 30 causes the fulcrum P skew of rocking arm 16, can guarantee that according to this embodiment's configuration the offset direction of fulcrum P is parallel to the straight dashed line that the axial centre Q of Control Shaft 22 is connected to the rotating center S of arm roller 18.So the change that suppresses reference arm angle of rotation Φ effectively is possible.As the fact was, the above-mentioned angle θ that offers slack adjuster 30 whatsoever should be at most 10 ° or littler as far as possible near zero under the situation, is arranged essentially parallel to the axis of slack adjuster 30 so that guarantee straight dashed line.
As mentioned above, might avoid when slack adjuster 30 stretch/shrink according to this embodiment's variable valve mechanism 10, beyond thought change takes place in valve disc operation angle and lifting capacity.And, control air inflow according to this embodiment's variable valve mechanism 10 by the lifting capacity and the operation angle that change valve disc 12.Therefore need make the control accuracy of the lifting capacity/operation angle of valve disc 12 be higher than the situation of using internal-combustion engine with common valve mechanism.When the configuration used according to this embodiment, might provide the variable valve mechanism that satisfies above-mentioned needs.
Describe the advantage that configuration provided in detail referring now to accompanying drawing 5A and 5B by this embodiment.Fig. 5 A and 5B show the admissible angle θ scope according to the slack adjuster 30 in first embodiment's the variable valve mechanism 10.More particularly, Fig. 5 A shows the reason of the cylinder-cylinder variation that causes the valve disc operation angle in the variable valve mechanism 10.Fig. 5 B shows that the cylinder of operation angle-cylinder changes and about the relation between the angle θ of slack adjuster 30.
As previous description, the change of the reference arm angle of rotation Φ of shaker arm 20, i.e. the position deflection of running roller point of contact 27 will cause the change of the operation angle and the lifting capacity of valve disc 12.Therefore, if the position offset of the running roller point of contact 27 of difference cylinder is different, the operation angle of the valve disc 12 of difference cylinder and lifting capacity are also with different.
Fig. 5 A show the valve opening characteristic that mechanically causes valve disc 12 (operation angle, lifting capacity, valve opening time, etc.) in the possible cause that changes of cylinder-cylinder.For explaining this purpose, below operation angle will be described.At first, the cylinder in the operation angle-cylinder variation may be to be caused by the head side precision.The head side precision determines that by the assembly precision of mechanical precision and parts wherein position component is stipulated by cylinder head, and these parts are valve disc 12, valve rod 14, rod end cover 15, rocking arm 16, slack adjuster 30, and other analog.More particularly, cylinder-cylinder operation angle taking place changes the reason that exceeds the head side precision and is that for example the position of the height of the valve rod 14 of difference cylinder and arm roller 18 is different with respect to the fulcrum P of rocking arm 16.
Described as Fig. 5 A, cause that other reason that cylinder-cylinder operation angle changes is to adjust precision, temperature effect and change in time.The relative position of the various parts on adjusting precision and will being positioned rocking arm 16 is relevant, and these parts are shaker arm 20, Control Shaft 22, control arm 34, vibration running roller arm 38 and camshaft 40.When the thermal expansion that causes the element of difference cylinder owing to for example layout of engine cooling water circulation path is different, with the variation at cylinder-cylinder operation angle of taking place to cause owing to Temperature Influence.When the various parts of difference cylinder when for example the wearing and tearing that take place of the sliding parts of arm roller 18 and slide roller 46 are different, because the variation at cylinder-cylinder operation angle that change causes will take place in time.
In air inflow mainly is by allowing variable valve mechanism to change in the internal-combustion engine of valve opening characteristic of valve disc, just according in the situation according to this embodiment's variable valve mechanism 10, particularly in low-load region, air inflow is mainly changed by cylinder-cylinder operation angle (the valve opening characteristic of valve disc) to be controlled, and this zone is the operation angle of valve disc and the zone that lifting capacity can accurately be controlled.In other words, this zone need be accurately controlled, so that reduce the variation of cylinder-cylinder intake air quantity.
In Fig. 5 A, the numerical value of representing cylinder-cylinder operation angle to change has shown the example of the desired value that admissible operation angle changes in actual internal-combustion engine.When the variation of cylinder-cylinder intake air quantity in the internal-combustion engine increases, change in torque will increase.Therefore, be difficult in operating internal-combustion engines under rare air fuel ratio.Therefore, fuel efficiency can not be improved.Above-mentioned admissible operation angle changing value need be used for guaranteeing the proper operation of internal-combustion engine.Owing to the combination of all above-mentioned reasons, for meeting the needs of motor, the example of Fig. 5 A has shown that admissible operation angle changing value needs less than 5 ℃ of A, because cylinder-cylinder operation angle changes; And be approximately 2.5 ℃ of A, because the reason of head side precision.
If, for example the height difference between the cylinder is a certain determined value, and is big more about the angle θ of slack adjuster 30, and the position deflection degree of running roller point of contact 27 is big more, this is owing to the slack adjuster stretch/shrink causes, promptly the operation angle of valve disc 12 shown in Fig. 5 B changes big more.Therefore, cylinder-cylinder operation angle changes has increased.The angle θ 1 that is shown in Fig. 5 B is and the corresponding angle of above-mentioned admissible operation angle changing value.In the example shown in Fig. 5 B, angle θ 1 is approximately 3.5 °.About the scope of the angle θ of slack adjuster 30 be 0 and θ 1 between, this scope is that cylinder-cylinder operation angle changes the angular range that is not more than admissible operation angle changing value.In other words, in the time of within angle θ is set in above-mentioned angular range, promptly be set to so that the axis of slack adjuster 30 when being arranged essentially parallel to axial centre Q (the rotating center Q of shaker arm 20) with Control Shaft 22 and being connected to the straight dashed line of rotating center S of arm roller 18 as angle θ, might guarantee that cylinder-cylinder operation angle becomes to be not more than admissible operation angle changing value.
In above-mentioned first embodiment who has described, variable valve mechanism 10 is configured to, so that the rotating center Q of shaker arm 20 is consistent with the centre of curvature R of non-pushing portion (non-pushes against surface) 24.But the present invention is not limited to this configuration.In can be applicable to alternative configuration of the present invention, the rotating center Q of shaker arm needn't be consistent with the centre of curvature R of non-pushing portion (non-pushes against surface), as long as when the axial direction of camshaft 40 is seen, the axis of slack adjuster 30 is arranged essentially parallel to the straight dashed line that the centre of curvature R of non-pushing portion 24 is connected to the rotating center S of arm roller 18.And, even the rotating center Q of shaker arm is not consistent with the centre of curvature R of non-pushing portion 24, as long as when the axial direction of camshaft 40 is seen, the axis of slack adjuster 30 is arranged essentially parallel to the straight dashed line that the centre of curvature R of non-pushing portion is connected to the rotating center S of arm roller, and the present invention can suitably provide advantage.More particularly, when the slack adjuster stretch/shrink, might avoid the valve opening characteristic of valve disc that beyond thought change takes place, and prevent that when the slack adjuster stretch/shrink valve opening characteristic of valve disc in the difference cylinder is different.And first embodiment supposes that Control Shaft 22 keeps shaker arm 20 in such a way, can allow shaker arm 20 vibrations.But the present invention is not limited to this shaker arm configuration.More particularly, shaker arm can rotate on axle rather than Control Shaft.
In above-mentioned first embodiment who has described, Control Shaft 22, running roller contact surface 32, control arm 34, and vibration running roller arm 38 with according to the present invention first or the regulating mechanism of second aspect consistent.
Second embodiment
Be described referring now to Fig. 6 to the 8 pair of second embodiment of the present invention.
Fig. 6 shows the configuration according to the variable valve mechanism 50 of second embodiment of the invention.Fig. 1 and the designated identical reference character of the same parts among Fig. 6, these same parts will simply be described or will not be described.
As previous description, when the height of the valve rod 14 of for example difference cylinder is different, cylinder-cylinder operation angle will takes place change and exceed the head side precision.This embodiment's supposition is adjusted cylinder-cylinder axis length change that the valve height is eliminated valve rod 14 by allowing rod end cover 15.More particularly, the valve Height Adjustment is finished by the slightly different rod end cover 15 of thickness of preparing several types, when execution is installed to cylinder head with various elements, guarantee that for the selected rod end cover 15 of each cylinder each valve rod 14 of cylinder has same valve rod height with suitable thickness.
[according to the advantage of this embodiment's variable valve mechanism 50]
Fig. 7 shows in the variable valve mechanism 50 according to second embodiment, the scope of the admissible angle θ of slack adjuster 30.In Fig. 7, what number line showed is not made main relation of time spent when the valve Height Adjustment by rod end cover 15, and the straight dashed line demonstration is relation main when this valve Height Adjustment is applied.
Be shown in the angle θ 2 of Fig. 7, satisfy the admissible operation angle changing value that motor requires with being adjusted when the height of valve rod 14 consistent.In example shown in Figure 7, angle θ 2 is approximately 7 °.When the height of valve rod 14 was adjusted in the above described manner, the cylinder-cylinder operation angle that might eliminate owing to cylinder-cylinder valve rod variable height causes changed, and this is owing to the cylinder that the head side precision causes-cylinder operation angle one of changes.Therefore, the angle θ that meets admissible operation angle changing value can be increased to θ 2 from θ 1.As description above, angle θ relevant with slack adjuster 30 in variable valve mechanism 50 is set in the scope, changes being not more than admissible operation angle changing value at this scope inside cylinder-cylinder operation angle.Therefore, the variable valve mechanism 50 according to this embodiment provides the degrees of freedom that increases when determining to be installed in the established angle of the slack adjuster 30 on the cylinder head.
As shown in Figure 8, be in the limited internal-combustion engine for degrees of freedom at the established angle of determining slack adjuster 30, be effective especially according to the configuration of this embodiment's variable valve mechanism 50.Fig. 8 shows the exemplary configurations of this internal-combustion engine.Fig. 8 has shown the layout of the gas handling system of in-cylinder injection type internal-combustion engine.Even when variable valve mechanism 50 is not applied to the internal-combustion engine of in-cylinder injection type, variable valve mechanism 50 need be located in the narrow space between suction port 52 and the spark-plug hole 54, and spark plug is installed there.For the internal-combustion engine of in-cylinder injection type, fuel injector 56 is positioned under the suction port 52 usually.Therefore, the space that is used to locate variable valve mechanism 50 has further been limited.And slack adjuster 30 need be positioned in the space of not interfering valve spring 58.If the oil that slack adjuster 30 receives by the outside supply, the inside of cylinder head need be provided with oilhole 60 to be used for fuel feeding.As mentioned above, the established angle of slack adjuster 30 on cylinder head limited by various parts on every side.
As the fact is, the parallel axes that the method that is used for the axial centre Q of mobile Control Shaft 22 can be used to guarantee slack adjuster 30 is connected to the straight dashed line of the rotating center S of arm roller 18 in the axial centre Q with Control Shaft 22, and wherein the established angle of slack adjuster is defined by above-mentioned.But when the axial centre Q of Control Shaft 22 moved, the axial centre of camshaft 40 also moved.If it is limited that the spacing between the axial centre of the axial centre of admission cam shaft and exhaust cam shaft changes, the axial centre of camshaft 40 can not move arbitrarily.If camshaft 40 moves on to outside the cylinder head, the cylinder head part frame will enlarge.
Even when employed internal-combustion engine is defined in top description, can adjust the height of the valve rod 14 that is used as suction valve according to this embodiment's variable valve mechanism 50, and carry out assembling so as above-mentioned angle θ within admissible operation angle excursion, thereby make and determining that variation that slack adjuster 30 is installed to the established angle on the cylinder head and prevents cylinder-cylinder operation angle surpasses when satisfying the value of motor needs, might provide effective degrees of freedom.
The major character and the advantage of the invention described above are summarized as follows:
A first aspect of the present invention comprises a kind of variable valve mechanism, and it comprises rocking arm, and an end of this rocking arm contacts with the horizontal end that does not have valve disc of valve rod, and the other end plays the effect of fulcrum, and the intermediate portion is provided with the arm roller.Slack adjuster, its elongation and contraction are to provide zero tappet clearance and to be positioned to support the fulcrum of described rocking arm.Shaker arm with vibration cam face, it is used for contact with the arm roller and with the rotation synchronous vibration of cam, thereby further provides the propagation of pressure with cam to arrive this rocking arm.Also provide regulating mechanism, to be used for changing the reference arm angle of rotation of shaker arm with respect to rocking arm, in order in predetermined adjustment range, to change valve disc operation angle and/or lifting capacity.The axis of slack adjuster is arranged essentially parallel to the straight dashed line that the rotating center of shaker arm is connected to the rotating center of arm roller.
A second aspect of the present invention comprises variable valve mechanism, and it comprises the Control Shaft that is driven by actuator.Regulating mechanism is set to be used for changing with respect to the rotation of camshaft the valve opening characteristic of valve disc according to the position of Control Shaft.Rocking arm, the one end contacts with the horizontal end that does not have valve disc of valve rod, and the other end plays the effect of fulcrum, and the intermediate portion also is provided with the arm roller.Slack adjuster, its elongation and contraction are to provide zero tappet clearance and to be positioned to support the fulcrum of rocking arm.Have the vibration member of vibration cam face, it comprises having the fixedly non-pushes against surface of curvature, is used for contact with the arm roller and with the rotation synchronous vibration of cam, thereby further provides the propagation of pressure with cam to arrive this rocking arm.When from axially the seeing of camshaft, the axis of slack adjuster is arranged essentially parallel to the straight dashed line that the centre of curvature of non-pushes against surface is connected to the rotating center of arm roller.
A third aspect of the present invention comprises the valve height arm control that is used to adjust the valve rod height.Angle between the axis of straight dashed line and slack adjuster can be set in the scope, and in this scope, the cylinder of valve disc valve opening characteristic-cylinder variation is no more than admissible changing value.
According to a first aspect of the invention, when the slack adjuster stretch/shrink, the point of contact that this aspect of the present invention can prevent to vibrate between cam face and the arm roller effectively changes, and the reference arm angle of rotation that can suppress shaker arm effectively changes.As a result, when the slack adjuster stretch/shrink, the present invention might avoid the operation angle of valve disc and/or lifting capacity that beyond thought change takes place.And when the slack adjuster stretch/shrink, the present invention can prevent that the valve disc valve opening characteristic of difference cylinder is because for example mechanical precision of variable valve mechanism element and assembly precision and different.
According to second aspect present invention, when whole device stretch/shrink was withered in the gap, the point of contact that this aspect of the present invention can prevent to vibrate between cam face and the arm roller effectively changed.As a result, when the slack adjuster stretch/shrink, the present invention might avoid the valve operation angle of valve disc and/or lifting capacity that beyond thought change takes place.And when the slack adjuster stretch/shrink, the present invention can prevent that the valve disc valve opening characteristic of difference cylinder is because for example mechanical precision of variable valve mechanism element and assembly precision and different.
According to a third aspect of the invention we, this aspect of the present invention might prevent that cylinder-cylinder variation of the valve opening characteristic of valve disc from exceeding the numerical value that satisfies the motor needs, thereby provides effective degrees of freedom when definite slack adjuster is installed to the established angle of internal-combustion engine.
And the present invention is not limited to these embodiments, under the prerequisite that does not depart from the scope of the invention, can make various changes and modifications.
Claims (3)
1. variable valve mechanism comprises:
Rocking arm, its end contacts with the horizontal end that does not have valve disc of valve rod, and the effect of fulcrum is played in the other end, and the intermediate portion is provided with the arm roller;
Slack adjuster, its elongation and contraction are to provide zero tappet clearance and to be positioned to support the fulcrum of described rocking arm;
Shaker arm with vibration cam face is used for contact with described arm roller and with the rotation synchronous vibration of cam, thereby the propagation of pressure of cam is arrived described rocking arm; And
Regulating mechanism is used for changing with respect to described rocking arm, for the operation angle that changes valve disc in predetermined adjustment range and/or lifting capacity the reference arm angle of rotation of described shaker arm,
The parallel axes of wherein said slack adjuster is connected to the straight dashed line of the rotating center of described arm roller in the rotating center with described shaker arm.
2. variable valve mechanism comprises:
Control Shaft by the actuator driving;
Regulating mechanism is used for according to the position of described Control Shaft and changes the valve opening characteristic of valve disc with respect to the rotation of camshaft;
Rocking arm, its end contacts with the horizontal end that does not have valve disc of valve rod, and the effect of fulcrum is played in the other end, and the intermediate portion is provided with the arm roller;
Slack adjuster, its elongation and contraction are to provide zero tappet clearance and to be positioned to support the fulcrum of described rocking arm; And
Have the vibration member of vibration cam face, it comprises having the fixedly non-pushes against surface of curvature, be used for contact and with the rotation synchronous vibration of cam, thereby the propagation of pressure of cam is arrived described rocking arm with described arm roller,
Wherein when from axially the seeing of described camshaft, the parallel axes of described slack adjuster is connected to the straight dashed line of the rotating center of described arm roller in the centre of curvature with described non-pushes against surface.
3. variable valve mechanism according to claim 1 and 2 also comprises:
Be used to adjust the valve height arm control of described valve rod height,
Angle between the axis of wherein said straight dashed line and described slack adjuster is set in the scope, and in this scope, the cylinder of the valve opening characteristic of valve disc-cylinder variation is positioned at permissible excursion.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004132564 | 2004-04-28 | ||
| JP2004132564 | 2004-04-28 | ||
| JP2005026682 | 2005-02-02 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1690372A CN1690372A (en) | 2005-11-02 |
| CN100559016C true CN100559016C (en) | 2009-11-11 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2005100689462A Expired - Fee Related CN100559016C (en) | 2004-04-28 | 2005-04-28 | Variable valve mechanism |
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| CN (1) | CN100559016C (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101317140B1 (en) * | 2007-08-01 | 2013-10-08 | 현대자동차주식회사 | Continuous variable valve lift apparatus |
| KR100969377B1 (en) * | 2008-04-30 | 2010-07-09 | 현대자동차주식회사 | Continuous variable valve lift apparatus |
| DE102016114664A1 (en) * | 2015-10-08 | 2017-04-13 | Toyota Jidosha Kabushiki Kaisha | Valve operating device for an internal combustion engine |
| CN105507979A (en) | 2015-12-17 | 2016-04-20 | 广州汽车集团股份有限公司 | Continuous variable valve lift system and automobile |
| CN111894696B (en) * | 2020-07-06 | 2021-08-31 | 一汽解放汽车有限公司 | Valve locking mechanism for engine cylinder deactivation and vehicle |
-
2005
- 2005-04-28 CN CNB2005100689462A patent/CN100559016C/en not_active Expired - Fee Related
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| CN1690372A (en) | 2005-11-02 |
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