CN116888347A

CN116888347A - Valve operating device

Info

Publication number: CN116888347A
Application number: CN202280015133.9A
Authority: CN
Inventors: 安德里亚斯·祖尔克; 托马斯·萨尔穆特; 马丁·克兰普费尔; 诺伯特·奥塞霍费尔; 拉斐尔·埃格
Original assignee: AVL List GmbH
Current assignee: AVL List GmbH
Priority date: 2021-02-18
Filing date: 2022-02-17
Publication date: 2023-10-13
Also published as: JP2024506693A; AT524829A1; WO2022174275A1; DE112022001117A5; AT524829B1; KR20230145572A

Abstract

The invention relates to a valve operating device (100) for operating at least one valve of a reciprocating piston machine, having: a first lever (210) and a second lever (211) rotatably mounted about a common axis of rotation (213), wherein the first lever (210) can be connected to at least one valve in such a way that an operating movement is transmitted to the valve; two cams (214, 215) arranged at the shaft (216), and wherein the operating lever (210, 211) engages the profile of the cams (214, 215); a mechanical coupling device (10) for connecting operating levers (210, 211), having a locking element (13B) which can be placed in two positions and is designed to transmit an operating movement of a second operating lever (211) to a first operating lever (210) at least in a first position of the locking element (13B); and a switching device (110) for switching the locking element (13B) of the coupling device (10) between positions, wherein the switching device (110) is configured such that a movement of the second operating lever (211) mechanically triggers a switching of the position of the locking element (13B). The invention also relates to an internal combustion engine (101) having such a valve operating device (100).

Description

Valve operating device

Technical Field

The invention relates to a valve operating device for operating at least one valve of a reciprocating piston machine, in particular an internal combustion engine, having: a first lever and a second lever, wherein the two levers are rotatably supported about a common axis of rotation, wherein the first lever is connectable with the at least one valve for transmitting an operational movement to the at least one valve; and a first cam and a second cam, wherein the two cams are arranged at the shaft, and the first lever engages a profile of the first cam and the second lever engages a profile of the second cam.

Background

Valve operating devices of this type and internal combustion engines having such valve operating devices are known in principle from the prior art.

As the demands on power, efficiency and emissions continue to increase, variable valve mechanisms, i.e. valve mechanisms with variable valve strokes, are becoming increasingly important in reciprocating piston internal combustion engines, in particular in reciprocating piston internal combustion engines operating in four-stroke operation and six-stroke operation.

In this case, the variable valve mechanism can be used to meet the demands of the engine designer and thermodynamic demands, i.e., depending on the operating situation of the engine, different valve lift curves can be transmitted to one or more valves instead, wherein the valve travel and the opening and closing times can be adapted.

This is typically accomplished by switching in the transfer path of the valve mechanism. Stroke switching and stroke cutoff systems with switchable cam followers, such as bucket lifters, roller lifters, or tilt rods, have been used in mass applications. Suitable for this are: for each additional alternative valve stroke, there must also be a corresponding cam as the stroking element-unless the alternative stroke is zero stroke.

There are different fields of application for the use of valve mechanisms with variable or changing valve travel. Some examples are listed below:

and (3) stroke switching: the stroke switching implementation uses at least two different valve lifts depending on the operating point. In this case, a smaller valve travel is used, which is specifically adapted to the part-load range and which improves the torque curve and reduces the consumption and emissions. The large valve stroke may be optimized for further power increases. Smaller valve strokes with smaller maximum strokes and shorter event lengths achieve a reduction in load exchange work (miller cycle) by significantly earlier intake closing time points and throttle elimination in the intake passage. Similar results may also be produced with the atkinson cycle, i.e., very late intake closure. In this case, the optimum filling of the combustion chamber also causes an increase in torque in the partial load range.

Cylinder deactivation: cylinder deactivation is primarily used in large capacity four-cylinder engines (e.g., engines having four, eight, ten, or twelve engine cylinders). Here, the selected engine cylinder is stopped by stroke cutoff at the intake and exhaust valves; in this case, complete decoupling from the cam path takes place. Due to the equidistant firing sequence, the common V8 and V12 engines can be switched to A4 or R6 engines here. The purpose of engine deactivation is to minimize load exchange losses and to perform a shift of the operating point to a higher average pressure and thus to a higher thermodynamic efficiency, whereby significant fuel savings can be achieved.

Engine braking operation: engine braking systems that achieve engine braking operation are becoming increasingly important in vehicle internal combustion engines, particularly for commercial vehicles, because they are cost-effective and space-saving additional braking systems that can reduce wheel braking, particularly in long downhill travel. Additionally, the increase in specific power of modern commercial vehicle engines is also dependent on the achievable increase in braking power.

In order to achieve an engine braking effect, it is known to provide an additional large valve in the engine cylinder of the internal combustion engine, by means of which a so-called decompression brake can be performed in the following manner: i.e. in particular in the case of a four-stroke engine or a six-stroke engine, cylinder decompression is performed via an additional engine valve at the end of the compression stroke. Thus, work performed on the compressed gas escapes via the exhaust system of the internal combustion engine. Furthermore, the internal combustion engine must perform work again in order to recharge the cylinders with gas. It is also known to produce an engine braking effect via a variable valve mechanism of the actual exhaust valve.

Various systems and concepts are known for varying valve travel. In particular, it is known to provide a mechanical or hydraulic coupling device between one or more valve actuating elements of the valve actuating device, which transmit a cam path, by means of which a switching in the transmission path of the valve mechanism can be achieved.

For example, document US2014/0326212 A1 shows a system for variable valve control, in particular for producing an engine braking effect, with a "lost motion" device with a hydraulically operable locking element for selectively locking or releasing a valve operating mechanism, so that a valve operating movement is selectively transmitted or not to one or more valves for changing the valve stroke and thereby producing, in particular, an engine braking effect.

In document WO 2015/022071 A1 a valve operating device for operating at least one first valve of a reciprocating piston machine, in particular an internal combustion engine, is disclosed, which can be used in particular for engine braking and which has a first tilting lever part, a second tilting lever part and a first switching element for changing the valve travel of the at least one first valve, wherein the first tilting lever part and the second tilting lever part are pivotably supported and arranged such that at least a first valve control movement can be transmitted from a first camshaft to the at least one first valve via the first tilting lever part and the second tilting lever part.

Document WO 2019/025511 A1 relates to a coupling device for a valve operating device for operating at least one valve of a reciprocating piston machine with a variable valve stroke, in particular for a reciprocating piston internal combustion engine, to a valve operating device and to a reciprocating piston machine, wherein the coupling device has a first coupling element, a second coupling element and a locking device. The first coupling element and the second coupling element can be displaced relative to each other along the first axis at least within defined limits, wherein a displacement of the two coupling elements relative to each other along the first axis can be blocked at least in the first direction by means of the locking means. The locking device has a locking element rotatable about a first axis in a circumferential direction at least within a defined range, wherein a relative displacement of the two coupling elements along the first axis is blocked in at least the first direction when the locking element is in the blocking position. The disclosure of this document is incorporated by reference into the present application.

The inventor's document AT 50710/2020 relates to a valve operating device for operating a valve of a reciprocating piston machine, having a coupling device with a locking element which can be placed in a first and a second position by means of a mechanical switching device and which is used for operating the coupling device, wherein the valve operating device in the first position transmits an operating movement for the valve, and wherein the switching device has: a guide bar and a parallel, relatively movable operating bar; a link guide element movably supported at the guide bar for moving the locking element between positions; a trigger element coupled to the link guide element, wherein the link guide element and the trigger element are clamped between two stops of the operating lever by means of a spring element, the spring element being associated with the stops, respectively, wherein the link guide element and the trigger element can be displaced by means of the operating lever in a direction along and/or parallel to the guide lever; and a blocking element which cooperates with the triggering element such that in a first state, upon displacement of the operating lever in the axial direction, the blocking element blocks a displacement of the triggering element and the link guide element in such a way that the spring element is preloaded, and in a second state, the displacement of the triggering element and the link guide element causes an operation of the coupling device. The disclosure of said document is also incorporated by reference.

Disclosure of Invention

It is an object of the present invention to provide an improved valve operating apparatus for variable valve control. In particular, it is an object of the present invention to provide a valve operating device for variable valve control which can clock valve travel switching particularly accurately.

The object is achieved by a valve operating device and an internal combustion engine according to the independent patent claims. Advantageous embodiments are claimed in the dependent claims.

A first aspect of the invention relates to a valve operating device for operating at least one valve of a reciprocating piston machine, in particular an internal combustion engine, the valve operating device having:

a first lever and a second lever, wherein the two levers are rotatably supported about a common axis of rotation, wherein the first lever is connectable with the at least one valve in a manner that imparts an operational movement to the at least one valve;

a first cam and a second cam, wherein the two cams are arranged, in particular, at a common axis, and the first lever engages the profile of the first cam and the second lever engages the profile of the second cam;

a mechanical coupling device via which the first and the second operating lever can be connected to each other, wherein the coupling device has a locking element which can be placed in a first position and a second position and is designed to transmit an operating movement of the second operating lever to the first operating lever at least in the first position of the locking element; and

Switching means for placing the locking element of the coupling device at least from the first position into the second position and vice versa, wherein the switching means are configured such that a movement of the second operating lever, in particular a movement which causes the at least one valve to close and/or a movement in the direction of the second cam mechanically triggers a switching of the position of the locking element.

A second aspect of the invention relates to an internal combustion engine having such a valve operating apparatus.

The invention is based on the idea of realizing a variable valve control by means of two operating levers, wherein the first operating lever permanently generates a valve operating movement and the second operating lever can be switched in, if necessary, by means of a switching device such that the valve operating movement generated by the second operating lever is superimposed with the valve operating movement of the first operating lever. In this case, the valve actuating movement of the second actuating lever is transmitted to the first actuating lever via the coupling device, so that only the first actuating lever is always actuated via the valve. In the case of a pull rod, this is preferably done via a push rod.

The first force transmission path via the first actuating lever is preferably not impaired by the presence of the second actuating lever. The coupling device guides the second force transmission path from the second lever to the first lever, from where it extends to the valve in the same way as the first force transmission path.

In this way, the present invention combines the advantages of a rigid lever with the advantages of adjustable valve control. On the one hand, a large force for operating the valve can be transmitted only via the first operating lever. On the other hand, fine tuning of the valve and/or supplemental operation of the valve may be achieved by switching on the second lever.

Furthermore, the invention realizes: the switching on or off of the operating movement is effected via a second operating lever by a movement of the operating lever itself. This enables particularly precise adjustment of the optimum switching point in time.

Furthermore, the switching of the clock control by the movement of the second lever may provide a maximally existing time window for a corresponding operation via the first lever or the second lever. The mechanical triggering of the switching process also ensures a particularly reliable triggering.

In an advantageous embodiment of the valve actuating device, the valve actuating device has a triggering element, wherein the switching device has a blocking element which is designed to interact with the triggering element in such a way that an axial displacement of the triggering element is blocked or released.

By providing a blocking element which cooperates with the triggering element, a mechanical triggering can be achieved.

In a further advantageous embodiment of the valve actuating device, the guide rod is fixed to the housing and is mounted so as to be axially displaceable in order to actuate the triggering element.

In this advantageous embodiment, the guide rod can be actuated directly by the actuator. No additional equipment for operating the trigger element is required.

In a further advantageous embodiment, the triggering element and the blocking element mechanically cooperate when the second actuating lever is moved in the direction of the shaft, so that a position shift of the locking element is triggered.

In this advantageous embodiment, the triggering element and the blocking element not only cooperate to limit the point in time of the axial displacement of the triggering element, but also trigger the switching of the position of the locking element.

In a further advantageous embodiment, the blocking element releases an axial displacement of the triggering element along the guide rod when the second actuating rod is moved away from the shaft.

Along with the aforementioned advantageous embodiment, the movement of the second actuating lever releases the movement of the triggering element away from the camshaft, the triggering element being displaced along the guide lever, whereby a subsequent movement of the second actuating lever in the axial direction triggers a switching of the position of the locking element. A particularly reliable switching process can thus be achieved.

In a further advantageous embodiment of the valve actuating device, the blocking element is supported on and can be pivotally supported relative to the second actuating lever, and the locking element is actuated via a switching element, in particular a switching lever or a connecting rod guide element.

The pivotable support of the blocking element at the second actuating lever effects a particularly advantageous interaction with the triggering element of the switching device. If the second operating lever is pivoted in the direction of the camshaft, the blocking element will come into contact with the triggering element and in this case pivot in its respect.

In a further advantageous embodiment of the valve actuating device, the triggering element has two actuating elements which are designed to change the position of the blocking element during a displacement of the second actuating lever in the direction of the shaft, so that the blocking element causes a switching of the position of the locking element.

In particular, the locking element is thereby pivoted.

As already explained, it is preferably proposed that: movement of the second lever away from the shaft causes movement of the trigger element and movement of the second lever toward the shaft causes pivoting of the blocking element.

In a further advantageous embodiment of the valve actuating device, the guide rod is oriented at least substantially parallel to the axis of rotation and/or the shaft.

This arrangement of the guide rods enables a particularly space-saving arrangement of the individual elements.

In a further advantageous embodiment of the valve operating device, the triggering element can be preloaded against the blocking element along the guide rod by means of at least one spring element when a position change of the locking element is to be effected, wherein the triggering element can only be displaced along the guide rod when the blocking element is unseated by a displacement of the second operating rod.

By pre-tightening the guiding rod, the triggering element can be operated independently of the actual point in time of the displacement. Thereby, an effective association can be created between the movement of the blocking element or the second lever and the movement of the trigger element.

In a further advantageous embodiment of the valve actuating device, the blocking element is designed as a switching rocker with a first coupling element, in particular a coupling head, the position of which changes when the blocking element is pivoted, and which interacts with a second coupling element, in particular a receptacle, of the switching element.

The switching rocker in the sense of the present invention is preferably configured as a triangle or a tricuspid type. The two ends of the triangle are used to operate the switching rocker, the coupling head being arranged at the third angle/tip. The switching rocker with coupling head provides a particularly simple mechanical solution for the blocking element.

In a further advantageous embodiment of the valve actuating device, the locking element is rotatably mounted on the second actuating lever and interacts with the second coupling element of the first actuating lever in its first position, wherein it can be placed in a stop in particular with the coupling element.

The rotationally supported locking element is a particularly simple and robust mechanical embodiment of the locking element.

In a further advantageous embodiment of the valve operating device, the axis of rotation of the locking element extends at least substantially parallel to the shaft.

Due to the high degree of symmetry, a particularly simple design of the valve operating device can be achieved.

In an advantageous embodiment of the valve actuating device, the first actuating lever and/or the second actuating lever is/are embodied as a tilting lever or as a tie rod.

In a further advantageous embodiment of the valve actuating device, the first actuating lever has a coupling section which engages around the second actuating lever such that it forms a stop for the second actuating lever and/or the coupling device, which limits the rotation of the second actuating lever relative to the first actuating lever about a common axis of rotation.

In this way, a particularly advantageous type of force transmission from the first lever to the second lever can be achieved. In particular, the valve actuating device can be constructed in a particularly space-saving manner, since all additional components at the second actuating lever can be arranged at the location of the support of the push rod in the first actuating lever.

In a further advantageous embodiment of the valve actuating device, the side wall of the second cam rises later than the side wall of the first cam with respect to the direction of the operating rotation of the shaft, and the contours of the first cam and the second cam are designed such that an actuating movement of the second actuating lever produces a valve lift curve that is greater and longer than the valve lift curve produced by the actuating movement of the first actuating lever.

As a result of the earlier rise of the side wall of the first cam, a relatively large force, which is created when the valve is opened, is exerted at the first lever, which is preferably of rigid construction and thus has a greater strength than the second lever. In addition, the second actuating lever can be designed in a targeted manner less firmly, whereby weight and space can be saved.

The features and advantages described above in relation to the first aspect of the invention apply correspondingly to the second aspect of the invention and vice versa.

Drawings

Additional advantages and features of the invention will emerge from the description which follows, with reference to the non-limiting embodiments illustrated in the accompanying drawings. The accompanying drawings at least partially schematically illustrate:

fig. 1 shows a perspective top view of a valve system of an internal combustion engine;

FIG. 2 illustrates a perspective top view of one embodiment of a valve operating apparatus;

FIG. 3 shows a top view of two valve levers of the valve operating apparatus according to FIG. 2;

FIG. 4 shows a cross-sectional view of the valve operating apparatus in plane I-I in FIG. 3;

fig. 5 shows a top view of a mechanism for switching a valve operating device in a first position of a locking element;

fig. 6 shows another top view of the mechanism for switching the valve operating device in the second position of the locking element;

Fig. 7 shows a perspective view of a second lever of the valve operating device;

fig. 8a, 9a, 10a, 11a show side views of the second valve lever and the second cam, respectively, in different rotational positions of the cams;

fig. 8b, 9b, 10b, 11b show top views of the switching element of the valve operating device in different positions;

fig. 8c, 9c, 10c, 11c show top views of enlarged details of the switching element in different orientations;

fig. 12, 13 show cross-sectional views of the trigger element in different loading positions;

FIG. 14 shows two different embodiments of valve lift curves that can be implemented with the valve operating device according to FIGS. 3 and 3; and

fig. 15 shows a schematic view of an internal combustion engine according to the invention.

Detailed Description

Fig. 1 shows a perspective view of a valve system of an internal combustion engine 101 with one embodiment of a valve operating device 100. Fig. 15 shows a schematic view of such an internal combustion engine 101, which in the shown embodiment has four cylinders 102, to which are associated respectively such a valve-operating device 100. Of course, the solution according to the invention can also be applied to differently configured internal combustion engines 101, in particular in terms of the number of cylinders 102.

Overall, four valves are operated in the embodiment shown in fig. 1, wherein the two front valves are operated by means of the valve operating device 100 via the push rod 220. Here, the first and second operation levers 210, 211 of the valve operation device 100 engage valve operation movements at the cams 214, 215, respectively. The valve operating movement may then be transmitted to the valve.

Preferably, a reset device 96 is provided to ensure contact between the second lever 211 and the second cam 215 when the second lever 211 is not loaded.

The embodiment of the valve-operating device 100 shown in fig. 1 is a so-called pull rod and accordingly has a receptacle 97 for a push rod 200 which transmits a valve-operating movement to at least one valve. However, the teachings described in relation to the embodiments can also be transferred to other forms of valve operating devices, in particular to tie rods with or without rollers at the ends or in the middle of the tie rod, and to valve operating rods for central support, so-called tilting rods, which have roller operating means, sliding operating means or push rod operating means.

Fig. 2 shows a perspective view of an exemplary embodiment of a valve actuating device 100, wherein the valve actuating device 100 forms a valve, not shown here, for actuating an internal combustion engine.

The valve actuating device 100 has a first actuating lever 210 and a second actuating lever 211, wherein the two actuating levers 210, 211 are rotatably mounted about a preferably common axis of rotation 213. The push rod 220 is connected to the first lever 210 to transmit an operation movement from the first lever 210 or the second lever 211 to the valve.

The first lever 210 is configured to engage the profile of the first cam 214 and the second lever 211 is configured to engage the profile of the second cam 215. The two cams 214, 215 are mounted in a rotationally fixed manner on a particularly common shaft 216. The first cam 214 preferably has a different profile in the circumferential direction of the shaft 216 than the second cam 215.

The first and second operation levers 210 and 211 are connected to each other via the coupling device 10. The coupling device 10 is particularly designed for transmitting an operating movement from the second operating lever 211 to the first operating lever 210 when the coupling device 10 is in the blocking state, or for converting a movement of the second operating lever 211 into a so-called lost motion movement when the coupling device 10 is in the release state.

In the illustrated embodiment, the coupling device 10 is arranged at the second operating lever 211 or is an integral part of the second operating lever 211. Preferably, the longitudinal axis of the coupling device 10 along which the length of the coupling device 10 can be adjusted is tangential to the trajectory of the second actuating lever 211 about the axis of rotation.

The first actuating lever 210 has, in particular, a coupling section 217, which preferably extends into the path of the second actuating lever 210. The coupling section 217 is connected, preferably screwed, to a second coupling element 12, as shown in fig. 2, which can cooperate with the first coupling element 11 for transmitting the operating movement.

For switching, the coupling device 10 preferably has a locking element 13b, which is preferably pivotable about an axis, so that the coupling element 11, which is preferably part of the locking element 13b and constitutes a stop 89 (not shown, see for example fig. 4 or 7), can be pivoted between at least two positions. The axis differs from the axis of rotation 213 of the actuating lever 210, 211 and is preferably oriented parallel to the axis of rotation 213 and/or the camshaft and/or the guide lever 83.

In the coupled state, the first coupling element 11, which is attached via the locking element 13b at the first operating lever 211, interacts with the second coupling element 12 of the first operating lever 210, so that a valve operating movement is transmitted from the first operating lever 210 to the second operating lever 211. The stop 89 of the first coupling element 11 is in contact with the second coupling element. This position of the locking element 13b is also referred to hereinafter as the first position or blocking position.

In contrast, in the released state of the coupling device 10, the locking element 13b is in a second position, hereinafter also referred to as the released position, in which the stop 89 (not shown, see for example fig. 4 or 7) of the first coupling element 11 does not interact with the second coupling element 12. To this end, in fig. 1, the locking element 13b is preferably pivoted clockwise by approximately 90 °, as will be described in further detail below.

The locking element 13b is preferably operated by means of a switching device 110 (not shown). The components of the switching device 110 are preferably fastened to the housing of the valve-controlled internal combustion engine and are supported here (both not shown). The switching device 110 (not shown in fig. 2) is operated here preferably hydraulically or electromechanically by means of an actuator (not shown), and is further preferably controlled by a control unit (ECU) of the internal combustion engine.

Fig. 3 shows a top view of the side of the valve-operating device 100 facing away from the axis of rotation 213 according to the embodiment of fig. 2.

The first lever 210 is shown on the left side of the illustration in fig. 3. A first path F, shown as a solid arrow, of force transmission from the first cam 214 to the first lever 210 to the push rod 220 via the first effector 218 ₁ Preferably extending substantially parallel to the direction of movement of the first lever 210.

The second lever 211 is shown on the right side of fig. 3. The force transmission from the second lever 211 to the first lever 210 takes place only when the coupling device 10 is in the blocking state. If the coupling device 10 is in the blocking state, a second path F of force transmission from the second cam 215 via the second effector 219 and the second lever 210 to the coupling device 10 ₂ Extending substantially parallel to the direction of movement of the second lever 211. Second path of force transmission F ₂ Preferably, the coupling device 10 extends via the coupling section 217 in particular substantially perpendicularly to the axis of movement of the second actuating lever 211 up to the first actuating lever 210 and up to the push rod 220.

From the above, it follows that: in the illustrated embodiment, path F ₁ Always enabled. Conversely, path F ₂ Is selectively turned on according to the state of the coupling device 10.

Fig. 4 shows a sectional view of an exemplary embodiment of the second actuating lever 211 and a part of the first valve actuating lever 210 of the valve actuating device 100 in the plane I-I of fig. 3, in which the center axis of the coupling device 10 lies.

As already explained in part with reference to fig. 2 and now fully visible in fig. 4, the coupling device 10 has a first coupling element 11, a locking element 13B with a pin 13A and additionally a second coupling element 12.

As already explained in part with reference to fig. 2 and now fully visible in fig. 4, the locking element 13b with the first coupling element 11 is part of the second actuating lever 211 or is supported at the latter. Furthermore, the coupling device 10 has a second coupling element 12 which is part of the first actuating lever 210 or is supported thereon.

The first coupling element 11 is thereby fixed in a force-transmitting manner to the second actuating lever 211, and the second coupling element 12 is correspondingly fixed in a force-transmitting manner to the first actuating lever 210, preferably to its coupling section 217, and is more preferably screwed in by means of a thread and fastened by means of a locking nut 221. The second coupling element 12 is preferably operated here via a stop 89 of the first coupling element 11. The column bottoms of the locking elements 13b, which form the stops 89, are preferably inwardly arched, and the free ends of the second coupling elements 12 are preferably correspondingly convexly arched.

The locking element 13b is rotatably supported at the second operating lever 211 and can be operated by means of a switching element 84 (in the embodiment shown in fig. 4, a switching link). The switching link 84 is in turn operated by means of a switching device 110. In this manner, the defined valve lift may be selectively activated or deactivated by the mechanical switching device 110.

The switching device 110 preferably has a blocking element 112, which in the exemplary embodiment shown is designed as a switching rocker and has a first coupling element 118, in particular a coupling head 118, which interacts with a second coupling element 119, in particular a receptacle, of the switching link 84.

In the embodiment shown, the blocking element 112 is pivotally supported in the plane shown at the second operating lever 211.

The switching device 110 also has a triggering element 111. The triggering element 111 is operated hydraulically or electromechanically by means of an actuator, not shown.

The triggering element 111 preferably has a first operating element 116 and a second operating element 117 (not visible in fig. 4) which co-act with the blocking element 112 to trigger the operation of the locking element 13b, as explained below with reference to fig. 5 and 6.

The valve-operating movement of the second operating lever 211 is engaged at the second cam 215 by means of the second effector 219. Accordingly, valve operation movement of the first lever 210 is engaged by the first effector 218 at the second cam 215 (not shown in fig. 5 and 6). If the locking element 13b is in the first position or blocking position, the operating movement of the first operating element 116 is transmitted to the first operating lever 210.

As also shown in fig. 5, the locking element 13b is in a first position, also referred to as a blocking position. Accordingly, the coupling device 10 is in a blocking state in which valve operating movement is transmitted from the second lever 211 to the first lever 210.

The first position is achieved by: the triggering element 111 displaceably mounted on the guide rod 83 fixed to the housing is in a position such that the second actuating element 117 interacts with the end of the blocking element 112 configured as a switching rocker. The coupling head 118 is thereby pivoted to the left in fig. 4. Since the coupling head 118 cooperates with the receptacle 119 of the switching link 84, the switching link 84 also moves to the left. The pin 13a of the locking element 13b is accommodated in a further receptacle of the switching link 84, so that the switching link 84 and the locking element 13b cooperate in such a way that the first coupling element 11 pivots to the right.

Fig. 6 shows a release state of the coupling device 10, in which the locking element 13b is in the second position or release position. In this case, the first coupling element does not interact with the second coupling element 12 of the coupling device 10, so that the valve actuating movement of the second actuating lever 211 is not transmitted to the first actuating lever 210 and is lost as a so-called lost motion.

In this case, the triggering element 111 of the switching device 110 on the guide bar 83 has the following positions: the position causes the other end of the switching rocker 112 to co-act with the first operating element 116 of the trigger element 111 such that the switching rocker pivots to the right. The movement is in turn transmitted via the coupling head 118 and the receptacle 119 to the switching link 84, which transmits the movement via the pin 13a to the locking element 13b, whereby the first coupling element 11 is pivoted to the left.

In fig. 7, a perspective top view of the valve-operating device 100 is shown without the first operating lever 210.

From the above-mentioned view, the attitude of the trigger element 111 and its first and second operating elements 116 and 117 with respect to the second operating lever 211 is shown.

As already explained with reference to fig. 5 and 6, the triggering element 111 is displaceably supported at the guide rod 83. In the exemplary embodiment shown, the guide lever 83 mounted in a fixed manner to the housing is oriented parallel to the axis of rotation 213 about which the first actuating lever 210 and the second actuating lever 211 are mounted in a rotatable manner. Here, the triggering element 111 can be moved between two guides (no reference numerals) of the guide bar 83.

Fig. 8 to 11 illustrate the operation of the embodiment shown in the drawings of the valve operating apparatus 100.

In the sub-diagrams marked "a" (fig. 8a, 9a, 10a, 11 a), a top view of the first valve stem 211 is shown from the following side: the first lever 210 will be arranged on the side in the complete valve operating apparatus 100. The positions of the triggering element 111 corresponding to the switching states are shown in the sub-diagrams identified with "b" (fig. 8b, 9b, 10b, 11 b), respectively, and the details of the triggering element 111 are shown in the sub-diagrams identified with "c" (fig. 8c, 9c, 10c, 11 c).

As is known from fig. 4 to 7: the second operating lever 211 has a switching device 110 which includes, among other things, the components of the guide lever 83 and the triggering element 111. The triggering element 111 in turn has a first actuating element 116 and a second actuating element 117 which interacts with the switching rocker 112 acting as a blocking element (switching rocker 112 is difficult to recognize in fig. 7 to 11, and no reference numerals are provided).

In addition, the second operating lever 211 has a locking element 13b with the first coupling element 11, both of which are part of the coupling device 10. This enables the second lever 211 to be coupled with the first lever 210.

The second effector 219 (in the illustrated case a wheel) receives valve operating movements at the second cam 215.

In fig. 8a, the attitude of the second cam is such that the cam lift will reach the second effector 219 soon due to the rotational direction of the camshaft. Due to the attitude of the locking element 13b or its first coupling element 11, the valve operating movement is transmitted to the first operating lever 210.

Fig. 8b also shows a top view of the switching device 110 in the following position: in which the switching device causes a first or blocking position of the locking element 13 b. The triggering element 111 is arranged on the guide lever 83 in such a way that its first actuating element 116 interacts with an end of the switching rocker 112, so that the locking element 13b is blocked in the first position or blocking position.

Fig. 8c shows an enlarged view of the whole of the guide rod 83 and the trigger element 111. The area of the triggering element 111 surrounding the guide rod 83 or the area in which the triggering element 111 is guided by the guide rod 83 is shown in a sectional view.

Thus, it becomes visible that: the spring element 93 is in the triggering element 111, which is held at the guide rod 83 by the first spring stop 98 and the second spring stop 99. The spring stops 98, 99 are designed such that they can be displaced toward the spring when the guide rod is moved, but are prevented from moving away from the spring.

In fig. 9a, the bulge of the second cam 215 is always in front of the second effector, but has been slightly approached by the rotation of the camshaft.

The locking element 13b should now be switched from the first position or blocking position into the second position or release position.

For this purpose, the guide bar 83 is moved to the left as indicated by the hatched arrows in fig. 9b and 9 c. Thereby, the switching rocker 112 is pushed downward from the second operating element 117 of the trigger element 111. However, since the switching rocker 112 does not change its position, one end of the switching rocker 112 is in contact with the first operating element 116. Further displacement of the trigger element 111 on the guide bar 83 is prevented here, as is shown in fig. 9c by the hatched arrow with bars. As the guide rod 83 is still further displaced, the spring element 93 is compressed in the trigger element 111 by displacing the second spring stop 99 towards the first spring stop 98.

In fig. 10a, the bulge of the cam 215 has reached the second effector 219, causing the second lever 211 to pivot upward. The first actuating lever 210 (not shown) here also pivots upwards due to the blocking position of the locking element 13 b.

Due to the pivoting, the other end of the switching rocker 112 releases the first operating element 116, as can be seen in the dashed circle in fig. 10 a. Thus, in the view of fig. 10b, the triggering element 111 can be displaced still further to the left on the guide rod 83, which is caused by the pretensioning of the spring element 93, which itself is relaxed. Accordingly, the spring element 93 is shown relaxed in fig. 10 c.

In fig. 11a, the bulge of the second cam 215 has pivoted into the following attitude: the posture causes the second operation lever 211 to pivot again toward the cam shaft or toward the base circle of the cam 215. By this pivoting movement, the other end of the switching rocker 112 is in contact with the first operating element 116 of the trigger element 111, so that the switching rocker 112 pivots to the right as indicated by the arrow in fig. 11 a. Thereby, the locking element 13b is pivoted to the left via the switching link 84 (not visible), as is also indicated by the arrow in fig. 11 a. Thereby, the locking element 13b reaches its second or release position.

In a corresponding manner, a switching from the second position or release position of the locking element 13b into the first position or blocking position can be performed by operating the guide rod 83 to the right. The trigger element 111 remains in its position as shown in fig. 11b and the spring element 93 remains relaxed as shown in fig. 11 c.

Fig. 12 and 13 each show a cross section through the triggering element 111. It will become clear here that: the first actuating element 116 and the second actuating element 117 of the triggering element 111 are flexibly preloaded by means of the spring element 94 or 95. This is achieved: if the switching rocker 112 or the blocking element is not pivotable (e.g. because it is blocked), the operating elements 116, 117, respectively, which are in contact with the switching rocker 112, can be avoided.

This may be useful, for example, when the locking element 13b should actually be introduced into the second position or release position, but blocked at the first lever 210, in particular at the second coupling element of the first lever 210. Thus, a force that would cause damage to the first operating element 116 can be transmitted by the movement of the first operating lever 210.

Fig. 13 shows the actuating elements 116, 117 in the pressed-in position, respectively, which would be occupied in the described overload situation.

Fig. 14 shows an embodiment of two different valve lift curves that can be realized by means of the valve operating device. Here, the valve opening is described in relation to the crank angle.

The valve lift curve IVC-480 belongs to the miller cycle and is caused by the first cam 214 (thus the so-called miller cam) in the embodiment shown in the preceding figures of the valve-operating device 100.

The miller operation of the internal combustion engine is particularly optimized for consumption, but the internal combustion engine cannot be started in the miller operation because the cylinder filling is too low.

The valve lift curve IVC-580 belongs to another combustion cycle in which the valve open time is longer and has 8.7 mm more valve travel than in the illustrated Miller cycle. The valve lift curve IVC-580 is caused by the second cam 215. Thus, valve lift curve IVC-580 covers valve lift curve IVC-480.

As illustrated in fig. 14, the rise of the valve lift curve IVC-580 is disposed in time after the rise of the lift curve IVC-480. Thereby, in the valve operation device 100, it is ensured that: the majority of the forces occurring when the valve is opened are viaThe stronger, rigid first lever 210 transmits (force flow F ₁ ). Only about one third of the force then acts on the variable or adjustable lever 211. The operating lever can therefore be designed to be of low strength and of small dimensions, in particular narrow.

Accordingly, in the valve-operating apparatus 100, the side wall of the second cam 215 rises later than the side wall of the first cam 214 with respect to the running rotational direction of the shaft 216. As a result, the actuating movement of the first actuating lever 210 is brought about at a different, preferably temporally earlier point in time than the actuating movement of the second actuating lever 211. Internal combustion engines, in particular so-called large engines, are preferably operated in the miller cycle for an operating duration of 90%. The valve lift curve IVC-580 is preferably used only at start-up and in temporary sailing operation (also referred to as coasting operation).

It should be noted that: the described embodiments are merely examples and are not intended to limit the scope, applicability, or configuration in any way. Rather, guidance for implementing at least one embodiment is provided by the foregoing description to those skilled in the art, in which various changes may be made without departing from the scope of protection afforded by the claims and the equivalent combination of these features, particularly as regards the function and arrangement of the components as described. In particular, the valve operating device may also be a push rod or a rocker or similar device. The switching device can also be configured differently, in particular according to the variant shown in WO 2019/025511 A1. On the other hand, the switching device described above with reference to the figures can also be used in connection with alternative coupling devices, for example the coupling device shown in document WO 2019/025511 A1. In this case, the switching device will operate the link guide element, in particular via the switching lever.

List of reference numerals

10. Coupling device

11. First coupling element

12. Second coupling element

13A pin

13B locking element

83. Guiding rod

84. Switching element for switching connecting rod

85. Connecting rod, claw and U-shaped section bar

89. Stop piece

93. 94, 95 spring element

96. Reset device

97. Housing part

98. First spring stop

99. Second spring stop

100. Valve operating device

110. Switching device

111. Trigger element

112. Barrier element

113. Switching window

114. Protection spring

115. Trigger pin

116. A first operating element

117. A second operating element

118. First coupling element

119. Second coupling element

210. First operating lever

211. A second operation lever

213. Axis of rotation

214. First cam

215. Second cam

216. Shaft

217. Coupling section

218. First effector

219. Second effector

220. Push rod

221. Lock nut

F ₁ First path of force transmission

F ₂ Second path of force transmission

Claims

1. Valve operating device (100) for operating at least one valve of a reciprocating piston machine, in particular an internal combustion engine, having:

a first lever (210) and a second lever (211), wherein the two levers (210, 211) are rotatably supported about a common axis of rotation (213), wherein the first lever (210) is connectable with the at least one valve for transmitting an operational movement to the at least one valve;

-a first cam (214) and a second cam (215), wherein the two cams (214, 215) are arranged, in particular, at a common axis (216), and the first lever (210) engages a contour (214) of the first cam (214) and the second lever (211) engages a contour of the second cam (215);

-a mechanical coupling device (10) via which a first lever (210) and a second lever (211) can be connected to each other, wherein the coupling device (10) has a locking element (13B) which can be placed in a first position and a second position and is designed for: transmitting an operating movement of the second operating lever (211) to the first operating lever (210) at least in the first position of the locking element (13B); and

-a switching device (110) for placing the locking element (13B) of the coupling device (10) at least from the first position into the second position and vice versa, wherein the switching device (110) is configured such that a movement of the second operating lever (211), in particular a movement causing the at least one valve to close and/or a movement in the direction of the shaft (216), mechanically triggers a position switching of the locking element (13B).

2. The valve-operating device (100) according to claim 1, wherein the switching device (110) has a triggering element (111) and a blocking element (112), which constitute for: co-acting in such a way as to block or release the axial displacement of the triggering element (111) along the guide rod (83), wherein the triggering element (111) is supported on the guide rod in such a way as to be capable of axial displacement.

3. Valve-operating device (100) according to claim 2, wherein the guide rod (83) is fixed to the housing and is supported axially displaceably for operating the trigger element.

4. A valve-operating device (100) according to claim 2 or 3, wherein upon movement of the second operating lever (211) in the direction of the shaft (216), the triggering element (111) and the blocking element (112) mechanically co-act such that a position switching of the locking element (13B) is triggered.

5. Valve-operating device (100) according to any one of claims 2 to 4, wherein the blocking element (112) releases an axial displacement of the triggering element (111) along the guiding rod (83) when the second operating rod (211) is moved away from the shaft (216).

6. Valve-operating device (100) according to any one of claims 2 to 5, wherein the blocking element (112) is supported at and pivotably supported relative to the second operating lever (211) and the locking element (13B) is operated via a switching element (84), in particular a switching lever or a link guide element.

7. Valve-operating device (100) according to any one of claims 2 to 6, wherein the triggering element (111) has two operating elements (116, 117) which are designed for: -changing the attitude of the blocking element (112) during the movement of the second operating lever (211) in the direction of the shaft (216) so that the blocking element (112) causes a position switching of the locking element (13B).

8. Valve-operating device (100) according to any one of claims 2 to 7, wherein the locking element (13B) in its first position interacts with the second coupling element (12) of the first operating lever (210), in particular can be placed in a stop.

9. Valve-operating device (100) according to any one of claims 2 to 8, wherein the axis of rotation of the locking element (13B) runs parallel to the shaft (216), the guide rod (83) and/or the axis of rotation (213).

10. Valve-operating device (100) according to any one of claims 2 to 9, wherein the guide rod (83) is oriented at least substantially parallel to the rotation axis (213) and/or the shaft (216).

11. Valve-operating device (100) according to any one of claims 2 to 10, wherein the triggering element (111) can be preloaded against the blocking element (112) along the guide rod (83) by means of at least one spring element (93, 94) when a position switching of the locking element (13B) should be caused, wherein the triggering element (111) can only be displaced along the guide rod (83) when the blocking element (112) is unseated by a movement of the second operating rod (211).

12. Valve-operating device (100) according to any one of claims 2 to 11, wherein the blocking element (112) is configured as a switching rocker with a first coupling element (118), in particular a coupling head, whose posture changes when the blocking element (112) is pivoted, and which interacts with a second coupling element (119), in particular a receptacle, of the switching element (84).

13. The valve operating apparatus (100) according to any one of claims 1 to 12, wherein the first operating lever (210) and/or the second operating lever (211) are configured as a tilting lever or a pulling lever.

14. Valve operating device (100) according to any one of claims 1 to 13, wherein the first operating lever (210) has a coupling section (217) which engages around the second operating lever (211) such that the coupling section forms a stop (89) for the second operating lever (211) and/or the coupling device (10) which limits a rotation of the second operating lever (211) relative to the first operating lever (210) about the common axis of rotation (213).

15. The valve operating apparatus (100) according to any one of claims 1 to 14, wherein a side wall of the second cam (215) rises later than a side wall of the first cam (214) with respect to a running rotational direction of the shaft (216), and wherein contours of the first cam (214) and the second cam (215) are configured such that an operational movement of the second operating lever (211) produces a valve lift curve (IVC-580) that is larger and longer than a valve lift curve (IVC-480) produced by an operational movement of the first operating lever (210).

16. An internal combustion engine (101) having at least one valve operating apparatus (100) according to any one of claims 1 to 15.