EP2010758B1 - Hydraulic support element for a lever-like cam follower of a valve drive of an internal combustion engine - Google Patents

Description

Field of the invention

• der Druckkolben komplett einteilig dargestellt ist;
• das Uinlenkelement mit seiner kopffernen Stirn unmittelbar auf dem Ringsteg steht sowie axial unterhalb von dem Durchlass direkt bis zu der kopffernen Stirn dichtend am Innenmantel des Druckkolbens anliegt; und
• die kopfseitige Stirn des Umlenkelements etwa auf oder axial oberhalb eines Drehmittelpunkts des Kugelkopfes liegt.

The invention relates to a hydraulic support member for a lever-like cam follower of a valve train of an internal combustion engine, with a pot-like housing which is installed with its outer shell in a cylinder head of the internal combustion engine or in a connected to the engine component and in its bore an axially movable, a storage space for Includes hydraulic means and acted upon by a spring means away from the housing pressure piston which projects beyond a front of the housing with a ball head for the cam follower and bore side has a ring land with a check valve, between which ring land and a bottom of the housing, a high pressure chamber for the hydraulic medium is formed which is fed from the reservoir via the check valve with the hydraulic means, wherein the housing is immanent at least one passage for the hydraulic fluid from the cylinder head, the radially inner with at least one Em passage in the pressure piston communicates and wherein in the reservoir a sleeve-like deflection element for the hydraulic medium, between the outer shell and an inner surface of the pressure piston, starting from the passage, a climbing path for the hydraulic medium is formed, at its end the hydraulic fluid along a head-side end of the deflection in its interior for direct accumulation in front of the check valve is conductive, and wherein

• the pressure piston is shown completely in one piece;
• the Uinlenkelement with its head-long forehead is directly on the ring land and abuts axially below the passage directly up to the head distant forehead seal on the inner surface of the pressure piston; and
• the head-side end of the deflecting element lies approximately on or axially above a center of rotation of the ball head.

Background of the invention

A support element is in the DE 10 2004 006 903 A1 disclosed. This has a multipart pressure piston, which is expensive to add. It can be seen that its deflecting element with its head end extends only approximately to a region of a constriction below the ball head and has a relatively large radial distance from the inner surface of the pressure piston above the passage. The deflecting element thus includes only an insufficient amount of hydraulic fluid. In addition, a hydraulic medium-tight fastening of the deflecting proves to be critical.

Due to the relatively low storable amount of hydraulic fluid can occur after start but also during operation of the internal combustion engine that there is not enough hydraulic fluid for a proper clearance compensation available. In addition, in the case of oblique installation of the support element, an excessive amount of hydraulic fluid can escape from the interior of the deflection element, so that the stated problem becomes more acute.

Furthermore, the JP 6 173622 A a support element, in which a deflecting element is accommodated in a pressure piston. Again, the deflecting extends only over a small part of the pressure piston.

Another support element goes out of the EP 0 361 637 A1 in which a deflecting element is accommodated in a one-piece pressure piston. A hollow cylindrical section of the deflecting element extends from a passage in the pressure piston to just below its ball head.

Finally, the reveals JP 2004 197665 A a hydraulic support element with a deflecting element having a pressure piston. This deflecting element extends into a ball head of the integrally formed pressure piston.

Object of the invention

The object of the invention is to provide a support element, in which a large amount of hydraulic fluid can be kept by a deflecting element.

Solution of the task

According to the invention, this object is achieved in that the deflecting element rests against the inner shell at least predominantly, except for the climbing path.

As a result, there is a sufficiently large supply of hydraulic fluid in the interior of the deflecting element. At the same time, the support element is designed particularly leak-proof. Due to the one-piece design of the pressure piston, the manufacturing costs prove to be favorable overall, as can be dispensed with a joining in the otherwise multi-part variants.

It is clear to the person skilled in the art that the deflecting element is inserted into the pressure piston before the ball head is closed by a production process such as press-flanging or the like. The deflecting element can be represented for example from a sheet metal material. However, it is also intended for a training in plastic.

Preferably, the deflecting element extends with its head-side forehead close to or at least as close as possible (oil passage) to the underside of the ball head, so that here a maximum high oil column can be included.

A simple variant of a fastening of the sleeve-like deflecting element on the inner surface of the pressure piston is present when it snapped to a region axially below a Ringeinformung, glued, crimped, pressed, welded, soldered, clamped o. The like. In this case, the aforementioned Ringeinformung be provided for particular axial fixation of the deflecting element.

Due to the fact that the deflecting element rests axially all around the passage in the pressure piston and all around the inner jacket thereof and with its head-long forehead rests on an annular web of the pressure piston with the check valve, a particularly good sealing of the riser path from the reservoir (interior of the deflecting element) is given.

Optionally, the ball head of the pressure piston may still have a passage such as a central bore, so that a lubrication of the cam follower is given in the contact area.

It is particularly preferred if the deflection element above the passage rests directly on this inner jacket except for the climbing path. Alternatively, the climbing path can also run in the inner jacket of the pressure piston and sealed by the deflecting element or be arranged completely in the pressure piston.

Another contribution towards leakage safety is given when the head-side end of the deflecting element is formed with a radially inwardly facing annular collar. This training proves to be particularly advantageous at obliquely to the perpendicular built-support.

Preferably, an outgoing from the passage climbing path is provided. However, circumferentially distributed paths can also be applied. Likewise, it is intended to multiple passages and passages (seen in the circumferential direction).

According to a development of the invention, the deflection can be installed against rotation in the pressure piston, in which case a simple to be displayed Longitudinal shaping is thought of a component that communicates with a complementary indentation on the other component.

As a cam follower that can be mounted on the support element, in particular a towing lever (switchable or nichtschaltbarer nature) but also to a rocker arm (switchable or nichtschaltbarer nature) is intended. Optionally, cam followers can rest, which serve for the simultaneous actuation of several identical gas exchange valves.

Short description of the drawing

Figur 1

eine bevorzugte Variante eines erfindungsgemäßen Abstützelements mit weitestgehend allumlaufend anliegendem Umlenkelement;

Figur 2

in einem Teilschnitt eine räumliche Darstellung des Druckkolbens nach Figur 1;

Figur 3

in einer räumlichen Ansicht das Umlenkelement aus Figur 1;

Figuren 4-6

in schematischen Teilansichten das Umlenkelement mit verschiedenartig ausgebildeten kopfseitigen Stirnen.

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

FIG. 1

a preferred variant of a support element according to the invention with largely allumend lying deflecting element;

FIG. 2

in a partial section a spatial representation of the pressure piston after FIG. 1 ;

FIG. 3

in a spatial view of the deflection FIG. 1 ;

Figures 4-6

in schematic partial views of the deflecting element with differently shaped head-side forehead.

Detailed description of the drawing

Shown is a hydraulic support element 1, consisting of a pot-like housing 2, in the bore 4 axially movable, a pressure piston 7 is installed. The housing 2 is closed by a bottom 12 and can over his Outer jacket 3 in a recording of a cylinder head not shown o. The like. Are installed stationary.

The pressure piston 7 protrudes with its ball head 9 a forehead 8 of the housing 2. On the ball head 9 at one end a rocker arm (switchable, non-switchable) are pivotally mounted. Axially below the ball head 9, a constriction 23 is arranged in the pressure piston 7. This guarantees a free pivoting mobility of the resting cam follower.

The pressure piston 7 includes a reservoir 5 for hydraulic fluid. This is the housing side limited by a ring land 10 with a check valve 11 attached thereto. Axially below the annular web 10, a high-pressure chamber 13 is formed. This is supplied with hydraulic fluid from the aforementioned storage space 5 via the check valve 11 in a known manner.

Furthermore, it is shown that the pressure piston 7 is acted upon out of the housing 2 by a spring means 6.

In the interior of the pressure piston 7, an axially almost continuous, sleeve-like deflection element 16 is installed. This is preferably (no condition) with his head distant forehead 22 on the ring land 10. Axially below a running inside the housing 2 Ringeinformung 29 (s. Fig. 3 ), the deflecting element 16 is sealingly applied to the inner shell 18 of the pressure piston 7. In approximately in the area of the ring indentation 29, the pressure piston 7 has a passage 15 for hydraulic fluid. This communicates with a passage 14 in the housing 2. In this case, an annular groove is introduced in the bore 4 of the housing 2, so that the pressure piston 7 can be installed without rotation.

The aforementioned deflecting element 16 extends in the one-piece in all variants pressure piston 7 with its head-side end 21 immediately below the ball head 9. It has according to FIG. 1 in this area a roof-like ring collar 30. This ensures a special leakage safety. According to the preferred embodiment according to FIG. 1 (see also FIGS. 2, 3 ) is the deflection element 16 to the climbing path 19 completely on the inner shell 18 of the pressure piston 7 at. It is only in the outer jacket 17 of the deflecting element 16, a longitudinal channel 24 is introduced as a riser 19, which is in fluid communication with the passage 15.

In this case, the deflecting element 16 should be installed against rotation. Specifically, this consists of a longitudinal shaping 26 on the deflection element 16, which is in operative connection with a complementary indentation 27 on the inner casing 18 of the pressure piston 7.

The Figures 4-6 show different variants of a design of the head-side end 21 of the deflecting 16. According to FIG. 4 can (see also FIG. 1 ) the deflecting element 16 in this area be sleeve-like open. However, it is also intended, as well as FIG. 5 shows, apply a radially inwardly whitening ring collar 30, which extends here like a roof chamfered.

To FIG. 6 the aforesaid annular collar 30 is employed orthogonal to the outer jacket 17 of the deflecting element 16. Exactly the latter two variants offer an additional leakage protection.

reference numerals

• 1) support element
• 2) housing
• 3) outer jacket
• 4) bore
• 5) pantry
• 6) Spring means
• 7) plunger
• 8) brow case
• 9) Ball head
• 10) annular web
• 11) Check valve
• 12) Soil
• 13) high pressure room
• 14) passage
• 15) passage
• 16) deflecting
• 17) outer shell
• 18) inner shell
• 19) rising path
• 20) end portion
• 21) head on the forehead
• 21a) interior
• 22) head forehead
• 23) necking
• 24) longitudinal channel
• 25) anti-rotation
• 26) Längsausformung
• 27) indentation
• 29) Ringeinformung
• 30) annular collar

Claims (8)

1. Hydraulic supporting element (1) for a lever-like cam follower of a valve train of an internal combustion engine, having a pot-like housing (2) which can be installed with its outer shell (3) into a cylinder head of the internal combustion engine or into a component which is connected to the internal combustion engine and, in a bore (4), has an axially movable pressure piston (7) which encloses a storage space (5) for hydraulic medium, is loaded away from the housing (2) by way of a spring means (6), protrudes beyond an end (8) of the housing (2) with a spherical head (9) for the cam follower and, on the bore side, has an annular web (10) with a check valve (11), between which annular web (10) and a bottom (12) of the housing (2) a high pressure space (13) for the hydraulic medium is formed, which high pressure space (13) can be fed with the hydraulic medium from the storage space (5) via the check valve (11), at least one passage (14) for the hydraulic medium out of the cylinder head being intrinsic to the housing (2), which passage (14) communicates radially on the inside with at least one through duct (15) in the pressure piston (7), and a sleeve-like deflection element (16) for the hydraulic medium running in the storage space (5), between the outer shell (17) of which deflection element (16) and an inner shell (18) of the pressure piston (7), starting from the through duct (15), a riser path (19) is formed for the hydraulic medium, in the end region (20) of which riser path (19) the hydraulic medium can be guided along a head-side end (21) of the deflection element (16) into its interior (21a) for direct accumulation in front of the check valve (11), and

   the pressure piston (7) being configured completely in one piece;

   the deflection element (16) standing with its end (22) which is remote from the head directly on the annular web (10) and bearing sealingly against the inner shell (18) of the pressure piston (7) axially below the through duct (15) directly as far as the end (22) which is remote from the head; and

   the head-side end (21) of the deflection element (16) lying approximately on or axially above a centre point of rotation of the spherical head (9), characterized

   in that the deflection element (16) bears axially above the through duct (15) at least predominantly against the inner shell (18), apart from the riser path (19).
2. Supporting element according to Claim 1, characterized in that the pressure piston (7) is provided with a constriction (23) axially below the spherical head (9) and above the housing (2).
3. Supporting element according to Claim 1, characterized in that, starting from the through duct (15), a longitudinal channel (24) is formed as riser path (19) in the deflection element (16) as far as the head-side end (21), and in that the deflection element (16) bears with its outer shell (17) outside the riser path (19) at least virtually completely against the inner shell (18) of the pressure piston (7).
4. Supporting element according to Claim 1 or 3, characterized in that the deflection element (16) runs via an anti-rotation safeguard (25) with respect to the pressure piston (7).
5. Supporting element according to Claim 4, if it refers back to Claim 3, characterized in that either the deflection element (16) or the pressure piston (7) has a longitudinal shaped-out formation (26) which is seated in a complementary formed recess (27) of the respectively other component (7, 16) for anti-rotation safeguard purposes.
6. Supporting element according to Claim 1, characterized in that, at least in the vicinity of the through duct (15), the pressure piston (7) is provided with a circumferential annular formed recess (29), on which the deflection element (16) experiences axial securing.
7. Supporting element according to Claim 2, characterized in that the head-side end (21) of the deflection element (16) is provided with a radially inwardly pointing annular collar (30).
8. Supporting element according to Claim 7, characterized in that the annular collar (30) runs approximately orthogonally with respect to the outer shell (17) of the deflection element (16) or is set against it in a roof-like manner.

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