Internal combustion piston engine with engine braking by opening of exhaust valves

Patent metadata

Field	Value
Publication number	US-9115654-B2
Application number	US-201113032807-A
Country	US
Kind code	B2
Filing date	Feb 23, 2011
Priority date	Feb 23, 2010
Publication date	Aug 25, 2015
Grant date	Aug 25, 2015

Abstract

An internal combustion engine including a piston in a cylinder, a cylinder head closing the cylinder, having intake and exhaust channels controlled by at least one intake and exhaust valve. The valves are actuable by a rocker arm or finger lever driven by a camshaft. A brake control device is provided having a hydraulic adjusting piston that opens the exhaust valve additionally and intermittently, a pressure source for hydraulic fluid is associated with the adjusting piston, and the supply to the adjusting piston is controlled by an electrically operable switching valve. A compression relief cam per cylinder/piston assembly is arranged on the camshaft, with the cam being operatively connected to a compression relief rocker arm or finger lever, and the adjusting piston is configured as a coupling pin for connecting the compression relief rocker arm or finger lever, to the rocker arm or finger lever of the exhaust valve.

First claim

The invention claimed is:

1. An internal combustion piston engine based on a four-stroke process, comprising a crankcase in which at least one cylinder/piston assembly is arranged, a piston being guided by a connecting rod connected to a crankshaft, at least one cylinder head for closing a cylinder, each of whose intake and exhaust channels are controlled by at least one intake valve and at least one exhaust valve, each of said intake and exhaust valves being actuable by a rocker arm or a finger lever driven by a camshaft, the rocker arms or finger levers being guided on at least one axle, and further comprising a brake control device comprising at least one hydraulic adjusting piston that engages a component that opens at least one of the exhaust valves additionally and intermittently, a pressure source for a hydraulic fluid being associated with an adjusting piston, and a supply of the hydraulic fluid to the adjusting piston being controlled by at least one electrically operable switching valve, a compression relief cam for each of the at least one cylinder/piston assembly of the internal combustion piston engine is arranged on the camshaft, said compression relief cam being operatively connected to a compression relief rocker arm or a compression relief finger lever, and the adjusting piston is configured as a coupling pin for connecting the compression relief rocker arm or the compression relief finger lever to the rocker arm or arms or finger lever or levers of the exhaust valve or valves, wherein the adjusting piston is operatively connected to cylinders that are fixed on the compression relief rocker arm or the compression relief finger lever and on the rocker arm or arms or finger lever or levers of the exhaust valve or valves, and the cylinders are at least partially closed at ends thereof turned away from each other, with one of the cylinders comprising on an outer end thereof a pressure fluid connection, and another one of the cylinders comprises on a turned-away end thereof a compression spring.

2. An internal combustion piston engine according to claim 1 , wherein the compression relief cam is arranged next to an exhaust cam or cams or between a plurality of the exhaust cams on the camshaft.

3. An internal combustion piston engine according to claim 1 , wherein an adjusting piston is arranged in each of the cylinders, the adjusting piston is loadable by the pressurized fluid and corresponds to a length of the cylinder, and, when the adjusting piston associated with a compression spring is situated in an end position realized through action of the compression spring, front surfaces of the adjusting pistons facing each other are arranged in a parting line between the compression relief rocker arm, or the compression relief finger lever, and an adjoining one of the rocker arms or the finger levers of the exhaust valve or valves.

4. An internal combustion piston engine according to claim 1 , wherein the pressure fluid connection of the adjusting piston is provided via bores in at least one of the compression rocker arm or the compression relief finger lever, or in the rocker arm or finger lever of the exhaust valves, which are operatively connected to at least one of a pressure fluid supply duct or a pressure fluid discharge duct in the axle.

5. An internal combustion piston engine according to claim 4 , wherein at least one of the pressure fluid supply or the pressure fluid discharge of each of the adjusting pistons is actuated by a respective electrically actuable control valve.

6. An internal combustion piston engine according to claim 5 , wherein the at least one of the pressure fluid supply duct or the pressure fluid discharge duct in the axle is divided into galleries associated to the switching valves.

7. An internal combustion piston engine according to claim 6 , wherein a division of the galleries is obtained by pressing balls or pins into bores of the axle until the balls or pins extend into the at least one of the pressure fluid supply duct or the pressure fluid discharge duct.

8. An internal combustion piston engine according claim 1 , wherein a free end of the compression relief rocker arm or the compression relief finger lever facing the exhaust valves is loaded in closing direction of the exhaust valves through a lost motion spring.

Assignees

• Schnell Oliver
• Schaeffler Technologies Ag

Inventors

• Schnell Oliver

Classifications

• F01L2820/033

  Hydraulic engines · CPC title

• F01L1/20

  Adjusting or compensating clearance · CPC title

• F01L13/065

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

• F01L1/267

  with means for varying the timing or the lift of the valves · CPC title

• F01L2001/467

  Lost motion springs · CPC title