U.S. patent application number 14/347445 was filed with the patent office on 2014-08-21 for powder metallurgy composite cam sheet and preparation method thereof.
The applicant listed for this patent is BEIJING HENGYUAN TIANQIAO POWER METALLURGY CO., LTD., GENERAL RESEARCH INSTITUTE FOR NONFERROUS METALS, GRIPM ADVANCED MATERIALS CO., LTD.. Invention is credited to Xiaojiang Dong, Xuebing Liang, Lei Wang, Limin Wang, Linshan Wang.
Application Number | 20140234650 14/347445 |
Document ID | / |
Family ID | 47994208 |
Filed Date | 2014-08-21 |
United States Patent
Application |
20140234650 |
Kind Code |
A1 |
Wang; Linshan ; et
al. |
August 21, 2014 |
POWDER METALLURGY COMPOSITE CAM SHEET AND PREPARATION METHOD
THEREOF
Abstract
According to the invention, there are disclosed a power
metallurgy composite cam sheet and a fabrication method thereof.
The power metallurgy composite cam sheet is constructed by
combining a power metallurgy cam be composited on a surface of a
matrix. The fabrication method of the power metallurgy composite
cam sheet includes sinter welding, braze welding, argon arc
welding, laser welding, hot pressing and other methods. The powder
metallurgy composite cam sheet fabricated by the invention has
merits of stable size, good impact toughness, good abrasion
resistance, low cost and so on, so that it can replace an integral
cam sheet that is currently fabricated by forging, drawing, power
metallurgy or other process. It is suitable for the case where a
hollow camshaft is prepared by mechanical assembly, hydraulic
forming, welding or other process, so that the usage requirements
of an assembled camshaft can be met.
Inventors: |
Wang; Linshan; (Beijing,
CN) ; Wang; Limin; (Beijing, CN) ; Liang;
Xuebing; (Beijing, CN) ; Dong; Xiaojiang;
(Beijing, CN) ; Wang; Lei; (Beijing, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GENERAL RESEARCH INSTITUTE FOR NONFERROUS METALS
BEIJING HENGYUAN TIANQIAO POWER METALLURGY CO., LTD.
GRIPM ADVANCED MATERIALS CO., LTD. |
Beijing
Beijing
Beijing |
|
CN
CN
CN |
|
|
Family ID: |
47994208 |
Appl. No.: |
14/347445 |
Filed: |
September 28, 2012 |
PCT Filed: |
September 28, 2012 |
PCT NO: |
PCT/CN2012/001330 |
371 Date: |
March 26, 2014 |
Current U.S.
Class: |
428/553 ; 419/6;
419/8; 428/548 |
Current CPC
Class: |
Y10T 428/12063 20150115;
Y10T 428/12028 20150115; B22F 3/14 20130101; B22F 7/08 20130101;
B22F 5/006 20130101; B22F 7/02 20130101; B22F 7/04 20130101; B22F
5/10 20130101 |
Class at
Publication: |
428/553 ;
428/548; 419/6; 419/8 |
International
Class: |
B22F 7/02 20060101
B22F007/02; B22F 7/04 20060101 B22F007/04 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 29, 2011 |
CN |
201110294040.8 |
Claims
1-10. (canceled)
11. A power metallurgy composite cam sheet, wherein, the power
metallurgy composite cam sheet is constructed by combining a power
metallurgy cam on a surface of a matrix, a thickness of the matrix
is in a range of 0.1-20 mm, and a thickness of the powder
metallurgy cam in the powder metallurgy composite cam sheet is in a
range of 0.5-50 mm.
12. The composite cam sheet according to claim 11, wherein, the
matrix in the power metallurgy composite cam sheet is a circular
tube or a special-shaped tube made of steel, nickel, titanium,
copper, or aluminum.
13. The composite cam sheet according to claim 11, wherein, the
power metallurgy cam in the power metallurgy composite cam sheet is
of an iron-based powder metallurgy material, a titanium-based power
metallurgy material, a nickel-based power metallurgy material or a
hard alloy.
14. A fabrication method of a power metallurgy composite cam sheet,
comprising the following step: combining a power metallurgy cam on
a surface of a matrix so as to form the power metallurgy composite
cam sheet.
15. The fabrication method of the power metallurgy composite cam
sheet according to claim 14, wherein the step of combining a power
metallurgy cam on a surface of a matrix comprises the following
steps: fabricating a pressed compact for the powder metallurgy cam
by using a conventional powder pressing method, fabricating a blank
for the powder metallurgy cam sheet at a temperature is in the
range of 600-1500.degree. C. for 10-120 minutes, and then welding
the matrix and the powder metallurgy cam together by using braze
welding, argon arc welding, or laser welding, wherein, material for
a solder may be copper, a copper alloy, nickel, a nickel alloy,
aluminum, an aluminum alloy, titanium, or a titanium alloy, and its
morphology is powder-shaped, wire-shaped, or piece-shaped, the
welding is carried out in an atmosphere of vacuum, hydrogen gas,
decomposed ammonia, or other protective atmosphere at a temperature
in a range of 600-1200.degree. C. for 10-120 minutes.
16. The fabrication method of the power metallurgy composite cam
sheet according to claim 14, wherein the step of combining a power
metallurgy cam on a surface of a matrix comprises the following
steps: placing a matrix on a core rod, and after powders are
filled, pressing the powders into a composite cam sheet pressed
compact, next, sinter welding the pressed compact at a temperature
is in a range of 600-1500.degree. C. for 10-120 minutes.
17. The fabrication method of the power metallurgy composite cam
sheet according to claim 14, wherein the step of combining a power
metallurgy cam on a surface of a matrix comprises the following
steps: placing matrix powders and cam powders in layers into a mold
by way of filling, then pressing the powders into a pressed compact
for the composite cam sheet, and lastly, sintering the pressed
compact at 600-1500.degree. C. for 10 to 120 minutes.
18. The fabrication method of the power metallurgy composite cam
sheet according to claim 14, wherein the step of combining a power
metallurgy cam on a surface of a matrix comprises the following
steps: placing a matrix on a core rod, and after powders are
filled, hot pressing the powders at 600-1400.degree. C. for 10 to
120 minutes.
19. The fabrication method of the power metallurgy composite cam
sheet according to claim 14, wherein the step of combining a power
metallurgy cam on a surface of a matrix comprises the following
steps: placing matrix powders and cam powders in layers into a mold
by way of filling, and then hot pressing the powders at
500-1400.degree. C. for 10 to 120 minutes
20. The fabrication method of the power metallurgy composite cam
sheet according to claim 14, wherein the step of combining a power
metallurgy cam on a surface of a matrix comprises the following
steps: fabricating a pressed compact for the powder metallurgy cam
by using a conventional powder pressing method, assembling it with
the matrix, and then sinter welding the pressed compact assembled
with the matrix at a temperature is in a range of 600-1500.degree.
C. for 10-120 minutes, the atmosphere for the sinter welding being
an atmosphere of hydrogen gas, an atmosphere of decomposed ammonia
or vacuum.
21. The fabrication method of the power metallurgy composite cam
sheet according to claim 14, wherein, the matrix in the power
metallurgy composite cam sheet is a circular tube or a
special-shaped tube made of steel, nickel, titanium, copper, or
aluminum.
22. The fabrication method of the power metallurgy composite cam
sheet according to claim 14, the power metallurgy cam in the power
metallurgy composite cam sheet is of an iron-based powder
metallurgy material, a titanium-based power metallurgy material, a
nickel-based power metallurgy material or a hard alloy.
23. The fabrication method of the power metallurgy composite cam
sheet according to claim 14, a thickness of the matrix is in a
range of 0.1-20 mm, and a thickness of the powder metallurgy cam in
the powder metallurgy composite cam sheet is in a range of 0.5-50
mm.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to the technical field of
powder metallurgy, and particularly, to a powder metallurgy
composite cam sheet and a preparation method thereof.
BACKGROUND OF THE INVENTION
[0002] Assembled camshafts have advantages of light weight,
flexible design and processing, good abrasion resistance and so on,
and have been widely used in engines for automobile and motorcycle.
Conventional cam sheets are produced generally by adopting forging,
extrusion, drawing or other processes, and then are subjected to a
surface quenching treatment. A steel piece is hot forged to be a
blank directly by using forging process, and then is subjected to
cold forging so as to fabricate a cam sheet with a high dimensional
accuracy. Cold forging can be used to prepare a cam sheet directly
as well. It is also possible that extrusion process is directly
used to fabricate a cam sheet, and then cold drawing is perfoimed
on it for size control, so that a cam sheet with a very high
dimensional accuracy is obtained. Besides, people have developed a
method in which a steel tube is adopted for preparation of a cam
sheet by way of cold drawing directly. The above processes have
shortcomings such as high production cost, difficult adjustment for
the composition of the material, etc.
[0003] As regards a cam sheet that is fabricated by using
conventional power metallurgy for the sake of reducing the cost, it
tends to crack upon assembly due to its drawbacks of low density,
poor impact toughness, etc. In order to ameliorate the above
shortcomings of the power metallurgy cam sheet, researchers perform
hot forging on the power metallurgy cam sheet to further enhance
its density, reduce its porosity, and improve impact toughness, and
then perform quenching on the surface, so that a power metallurgy
cam sheet satisfying usage requirements is attained. The above
process has shortcomings of relatively high production cost and so
on.
SUMMARY OF THE INVENTION
[0004] An object of the present invention is to provide a powder
metallurgy composite cam sheet and a fabrication method thereof,
aiming at shortcomings in prior art.
[0005] The power metallurgy composite cam sheet provided by the
invention is characterized in that, the power metallurgy composite
cam sheet is constructed by combining a power metallurgy on a
surface of a matrix.
[0006] The matrix in the power metallurgy composite cam sheet may
be a circular tube or a special-shaped tube with a thickness ranged
from 0.1-20 mm that is made of steel, nickel, titanium, copper,
aluminum or other material.
[0007] The power metallurgy cam in the power metallurgy composite
cam sheet may be of an iron-based powder metallurgy material, a
titanium-based power metallurgy material, a nickel-based power
metallurgy material, a hard alloy, or the like. Its thickness may
be in the range of 0.5-50 mm.
[0008] The fabrication method of the power metallurgy composite cam
sheet includes sinter welding, braze welding, argon arc welding,
laser welding, hot pressing and so on, which will be described as
follows, respectively.
[0009] (1) A powder metallurgy cam pressed compact is fabricated by
using a conventional powder pressing method, assembled with the
matrix, and then subjected to sinter welding under such process
conditions that the temperature is in the range of 600-1500.degree.
C. and the time is in the range of 10-120 minutes, the atmosphere
for the sinter welding being an atmosphere of hydrogen gas,
decomposed ammonia, vacuum, or the like, to be fabricated into a
powder metallurgy composite cam sheet.
[0010] (2) A powder metallurgy cam pressed compact is fabricated by
using a conventional powder pressing method, a blank for a powder
metallurgy cam sheet is fabricated by it under such process
conditions that the temperature is in the range of 600-1500.degree.
C. and the time is in the range of 10-120 minutes, and then a
matrix and the powder metallurgy cam are welded together by using
braze welding, argon arc welding, laser welding or other process,
so as to fabricate a powder metallurgy composite cam sheet. Where,
material for the solder may be copper, a copper alloy, nickel, a
nickel alloy, aluminum, an aluminum alloy, titanium, a titanium
alloy, or the like, and morphology of the solder may be
powder-shaped, wire-shaped, piece-shaped, or the like. It is
carried out in an atmosphere of vacuum, hydrogen gas, decomposed
ammonia, or the like, the temperature being in the range of
600-1200.degree. C., and the time being in the range of 10-120
minutes.
[0011] (3) A matrix is placed on a core rod, and after powders are
filled, it is pressed to be fabricated into a composite cam sheet
compact. Then, it is subjected to sinter welding under such process
conditions that the temperature is in the range of 600-1500.degree.
C. and the time is in the range of 10-120 minutes, to be fabricated
into a power metallurgy composite cam sheet.
[0012] (4) Matrix powders and cam powders are placed in layers into
a mold by way of filling, and then are pressed to be fabricated
into a composite cam sheet compact. At last, it is sintered at
600-1500.degree. C. for 10 to 120 minutes, to be fabricated into a
powder metallurgy composite cam sheet.
[0013] (5) A matrix is placed on a core rod, and after powders are
filled, it is hot pressed at 500-1400.degree. C. for 10 to 120
minutes, to be fabricated into a powder metallurgy composite cam
sheet.
[0014] (6) It is possible that matrix powders and cam powders are
placed in layers into a mold by way of filling, and then are hot
pressed at 500-1400.degree. C. for 10 to 120 minutes, to be
fabricated into a powder metallurgy composite cam sheet.
[0015] The invention has the following beneficial effects: the
powder metallurgy composite cam sheet fabricated by the invention
has merits of stable size, good impact toughness, good abrasion
resistance, low cost and so on, so that it can replace an integral
cam sheet that is currently fabricated by forging, drawing, power
metallurgy or other process. It is suitable for the case where a
hollow camshaft is prepared by mechanical assembly, hydraulic
forming, welding or other process, so that the usage requirements
of an assembled camshaft can be met.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a structurally schematic view illustrating a power
metallurgy composite cam sheet according to the invention.
[0017] Reference numerals in the FIGURE: 1 denotes the power
metallurgy composite cam sheet; 11 denotes a matrix; and 12 denotes
a cam.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] According to the invention, there are proposed a powder
metallurgy composite cam sheet and a fabrication method thereof,
which includes powder metallurgy, sinter welding, braze welding,
argon arc welding, laser welding, hot pressing and other methods.
In the structurally schematic view illustrating a power metallurgy
composite cam sheet that is shown in FIG. 1, a powder metallurgy
cam 12 is combining on a matrix 11. Hereinafter, the invention will
be described further by giving exemplary embodiments. However, they
are not used to limit the invention in any way.
Embodiment 1
[0019] A 45# steel pipe of O20.times.3.times.13 mm is subjected to
surface sand blasting for rust removal, degreasing, cleaning and
other treatment. A cam sheet green compact having an inner hole of
O20.1.times.5.times.13 mm (with a top part of 37.3 mm) is produced
with mixed powders having chemical compositions of
Fe--Cr--Mo--Si--P--C by pressing at 600 MPa, and then, the steel
pipe and the cam sheet green compact are assembled together, and
subjected to sinter welding at a temperature of 1120.degree. C., in
H.sub.2 atmosphere for 30 minutes, so that a power metallurgy
composite cam sheet is fabricated.
Embodiment 2
[0020] A cam sheet green compact having an inner hole of
O25.3.times.3.times.13 mm (with a top part of 37.3 mm) is produced
with mixed powders having chemical compositions of
Fe--Cr--Mo--Si--P--C by pressing at 600 MPa, and then, it is
subjected to sintering at a temperature of 1120.degree. C., in
H.sub.2 atmosphere for 30 minutes, so that a power metallurgy cam
sheet is fabricated. A 45# steel pipe of O25.times.2.times.13 mm is
subjected to surface sand blasting for rust removal, degreasing,
cleaning and other treatment, and then, the steel pipe and the
powder metallurgy cam sheet are assembled together with a copper
foil placed therebetween, and subjected to welding at a temperature
of 1115.degree. C., in decomposed ammonia atmosphere for 20
minutes, so that a power metallurgy composite cam sheet is
fabricated.
Embodiment 3
[0021] A cam sheet compact having an inner hole of
O25.3.times.3.times.13 mm (with a top part of 37.3 mm) is produced
with mixed powders having chemical compositions of
Fe--Cr--Mo--Si--P--C by pressing at 600 MPa, and then, it is
subjected to sintering at a temperature of 1120.degree. C., in
H.sub.2 atmosphere for 30 minutes, so that a power metallurgy cam
sheet is fabricated. A 45# steel pipe of O25.times.2.times.13 mm is
subjected to surface sand blasting for rust removal, degreasing,
cleaning and other treatment, and then, the steel pipe and the
powder metallurgy cam sheet are assembled together, and fabricated
to be a powder metallurgy composite cam sheet by way of laser
welding.
Embodiment 4
[0022] A cam sheet having an inner hole of O35.3.times.3.times.20
mm (with a top part of 50 mm) is produced with the use of a hard
alloy of YG12(WC_Co12) by processing. A 45# steel pipe of
O35.times.4.times.20 mm is subjected to surface sand blasting for
rust removal, degreasing, cleaning and other treatment, and then,
the steel pipe and the powder metallurgy cam sheet are assembled
together with a AgCu28 solder of 0.03 mm placed therebetween, and
subjected to braze welding at a temperature ranged from
820-850.degree. C., under vacuum for 20 minutes, so that a power
metallurgy composite cam sheet is fabricated.
[0023] The foregoing are merely preferable embodiments of the
invention, but the protection scope of the invention is not limited
thereto. All changes or replacements, as would be obvious to those
skilled in the art within the technical scope disclosed by the
invention, shall be embraced in the protection scope of the
invention. Therefore, the protection scope of the invention shall
be defined by protection scope of claims.
* * * * *