DE102015223881A1 - Hydraulic clearance compensation device for a valve train of an internal combustion engine - Google Patents

Abstract

In a hydraulic lash adjuster for a valve train of an internal combustion engine, with a receiving housing (14), arranged in this piston (15) and in the receiving housing (14) movably guided inner housing (16) which is closed with a front end support head (18) and a pressure chamber (19) delimited by the pressure surface of the piston (15), the inner housing (16) and the piston (15) being connected in the pressure space (19) between the support head (18) and the piston (15). 15) arranged return spring (20) are supported against each other, the play compensation device according to the invention as a roller tappet (7) with an outer housing (10) is formed, in which the receiving housing (14) is fitted as part of a hydraulic compensating element, wherein the outer housing (10) in the region of its axial end surrounding the support head (18) of the inner housing (16), a conical insertion geometry on its inner wall ie (21) with an inner retaining groove (22) for mounting a retaining ring (23) for securing the position of the receiving housing (14) in the outer housing (10).

Description

The invention relates to a hydraulic clearance compensation device for a valve train of an internal combustion engine, comprising a receiving housing, a piston arranged therein and a movably guided in the receiving housing inner housing which is closed at the front end with a support head and a pressure chamber which is bounded by the pressure surface of the piston wherein the inner housing and the piston are supported against each other via a return spring disposed in the pressure space between the support head and the piston.

Background of the invention

A valve train for an internal combustion engine is, for example, from the document DE 101 42 329 A1 out. In this an elongated anti-rotation bridge is mentioned, which has at intervals arranged one behind the other receiving spaces for valve tappets. In each receiving space designed as a roller tappet valve stem is arranged, which is directed at one axial end with a plunger roller on a cam of a camshaft, while acting on its other axial end of a push rod.

A clearance compensation device of the type mentioned is from the document DE 10 2012 200 755 A1 known. In this device, the problem to be solved, to simplify their production and to make cost-effective. About the structural arrangement of the receiving housing of the device in the valve train this document specifications are not apparent.

Summary of the invention

The invention is therefore based on the object to provide a device with an integrated hydraulic compensation element, which can be delivered captive and installed without assembly problems in the internal combustion engine.

This object is achieved in that the play compensation device is designed as a roller tappet with an outer housing in which the receiving housing is used as part of a hydraulic compensating element suitably, wherein the outer housing in the region surrounding the supporting head of the inner housing axial end on its inner wall a conical insertion geometry Having an inner retaining groove for mounting a retaining ring for securing the position of the receiving housing in the outer housing.

The securing ring can be displaced in a simple manner by means of a mounting tool on the inner wall of the outer housing in this axially on the inner wall and locked in the inner retaining groove of the receiving housing.

Short description of the drawing

An embodiment of the invention is illustrated in the drawing and will be described together with two embodiments of the prior art in the following. Show it

1 a roller tappet according to the invention, which is installed between a push rod at its lower end and a cam of a camshaft at its upper end, in longitudinal section;

2 the roller tappet according to 1 in a rotated about its longitudinal axis by 90 ° position, in longitudinal section;

3 a cross section through the roller tappet according to line III-III of 1 ;

4 the range of 1 in which are located in the roller tappet outer housing a conical insertion geometry and a retaining groove, in an enlarged view;

5 a clearance compensation device for a valve train according to the prior art, in a longitudinal section;

6 a valve train me four roller tappets according to the prior art, in a view.

Detailed description of the drawing

A previously known, in 6 illustrated valve train includes a camshaft with cams, which are intended to act on ram rollers of roller tappets. The roller tappet are held at their ends, which are remote from the plunger rollers, longitudinally displaceable in a common anti-rotation bridge and secured against rotation. The anti-rotation bridge with the roller tappets is mounted in the engine block of the internal combustion engine. By the subsequent installation of an associated push rod for each roller tappet, which, however, is shown only for a roller tappet, this is pushed out of each retaining grooves of the bridge until it gets in contact with the associated cam of the camshaft.

As another prior art embodiment is in 5 a clearance compensation device shown. It serves to compensate the valve clearance of a gas exchange valve in an internal combustion engine, wherein the gas exchange valve can be actuated by a cam follower, not shown in the valve train. The device has a receptacle 1 , a fixedly arranged in this piston 2 and one in the recording 1 movably guided housing 3 on. At the with a support head 4 closed hollow cylindrical housing 3 the cam follower can be supported. The housing 3 includes a pressure space through the frontal pressure surface of the piston 2 is limited. The piston and the housing are via a return spring 5 supported against each other, in the pressure space between the support head 4 and the piston 2 is arranged. Below the support point of the return spring 5 in the case 3 is a central cavity 6 in the support head 4 formed, which forms a part of the pressure chamber. In the area of the cavity 6 is by a slight constriction an undercut on the support head 4 executed. The constriction forms at its the front end of the Abstützkopfes 4 facing edge an annular edge 8th , which defines there a frontally flattened crowned investment area. The cavity 6 points to the front end of the support head 4 towards a pocket-like section 9 on, which lies in the mounted state at the lowest point of the pressure chamber in the gravitational field and thus forms a contamination collecting bag.

A hydraulic lash adjuster according to the invention, which consists of the 1 to 4 is apparent as a roller tappet 7 with an outer housing 10 executed. The roller tappet has a tappet roller at its upper end 11 on. The plunger roller is rotatably mounted there with a rolling bearing. On the ram roll 11 acts a cam 12 a camshaft 13 one. The outer housing 10 is executed circular cylindrical. It contains as a recording also a circular cylindrical receiving housing 14 with a piston arranged therein 15 , of an axially displaceable, circular cylindrical inner housing 16 is surrounded. This is from the bottom of the outer casing 10 out into the annular cavity between the receiving housing 14 and the piston 15 partially inserted. The inner case 16 has at its lower end in a push rod 17 mounted support head 18 on, with which it is closed. In its lower part contains the inner housing 16 a pressure room 19 , In this is designed as a helical compression spring return spring 20 arranged, which with one end in the region of the support head 18 in the inner housing 16 and with the other end on the lower end of the piston 15 is supported.

The outer housing 10 is open at the end in the region of its lower axial end. It has there on its inner wall a conical insertion geometry 21 on, at the upper end of an inner retaining groove 22 followed. In this case, the inner cross section of the outer housing tapers 10 in the direction from bottom to top to the top of the insertion geometry 21 located inner retaining groove 22 of the outer ring 10 , This makes it possible in the assembly of the roller tappet 7 for securing the position of the receiving housing 14 in the outer casing 10 a circlip 23 to be mounted in a simple manner, which, however, in 4 not yet shown. As 2 shows, can with a mounting tool 24 the receiving housing 14 in the outer casing 10 pushed into its upper end position and at the same time the retaining ring 23 via the conical insertion geometry 21 on the inner wall of the outer housing 10 be moved axially from bottom to top. This is the circlip 23 constricted in its outer diameter until it enters the inner retaining groove 22 engages and thus the arrangement of the receiving housing 14 in the outer casing 10 safeguards.

LIST OF REFERENCE NUMBERS

 1

admission

 2

piston

 3

casing

 4

Abstützkopf

 5

Return spring

 6

cavity

 7

roller plunger

 8th

annular edge

 9

bag-like section

 10

outer casing

 11

tappet roller

 12

cam

 13

camshaft

 14

receiving housing

 15

piston

 16

inner housing

 17

pushrod

 18

Abstützkopf

 19

pressure chamber

 20

Return spring

 21

introduction geometry

 22

inner holding groove

 23

circlip

 24

assembly tool

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10142329 A1 [0002]
• DE 102012200755 A1 [0003]

Claims (2)

Hydraulic clearance compensation device for a valve train of an internal combustion engine, with a housing ( 14 ), in this arranged piston ( 15 ) and one in the receiving housing ( 14 ) movably guided inner housing ( 16 ) equipped with a support head ( 18 ) is closed at the front and a pressure chamber ( 19 ) formed by the pressure surface of the piston ( 15 ) is limited, wherein the inner housing ( 16 ) and the piston ( 15 ) via one in the pressure chamber ( 19 ) between the support head ( 18 ) and the piston ( 15 ) arranged return spring ( 20 ) are supported against each other, characterized in that the play compensation device as a roller tappet ( 7 ) with an outer housing ( 10 ) is formed, in which the receiving housing ( 14 ) is inserted as part of a hydraulic compensating element fitting, wherein the outer housing ( 10 ) in the area of its support head ( 18 ) of the inner housing ( 16 ) surrounding its axial end on its inner wall a conical insertion geometry ( 21 ) with an inner retaining groove ( 22 ) for mounting a retaining ring ( 23 ) for securing the position of the receiving housing ( 14 ) in the outer housing ( 10 ) having. A clearance compensation device according to claim 1, characterized in that the retaining ring ( 23 ) by means of an assembly tool ( 24 ) via the conical insertion geometry ( 21 ) on the inner wall of the outer housing ( 10 ) axially displaced therein and into the inner retaining groove ( 22 ) of the outer housing ( 10 ) is engaged.

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