DE102008027886A1 - Disconnectable valve gear for internal combustion engine, has gas shuttle valve whose shank is enclosed by valve spring, where spring plate axially runs below another spring plate and is connected to shank - Google Patents

Abstract

The valve gear (1) has a gas shuttle valve (2) designed as a reciprocating poppet valve. A shank (3) of the valve is enclosed by a valve spring (4). A device (15) is provided for holding the valve in a closed position for the case of decoupling. The device includes a spring plate (16) with a valve spring (17). The valve spring (17) is concentrically enclosed by the valve spring (4), and is supported at a cylinder head (5) at one end and at a lower side (16a) of the spring plate at another end. The spring plate (16) axially runs below another spring plate (7) and is connected to the shank.

Description

Field of the invention

The The invention relates to a deactivatable valve drive of an internal combustion engine, with a gas exchange valve whose shaft is enclosed by a valve spring is the one against a cylinder head and the other end against a bottom of an axially freely movable relative to the shaft Spring plate is supported, the cylinder head distant forehead contacted by an at least indirectly from a Hubnocken Following member is acted upon, wherein the shaft at least one radial opening with a coupling agent that in the coupling case [full valve lift] over a slide radially outward to one on the spring plate arranged cam surface is shifted, so that the Spring plate is connected to the shaft at Nockenhub, where in Decoupling case [0-valve lift] the slider is moved so that the coupling agent over the driver surface radially inward, the radial opening not outstanding, is shifted, such that the spring plate is axially movable with respect to the shaft and wherein a Before direction for holding the gas exchange valve in its closed position is applied for the decoupling case.

Background of the invention

Such a valve train is in the DE 10 2007 013 947 described. Its device for holding consists of a complex spring-ball mechanism, which, the shank of the gas exchange valve enclosing, is partially installed in the cylinder head. The skilled artisan first recognizes that the example of 7 resulting mechanism is relatively complex and that elaborate changes to the cylinder head prove necessary. Exactly in this cylinder head area, however, it can happen due to the confined space conditions that an installation of the holding device proves to be virtually impossible. Furthermore, it is found that the locking mechanism is subjected to enormous wear on the balls on the outer surface of the shaft.

Object of the invention

task The invention is therefore a valvetrain of the aforementioned type to create in which the mentioned disadvantages with simple means are eliminated.

Solution of the task

According to the invention This object is achieved in that the device for Holding a further spring plate having a further valve spring, the latter being concentrically enclosed by the valve spring and at one end on the cylinder head and at the other end on a lower side the other spring plate is supported, which further Spring plate runs axially below the spring plate and with connected to the shaft.

Consequently There is a valve train, which eliminates the disadvantages indicated are. The device for holding the gas exchange valve in the decoupling case is relatively simple, easy to assemble and takes up no additional space in the cylinder head area. It also states that the proposal Valve gear in the radial direction does not build larger.

As an actuator for acting on the slide, which is preferably located in a frontal blind bore of the shaft, for example, an electromagnetic "switch" is conceivable and provided, as in the cited above DE 10 2007 013 947 proposed. This can for example be attached to the side of the cylinder head and act on a free end of the slider.

Clear is that instead of each one spring for the valve plate and the other valve disc also applied a respective spring package can be. Optionally, at least one of the springs as an air spring be shown.

easy Measures of integration of the two spring plates are the subject another subclaim. Accordingly, a "nested" construction proposed, according to which the spring plate of the "regular" closing spring on the outer jacket of a tubular extension of the other Spring plate of the holding device runs. For weight minimization can at least one of the spring plates be provided with perforations.

expedient it is not to fix the other spring plate firmly on the shaft, but only about him through outstanding coupling means to connect with the shaft. As a coupling agent, for example a cylindrical slide in question, the two-sided forehead spherical can be trained.

Around To minimize the component load in the coupling region, it is more expedient Specification of the invention proposed, at least two themselves diametrically opposite or three circumferentially to apply equally distributed coupling agent. The invention works but also with only one coupling agent or more than three Coupling means.

As a follower in the valve train is intended to a lever-like cam follower such as a towing, swing or rocker arm. It is ever conceivable but also to arrange a bucket tappet in this area or is also intended for a push rod valve drive.

When Stop for not firmly connected to the shaft tubular approach of the other spring plate is a radial projection as an explosive or retaining ring provided on which a cam-side Forehead of the tubular approach strikes. Important is on in each case an easy movability of the coupling agent in their Coupling or decoupling position.

Short description of the drawing

The Invention is suitably with reference to the drawing explained in more detail. It shows the only figure in a longitudinal section of the invention Valve gear with holding device.

Detailed description the drawing

Shown is a valve train 1 an internal combustion engine. This has a designed as a Tellerhubventil disconnectable gas exchange valve 2 whose shaft 3 from a valve spring 4 is enclosed. The latter acts at one end against a cylinder head 5 and other ends against a bottom 6 one axially opposite the shaft 3 freely movable spring plate 7 ,

A cylinder head distant, ring-like forehead 8th of the spring plate 7 is of a trained here as a drag lever follower 10 acted upon, which follower 10 from a lift cam 9 is contacted. Inside the valve spring 4 runs another valve spring 17 , the one also on the cylinder head 5 is supported. With its other end it acts against a bottom 16a another spring plate 16 that is axially below the spring plate 7 sitting. The other spring plate 16 forms together with the aforementioned further valve spring 17 a device 15 for holding the gas exchange valve 2 in its closed position for the decoupling case.

The aforementioned additional spring plate 16 goes radially inside in a tubular approach 17a over which for weight savings with perforations 35 is provided. An inner jacket 20 of the approach 17a runs directly on the outer jacket 21 of the shaft 3 ,

A cam-shaped forehead 24 of the approach 17a is located on a trained as a safety or snap ring radial projection 23 on which radial projection 23 on the outer jacket 21 of the shaft 3 is attached cam side.

The tube-like approach 17a as well as the shaft 3 have ever coupling agent 12 mutually aligned radial openings 22 . 11 , In this way, the piston-like coupling means extends 12 whose foreheads 33 . 34 are shown crowned.

Furthermore, it can be seen that the shaft 3 a blind hole 25 has. In the latter runs a rod-like slide 13 , This has a first resting section 31 constricted training, in the direction away from the cam a second latching section 32 contrast raised and slightly wedge-like geometry connects.

In the coupling state shown here (full valve lift) is the respective coupling agent 12 with his inner forehead 33 at the second, raised rest section 32 at. Radially outside is the respective coupling agent 12 with his outer forehead 34 in front of a second section 37 on an inner edge 38 of the spring plate 7 , At the second conical section 37 closes radially inside a sleeve-like third section 39 on, which on the outer jacket 18 the above approach 17a axially movable.

Should the valve gear 1 are switched off, so in the cam base circle of the drawing indicated actuator 27 in contact with the free end 26 of the slider 13 brought. This can be realized in such a way that with running cam edge of the shaft 3 with slider 13 in a quasi-stationary stop of the actuator 27 "Runs". The slider 13 is thus moved in the cam-distant direction such that its first, constricted section 36 in flight to the respective coupling agent 12 is. When cam lift actuates the follower 10 the cylinder head distant forehead 8th of the spring plate 7 and this shifts over its cone-like section 37 the corresponding coupling agent 12 so inside, that it no longer radially beyond the outer shell 18 the tubular approach 17a also available. Thus, the spring plate 7 perform a Leerhubbewegung and its valve spring 4 acts as a so-called lost-motion spring.

There is also a bump cap 40 provided, which is a cam-side forehead 41 of the gas exchange valve 2 overlaps. At a lower edge 42 of the coping 40 finds in the decoupling mode the cylinder head distant forehead 8th of the spring plate 7 a stop. A corresponding coupling play is expediently provided here. The bumper cap 40 is in the range of its lower edge 42 radially inside in an annular groove 43 the other spring plate 16 engaged.

As shown, the free end is 26 of the slider 13 bottom side through the stop cap 40 guided and with a ring heel 44 secured inside.

In this shutdown mode, the Vorrich tung 15 to hold with another spring plate 16 and further valve spring 17 for having the gas exchange valve 2 maintains its closed position.

Should the gas exchange valve 2 be switched back on, then the actor 27 deactivated and it comes the return means 29 (Compression spring) is used, which at one end against a bore-side end 28 of the slider 13 acts and with its other end on a bottom of the hole 30 the Sackboh tion 25 supported. It shifts in the cam base circle (largely power-free state) the respective coupling agent 12 radially outward until just before the cone-like second section 37 of the spring plate 7 ,

1

valve train

2

Gas exchange valve

3

shaft

4

valve spring

5

cylinder head

6

bottom

7

spring plate

8th

cylinder head afar forehead

9

lift cams

10

follower

11

radial opening

12

coupling means

13

pusher

14

entraining

15

contraption to hold

16

Another spring plate

16a

bottom

17

Further valve spring

17a

tubular approach

18

outer sheath

19

drilling spring plate

20

inner sheath approach

21

outer sheath shaft

22

Further radial opening

23

radial projection

24

cam side forehead

25

blind hole

26

free The End

27

actuator

28

drilling sided The End

29

Return means

30

hole bottom

31

first detent portion

32

second detent portion

33

forehead

34

forehead

35

perforation

36

first Section approach

37

second Section approach

38

inner edge

39

third Section approach

40

stop cap

41

cam side forehead

42

lower edge

43

ring groove

44

annular shoulder

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 102007013947 [0002, 0006]

Claims (10)

Switchable valve train ( 1 ) of an internal combustion engine, with a gas exchange valve ( 2 ) whose shaft ( 3 ) of a valve spring ( 4 ), which at one end against a cylinder head ( 5 ) and at the other end against a bottom ( 6 ) an axial with respect to the shaft ( 3 ) freely movable spring plate ( 7 ) is supported, whose cylinder head distant forehead ( 8th ) of one at least indirectly from a lift cam ( 9 ) contacted follower ( 10 ) is applied, wherein the shaft ( 3 ) at least one radial opening ( 11 ) with a coupling agent ( 12 ) in the coupling case [full valve lift] via a slide ( 13 ) radially outwardly to one on the spring plate ( 7 ) arranged driving surface ( 14 ), so that the spring plate ( 7 ) with the shaft ( 3 ) is connected at cam lift, wherein in the decoupling case [0-valve lift] the slide ( 13 ) is moved so that the coupling agent ( 12 ) over the driver surface ( 14 ) radially inward, the radial opening ( 11 ) is not outstanding, shifted, such that the spring plate ( 7 ) axially movable relative to the shaft ( 3 ) and wherein a device ( 15 ) for holding the gas exchange valve ( 2 ) is applied in its closed position for the decoupling case, characterized in that the device ( 15 ) for holding another spring plate ( 16 ) with another valve spring ( 17 ), the latter concentrically of the valve spring ( 4 ) and one end on the cylinder head ( 5 ) and at the other end at a lower side ( 16a ) of the further spring plate ( 16 ) is supported, which further spring plate ( 16 ) axially un below the spring plate ( 7 ) and with the shaft ( 3 ) connected is. Valve gear according to claim 1, characterized in that the further spring plate ( 16 radially inwardly into a tubular, cam-extending extension (FIG. 17a ), on its outer shell ( 18 ) the spring plate ( 7 ) with its bore ( 19 ), wherein an inner jacket ( 20 ) of the approach ( 17a ) on the outer jacket ( 21 ) of the shaft ( 3 ) of the gas exchange valve ( 2 ) and wherein the radial opening ( 11 ) of the shaft ( 3 ) to another radial opening ( 22 ) in the tubular approach ( 17a ) is in flight through which the coupling agent ( 12 ). Valve gear according to claim 2, characterized in that the further spring plate ( 16 ) not firmly on the shaft ( 3 ) and via the penetrating coupling agent ( 12 ) is connected to this. Valve gear according to claim 3, characterized in that on the outer casing ( 21 ) of the shaft ( 3 ), on the cam side, a radial projection ( 23 ) runs like a ring, on which a cam-side forehead ( 24 ) of the tubular approach ( 17a ) of the further spring plate ( 16 ) finds a stop. Valve gear according to claim 2, characterized in that in an end blind bore ( 25 ) of the shaft ( 3 ) the rod-like slide ( 13 ) whose free end ( 26 ) by an actor ( 27 ) and its bore-side end ( 28 ) of an oppositely acting return means ( 29 ) like one at the bottom of the hole ( 30 ) supporting pressure spring is applied, which slide ( 13 ) a first latching portion ( 31 ) immanent annular contour, to which a second latching portion ( 32 ) contrast, sublime contour, wherein for the coupling case of the slider ( 13 ) via the return means ( 29 ) is shifted such that the coupling agent ( 12 ) by the inner to position on the second latching portion ( 32 ) sections radially outwardly immediately in front of the driver surface ( 14 ) of the spring plate ( 7 ) and wherein for the decoupling case the slider ( 13 ) via the actuator ( 27 ) is shifted in cam-distant direction, that the coupling agent ( 12 ) the first latching section ( 31 ) is opposite, such that at cam start and valve lift the coupling means ( 12 ) by abutment against the cone-like driving surface ( 14 ) of the "downwards" moving spring plate ( 7 ) radially inward, the radial opening ( 22 ) of the tubular approach ( 17a ) is not outstanding to the outside, moved. Valve gear according to one of the preceding claims, characterized in that the coupling means ( 12 ) is designed as a cylindrical slide whose forehead ( 33 . 34 ) are spherical or cone-like. Valve gear according to one of the preceding claims, characterized in that either two diametrically opposite or three circumferentially equally distributed coupling means ( 12 ) are provided. Valve gear according to claim 2, characterized in that the approach ( 17a ) of the further spring plate ( 16 ) with perforations ( 35 ) is provided. Valve gear according to one of the preceding claims, characterized in that the spring plate ( 7 ) of a ring-like, largely thin-walled first section ( 36 ) with the underside ( 6 ) as an attachment for the valve spring ( 4 ), which at its inner edge ( 38 ) only in a cone-like in the cam direction extending second section ( 37 ) with the driver surface ( 14 ), to which a third, cylindrical section ( 39 ) with the bore ( 19 ), which is the forehead ( 8th ) for the contact of the lifting cam ( 9 ) having. Valve gear according to claim 1, characterized in that as a follower member ( 10 ) a lever-like cam follower such as a towing, rocking or rocker arm is provided.