U.S. patent application number 13/265048 was filed with the patent office on 2012-02-09 for method for producing a component of a synchronization device for a manual transmission.
This patent application is currently assigned to Diehl Metall Stiftung & Co. KG. Invention is credited to Martin Doernhoefer, Meinrad Holderied, Marion Merklein.
Application Number | 20120030929 13/265048 |
Document ID | / |
Family ID | 42773044 |
Filed Date | 2012-02-09 |
United States Patent
Application |
20120030929 |
Kind Code |
A1 |
Merklein; Marion ; et
al. |
February 9, 2012 |
METHOD FOR PRODUCING A COMPONENT OF A SYNCHRONIZATION DEVICE FOR A
MANUAL TRANSMISSION
Abstract
The invention relates to a method for producing a component of a
synchronization device for manual transmissions, in particular a
synchronizer ring (1, 2, 3), wherein a round blank produced from
metal is formed in a plurality of forming steps. In order to
simplify the production process, it is proposed according to the
invention that at least one of the forming steps is a hot forming
step in which the round blank is partially heated to a temperature
of more than 600.degree. C. and is then formed in the partially
heated forming portion.
Inventors: |
Merklein; Marion;
(Nuernberg, DE) ; Doernhoefer; Martin;
(Simmelsdorf, DE) ; Holderied; Meinrad;
(Igensdorf, DE) |
Assignee: |
Diehl Metall Stiftung & Co.
KG
Roethenbach
DE
|
Family ID: |
42773044 |
Appl. No.: |
13/265048 |
Filed: |
May 6, 2010 |
PCT Filed: |
May 6, 2010 |
PCT NO: |
PCT/EP2010/002772 |
371 Date: |
October 18, 2011 |
Current U.S.
Class: |
29/592 |
Current CPC
Class: |
C21D 7/13 20130101; B23P
15/00 20130101; Y10T 29/49 20150115; B21D 53/26 20130101; F16D
23/025 20130101; B21D 53/16 20130101; B21K 1/30 20130101; F16D
2250/00 20130101; B21D 37/16 20130101; C21D 9/32 20130101; C21D
1/673 20130101; C21D 9/40 20130101; B23P 15/14 20130101 |
Class at
Publication: |
29/592 |
International
Class: |
B21D 53/16 20060101
B21D053/16 |
Foreign Application Data
Date |
Code |
Application Number |
May 14, 2009 |
DE |
10 2009 021 307.4 |
Claims
1. A method for producing a component of a synchronization device
for a manual transmission, in particular a synchronizer ring,
wherein a round blank produced from metal is formed in a plurality
of forming steps, wherein at least one of the forming steps is a
hot forming step in which the round blank is partially heated to a
temperature of more than 600.degree. C. and is then formed in the
partially heated forming portion.
2. The method as claimed in claim 1, wherein the round blank is
produced by means of stamping.
3. The method as claimed in claim 1, wherein at least one of the
forming steps is a cold forming step.
4. The method as claimed in claim 1, wherein the round blank is
produced from steel.
5. The method as claimed in claim 1, wherein the forming portion is
heated to a temperature above the austenitization temperature.
6. The method as claimed in claim 1, wherein the forming portion is
at least partially quenched and consequently hardened.
7. The method as claimed in claim 1, wherein the forming portion is
quenched during forming and consequently hardened.
8. The method as claimed in claim 1, wherein the round blank is
partially heated by means of laser or induction.
9. The method as claimed in claim 1, wherein the thermal energy
required for partial heating is supplied to the forming portion in
less than 3 seconds.
10. The method as claimed in claim 1, wherein a cooled forming tool
is used for quenching.
11. The method as claimed in claim 1, one of the preceding claims,
wherein the hot forming step is carried out as a cycle in a cyclic
sequence of forming and/or stamping steps.
12. A component of a synchronization device for a manual
transmission, in particular a synchronizer ring, comprising at
least one press-hardened forming portion.
13. The component as claimed in claim 12, wherein the
press-hardened forming portion has one of the following
configurations: toothing (4), indexing stud (5), centering stud
(6), driving tab (7), driving stud (11), connecting web (14).
14. The method as claimed in claim 3, wherein the cold forming step
is deep drawing.
15. The method as claimed in claim 1, wherein the round blank is
produced from a steel alloy.
16. The method as claimed in claim 5, wherein the forming portion
is heated to a temperature of 850.degree. C. to 1000.degree. C.
17. The method as claimed in claim 6, wherein the forming portion
is consequently hardened by contact hardening.
18. The method as claimed in claim 9, wherein the thermal energy
required for partial heating is supplied to the forming portion in
less than 1 second.
Description
[0001] The invention relates to a method for producing a component
of a synchronization device for a manual transmission according to
the preamble of claim 1, and also to a component of a
synchronization device for a manual transmission.
[0002] Such a method is known from DE 35 19 811 52. Here, a round
blank which has been stamped from a metal sheet is subjected to a
multiplicity of cold forming steps in succession. In order to
produce a specific predefined contour extending merely over a
partial portion of the component, e.g. toothing, a plurality of
successive cold forming substeps are often additionally required.
In this case, firstly preforms of the contour are produced, and the
contour is finally produced in a last cold forming substep. For
each of the cold forming substeps, it is necessary to provide a
complex and expensive forming tool. If the contour changes, it is
necessary to change the corresponding forming tools. As a whole,
the known method is therefore complex and expensive.
[0003] A further disadvantage of the known method is that the
synchronizer rings produced thereby, for example, subsequently have
to be hardened in their functional regions, for example in the case
of contours, such as toothed systems, indexing studs, centering
studs or driving tabs.
[0004] It is an object of the present invention to eradicate the
disadvantages according to the prior art. The intention in
particular is to specify an extremely simple and cost-effective
method for producing a component of a synchronization device for a
manual transmission, in particular a synchronizer ring. A further
aim of the invention consists in the specification of a component,
which is extremely inexpensive and simple to produce, of a
synchronization device for a manual transmission, in particular a
synchronizer ring.
[0005] This object is achieved by the features of claims 1 and 12.
Expedient configurations of the invention are apparent from the
features of claims 2 to 10 and 13.
[0006] In a method for producing a component of a synchronization
device for a manual transmission, in particular a synchronizer
ring, it is provided according to the invention that at least one
of the forming steps is a hot forming step in which the round blank
is partially heated to a temperature of more than 600.degree. C.
and is then formed in the partially heated forming portion. In a
departure from the prior art, the invention provides that the
plurality of cold forming substeps for producing a desired contour
are replaced in each case by a single hot forming step. In order to
carry out the hot forming step according to the invention, the
round blank is heated merely in portions, specifically in the
region of the forming portion to be formed, to a temperature of
more than 600.degree. C., preferably to a temperature in the range
of 650.degree. C. to 850.degree. C., and is then formed in this
partially heated forming portion. In this case, the formed portion
can be cooled at a predefined cooling rate and a specific
microstructure can thus be set.
[0007] According to an advantageous configuration, the round blank
is produced by means of stamping. Within the context of the present
invention, the term "round blank" is understood in general terms.
It is generally a metal sheet with a substantially round outer
contour.
[0008] Within the context of the present invention, a round blank
can also be, in particular, an annular body. The proposed method
for producing the round blank by means of stamping is particularly
cost-effective. It goes without saying that it is also possible to
produce the round blank by other common processes, for example
sawing, water jet cutting or laser cutting.
[0009] It is expedient that at least one of the forming steps is a
cold forming step, preferably deep drawing. Such a cold forming
step, as is known according to the prior art, is retained
particularly when it can be carried out in a single step. By way of
example, it is possible to give the round blank a conical shape in
a cold forming step.
[0010] The round blank is advantageously produced from steel,
preferably from a steel alloy. If the intention is to form, but not
harden, a component, micro-alloyed steels, e.g. HC260LA, and
low-alloy or unalloyed steels, for example D04, have proved to be
particularly suitable. If the intention is to harden a component at
least in partial regions, standard heat-treated steels have proved
to be particularly suitable, as defined for example in EN 10132.
Steels such as C45 are also suitable. Steel alloys, e.g. 22MnB5 or
80CrV2, have also proved to be expedient.
[0011] According to an advantageous configuration, the round blank
is deformed in the forming portion and then at least partially
hardened during the hot forming step. For this purpose, the forming
portion is heated to a temperature above the austenitization
temperature. The austenitization temperature depends on the steel
or on the steel alloy. It is usually in the range of 850.degree. C.
to 1000.degree. C. The quenching of the forming portion heated to a
temperature above the austenitization temperature, which takes
place after the forming, hardens said portion. The quenching is
preferably effected by at least partial contact between the forming
portion (contact hardening) and a heat sink, for example a metal
mold matched to the shape of the forming portion. By using the
proposed method steps, it is advantageously possible for selected
regions of the forming portion to be hardened.
[0012] According to a particularly advantageous configuration, the
round blank is not only deformed but also press-hardened in the
forming portion during the hot forming step. For this purpose, the
forming portion is heated to a temperature above the
austenitization temperature. The austenitization temperature
depends on the steel or on the steel alloy. It is usually in the
range of 850.degree. C. to 1000.degree. C. The quenching of the
forming portion heated to a temperature above the austenitization
temperature, which takes place at the same time as forming, hardens
said portion. By using the proposed method steps, it is possible to
dispense with the hardening method which follows the shaping
according to the prior art. Shaping and hardening can be effected
at the same time according to the method proposed according to the
invention. As a result, the method proposed according to the
invention is particularly efficient.
[0013] According to a further expedient configuration, the round
blank is partially heated by means of laser or induction. With the
processes mentioned, it is possible to transfer a high thermal
energy to the portion of the round blank to be formed particularly
quickly. The forming portion of the round blank generally amounts
to less than 50%, preferably less than 30%, in particular less than
20%, of the volume thereof. That is to say, during the partial
heating of the forming portion which is proposed according to the
invention, exclusively this portion is heated to the given
temperature. The remaining portions of the round blank are not
heated up to this temperature.
[0014] According to a further advantageous configuration, the
thermal energy required for partial heating is supplied to the
forming portion in less than three seconds, preferably less than
one second. It is thereby possible to keep the introduction of heat
limited to the predefined forming portion. In addition, the short
heat introduction times proposed make a particularly rapid
procedure possible.
[0015] It has proved to be particularly expedient, in particular in
large-scale production, to use a cooled forming tool for quenching.
As a result of contact with the forming tool, the forming portion
is formed to the desired contour, quenched at the same time and
consequently hardened. Here, the formed metal sheet is usually
hardened down to a depth of 0.5 to 2 mm.
[0016] The method according to the invention also makes it
possible, in particular, to stamp the round blank after the hot
forming step. This also holds true when a forming region of the
round blank has been hardened by the hot forming step. In this
case, the following stamping step is expediently limited to those
regions of the round blank which have not been previously
hardened.
[0017] According to a further advantageous configuration, the hot
forming step is carried out as a cycle in a cyclic sequence of
forming and/or stamping steps. That is to say, the hot forming step
can be implemented in a cyclically working line for the large-scale
production of components of a synchronization device.
[0018] It is also proposed according to the invention that a
component of a synchronization device for a manual transmission, in
particular a synchronizer ring, has at least one press-hardened
forming portion. Here, the press-hardened forming portion can have
one of the following configurations: toothing, indexing stud,
centering stud, driving tab, driving stud, connecting web.
[0019] Within the context of the present invention, a
"synchronization device" is understood to mean a device which
adapts a rotational speed differential between the shaft and the
gear wheel to be shifted. In addition to at least one synchronizer
ring, the synchronization device can also comprise further
components, such as a sliding sleeve, a sleeve carrier and also a
gear wheel or loose wheel. By way of example, reference is made to
the synchronization device disclosed in DE 10 2005 035 941 B3. The
disclosure content of the exemplary embodiment in said document is
hereby incorporated.
[0020] In the text which follows, exemplary embodiments of the
invention are explained in more detail, in particular on the basis
of the single drawing.
[0021] The single drawing shows, in a perspective view, a
synchronization assembly of a synchronization device (not shown in
further detail here). The synchronization assembly comprises an
outer ring 1, an intermediate ring 2 and an inner ring 3.
[0022] The outer ring is provided with toothing or gear toothing 4
in portions on its outer circumference. The reference symbol 5
denotes centering studs and the reference symbol 6 denotes indexing
studs with indexing stud side faces 6a, which are fitted between
the portions of the toothing 4. Driving tabs 7 with driving tab
side faces 7a extend from the inner circumference. An inner
circumferential surface of the outer ring 1 forms a first friction
surface 8.
[0023] The intermediate ring 2 has a second friction surface 9 on
its inner circumference and a third friction surface 10 on its
outer circumference. The reference symbol 11 denotes driving studs
with driving stud side faces 11a which extend in the axial
direction.
[0024] The inner ring 3 has a fourth friction surface 12 on its
inner circumference and a fifth friction surface 13 on its outer
circumference. The reference symbol 14 denotes connecting studs
which extend axially in the direction of the outer ring 1.
Production of the Outer Ring
[0025] In order to produce the outer ring 1, firstly a round blank
of annular form is stamped out from a suitable steel sheet, for
example of the steel grade C45 or 80CrV2. Then, a conical geometry
is given to the round blank in a conventional deep-drawing step.
This is followed by a hot forming and calibration step, in which
the conical portion produced is initially heated in portions to a
temperature above the austenitization temperature and is then
calibrated and press-hardened with a cooled pressing tool.
[0026] In a further step, the toothing 4 is then preformed by means
of stamping. The preformed toothing is partially heated to a
temperature above the austenitization temperature and is then
formed to its predefined contour in a first hot forming step with a
cooled pressing tool. Here, the toothing 4 is press-hardened at the
same time.
[0027] In further hot forming steps, the indexing studs 5 and also
the centering studs 6 are then formed. In this case, too, the
appropriate forming regions are partially heated to a temperature
above the austenitization temperature and are then formed to their
predefined contour with a cooled pressing tool, and press-hardened
at the same time.
[0028] In a further stamping step, the driving tabs 7 are
preformed. In a further hot forming step, the driving tabs 7 are
then partially heated in turn to a temperature above the
austenitization temperature and are formed to their predefined
contour with a cooled pressing tool. Here, they are press-hardened
at the same time.
[0029] Within the context of the present invention, not every hot
forming step has to be accompanied by press-hardening. By way of
example, it is also possible to carry out one or more of the hot
forming steps at a temperature below the austenitization
temperature.
[0030] If the intention is to harden the forming region to be
subjected to hot forming and press-hardening with the forming tool
should not suffice for this purpose, it is additionally possible
for, e.g. lateral, contact pressure to be applied after repeated
heating to a temperature above the austenitization temperature.
This is expedient particularly for the production of the indexing
stud side faces 2a, the driving stud side faces 8a and also the
connecting web side faces 12a and the driving tab side faces
3a.
[0031] The intermediate ring 2 and the inner ring 3 can be produced
in a similar way. Here, too, an annular round blank is firstly
stamped out. Then, the round blank is given a conical shape by deep
drawing. The cone is calibrated in turn in a hot forming and
calibration step. The conical geometry can be set exactly in this
case. At the same time, it is thereby possible to achieve
press-hardening, in particular of the friction surfaces.
[0032] This is followed by the production of the driving studs 11
and connecting studs 14. Just like the centering studs 5 and
indexing studs 6, these can initially be preformed by means of
stamping and then be formed to their end contour in a single hot
forming step, it being possible for press-hardening to be effected
in each case. The driving stud side faces 11a and the connecting
web side faces 14a can be hardened, if necessary, by the lateral
application of contact pressure.
[0033] The method proposed according to the invention simplifies
the production process significantly and makes it more
cost-effective, in particular in the case of synchronizer rings. To
this end, conventional cold forming steps can be combined with hot
forming steps. The hot forming steps make it possible to achieve a
high degree of forming. It is possible to replace a plurality of
the cold forming substeps required for producing the same degree of
forming with a single hot forming step. At the same time, it is
possible to press-harden the respective functional surfaces with
the hot forming step. As a whole, this results in a considerably
reduced number of production steps. A costly downstream hardening
process can be dispensed with.
LIST OF REFERENCE SYMBOLS
[0034] 1 Outer ring [0035] 2 Intermediate ring [0036] 3 Inner ring
[0037] 4 Toothing [0038] 5 Indexing stud [0039] 6a Centering stud
[0040] 6a Centering stud side face [0041] 7 Driving tab [0042] 7a
Driving tab side face [0043] 8 First friction surface [0044] 9
Second friction surface [0045] 10 Third friction surface [0046] 11
Driving stud [0047] 11a Driving stud side face [0048] 12 Fourth
friction surface [0049] 13 Fifth friction surface [0050] 14
Connecting web [0051] 14a Connecting web side face
* * * * *