DE102019008969A1 - Valve actuation device for an internal combustion engine and a method for operating such a valve actuation device - Google Patents

Abstract

The invention relates to a valve actuation device (10) for actuating at least one gas exchange valve (12) of an internal combustion engine (14), with at least one rocker arm (34) which rotates around a pivot axis (36) between at least one starting position and at least one actuation position for actuating the gas exchange valve ( 12) is pivotable, with at least one actuating element (50) held on the rocker arm (34) so as to be movable along a direction of movement (52) relative to the rocker arm (34), with its mediation when the rocker arm (34) moves from the starting position into the Actuating position, the gas exchange valve (12) can be actuated by means of the rocker arm (34), and with a chamber (54) which is partially delimited by the actuating element (50) and which can be supplied with a fluid, also comprising at least one pressure accumulator (62) in which at a movement of the rocker arm (34) from the starting position into the actuating position the fluid a can be conveyed from the chamber (54) by means of the actuating element (50).

Description

The invention relates to a valve actuation device for an internal combustion engine according to the preamble of claim 1. Furthermore, the invention relates to a method for operating such a valve actuation device according to the preamble of claim 10.

Such a valve actuation device for actuating at least one gas exchange valve of an internal combustion engine and a method for operating such a valve actuation device are, for example, already the EP 2 425 105 B1 as known. The valve actuating device comprises at least one rocker arm and can be pivoted about a pivot axis between at least one starting position and at least one actuating position for actuating the gas exchange valve. The valve actuation device also comprises at least one actuating element which is held on the rocker arm so as to be movable along a direction of movement relative to the rocker arm, under whose mediation or via which the gas exchange valve can be actuated, in particular opened, by means of the rocker arm when the rocker arm moves from the starting position into the actuating position . In addition, the valve actuation device has a chamber which is partially delimited by the actuation element and which can be supplied with a fluid, in particular a liquid.

In addition, the US 2017/0002702 A1 a four-stroke internal combustion engine which has at least one cylinder and one piston arranged in the cylinder.

The object of the present invention is to further develop a valve actuation device and a method of the type mentioned at the beginning in such a way that a particularly advantageous operation of the internal combustion engine can be implemented in a particularly simple manner.

This object is achieved by a valve actuating device with the features of claim 1 and by a method with the features of claim 10. Advantageous configurations with expedient developments of the invention are specified in the remaining claims.

A first aspect of the invention relates to a valve actuation device for actuating at least one gas exchange valve of an internal combustion engine, in particular for a motor vehicle such as a motor vehicle. This means that the motor vehicle, which is preferably designed as a utility vehicle, in its fully manufactured state has the internal combustion engine, which is preferably designed as a reciprocating piston engine, and can be driven by means of the internal combustion engine. The gas exchange valve is preferably an outlet valve via which a gas, in particular exhaust gas, can be discharged from a combustion chamber of the internal combustion engine or can flow out.

The valve actuation device comprises at least one rocker arm which can be pivoted about a pivot axis between at least one starting position and at least one actuation position for actuating the gas exchange valve, in particular relative to at least one component of the valve actuation device. The component is, for example, a bearing axis, also referred to simply as an axis or rocker arm axis, on which the rocker arm can be mounted so as to be pivotable about the pivot axis relative to the bearing axis. By pivoting or moving the rocker arm from the starting position into the actuating position, the gas exchange valve can be or is actuated by means of the rocker arm. The operability or actuation of the gas exchange valve can in particular be understood to mean that the gas exchange valve can be opened or is opened by actuating the gas exchange valve.

For example, during engine braking operation or during engine braking operation of the internal combustion engine, the gas exchange valve can be or is actuated by means of the rocker arm, in particular such that the internal combustion engine works as an engine brake or that an engine brake of the internal combustion engine is activated. The rocker arm assigned to an engine brake is also referred to as a brake rocker arm. In other words, in the engine braking mode or during the engine braking mode, which is also referred to as braking mode, an engine brake of the internal combustion engine is activated, so that the internal combustion engine operates as an engine brake in the engine braking mode. The engine brake or the engine braking mode is designed in particular as a decompression brake, as is already sufficiently known from the general prior art. During engine braking operation, the gas exchange valve can be or will be actuated by means of the rocker arm, for example, in such a way that a compressed gas, which is or has been compressed, for example by means of a piston of the internal combustion engine that partially delimits the aforementioned combustion chamber, in particular in the compressed state of the gas, from the combustion chamber via the gas exchange valve is drained, in particular by opening the gas exchange valve, so that the compression energy contained in the compressed gas is at least largely unused and is therefore not or only very slightly used after the compression of the gas to move the piston from its top dead center to its bottom dead center. The internal combustion engine must or had to provide compression energy to compress the gas before the compressed gas is released. Since this performed compression work, which is contained in the compressed gas, is not used or only very slightly used to drive the piston and thus an output shaft of the internal combustion engine, which is designed as a crankshaft and in particular is articulated to the piston via a connecting rod, the motor vehicle braked in the engine braking mode and thus by means of the internal combustion engine functioning as an engine brake, or an excessive increase in a driving speed at which the motor vehicle is traveling can be avoided by the engine braking mode.

The valve actuation device comprises at least one actuation element, designed for example as a piston or pin, which is movably held on the rocker arm and can be moved along a direction of movement relative to the rocker arm, in particular in a translatory manner. In other words, the actuating element is held on the rocker arm so that it can move along a direction of movement relative to the rocker arm, so that the actuating element can also be pivoted about the pivot axis with the rocker arm, for example, between the starting position and the actuating position. With the intermediary of the actuation element, the gas exchange valve can be actuated, in particular opened, by means of the rocker arm when the rocker arm moves from the initial position into the actuated position. In other words, the actuating element is arranged in such a way that, for example, during engine braking operation, that is, while engine braking operation and thus the engine brake are activated, an actuating force for actuating the gas exchange valve acts from the rocker arm via the actuating element on the gas exchange valve, whereby the gas exchange valve over the actuating element can be or is actuated by means of the rocker arm, in particular in the manner of a decompression brake.

The valve actuation device also has a chamber which is partially delimited by the actuation element and which can be supplied with a fluid, in particular with a liquid such as an oil. This means that the fluid can or can be introduced into the chamber. The chamber is arranged, for example, in the rocker arm and is delimited partially by the actuating element and partially by the rocker arm, in particular directly.

In order to be able to implement a particularly advantageous operation of the internal combustion engine in a particularly cost-effective manner, the invention provides that the valve actuation device has at least one pressure accumulator, in which the actuation position can convey the fluid from the chamber by means of the actuation element when the rocker arm is moved from the initial position is. In other words, the actuating element can be moved, for example, in the direction of movement relative to the rocker arm between at least one transfer position and at least one conveying position, in particular translationally. For example, a movement of the actuating element from the conveying position into the transfer position leads to an increase in volume of the chamber. Thus, for example, a movement of the actuating element from the transfer position into the conveying position leads to a reduction in volume of the chamber. For example, during engine braking operation, i.e. when the engine brake is activated, the actuating element is secured against movement from the transfer position into the conveying position, in particular hydraulically and / or by means of the fluid received in the chamber, in particular in such a way that during the movement of the Rocker arm from the initial position into the actuating position prevents the fluid from flowing out of the chamber, so that when the rocker arm is pivoted from the initial position into the actuating position while the actuating element is secured against movement from the transfer position into the delivery position, the gas exchange valve opens the manner described above is actuated via the actuating element by means of the rocker arm, and consequently the actuating force is transmitted from the rocker arm to the gas exchange valve via the actuating element.

The engine braking operation coincides, for example, with unfired operation of the combustion chamber or the internal combustion engine, so that combustion processes do not occur during unfired operation in the combustion chamber, in particular in the internal combustion engine as a whole.

If the engine braking mode and thus the engine brake are deactivated, for example the actuating element is released for a movement from the transfer position into the conveying position, in particular by allowing the fluid initially received in the chamber during or during the movement of the rocker arm from the starting position can flow out of the chamber in the actuating position or flows out. The engine braking mode is deactivated, for example, during fired operation of the internal combustion engine, with combustion processes taking place during fired operation in the combustion chamber, in particular in the internal combustion engine. During the fired operation, there is no actuation of the gas exchange valve effected by means of the rocker arm and taking place in the manner of a decompression brake or an actuation of the engine brake. If, for example, the rocker arm is pivoted from the starting position into the actuating position while the actuating element is released for movement from the transfer position into the conveying position, the actuating element, for example, is moved out of the transfer position by a reaction or movement force acting at least indirectly on the actuating element from the gas exchange valve moved into the conveying position relative to the rocker arm along the direction of movement, while an actuation or opening of the gas exchange valve does not take place. The movement of the actuating element from the transfer position into the conveying position is accompanied by a reduction in volume of the chamber, whereby the fluid initially received in the chamber, which, for example, was introduced into the chamber before the volume reduction of the chamber and is consequently received in the chamber, by means of the actuation element is conveyed out of the chamber and conveyed into the pressure accumulator. As a result, the fluid conveyed out of the chamber by means of the actuating element and conveyed into the pressure accumulator is received or stored in the pressure accumulator. In this way, the actuating element can be used, for example, as a pressure pump, in particular as a high-pressure pump, by means of which the fluid can be conveyed at a pressure to and in particular into the pressure accumulator, the fluid with the pressure being stored in the pressure accumulator by means of the pressure accumulator can. In other words, the aforementioned pressure can be brought about or generated by means of the actuating element. This pressure generation can be realized by means of a component that is already present in the form of the actuating element and thus in a way that is favorable in terms of weight, cost and space. By using the pressure accumulator, the fluid having the pressure can be stored inexpensively, in terms of installation space and weight and, for example, after the fluid has been conveyed into the pressure accumulator, it can be used as required. Overall, it can be seen that the actuating element, for example, when the actuating element is designed as a piston, is used together with the rocker arm as a piston pump in order to convey the fluid into the pressure accumulator and in the pressure accumulator with one, in particular by means of the actuating element generated to store pressure in the pressure accumulator.

In order to be able to convey the fluid particularly advantageously and store it in the pressure accumulator so that particularly advantageous operation of the internal combustion engine can be implemented, one embodiment of the invention provides that the valve actuation device has a spring element. By means of the spring element, when the rocker arm moves out of the actuating position into the starting position, the actuating element can be moved along the direction of movement relative to the rocker arm from the conveying position into the transfer position, in particular in a translatory manner. In this way, a defined and targeted movement of the actuating element from the conveying position into the transfer position can be brought about. Since a movement of the actuating element from the conveying position into the transfer position is accompanied by an increase in volume of the chamber, the fluid can be introduced into the chamber, in particular sucked in by means of the actuating element, for example by or during the movement of the actuating element from the conveying position into the transfer position . As a result, a targeted and needs-based delivery of the fluid via the chamber in the pressure accumulator can be guaranteed.

The pressure accumulator is preferably, in particular completely, arranged outside the rocker arm and outside the actuating element, as a result of which, for example, a particularly large amount of the fluid can be stored in the pressure accumulator. For example, the internal combustion engine can have a plurality of combustion chambers and a rocker arm for each combustion chamber, to which the previous and following statements on the rocker arm can be transferred and vice versa. Thus, several rocker arms and several chambers can be provided, wherein, for example, the fluid from the several chambers, in particular under pressure, can be received and stored in the pressure accumulator or in one and the same pressure accumulator. In this way, a supply of at least one device of the internal combustion engine with the, in particular pressurized, fluid from the pressure accumulator can be ensured in a particularly simple and, in particular, weight, cost and space-saving manner. Since the fluid is to be stored or stored in the pressure accumulator with the aforementioned pressure or under pressure, the fluid can be provided by the pressure accumulator as a pressure fluid, in particular as a pressure oil. The pressure fluid that can be provided by the pressure accumulator can be used, for example, to include at least one device in the internal combustion engine to supply the pressure fluid and thereby to operate or actuate by means of the pressure fluid.

Another embodiment is characterized in that the movement of the actuating element from the conveying position into the transfer position leads to an increase in volume of the chamber or causes an increase in volume of the chamber. In other words, the volume of the chamber can preferably be increased by moving the actuating element from the conveying position into the transfer position.

It has been shown to be particularly advantageous if at least one portion of the actuating element arranged in the conveying position in the rocker arm moves out of the rocker arm during or as a result of the actuation element moving from the conveying position into the transfer position, in particular along the direction of movement and / or translationally . As a result, a double function of the rocker arm and the actuating element can be implemented in a particularly advantageous manner, so that the number of parts, the costs, the weight and the space requirement can be kept particularly low. As part of the double function, the rocker arm and the actuating element are used on the one hand during engine braking mode or when the engine braking mode is activated to implement the engine brake described above or to operate the internal combustion engine as an engine brake, in particular in the form of a decompression brake. For this purpose - while the engine braking mode is activated - the actuating element is secured against movement from the transfer position into the conveying position, so that when the rocker arm and with it the actuating element are pivoted from the starting position into the actuating position, the gas exchange valve via the actuating element by means of the rocker arm , in particular in the manner of a decompression brake, actuated, in particular opened, is. On the other hand, in the context of the double function, the rocker arm and the actuating element are used as a pump, in particular as a piston pump, by means of which the fluid is removed from the engine, in particular when the engine braking mode is deactivated, i.e. when the engine braking mode is deactivated and thus in particular during the fired operation of the internal combustion engine Chamber is promoted into the pressure accumulator. The or a pivoting of the rocker arm from the starting position into the actuating position, when the actuating element is released for movement from the transfer position into the conveying position, causes a movement of the actuating element from the transfer position into the conveying position, since when the rocker arm moves out of the Starting position is pivoted into the actuating position, the actuating element, which is initially in the transfer position, is supported at least indirectly, in particular directly, on the gas exchange valve, for example, in its closed position, or in at least indirect, in particular direct, support with the gas exchange valve, for example, in its closed position comes. As a result, the above-described motive force occurs, which acts at least indirectly from the gas exchange valve on the actuating element, in particular such that the actuating element is moved from the transfer position into the conveying position by means of the motive force. As a result, the fluid previously introduced into the chamber and thus received in the chamber is conveyed out of the chamber and conveyed into the pressure accumulator.

If the rocker arm is then pivoted from the actuating position into the initial position, in particular pivoted back, the actuating element is moved from the conveying position into the initial position, in particular by means of the spring element. This is associated, for example, with an increase in the volume of the chamber, so that fluid can be introduced into the chamber, in particular sucked in. The fluid initially received in the chamber can then be conveyed out of the chamber again in the manner described and conveyed into the pressure accumulator.

In order to be able to realize a particularly advantageous operation of the internal combustion engine in a particularly cost-effective manner, it is provided in a further embodiment of the invention that the valve actuation device has at least one camshaft, by means of which the gas exchange valve via the rocker arm and / or at least one additionally provided to the gas exchange valve, second gas exchange valve of the internal combustion engine can be actuated. The camshaft has, for example, a cam which can be rotated with the camshaft about a camshaft axis of rotation. For example, by means of the cam and thus by means of the camshaft, the rocker arm can be actuated and thereby pivoted from the initial position into the actuating position, so that the rocker arm can be pivoted from the initial position into the actuating position by means of the cam or by means of the camshaft. As a result, the previously described actuation of the gas exchange valve when the engine brake is deactivated is conditioned or brought about, and when the engine brake is activated, the previously described conveying of the fluid by means of the camshaft is brought about or caused.

The valve actuation device also comprises at least one phase adjuster, by means of which the camshaft is phase adjustable, that is to say rotatable, relative to the aforementioned output shaft of the internal combustion engine. The camshaft can, for example, be driven by the output shaft and thereby rotatable about the camshaft axis of rotation. The camshaft can be rotated relative to the output shaft by means of the phase adjuster, in particular while the camshaft is coupled to the output shaft, in particular in a torque-transmitting manner. As a result, valve control times, that is to say times at which the respective gas exchange valve is actuated by means of the camshaft, can be set, that is to say changed or varied, for example by means of the phase adjuster.

The phase adjuster can be supplied with the fluid received or stored in the pressure reservoir by means of the pressure accumulator, as a result of which the phase adjuster can be used to adjust the phase of the camshaft relative to the output shaft. In other words, the phase adjuster can be supplied with the pressure fluid stored in the pressure accumulator, whereby the phase adjuster can be actuated or operated by means of the pressure fluid, and whereby the camshaft can be rotated relative to the output shaft by means of the phase adjuster. The invention thus enables a particularly cost-effective supply of the phase adjuster with the pressure fluid, so that the camshaft can be rotated, that is to say phase-adjusted, relative to the output shaft in a particularly cost-effective manner.

Since the phase adjuster can be supplied with the pressure fluid from the pressure accumulator and thus operated by means of the pressure fluid from the pressure accumulator, and since the pressure fluid is preferably a liquid, the phase adjuster, also referred to as a camshaft adjuster or camshaft adjuster, is a hydraulic phase adjuster. The invention is based on the following findings: In modern internal combustion engines, the use of hydraulic camshaft actuators to change the phase position of the camshaft is becoming increasingly difficult, in particular through optimizations in the engine oil circuit with regard to pressure and volume flow. Mechanical locking elements in the camshaft adjuster are usually used to implement an automatic start-stop system and thus, for example, in start-stop conditions, in order to ensure defined start conditions, for example when the internal combustion engine is automatically started after an automatic deactivation.

In order to be able to realize this, it is usually provided that an oil circulation system of an internal combustion engine is divided into a low-pressure circuit and a high-pressure circuit. To this end, it is usually necessary to use a corresponding pressure control on an oil pump to deliver the oil, or a pump with variable delivery capacity is used to deliver the oil. It is also conceivable to use an electrical auxiliary oil pump. In addition, camshaft adjusters with an integrated oil supply are conceivable in order to achieve a sufficiently high adjustment speed. With regard to a camshaft adjuster, it is particularly desirable to achieve high adjustment speeds with which the camshaft can be adjusted in phase.

The invention now uses the actuating element provided anyway in order to realize the above-described, in particular hydraulic, pump and consequently to bring about a sufficiently high pressure of the fluid by means of the pump and to store the fluid with the pressure in the pressure accumulator. In this way, an advantageous supply of the phase adjuster with the pressure fluid can be ensured in a simple manner, whereby sufficiently high adjustment speeds can be achieved by using the high pressure fluid to operate or actuate the phase adjuster, with which the camshaft is phase adjusted relative to the output shaft by means of the phase adjuster can be. The conveyance of the fluid into the pressure accumulator, as a result of which the fluid is stored in the pressure accumulator and is stored with the pressure in the pressure accumulator, is also referred to as charging the pressure accumulator.

The camshaft that can be adjusted by means of the phaser is, for example, an intake camshaft, by means of which at least one intake valve of the internal combustion engine can be actuated. It is also conceivable that the camshaft is an exhaust camshaft, by means of which at least one exhaust valve of the internal combustion engine can be actuated. In other words, the gas exchange valve which can be actuated by means of the camshaft can be an inlet valve or an outlet valve. In particular, it is conceivable to supply several phase adjusters with the fluid stored in the pressure accumulator, for example a first of the phase adjusters being assigned to an intake camshaft and a second of the phase adjusters to an exhaust camshaft. In this way, particularly advantageous operation of the internal combustion engine can be ensured in a particularly simple manner.

In particular, it is conceivable that the camshaft is rotated relative to the output shaft, that is to say phase adjusted, by means of the phase adjuster when the engine brake is activated in comparison to a state in which the engine brake is deactivated. In particular, it is conceivable to use the inlet camshaft and the outlet camshaft to adjust the phase adjuster at the same time, in particular when activating or deactivating the engine braking mode, by supplying the phase adjuster with the fluid from the pressure accumulator. Furthermore, it is alternatively or additionally conceivable, for example, to use the fluid from the pressure accumulator to secure the actuating element against movement from the transfer position into the conveying position or to secure the actuating element against movement from the transfer position into the conveying position.

The use of the pressure accumulator makes it possible in particular to provide a particularly large amount of the fluid having the pressure in a short time, so that switching tasks can be implemented with a sufficiently high adjustment speed. These switching tasks include, for example, activating or deactivating the engine braking mode. The switching tasks thus include, for example, a phase adjustment of the camshaft relative to the output shaft that is brought about or to be brought about by means of the phase adjuster. Alternatively or additionally, the switching tasks include securing the actuating element against movement from the transfer position into the conveying position.

The invention makes it possible to avoid pressure regulation of a pump such as an oil pump. The pump is used, for example, to convey the fluid through a fluid circuit and / or to convey the fluid, in particular via the fluid circuit, into the chamber. Furthermore, a pump with variable delivery capacity for delivering the fluid can be dispensed with, and the invention also enables an additional electrical pump to be dispensed with. As a result, the number of parts, costs, weight and space requirements can be kept particularly low.

Compared to conventional solutions, conventionally provided springs on the rocker arms can also be dispensed with, in particular by using the pressure accumulator as a hydraulic spring, for example to move the actuating element from the conveying position into the transfer position. In particular, the use of the pressure accumulator enables particularly fast switchover times or switch-on and switch-off times, for example to switch between the fired mode and the engine braking mode. In particular, the invention can be used particularly advantageously for start-stop systems or for start-stop applications.

In order to implement a particularly advantageous operation of the internal combustion engine and thereby, for example, activate and deactivate the engine braking mode in a particularly defined and needs-based manner and thus, for example, to be able to switch between the engine braking mode and the fired mode as required, it is provided in a further embodiment of the invention that the valve actuation device has at least one supply line having. The fluid conveyed from the chamber by means of the actuating element can flow through the supply line. The fluid conveyed by means of the actuating element and thereby flowing through the feed line from the chamber can be fed to and in particular into the pressure accumulator by means of the feed line. In this case, at least one valve element is arranged in the supply line, which valve element can be adjusted between at least one closed state and at least one released state. In the closed state, the supply line is blocked by means of the valve element at least in the direction of the pressure accumulator, so that no fluid can flow from the chamber via the supply line to and into the pressure accumulator. In the release state, the valve element releases the supply line at least in the direction of the pressure accumulator, so that in the release state the fluid can flow from the chamber via the supply line to and in particular into the pressure accumulator.

The closed state is a first state or is also referred to as the first state, the release state also being referred to as the second state or being a second state. The closed state corresponds, for example, to at least one closed position of the valve element, the released state, for example, corresponds to at least one released position of the valve element. In this case, for example, the valve element can be moved between the closed position and the release position, in particular translationally and / or relative to the aforementioned component.

In order to be able to activate and deactivate the engine braking mode in a particularly simple and thus inexpensive manner and thus, for example, to be able to switch between engine braking mode and fired mode, a further embodiment of the invention provides that the valve actuating device has an actuating line via which the valve element is operated by means of the pressure accumulator with the internal pressure accumulator absorbed fluid can be supplied, in particular acted upon, whereby the valve element can be adjusted from at least one of the states to the other state, in particular from the closed state to the released state. By supplying, in particular acting on, the valve element with the fluid from the pressure accumulator via the actuating line, the fluid can, for example, exert a switching force on the valve element at least indirectly, in particular directly. The valve element is switched from one state to the other by means of the switching force State, in particular from the release state to the shooting state, adjustable. As a result, a particularly simple and thus inexpensive adjustment of the valve element from one state to the other can be effected.

A further embodiment is characterized in that a valve device is arranged in the actuation line, which can be adjusted between at least one blocking state, which blocks the actuation line at least in the direction of the valve element, as the third state and at least one open state, which releases the actuation line at least in the direction of the valve element, as the fourth state . As a result, the engine braking mode can be activated and deactivated particularly as required.

It has been shown to be particularly advantageous if the valve device is designed as an electrically actuatable valve device and can thereby be adjusted from the third state to the fourth state and / or from the fourth state to the third state by means of electrical energy, in particular electrical current. As a result, an adjustment of the valve device and, as a result, an adjustment of the valve element can be effected particularly as required.

The locked state corresponds, for example, to a locked position, the open state, for example, corresponding to an open position. In this case, for example, the valve element can be moved between the blocking position and the open position, in particular translationally and / or relative to the component. As a result, the space requirement can be kept particularly low.

A second aspect of the invention relates to a method for operating a valve actuation device, in particular a valve actuation device according to the invention according to the first aspect of the invention, for actuating at least one gas exchange valve of an internal combustion engine, in particular for a motor vehicle. In the method, the valve actuating device has a rocker arm which can be pivoted about a pivot axis between at least one starting position and at least one actuating position for actuating the gas exchange valve. In the method, the valve actuation device also has an actuation element held on the rocker arm so that it can move relative to the rocker arm along a direction of movement, in particular in a translatory manner, under whose mediation the gas exchange valve can be actuated by means of the rocker arm when the rocker arm moves from the starting position into the actuating position. In addition, in the method, a chamber that is partially delimited by the actuating element, in particular directly, is supplied with a fluid, in particular with a liquid such as an oil. For this purpose, for example, the fluid is conveyed by means of a pump, in particular conveyed into the chamber.

In order to be able to implement a particularly advantageous operation of the internal combustion engine in a particularly cost-effective manner, it is provided in the second aspect of the invention that the valve actuation device has a pressure accumulator. During or as a result of or due to a movement of the rocker arm from the starting position into the actuating position, the fluid is conveyed from the chamber into the pressure accumulator by means of the actuating element. Advantages and advantageous configurations of the first aspect of the invention are to be regarded as advantages and advantageous configurations of the second aspect of the invention and vice versa.

Further advantages, features and details of the invention emerge from the following description of a preferred exemplary embodiment and with reference to the drawing.

Further advantages, features and details of the invention emerge from the following description of a preferred exemplary embodiment and with reference to the drawing. The features and combinations of features mentioned above in the description as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the single figure can be used not only in the specified combination, but also in other combinations or on their own, without the frame to leave the invention.

The single figure of the drawing shows a schematic representation of a valve actuation device according to the invention for actuating at least one gas exchange valve of an internal combustion engine for a motor vehicle.

The single FIGURE shows a valve actuation device in a schematic representation 10 for actuating at least one gas exchange valve 12th an internal combustion engine 14th , which can be seen in detail in the figure. The internal combustion engine 14th comprises the valve actuating device in its fully manufactured state 10 . For example, the internal combustion engine 14th Part of a motor vehicle which, in its fully manufactured state, includes internal combustion engine 2614 and by means of the internal combustion engine 14th is drivable. The internal combustion engine 14th has a crankcase 16 on which at least one cylinder 18th has, forms or limited. In the cylinder 18th is a piston 20th translational movably added so that the piston 20th relative to the crankcase 16 is translationally movable. The piston 20th is about a connecting rod 22nd articulated with a crankshaft shown particularly schematically in the figure 24 coupled, with the crankshaft 24 around a crankshaft rotation axis 26th relative to the crankcase 16 is rotatable. The cylinder 18th , The piston 20th and a cylinder head not shown in detail 29 each partially delimit a combustion chamber 28 the internal combustion engine 14th , the gas exchange valve 12th the combustion chamber 28 assigned. The gas exchange valve 12th is in the cylinder head in a known manner 29 kept mobile. In particular, the gas exchange valve 12th used for a charge exchange or a charge exchange of the combustion chamber 28 to control. Under the gas exchange there is an influx of air into the combustion chamber 28 and an outflow of a gas such as exhaust gas from the combustion chamber 28 to understand. For example, the gas exchange valve 12th designed as an outlet valve, via which a gas such as exhaust gas or air from the combustion chamber 28 can flow out. The previous and following explanations on the gas exchange valve 12th can, however, also easily access an inlet valve and an actuation of the inlet valve of the internal combustion engine 14th be transmitted.

The gas exchange valve 12th is along one in the figure by a double arrow 30th illustrated actuation direction relative to the crankcase 16 or to the cylinder head 29 movable between at least one closed position and at least one open position, in particular translationally. The gas exchange valve 12th is a valve spring 32 assigned, which by opening the gas exchange valve 12th , that is, by moving the gas exchange valve 12th stretched from the closed position into the open position and in particular compressed and as a result provides a spring force. The gas exchange valve is opened by means of the spring force 12th movable from the open position into the closed position and in particular to hold in the closed position.

The gas exchange valve 12th is along the actuation direction relative to the cylinder head 29 , in particular translationally, movable on the cylinder head 29 held or stored and thus along the direction of actuation relative to the cylinder head 29 translationally movable between the open position and the closed position. The cylinder head 29 is separate from the crankcase 16 formed and with the crankcase 16 connected. The cylinder head 29 forms or limits one of the gas exchange valve 12th and the combustion chamber 28 associated and for example designed as an outlet channel gas channel, in which, for example, the gas from the combustion chamber 28 via the gas exchange valve 12th can flow out, especially when the gas exchange valve 12th is open, i.e. when the gas exchange valve is open 12th is in its open position.

The valve actuator 10 includes one of the gas exchange valve 12th assigned rocker arm 34 , which around a pivot axis 36 relative to a present as an axis 38 formed component is pivotable between at least one starting position and at least one actuating position. The axis 38 is also referred to as the rocker arm axis and is a component of the valve actuation device 10 or the internal combustion engine 14th .

The valve actuating device also comprises 10 a camshaft 40 which around a camshaft axis of rotation 42 relative to the cylinder head 29 , relative to the crankcase 16 and for example relative to the component (axis 38 ) is rotatable. The axis of rotation of the crankshaft is here 26th from the camshaft rotation axis 42 spaced, the camshaft axis of rotation 42 and the crankshaft rotation axis 26th run parallel to each other. The pivot axis 36 is from the crankshaft rotation axis 26th and from the camshaft rotation axis 42 spaced and runs parallel to the camshaft axis of rotation 42 and to the crankshaft rotation axis 26th . The camshaft 40 has a cam 44 on, by means of which the rocker arm 34 , in particular via a transmission element 46 , can be actuated and is thereby in particular pivotable from the starting position into the actuating position.

In the embodiment shown in the figure, the rocker arm is actuated 34 the gas exchange valve 12th , in particular exclusively, during an engine braking operation of the internal combustion engine 14th . For example, the internal combustion engine does not take place during fired operation 14th one by means of the rocker arm 34 caused actuation of the gas exchange valve 12th . Is the rocker arm 34 As in the embodiment shown in the figure, an engine brake is assigned, the rocker arm 34 also known as brake rocker arms or engine brake rocker arms. The internal combustion engine works in the engine braking mode or during the engine braking mode 14th as an engine brake, in particular in the manner of a decompression brake, by means of which the motor vehicle can be braked, for example. This can in particular be understood to mean that a speed at which the motor vehicle is traveling is reduced and / or that an excessive increase in the speed, also referred to as the driving speed, is avoided by means of the engine brake. The gas exchange valve is activated during engine braking 12th by means of the rocker arm 34 operated in particular in the manner of a decompression brake, which is already sufficiently known from the general prior art. Again In other words, it is preferably provided that the engine brake, which is activated during engine braking operation, is designed as a decompression brake. Thus the cam is 44 preferably a so-called brake cam.

The transmission element 46 is for example a roller which is rotatable on the rocker arm 34 can be held. In one of the cams 44 different base circle phase 48 the camshaft 40 omitted by the camshaft 40 effected actuation or pivoting of the rocker arm 34 from the starting position to the actuation position, so that the rocker arm 34 by means of the cam 44 can be actuated and thus pivoted from the starting position into the actuating position. Overall it can be seen that the gas exchange valve 12th via the rocker arm 34 from or by means of the camshaft 40 operated, in particular opened, can be.

The valve actuator 10 also includes a present as a piston 50 formed actuating element, which along a direction of movement relative to the rocker arm 34 translationally movable on the rocker arm 34 is held. The direction of movement is indicated in the figure by a double arrow 52 illustrated. The piston 50 is relative to the rocker arm along the direction of movement 34 Can be moved translationally between at least one conveying position shown in the figure and at least one transmission position. At least a partial area is in the conveying position T of the piston 50 in the rocker arm 34 or within the rocker arm 34 arranged. However, at least the partial area is in the transfer position T outside of the rocker arm 34 arranged. In other words, the piston will 50 from the conveying position to the transfer position along the direction of movement relative to the rocker arm 34 moved in a translatory manner, it is thereby in the conveying position in the rocker arm 34 arranged sub-area T from the rocker arm 34 moved out along the direction of movement. Will the piston 50 along the direction of movement relative to the rocker arm 34 Moved in a translatory manner from the transfer position into the conveying position, the position in the transfer position is outside of the rocker arm 34 arranged sub-area T along the direction of movement in the rocker arm 34 moved in.

The valve actuator 10 also has a chamber shown particularly schematically in the figure 54 on, which presently at least partially, in particular at least predominantly or completely, in the rocker arm 34 arranged and in each case partially by the rocker arm 34 and through the piston 50 is limited. The chamber can be supplied with a fluid. In other words, the fluid can be introduced or introduced into the chamber. The fluid is preferably a liquid. In particular, the fluid or the liquid is an oil, also referred to as engine oil, which, for example, flows through a circuit also referred to as an oil circuit or fluid circuit. In other words, the valve actuation device 10 or the internal combustion engine 14th comprise a circuit, also referred to as a fluid circuit or an oil circuit, through which the fluid can flow. For example, a pump, not shown in the figure, is arranged in the circuit, by means of which the fluid can be conveyed or is conveyed through the circuit. If the fluid is in the form of an oil, the pump is also referred to as an oil pump.

In the figure, a channel, also referred to as an oil channel or designed as an oil channel, is particularly schematically shown 56 it can be seen which is through which the fluid, in particular the oil, can flow. For example, the channel is 56 a so-called main oil gallery, which is at least partially, in particular at least predominantly or completely, in the crankcase 16 or within the crankcase 16 runs or is recorded. In particular is the channel 56 completely circumferentially through the crankcase along its circumferential direction 16 , especially direct, limited, so that the channel 56 oil flowing through the crankcase 16 or one the channel 56 in the circumferential direction directly delimiting the wall of the crankcase 16 can touch directly.

The valve actuator 10 also includes a supply line also referred to as a supply channel 58 which across the canal 56 with which the channel 56 flowing through oil can be supplied. Thus, at least part of the channel 56 flowing oil from the channel 56 outflow and into the supply line 58 flow in and then the supply line 58 flow through. By means of the supply line 58 is that the supply line 58 oil flowing through to and in particular into the chamber 54 can be initiated so that the chamber 54 via the supply line 58 with the oil, especially from the sewer 56 , can be supplied. In the embodiment shown in the figure, the supply line branches off 58 from the canal 56 starting with the supply line 58 for example at least partially, in particular at least predominantly or completely, outside the crankcase 16 can run. It is also conceivable that the supply line 58 at least partially, in particular at least predominantly, in the crankcase 16 runs.

It can be seen from the figure that in the supply line 58 a check valve 60 is arranged, which in the direction of the chamber 54 opens and locks in the opposite direction. This enables the supply line 58 oil flowing through via the check valve 60 from the supply line 58 outflow and into the chamber 54 flow in, causing the chamber 54 with which the oil can be supplied or is supplied. However, the check valve avoids this 60 that the oil from the chamber 54 via the check valve 60 back to the supply line 58 can flow. A first pressure of the oil can, for example, be brought about by means of the oil pump. In other words, by means of the oil pump, the oil can flow through the channel at a first pressure 56 and through the supply line 58 be promoted. This first print is with p _LP and is also referred to as low pressure. This means that the chamber 54 via the supply line 58 can be or is supplied with the oil having the low pressure, in particular by means of the pump.

In order to now operate the internal combustion engine particularly advantageously in a particularly cost-effective manner 14th to be able to realize, has the valve actuation device 10 a pressure accumulator 62 on. The pressure accumulator 62 is also referred to as a pressure accumulator or is a pressure accumulator. Alternatively or additionally, there is the pressure accumulator 62 at least partially, in particular at least predominantly or completely, outside the rocker arm 34 , outside the chamber 54 and outside of the piston 50 as well as outside the gas exchange valve 12th arranged. In particular, the pressure accumulator 62 at least partially, in particular at least predominantly or completely, outside the crankcase 16 and outside the combustion chamber 28 arranged. As will be explained in more detail below, when or as a result of a movement of the rocker arm 34 the oil from the chamber from the starting position to the actuating position 54 by means of the piston 50 in the pressure accumulator 62 conveyable and subsequently in the pressure accumulator 62 recordable or storable. This can be done by means of the piston 50 , especially by pumping the oil out of the chamber 54 in the pressure accumulator 62 , one opposite the first print p _LP greater second pressure of the oil can be caused or generated, the second pressure also being referred to as high pressure. The high pressure is shown in the figure p _HP designated. The oil can with the high pressure in the pressure accumulator 62 get saved. In other words, it has in the pressure accumulator 62 stored oil to the high pressure.

It can be seen from the figure that a movement of the piston 50 from the delivery position to the transfer position to increase the volume of the chamber 54 leads or with an increase in volume of the chamber 54 accompanies or an increase in volume of the chamber 54 causes. As a result, there is movement of the piston 50 from the transfer position to the delivery position to a reduction in volume of the chamber 54 so that by moving the piston 50 the oil from the transfer position to the delivery position, which was previously via the supply line 58 into the chamber 54 was initiated by means of the piston 50 out of the chamber 54 conveyed out and into the pressure accumulator 62 is promoted into it. This movement of the piston 50 from the transfer position to the conveying position is achieved by pivoting the rocker arm 34 causes from the starting position in the actuating position. In other words, be the rocker arm 34 and with this the one on the rocker arm 34 held piston 50 by means of the cam 44 pivoted from the starting position into the actuating position, while the piston 50 is released for a movement from the transfer position into the delivery position, the piston, which is initially in the transfer position, comes into at least indirect, in particular direct, support contact with the gas exchange valve 12th . The gas exchange valve is located here 12th in its closed position or is by means of the valve spring 32 held in the closed position. The gas exchange valve exercises through the support system described above 12th in that it is by means of the valve spring 32 is held in the closed position, at least indirectly a reaction or movement force on the piston, which is initially in the transfer position 50 out. The piston becomes by means of the motive force 50 in that it is released for a movement from the transfer position into the conveying position, from the transfer position into the conveying position along the direction of movement relative to the rocker arm 34 moved translationally. This will cause it to be in the chamber first 54 located oil by means of the piston 50 out of the chamber 54 conveyed out and into the pressure accumulator 62 promoted in.

In particular is the piston 50 during the fired operation of the internal combustion engine 14th released for a movement from the transfer position into the conveying position. To activate the engine braking mode or during the engine braking mode, however, the piston is 50 secured against movement from the transfer position into the conveying position, in particular hydraulically. Then the aforementioned support system does not cause the piston 50 is moved from the transfer position to the delivery position, but the support system causes the gas exchange valve 12th with the mediation of the piston 50 by means of the rocker arm 34 against the valve spring 32 or contrary to that caused by the valve spring 32 provided spring force is actuated and is opened in the present case.

It is also conceivable that the rocker arm 34 a gas exchange valve designed as an inlet valve as a so-called inlet rocker arm 12th actuated.

The valve actuator 10 comprises at least one phaser 64 , which is also referred to as a camshaft adjuster or camshaft adjuster. Using the phase adjuster 64 can the camshaft 40 relative to the crankshaft 24 out of phase, that is, twisted. The valve actuation device comprises 10 an actuating line 66, also referred to as an actuating channel, via which the phase adjuster 64 with the oil from the pressure accumulator 62 , that is, with the one in the accumulator 62 absorbed oil can be supplied, whereby by means of the phase adjuster 64 the camshaft 40 relative to the crankshaft 24 phase adjustable, that is, rotatable. The phase adjuster instructs you to do this 64 for example chambers A. and B. on which in the circumferential direction of the phaser 64 follow one another. Via a valve unit arranged in the actuating line 66 68 can supply the phaser 64 with the oil from the pressure accumulator 62 can be adjusted as required, for example by means of the phase adjuster 64 one relative to the crankshaft 24 subsequent rotation of the camshaft 40 can be effected in a first direction of rotation and in a second direction of rotation opposite to the first direction of rotation.

There is a check valve in the control line 66 70 arranged over which the valve unit 68 and thus the phaser 64 with the oil from the pressure accumulator 62 can be supplied. The check valve 70 opens in the direction of the valve unit 68 or in the direction of the phaser 64 and locks in the opposite direction, i.e. in the direction of the pressure accumulator 62 . Thus, oil can flow out of the control line 66 via the check valve 70 to the valve unit 68 and through the valve unit 68 in the phase adjuster 64 flow, but no oil can come out of the phaser 64 via the valve unit 68 and the check valve 70 flow into the control line 66.

The valve actuator 10 also includes a return line 72 about what oil from the phaser 64 for example in a reservoir 74 can flow. For example, the oil can be taken from the reservoir 74 back into the canal using the oil pump 56 and thus into the supply line 58 be promoted. Because the oil with the opposite of the first pressure p _LP larger and also referred to as high pressure second pressure p _HP in the pressure accumulator 62 can be stored, it will be in the pressure memory 62 stored or recorded and by means of the pressure accumulator 62 Available oil also known as pressure oil. Overall, it can be seen that by means of the valve actuation device 10 the second print p _HP and thus the pressure oil can be produced in a particularly simple and therefore cost-effective, space-saving and weight-saving manner. The phaser can also 64 by means of the valve actuation device 10 in a particularly cost-effective way as well as particularly needs-based with the pressure oil from the pressure accumulator 62 are supplied. Because the pressure oil has the high, second pressure p _HP has, sufficiently high adjustment speeds can be achieved with which the camshaft 40 by means of the phase adjuster 64 relative to the crankshaft 24 twisted, that is, can be phased.

The valve actuator 10 also includes at least one of the means of the piston 50 pumped oil from the chamber 54 Passable feed line 76 by means of which or via which the means of the piston 50 funded and thereby the supply line 76 oil flowing through to and in particular into the pressure accumulator 62 is or is to be led. It is in the supply line 76 one also as a control valve 78 designated valve element arranged, which between at least one the supply line 76 at least in the direction of the accumulator 62 blocking closed state as the first state and at least one of the supply line 76 at least in the direction of the accumulator 62 releasing and releasing state shown in the figure is adjustable as a second state. The closed state corresponds, for example, to a closed position of the control valve 78 , wherein the release state with a release position of the control valve 78 corresponds.

The control valve 78 is a feather 80 assigned, which is more strongly tensioned in the closed state or in the closed position than in the released state or in the released position and consequently at least in the closed state or in the closed position provides a spring force by means of which the control valve 78 is adjustable, in particular movable, from the closed state or from the closed position into the release state or into the release position. In particular, the control valve 78 by means of the spring 80 or by means of the spring 80 provided spring force are held in the release state or in the release position, the release state or the release position being shown in the figure. The feather 80 is for example on the one hand at least indirectly, in particular directly, on the control valve 78 and on the other hand, at least indirectly, in particular directly, on the rocker arm 34 supported. It is conceivable that the control valve 78 and / or the spring 80 in the rocker arm 34 are arranged. At least part of the feed line runs here 76 through or in or within the axis 38 . Alternatively or additionally, at least part of the supply line runs 58 through and thus in or within the axis 38 . Furthermore, at least a further part of the feed line runs 76 off axis 38 and inside the rocker arm 34 . Alternatively or additionally, at least a further part of the supply line runs 58 off axis 38 and inside the rocker arm 34 .

It is also in the supply line 76 a check valve 82 arranged, which in the flow direction of the out of the chamber through the supply line 76 and at the same time to and into the pressure accumulator 62 flowing oil downstream of the control valve 78 and especially downstream of the axis 38 is arranged. Preferably the check valve is 82 , especially completely, outside of the rocker arm 34 and / or off-axis 38 arranged. The check valve 82 opens in the direction of the accumulator 62 and closes in the opposite direction and thus in the direction of the chamber 54 so that no oil goes through the check valve 82 into the chamber 54 can flow.

It can also be seen in the figure that within the axis 38 a high pressure oil gallery 84 runs which of the high pressure oil from the chamber 54 is permeable. Also, the axis points 38 a low pressure oil gallery 86 on which of the low-pressure oil from the channel 56 or from the supply line 58 is permeable. In particular, it is conceivable that at least part of the high pressure oil gallery 84 part of the supply line 76 is. Alternatively or additionally, there is at least part of the low-pressure oil gallery 86 at least part of the supply line 58 . Here is the check valve, for example 82 downstream of the high pressure oil gallery 84 arranged. Thus, for example, no oil can leave the pressure accumulator 62 via the check valve 82 into the high pressure oil gallery 84 stream. The high pressure oil gallery 84 and the low pressure oil gallery 86 run within the axis 38 and preferably outside of the rocker arm 34 .

The valve actuator 10 also includes a spring element 88 which, on the one hand, at least indirectly, in particular directly, on the piston along the direction of movement 50 and on the other hand, at least indirectly, in particular directly, on the rocker arm 34 is supportable or supported. The spring element 88 is more tensioned in the conveying position than in the transfer position, so that the spring element 88 at least in the conveying position provides a spring force acting at least indirectly, in particular directly, on the piston along the direction of movement. By means of the spring element 88 provided spring force can be the piston 50 moved from the conveying position into the transfer position and preferably held in the transfer position. The piston is thus deactivated, in particular while the engine braking mode is deactivated 50 released for a movement from the transfer position into the conveying position, and is meanwhile the rocker arm 34 pivoted from the starting position into the actuating position, the piston 50 against the spring element 88 or contrary to that of the spring element 88 provided spring force as a result of the support system described above or moved by means of the motive force from the transfer position into the conveying position. This is the spring element 88 stretched and compressed in the present case. The spring element is preferably 88 at least partially, in particular at least predominantly or completely, in the rocker arm 34 arranged. In particular, the piston 50 by means of the cam 44 respectively during the cam 44 with the transmission element 46 cooperates moved from the transfer position to the conveying position. For example, that of the spring element holds 88 provided spring force the rocker arm 34 via the transmission element 46 in cooperation with the camshaft 40 so, for example, during the base circle phase 48 The piston 50 by means of the spring element 88 or by means of the spring element 88 provided spring force from the conveying position into the transfer position along the direction of movement relative to the rocker arm 34 is moved translationally.

Overall it can be seen that the rocker arm 34 and the piston 50 used as a piston pump to get the oil out of the channel 56 about the chamber 54 , especially periodically, in the pressure accumulator 62 to promote and as a result with the high pressure in the pressure accumulator 62 save.

The valve actuator 10 has an actuation line 90 on which the control valve 78 by means of the accumulator 62 with the one in the accumulator 62 absorbed oil can be supplied, in particular acted upon. By supplying, in particular pressurizing, the control valve 78 with the oil the pressure accumulator 62 via the actuation line 90 is or will be the control valve 78 movable or moved from the release state or from the release position into the closed state, in particular against the spring 80 or contrary to that by the spring 80 provided spring force. This means that the control valve 78 by adjusting the control valve 78 is tensioned, in particular compressed, from the release state into the closed state. By pressurizing the control valve 78 with the oil from the pressure accumulator 62 via the actuation line 90 practice this, especially in the control line 90 absorbed, oil an at least indirectly, in particular directly, on the control valve 78 acting force due to the high pressure of the oil from the pressure accumulator 62 greater than the spring force of the spring 80 is. This becomes the control valve 78 contrary to that of the pen 80 provided spring force adjusted from the release state into the closed state, in particular moved.

To the control valve 78 To be able to adjust as needed is in the actuation line 90 a valve device 92 arranged, which between at least one the actuation line 90 at least in the direction of the control valve 78 blocking locked state and at least one of the actuating line 90 at least in the direction of the control valve 78 releasing open state is adjustable. In the figure, the blocking state of the valve device is shown 92 shown. The blocking state corresponds to a blocking position of the valve device 92 , wherein the open state with an open position of the valve device 92 corresponds. This means that the valve device 92 assumes the blocking position in the blocking state, the valve device 92 assumes the open position in the open state. Thus, the valve device 92 , in particular translationally and / or relative to the component, between the blocking position and the open position of the valve device 92 adjustable, in particular movable.

It can be seen from the figure that the valve device 92 a check valve 94 has, which in the blocking state in the actuation line 90 is arranged and in the direction of the control valve 78 blocks and in the opposite direction and thereby in the direction of the accumulator 62 opens. Thus, for example, in the blocking state of the control valve 78 incoming oil via the check valve 94 in the direction of the accumulator 62 or in the pressure accumulator 62 flow, but no oil from the pressure accumulator can in the blocking state 62 via the valve device 92 to the control valve 78 stream. At least a first part of the control line 90 runs for example outside of the rocker arm 34 and / or off-axis 38 . At least a second part of the control line 90 runs, for example, within the rocker arm 34 and off-axis 38 . It is also conceivable that at least a third part of the actuation line 90 within the axis 38 and especially outside of the rocker arm 34 runs. The third part comprises the actuation line 90 for example an activation oil _gallery p JB, via which the pressure accumulator 62 coming and the control line 90 oil flowing through to the control valve 78 is guided to thereby the control valve 78 via the actuation line 90 with the pressure oil from the pressure accumulator 62 to act on and then move, for example, from the release state to the closed state. This activates the engine braking mode, so that the activation oil _{gallery p JB is used} to activate the engine brake.

In the embodiment shown in the figure, the valve device 92 designed as an electrically actuatable valve device. In particular, the electrically actuatable valve device can be a solenoid valve. This allows the valve device 92 adjusted, in particular moved, with electrical energy, in particular by means of electrical current, for example from the locked state or from the locked position into the open state or into the open position. Here is the valve device 92 another feather 96 assigned, which in the open state or in the open position of the valve device 92 is stretched, in particular compressed, more strongly than in the locked state or in the locked position. This sets the spring 96 at least in the open state or in the open position of the valve device 92 a spring force ready by means of which the valve device 92 can be moved from the open state or from the open position into the locked state, in particular into the locked position and, in particular, can be held in the locked state or in the locked position. Overall it can be seen that the valve device 92 by means of electrical energy against the spring 96 or contrary to that of the spring 96 provided spring force is adjustable, in particular movable, from the locked state into the open state. The valve device is preferably 92 and / or the spring 96 completely outside of the rocker arm 34 arranged. It is also conceivable that the spring 80 inside the rocker arm 34 is arranged. Compared to traditional solutions, the piston becomes 50 by means of the spring element 88 during the base circle phase 48 not held in the conveying position and thus in a retracted position, but in the transfer position and thus in an extended position. This allows the rocker arm 34 and the piston 50 used as a piston pump to get the oil out of the chamber 54 in the pressure accumulator 62 to promote.

In other words, this and the pivoting of the rocker arm 34 the oil from the chamber from the starting position to the actuating position 54 promoted, especially during the piston, also known as a brake piston 50 at least indirectly, in particular directly, on the gas exchange valve 12th , is supported in particular at the valve end. In a closing phase, that is, when the previously moved from the starting position into the actuating position by means of the cam 44 moving rocker arms 34 back from the When the actuating position is moved into the starting position, the rocker arm, also referred to simply as a lever, is used 34 by the from the spring element 88 provided spring force, which acts at least indirectly on the brake piston, in at least an indirect support system and thus in cooperation with the camshaft 40 held, especially until the base circle phase 48 is reached.

That from the chamber 54 Pumped oil reaches the pivotable mounting of the rocker arm via at least one or more bearings, for example 34 , especially on the axis 38 , in the high pressure oil gallery 84 the axis 38 so that the oil, for example, in the high pressure oil gallery 84 is collected. In particular, for example, the oil from all chambers of all rocker arms in the high pressure oil gallery 84 collected from where the oil in the accumulator 62 is directed. The pressure accumulator 62 is on the opposite of the first print p _LP higher second pressure p _H ^p designed. Upstream of the accumulator 62 and particularly downstream of the high pressure oil gallery 84 the check valve designed as a pressure check valve sits 82 , which causes a backflow of the oil from the pressure accumulator 62 prevented. The oil and thus a volume flow of the oil that is in the pressure accumulator 62 , especially via the feed line 76 , arrives, for example, is the sum of all partial flows from all brake pistons of all rocker arms. It can also be seen that the check valve 60 acts as a suction check valve, the oil from the supply line in the aforementioned closing phase 58 or from the canal 56 into the chamber 54 lets, with the check valve 60 during a so-called opening phase, during which the rocker arm is 34 Moved from the starting position into the actuating position, the supply line 58 for the oil from the chamber 54 locks.

The oil that went into the chamber 54 is provided via a low-pressure oil supply, which the main oil gallery and the low-pressure oil gallery 86 includes. The pressure check valve is preferably not located directly in the rocker arm 34 , but preferably outside of the rocker arm 34 and off-axis 38 and preferably in front of the pressure accumulator 62 , especially before the pressure accumulator enters 62 , through whose entry the oil from the supply line 76 in the pressure accumulator 62 can flow in. As a result, an exchange of oil volume between the individual chambers or the individual rocker arms can take place, since these are each in accordance with the ignition sequence of the internal combustion engine 14th are in different lifting phases or movement phases. As a result, the total oil volume flow can be kept low. At the same time, the effort for individual check valves on the rocker arms is kept low or avoided.

Once in the accumulator 62 a certain pressure level has been or will be reached, the pressure check valve (check valve 82 ) an unlocking piston is activated, which the non-return valve 82 opens, in particular both in the direction of the accumulator 62 as well as towards the chamber 54 . This allows the oil from the pressure accumulator 62 back via the feed line 76 to and in particular to the chamber 54 , in particular via the control valve which is in the release state 78 stream. As a result, the pressure accumulator 62 act as a hydraulic spring, which for example the spring element 88 when the piston moves 50 supported from the delivery position to the transfer position. In other words, the spring element designed as a mechanical spring can be used by the hydraulic spring 88 be supported, in particular with regard to bringing about a movement of the piston from the delivery position into the transfer position, so that the spring element 88 can be dimensioned particularly small and thus space-saving and weight-saving. In addition, an overpressure valve of a high-pressure oil circuit, which may otherwise be required, can be dispensed with, since the total delivery rate becomes zero if the pressure check valve is opened. In this way, the hydraulic-mechanical efficiency of the overall system can also be improved.

When activating or switching on the engine brake, for example, the control valve 78 , which is in the rocker arm 34 on a pressure side of the chamber 54 is located, closed, that is, adjusted to the closed state. This can initially do this in the chamber 54 absorbed oil no longer, especially via the supply line 76 , out of the chamber 54 pour in. This will make the piston 50 secured against movement from the transfer position into the conveying position. In other words, there is a retraction movement of the piston 50 , which in the course of its retraction movement from the transfer position into the conveying position along the direction of movement relative to the rocker arm 34 for example can move, blocked or avoided. As a result, the gas exchange valve 12th over the piston 50 and the rocker arm 34 by means of the cam 44 be operated, in particular in the manner of a decompression brake. This means that the previously described pumping function of the piston 50 then when the control valve 78 is in the closed state, is deactivated, so that then no more oil from the chamber 54 in the pressure accumulator 62 is promoted.

When activating or switching on the engine brake, the pressure accumulator 62 unload. This means that at least part of the in the pressure accumulator 62 absorbed oil from the pressure accumulator 62 discharged and, in particular via the control line 66, to the phase adjuster 64 and, in particular, via the control line 90 , to the control valve 78 is performed to thereby on the one hand for the engine braking operation the camshaft 40 relative to the crankshaft 24 to twist and on the other hand the control valve 78 to understand from the release state to the closed state. By unloading the accumulator 62 if pressure oil is no longer available, for example. However, a shuttle valve can be used 98 the valve actuator 10 a supply of the valve device, designed for example as an electrical control valve 92 or a supply of the control valve 78 , in particular via the valve device 92 , with the low-pressure oil, especially from the channel 56 , be ensured, and via the shuttle valve 98 can supply the phaser 64 with the oil exhibiting the low pressure, in particular from the channel 56 , be ensured, in particular until the engine braking operation is ended.

When deactivating or switching off the engine brake, the control valve is 78 opened, whereby again by means of the piston 50 the oil from the chamber 54 in the pressure accumulator 62 can be pumped. Because the piston is also known as the brake piston 50 extends with spring assistance, that is, by means of the spring element 88 provided spring force is moved from the conveying position into the transfer position, whereby at least the partial area T from the rocker arm 34 is moved out, and thereby that the chamber 54 is always filled with oil, a switching time for activating the engine brake or the engine braking mode can be reduced compared to conventional systems. When the engine brake is deactivated, a switching time required to deactivate the engine brake is due to the particularly high pressure level of the oil from the pressure accumulator 62 and a correspondingly stronger return spring has a positive effect, the return spring, for example, the spring 96 and / or the spring 80 can be.

List of reference symbols

10

Valve actuator

12th

Gas exchange valve

14th

Internal combustion engine

16

Crankcase

18th

cylinder

20th

piston

22nd

Connecting rod

24

crankshaft

26th

Crankshaft rotation axis

28

Combustion chamber

29

Cylinder head

30th

Double arrow

32

Valve spring

34

rocker arm

36

Swivel axis

38

axis

40

camshaft

42

Camshaft rotation axis

44

cam

46

Transmission element

48

Base circle phase

50

piston

52

Double arrow

54

chamber

56

channel

58

supply line

60

check valve

62

Pressure accumulator

64

Phase adjuster

68

Valve unit

70

check valve

72

Return line

74

reservoir

76

Feed line

78

Control valve

80

feather

82

check valve

84

High pressure oil gallery

86

Low pressure oil gallery

88

Spring element

90

Actuation line

92

Valve device

94

check valve

96

feather

98

Shuttle valve

A.

chamber

B.

chamber

T

Sub-area

pHP

High pressure

pLP

Low pressure

PJB

Activation oil gallery

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 2425105 B1 [0002]
• US 2017/0002702 A1 [0003]

Claims (10)

Valve actuating device (10) for actuating at least one gas exchange valve (12) of an internal combustion engine (14), with at least one rocker arm (34) which can be pivoted about a pivot axis (36) between at least one starting position and at least one actuating position for actuating the gas exchange valve (12) , with at least one actuating element (50) held on the rocker arm (34) so as to be movable along a direction of movement (52) relative to the rocker arm (34), with the intermediary of which, when the rocker arm (34) moves from the starting position into the actuating position, the gas exchange valve ( 12) can be actuated by means of the rocker arm (34), and with a chamber (54) which is partially delimited by the actuating element (50) and which can be supplied with a fluid, characterized by at least one pressure accumulator (62) in which, when the rocker arm moves (34) from the starting position into the actuating position, the fluid from the chamber (54) by means of of the actuating element (50) can be conveyed. Valve actuation device (10) according to Claim 1 , characterized by a spring element (88), by means of which, when the rocker arm (34) moves from the actuating position into the starting position, the actuating element (50) can be moved along the direction of movement (52) relative to the rocker arm (34) from a conveying position into a transfer position is. Valve actuation device (10) according to Claim 2 , characterized in that the movement of the actuating element (50) from the conveying position into the transfer position causes an increase in volume of the chamber (54). Valve actuation device (10) according to Claim 2 or 3 , characterized in that at least one portion (T) of the actuating element (50) arranged in the rocker arm (34) in the conveying position moves out of the rocker arm (34) when the actuating element (50) is moved from the conveying position into the transfer position. Valve actuation device (10) according to one of the preceding claims, characterized by : - at least one camshaft (40), by means of which the gas exchange valve (12) via the rocker arm (34) and / or at least one second gas exchange valve of the internal combustion engine provided in addition to the gas exchange valve ( 14) is actuatable; and - at least one phase adjuster (64) by means of which the camshaft (40) can be phase-adjusted relative to a crankshaft (24) of the internal combustion engine (14), the phase adjuster (64) by means of the pressure accumulator (62) with that in the pressure accumulator (62) ) absorbed fluid can be supplied, whereby the camshaft (40) can be phase-adjusted relative to the crankshaft (24) by means of the phase adjuster (64). Valve actuating device (10) according to one of the preceding claims, characterized by : at least one feed line (76) through which the fluid conveyed by means of the actuating element (50) can flow, by means of which the feed line (76) conveyed by means of the actuating element (50) and thereby flowing through Fluid is to be fed from the chamber (54) into the pressure accumulator (62); and - at least one valve element (78) arranged in the supply line (76), which between at least one closing state blocking the supply line (76) at least in the direction of the pressure accumulator (62) as the first state and at least one of the supply line (76) at least in the direction of the Pressure accumulator (62) releasing release state is adjustable as a second state. Valve actuation device (10) according to Claim 6 , characterized by an actuating line (90) via which the valve element (78) can be supplied with the fluid received in the pressure accumulator (62) by means of the pressure accumulator (62), whereby the valve element (78) from at least one of the states to the other state is adjustable. Valve actuation device (10) according to Claim 7 , characterized in that a valve device (92) is arranged in the actuating line (90), which between at least one locking state blocking the actuating line (90) at least in the direction of the valve element (78) as a third state and at least one of the actuating line (90) at least is adjustable in the direction of the valve element (78) releasing open state as a fourth state. Valve actuation device (10) according to Claim 8 , characterized in that the valve device (92) is designed as an electrically actuatable valve device and is thereby adjustable by means of electrical energy from the third state to the fourth state and / or from the fourth state to the third state. Method for operating a valve actuation device (10) for actuating at least one gas exchange valve (12) of an internal combustion engine (14), in which the valve actuation device (10) has: a rocker arm (34) which can be pivoted about a pivot axis (36) between at least one starting position and at least one actuating position for actuating the gas exchange valve (12); - an actuating element (50) held on the rocker arm (34) so as to be movable relative to the rocker arm (34) along a direction of movement (52), with the intermediary of which, when the rocker arm (34) moves from the starting position into the actuating position, the gas exchange valve (12) can be actuated by means of the rocker arm (34); and - a chamber (54) which is partially delimited by the actuating element (50) and which is supplied with a fluid, characterized by a pressure accumulator (62) in which the fluid is discharged when the rocker arm (34) is moved from the starting position into the actuating position the chamber (54) is conveyed by means of the actuating element (50).

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