U.S. patent application number 11/278746 was filed with the patent office on 2007-04-12 for manufacturing method of semi-finished piston with inner cooling channel through liquid extrusion process.
Invention is credited to Zengjian Feng, Xiaobo Gao, Yanpeng Liu, Xuejun Ma, Xiao Sun, Hongmin Wang, Guohua Zhang, Shibo Zhao.
Application Number | 20070079948 11/278746 |
Document ID | / |
Family ID | 37910159 |
Filed Date | 2007-04-12 |
United States Patent
Application |
20070079948 |
Kind Code |
A1 |
Zhang; Guohua ; et
al. |
April 12, 2007 |
Manufacturing Method of Semi-Finished Piston with Inner Cooling
Channel through Liquid Extrusion Process
Abstract
This invention has provided a manufacturing method of
semi-finished piston with inner cooling channel through liquid
extrusion process, including the following steps: a) produce a
wear-resistant cast iron ring with coupling hooks and a common salt
and corundum dissoluble core with convex edges; b) fix the
wear-resistant cast iron ring in the casting moulds after being
aluminized; c) fix the dissoluble core after being pre-heated on
the wear-resistant cast iron ring with coupling hooks and convex
edges; d) fill in the casting mould with aluminum alloy liquid,
compressing and molding. The dissoluble core can be accurately
fixed in the casting mould through coupling hooks and convex edges.
When the semi-finished piston has been manufactured into finished
product, it shall be characterized by high compactness and high
mechanical property resulted from liquid extrusion technology.
Meanwhile, because of the cooling channel, the temperature in the
combustion chamber of the head and ring groove is reduced, the load
capacity of the piston is greatly improved, and the
manufacturability becomes better.
Inventors: |
Zhang; Guohua; (Binzhou
City, CN) ; Sun; Xiao; (Binzhou City, CN) ;
Gao; Xiaobo; (Binzhou City, CN) ; Zhao; Shibo;
(Binzhou City, CN) ; Liu; Yanpeng; (Binzhou City,
CN) ; Wang; Hongmin; (Binzhou City, CN) ; Ma;
Xuejun; (Binzhou City, CN) ; Feng; Zengjian;
(Binzhou City, CN) |
Correspondence
Address: |
GLOBAL IP SERVICES
2462 ROCK ST.
APT. 6
MOUNTAIN VIEW
CA
94043
US
|
Family ID: |
37910159 |
Appl. No.: |
11/278746 |
Filed: |
April 5, 2006 |
Current U.S.
Class: |
164/98 ; 164/369;
164/522 |
Current CPC
Class: |
B22C 9/105 20130101;
B22D 17/24 20130101; B22D 19/0027 20130101; B22C 9/108
20130101 |
Class at
Publication: |
164/098 ;
164/522; 164/369 |
International
Class: |
B22D 19/08 20060101
B22D019/08; B22C 9/10 20060101 B22C009/10 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 8, 2005 |
CN |
200510044839.6 |
Claims
1. A method of manufacturing semi-finished piston with inner
cooling channel through liquid extrusion process comprising: a)
producing a wear-resistant cast iron ring with coupling hooks and a
common salt and corundum dissoluble core with convex edges; b)
fixing the wear-resistant cast iron rings in a casting mould after
being aluminized; c) fixing the dissoluble cores, after being
pre-heated, on the wear-resistant cast iron ring with coupling
hooks and convex edges; d) filling in the casting moulds with
aluminum alloy liquid, compressing and molding.
2. The method of claim 1 wherein the dissoluble core is
manufactured as follows: a) crush the common slat and corundum
until they can pass 80.about.120 screen, and heat them to
450.about.550.degree. C. to remove moisture and other volatile
impurities; b) distribute the corundum 20.about.40% weight per
share, and the salt 60.about.80% weight per share, and then mix
them up; c) put the mixture in a mould, compressing and molding; d)
process the surface of the molded dissoluble core; e) bake the
processed dissoluble core in a baking furnace, and then take it
out.
3. The method of claim 1 wherein the corundum is barium oxide or
zirconia.
4. The method of claim 2, wherein the corundum is barium oxide or
zirconia.
Description
CROSS REFERENCE TO THE RELATED PATENTS
[0001] This application claims the priority benefit of the Chinese
patent application No. 200510044839.6 filed on Oct. 8, 2005.
FIELD OF THE INVENTION
[0002] The present invention has provided a kind of manufacturing
method of semi-finished piston, especially the one with inner
cooling channel.
BACKGROUND OF THE INVENTION
[0003] At present, engines used intrucks, engineering machinery,
railvehicles and ships are developed into that of high efficiency
and heavy load with increased strength and strict discharge
requirement. Temperature of the piston head can be effectively
reduced and performance of the engine can be greatly improved by
adding an inner cooling channel on the head of the piston. Liquid
extrusion technology can make the structure much more compact and
improve mechanical property of the piston. Therefore, the service
performance can be greatly enhanced by combining these two kinds of
technologies. The inner cooling channel is formed by fixing
dissoluble cores at the head of semi-finished piston, and then
washing them away. However, being limited by extrusion technology,
the dissoluble cores can not be positioned and fixed by the mould
itself. At present the material of cores used to form the inner
cooling channel is salt. During the manufacturing procedure,
aluminum alloy liquid can immerge into the core under high
temperature and high pressure. When the semi-finished piston has
been manufactured, dissoluble cored can not be totally washed away,
which may affect the cooling effect in the future. Therefore, the
manufacturing method of semi-finished piston with inner cooling
channel through liquid extrusion process has not been realized.
Only those semi-finished pistons without inner cooling channel can
be produced by liquid extrusion method, while semi-finished pistons
with inner channel can only be produced by using ordinary
manufacturing method.
SUMMARY OF THE INVENTION
[0004] This invention aims to provide a manufacturing method of
semi-finished piston with inner cooling channel through liquid
extrusion process to realize the improvement of structural
compactness of piston as well as the formation of inner cooling
channel.
[0005] The manufacturing method of semi-finished piston with inner
cooling channel through liquid extrusion process includes the
following steps: [0006] a) produce a wear-resistant cast iron ring
with coupling hooks and a common salt and corundum dissoluble core
with convex edges; [0007] b) fix the wear-resistant cast iron ring
in the casting mould after being aluminized; [0008] c) fix the
dissoluble core, after being pre-heated, on the wear-resistant cast
iron ring with coupling hooks and convex edges; [0009] d) fill in
the casting mould with aluminum alloy liquid, compressing and
molding.
[0010] By using this manufacturing method, the dissoluble core can
be accurately fixed in the casting mould through coupling hooks and
convex edges. Compared with other dissoluble cores, the one made of
common salt and corundum is of low thermal coefficient of expansion
and dimensional stability. The intensity and density are high. And
it cannot soak into melted aluminum liquid. The aluminum alloy can
not immerge into the core under high pressure and high temperature,
which will be better for it to be cleared away when forming the
inner cooling channel. It has high ability to resist chilling and
heating with better manufacturability. When being washed away, the
salt can be dissolved quickly. When the semi-finished piston has
been manufactured into finished product, it shall be characterized
by high compactness and high mechanical property resulted from
liquid extrusion technology. Because of cooling channel, the
temperature in the combustion chamber of the head and the ring
groove shall be reduced, and carrying capacity of the piston shall
be greatly improved. It can meet the performance requirements of
high-power and heavy-load engines. Meanwhile, the manufacturability
shall be better.
BRIEF DESCRIPTION OF THE INVENTION
[0011] FIG. 1 is a sketch drawing of the semi-finished piston
manufactured by the method of present invention.
[0012] FIG. 2 is a sketch drawing of the finished piston made from
the semi-finished piston. FIG. 3 is a front cross section view of
the wear-resistant cast iron ring.
[0013] FIG. 4 is a top view of the FIG. 3.
[0014] FIG. 5 is a front cross section view of the dissoluble
core.
[0015] FIG. 6 is a top view of the FIG. 5.
[0016] FIG. 7 is a perspective view of the dissoluble core fixed on
the wear-resistant cast iron ring.
[0017] FIG. 8 is a cross section view of the wear-resistant cast
iron ring fixed on the casting mould.
[0018] Numbers in the FIG: 1--combustion chamber, 2--head;
3--wear-resistant cast iron ring; 3-1--coupling hook; 4--dissoluble
core; 4-1--convex edge; 5--ring edge; 6--pinhole; 7--skirt;
8--inner cooling channel; 9--internal mould; 10--hold-up ring;
11--external mould; 12--bottom mould.
DETAIL DESCRIPTION OF THE INVENTION
[0019] The present invention will be described in detail with
reference to the attached drawings.
[0020] The above-mentioned dissoluble core (4) is produced as
follows: [0021] a) crush the common slat and corundum until they
can pass 80.about.120 screen, and heat them to
450.about.550.degree. C. to remove moisture and other volatile
impurities; [0022] b) distribute corundum 20.about.40% weight per
share, and salt 60.about.80% weight per share, and then mix them
up; [0023] c) put the mixture in the mould, compressing and
molding; [0024] d) process the surface of the molded dissoluble
core by the lathe; [0025] e) bake the lathe processed dissoluble
core in baking furnace, and then take it out.
[0026] Dissoluble core with common salt as cementing medium and
corundum grain as basal body can be produced according to the above
methods. When semi-finished piston has been produced, drill an oil
inlet/outlet hole, connected with inner chamber of the piston, at
the lower part of the core. Fill water into the hole letting the
salt be dissolved and the corundum grain be washed away to form
inner cooling channel (8). When baking the dissoluble core in
baking furnace, the temperature shall be a little bit higher that
used for present salt core.
[0027] The above-mentioned corundum can also be made of barium
oxide, zirconia or other similar materials.
[0028] The number of coupling hooks on wear-resistant cast iron
ring and convex edges on the core shall be three or more than three
respectively. Compressing and molding technique is the same as that
in the present liquid extrusion technology. And aluminizing
treatment is the same as that in present technology.
[0029] As illustrated in FIG. 1, semi-finished piston produced by
liquid extrusion technology comprises a head (2), a ring edge (5)
and a skirt (7). There is a pinhole (6) on the skirt, and a
combustion chamber (1) on the head. The first ring groove is
composed of a wear-resistant cast iron ring (3) with coupling hooks
(3-1) inside. The cast iron ring is connected with the dissoluble
core through the coupling hooks and convex edges on the dissoluble
core (4) inside the semi-finished piston.
[0030] As illustrated in FIG. 8, the casting mould is composed of
internal mould (9), hold-up ring (10), external mould (11) and
bottom mould (12). Semi-finished piston produced by this method can
be manufactured into finished piston shown in FIG. 2 through
conventional T6 heat treatment and further machining.
[0031] This invention has only described and illustrated its
typical form, based on which people with common knowledge in this
field can make many proper diversifications and modifications. For
example, high performance piston with inner cooling channel,
wear-resistant cast iron ring as well as combustion chamber of
partially strengthened composite material can be produced by using
this invention.
* * * * *