Valve train of an internal combustion engine

Patent metadata

Field	Value
Publication number	US-11041416-B2
Application number	US-202016817580-A
Country	US
Kind code	B2
Filing date	Mar 12, 2020
Priority date	Mar 13, 2019
Publication date	Jun 22, 2021
Grant date	Jun 22, 2021

Abstract

A valve train of an internal combustion engine may include a camshaft, first and second cams, a rocker arm assembly having a displacement bolt, which may be adjustable between at least first and second positions in the axial direction and on which at least one cam roller, may be mounted in an axially fixed and rotatable manner, wherein the displacement bolt may be mounted in associated bearing lugs of the rocker arm assembly, a guide contour arranged on the camshaft and having first and second guide tracks, a switching pin, which may be arranged in the displacement bolt and which may optionally engage with the first or second guide track to adjust the displacement bolt between the first and second positions. In the first and second positions, the cam roller may cooperate with the first and second cams, respectively. First and second catch recesses may be provided on the displacement bolt. A catch device may engage with a catch element, which may be biased into the first or second catch recess and which may secure the displacement bolt in the first or second position. The first and second guide tracks may cross one another in a crossing region. A third catch recess may be provided between the first and second catch recesses, wherein a first catch protuberance may be arranged between the first and the third catch recesses, and a second catch protuberance may be arranged between the second and the third catch recesses, wherein the catch element may engage with the third catch recess in the crossing region.

First claim

The invention claimed is:

1. A valve train of an internal combustion engine, the valve train comprising:
a camshaft including a first cam and a second cam arranged axially adjacent to the first cam;
a rocker arm assembly including:
a displacement bolt extending parallel to the camshaft and configured to be axially adjusted between at least a first position and a second position with respect to the rocker arm assembly; and
at least one cam roller rotatably mounted on the displacement bolt;

a guide contour arranged on the camshaft, the guide contour including a first guide track and a second guide track; and
a switching pin extending perpendicularly through the displacement bolt, the switching pin configured to alternately engage the first and second guide tracks so as to adjust the displacement bolt between the first and second positions;
wherein the at least one cam roller cooperates engages the first cam when the displacement bolt is in the first position, and the at least one cam roller engages the second cam when the displacement bolt is in the second position;
wherein the displacement bolt comprises a catch unit including a first catch recess and a second catch recess arranged axially adjacent to the first catch recess;
wherein the rocker arm assembly further includes a catch device configured to alternately bias a catch element into engagement with the first and second catch recesses so as to secure the displacement bolt in the first and second positions, respectively;
wherein the first and second guide tracks intersect each other in a crossing region of the guide contour;
wherein the catch unit further includes a third catch recess arranged between the first catch recess and the second catch recess, a first catch protuberance arranged between the first and third catch recesses, and a second catch protuberance arranged between the second and third catch recesses; and
wherein the catch element engages the third catch recess when the switching pin is in the crossing region.

2. The valve train according to claim 1 , wherein at least one of the first catch protuberance and the second catch protuberance has a rounded or pointed tip.

3. The valve train according to claim 1 , wherein:
a first edge of the first catch protuberance, sloping towards the third catch recess, has a greater down-grade than a second edge of the first catch protuberance, sloping towards the first catch recess; and/or
a first edge of the second catch protuberance, sloping towards the third catch recess, has a greater down-grade than a second edge of the second catch protuberance, sloping towards the second catch recess.

4. The valve train according to claim 1 , wherein the catch element is formed as a ball.

5. The valve train according to claim 1 , wherein:
an axial length of the third catch recess is greater than an axial length of the first catch recess and an axial length of the second catch recess; and/or
a radial height of at least one of the first catch protuberance and the second catch protuberance is less than a radius of the displacement bolt.

6. The valve train according to claim 1 , wherein at least one of the first catch protuberance and the second catch protuberance is at least one of cured, heat-treated, and coated.

7. A displacement bolt for a valve train, the displacement bolt comprising:
a catch unit including:
a first catch recess and a second catch recess arranged axially adjacent to the first catch recess;
a third catch recess arranged between the first catch recess and the second catch recess;
a first catch protuberance arranged between the first and third catch recesses; and
a second catch protuberance arranged between the second and third catch recesses.

8. The displacement bolt according to claim 7 , wherein at least one of the first catch protuberance and the second catch protuberance has a rounded or a pointed tip.

9. The displacement bolt according to claim 7 , wherein:
a first edge of the first catch protuberance, sloping towards the third catch recess, has a greater down-grade than a second edge of the first catch protuberance, sloping towards the first catch recess; and/or
a first edge of the second catch protuberance, sloping towards the third catch recess, has a greater down-grade than a second edge of the second catch protuberance, sloping towards the second catch recess.

10. The displacement bolt according to claim 7 , wherein:
an axial length of the third catch recess is greater than an axial length of the first catch recess and an axial length of the second catch recess; and
a radial height of at least one of the first catch protuberance and the second catch protuberance is less than a radius of the displacement bolt.

11. The displacement bolt according to claim 7 , wherein at least one of the first catch protuberance and the second catch protuberance is at least one of cured, heat-treated, and coated.

12. The displacement bolt according to claim 7 , wherein the catch unit is formed separately from the displacement bolt and consists of a different material than the rest of the displacement bolt.

13. The displacement bolt according to claim 12 , wherein the catch unit consists of a ceramic material or a metal matrix composite material.

14. The displacement bolt according to claim 12 , wherein the catch unit is sintered.

15. The displacement bolt according to claim 13 , wherein the catch unit is connected to the displacement bolt via a substance-to-substance bond.

16. The valve train according to claim 1 , wherein the catch unit is formed separately from the displacement bolt and consists of a different material than the displacement bolt.

17. The valve train according to claim 16 , wherein the catch unit consists of a ceramic material or a metal matrix composite material.

Assignees

• Mahle Int Gmbh

Inventors

• Altherr Patrick
• Ihne Thorsten
• Kirschner Herrn R
• Mohler Mario
• Walch Markus

Classifications

• F01L1/0532

  the cams being directly in contact with the driven valve · CPC title

• F01L1/181

  Centre pivot rocking arms · CPC title

• F01L2013/0052

  with cams provided on an axially slidable sleeve · CPC title

• F01L2013/001

  Deactivating cylinders · CPC title

• F01L1/18

  Rocking arms or levers · CPC title