Title of Invention

"WEAR-RESISTANT SYNCHRONIZER RING FOR AUTOMATIC TRANSMISSIONS MADE OF IMPROVED WEAR-RESISTANT COPPER ALLOY"

Abstract There is disclosed a wear-resistant synchronizer ring for automatic transmissions made of an improved wear-resistant copper alloy having the following composition - Zn : 20 to 40 wt % ; Al : 2 to 11 wt % ; at least one element selected from a group consisting of Fe, Ni, Co : 1 to 5 wt % ; Ti : 0.1 to 4 wt % ; Mn : 0.02~0.08 wt % and/or S : 0.0005 to 0.01 wt % ; Mg : 0.01 to 0.5 wt % optionally; and Cu and unavoidable impurities: balance.
Full Text The present invention relates to a wear-resistant synchronizer ring for automatic transmissions made of improved wear-resistant copper alloy, and/
in particular, to a synchronizer-ring
for automatic transmissions having improved wear resistance
over conventional rings. These automatic transmissions are
used in internal combustion-engines. This application is divided out of Indian Patent Application NO.1313/CAL/95.
In the prior art, a synchronizer-ring for automatic
transmissions was made of copper alloy having the following
composition :
Zn : 17 to 40 wt. % ;
Al : 2 to 11 wt. % ;
at least one element selected
from a group consisting of Fe, Ni and Co : 0.02 to 3 wt. % ;
one element or at least two
elements selected from a
group consisting of Ti, Zr and V : 0.1 to 3.5 wt. % ;
one element or at least two
elements selected from a
group consisting of P, Mg and Ca : 0.003 to 0.3 wt. % ;
Mn : 0.1 to 4 Wt. % ; and
Cu accompanied by unavoidable impurities : Balance
In this connection, reference is made to Japanese Patent No.
65-55347 (laid open).
Due to increase in the power of internal combustion engines in the recent years, synchronizer-rings for automatic transmissions are required to meet demands of higher load and higher rotation speed. Prior art synchronizer-rings made of prior art copper alloys are not able to meet the severe conditions of present day use and do
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not have sufficient wear resistance. As a result, the life time of these rings is shortened.
Object of the present invention is to obtain a synchronizer-ring of copper alloy having better wear resistance than conventional synchronizer-rings.
It has now been found that by reducing the content of Mn in alloy composition of the conventional synchronizer rings, the wear resistance can be increased.
Accordingly the present invention provides a wear-resistant synchronizer ring for automatic transmissions made in the manner such as herein described, from an improved wear-resistant copper alloy which has the
following composition -
Zn : 20 to 40 wt % ;
Al : 2 to 11 wt % ;
at least one element selected from a group consisting of
Fe, Ni, Co : 1 to 5 wt % ;
Ti : 0.1 to 4 wt % ;
Mn : 0.02~0.08 wt % and/or S : 0.0005 to 0.01 wt % ;
Mg : 0.01 to 0.5 wt % optionally; and
Cu and unavoidable impurities: balance.
The composition is made by well known methods for making alloys. The synchronizer rings of the present invention have better wear resistance than those known in the prior art and these rings are used in automatic transmissions of internal combustion-engines.



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ZN AND A1 in the composition of the alloy used for the synchronizer ring
according to the present invention have the effect of increasing strength and toughness of the
synchronizer-ring. When Zn content is less than 20% or Al content is less than 2%, the desired strength and toughness cannot be achieved. Similarly when Zn content exceeds 40% or Al content exceeds 11%, both strength and toughness decrease considerably. So, the Zn content should be 20 to 40% and Al content should be 2 to 11%. The preferred range is Zn : 25 to 40% and Al : 2 to 7% .
At least one element selected from a group consisting of Fe, Ni and Co (hereinafter referred to as iron family metal) and Ti form intermetallic compounds which have the effect of enhancing the wear resistance by dispersion into the matrix. Desired effects cannot be achieved with iron family metal content less than 1% or Ti content less than 0.1%. If the iron family metal content exceeds 5% or the Ti content exceeds 4%, the toughness decreases considerably. Accordingly, the iron family metal content should be in the range of 1 to 5% and Ti content should be in the range of 0.1 to 4%. Preferably, the iron family metal content should be 2 to 4% and the Ti content should be 0.1 to 4%.
Mn content less than in conventional composition improves wear resistance of the synchronizer ring. But Mn content less than 0.01 % is not so effective as to improve wear resistance. Also Mn content over 0.1% reduces wear
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resistance and affects hot workability. Therefore, Mn content should be in the range of 0.01 to less than 0.1 % and preferably in the range of 0.03 to 0.07%.
Inclusion of S improves wear resistance furthermore. But S content less than 0-0005 % does not give sufficient effect while more than 0.01% reduces hot workability. Therefore, the S content should be in the range of 0.0005 to 0.01 %, and preferably in the range of 0.001 to 0.005 % .
Mg improves hardness, especially at high temperatures. Therefore Mg has the effect of exhibiting excellent wear resistance under operating conditions at high load and / or high speed of rotation. While Mg content below 0.01 % does not give the desired effect, Mg content over 0.5 % results in lower toughness. Therefore Mg content should be in the range of 0.01 to 0.5 and preferably in the range of 0.05 to 0.35 %.
It will be apparent to a person skilled in the art that the copper alloy composition as aforesaid can be manufactured by well known techniques in the field of alloy making.
Example :
The following example shows the improvement effected by the present invention, although the example does not limit
the scope described and claimed herein.
Copper alloys having composition as shown in Tables 1/ 2 and 3 were prepared in a high frequency melting furnace and ingots having 65mm 0 and
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22.0mra length were made by die casting. These inqots were hot forged at 750 C to prepare synchronizer-ring blanks having 15 mm thickness, 100 mm width and 300 mm length. These blanks were cut to prepare test pieces 1 to 30 which form the synchronizer-rings of the present invention indicated as Test pieces S I in the Tables. Test pieces 1 to 3 in Table 3 were prepared from conventional alloy compositions. These are designated as S II in Table 3. In addition, a circular carburizing and quenching steel (with surface toughness of
2.0 to 2.5 Rz) was used for preparing a counterpart member.
Table 1

S I : THE INVENTION'S TEST PIECES S II : CONVENTIONAL TEST PIECES
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Table 2

S I : THE INVENTION'S TEST PIECES S II : CONVENTIONAL TEST PIECES
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Table 3

S I : THE INVENTION'S TEST PIECES S II : CONVENTIONAL TEST PIECES
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Table 4

SI : THE INVENTION' S TEST PIECES SIT : CONVENTIONAL TEST PIECES
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Table 5

SI : THE INVENTION'S TEST PIECES SIL: CONVENTIONAL TEST PIECES
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In the accompanying drawing, the sole figure shows diagramattically the wear testing means adopted for the test pieces SI and S II.
The test piece 1 and counter-part member 2 were positioned in a container 3 containing transmission oil 4. A load 5 of 50 Kg was applied on the test piece 1 pressing the counterpart member 2 rotating under the following conditions:
Sliding velocity : 5 m/s ; Sliding distance : 10 km ; and transmission oil temperature : 80 C
The test was carried out for each of the S I samples 1 to 30 and S II samples 1 to 3. Wear depths of the test pieces were measured. The results of the measurements are shown in Tables 1 to 3 for evaluation of the wear resistance of the S I and S II test pieces.
It can be seen from Tables 1 to 3 that S I test pieces 1 to 30 have more excellent wear resistance than the S II test pieces 1 to 3 of Table 3, the latter being made of prior art conventional compositions. Synchronizer-rings made of copper alloys of the present invention's S I test pieces have thus more excellent wear resistance as compared to synchronizer-rings made of copper alloys prior art of S II test pieces.
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Thus synchronizer-rings of the
present invention have better wear resistance than those made of conventional copper alloys, and even when used under severe conditions, have a longer life.
Although the invention has been described above with reference to examples, a man skilled in the art will appreciate that the scope of the invention is not limited to the particular examples, but may include proportions of the ingredients falling within the scope of the invention claimed hereinafter in the statement of claims.
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We claim:
1. A wear-resistant synchronizer ring for automatic
in the manner, such as herein described,from transmissions made an improved wear-resistant copper alloy
which has the following composition -Zn : 20 to 40 wt % ; Al : 2 to 11 wt % ;
at least one element selected from a group consisting of Fe, Ni, Co : 1 to 5 wt % ; Ti : 0.1 to 4 wt% ;
Mn : 0.02 ~ 0.08 wt % and/or S : 0.0005 to 0.01 wt % ; Mg : 0.01 to 0.5 wt % optionally; and Cu and unavoidable impurities: balance.
2. A wear-resistant synchronizer ring, as claimed in claim
1, wherein said composition contains 2 to 7 wt % of Al.
3. A wear-resistant synchronizer ring, as claimed in claim
1 or 2, wherein said composition contains 25 to 40 wt % of
Zn.
4. A wear-resistant synchronizer ring, as claimed in any of
claims 1 to 3, wherein content of said at least one element
selected from the group consisting of Fe, Ni and Co is 2 to 4
wt %.
5. A wear-resistant synchronizer ring, as claimed in any of
the preceding claims wherein said composition contains 0.03
to 0.07 wt % of Mn.
6. A wear-resistant synchronizer ring, as claimed in any
preceding claim, wherein S content is 0.001 to 0.005 wt % .
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7. A wear-resistant synchronizer ring, as claimed in any
preceding claim, wherein Mg content is 0.05 to 0.35 wt % .
8. A wear-resistant synchronizer-ring for automatic
transmissions substantially as herein described, particularly
with reference to the example and the accompanying drawings.
There is disclosed a wear-resistant synchronizer ring for automatic transmissions made of an improved wear-resistant copper alloy having the following composition -
Zn : 20 to 40 wt % ;
Al : 2 to 11 wt % ;
at least one element selected from a group consisting of
Fe, Ni, Co : 1 to 5 wt % ;
Ti : 0.1 to 4 wt % ;
Mn : 0.02~0.08 wt % and/or S : 0.0005 to 0.01 wt % ;
Mg : 0.01 to 0.5 wt % optionally; and
Cu and unavoidable impurities: balance.

Documents:

00358-cal-2000 abstract.pdf

00358-cal-2000 assignment.pdf

00358-cal-2000 claims.pdf

00358-cal-2000 correspondence.pdf

00358-cal-2000 description(complete).pdf

00358-cal-2000 drawings.pdf

00358-cal-2000 form-1.pdf

00358-cal-2000 form-2.pdf

00358-cal-2000 form-3.pdf

00358-cal-2000 g.p.a.pdf

00358-cal-2000 letters patent.pdf

00358-cal-2000 reply f.e.r.pdf

358-CAL-2000-(20-04-2012)-CORRESPONDENCE.pdf

358-CAL-2000-(20-04-2012)-OTHERS.pdf


Patent Number 206850
Indian Patent Application Number 358/CAL/2000
PG Journal Number 20/2007
Publication Date 18-May-2007
Grant Date 15-May-2007
Date of Filing 21-Jun-2000
Name of Patentee MITSUBISHI MATERIALS CORPORATION
Applicant Address 1-5-1,OTEMACHI,CHIYODA-KU,TOKYO 100,
Inventors:
# Inventor's Name Inventor's Address
1 MAE YOSHIHARU C/O.SOHGO-KENKYUSHO MITSHUBISHI MATERIALS CORPORATION 1-297,KITABUKURO-CHO OMIYA-SHI,SAITAMA-KEN
2 KOBAYASHI MASAO C/O.SOHGO-KENKYUSHO MITSUBISHI MATERIALS CORPORATION 1-297,KITABUKURO-CHO OMIYA-SHI,SAITAMA-KEN
PCT International Classification Number C 22C 9/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 HEI6-340659 1994-10-27 Japan