Apparatus for switching the operation of a change valve of a combustion engine

Information

  • Patent Grant
  • 6752107
  • Patent Number
    6,752,107
  • Date Filed
    Friday, December 7, 2001
    22 years ago
  • Date Issued
    Tuesday, June 22, 2004
    20 years ago
Abstract
An apparatus for converting or changing the operation of a charge valve of a combustion engine, which comprises a camshaft with at least one valve cam, a swing lever supported on a machine-mounted component, which comprises a contact element for maintaining a contact member in a disposition on the valve cam and which actuates the valve, a coupling member mounted on the swing lever, which, in a first position, translates a movement of the contact member via the valve cam to the swing lever and, in a second position, interrupts the movement translation, and a switch device for moving the coupling member between its first and second positions and retaining apparatus mounted on the swing lever for retaining the coupling member in its second position.
Description




BACKGROUND OF THE INVENTION




The present invention relates to an apparatus for switching the operation of a charge valve of an internal combustion engine according to the main concept of the principal claim.




A reduction in the consumption of combustion fuel has, in recent times, assumed increasing importance. One possibility to thus reduce combustion fuel consumption, offered in connection with multiple cylinder motors, is the timed placement out of service of individual cylinders, whereby the remaining cylinders operate with a higher average pressure and, thereby, a reduced specific fuel consumption. To place a cylinder out of operation, not only an interruption of the combustion fuel delivery is required; as well, the charging flow to the corresponding cylinder must also be deliberately interrupted, in that the one or more charging valves, especially the inlet or intake valves, of the respective cylinder are placed out of operation.




A further, important development goal lies in the reduction or decrease of the pollutant content in the exhaust gasses. The starting points for such improvements are to be found in the valve opening functions which are accommodated to the respective operational ranges, whereby optimal combustion conditions can be achieved.




In view of the above-noted reasons, there is a strong need for an adjustable or, respectively, convertible valve operating apparatus.




DE 19 82 8945 A1 discloses an apparatus for the activation and complete de-activation of a charging valve. In connection with this apparatus, the retention of a coupling lever, whose position determines the activation or de-activation of the valve, is effected by means of an electro-magnet disposed in a motor housing or on the cylinder head. In total, this known apparatus requires modifications of the motor housing or the cylinder head, in order to be subsequently installed thereon at a post-engine manufacturing time.




EP 0 016 068 describes an apparatus for converting the operation of a charging valve of a combustion powered engine, which works with a swing lever and a contact lever disposed in contacting relation with the swing lever. A spring, which presses the contact lever into a following disposition on the camshaft, is supported between the swing lever and the contact lever, so that, in this regard, no modification of the cylinder head via a subsequent installation effort is required. The actuation and retaining apparatus for actuating the coupling member is, however, configured as a hydraulic cylinder mounted on the cylinder head or, respectively, the motor housing, the hydraulic cylinder having a tappet which engages a contact surface of a coupling lever which is secured in a non-rotating manner with the coupling member, so that a friction contact occurs between the tappet and the contact surface. The arrangement according to EP 0 016 068 requires, in total, considerable installation room and is, especially because of the hydraulic cylinder, not capable of being subsequently installed on the cylinder head without a necessary modification thereof.




EP 0 995 885 A2 describes a valve actuating mechanism with an outer swing lever for engagement with a cam during the high stroke thereof and an inner swing lever for engagement with a cam during a lower stroke thereof. The ends of the swing lever disposed adjacent the charge valve of a combustion engine are connected to one another via connecting taps. On the other ends of the swing lever, a locking mechanism is provided, which comprises a pin which is movable back and forth between a locking position and a release position.




DE 37 01 480 A1, which describes the state-of-the-art apparatus which is improved upon by the apparatus of the present invention describes a valve actuating system in which the spring which biases the contact lever in the direction of a disposition of the contact lever onto the cam is supported on the cylinder head. This means that an available cylinder head for the subsequent installation of the valve actuating system must be modified, which is expensive. Moreover, a hydraulic cylinder with a tappet is provided for the release, or respectively, the blocking, of the movement which is translated between the contact lever and the swing lever, with the hydraulic cylinder being provided with hydraulic fluid via a hydraulic element on which the swing lever is supported and the swing lever requiring bores, which are expensive to provide, for permitting passage therethrough of the hydraulic fluid.




The present invention inventively provides a solution which advances the state-of-the-art apparatus, in that it has a simple configuration for a conventional combustion engine and can be installed thereon with the least possible modification while providing a high measure of operational reliability.




SUMMARY OF THE INVENTION




In accordance with the present invention, the spring which biases the contact lever in a direction into a disposition of the contact lever on the valve cam extends directly between the swing lever and the contact lever so that, in this regard, no modification of the cylinder head is required.




Furthermore, the respective movement of the coupling member of the apparatus into its first and second positions is deliberately and synchronously effected by the rotation of the camshaft, so that the coupling member need only be retained in its second position. This permits a simple configuration of the retaining apparatus.











BRIEF DESCRIPTION OF THE DRAWINGS




The invention is described in the following description in connection with the schematic drawings and is explained in further details therewith.




The Figures of the drawings show:





FIG. 1

is a first embodiment of the inventive apparatus in an exploded perspective view,





FIGS. 2 and 3

are two perspective views of the assembled apparatus shown in

FIG. 1

,





FIG. 4

shows the arrangement of

FIG. 1

at a different view thereat of the exploded perspective illustration of the arrangement,





FIGS. 5 and 6

are two perspective views of the embodiment shown in

FIG. 1

from different viewpoints,





FIGS. 7 and 8

show a modified embodiment of the apparatus in perspectives similar to those shown, respectively, in

FIGS. 5 and 6

,





FIGS. 9 and 10

are perspective views similar to those of

FIGS. 2 and 3

of a modified embodiment of the inventive apparatus,





FIG. 11

shows the embodiment of the apparatus as shown in

FIGS. 9 and 10

in an exploded perspective view,





FIGS. 12 and 13

show several functional components of the apparatus according to the two different positions of the coupling member shown in

FIGS. 9-11

,





FIG. 14

is a detailed view of the engagement between a blocking bolt and a coupling lever, and





FIG. 15

is an exploded view of a further embodiment of the inventive apparatus.











DESCRIPTION OF PREFERRED EMBODIMENTS




In all of the hereinafter following figures, functionally similar building components are designated with the same reference characters.




As seen in

FIGS. 1

to


3


, a swing lever, which is collectively designated with the reference character


10


, comprises two swing arms


12


extending parallel to one another which are rigidly connected to one another at their lower rear portions via a flange


14


(

FIGS. 4 and 5

) or are, respectively, unitarily connected with this flange. The swing lever arms, in their rear regions in the vicinity of the flange


14


, are provided with holes


16


, in which a coupling bolt


18


is rotatively mounted, the coupling bolt having a cut out


20


. A coupling lever


22


is secured in a non-rotating manner to the coupling bolt


18


, the coupling lever being biased, in the installed condition of the coupling bolt


18


in the swing lever


10


, in a counter clockwise direction by a rotation spring


24


connected to the coupling lever and the swing lever


10


.




A contact lever, which is collectively designated with the reference character


30


is, in a manner similar to the swing lever


10


, configured with two contact lever arms


32


, which are rigidly connected to one another by a flange


33


(

FIG. 4

) or, respectively, are unitarily rigidly connected with one another.




The contact lever


30


is dimensioned such that it is receivable between the arms of the swing lever


10


. By means of a bolt


34


, which extends through pivot openings


36


at the forward end of the arms


12


and


32


and, as desired, is rotatably disposed therein via bushings


38


, the contact lever


30


is rotatable relative to the swing lever


10


. In the assembled condition of the swing arm


10


, a spring


44


is arranged between an appendage


40


projecting from the swing arm


10


and a bracket


42


provided on the contact lever


30


, the spring


44


biasing the contact lever


30


for a swing movement in the counter-clockwise manner relative to the swing lever


10


.




The contact lever arms


32


are provided at spacings from the pivot openings


36


with each having a respective additional pivot opening


46


, the pivot openings


46


securing between the arms


32


a rotation bolt


49


(

FIG. 4

) on which a contact roll or roller


48


is mounted.




On the right-hand swing lever arm


12


, as seen in

FIG. 1

, an extension


50


is provided on which an electromagnet


52


is mounted between the two arms


12


by means of a screw


53


, the electro-magnet comprising an electro-magnetically actuable blocking bolt


54


which can be extended outwardly into a hole


55


formed in the extension


50


and which cooperates with an appendage


56


(

FIG. 14

) of the coupling lever


22


. The coupling lever


22


comprises a contact surface


58


whose function is explained in more detail hereinafter.




The assembly of the above-described apparatus is as follows:




The coupling bolt


18


is assembled together with the coupling lever


22


and, with the intermediate arrangement of the rotational spring


24


, is extended through the holes


16


and axially non-displaceably secured to the swing lever


10


. The contact roller


48


is disposed on the contact lever


30


and the contact lever


30


is, via the bolt


34


, disposed on the swing lever


10


. The electro-magnet


52


is mounted to the extension


50


and is connected via non-illustrated connectors with a control device.




The entire working assembly, with the flange


14


of its swing lever


10


having one or more corresponding cut outs


60


, is disposed on a hydraulic power compensating element


62


which itself is on the cylinder head of a non-illustrated combustion engine, whereby the bolt


34


comes into contact with the shaft of a valve


64


which is pressed in its closing direction by a return spring


66


.




Thereafter, a camshaft


68


is installed which comprises a valve cam


70


for contacting the contact roller


48


and a coupling cam


72


, which cooperates with the contact surface


58


of the coupling lever


22


. As can be seen, the coupling cam


72


is arranged relative to the valve cam


70


such that the radially raised portion of the coupling cam is angularly coincident with the region of the base circle of the valve cam


70


. The camshaft


68


includes circular cylindrical contact surfaces


74


disposed on both sides of the valve cam which cooperate with the outer surface regions


76


of the swing lever arms


12


.




The arrangement between the cut out


20


in the coupling bolt


18


, the rotational position of the coupling lever


22


or, respectively, the rotational position of the coupling bolt


18


, and the arms


32


of the contact lever


30


is such that the arms of the contact lever


30


can pass through the cut out


20


of the coupling bolt


18


, if the coupling lever


22


is disposed in the position into which it moves in a clockwise direction, as shown in

FIG. 1

, due to the engagement of the coupling lever by the radially raised portion of the coupling cam


72


. If the coupling lever


22


, in contrast, is disposed in the position it assumes as it follows the base circle of the coupling cam


72


, the cut out


20


will have been rotated such that the arm


32


of the contact lever


30


cannot move past the cut out


20


but is, instead, as a result of the seating engagement between the coupling bolt


18


and the cut out


78


formed in the arm


32


, disposed in a form locking or keyed manner with the coupling bolt


18


so that the contact lever


30


cannot swing away from the swing lever


10


.




The arrangement between the outer surface region


76


of the swing lever arm


12


and the contact surface


74


of the camshaft


68


is such that the bolt


34


is constantly in at least adjacent disposition to the valve shaft, even if the contour of the valve cam


70


is not translated by the contact lever


30


to the swing lever


10


.




The function of the above-described apparatus is as follows:




It is assumed that the electro-magnet


52


is not actuated, so that the blocking bolt


52


does not extend through the hole


55


formed in the extension


50


. If the valve cam


70


presses the contact roller


48


downwardly, as viewed with respect to

FIG. 1

, the movement of the contact roller


48


is translated to the swing lever


10


due to the seating engagement between the contact lever


30


and the coupling bolt


18


, whereby the bolt


34


actuates the valve


64


.




The entire arrangement is disposed such that, as a result of the biasing force of the tolerance compensating element


62


, the contact roller


48


is disposed on the base circle of the valve cam


70


or, respectively, the outer surface region


76


of the swing lever arm


12


is disposed on the contact surface


74


of the camshaft


68


. If, during the effective operation of the base circle of the valve cam


70


, the coupling cam


72


engages the contact surface


58


, the coupling bolt


18


is rotated such that the cut out


20


rotates toward the arms of the contact lever


30


without the arms initially passing through the cut out. If the coupling lever


22


is retained by the actuation of the electro-magnet


52


through the rotational position of the radially raised portion of the coupling cam


72


(the blocking bolt


54


of the electro-magnet


52


grips or contacts the appendage


56


of the coupling lever


22


), the contact lever


30


can, during the thereafter-following actuation, be moved by the valve cam


70


through the cut out


20


and thereby swing into the swing lever


10


, so that the valve


64


is not actuated.




It is to be understood that the electro-magnet


52


is respectively actuated by a non-illustrated control device at least for capturing or, respectively, retaining, the coupling lever


22


, if the contact roller


48


has contacted the base circle of the valve cam


70


or, respectively, has contacted the base circle of the coupling cam


72


as the coupling lever


22


is rotated in the clockwise direction as shown in FIG.


1


.




As can be understood from the foregoing description, the entire described building components can be mounted in a simple manner on the cylinder head before the installation of the camshaft instead of the mounting of a conventional valve actuating lever, whereby the cut out


60


formed in the flange


14


provides for a secure and reliable securement of the building components on the tolerance compensating element


62


and a cut out


80


formed in the bolt


34


and opening toward the valve shaft provides for a flat disposition on the valve shaft.




The afore-described arrangement can be reconfigured or modified in many ways: for example, the coupling bolt


18


can be provided with two cut outs


20


each of which corresponds to one of its arms. Furthermore, the coupling bolt


18


and the contact lever


30


can be configured such that the contact lever in one of the rotational positions of the coupling bolt lies against the coupling bolt and, in another rotational position, moves past the coupling bolt.




As seen in

FIG. 1

, in individually depicted broken-line positions, the cylindrical contact surfaces


74


are provided with assistance cams


82


. In one configuration of the camshaft


68


with such assistance cams


82


, in the event of a “captured” coupling lever (interruption of the movement translation between the contact roller


48


and the swing lever


10


), the swing lever


10


is immediately or directly actuated by the assistance cams, which are disposed on the cuter surface regions


76


. In this manner, the valve


64


can be actuated with two different opening functions corresponding to the valve cam


70


and the assistance cams


82


.





FIGS. 7 and 8

show an embodiment which, relative to the afore-described embodiment, is only slightly modified. The difference lies in that the electro-magnet


52


of the previously described embodiment is replaced by a hydraulic cylinder


84


so that the blocking bolt


54


for capturing, or respectively, fixedly retaining, the coupling lever


22


is hydraulically actuated. The hydraulic pressure can be directly absorbed by the tolerance compensating device


62


, whereby the hydraulic cylinder


84


can be configured such that it captures the coupling lever


82


at a high hydraulic pressure or at a low hydraulic pressure and fixedly retains the coupling lever, or respectively, releases the coupling lever. It is to be further understood that, as well in this embodiment as in the previously described embodiment, the coupling lever


22


can be configured with a ramp extending to the blocking bolt


54


on which the extended-out blocking bolt


54


is disposed and which thereby captures the coupling lever


22


, if the coupling lever has been moved by the coupling cam


72


in the clockwise direction into its respective position in which the movement translation between the contact roller


48


and the valve actuation bolt


34


has been interrupted.




A further embodiment of the inventive apparatus is shown in

FIGS. 9-13

. This embodiment is distinguished from the previous embodiments in that the coupling bolt


18


is not, as in the previous embodiments, rotatable, but, rather, is displaceably supported in the swing lever arms


12


, and the actuation or switch device


86


, which is configured as an electromagnet or a hydraulic cylinder and secured to the swing arm


10


, is displaced in the direction of the double arrows shown in FIG.


12


. As seen in particular in

FIGS. 12 and 13

, the coupling bolt


18


, which has two cut-outs


20


, is in its first position, as shown in

FIG. 12

, whereby, in this position, the coupling bolt is displaced axially such that the cut outs


20


are to the side relative to the contact lever arms


32


of the contact lever


30


, so that the contact lever


30


is in form locking or keyed engagement with the coupling bolt


18


and a swing movement of the contact lever


30


is translated to the swing lever


10


.




As seen in

FIG. 13

, the coupling bolt


18


can be displaced toward the left out of its position as shown in

FIG. 12

so that the cut outs


20


are located in the region of the contact lever arms


32


and the contact lever


30


can pass through the coupling bolt


18


, such that a swing movement of the contact lever


30


via the valve cam


70


does not correspondingly take along the swing lever


10


, in which the coupling bolt


18


is supported, and the valve is correspondingly not actuated.




It is to be understood that the actuation of the switch unit


86


in accordance with the embodiment shown in

FIGS. 9-13

is preferably synchronized with the camshaft rotation such that the switch unit


86


, if the valve is to be placed out of operation, is actuated while the contact roller


48


is in following contact with the base circle of the valve cam


70


. Similarly, the valve in this phase position is again turned off or de-activated.




In the embodiment shown in

FIGS. 9-13

, the camshaft


68


does not support any coupling cams so that this embodiment can be installed on conventional cylinder heads without any modification.




The invention can be altered or reconfigured in many ways. In this regard, individual ones of the afore-described features can be combined with one another and/or can additionally be reconfigured. For example, the coupling bolt


18


in the embodiment shown in

FIGS. 9-13

can, as well, be rotatable. Furthermore, the bolt


34


need not necessarily or invariably directly actuate the valve; instead, the swing lever can be configured with an additional flange which actuates the valve. Additionally, the configuration of the swing lever can be such that the swing lever simultaneously actuates two valves such as, for example, two inlet valves. The retaining or, respectively, capture, device for the coupling lever


22


can be configured in the form of an electro-magnet which operates to immediately or directly capture the coupling lever


22


, which is configured as an anchor, and so forth. The coupling member can be configured integrally or unitarily with the coupling lever. The cut outs


20


can be replaced through any other embodiment by which a form locking can be achieved and which is releasable.





FIG. 14

shows an advantageous detail of the blocking bolt on the appendage on the coupling lever


22


as it is shown, for example, with regard to the embodiment shown in FIGS.


1


-


8


: the appendage


56


of the coupling lever is provided with ribs


88


which can seat in an annular groove


90


formed in the blocking bolt. If the coupling lever


22


is moved by the coupling cam in accordance with

FIG. 14

to the rear to the widest possible extent, the blocking bolt


54


is moved toward the right and maintains the coupling lever in a retained position during its subsequently falling forward movement, whereby the blocking bolt is blocked by virtue of the engagement between the ribs


88


and annular groove


90


from making a movement toward the left as shown in FIG.


14


. Correspondingly, the electro-magnet need not be activated to engage the blocking bolt as long as this engagement exists. The engagement releases, in turn, if the coupling lever moves into contact with the apex or radially outermost portion of the coupling cam. An advantage which is achieved with the embodiment according to

FIG. 14

is that the signal to the actuator the electro-magnets


52


to lock or release can be given in a wide range and is substantially independent of the angle position of the camshaft. The locking and releasing follows always through a predetermined angular range of the coupling cam.





FIG. 15

shows a changed or reconfigured construction of the swing lever, the coupling lever, and the camshaft. In this embodiment, the swing lever is arranged within the contact lever


30


. The rotational support bolt


49


, which rotatably supports the pair of contact rollers


48


each on a side of the contact lever


30


, extends through a large opening of the swing lever


10


. The outer surface region


76


of the swing lever


10


, which cooperates with a cylindrical contact surface


74


of the camshaft


68


, is centrally disposed on the swing lever. The camshaft


68


is correspondingly configured with a cylindrical contact surface


74


and two valve cams


70


. Also, in the embodiment according to

FIG. 15

, a coupling cam and a corresponding coupling lever can be provided, these components not being shown. The arrangement according to

FIG. 15

can, for example, then be advantageous if the free access to the seat of the valve spring in the non-actuated position is very limited.




The specification incorporates by reference the disclosure of German priority document 100 60 890.6-13 filed on Dec. 7, 2000.




The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims.



Claims
  • 1. An apparatus for selectively enabling and disabling the operation of a charge valve of an internal combustion engine, comprising:a cam shaft having a rotation axis; a coupling cam and at least one valve cam each mounted to the cam shaft for rotation therewith, the coupling cam and the valve cam each having a cam profile comprising a follower displacing portion extending to the radially outermost location of the profile relative to the cam shaft rotation axis and a dwell portion at a lesser radial distance from the cam shaft rotation axis than the follower displacing portion; a swing lever having one portion supported on a component of the internal combustion engine; a contact lever movably mounted to the swing lever at a first location thereon spaced from the one portion of the swing lever; contact lever biasing means for biasing the contact lever into contact with the valve cam, the contact lever biasing means having one end connected to the swing lever and another end connected to the contact lever; a coupling member movably supported by the swing lever at a second location thereon spaced from the first location on the swing lever at which the contact lever is movably mounted, the coupling member including a bolt rotatably mounted in the swing lever and the coupling member being movable between a non-interfering position in which the contact lever, in response to engagement thereof by the follower displacing portion of the valve cam, moves, without interference from the coupling member, into contact with the swing lever to thereby impart a movement to the swing lever which enables the operation of the charge valve and a blocking position in which the coupling member blocks contact between the contact lever and the swing lever such that the contact lever cannot impart movement to the swing lever; coupling member biasing means for biasing the coupling member into contact with the coupling cam, the coupling member biasing means having one end connected to the swing lever and another end connected to the coupling member; and means for releasably maintaining the coupling member in its blocking position, the follower displacing cam profile portion of the valve cam and the follower displacing cam profile portion of the coupling cam being angularly offset from one another relative to the cam shaft rotation axis such that the follower displacing cam profile portion of the coupling cam displaces the coupling member from its non-interfering position into its blocking position during a rotating movement of the cam shaft during which the contact lever follows the dwell portion of the valve cam.
  • 2. An apparatus according to claim 1, wherein the swing lever includes a pair of swing lever arms at a spacing from one another through which the contact lever moves, the swing lever arms being connected to one another by a flange and the contact lever includes a pair of contact lever arms interconnected to one another by a flange on which is mounted a contact roller adapted for following movement along the cam profile of the valve cam.
  • 3. An apparatus according to claim 2, wherein the contact lever arms are rotatably mounted on the swing lever arms by a bolt, the bolt contacting the charge valve to thereby move the charge valve.
  • 4. An apparatus according to claim 2, wherein the coupling member includes at least one cut out dimensioned to permit movement of the contact lever arms therethrough in the non-interfering position of the coupling member.
  • 5. An apparatus according to claim 1, wherein the means for releasably retaining the coupling member in its blocking position includes an electro-magnet.
  • 6. An apparatus according to claim 1, wherein the means for releasably retaining the coupling member in its blocking position includes an axially displaceable blocking bolt which is axially displaceable into an axially displaced disposition in which the blocking bolt blocks the path of movement of an appendage of the coupling member, the blocking bolt and the appendage of the coupling member cooperating with one another in the axially displaced disposition of the blocking bolt such that the blocking bolt is prevented from movement out of its axially displaced disposition.
  • 7. An apparatus according to claim 1, wherein the cam shaft includes a cylindrical surface which the swing lever follows while the coupling member is in its blocking position.
  • 8. An apparatus according to claim 1, wherein the cam shaft includes an assistance cam which moves the coupling member into a second non-interfering position in which the contact lever moves, without interference from the coupling member, into contact with the swing lever to thereby impart a movement to the swing lever which enables the operation of the charge valve, the assistance cam moving the coupling member into its second non-interfering position at a different angular position of the cam shaft than the angular position of the cam shaft at which the coupling member is moved into its non-interfering position by the coupling cam.
  • 9. An apparatus according to claim 1, wherein the component of the internal combustion engine on which the one portion of the swing lever is supported is a hydraulic compensating element.
Priority Claims (1)
Number Date Country Kind
100 60 890 Dec 2000 DE
US Referenced Citations (5)
Number Name Date Kind
5655488 Hampton et al. Aug 1997 A
6032624 Tsuruta et al. Mar 2000 A
6318317 Hubschle Nov 2001 B1
6321705 Fernandez et al. Nov 2001 B1
6325030 Spath et al. Dec 2001 B1
Foreign Referenced Citations (5)
Number Date Country
3526542 Feb 1986 DE
3701480 Jul 1987 DE
198 28 945 Jan 2000 DE
0 016 068 Oct 1980 EP
0 995 885 Apr 2000 EP