EP2102454B1 - Rotationally locked tappet of a valve timing mechanism - Google Patents

Abstract

An anti-rotationally secured tappet of a valve drive of an internal combustion engine may include a bucket tappet including an external lateral surface. A floor and a skirt for may be arranged between a cam and a valve of the valve drive and guided in a receiving bore of a cylinder head. The skirt may include an internal lateral surface and the cylinder head may include a guide groove. A radially outward protruding anti-rotation component may be arranged in a recess of the skirt that glides in the guide groove of the cylinder head. Two spring arms may be included with the anti-rotation component and extend in a circumferential direction of the tappet.

Description

The invention relates to a rotationally secured ram of a valve train of an internal combustion engine according to the preamble of patent claim 1 and a non-rotating ram according to the preamble of patent claim 1.

From the DE 196 00 852 A1 is a non-rotating ram of a valve train of an internal combustion engine, preferably a consisting of a bottom and a shirt existing bucket tappet, which is arranged between a cam and a valve and is guided in a receiving bore of a cylinder head. In this case, a rotation is arranged in a recess of the shirt, which slides in a guide groove of the cylinder head. The rotation is formed as an elastic spring element and consists of a back and two adjoining clips, which are clipped into two longitudinal slots in the shirt of the plunger. The disadvantage here is that a space is greatly limited due to the length of the clips on the inside of the plunger and also the two legs of the two clasp must have a high spring preload to ensure a necessary tight fit of rotation, so that especially in thin-walled shirts Inadmissible high stress of the material of the shirt can not be excluded.

Another anti-rotation ram is for example from the DE 195 01 061 A1 known.

The invention is concerned with the problem of providing an improved embodiment for a generic rotation-secured ram, in which a rotation is structurally simple design and is easy and firm to connect to the plunger without it comes to unacceptably high voltage spikes in the material of the plunger.

According to the invention, this problem is solved by the subject matters of the independent claims. Advantageous embodiments are the subject of the dependent claims.

The invention is based on the general idea to provide in an anti-rotation two extending in the circumferential direction of a plunger spring arms, which ensure a fixation of the anti-rotation over the two spring arms mounted on the ram against rotation. The two spring arms are at least partially on either an outer lateral surface of the plunger or from an inner surface of the shirt of the rotationally secured plunger and fix the rotation on the plunger by a radially acting on this clamping force. The shirt also includes a transition region to a bottom of the plunger. If the two spring arms of the anti-rotation rest on the inner circumferential surface, they have a larger radius than the inner circumferential surface, whereby the spring arms are radially outwardly bracing against the inner circumferential surface of the shirt of the plunger. With a rotation lock with spring arms which bear against the outer lateral surface, they have a smaller radius compared to the outer lateral surface, so that they clamp around the plunger with an anti-rotation lock fixed on the plunger and press against the outer jacket surface of the shirt / plunger with a radially inwardly acting force. Due to the anti-rotation device according to the invention a large clamping force can be transmitted due to the circumferentially radially adjacent spring arms, without a local surface pressure and thus a material overload must be taken into account. In addition, such an anti-rotation device can be produced as a cost-effective sheet-metal forming part, which in particular makes it possible to reduce the production costs.

Appropriately arranged on the inner circumferential surface of the shirt, the spring arms of the rotation at least partially receiving radial annular groove. Such an annular groove simplifies the installation of the anti-rotation device on the plunger considerably and fixes the latter in the assembled state in the axial direction on the plunger. In addition, such a radial annular groove can be integrated without much additional effort in an already required turning of the plunger, so that there are no significant additional costs. The annular groove also offers a possibility of forced positioning of the rotation, since it forcibly predetermines a predetermined and predefined position of the rotation in the assembled state. In an anti-rotation with voltage applied to the outer surface spring arms a radially outwardly open annular groove is provided on the outer lateral surface, which the spring arms of the rotation completely absorbs, so that they do not protrude at any point radially beyond an outer circumference of the outer circumferential surface.

The invention further based on the general idea, the rotation as a nose-like insert element, ie without spring arms, wherein the insert element is held in a radially outwardly open and radially inwardly closed groove on the plunger form and / or non-positively. Such a design of the rotation simplifies the latter again considerably, with a positive connection between the rotation and the groove, for example by means of soldering, gluing or welding can be achieved. This rotation lock is arranged in the bottom region of a, a bottom and an adjoining shirt having tappet. Conceivable here is also a connection between the anti-rotation and the associated groove in the manner of a dovetail connection, wherein the rotation has a dovetail-like cross-section, while the groove has a complementary undercut cross section, so that the rotation is positively held in the groove.

Advantageous, explained in more detail below embodiments are shown in the drawings.

Fig. 1

eine Teilansicht auf einen erfindungsgemäßen verdrehgesicherten Stößel mit einer Verdreh- sicherung als Außenclip,

Fig. 2a bis c

unterschiedliche Darstellungen der Verdrehsi- cherung nach Fig. 1,

Fig. 3a bis

d eine Schnittdarstellung durch eine Verdrehsi- cherung und einen verdrehgesicherten Stößel nach Fig. 1,

Fig. 4

einen Verdrehsicherung als Innenclip,

Fig. 5

eine Darstellung wie in Fig. 4 jedoch aus ei- ner anderen Perspektive,

Fig. 6a

eine Längsschnittdarstellung durch einen ver- drehgesicherten Stößel nach Fig. 4,

Fig. 6b

eine Verdrehsicherung als Innenclip,

Fig. 7

eine Verdrehsicherung gemäß Fig. 6b in einem verdrehgesicherten Stößel gemäß Fig. 6a,

Fig. 8

einen Querschnitt durch einen verdrehgesi- cherten Stößel gemäß Fig. 7 im Bereich der Verdrehsicherung,

Fig. 9

eine Ansicht auf einen verdrehgesicherten Stößel mit einer darin angeordneten Verdreh- sicherung,

Fig. 10

eine Darstellung wie in Fig. 7, jedoch bei einer anderen Ausführungsform,

Fig. 11a, b

eine Darstellung wie in Fig. 6a, b, jedoch bei einer anderen Ausführungsform,

Fig. 12

eine Querschnittdarstellung durch einen ver- drehgesicherten Stößel gemäß Fig. 10 im Be- reich der Verdrehsicherung,

Fig. 13

eine Darstellung wie in Fig. 9, jedoch bei einer anderen Ausführungsform,

Fig. 14

einen verdrehgesicherten Stößel mit einer als Einsatzelement ausgebildeten Verdrehsiche- rung,

Fig. 15a bis c

einen Querschnitt durch einen erfindungsgemä- ßen verdrehgesicherten Stößel im Bereich der Verdrehsicherung.

These show, in each case schematically,

Fig. 1

2 shows a partial view of a twist-free ram according to the invention with a rotation lock as outer clip,

Fig. 2a to c

different representations of the anti-rotation lock Fig. 1 .

Fig. 3a to

d is a sectional view through a security against rotation and a non-rotating ram after Fig. 1 .

Fig. 4

an anti-twist as inner clip,

Fig. 5

a representation like in Fig. 4 but from a different perspective,

Fig. 6a

a longitudinal section through a twist-secured ram after Fig. 4 .

Fig. 6b

an anti-twist as inner clip,

Fig. 7

a rotation according to Fig. 6b in a non-rotating ram according to Fig. 6a .

Fig. 8

a cross section through a non-rotating ram in accordance with Fig. 7 in the area of rotation,

Fig. 9

a view of a rotation-secured ram with an anti-rotation device disposed therein,

Fig. 10

a representation like in Fig. 7 but in another embodiment,

Fig. 11a, b

a representation like in Fig. 6a, b but in another embodiment,

Fig. 12

a cross-sectional view through a twist-secured plunger according to Fig. 10 in the area of rotation prevention,

Fig. 13

a representation like in Fig. 9 but in another embodiment,

Fig. 14

a rotation-secured ram with a twist-lock element designed as an insert element,

Fig. 15a to c

a cross section through an inventive rotationally secured ram in the field of rotation.

Corresponding Fig. 1 a non-rotating ram 1 of a valve train of an otherwise not shown internal combustion engine has a bottom 2 and a shirt 3. The non-rotating plunger 1 is preferably designed as a bucket tappet and usually between a cam, not shown and a valve, also not shown, arranged for example between a control cam and a gas exchange valve. In this arrangement, the plunger 1 in a receiving bore, not shown, of a cylinder head 4 (see. Fig. 3d ) an oscillating reciprocating motion, wherein in the cylinder head 4, a guide groove 5 is provided, in which a radially outwardly protruding against rotation 6 of the rotationally secured plunger 1 engages. The anti-rotation device 6 is arranged in a recess 7 of the shirt 3 of the plunger 1.

According to Fig. 1 , The anti-rotation device 6, two in the circumferential direction of the shirt 3 and the plunger 1 extending spring arms 8, 8 ', which abut at least partially on an outer circumferential surface 10 of the plunger 1 and by a radially inward on the shirt 3 and the ram 1 acting clamping force the anti-rotation 6 on the plunger 1 fix. It is on the outer surface 10 of the shirt 3 and the plunger 1, a, the spring arms 8, 8 'of the rotation 6 completely receiving and radially inwardly recessed annular groove 9 is provided (see. Fig. 2b ), so that the spring arms 8, 8 'at any point in the radial direction beyond an outer circumferential surface 10 of the plunger 1 radially outwardly.

Fig. 2a shows such an anti-rotation device 6, with its two circumferentially extending spring arms 8, 8 ', which meet in the region of a radially outwardly projecting back 11. The anti-rotation 6 may be formed as a sheet metal forming part, wherein the two spring arms 8, 8 'in a rotation according to the Fig. 1 to 3 have a smaller radius compared to the outer circumferential surface 10, so that press the spring arms 8, 8 'mounted on the plunger 1 against rotation 6 on the outer circumferential surface 10 or in the arranged there annular groove 9 with radially inwardly directed force. The back 11 is in accordance with Fig. 2b and c in a radially inwardly recessed axial groove 12, wherein it engages with at least one back region 13, in particular with a lateral back region 13, positively against a longitudinal edge 14 of the axial groove 12. As a result, the anti-rotation device 6 is secured in the assembled state against displacement in the circumferential direction.

In Fig. 3a is a cross section through the rotationally secured plunger 1 in the region of the annular groove 9, wherein also the radially inwardly recessed axial groove 12 can be seen. The rotation according to the Fig. 3b is preferably formed as a sheet metal bent part, wherein the back 11 surrounds a locking element 15, which engages on the one hand in the axial groove 12 and on the other hand from the back 11 of the rotation 6 is included, thereby securing against an adjustment in the circumferential direction. In Fig. 3d the anti-rotation device 6 is shown as it is guided with its back 11 in the guide groove 5 of the cylinder head 4 and thereby secures the plunger 1 against rotation. In this case, usually the two spring arms 8, 8 'of the rotation 6 in the circumferential direction formed so long that they together at least more than 180 ° overlapping clasp (see. Fig. 2a ) form.

The rotation 6 according to the Fig. 1 to 3 Thus, the back 11 is preferably designed to be complementary to the cross-sectional profile of the guide groove 5, whereby an exact guidance of the plunger 1 in the receiving bore on the cylinder head 4 can be ensured. The annular groove 9 may generally be formed either completely or only partially encircling. The two spring arms 8, 8 'in this case have not built anti-rotation 6 in comparison to the outer radius of the plunger 1 smaller radius, whereby they exert a clamping force on the latter when clipped onto the shirt 3 and thus the rotation 6 reliably on the shirt 3 and Fix ram 1. A rotation of the anti-rotation device 6 in the circumferential direction is prevented by the overall wider running back 11 of the rotation 6, which is supported in the axial groove 12 and at the longitudinal edge 14 of the axial groove 12. In a merely partially encircling annular groove 9, a safeguard against rotation in the circumferential direction of the rotation 6 could be realized by correspondingly limited spring arms 8, 8 ', so that in such a case could be dispensed with a wider version of the back 11, which is advantageous for the manufacturability of the rotation 6 affects. In general, the shape of the spine 11, which represents the guide surface in the guide groove 5, may be either cylindrical, partially cylindrical, or even rectangular.

The advantage of the anti-rotation device according to the invention is that due to the design, an axial displacement of the Anti-rotation 6 and a rotation of these due to the annular groove 9 and axial groove 12 is not possible. By the spring tension forces of the two spring arms 8, 8 ', which circumferentially radially act on a large area, also a high holding force can be realized, the surface pressure is relatively low due to the large area. so that no deformation of the plunger 1 can be expected. Furthermore, in the operation of the anti-rotation 6 no release of the anti-rotation 6 is possible. A mounting of the rotation 6 is due to the self-positioning in the annular groove 9 and the axial groove 12 and the spring forces of the two spring arms 8, 8 'very simple and without complex devices and tools possible.

According to the Fig. 4 to 11 a variant of the rotation 6 is shown, in which the two spring arms 8, 8 'at least partially create an inner circumferential surface 16 of the shirt 3 and fix by a radially outwardly acting on the shirt 3 clamping force, the rotation 6 on the shirt 3. In the embodiments or variants shown here, the two spring arms 8, 8 'have a larger radius compared to the outer radius of the plunger 1, so that when the rotation lock 6 is mounted, the two spring arms 8, 8' press against the inner circumferential surface 16 from the inside. The back 11 projects through the configured as through hole recess 7 'through the shirt 3 radially outward and thereby allows the protection against rotation of the plunger 1 in the receiving bore of the cylinder head 4. According Fig. 6a is a longitudinal section through the plunger 1 according to the invention, wherein on the inner A circumferential surface 16 is provided a radially outwardly recessed annular groove 9 ', in which the two spring arms 8, 8' of the anti-rotation 6 engage. In this case, the two spring arms 8, 8 'in the region of their free ends each have a radially outwardly projecting projection 17, 17', so that the spring arms 8, 8 ', for example, only in the region of these projections 17, 17' or further projections 17 ". and 17 '''on the inner circumferential surface 16 and the annular groove 9 abut (see. Fig. 8 ). It is also conceivable that in the region of the outwardly projecting projections 17, 17 'on the spring arms 8, 8' in the shirt 3 a respective associated recess 18, 18 'is provided, in which the anti-rotation 6 engages with their projections 17, 17' ,

According to Fig. 8 the anti-rotation device 6 on each spring arm 8, 8 'in each case two projections 17, which allow only a regional concern of the spring arms 8, 8' on the inner circumferential surface 16. In this embodiment, the recess 7 in the shirt 3 according to Fig. 9 designed so that the rotation 6 with their lateral back portions 13, 13 'at the respective longitudinal edge 19, 19' of the recess 7 'applies and thereby rotation of the anti-rotation device 6 is prevented in the circumferential direction. A similar representation also offers 6 and 7 ,

In contrast, according to the Fig. 10 to 13 Recesses 18 provided in the shirt 3, in which at the free ends of the two spring arms 8, 8 'arranged projections 17, 17' engage, thereby rotating the anti-rotation 6 in Prevent circumferential direction. According to Fig. 13 in this case, the recess 7 is formed circular, wherein the back 11 also bears with back portions 13 and 13 'at an edge 20 of the through hole 7 and also by this fact twisting the rotation 6 can be prevented in the circumferential direction.

According to the embodiment of the anti-rotation 6 in FIGS. 14 and 15 the anti-rotation device 6 is formed as a nose-like insert member 21 which is held in a radially outwardly open and radially inwardly closed groove, in particular an axial groove 12 on the plunger 1 form and / or non-positively. In this case, the radially outwardly open and radially inwardly closed groove 12 is arranged in the bottom region of the plunger 1, ie in the region in which a wall thickness of the shirt 3 and the bottom 2 is significantly greater than in the rest of the shirt area. The anti-rotation device 6 in this case preferably consists of a solid insert element 21, wherein the plunger 1 facing surface of the insert element 21 is preferably formed as a flat surface, which is placed on a likewise flat groove bottom 22. An attachment of the anti-rotation 6 and the insert element 21 in the groove 12 can be done for example by means of soldering, welding and / or gluing. It is also conceivable that the groove 12 is designed as an undercut groove, for example in the manner of a dovetail joint, and the insert element 21 has a spring formed complementary thereto, whereby not only a frictional connection but also a positive connection between the insert element 21 and the plunger 1 can be achieved.

It is also conceivable that the groove 12 is formed as the insert element 21 on all sides enclosing recess, so that no detachment of the insert element 21 is possible even in case of failure of the cohesive connection. The groove 12 or a similar depression in the plunger 1 can be easily produced by a cost milling, while the insert element 21 is inexpensive to produce as a massive forming part. The assembly of the insert element 21 is simply possible due to the self-positioning of the rotation 6 in the groove 12 and in the recess 7, whereby an assembly cost is reduced.

All features described in the description and in the following claims can be essential to the invention, both individually and in any desired form.

Claims (9)

1. A rotationally locked tappet (1) of a valve train of an internal combustion engine, preferably a bucket tappet consisting of a bottom (2) and a skirt (3), which tappet is arranged between a cam and a valve and is guided in a receiving bore of a cylinder head (4), wherein in a recess (7, 7') of the skirt (3), a radially outwardly projecting anti-rotation safeguard (6) is arranged which slides in a guide groove (5) of the cylinder head (4),
   characterized in
   that the anti-rotation safeguard (6) has two spring arms (8, 8') which extend in the circumferential direction of the tappet (1) and which rest at least in regions either against an inner circumferential surface (16) of the skirt (3) or against an outer circumferential surface (10) of the tappet (1) and fix the anti-rotation safeguard (6) on the tappet (1) by a clamping force which acts radially on said tappet (1).
2. The tappet according to claim 1,
   characterized in
   that on the inner circumferential surface (16) of the skirt (3), a radial annular groove (9') is arranged which receives the spring arms (8, 8') of the anti-rotation safeguard at least partially.
3. The tappet according to claim 1 or claim 2,
   characterized in
   that the spring arms (8, 8') of the anti-rotation safeguard (6) together form a clip covering at least more than 180°.
4. The tappet according to any one of the claims 1 to 3,
   characterized in
   that for an anti-rotation safeguard (6) having spring arms (8, 8') resting against the inner circumferential surface (16) of the skirt (3), a radially outwardly projecting back (11) is provided which force-fittingly extends at least in the circumferential direction through a through-opening (7').
5. The tappet according to any one of the claims 1 to 3,
   characterized in
   that for an anti-rotation safeguard (6) having spring arms (8, 8') resting against the outer circumferential surface (10) of the skirt (3), a radially outwardly projecting back (11) is formed which engages by means of a back region (13) in an axial groove (12) which is radially recessed on the outer circumferential surface (10) of the skirt (3).
6. The tappet according to claim 5
   characterized in
   that the back region (13, 13') is force-fittingly connected in the circumferential direction to the axial groove (12).
7. The tappet according to any one of the claims 1 to 4 or 6,
   characterized in
   that in the region of their free ends, the two spring arms (8, 8') each have a radially outwardly projecting projection (17, 17') which engages in an associated recess (18, 18') in the skirt (3) of the tappet (1).
8. A rotationally locked tappet (1) of a valve train of an internal combustion engine, preferably a bucket tappet consisting of a bottom (2) and a skirt (3), which tappet is arranged between a cam and a valve and is guided in a receiving bore of a cylinder head (4), wherein in a recess (7, 12), an anti-rotation safeguard (6) is arranged which slides in a guide groove (5) of the cylinder head (4),
   characterized by the features

   - the anti-rotation safeguard (6) is formed as nose-like insertion element (21) which is form-fittingly and/or force-fittingly retained in a recess (7, 12) on the tappet (1), which recess is open radially outwardly and closed radially inwardly,

   - the recess (7, 12) is arranged in the bottom region of the tappet (1),

   - the recess (12) is configured as undercut groove and the insertion element (21) has a spring which is formed complementary thereto.
9. The tappet according to claim 8,
   characterized in
   that the insertion element (21) is adhered or soldered or welded to the tappet (1).

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