Valve operating device

Abstract

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

Description

Technical Field

[0001] The present invention relates to a valve operating device for operating at least one valve of a reciprocating piston machine, particularly an internal combustion engine, the valve operating device comprising: a first operating lever and a second operating lever, wherein the two operating levers are rotatably supported about a common axis of rotation, wherein the first operating lever is connectable to at least one valve to transmit an operating movement to at least one valve; and a first cam and a second cam, wherein the two cams are arranged at an axis, and the first operating lever engages the profile of the first cam and the second operating lever engages the profile of the second cam. Background Technology

[0002] This type of valve-operated device, and the internal combustion engine having such a valve-operated device, are known in principle from the prior art.

[0003] As requirements for power, efficiency, and emissions continue to increase, variable valve mechanisms, i.e., valve mechanisms with variable valve stroke, are becoming increasingly important in reciprocating piston internal combustion engines, especially in four-stroke and six-stroke reciprocating piston internal combustion engines.

[0004] Here, by means of a variable valve mechanism, the needs of internal combustion engine designers and thermodynamic expectations can be met, that is, depending on the operating conditions of the internal combustion engine, different valve lift profiles can be passed to one or more valves, in which valve stroke and opening and closing times can be adapted.

[0005] This is typically achieved by switching the transmission path within the valve mechanism. Stroke switching and cut-off systems with switchable cam followers, such as bucket tappets, roller tappets, or tilting bars, are widely used in various applications. The applicable rule here is that for each additional alternative valve stroke, a corresponding cam must also be present as the stroke-assigning element—unless the alternative stroke is zero.

[0006] There are different application areas for valve mechanisms with variable or alternating valve strokes. Some examples are listed below:

[0007] Stroke switching: Stroke switching enables the use of at least two different valve lifts depending on the operating point. Here, a smaller valve lift specifically coordinated for the partial load range is used, which improves the torque curve and reduces consumption and emissions. A larger valve lift can be optimized for further power increases. A smaller valve lift with a smaller maximum lift and shorter event length reduces load-exchange work (Miller cycle) through a significantly earlier intake shut-off time and elimination of throttling in the intake manifold. Similar results can also be achieved with the Atkinson cycle, i.e., very late intake shut-off. Here, optimal combustion chamber filling also leads to an increase in torque over the partial load range.

[0008] Cylinder deactivation: Cylinder deactivation is primarily used in high-displacement four-cylinder engines (such as engines with four, eight, ten, or twelve cylinders). Here, the selected cylinder is deactivated by cutting off the stroke at the intake and exhaust valves; complete decoupling from the camshaft travel occurs. Due to the equidistant firing order, common V8 and V12 engines can be switched to A4 or R6 engines. The purpose of cylinder deactivation is to minimize load exchange losses and shift the operating point to a higher mean pressure, thereby shifting towards higher thermodynamic efficiency, resulting in significant fuel savings.

[0009] Engine braking operation: Engine braking systems, which enable engine braking operation, are becoming increasingly important in vehicle internal combustion engines, especially in commercial vehicles, because they are a cost-effective and space-saving supplementary braking system that can reduce wheel braking, particularly during long downhill driving. Additionally, the increased power-to-weight ratio of modern commercial vehicle engines also depends on increased achievable braking power.

[0010] To achieve engine braking, it is known that an additional large valve is provided in the engine cylinder of an internal combustion engine. This additional large valve allows for decompression braking, particularly in four-stroke or six-stroke engines, by means of a cylinder decompression valve at the end of the compression stroke. The work done on the compressed gas is then released through the engine's exhaust system. Furthermore, the engine must perform work to refill the cylinder with gas. Engine braking effects are also known to be achieved via a variable valve mechanism of the actual exhaust valve.

[0011] Various systems and concepts are known for altering valve stroke. In particular, it is known to provide mechanical or hydraulic coupling devices between one or more valve-operating elements that transmit cam stroke in a valve-operating device, by means of which switching in the transmission path of the valve mechanism can be achieved.

[0012] For example, document US 2014 / 0326212 A1 discloses a system for variable valve control, particularly for generating an engine braking effect, the system having an "air-operated" device with a hydraulically operable locking element to selectively lock or release the valve operating mechanism, such that valve operating movement is selectively transmitted or not transmitted to one or more valves, in order to change the valve stroke and thereby generate an engine braking effect.

[0013] Document WO 2015 / 022071 A1 discloses a valve operating device for operating at least one first valve of a reciprocating piston machine, particularly an internal combustion engine. The valve operating device is particularly suitable for engine braking and has a first tilting rod member, a second tilting rod member, and a first switching element for changing the valve stroke of at least one first valve. The first and second tilting rod members are pivotally supported and arranged such that control movement of at least one first valve can be transmitted from a first camshaft via the first and second tilting rod members to at least one first valve.

[0014] Document WO 2019 / 025511 A1 relates to a coupling device for a valve-operated apparatus for operating at least one valve of a reciprocating piston machine having a variable valve stroke, particularly a coupling device for a valve-operated apparatus of a reciprocating piston internal combustion engine. The coupling device includes a first coupling element, a second coupling element, and a locking device. The first and second coupling elements are displaceable relative to each other along a first axis, at least within defined limits, wherein the relative displacement of the two coupling elements along the first axis can be blocked by the locking device, at least in a first direction. The locking device has a locking element that is rotatable about the first axis in a circumferential direction, at least within a defined range, wherein when the locking element is in the blocking position, the relative displacement of the two coupling elements along the first axis is blocked, at least in the first direction. The disclosure of this document is incorporated herein by reference.

[0015] The applicant'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 that can be positioned in first and second positions by means of a mechanical switching device and the locking element is used to operate the coupling device, wherein the valve operating device transmits an operational movement for the valve in the first position, and wherein the switching device has: a guide rod and a parallel, relatively movable operating rod; a linkage guide element movably supported at the guide rod for moving the locking element between positions; a trigger element coupled to the linkage guide element, wherein the linkage guide element and the trigger element are clamped between two stops on the operating rod by means of spring elements, each spring element being associated with a stop, wherein the linkage guide element and the trigger element can be displaced by means of the operating rod in a direction along and / or parallel to the guide rod; and a blocking element acting with the trigger element such that, in a first state, when the operating rod moves in an axial direction, the blocking element blocks the displacement of the trigger element and the linkage guide element in a manner that preloads the spring element, and in a second state, the displacement of the trigger element and the linkage guide element causes operation of the coupling device. The publicly available information in the aforementioned document is also incorporated herein by reference. Summary of the Invention

[0016] The object of this invention is to provide an improved valve operating device for variable valve control. In particular, the object of this invention is to provide a valve operating device for variable valve control that can perform clock control on valve stroke switching with particularly precise accuracy.

[0017] A first aspect of the invention relates to a valve operating device for operating at least one valve of a reciprocating piston machine, particularly an internal combustion engine, said valve operating device comprising:

[0018] A first operating lever and a second operating lever, wherein the two operating levers are rotatably supported about a common axis of rotation, wherein the first operating lever can be connected to at least one valve in such a way as to transmit an operational movement to at least one valve;

[0019] A first cam and a second cam, wherein the two cams are arranged at a common axis, and a first operating lever engages the profile of the first cam and a second operating lever engages the profile of the second cam.

[0020] A mechanically coupled device that connects a first operating lever and a second operating lever to each other, wherein the coupling device has a locking element that can be positioned in a first position and a second position and is designed to transmit operative movement of the second operating lever to the first operating lever, at least in the first position of the locking element; and

[0021] A switching device for moving a locking element of a coupled device from at least a first position to a second position and vice versa, wherein the switching device is configured such that movement of a second operating lever, particularly movement causing at least one valve to close and / or movement toward a second cam, mechanically triggers a position switch of the locking element.

[0022] A second aspect of the invention relates to an internal combustion engine having such a valve-operated device.

[0023] This invention is based on a scheme for variable valve control using two levers. A first lever permanently generates valve actuation movement, and a second lever can be engaged when needed via a switching device, such that the valve actuation movement generated by the second lever is superimposed on the valve actuation movement of the first lever. Here, the valve actuation movement of the second lever is transmitted to the first lever via a coupling device, ensuring that only the first lever actuates the valve. In the case of a pull lever, this is preferably achieved via a push lever.

[0024] Here, the first force transmission path via the first operating lever is preferably not impaired by the presence of the second operating lever. The coupling device guides the second force transmission path from the second operating lever to the first operating lever, from where the force transmission path extends to the valve in the same manner as the first force transmission path.

[0025] In this way, the present invention combines the advantages of a rigid operating lever with the advantages of adjustable valve control. On the one hand, a large force for operating the valve can be transmitted solely via the first operating lever. On the other hand, fine-tuning and / or supplementary operation of the valve can be achieved by engaging the second operating lever.

[0026] Furthermore, this invention achieves the switching on or off via a second operating lever by moving the operating lever itself. This allows for particularly precise adjustment of the optimal switching timing.

[0027] Furthermore, the clock-controlled switching via the movement of the second lever provides a maximum available time window for the corresponding operation via the first or second lever. The mechanical triggering of the switching process also ensures particularly reliable triggering.

[0028] In an advantageous design of the valve operating device, the valve operating device has a triggering element, wherein the switching device has a blocking element configured to work in conjunction with the triggering element in a manner that blocks or releases the axial displacement of the triggering element.

[0029] Mechanical triggering can be achieved by setting a blocking element that works in conjunction with the triggering element.

[0030] In another advantageous design of the valve operating device, the guide rod is fixed to the housing and supported by axial displacement to operate the trigger element.

[0031] In this advantageous design, the guide rod can be directly operated by the actuator. No additional equipment is required for operating the triggering element.

[0032] In another advantageous design, when the second operating lever moves toward the axis, the triggering element and the blocking element work together mechanically to switch the position of the trigger locking element.

[0033] In this advantageous design, the triggering element and the blocking element not only work together to define the timing of the axial displacement of the triggering element, but also trigger the position switching of the locking element.

[0034] In another advantageous design, as the second operating lever moves away from the axis, the blocking element releases the trigger element to displace axially along the guide rod.

[0035] Along with the aforementioned advantageous design, the movement of the second operating lever releases the movement of the trigger element away from the camshaft. The trigger element displaces along the guide rod, thereby triggering a subsequent movement of the second operating lever in the axial direction to switch the position of the locking element. This allows for a particularly reliable switching process.

[0036] In another advantageous design of the valve operating device, the blocking element is supported at the second operating lever and is pivotally supported relative to the second operating lever, and the locking element is operated via a switching element, particularly a switching lever or linkage guiding element.

[0037] The pivotable support of the blocking element at the second operating lever achieves a particularly advantageous synergy with the triggering element of the switching device. If the second operating lever pivots toward the camshaft, the blocking element will contact the triggering element and, in that case, pivot in its direction.

[0038] In another advantageous design of the valve operating device, the triggering element has two operating elements designed to change the posture of the blocking element during the movement of the second operating lever in the axial direction, such that the blocking element causes the locking element to switch positions.

[0039] Specifically, the locking element pivots from here.

[0040] As already explained, it is preferably proposed that the movement of the second operating lever away from the axis causes the movement of the triggering element, and the movement of the second operating element toward the axis causes the pivoting of the blocking element.

[0041] In another advantageous design of the valve operating device, the guide rod is at least substantially parallel to the axis of rotation and / or axially oriented.

[0042] This arrangement of the guide rods allows for a particularly space-efficient arrangement of the various components.

[0043] In another advantageous design of the valve operating device, when the position of the locking element is to be switched, the trigger element can be preloaded against the blocking element along the guide rod by means of at least one spring element, wherein the trigger element can only be displaced along the guide rod when the blocking element is displaced by the movement of the second operating rod.

[0044] By using a pre-tensioned guide rod, the trigger element can be operated independently of the actual point in time of displacement. This allows for the creation of an effective correlation between the movement of the blocking element or the second operating lever and the movement of the trigger element.

[0045] In another advantageous design of the valve operating device, the blocking element is configured as a switching rocker with a first connecting element, particularly a connecting head, the posture of the first coupling element changes when the blocking element pivots, and the first coupling element works together with the second coupling element of the switching element, particularly the receiving portion.

[0046] For the purposes of this invention, the switching rocker is preferably configured as a triangle or a three-pointed star. The two ends of the triangle are used to operate the switching rocker, and a connecting head is arranged at the first triangle / point. The switching rocker with the connecting head provides a particularly simple mechanical solution for the blocking element.

[0047] In another advantageous design of the valve operating device, the locking element is rotatably supported on the second operating lever and acts in its first position with the second coupling element of the first operating lever, wherein it and the coupling element are particularly capable of being placed in a stop.

[0048] The locking element of the rotating bearing is a particularly simple and robust mechanical implementation of the locking element.

[0049] In another advantageous design of the valve operating device, the rotation axis of the locking element is at least substantially parallel to the shaft extension.

[0050] Due to its high degree of symmetry, a particularly simple design scheme for valve-operated equipment can be achieved.

[0051] In an advantageous design of the valve operating device, the first operating lever and / or the second operating lever are configured as tilting levers or pull levers.

[0052] In another advantageous design of the valve operating device, the first operating lever has a coupling section that surrounds and engages the second operating lever such that the coupling section forms a stop for the second operating lever and / or the coupling device, the stop restricting the rotation of the second operating lever relative to the first operating lever about a common axis of rotation.

[0053] This allows for a particularly advantageous type of force transmission from the first operating lever to the second operating lever. In particular, the valve operating device can be constructed with exceptional space-saving efficiency because all additional components at the second operating lever can be positioned where the push rod is supported in the first operating lever.

[0054] In another advantageous design of the valve operating device, the sidewall of the second cam rises later than the sidewall of the first cam in the direction of rotation of the shaft, and the profiles of the first and second cams are configured such that the operating movement of the second operating lever produces a valve lift curve that is larger and takes longer than the valve lift curve produced by the operating movement of the first operating lever.

[0055] Because the sidewall of the first cam rises earlier, a relatively larger force is applied to the first operating lever when the valve opens. The first operating lever is preferably rigidly configured and thus has greater strength than the second operating lever. Furthermore, the second operating lever can be intentionally designed to be less rigid, thereby saving weight and space.

[0056] The features and advantages described above that relate to the first aspect of the invention are applicable accordingly to the second aspect of the invention, and vice versa. Attached Figure Description

[0057] Other advantages and features of the invention will become apparent from the following description and with reference to the non-limiting embodiments shown in the accompanying drawings. The drawings at least partially illustrate:

[0058] Figure 1 A three-dimensional top view of the valve system of an internal combustion engine is shown;

[0059] Figure 2 A perspective top view showing an embodiment of a valve operating device;

[0060] Figure 3 Showing according to Figure 2 A top view of the two valve operating levers of the valve operating device;

[0061] Figure 4 Showing valve operating device in Figure 3 A cross-sectional view of plane II in the diagram;

[0062] Figure 5 A top view shows a mechanism for switching the valve operating device in the first position of the locking element;

[0063] Figure 6 Another top view shows the mechanism for switching the valve operating device in the second position of the locking element;

[0064] Figure 7 A perspective view of the second operating lever of the valve operating device is shown;

[0065] Figure 8a , 9a Figures 10a and 11a show side views of the second valve operating lever and the second cam, which are in different rotational positions of the cam, respectively.

[0066] Figure 8b , 9b Figures 10b and 11b show top views of the switching elements of the valve-operated device in different positions;

[0067] Figure 8c , 9c 10c and 11c show magnified top views of the switching elements in different orientations;

[0068] Figure 12 , 13 Cross-sectional views of the triggering element in different loading postures are shown;

[0069] Figure 14 It can be shown that it can be achieved by means of... Figure 3 and Figure 3 Examples of two different valve lift curves achieved by the valve operating device; and

[0070] Figure 15A schematic diagram of an internal combustion engine according to the present invention is shown. Detailed Implementation

[0071] Figure 1 A perspective view of the valve system of an internal combustion engine 101 having a valve operating device 100 is shown in one embodiment. Figure 15 A schematic diagram of such an internal combustion engine 101 is shown, which in the illustrated embodiment has four cylinders 102, each associated with a valve-operating device 100. Of course, the solution according to the invention can also be applied to internal combustion engines 101 with different configurations, particularly in terms of the number of cylinders 102.

[0072] Overall, in Figure 1 In the illustrated embodiment, four valves are operated, with two of the front valves operated via push rods 220 using a valve operating device 100. Here, the first operating lever 210 and the second operating lever 211 of the valve operating device 100 engage with valve operating movements at cams 214 and 215, respectively. These valve operating movements can then be transmitted to the valves.

[0073] Preferably, a reset device 96 is provided to ensure contact between the second operating lever 211 and the second cam 215 when the second operating lever 211 is not loaded.

[0074] Valve operating device 100 Figure 1 The embodiment shown is a so-called pull rod, and correspondingly has a receiving portion 97 for a push rod 200, which transmits valve-operated movement to at least one valve. However, the teachings described with respect to the embodiment can also be transferred to other forms of valve-operating devices, particularly to pull rods with or without rollers at the ends or middle of the pull rod, and valve-operating levers for central support, i.e., so-called tilting rods, which have roller-operating, sliding, or push rod-operating mechanisms.

[0075] Figure 2 A perspective view of one embodiment of a valve operating device 100 is shown, wherein the valve operating device 100 constitutes a valve (not shown) for operating an internal combustion engine.

[0076] The valve operating device 100 has a first operating lever 210 and a second operating lever 211, wherein the two operating levers 210, 211 are rotatably supported about a preferred common axis of rotation 213. A push rod 220 is connected to the first operating lever 210 to transmit an operating movement from the first operating lever 210 or the second operating lever 211 to the valve.

[0077] The first operating lever 210 is configured to engage the profile of the first cam 214, and the second operating lever 211 is configured to engage the profile of the second cam 215. The two cams 214 and 215 are anti-rotationally supported on a particularly common shaft 216. The first cam 214 preferably has a different profile from the second cam 215 in the circumferential direction of the shaft 216.

[0078] The first operating lever 210 and the second operating lever 211 are connected to each other via a coupling device 10. The coupling device 10 is specifically designed to transmit operational movement from the second operating lever 211 to the first operating lever 210 when the coupling device 10 is in a blocked state, or to convert movement of the second operating lever 211 into so-called idle movement when the coupling device 10 is in a released state.

[0079] In the illustrated embodiment, the coupling device 10 is arranged at or as part of the second operating lever 211. Preferably, the longitudinal axis of the coupling device 10 is tangent to the trajectory of the second operating lever 211 about its rotation axis, wherein the length of the coupling device 10 can be adjusted along the longitudinal axis.

[0080] The first operating lever 210 particularly has a coupling section 217, which preferably extends into the trajectory of the second operating lever 210. The coupling section 217 is connected to the second coupling element 12, preferably screwed on, as in... Figure 2 As shown, the second coupling element can work together with the first coupling element 11 to transmit operative movement.

[0081] For switching purposes, the coupling device 10 preferably has a locking element 13b, which is preferably pivotable about an axis, such that it is preferably part of the locking element 13b and constitutes a stop 89 (not shown, see, for example, see...). Figure 4 or Figure 7 The coupling element 11 can pivot between at least two orientations. Here, the axis is different from the rotation axis 213 of the operating levers 210, 211, and is preferably oriented parallel to the rotation axis 213 and / or the camshaft and / or the guide rod 83.

[0082] In the coupled state, the first coupling element 11, attached to the first operating lever 211 via the locking element 13b, works in conjunction with the second coupling element 12 of the first operating lever 210 to transmit valve operation movement from the first operating lever 210 to the second operating lever 211. Here, the stop 89 of the first coupling element 11 contacts the second coupling element. The position of the locking element 13b is also referred to hereinafter as the first position or the blocking position.

[0083] Conversely, in the released state of the coupling device 10, the locking element 13b is in the second position, hereinafter also referred to as the released position, in which the stop 89 of the first coupling element 11 (not shown, see example) Figure 4 or Figure 7 It does not work in conjunction with the second coupling element 12. Therefore, Figure 1 In this case, the locking element 13b is preferably pivoted clockwise by approximately 90°, as described in further detail below.

[0084] The locking element 13b is preferably operated by means of a switching device 110 (not shown). Components of the switching device 110 are preferably fixed to and supported by the housing of the internal combustion engine whose valve is controlled (both are not shown). Here, the switching device 110 is preferably operated hydraulically or electromechanically by means of an actuator (not shown). Figure 2 (not shown in the image), and is further preferably controlled by the control unit (ECU) of the internal combustion engine.

[0085] Figure 3 Showing according to Figure 2 A top view of the valve operating device 100 of the embodiment, on the side opposite to the rotation axis 213.

[0086] The first operating lever 210 is in Figure 3 The left side of the diagram is shown. The first path F1, shown as a solid arrow, for the force transmission from the first cam 214 via the first actuator 218 to the first operating lever 210 and then to the push rod 220, preferably extends substantially parallel to the direction of movement of the first operating lever 210.

[0087] The second operating lever 211 is in Figure 3 The right side is shown. Force transmission from the second operating lever 211 to the first operating lever 210 occurs only when the coupling device 10 is in the blocked state. If the coupling device 10 is in the blocked state, a second path F2 for force transmission from the second cam 215 via the second actuator 219 and the second operating lever 210 to the coupling device 10 extends substantially parallel to the direction of movement of the second operating lever 211. The second path F2 for force transmission preferably extends from the coupling device 10 via the coupling section 217, particularly substantially perpendicular to the axis of movement of the second operating lever 211, to the first operating lever 210 and to the push rod 220.

[0088] From the above, it can be concluded that in the illustrated embodiment, path F1 is always enabled. Conversely, path F2 is selectively enabled based on the state of coupled device 10.

[0089] Figure 4 An embodiment showing a second operating lever 211 and part of a first valve operating lever 210 of a valve operating device 100 is shown. Figure 3The cross-sectional view in plane II, wherein the central axis of the coupling device 10 is located in said plane.

[0090] If you have already referred to Figure 2 Partially explained and now in Figure 4 As is fully visible in the image, 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.

[0091] If you have already referred to Figure 2 Partially explained and now in Figure 4 As is clearly visible, the locking element 13b with the first coupling element 11 is part of or supported on the second operating lever 211. Furthermore, the coupling device 10 has a second coupling element 12, which is part of or supported on the first operating lever 210.

[0092] Here, the first coupling element 11 is fixed to the second operating lever 211 by force transmission, and the second coupling element 12 is correspondingly fixed to the first operating lever 210 by force transmission—preferably at its coupling section 217—and more preferably by screwing in by means of a thread and fastening by means of a locking nut 221. Here, the second coupling element 12 is preferably operated via the stop 89 of the first coupling element 11. The bottom of the post constituting the stop 89 of the locking element 13b is preferably arched inward, and the free end of the second coupling element 12 is preferably correspondingly convexly arched.

[0093] Locking element 13b is rotatably supported at the second operating lever 211 and can be engaged by means of switching element 84. Figure 4 In the illustrated embodiment, this is operated by a switching linkage. The switching linkage 84 is in turn operated by a switching device 110. In this way, the defined valve lift can be selectively enabled or disabled by the mechanical switching device 110.

[0094] The switching device 110 preferably has a blocking element 112, which in the illustrated embodiment is configured as a switching rocker and has a first connecting element 118, particularly a connecting head 118, which works together with a second connecting element 119 of the switching link 84, particularly a receiving portion.

[0095] In the illustrated embodiment, the blocking element 112 is pivotally supported at the second operating lever 211 in the illustrated plane.

[0096] The switching device 110 also has a trigger element 111. The trigger element 111 operates hydraulically or electromechanically by means of an actuator (not shown).

[0097] The trigger element 111 preferably has a first operating element 116 and a second operating element 117. Figure 4 (Not visible in the text), the first and second operating elements work together with the blocking element 112 to trigger the operation of the locking element 13b, as described below. Figure 5 and Figure 6 explain.

[0098] The valve-operated movement of the second operating lever 211 is engaged at the second cam 215 by means of the second actuator 219. Correspondingly, the valve-operated movement of the first operating lever 210 is engaged at the second cam 215 by means of the first actuator 218. Figure 5 and 6 (Not shown in the image) Engagement. If the locking element 13b is in the first position or the blocking position, the operational movement of the first operating element 116 is transmitted to the first operating lever 210.

[0099] For example Figure 5 As shown, locking element 13b is in the first position, also known as the blocking position. Accordingly, coupling device 10 is in the blocking state, in which valve operation movement is transmitted from the second operating lever 211 to the first operating lever 210.

[0100] The first position is achieved by placing the trigger element 111, which is displaceably supported at the guide rod 83 fixed to the housing, in an orientation that causes the second operating element 117 to interact with the end of the blocking element 112, which is configured as a switching rocker. Thus, the connector 118 is in... Figure 4 The switch lever 84 pivots to the left. Because the connecting head 118 and the receiving portion 119 of the switching lever 84 work together, the switching lever 84 also moves to the left. The pin 13a of the locking element 13b is received in another receiving portion of the switching lever 84, such that the switching lever 84 and the locking element 13b work together to pivot the first coupling element 11 to the right.

[0101] exist Figure 6 The diagram shows the released state of the coupling device 10, in which the locking element 13b is in the second position or the released position. In this case, the first coupling element does not cooperate with the second coupling element 12 of the coupling device 10, so that the valve operation movement of the second operating lever 211 is not transmitted to the first operating lever 210 and is thus lost as a so-called idle movement.

[0102] In this configuration, the trigger element 111 of the switching device 110 on the guide rod 83 is positioned such that the other end of the switching rocker 112 interacts with the first operating element 116 of the trigger element 111, causing the switching rocker to pivot to the right. This movement is then transmitted via the connector 118 and the receiving portion 119 to the switching link 84, which transmits this movement via the pin 13a to the locking element 13b, thereby pivoting the first coupling element 11 to the left.

[0103] exist Figure 7 The figure shows a perspective top view of the valve operating device 100 without the first operating lever 210.

[0104] The view shows the orientation of the trigger element 111 and its first operating element 116 and second operating element 117 relative to the second operating lever 211.

[0105] If you have already referred to Figure 5 and Figure 6 As explained, the trigger element 111 is displaceably supported at the guide rod 83. In the illustrated embodiment, the guide rod 83, supported in a manner fixed to the housing, is oriented parallel to the rotation axis 213, and the first operating lever 210 and the second operating lever 211 are rotatably supported about the rotation axis. Here, the trigger element 111 can move between the two guides (not shown) of the guide rod 83.

[0106] Figures 8 to 11 illustrate the operation of the embodiment of the valve operating device 100 shown in the figures.

[0107] In the subgraph marked with "a" ( Figure 8a , Figure 9a , Figure 10a , Figure 11a The top view of the first valve stem 211 is shown in the figure below from the following side: In the complete valve operating device 100, the first operating lever 210 is arranged on said side. In the sub-figure marked "b" ( Figure 8b , Figure 9b , Figure 10b , Figure 11b The positions of the trigger element 111 corresponding to the switching states are shown in the diagram, and in the sub-diagram marked with "c" ( Figure 8c , Figure 9c , Figure 10c , Figure 11c Details of trigger element 111 are shown in the figure.

[0108] As from Figures 4 to 7It is known that: the second operating lever 211 has a switching device 110, which, among other things, includes a guide lever 83 and a trigger element 111. The trigger element 111 further has a first operating element 116 and a second operating element 117, the second operating element cooperating with a switching rocker 112 acting as a blocking element (the switching rocker 112 in...). Figures 7 to 1 (1) It is difficult to identify, so no attached labels were set).

[0109] Additionally, the second operating lever 211 has a locking element 13b with a first coupling element 11, both of which are part of the coupling device 10. This allows the second operating lever 211 to be coupled to the first operating lever 210.

[0110] The second actuator 219 (a wheel in the case shown) receives valve-operated movement at the second cam 215.

[0111] exist Figure 8a In this configuration, the orientation of the second cam causes the cam lift to quickly reach the second actuator 219 due to the rotation direction of the camshaft. The valve operation movement is transmitted to the first operating lever 210 due to the orientation of the locking element 13b or its first coupling element 11.

[0112] exist Figure 8b The diagram also shows a top view of the switching device 110 in an orientation in which the switching device induces a first position or a blocking position for the locking element 13b. Here, the trigger element 111 is arranged on the guide rod 83 such that its first operating element 116 interacts with one end of the switching rocker 112, causing the locking element 13b to be blocked in the first position or the blocking position.

[0113] Figure 8c An enlarged view of the guide rod 83 and the trigger element 111 as a whole is shown. The area of ​​the trigger element 111 surrounding the guide rod 83, or the area in which the trigger element 111 is guided by the guide rod 83, is shown in cross-section here.

[0114] It is thus evident that the spring element 93 is located within the trigger element 111, and the spring element is held at the guide rod 83 by a first spring stop 98 and a second spring stop 99. The spring stops 98 and 99 are configured such that they can displace toward the spring as the guide rod moves, but are prevented from moving away from the spring.

[0115] exist Figure 9a In the process, the raised portion of the second cam 215 is always ahead of the second actuator, but due to the rotation of the camshaft, it has already come slightly closer to the second actuator.

[0116] Locking element 13b should now switch from the first position or blocking position to the second position or releasing position.

[0117] Therefore, such as Figure 9b and Figure 9c As indicated by the shaded arrow, the guide rod 83 moves to the left. This pushes the switching rocker 112 downwards 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 contacts the first operating element 116. This prevents further displacement of the trigger element 111 on the guide rod 83, as... Figure 9c As indicated by the shaded arrow with a bar. Since the guide rod 83 continues to displace further, the spring element 93 is compressed in the trigger element 111 by displacing the second spring stop 99 toward the first spring stop 98.

[0118] exist Figure 10a In the middle, the raised portion of cam 215 has reached the second actuator 219, causing the second operating lever 211 to pivot upward. Due to the blocking position of locking element 13b, the first operating lever 210 (not shown) will also pivot upward here.

[0119] Due to the pivoting, the other end of the switching rocker 112 releases the first operating element 116, as in Figure 10a It can be seen within the dotted circle. Therefore, in Figure 10b In the view, the trigger element 111 can be further displaced to the left on the guide rod 83, caused by the preload of the spring element 93, which itself is relaxed. Accordingly, the spring element 93... Figure 10c The text shows a relaxed state.

[0120] exist Figure 11a In the middle, the raised portion of the second cam 215 has pivoted to an attitude such that the second operating lever 211 pivots again toward the camshaft or toward the base circle of the cam 215. Through this pivoting movement, the other end of the switching rocker 112 contacts the first operating element 116 of the trigger element 111, causing the switching rocker 112 to... Figure 11a As indicated by the arrow, it pivots to the right. Consequently, locking element 13b pivots to the left via switching link 84 (not visible), also via... Figure 11a The arrow in the diagram indicates this. Thus, locking element 13b reaches its second position or released position.

[0121] Correspondingly, by operating the guide lever 83 to the right, switching can be performed from the second or released position of the locking element 13b to the first or blocking position. The trigger element 111 remains in its position as... Figure 11b In the position shown, and the spring element 93 remains relaxed, as... Figure 11c As shown in the image.

[0122] exist Figure 12 and Figure 13 The cross-sections through the trigger element 111 are shown in the figures. It becomes clear here that the first operating element 116 and the second operating element 117 of the trigger element 111 are flexibly preloaded by spring elements 94 or 95. This allows the operating elements 116 and 117, which are respectively in contact with the switching rocker 112, to be avoided if the switching rocker 112 or the blocking element cannot pivot (e.g., because it is blocked).

[0123] For example, this can be useful when locking element 13b should actually be engaged in the second or released position, but is blocked at the first operating lever 210, particularly at the second coupling element of the first operating lever 210. Thus, a force that could damage the first operating element 116 can be transmitted through movement of the first operating lever 210.

[0124] exist Figure 13 In the diagram, operating elements 116 and 117 are shown in the pressed-in position, which will occupy the position under the described overload condition.

[0125] Figure 14 Examples of two different valve lift profiles achievable using valve operating devices are shown. Here, the valve opening is explained in relation to the crankshaft angle.

[0126] The valve lift curve IVC-480 belongs to the Miller cycle and is caused by the first cam 214 (therefore, the so-called Miller cam) in the embodiment shown in the figure in front of the valve operating device 100.

[0127] Miller operation of an internal combustion engine is specifically optimized for energy consumption, but the engine cannot be started during Miller operation due to low cylinder fill.

[0128] Valve lift profile IVC-580 belongs to another combustion cycle, where the valve opening time is longer and the valve travel is 8.7 mm longer than that in the Miller cycle shown. Valve lift profile IVC-580 is induced by the second cam 215. Therefore, valve lift profile IVC-580 overwrites valve lift profile IVC-480.

[0129] like Figure 14 As shown, the rise of the valve lift curve IVC-580 is time-sequentially set after the rise of the lift curve IVC-480. This ensures in the valve operating device 100 that the majority of the force occurring when the valve opens is transmitted via the more robust and rigid first operating lever 210 (force flow F1). Only about one-third of the force then acts on the variable or adjustable operating lever 211. Therefore, the operating lever can be designed with lower strength and smaller dimensions, particularly a narrower one.

[0130] Accordingly, in the valve operating device 100, the sidewall of the second cam 215 rises later than the sidewall of the first cam 214 relative to the direction of rotation of the shaft 216. Thus, the actuation movement of the first operating lever 210 occurs at a different, preferably earlier, time point compared to the actuation movement of the second operating lever 211. Internal combustion engines, especially so-called large engines, preferably operate in the Miller cycle for 90% of their operating duration. The valve lift curve IVC-580 is preferably used only during startup and in temporary cruising operations (also known as taxiing operations).

[0131] It should be noted that the described embodiments are merely examples and are not intended to limit the scope, application, or structure in any way. Rather, for those skilled in the art, the foregoing description provides guidance for implementing at least one embodiment, wherein various changes can be made without departing from the scope of protection derived from the claims and equivalent combinations of these features, particularly regarding the function and arrangement of the described components. In particular, the valve operating device can also be a push rod, rocker arm, or similar device. The switching device can also be configured differently, particularly according to the variant shown in document WO 2019 / 025511 A1. On the other hand, the switching device described above with reference to the accompanying drawings can also be used in conjunction with alternative coupling devices, such as the coupling device shown in document WO 2019 / 025511 A1. In this case, the switching device operates the linkage guide element, particularly via a switching lever.

[0132]

Claims

1. A valve operating device (100) for operating at least one valve of a reciprocating piston machine, comprising: a first operating lever (210) and a second operating lever (211), wherein the two operating levers (210, 211) are rotatably supported about a common axis of rotation (213), wherein the first operating lever (210) is connectable to the at least one valve to transmit an operating movement to the at least one valve; a first cam (214) and a second cam (215), wherein the two cams (214, 215) are arranged at a shaft (216), and the first operating lever (210) engages the profile of the first cam (214) and the second operating lever (211) engages the profile of the first cam (214). The profile of the second cam (215); a mechanical coupling device (10) via which a first operating lever (210) and a second operating lever (211) can be connected to each other, wherein the mechanical coupling device (10) has a locking element (13B) capable of being positioned in a first position and a second position and is designed to: at least in the first position of the locking element (13B) transmit the operational movement of the second operating lever (211) to the first operating lever (210); and a switching device (110) for moving the locking element (13B) of the mechanical coupling device (10) at least from the first position to the second position, and vice versa, wherein, The switching device (110) includes a blocking element (112) pivotally supported at the second operating lever (211) and a triggering element (111) displaceably supported at a guide rod (83) fixed to the housing. The triggering element (111) has a first operating element (116) and a second operating element (117) that work together with the blocking element (112). The switching device (110) is configured such that movement of the second operating lever (211) mechanically triggers a position switch of the locking element (13B).

2. The valve operating device (100) according to claim 1, wherein the reciprocating piston machine is an internal combustion engine.

3. The valve operating device (100) according to claim 1, wherein the switching device (110) is configured such that the second operating lever (211) causes a movement to close the at least one valve and / or a movement in the direction of the axis (216) mechanically triggers a position switch of the locking element (13B).

4. The valve operating device (100) according to claim 1, wherein the triggering element (111) and the blocking element (112) are configured to act together to block or release the axial displacement of the triggering element (111) along the guide rod (83), wherein the triggering element (111) is supported at the guide rod in a manner that allows for axial displacement.

5. The valve operating device (100) according to claim 1, wherein the guide rod (83) is axially displaceable to operate the trigger element.

6. The valve operating device (100) according to claim 1, wherein when the second operating lever (211) moves toward the axis (216), the triggering element (111) and the blocking element (112) mechanically cooperate to trigger the position switching of the locking element (13B).

7. The valve operating device (100) according to claim 1, wherein when the second operating lever (211) moves away from the axis (216), the blocking element (112) releases the axial displacement of the triggering element (111) along the guide rod (83).

8. The valve operating device (100) according to claim 1, wherein the blocking element (112) is supported at the second operating lever (211) and pivotally supported relative to the second operating lever, and the locking element (13B) is operated via the switching element (84).

9. The valve operating device (100) according to claim 8, wherein the switching element (84) is a switching rod or connecting rod guide element.

10. The valve operating device (100) according to claim 1, wherein the two operating elements (116, 117) are designed to: change the orientation of the blocking element (112) during the movement of the second operating lever (211) toward the axis (216), such that the blocking element (112) causes the position switching of the locking element (13B).

11. The valve operating device (100) according to claim 1, wherein the locking element (13B) in its first position works in conjunction with the second coupling element (12) of the first operating lever (210).

12. The valve operating device (100) according to claim 11, wherein the locking element (13B) in its first position is capable of being placed in a stop with the second coupling element (12) of the first operating lever (210).

13. The valve operating device (100) according to claim 1, wherein the rotation axis of the locking element (13B) extends parallel to the shaft (216), the guide rod (83) and / or the rotation axis (213).

14. The valve operating device (100) according to claim 1, wherein the guide rod (83) is oriented at least substantially parallel to the axis of rotation (213) and / or the shaft (216).

15. The valve operating device (100) according to claim 1, wherein when the position of the locking element (13B) is to be switched, the triggering element (111) is preloaded against the blocking element (112) along the guide rod (83) by means of at least one spring element (93, 94), wherein the triggering element (111) is displaced along the guide rod (83) only when the blocking element (112) is displaced by the movement of the second operating rod (211).

16. The valve operating device (100) according to claim 8, wherein the blocking element (112) is configured as a switching rocker with a first connecting element (118), the posture of the first connecting element changes when the blocking element (112) is pivoted, and the first connecting element works together with a second connecting element (119) of the switching element (84).

17. The valve operating device (100) according to claim 16, wherein the first connecting element (118) is a connector.

18. The valve operating device (100) according to claim 16, wherein the second connecting element (119) is a receiving portion.

19. The valve operating device (100) according to claim 1, wherein the first operating lever (210) and / or the second operating lever (211) are configured as tilting levers or pull levers.

20. The valve operating device (100) according to claim 1, wherein the first operating lever (210) has a coupling section (217) that surrounds and engages the second operating lever (211) such that the coupling section forms a stop (89) with respect to the second operating lever (211) and / or the coupling device (10), the stop restricting the rotation of the second operating lever (211) relative to the first operating lever (210) about a common axis of rotation (213).

21. The valve operating device (100) according to claim 1, wherein the sidewall of the second cam (215) rises later than the sidewall of the first cam (214) in the direction of rotation of the shaft (216), and wherein the profiles of the first cam (214) and the second cam (215) are configured such that the operating movement of the second operating lever (211) produces a second valve lift curve (IVC-580) that is larger and longer than the first valve lift curve (IVC-480) produced by the operating movement of the first operating lever (210).

22. An internal combustion engine (101) having at least one valve operating device (100) according to any one of claims 1 to 21.

Images