DE10205888B4 - Hydraulic valve actuator - Google Patents

Abstract

Hydraulic valve actuating device for a cylinder valve (4) of an internal combustion engine with
a chamber (52) having a connection device for connection to a hydraulic circuit,
a plunger (20) for actuating the cylinder valve (4), which by means of a pressurized, in at least a portion of the chamber (52) moved hydraulic fluid of the hydraulic circuit between a first end position corresponding to a closed cylinder valve (4), and a second End position corresponding to an open cylinder valve (4), is reciprocable, and
a fluid damper device (24, 38, 43, 44, 46, 68, 78), by means of which a flow of hydraulic fluid, which is coupled to the movement of the plunger (20) in the first end position in a predetermined range near the first end position, so can be limited, that the plunger (20) is braked,
characterized,
in that the damping effect of the fluid damper device (24, 38, 43, 44, 46, 68, 78) at a position of the plunger (20) in the predetermined range upon movement of the fluid damper device (20) is ...

Description

The The present invention relates to a hydraulic valve actuating device for a Cylinder valve of an internal combustion engine.

So far the valvetrain of cylinder valves of internal combustion engines, especially gasoline engines, about Camshafts. Increased Requirements for fuel consumption and / or engine power, but also with regard to a reduction of pollutant emissions require in the future, however, more flexible valve controls or Valve train concepts. In particular, parameters should be a valve control such as B. the valve opening and closing times and the valve lift preferably be freely controllable. At appropriate Valve train concepts, which are also known in English as "programmable-valve train "concepts must be designated, the camshaft of an internal combustion engine by electronically controlled actuators or valve actuators be replaced. It can be for each Cylinder valve a valve actuator be provided.

To achieve such a valvetrain electro-hydraulically actuated valve controls can be used, as for example from the DE 197 49 303 A1 are known. A corresponding valve actuating device has a chamber and a ram arranged in the chamber, which is directly coupled to a cylinder valve. The chamber above the plunger is connected to a hydraulic circuit whereby a flow of pressurized hydraulic fluid into the chamber above the plunger and a flow of hydraulic fluid from that chamber back to a reservoir of the hydraulic circuit is controllable by electrical switchable valves. Increasing fluid pressure in the chamber thereby moves the plunger and thus the cylinder valve against the force of a valve spring in an open position. A decrease in the fluid pressure then leads to a closing of the cylinder valve, inter alia, due to the force of the valve spring.

Meets the cylinder valve when closing at high speed on a valve seat in a cylinder head, However, in which the cylinder valve is arranged, excessive valve train noises are produced. Further reduces the life of both the cylinder valve and the valve seat with increasing impact velocity of the cylinder valve on the valve seat.

Of the present invention is based on the object, a hydraulic Valve actuator for a Cylinder valve of an internal combustion engine and a method for hydraulic activity to provide a cylinder valve of an internal combustion engine, at the or the excessive valve train noise and an early one Wear in the region of the valve seat can be avoided.

The Task is solved by a hydraulic valve actuator for a cylinder valve an internal combustion engine with the features of claim 1. Thus the opening behavior the valve is not adversely affected, it is provided according to the invention, that the flow of hydraulic fluid when moving within the predetermined range to the first end position more limited becomes in reverse within movement within the given range Direction. In the fiction, contemporary valve operating device it is intended that the damping effect of the liquid damper device at a position of the plunger in the predetermined range upon movement of the plunger in the direction of the first End position is greater as when moving in the opposite direction.

The Task is still solved by a method of hydraulically actuating a cylinder valve an internal combustion engine having the features of claim 15.

In the valve actuating device according to the invention is a pestle to activity the cylinder valve provided by means of a pressurized, at least a portion of the chamber moving hydraulic fluid a hydraulic circuit between two end positions back and forth is. The first end position corresponds to a closed, the second End position one open Cylinder valve. The force necessary to move the ram must not necessarily alone by the pressurized hydraulic fluid exercised but it may also, for example, the force of a valve spring contribute to the movement of the plunger of the cylinder valve. In particular the opening of the cylinder valve by a high pressure of the hydraulic fluid under compression of a valve spring of the cylinder valve, can at Drop of hydraulic fluid pressure the cylinder valve and thus the ram through the restorer Force the valve spring driven toward the first end position become.

The Valve operating device according to the invention can preferably still electrically switchable hydraulic valves for Control of the pressure of the hydraulic fluid in the valve actuator or their chamber.

According to the invention, a flow of hydraulic fluid coupled to the movement of the plunger into the first end position is limited so that the movement of the plunger coupled to this flow is decelerated. A significant slowdown he follows only in a predetermined range, so that the movement of the plunger is not slowed down in the first end position over the entire stroke of the plunger, but only in the predetermined range. In the hydraulic valve operating device according to the present invention in which flow restriction is made by the liquid damper device, depending on the construction of the liquid damper device, flow coupled to movement of the plunger to the first end position may be limited to a certain extent outside the predetermined range near the first end position However, this limitation and an associated braking of the plunger movement outside the predetermined range is lower, preferably substantially lower, than in the predetermined range.

Of the predetermined range is located near the first end position and is expediently limited by this. The size of the given In particular, the range may be determined by how much and over what route the ram braked should be, so that on the one hand, the closing behavior of the cylinder valve is not severely impaired On the other hand, but also a protection of the valve seat is achieved becomes. About that In addition, there is a connection with the fluid damper device used achievable limit on the flow of hydraulic fluid and thus the achievable delay, because within the given range a predetermined deceleration effect must be achieved.

The inventive method and the valve actuating device according to the invention So allow a very simple reduction of the impact speed a valve disc of a cylinder valve on a valve seat alone by using the for the operation used hydraulic fluid.

preferred embodiments and further developments of the invention are in the description, the Drawings and the claims described.

The damping the movement of the plunger in the given range near the first end position could in principle also during a movement of the plunger in the predetermined range from the first end position out and thus the opening behavior of the valve impaired. It is therefore preferred that the flow of hydraulic fluid when moving within the predetermined range to the first end position stronger is limited than when moving within the specified range in the opposite direction. In the valve actuating device according to the invention it is preferable that the damping effect of the liquid damper device at a position of the plunger in the predetermined range upon movement of the plunger in the direction of the first End position is greater as when moving in the opposite direction.

Basically the liquid damper device be arranged arbitrarily, as long as they are the flow of hydraulic fluid when moving to the first end position within the predetermined range limited. In particular, could they are located in an area of the chamber where no movement the plunger takes place. However, it is preferred that the chamber has a damping section and a Working section with one permanently with the connection device connected head portion, that the damping portion at a Position of the plunger between the first end position and a predetermined range corresponding Separation position by the plunger of separated from the working section and by movement of the plunger of the detachment position in the direction of the first end position reduced in size is and that the fluid damper device the damping section and a throttle device connecting it to the head section includes, with the movement of the plunger in the first end position in the predetermined area near the first end position of the river of hydraulic fluid between the damping section and the head portion is limited.

In this embodiment of the valve actuating device according to the invention, therefore, a damping section is separated from the chamber by the plunger, when the plunger is located between the first end position and a detachment position corresponding to the predetermined area. Upon movement of the plunger within the predetermined range, ie here between Abtrennposition and first end position in the direction of the first end position to the attenuation section is reduced, so that further movement of the plunger can only take place if existing in the then separated damping portion existing hydraulic fluid from the Damping section can be moved out. However, since the damping portion is separated from the chamber by the plunger, hydraulic fluid present in the damping portion can only be moved through the throttle device into the head portion connected to the connection device. By the throttle device, however, the flow of hydraulic fluid from the damping portion is limited in the head portion, so that the coupled with the flow of the hydraulic fluid movement of the plunger is decelerated to the first end position. In this case, in particular, the damping portion may be connected to the working portion when the plunger is outside the predetermined range, so that at ei ner movement of the plunger outside the predetermined range does not result in a significant limitation of the movement of the hydraulic fluid in the damping portion, which could dampen or slow down the movement of the plunger and thus the valve or.

These embodiment is characterized in particular by the fact that the plunger two at the same time Functions takes over, namely on the one hand, the operation the valve and the other the separation and reduction of the Damping section of the Liquid damper device. As a result, the structure of the valve of the valve operating device be substantially simplified, whereby the valve actuator is much easier to produce and at the same time their reliability is increased.

Prefers is the flow through the throttle device at least in a predetermined Range of pressure differences between the head portion and the damping section at one the pressure in the damping section by a predetermined first amount exceeding pressure in the Head section larger than at one, the pressure in the head section about a predetermined second Exceed amount Pressure in the damping section. This ensures that at an opening of the cylinder valve, wherein at least at times the pressure in the head portion is greater as in the damping section, the opening the cylinder valve is not or less hindered than the movement of the cylinder valve when closing.

Prefers the damping section has two Connections to the head section. The throttle device comprises a valve located in one of the connections, which seals the connection shuts off when the pressure in the damping section by a predetermined Amount greater than the pressure in the head section is.

These Formation of the damping section and allows the throttle device So the described in the last paragraph, preferred behavior the throttle device by one of two connections to the Head section can be shut off by a valve when the pressure in the damping section by a predetermined amount greater than the pressure in the head section is. This is usually during exercise of the plunger in the first end position within the given range of the case, but not when moving out of the first end position. The second Connection in which the valve is not arranged, serves as a connection, through the while the movement of the plunger in the first end position within the predetermined range hydraulic fluid flows. In this area, then the limitation of the river takes place, for which the throttle device may comprise corresponding means. In particular, the second connection can be used as a throttle, d. H. here flow-limiting device may be formed.

Especially Preferably, the valve is designed as a ball valve, on the one hand a robust closing behavior and on the other hand is easy and inexpensive to produce. The Ball valve acts in a sense as a check valve and allows so a particularly big one Difference between the limitation of the flow of hydraulic fluid at Move to the first end position and limit the movement out of the first end position.

The Throttling device with which the flow of hydraulic fluid from the damping section can be limited in the head section can be designed very differently be.

at a preferred embodiment is the second connection as a nozzle or throttle designed so that the flow of hydraulic fluid in the desired Scope is limited.

at a particularly preferred embodiment the valve actuating device according to the invention the plunger is so formed and while a reduction of the damping section so guided, that between the pestle and one Section of a wall of the chamber, a compound of the damping portion is formed to the working portion, by the hydraulic fluid from the damping section in the working section is pressable to a movement of the plunger in decelerate the first end position. The limitation of the flow of hydraulic fluid So here is the fact that the damping section during movement separated in the predetermined area and between plunger and guide the plunger a close Compound is formed by the case of a reduction of the damping section hydraulic fluid depressed becomes. As a result, then the movement of the plunger in the first end position can be braked within the given range. Together with the Section of the chamber wall takes over the plunger here So as another function, the limitation of the flow of hydraulic fluid the damping section in the working section, which in turn additional parts in the hydraulic inventive Valve actuation direction be avoided, which not only allows more cost-effective production, but also allows a more robust function.

The connection of the damping portion to the working portion by the plunger and the portion of the chamber wall can be done differently. In a preferred embodiment a hollow cylindrical head portion is provided, the interior of which forms at least part of the working portion, and the plunger has a cylindrical, at least partially insertable into the interior of the hollow cylindrical head portion, and then with the one head portion forming a gap area. The area and shape of the gap essentially determines the flow-limiting effect of the connection thus formed between the damping section and the working section. Since both hollow cylindrical areas and cylindrical areas can be produced very inexpensively with high precision, this embodiment of the valve actuating device according to the invention is particularly easy to produce.

at Another particularly preferred embodiment is also a hollow cylindrical head part provided, the interior of which at least one Part of the working section forms. However, the plunger has a cylindrical, in the interior of the hollow cylindrical head part at least partially insertable Area on, taking on the inner surface of the headboard in the area the working portion and / or on the outer surface of the cylindrical portion Recesses are provided over the the damping section is connected to the working section when the damping section is separated from the working section. The provision of recesses can be combined in particular with the formation of a gap become. However, if this is not the case, the inner surface of the Headboard at the same time as a guide for the Pestle, so that his movement performed better is. About that can out the recesses can be designed very differently to a desired one To achieve throttle behavior.

conditioned due to different operating temperatures of the engine and thus the valve can change the length of the valve, which may cause the operation the cylinder valve by the hydraulic valve actuating device according to the invention be affected could. It is therefore preferred that a clearance compensation device be provided is, with the length changes of the cylinder valve are compensatable, so that the plunger always can reach the first end position.

Especially Preferably, the plunger has a Actuator body for activity the cylinder valve and thus on the play compensation device coupled damping body on, with the the damping section is separable from the working section. In this embodiment is the length the plunger to Compensation of length changes of the cylinder valve changeable by the actuator body and the damping body against each other movable over the lash adjuster are coupled. This structure allows a particularly simple clearance compensation device spatially from the hydraulic fluid and especially separated the damping section is and their function is therefore not directly influenced.

Especially is preferred between the actuator body and the damping body Spring element arranged to a game due to a change in length of the cylinder valve. Such a device draws especially by their simplicity and thus robustness and a inexpensive Production off.

Operating body and Damping body are doing so within predetermined limits against each other. It is it is particularly preferred that the actuating body and the damping body means a snap connection are coupled against each other displaceable, so that the relative movement of actuator body and damping body is limited.

This Construction possible a particularly simple assembly of the actuating body and the damping body to a pestle.

in the With regard to a particularly simple and therefore cost-effective production the inventive hydraulic Valve actuator it is preferred that the outside diameter of the Actuator body and the maximum outside diameter equal to the damping body are big and that a leadership for the Ram a hollow cylindrical Section comprises, in which at least partially the actuating body and the damping body are guided. As a result, in particular without considerable effort a secure Leadership of Pestle with Play compensation device ensured. About that out is such a leadership particularly simple and therefore inexpensive to produce.

In the intermediate space between the damping body and the actuating body, hydraulic fluid can accumulate as a result of leaks along the guide between the damping body and the actuating body. If it is not possible to compensate for the amount of hydraulic fluid present in the intermediate space, this could impair the function of the clearance compensation device described above. It is therefore preferred that a gap present between the actuating body and the damping body is connected to the working and / or head section via a compensating valve device, by means of which at least in the first end position of the plunger hydraulic fluid from the head and / or working section into the intermediate space is feasible. The flow through the valve device itself in the open state is preferably so low that only the movement of the plunger or the pressure change of the hydraulic fluid for actuating the Cylinder valve does not lead to a significant change in the amount of hydraulic fluid in the gap. The compensation is preferably made during the long compared to the opening and closing times period during which the plunger is in the first end position.

Basically the inventive hydraulic Valve actuator for cylinder valves any internal combustion engine suitable, especially so that of gasoline or diesel engines.

preferred embodiments The invention will now be described by way of example with reference to the drawings. It demonstrate:

1 3 a sectional view through a section of a cylinder head with a cylinder valve and a section of a hydraulic valve actuating device according to the invention according to a preferred embodiment of the invention,

2 an enlarged sectional view of the head portion of the hydraulic valve actuating device in 1 in a first end position,

3 the same view as in 2 in which, however, the plunger is in a Abtrennposition, and

4 a detail view of a head portion of a hydraulic valve actuating device according to a second preferred embodiment of the invention.

In 1 is in a cylinder head 2 a cylinder valve 4 arranged by means of a hydraulic valve actuator 6 is operable.

The cylinder valve 4 is with its valve stem 8th in a corresponding bearing of the cylinder head 2 slidably mounted. The valve is between one open and one in 1 shown, closed position back and forth, where it is, inter alia, by means of a valve spring 10 , which is compressed when the valve is opened, is closable.

A valve plate 12 of the cylinder valve 4 is in the closed position of the valve on a valve seat 14 in the cylinder head 2 close to and from the valve spring 10 against the valve seat 14 drawn.

In the direction of movement of the cylinder valve 4 is located on the cylinder head 2 the hydraulic valve actuator 6 , This has a in the figures only partially shown housing 16 , a ram housing disposed therein 18 , one in the plunger housing 18 slidably arranged plunger 20 with an actuator body 22 and a damping body 24 as well as a guide nut 26 on.

The ram housing 18 and the ram guided in it 20 are in the case 16 by means of the in the housing 16 screwed in guide nut 26 held. This also serves to guide and fasten the housing 16 in the cylinder head 2 , The attachment is made such that the plunger 20 coaxial with the valve stem 8th is arranged so that the cylinder valve 4 by means of the plunger 20 is operable.

The ram housing 18 with the pestle 20 sits in a cylindrical hole 28 in the case 16 that with an input channel 30 to which an inflow of a hydraulic circuit, not shown, can be connected, and an output channel 32 , to which the low-pressure side of a hydraulic circuit can be connected, is connected.

The inflow or outflow of hydraulic fluid from or into a hydraulic circuit to the inlet channel 30 or from the outlet channel 32 is not shown in the figures, electrically operated control valves of the valve actuator 6 controllable.

One in the direction of the cylinder valve 4 pointing area of the hole 28 is through an O-ring 34 placed in a corresponding groove of the plunger housing 18 lies against the inlet duct 30 and the outlet channel 32 connected area of the hole 28 sealed.

The ram housing 18 includes a hollow cylindrical tappet guide 36 and one on the hollow cylindrical tappet guide 36 seated headboard 38 ,

The in the ram guide 36 guided pestles 20 or the actuator body 22 indicates the actuation of the valve stem 8th on its valve-side end face a coaxial pin 40 on, passing through a corresponding opening in the guide nut 26 is guided and with the valve stem 8th of the cylinder valve 4 is in contact. The pestle 20 can be as far out of the ram housing 18 be extended until the valve-side end face of the plunger 20 at the lead nut 26 strikes.

The headboard 38 and the guide mother 26 thus limit the possible movement of the plunger 20 between a first, in 1 shown end position in which the cylinder valve 4 is closed, and a second end position in which the plunger 20 maximally extended and the cylinder valve 4 is open.

In the 2 and 3 is the head area the hydraulic valve actuator 6 shown in more detail.

The ram guide 36 points in an area near the inlet channel 30 and the outlet channel 32 a reduced outer diameter, leaving a gap 41 between an inner wall of the housing 16 and an outer wall of the tappet guide 36 results in the inlet channel 30 and the outlet channel 32 lead.

The headboard 38 is formed substantially hollow cylindrical. The outer diameter of the head part 38 corresponds to the ram guide 36 at the end. The ram housing 18 therefore points in the area near the inlet duct 30 and the outlet channel 32 Overall, a reduced outer diameter, so that the gap 41 between outer wall of the tappet guide 36 and the inner wall of the housing to the end of the bore 28 continues.

At the headboard 38 is one of the ram guide 36 facing portion formed with a reduced outer diameter, the inner diameter of the tappet guide 36 equivalent. The headboard 38 sits with the shoulder formed by the outer diameter reduction on the tappet guide 36 with the reduced outside diameter area in the tappet guide 36 is arranged.

The hollow cylindrical area of the head part 38 also has a smaller inner diameter than the likewise hollow cylindrical tappet guide 36 ,

The end face of the head part 38 has a cross slot 42 on, through which the interior of the headboard 38 with the lateral outer area of the head part 38 connected is. The headboard 38 supports itself with its end face on the housing 16 from.

In the headboard 38 is still one with an arm of the Phillips 42 connected first channel 43 arranged, via a ball valve 46 with a second channel 44 connected is. The second channel 44 leads parallel to the axis of the tappet guide 36 in the interior of the ram guide 36 ,

The gap 41 between the lateral inner wall of the housing 16 and the plunger housing 18 and the cross slot 42 thus form a coherent area 50 into the inlet channel 30 and the outlet channel 32 lead.

A ball of the ball valve 46 is by a in a corresponding groove of the head part 38 arranged disc spring 48 towards the first channel 43 pressed and seals this depending on the pressure difference between the first channel 43 and the second channel 44 from.

The inlet channel 30 , the outlet channel 32 , the area 50 between the plunger housing 18 and the housing 16 , the channels 43 and 44 as well as the interiors of the headboard 38 and the ram guide 36 therefore form a chamber 52 in which the pestle 20 by means of the inlet channel 30 supplied, pressurized hydraulic fluid is movable.

As previously described, the ram comprises 20 the actuator body 22 and the damping body 24 , The damping body 24 and the actuator body 22 are slidably connected to form a lash adjuster relative to each other.

For this purpose, the actuator body 22 at his the damping body 24 facing the end of a tubular approach 53 on, whose outer diameter is smaller than the inner diameter of the tappet guide 36 , In the area of the free end of the tubular extension 53 is a circumferential rib 54 educated.

In the damping body 24 is at his, the actuator body 22 facing the end of a pot 56 formed, the inner diameter of the outer diameter of the tubular extension 52 at the height of the rib 54 corresponds, so that this and thus also the actuator body 22 in the pot 56 is guided.

In the pot wall is a circumferential groove 58 educated. One over the rib 54 pushed circlip 60 is in this groove 58 engaged, so that the actuator body 22 opposite the damping body 24 limited by the distance between the groove 58 and the bottom of the pot 56 as well as the distance between the rib 54 and the end face of the operating body 22 is reciprocable. The snap ring 60 together with the rib 54 prevents too wide movement of the actuator body 22 from the damping body 24 path. The use of the snap ring allows a very simple installation of the plunger 20 from the actuator body 22 and the damping body 24 because these need only be pushed one upon the other, with the rib 54 over the snap ring 60 snaps.

Inside the tubular neck 53 and in a recess in the bottom of the pot 56 is a play compensation pen 62 arranged, which is the actuator body 22 from the damping body 24 pushes.

Between the damping body 24 and the actuator body 22 is such a gap 64 formed whose volume from the distance of the beta actuating body 22 from the damping body 24 depends.

The damping body 24 points to its the headboard 38 facing end face a cylindrical approach 66 on, whose outer diameter is slightly smaller than the inner diameter of the head part 38 , In the area of the end face of the damping body 24 in which these are in the cylindrical approach 66 goes over, is a circumferential throat 70 educated. Between the cylindrical approach 66 and the inner wall of the head part 38 So there is a gap 68 when the damping body 24 in a corresponding position.

It will now be the operation of the hydraulic valve actuating device 6 described.

To explain the function be in the chamber 52 a head section 72 which is the area of the chamber 52 that contains hydraulic fluid when the plunger 20 in the first end position, but not the second channel 46 includes, a work section 74 the chamber 52 that except the second channel 46 during the movement of the plunger 20 maximum part of the chamber accessible to hydraulic fluid 52 includes, as well as a damping section 76 Are defined. The damping section 76 covers the area of the chamber 52 that is between the ball valve 46 and the pestle 20 in a position between the first end position and a, in 3 shown detachment position of the plunger 20 is formed. In this Abtrennposition is the end face of the cylindrical projection 66 at the height of the cylinder valve 4 facing end face of the head part 38 ,

One for a deceleration of the plunger 20 and thus the cylinder valve 4 predetermined range of plunger positions is the area between the first end position and the detachment position. In this area of the plunger positions is the damping section 76 from the head section 72 through the cylindrical approach 66 separated, with only one connection across the gap 68 between the cylindrical approach 66 and the inner wall of the headboard 38 given is.

As in 1 recognizable, corresponds to the first end position of the plunger 20 a closed cylinder valve 4 , In this first end position is, as in 2 shown the ball valve 46 by the pressure of the disc spring 48 closed. Furthermore, the damping body is located 24 at the headboard 38 at.

When increasing the pressure of the hydraulic fluid in the chamber 52 becomes the pestle 20 in the direction of the cylinder valve 4 moves, which opens it. Due to the increased pressure in the first channel 43 and one by the movement of the damping body 24 resulting negative pressure in the second channel 44 becomes the ball valve 46 open, allowing hydraulic fluid through both the first channel 43 and the second channel 44 as well as the interior of the headboard 38 can flow. This will cause a quick opening of the cylinder valve 4 guaranteed.

Moves the plunger 20 beyond the separation position towards the second end position in which the plunger 20 maximally extended and the cylinder valve 4 is opened, the damping section 76 with the head section 72 connected, so that hydraulic fluid together with the plunger 20 unhindered in the direction of the second end position of the plunger 20 can move.

During this movement of the plunger 20 and thus the cylinder valve 4 becomes the valve spring 10 pressed together.

If the pressure of the hydraulic fluid is now reduced, the valve spring pushes 10 the cylinder valve 4 back to the closed position, causing the plunger 20 towards the headboard 38 is moved. This is in the working section 74 contained hydraulic fluid through the chamber 52 and in particular the outlet channel 32 pressed back into the hydraulic circuit. This backflow of hydraulic fluid is carried out until reaching the Abtrennposition practically without much attenuation, as to the entire inner cross section of the head part 38 is available.

Now reaches the damping body 24 the separation position becomes the damping section 76 from the working section 74 separated and in a further movement of the damping body 22 reduced in the direction of the first end position (see. 3 ).

In this case, hydraulic fluid is in the damping section 76 through the gap 68 between the cylindrical approach 66 and the inner wall of the headboard 38 pressed, causing the flow of hydraulic fluid from the damping section 76 into the working section 74 is severely limited (cf. 2 ). This results in a deceleration of the movement of the plunger given only in the predetermined range between the detaching position and the first end position and only in the direction of movement to the first end position 20 , This also causes the movement of the cylinder valve 4 towards the valve seat 14 dampened, leaving the cylinder valve 4 or the valve disk 12 only with comparatively low speed on the valve seat 14 impacts.

The play compensation spring 62 that the actuator body 22 and the damping body 24 out presses each other, thereby ensuring that the damping body 24 within given tolerances of the length of the valve stem 8th always reached the Abtrennposition and in particular the first end position.

The damping or the deceleration effect can be achieved by a suitable choice of the outer diameter of the damping body 24 , the inner diameter of the head part 38 , the height of the cylindrical approach 66 and the width and design of the gap 68 vote. Here, the design of the gap 68 in particular by a bevel of the damping body 24 facing edge of the headboard 38 and the shape of the throat 70 to be changed.

In 4 a second embodiment of a valve operating device according to the invention is shown.

The Valve actuator according to a second embodiment differs from the valve operating device just described in the training of the lash adjuster. The main difference consists in the formation of the damping body, so that for all others Parts of the valve actuator the same reference numerals can be used as before.

The damping body 78 , otherwise the damping body 24 corresponds, has a coaxially arranged compensation channel 80 put in a ball valve pot 82 which ends in the bottom of a pot 56 in the first embodiment corresponding pot 84 is trained.

The ball valve pot 82 has a shoulder running along its wall 86 on, on which a substantially cylindrical closure body 88 seated.

The closure body 88 , the outer diameter of the inner diameter of the Kugelventiltopfs 82 corresponds to the opening is in the ball valve pot 82 pressed.

In between the closure body 88 and the bottom of the ball valve pot 82 trained space is a ball valve as a compensation valve 90 arranged, whose ball by a ball valve spring 92 against the equalization channel 80 is pressed. The ball valve spring 92 relies on the closure body 88 from

The closure body 88 also has another compensation channel 94 on that the equalization channel 80 and the adjoining portion of the ball valve pot 82 with the beyond the closure body 88 lying portion of the ball valve pot 82 and the interior of the tubular extension 53 of the actuator body 22 combines.

Furthermore, the closure body is used 88 the positioning of the play compensation spring 62 and the ball valve spring 88 what he appropriate pin 96 and 98 has at its ends.

The connection of actuator body 22 and damping body 78 as well as the function of the play compensation spring 62 correspond to those in the first embodiment.

The gap 64 between the actuator body 22 and the damping body 78 However, here is filled with hydraulic fluid, with a balance of the hydraulic fluid volume in the intermediate space 64 with the head section 72 over the further equalization channel 94 , the ball valve 90 and the equalization channel 80 is possible.

The cross section of the compensation channel 80 is so small that during the opening and closing phases, ie the movement of the plunger 20 , no significant flow of hydraulic fluid through the compensation channel 80 occurs. However, during rest periods during which the hydraulic valve actuator is not moved, which is about 75% of the time, the amount of fluid may be equalized.

In the first end position presses the play compensation spring 62 the damping body 78 to the end face of the head part facing it 38 , Through the equalization channel 80 and the ball valve 90 entering liquid then allows filling of the gap 64 as far as this is necessary due to the pressure conditions. The closure body 88 limits the maximum stroke of the ball valve 86 ,

2

cylinder head

4

Rotary valve

6

hydraulic Valve actuator

8th

valve stem

10

valve spring

12

valve disc

14

valve seat

16

casing

18

tappet housing

20

tappet

22

operating body

24

damping body

26

lead nut

28

cylindrical drilling

30

inlet channel

32

exhaust port

34

O-ring

36

tappet guide

38

headboard

40

spigot

41

gap

42

Phillips

43

first channel

44

second channel

46

ball valve

48

Woodruff

50

Area between tappet guide and casing

52

chamber

53

tubular approach

54

rib

56

pot

58

groove

60

snap ring

62

Clearance compensation spring

64

gap

66

cylindrical approach

68

gap

70

throat

72

header

74

working section

76

damping section

78

damping body

80

compensation channel

82

Ball valve pot

84

pot

86

shoulder

88

closure body

90

ball valve

92

Ball valve spring

94

Another compensation channel

96

spigot

98

spigot

Claims (15)

Hydraulic valve actuating device for a cylinder valve ( 4 ) an internal combustion engine with a chamber ( 52 ), which has a connection device for connection to a hydraulic circuit, a plunger ( 20 ) for actuating the cylinder valve ( 4 ), which by means of a pressurized, in at least a portion of the chamber ( 52 ) hydraulic fluid of the hydraulic circuit between a first end position, the a closed cylinder valve ( 4 ) and a second end position corresponding to an open cylinder valve ( 4 ), is reciprocable, and a liquid damper device ( 24 . 38 . 43 . 44 . 46 . 68 . 78 ), by means of which a flow of hydraulic fluid associated with the movement of the plunger ( 20 ) is coupled in the first end position in a predetermined region near the first end position, can be limited so that thereby the plunger ( 20 ) can be braked, characterized in that the damping effect of the liquid damper device ( 24 . 38 . 43 . 44 . 46 . 68 . 78 ) at a position of the plunger ( 20 ) in the predetermined range during movement of the plunger ( 20 ) is greater in the direction of the first end position than in the reverse direction. Hydraulic valve actuating device according to claim 1, characterized in that the chamber ( 52 ) a damping section ( 76 ) and a working section ( 74 ) with a head section permanently connected to the connection device ( 72 ), that the damping section ( 76 ) at a position of the plunger ( 20 ) between the first end position and a detachment position corresponding to the predetermined area by the plunger ( 20 ) of the working section ( 74 ) separated and by movement of the plunger ( 20 ) is reducible from the separation separation position toward the first end position, and that the liquid damper device ( 24 . 38 . 43 . 44 . 46 . 68 . 78 ) the damping section ( 76 ) and one with the head section ( 72 ) connecting throttle device ( 24 . 38 , 68 . 78 ), with which upon movement of the plunger ( 20 ) in the first end position in the predetermined region near the first end position of the flow of hydraulic fluid between the damping portion ( 76 ) and the head section ( 72 ) is limited. Hydraulic valve actuating device according to claim 3, characterized in that the flow through the throttle device ( 24 . 38 , 68 . 78 ) at least in a predetermined range of pressure differences between the head portion ( 72 ) and the damping section ( 76 ) at a pressure in the damping section ( 76 ) by a predetermined first amount exceeding pressure in the head portion ( 72 ) is greater than the pressure in the head section ( 72 ) by a predetermined second amount exceeding pressure in the damping portion ( 76 ). Hydraulic valve actuating device according to claim 2 or 3, characterized in that the damping section ( 76 ) two compounds ( 43 . 44 . 68 ) to the head section ( 72 ), and that the throttle device ( 24 . 38 , 68 . 78 ) in one of the compounds ( 43 . 44 ) arranged valve ( 46 ) having the compound ( 43 . 44 ) shuts off when the pressure in the damping section ( 76 ) by a predetermined amount greater than the pressure in the head portion ( 72 ). Hydraulic valve actuating device according to claim 4, characterized in that the Valve a ball valve ( 46 ). Hydraulic valve actuating device according to one of claims 1 to 5, characterized in that the plunger ( 20 ) and during a reduction of the attenuation section ( 76 ) is guided so that between the plunger ( 20 ) and a portion of a wall of the chamber ( 52 ) a connection ( 68 ) of the damping section ( 76 ) to the working section ( 74 ) is formed by the hydraulic fluid from the damping section ( 76 ) into the working section ( 74 ) is pressable to a movement of the plunger ( 20 ) decelerate to the first end position. Hydraulic valve actuating device according to claim 6, characterized in that a hollow cylindrical head part ( 38 ) is provided, the interior of which at least a part of the working section ( 74 ), and that the plunger ( 20 ) a cylindrical, in the interior of the hollow cylindrical head part ( 38 ) at least partially insertable, and then with the head part ( 38 ) a gap ( 68 ) forming area ( 66 ) having. Hydraulic valve actuating device according to claim 6 or 7, characterized in that a hollow cylindrical head part ( 38 ) is provided, the interior of which at least a part of the working section ( 74 ), and that the plunger ( 20 ) a cylindrical, in the interior of the hollow cylindrical head part ( 38 ) at least partially insertable region, wherein on the inner surface of the head part ( 38 ) in the area of the working section ( 74 ) and / or on the outer surface of the cylindrical portion recesses are provided, via which the damping portion ( 76 ) with the working section ( 74 ) is connected when the damping section ( 76 ) of the working section ( 74 ) is separated. Hydraulic valve actuating device according to one of Claims 1 to 8, characterized by a clearance compensation device ( 60 . 62 . 80 . 90 . 92 . 94 ), with the length changes of the cylinder valve ( 4 ) are compensatable so that the plunger ( 20 ) can always reach the first end position. Hydraulic valve actuating device according to claim 9, characterized in that the plunger ( 20 ) an actuating body ( 22 ) for actuating the cylinder valve ( 4 ) and thus via the lash adjuster device ( 60 . 62 . 80 . 90 . 92 . 94 ) coupled damping body ( 24 . 78 ), with which the damping section ( 76 ) of the working section ( 74 ) is separable. Hydraulic valve actuating device according to claim 10, characterized in that between the actuating body ( 22 ) and the damping body ( 24 . 78 ) a spring element ( 62 ) is arranged. Hydraulic valve actuating device according to claim 10 or 11, characterized in that the actuating body ( 22 ) and the damping body ( 24 . 78 ) by means of a snap connection ( 54 . 58 . 60 ) are mutually displaceable coupled. Hydraulic valve actuating device according to one of claims 10 to 12, characterized in that the outer diameter of the actuating body ( 22 ) and the maximum outer diameter of the damping body ( 24 . 78 ) are the same size, and that a leadership ( 18 ) for the pestle ( 20 ) comprises a hollow cylindrical portion in which at least partially the actuating body ( 22 ) and the damping body ( 24 . 78 ) are guided. Hydraulic valve actuating device according to one of claims 10 to 13, characterized in that a between the actuating body ( 22 ) and the damping body ( 78 ) existing space ( 64 ) with the work and / or head section ( 74 . 72 ) via a compensating valve device ( 80 . 90 . 94 ) is connected by means of which in the first end position of the plunger ( 20 ) Hydraulic fluid from the head and / or working section ( 72 . 74 ) into the space ( 64 ) is feasible. Method for the hydraulic actuation of a cylinder valve ( 4 ) an internal combustion engine, in which by changing the pressure of a hydraulic fluid to form a flow of hydraulic fluid, a plunger ( 20 ) between a first end position corresponding to a closed cylinder valve ( 4 ) and a second end position corresponding to an open cylinder valve ( 4 ), is reciprocated, and in which one with the movement of the plunger ( 20 ) in the first end position in a predetermined region near the first end position coupled flow of hydraulic fluid is limited so that thereby the plunger ( 20 ) is substantially slowed down only in the predetermined range, characterized in that the flow of the hydraulic fluid is more limited when moving within the predetermined range in the first end position than when moving within the predetermined range in the reverse direction.