U.S. patent application number 13/036384 was filed with the patent office on 2011-09-15 for internal combustion piston engine with an adjustable inflating element.
This patent application is currently assigned to Schaeffler Technologies GmbH & Co. KG. Invention is credited to Peter Sailer, Oliver Schnell, Oliver Witter.
Application Number | 20110220052 13/036384 |
Document ID | / |
Family ID | 44507964 |
Filed Date | 2011-09-15 |
United States Patent
Application |
20110220052 |
Kind Code |
A1 |
Sailer; Peter ; et
al. |
September 15, 2011 |
INTERNAL COMBUSTION PISTON ENGINE WITH AN ADJUSTABLE INFLATING
ELEMENT
Abstract
An internal combustion piston engine based on a four-stroke
process, having a crankcase in which at least one cylinder/piston
assembly is arranged, the piston being guided by a connecting rod
connected to a crankshaft. At least one cylinder head (1) closes
the cylinder, each of whose intake and exhaust channels are
controlled by at least one intake valve and at least one exhaust
valve (2, 2a). The intake and exhaust valves are actuable by a
finger lever or a rocker arm driven by a camshaft (12) through
intake and exhaust cams. The finger levers or rocker arms are
guided on at least one axle (10). At least one additional cam is
provided in the region of the base circle of the outlet cam for an
additional opening of the at least one exhaust valve (2, 2a), and a
control element is installed between the finger lever or rocker arm
and the exhaust valve or valves (2, 2a), which control element can
be connected to a pressure oil source and has a variable length, so
that the additional cam is active during a compression relief
operation and inactive during a pure engine operation. The control
element is configured as an inflating element (8) and is
operatively connected through a working piston (7), with
interposition of a spacer, to a bridge (4) associated to a
plurality of exhaust valves (2, 2a), or is operatively connected to
a valve stem of an exhaust valve.
Inventors: |
Sailer; Peter; (Erlangen,
DE) ; Schnell; Oliver; (Veitsbronn, DE) ;
Witter; Oliver; (Westhausen, DE) |
Assignee: |
Schaeffler Technologies GmbH &
Co. KG
Herzogenaurach
DE
|
Family ID: |
44507964 |
Appl. No.: |
13/036384 |
Filed: |
February 28, 2011 |
Current U.S.
Class: |
123/90.46 |
Current CPC
Class: |
F02M 26/01 20160201;
F01L 13/065 20130101; F01L 1/2411 20130101; F01L 13/085 20130101;
F01L 1/267 20130101; F01L 2305/00 20200501; F01L 2800/10 20130101;
F01L 1/08 20130101 |
Class at
Publication: |
123/90.46 |
International
Class: |
F01L 1/18 20060101
F01L001/18 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 15, 2010 |
DE |
102010011455.3 |
Claims
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, the piston being guided by a
connecting rod connected to a crankshaft, further comprising at
least one cylinder head for closing the cylinder, intake and
exhaust channels for each of the cylinders are controlled by at
least one intake valve and at least one exhaust valve, said intake
and exhaust valves being actuable by a finger lever or a rocker arm
driven by a camshaft through intake and exhaust cams, the finger
levers or rocker arms being guided on at least one axle, at least
one additional cam in a region of a base circle of the exhaust cam
for an additional opening of the at least one exhaust valve, and a
control element is installed between the finger lever or rocker arm
and the at least one exhaust valve, the control element is
connectable to a pressurized oil source and has a length that is
variable, so that the additional cam is active during a compression
relief operation and inactive during a pure engine operation, the
control element is configured as an inflating element and is
operatively connected through a working piston, with interposition
of a spacer, to a bridge associated with a plurality of the exhaust
valves, or is operatively connected to a valve stem of the exhaust
valve.
2. An internal combustion piston engine according to claim 1,
wherein a valve lash is adjusted by using spacers configured with
graded heights.
3. An internal combustion piston engine according to claim 2,
wherein the spacers are configured as ball sockets which are
operatively connected to a ball head of the working piston.
4. An internal combustion piston engine according to claim 1,
wherein the inflating element comprises components of a hydraulic
valve lash adjusting element including a working piston, a housing,
a resetting spring, a piston and a non-return valve on the piston,
and that a control piston is additionally provided and loaded on
one side by a spring and on another side by pressure oil, wherein
the control piston can be operatively connected to the valve body
of the non-return valve in an opening direction.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of German Patent
Application No. 102010011455.3, filed Mar. 15, 2010, which is
incorporated herein by reference as if fully set forth.
FIELD OF THE INVENTION
[0002] An internal combustion piston engine based on a four-stroke
process, comprising a crankcase in which at least one
cylinder/piston assembly is arranged, the piston being guided by a
connecting rod connected to a crankshaft, further comprising at
least one cylinder head for closing the cylinder, each of whose
intake and exhaust channels are controlled by at least one intake
valve and one exhaust valve, said intake and exhaust valves being
actuable by a finger lever or a rocker arm driven by a camshaft
through intake and exhaust cams, the finger levers or rocker arms
being guided on at least one axle, further comprising at least one
additional cam in the region of the base circle of the outlet cam
for an additional opening of at least one exhaust valve, and also
comprising a control element that is installed between the finger
lever or rocker arm and the exhaust valve or valves, which control
element can be connected to a pressurized oil source and whose
length is variable, so that the additional cam is active during a
compression relief operation and inactive during a pure engine
operation.
BACKGROUND OF THE INVENTION
[0003] A generic internal combustion piston engine of the pre-cited
type is known from U.S. Pat. No. 3,809,033. An actuating piston
installed in the rocker arm of this engine is operatively connected
to a bridge associated with two exhaust valves. The pressure
chamber of the actuating valve is controlled by a control valve, so
that oil pressure can be increased and decreased and the actuating
piston can be retracted for the performance operation of the
internal combustion engine and be extended for the braking
operation. The additional cam is active in the one case and
inactive in the other. The valve lash is adjusted by means of a
screw on the other end of the rocker arm.
[0004] A drawback of this configuration is that the oil pressure is
used directly for the actuation of the piston, so that a high
pressure or a larger piston cross-section is required and strong
pressure fluctuations can occur. Moreover, additional measures are
required during engine operation in order to avoid vibrations of
the transmitting elements resulting from larger lash in the base
circle region of the outlet cam. Furthermore, the additional valve
lash adjusting screw is considered as a drawback because,
irrespective of the additional complexity and expense caused by the
thread and the like, it constitutes an undesired additional
mass.
[0005] Further, an internal combustion piston engine comprising a
compression relief device is also known (DE 30 03 566 A1). In this
internal combustion engine, the additional cam is configured as a
movable component that can be pushed into the base circle contour
or pushed outwards out of the base circle contour. For this
purpose, the camshaft has a hollow configuration and comprises an
actuating device which displaces the additional cam. The actuating
device must further also comprise actuating elements outside of the
camshaft through which actuating elements the actuating device is
controlled. Besides this, the valve lash for the engine operation
must be adjusted separately.
[0006] The required structural complexity for extending and
retracting the additional cams is considerably high and
cost-intensive and therefore considered as a drawback.
SUMMARY OF THE INVENTION
[0007] It is therefore the object of the invention to improve an
internal combustion piston engine with the initially described
features, so as to provide an effective engine brake through
intermittent opening of one or more exhaust valves in the region of
the upper dead center of the internal combustion piston engine,
which brake must be realizable through simple measures and low
costs. In addition, this should be accomplished in connection with
components of a hydraulic lash adjusting element. Moreover, valve
lash must be adjustable in a simple manner.
[0008] The invention achieves the above object by the fact that the
control element is configured as an inflating element and is
operatively connected through a working piston, with interposition
of a spacer, to a bridge associated to a plurality of exhaust
valves, or is operatively connected to a valve stem of an exhaust
valve.
[0009] By reason of this configuration, only a low pressure is
required as a control oil pressure because the inflating element
builds up pressure by itself.
[0010] Moreover, by the use of spacers configured with graded
heights, the valve lash can be adjusted by correspondingly
replacing the spacer with another suitable spacer.
[0011] It may be pointed out that, in addition to being used as an
engine brake in form of a compression relief device the inventive
configuration can also be used for internal gas recirculation or
for hybridization.
[0012] In an advantageous development of the invention, the spacers
are configured as ball sockets which are operatively connected to a
ball head of a working piston. Through the use of a ball socket and
a ball head, undesired surface pressures are avoided. Moreover,
ball sockets possess the advantage that they can be fixed safe
against loss on the ball head of the working piston of the
inflating element, and the bridge or the valve stem does not
require any additional receptions.
[0013] According to a further proposition of the invention, the
inflating element comprises the components of a hydraulic valve
lash adjusting element (HVA) such as working piston, housing,
resetting spring, piston and non-return valve on the piston, a
control piston being additionally provided and loaded on one side
by a spring and on the other side by pressure oil, and the control
piston is operatively connected to the valve body of the non-return
valve in opening direction.
[0014] When the control piston is loaded with reduced oil pressure,
the spring presses the control piston against the valve body of the
non-return valve, which is preferably configured as a ball, and
opens this. As a result, the control element can get shortened, so
that the additional cam is inactive and no compression relief
opening of the exhaust valve or valves takes place. The non-return
valve, however, still remains active so that no uncontrolled lash
is produced in the region of the base circle of the exhaust valve
and no uncontrolled vibrations of the transmitting elements occur.
The finger lever or rocker arm, if necessary also an installed
tappet, is therefore in constant contact with the additional cam.
The additional lift, however, is suppressed in this case by the
inflating element.
[0015] When the control piston is loaded through oil pressure, the
non-return valve can close and a pressure is built up in the high
pressure chamber between housing, working piston and piston. The
thus configured high pressure chamber causes the activation of the
additional cam which leads to a switching-on of the compression
relief device, the gas recirculation device or a hybridization
device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] For a further elucidation of the invention reference will be
made to the appended drawings in which one example of embodiment is
shown in simplified illustrations. The figures show:
[0017] FIG. 1: a side view of a valve train including a partial
section through a cylinder head, a camshaft, an axle for the rocker
arm and a bridge, and
[0018] FIG. 2: a section through the end of a rocker arm, an
inflating element and a bridge.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] In FIGS. 1 and 2 a cylinder head of an internal combustion
piston engine, as far as specifically shown, is identified at 1.
The exhaust channels of the engine are controlled by two exhaust
valves 2 and 2a that are guided in the cylinder head 1 and biased
in closing direction by valve springs 3 and 3a. A bridge 4 is
associated to the valve stems of the exhaust valves 2 and 2a and
engages around the ends of the valve stems while being operatively
connected to a ball socket 5 supported on a ball head 6 of a
working piston 7 which is a component part of an inflating element
generally identified at 8. The inflating element 8 is installed in
a recess of a rocker arm 9 and supplied with oil from an oil bore
in the rocker arm 9, not specifically shown. The rocker arm 9 is
mounted on an axle 10 comprising oil channels 11 and 11a which are
connected to the oil circulation of the internal combustion piston
engine. The oil pressure delivered to the inflating element 8 can
be varied through a control valve, not illustrated. The rocker arm
9 is operatively connected through its other end, not specifically
shown, to an exhaust cam of a camshaft 12, preferably through a
roller. In the base circle region, the exhaust cam comprises at
least one additional cam, separately from the exhaust valve lobes,
for an additional opening of the exhaust valves in correspondence
with the operation of the internal combustion engine. The inflating
element 8 comprises a housing 13 that is inserted into the rocker
arm 9 and guides the working piston. The housing 13 and the working
piston 7 define a pressure chamber that is controlled by a
non-return valve 14 which is arranged on a piston 15. A resetting
spring 16 is installed between the piston 15 and the working piston
7 and biases the working piston in direction of the ball head 6.
The stroke of the working piston 7 is limited, so that the pressure
chamber cannot expand indefinitely even after pressure build-up.
The piston 15 and the non-return valve 16 are adjoined by a control
piston 17 that is biased by a spring 18 in direction of the piston
15, which spring 18 is supported on the housing 13. In the region
between the control valve 17 and the piston 15, the housing 13
comprises a bore 19 that can be supplied with pressure oil through
an intermediate space between the housing 13 and the rocker arm 9.
The installation space of the spring 18 communicates with the
surrounding pressure through a vent bore, so that a pressure
build-up is avoided.
[0020] The mounting points between the bridge 4 and the ball socket
5 and between the ball socket 5 and the ball head 6 are supplied
with oil for lubrication through a central bore 20 in the working
piston 7.
LIST OF REFERENCES
[0021] 1 Cylinder head
[0022] 2, 2a Exhaust valves
[0023] 3, 3a Valve springs
[0024] 4 Bridge
[0025] 5 Ball socket
[0026] 6 Ball head
[0027] 7 Working piston
[0028] 8 Inflating element
[0029] 9 Rocker arm
[0030] 10 Axle
[0031] 11, 11a Oil channels
[0032] 12 Camshaft
[0033] 13 Housing
[0034] 14 Non-return valve
[0035] 15 Piston
[0036] 16 Resetting spring
[0037] 17 Control piston
[0038] 18 Spring
[0039] 19 Bore
[0040] 20 Oil bore
* * * * *