U.S. patent application number 10/579189 was filed with the patent office on 2007-04-26 for internal combustion engine component and method for the production thereof.
This patent application is currently assigned to DAIMLERCHRYSLER AG. Invention is credited to Juergen Claus, Roberto De Zolt, Reiner Heigl, Wolf Saeltzer.
Application Number | 20070089812 10/579189 |
Document ID | / |
Family ID | 34585146 |
Filed Date | 2007-04-26 |
United States Patent
Application |
20070089812 |
Kind Code |
A1 |
Claus; Juergen ; et
al. |
April 26, 2007 |
Internal combustion engine component and method for the production
thereof
Abstract
Disclosed is an internal combustion engine component (1)
comprising at least one area (4) that is subject to a greater
thermal load then another area (5) during operation of the internal
combustion engine. The area (4) that is subjected to a greater
thermal load is provided with a lower heat expansion coefficient
(.alpha..sub.2) then the area (5) which is subject to a lower
thermal load.
Inventors: |
Claus; Juergen; (Weinstadt,
DE) ; De Zolt; Roberto; (Fellbach, DE) ;
Heigl; Reiner; (Remseck, DE) ; Saeltzer; Wolf;
(Boblingen, DE) |
Correspondence
Address: |
AKERMAN SENTERFITT
P.O. BOX 3188
WEST PALM BEACH
FL
33402-3188
US
|
Assignee: |
DAIMLERCHRYSLER AG
|
Family ID: |
34585146 |
Appl. No.: |
10/579189 |
Filed: |
November 3, 2004 |
PCT Filed: |
November 3, 2004 |
PCT NO: |
PCT/EP04/12413 |
371 Date: |
July 20, 2006 |
Current U.S.
Class: |
148/549 |
Current CPC
Class: |
C23C 26/02 20130101;
F02F 2001/008 20130101; F02F 2200/06 20130101; F02F 1/00 20130101;
F01L 3/04 20130101; C23C 24/10 20130101 |
Class at
Publication: |
148/549 |
International
Class: |
C22F 1/04 20060101
C22F001/04 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 15, 2003 |
DE |
103 53 473.3 |
Claims
1-12. (canceled)
13. A process for production of an aluminum alloy component of an
internal combustion engine, which includes at least one area, which
during operation of the internal combustion engine is thermally
higher loaded than another area, comprising: melting that area (4)
which is thermally higher loaded during the operation of the
internal combustion engine by means of a beam process, introducing
an additive (8) into the melt pool (6) resulting from the melting,
and resolidifying said melt pool to develop in the thermal higher
loaded area (4) a lower thermal coefficient of expansion
(.alpha..sub.2) relative to the thermal lower loaded area (5).
14. A process according to claim 13, wherein a laser beam is
employed for carrying out the beam process.
15. A process according to claim 13, wherein a ceramic material is
employed as the additive (8).
16. A process according to claim 13, wherein that the additive is
an inter-metallic compound.
17. A process according to claim 13, wherein in the thermal higher
loaded area (4) a composition is formed which is modified relative
to the thermal less loaded area (5).
18. A process according to claim 13, wherein the component is a
cylinder head (1a).
19. A process according to claim 18, wherein the thermal higher
loaded area (4) is an intermediate area (4a) located between
respective valve bores (3).
20. A process according to claim 13, wherein the component (1) is a
piston.
21. A process according to claim 18, wherein the thermal higher
loaded area (4) is a piston bowl or a recess edge.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a national stage of PCT/EP2004/012413
filed Nov. 3, 2004 and based upon DE 103 53 473.3 filed on Nov. 15,
2003 under the International Convention.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention concerns a component of an internal combustion
engine of the type defined in greater detail hereinafter. The
invention further concerns a process for production of a component
of an internal combustion engine.
[0004] 2. Description of Related Art
[0005] In components of internal combustion engines, such as, for
example, cylinder heads or pistons, a problem frequently occurs
during thermal cycling in that, in the case of prevention of
thermal expansion in higher loaded areas, mechanical tensions are
induced in these areas which are so high that, due to the strong
plasticization and the therewith associated material fatigue in
these areas, crack formation occurs. This prevention of thermal
expansion occurs because the thermally higher loaded materials tend
to more strongly expand than the thermally less loaded materials.
Since the thermally higher loaded areas are generally in the middle
of the component, an outwards expansion is not possible, and the
result is the above mentioned tensions, in particular pressure
tensions, which during the cooling process convert into contraction
tensions, which can exceed the materials' strength.
[0006] To solve the problems, it has been attempted in accordance
with the general state of the art to improve the casting technique
and to employ a subsequent thermal treatment to produce a fine and
stable-as-possible microstructure. These measures, however, extend
evenly across the entire component, so that the above-described
problems cannot be overcome by these measures.
SUMMARY OF THE INVENTION
[0007] It is thus the task of the present invention to provide a
component of an internal combustion engine and a process for
production thereof in which, even in the case of varying high
thermal loads distributed across different areas of the component,
the problems known from the state of the art with regard to the
failure of the component can be avoided.
[0008] The problem is inventively solved by the characteristics set
forth below.
[0009] In accordance with the invention, the thermally highly
loaded area of the component exhibits a lower thermal coefficient
of expansion than the thermally less loaded area, which leads
thereto, that the entire component can expand evenly during an
increase in temperature. As a result thereof that the various areas
of the inventive component expand evenly, there are smaller
inhibitions in expansion, and thus smaller occurrence of the
plastic deformation areas, so that upon heating and subsequent
cooling essentially only small, or as the case may be, very minimal
tensions are produced in the component, whereby the conventionally
present danger of crack formation, attributable to the exceeding of
the permissible tensions, is ultimately prevented.
[0010] By the inventive adaptation of the thermal coefficient of
expansions to the thermal conditions within the component, the
occurrence of a material fatiguing and/or a crack formation at a
later point in time, or as the case may be, following higher loads,
can be delayed, so that the inventive component can be employed in
internal combustion engines with higher power and/or to lengthen
the life span.
[0011] A process for production of an inventive component can be
seen from the characteristics of claim 9.
[0012] Therein the base material of the component is melted and an
additive is introduced, which results in a changed thermal
coefficient of expansion in the thermally higher loaded area. This
manner of proceeding makes possible a particularly precise control
of the alloy composition in the thermally higher loaded area.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Advantageous embodiments of the invention are indicated in
the dependent claims. In the following, an illustrative example of
invention will be described in principle on the basis of the
figure.
[0014] There is shown in:
[0015] FIG. 1 a view of an inventive component in a first
condition;
[0016] FIG. 2 a section through an intermediate area of the
cylinder head according to the line II-II from FIG. 1 in a first
condition;
[0017] FIG. 3 the intermediate area of the cylinder head from FIG.
2 in a second condition;
[0018] FIG. 4 the intermediate area of the cylinder head from FIG.
2 in a third condition;
[0019] FIG. 5 a view of the component from FIG. 1 in a second
condition;
[0020] FIG. 6 a view of the component from FIG. 1 in a third
condition;
[0021] FIG. 7 a view of a component according to the state of the
art in a first condition;
[0022] FIG. 8 a view of a component according to FIG. 7 in a second
condition; and
[0023] FIG. 9 a view of the component from FIG. 7 in a third
condition.
DETAILED DESCRIPTION OF THE INVENTION
[0024] FIGS. 7, 8 and 9 show a component 1 of an internal
combustion engine--not shown in its entirety--as known from the
state of the art. The component 1 is in the present case a cylinder
head 1a, wherein FIGS. 1, 5 and 6 show a view on the separating
surface 2 of the cylinder head 1a. In place of the cylinder head 1a
the component 1 could just as well be a piston or another thermally
very strongly loaded component of an internal combustion
engine.
[0025] The cylinder head 1a includes multiple valve bores 3,
between which a thermally higher loaded area 4 is located, which in
the following is referred to as the intermediate area 4a. This
intermediate area 4a is, during operation of the internal
combustion engine, higher thermally loaded than the rest of the
component 1 or, as the case may be, than other areas 5 of the
component 1. Since the internal combustion engine associated with
the cylinder head 1a has three, or as the case may be, six
cylinders, a total of three intermediate areas 4a are provided.
Since four valve bores 3 are provided for each cylinder, the
intermediate areas 4a essentially have a cross-shaped design. If
two valve bores 3 were provided per cylinder, then the intermediate
areas 2a could also have a linear design. In the case of a piston,
the thermally higher loaded area 4 would likely be the piston bowl.
Of course, the number of cylinders in the internal combustion
engine could be varied as desired.
[0026] If the component 1 is comprised in its entirety of a
homogeneous material, preferably of an aluminum material, in
particular, an aluminum-silicon alloy, it would exhibit a constant
thermal co-efficient of expansion .alpha..sub.1. The temperature of
the component 1 is, in the case of the not-heated condition as
shown in FIG. 7, likewise at a constant level T.sub.0.
[0027] FIG. 8 shows the component 1 in its heated condition.
Therein there exists internally of the component 1, namely in the
thermally higher loaded area 4, an elevated temperature T.sub.2 in
comparison to the lower temperature T.sub.1 in the area 5. Since
the expansion of the thermally higher loaded area 4 is, however,
prevented by the lower expansion of the area 5, a plasticization of
the area 4 results in the heated condition.
[0028] If, as shown in FIG. 9, the component 1 is cooled back to
the temperature T.sub.0, this leads to contraction tensions
internally of the component 1, in particular in the thermally
higher loaded area 4, which could ultimately lead to the formation
of a crack as indicated by dashed lines. A formation of cracks can
also occur in a--here not shown--spark plug bore or at a--likewise
not shown--injection bore hole.
[0029] FIGS. 1 through 6 show the component 1 according to the
present invention. In order, in contrast to the above-described
problem, to achieve an even expansion of the component 1 during the
operation of the internal combustion engine, the thermally higher
loaded area 4 exhibits a lower coefficient of expansion
.alpha..sub.2 then the thermally less loaded area 5, which also
continues to exhibit a thermal coefficient of expansion
.alpha..sub.1. The untreated condition of the component 1 is shown
in FIGS. 1 and 2.
[0030] In order to produce the component 1, the higher loaded area
4 is melted, so that a melt pool 5 results, as shown in FIG. 3.
This melting is preferably carried out using a beam process, and in
particular using a laser beam 7. As an alternative to employment of
the laser beam 7 an electron beam or the like could be employed.
Further, it would also be possible to produce the melt pool 6 by
means of a WIG process or in another suitable mode and manner.
[0031] As shown in FIG. 4, an additive 8 is introduced into the
melt pool 6, which leads to the described reduction in the thermal
coefficient of expansion .alpha..sub.1 of the component 1 to the
valve .alpha..sub.2 for the higher loaded area 4. Preferably, as
the additive 8, a ceramic material (in the form of powder or
bristles; for example Al.sub.2O.sub.3) is employed. Further, the
additive can be comprised of silicon or be in the form of an
intra-metallic dispersion, for example on the basis of
Al--Fe--Zr/Ce.
[0032] From the illustration according to FIG. 5 it can be seen
that during the operation of the internal combustion engine, that
is, during the relevant heating of the component 1 over the two
areas 4 and 5, despite the higher temperature T.sub.2 of the
thermally higher loaded area 4, an even expansion is produced,
since the material of the thermally higher loaded area 4 expands
less then the material of the thermally less loaded area 5 and thus
is not hindered in its expansion thereby.
[0033] Finally, FIG. 6 shows the condition after cooling of the
component 1 and it can be t no formation of cracks is
indicated.
[0034] Now that the invention has been described, we claim:
* * * * *