Length-adjustable connecting rod

Patent metadata

Field	Value
Publication number	US-2016237889-A1
Application number	US-201415028638-A
Country	US
Kind code	A1
Filing date	Oct 13, 2014
Priority date	Oct 18, 2013
Publication date	Aug 18, 2016
Grant date	—

Abstract

The invention relates to a length-adjustable connecting rod ( 1 ) for a reciprocating-piston machine, in particular for an internal combustion engine, comprising at least one first rod part ( 6 ) having a small connecting rod eye ( 2 ) and a second rod part ( 9 ) having a large connecting rod eye ( 4 ), which two rod parts can be moved in relation to each other and/or in each other in a telescopic manner, wherein the second rod part forms a guiding cylinder ( 8 ) and the first rod part forms a piston element ( 7 ) that can be longitudinally displaced in the guiding cylinder, wherein a first high-pressure chamber ( 10 ) is spanned between the second rod part and the piston element on the side of the piston element facing the large connecting rod eye, into which first high-pressure chamber at least one first oil channel ( 20 ) leads, in which in particular a first check valve ( 21 ) opening in the direction of the first high-pressure chamber is arranged, wherein at least a first return channel ( 22 ) extends from the first high-pressure chamber, an outflow cross-section of which return channel can be closed by a control valve ( 13 ) in a first position and can be opened by the control valve in a second position, wherein the control valve preferably has a control piston ( 15 ) that can be axially displaced in an accommodating bore ( 14 ) of the second rod part of the connecting rod, which control piston in particular can be moved into the first position by means of a return spring ( 16 ) and can be moved into the second position against the force of the return spring by means of an actuating force. In order to be able to change the compression ratio as simply possible, the piston element according to the invention is designed as a piston that is operative at both ends.

First claim

1 - 14 . (canceled)

15 . A length-adjustable connecting rod for a reciprocating-piston machine, comprising at least one first rod part having a small connecting rod eye and a second rod part having a large connecting rod eye, which two rod parts can be moved in relation to each other and/or in each other in a telescopic manner, wherein the second rod part forms a guiding cylinder and the first rod part forms a piston element that can be longitudinally displaced in the guiding cylinder, wherein a first high-pressure chamber is spanned between the second rod part and the piston element on the side of the piston element facing the large connecting rod eye, into which first high-pressure chamber at least one first oil channel leads, in which in particular a first check valve opening in the direction of the first high-pressure chamber is arranged, wherein at least a first return channel extends from the first high-pressure chamber, an outflow cross section of which return channel can be closed by a control valve in a first position and can be opened by the control valve in a second position, wherein the piston element is designed as a double acting piston.

16 . The connecting rod according to claim 15 , wherein the first position of the control valve is associated with an extended position of the first rod part and the second position of the control valve is associated with a retracted position of the first rod part.

17 . The connecting rod according to claim 16 , wherein the first rod part can be hydraulically locked relative to the second rod part both in the extended position and also in the retracted position.

18 . The connecting rod according to claim 15 , wherein on the side of the piston element facing toward the small rod eye a second high-pressure chamber is spanned between a holding part, which is fixedly connected to the second rod part, and the piston element, into which second high-pressure chamber at least one second oil channel leads.

19 . The connecting rod according to claim 18 , wherein in the second high-pressure chamber a second check valve is arranged, which opens in the direction of the first high-pressure chamber.

20 . The connecting rod according to claim 18 , wherein the second oil channel and/or the second return channel is/are arranged outside a longitudinal center plane of the connecting rod, which encloses the longitudinal axis of the connecting rod.

21 . The connecting rod according to claim 18 , wherein the feed cross section to the second oil channel can be closed by the control valve in the first position and can be opened in the second position.

22 . The connecting rod according to claim 15 , wherein at least one second return channel extends from the second high-pressure chamber, the outflow cross section of which can be dosed by the control valve in the second position and can be opened in the first position.

23 . The connecting rod according to claim 15 , wherein only the first and second return channels can be controlled by the control valve.

24 . The connecting rod according to claim 15 , wherein at least one return flow throttle is arranged in a feed line to the control valve.

25 . The connecting rod according to claim 15 , wherein the holding part is formed by a replaceable stop sleeve, which protrudes into the guide cylinder.

26 . The connecting rod according to claim 25 , wherein the stop sleeve is screwed together with the second rod part.

27 . The connecting rod according to claim 15 , wherein the feed cross section to the first oil channel can be closed by the control valve in the second position and can be opened in the first position.

28 . The connecting rod according to claim 15 , wherein the actuation of the control piston is performed hydraulically by oil pressure or electromagnetically.

29 . The connecting rod according to claim 28 , wherein the actuation of the control piston is performed against the force of a return spring.

30 . The connecting rod according to claim 28 , wherein the control piston consists of ferromagnetic material or has a permanent magnet element, which interacts with an induction coil arranged in the crankcase.

31 . The connecting rod according to claim 28 , wherein the control piston can be locked in at least one position by at least one locking element.

32 . The connecting rod according to claim 31 , wherein the locking element is formed by a spring-loaded pressure part.

33 . The connecting rod according to claim 31 , wherein the locking element has a spring-loaded pressure body, which acts on the control piston transversely to the movement direction thereof.

34 . The connecting rod according to claim 15 , wherein the control valve has a control piston that can be axially displaced in an accommodating bore of the second rod part of the connecting rod, which control piston in particular can be moved into the first position by means of a return spring and can be moved into the second position against the force of the return spring by means of an actuating force.

35 . The connecting rod according to claim 15 , wherein the piston element is designed as a stepped piston.

Assignees

• Avl List Gmbh

Inventors

• Melde-Tuczai Helmut
• Lichtenegger Stefan
• Hoedl Bernhard

Classifications

• F16C7/06 Primary

  Adjustable connecting-rods · CPC title

• F02B75/045 Primary

  by means of a variable connecting rod length · CPC title

• F02F1/00

  Cylinders; Cylinder heads · CPC title

• F02F3/00

  Pistons · CPC title

• F16C7/04

  with elastic intermediate part of fluid cushion · CPC title