Lash compensator spring end cap

Patent metadata

Field	Value
Publication number	US-10072535-B2
Application number	US-201715402576-A
Country	US
Kind code	B2
Filing date	Jan 10, 2017
Priority date	Jan 10, 2017
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

A lash compensator for a valve train component of an internal combustion engine is provided that includes an end-cap arranged within a reverse-spring control valve assembly of an axially moveable piston. The piston has a first reservoir and an inner radial wall configured with a through-aperture. The reverse-spring control valve assembly has a control valve housing, a bias spring, an end-cap, and a closing body. The end-cap is configured with a cupped end; an inner side of the cupped end receives a second lower end of the bias spring, and an outer side of the cupped end engages an upper portion of the closing body. The end-cap minimizes or eliminates the variation in flow resistance caused by a variation in end-coil geometry of the second lower end of the bias spring.

First claim

What I claim is:

1. A lash compensator for a valve train of an internal combustion engine comprising:
a central axis;
a piston assembly configured for axial movement within a bore of an outer housing, the piston assembly including:
a piston having:
a first reservoir; and,
an inner radial wall configured with a through-aperture; and,

a control valve assembly having:
a control valve housing configured with at least one fluid port, a first side of a retaining end of the control valve housing engaged with a bottom surface of the piston;
a bias spring axially aligned with the through-aperture, a first upper end of the bias spring engaged with the bottom surface of the piston; and,
an end-cap configured with a cupped end, an inner side of the cupped end receiving a second lower end of the bias spring and an outer side of the cupped end engaging an upper portion of a closing body, including a ball, the closing body axially guided by the control valve housing to move from a first open position to a second closed position.

2. The lash compensator of claim 1 , further comprising:
a spring having a third upper end engaged with a second side of the retaining end of the control valve housing and a fourth lower end engaged with a bottom surface of the bore of the outer housing.

3. The lash compensator of claim 2 , wherein the bottom surface of the piston and the bottom surface of the bore define a high pressure chamber.

4. The lash compensator of claim 3 , wherein the first open position allows flow of hydraulic fluid through the through-aperture between the high pressure chamber and the first reservoir and the second closed position prevents flow of hydraulic fluid through the through-aperture.

5. The lash compensator of claim 4 , wherein:
the closing body engages a stop arranged on the control valve housing in the first open position, the stop arranged at an end opposite the retaining end; and,
the closing body engages a valve seat formed on the bottom surface of the piston in the second closed position.

6. The lash compensator of claim 1 , wherein the bias spring biases the closing body to the first open position.

7. The lash compensator of claim 1 , wherein the cupped end of the end-cap is configured with a through-hole.

8. The lash compensator of claim 1 , wherein the cupped end of the end-cap is configured with a piloting land.

9. The lash compensator of claim 1 , wherein the piston assembly is a component within a valve lifter.

10. The lash compensator of claim 1 , wherein the piston assembly is a component within a pivot element.

11. The lash compensator of claim 1 , wherein the piston assembly is a component within a rocker arm.

12. The lash compensator of claim 1 , wherein the piston assembly is a component with a tappet.

13. The lash compensator of claim 1 , wherein the end-cap is made from metal.

14. The lash compensator of claim 13 , wherein the end-cap is formed from a stamping process.

15. The lash compensator of claim 13 , wherein the end-cap is formed from a powdered metal process.

16. The lash compensator of claim 1 , wherein the end-cap is made from plastic.

17. The lash compensator of claim 16 , wherein the end-cap is formed from an injection molding process.

18. A lash compensator for a valve train of an internal combustion engine comprising:
a piston assembly configured for axial movement within a bore of an outer housing, the piston assembly including:
a piston having:

a first reservoir; and,
a through-aperture arranged within an inner radial wall; and,
a control valve assembly having:
a control valve housing configured with at least one fluid port, a first side of a retaining end of the control valve housing engaged with a bottom surface of the piston;
a bias spring axially aligned with the through-aperture, a first upper end of the bias spring engaged with the bottom surface of the piston; and,
an end-cap configured with a cupped end, an inner side of the cupped end receiving a second lower end of the bias spring and an outer side of the cupped end engaging an upper portion of a closing body, including a ball;
the closing body axially disposed within and guided by the control valve housing to move from a first open position to a second closed position;
the closing body engaging a stop arranged on the control valve housing in the first open position, the stop located at an end opposite the retaining end; and,
the closing body engaging a valve seat formed on the bottom surface of the piston in the second closed position; and
a return spring having a third upper end engaged with a second side of the retaining end of the control valve housing and a fourth lower end engaged with a bottom surface of the bore of the housing.

Assignees

• Schaeffler Technologies Ag

Inventors

• Stallmann John

Classifications

• F01L1/143

  for use with overhead camshafts · CPC title

• F01L2301/00

  Using particular materials · CPC title

• F01L13/065

  Compression release engine retarders of the "Jacobs Manufacturing" type · CPC title

• F01L2305/00

  Valve arrangements comprising rollers · CPC title

• F01L1/08

  Shape of cams · CPC title