AT522750A1 - VARIABLE VALVE DRIVE DEVICE - Google Patents

Abstract

The invention relates to a variable valve drive device (1) for the variable control of valves (2) of an internal combustion engine, the valve drive device (1) having at least one lever (3) which can be pivoted about an axis of rotation (D) and which has a first end (3a) at a valve (2) for its actuation and at least one second end (3b) rests against a transmission device (100, 100 ') for transmitting cam lobes of a camshaft (5a), the transmission device (100, 100') having at least one tappet ( 4) and a scanning lever (6, 6 ') articulated to the plunger (4) via an articulation axis (4f), the scanning lever (6, 6') having at least one first point of application (6a) which is connected to the camshaft ( 5a) can be brought into contact, and has at least one second point of application (6b, 6b ') for an actuating element (10, 10'; 20; 30, 30 '; 40, 40'; 50, 50 '; 60, 60') .

Description

The invention relates to a variable valve drive device for the variable control of valves of an internal combustion engine, the valve drive device having at least one lever which can be pivoted about an axis of rotation and which has a first end on a valve for its actuation and at least a second end on a transmission device for transmitting cam lobes a camshaft. The invention also relates to an internal combustion engine

at least one such variable valve train device.

The invention also relates to an internal combustion engine with at least one such valve drive device.

Valve drive devices are used for the gas exchange in internal combustion engines, the valves opening and closing the inlet and outlet channels. The movement of the valve is triggered by the rotation of a camshaft and this displacement is caused by transmission elements from the camshaft to the

Transfer valve.

With conventional valve trains, the opening duration and stroke of the valve are permanently assigned to a specific crank angle of the internal combustion engine. However, in order to achieve an increase in efficiency depending on the respective operating point of the internal combustion engine, there has long been an endeavor to provide variable valve trains for engines of any type, in particular for commercial vehicles, trucks, rail vehicles such as locomotives or for ships. Here is that

Aim to achieve a high degree of variability in a simple way.

This variability is achieved, for example, by means of electromechanically or hydraulically actuated valve drive devices. The valves are operated directly. The valves directly actuated in this way can thus be individually controlled individually. What these systems have in common, however, is that, due to the required reaction or Switching times are unsuitable for high speeds. Furthermore, these directly operated valves are very expensive.

An effective means of providing two different control curves for a valve to achieve the variability described is with the use of each

given two scanning levers. The two pick-up levers alternately transmit the curve

a first control cam of the camshaft or a second control cam of the

Camshaft.

Switching between these two scanning levers is easy to implement, for example by means of a hydraulic locking element. Due to the simple possibility of switching between the couplings with the camshaft are

these variants are also suitable for high speeds.

Such variable valve trains are for example from DE 100 60 890 A1,

US 2006/0086330 A1 and DE 103 10 220 A1 are known. Two levers - or at least one two-part lever - are provided, each lever or part being assigned to different cams of the camshaft and, in this way, the respective control cam on the valve when blocked by a blocking element

is transmitted.

The disadvantage of such variable valve drive devices, however, is that the valve lift and the valve opening duration are determined solely by the geometry of the cam and can only be varied between these two control cams. In addition, the two scanning levers can only be locked in certain locked positions. For example, in DE 100 60 890 A1, the two locking levers must be arranged in a first position in which the locking pin locks the movement of the two scanning levers relative to one another. An overlay of the

both control cams by the scanning lever is also not possible.

Furthermore, these solutions do not or cannot deactivate individual valves

difficult to realize.

The object of the present invention is to eliminate the disadvantages of the known prior art and to provide a valve drive device for the variable actuation and / or activation and deactivation of a valve or a valve group

to provide.

This task is accomplished by a variable valve train device of the introduction

mentioned type according to the invention in that the transmission device has at least one tappet and a scanning lever articulated to the tappet via a pivot axis, the scanning lever having at least a first

Has point of application that can be brought into contact with the camshaft, and

has at least one second point of application for an actuating element.

The contact of the transmission device with the camshaft can be varied or also deactivated by the actuatable scanning lever, whereby the variability of the valve drive device according to the invention can be realized. The

mechanical design allows fast switching times.

The lever of the valve drive device is favorably as a rocker arm or

Rocker arm executed.

The scanning lever is advantageously arranged pivotably at least about the articulation axis and can be brought into and out of engagement with the camshaft by the actuating element, the articulation axis preferably being oriented normal to a longitudinal axis of the tappet. This enables the complexity of the valve drive device to be reduced. The scanning lever can be brought into engagement with the camshaft, so that cam lobes of the camshaft are passed on to the transmission device and the lever, or are brought out of engagement, whereby the cam lobes of the

Do not affect the camshaft on the transmission device or the lever.

In order to utilize the lever as much as possible and to provide a favorable arrangement, it is provided in a special embodiment that the scanning lever is connected in an articulated manner to the actuating element in the second point of application on a side remote from the plunger. Jointly connected here means that the scanning lever and / or the actuating element can each execute movements around the second point of application independently of one another.

A particularly simple possibility for contacting the lever and tappet and particularly high variability of the valve drive device results when two transmission devices are provided and the lever has two thumbs on the camshaft side for interacting with the tappets. The two thumbs

then act as the second ends of the lever.

To prevent noise and damage during operation, the plunger is advantageously by the force of a spring in the direction of the

Camshaft pressed.

In a variant, the plunger is arranged in a guide and is movably guided in the direction of its longitudinal axis. The guide is preferably fixed to the housing with respect to the plunger. This means that the guide cannot move even if the ram is moved during operation. The guide is particularly preferably arranged in a fixed manner within an internal combustion engine in which the valve drive device is used. In particular, the guide is designed so that the movement of the plunger takes place in a plane that is defined by the

The longitudinal axis of the tappet and a longitudinal axis of the crankshaft is spanned.

In a further variant of the invention, the guide has at least one, preferably two opposite slots running parallel to the longitudinal axis of the tappet for receiving a pin arranged in the tappet and extending transversely to its longitudinal axis. The pin is preferably arranged normal to the longitudinal axis of the plunger. The pin expediently protrudes beyond the outer surface of the plunger or is designed to be raised above its outer surface. This ensures engagement in the slot or slots. In this way, the tappet can be guided and rotation of the tappet is prevented, so that there is a security against rotation. The slots preferably only extend over part of the longitudinal extent

the leadership. This limits the movement of the plunger in the guide.

For better guidance of the scanning lever and to limit its rotation and / or displacement, it is expediently provided that each scanning lever has a support surface which can be brought into engagement with a machine-fixed support element of an internal combustion engine, in order to pivot the scanning lever about the articulation axis, preferably a pivoting of the Sensing lever to limit the articulation axis in an engagement position with the camshaft. The support surface and the support element are designed so that they slide

can be led to each other.

It is particularly favorable if the actuating element has a pneumatic and / or electrical and / or hydraulic actuator in order to bring the scanning lever into and out of engagement with the camshaft.

In a variant, the actuating element has a rotatable actuating shaft and an actuating rod articulated therewith, wherein the

Operating rod articulated with the second point of application of the scanning lever

is connected and the scanning lever can be brought into and out of engagement with the camshaft by moving the actuating element by rotating the actuating shaft. Due to the purely mechanical transmission, a particularly fast change between the positions can be realized, since dead times are only caused by elasticities in the material.

In order to prevent the individual components from lifting off from one another in a particularly simple manner, which can lead to the development of noise and wear, a further variant provides that the actuating rod comprises at least one spring element that connects the actuating rod between the scanning lever and the actuating shaft

biases.

In order to prevent, for example, switching outside the base circle phase in a simple manner, at least one locking device is advantageously provided which can be brought into engagement with a scanning lever and / or an actuating element for locking its movement.

The locking device can advantageously be actuated via at least one control shaft.

In one variant, the locking device has at least one displaceable locking element which with a stop on the actuating element in and out

Can be brought into engagement.

In a further variant, the locking device has at least one rotatable locking pawl that engages and disengages with a stop on the actuating element

can be brought.

In order to optimize the valve train with regard to weight and costs, it is advantageous if the pawl can be moved and / or rotated by an activation element via which the pawl can be connected to the camshaft, the camshaft having control bumps for actuating the activation element. This can save a separate control shaft and its tasks from the

Camshaft are also taken over.

The object of the invention is also achieved by an internal combustion engine mentioned at the beginning with at least one variable valve drive device of the above

mentioned type solved.

The invention is described below with reference to the non-limiting exemplary embodiments in the figures. Show in it:

1 shows a valve drive device according to the invention in a first position for transmitting a cam lift to a valve;

1a shows a valve drive device according to the invention in a variant for transmitting two different cam strokes to a valve in a first one

Execution in a first position;

1b shows a detail of the valve drive device according to FIG. 1a;

1c shows a sectional view of an actuating rod of a valve drive device according to FIG. 1a, the section being carried out through a pin in the actuating rod;

2a shows the valve drive device according to FIG. 1a in a second position; FIG. 2b shows a detail of the valve drive device according to FIG. 2a;

3 shows the valve drive device according to FIG. 1a and FIG. 2a in a plan view;

4 shows a valve drive device according to the invention in a variant for

Transmission of two different cam strokes to one valve in a second

Execution in a first position;

FIG. 5 shows the valve drive device from FIG. 4 in a second position; FIG.

5a shows a sectional view of an actuating rod of a valve drive device according to FIG. 5, the section being carried out through a pin in the actuating rod;

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6 shows a valve drive device according to the invention in a variant for

Transmission of two different cam strokes to one valve in a third

Execution; 7 shows the valve drive device according to the third embodiment in plan; 8 shows a valve drive device according to the invention in a variant for

Transmission of two different cam strokes to one valve in a fourth

Execution in a first position;

9 shows the valve drive device in a fourth embodiment in a second position;

10 shows the valve drive device according to the fourth embodiment in plan; 11 shows a valve drive device according to the invention in a variant for

Transmission of two different cam strokes to one valve in a fifth

Execution;

11a shows a detail from FIG. 11 in a sectional view along the line XI-XI in

11, the outlines being shown only schematically in the section;

12 shows the valve drive device according to the fifth embodiment in plan; 13 shows a valve drive device according to the invention in a variant for

Transmission of two different cam strokes to one valve in a sixth

Execution;

14 shows the valve drive device according to the sixth embodiment in plan;

15 shows a valve drive device according to the invention in a variant for

Transmission of two different cam strokes to a valve in a seventh embodiment; and

16 shows the valve drive device according to the seventh embodiment in

Layout,

1 shows a first variant of a valve drive device 1 according to the invention for transmitting a cam lift to a valve 2. In the embodiment shown, the valve 2 is designed as a poppet valve. Here, the valve 2 can be provided for releasing an inlet channel or an outlet channel. When the valve 2 is opened, the combustion chamber of an internal combustion engine (not shown in detail) is connected to it

Channel connected to the flow and the gas exchange takes place.

Cam lobes of cams 5 on a camshaft 5a are over the

Transfer valve drive device 1 to valve 2 or not transfer it.

The valve 2 is arranged adjacent to the first end 3 a of a lever 3 pivotable about an axis of rotation D. In the embodiments shown, the lever 3 is designed as a rocker arm, but in alternative designs it can also be designed as a rocker arm. The lever 3 rests with a second end 3b

a plunger 4 of a transmission device 100.

By means of the transmission device 100, the cam elevations of the camshaft 5a can be transmitted to the valve 2 via the lever 3. For this purpose, the transmission device 100 has the plunger 4, a scanning lever 6 articulated to the plunger 4 via an articulation axis 4f, and an actuating element 10

on.

The scanning lever 6 is arranged to be pivotable about the articulation axis 4f and has a first point of application 6a which - for example via a roller body 6c, which has its center in the first point of application 6a - is in contact with the camshaft 5a

can be brought. The roller body 6c rests on contact with the camshaft 5a.

The actuating element 10 acts on the scanning lever 6 via a second point of application 6b, in particular via an articulated connection. Depending on the action of the actuating element 10, the scanning lever 6 is with the

Camshaft 5a engaged or not and the cam lobes of the

Camshaft 5a are transmitted to valve 2 or not. In other words, the scanning lever 6 is connected to the camshaft 5a by the actuating element 10

and disengageable. With the transmission device 100, the

Achieve variability of the valve train device 1 according to the invention.

The tappet 4 of the transmission device 100 is arranged inside a guide 4a, which is fixedly arranged with respect to the tappet 4, e.g. in the crankcase of the internal combustion engine, and is slidably guided along its longitudinal axis A. At its upper, lever-side end, the guide 4a has a stop 4c which essentially acts as an element delimiting the cross-section of the guide 4a

is executed.

The tappet 4 has a first section 41 which is rod-shaped and, when used as intended, is located in the area of the tappet 4 facing the lever 3. A second section 42, which is designed as a hollow cylinder in the illustrated embodiment, is located in the area of the tappet 4 facing the camshaft 5a. The diameter of the first section 41 is made smaller in the illustrated embodiment than the diameter of the second section 42. At the transition between the first 41 and the second section 42 thus result in a shoulder 43.

A spring 4b is arranged around the first section 41 of the tappet 4 facing the rocker arm 3. The spring 4b rests with one end on the stop 4c implemented in the guide 4a and with its other end on the

Paragraph 43, which forms the transition between the first 41 and the second section 42 of the plunger 4. This spring 4b turns the plunger 4 into

Pushed toward the camshaft 5a.

In order to limit the movement of the tappet 4 in the direction of the camshaft 5a caused by the spring 4b, the guide 4a has two slots 4e running parallel to the longitudinal axis A of the tappet 4, whereby only one or more such slots 4e can be provided. The slots 4e are in the illustrated embodiment in the area of the camshaft 5a facing

Run 4a. In the slots 4e is arranged in the plunger 4

Pin 4d out. This pin 4d is arranged transversely, in particular normal to the longitudinal axis A of the tappet 4 and protrudes beyond the outer surface of the tappet 4 into the slots 4e. In addition to limiting the movement of the tappet 4 in the direction of the camshaft 5a, the pin 4d also serves to prevent the tappet 4 from rotating

in the guide 4a.

The scanning lever 6 is provided between the camshaft 5a and the tappet 4. The articulation axis 4f, via which the scanning lever 6 is articulated to the plunger 4, is oriented essentially normal to the longitudinal axis A of the plunger 4.

Articulated connection here means that the plunger 4 and scanning lever 6 can be moved independently of one another about the articulation axis 4f.

The positions of the articulation axis 4f, the first point of application 6a and the second point of application 6b define a triangle in the illustrated embodiment. The scanning lever 6 also has a substantially triangular shape. In the embodiment shown, the second point of application 6b is on one of the plunger 4

or the articulation axis 4f located at the furthest position.

By means of the actuating element 10, the scanning lever 6 can be pivoted about the articulation axis 4f. A first position corresponds to an engagement position with the camshaft 5a, in which the cam lobes of the cam 5 can be transferred to the valve 2. In a second position, the scanning lever 6 is out of engagement with the camshaft 5a, so no cam elevations are transmitted. In order, in particular, to make it easier or repeatable to design and define the assumption of the first position, the engagement position, the scanning lever 6 has a support surface 7. The support surface 7 is opposite the second point of application 6b on the scanning lever 6, that is, between the

Articulation axis 4f and the first point of application 6a, positioned.

When the scanning lever 6 is pivoted, the support surface 7 can be brought into engagement with a support element 7a, so that the pivoting about the articulation axis 4f is limited. The support element 7a is arranged fixed to the machine with respect to the plunger 4 or the scanning lever 6, that is to say immobile. In particular, the support element 7a is designed as a part of the internal combustion engine fixed to the housing, in which the inventive

Valve drive device 1 is used.

When the scanning lever 6 is pivoted, the support surface 7 cooperates with the support element 7a in such a way that the pivoting is ended in a position which corresponds to the position of engagement of the scanning lever 6 with the camshaft 5a. The support element 7a thus defines an end point of the pivoting of the scanning lever 6 in a first direction and the

Position of engagement of the scanning lever 6 with the camshaft 5a. Support surface 7 and support element 7a are designed in such a way - in particular with regard to their surface - that a sliding movement against one another is possible. In the engagement position of the scanning lever 6, i.e. when there is contact with the camshaft 5a, the support surface 7 together with the support element 7a, which is fixed to the housing - for example in the crankcase of the internal combustion engine - serves as a guide for the stroke along the axis A of the tappet 4.

In the first embodiment of the valve drive device 1 according to FIG. 1, the actuating element 10 has an actuating shaft 11. This actuating shaft 11 is rotatable about its axis B (runs normal to the plane of the drawing in Fig. 1, therefore not shown - but see e.g. Fig. 3), which is parallel to the camshaft 5a or its longitudinal axis and parallel to the axis of rotation D of the rocker arm 3 is arranged. This axis B of the actuating shaft 11 - the actuating shaft axis - furthermore runs parallel to the articulation axis 4f

oriented.

A crank arm 12 is firmly connected at one end to the actuating shaft 11, at the other end of the crank arm 12 an actuating rod 13 is articulated, which in turn is articulated to the second point of application 6b of the

Sampling lever 6 is connected. The crank arm 12 and the operating rod 13 thus connect the operating shaft 11 and the second point of application 6b of the scanning lever 6. Rotating the operating shaft 11 thus causes the scanning lever 6 to move into or out of engagement with the camshaft 5a. In other words, the scanning lever 6 by moving the actuating element 10 by rotating the

Actuating shaft 11 can be brought into and out of engagement with camshaft 5a.

It should be noted that the movement of the actuating shaft 11 must be coordinated with the cam contours of the camshaft 5a, since actuation should ideally only take place when the base circle G and no cam 5 of the scanning lever 6 or the roller body 6c in the first point of application 6a is facing. In order to prevent blockages of the valve drive device 1, the actuating rod 13 is designed in such a way that it can accommodate the movements of the

Crank arm 12 of the actuating shaft 11 can follow and against this

pivoted and still remains firmly connected to the scanning lever 6. To

the actuating rod 13 has at least one spring element 13e which the

Actuating rod 13 is prestressed between scanning lever 6 and actuating shaft 11.

The actuating rod 13 has a first part 13a which is connected to the scanning lever 6 at the second point of application 6b. A second part 13b of the actuating rod 13 is connected to the crank arm 12. In the embodiment shown, the first part 13a is made hollow and the second part 13b is slidably guided inside the first part 13a. The length of the

Actuating rod 13 is thus variable.

In order to limit the movement of the first part 13a and the second part 13b relative to one another, a pin 13c which is fixedly connected to the second part 13b is provided and which is guided in slots 13d of the first part 13a. The second part 13b can therefore be displaced within the first part 13a to a limited extent from the ends of the slots 13d. By means of the spring element 13e, the parts 13a, 13b are pressed away from one another, so that the actuating rod 13 is at a maximum

Length extension is biased.

By pivoting the crank arm 12 and the actuating rod 13 relative to one another and the change in position between the first part 13a and the second

Part 13b changes an absolute length L of the actuating element 10 from the axis B to the second point of application 6b. If when twisting the

Operating shaft 11 of the scanning lever 6 is pivoted by means of the crank arm 12 and operating rod 13 in the direction of the engagement position with the camshaft 5a and the roller body 6c abuts against a cam 5, the spring element 13e is compressed and there is no damage in the valve drive device 1. If the If the camshaft 5a has rotated further to the base circle G, the parts 13a, 13b can move again by the spring tension in the direction of the maximum length extension of the actuating rod 13 and the valve drive device 1 can be brought into the engagement position. In order to limit the pivoting - as already described above - the support surface 7 is arranged on the scanning lever 6, which in the case of pivoting with

the support element 7a fixed to the housing cooperates.

The basic function of the valve drive device 1 according to the invention was explained in FIG. 1 using an embodiment in which only one

Transmission device 100 is provided so that a transmission of the

Cam lift on valve 2 is either activated or deactivated. In FIGS. 1a to 16, variants are shown in which two different cam elevations can be transferred to a valve 2 and accordingly two identically constructed transfer devices 100, 100 'are provided. In addition to activating and deactivating valve 2, this also enables various cam elevation curves to be implemented. For this purpose, the cams 5 have different cam profiles for the two scanning levers 6. This serves to implement different control times depending on the crank angle of the internal combustion engine, depending on the intervening scanning lever 6.

In the following explanations, two transmission devices 100, 100 'are referred to, which are arranged one behind the other in the direction of the camshaft 5a. Elements of the front transmission device 100 facing the viewer are provided with normal reference symbols, while elements of the rear transmission device 100 ‘, which are often partially or completely covered by the front transmission device 100

ouch

are each provided with a dash “‘ ”. For the sake of clarity, often only one reference symbol is used, which denotes the features of the front 100 and the rear transmission device 100 ‘, if not

otherwise stated.

The features explained in connection with FIGS. 1 a to 16 can of course also be applied to the application according to FIG. 1 with only one

Transfer device 100 transferred.

Fig. 1a shows an embodiment with two transmission devices 100, 100 'which are arranged one behind the other as seen in the direction of the camshaft 5a. It can therefore only be seen on the basis of the scanning levers 6, 6 ', the actuating shafts 11, 11' and the crank arms 12, 12 'that two transmission devices 100, 100' are provided. The front scanning lever 6 is brought out of engagement with the camshaft 5a and the cam lift of the cam 5 assigned to it does not act on the valve 2. The rear scanning lever 6 'is in the engagement position - the support surface 7' is in engagement with the support element (not shown in Fig. 1a). Since the roller body 6c ‘rests on the base circle, the valve 2 is closed. In Fig. 1b it can be seen how in

the actuating rod 13, the pin 13c rests at the end of the slot 13d and

thereby by rotating the actuating shaft 11 of the scanning lever 6 from the

Camshaft 5a is pulled away.

Fig. 2a shows the arrangement of Fig. 1a in a position in which the scanning lever 6 of the front transmission device 100 is in engagement with the camshaft 5a and the tappet 4 of which transmits the cam elevation of the cam 5 via the lever 3 to the valve 2, so that the maximum stroke is reached. It can also be seen here how the spring 4b of the plunger 4 is compressed against the stop 4c. At the maximum stroke of the valve 2, the pin 4d in the guide 4a of the plunger 4 is lifted off. The pin 4d reaches its highest position relative to the camshaft 5a.

The spring 4b is compressed against the stop 4c.

Fig. 2b shows in a detailed view how the parts 13a, 13b of the actuating rod 13 are compressed so that the spring element 13e is compressed

becomes,

In this position the scanning lever 6 is the front one

Transmission device 100 pressed towards cam 5.

Fig. 3 shows the plan of the situation shown in Fig. 2a. It can be seen that the rocker arm has two thumbs 8, 8 ', which are each in contact with a plunger 4 of one of the transmission devices 100, 100' or designed for this purpose are alternating with one or the other plunger 4 in

To be in contact. The thumbs 8, 8 ‘form the second ends 3b of the lever 3.

Only the differences between versions two to seven are described below. The other functions and components correspond to those of the embodiments according to FIGS. 1 to 3. For the sake of clarity, only those reference numerals are drawn in that are necessary for understanding the function

are necessary.

4 and 5 again show a valve drive device 1 with two transmission devices 100, 100 'arranged one behind the other in the direction of the crankshaft 5a. In contrast to the first embodiment, the illustrated second embodiment is set up so that movement of the scanning lever 6 is permitted only in the base circle phase of the camshaft 5a outside of the engagement. Then there are different

executed actuating elements 20 are used and there are additional

Locking devices 21, 21 ‘provided.

The operating element 20 is constructed in the same way as the operating element 10 of the valve drive device 1 in the first embodiment, but has a stop 22, 22 ‘in the area of the articulated connection to the second contact point 6b of the scanning lever 6. The stop 22, 22 ‘is designed to interact with a locking element 25, 25‘ in such a way that a movement of the actuating element 20 is possible or not. According to FIG. 4, the stop 22 is arranged on a first part 27 a of an actuating rod 27. The second part 13b of the actuating rod 27 corresponds to the second part 13b in the first embodiment of the valve drive. All other elements of the

Actuating element 20 have the same reference numerals as in the first embodiment

and are the same in their design and functionality.

The locking device 21, 21 ′ comprises a control shaft 23 which is oriented essentially parallel to the camshaft 5 a and has a control cam 24. This can also be used in the case of one behind the other

Transmission devices 100, 100 ‘a common control shaft 23 can be provided, which has an associated control cam 24, 24 ° for each transmission device 100, 100‘. This control cam 24, 24 ° is tapped in each case by a locking element 25, 25 'which can be displaced in the direction of the actuating element 20 and which in the embodiment shown has the shape of a hollow prism with an approximately square base, which is arranged around the control cam 24, 24 ° is. The locking element 25, 25 ‘is displaced by the control shaft 23, in particular its control cam 24, 24‘, against the force of a spring 26, 26 ‘. The spring 26, 26 is arranged together with the blocking element 25, 25 ‘in a guide 27b, 27b‘, the blocking element 25 being arranged displaceably in the guide 27b, 27b ‘. The guide 27b, 27b ‘can for example be permanently located in the crankcase. Moving the blocking element 25, 25 ‘causes an interaction with the stop 22, 22‘, so that the actuating element 20 is blocked and the scanning lever 6, 6 ‘cannot move. When the locking element 25, 25 ‘is brought out of engagement with the stop 22, 22‘ again, the actuating element 20 can be released again

move.

The control cam 24, 24 ° of the control shaft 23 is designed in such a way that it has an effective shape that is reversed to that of the cam 5 of the camshaft 5a. This means that either the cam 5 is in a position in which a movement of the valve 2 is effected via the transmission device 100, 100 ', and the blocking element 25, 25' is stationary, or the control cam 24, 24 ° of the control shaft 23 the locking element 25, 25 'is moved in the direction of the stop 22, 22' and the camshaft 5a is in a base circle phase G.

The reverse cam 24, 24 ‘to the camshaft 5a ensures that the locking only acts on the elevation of the cam 5 (outside the base circle phase) when the scanning lever 6, 6‘ engages, and switching therefore only takes place in the base circle

Phase is possible. The base circle is marked with G in the figures.

The scanning lever 6 ‘of the rear transmission device 100‘ in FIG. 4 is on

Base circle G shown attached.

The scanning lever 6 of the front transmission device 100 is disengaged from the camshaft 5a. In the position shown, the locking element 25 is raised so that a movement of the scanning lever 6 through the actuating rod 13 is possible. The scanning lever 6 can therefore be brought into engagement with the camshaft 5a.

The locking element 25, 25 ‘is represented by a pin which is moved up and down by the control shaft 23 depending on the phase position. The control cam 24, 24 'on the control shaft 23 is designed so that engagement is only possible in the phase in which the roller body 6c arranged in the first point of application comes into contact with the base circle G of the camshaft 5a. This avoids

that the roller body 6c strikes against the cam 5 in the lifting phase.

When an end position, either in engagement or outside of it, is reached, the locking element 25 no longer has any contact with the stop 22 of the actuating element 20. Wear on this pairing is thereby avoided.

In Fig. 5, the valve drive device 1 of the second embodiment is shown in a second position, the locking device 21 ‘for the rear transmission device 100‘ is closed. The scanning lever 6 of the front

Transmission device 100 is through the actuator 20 to the camshaft

5a displaced and slides with the support surface 7 on its opposite in the crankcase when the camshaft 5a rotates and the cam lobe of the cam 5 interacts with the roller body 6c. The valve 2 is in the position shown in the maximum stroke. Switching of the rear transmission device 100 ‘is prevented by the blocking element 25‘ and the stop 22 ‘rests on the blocking element 25.. The movement of the actuating element 20 of the rear transmission device 100 ‘is prevented by this stop 22‘ in this position. As shown, the valve 2 is in

Stroke maximum.

In the first and second embodiment, the scanning lever 6 is lifted off the cam 5 by shortening the distance L between the actuating shaft 11 and the second point of application 6b, and the second point of application 6a in FIG

Swiveled towards the actuating shaft 11.

6 and 7 show the valve drive device 1 in a third embodiment for opposite directions of rotation of the camshaft 5a, which involves a different arrangement of the components already known. Two transmission devices 100, 100 ′ arranged one behind the other in the direction of the camshaft 5a are again provided. In contrast to the first and the second embodiment, a stop 33 of an actuating element 30 is arranged in such a way that a locking device 31 with a locking element 32 is effected from a side of the actuating element 30 facing away from the plunger 4. The blocking element 32 is actuated, for example, by a pneumatic and / or electrical and / or hydraulic actuator, which is not shown in the figures

is shown in more detail.

In the third embodiment, the scanning lever 6, 6 ‘is pushed away from the operating shaft 11 by extending an operating element 30 and away from the camshaft 5a with the first point of application 6a. The scanning lever 6, 6 ‘is designed in such a way that when the first point of application 6a is pivoted away from the camshaft 5a, the scanning lever 6 does not come into contact with the cam 5 by means of roller bodies 6c.

The locking element 32 again engages in the stop 33 in order to bring the scanning lever 6 into engagement with the camshaft 5a outside the

To prevent base circle phase. The locking element 32 prevents engagement in the

Stop 33 a rotation of the scanning lever 6 about the pivot axis 4Ff in a direction towards the actuating shaft 11. The stop 33 is arranged on a first part 34 a of an actuating rod 34.

The first part 34a of the actuating rod 34 is partially designed as a hollow cylinder. A second part 34b of the actuating rod 34 is guided in the interior of the first part 34a. A spring element 34e is arranged around the second part 34b and is supported on a stop at one end to the joint on the crank arm 12

is.

At the other end, the movement of the spring element 34e is limited by a shoulder in the interior of the hollow cylindrical first part 34a. To again limit the maximum movement, a pin 34c is slidably provided in slots 34d of the first part 34a of the operating rod 34.

6 shows the embodiment of the actuating element 30 for an embodiment of a camshaft 5a, which rotates clockwise with respect to the representation in the figure. The support of the scanning lever 6 is in the form of a support element 7a, in order to define the engagement position, on the opposite side than in the previous versions. The actuating element 30 is now designed so that it is pulled into engagement and is pressed when the sensing lever 6 with the roller body 6c out of engagement

should be taken.

7 shows the plan of this arrangement. The rocker arm 3 has two thumbs 8, 8 ‘

which alternately come into contact with one or the other tappet 4.

8 to 10 show a fourth embodiment of the valve drive device 1 according to the invention with two transmission devices 100, 100 'arranged one behind the other in the direction of the camshaft 5a, which differ from the previous ones

Versions by the details of the locking device 41, 41 ‘differs.

In a first position shown in FIG. 8, the locking device 41 assigned to the front transmission device 100 is open. The locking device 41 of the fourth embodiment is assigned to an actuating element 40, with a stop 22 on a first, like the second embodiment

Part 27a of the actuating rod 27 is arranged. In this stop 22 engages

rotatable locking element in the form of a pawl 42 a. The pawl 42 is rotatably mounted on a pivot point 44 fixed to the housing and is articulated to a control rod 43, so that the pawl 42 can be rotated about the pivot point 44 by means of the control rod 43. The pawl 42 is hook-shaped in the embodiment shown and the articulation point 44 is arranged essentially in an apex of this hook. The control rod 43 serves as an activation element. Here, hook-shaped is understood to mean a shape with at least two successive sections that surround at least one

Vertices are curved.

In addition to its actuating function for the valve 2, the camshaft 5a is also used as a control shaft for the locking device 41. The control rod 43 is arranged inclined relative to the longitudinal extension of the actuating element 40. The control curve for the locking device 41 is arranged in phase with the cam lift of the cam for the valve lift that the release for the switching movement is only possible in the base circle phase of the valve 2. The direction of rotation of the camshaft 5a is counterclockwise in the embodiment shown.

The locking pawl 42 is rotated by translational displacement of the control rod 43, which is caused by rotation of the camshaft 5a. So that no kinematic constraints lead to tension, the pawl 42 is articulated with the control rod 43 with play. For this purpose, the control rod 43 and the pawl 42 have a slot in relation to one another in which a guide pin of the other is slidably guided. The control rod 43 is against the cam 24 of the camshaft 5a, which is used to move the

Control rod 43 is used, biased by a spring 45.

FIG. 9 shows the fourth embodiment in a position in which the rear transmission device 100 ‘is blocked by the pawl 42 engaging with the stop 22. This results in a locked position of the actuating element 40 'due to the closed locking device 41'. The scanning lever 6 of the front transmission device 100 is engaged with the camshaft 5a.

Fig. 10 shows the floor plan for this with the rocker arm 3 with the two thumbs 8, 8 ‘and the two transmission devices 100, 100‘. Here you can see how the

Transmission devices 100, 100 ‘in the direction of the camshaft 5a

are arranged one behind the other.

11 shows a fifth embodiment of the valve drive device 1, which is essentially the fourth embodiment in a variant for opposite directions of rotation of the camshaft 5a. The control rod 43 that the

Control rod 43 of the fourth embodiment corresponds to the function, is arranged inclined downward, away from an actuating element 50. The appearance and the function of both actuating elements 50 of the fifth embodiment correspond to the third embodiment, which is shown in FIGS. 6 and 7. The locking device 41 is designed as in the fourth embodiment and is closed in this FIG. 11. In this embodiment, the camshaft 5a also functions as a control shaft for the locking device 41. FIG. 11a shows a sectional view along the line XI-XI in FIG. 11.

FIG. 12 shows the floor plan of the fifth embodiment according to FIG. 11.

13 to 16 show valve drive devices 1 in a sixth and seventh embodiment, where actuating devices 60, 70 using actuator devices 61, 61, are shown. The actuation of the scanning levers 6, 6 'in engagement or out of engagement with the camshaft 5a takes place through these actuator devices 61, 61', which have, for example, a pneumatic and / or electrical and / or hydraulic actuator. This has the advantage that the phase position of the base circle G can be taken into account via a motor control and the system does not require an additional control shaft. The actuator devices 61, 61 are located on the one hand articulated at a mounting point 62, 62 '' fixed to the housing in the internal combustion engine and on the other hand articulated to the second point of application 6b on the scanning lever 6,

6 connected.

In the sixth embodiment (FIGS. 13 and 14) the direction of rotation of the camshaft 5a is counterclockwise. To define the engagement position with the camshaft, a support element 7a fixed to the machine or the housing is again provided, which is arranged on the opposite side of the camshaft 5a with respect to the fixed point 62, 62 'of the actuator devices 61, 61'. The situation is therefore as in the case of the statements made in FIGS. 1 to 5 are shown. In

the seventh embodiment (Fig. 15 and 16) is the direction of rotation of the camshaft 5a in

21738

Clockwise. The support element 7a ‘is therefore arranged with respect to the camshaft 5a on the same side as the actuating device 60 or its mounting point 62, 62‘ fixed to the housing.

Claims (1)

PATENT CLAIMS Variable valve drive device (1) for the variable control of valves (2) of an internal combustion engine, the valve drive device (1) having at least one lever (3) which can be pivoted about an axis of rotation (D) and which has a first end (3a) on a valve (2 ) for its actuation and with at least one second end (3b) on a transmission device (100, 100 ') for transmitting cam lobes of a camshaft (5a), characterized in that the transmission device (100, 100') has at least one tappet (4 ) and a scanning lever (6, 6 ') articulated to the plunger (4) via an articulation axis (4f), the scanning lever (6, 6') having at least one first point of application (6a) which is connected to the camshaft (5a ) can be brought into contact, and has at least one second point of application (6b, 6b ') for an actuating element (10, 10'; 20; 30, 30 '; 40, 40'; 50, 50 '; 60, 60'). Variable valve drive device (1) according to claim 1, characterized in that the scanning lever (6, 6 ') is arranged to be pivotable at least about the articulation axis (4f) and is supported by the actuating element (10, 10'; 20; 30, 30 '; 40, 40 '; 50, 50'; 60, 60 ') can be brought into and out of engagement with the camshaft (5a), the articulation axis (4f) preferably being normal to a Longitudinal axis (A) of the plunger (4) is oriented. Variable valve drive device (1) according to claim 1 or 2, characterized in that the scanning lever (6, 6 ') on a side remote from the tappet (4) in the second point of application (6b, 6b') with the actuating element (10, 10 ') ; 20; 30, 30 '; 40, 40'; 50, 50 '; 60, 60') articulated connected is. Variable valve drive device (1) according to one of the preceding claims, characterized in that two transmission devices (100, 100 ‘) are provided and the lever (3) on the camshaft side has two thumbs (8, 8 ‘) to interact with the tappets (4). Variable valve drive device (1) according to one of the preceding claims, characterized in that the tappet (4) is pressed in the direction of the camshaft (5a) by the force of a spring (4b). 11. 23 Variable valve drive device (1) according to one of the preceding claims, characterized in that the tappet (4) is arranged in a guide (4a) and is movably guided in the direction of its longitudinal axis (A). Variable valve drive device (1) according to claim 6, characterized in that the guide (4a) has at least one, preferably two opposite slots (4e) running parallel to the longitudinal axis (A) of the tappet (4) for receiving one in the tappet (4) arranged, transversely to its longitudinal axis (A) extending pin (4d). Variable valve drive device (1) according to one of the preceding claims, characterized in that each scanning lever (6) has a support surface (7, 7 ') which can be brought into engagement with a support element (7a, 7a') of an internal combustion engine fixed to the machine in order to achieve a Pivoting of the scanning lever (6, 6 °) about the articulation axis (4f), preferably a pivoting of the scanning lever (6, 6 ') about the articulation axis (4f) into an engagement position the camshaft (5a) to limit. Variable valve drive device (1) according to one of the preceding claims, characterized in that the actuating element (60, 60 ') has a pneumatic and / or electrical and / or hydraulic actuator (61, 61') to move the scanning lever (6, 6 ') ) in and out of engagement with the Bring camshaft (5a). Variable valve drive device (1) according to one of claims 1 to 8, characterized in that the actuating element (10, 10 '; 20; 30, 30'; 40, 40 '; 50, 50'; 60, 60 ') has a rotatable actuating shaft (11, 11 ') and an actuating rod (13, 13'; 27; 34, 34 °) articulated therewith, the actuating rod (13, 13 '; 27; 34, 34 °) being articulated with the second point of application (6b , 6b ') of the scanning lever (6, 6') is connected and the scanning lever (6, 6 ') is connected by moving the actuating element (10, 10'; 20; 30, 30 '; 40, 40'; 50, 50 '; 60, 60 ') by turning the actuating shaft (11, 11 ‘) can be brought into and out of engagement with the camshaft (5a). Variable valve drive device (1) according to claim 10, characterized in that the actuating rod (13, 13 ‘; 27; 34, 34 ') comprises at least one spring element (13e; 34e) which the actuating rod 24/38 (13, 13 ‘; 27; 34, 34 °) between the scanning lever (6, 6‘) and the actuating shaft (11, 11 ‘). 12. Variable valve drive device (1) according to one of the preceding claims, characterized in that at least one locking device (21, 21 '; 31; 41, 41') is provided, which with a scanning lever (6, 6 ') and / or a Actuating element (10, 10 '; 20; 30, 30'; 40, 40 '; 50, 50'; 60, 60 ') can be brought into engagement to block its movement, with preferably. the locking device (21, 21 ‘; 31; 41, 41 °) can be actuated via at least one control shaft (23). 13. Variable valve drive device (1) according to claim 12, characterized in that the locking device (21, 21 '; 31; 41, 41') has at least one movable and / or displaceable locking element (25, 25 '; 32; 42, 42') ) which can be brought into and out of engagement with a stop (22, 22 '; 33) on the actuating element (10, 10'; 20; 30, 30 '; 40, 40'; 50, 50 '; 60, 60') is. 14. Variable valve drive device (1) according to claim 12, characterized in that the locking device (21, 21 '; 31; 41, 41') has at least one rotatable locking pawl (42, 42 ') which is provided with a stop (22, 22 '; 33) on the actuating element (10, 10'; 20; 30, 30 '; 40, 40'; 50, 50 '; 60, 60') can be brought into and out of engagement, preferably the pawl (42, 42 ' ) is movable and / or rotatable by an activation element (43, 43 '), via which the pawl (42, 42') can be connected to the camshaft (5a), the camshaft (5a) having control protrusions (24) for actuating the activation element (43, 43 '). 15. Internal combustion engine with at least one variable valve drive device (1) according to one of claims 1 to 16. 04/07/2019 WR