U.S. patent application number 14/103952 was filed with the patent office on 2014-04-10 for electrical heating device with a plate element comprising conductive paths and method for the manufacture of a plate element of this nature.
This patent application is currently assigned to Eberspacher catem GmbH & Co. KG. The applicant listed for this patent is Eberspacher catem GmbH & Co. KG. Invention is credited to Franz Bohlender, Dieter Emanuel, Michael Niederer, Kurt Walz.
Application Number | 20140096388 14/103952 |
Document ID | / |
Family ID | 44337380 |
Filed Date | 2014-04-10 |
United States Patent
Application |
20140096388 |
Kind Code |
A1 |
Bohlender; Franz ; et
al. |
April 10, 2014 |
ELECTRICAL HEATING DEVICE WITH A PLATE ELEMENT COMPRISING
CONDUCTIVE PATHS AND METHOD FOR THE MANUFACTURE OF A PLATE ELEMENT
OF THIS NATURE
Abstract
An electrical heating includes a plurality of electrical heating
elements which are held by a housing and which abut heat conducting
surfaces over which a medium to be heated flows. The electrical
heating elements comprise contact lugs, arranged essentially at the
same height, that are connected through a plate element. The plate
element includes conductive paths and contact lug receptacles for
the contact lugs. The plate element may include a carrier plate of
non-conducting material and a stamped out metal plate that are
joined together to form one unit. A method of manufacturing a plate
element of this nature includes manufacturing the carrier plate by
injection moulding and subjecting a metal plate to stamping
operations to form area elements which are joined together by
connecting ridges and in which the contact lug receptacles are
located. The carrier plate and the metal plate are then joined, and
the connecting ridges are then parted.
Inventors: |
Bohlender; Franz; (Kandel,
DE) ; Walz; Kurt; (Hagenbach, DE) ; Niederer;
Michael; (Kapellen Drusweiler, DE) ; Emanuel;
Dieter; (Annweiler, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Eberspacher catem GmbH & Co. KG |
Herxheim |
|
DE |
|
|
Assignee: |
Eberspacher catem GmbH & Co.
KG
Herxheim
DE
|
Family ID: |
44337380 |
Appl. No.: |
14/103952 |
Filed: |
December 12, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13433513 |
Mar 29, 2012 |
|
|
|
14103952 |
|
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|
|
Current U.S.
Class: |
29/890.04 |
Current CPC
Class: |
H05K 2201/10303
20130101; H05K 3/326 20130101; Y10T 29/49128 20150115; H05K 3/202
20130101; Y10T 29/49368 20150115; F24H 1/121 20130101; F24H 1/009
20130101; F24H 3/0405 20130101 |
Class at
Publication: |
29/890.04 |
International
Class: |
F24H 1/12 20060101
F24H001/12 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 30, 2011 |
EP |
11002637.4 |
Claims
1. A method of manufacturing a plate element comprising conductive
paths, the method comprising: forming a carrier plate from a
plastic material via injection moulding, subjecting a metal plate
to stamping operations to form area elements which are joined
together by connecting ridges and in which are provided contact lug
receptacles, then joining the carrier plate and the metal plate,
and then parting the connecting ridges.
2. A method according to claim 2, wherein, during joining, each
area element is positively locked to the carrier plate.
3. A method according to claim 2, wherein flat plugs are inserted
into flat plug holders and lock in the flat plug holders at the end
of the insertion movement and are electrically connected to the
assigned area elements in flat plug contact receptacles formed on
the metal plate.
Description
Cross Reference to Related Application
[0001] This application is a divisional of co-pending and commonly
assigned U.S. patent application Ser. No. 13/433,513, filed Mar.
29, 2012, entitled "Electrical Heating Device with a Plate Element
Comprising Conductive Paths and Method for the Manufacture of a
Plate Element of This Nature", the contents of which are hereby
incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an electrical heating
device with a plurality of electrical heating elements, which are
held by a housing and abut heat conducting surfaces over which the
medium to be heated can flow. The heating elements of the
electrical heating device are provided with contact lugs for their
electrical connection. All or some of the contact lugs are arranged
essentially at the same height and are connected by a plate element
which is provided with conductive paths and comprises contact lug
receptacles for electrically contacting the contact lugs.
[0004] 2. Description of the Related Art
[0005] An electrical heating device of this nature is known for
example from EP 1 872 986 A1 which originates from the applicant.
With this state of the art the housing forms a chamber in which the
heat of the electrical heating elements is transferred to a liquid
medium. For this purpose the electrical heating elements are
located in several U-shaped heating chambers and are in thermal
conducting contact with the walls of the heating chambers, over
which the liquid flows on the outside.
[0006] A generic electrical heating device can however also be
formed by an electrical auxiliary heater for heating the air in the
vehicle passenger compartment. In this case the housing is normally
formed by a frame in which a plurality of electrical heating
elements are held in a layer structure, which comprises radiator
elements, which abut the electrical heating elements and over which
the air to be heated flows. The electrical heating elements here
also comprise PTC elements with sheet metal bands abutting them on
both sides. Single sheet metal bands are brought out over the layer
structure to form contact lugs at the side. An electrical heating
device of this nature is for example described in EP 1 157 867
A1.
[0007] With the generic heating devices there is the necessity of
simply contacting the electrical heating elements. Here, normally
the electrical heating elements are pre-assembled in the housing
before any electrical connection is made to the electrical heating
elements. Consequently, often a plug connection is required which
facilitates a simple but effective and permanent electrical
connection to the contact lugs of the electrical heating
elements.
[0008] The electrical heating device known from EP 1 872 986 A1 has
a plurality of electrical heating elements provided in parallel
rows. Each heating element has two contact lugs, which each have to
be connected via the plate element. In this respect EP 1 872 986 A1
discloses a conductor board with conductive paths for the relevant
contact lugs and contact lug receptacles which are electrically
connected to the conductive paths, groups various contact lugs to a
heating circuit and furthermore bears flat plugs. These flat plugs
are accommodated in receptacles of a further conductor board and
are electrically connected to the said conductor board, which
comprises the circuit for the open and closed-loop control of the
electrical heating device and by which the individual heating
circuits can be switched.
[0009] The manufacture of a circuit board is however
cost-intensive. Furthermore, due to the specific conductive paths,
the circuit board does not allow any adaptation for forming
different heating circuits or different conductive paths.
Furthermore, the contact lug receptacles are for example, soldered
onto the conductor board and are thus electrically connected to the
conductive paths. This requires not only an elaborate manufacturing
method, but furthermore limits the temperature at which the
prior-art plate elements can be used.
SUMMARY OF THE INVENTION
[0010] An intention of this present invention is to provide a plate
element comprising conductive paths, which can be more simply and
more cost-effectively manufactured. Furthermore, an intention of
this present invention is to specify a method of manufacturing a
plate element.
[0011] For the solution of the device-related problem the present
invention specifies an electrical heating device having the
features of claim 1. This differs from the prior-art electrical
heating device in that the plate element comprises a carrier plate
of a non-conducting material and a stamped metal plate. The carrier
plate and the stamped metal plate are connected to form one
unit.
[0012] The carrier plate is normally manufactured from an
electrically non-conducting plastic, preferably by means of
injection moulding, so that the carrier plate can comprise further
functional surfaces or elements, which facilitate installation in
or on the housing, which serves the completion of the housing or
the assembly of further components such as the electronics or cable
routing. As a plastic, Procan, PPT GF30 (CTI 600) or another
relatively heat resistant plastic can be considered. This offers
the possibility of subjecting the plate element to higher
temperatures, in particular when the electrical interface to the
metal plate occurs solely via plugging and without any solder
connection. The component providing the structural integrity of the
plate element, i.e. the carrier plate, can be formed as required
and is only limited by the possibilities of manufacture by
injection moulding. With the plate elements according to the
invention the conductive paths are however formed by a stamped
metal plate. This stamped metal plate can be prepared economically
and then connected to the carrier plate.
[0013] The joining of the various components for the electrical
interface of the electrical heating elements to the plate elements
can be thus avoided in that the contact lug receptacles are formed
in one part by stamping and bending on the metal plate, as is
suggested in a further development. For this purpose the metal
plate is formed preferably from a hard-drawn, well contacting
material, such as for example CuSnNi1Mg, which is coated with a
thin coating of a few .mu.m of silver and/or copper/tin. Here, for
the defined contacting of the contact lugs on oppositely situated
lateral faces of the contact lugs, the contact lug receptacles have
abuttable contact springs which abut the contact lugs under a
certain tension.
[0014] The invention therefore offers the possibility of forming
the conductive paths and the elements required for the connection
of the contact lugs as one part by stamping and bending of a metal
plate which, for stiffening and positioning on the housing, is
joined to the carrier plate which is specially formed for this and
is manufactured from economical plastic.
[0015] For the further simplification of the electrical connection,
according to a preferred embodiment of the present invention, it is
suggested that at least one flat plug is provided which is held by
a flat plug holder formed as one part on the carrier plate. The
fiat plug(s) normally protrude from the carrier plate on one side
and namely on the upper side facing away from the metal plate. For
the electrical contacting of the flat plug the metal plate
comprises a flat plug contact receptacle correspondingly formed to
the flat plug. This flat plug contact receptacle is also preferably
provided with contact springs so that electrical contacting of the
flat plug occurs solely by insertion of the said plug into the flat
plug contact receptacle.
[0016] Following that, the stamped metal plate of the plate element
according to the present invention comprises conductive paths and
receptacles for the contact lugs on one hand and the flat plugs on
the other, preferably only cut out by stamping, through which
electrical contacting occurs directly to the conductive paths by
insertion of the contact lug or the flat plug. The plate element of
the present invention can therefore easily make contact to the
electrical heating elements arid to a power supply or a circuit for
this purpose. The plate element with the features of claim 1 and
the further development according to the claims dependent on it can
also be essential to the invention on its own and without the
electrical heating device.
[0017] The flat plug is preferably formed from a sheet metal strip
and has at least one locking protrusion which protrudes from the
lateral faces of the sheet metal strip and is made by stamping and
bending. The flat plug locks to the flat plug holder through this
locking protrusion. Normally, the flat plug holder comprises an
undercut for this which is formed next to an insertion and
retaining channel for the flat plug and in which the locking
protrusion clips in after the locking protrusion has passed the
said channel. The locking protrusion then, due to the abutment to
the undercut, prevents the flat plug from being pulled out in the
opposite direction.
[0018] For an easy connection between the carrier plate and the
stamped metal plate retaining elements are provided on the carrier
plate, preferably formed as one part, by which the metal plate can
be locked to the carrier plate. The joining movement then
preferably leads to a positive locking joint between the stamped
metal plate and the carrier plate.
[0019] The carrier plate here normally has a plurality of
appropriate retaining elements which are formed as one part on the
carrier plate. Normally, they grip over at least the marginal
region of the stamped metal plate.
[0020] For the secure and all-over attachment of the metal plate to
the carrier element the metal plate comprises a retaining opening
assigned to the retaining element which is penetrated by the
retaining element for locking with respect to the metal plate.
Often the stamped metal plate comprises a plurality of retaining
openings of this nature also in its central area. Thus, the stamped
metal plate is locked to the carrier plate and therefore securely
held not only at the edge, but also at various points in its
central region and preferably over its complete longitudinal
extension.
[0021] Particularly secure locking arises according to a preferred
embodiment of the present invention in which the retaining opening
is bridged essentially centrally by a retaining element ridge,
which is formed in one part on the carrier plate and from which
spring bars formed on it on both sides and latching lugs provided
on it, gripping behind the metal plate. protrude downwards.
[0022] According to a preferred further development of the present
invention, the metal plate has a plurality of area elements which
are assigned to a heating circuit of the electrical heating device
and which group the electrical conductive paths. These area
elements are initially connected together by connecting ridges so
that the metal plate can be prepared as a uniform component by
stamping and bending. At least one of the flat plugs is assigned to
each individual area element. The carrier plate comprises stamped
openings which leave the connecting ridges free. The connecting
ridge normally penetrates an appropriate stamped opening
approximately centrally. The stamped opening, normally formed by
means of injection moulding, facilitates the penetration of the
connecting ridges after assembly of the stamped metal plate in
order to electrically insulate the individual area elements from
one another, Here, normally at least one of the retaining elements
is assigned to each individual area element on the carrier-plate
side.
[0023] According to the co-ordinated method-related aspect of the
present invention, the plate element comprising the conductive
paths is manufactured in that initially the metal plate for forming
the conductive paths as well as the area elements joined together
by connecting ridges and the contact lug receptacles provided in
the area elements is processed by stamping or bending. Joining to
the carrier plate only occurs thereafter. According to the
invention this is manufactured from plastic by means of injection
moulding. The connecting ridges are only parted after the joining
process in order to electrically isolate the previously uniformly
manufactured and mutually connected area elements. Often the
carrier plate is initially manufactured independently of the metal
plate. However, it cannot be excluded that both components are
joined by overmoulding the metal plate and the carrier plate is
manufactured at the same time.
[0024] Within the scope of the method according to the invention,
during joining, preferably each area element is joined positively
locked to the carrier plate in order to hold the individual area
elements securely on the carrier plate even after the connecting
ridges are parted.
[0025] According to a further preferred embodiment of the technique
according to the invention, the flat plug is inserted into the
assigned flat plug holder after the carrier plate and metal plate
have been joined. At the end of this insertion movement, which is
normally specified by an insertion stop formed on the flat plug,
the flat plug locks in the flat plug contact holder and flat plug
contact receptacles formed on the plate element come into
electrical contact with the corresponding flat plugs in a plugged
connection. Consequently, within the scope of the insertion
movement a mechanical attachment of the flat plug and also an
electrical coupling to the stamped metal plate are produced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Further details and advantages of the present invention are
given in the following description of an embodiment in conjunction
with the drawing. This shows the following:
[0027] FIG. 1 a perspective exploded illustration of an upper-side
view of a plate element according to the embodiment;
[0028] FIG. 2 a perspective exploded illustration of an underside
view of a plate element according to the embodiment;
[0029] FIG. 3 a perspective plan view of the upper side of the
embodiment illustrated in FIGS. 1 and 2 after the joining of all
components;
[0030] FIG. 4 a perspective plan view of the underside of the
embodiment illustrated in FIGS. 1 and 2 after the joining of all
components;
[0031] FIG. 5 a cross-sectional view along the line V-V according
to FIG. 3;
[0032] FIG. 6 a cross-sectional view along the line VI-VI according
to the illustration in FIG. 3; and
[0033] FIG. 7 the detail VII according to FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0034] The component in the figures is the plate element of a
heating device, which is already known from, for example, EP 1 872
986 A1, with a plurality of electrical heating elements arranged in
parallel rows. In this respect reference is made to the specific
description of EP 1 872 986 A1. The disclosure of this patent
application is included by reference in the disclosure of this
present application. In the following specific description only the
component designated as a distributor plate in EP 1 872 986 A1 is
dealt with in detail.
[0035] This plate element is labelled in the figures with reference
numeral 1 and consists of a metal plate 10, a carrier plate 20 and
a plurality of flat plugs 30.
[0036] Furthermore, in the figures the upper side of the relevant
component is labelled with reference numeral 2 and the underside
with reference numeral 3.
[0037] The metal plate 10 is formed by stamping and bending a
hard-drawn contact material, such as for example CuSnNi1Mg with a
2.5 .mu.m thick silver coating. Due to the stamping operations the
metal plate is reshaped to a grid-shaped form. The metal plate 10
has five area elements 11, which are each connected to one another
by connecting ridges 12. Each area element 11 has a plurality of
contact lug receptacles 13, which are formed by cutting an
insertion opening leaving the contact springs 14, which protrude
downwards from oppositely situated margins of the insertion
opening. These stamped out contact springs are arranged with
respect to the upper side 2 of the metal plate 10 by bending such
that from the underside 3 a slight funnel-shaped taper to the tips
of the contact springs 14 is produced.
[0038] The flat plug contact receptacles labelled with reference
numeral 15 are also provided with appropriate contact springs 14.
For each area element 11.1 to 11.5 a flat plug contact receptacle
15.1 to 15.5 is provided (FIG. 3).
[0039] Furthermore, rectangular retaining openings 16 and inner
openings 17 are formed on the metal plate 10 by stamping. The
remaining material of the metal plate 10 partially forms
ridge-shaped, partially planar conductive paths 18. All functional
elements and functional areas of the metal plate 10 are solely
formed by stamping and stamping/bending operations on a
panel-shaped, sheet metal, semi-finished product.
[0040] The carrier plate 20 forms a flat contact base 21 for the
metal plate 10, over which stiffening segments 22 extend which
penetrate into the inner openings 17 of the metal plate 10. The
contour of the stiffening segments 22 essentially corresponds to
the marginal contour of the assigned area elements 11, so that the
metal plate 10 is aligned relative to the carrier plate 20 and the
metal plate 10 can only abut it in the predefined direction
relative to the carrier plate 20. The contact base 21 furthermore
has spring bars 23 with latching lugs 24 protruding over it which
are illustrated enlarged in FIG. 6 and form retaining elements for
the positively locked retention of the metal plate 10 on the
carrier plate 20. For this the spring bars 23 and the latching lugs
24 pass through the retaining openings 16 and the latching lugs 24
grip behind the underside 3 of the metal plate 10. The spring bars
23 extend from a retaining element ridge 25 which, after the
joining the metal plate 10 and carrier plate 20, bridges the
retaining openings 16 approximately centrally (cf. FIG. 6). The
contact bases 21.4 and 21.5 for the area elements 11.4 and 11.5 are
limited at the edge by spring bars 23.4, 23.5 with assigned
latching lugs, which in the joined state interact with the margins
of the corresponding area elements 11.4 and 11.5 and fix them
positively locked.
[0041] Also the outer contour of the metal plate 10 is
circumferentially gripped, positively locked by spring bars 23.
[0042] Corresponding to the position of the connecting ridges 12
the carrier plate 20 comprises stamped openings 26. In the joined
state the connecting ridges 12 are located approximately centrally
in these stamped openings 26.
[0043] The upper side 2 of the carrier plate 20 which can be seen
in FIG. 1 has five flat plug holders 27 and in each case three
supports 28 distributed on the longitudinal side protruding over
it, the said supports terminating at the same height as the fiat
plug holders 27. Each flat plug holder 27 has an insertion channel
27.1, which is formed adapted to the thickness of the flat plug 30
and which leads to a receiving region 27.2, which is surrounded
circumferentially by the plastic material forming the carrier plate
20 and forms an undercut. Finally, corresponding to the contact
lugs--or flat plug contact receptacles 13, 15, contact insertion
openings 29 are left free on the carrier plate 20.
[0044] All previously described elements of the carrier plate 20
are formed with it as one part in the course of the injection
moulding of the carrier plate 20.
[0045] The flat plug 30 has locking protrusions 32 protruding from
oppositely situated lateral faces 31 which are formed by stamping
out and bending out of the plane of the sheet of the flat plug 30.
Furthermore, insertion stops 33 protrude downwards laterally from
the flat plug 30, for the accommodation of which the free face side
of the flat plug holder 27 is provided with a groove 27.3.
[0046] With the illustrated embodiment initially the carrier plate
20 is made as one part by means of injection moulding from a
heat-resistant plastic, for example, PBT. The metal plate 10 is
prepared by stamping and bending. Then, the two components 10, 20
are positioned relative to one another. The carrier plate 20 is
here normally orientated with its underside 3 facing upwards. After
the metal plate 10 is placed in position, a joining tool presses
the metal plate 10 against the contact bases 21 of the carrier
plate 20. In doing this the latching lugs 24 latch against the
edges of the retaining opening 16 or against the longitudinal edge
of the area elements 11,4, 11.5, In a similar manner spring bars
23, provided on the longitudinal edge of the carrier plate 20,
latch against the metal plate 10 along its outer contour.
[0047] Then, a parting operation is carried out by a parting tool,
for example by a punching tool, in the course of which the
connecting ridges 12 are parted. A punching stamp is introduced
through the stamped openings and the connecting ridges 12 sheared
off. The rest of the connecting ridges 12 can be seen in particular
in FIG. 4 in the region of the stamped openings 26. Five area
elements 11.1 to 11.5 are produced electrically isolated from one
another.
[0048] Thereafter, the flat plugs 30 are introduced from the upper
side 2 into the respective insertion channels 27.1 of the assigned
flat plug holders 27. Within the scope of this insertion movement
the locking protrusions 32 are forced back elastically into the
plane of the flat plug material 30. Finally, the tip of the flat
plug 30 presses against the contact spring 14 of the flat plug
receptacles 15 so that the contact springs 14 of the flat plug
receptacles 15, which are initially formed like the contact lug
receptacles 13 and which are also taken along, extending beyond the
upper side 2 of the metal plate 10 and are bent over extending
beyond the underside 3. The exact guidance of the flat plug 30
through the insertion channels 27.1 simplifies this reshaping
movement of the contact springs 14. The flat plugs 30 are normally
pressed in by machine. The insertion movement of the flat plugs
terminates when the insertion stops 33 abut the bottom of the
groove 27.3 of the flat plug holder 27. This position is
illustrated in FIG. 5 in the sectional illustration.
[0049] The plate element 1 prepared in this way is then pushed onto
the contact lugs of the individual electrical heating elements to
group them into heating circuits according to the area elements
11.1 to 11.5. One of the contact lugs of the relevant electrical
heating elements is here always contacted by the area element 11.1,
which is connected to ground, whereas the other area elements 11.2
to 11.4 are connected via the assigned flat plugs 30.2 to 30.5 to
switches, in particular power switches, which are soldered to a
conductor board, which is placed on the supports 28 and face-side
ends of the flat plug holders 27 and has flat plug receptacles for
the electrical contacting of the flat plugs 30 to the conductive
paths (cf. EP 1 872 986 A1).
[0050] It is pointed out that with the embodiment the heating
circuits can be changed in a simple manner by dispensing with the
full removal of all connecting ridges 12.
* * * * *