EP4196667A1

EP4196667A1 - Sliding cam system

Info

Publication number: EP4196667A1
Application number: EP21759285.6A
Authority: EP
Inventors: Marcel WEIDAUER
Original assignee: ThyssenKrupp AG; Thyssenkrupp Dynamic Components GmbH
Current assignee: ThyssenKrupp AG; Thyssenkrupp Dynamic Components GmbH
Priority date: 2020-08-12
Filing date: 2021-08-10
Publication date: 2023-06-21
Also published as: CN116034212A; DE102020210259A1; US20240035398A1; WO2022034104A1; US12031460B2

Abstract

A sliding cam system for an internal combustion engine with an adjusting element (16), wherein the adjusting element (16) comprises at least three coupling pins (17a, 17b, 17c), wherein a first coupling pin (17a) is arranged in the region of the primary sliding cam element (12a), and a second coupling pin (17b) is arranged in the region of the first secondary sliding cam element (12b), and a third coupling pin (17c) is arranged in the region of the second secondary sliding cam element (12c), and the coupling pins (17a, 17b, 17c) interact in each case with a switching slotted guide (13) of the respective associated sliding cam element (12a, 12b, 12c) in such a way that a movement, initiated by an actuator pin (15), of a primary sliding cam element (12a) can be transferred by the adjusting element (16) to secondary sliding cam elements (12b, 12c), wherein the sliding cam system is set up in such a way that a switching operation of the first secondary sliding cam element (12b) takes place at least in part at the same time as the switching operation of the second secondary sliding cam element (12c).

Description

sliding cam system

The invention relates to a sliding cam system for an internal combustion engine according to the preamble of claim 1.

A sliding cam system of the type mentioned above is known, for example, from DE 10 2011 054 218 A1.

A rotatably mounted camshaft is provided in the known sliding cam system. The camshaft includes multiple slide cams. The sliding cams can be moved axially. The axial movement of the sliding cams is initiated by an actuator.

For this purpose, a coupling rod is firmly connected via a shift fork to a sliding cam, which is moved axially directly by the actuator. With an axial movement of the slide cam, the coupling rod moves with the slide cam.

The coupling rod includes scenes. The scenes are firmly connected to the coupling rod. The scenes are each assigned to a further sliding cam. The further sliding cams have pins which interact with the respectively assigned links in such a way that the further sliding cams are displaced in accordance with the movement of the sliding cam which is firmly connected to the coupling rod.

From the applicant's patent application PCT/EP2020/058182 or DE 10 2019 107 626.9, a sliding cam system for an internal combustion engine with at least one camshaft has become known, comprising a support shaft with at least two sliding cam elements. The sliding cam elements each comprise a shift gate with at least one shift groove, the sliding cam elements being displaceable axially with respect to the carrier shaft by at least one actuator pin. At least one adjustment element is arranged parallel to a longitudinal axis of the support shaft, the adjustment element being axially displaceable in the direction of the longitudinal axis of the support shaft.

Although an advantageous sliding cam system has already been proposed here, improvements can still be made, in particular with regard to the maximum switching speed and the masses to be moved. In the prior art, particularly in the case of the shifting cam system according to PCT/EP2020/058182 or DE 10 2019 107 626.9, the shifting range of the shifting grooves is limited to 120° NW, which ultimately represents the groove length of the respective shifting cam element used for shifting. The resulting kinematics, in turn, limit the masses to be moved of the sliding camshaft and, ultimately, the maximum switching speed.

This is where the present invention comes in and has set itself the task of providing an improved shifting cam system, in particular specifying a shifting cam system in which an axial shifting of a shifting cam element at an increased speed and/or an axial shifting of a shifting cam element with a greater mass can be achieved.

According to the invention, this object is achieved by a sliding cam system having the characterizing features of claim 1.

Because the shifting cam system is set up in such a way that a shifting process of a first secondary shifting cam element takes place at least partially simultaneously with the shifting process of a secondary shifting cam element, the shifting range can be increased and thus an axial shifting of a shifting cam element at an increased speed and/or an axial shifting of a Sliding cam element with greater mass can be achieved over a known sliding cam system

Further advantageous refinements of the proposed invention result in particular from the features of the dependent claims. The objects or features of the various claims can in principle be combined with one another as desired.

In an advantageous embodiment of the invention, it can be provided that the sliding cam system is set up in such a way that the switching process of a first secondary sliding cam element begins immediately after the switching process of the primary sliding cam element has ended and that the switching process of a second secondary sliding cam element begins after the beginning and before the end of the switching process of the first secondary sliding cam element. In a further advantageous embodiment of the invention, it can be provided that the shift cam system is set up in such a way that the beginning of the shifting process of a first secondary shifting cam element and the beginning of the shifting process of a second secondary shifting cam element take place simultaneously.

In a further advantageous embodiment of the invention, it can be provided that the lengths of the displacement areas of the sliding cam elements are the same, in particular that °NW 121a/S=°NW 121b/S=°NW 121c/S.

In a further advantageous embodiment of the invention it can be provided that the length of the displacement areas of all sliding cam elements is different, in particular that °NW 121a/S * °NW 121b/S * °NW 121c/S applies.

In a further advantageous embodiment of the invention, it can be provided that the displacement ranges of the sliding cam elements are greater than 120°NW, in particular that °NW 121a/S > 120° or °NW 121b/S > 120° or °NW 121c/ S > 120°.

In a further advantageous embodiment of the invention, it can be provided that the beginning of the switching section °NW121b/SA at the beginning of the cam °NW122b/NA is not the same as the beginning of the switching section NW121C/SA at the beginning of the cam °NW122c/NA, in other words that the angular position of the Shifting range for the respective cam tip is different for the secondary shifting cam elements, in particular that °NW121b/SA to °NW122b/NA is unequal °NW121c/SA to °NW122c/NA.

In a further advantageous embodiment of the invention, it can be provided that the length of the shifting area of the first shifting groove on the primary shifting cam element is greater than the length of the shifting areas of the shifting grooves on the secondary shifting cam elements.

In a further advantageous embodiment of the invention, it can be provided that the length of the shifting area of the shifting groove on at least one secondary shifting cam element is greater than the length of the shifting area on the primary shifting cam element and/or possibly further secondary shifting cam elements. In a further advantageous embodiment of the invention it can be provided that more than two secondary sliding cam elements are coupled with a connecting element.

In a further advantageous embodiment of the invention, it can be provided that the secondary sliding cam elements are not identical parts, in particular with regard to the displacement area and/or cam contour.

In a further advantageous embodiment of the invention, it can be provided that the cam contours of the secondary sliding cam elements are arranged identically, in particular are arranged angularly offset only according to the firing sequence, e.g. offset by 120° and are identical with regard to the cam contour. However, depending on the thermodynamic requirements, both the arrangement and the cam profile shape / cam profile length can differ.

In a further advantageous embodiment of the invention it can be provided that the sliding cam system is set up in such a way that the switching process of the

Primary sliding cam element is completed before the shifting of a

Secondary sliding cam element takes place. Preferably, displacement of the primary sliding cam member occurs only while the locking disc is released and displacement of the secondary cam members can preferably only occur when the locking disc is locked.

In a further advantageous embodiment of the invention, it can be provided that the sliding cam system is set up in such a way that the switching process of a first secondary sliding cam element begins immediately after the switching process of the primary sliding cam element has ended, with the switching process of a further (second) secondary sliding cam element preferably starting after the beginning and before the end of the Switching process of the first secondary sliding cam element begins. Further features and advantages of the present invention become clear from the following description of preferred exemplary embodiments with reference to the attached figures. show in it

1 is a perspective view of one embodiment of a prior art cam shift system;

FIG. 2 is another perspective view of an embodiment of a prior art shift cam system; FIG.

Fig. 3 is a side view of an embodiment of a prior art shift cam system;

4 is another side view of an embodiment of a prior art shift cam system;

Fig. 5 is a side view of another embodiment of a prior art shift cam system;

6 shows a diagram “lift [mm]/blocking range [λ] versus angle [°NW]” for a shift cam system according to the prior art;

7 shows a perspective view of an embodiment of a sliding cam system according to the invention;

7a shows a perspective view of a camshaft of an embodiment of a sliding cam system according to the invention;

8 shows a primary slide cam element of a slide cam system according to the invention in a perspective view;

9 shows a primary slide cam element of a slide cam system according to the invention in a side view;

Fig. 10 shows a section A-A according to Fig. 9;

11 shows a perspective view of a first secondary shifting cam element of a shifting cam system according to the invention; 12 shows a side view of a first secondary shifting cam element of a shifting cam system according to the invention;

Fig. 13 is a section C-C of Fig. 12;

Fig. 13a shows a section C-C according to Fig. 12;

14 shows a second secondary shifting cam element of a shifting cam system according to the invention in a perspective view;

15 shows a second secondary shifting cam element of a shifting cam system according to the invention in a side view;

Fig. 16 shows a section B-B according to Fig. 15;

Fig. 16a shows a section B-B according to Fig. 15;

17 shows a locking element (locking disk) for a sliding cam system according to the invention;

18 shows a diagram “lift [mm]/blocking range [ ] over the angle [°NW]” for a sliding cam system according to the invention according to FIG. 7.

The following reference symbols are used in the following figures:

10 camshaft

11 carrier shaft

12a primary slide cam element

12b first secondary slide cam element

12c second secondary slide cam element

13 shift gate

14 shift groove

14a first shift groove

14b second shift groove

15 actuator pin

16 adjustment element

17a first coupling pin

17b second coupling pin 17c third coupling pin

18 receiving element

19 locking element

20 rolling bearings

21 retaining rings

22 cam contour

23 actuator

24 Restricted Area Restrictor Disc

25 full stroke profile cylinder.1 (VH profile cylinder 1)

26 full stroke profile cylinder.3 (VH profile cylinder 3)

27 Full Lift Profile Cylinder.2 (VH Profile Cylinder 2)

28 partial stroke profile cylinder.1 (TH profile cylinder 1)

29 partial stroke profile cylinder.3 (TH profile cylinder 3)

30 partial stroke profile cylinder.2 (TH profile cylinder 2)

31 axial stroke cylinder.1

32 axial stroke cylinder.2

33 axial stroke cylinder.3

34 Area of simultaneity of the axial movement of the secondary sliding cam elements (BG)

121a first switching groove of the primary sliding cam element 12a

121a' second switching groove of the primary sliding cam element 12a

121b switching groove of the first secondary sliding cam element 12b

121c switching groove of the second secondary sliding cam element 12c

122a first cam contour of the primary sliding cam element 12a

122a' second cam contour of the primary sliding cam element 12a

122b first cam contour of the first secondary sliding cam element 12b

122b' second cam contour of the first secondary sliding cam element 12b

122c first cam contour of the second secondary sliding cam element 12c

122c' second cam contour of the second secondary sliding cam element 12c

°NW 121a/S angular length of the shifting range 121a/S of the first shifting groove 121a of the

Primary slide cam element 12a

°NW 121a/F Angular length of the freewheel 12 la/F of the first shifting groove 121a des

Primary slide cam element 12a °NW 12 lb/S Angular length of the shifting range 121 b/S of the indexing groove 121b of the first

Secondary slide cam element 12b

°NW 12 lb/F Angular length of the free wheel 121 b/F of the shift groove 121b of the first

Secondary slide cam element 12b

°NW 121c/S Angular length of the shifting range 121c/S of the shift groove 121c of the second secondary shift cam member 12c

°NW 12 lc/F Angular length of the freewheel 12 lc/F of the shift groove 121c of the second

Secondary slide cam element 12c

°NW121a/SA Beginning of the shifting range of the first shifting groove 121a of the

Primary slide cam element 12a

°NW121a/SE End of the shifting range of the first shifting groove 121a of the

Primary slide cam element 12a

°NW121b/SA Beginning of the shifting range of the shifting groove 121b of the first secondary shifting cam element 12b

°NW121b/SE End of the shifting range of the shifting groove 121b of the first secondary shifting cam element 12b

°NW121c/SA Beginning of the sliding range of the switching groove 121c of the second secondary sliding cam element 12c

°NW121c/SE End of the shifting range of the shifting groove 121c of the second

Secondary slide cam element 12c

°NW122b/NA Beginning of the first cam contour 122b of the first secondary sliding cam element 12b

°NW122c/NA Beginning of the first cam contour 122c of the second secondary sliding cam element 12c

NS122b cam tip of the first cam contour of the first secondary slide cam element 12b

NS122c Cam tip of the first cam contour of the second secondary slide cam element 12c

Figures 1 to 4 show the same embodiment of a sliding cam system from different perspectives.

The shift cam system for an internal combustion engine having at least one camshaft 10 comprises a support shaft 11. On the support shaft 11 are a primary shift cam element 12a and a first Secondary sliding cam element 12b is arranged to be axially movable relative to a longitudinal axis of the support shaft 11 and, in particular, to be rotated. It is conceivable that more than two sliding cam elements are arranged on the support shaft 11 . The carrier shaft 11 preferably comprises three roller bearings 20. One roller bearing 20 is arranged at the axial ends of the carrier shaft 11 and another roller bearing 20 is arranged between the sliding cam elements 12a, 12b. The roller bearings 20 are preferably locked by retaining rings 21. The number of roller bearings 20 and retaining rings 21 and the positions of the bearing points are variable. The sliding cam elements 12a, 12b include a shift gate 13 and a cam contour 22.

The shifting gate 13 of the first sliding cam element 12a comprises a first and a second shifting groove 14a, 14b. The switching grooves 14a, 14b are at least partially V-shaped. In other words, the width of the two switching grooves 14a, 14b is not constant. The width is the distance between the flanks of the switching grooves 14a, 14b in the axial direction to the carrier shaft 11 to understand. The flanks of the switching grooves 14a, 14b approach one another in the V-shaped section.

The two switching grooves 14a, 14b are preferably arranged at the same angle of rotation. The first switching groove 14a preferably has a larger radius than the second switching groove 14b.

The radius is to be understood as the amount of the distance between the groove base of the first or the second shifting groove 14a, 14b and the central longitudinal axis of the carrier shaft 11. Thus, the outer diameter of the shift gate 13 and the radius of the groove base determine the depth of the groove.

The first switching groove 14a preferably includes a step. In other words, the first switching groove 14a is designed as a projection or a shoulder. The first switching groove 14a preferably has a varying radius. That is, the first switching groove 14a has sections with a larger radius and a smaller radius. The radius is changed steplessly. The areas are each assigned to an entry area, an exit area or a shifting area.

The second switching groove 14b preferably has a constant radius. The width of the second switching groove 14b is smaller than the width of the first switching groove 14a.

Two actuator pins 15 are arranged on the carrier shaft 11 . The actuator pins 15 can essentially only be moved in one direction orthogonal to the central longitudinal axis of the carrier shaft 11 . The actuator pins 15 are assigned to the first switching groove 14a. Ie the actuator pins only work together with the first switching groove 14a. The actuator pins 15 are spaced apart from one another in the axial direction of the support shaft 11 . As a result, depending on the position of the primary sliding cam element, one of the two actuator pins 15 can be inserted into the first switching groove 14a. By inserting the actuator pins 15, an axial movement of the primary sliding cam element 14a can be initiated. For this purpose, an actuator pin 15 is inserted into the first switching groove 14a. Due to the reduction in the groove width, the introduced actuator pin 15 interacts with a flank of the first switching groove 14a. More precisely, the introduced actuator pin 15 acts on a flank of the first switching groove 14a with a force directed against the flank. This results in the axial displacement of the primary sliding cam element 12a. The direction of the shift thus depends on the flank with which the introduced actuator pin

15 cooperates. An actuator pin 15 is assigned to each flank of the first switching groove 14a.

An adjustment element 16 is arranged parallel to the carrier shaft 11 . The adjusting element 16 can be moved axially. The adjusting element is offset by 90° to the actuator pins 15. Alternatively, other angular offsets are conceivable. The adjusting element 16 comprises a first and a second coupling pin 17a, 17b and a receiving element 18. The first and the second coupling pin 17a, 17b are each arranged on an axial end of the adjusting element 16. The receiving element 18 comprises three extensions and is arranged between the axial ends of the adjustment element 16 . The coupling pins 17a, 17b and the receiving element 18 extend orthogonally to the central longitudinal axis of the carrier shaft 11.

The first coupling pin 17a is assigned to the second switching groove 14b of the primary sliding cam element 12a. The first and the second coupling pin 17a, 17b are arranged on the adjustment element 16 in a substantially rotatable manner. The first coupling pin 17a is permanently engaged with the second switching groove 14b of the primary slide cam element 12a.

The first coupling pin 17a is subjected to a force by a flank of the second switching groove 14b. The adjustment element 16 is displaced in the effective direction of the force. Since the adjustment element

16 and thus the coupling pins 17a, 17b are offset from one another by 90° in the circumferential direction and the first and the second switching groove 14a, 14b are arranged at the same angle of rotation, the displacement of the adjustment element 16 takes place correspondingly with a time offset or phase shift.

The second coupling pin 17b is arranged in the area of the first secondary sliding cam element 12b. The first secondary sliding cam element 12b includes a switching groove 14. The switching groove 14 has a V-shaped section. The second coupling pin 17b is permanently engaged with the switching groove 14. The switching groove 14 of the first secondary sliding cam element 12b is arranged in such a way that a time-delayed switching of the first secondary sliding cam element 12b with respect to the primary sliding cam element 12a can be implemented.

By moving the adjusting element 16, the second coupling pin 17b is moved axially in the switching groove 14. More precisely, the second coupling pin 17b is moved to one of the flanks of the switching groove 14. The second coupling pin 17b interacts with the switching groove 14 in essentially the same way as the actuator pins 15 interact with the first switching groove 14a of the primary sliding cam element 12a.

The carrier shaft 11 comprises a locking element 19 in the form of a circular disk. Alternatively, other geometries are conceivable. The locking member 19 is interposed between the first and first secondary slide cam members 12a, 12b. The locking element 19 is axially delimited by the receiving element 18 . The locking element 19 has a supporting function. The locking element 19 forms an abutment for the receiving element 18. The locking element 19 absorbs the forces during the shifting process and thus enables the adjustment element 16 to be fixed. Furthermore, the interaction of the receiving element 18 and the locking element 19 prevents the primary sliding cam element 12a from being displaced unintentionally . The receiving element 18 includes two receptacles for the locking element 19. The locking element 19 includes a recess. This allows the adjustment element to be displaced by the circular disc. For this purpose, the recess is arranged in the area of the corresponding angle of rotation. The recess is arranged in the circular disc in such a way that the adjustment element 16 is moved through the recess when there is an axial movement. It is conceivable that the adjustment element 16 additionally includes a spring-ball detent (not shown).

In summary, the shifting cam system described above enables the shifting cam elements 12a, 12b to be shifted out of phase by the adjusting element 16 using a single actuator. As a result, the total number of actuators in the sliding cam system can be significantly reduced.

FIG. 5 describes another embodiment of a prior art slide cam system. The shifting cam system essentially corresponds to the shifting cam system according to FIGS. 1 to 4. In contrast to the system described above, the shifting cam system shown comprises a second secondary shifting cam element 12c and in particular the primary shifting cam element 12a has a different shifting gate.

The locking element 19 is preferably arranged between the second and the third sliding cam element 12b, 12c. The locking element 19 comprises a circular disc with a recess. An extension is arranged on the adjusting element 16 in the area of the circular disk. The circular disc forms an abutment for the extension. The circular disk interacts with the extension during a displacement process in such a way that the first coupling pin is relieved during the displacement process. In other words, the extension is supported against the circular disc. The recess is arranged on the angle of rotation at which the displacement of the first adjustment element 16 takes place. An actuator is marked with the reference number 23 . FIG. 6 shows “a diagram “stroke [mm]/locking range [ ] over the angle [°NW]” for a sliding cam system according to FIG. 5”.

In the diagram according to FIG. 6, the valve lifts resulting from the respective cam contours (large lift) of the embodiment of a sliding cam system according to the prior art according to FIG. 5 are shown as “VH profile cyl. 1", "VH profile cyl. 2” and “VH profile cyl. 3" drawn.

In the diagram according to FIG. 6, the valve lifts resulting from the respective cam contours (small lift) of the embodiment of a sliding cam system according to the prior art according to FIG. 5 are shown as “TH profile cyl. 1", "TH profile cyl. 2” and “TH profile cyl. 3" drawn.

The blocking areas of the blocking disk or locking element 19 are also plotted in the diagram according to FIG. 6 .

For further details and also further embodiments, reference can be made to the applicant's PCT/EP2020/058182 or DE 10 2019 107 626.9, to which express reference is made here.

Further improvements regarding the switching of the shift cam elements are described below.

A preferred embodiment of the present invention is illustrated in Figures 7-18. The embodiment of the sliding cam system according to the invention described there has a primary sliding cam element 12a, a first secondary sliding cam element 12b and a second secondary sliding cam element 12c. Furthermore, the locking element 19 can also be addressed as a locking disk. Furthermore, the adjustment element 16 can also be addressed as a push rod.

The shifting cam elements each have a shifting groove 121a, 121a', 121b, 121c, i.e. the primary shifting cam element 12a the shifting groove 121a and 121a', the first secondary shifting cam element 12b the shifting groove 121b and the second secondary shifting cam element 12c the shifting groove 121c.

The switching groove 121a is provided for engaging the actuator pins 15, whereas the switching groove 121a' is provided for engaging the first switching pin 17a of the connecting element 16.

The switching groove 121b is provided correspondingly for the engagement of the second switching pin 17b and the switching groove 121c is provided correspondingly for the engagement of the third switching pin 17c. The operating principle is as outlined above, the primary sliding cam element 12a is axially displaced in a targeted manner via the actuator or the engagement of the actuator pins 15 in the switching groove 121a during the rotation of the camshaft 10 . The adjusting element 16 is axially displaced by the engagement of the first switching pin 17a in the switching groove 121a', as a result of which the switching pins 17b and 17c are also correspondingly displaced.

The switching groove 121a of the primary sliding cam element 12a has at least one displacement area 121a/S and one freewheeling area 121a/F in the circumferential direction. The displacement area 121a/S is characterized in particular by a switching groove side cheek that is inclined relative to the longitudinal axis/rotational axis L of the primary sliding cam element 12a or carrier shaft. In other words, this is the area with which the primary element 12a and, through the operative connection between the switching groove 121a' and the switching pin 17a, the connecting element 16 are axially displaced. In contrast, the freewheeling area is that area of the switching groove 121a in which no axial displacement of the connecting element 16 takes place. The shifting area can also be addressed as a switching area.

The switching groove 121b of the first secondary sliding cam element 12b has at least one displacement area 121b/S and one freewheeling area 121b/F in the circumferential direction. The displacement area 121b/S is characterized in particular by a switching groove side cheek that is inclined relative to the longitudinal axis/rotational axis L of the secondary displacement cam element 12b or carrier shaft. In other words, this is the area on which a shifted switching pin 17b rests and axially shifts the secondary shifting cam element 12b in the desired direction. In contrast, the freewheeling area is that area of the switching groove 121b in which no axial displacement of the secondary sliding cam element 12b takes place. This area is characterized in particular by the fact that there is no contact with the switching groove side wall during the movement of the connecting element.

To avoid repetition, it can be pointed out that the second secondary sliding cam element 12c or its switching groove 121c also has a sliding area 121c/S and a freewheeling area 121c/F. The switching pin 17c of the adjustment element 16 engages here accordingly. With regard to the function, reference can be made to the previous paragraph on the first secondary sliding cam element 12b.

The sliding cam elements each have at least two cam contours. A cam contour can also be designed as a so-called zero-lift cam. The cam contours differ from one another and lead in particular to different strokes of the activated valve (not shown). The primary sliding cam element 12a preferably has a first cam contour 122a and a second cam contour 122a'. The first secondary slide cam element 12b preferably has a first cam contour 122b and a second cam contour 122b'. The second secondary slide cam element 12c preferably has a first cam contour 122c and a second cam contour 122c'. No cam contour of the primary sliding cam element 12a is shown in FIGS. 7 and 7a merely for the sake of better illustration. However, reference can be made to FIGS. 8 to 10 here.

The displacement ranges can be determined in more detail with regard to their angular length and also with regard to their start and end.

So can the angle lengths

° NW 121a/S angular length of the shifting range 121a/S of the first shifting groove 121a of the primary shifting cam element 12a

°NW 12 la/F Angular length of the freewheel 12 la/F of the first shift groove 121a des

Primary slide cam element 12a

°NW 12 lb/S Angular length of the shifting range 121 b/S of the indexing groove 121b of the first

Secondary slide cam element 12b

°NW 12 lb/F Angular length of the freewheel 12 lb/F of the shift groove 121b of the first

Secondary slide cam element 12b

Secondary sliding cam element 12c or beginning and end of the shifting areas

Primary slide cam element 12a

°NW121a/SE End of the shifting range of the first shifting groove 121a of the

Primary slide cam element 12a

°NW121b/SA Beginning of the shifting range of the indexing groove 121b of the first

Secondary slide cam element 12b

°NW121b/SE End of the shifting range of the shifting groove 121b of the first

Secondary slide cam element 12b °NW121c/SA Beginning of the shifting range of the shifting groove 121c of the second secondary shifting cam element 12c

°NW121c/SE end of the sliding range of the switching groove 121c of the second secondary sliding cam element 12c as mentioned above.

According to the invention, it is provided that the sliding cam system is set up in such a way that a switching process of the first secondary sliding cam element 12b takes place at least partially simultaneously with the switching process of the second secondary sliding cam element 12c.

According to the invention, the partially simultaneous switching of the secondary sliding cam elements is understood as follows: the displacement areas of the respective secondary sliding cams are angularly aligned with one another in such a way that they have sections in which the coupling pin of the adjustment element for axial displacement of the first secondary sliding cam element and the coupling pin of the adjustment element for axial displacement of the second secondary sliding cam element at the same time (concurrently) are in operative contact, so that an axial displacement of the second secondary cam element begins at least while the axial displacement of the first secondary sliding cam element takes place.

The angular orientation, i. H. the arrangement and length of the respective corresponding displacement areas of the secondary links are always dependent on the design of the motor or the respective installation space requirements of the internal combustion engine, such as the radial arrangement and position of the adjustment element.

It can preferably be provided that the shifting cam system is set up in such a way that the shifting process of the first secondary shifting cam element 12b begins immediately after the end of the shifting process of the primary shifting cam element 12a and that the switching process of the second secondary shifting cam element 12c begins after the beginning and before the end of the shifting process of the first secondary sliding cam element 12b. More preferably, it can be provided that the shifting cam system is set up in such a way that the beginning of the shifting process of the first secondary shifting cam element 12b and the beginning of the shifting process of the second secondary shifting cam element 12c take place simultaneously.

More preferably, it can be provided that the radial length of the displacement ranges °NW121a/S, °NW121b/S and °NW121c/S (angle ranges) of all sliding cam elements 12a, 12b, 12c are the same, in particular that °NW121a/S=°NW121b /S = °NW121c/S.

More preferably, it can be provided that the radial length of the displacement ranges °NW121a/S, °NW121b/S and °NW121c/S (angle ranges) of all sliding cam elements 12a, 12b, 12c is different, in particular that °NW121a/S * °NW121b applies /S * °NW121c/S.

More preferably, it can be provided that the displacement ranges of the sliding cam elements are greater than 120°NW, in particular that °NW121a/S>120° or °NW121b/S>120° or °NW121c/S>120°.

More preferably, it can be provided that the sliding cam system is set up such that the offset of the switching section °NW121b/SA to the start of the cam °NW122b/NA is unequal to the offset of the switching section °NW121c/SA to the start of the cam °NW122c/NA.

More preferably, it can be provided that the length of the displacement range °NW121a/S of the first shifting groove 121a on the primary sliding cam element 12a is greater than the length of the displacement ranges °NW121b/S or °NW121c/S of the shifting grooves 121b or 121c on the secondary shifting cam element 12b or .12c.

More preferably, it can be provided that the length of the displacement range °NW121b/S or °NW121c/S of the switching groove 121b or 121c on at least one secondary sliding cam element 12b or 12c is greater than the length of the displacement range °NW121a/S on the primary sliding cam element 12a and /or, if necessary, further secondary sliding cam elements (°NW121x/S or 12x). The x stands here as an index for further secondary sliding cam elements.

More preferably, it can be provided that more than two secondary sliding cam elements 12b, 12c are coupled with a connecting element 16, in particular for applications in internal combustion engines with more than 3 cylinders in a row arrangement. Provision can preferably be made for the switching groove on a secondary sliding element to be larger than on the primary sliding element and/or larger than on at least one further secondary sliding element. The sliding cam system is also applicable to 5, 6, 8, 10, 12 cylinder internal combustion engines. The sliding cam system can also be designed in three stages (or more) based on the number of cam contours 122x ^y . "X" is the index for the respective sliding cam element, "Y" is the index for the respective cam contour.

Compared to a shifting cam system according to the prior art, the present invention changes the length and the arrangement of the shifting grooves (area of axial shifting) of the secondary shifting gates in relation to the respective cam tip in such a way that ultimately an overlapping shifting of the secondary elements is achieved.

With the primary sliding cam element 12a, as well as with the secondary sliding cam elements 12b and 12c, this can result in an angular length of the displacement area 121a/S of the primary sliding cam element 12a of °NW121a/S > 120°, an angular length of the displacement area 121b/S of the first secondary sliding cam element 12b of °NW121b /S > 120° and/or an angular length of the displacement area 121c/S of the second secondary sliding cam element 12c of °NW121c/S> 120°, in particular to an angular length °NW121a/S, °NW121b/S, °NW121c/S of the displacement areas 121a /S, 121b/S, 121c/S of the switching grooves 121a, 121b, 121c of, for example, 153°NW each.

Provision can also preferably be made for the angular position of the displacement area to be different for the respective cam tip for the secondary displacement cam element, in particular that °NW121b/SA to °NW122b/NA is unequal °NW121c/SA to °NW122c/NA.

Furthermore, it can preferably be provided that secondary sliding cam elements are not identical parts, in particular with regard to the displacement area (arrangement, length) and/or cam contour (arrangement, length).

The arrangement of the displacement areas for the respective cam tip should be different, the length can be different. If the secondary cams have different mass properties, the shifting behavior can be adjusted, for example, by matching the length of the shifting grooves to the mass.

In a specific and preferred embodiment of the invention, it can be provided that the beginning of the switching section °NW121b/SA to the cam tip NS122b of the first secondary shifting cam is 143° and the beginning of the switching section NW121C/SA to the cam tip NS122c of the second secondary shifting cam is 203°, with others Words that the angular position of the displacement range for the respective cam tip secondary slide cam elements is different, specifically that °NW121b/SA to NS122b is unequal °NW121c/SA to NS122c.

Provision can also preferably be made for the cam contours of the secondary sliding cam elements to be arranged in the same way, in particular only to be angularly offset according to the firing sequence, e.g. offset by 120°, and to be identical in terms of the cam contour. However, depending on the thermodynamic requirements, both the arrangement and the cam profile shape / cam profile length can differ.

In particular with regard to the “Diagram “stroke [mm]/locking range [] over the angle [°NW]” for a sliding cam system according to the invention according to FIG. 7” (FIG. 18), it can be clearly seen that the switching process of the primary sliding cam element 12a has been completed should be before the switching process of a secondary sliding cam element 12b, 12c can take place. This is due in particular to the function of the locking disk 19.

Also with regard to the diagram according to FIG. 18, it can be clearly seen here that the switching process or the axial displacement of a first secondary sliding cam element 12b begins immediately after the switching process of the primary sliding cam element has ended. The switching process of a further (second) secondary sliding cam element preferably begins after the start and before the end of the switching process of the first secondary sliding cam element. In the extreme case, the first secondary shifting cam element and the further secondary shifting cam element or elements shift simultaneously - i.e. the beginning of the shifting processes takes place at the same time.

In the diagram according to FIG. 18, the valve lifts resulting from the first cam contours 122a, 122b and 122c are shown as “VH profile cyl. 1", "VH profile cyl. 2” and “VH profile cyl. 3" drawn.

In the diagram according to FIG. 18, the valve lifts resulting from the first cam contours 122a', 122b' and 122c' are shown as “TH profile cyl. 1", "TH profile cyl. 2” and “TH profile cyl. 3" drawn.

The blocking areas of the blocking disk or locking element 19 are also plotted in the diagram according to FIG. 18 .

Also, an "area of simultaneity of the axial movement of the secondary sliding cam elements" was drawn in as BG. The overlapping of the axial displacement of the secondary sliding cam elements, which is essential to the invention, can be seen here.

It is also recognizable, but not essential for the essence of the invention, that the valve lifts resulting from the first cam contours 122a, 122b and 122c are defined as “VH profile cyl. 1", "VH profile cyl. 2” and “VH profile cyl. 3” or valve lifts resulting from the first cam contours 122a′, 122b′ and 122c′ as “TH profile cyl. 1", "TH profile cyl. 2” and “TH profile cyl. 3" overlap in time.

Of course, features and details that are described in connection with a method also apply in connection with the device according to the invention and vice versa, so that with regard to the disclosure of the individual aspects of the invention reference is or can always be made to one another. In addition, an optionally described method according to the invention can be carried out with the device according to the invention.

Claims

Expectations

1. Sliding cam system for an internal combustion engine with at least one camshaft (10), comprising a support shaft (11) with at least one primary sliding cam element (12a), a first secondary sliding cam element (12b) and at least one second secondary sliding cam element (12c), each having a shift gate (13) with at least one switching groove (14), wherein the primary sliding cam element (12a) can be displaced axially to the carrier shaft (11) by at least one actuator pin (15) and at least one adjusting element (16) is arranged parallel to a longitudinal axis of the carrier shaft (11). , wherein the adjusting element (16) is axially displaceable in the direction of the longitudinal axis of the support shaft (11), wherein the adjusting element (16) has at least three coupling pins (17a, 17b, 17c), a first coupling pin (17a) im Area of the primary sliding cam element (12a) is arranged and a second coupling pin (17b) in the area of the first secondary sliding cam element (12b) and a d third coupling pin (17c) is arranged in the region of the second secondary cam element (12c) and the coupling pins (17a, 17b, 17c) each interact with a shift gate (13) of the respective associated cam element (12a, 12b, 12c) in such a way that that a movement of the primary sliding cam element (12a) initiated by the actuator pin (15) can be transmitted to the secondary sliding cam elements (12b, 12c) by the adjusting element (16), characterized in that the sliding cam system is set up in such a way that a switching process of the first secondary sliding cam element (12b) takes place at least partially simultaneously with the switching action of the second secondary sliding cam element (12c).

2. Sliding cam system according to Claim 1, characterized in that the sliding cam system is set up in such a way that the switching process of the first secondary sliding cam element (12b) begins immediately after the switching process of the primary sliding cam element (12a) has ended and that the switching process of the second secondary sliding cam element (12c) begins after the start and before the end of the switching process of the first secondary slide cam element (12b).

3. Sliding cam system according to at least one of the preceding claims, characterized in that the sliding cam system is set up such that the start of the switching process of the first secondary sliding cam element (12b) and the start of the switching process of the second secondary sliding cam element (12c) occur simultaneously.

4. Sliding cam system according to at least one of the preceding claims, characterized in that the length of the displacement areas (°NW121a/S, °NW121b/S and °NW121c/S) of the sliding cam elements (12a, 12b, 12c) are the same, in particular that °NW121a/S = °NW121b/S = °NW121c/S. Sliding cam system according to at least one of the preceding claims, characterized in that the radial length of the displacement areas (°NW121a/S, °NW121b/S and °NW121c/S) of all sliding cam elements (12a, 12b, 12c) is different, in particular that ° NW121a/S * °NW121b/S * °NW121c/S. Sliding cam system according to at least one of the preceding claims, characterized in that the displacement ranges (°NW121a/S, °NW121b/S and °NW121c/S) of the sliding cam elements (12a, 12b, 12c) are greater than 120°NW, in particular that ° NW121a/S > 120° or °NW121b/S > 120° or °NW121c/S > 120°. Sliding cam system according to at least one of the preceding claims, characterized in that the sliding cam system is set up in such a way that the beginning of the switching section °NW121b/SA to the beginning of the cam °NW122b/NA is unequal to the beginning of the switching section °NW121c/SA to the beginning of the cam °NW122c/NA. Sliding cam system according to at least one of the preceding claims, characterized in that the length of the displacement area (°NW121a/S) of the first switching groove (121a) on the primary sliding cam element (12a) is greater than the length of the displacement areas (°NW121b/S or °NW121c/ S) the switching grooves (121b or 121c) on the secondary sliding cam element (12b or 12c). Sliding cam system according to at least one of the preceding claims, characterized in that the length of the displacement range (°NW121b/S or °NW121c/S) of the switching groove (121b or 121c) on at least one secondary sliding cam element (12b or 12c) is greater than that Length of the displacement area (°NW121a/S) on the primary sliding cam element (12a) and/or, if necessary, further secondary sliding cam elements (°NW121x/S or 12x). Sliding cam system according to at least one of the preceding claims, characterized in that more than two secondary sliding cam elements (12b, 12c) are coupled with a connecting element (16). Sliding cam system according to at least one of the preceding claims, characterized in that the secondary sliding cam elements are not identical parts, in particular with regard to the displacement area and/or cam contour. Sliding cam system according to at least one of the preceding claims, characterized in that the cam contours of the secondary sliding cam elements are arranged identically, in particular are angularly offset only according to the firing sequence, eg offset by 120°, and are identical with regard to the cam contour. Sliding cam system according to at least one of the preceding claims, characterized in that the sliding cam system is arranged such that the switching operation of the primary sliding cam element (12a) is completed before the switching operation of a secondary sliding cam element (12b, 12c) takes place. Sliding cam system according to at least one of the preceding claims, characterized in that the sliding cam system is set up in such a way that the switching process of a first secondary sliding cam element (12b) begins immediately after the switching process of the primary sliding cam element (12a) has ended, with the switching process of a further (second) secondary sliding cam element ( 12c) preferably after the beginning and before the end of the switching process of the first secondary sliding cam element (12b). Sliding cam system according to at least one of the preceding claims, characterized in that the beginning of the switching section °NW121b/SA to the cam tip NS122b of the first secondary sliding cam is 143° and the beginning of the switching section NW121c/SA to the cam tip NS122c of the second secondary sliding cam is 203°.