Support element for a valve train of an internal combustion engine, and method for production of support element

Patent metadata

Field	Value
Publication number	US-9429048-B2
Application number	US-201514703052-A
Country	US
Kind code	B2
Filing date	May 4, 2015
Priority date	May 9, 2014
Publication date	Aug 30, 2016
Grant date	Aug 30, 2016

Abstract

A support element for the valve train of an internal combustion engine, having a hollow cylindrical housing that holds a displaceable piston. The piston has a hollow cylindrical pressure part and a pot-shaped work part axially adjacent thereto. An inner space of these parts forms a storage space for hydraulic medium. A high pressure space is defined by a base of the work part and the housing. The storage space and the high pressure space are connected hydraulically by a non-return valve with a ball for automatic lash compensation of the valve train. The piston is supported by a compression spring on the housing base, and a retaining ring is arranged radially between the pressure part and the housing, which limits axial travel of the piston. The ball is movably held in the base of the work part in an axial ball guide having first and second integrally formed ball seats.

First claim

The invention claimed is:

1. A hydraulic support element for insertion into a receptacle hole of a cylinder head of an internal combustion engine for lash compensation of a valve train of the internal combustion engine, the hydraulic support element comprising a hollow cylindrical housing including an outer lateral surface and a radially inner axial hole, a piston located in the radially inner axial hole, the piston is displaced coaxial to a longitudinal center axis in use, the piston includes an essentially hollow cylindrical pressure part and a pot-shaped work part connecting axially to said pressure part, at least one axial end-side head of the pressure part projects past a housing edge and is used as a support for a cam follower, an inner space of the pressure part and also an inner space of the work part form a storage space for a hydraulic medium, a high pressure space for the hydraulic medium defined by a base of the pot-shaped work part and the hole of the housing, a non-return valve hydraulically connects the storage space and the high pressure space, the non-return valve includes a ball for automatic lash compensation of the valve train, a compression spring is located between the base of the pot-shaped work part of the piston and a housing base to support the piston, and a retaining ring is arranged radially between the pressure part of the piston and the housing, said retaining ring limits an axial travel of the piston, an axially oriented ball guide is located on the base of the piston, the ball is displaceably held in the base of the work part in the axially oriented ball guide for displacement in the axial direction, the ball guide has a storage space side first ball seat and a high pressure space side second ball seat, and the two ball seats are formed with the base of the work part of the piston.

2. The support element according to claim 1 , wherein the first ball seat closes completely hydraulically for said ball contacting the first ball seat.

3. The support element according to claim 2 , wherein the second ball seat remains at least partially open for said ball contacting the second ball seat.

4. The support element according to claim 1 , wherein the second ball seat has at least one radially inward directed projection or is formed by at least one projection.

5. The support element according to claim 1 , wherein an axial material thickness of the base of the work part of the piston is equal to or greater than a diameter of the ball of the non-return valve.

6. A method for production of a hydraulic support element, comprising the following steps:
a) producing a pot-shaped work part of a piston of the hydraulic support element, which has, in a base thereof, an axially oriented ball guide that has a cylindrical section and an end-side narrowing section adjacent to said cylindrical section, wherein the narrowing section has a smaller diameter than a ball to be inserted into the ball guide and forms a storage space side first ball seat,
b) inserting a ball into the ball guide of the work part of the piston,
c) shaping the base of the work part of the piston on a high pressure space side bottom side thereof in the area of the ball guide for forming at least one radially inward pointing projection for forming a high pressure space side second ball seat, wherein the ball is held captively in the ball guide in interaction with the storage space side first ball seat and moves in an axial direction, and
d) axially inserting the piston into a housing of the hydraulic support element.

7. The method according to claim 6 , wherein the shaping in method step c) is performed by impact extrusion of the work part of the piston that is not hardened at least in some areas.

8. The method according to claim 6 , wherein the shaping in the method step c) is realized by orbital forming or by radial spot forming of the work part of the piston that is hardened at least in some areas.

9. The method according to claim 6 , wherein, before the method step a) or after the method step d), at least one of the ball, the work part, or a pressure part of the piston is subjected to a heat treatment for hardening at least in some areas.

10. The method according to claim 6 , wherein, for installation of the support element in method step d), inserting at least one compression spring acting on the work part of the piston, inserting the shaped work part of the piston having the ball held therein, inserting a pressure part of the piston, and inserting a retaining ring into a hole of the housing of the hydraulic support element and securing the retaining ring in the housing in the axial direction.

Assignees

• Schaeffler Technologies Ag

Inventors

• Dupke Stefan
• Gredy Horst
• Blasch Jochen

Classifications

• F01L1/24

  by fluid means, e.g. hydraulically · CPC title

• F01L2001/2433

  Self contained, e.g. sealed hydraulic lash adjusters · CPC title

• F01L2303/00

  Manufacturing of components used in valve arrangements · CPC title

• F01L1/2405 Primary

  by means of a hydraulic adjusting device located between the cylinder head and rocker arm · CPC title

• F01L2309/00

  Self-contained lash adjusters · CPC title