WO2010043514A1 - Switchable component for a valve drive of an internal combustion engine - Google Patents

Abstract

The invention relates to a switchable component (1) for a valve drive of an internal combustion engine, having a housing (2), in the bore (3) of which an inner element (4) is held, the head (5) of which projects above a rim (6) of the housing (2), wherein the elements (2, 4) are loaded axially away from each other by a lost-motion spring (7) inserted between said elements and at least one coupling piston (9) sits in an opening (8) of the inner element (4), sections of said coupling piston being able, in an axially removed relative position, to be moved over a ring surface (10) between said elements to a carrier surface (11) of the housing (2), wherein a retaining ring packet (13) having a circular arc-shaped outer surface (14) lies in a ring groove (12) of the bore (3) of the housing (2). A ring face (16) of the inner element (4) sits against the underside (15) of said retaining ring packet in the extended state so that the relative position is defined. The retaining ring packet (13), starting from at least one of the surfaces of said retaining ring packet [outer surface (14)/inner surface (16a)], is designed with recesses (16b) for forming tab-like sections (16c) lying circumferentially between said recesses.

Description

 Name of the invention

Switchable component for a valve train of an internal combustion engine

description

Field of the invention

Switchable component for a valve drive of an internal combustion engine, in particular plunger or support element, with a housing in the bore of an inner element is received, which lies with its head in the region of an edge of the housing or this projecting, the elements axially away from each other by a between these clamped lost-motion spring are acted upon and sitting in a recess of one of the elements at least one Koppelkolben, which in an axially remote relative position of the elements, over an annular surface between them away, in sections in a driver surface of the respective other element is displaced , wherein in an annular groove of the bore of the housing, a securing ring or a retaining ring package abuts with kreisbogenförmigem outer jacket, against the underside of the inner element abuts in the extended state with an annular end, so that the relative position is defined. Background of the invention

From the prior art switchable components such as roller tappet or support elements are previously known, in which one or two superimposed retaining rings are snapped into an annular groove whose housing. On a bottom of these circlips proposes the relatively axially movable inner element with an annular shoulder or an annular end. Thus, a height stop for the inner element in its extended position is given in the first place, so that the at least one coupling piston in the inner element to the driving surface in the housing is in alignment.

Furthermore, the coupling play can be adjusted via retaining rings arranged in a group of thicknesses (minimally necessary and, over a wide series of similar components, optimally set idle travel, which path the coupling means travels in the extended position and on the cam stroke until its driving surface is reached directly). Reference is hereby made to the documents U.S. Pat. 6,321, 704 (see Figures 2, 3) and DE 102 04 672 referenced. Usually find here standardized or similar Liehe retaining rings for use holes, which have on the principle of "bending beam", starting from their ring eyes, an increasing width, which width is greatest in a region opposite the ring eyes. This increase in width is realized on the inner jacket of the retaining rings.

It is disadvantageous in the aforementioned embodiments that the inner element at height stop on the underside of the corresponding locking ring, due to its increasing width, only an insufficiently large "sickle-like" bearing surface is available.Furthermore, it is found that a use of the above circlips in particular In the case of very small component diameters, it proves to be problematic in this case, where plastic bending or, in general, undesirably excessive stresses in the ring material occur during bending together in the case of assembly. Object of the invention

The invention has for its object to provide a component of the aforementioned type, in which the indicated disadvantages are eliminated.

Solution of the task

According to the invention, this object is achieved in that the securing ring / securing ring package, starting from at least one of its lateral surfaces [outer jacket / inner jacket], is designed with free positions for forming circumferentially intervening, flap-like sections.

Thus, there is a component in which the cited disadvantages are eliminated. In the first place, the at least one securing ring is intended to serve as a height stop for the inner element. However, it is also preferable to keep the one or more retaining rings grouped in the assembly so that the same coupling play can be set.

Furthermore, it is provided according to a particularly advantageous variant of the invention to provide over the at least one locking ring also a rotation of the inner member to the housing via mutually communicating flats.

Due to the proposed exemptions, which in concretizing the invention give the respective circlip on its corresponding outer surface, for example, a wave- or box-like profile, there is a particularly stress-optimized variant. Occurring bending stresses, especially during assembly (bending together and then snapping into the annular groove of the bore of the housing) are not here more on the principle of "bending beam" over a path evenly, but distributed on discrete zones on the principle of "flexible pipe". At the same time, the inner element is located on the corresponding locking ring a sufficiently large area, so that the tendency to tilt or the surface pressure in this area is significantly reduced.

Furthermore, it is found that when using the at least one securing ring, its mounting forces are kept within reasonable limits and it no longer comes to plastic deformation on the circlip especially for very small component diameters.

When integrating the proposed anti-rotation surface can be dispensed with elaborate separate anti-rotation measures, such as such over pressed into the housing pins o. The like.

The at least one locking ring with the exemptions according to the invention can have a constant width. However, it can also be designed so that it has, for example, at its opposite the ring eyes section a largest and in the section of the ring eyes a smallest (average) width.

For the expert, at this point a variety of design possibilities of the lateral surfaces of the corresponding locking ring. It is important at this point only that the bending stress is well distributed to discrete zones.

If, as proposed in a further development of the invention, shown on a radially projecting from the inner shell of the corresponding locking ring flattening an anti-rotation, it is particularly appropriate to let the ring eyes of the corresponding locking ring protrude radially outward into an opening of the housing and there to fix on their outsides on respective inner sides of the opening. Thus, a possibly occurring torque can be well received. In a further development of the invention, it is proposed to apply the annular groove of the bore of the housing for receiving the at least one securing ring directly in the region of the edge of the housing. However, it is also conceivable and intended to arrange the annular groove on a different height section of the bore of the housing, if necessary, the at least one securing ring can also run on the outer jacket of the inner element and with Such a configuration is expressly included within the scope of the invention.

Finally, it is proposed to position two diametrically opposed coupling pistons in the radial bore of the inner element, which in the coupling case can be displaced in the housing in the housing, for example in the form of a window, bore, annular groove or annular groove segment. The respective piston can, starting from its radially outer end, be flattened in sections on its "coupling side." However, it is also conceivable and intended to make the coupling piston cylindrical.

As a switchable component with the measures according to the invention is particularly, but not exclusively, thought of a switchable support element or a switchable roller or mushroom plunger. Preferably, the switchable component should be provided with a hydraulic lash adjuster.

By means of the at least one circlip according to the invention, it is thus possible a) to represent only one height stop, b) to make a height stop and an adjustment of a coupling play, c) to realize a height stop and an anti-rotation lock, d) to create only one twist lock or e) make a height stop and a rotation and simultaneously adjust the coupling play. It is clear that the variant "adjustment of the coupling game" includes the height stop preferred. Short description of the drawing

The invention is suitably explained in more detail with reference to the drawing. Show it:

FIG. 1 shows a component designed as a support element in a longitudinal section with two coupling pistons;

FIG. 2 shows the component according to FIG. 1, but rotated by 90 °, and FIG

• Figures 3 to 8 cross sections through the component in the section of the retaining rings.

Detailed description of the drawing

FIGS. 1, 2 disclose a switchable component 1 designed as a support element. This consists of a pot-shaped housing 2 in whose bore 3 an inner element 4 is accommodated so as to be axially movable. The latter projects beyond its head 5 an edge 6 of the housing 2. On the aforementioned head 5 can be supported at one end a drag lever.

The inner element 4 has in its lower portion designed as a radial bore recess 8. In this are, spring-loaded radially outwardly, two coupling piston 9 diametrically opposite, in which case a coupling state is shown. The respective coupling piston 9 engages with its underside shown in sections flat counter surface 29 in a trained as a window ter driving surface 11 in the housing 2 and thus bridges an annular surface 10 between the housing 2 and the inner member. 4 Between a lower side of the inner element 4 and a bottom of the housing 2, a lost-motion spring 7 is installed in a manner known per se. This acts on the inner member 4 axially out of the housing 2.

As can further be seen from FIGS. 1, 2, the bore 3 of the housing 2, near its edge 6, has an annular groove 12. In this runs a retaining ring package 13, consisting of two superimposed locking rings. The retaining ring packet 13 projects radially inwardly slightly beyond the annular surface 10 between the components 2, 4. The inner element 4 abuts against an underside 15 of the securing ring packet 13 with an annular end 16. Thus, a coupling position of the coupling piston 9 is given as shown. At the same time, the coupling play "fine-tuned" (see DE 102 04 672 cited above) is achieved by retaining rings 13 (thickness-equivalent lower and thickness-variable upper securing ring) arranged in groups of thicknesses in this variant. Alternatively, thickness-grouped coupling pistons 9 can be kept in stock or in combination with thickness-grouped securing rings 13.

As can be seen from FIG. 2, the inner element 4 on the outer casing 22 has a longitudinal contact 21 at a section intersecting the edge 6 of the housing 2. With this, a bight-chord-like flattening 20 projecting radially inward from the inner jacket 16a of the respective securing ring 13 communicates (See Fig. 3 to 8). Ring eyes 17, 18 of the securing ring 13, which are diametrically opposed to the longitudinal flat 21, protrude radially outward and protrude into an opening 23 of the housing 2 (see Figure 4). They lie with their outer sides 25, 26 on upright end walls 27, 28 of the opening 23 and support a possible torque outstanding. Thus, a simply constructed anti-rotation of the inner member 4 relative to the housing 2 is shown and it can be dispensed with intro- ducing measures as described above.

The following explanations relate to the specific embodiment of the at least one securing ring 13. In this case, the retaining ring 13, based on standardized retaining rings for holes, a constant outside diameter (outer circle A). On the outer casing 14 and / or on the inner casing 16a of the securing ring 13 are formed exemptions 16b for forming circumferentially intervening, flap-like sections 16c. The locking ring 13 has according to Figure 3, a corrugated profile, according to Figure 4, a groove profile, according to Figures 5, 6, a tooth or box profile and according to Figures 7, 8, in turn, a wave profile.

Due to the design according to the invention of the at least one securing ring 13, the bending stresses in the assembly case, especially in the case of very small bore diameters, are significantly minimized compared to the previous solutions and the risk of plastic deformation on the retaining ring 13 is reduced or eliminated.

Furthermore, it is found that due to the measures according to the invention, the inner element 4 has an excellently formed bearing surface when it rests with its annular end 16 on an underside 15 of the retaining ring packet 13, so that the component load and tilt tendency of the inner element 4 is reduced.

List of reference numbers and symbols

1) component 28) end wall

2) housing 35 29) mating surface 3) bore A) enveloping circle

4) inner element B) enveloping circle

5) head

6) edge

7) Lost motion spring 8) recess

9) Coupling piston

10) annular surface

11) driving surface

12) annular groove 13) retaining ring, retaining ring package

14) outer shell

15) Base

16) ring end 16a) inner sheath

16b) exemption

16c) section

17) ring eye

18) ring eye 19) section

20) flattened portion

21) longitudinal flat

22) outer surface area

23) opening 24) not awarded

25) outside

26) outside

27) end wall

Claims

claims 1. Switchable component (1) for a valve train of an internal combustion engine, in particular plunger or support element, with a housing (2), in the bore (3) an inner element (4) is received, with its head (5) in the region of an edge (6) of the housing (2) or projects beyond this, wherein the elements (2, 4) axially away from each other by a clamped therebetween Lost-motion spring (7) are acted upon and in a recess (8) of one of the elements ( 4, 2) at least one coupling piston (9) is seated, which in an axially remote relative position of the elements (4, 2), via an annular surface (10) between them away, in sections in a driver surface (11) of the other Elements (2, 4) is displaceable, wherein in an annular groove (12) of the bore (3) of the housing (2) a locking ring or a retaining ring package (13) with arcuate outer jacket (14) abuts against the underside (15), the inner element (4) strikes in the extended state with an annular end (16), so that the relative position is defined, characterized in that the securing ring / securing ring packet (13), starting from at least one of its lateral surfaces [outer casing (14) / inner casing (13)] 16a)], with exemptions (16b) for forming circumferentially intermediate, flap-like sections (16c) is formed. 2. Component according to claim 1, characterized in that between enveloping circles (A, B) of the securing ring / retaining ring package (13) formed and of which one to the other ring eye (17, 18) extending ring is formed with a substantially constant width. 3. Component according to claim 1, characterized in that between enveloping circles (A, B) of the securing ring / retaining ring packet (13) formed ring in its ring eyes (17, 18) of the securing ring / fuse ring package (13) opposite portion (19) one biggest Width has, which width decreases from the portion (19) in the circumferential direction on the ring eyes (17, 18) seen at the inner enveloping circle (B). 4. Component according to claim 1, characterized in that on the retaining ring / the retaining ring package (13) a coupling play is finely adjusted, wherein in the case of use of only one securing ring (13) this is stored in a group thickness grouped and wherein in the case of use of the circlip package (13) [two or more circlips] in a mounting thick constant lower and thick topmost retaining rings (13) are kept. 5. Component according to claim 1 or 4, characterized in that from the inner jacket (16a) of the securing ring / retaining ring package (13) a bow chord-like flattening (20) projects radially inwards, with a complementary Längsanflachung (21) on an outer circumferential surface (22). the inner element (4) cooperates, ring eyes (17, 18) of the Circlip / retaining ring packages (13) bent radially outwardly in an opening (23) of the housing (2) sit and with their outer sides (25, 26) on end walls (27, 28) of the opening (23) lie, such that an anti-rotation of the inner member (4) to the housing (2) is shown. 6. Component according to claim 1, characterized in that the annular groove (12) of the bore (3) of the housing (2) for receiving the securing ring / retaining ring package (13) directly in the region of the edge (6) of the housing (2). 7. Component according to claim 1, characterized in that the exemptions (16b) in conjunction with the flap-like portions (16c) of the respective lateral surface [outer jacket (14) / inner jacket (16a)] impart a wave, tooth or box-like profile. 8. The component according to claim 1, characterized in that the recess (8) in the inner element (4) and is formed as a radial bore in which exactly two coupling piston (9) are opposite, wherein the driving surface (11) in the housing (2 ) either as a window, bore, Ring groove or is formed as an annular groove segment, wherein a mating surface (29) of the Koppelkobens (9) for this purpose is complementary [flat or cylindrical].